[RESEND,v3,2/2] usb: dwc3: Add driver for Xilinx platforms

Add a new driver for supporting Xilinx platforms. This driver is used
for some sequence of operations required for Xilinx USB controllers.
This driver is also used to choose between PIPE clock coming from SerDes
and the Suspend Clock. Before the controller is out of reset, the clock
selection should be changed to PIPE clock in order to make the USB
controller work. There is a register added in Xilinx USB controller
register space for the same.

Signed-off-by: Manish Narani <manish.narani@xilinx.com>
---
 drivers/usb/dwc3/Kconfig          |   9 +
 drivers/usb/dwc3/Makefile         |   1 +
 drivers/usb/dwc3/dwc3-of-simple.c |   1 -
 drivers/usb/dwc3/dwc3-xilinx.c    | 334 ++++++++++++++++++++++++++++++
 4 files changed, 344 insertions(+), 1 deletion(-)
 create mode 100644 drivers/usb/dwc3/dwc3-xilinx.c

On Tue, 15 Dec 2020 12:24:51 +0530, Manish Narani wrote:
> Add a new driver for supporting Xilinx platforms. This driver is used
> for some sequence of operations required for Xilinx USB controllers.
> This driver is also used to choose between PIPE clock coming from SerDes
> and the Suspend Clock. Before the controller is out of reset, the clock
> selection should be changed to PIPE clock in order to make the USB
> controller work. There is a register added in Xilinx USB controller
> register space for the same.
> 
> Signed-off-by: Manish Narani <manish.narani@xilinx.com>
> ---
>  drivers/usb/dwc3/Kconfig          |   9 +
>  drivers/usb/dwc3/Makefile         |   1 +
>  drivers/usb/dwc3/dwc3-of-simple.c |   1 -
>  drivers/usb/dwc3/dwc3-xilinx.c    | 334 ++++++++++++++++++++++++++++++
>  4 files changed, 344 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/usb/dwc3/dwc3-xilinx.c
> 
> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> index 7a2304565a73..0e00e6dfccd8 100644
> --- a/drivers/usb/dwc3/Kconfig
> +++ b/drivers/usb/dwc3/Kconfig
> @@ -139,4 +139,13 @@ config USB_DWC3_QCOM
>  	  for peripheral mode support.
>  	  Say 'Y' or 'M' if you have one such device.
>  
> +config USB_DWC3_XILINX
> +	tristate "Xilinx Platforms"
> +	depends on (ARCH_ZYNQMP || ARCH_VERSAL) && OF
> +	default USB_DWC3
> +	help
> +	  Support Xilinx SoCs with DesignWare Core USB3 IP.
> +	  This driver handles both ZynqMP and Versal SoC operations.
> +	  Say 'Y' or 'M' if you have one such device.
> +
>  endif
> diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
> index ae86da0dc5bd..add567578b1f 100644
> --- a/drivers/usb/dwc3/Makefile
> +++ b/drivers/usb/dwc3/Makefile
> @@ -51,3 +51,4 @@ obj-$(CONFIG_USB_DWC3_MESON_G12A)	+= dwc3-meson-g12a.o
>  obj-$(CONFIG_USB_DWC3_OF_SIMPLE)	+= dwc3-of-simple.o
>  obj-$(CONFIG_USB_DWC3_ST)		+= dwc3-st.o
>  obj-$(CONFIG_USB_DWC3_QCOM)		+= dwc3-qcom.o
> +obj-$(CONFIG_USB_DWC3_XILINX)		+= dwc3-xilinx.o
> diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c
> index e62ecd22b3ed..71fd620c5161 100644
> --- a/drivers/usb/dwc3/dwc3-of-simple.c
> +++ b/drivers/usb/dwc3/dwc3-of-simple.c
> @@ -172,7 +172,6 @@ static const struct dev_pm_ops dwc3_of_simple_dev_pm_ops = {
>  
>  static const struct of_device_id of_dwc3_simple_match[] = {
>  	{ .compatible = "rockchip,rk3399-dwc3" },
> -	{ .compatible = "xlnx,zynqmp-dwc3" },
>  	{ .compatible = "cavium,octeon-7130-usb-uctl" },
>  	{ .compatible = "sprd,sc9860-dwc3" },
>  	{ .compatible = "allwinner,sun50i-h6-dwc3" },
> diff --git a/drivers/usb/dwc3/dwc3-xilinx.c b/drivers/usb/dwc3/dwc3-xilinx.c
> new file mode 100644
> index 000000000000..7e485951d2f7
> --- /dev/null
> +++ b/drivers/usb/dwc3/dwc3-xilinx.c
> @@ -0,0 +1,334 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/**
> + * dwc3-xilinx.c - Xilinx DWC3 controller specific glue driver
> + *
> + * Authors: Manish Narani <manish.narani@xilinx.com>
> + *          Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/clk.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/of_platform.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/reset.h>
> +#include <linux/of_address.h>
> +#include <linux/delay.h>
> +#include <linux/firmware/xlnx-zynqmp.h>
> +#include <linux/io.h>
> +
> +#include <linux/phy/phy.h>
> +
> +/* USB phy reset mask register */
> +#define XLNX_USB_PHY_RST_EN			0x001C
> +#define XLNX_PHY_RST_MASK			0x1
> +
> +/* Xilinx USB 3.0 IP Register */
> +#define XLNX_USB_TRAFFIC_ROUTE_CONFIG		0x005C
> +#define XLNX_USB_TRAFFIC_ROUTE_FPD		0x1
> +
> +/* Versal USB Reset ID */
> +#define VERSAL_USB_RESET_ID			0xC104036
> +
> +#define XLNX_USB_FPD_PIPE_CLK			0x7c
> +#define PIPE_CLK_DESELECT			1
> +#define PIPE_CLK_SELECT				0
> +#define XLNX_USB_FPD_POWER_PRSNT		0x80
> +#define PIPE_POWER_ON				1
> +#define PIPE_POWER_OFF				0

Don't use values for the defines, but rather define the bit. Its name in the
register reference is "option". Therefore, define it as

	#define FPD_POWER_PRSNT_OPTION			BIT(0)

and set/unset the bit in the code. The same for the other registers/bits.

> +
> +struct dwc3_xlnx {
> +	int				num_clocks;
> +	struct clk_bulk_data		*clks;
> +	struct device			*dev;
> +	void __iomem			*regs;
> +	int				(*pltfm_init)(struct dwc3_xlnx *data);
> +};
> +
> +static void dwc3_xlnx_mask_phy_rst(struct dwc3_xlnx *priv_data, bool mask)
> +{
> +	u32 reg;
> +
> +	/*
> +	 * Enable or disable ULPI PHY reset from USB Controller.
> +	 * This does not actually reset the phy, but just controls
> +	 * whether USB controller can or cannot reset ULPI PHY.
> +	 */
> +	reg = readl(priv_data->regs + XLNX_USB_PHY_RST_EN);
> +
> +	if (mask)
> +		reg &= ~XLNX_PHY_RST_MASK;
> +	else
> +		reg |= XLNX_PHY_RST_MASK;
> +
> +	writel(reg, priv_data->regs + XLNX_USB_PHY_RST_EN);
> +}
> +
> +static int dwc3_xlnx_init_versal(struct dwc3_xlnx *priv_data)
> +{
> +	struct device		*dev = priv_data->dev;
> +	int			ret;
> +
> +	dwc3_xlnx_mask_phy_rst(priv_data, false);
> +
> +	/* Assert and De-assert reset */
> +	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
> +				     PM_RESET_ACTION_ASSERT);
> +	if (ret < 0) {
> +		dev_err_probe(dev, ret, "failed to assert Reset\n");
> +		return ret;
> +	}
> +
> +	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
> +				     PM_RESET_ACTION_RELEASE);
> +	if (ret < 0) {
> +		dev_err_probe(dev, ret, "failed to De-assert Reset\n");
> +		return ret;
> +	}
> +
> +	dwc3_xlnx_mask_phy_rst(priv_data, true);
> +
> +	return 0;
> +}
> +
> +static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data)
> +{
> +	struct device		*dev = priv_data->dev;
> +	struct reset_control	*crst, *hibrst, *apbrst;
> +	struct phy		*usb3_phy;
> +	int			ret;
> +	u32			reg;
> +
> +	crst = devm_reset_control_get_exclusive(dev, "usb_crst");

The resets and reset-names are not documented in the dt-binding.

> +	if (IS_ERR(crst)) {
> +		ret = PTR_ERR(crst);
> +		dev_err_probe(dev, ret,
> +			      "failed to get core reset signal\n");
> +		goto err;
> +	}
> +
> +	hibrst = devm_reset_control_get_exclusive(dev, "usb_hibrst");
> +	if (IS_ERR(hibrst)) {
> +		ret = PTR_ERR(hibrst);
> +		dev_err_probe(dev, ret,
> +			      "failed to get hibernation reset signal\n");
> +		goto err;
> +	}
> +
> +	apbrst = devm_reset_control_get_exclusive(dev, "usb_apbrst");
> +	if (IS_ERR(apbrst)) {
> +		ret = PTR_ERR(apbrst);
> +		dev_err_probe(dev, ret,
> +			      "failed to get APB reset signal\n");
> +		goto err;
> +	}
> +
> +	ret = reset_control_assert(crst);
> +	if (ret < 0) {
> +		dev_err(dev, "Failed to assert core reset\n");
> +		goto err;
> +	}
> +
> +	ret = reset_control_assert(hibrst);
> +	if (ret < 0) {
> +		dev_err(dev, "Failed to assert hibernation reset\n");
> +		goto err;
> +	}
> +
> +	ret = reset_control_assert(apbrst);
> +	if (ret < 0) {
> +		dev_err(dev, "Failed to assert APB reset\n");
> +		goto err;
> +	}
> +
> +	usb3_phy = devm_phy_get(dev, "usb3-phy");

Error handling is missing.

The "usb3-phy" phy binding in not documented in the dt-binding.

Thanks,

Michael

> +
> +	ret = phy_init(usb3_phy);
> +	if (ret < 0) {
> +		phy_exit(usb3_phy);
> +		goto err;
> +	}
> +
> +	ret = reset_control_deassert(apbrst);
> +	if (ret < 0) {
> +		dev_err(dev, "Failed to release APB reset\n");
> +		goto err;
> +	}
> +
> +	/* Set PIPE Power Present signal in FPD Power Present Register*/
> +	writel(PIPE_POWER_ON, priv_data->regs + XLNX_USB_FPD_POWER_PRSNT);
> +
> +	/* Set the PIPE Clock Select bit in FPD PIPE Clock register */
> +	writel(PIPE_CLK_SELECT, priv_data->regs + XLNX_USB_FPD_PIPE_CLK);
> +
> +	ret = reset_control_deassert(crst);
> +	if (ret < 0) {
> +		dev_err(dev, "Failed to release core reset\n");
> +		goto err;
> +	}
> +
> +	ret = reset_control_deassert(hibrst);
> +	if (ret < 0) {
> +		dev_err(dev, "Failed to release hibernation reset\n");
> +		goto err;
> +	}
> +
> +	ret = phy_power_on(usb3_phy);
> +	if (ret < 0) {
> +		phy_exit(usb3_phy);
> +		goto err;
> +	}
> +
> +	/*
> +	 * This routes the USB DMA traffic to go through FPD path instead
> +	 * of reaching DDR directly. This traffic routing is needed to
> +	 * make SMMU and CCI work with USB DMA.
> +	 */
> +	if (of_dma_is_coherent(dev->of_node) || device_iommu_mapped(dev)) {
> +		reg = readl(priv_data->regs + XLNX_USB_TRAFFIC_ROUTE_CONFIG);
> +		reg |= XLNX_USB_TRAFFIC_ROUTE_FPD;
> +		writel(reg, priv_data->regs + XLNX_USB_TRAFFIC_ROUTE_CONFIG);
> +	}
> +
> +err:
> +	return ret;
> +}
> +
> +static const struct of_device_id dwc3_xlnx_of_match[] = {
> +	{
> +		.compatible = "xlnx,zynqmp-dwc3",
> +		.data = &dwc3_xlnx_init_zynqmp,
> +	},
> +	{
> +		.compatible = "xlnx,versal-dwc3",
> +		.data = &dwc3_xlnx_init_versal,
> +	},
> +	{ /* Sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, dwc3_xlnx_of_match);
> +
> +static int dwc3_xlnx_probe(struct platform_device *pdev)
> +{
> +	struct dwc3_xlnx		*priv_data;
> +	struct device			*dev = &pdev->dev;
> +	struct device_node		*np = dev->of_node;
> +	const struct of_device_id	*match;
> +	void __iomem			*regs;
> +	int				ret;
> +
> +	priv_data = devm_kzalloc(dev, sizeof(*priv_data), GFP_KERNEL);
> +	if (!priv_data)
> +		return -ENOMEM;
> +
> +	regs = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(regs)) {
> +		ret = PTR_ERR(regs);
> +		dev_err_probe(dev, ret, "failed to map registers\n");
> +		return ret;
> +	}
> +
> +	match = of_match_node(dwc3_xlnx_of_match, pdev->dev.of_node);
> +
> +	priv_data->pltfm_init = match->data;
> +	priv_data->regs = regs;
> +	priv_data->dev = dev;
> +
> +	platform_set_drvdata(pdev, priv_data);
> +
> +	ret = devm_clk_bulk_get_all(priv_data->dev, &priv_data->clks);
> +	if (ret < 0)
> +		return ret;
> +
> +	priv_data->num_clocks = ret;
> +
> +	ret = clk_bulk_prepare_enable(priv_data->num_clocks, priv_data->clks);
> +	if (ret)
> +		return ret;
> +
> +	ret = priv_data->pltfm_init(priv_data);
> +	if (ret)
> +		goto err_clk_put;
> +
> +	ret = of_platform_populate(np, NULL, NULL, dev);
> +	if (ret)
> +		goto err_clk_put;
> +
> +	pm_runtime_set_active(dev);
> +	pm_runtime_enable(dev);
> +	pm_suspend_ignore_children(dev, false);
> +	pm_runtime_get_sync(dev);
> +
> +	return 0;
> +
> +err_clk_put:
> +	clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data->clks);
> +	clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);
> +
> +	return ret;
> +}
> +
> +static int dwc3_xlnx_remove(struct platform_device *pdev)
> +{
> +	struct dwc3_xlnx	*priv_data = platform_get_drvdata(pdev);
> +	struct device		*dev = &pdev->dev;
> +
> +	of_platform_depopulate(dev);
> +
> +	clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data->clks);
> +	clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);
> +	priv_data->num_clocks = 0;
> +
> +	pm_runtime_disable(dev);
> +	pm_runtime_put_noidle(dev);
> +	pm_runtime_set_suspended(dev);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused dwc3_xlnx_suspend_common(struct device *dev)
> +{
> +	struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);
> +
> +	clk_bulk_disable(priv_data->num_clocks, priv_data->clks);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused dwc3_xlnx_resume_common(struct device *dev)
> +{
> +	struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);
> +
> +	return clk_bulk_enable(priv_data->num_clocks, priv_data->clks);
> +}
> +
> +static int __maybe_unused dwc3_xlnx_runtime_idle(struct device *dev)
> +{
> +	pm_runtime_mark_last_busy(dev);
> +	pm_runtime_autosuspend(dev);
> +
> +	return 0;
> +}
> +
> +static UNIVERSAL_DEV_PM_OPS(dwc3_xlnx_dev_pm_ops, dwc3_xlnx_suspend_common,
> +			    dwc3_xlnx_resume_common, dwc3_xlnx_runtime_idle);
> +
> +static struct platform_driver dwc3_xlnx_driver = {
> +	.probe		= dwc3_xlnx_probe,
> +	.remove		= dwc3_xlnx_remove,
> +	.driver		= {
> +		.name		= "dwc3-xilinx",
> +		.of_match_table	= dwc3_xlnx_of_match,
> +		.pm		= &dwc3_xlnx_dev_pm_ops,
> +	},
> +};
> +
> +module_platform_driver(dwc3_xlnx_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Xilinx DWC3 controller specific glue driver");
> +MODULE_AUTHOR("Manish Narani <manish.narani@xilinx.com>");
> +MODULE_AUTHOR("Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>");
> -- 
> 2.17.1
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>

Hi!

On Tue, Dec 15, 2020 at 12:24:51PM +0530, Manish Narani wrote:
>Add a new driver for supporting Xilinx platforms. This driver is used

>for some sequence of operations required for Xilinx USB controllers.

>This driver is also used to choose between PIPE clock coming from SerDes

>and the Suspend Clock. Before the controller is out of reset, the clock

>selection should be changed to PIPE clock in order to make the USB

>controller work. There is a register added in Xilinx USB controller

>register space for the same.


I tried out this driver with the vanilla kernel on an zynqmp. Without
this patch the USB-Gadget is already acting buggy. In the gadget mode,
some iterations of plug/unplug results to an stalled gadget which will
never come back without a reboot.

With the corresponding code of this driver (reset assert, clk modify,
reset deassert) in the downstream kernels phy driver we found out it is
totaly stable. But using this exact glue driver which should do the same
as the downstream code, the gadget still was buggy the way described
above.

I suspect the difference lays in the different order of operations.
While the downstream code is runing the resets inside the phy driver
which is powered and initialized in the dwc3-core itself. With this glue
layser approach of this patch the whole phy init is done before even
touching dwc3-core in any way. It seems not to have the same effect,
though.

If really the order of operations is limiting us, we probably need
another solution than this glue layer. Any Ideas?

Regards,
Michael

>

>Signed-off-by: Manish Narani <manish.narani@xilinx.com>

>---

> drivers/usb/dwc3/Kconfig          |   9 +

> drivers/usb/dwc3/Makefile         |   1 +

> drivers/usb/dwc3/dwc3-of-simple.c |   1 -

> drivers/usb/dwc3/dwc3-xilinx.c    | 334 ++++++++++++++++++++++++++++++

> 4 files changed, 344 insertions(+), 1 deletion(-)

> create mode 100644 drivers/usb/dwc3/dwc3-xilinx.c

>

>diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig

>index 7a2304565a73..0e00e6dfccd8 100644

>--- a/drivers/usb/dwc3/Kconfig

>+++ b/drivers/usb/dwc3/Kconfig

>@@ -139,4 +139,13 @@ config USB_DWC3_QCOM

> 	  for peripheral mode support.

> 	  Say 'Y' or 'M' if you have one such device.

>

>+config USB_DWC3_XILINX

>+	tristate "Xilinx Platforms"

>+	depends on (ARCH_ZYNQMP || ARCH_VERSAL) && OF

>+	default USB_DWC3

>+	help

>+	  Support Xilinx SoCs with DesignWare Core USB3 IP.

>+	  This driver handles both ZynqMP and Versal SoC operations.

>+	  Say 'Y' or 'M' if you have one such device.

>+

> endif

>diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile

>index ae86da0dc5bd..add567578b1f 100644

>--- a/drivers/usb/dwc3/Makefile

>+++ b/drivers/usb/dwc3/Makefile

>@@ -51,3 +51,4 @@ obj-$(CONFIG_USB_DWC3_MESON_G12A)	+= dwc3-meson-g12a.o

> obj-$(CONFIG_USB_DWC3_OF_SIMPLE)	+= dwc3-of-simple.o

> obj-$(CONFIG_USB_DWC3_ST)		+= dwc3-st.o

> obj-$(CONFIG_USB_DWC3_QCOM)		+= dwc3-qcom.o

>+obj-$(CONFIG_USB_DWC3_XILINX)		+= dwc3-xilinx.o

>diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c

>index e62ecd22b3ed..71fd620c5161 100644

>--- a/drivers/usb/dwc3/dwc3-of-simple.c

>+++ b/drivers/usb/dwc3/dwc3-of-simple.c

>@@ -172,7 +172,6 @@ static const struct dev_pm_ops dwc3_of_simple_dev_pm_ops = {

>

> static const struct of_device_id of_dwc3_simple_match[] = {

> 	{ .compatible = "rockchip,rk3399-dwc3" },

>-	{ .compatible = "xlnx,zynqmp-dwc3" },

> 	{ .compatible = "cavium,octeon-7130-usb-uctl" },

> 	{ .compatible = "sprd,sc9860-dwc3" },

> 	{ .compatible = "allwinner,sun50i-h6-dwc3" },

>diff --git a/drivers/usb/dwc3/dwc3-xilinx.c b/drivers/usb/dwc3/dwc3-xilinx.c

>new file mode 100644

>index 000000000000..7e485951d2f7

>--- /dev/null

>+++ b/drivers/usb/dwc3/dwc3-xilinx.c

>@@ -0,0 +1,334 @@

>+// SPDX-License-Identifier: GPL-2.0

>+/**

>+ * dwc3-xilinx.c - Xilinx DWC3 controller specific glue driver

>+ *

>+ * Authors: Manish Narani <manish.narani@xilinx.com>

>+ *          Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>

>+ */

>+

>+#include <linux/module.h>

>+#include <linux/kernel.h>

>+#include <linux/slab.h>

>+#include <linux/clk.h>

>+#include <linux/of.h>

>+#include <linux/platform_device.h>

>+#include <linux/dma-mapping.h>

>+#include <linux/of_platform.h>

>+#include <linux/pm_runtime.h>

>+#include <linux/reset.h>

>+#include <linux/of_address.h>

>+#include <linux/delay.h>

>+#include <linux/firmware/xlnx-zynqmp.h>

>+#include <linux/io.h>

>+

>+#include <linux/phy/phy.h>

>+

>+/* USB phy reset mask register */

>+#define XLNX_USB_PHY_RST_EN			0x001C

>+#define XLNX_PHY_RST_MASK			0x1

>+

>+/* Xilinx USB 3.0 IP Register */

>+#define XLNX_USB_TRAFFIC_ROUTE_CONFIG		0x005C

>+#define XLNX_USB_TRAFFIC_ROUTE_FPD		0x1

>+

>+/* Versal USB Reset ID */

>+#define VERSAL_USB_RESET_ID			0xC104036

>+

>+#define XLNX_USB_FPD_PIPE_CLK			0x7c

>+#define PIPE_CLK_DESELECT			1

>+#define PIPE_CLK_SELECT				0

>+#define XLNX_USB_FPD_POWER_PRSNT		0x80

>+#define PIPE_POWER_ON				1

>+#define PIPE_POWER_OFF				0

>+

>+struct dwc3_xlnx {

>+	int				num_clocks;

>+	struct clk_bulk_data		*clks;

>+	struct device			*dev;

>+	void __iomem			*regs;

>+	int				(*pltfm_init)(struct dwc3_xlnx *data);

>+};

>+

>+static void dwc3_xlnx_mask_phy_rst(struct dwc3_xlnx *priv_data, bool mask)

>+{

>+	u32 reg;

>+

>+	/*

>+	 * Enable or disable ULPI PHY reset from USB Controller.

>+	 * This does not actually reset the phy, but just controls

>+	 * whether USB controller can or cannot reset ULPI PHY.

