diff mbox

[v5.1] phy: rockchip-usb: add handler for usb-uart functionality

Message ID 56CAF4DE.2060708@ti.com
State New
Headers show

Commit Message

Kishon Vijay Abraham I Feb. 22, 2016, 11:45 a.m. UTC 
Hi,

On Monday 22 February 2016 05:11 PM, Heiko Stuebner wrote:
> Most newer Rockchip SoCs provide the possibility to use a usb-phy

> as passthrough for the debug uart (uart2), making it possible to

> for example get console output without needing to open the device.

> 

> This patch adds an early_initcall to enable this functionality

> conditionally via the commandline and also disables the corresponding

> usb controller in the devicetree.

> 

> Currently only data for the rk3288 is provided, but at least the

> rk3188 and arm64 rk3368 also provide this functionality and will be

> enabled later.

> 

> On a spliced usb cable the signals are tx on white wire(D+) and

> rx on green wire(D-).

> 

> The one caveat is that currently the reconfiguration of the phy

> happens as early_initcall, as the code depends on the unflattened

> devicetree being available. Everything is fine if only a regular

> console is active as the console-replay will happen after the

> reconfiguation. But with earlycon active output up to smp-init

> currently will get lost.

> 

> The phy is an optional property for the connected dwc2 controller,

> so we still provide the phy device but fail all phy-ops with -EBUSY

> to make sure the dwc2 does not try to transmit anything on the

> repurposed phy.

> 

> Signed-off-by: Heiko Stuebner <heiko@sntech.de>

> ---

> changes in v5.1:

> - fix corruptions that happened when sending v5


I still see the corruption.

This is how I see the patch after downloading (from both mutt and thunderbird)
@@ -3486,6 +3486,12 @@ bytes respectively. Such letter suffixes can also be=
 entirely omitted.
=20
        ro              [KNL] Mount root device read-only on boot
=20
+       rockchip.usb_uart
+                       Enable the uart passthrough on the designated usb port
+                       on Rockchip SoCs. When active, the signals of the
+                       debug-uart get routed to the D+ and D- pins of the usb
+                       port and the regular usb controller gets disabled.
+
        root=3D         [KNL] Root filesystem
                        See name_to_dev_t comment in init/do_mounts.c.
=20

> changes in v5:

> - only compile debug uart functionality if the phy is compiled in

>   fixes initcall conflict and debug functionality also is only really

>   usable if it's available early

> changes in v4:

> - drop the rest of the phy-series, as the patches have gotten applied

> 

> So far, this hasn't gotten eyeballs yet, so citing discussion-parts from

> the v3 coverletter:

> 

> The patch, while not associated with the new pll handling, also builds

> on the groundwork introduced there and adds support for the function

> repurposing one of the phys as passthrough for uart-data. This enables

> attaching a ttl converter to the D+ and D- pins of an usb cable to

> receive uart data this way, when it is not really possible to attach

> a regular serial console to a board.

> 

> One point of critique in my first iteration [0] of this was, that

> due to when the reconfiguration happens we may miss parts of the logs

> when earlycon is enabled. So far early_initcall gets used as the

> unflattened devicetree is necessary to set this up. Doing this for

> example in the early_param directly would require parsing the flattened

> devicetree to get needed nodes and properties.

> 

> I still maintain that if you're working on anything before smp-bringup

> you should use a real dev-board instead or try to solder uart cables

> on hopefully available test-points  .

> 

> 

>  Documentation/kernel-parameters.txt |   6 +

>  drivers/phy/phy-rockchip-usb.c      | 233 ++++++++++++++++++++++++++++++------

>  2 files changed, 203 insertions(+), 36 deletions(-)

> 

> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt

> index 87d40a7..d91417b 100644

> --- a/Documentation/kernel-parameters.txt

> +++ b/Documentation/kernel-parameters.txt

> @@ -3486,6 +3486,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.

>  

>  	ro		[KNL] Mount root device read-only on boot

>  

> +	rockchip.usb_uart

> +			Enable the uart passthrough on the designated usb port

> +			on Rockchip SoCs. When active, the signals of the

> +			debug-uart get routed to the D+ and D- pins of the usb

> +			port and the regular usb controller gets disabled.

> +

>  	root=		[KNL] Root filesystem

>  			See name_to_dev_t comment in init/do_mounts.c.