>+	 */

>+	reg = readl(priv_data->regs + XLNX_USB_PHY_RST_EN);

>+

>+	if (mask)

>+		reg &= ~XLNX_PHY_RST_MASK;

>+	else

>+		reg |= XLNX_PHY_RST_MASK;

>+

>+	writel(reg, priv_data->regs + XLNX_USB_PHY_RST_EN);

>+}

>+

>+static int dwc3_xlnx_init_versal(struct dwc3_xlnx *priv_data)

>+{

>+	struct device		*dev = priv_data->dev;

>+	int			ret;

>+

>+	dwc3_xlnx_mask_phy_rst(priv_data, false);

>+

>+	/* Assert and De-assert reset */

>+	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,

>+				     PM_RESET_ACTION_ASSERT);

>+	if (ret < 0) {

>+		dev_err_probe(dev, ret, "failed to assert Reset\n");

>+		return ret;

>+	}

>+

>+	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,

>+				     PM_RESET_ACTION_RELEASE);

>+	if (ret < 0) {

>+		dev_err_probe(dev, ret, "failed to De-assert Reset\n");

>+		return ret;

>+	}

>+

>+	dwc3_xlnx_mask_phy_rst(priv_data, true);

>+

>+	return 0;

>+}

>+

>+static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data)

>+{

>+	struct device		*dev = priv_data->dev;

>+	struct reset_control	*crst, *hibrst, *apbrst;

>+	struct phy		*usb3_phy;

>+	int			ret;

>+	u32			reg;

>+

>+	crst = devm_reset_control_get_exclusive(dev, "usb_crst");

>+	if (IS_ERR(crst)) {

>+		ret = PTR_ERR(crst);

>+		dev_err_probe(dev, ret,

>+			      "failed to get core reset signal\n");

>+		goto err;

>+	}

>+

>+	hibrst = devm_reset_control_get_exclusive(dev, "usb_hibrst");

>+	if (IS_ERR(hibrst)) {

>+		ret = PTR_ERR(hibrst);

>+		dev_err_probe(dev, ret,

>+			      "failed to get hibernation reset signal\n");

>+		goto err;

>+	}

>+

>+	apbrst = devm_reset_control_get_exclusive(dev, "usb_apbrst");

>+	if (IS_ERR(apbrst)) {

>+		ret = PTR_ERR(apbrst);

>+		dev_err_probe(dev, ret,

>+			      "failed to get APB reset signal\n");

>+		goto err;

>+	}

>+

>+	ret = reset_control_assert(crst);

>+	if (ret < 0) {

>+		dev_err(dev, "Failed to assert core reset\n");

>+		goto err;

>+	}

>+

>+	ret = reset_control_assert(hibrst);

>+	if (ret < 0) {

>+		dev_err(dev, "Failed to assert hibernation reset\n");

>+		goto err;

>+	}

>+

>+	ret = reset_control_assert(apbrst);

>+	if (ret < 0) {

>+		dev_err(dev, "Failed to assert APB reset\n");

>+		goto err;

>+	}

>+

>+	usb3_phy = devm_phy_get(dev, "usb3-phy");

>+

>+	ret = phy_init(usb3_phy);

>+	if (ret < 0) {

>+		phy_exit(usb3_phy);

>+		goto err;

>+	}

>+

>+	ret = reset_control_deassert(apbrst);

>+	if (ret < 0) {

>+		dev_err(dev, "Failed to release APB reset\n");

>+		goto err;

>+	}

>+

>+	/* Set PIPE Power Present signal in FPD Power Present Register*/

>+	writel(PIPE_POWER_ON, priv_data->regs + XLNX_USB_FPD_POWER_PRSNT);

>+

>+	/* Set the PIPE Clock Select bit in FPD PIPE Clock register */

>+	writel(PIPE_CLK_SELECT, priv_data->regs + XLNX_USB_FPD_PIPE_CLK);

>+

>+	ret = reset_control_deassert(crst);

>+	if (ret < 0) {

>+		dev_err(dev, "Failed to release core reset\n");

>+		goto err;

>+	}

>+

>+	ret = reset_control_deassert(hibrst);

>+	if (ret < 0) {

>+		dev_err(dev, "Failed to release hibernation reset\n");

>+		goto err;

>+	}

>+

>+	ret = phy_power_on(usb3_phy);

>+	if (ret < 0) {

>+		phy_exit(usb3_phy);

>+		goto err;

>+	}

>+

>+	/*

>+	 * This routes the USB DMA traffic to go through FPD path instead

>+	 * of reaching DDR directly. This traffic routing is needed to

>+	 * make SMMU and CCI work with USB DMA.

>+	 */

>+	if (of_dma_is_coherent(dev->of_node) || device_iommu_mapped(dev)) {

>+		reg = readl(priv_data->regs + XLNX_USB_TRAFFIC_ROUTE_CONFIG);

>+		reg |= XLNX_USB_TRAFFIC_ROUTE_FPD;

>+		writel(reg, priv_data->regs + XLNX_USB_TRAFFIC_ROUTE_CONFIG);

>+	}

>+

>+err:

>+	return ret;

>+}

>+

>+static const struct of_device_id dwc3_xlnx_of_match[] = {

>+	{

>+		.compatible = "xlnx,zynqmp-dwc3",

>+		.data = &dwc3_xlnx_init_zynqmp,

>+	},

>+	{

>+		.compatible = "xlnx,versal-dwc3",

>+		.data = &dwc3_xlnx_init_versal,

>+	},

>+	{ /* Sentinel */ }

>+};

>+MODULE_DEVICE_TABLE(of, dwc3_xlnx_of_match);

>+

>+static int dwc3_xlnx_probe(struct platform_device *pdev)

>+{

>+	struct dwc3_xlnx		*priv_data;

>+	struct device			*dev = &pdev->dev;

>+	struct device_node		*np = dev->of_node;

>+	const struct of_device_id	*match;

>+	void __iomem			*regs;

>+	int				ret;

>+

>+	priv_data = devm_kzalloc(dev, sizeof(*priv_data), GFP_KERNEL);

>+	if (!priv_data)

>+		return -ENOMEM;

>+

>+	regs = devm_platform_ioremap_resource(pdev, 0);

>+	if (IS_ERR(regs)) {

>+		ret = PTR_ERR(regs);

>+		dev_err_probe(dev, ret, "failed to map registers\n");

>+		return ret;

>+	}

>+

>+	match = of_match_node(dwc3_xlnx_of_match, pdev->dev.of_node);

>+

>+	priv_data->pltfm_init = match->data;

>+	priv_data->regs = regs;

>+	priv_data->dev = dev;

>+

>+	platform_set_drvdata(pdev, priv_data);

>+

>+	ret = devm_clk_bulk_get_all(priv_data->dev, &priv_data->clks);

>+	if (ret < 0)

>+		return ret;

>+

>+	priv_data->num_clocks = ret;

>+

>+	ret = clk_bulk_prepare_enable(priv_data->num_clocks, priv_data->clks);

>+	if (ret)

>+		return ret;

>+

>+	ret = priv_data->pltfm_init(priv_data);

>+	if (ret)

>+		goto err_clk_put;

>+

>+	ret = of_platform_populate(np, NULL, NULL, dev);

>+	if (ret)

>+		goto err_clk_put;

>+

>+	pm_runtime_set_active(dev);

>+	pm_runtime_enable(dev);

>+	pm_suspend_ignore_children(dev, false);

>+	pm_runtime_get_sync(dev);

>+

>+	return 0;

>+

>+err_clk_put:

>+	clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data->clks);

>+	clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);

>+

>+	return ret;

>+}

>+

>+static int dwc3_xlnx_remove(struct platform_device *pdev)

>+{

>+	struct dwc3_xlnx	*priv_data = platform_get_drvdata(pdev);

>+	struct device		*dev = &pdev->dev;

>+

>+	of_platform_depopulate(dev);

>+

>+	clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data->clks);

>+	clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);

>+	priv_data->num_clocks = 0;

>+

>+	pm_runtime_disable(dev);

>+	pm_runtime_put_noidle(dev);

>+	pm_runtime_set_suspended(dev);

>+

>+	return 0;

>+}

>+

>+static int __maybe_unused dwc3_xlnx_suspend_common(struct device *dev)

>+{

>+	struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);

>+

>+	clk_bulk_disable(priv_data->num_clocks, priv_data->clks);

>+

>+	return 0;

>+}

>+

>+static int __maybe_unused dwc3_xlnx_resume_common(struct device *dev)

>+{

>+	struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);

>+

>+	return clk_bulk_enable(priv_data->num_clocks, priv_data->clks);

>+}

>+

>+static int __maybe_unused dwc3_xlnx_runtime_idle(struct device *dev)

>+{

>+	pm_runtime_mark_last_busy(dev);

>+	pm_runtime_autosuspend(dev);

>+

>+	return 0;

>+}

>+

>+static UNIVERSAL_DEV_PM_OPS(dwc3_xlnx_dev_pm_ops, dwc3_xlnx_suspend_common,

>+			    dwc3_xlnx_resume_common, dwc3_xlnx_runtime_idle);

>+

>+static struct platform_driver dwc3_xlnx_driver = {

>+	.probe		= dwc3_xlnx_probe,

>+	.remove		= dwc3_xlnx_remove,

>+	.driver		= {

>+		.name		= "dwc3-xilinx",

>+		.of_match_table	= dwc3_xlnx_of_match,

>+		.pm		= &dwc3_xlnx_dev_pm_ops,

>+	},

>+};

>+

>+module_platform_driver(dwc3_xlnx_driver);

>+

>+MODULE_LICENSE("GPL v2");

>+MODULE_DESCRIPTION("Xilinx DWC3 controller specific glue driver");

>+MODULE_AUTHOR("Manish Narani <manish.narani@xilinx.com>");

>+MODULE_AUTHOR("Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>");

>-- 

>2.17.1

>

>

>_______________________________________________

>linux-arm-kernel mailing list

>linux-arm-kernel@lists.infradead.org

>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel


-- 
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Hi,

Michael Grzeschik <mgr@pengutronix.de> writes:
> On Tue, Dec 15, 2020 at 12:24:51PM +0530, Manish Narani wrote:

>>Add a new driver for supporting Xilinx platforms. This driver is used

>>for some sequence of operations required for Xilinx USB controllers.

>>This driver is also used to choose between PIPE clock coming from SerDes

>>and the Suspend Clock. Before the controller is out of reset, the clock

>>selection should be changed to PIPE clock in order to make the USB

>>controller work. There is a register added in Xilinx USB controller

>>register space for the same.

>

> I tried out this driver with the vanilla kernel on an zynqmp. Without

> this patch the USB-Gadget is already acting buggy. In the gadget mode,

> some iterations of plug/unplug results to an stalled gadget which will

> never come back without a reboot.

>

> With the corresponding code of this driver (reset assert, clk modify,

> reset deassert) in the downstream kernels phy driver we found out it is

> totaly stable. But using this exact glue driver which should do the same

> as the downstream code, the gadget still was buggy the way described

> above.

>

> I suspect the difference lays in the different order of operations.

> While the downstream code is runing the resets inside the phy driver

> which is powered and initialized in the dwc3-core itself. With this glue

> layser approach of this patch the whole phy init is done before even

> touching dwc3-core in any way. It seems not to have the same effect,

> though.

>

> If really the order of operations is limiting us, we probably need

> another solution than this glue layer. Any Ideas?


might be a good idea to collect dwc3 trace events. Can you do that?

-- 
balbi

On Mon, Jan 18, 2021 at 05:24:38PM +0200, Felipe Balbi wrote:
>
>Hi,
>
>Michael Grzeschik <mgr@pengutronix.de> writes:
>> On Tue, Dec 15, 2020 at 12:24:51PM +0530, Manish Narani wrote:
>>>Add a new driver for supporting Xilinx platforms. This driver is used
>>>for some sequence of operations required for Xilinx USB controllers.
>>>This driver is also used to choose between PIPE clock coming from SerDes
>>>and the Suspend Clock. Before the controller is out of reset, the clock
>>>selection should be changed to PIPE clock in order to make the USB
>>>controller work. There is a register added in Xilinx USB controller
>>>register space for the same.
>>
>> I tried out this driver with the vanilla kernel on an zynqmp. Without
>> this patch the USB-Gadget is already acting buggy. In the gadget mode,
>> some iterations of plug/unplug results to an stalled gadget which will
>> never come back without a reboot.
>>
>> With the corresponding code of this driver (reset assert, clk modify,
>> reset deassert) in the downstream kernels phy driver we found out it is
>> totaly stable. But using this exact glue driver which should do the same
>> as the downstream code, the gadget still was buggy the way described
>> above.
>>
>> I suspect the difference lays in the different order of operations.
>> While the downstream code is runing the resets inside the phy driver
>> which is powered and initialized in the dwc3-core itself. With this glue
>> layser approach of this patch the whole phy init is done before even
>> touching dwc3-core in any way. It seems not to have the same effect,
>> though.
>>
>> If really the order of operations is limiting us, we probably need
>> another solution than this glue layer. Any Ideas?
>
>might be a good idea to collect dwc3 trace events. Can you do that?

I already did that. In case the port is not working properly, the port
was producing several "Erratic Errors" between the plug/unplug events.

This was not the case until the reset_assert, pll configure,
reset_deassert sequence was applied like in the downstream kernels
phy driver on phy_init.

Regards,
Michael

Hello!

On Mon, Jan 18, 2021 at 02:42:24PM +0100, Michael Grzeschik wrote:
>Hi!
>
>On Tue, Dec 15, 2020 at 12:24:51PM +0530, Manish Narani wrote:
>>Add a new driver for supporting Xilinx platforms. This driver is used
>>for some sequence of operations required for Xilinx USB controllers.
>>This driver is also used to choose between PIPE clock coming from SerDes
>>and the Suspend Clock. Before the controller is out of reset, the clock
>>selection should be changed to PIPE clock in order to make the USB
>>controller work. There is a register added in Xilinx USB controller
>>register space for the same.
>
>I tried out this driver with the vanilla kernel on an zynqmp. Without
>this patch the USB-Gadget is already acting buggy. In the gadget mode,
>some iterations of plug/unplug results to an stalled gadget which will
>never come back without a reboot.
>
>With the corresponding code of this driver (reset assert, clk modify,
>reset deassert) in the downstream kernels phy driver we found out it is
>totaly stable. But using this exact glue driver which should do the same
>as the downstream code, the gadget still was buggy the way described
>above.
>
>I suspect the difference lays in the different order of operations.
>While the downstream code is runing the resets inside the phy driver
>which is powered and initialized in the dwc3-core itself. With this glue
>layser approach of this patch the whole phy init is done before even
>touching dwc3-core in any way. It seems not to have the same effect,
>though.
>
>If really the order of operations is limiting us, we probably need
>another solution than this glue layer. Any Ideas?

I found out what the difference between the Downstream and this
Glue is. When using vanilla with this Glue code we may not set
the following bit:

https://www.xilinx.com/html_docs/registers/ug1087/ug1087-zynq-ultrascale-registers.html#usb3_regs___fpd_power_prsnt.html

>>+	/* Set PIPE Power Present signal in FPD Power Present Register*/
>>+	writel(PIPE_POWER_ON, priv_data->regs + XLNX_USB_FPD_POWER_PRSNT);

When I comment this out, the link stays stable. This is different in
the Downstream Xilinx Kernel, where the bit is also set but has no
negativ effect.

Manish, can you give me a pointer what to look for?
So setting this will also work with mainline?

Regards,
Michael

>>
>>Signed-off-by: Manish Narani <manish.narani@xilinx.com>
>>---
>>drivers/usb/dwc3/Kconfig          |   9 +
>>drivers/usb/dwc3/Makefile         |   1 +
>>drivers/usb/dwc3/dwc3-of-simple.c |   1 -
>>drivers/usb/dwc3/dwc3-xilinx.c    | 334 ++++++++++++++++++++++++++++++
>>4 files changed, 344 insertions(+), 1 deletion(-)
>>create mode 100644 drivers/usb/dwc3/dwc3-xilinx.c
>>
>>diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
>>index 7a2304565a73..0e00e6dfccd8 100644
>>--- a/drivers/usb/dwc3/Kconfig
>>+++ b/drivers/usb/dwc3/Kconfig
>>@@ -139,4 +139,13 @@ config USB_DWC3_QCOM
>>	  for peripheral mode support.
>>	  Say 'Y' or 'M' if you have one such device.
>>
>>+config USB_DWC3_XILINX
>>+	tristate "Xilinx Platforms"
>>+	depends on (ARCH_ZYNQMP || ARCH_VERSAL) && OF
>>+	default USB_DWC3
>>+	help
>>+	  Support Xilinx SoCs with DesignWare Core USB3 IP.
>>+	  This driver handles both ZynqMP and Versal SoC operations.
>>+	  Say 'Y' or 'M' if you have one such device.
>>+
>>endif
>>diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
>>index ae86da0dc5bd..add567578b1f 100644
>>--- a/drivers/usb/dwc3/Makefile
>>+++ b/drivers/usb/dwc3/Makefile
>>@@ -51,3 +51,4 @@ obj-$(CONFIG_USB_DWC3_MESON_G12A)	+= dwc3-meson-g12a.o
>>obj-$(CONFIG_USB_DWC3_OF_SIMPLE)	+= dwc3-of-simple.o
>>obj-$(CONFIG_USB_DWC3_ST)		+= dwc3-st.o
>>obj-$(CONFIG_USB_DWC3_QCOM)		+= dwc3-qcom.o
>>+obj-$(CONFIG_USB_DWC3_XILINX)		+= dwc3-xilinx.o
>>diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-of-simple.c
>>index e62ecd22b3ed..71fd620c5161 100644
>>--- a/drivers/usb/dwc3/dwc3-of-simple.c
>>+++ b/drivers/usb/dwc3/dwc3-of-simple.c
>>@@ -172,7 +172,6 @@ static const struct dev_pm_ops dwc3_of_simple_dev_pm_ops = {
>>
>>static const struct of_device_id of_dwc3_simple_match[] = {
>>	{ .compatible = "rockchip,rk3399-dwc3" },
>>-	{ .compatible = "xlnx,zynqmp-dwc3" },
>>	{ .compatible = "cavium,octeon-7130-usb-uctl" },
>>	{ .compatible = "sprd,sc9860-dwc3" },
>>	{ .compatible = "allwinner,sun50i-h6-dwc3" },
>>diff --git a/drivers/usb/dwc3/dwc3-xilinx.c b/drivers/usb/dwc3/dwc3-xilinx.c
>>new file mode 100644
>>index 000000000000..7e485951d2f7
>>--- /dev/null
>>+++ b/drivers/usb/dwc3/dwc3-xilinx.c
>>@@ -0,0 +1,334 @@
>>+// SPDX-License-Identifier: GPL-2.0
>>+/**
>>+ * dwc3-xilinx.c - Xilinx DWC3 controller specific glue driver
>>+ *
>>+ * Authors: Manish Narani <manish.narani@xilinx.com>
>>+ *          Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>
>>+ */
>>+
>>+#include <linux/module.h>
>>+#include <linux/kernel.h>
>>+#include <linux/slab.h>
>>+#include <linux/clk.h>
>>+#include <linux/of.h>
>>+#include <linux/platform_device.h>
>>+#include <linux/dma-mapping.h>
>>+#include <linux/of_platform.h>
>>+#include <linux/pm_runtime.h>
>>+#include <linux/reset.h>
>>+#include <linux/of_address.h>
>>+#include <linux/delay.h>
>>+#include <linux/firmware/xlnx-zynqmp.h>
>>+#include <linux/io.h>
>>+
>>+#include <linux/phy/phy.h>
>>+
>>+/* USB phy reset mask register */
>>+#define XLNX_USB_PHY_RST_EN			0x001C
>>+#define XLNX_PHY_RST_MASK			0x1
>>+
>>+/* Xilinx USB 3.0 IP Register */
>>+#define XLNX_USB_TRAFFIC_ROUTE_CONFIG		0x005C
>>+#define XLNX_USB_TRAFFIC_ROUTE_FPD		0x1
>>+
>>+/* Versal USB Reset ID */
>>+#define VERSAL_USB_RESET_ID			0xC104036
>>+
>>+#define XLNX_USB_FPD_PIPE_CLK			0x7c
>>+#define PIPE_CLK_DESELECT			1
>>+#define PIPE_CLK_SELECT				0
>>+#define XLNX_USB_FPD_POWER_PRSNT		0x80
>>+#define PIPE_POWER_ON				1
>>+#define PIPE_POWER_OFF				0
>>+
>>+struct dwc3_xlnx {
>>+	int				num_clocks;
>>+	struct clk_bulk_data		*clks;
>>+	struct device			*dev;
>>+	void __iomem			*regs;
>>+	int				(*pltfm_init)(struct dwc3_xlnx *data);
>>+};
>>+
>>+static void dwc3_xlnx_mask_phy_rst(struct dwc3_xlnx *priv_data, bool mask)
>>+{
>>+	u32 reg;
>>+
>>+	/*
>>+	 * Enable or disable ULPI PHY reset from USB Controller.
>>+	 * This does not actually reset the phy, but just controls
>>+	 * whether USB controller can or cannot reset ULPI PHY.
>>+	 */
>>+	reg = readl(priv_data->regs + XLNX_USB_PHY_RST_EN);
>>+
>>+	if (mask)
>>+		reg &= ~XLNX_PHY_RST_MASK;
>>+	else
>>+		reg |= XLNX_PHY_RST_MASK;
>>+
>>+	writel(reg, priv_data->regs + XLNX_USB_PHY_RST_EN);
>>+}
>>+
>>+static int dwc3_xlnx_init_versal(struct dwc3_xlnx *priv_data)
>>+{
>>+	struct device		*dev = priv_data->dev;
>>+	int			ret;
>>+
>>+	dwc3_xlnx_mask_phy_rst(priv_data, false);
>>+
>>+	/* Assert and De-assert reset */
>>+	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
>>+				     PM_RESET_ACTION_ASSERT);
>>+	if (ret < 0) {
>>+		dev_err_probe(dev, ret, "failed to assert Reset\n");
>>+		return ret;
>>+	}
>>+
>>+	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
>>+				     PM_RESET_ACTION_RELEASE);
>>+	if (ret < 0) {
>>+		dev_err_probe(dev, ret, "failed to De-assert Reset\n");
>>+		return ret;
>>+	}
>>+
>>+	dwc3_xlnx_mask_phy_rst(priv_data, true);
>>+
>>+	return 0;
>>+}
>>+
>>+static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data)
>>+{
>>+	struct device		*dev = priv_data->dev;
>>+	struct reset_control	*crst, *hibrst, *apbrst;
>>+	struct phy		*usb3_phy;
>>+	int			ret;
>>+	u32			reg;
>>+
>>+	crst = devm_reset_control_get_exclusive(dev, "usb_crst");
>>+	if (IS_ERR(crst)) {
>>+		ret = PTR_ERR(crst);
>>+		dev_err_probe(dev, ret,
>>+			      "failed to get core reset signal\n");
>>+		goto err;
>>+	}
>>+
>>+	hibrst = devm_reset_control_get_exclusive(dev, "usb_hibrst");
>>+	if (IS_ERR(hibrst)) {
>>+		ret = PTR_ERR(hibrst);
>>+		dev_err_probe(dev, ret,
>>+			      "failed to get hibernation reset signal\n");
>>+		goto err;
>>+	}
>>+
>>+	apbrst = devm_reset_control_get_exclusive(dev, "usb_apbrst");
>>+	if (IS_ERR(apbrst)) {
>>+		ret = PTR_ERR(apbrst);
>>+		dev_err_probe(dev, ret,
>>+			      "failed to get APB reset signal\n");
>>+		goto err;
>>+	}
>>+
>>+	ret = reset_control_assert(crst);
>>+	if (ret < 0) {
>>+		dev_err(dev, "Failed to assert core reset\n");
>>+		goto err;
>>+	}
>>+
>>+	ret = reset_control_assert(hibrst);
>>+	if (ret < 0) {
>>+		dev_err(dev, "Failed to assert hibernation reset\n");
>>+		goto err;
>>+	}
>>+
>>+	ret = reset_control_assert(apbrst);
>>+	if (ret < 0) {
>>+		dev_err(dev, "Failed to assert APB reset\n");
>>+		goto err;
>>+	}
>>+
>>+	usb3_phy = devm_phy_get(dev, "usb3-phy");
>>+
>>+	ret = phy_init(usb3_phy);
>>+	if (ret < 0) {
>>+		phy_exit(usb3_phy);
>>+		goto err;
>>+	}
>>+
>>+	ret = reset_control_deassert(apbrst);
>>+	if (ret < 0) {
>>+		dev_err(dev, "Failed to release APB reset\n");
>>+		goto err;
>>+	}
>>+
>>+	/* Set PIPE Power Present signal in FPD Power Present Register*/
>>+	writel(PIPE_POWER_ON, priv_data->regs + XLNX_USB_FPD_POWER_PRSNT);

This is somehow leading to an unstable link when using vanilla.

>>+
>>+	/* Set the PIPE Clock Select bit in FPD PIPE Clock register */
>>+	writel(PIPE_CLK_SELECT, priv_data->regs + XLNX_USB_FPD_PIPE_CLK);
>>+
>>+	ret = reset_control_deassert(crst);
>>+	if (ret < 0) {
>>+		dev_err(dev, "Failed to release core reset\n");
>>+		goto err;
>>+	}
>>+
>>+	ret = reset_control_deassert(hibrst);
>>+	if (ret < 0) {
>>+		dev_err(dev, "Failed to release hibernation reset\n");
>>+		goto err;
>>+	}
>>+
>>+	ret = phy_power_on(usb3_phy);
>>+	if (ret < 0) {
>>+		phy_exit(usb3_phy);
>>+		goto err;
>>+	}
>>+
>>+	/*
>>+	 * This routes the USB DMA traffic to go through FPD path instead
>>+	 * of reaching DDR directly. This traffic routing is needed to
>>+	 * make SMMU and CCI work with USB DMA.
>>+	 */
>>+	if (of_dma_is_coherent(dev->of_node) || device_iommu_mapped(dev)) {
>>+		reg = readl(priv_data->regs + XLNX_USB_TRAFFIC_ROUTE_CONFIG);
>>+		reg |= XLNX_USB_TRAFFIC_ROUTE_FPD;
>>+		writel(reg, priv_data->regs + XLNX_USB_TRAFFIC_ROUTE_CONFIG);
>>+	}
>>+
>>+err:
>>+	return ret;
>>+}
>>+
>>+static const struct of_device_id dwc3_xlnx_of_match[] = {
>>+	{
>>+		.compatible = "xlnx,zynqmp-dwc3",
>>+		.data = &dwc3_xlnx_init_zynqmp,
>>+	},
>>+	{
>>+		.compatible = "xlnx,versal-dwc3",
>>+		.data = &dwc3_xlnx_init_versal,
>>+	},
>>+	{ /* Sentinel */ }
>>+};
>>+MODULE_DEVICE_TABLE(of, dwc3_xlnx_of_match);
>>+
>>+static int dwc3_xlnx_probe(struct platform_device *pdev)
>>+{
>>+	struct dwc3_xlnx		*priv_data;
>>+	struct device			*dev = &pdev->dev;
>>+	struct device_node		*np = dev->of_node;
>>+	const struct of_device_id	*match;
>>+	void __iomem			*regs;
>>+	int				ret;
>>+
>>+	priv_data = devm_kzalloc(dev, sizeof(*priv_data), GFP_KERNEL);
>>+	if (!priv_data)
>>+		return -ENOMEM;
>>+
>>+	regs = devm_platform_ioremap_resource(pdev, 0);
>>+	if (IS_ERR(regs)) {
>>+		ret = PTR_ERR(regs);
>>+		dev_err_probe(dev, ret, "failed to map registers\n");
>>+		return ret;
>>+	}
>>+
>>+	match = of_match_node(dwc3_xlnx_of_match, pdev->dev.of_node);
>>+
>>+	priv_data->pltfm_init = match->data;
>>+	priv_data->regs = regs;
>>+	priv_data->dev = dev;
>>+
>>+	platform_set_drvdata(pdev, priv_data);
>>+
>>+	ret = devm_clk_bulk_get_all(priv_data->dev, &priv_data->clks);
>>+	if (ret < 0)
>>+		return ret;
>>+
>>+	priv_data->num_clocks = ret;
>>+
>>+	ret = clk_bulk_prepare_enable(priv_data->num_clocks, priv_data->clks);
>>+	if (ret)
>>+		return ret;
>>+
>>+	ret = priv_data->pltfm_init(priv_data);
>>+	if (ret)
>>+		goto err_clk_put;
>>+
>>+	ret = of_platform_populate(np, NULL, NULL, dev);
>>+	if (ret)
>>+		goto err_clk_put;
>>+
>>+	pm_runtime_set_active(dev);
>>+	pm_runtime_enable(dev);
>>+	pm_suspend_ignore_children(dev, false);
>>+	pm_runtime_get_sync(dev);
>>+
>>+	return 0;
>>+
>>+err_clk_put:
>>+	clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data->clks);
>>+	clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);
>>+
>>+	return ret;
>>+}
>>+
>>+static int dwc3_xlnx_remove(struct platform_device *pdev)
>>+{
>>+	struct dwc3_xlnx	*priv_data = platform_get_drvdata(pdev);
>>+	struct device		*dev = &pdev->dev;
>>+
>>+	of_platform_depopulate(dev);
>>+
>>+	clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data->clks);
>>+	clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);
>>+	priv_data->num_clocks = 0;
>>+
>>+	pm_runtime_disable(dev);
>>+	pm_runtime_put_noidle(dev);
>>+	pm_runtime_set_suspended(dev);
>>+
>>+	return 0;
>>+}
>>+
>>+static int __maybe_unused dwc3_xlnx_suspend_common(struct device *dev)
>>+{
>>+	struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);
>>+
>>+	clk_bulk_disable(priv_data->num_clocks, priv_data->clks);
>>+
>>+	return 0;
>>+}
>>+
>>+static int __maybe_unused dwc3_xlnx_resume_common(struct device *dev)
>>+{
>>+	struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);
>>+
>>+	return clk_bulk_enable(priv_data->num_clocks, priv_data->clks);
>>+}
>>+
>>+static int __maybe_unused dwc3_xlnx_runtime_idle(struct device *dev)
>>+{
>>+	pm_runtime_mark_last_busy(dev);
>>+	pm_runtime_autosuspend(dev);
>>+
>>+	return 0;
>>+}
>>+
>>+static UNIVERSAL_DEV_PM_OPS(dwc3_xlnx_dev_pm_ops, dwc3_xlnx_suspend_common,
>>+			    dwc3_xlnx_resume_common, dwc3_xlnx_runtime_idle);
>>+
>>+static struct platform_driver dwc3_xlnx_driver = {
>>+	.probe		= dwc3_xlnx_probe,
>>+	.remove		= dwc3_xlnx_remove,
>>+	.driver		= {
>>+		.name		= "dwc3-xilinx",
>>+		.of_match_table	= dwc3_xlnx_of_match,
>>+		.pm		= &dwc3_xlnx_dev_pm_ops,
>>+	},
>>+};
>>+
>>+module_platform_driver(dwc3_xlnx_driver);
>>+
>>+MODULE_LICENSE("GPL v2");
>>+MODULE_DESCRIPTION("Xilinx DWC3 controller specific glue driver");
>>+MODULE_AUTHOR("Manish Narani <manish.narani@xilinx.com>");
>>+MODULE_AUTHOR("Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>");
>>-- 
>>2.17.1
>>
>>
>>_______________________________________________
>>linux-arm-kernel mailing list
>>linux-arm-kernel@lists.infradead.org
>>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
>-- 
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>Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |



>_______________________________________________
>linux-arm-kernel mailing list
>linux-arm-kernel@lists.infradead.org
>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Hi Michael,

> -----Original Message-----
> From: Michael Grzeschik <mgr@pengutronix.de>
> Sent: Friday, January 22, 2021 1:39 PM
> To: Manish Narani <MNARANI@xilinx.com>
> Cc: devicetree@vger.kernel.org; kernel@pengutronix.de; balbi@kernel.org;
> gregkh@linuxfoundation.org; linux-usb@vger.kernel.org; Michal Simek
> <michals@xilinx.com>; linux-kernel@vger.kernel.org; robh+dt@kernel.org;
> git <git@xilinx.com>; p.zabel@pengutronix.de; linux-arm-
> kernel@lists.infradead.org
> Subject: Re: [RESEND PATCH v3 2/2] usb: dwc3: Add driver for Xilinx
> platforms
> 
> Hello!
> 
> On Mon, Jan 18, 2021 at 02:42:24PM +0100, Michael Grzeschik wrote:
> >Hi!
> >
> >On Tue, Dec 15, 2020 at 12:24:51PM +0530, Manish Narani wrote:
> >>Add a new driver for supporting Xilinx platforms. This driver is used
> >>for some sequence of operations required for Xilinx USB controllers.
> >>This driver is also used to choose between PIPE clock coming from SerDes
> >>and the Suspend Clock. Before the controller is out of reset, the clock
> >>selection should be changed to PIPE clock in order to make the USB
> >>controller work. There is a register added in Xilinx USB controller
> >>register space for the same.
> >
> >I tried out this driver with the vanilla kernel on an zynqmp. Without
> >this patch the USB-Gadget is already acting buggy. In the gadget mode,
> >some iterations of plug/unplug results to an stalled gadget which will
> >never come back without a reboot.
> >
> >With the corresponding code of this driver (reset assert, clk modify,
> >reset deassert) in the downstream kernels phy driver we found out it is
> >totaly stable. But using this exact glue driver which should do the same
> >as the downstream code, the gadget still was buggy the way described
> >above.
> >
> >I suspect the difference lays in the different order of operations.
> >While the downstream code is runing the resets inside the phy driver
> >which is powered and initialized in the dwc3-core itself. With this glue
> >layser approach of this patch the whole phy init is done before even
> >touching dwc3-core in any way. It seems not to have the same effect,
> >though.
> >
> >If really the order of operations is limiting us, we probably need
> >another solution than this glue layer. Any Ideas?
> 
> I found out what the difference between the Downstream and this
> Glue is. When using vanilla with this Glue code we may not set
> the following bit:
> 
> https://www.xilinx.com/html_docs/registers/ug1087/ug1087-zynq-
> ultrascale-registers.html#usb3_regs___fpd_power_prsnt.html
> 
> >>+	/* Set PIPE Power Present signal in FPD Power Present Register*/
> >>+	writel(PIPE_POWER_ON, priv_data->regs +
> XLNX_USB_FPD_POWER_PRSNT);
> 
> When I comment this out, the link stays stable. This is different in
> the Downstream Xilinx Kernel, where the bit is also set but has no
> negativ effect.
> 
> Manish, can you give me a pointer what to look for?
> So setting this will also work with mainline?
I am looking further on this but from what I see here is that,
In order to make USB function properly, there are some dt changes needed in mainline for
USB node which include defining clocks coming from serdes.
The DT changes are pending to be sent to mainline.
Can you share the DT settings for USB node on your side?
Meanwhile I will keep updating on the same.

Thanks,
Manish

> 
> Regards,
> Michael
> 
> >>
> >>Signed-off-by: Manish Narani <manish.narani@xilinx.com>
> >>---
> >>drivers/usb/dwc3/Kconfig          |   9 +
> >>drivers/usb/dwc3/Makefile         |   1 +
> >>drivers/usb/dwc3/dwc3-of-simple.c |   1 -
> >>drivers/usb/dwc3/dwc3-xilinx.c    | 334
> ++++++++++++++++++++++++++++++
> >>4 files changed, 344 insertions(+), 1 deletion(-)
> >>create mode 100644 drivers/usb/dwc3/dwc3-xilinx.c
> >>
> >>diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> >>index 7a2304565a73..0e00e6dfccd8 100644
> >>--- a/drivers/usb/dwc3/Kconfig
> >>+++ b/drivers/usb/dwc3/Kconfig
> >>@@ -139,4 +139,13 @@ config USB_DWC3_QCOM
> >>	  for peripheral mode support.
> >>	  Say 'Y' or 'M' if you have one such device.
> >>
> >>+config USB_DWC3_XILINX
> >>+	tristate "Xilinx Platforms"
> >>+	depends on (ARCH_ZYNQMP || ARCH_VERSAL) && OF
> >>+	default USB_DWC3
> >>+	help
> >>+	  Support Xilinx SoCs with DesignWare Core USB3 IP.
> >>+	  This driver handles both ZynqMP and Versal SoC operations.
> >>+	  Say 'Y' or 'M' if you have one such device.
> >>+
> >>endif
> >>diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
> >>index ae86da0dc5bd..add567578b1f 100644
> >>--- a/drivers/usb/dwc3/Makefile
> >>+++ b/drivers/usb/dwc3/Makefile
> >>@@ -51,3 +51,4 @@ obj-$(CONFIG_USB_DWC3_MESON_G12A)	+=
> dwc3-meson-g12a.o
> >>obj-$(CONFIG_USB_DWC3_OF_SIMPLE)	+= dwc3-of-simple.o
> >>obj-$(CONFIG_USB_DWC3_ST)		+= dwc3-st.o
> >>obj-$(CONFIG_USB_DWC3_QCOM)		+= dwc3-qcom.o
> >>+obj-$(CONFIG_USB_DWC3_XILINX)		+= dwc3-xilinx.o
> >>diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-
> of-simple.c
> >>index e62ecd22b3ed..71fd620c5161 100644
> >>--- a/drivers/usb/dwc3/dwc3-of-simple.c
> >>+++ b/drivers/usb/dwc3/dwc3-of-simple.c
> >>@@ -172,7 +172,6 @@ static const struct dev_pm_ops
> dwc3_of_simple_dev_pm_ops = {
> >>
> >>static const struct of_device_id of_dwc3_simple_match[] = {
> >>	{ .compatible = "rockchip,rk3399-dwc3" },
> >>-	{ .compatible = "xlnx,zynqmp-dwc3" },
> >>	{ .compatible = "cavium,octeon-7130-usb-uctl" },
> >>	{ .compatible = "sprd,sc9860-dwc3" },
> >>	{ .compatible = "allwinner,sun50i-h6-dwc3" },
> >>diff --git a/drivers/usb/dwc3/dwc3-xilinx.c b/drivers/usb/dwc3/dwc3-
> xilinx.c
> >>new file mode 100644
> >>index 000000000000..7e485951d2f7
> >>--- /dev/null
> >>+++ b/drivers/usb/dwc3/dwc3-xilinx.c
> >>@@ -0,0 +1,334 @@
> >>+// SPDX-License-Identifier: GPL-2.0
> >>+/**
> >>+ * dwc3-xilinx.c - Xilinx DWC3 controller specific glue driver
> >>+ *
> >>+ * Authors: Manish Narani <manish.narani@xilinx.com>
> >>+ *          Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>
> >>+ */
> >>+
> >>+#include <linux/module.h>
> >>+#include <linux/kernel.h>
> >>+#include <linux/slab.h>
> >>+#include <linux/clk.h>
> >>+#include <linux/of.h>
> >>+#include <linux/platform_device.h>
> >>+#include <linux/dma-mapping.h>
> >>+#include <linux/of_platform.h>
> >>+#include <linux/pm_runtime.h>
> >>+#include <linux/reset.h>
> >>+#include <linux/of_address.h>
> >>+#include <linux/delay.h>
> >>+#include <linux/firmware/xlnx-zynqmp.h>
> >>+#include <linux/io.h>
> >>+
> >>+#include <linux/phy/phy.h>
> >>+
> >>+/* USB phy reset mask register */
> >>+#define XLNX_USB_PHY_RST_EN			0x001C
> >>+#define XLNX_PHY_RST_MASK			0x1
> >>+
> >>+/* Xilinx USB 3.0 IP Register */
> >>+#define XLNX_USB_TRAFFIC_ROUTE_CONFIG		0x005C
> >>+#define XLNX_USB_TRAFFIC_ROUTE_FPD		0x1
> >>+
> >>+/* Versal USB Reset ID */
> >>+#define VERSAL_USB_RESET_ID			0xC104036
> >>+
> >>+#define XLNX_USB_FPD_PIPE_CLK			0x7c
> >>+#define PIPE_CLK_DESELECT			1
> >>+#define PIPE_CLK_SELECT				0
> >>+#define XLNX_USB_FPD_POWER_PRSNT		0x80
> >>+#define PIPE_POWER_ON				1
> >>+#define PIPE_POWER_OFF				0
> >>+
> >>+struct dwc3_xlnx {
> >>+	int				num_clocks;
> >>+	struct clk_bulk_data		*clks;
> >>+	struct device			*dev;
> >>+	void __iomem			*regs;
> >>+	int				(*pltfm_init)(struct dwc3_xlnx *data);
> >>+};
> >>+
> >>+static void dwc3_xlnx_mask_phy_rst(struct dwc3_xlnx *priv_data, bool
> mask)
> >>+{
> >>+	u32 reg;
> >>+
> >>+	/*
> >>+	 * Enable or disable ULPI PHY reset from USB Controller.
> >>+	 * This does not actually reset the phy, but just controls
> >>+	 * whether USB controller can or cannot reset ULPI PHY.
> >>+	 */
> >>+	reg = readl(priv_data->regs + XLNX_USB_PHY_RST_EN);
> >>+
> >>+	if (mask)
> >>+		reg &= ~XLNX_PHY_RST_MASK;
> >>+	else
> >>+		reg |= XLNX_PHY_RST_MASK;
> >>+
> >>+	writel(reg, priv_data->regs + XLNX_USB_PHY_RST_EN);
> >>+}
> >>+
> >>+static int dwc3_xlnx_init_versal(struct dwc3_xlnx *priv_data)
> >>+{
> >>+	struct device		*dev = priv_data->dev;
> >>+	int			ret;
> >>+
> >>+	dwc3_xlnx_mask_phy_rst(priv_data, false);
> >>+
> >>+	/* Assert and De-assert reset */
> >>+	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
> >>+				     PM_RESET_ACTION_ASSERT);
> >>+	if (ret < 0) {
> >>+		dev_err_probe(dev, ret, "failed to assert Reset\n");
> >>+		return ret;
> >>+	}
> >>+
> >>+	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
> >>+				     PM_RESET_ACTION_RELEASE);
> >>+	if (ret < 0) {
> >>+		dev_err_probe(dev, ret, "failed to De-assert Reset\n");
> >>+		return ret;
> >>+	}
> >>+
> >>+	dwc3_xlnx_mask_phy_rst(priv_data, true);
> >>+
> >>+	return 0;
> >>+}
> >>+
> >>+static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data)
> >>+{
> >>+	struct device		*dev = priv_data->dev;
> >>+	struct reset_control	*crst, *hibrst, *apbrst;
> >>+	struct phy		*usb3_phy;
> >>+	int			ret;
> >>+	u32			reg;
> >>+
> >>+	crst = devm_reset_control_get_exclusive(dev, "usb_crst");
> >>+	if (IS_ERR(crst)) {
> >>+		ret = PTR_ERR(crst);
> >>+		dev_err_probe(dev, ret,
> >>+			      "failed to get core reset signal\n");
> >>+		goto err;
> >>+	}
> >>+
> >>+	hibrst = devm_reset_control_get_exclusive(dev, "usb_hibrst");
> >>+	if (IS_ERR(hibrst)) {
> >>+		ret = PTR_ERR(hibrst);
> >>+		dev_err_probe(dev, ret,
> >>+			      "failed to get hibernation reset signal\n");
> >>+		goto err;
> >>+	}
> >>+
> >>+	apbrst = devm_reset_control_get_exclusive(dev, "usb_apbrst");
> >>+	if (IS_ERR(apbrst)) {
> >>+		ret = PTR_ERR(apbrst);
> >>+		dev_err_probe(dev, ret,
> >>+			      "failed to get APB reset signal\n");
> >>+		goto err;
> >>+	}
> >>+
> >>+	ret = reset_control_assert(crst);
> >>+	if (ret < 0) {
> >>+		dev_err(dev, "Failed to assert core reset\n");
> >>+		goto err;
> >>+	}
> >>+
> >>+	ret = reset_control_assert(hibrst);
> >>+	if (ret < 0) {
> >>+		dev_err(dev, "Failed to assert hibernation reset\n");
> >>+		goto err;
> >>+	}
> >>+
> >>+	ret = reset_control_assert(apbrst);
> >>+	if (ret < 0) {
> >>+		dev_err(dev, "Failed to assert APB reset\n");
> >>+		goto err;
> >>+	}
> >>+
> >>+	usb3_phy = devm_phy_get(dev, "usb3-phy");
> >>+
> >>+	ret = phy_init(usb3_phy);
> >>+	if (ret < 0) {
> >>+		phy_exit(usb3_phy);
> >>+		goto err;
> >>+	}
> >>+
> >>+	ret = reset_control_deassert(apbrst);
> >>+	if (ret < 0) {
> >>+		dev_err(dev, "Failed to release APB reset\n");
> >>+		goto err;
> >>+	}
> >>+
> >>+	/* Set PIPE Power Present signal in FPD Power Present Register*/
> >>+	writel(PIPE_POWER_ON, priv_data->regs +
> XLNX_USB_FPD_POWER_PRSNT);
> 
> This is somehow leading to an unstable link when using vanilla.
> 
> >>+
> >>+	/* Set the PIPE Clock Select bit in FPD PIPE Clock register */
> >>+	writel(PIPE_CLK_SELECT, priv_data->regs +
> XLNX_USB_FPD_PIPE_CLK);
> >>+
> >>+	ret = reset_control_deassert(crst);
> >>+	if (ret < 0) {
> >>+		dev_err(dev, "Failed to release core reset\n");
> >>+		goto err;
> >>+	}
> >>+
> >>+	ret = reset_control_deassert(hibrst);
> >>+	if (ret < 0) {
> >>+		dev_err(dev, "Failed to release hibernation reset\n");
> >>+		goto err;
> >>+	}
> >>+
> >>+	ret = phy_power_on(usb3_phy);
> >>+	if (ret < 0) {
> >>+		phy_exit(usb3_phy);
> >>+		goto err;
> >>+	}
> >>+
> >>+	/*
> >>+	 * This routes the USB DMA traffic to go through FPD path instead
> >>+	 * of reaching DDR directly. This traffic routing is needed to
> >>+	 * make SMMU and CCI work with USB DMA.
> >>+	 */
> >>+	if (of_dma_is_coherent(dev->of_node) ||
> device_iommu_mapped(dev)) {
> >>+		reg = readl(priv_data->regs +
> XLNX_USB_TRAFFIC_ROUTE_CONFIG);
> >>+		reg |= XLNX_USB_TRAFFIC_ROUTE_FPD;
> >>+		writel(reg, priv_data->regs +
> XLNX_USB_TRAFFIC_ROUTE_CONFIG);
> >>+	}
> >>+
> >>+err:
> >>+	return ret;
> >>+}
> >>+
> >>+static const struct of_device_id dwc3_xlnx_of_match[] = {
> >>+	{
> >>+		.compatible = "xlnx,zynqmp-dwc3",
> >>+		.data = &dwc3_xlnx_init_zynqmp,
> >>+	},
> >>+	{
> >>+		.compatible = "xlnx,versal-dwc3",
> >>+		.data = &dwc3_xlnx_init_versal,
> >>+	},
> >>+	{ /* Sentinel */ }
> >>+};
> >>+MODULE_DEVICE_TABLE(of, dwc3_xlnx_of_match);
> >>+
> >>+static int dwc3_xlnx_probe(struct platform_device *pdev)
> >>+{
> >>+	struct dwc3_xlnx		*priv_data;
> >>+	struct device			*dev = &pdev->dev;
> >>+	struct device_node		*np = dev->of_node;
> >>+	const struct of_device_id	*match;
> >>+	void __iomem			*regs;
> >>+	int				ret;
> >>+
> >>+	priv_data = devm_kzalloc(dev, sizeof(*priv_data), GFP_KERNEL);
> >>+	if (!priv_data)
> >>+		return -ENOMEM;
> >>+
> >>+	regs = devm_platform_ioremap_resource(pdev, 0);
> >>+	if (IS_ERR(regs)) {
> >>+		ret = PTR_ERR(regs);
> >>+		dev_err_probe(dev, ret, "failed to map registers\n");
> >>+		return ret;
> >>+	}
> >>+
> >>+	match = of_match_node(dwc3_xlnx_of_match, pdev->dev.of_node);
> >>+
> >>+	priv_data->pltfm_init = match->data;
> >>+	priv_data->regs = regs;
> >>+	priv_data->dev = dev;
> >>+
> >>+	platform_set_drvdata(pdev, priv_data);
> >>+
> >>+	ret = devm_clk_bulk_get_all(priv_data->dev, &priv_data->clks);
> >>+	if (ret < 0)
> >>+		return ret;
> >>+
> >>+	priv_data->num_clocks = ret;
> >>+
> >>+	ret = clk_bulk_prepare_enable(priv_data->num_clocks, priv_data-
> >clks);
> >>+	if (ret)
> >>+		return ret;
> >>+
> >>+	ret = priv_data->pltfm_init(priv_data);
> >>+	if (ret)
> >>+		goto err_clk_put;
> >>+
> >>+	ret = of_platform_populate(np, NULL, NULL, dev);
> >>+	if (ret)
> >>+		goto err_clk_put;
> >>+
> >>+	pm_runtime_set_active(dev);
> >>+	pm_runtime_enable(dev);
> >>+	pm_suspend_ignore_children(dev, false);
> >>+	pm_runtime_get_sync(dev);
> >>+
> >>+	return 0;
> >>+
> >>+err_clk_put:
> >>+	clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data-
> >clks);
> >>+	clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);
> >>+
> >>+	return ret;
> >>+}
> >>+
> >>+static int dwc3_xlnx_remove(struct platform_device *pdev)
> >>+{
> >>+	struct dwc3_xlnx	*priv_data = platform_get_drvdata(pdev);
> >>+	struct device		*dev = &pdev->dev;
> >>+
> >>+	of_platform_depopulate(dev);
> >>+
> >>+	clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data-
> >clks);
> >>+	clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);
> >>+	priv_data->num_clocks = 0;
> >>+
> >>+	pm_runtime_disable(dev);
> >>+	pm_runtime_put_noidle(dev);
> >>+	pm_runtime_set_suspended(dev);
> >>+
> >>+	return 0;
> >>+}
> >>+
> >>+static int __maybe_unused dwc3_xlnx_suspend_common(struct device
> *dev)
> >>+{
> >>+	struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);
> >>+
> >>+	clk_bulk_disable(priv_data->num_clocks, priv_data->clks);
> >>+
> >>+	return 0;
> >>+}
> >>+
> >>+static int __maybe_unused dwc3_xlnx_resume_common(struct device
> *dev)
> >>+{
> >>+	struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);
> >>+
> >>+	return clk_bulk_enable(priv_data->num_clocks, priv_data->clks);
> >>+}
> >>+
> >>+static int __maybe_unused dwc3_xlnx_runtime_idle(struct device *dev)
> >>+{
> >>+	pm_runtime_mark_last_busy(dev);
> >>+	pm_runtime_autosuspend(dev);
> >>+
> >>+	return 0;
> >>+}
> >>+
> >>+static UNIVERSAL_DEV_PM_OPS(dwc3_xlnx_dev_pm_ops,
> dwc3_xlnx_suspend_common,
> >>+			    dwc3_xlnx_resume_common,
> dwc3_xlnx_runtime_idle);
> >>+
> >>+static struct platform_driver dwc3_xlnx_driver = {
> >>+	.probe		= dwc3_xlnx_probe,
> >>+	.remove		= dwc3_xlnx_remove,
> >>+	.driver		= {
> >>+		.name		= "dwc3-xilinx",
> >>+		.of_match_table	= dwc3_xlnx_of_match,
> >>+		.pm		= &dwc3_xlnx_dev_pm_ops,
> >>+	},
> >>+};
> >>+
> >>+module_platform_driver(dwc3_xlnx_driver);
> >>+
> >>+MODULE_LICENSE("GPL v2");
> >>+MODULE_DESCRIPTION("Xilinx DWC3 controller specific glue driver");
> >>+MODULE_AUTHOR("Manish Narani <manish.narani@xilinx.com>");
> >>+MODULE_AUTHOR("Anurag Kumar Vulisha
> <anurag.kumar.vulisha@xilinx.com>");
> >>--
> >>2.17.1
> >>
> >>
> >>_______________________________________________
> >>linux-arm-kernel mailing list
> >>linux-arm-kernel@lists.infradead.org
> >>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> >
> >--
> >Pengutronix e.K.                           |                             |
> >Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
> >31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
> >Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
> 
> 
> 
> >_______________________________________________
> >linux-arm-kernel mailing list
> >linux-arm-kernel@lists.infradead.org
> >http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 
> 
> --
> Pengutronix e.K.                           |                             |
> Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
> 31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