>  

> diff --git a/drivers/phy/phy-rockchip-usb.c b/drivers/phy/phy-rockchip-usb.c

> index 33a80eb..f62d899 100644

> --- a/drivers/phy/phy-rockchip-usb.c

> +++ b/drivers/phy/phy-rockchip-usb.c

> @@ -30,21 +30,23 @@

>  #include <linux/regmap.h>

>  #include <linux/mfd/syscon.h>

>  

> -/*

> - * The higher 16-bit of this register is used for write protection

> - * only if BIT(13 + 16) set to 1 the BIT(13) can be written.

> - */

> -#define SIDDQ_WRITE_ENA	BIT(29)

> -#define SIDDQ_ON		BIT(13)

> -#define SIDDQ_OFF		(0 << 13)

> +static int enable_usb_uart;

> +

> +#define HIWORD_UPDATE(val, mask) \

> +		((val) | (mask) << 16)

> +

> +#define UOC_CON0_SIDDQ BIT(13)

>  

>  struct rockchip_usb_phys {

>  	int reg;

>  	const char *pll_name;

>  };

>  

> +struct rockchip_usb_phy_base;

>  struct rockchip_usb_phy_pdata {

>  	struct rockchip_usb_phys *phys;

> +	int (*init_usb_uart)(struct regmap *grf);

> +	int usb_uart_phy;

>  };

>  

>  struct rockchip_usb_phy_base {

> @@ -61,13 +63,15 @@ struct rockchip_usb_phy {

>  	struct clk      *clk480m;

>  	struct clk_hw	clk480m_hw;

>  	struct phy	*phy;

> +	bool		uart_enabled;

>  };

>  

>  static int rockchip_usb_phy_power(struct rockchip_usb_phy *phy,

>  					   bool siddq)

>  {

> -	return regmap_write(phy->base->reg_base, phy->reg_offset,

> -			    SIDDQ_WRITE_ENA | (siddq ? SIDDQ_ON : SIDDQ_OFF));

> +	u32 val = HIWORD_UPDATE(siddq ? UOC_CON0_SIDDQ : 0, UOC_CON0_SIDDQ);

> +

> +	return regmap_write(phy->base->reg_base, phy->reg_offset, val);

>  }

>  

>  static unsigned long rockchip_usb_phy480m_recalc_rate(struct clk_hw *hw,

> @@ -108,7 +112,7 @@ static int rockchip_usb_phy480m_is_enabled(struct clk_hw *hw)

>  	if (ret < 0)

>  		return ret;

>  

> -	return (val & SIDDQ_ON) ? 0 : 1;

> +	return (val & UOC_CON0_SIDDQ) ? 0 : 1;

>  }

>  

>  static const struct clk_ops rockchip_usb_phy480m_ops = {

> @@ -122,6 +126,9 @@ static int rockchip_usb_phy_power_off(struct phy *_phy)

>  {

>  	struct rockchip_usb_phy *phy = phy_get_drvdata(_phy);

>  

> +	if (phy->uart_enabled)

> +		return -EBUSY;

> +

>  	clk_disable_unprepare(phy->clk480m);

>  

>  	return 0;

> @@ -131,6 +138,9 @@ static int rockchip_usb_phy_power_on(struct phy *_phy)

>  {

>  	struct rockchip_usb_phy *phy = phy_get_drvdata(_phy);

>  

> +	if (phy->uart_enabled)

> +		return -EBUSY;

> +

>  	return clk_prepare_enable(phy->clk480m);

>  }

>  

> @@ -144,8 +154,10 @@ static void rockchip_usb_phy_action(void *data)

>  {

>  	struct rockchip_usb_phy *rk_phy = data;

>  

> -	of_clk_del_provider(rk_phy->np);

> -	clk_unregister(rk_phy->clk480m);

> +	if (!rk_phy->uart_enabled) {

> +		of_clk_del_provider(rk_phy->np);

> +		clk_unregister(rk_phy->clk480m);

> +	}

>  

>  	if (rk_phy->clk)

>  		clk_put(rk_phy->clk);

> @@ -194,30 +206,35 @@ static int rockchip_usb_phy_init(struct rockchip_usb_phy_base *base,

>  		return -EINVAL;

>  	}

>  

> -	if (rk_phy->clk) {

> -		clk_name = __clk_get_name(rk_phy->clk);

> -		init.flags = 0;

> -		init.parent_names = &clk_name;

> -		init.num_parents = 1;