On Fri, Jan 22, 2021 at 01:06:22PM +0000, Manish Narani wrote:
>Hi Michael,
>
>> -----Original Message-----
>> From: Michael Grzeschik <mgr@pengutronix.de>
>> Sent: Friday, January 22, 2021 1:39 PM
>> To: Manish Narani <MNARANI@xilinx.com>
>> Cc: devicetree@vger.kernel.org; kernel@pengutronix.de; balbi@kernel.org;
>> gregkh@linuxfoundation.org; linux-usb@vger.kernel.org; Michal Simek
>> <michals@xilinx.com>; linux-kernel@vger.kernel.org; robh+dt@kernel.org;
>> git <git@xilinx.com>; p.zabel@pengutronix.de; linux-arm-
>> kernel@lists.infradead.org
>> Subject: Re: [RESEND PATCH v3 2/2] usb: dwc3: Add driver for Xilinx
>> platforms
>>
>> Hello!
>>
>> On Mon, Jan 18, 2021 at 02:42:24PM +0100, Michael Grzeschik wrote:
>> >Hi!
>> >
>> >On Tue, Dec 15, 2020 at 12:24:51PM +0530, Manish Narani wrote:
>> >>Add a new driver for supporting Xilinx platforms. This driver is used
>> >>for some sequence of operations required for Xilinx USB controllers.
>> >>This driver is also used to choose between PIPE clock coming from SerDes
>> >>and the Suspend Clock. Before the controller is out of reset, the clock
>> >>selection should be changed to PIPE clock in order to make the USB
>> >>controller work. There is a register added in Xilinx USB controller
>> >>register space for the same.
>> >
>> >I tried out this driver with the vanilla kernel on an zynqmp. Without
>> >this patch the USB-Gadget is already acting buggy. In the gadget mode,
>> >some iterations of plug/unplug results to an stalled gadget which will
>> >never come back without a reboot.
>> >
>> >With the corresponding code of this driver (reset assert, clk modify,
>> >reset deassert) in the downstream kernels phy driver we found out it is
>> >totaly stable. But using this exact glue driver which should do the same
>> >as the downstream code, the gadget still was buggy the way described
>> >above.
>> >
>> >I suspect the difference lays in the different order of operations.
>> >While the downstream code is runing the resets inside the phy driver
>> >which is powered and initialized in the dwc3-core itself. With this glue
>> >layser approach of this patch the whole phy init is done before even
>> >touching dwc3-core in any way. It seems not to have the same effect,
>> >though.
>> >
>> >If really the order of operations is limiting us, we probably need
>> >another solution than this glue layer. Any Ideas?
>>
>> I found out what the difference between the Downstream and this
>> Glue is. When using vanilla with this Glue code we may not set
>> the following bit:
>>
>> https://www.xilinx.com/html_docs/registers/ug1087/ug1087-zynq-
>> ultrascale-registers.html#usb3_regs___fpd_power_prsnt.html
>>
>> >>+	/* Set PIPE Power Present signal in FPD Power Present Register*/
>> >>+	writel(PIPE_POWER_ON, priv_data->regs +
>> XLNX_USB_FPD_POWER_PRSNT);
>>
>> When I comment this out, the link stays stable. This is different in
>> the Downstream Xilinx Kernel, where the bit is also set but has no
>> negativ effect.
>>
>> Manish, can you give me a pointer what to look for?
>> So setting this will also work with mainline?
>I am looking further on this but from what I see here is that,
>In order to make USB function properly, there are some dt changes needed in mainline for
>USB node which include defining clocks coming from serdes.
>The DT changes are pending to be sent to mainline.

Can you push that state somewhere, so I could test it?
Or is in the downstream kernel some things to copy?

>Can you share the DT settings for USB node on your side?

Here is my current configuration for the device node at usb0:

zynqmp.dtsi

zynqmp_reset: reset-controller {
	compatible = "xlnx,zynqmp-reset";
	#reset-cells = <1>;
};

usb0: usb@ff9d0000 {
	#address-cells = <2>;
	#size-cells = <2>;
	status = "disabled";
	compatible = "xlnx,zynqmp-dwc3";
	reg = <0x0 0xff9d0000 0x0 0x100>;
	clock-names = "bus_clk", "ref_clk";
	power-domains = <&zynqmp_firmware PD_USB_0>;
	ranges;
	resets = <&zynqmp_reset ZYNQMP_RESET_USB0_CORERESET>,
		<&zynqmp_reset ZYNQMP_RESET_USB0_HIBERRESET>,
		<&zynqmp_reset ZYNQMP_RESET_USB0_APB>;
	reset-names = "usb_crst", "usb_hibrst", "usb_apbrst";
	phy-names = "usb3-phy";
	phys = <&psgtr 2 PHY_TYPE_USB3 0 2>;

	usb0_dwc3: dwc3@fe200000 {
		compatible = "snps,dwc3";
		interrupt-parent = <&gic>;
		interrupts = <0 65 4>;
		clock-names = "ref", "bus_early", "suspend";
		reg = <0x0 0xfe200000 0x0 0x40000>;
	};
};

platform.dts

&usb0 {
	status = "okay";
	phy-names = "usb3-phy";
	phys = <&psgtr 2 PHY_TYPE_USB3 0 2>;
};

&usb0_dwc3 {
	dr_mode = "peripheral";

	/* The following quirks are required, since the bInterval is 1 and we
	 * handle steady ISOC streaming. See Usecase 3 in commit 729dcffd1ed3
	 * ("usb: dwc3: gadget: Add support for disabling U1 and U2 entries").
	 */
	snps,dis-u1-entry-quirk;
	snps,dis-u2-entry-quirk;
};


>Meanwhile I will keep updating on the same.

Thanks, that sounds great!

Regards,
Michael

>> >>Signed-off-by: Manish Narani <manish.narani@xilinx.com>
>> >>---
>> >>drivers/usb/dwc3/Kconfig          |   9 +
>> >>drivers/usb/dwc3/Makefile         |   1 +
>> >>drivers/usb/dwc3/dwc3-of-simple.c |   1 -
>> >>drivers/usb/dwc3/dwc3-xilinx.c    | 334
>> ++++++++++++++++++++++++++++++
>> >>4 files changed, 344 insertions(+), 1 deletion(-)
>> >>create mode 100644 drivers/usb/dwc3/dwc3-xilinx.c
>> >>
>> >>diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
>> >>index 7a2304565a73..0e00e6dfccd8 100644
>> >>--- a/drivers/usb/dwc3/Kconfig
>> >>+++ b/drivers/usb/dwc3/Kconfig
>> >>@@ -139,4 +139,13 @@ config USB_DWC3_QCOM
>> >>	  for peripheral mode support.
>> >>	  Say 'Y' or 'M' if you have one such device.
>> >>
>> >>+config USB_DWC3_XILINX
>> >>+	tristate "Xilinx Platforms"
>> >>+	depends on (ARCH_ZYNQMP || ARCH_VERSAL) && OF
>> >>+	default USB_DWC3
>> >>+	help
>> >>+	  Support Xilinx SoCs with DesignWare Core USB3 IP.
>> >>+	  This driver handles both ZynqMP and Versal SoC operations.
>> >>+	  Say 'Y' or 'M' if you have one such device.
>> >>+
>> >>endif
>> >>diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
>> >>index ae86da0dc5bd..add567578b1f 100644
>> >>--- a/drivers/usb/dwc3/Makefile
>> >>+++ b/drivers/usb/dwc3/Makefile
>> >>@@ -51,3 +51,4 @@ obj-$(CONFIG_USB_DWC3_MESON_G12A)	+=
>> dwc3-meson-g12a.o
>> >>obj-$(CONFIG_USB_DWC3_OF_SIMPLE)	+= dwc3-of-simple.o
>> >>obj-$(CONFIG_USB_DWC3_ST)		+= dwc3-st.o
>> >>obj-$(CONFIG_USB_DWC3_QCOM)		+= dwc3-qcom.o
>> >>+obj-$(CONFIG_USB_DWC3_XILINX)		+= dwc3-xilinx.o
>> >>diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-
>> of-simple.c
>> >>index e62ecd22b3ed..71fd620c5161 100644
>> >>--- a/drivers/usb/dwc3/dwc3-of-simple.c
>> >>+++ b/drivers/usb/dwc3/dwc3-of-simple.c
>> >>@@ -172,7 +172,6 @@ static const struct dev_pm_ops
>> dwc3_of_simple_dev_pm_ops = {
>> >>
>> >>static const struct of_device_id of_dwc3_simple_match[] = {
>> >>	{ .compatible = "rockchip,rk3399-dwc3" },
>> >>-	{ .compatible = "xlnx,zynqmp-dwc3" },
>> >>	{ .compatible = "cavium,octeon-7130-usb-uctl" },
>> >>	{ .compatible = "sprd,sc9860-dwc3" },
>> >>	{ .compatible = "allwinner,sun50i-h6-dwc3" },
>> >>diff --git a/drivers/usb/dwc3/dwc3-xilinx.c b/drivers/usb/dwc3/dwc3-
>> xilinx.c
>> >>new file mode 100644
>> >>index 000000000000..7e485951d2f7
>> >>--- /dev/null
>> >>+++ b/drivers/usb/dwc3/dwc3-xilinx.c
>> >>@@ -0,0 +1,334 @@
>> >>+// SPDX-License-Identifier: GPL-2.0
>> >>+/**
>> >>+ * dwc3-xilinx.c - Xilinx DWC3 controller specific glue driver
>> >>+ *
>> >>+ * Authors: Manish Narani <manish.narani@xilinx.com>
>> >>+ *          Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>
>> >>+ */
>> >>+
>> >>+#include <linux/module.h>
>> >>+#include <linux/kernel.h>
>> >>+#include <linux/slab.h>
>> >>+#include <linux/clk.h>
>> >>+#include <linux/of.h>
>> >>+#include <linux/platform_device.h>
>> >>+#include <linux/dma-mapping.h>
>> >>+#include <linux/of_platform.h>
>> >>+#include <linux/pm_runtime.h>
>> >>+#include <linux/reset.h>
>> >>+#include <linux/of_address.h>
>> >>+#include <linux/delay.h>
>> >>+#include <linux/firmware/xlnx-zynqmp.h>
>> >>+#include <linux/io.h>
>> >>+
>> >>+#include <linux/phy/phy.h>
>> >>+
>> >>+/* USB phy reset mask register */
>> >>+#define XLNX_USB_PHY_RST_EN			0x001C
>> >>+#define XLNX_PHY_RST_MASK			0x1
>> >>+
>> >>+/* Xilinx USB 3.0 IP Register */
>> >>+#define XLNX_USB_TRAFFIC_ROUTE_CONFIG		0x005C
>> >>+#define XLNX_USB_TRAFFIC_ROUTE_FPD		0x1
>> >>+
>> >>+/* Versal USB Reset ID */
>> >>+#define VERSAL_USB_RESET_ID			0xC104036
>> >>+
>> >>+#define XLNX_USB_FPD_PIPE_CLK			0x7c
>> >>+#define PIPE_CLK_DESELECT			1
>> >>+#define PIPE_CLK_SELECT				0
>> >>+#define XLNX_USB_FPD_POWER_PRSNT		0x80
>> >>+#define PIPE_POWER_ON				1
>> >>+#define PIPE_POWER_OFF				0
>> >>+
>> >>+struct dwc3_xlnx {
>> >>+	int				num_clocks;
>> >>+	struct clk_bulk_data		*clks;
>> >>+	struct device			*dev;
>> >>+	void __iomem			*regs;
>> >>+	int				(*pltfm_init)(struct dwc3_xlnx *data);
>> >>+};
>> >>+
>> >>+static void dwc3_xlnx_mask_phy_rst(struct dwc3_xlnx *priv_data, bool
>> mask)
>> >>+{
>> >>+	u32 reg;
>> >>+
>> >>+	/*
>> >>+	 * Enable or disable ULPI PHY reset from USB Controller.
>> >>+	 * This does not actually reset the phy, but just controls
>> >>+	 * whether USB controller can or cannot reset ULPI PHY.
>> >>+	 */
>> >>+	reg = readl(priv_data->regs + XLNX_USB_PHY_RST_EN);
>> >>+
>> >>+	if (mask)
>> >>+		reg &= ~XLNX_PHY_RST_MASK;
>> >>+	else
>> >>+		reg |= XLNX_PHY_RST_MASK;
>> >>+
>> >>+	writel(reg, priv_data->regs + XLNX_USB_PHY_RST_EN);
>> >>+}
>> >>+
>> >>+static int dwc3_xlnx_init_versal(struct dwc3_xlnx *priv_data)
>> >>+{
>> >>+	struct device		*dev = priv_data->dev;
>> >>+	int			ret;
>> >>+
>> >>+	dwc3_xlnx_mask_phy_rst(priv_data, false);
>> >>+
>> >>+	/* Assert and De-assert reset */
>> >>+	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
>> >>+				     PM_RESET_ACTION_ASSERT);
>> >>+	if (ret < 0) {
>> >>+		dev_err_probe(dev, ret, "failed to assert Reset\n");
>> >>+		return ret;
>> >>+	}
>> >>+
>> >>+	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
>> >>+				     PM_RESET_ACTION_RELEASE);
>> >>+	if (ret < 0) {
>> >>+		dev_err_probe(dev, ret, "failed to De-assert Reset\n");
>> >>+		return ret;
>> >>+	}
>> >>+
>> >>+	dwc3_xlnx_mask_phy_rst(priv_data, true);
>> >>+
>> >>+	return 0;
>> >>+}
>> >>+
>> >>+static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data)
>> >>+{
>> >>+	struct device		*dev = priv_data->dev;
>> >>+	struct reset_control	*crst, *hibrst, *apbrst;
>> >>+	struct phy		*usb3_phy;
>> >>+	int			ret;
>> >>+	u32			reg;
>> >>+
>> >>+	crst = devm_reset_control_get_exclusive(dev, "usb_crst");
>> >>+	if (IS_ERR(crst)) {
>> >>+		ret = PTR_ERR(crst);
>> >>+		dev_err_probe(dev, ret,
>> >>+			      "failed to get core reset signal\n");
>> >>+		goto err;
>> >>+	}
>> >>+
>> >>+	hibrst = devm_reset_control_get_exclusive(dev, "usb_hibrst");
>> >>+	if (IS_ERR(hibrst)) {
>> >>+		ret = PTR_ERR(hibrst);
>> >>+		dev_err_probe(dev, ret,
>> >>+			      "failed to get hibernation reset signal\n");
>> >>+		goto err;
>> >>+	}
>> >>+
>> >>+	apbrst = devm_reset_control_get_exclusive(dev, "usb_apbrst");
>> >>+	if (IS_ERR(apbrst)) {
>> >>+		ret = PTR_ERR(apbrst);
>> >>+		dev_err_probe(dev, ret,
>> >>+			      "failed to get APB reset signal\n");
>> >>+		goto err;
>> >>+	}
>> >>+
>> >>+	ret = reset_control_assert(crst);
>> >>+	if (ret < 0) {
>> >>+		dev_err(dev, "Failed to assert core reset\n");
>> >>+		goto err;
>> >>+	}
>> >>+
>> >>+	ret = reset_control_assert(hibrst);
>> >>+	if (ret < 0) {
>> >>+		dev_err(dev, "Failed to assert hibernation reset\n");
>> >>+		goto err;
>> >>+	}
>> >>+
>> >>+	ret = reset_control_assert(apbrst);
>> >>+	if (ret < 0) {
>> >>+		dev_err(dev, "Failed to assert APB reset\n");
>> >>+		goto err;
>> >>+	}
>> >>+
>> >>+	usb3_phy = devm_phy_get(dev, "usb3-phy");
>> >>+
>> >>+	ret = phy_init(usb3_phy);
>> >>+	if (ret < 0) {
>> >>+		phy_exit(usb3_phy);
>> >>+		goto err;
>> >>+	}
>> >>+
>> >>+	ret = reset_control_deassert(apbrst);
>> >>+	if (ret < 0) {
>> >>+		dev_err(dev, "Failed to release APB reset\n");
>> >>+		goto err;
>> >>+	}
>> >>+
>> >>+	/* Set PIPE Power Present signal in FPD Power Present Register*/
>> >>+	writel(PIPE_POWER_ON, priv_data->regs +
>> XLNX_USB_FPD_POWER_PRSNT);
>>
>> This is somehow leading to an unstable link when using vanilla.
>>
>> >>+
>> >>+	/* Set the PIPE Clock Select bit in FPD PIPE Clock register */
>> >>+	writel(PIPE_CLK_SELECT, priv_data->regs +
>> XLNX_USB_FPD_PIPE_CLK);
>> >>+
>> >>+	ret = reset_control_deassert(crst);
>> >>+	if (ret < 0) {
>> >>+		dev_err(dev, "Failed to release core reset\n");
>> >>+		goto err;
>> >>+	}
>> >>+
>> >>+	ret = reset_control_deassert(hibrst);
>> >>+	if (ret < 0) {
>> >>+		dev_err(dev, "Failed to release hibernation reset\n");
>> >>+		goto err;
>> >>+	}
>> >>+
>> >>+	ret = phy_power_on(usb3_phy);
>> >>+	if (ret < 0) {
>> >>+		phy_exit(usb3_phy);
>> >>+		goto err;
>> >>+	}
>> >>+
>> >>+	/*
>> >>+	 * This routes the USB DMA traffic to go through FPD path instead
>> >>+	 * of reaching DDR directly. This traffic routing is needed to
>> >>+	 * make SMMU and CCI work with USB DMA.
>> >>+	 */
>> >>+	if (of_dma_is_coherent(dev->of_node) ||
>> device_iommu_mapped(dev)) {
>> >>+		reg = readl(priv_data->regs +
>> XLNX_USB_TRAFFIC_ROUTE_CONFIG);
>> >>+		reg |= XLNX_USB_TRAFFIC_ROUTE_FPD;
>> >>+		writel(reg, priv_data->regs +
>> XLNX_USB_TRAFFIC_ROUTE_CONFIG);
>> >>+	}
>> >>+
>> >>+err:
>> >>+	return ret;
>> >>+}
>> >>+
>> >>+static const struct of_device_id dwc3_xlnx_of_match[] = {
>> >>+	{
>> >>+		.compatible = "xlnx,zynqmp-dwc3",
>> >>+		.data = &dwc3_xlnx_init_zynqmp,
>> >>+	},
>> >>+	{
>> >>+		.compatible = "xlnx,versal-dwc3",
>> >>+		.data = &dwc3_xlnx_init_versal,
>> >>+	},
>> >>+	{ /* Sentinel */ }
>> >>+};
>> >>+MODULE_DEVICE_TABLE(of, dwc3_xlnx_of_match);
>> >>+
>> >>+static int dwc3_xlnx_probe(struct platform_device *pdev)
>> >>+{
>> >>+	struct dwc3_xlnx		*priv_data;
>> >>+	struct device			*dev = &pdev->dev;
>> >>+	struct device_node		*np = dev->of_node;
>> >>+	const struct of_device_id	*match;
>> >>+	void __iomem			*regs;
>> >>+	int				ret;
>> >>+
>> >>+	priv_data = devm_kzalloc(dev, sizeof(*priv_data), GFP_KERNEL);
>> >>+	if (!priv_data)
>> >>+		return -ENOMEM;
>> >>+
>> >>+	regs = devm_platform_ioremap_resource(pdev, 0);
>> >>+	if (IS_ERR(regs)) {
>> >>+		ret = PTR_ERR(regs);
>> >>+		dev_err_probe(dev, ret, "failed to map registers\n");
>> >>+		return ret;
>> >>+	}
>> >>+
>> >>+	match = of_match_node(dwc3_xlnx_of_match, pdev->dev.of_node);
>> >>+
>> >>+	priv_data->pltfm_init = match->data;
>> >>+	priv_data->regs = regs;
>> >>+	priv_data->dev = dev;
>> >>+
>> >>+	platform_set_drvdata(pdev, priv_data);
>> >>+
>> >>+	ret = devm_clk_bulk_get_all(priv_data->dev, &priv_data->clks);
>> >>+	if (ret < 0)
>> >>+		return ret;
>> >>+
>> >>+	priv_data->num_clocks = ret;
>> >>+
>> >>+	ret = clk_bulk_prepare_enable(priv_data->num_clocks, priv_data-
>> >clks);
>> >>+	if (ret)
>> >>+		return ret;
>> >>+
>> >>+	ret = priv_data->pltfm_init(priv_data);
>> >>+	if (ret)
>> >>+		goto err_clk_put;
>> >>+
>> >>+	ret = of_platform_populate(np, NULL, NULL, dev);
>> >>+	if (ret)
>> >>+		goto err_clk_put;
>> >>+
>> >>+	pm_runtime_set_active(dev);
>> >>+	pm_runtime_enable(dev);
>> >>+	pm_suspend_ignore_children(dev, false);
>> >>+	pm_runtime_get_sync(dev);
>> >>+
>> >>+	return 0;
>> >>+
>> >>+err_clk_put:
>> >>+	clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data-
>> >clks);
>> >>+	clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);
>> >>+
>> >>+	return ret;
>> >>+}
>> >>+
>> >>+static int dwc3_xlnx_remove(struct platform_device *pdev)
>> >>+{
>> >>+	struct dwc3_xlnx	*priv_data = platform_get_drvdata(pdev);
>> >>+	struct device		*dev = &pdev->dev;
>> >>+
>> >>+	of_platform_depopulate(dev);
>> >>+
>> >>+	clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data-
>> >clks);
>> >>+	clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);
>> >>+	priv_data->num_clocks = 0;
>> >>+
>> >>+	pm_runtime_disable(dev);
>> >>+	pm_runtime_put_noidle(dev);
>> >>+	pm_runtime_set_suspended(dev);
>> >>+
>> >>+	return 0;
>> >>+}
>> >>+
>> >>+static int __maybe_unused dwc3_xlnx_suspend_common(struct device
>> *dev)
>> >>+{
>> >>+	struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);
>> >>+
>> >>+	clk_bulk_disable(priv_data->num_clocks, priv_data->clks);
>> >>+
>> >>+	return 0;
>> >>+}
>> >>+
>> >>+static int __maybe_unused dwc3_xlnx_resume_common(struct device
>> *dev)
>> >>+{
>> >>+	struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);
>> >>+
>> >>+	return clk_bulk_enable(priv_data->num_clocks, priv_data->clks);
>> >>+}
>> >>+
>> >>+static int __maybe_unused dwc3_xlnx_runtime_idle(struct device *dev)
>> >>+{
>> >>+	pm_runtime_mark_last_busy(dev);
>> >>+	pm_runtime_autosuspend(dev);
>> >>+
>> >>+	return 0;
>> >>+}
>> >>+
>> >>+static UNIVERSAL_DEV_PM_OPS(dwc3_xlnx_dev_pm_ops,
>> dwc3_xlnx_suspend_common,
>> >>+			    dwc3_xlnx_resume_common,
>> dwc3_xlnx_runtime_idle);
>> >>+
>> >>+static struct platform_driver dwc3_xlnx_driver = {
>> >>+	.probe		= dwc3_xlnx_probe,
>> >>+	.remove		= dwc3_xlnx_remove,
>> >>+	.driver		= {
>> >>+		.name		= "dwc3-xilinx",
>> >>+		.of_match_table	= dwc3_xlnx_of_match,
>> >>+		.pm		= &dwc3_xlnx_dev_pm_ops,
>> >>+	},
>> >>+};
>> >>+
>> >>+module_platform_driver(dwc3_xlnx_driver);
>> >>+
>> >>+MODULE_LICENSE("GPL v2");
>> >>+MODULE_DESCRIPTION("Xilinx DWC3 controller specific glue driver");
>> >>+MODULE_AUTHOR("Manish Narani <manish.narani@xilinx.com>");
>> >>+MODULE_AUTHOR("Anurag Kumar Vulisha
>> <anurag.kumar.vulisha@xilinx.com>");
>> >>--
>> >>2.17.1
>> >>
>> >>
>> >>_______________________________________________
>> >>linux-arm-kernel mailing list
>> >>linux-arm-kernel@lists.infradead.org
>> >>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>> >
>> >--
>> >Pengutronix e.K.                           |                             |
>> >Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>> >31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>> >Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>>
>>
>>
>> >_______________________________________________
>> >linux-arm-kernel mailing list
>> >linux-arm-kernel@lists.infradead.org
>> >http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>
>>
>> --
>> Pengutronix e.K.                           |                             |
>> Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>> 31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>
>_______________________________________________
>linux-arm-kernel mailing list
>linux-arm-kernel@lists.infradead.org
>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>