> +	if (enable_usb_uart && base->pdata->usb_uart_phy == i) {

> +		dev_dbg(base->dev, "phy%d used as uart output\n", i);

> +		rk_phy->uart_enabled = true;

>  	} else {

> -		init.flags = CLK_IS_ROOT;

> -		init.parent_names = NULL;

> -		init.num_parents = 0;

> -	}

> +		if (rk_phy->clk) {

> +			clk_name = __clk_get_name(rk_phy->clk);

> +			init.flags = 0;

> +			init.parent_names = &clk_name;

> +			init.num_parents = 1;

> +		} else {

> +			init.flags = CLK_IS_ROOT;

> +			init.parent_names = NULL;

> +			init.num_parents = 0;

> +		}

>  

> -	init.ops = &rockchip_usb_phy480m_ops;

> -	rk_phy->clk480m_hw.init = &init;

> +		init.ops = &rockchip_usb_phy480m_ops;

> +		rk_phy->clk480m_hw.init = &init;

>  

> -	rk_phy->clk480m = clk_register(base->dev, &rk_phy->clk480m_hw);

> -	if (IS_ERR(rk_phy->clk480m)) {

> -		err = PTR_ERR(rk_phy->clk480m);

> -		goto err_clk;

> -	}

> +		rk_phy->clk480m = clk_register(base->dev, &rk_phy->clk480m_hw);

> +		if (IS_ERR(rk_phy->clk480m)) {

> +			err = PTR_ERR(rk_phy->clk480m);

> +			goto err_clk;

> +		}

>  

> -	err = of_clk_add_provider(child, of_clk_src_simple_get,

> -				  rk_phy->clk480m);

> -	if (err < 0)

> -		goto err_clk_prov;

> +		err = of_clk_add_provider(child, of_clk_src_simple_get,

> +					rk_phy->clk480m);

> +		if (err < 0)

> +			goto err_clk_prov;

> +	}

>  

>  	err = devm_add_action(base->dev, rockchip_usb_phy_action, rk_phy);

>  	if (err)

> @@ -230,13 +247,21 @@ static int rockchip_usb_phy_init(struct rockchip_usb_phy_base *base,

>  	}

>  	phy_set_drvdata(rk_phy->phy, rk_phy);

>  

> -	/* only power up usb phy when it use, so disable it when init*/

> -	return rockchip_usb_phy_power(rk_phy, 1);

> +	/*

> +	 * When acting as uart-pipe, just keep clock on otherwise

> +	 * only power up usb phy when it use, so disable it when init

> +	 */

> +	if (rk_phy->uart_enabled)

> +		return clk_prepare_enable(rk_phy->clk);

> +	else

> +		return rockchip_usb_phy_power(rk_phy, 1);

>  

>  err_devm_action:

> -	of_clk_del_provider(child);

> +	if (!rk_phy->uart_enabled)

> +		of_clk_del_provider(child);

>  err_clk_prov:

> -	clk_unregister(rk_phy->clk480m);

> +	if (!rk_phy->uart_enabled)

> +		clk_unregister(rk_phy->clk480m);

>  err_clk:

>  	if (rk_phy->clk)

>  		clk_put(rk_phy->clk);

> @@ -259,6 +284,86 @@ static const struct rockchip_usb_phy_pdata rk3188_pdata = {

>  	},

>  };

>  

> +#define RK3288_UOC0_CON0				0x320

> +#define RK3288_UOC0_CON0_COMMON_ON_N			BIT(0)

> +#define RK3288_UOC0_CON0_DISABLE			BIT(4)

> +

> +#define RK3288_UOC0_CON2				0x328

> +#define RK3288_UOC0_CON2_SOFT_CON_SEL			BIT(2)

> +

> +#define RK3288_UOC0_CON3				0x32c

> +#define RK3288_UOC0_CON3_UTMI_SUSPENDN			BIT(0)

> +#define RK3288_UOC0_CON3_UTMI_OPMODE_NODRIVING		(1 << 1)

> +#define RK3288_UOC0_CON3_UTMI_OPMODE_MASK		(3 << 1)

> +#define RK3288_UOC0_CON3_UTMI_XCVRSEELCT_FSTRANSC	(1 << 3)

> +#define RK3288_UOC0_CON3_UTMI_XCVRSEELCT_MASK		(3 << 3)

> +#define RK3288_UOC0_CON3_UTMI_TERMSEL_FULLSPEED		BIT(5)

> +#define RK3288_UOC0_CON3_BYPASSDMEN			BIT(6)

> +#define RK3288_UOC0_CON3_BYPASSSEL			BIT(7)

> +

> +/*

> + * Enable the bypass of uart2 data through the otg usb phy.