On Fri, Jan 22, 2021 at 02:34:52PM +0100, Michael Grzeschik wrote:
>On Fri, Jan 22, 2021 at 01:06:22PM +0000, Manish Narani wrote:
>>Hi Michael,
>>
>>>-----Original Message-----
>>>From: Michael Grzeschik <mgr@pengutronix.de>
>>>Sent: Friday, January 22, 2021 1:39 PM
>>>To: Manish Narani <MNARANI@xilinx.com>
>>>Cc: devicetree@vger.kernel.org; kernel@pengutronix.de; balbi@kernel.org;
>>>gregkh@linuxfoundation.org; linux-usb@vger.kernel.org; Michal Simek
>>><michals@xilinx.com>; linux-kernel@vger.kernel.org; robh+dt@kernel.org;
>>>git <git@xilinx.com>; p.zabel@pengutronix.de; linux-arm-
>>>kernel@lists.infradead.org
>>>Subject: Re: [RESEND PATCH v3 2/2] usb: dwc3: Add driver for Xilinx
>>>platforms
>>>
>>>Hello!
>>>
>>>On Mon, Jan 18, 2021 at 02:42:24PM +0100, Michael Grzeschik wrote:
>>>>Hi!
>>>>
>>>>On Tue, Dec 15, 2020 at 12:24:51PM +0530, Manish Narani wrote:
>>>>>Add a new driver for supporting Xilinx platforms. This driver is used
>>>>>for some sequence of operations required for Xilinx USB controllers.
>>>>>This driver is also used to choose between PIPE clock coming from SerDes
>>>>>and the Suspend Clock. Before the controller is out of reset, the clock
>>>>>selection should be changed to PIPE clock in order to make the USB
>>>>>controller work. There is a register added in Xilinx USB controller
>>>>>register space for the same.
>>>>
>>>>I tried out this driver with the vanilla kernel on an zynqmp. Without
>>>>this patch the USB-Gadget is already acting buggy. In the gadget mode,
>>>>some iterations of plug/unplug results to an stalled gadget which will
>>>>never come back without a reboot.
>>>>
>>>>With the corresponding code of this driver (reset assert, clk modify,
>>>>reset deassert) in the downstream kernels phy driver we found out it is
>>>>totaly stable. But using this exact glue driver which should do the same
>>>>as the downstream code, the gadget still was buggy the way described
>>>>above.
>>>>
>>>>I suspect the difference lays in the different order of operations.
>>>>While the downstream code is runing the resets inside the phy driver
>>>>which is powered and initialized in the dwc3-core itself. With this glue
>>>>layser approach of this patch the whole phy init is done before even
>>>>touching dwc3-core in any way. It seems not to have the same effect,
>>>>though.
>>>>
>>>>If really the order of operations is limiting us, we probably need
>>>>another solution than this glue layer. Any Ideas?
>>>
>>>I found out what the difference between the Downstream and this
>>>Glue is. When using vanilla with this Glue code we may not set
>>>the following bit:
>>>
>>>https://www.xilinx.com/html_docs/registers/ug1087/ug1087-zynq-
>>>ultrascale-registers.html#usb3_regs___fpd_power_prsnt.html
>>>
>>>>>+	/* Set PIPE Power Present signal in FPD Power Present Register*/
>>>>>+	writel(PIPE_POWER_ON, priv_data->regs +
>>>XLNX_USB_FPD_POWER_PRSNT);
>>>
>>>When I comment this out, the link stays stable. This is different in
>>>the Downstream Xilinx Kernel, where the bit is also set but has no
>>>negativ effect.
>>>
>>>Manish, can you give me a pointer what to look for?
>>>So setting this will also work with mainline?
>>I am looking further on this but from what I see here is that,
>>In order to make USB function properly, there are some dt changes needed in mainline for
>>USB node which include defining clocks coming from serdes.
>>The DT changes are pending to be sent to mainline.
>
>Can you push that state somewhere, so I could test it?
>Or is in the downstream kernel some things to copy?
>
>>Can you share the DT settings for USB node on your side?
>
>Here is my current configuration for the device node at usb0:
>
>zynqmp.dtsi
>
>zynqmp_reset: reset-controller {
>	compatible = "xlnx,zynqmp-reset";
>	#reset-cells = <1>;
>};
>
>usb0: usb@ff9d0000 {
>	#address-cells = <2>;
>	#size-cells = <2>;
>	status = "disabled";
>	compatible = "xlnx,zynqmp-dwc3";
>	reg = <0x0 0xff9d0000 0x0 0x100>;
>	clock-names = "bus_clk", "ref_clk";
>	power-domains = <&zynqmp_firmware PD_USB_0>;
>	ranges;
>	resets = <&zynqmp_reset ZYNQMP_RESET_USB0_CORERESET>,
>		<&zynqmp_reset ZYNQMP_RESET_USB0_HIBERRESET>,
>		<&zynqmp_reset ZYNQMP_RESET_USB0_APB>;
>	reset-names = "usb_crst", "usb_hibrst", "usb_apbrst";
>	phy-names = "usb3-phy";
>	phys = <&psgtr 2 PHY_TYPE_USB3 0 2>;
>
>	usb0_dwc3: dwc3@fe200000 {
>		compatible = "snps,dwc3";
>		interrupt-parent = <&gic>;
>		interrupts = <0 65 4>;
>		clock-names = "ref", "bus_early", "suspend";
>		reg = <0x0 0xfe200000 0x0 0x40000>;
>	};
>};
>
>platform.dts
>
>&usb0 {
>	status = "okay";
>	phy-names = "usb3-phy";
>	phys = <&psgtr 2 PHY_TYPE_USB3 0 2>;
>};
>
>&usb0_dwc3 {
>	dr_mode = "peripheral";
>
>	/* The following quirks are required, since the bInterval is 1 and we
>	 * handle steady ISOC streaming. See Usecase 3 in commit 729dcffd1ed3
>	 * ("usb: dwc3: gadget: Add support for disabling U1 and U2 entries").
>	 */
>	snps,dis-u1-entry-quirk;
>	snps,dis-u2-entry-quirk;
>};
>
>
>>Meanwhile I will keep updating on the same.
>
>Thanks, that sounds great!

I have more feedback regarding this issues. As we saw new uncommon
effects, when using the glue. Regarding to get the plug/unplug behaviour
stable, we sticked with leaving out the setting of PIPE_POWER_ON in that
driver. Unfortunately, with that change, the dwc3 is not only not
sending any Erratic Errors any more, but also is lacking to send
disconnect interrupts.

Double checking with downstream shows that disconnects are working
completely fine in your downstream stack.

I think we should really need to know why PIPE_POWER_ON is making
a difference before we can say the dwc3 is stable with that glue.

Regards,
Michael

>>>>>Signed-off-by: Manish Narani <manish.narani@xilinx.com>
>>>>>---
>>>>>drivers/usb/dwc3/Kconfig          |   9 +
>>>>>drivers/usb/dwc3/Makefile         |   1 +
>>>>>drivers/usb/dwc3/dwc3-of-simple.c |   1 -
>>>>>drivers/usb/dwc3/dwc3-xilinx.c    | 334
>>>++++++++++++++++++++++++++++++
>>>>>4 files changed, 344 insertions(+), 1 deletion(-)
>>>>>create mode 100644 drivers/usb/dwc3/dwc3-xilinx.c
>>>>>
>>>>>diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
>>>>>index 7a2304565a73..0e00e6dfccd8 100644
>>>>>--- a/drivers/usb/dwc3/Kconfig
>>>>>+++ b/drivers/usb/dwc3/Kconfig
>>>>>@@ -139,4 +139,13 @@ config USB_DWC3_QCOM
>>>>>	  for peripheral mode support.
>>>>>	  Say 'Y' or 'M' if you have one such device.
>>>>>
>>>>>+config USB_DWC3_XILINX
>>>>>+	tristate "Xilinx Platforms"
>>>>>+	depends on (ARCH_ZYNQMP || ARCH_VERSAL) && OF
>>>>>+	default USB_DWC3
>>>>>+	help
>>>>>+	  Support Xilinx SoCs with DesignWare Core USB3 IP.
>>>>>+	  This driver handles both ZynqMP and Versal SoC operations.
>>>>>+	  Say 'Y' or 'M' if you have one such device.
>>>>>+
>>>>>endif
>>>>>diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
>>>>>index ae86da0dc5bd..add567578b1f 100644
>>>>>--- a/drivers/usb/dwc3/Makefile
>>>>>+++ b/drivers/usb/dwc3/Makefile
>>>>>@@ -51,3 +51,4 @@ obj-$(CONFIG_USB_DWC3_MESON_G12A)	+=
>>>dwc3-meson-g12a.o
>>>>>obj-$(CONFIG_USB_DWC3_OF_SIMPLE)	+= dwc3-of-simple.o
>>>>>obj-$(CONFIG_USB_DWC3_ST)		+= dwc3-st.o
>>>>>obj-$(CONFIG_USB_DWC3_QCOM)		+= dwc3-qcom.o
>>>>>+obj-$(CONFIG_USB_DWC3_XILINX)		+= dwc3-xilinx.o
>>>>>diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-
>>>of-simple.c
>>>>>index e62ecd22b3ed..71fd620c5161 100644
>>>>>--- a/drivers/usb/dwc3/dwc3-of-simple.c
>>>>>+++ b/drivers/usb/dwc3/dwc3-of-simple.c
>>>>>@@ -172,7 +172,6 @@ static const struct dev_pm_ops
>>>dwc3_of_simple_dev_pm_ops = {
>>>>>
>>>>>static const struct of_device_id of_dwc3_simple_match[] = {
>>>>>	{ .compatible = "rockchip,rk3399-dwc3" },
>>>>>-	{ .compatible = "xlnx,zynqmp-dwc3" },
>>>>>	{ .compatible = "cavium,octeon-7130-usb-uctl" },
>>>>>	{ .compatible = "sprd,sc9860-dwc3" },
>>>>>	{ .compatible = "allwinner,sun50i-h6-dwc3" },
>>>>>diff --git a/drivers/usb/dwc3/dwc3-xilinx.c b/drivers/usb/dwc3/dwc3-
>>>xilinx.c
>>>>>new file mode 100644
>>>>>index 000000000000..7e485951d2f7
>>>>>--- /dev/null
>>>>>+++ b/drivers/usb/dwc3/dwc3-xilinx.c
>>>>>@@ -0,0 +1,334 @@
>>>>>+// SPDX-License-Identifier: GPL-2.0
>>>>>+/**
>>>>>+ * dwc3-xilinx.c - Xilinx DWC3 controller specific glue driver
>>>>>+ *
>>>>>+ * Authors: Manish Narani <manish.narani@xilinx.com>
>>>>>+ *          Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>
>>>>>+ */
>>>>>+
>>>>>+#include <linux/module.h>
>>>>>+#include <linux/kernel.h>
>>>>>+#include <linux/slab.h>
>>>>>+#include <linux/clk.h>
>>>>>+#include <linux/of.h>
>>>>>+#include <linux/platform_device.h>
>>>>>+#include <linux/dma-mapping.h>
>>>>>+#include <linux/of_platform.h>
>>>>>+#include <linux/pm_runtime.h>
>>>>>+#include <linux/reset.h>
>>>>>+#include <linux/of_address.h>
>>>>>+#include <linux/delay.h>
>>>>>+#include <linux/firmware/xlnx-zynqmp.h>
>>>>>+#include <linux/io.h>
>>>>>+
>>>>>+#include <linux/phy/phy.h>
>>>>>+
>>>>>+/* USB phy reset mask register */
>>>>>+#define XLNX_USB_PHY_RST_EN			0x001C
>>>>>+#define XLNX_PHY_RST_MASK			0x1
>>>>>+
>>>>>+/* Xilinx USB 3.0 IP Register */
>>>>>+#define XLNX_USB_TRAFFIC_ROUTE_CONFIG		0x005C
>>>>>+#define XLNX_USB_TRAFFIC_ROUTE_FPD		0x1
>>>>>+
>>>>>+/* Versal USB Reset ID */
>>>>>+#define VERSAL_USB_RESET_ID			0xC104036
>>>>>+
>>>>>+#define XLNX_USB_FPD_PIPE_CLK			0x7c
>>>>>+#define PIPE_CLK_DESELECT			1
>>>>>+#define PIPE_CLK_SELECT				0
>>>>>+#define XLNX_USB_FPD_POWER_PRSNT		0x80
>>>>>+#define PIPE_POWER_ON				1
>>>>>+#define PIPE_POWER_OFF				0
>>>>>+
>>>>>+struct dwc3_xlnx {
>>>>>+	int				num_clocks;
>>>>>+	struct clk_bulk_data		*clks;
>>>>>+	struct device			*dev;
>>>>>+	void __iomem			*regs;
>>>>>+	int				(*pltfm_init)(struct dwc3_xlnx *data);
>>>>>+};
>>>>>+
>>>>>+static void dwc3_xlnx_mask_phy_rst(struct dwc3_xlnx *priv_data, bool
>>>mask)
>>>>>+{
>>>>>+	u32 reg;
>>>>>+
>>>>>+	/*
>>>>>+	 * Enable or disable ULPI PHY reset from USB Controller.
>>>>>+	 * This does not actually reset the phy, but just controls
>>>>>+	 * whether USB controller can or cannot reset ULPI PHY.
>>>>>+	 */
>>>>>+	reg = readl(priv_data->regs + XLNX_USB_PHY_RST_EN);
>>>>>+
>>>>>+	if (mask)
>>>>>+		reg &= ~XLNX_PHY_RST_MASK;
>>>>>+	else
>>>>>+		reg |= XLNX_PHY_RST_MASK;
>>>>>+
>>>>>+	writel(reg, priv_data->regs + XLNX_USB_PHY_RST_EN);
>>>>>+}
>>>>>+
>>>>>+static int dwc3_xlnx_init_versal(struct dwc3_xlnx *priv_data)
>>>>>+{
>>>>>+	struct device		*dev = priv_data->dev;
>>>>>+	int			ret;
>>>>>+
>>>>>+	dwc3_xlnx_mask_phy_rst(priv_data, false);
>>>>>+
>>>>>+	/* Assert and De-assert reset */
>>>>>+	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
>>>>>+				     PM_RESET_ACTION_ASSERT);
>>>>>+	if (ret < 0) {
>>>>>+		dev_err_probe(dev, ret, "failed to assert Reset\n");
>>>>>+		return ret;
>>>>>+	}
>>>>>+
>>>>>+	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
>>>>>+				     PM_RESET_ACTION_RELEASE);
>>>>>+	if (ret < 0) {
>>>>>+		dev_err_probe(dev, ret, "failed to De-assert Reset\n");
>>>>>+		return ret;
>>>>>+	}
>>>>>+
>>>>>+	dwc3_xlnx_mask_phy_rst(priv_data, true);
>>>>>+
>>>>>+	return 0;
>>>>>+}
>>>>>+
>>>>>+static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data)
>>>>>+{
>>>>>+	struct device		*dev = priv_data->dev;
>>>>>+	struct reset_control	*crst, *hibrst, *apbrst;
>>>>>+	struct phy		*usb3_phy;
>>>>>+	int			ret;
>>>>>+	u32			reg;
>>>>>+
>>>>>+	crst = devm_reset_control_get_exclusive(dev, "usb_crst");
>>>>>+	if (IS_ERR(crst)) {
>>>>>+		ret = PTR_ERR(crst);
>>>>>+		dev_err_probe(dev, ret,
>>>>>+			      "failed to get core reset signal\n");
>>>>>+		goto err;
>>>>>+	}
>>>>>+
>>>>>+	hibrst = devm_reset_control_get_exclusive(dev, "usb_hibrst");
>>>>>+	if (IS_ERR(hibrst)) {
>>>>>+		ret = PTR_ERR(hibrst);
>>>>>+		dev_err_probe(dev, ret,
>>>>>+			      "failed to get hibernation reset signal\n");
>>>>>+		goto err;
>>>>>+	}
>>>>>+
>>>>>+	apbrst = devm_reset_control_get_exclusive(dev, "usb_apbrst");
>>>>>+	if (IS_ERR(apbrst)) {
>>>>>+		ret = PTR_ERR(apbrst);
>>>>>+		dev_err_probe(dev, ret,
>>>>>+			      "failed to get APB reset signal\n");
>>>>>+		goto err;
>>>>>+	}
>>>>>+
>>>>>+	ret = reset_control_assert(crst);
>>>>>+	if (ret < 0) {
>>>>>+		dev_err(dev, "Failed to assert core reset\n");
>>>>>+		goto err;
>>>>>+	}
>>>>>+
>>>>>+	ret = reset_control_assert(hibrst);
>>>>>+	if (ret < 0) {
>>>>>+		dev_err(dev, "Failed to assert hibernation reset\n");
>>>>>+		goto err;
>>>>>+	}
>>>>>+
>>>>>+	ret = reset_control_assert(apbrst);
>>>>>+	if (ret < 0) {
>>>>>+		dev_err(dev, "Failed to assert APB reset\n");
>>>>>+		goto err;
>>>>>+	}
>>>>>+
>>>>>+	usb3_phy = devm_phy_get(dev, "usb3-phy");
>>>>>+
>>>>>+	ret = phy_init(usb3_phy);
>>>>>+	if (ret < 0) {
>>>>>+		phy_exit(usb3_phy);
>>>>>+		goto err;
>>>>>+	}
>>>>>+
>>>>>+	ret = reset_control_deassert(apbrst);
>>>>>+	if (ret < 0) {
>>>>>+		dev_err(dev, "Failed to release APB reset\n");
>>>>>+		goto err;
>>>>>+	}
>>>>>+
>>>>>+	/* Set PIPE Power Present signal in FPD Power Present Register*/
>>>>>+	writel(PIPE_POWER_ON, priv_data->regs +
>>>XLNX_USB_FPD_POWER_PRSNT);
>>>
>>>This is somehow leading to an unstable link when using vanilla.
>>>
>>>>>+
>>>>>+	/* Set the PIPE Clock Select bit in FPD PIPE Clock register */
>>>>>+	writel(PIPE_CLK_SELECT, priv_data->regs +
>>>XLNX_USB_FPD_PIPE_CLK);
>>>>>+
>>>>>+	ret = reset_control_deassert(crst);
>>>>>+	if (ret < 0) {
>>>>>+		dev_err(dev, "Failed to release core reset\n");
>>>>>+		goto err;
>>>>>+	}
>>>>>+
>>>>>+	ret = reset_control_deassert(hibrst);
>>>>>+	if (ret < 0) {
>>>>>+		dev_err(dev, "Failed to release hibernation reset\n");
>>>>>+		goto err;
>>>>>+	}
>>>>>+
>>>>>+	ret = phy_power_on(usb3_phy);
>>>>>+	if (ret < 0) {
>>>>>+		phy_exit(usb3_phy);
>>>>>+		goto err;
>>>>>+	}
>>>>>+
>>>>>+	/*
>>>>>+	 * This routes the USB DMA traffic to go through FPD path instead
>>>>>+	 * of reaching DDR directly. This traffic routing is needed to
>>>>>+	 * make SMMU and CCI work with USB DMA.
>>>>>+	 */
>>>>>+	if (of_dma_is_coherent(dev->of_node) ||
>>>device_iommu_mapped(dev)) {
>>>>>+		reg = readl(priv_data->regs +
>>>XLNX_USB_TRAFFIC_ROUTE_CONFIG);
>>>>>+		reg |= XLNX_USB_TRAFFIC_ROUTE_FPD;
>>>>>+		writel(reg, priv_data->regs +
>>>XLNX_USB_TRAFFIC_ROUTE_CONFIG);
>>>>>+	}
>>>>>+
>>>>>+err:
>>>>>+	return ret;
>>>>>+}
>>>>>+
>>>>>+static const struct of_device_id dwc3_xlnx_of_match[] = {
>>>>>+	{
>>>>>+		.compatible = "xlnx,zynqmp-dwc3",
>>>>>+		.data = &dwc3_xlnx_init_zynqmp,
>>>>>+	},
>>>>>+	{
>>>>>+		.compatible = "xlnx,versal-dwc3",
>>>>>+		.data = &dwc3_xlnx_init_versal,
>>>>>+	},
>>>>>+	{ /* Sentinel */ }
>>>>>+};
>>>>>+MODULE_DEVICE_TABLE(of, dwc3_xlnx_of_match);
>>>>>+
>>>>>+static int dwc3_xlnx_probe(struct platform_device *pdev)
>>>>>+{
>>>>>+	struct dwc3_xlnx		*priv_data;
>>>>>+	struct device			*dev = &pdev->dev;
>>>>>+	struct device_node		*np = dev->of_node;
>>>>>+	const struct of_device_id	*match;
>>>>>+	void __iomem			*regs;
>>>>>+	int				ret;
>>>>>+
>>>>>+	priv_data = devm_kzalloc(dev, sizeof(*priv_data), GFP_KERNEL);
>>>>>+	if (!priv_data)
>>>>>+		return -ENOMEM;
>>>>>+
>>>>>+	regs = devm_platform_ioremap_resource(pdev, 0);
>>>>>+	if (IS_ERR(regs)) {
>>>>>+		ret = PTR_ERR(regs);
>>>>>+		dev_err_probe(dev, ret, "failed to map registers\n");
>>>>>+		return ret;
>>>>>+	}
>>>>>+
>>>>>+	match = of_match_node(dwc3_xlnx_of_match, pdev->dev.of_node);
>>>>>+
>>>>>+	priv_data->pltfm_init = match->data;
>>>>>+	priv_data->regs = regs;
>>>>>+	priv_data->dev = dev;
>>>>>+
>>>>>+	platform_set_drvdata(pdev, priv_data);
>>>>>+
>>>>>+	ret = devm_clk_bulk_get_all(priv_data->dev, &priv_data->clks);
>>>>>+	if (ret < 0)
>>>>>+		return ret;
>>>>>+
>>>>>+	priv_data->num_clocks = ret;
>>>>>+
>>>>>+	ret = clk_bulk_prepare_enable(priv_data->num_clocks, priv_data-
>>>>clks);
>>>>>+	if (ret)
>>>>>+		return ret;
>>>>>+
>>>>>+	ret = priv_data->pltfm_init(priv_data);
>>>>>+	if (ret)
>>>>>+		goto err_clk_put;
>>>>>+
>>>>>+	ret = of_platform_populate(np, NULL, NULL, dev);
>>>>>+	if (ret)
>>>>>+		goto err_clk_put;
>>>>>+
>>>>>+	pm_runtime_set_active(dev);
>>>>>+	pm_runtime_enable(dev);
>>>>>+	pm_suspend_ignore_children(dev, false);
>>>>>+	pm_runtime_get_sync(dev);
>>>>>+
>>>>>+	return 0;
>>>>>+
>>>>>+err_clk_put:
>>>>>+	clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data-
>>>>clks);
>>>>>+	clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);
>>>>>+
>>>>>+	return ret;
>>>>>+}
>>>>>+
>>>>>+static int dwc3_xlnx_remove(struct platform_device *pdev)
>>>>>+{
>>>>>+	struct dwc3_xlnx	*priv_data = platform_get_drvdata(pdev);
>>>>>+	struct device		*dev = &pdev->dev;
>>>>>+
>>>>>+	of_platform_depopulate(dev);
>>>>>+
>>>>>+	clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data-
>>>>clks);
>>>>>+	clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);
>>>>>+	priv_data->num_clocks = 0;
>>>>>+
>>>>>+	pm_runtime_disable(dev);
>>>>>+	pm_runtime_put_noidle(dev);
>>>>>+	pm_runtime_set_suspended(dev);
>>>>>+
>>>>>+	return 0;
>>>>>+}
>>>>>+
>>>>>+static int __maybe_unused dwc3_xlnx_suspend_common(struct device
>>>*dev)
>>>>>+{
>>>>>+	struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);
>>>>>+
>>>>>+	clk_bulk_disable(priv_data->num_clocks, priv_data->clks);
>>>>>+
>>>>>+	return 0;
>>>>>+}
>>>>>+
>>>>>+static int __maybe_unused dwc3_xlnx_resume_common(struct device
>>>*dev)
>>>>>+{
>>>>>+	struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);
>>>>>+
>>>>>+	return clk_bulk_enable(priv_data->num_clocks, priv_data->clks);
>>>>>+}
>>>>>+
>>>>>+static int __maybe_unused dwc3_xlnx_runtime_idle(struct device *dev)
>>>>>+{
>>>>>+	pm_runtime_mark_last_busy(dev);
>>>>>+	pm_runtime_autosuspend(dev);
>>>>>+
>>>>>+	return 0;
>>>>>+}
>>>>>+
>>>>>+static UNIVERSAL_DEV_PM_OPS(dwc3_xlnx_dev_pm_ops,
>>>dwc3_xlnx_suspend_common,
>>>>>+			    dwc3_xlnx_resume_common,
>>>dwc3_xlnx_runtime_idle);
>>>>>+
>>>>>+static struct platform_driver dwc3_xlnx_driver = {
>>>>>+	.probe		= dwc3_xlnx_probe,
>>>>>+	.remove		= dwc3_xlnx_remove,
>>>>>+	.driver		= {
>>>>>+		.name		= "dwc3-xilinx",
>>>>>+		.of_match_table	= dwc3_xlnx_of_match,
>>>>>+		.pm		= &dwc3_xlnx_dev_pm_ops,
>>>>>+	},
>>>>>+};
>>>>>+
>>>>>+module_platform_driver(dwc3_xlnx_driver);
>>>>>+
>>>>>+MODULE_LICENSE("GPL v2");
>>>>>+MODULE_DESCRIPTION("Xilinx DWC3 controller specific glue driver");
>>>>>+MODULE_AUTHOR("Manish Narani <manish.narani@xilinx.com>");
>>>>>+MODULE_AUTHOR("Anurag Kumar Vulisha
>>><anurag.kumar.vulisha@xilinx.com>");
>>>>>--
>>>>>2.17.1
>>>>>
>>>>>
>>>>>_______________________________________________
>>>>>linux-arm-kernel mailing list
>>>>>linux-arm-kernel@lists.infradead.org
>>>>>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>>>
>>>>--
>>>>Pengutronix e.K.                           |                             |
>>>>Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>>>>31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>>>>Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>>>
>>>
>>>
>>>>_______________________________________________
>>>>linux-arm-kernel mailing list
>>>>linux-arm-kernel@lists.infradead.org
>>>>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>>
>>>
>>>--
>>>Pengutronix e.K.                           |                             |
>>>Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>>>31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>>>Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>>
>>_______________________________________________
>>linux-arm-kernel mailing list
>>linux-arm-kernel@lists.infradead.org
>>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>
>
>-- 
>Pengutronix e.K.                           |                             |
>Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |



>_______________________________________________
>linux-arm-kernel mailing list
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>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Hi Manish!

On Thu, Jan 28, 2021 at 12:36:07AM +0100, Michael Grzeschik wrote:
>On Fri, Jan 22, 2021 at 02:34:52PM +0100, Michael Grzeschik wrote:
>>On Fri, Jan 22, 2021 at 01:06:22PM +0000, Manish Narani wrote:
>>>Hi Michael,
>>>
>>>>-----Original Message-----
>>>>From: Michael Grzeschik <mgr@pengutronix.de>
>>>>Sent: Friday, January 22, 2021 1:39 PM
>>>>To: Manish Narani <MNARANI@xilinx.com>
>>>>Cc: devicetree@vger.kernel.org; kernel@pengutronix.de; balbi@kernel.org;
>>>>gregkh@linuxfoundation.org; linux-usb@vger.kernel.org; Michal Simek
>>>><michals@xilinx.com>; linux-kernel@vger.kernel.org; robh+dt@kernel.org;
>>>>git <git@xilinx.com>; p.zabel@pengutronix.de; linux-arm-
>>>>kernel@lists.infradead.org
>>>>Subject: Re: [RESEND PATCH v3 2/2] usb: dwc3: Add driver for Xilinx
>>>>platforms
>>>>
>>>>Hello!
>>>>
>>>>On Mon, Jan 18, 2021 at 02:42:24PM +0100, Michael Grzeschik wrote:
>>>>>Hi!
>>>>>
>>>>>On Tue, Dec 15, 2020 at 12:24:51PM +0530, Manish Narani wrote:
>>>>>>Add a new driver for supporting Xilinx platforms. This driver is used
>>>>>>for some sequence of operations required for Xilinx USB controllers.
>>>>>>This driver is also used to choose between PIPE clock coming from SerDes
>>>>>>and the Suspend Clock. Before the controller is out of reset, the clock
>>>>>>selection should be changed to PIPE clock in order to make the USB
>>>>>>controller work. There is a register added in Xilinx USB controller
>>>>>>register space for the same.
>>>>>
>>>>>I tried out this driver with the vanilla kernel on an zynqmp. Without
>>>>>this patch the USB-Gadget is already acting buggy. In the gadget mode,
>>>>>some iterations of plug/unplug results to an stalled gadget which will
>>>>>never come back without a reboot.
>>>>>
>>>>>With the corresponding code of this driver (reset assert, clk modify,
>>>>>reset deassert) in the downstream kernels phy driver we found out it is
>>>>>totaly stable. But using this exact glue driver which should do the same
>>>>>as the downstream code, the gadget still was buggy the way described
>>>>>above.
>>>>>
>>>>>I suspect the difference lays in the different order of operations.
>>>>>While the downstream code is runing the resets inside the phy driver
>>>>>which is powered and initialized in the dwc3-core itself. With this glue
>>>>>layser approach of this patch the whole phy init is done before even
>>>>>touching dwc3-core in any way. It seems not to have the same effect,
>>>>>though.
>>>>>
>>>>>If really the order of operations is limiting us, we probably need
>>>>>another solution than this glue layer. Any Ideas?
>>>>
>>>>I found out what the difference between the Downstream and this
>>>>Glue is. When using vanilla with this Glue code we may not set
>>>>the following bit:
>>>>
>>>>https://www.xilinx.com/html_docs/registers/ug1087/ug1087-zynq-
>>>>ultrascale-registers.html#usb3_regs___fpd_power_prsnt.html
>>>>
>>>>>>+	/* Set PIPE Power Present signal in FPD Power Present Register*/
>>>>>>+	writel(PIPE_POWER_ON, priv_data->regs +
>>>>XLNX_USB_FPD_POWER_PRSNT);
>>>>
>>>>When I comment this out, the link stays stable. This is different in
>>>>the Downstream Xilinx Kernel, where the bit is also set but has no
>>>>negativ effect.
>>>>
>>>>Manish, can you give me a pointer what to look for?
>>>>So setting this will also work with mainline?
>>>I am looking further on this but from what I see here is that,
>>>In order to make USB function properly, there are some dt changes needed in mainline for
>>>USB node which include defining clocks coming from serdes.
>>>The DT changes are pending to be sent to mainline.
>>
>>Can you push that state somewhere, so I could test it?
>>Or is in the downstream kernel some things to copy?
>>
>>>Can you share the DT settings for USB node on your side?
>>
>>Here is my current configuration for the device node at usb0:
>>
>>zynqmp.dtsi
>>
>>zynqmp_reset: reset-controller {
>>	compatible = "xlnx,zynqmp-reset";
>>	#reset-cells = <1>;
>>};
>>
>>usb0: usb@ff9d0000 {
>>	#address-cells = <2>;
>>	#size-cells = <2>;
>>	status = "disabled";
>>	compatible = "xlnx,zynqmp-dwc3";
>>	reg = <0x0 0xff9d0000 0x0 0x100>;
>>	clock-names = "bus_clk", "ref_clk";
>>	power-domains = <&zynqmp_firmware PD_USB_0>;
>>	ranges;
>>	resets = <&zynqmp_reset ZYNQMP_RESET_USB0_CORERESET>,
>>		<&zynqmp_reset ZYNQMP_RESET_USB0_HIBERRESET>,
>>		<&zynqmp_reset ZYNQMP_RESET_USB0_APB>;
>>	reset-names = "usb_crst", "usb_hibrst", "usb_apbrst";
>>	phy-names = "usb3-phy";
>>	phys = <&psgtr 2 PHY_TYPE_USB3 0 2>;
>>
>>	usb0_dwc3: dwc3@fe200000 {
>>		compatible = "snps,dwc3";
>>		interrupt-parent = <&gic>;
>>		interrupts = <0 65 4>;
>>		clock-names = "ref", "bus_early", "suspend";
>>		reg = <0x0 0xfe200000 0x0 0x40000>;
>>	};
>>};
>>
>>platform.dts
>>
>>&usb0 {
>>	status = "okay";
>>	phy-names = "usb3-phy";
>>	phys = <&psgtr 2 PHY_TYPE_USB3 0 2>;
>>};
>>
>>&usb0_dwc3 {
>>	dr_mode = "peripheral";
>>
>>	/* The following quirks are required, since the bInterval is 1 and we
>>	 * handle steady ISOC streaming. See Usecase 3 in commit 729dcffd1ed3
>>	 * ("usb: dwc3: gadget: Add support for disabling U1 and U2 entries").
>>	 */
>>	snps,dis-u1-entry-quirk;
>>	snps,dis-u2-entry-quirk;
>>};
>>
>>
>>>Meanwhile I will keep updating on the same.
>>
>>Thanks, that sounds great!
>
>I have more feedback regarding this issues. As we saw new uncommon
>effects, when using the glue. Regarding to get the plug/unplug behaviour
>stable, we sticked with leaving out the setting of PIPE_POWER_ON in that
>driver. Unfortunately, with that change, the dwc3 is not only not
>sending any Erratic Errors any more, but also is lacking to send
>disconnect interrupts.
>
>Double checking with downstream shows that disconnects are working
>completely fine in your downstream stack.
>
>I think we should really need to know why PIPE_POWER_ON is making
>a difference before we can say the dwc3 is stable with that glue.

After bisecting your v5.4 and mainline we found out that this all is
working fine, when setting "snps,dis_u3_susphy_quirk" in the zynqmp.dtsi
dwc3 node.

The code handling this quirk was introduced after v5.4, so this was
never an issue with your downstream stack.

"9ba3aca8 usb: dwc3: Disable phy suspend after power-on reset"

We need to know if adding snps,dis_u3_susphy_quirk to the dwc nodes
is generally necessary for zynqmp, so we can fix for everyone.

Ryone.
Michael

>Regards,
>Michael
>
>>>>>>Signed-off-by: Manish Narani <manish.narani@xilinx.com>
>>>>>>---
>>>>>>drivers/usb/dwc3/Kconfig          |   9 +
>>>>>>drivers/usb/dwc3/Makefile         |   1 +
>>>>>>drivers/usb/dwc3/dwc3-of-simple.c |   1 -
>>>>>>drivers/usb/dwc3/dwc3-xilinx.c    | 334
>>>>++++++++++++++++++++++++++++++
>>>>>>4 files changed, 344 insertions(+), 1 deletion(-)
>>>>>>create mode 100644 drivers/usb/dwc3/dwc3-xilinx.c
>>>>>>
>>>>>>diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
>>>>>>index 7a2304565a73..0e00e6dfccd8 100644
>>>>>>--- a/drivers/usb/dwc3/Kconfig
>>>>>>+++ b/drivers/usb/dwc3/Kconfig
>>>>>>@@ -139,4 +139,13 @@ config USB_DWC3_QCOM
>>>>>>	  for peripheral mode support.
>>>>>>	  Say 'Y' or 'M' if you have one such device.
>>>>>>
>>>>>>+config USB_DWC3_XILINX
>>>>>>+	tristate "Xilinx Platforms"
>>>>>>+	depends on (ARCH_ZYNQMP || ARCH_VERSAL) && OF
>>>>>>+	default USB_DWC3
>>>>>>+	help
>>>>>>+	  Support Xilinx SoCs with DesignWare Core USB3 IP.
>>>>>>+	  This driver handles both ZynqMP and Versal SoC operations.
>>>>>>+	  Say 'Y' or 'M' if you have one such device.
>>>>>>+
>>>>>>endif
>>>>>>diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
>>>>>>index ae86da0dc5bd..add567578b1f 100644
>>>>>>--- a/drivers/usb/dwc3/Makefile
>>>>>>+++ b/drivers/usb/dwc3/Makefile
>>>>>>@@ -51,3 +51,4 @@ obj-$(CONFIG_USB_DWC3_MESON_G12A)	+=
>>>>dwc3-meson-g12a.o
>>>>>>obj-$(CONFIG_USB_DWC3_OF_SIMPLE)	+= dwc3-of-simple.o
>>>>>>obj-$(CONFIG_USB_DWC3_ST)		+= dwc3-st.o
>>>>>>obj-$(CONFIG_USB_DWC3_QCOM)		+= dwc3-qcom.o
>>>>>>+obj-$(CONFIG_USB_DWC3_XILINX)		+= dwc3-xilinx.o
>>>>>>diff --git a/drivers/usb/dwc3/dwc3-of-simple.c b/drivers/usb/dwc3/dwc3-
>>>>of-simple.c
>>>>>>index e62ecd22b3ed..71fd620c5161 100644
>>>>>>--- a/drivers/usb/dwc3/dwc3-of-simple.c
>>>>>>+++ b/drivers/usb/dwc3/dwc3-of-simple.c
>>>>>>@@ -172,7 +172,6 @@ static const struct dev_pm_ops
>>>>dwc3_of_simple_dev_pm_ops = {
>>>>>>
>>>>>>static const struct of_device_id of_dwc3_simple_match[] = {
>>>>>>	{ .compatible = "rockchip,rk3399-dwc3" },
>>>>>>-	{ .compatible = "xlnx,zynqmp-dwc3" },
>>>>>>	{ .compatible = "cavium,octeon-7130-usb-uctl" },
>>>>>>	{ .compatible = "sprd,sc9860-dwc3" },
>>>>>>	{ .compatible = "allwinner,sun50i-h6-dwc3" },
>>>>>>diff --git a/drivers/usb/dwc3/dwc3-xilinx.c b/drivers/usb/dwc3/dwc3-
>>>>xilinx.c
>>>>>>new file mode 100644
>>>>>>index 000000000000..7e485951d2f7
>>>>>>--- /dev/null
>>>>>>+++ b/drivers/usb/dwc3/dwc3-xilinx.c
>>>>>>@@ -0,0 +1,334 @@
>>>>>>+// SPDX-License-Identifier: GPL-2.0
>>>>>>+/**
>>>>>>+ * dwc3-xilinx.c - Xilinx DWC3 controller specific glue driver
>>>>>>+ *
>>>>>>+ * Authors: Manish Narani <manish.narani@xilinx.com>
>>>>>>+ *          Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>
>>>>>>+ */
>>>>>>+
>>>>>>+#include <linux/module.h>
>>>>>>+#include <linux/kernel.h>
>>>>>>+#include <linux/slab.h>
>>>>>>+#include <linux/clk.h>
>>>>>>+#include <linux/of.h>
>>>>>>+#include <linux/platform_device.h>
>>>>>>+#include <linux/dma-mapping.h>
>>>>>>+#include <linux/of_platform.h>
>>>>>>+#include <linux/pm_runtime.h>
>>>>>>+#include <linux/reset.h>
>>>>>>+#include <linux/of_address.h>
>>>>>>+#include <linux/delay.h>
>>>>>>+#include <linux/firmware/xlnx-zynqmp.h>
>>>>>>+#include <linux/io.h>
>>>>>>+
>>>>>>+#include <linux/phy/phy.h>
>>>>>>+
>>>>>>+/* USB phy reset mask register */
>>>>>>+#define XLNX_USB_PHY_RST_EN			0x001C
>>>>>>+#define XLNX_PHY_RST_MASK			0x1
>>>>>>+
>>>>>>+/* Xilinx USB 3.0 IP Register */
>>>>>>+#define XLNX_USB_TRAFFIC_ROUTE_CONFIG		0x005C
>>>>>>+#define XLNX_USB_TRAFFIC_ROUTE_FPD		0x1
>>>>>>+
>>>>>>+/* Versal USB Reset ID */
>>>>>>+#define VERSAL_USB_RESET_ID			0xC104036
>>>>>>+
>>>>>>+#define XLNX_USB_FPD_PIPE_CLK			0x7c
>>>>>>+#define PIPE_CLK_DESELECT			1
>>>>>>+#define PIPE_CLK_SELECT				0
>>>>>>+#define XLNX_USB_FPD_POWER_PRSNT		0x80
>>>>>>+#define PIPE_POWER_ON				1
>>>>>>+#define PIPE_POWER_OFF				0
>>>>>>+
>>>>>>+struct dwc3_xlnx {
>>>>>>+	int				num_clocks;
>>>>>>+	struct clk_bulk_data		*clks;
>>>>>>+	struct device			*dev;
>>>>>>+	void __iomem			*regs;
>>>>>>+	int				(*pltfm_init)(struct dwc3_xlnx *data);
>>>>>>+};
>>>>>>+
>>>>>>+static void dwc3_xlnx_mask_phy_rst(struct dwc3_xlnx *priv_data, bool
>>>>mask)
>>>>>>+{
>>>>>>+	u32 reg;
>>>>>>+
>>>>>>+	/*
>>>>>>+	 * Enable or disable ULPI PHY reset from USB Controller.
>>>>>>+	 * This does not actually reset the phy, but just controls
>>>>>>+	 * whether USB controller can or cannot reset ULPI PHY.
>>>>>>+	 */
>>>>>>+	reg = readl(priv_data->regs + XLNX_USB_PHY_RST_EN);
>>>>>>+
>>>>>>+	if (mask)
>>>>>>+		reg &= ~XLNX_PHY_RST_MASK;
>>>>>>+	else
>>>>>>+		reg |= XLNX_PHY_RST_MASK;
>>>>>>+
>>>>>>+	writel(reg, priv_data->regs + XLNX_USB_PHY_RST_EN);
>>>>>>+}
>>>>>>+
>>>>>>+static int dwc3_xlnx_init_versal(struct dwc3_xlnx *priv_data)
>>>>>>+{
>>>>>>+	struct device		*dev = priv_data->dev;
>>>>>>+	int			ret;
>>>>>>+
>>>>>>+	dwc3_xlnx_mask_phy_rst(priv_data, false);
>>>>>>+
>>>>>>+	/* Assert and De-assert reset */
>>>>>>+	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
>>>>>>+				     PM_RESET_ACTION_ASSERT);
>>>>>>+	if (ret < 0) {
>>>>>>+		dev_err_probe(dev, ret, "failed to assert Reset\n");
>>>>>>+		return ret;
>>>>>>+	}
>>>>>>+
>>>>>>+	ret = zynqmp_pm_reset_assert(VERSAL_USB_RESET_ID,
>>>>>>+				     PM_RESET_ACTION_RELEASE);
>>>>>>+	if (ret < 0) {
>>>>>>+		dev_err_probe(dev, ret, "failed to De-assert Reset\n");
>>>>>>+		return ret;
>>>>>>+	}
>>>>>>+
>>>>>>+	dwc3_xlnx_mask_phy_rst(priv_data, true);
>>>>>>+
>>>>>>+	return 0;
>>>>>>+}
>>>>>>+
>>>>>>+static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data)
>>>>>>+{
>>>>>>+	struct device		*dev = priv_data->dev;
>>>>>>+	struct reset_control	*crst, *hibrst, *apbrst;
>>>>>>+	struct phy		*usb3_phy;
>>>>>>+	int			ret;
>>>>>>+	u32			reg;
>>>>>>+
>>>>>>+	crst = devm_reset_control_get_exclusive(dev, "usb_crst");
>>>>>>+	if (IS_ERR(crst)) {
>>>>>>+		ret = PTR_ERR(crst);
>>>>>>+		dev_err_probe(dev, ret,
>>>>>>+			      "failed to get core reset signal\n");
>>>>>>+		goto err;
>>>>>>+	}
>>>>>>+
>>>>>>+	hibrst = devm_reset_control_get_exclusive(dev, "usb_hibrst");
>>>>>>+	if (IS_ERR(hibrst)) {
>>>>>>+		ret = PTR_ERR(hibrst);
>>>>>>+		dev_err_probe(dev, ret,
>>>>>>+			      "failed to get hibernation reset signal\n");
>>>>>>+		goto err;
>>>>>>+	}
>>>>>>+
>>>>>>+	apbrst = devm_reset_control_get_exclusive(dev, "usb_apbrst");
>>>>>>+	if (IS_ERR(apbrst)) {
>>>>>>+		ret = PTR_ERR(apbrst);
>>>>>>+		dev_err_probe(dev, ret,
>>>>>>+			      "failed to get APB reset signal\n");
>>>>>>+		goto err;
>>>>>>+	}
>>>>>>+
>>>>>>+	ret = reset_control_assert(crst);
>>>>>>+	if (ret < 0) {
>>>>>>+		dev_err(dev, "Failed to assert core reset\n");
>>>>>>+		goto err;
>>>>>>+	}
>>>>>>+
>>>>>>+	ret = reset_control_assert(hibrst);
>>>>>>+	if (ret < 0) {
>>>>>>+		dev_err(dev, "Failed to assert hibernation reset\n");
>>>>>>+		goto err;
>>>>>>+	}
>>>>>>+
>>>>>>+	ret = reset_control_assert(apbrst);
>>>>>>+	if (ret < 0) {
>>>>>>+		dev_err(dev, "Failed to assert APB reset\n");
>>>>>>+		goto err;
>>>>>>+	}
>>>>>>+
>>>>>>+	usb3_phy = devm_phy_get(dev, "usb3-phy");
>>>>>>+
>>>>>>+	ret = phy_init(usb3_phy);
>>>>>>+	if (ret < 0) {
>>>>>>+		phy_exit(usb3_phy);
>>>>>>+		goto err;
>>>>>>+	}
>>>>>>+
>>>>>>+	ret = reset_control_deassert(apbrst);
>>>>>>+	if (ret < 0) {
>>>>>>+		dev_err(dev, "Failed to release APB reset\n");
>>>>>>+		goto err;
>>>>>>+	}
>>>>>>+
>>>>>>+	/* Set PIPE Power Present signal in FPD Power Present Register*/
>>>>>>+	writel(PIPE_POWER_ON, priv_data->regs +
>>>>XLNX_USB_FPD_POWER_PRSNT);
>>>>
>>>>This is somehow leading to an unstable link when using vanilla.
>>>>
>>>>>>+
>>>>>>+	/* Set the PIPE Clock Select bit in FPD PIPE Clock register */
>>>>>>+	writel(PIPE_CLK_SELECT, priv_data->regs +
>>>>XLNX_USB_FPD_PIPE_CLK);
>>>>>>+
>>>>>>+	ret = reset_control_deassert(crst);
>>>>>>+	if (ret < 0) {
>>>>>>+		dev_err(dev, "Failed to release core reset\n");
>>>>>>+		goto err;
>>>>>>+	}
>>>>>>+
>>>>>>+	ret = reset_control_deassert(hibrst);
>>>>>>+	if (ret < 0) {
>>>>>>+		dev_err(dev, "Failed to release hibernation reset\n");
>>>>>>+		goto err;
>>>>>>+	}
>>>>>>+
>>>>>>+	ret = phy_power_on(usb3_phy);
>>>>>>+	if (ret < 0) {
>>>>>>+		phy_exit(usb3_phy);
>>>>>>+		goto err;
>>>>>>+	}
>>>>>>+
>>>>>>+	/*
>>>>>>+	 * This routes the USB DMA traffic to go through FPD path instead
>>>>>>+	 * of reaching DDR directly. This traffic routing is needed to
>>>>>>+	 * make SMMU and CCI work with USB DMA.
>>>>>>+	 */
>>>>>>+	if (of_dma_is_coherent(dev->of_node) ||
>>>>device_iommu_mapped(dev)) {
>>>>>>+		reg = readl(priv_data->regs +
>>>>XLNX_USB_TRAFFIC_ROUTE_CONFIG);
>>>>>>+		reg |= XLNX_USB_TRAFFIC_ROUTE_FPD;
>>>>>>+		writel(reg, priv_data->regs +
>>>>XLNX_USB_TRAFFIC_ROUTE_CONFIG);
>>>>>>+	}
>>>>>>+
>>>>>>+err:
>>>>>>+	return ret;
>>>>>>+}
>>>>>>+
>>>>>>+static const struct of_device_id dwc3_xlnx_of_match[] = {
>>>>>>+	{
>>>>>>+		.compatible = "xlnx,zynqmp-dwc3",
>>>>>>+		.data = &dwc3_xlnx_init_zynqmp,
>>>>>>+	},
>>>>>>+	{
>>>>>>+		.compatible = "xlnx,versal-dwc3",
>>>>>>+		.data = &dwc3_xlnx_init_versal,
>>>>>>+	},
>>>>>>+	{ /* Sentinel */ }
>>>>>>+};
>>>>>>+MODULE_DEVICE_TABLE(of, dwc3_xlnx_of_match);
>>>>>>+
>>>>>>+static int dwc3_xlnx_probe(struct platform_device *pdev)
>>>>>>+{
>>>>>>+	struct dwc3_xlnx		*priv_data;
>>>>>>+	struct device			*dev = &pdev->dev;
>>>>>>+	struct device_node		*np = dev->of_node;
>>>>>>+	const struct of_device_id	*match;
>>>>>>+	void __iomem			*regs;
>>>>>>+	int				ret;
>>>>>>+
>>>>>>+	priv_data = devm_kzalloc(dev, sizeof(*priv_data), GFP_KERNEL);
>>>>>>+	if (!priv_data)
>>>>>>+		return -ENOMEM;
>>>>>>+
>>>>>>+	regs = devm_platform_ioremap_resource(pdev, 0);
>>>>>>+	if (IS_ERR(regs)) {
>>>>>>+		ret = PTR_ERR(regs);
>>>>>>+		dev_err_probe(dev, ret, "failed to map registers\n");
>>>>>>+		return ret;
>>>>>>+	}
>>>>>>+
>>>>>>+	match = of_match_node(dwc3_xlnx_of_match, pdev->dev.of_node);
>>>>>>+
>>>>>>+	priv_data->pltfm_init = match->data;
>>>>>>+	priv_data->regs = regs;
>>>>>>+	priv_data->dev = dev;
>>>>>>+
>>>>>>+	platform_set_drvdata(pdev, priv_data);
>>>>>>+
>>>>>>+	ret = devm_clk_bulk_get_all(priv_data->dev, &priv_data->clks);
>>>>>>+	if (ret < 0)
>>>>>>+		return ret;
>>>>>>+
>>>>>>+	priv_data->num_clocks = ret;
>>>>>>+
>>>>>>+	ret = clk_bulk_prepare_enable(priv_data->num_clocks, priv_data-
>>>>>clks);
>>>>>>+	if (ret)
>>>>>>+		return ret;
>>>>>>+
>>>>>>+	ret = priv_data->pltfm_init(priv_data);
>>>>>>+	if (ret)
>>>>>>+		goto err_clk_put;
>>>>>>+
>>>>>>+	ret = of_platform_populate(np, NULL, NULL, dev);
>>>>>>+	if (ret)
>>>>>>+		goto err_clk_put;
>>>>>>+
>>>>>>+	pm_runtime_set_active(dev);
>>>>>>+	pm_runtime_enable(dev);
>>>>>>+	pm_suspend_ignore_children(dev, false);
>>>>>>+	pm_runtime_get_sync(dev);
>>>>>>+
>>>>>>+	return 0;
>>>>>>+
>>>>>>+err_clk_put:
>>>>>>+	clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data-
>>>>>clks);
>>>>>>+	clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);
>>>>>>+
>>>>>>+	return ret;
>>>>>>+}
>>>>>>+
>>>>>>+static int dwc3_xlnx_remove(struct platform_device *pdev)
>>>>>>+{
>>>>>>+	struct dwc3_xlnx	*priv_data = platform_get_drvdata(pdev);
>>>>>>+	struct device		*dev = &pdev->dev;
>>>>>>+
>>>>>>+	of_platform_depopulate(dev);
>>>>>>+
>>>>>>+	clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data-
>>>>>clks);
>>>>>>+	clk_bulk_put_all(priv_data->num_clocks, priv_data->clks);
>>>>>>+	priv_data->num_clocks = 0;
>>>>>>+
>>>>>>+	pm_runtime_disable(dev);
>>>>>>+	pm_runtime_put_noidle(dev);
>>>>>>+	pm_runtime_set_suspended(dev);
>>>>>>+
>>>>>>+	return 0;
>>>>>>+}
>>>>>>+
>>>>>>+static int __maybe_unused dwc3_xlnx_suspend_common(struct device
>>>>*dev)
>>>>>>+{
>>>>>>+	struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);
>>>>>>+
>>>>>>+	clk_bulk_disable(priv_data->num_clocks, priv_data->clks);
>>>>>>+
>>>>>>+	return 0;
>>>>>>+}
>>>>>>+
>>>>>>+static int __maybe_unused dwc3_xlnx_resume_common(struct device
>>>>*dev)
>>>>>>+{
>>>>>>+	struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);
>>>>>>+
>>>>>>+	return clk_bulk_enable(priv_data->num_clocks, priv_data->clks);
>>>>>>+}
>>>>>>+
>>>>>>+static int __maybe_unused dwc3_xlnx_runtime_idle(struct device *dev)
>>>>>>+{
>>>>>>+	pm_runtime_mark_last_busy(dev);
>>>>>>+	pm_runtime_autosuspend(dev);
>>>>>>+
>>>>>>+	return 0;
>>>>>>+}
>>>>>>+
>>>>>>+static UNIVERSAL_DEV_PM_OPS(dwc3_xlnx_dev_pm_ops,
>>>>dwc3_xlnx_suspend_common,
>>>>>>+			    dwc3_xlnx_resume_common,
>>>>dwc3_xlnx_runtime_idle);
>>>>>>+
>>>>>>+static struct platform_driver dwc3_xlnx_driver = {
>>>>>>+	.probe		= dwc3_xlnx_probe,
>>>>>>+	.remove		= dwc3_xlnx_remove,
>>>>>>+	.driver		= {
>>>>>>+		.name		= "dwc3-xilinx",
>>>>>>+		.of_match_table	= dwc3_xlnx_of_match,
>>>>>>+		.pm		= &dwc3_xlnx_dev_pm_ops,
>>>>>>+	},
>>>>>>+};
>>>>>>+
>>>>>>+module_platform_driver(dwc3_xlnx_driver);
>>>>>>+
>>>>>>+MODULE_LICENSE("GPL v2");
>>>>>>+MODULE_DESCRIPTION("Xilinx DWC3 controller specific glue driver");
>>>>>>+MODULE_AUTHOR("Manish Narani <manish.narani@xilinx.com>");
>>>>>>+MODULE_AUTHOR("Anurag Kumar Vulisha
>>>><anurag.kumar.vulisha@xilinx.com>");
>>>>>>--
>>>>>>2.17.1
>>>>>>
>>>>>>
>>>>>>_______________________________________________
>>>>>>linux-arm-kernel mailing list
>>>>>>linux-arm-kernel@lists.infradead.org
>>>>>>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>>>>
>>>>>--
>>>>>Pengutronix e.K.                           |                             |
>>>>>Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>>>>>31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>>>>>Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>>>>
>>>>
>>>>
>>>>>_______________________________________________
>>>>>linux-arm-kernel mailing list
>>>>>linux-arm-kernel@lists.infradead.org
>>>>>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>>>
>>>>
>>>>--
>>>>Pengutronix e.K.                           |                             |
>>>>Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>>>>31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>>>>Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>>>
>>>_______________________________________________
>>>linux-arm-kernel mailing list
>>>linux-arm-kernel@lists.infradead.org
>>>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>>
>>
>>-- 
>>Pengutronix e.K.                           |                             |
>>Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>>31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>>Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
>
>
>
>>_______________________________________________
>>linux-arm-kernel mailing list
>>linux-arm-kernel@lists.infradead.org
>>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
>
>-- 
>Pengutronix e.K.                           |                             |
>Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |



>_______________________________________________
>linux-arm-kernel mailing list
>linux-arm-kernel@lists.infradead.org
>http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Hi Michael,

> -----Original Message-----
> From: Michael Grzeschik <mgr@pengutronix.de>
> Sent: Tuesday, February 9, 2021 5:26 AM
> To: Manish Narani <MNARANI@xilinx.com>
> Cc: devicetree@vger.kernel.org; p.zabel@pengutronix.de; balbi@kernel.org;
> gregkh@linuxfoundation.org; linux-usb@vger.kernel.org; linux-
> kernel@vger.kernel.org; robh+dt@kernel.org; Michal Simek
> <michals@xilinx.com>; git <git@xilinx.com>; kernel@pengutronix.de; linux-
> arm-kernel@lists.infradead.org
> Subject: Re: [RESEND PATCH v3 2/2] usb: dwc3: Add driver for Xilinx
> platforms
> 
> Hi Manish!
> 
> On Thu, Jan 28, 2021 at 12:36:07AM +0100, Michael Grzeschik wrote:
> >On Fri, Jan 22, 2021 at 02:34:52PM +0100, Michael Grzeschik wrote:
> >>On Fri, Jan 22, 2021 at 01:06:22PM +0000, Manish Narani wrote:
> >>>Hi Michael,
> >>>
> >>>>-----Original Message-----
> >>>>From: Michael Grzeschik <mgr@pengutronix.de>
> >>>>Sent: Friday, January 22, 2021 1:39 PM
> >>>>To: Manish Narani <MNARANI@xilinx.com>
> >>>>Cc: devicetree@vger.kernel.org; kernel@pengutronix.de;
> balbi@kernel.org;
> >>>>gregkh@linuxfoundation.org; linux-usb@vger.kernel.org; Michal Simek
> >>>><michals@xilinx.com>; linux-kernel@vger.kernel.org;
> robh+dt@kernel.org;
> >>>>git <git@xilinx.com>; p.zabel@pengutronix.de; linux-arm-
> >>>>kernel@lists.infradead.org
> >>>>Subject: Re: [RESEND PATCH v3 2/2] usb: dwc3: Add driver for Xilinx
> >>>>platforms
> >>>>
> >>>>Hello!
> >>>>
> >>>>On Mon, Jan 18, 2021 at 02:42:24PM +0100, Michael Grzeschik wrote:
> >>>>>Hi!
> >>>>>
> >>>>>On Tue, Dec 15, 2020 at 12:24:51PM +0530, Manish Narani wrote:
> >>>>>>Add a new driver for supporting Xilinx platforms. This driver is used
> >>>>>>for some sequence of operations required for Xilinx USB controllers.
> >>>>>>This driver is also used to choose between PIPE clock coming from
> SerDes
> >>>>>>and the Suspend Clock. Before the controller is out of reset, the clock
> >>>>>>selection should be changed to PIPE clock in order to make the USB
> >>>>>>controller work. There is a register added in Xilinx USB controller
> >>>>>>register space for the same.
> >>>>>
> >>>>>I tried out this driver with the vanilla kernel on an zynqmp. Without
> >>>>>this patch the USB-Gadget is already acting buggy. In the gadget mode,
> >>>>>some iterations of plug/unplug results to an stalled gadget which will
> >>>>>never come back without a reboot.
> >>>>>
> >>>>>With the corresponding code of this driver (reset assert, clk modify,
> >>>>>reset deassert) in the downstream kernels phy driver we found out it is
> >>>>>totaly stable. But using this exact glue driver which should do the same
> >>>>>as the downstream code, the gadget still was buggy the way described
> >>>>>above.
> >>>>>
> >>>>>I suspect the difference lays in the different order of operations.
> >>>>>While the downstream code is runing the resets inside the phy driver
> >>>>>which is powered and initialized in the dwc3-core itself. With this glue
> >>>>>layser approach of this patch the whole phy init is done before even
> >>>>>touching dwc3-core in any way. It seems not to have the same effect,
> >>>>>though.
> >>>>>
> >>>>>If really the order of operations is limiting us, we probably need
> >>>>>another solution than this glue layer. Any Ideas?
> >>>>
> >>>>I found out what the difference between the Downstream and this
> >>>>Glue is. When using vanilla with this Glue code we may not set
> >>>>the following bit:
> >>>>
> >>>>https://www.xilinx.com/html_docs/registers/ug1087/ug1087-zynq-
> >>>>ultrascale-registers.html#usb3_regs___fpd_power_prsnt.html
> >>>>
> >>>>>>+	/* Set PIPE Power Present signal in FPD Power Present
> Register*/
> >>>>>>+	writel(PIPE_POWER_ON, priv_data->regs +
> >>>>XLNX_USB_FPD_POWER_PRSNT);
> >>>>
> >>>>When I comment this out, the link stays stable. This is different in
> >>>>the Downstream Xilinx Kernel, where the bit is also set but has no
> >>>>negativ effect.
> >>>>
> >>>>Manish, can you give me a pointer what to look for?
> >>>>So setting this will also work with mainline?
> >>>I am looking further on this but from what I see here is that,
> >>>In order to make USB function properly, there are some dt changes
> needed in mainline for
> >>>USB node which include defining clocks coming from serdes.
> >>>The DT changes are pending to be sent to mainline.
> >>
> >>Can you push that state somewhere, so I could test it?
> >>Or is in the downstream kernel some things to copy?
> >>
> >>>Can you share the DT settings for USB node on your side?
> >>
> >>Here is my current configuration for the device node at usb0:
> >>
> >>zynqmp.dtsi
> >>
> >>zynqmp_reset: reset-controller {
> >>	compatible = "xlnx,zynqmp-reset";
> >>	#reset-cells = <1>;
> >>};
> >>
> >>usb0: usb@ff9d0000 {
> >>	#address-cells = <2>;
> >>	#size-cells = <2>;
> >>	status = "disabled";
> >>	compatible = "xlnx,zynqmp-dwc3";
> >>	reg = <0x0 0xff9d0000 0x0 0x100>;
> >>	clock-names = "bus_clk", "ref_clk";
> >>	power-domains = <&zynqmp_firmware PD_USB_0>;
> >>	ranges;
> >>	resets = <&zynqmp_reset ZYNQMP_RESET_USB0_CORERESET>,
> >>		<&zynqmp_reset ZYNQMP_RESET_USB0_HIBERRESET>,
> >>		<&zynqmp_reset ZYNQMP_RESET_USB0_APB>;
> >>	reset-names = "usb_crst", "usb_hibrst", "usb_apbrst";
> >>	phy-names = "usb3-phy";
> >>	phys = <&psgtr 2 PHY_TYPE_USB3 0 2>;
> >>
> >>	usb0_dwc3: dwc3@fe200000 {
> >>		compatible = "snps,dwc3";
> >>		interrupt-parent = <&gic>;
> >>		interrupts = <0 65 4>;
> >>		clock-names = "ref", "bus_early", "suspend";
> >>		reg = <0x0 0xfe200000 0x0 0x40000>;
> >>	};
> >>};
> >>
> >>platform.dts
> >>
> >>&usb0 {
> >>	status = "okay";
> >>	phy-names = "usb3-phy";
> >>	phys = <&psgtr 2 PHY_TYPE_USB3 0 2>;
> >>};
> >>
> >>&usb0_dwc3 {
> >>	dr_mode = "peripheral";
> >>
> >>	/* The following quirks are required, since the bInterval is 1 and we
> >>	 * handle steady ISOC streaming. See Usecase 3 in commit
> 729dcffd1ed3
> >>	 * ("usb: dwc3: gadget: Add support for disabling U1 and U2
> entries").
> >>	 */
> >>	snps,dis-u1-entry-quirk;
> >>	snps,dis-u2-entry-quirk;
> >>};
> >>
> >>
> >>>Meanwhile I will keep updating on the same.
> >>
> >>Thanks, that sounds great!
> >
> >I have more feedback regarding this issues. As we saw new uncommon
> >effects, when using the glue. Regarding to get the plug/unplug behaviour
> >stable, we sticked with leaving out the setting of PIPE_POWER_ON in that
> >driver. Unfortunately, with that change, the dwc3 is not only not
> >sending any Erratic Errors any more, but also is lacking to send
> >disconnect interrupts.
> >
> >Double checking with downstream shows that disconnects are working
> >completely fine in your downstream stack.
> >
> >I think we should really need to know why PIPE_POWER_ON is making
> >a difference before we can say the dwc3 is stable with that glue.
> 
> After bisecting your v5.4 and mainline we found out that this all is
> working fine, when setting "snps,dis_u3_susphy_quirk" in the zynqmp.dtsi
> dwc3 node.
> 
> The code handling this quirk was introduced after v5.4, so this was
> never an issue with your downstream stack.
> 
> "9ba3aca8 usb: dwc3: Disable phy suspend after power-on reset"
> 
> We need to know if adding snps,dis_u3_susphy_quirk to the dwc nodes
> is generally necessary for zynqmp, so we can fix for everyone.

Yes, it is necessary for DWC3 on ZynqMP platform. This property should be
added to the DT node.

Thanks,
Manish

Hi Manish,

On Tue, Feb 09, 2021 at 06:01:58AM +0000, Manish Narani wrote:
>Hi Michael,

>

>> -----Original Message-----

>> From: Michael Grzeschik <mgr@pengutronix.de>

>> Sent: Tuesday, February 9, 2021 5:26 AM

>> To: Manish Narani <MNARANI@xilinx.com>

>> Cc: devicetree@vger.kernel.org; p.zabel@pengutronix.de; balbi@kernel.org;

>> gregkh@linuxfoundation.org; linux-usb@vger.kernel.org; linux-

>> kernel@vger.kernel.org; robh+dt@kernel.org; Michal Simek

>> <michals@xilinx.com>; git <git@xilinx.com>; kernel@pengutronix.de; linux-

>> arm-kernel@lists.infradead.org

>> Subject: Re: [RESEND PATCH v3 2/2] usb: dwc3: Add driver for Xilinx

>> platforms

>>

>> Hi Manish!

>>

>> On Thu, Jan 28, 2021 at 12:36:07AM +0100, Michael Grzeschik wrote:

>> >On Fri, Jan 22, 2021 at 02:34:52PM +0100, Michael Grzeschik wrote:

>> >>On Fri, Jan 22, 2021 at 01:06:22PM +0000, Manish Narani wrote:

>> >>>Hi Michael,

>> >>>

>> >>>>-----Original Message-----

>> >>>>From: Michael Grzeschik <mgr@pengutronix.de>

>> >>>>Sent: Friday, January 22, 2021 1:39 PM

>> >>>>To: Manish Narani <MNARANI@xilinx.com>

>> >>>>Cc: devicetree@vger.kernel.org; kernel@pengutronix.de;

>> balbi@kernel.org;

>> >>>>gregkh@linuxfoundation.org; linux-usb@vger.kernel.org; Michal Simek

>> >>>><michals@xilinx.com>; linux-kernel@vger.kernel.org;

>> robh+dt@kernel.org;

>> >>>>git <git@xilinx.com>; p.zabel@pengutronix.de; linux-arm-

>> >>>>kernel@lists.infradead.org

>> >>>>Subject: Re: [RESEND PATCH v3 2/2] usb: dwc3: Add driver for Xilinx

>> >>>>platforms

>> >>>>

>> >>>>Hello!

>> >>>>

>> >>>>On Mon, Jan 18, 2021 at 02:42:24PM +0100, Michael Grzeschik wrote:

>> >>>>>Hi!

>> >>>>>

>> >>>>>On Tue, Dec 15, 2020 at 12:24:51PM +0530, Manish Narani wrote:

>> >>>>>>Add a new driver for supporting Xilinx platforms. This driver is used

>> >>>>>>for some sequence of operations required for Xilinx USB controllers.

>> >>>>>>This driver is also used to choose between PIPE clock coming from

>> SerDes

>> >>>>>>and the Suspend Clock. Before the controller is out of reset, the clock

>> >>>>>>selection should be changed to PIPE clock in order to make the USB

>> >>>>>>controller work. There is a register added in Xilinx USB controller

>> >>>>>>register space for the same.

>> >>>>>

>> >>>>>I tried out this driver with the vanilla kernel on an zynqmp. Without

>> >>>>>this patch the USB-Gadget is already acting buggy. In the gadget mode,

>> >>>>>some iterations of plug/unplug results to an stalled gadget which will

>> >>>>>never come back without a reboot.

>> >>>>>

>> >>>>>With the corresponding code of this driver (reset assert, clk modify,

>> >>>>>reset deassert) in the downstream kernels phy driver we found out it is

>> >>>>>totaly stable. But using this exact glue driver which should do the same

>> >>>>>as the downstream code, the gadget still was buggy the way described

>> >>>>>above.

>> >>>>>

>> >>>>>I suspect the difference lays in the different order of operations.

>> >>>>>While the downstream code is runing the resets inside the phy driver

>> >>>>>which is powered and initialized in the dwc3-core itself. With this glue

>> >>>>>layser approach of this patch the whole phy init is done before even

>> >>>>>touching dwc3-core in any way. It seems not to have the same effect,

>> >>>>>though.

>> >>>>>

>> >>>>>If really the order of operations is limiting us, we probably need

>> >>>>>another solution than this glue layer. Any Ideas?

>> >>>>

>> >>>>I found out what the difference between the Downstream and this

>> >>>>Glue is. When using vanilla with this Glue code we may not set

>> >>>>the following bit:

>> >>>>

>> >>>>https://www.xilinx.com/html_docs/registers/ug1087/ug1087-zynq-

>> >>>>ultrascale-registers.html#usb3_regs___fpd_power_prsnt.html

>> >>>>

>> >>>>>>+	/* Set PIPE Power Present signal in FPD Power Present

>> Register*/

>> >>>>>>+	writel(PIPE_POWER_ON, priv_data->regs +

>> >>>>XLNX_USB_FPD_POWER_PRSNT);

>> >>>>

>> >>>>When I comment this out, the link stays stable. This is different in

>> >>>>the Downstream Xilinx Kernel, where the bit is also set but has no

>> >>>>negativ effect.

>> >>>>

>> >>>>Manish, can you give me a pointer what to look for?

>> >>>>So setting this will also work with mainline?

>> >>>I am looking further on this but from what I see here is that,

>> >>>In order to make USB function properly, there are some dt changes

>> needed in mainline for

>> >>>USB node which include defining clocks coming from serdes.

>> >>>The DT changes are pending to be sent to mainline.

>> >>

>> >>Can you push that state somewhere, so I could test it?

>> >>Or is in the downstream kernel some things to copy?

>> >>

>> >>>Can you share the DT settings for USB node on your side?

>> >>

>> >>Here is my current configuration for the device node at usb0:

>> >>

>> >>zynqmp.dtsi

>> >>

>> >>zynqmp_reset: reset-controller {

>> >>	compatible = "xlnx,zynqmp-reset";

>> >>	#reset-cells = <1>;

>> >>};

>> >>

>> >>usb0: usb@ff9d0000 {

>> >>	#address-cells = <2>;

>> >>	#size-cells = <2>;

>> >>	status = "disabled";

>> >>	compatible = "xlnx,zynqmp-dwc3";

>> >>	reg = <0x0 0xff9d0000 0x0 0x100>;

>> >>	clock-names = "bus_clk", "ref_clk";

>> >>	power-domains = <&zynqmp_firmware PD_USB_0>;

>> >>	ranges;

>> >>	resets = <&zynqmp_reset ZYNQMP_RESET_USB0_CORERESET>,

>> >>		<&zynqmp_reset ZYNQMP_RESET_USB0_HIBERRESET>,

>> >>		<&zynqmp_reset ZYNQMP_RESET_USB0_APB>;

>> >>	reset-names = "usb_crst", "usb_hibrst", "usb_apbrst";

>> >>	phy-names = "usb3-phy";

>> >>	phys = <&psgtr 2 PHY_TYPE_USB3 0 2>;

>> >>

>> >>	usb0_dwc3: dwc3@fe200000 {

>> >>		compatible = "snps,dwc3";

>> >>		interrupt-parent = <&gic>;

>> >>		interrupts = <0 65 4>;

>> >>		clock-names = "ref", "bus_early", "suspend";

>> >>		reg = <0x0 0xfe200000 0x0 0x40000>;

>> >>	};

>> >>};

>> >>

>> >>platform.dts

>> >>

>> >>&usb0 {

>> >>	status = "okay";

>> >>	phy-names = "usb3-phy";

>> >>	phys = <&psgtr 2 PHY_TYPE_USB3 0 2>;

>> >>};

>> >>

>> >>&usb0_dwc3 {

>> >>	dr_mode = "peripheral";

>> >>

>> >>	/* The following quirks are required, since the bInterval is 1 and we

>> >>	 * handle steady ISOC streaming. See Usecase 3 in commit

>> 729dcffd1ed3

>> >>	 * ("usb: dwc3: gadget: Add support for disabling U1 and U2

>> entries").

>> >>	 */

>> >>	snps,dis-u1-entry-quirk;

>> >>	snps,dis-u2-entry-quirk;

>> >>};

>> >>

>> >>

>> >>>Meanwhile I will keep updating on the same.

>> >>

>> >>Thanks, that sounds great!

>> >

>> >I have more feedback regarding this issues. As we saw new uncommon

>> >effects, when using the glue. Regarding to get the plug/unplug behaviour

>> >stable, we sticked with leaving out the setting of PIPE_POWER_ON in that

>> >driver. Unfortunately, with that change, the dwc3 is not only not

>> >sending any Erratic Errors any more, but also is lacking to send

>> >disconnect interrupts.

>> >

>> >Double checking with downstream shows that disconnects are working

>> >completely fine in your downstream stack.

>> >

>> >I think we should really need to know why PIPE_POWER_ON is making

>> >a difference before we can say the dwc3 is stable with that glue.

>>

>> After bisecting your v5.4 and mainline we found out that this all is

>> working fine, when setting "snps,dis_u3_susphy_quirk" in the zynqmp.dtsi

>> dwc3 node.

>>

>> The code handling this quirk was introduced after v5.4, so this was

>> never an issue with your downstream stack.

>>

>> "9ba3aca8 usb: dwc3: Disable phy suspend after power-on reset"

>>

>> We need to know if adding snps,dis_u3_susphy_quirk to the dwc nodes

>> is generally necessary for zynqmp, so we can fix for everyone.

>

>Yes, it is necessary for DWC3 on ZynqMP platform. This property should be

>added to the DT node.


For now this quirk does solve the issues regarding the pluging
behaviour. But we would like to know why?

Is the phy not properly configured/connected to serve the phy
suspend as intended for the dwc3 stack? Is this a real Hardware issue,
or does this quirk only disable the suspend behaviour even though it
would work properly when configured correctly in software.


The second question is addressing the dwc3 xilinx glue driver
you are trying to mainline. We found that the driver is pulling and
releasing some resets before and after changing the pll frequency
comming from the reference clk lines. After that the undocumented
registers XLNX_USB_FPD_POWER_PRSNT and XLNX_USB_FPD_PIPE_CLK are changed
according to the updated pll frequency. What do these bit change?
Is this an internal configuration every dwc3 user on the zynqmp has
to do or does this differ from user to user?

Regards,
Michael

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Adding Tinh Nguyen to CC:

On Tue, Feb 09, 2021 at 09:02:00PM +0100, Michael Grzeschik wrote:
>Hi Manish,
>
>On Tue, Feb 09, 2021 at 06:01:58AM +0000, Manish Narani wrote:
>>Hi Michael,
>>
>>>-----Original Message-----
>>>From: Michael Grzeschik <mgr@pengutronix.de>
>>>Sent: Tuesday, February 9, 2021 5:26 AM
>>>To: Manish Narani <MNARANI@xilinx.com>
>>>Cc: devicetree@vger.kernel.org; p.zabel@pengutronix.de; balbi@kernel.org;
>>>gregkh@linuxfoundation.org; linux-usb@vger.kernel.org; linux-
>>>kernel@vger.kernel.org; robh+dt@kernel.org; Michal Simek
>>><michals@xilinx.com>; git <git@xilinx.com>; kernel@pengutronix.de; linux-
>>>arm-kernel@lists.infradead.org
>>>Subject: Re: [RESEND PATCH v3 2/2] usb: dwc3: Add driver for Xilinx
>>>platforms
>>>
>>>Hi Manish!
>>>
>>>On Thu, Jan 28, 2021 at 12:36:07AM +0100, Michael Grzeschik wrote:
>>>>On Fri, Jan 22, 2021 at 02:34:52PM +0100, Michael Grzeschik wrote:
>>>>>On Fri, Jan 22, 2021 at 01:06:22PM +0000, Manish Narani wrote:
>>>>>>Hi Michael,
>>>>>>
>>>>>>>-----Original Message-----
>>>>>>>From: Michael Grzeschik <mgr@pengutronix.de>
>>>>>>>Sent: Friday, January 22, 2021 1:39 PM
>>>>>>>To: Manish Narani <MNARANI@xilinx.com>
>>>>>>>Cc: devicetree@vger.kernel.org; kernel@pengutronix.de;
>>>balbi@kernel.org;
>>>>>>>gregkh@linuxfoundation.org; linux-usb@vger.kernel.org; Michal Simek
>>>>>>><michals@xilinx.com>; linux-kernel@vger.kernel.org;
>>>robh+dt@kernel.org;
>>>>>>>git <git@xilinx.com>; p.zabel@pengutronix.de; linux-arm-
>>>>>>>kernel@lists.infradead.org
>>>>>>>Subject: Re: [RESEND PATCH v3 2/2] usb: dwc3: Add driver for Xilinx
>>>>>>>platforms
>>>>>>>
>>>>>>>Hello!
>>>>>>>
>>>>>>>On Mon, Jan 18, 2021 at 02:42:24PM +0100, Michael Grzeschik wrote:
>>>>>>>>Hi!
>>>>>>>>
>>>>>>>>On Tue, Dec 15, 2020 at 12:24:51PM +0530, Manish Narani wrote:
>>>>>>>>>Add a new driver for supporting Xilinx platforms. This driver is used
>>>>>>>>>for some sequence of operations required for Xilinx USB controllers.
>>>>>>>>>This driver is also used to choose between PIPE clock coming from
>>>SerDes
>>>>>>>>>and the Suspend Clock. Before the controller is out of reset, the clock
>>>>>>>>>selection should be changed to PIPE clock in order to make the USB
>>>>>>>>>controller work. There is a register added in Xilinx USB controller
>>>>>>>>>register space for the same.
>>>>>>>>
>>>>>>>>I tried out this driver with the vanilla kernel on an zynqmp. Without
>>>>>>>>this patch the USB-Gadget is already acting buggy. In the gadget mode,
>>>>>>>>some iterations of plug/unplug results to an stalled gadget which will
>>>>>>>>never come back without a reboot.
>>>>>>>>
>>>>>>>>With the corresponding code of this driver (reset assert, clk modify,
>>>>>>>>reset deassert) in the downstream kernels phy driver we found out it is
>>>>>>>>totaly stable. But using this exact glue driver which should do the same
>>>>>>>>as the downstream code, the gadget still was buggy the way described
>>>>>>>>above.
>>>>>>>>
>>>>>>>>I suspect the difference lays in the different order of operations.
>>>>>>>>While the downstream code is runing the resets inside the phy driver
>>>>>>>>which is powered and initialized in the dwc3-core itself. With this glue
>>>>>>>>layser approach of this patch the whole phy init is done before even
>>>>>>>>touching dwc3-core in any way. It seems not to have the same effect,
>>>>>>>>though.
>>>>>>>>
>>>>>>>>If really the order of operations is limiting us, we probably need
>>>>>>>>another solution than this glue layer. Any Ideas?
>>>>>>>
>>>>>>>I found out what the difference between the Downstream and this
>>>>>>>Glue is. When using vanilla with this Glue code we may not set
>>>>>>>the following bit:
>>>>>>>
>>>>>>>https://www.xilinx.com/html_docs/registers/ug1087/ug1087-zynq-
>>>>>>>ultrascale-registers.html#usb3_regs___fpd_power_prsnt.html
>>>>>>>
>>>>>>>>>+	/* Set PIPE Power Present signal in FPD Power Present
>>>Register*/
>>>>>>>>>+	writel(PIPE_POWER_ON, priv_data->regs +
>>>>>>>XLNX_USB_FPD_POWER_PRSNT);
>>>>>>>
>>>>>>>When I comment this out, the link stays stable. This is different in
>>>>>>>the Downstream Xilinx Kernel, where the bit is also set but has no
>>>>>>>negativ effect.
>>>>>>>
>>>>>>>Manish, can you give me a pointer what to look for?
>>>>>>>So setting this will also work with mainline?
>>>>>>I am looking further on this but from what I see here is that,
>>>>>>In order to make USB function properly, there are some dt changes
>>>needed in mainline for
>>>>>>USB node which include defining clocks coming from serdes.
>>>>>>The DT changes are pending to be sent to mainline.
>>>>>
>>>>>Can you push that state somewhere, so I could test it?
>>>>>Or is in the downstream kernel some things to copy?
>>>>>
>>>>>>Can you share the DT settings for USB node on your side?
>>>>>
>>>>>Here is my current configuration for the device node at usb0:
>>>>>
>>>>>zynqmp.dtsi
>>>>>
>>>>>zynqmp_reset: reset-controller {
>>>>>	compatible = "xlnx,zynqmp-reset";
>>>>>	#reset-cells = <1>;
>>>>>};
>>>>>
>>>>>usb0: usb@ff9d0000 {
>>>>>	#address-cells = <2>;
>>>>>	#size-cells = <2>;
>>>>>	status = "disabled";
>>>>>	compatible = "xlnx,zynqmp-dwc3";
>>>>>	reg = <0x0 0xff9d0000 0x0 0x100>;
>>>>>	clock-names = "bus_clk", "ref_clk";
>>>>>	power-domains = <&zynqmp_firmware PD_USB_0>;
>>>>>	ranges;
>>>>>	resets = <&zynqmp_reset ZYNQMP_RESET_USB0_CORERESET>,
>>>>>		<&zynqmp_reset ZYNQMP_RESET_USB0_HIBERRESET>,
>>>>>		<&zynqmp_reset ZYNQMP_RESET_USB0_APB>;
>>>>>	reset-names = "usb_crst", "usb_hibrst", "usb_apbrst";
>>>>>	phy-names = "usb3-phy";
>>>>>	phys = <&psgtr 2 PHY_TYPE_USB3 0 2>;
>>>>>
>>>>>	usb0_dwc3: dwc3@fe200000 {
>>>>>		compatible = "snps,dwc3";
>>>>>		interrupt-parent = <&gic>;
>>>>>		interrupts = <0 65 4>;
>>>>>		clock-names = "ref", "bus_early", "suspend";
>>>>>		reg = <0x0 0xfe200000 0x0 0x40000>;
>>>>>	};
>>>>>};
>>>>>
>>>>>platform.dts
>>>>>
>>>>>&usb0 {
>>>>>	status = "okay";
>>>>>	phy-names = "usb3-phy";
>>>>>	phys = <&psgtr 2 PHY_TYPE_USB3 0 2>;
>>>>>};
>>>>>
>>>>>&usb0_dwc3 {
>>>>>	dr_mode = "peripheral";
>>>>>
>>>>>	/* The following quirks are required, since the bInterval is 1 and we
>>>>>	 * handle steady ISOC streaming. See Usecase 3 in commit
>>>729dcffd1ed3
>>>>>	 * ("usb: dwc3: gadget: Add support for disabling U1 and U2
>>>entries").
>>>>>	 */
>>>>>	snps,dis-u1-entry-quirk;
>>>>>	snps,dis-u2-entry-quirk;
>>>>>};
>>>>>
>>>>>
>>>>>>Meanwhile I will keep updating on the same.
>>>>>
>>>>>Thanks, that sounds great!
>>>>
>>>>I have more feedback regarding this issues. As we saw new uncommon
>>>>effects, when using the glue. Regarding to get the plug/unplug behaviour
>>>>stable, we sticked with leaving out the setting of PIPE_POWER_ON in that
>>>>driver. Unfortunately, with that change, the dwc3 is not only not
>>>>sending any Erratic Errors any more, but also is lacking to send
>>>>disconnect interrupts.
>>>>
>>>>Double checking with downstream shows that disconnects are working
>>>>completely fine in your downstream stack.
>>>>
>>>>I think we should really need to know why PIPE_POWER_ON is making
>>>>a difference before we can say the dwc3 is stable with that glue.
>>>
>>>After bisecting your v5.4 and mainline we found out that this all is
>>>working fine, when setting "snps,dis_u3_susphy_quirk" in the zynqmp.dtsi
>>>dwc3 node.
>>>
>>>The code handling this quirk was introduced after v5.4, so this was
>>>never an issue with your downstream stack.
>>>
>>>"9ba3aca8 usb: dwc3: Disable phy suspend after power-on reset"
>>>
>>>We need to know if adding snps,dis_u3_susphy_quirk to the dwc nodes
>>>is generally necessary for zynqmp, so we can fix for everyone.
>>
>>Yes, it is necessary for DWC3 on ZynqMP platform. This property should be
>>added to the DT node.
>
>For now this quirk does solve the issues regarding the pluging
>behaviour. But we would like to know why?
>
>Is the phy not properly configured/connected to serve the phy
>suspend as intended for the dwc3 stack? Is this a real Hardware issue,
>or does this quirk only disable the suspend behaviour even though it
>would work properly when configured correctly in software.
>
>
>The second question is addressing the dwc3 xilinx glue driver
>you are trying to mainline. We found that the driver is pulling and
>releasing some resets before and after changing the pll frequency
>comming from the reference clk lines. After that the undocumented
>registers XLNX_USB_FPD_POWER_PRSNT and XLNX_USB_FPD_PIPE_CLK are changed
>according to the updated pll frequency. What do these bit change?
>Is this an internal configuration every dwc3 user on the zynqmp has
>to do or does this differ from user to user?
>
>Regards,
>Michael
>
>-- 
>Pengutronix e.K.                           |                             |
>Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
>31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
>Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |



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