> + * Original description in the TRM.

> + * 1. Disable the OTG block by setting OTGDISABLE0 to 1’b1.

> + * 2. Disable the pull-up resistance on the D+ line by setting

> + *    OPMODE0[1:0] to 2’b01.

> + * 3. To ensure that the XO, Bias, and PLL blocks are powered down in Suspend

> + *    mode, set COMMONONN to 1’b1.

> + * 4. Place the USB PHY in Suspend mode by setting SUSPENDM0 to 1’b0.

> + * 5. Set BYPASSSEL0 to 1’b1.

> + * 6. To transmit data, controls BYPASSDMEN0, and BYPASSDMDATA0.

> + * To receive data, monitor FSVPLUS0.

> + *

> + * The actual code in the vendor kernel does some things differently.

> + */

> +static int __init rk3288_init_usb_uart(struct regmap *grf)

> +{

> +	u32 val;

> +	int ret;

> +

> +	/*

> +	 * COMMON_ON and DISABLE settings are described in the TRM,

> +	 * but were not present in the original code.

> +	 * Also disable the analog phy components to save power.

> +	 */

> +	val = HIWORD_UPDATE(RK3288_UOC0_CON0_COMMON_ON_N

> +				| RK3288_UOC0_CON0_DISABLE

> +				| UOC_CON0_SIDDQ,

> +			    RK3288_UOC0_CON0_COMMON_ON_N

> +				| RK3288_UOC0_CON0_DISABLE

> +				| UOC_CON0_SIDDQ);

> +	ret = regmap_write(grf, RK3288_UOC0_CON0, val);

> +	if (ret)

> +		return ret;

> +

> +	val = HIWORD_UPDATE(RK3288_UOC0_CON2_SOFT_CON_SEL,

> +			    RK3288_UOC0_CON2_SOFT_CON_SEL);

> +	ret = regmap_write(grf, RK3288_UOC0_CON2, val);

> +	if (ret)

> +		return ret;

> +

> +	val = HIWORD_UPDATE(RK3288_UOC0_CON3_UTMI_OPMODE_NODRIVING

> +				| RK3288_UOC0_CON3_UTMI_XCVRSEELCT_FSTRANSC

> +				| RK3288_UOC0_CON3_UTMI_TERMSEL_FULLSPEED,

> +			    RK3288_UOC0_CON3_UTMI_SUSPENDN

> +				| RK3288_UOC0_CON3_UTMI_OPMODE_MASK

> +				| RK3288_UOC0_CON3_UTMI_XCVRSEELCT_MASK

> +				| RK3288_UOC0_CON3_UTMI_TERMSEL_FULLSPEED);

> +	ret = regmap_write(grf, RK3288_UOC0_CON3, val);

> +	if (ret)

> +		return ret;

> +

> +	val = HIWORD_UPDATE(RK3288_UOC0_CON3_BYPASSSEL

> +				| RK3288_UOC0_CON3_BYPASSDMEN,

> +			    RK3288_UOC0_CON3_BYPASSSEL

> +				| RK3288_UOC0_CON3_BYPASSDMEN);

> +	ret = regmap_write(grf, RK3288_UOC0_CON3, val);

> +	if (ret)

> +		return ret;

> +

> +	return 0;

> +}

> +

>  static const struct rockchip_usb_phy_pdata rk3288_pdata = {

>  	.phys = (struct rockchip_usb_phys[]){

>  		{ .reg = 0x320, .pll_name = "sclk_otgphy0_480m" },

> @@ -266,6 +371,8 @@ static const struct rockchip_usb_phy_pdata rk3288_pdata = {

>  		{ .reg = 0x348, .pll_name = "sclk_otgphy2_480m" },

>  		{ /* sentinel */ }

>  	},

> +	.init_usb_uart = rk3288_init_usb_uart,

> +	.usb_uart_phy = 0,

>  };

>  

>  static int rockchip_usb_phy_probe(struct platform_device *pdev)

> @@ -328,6 +435,60 @@ static struct platform_driver rockchip_usb_driver = {

>  

>  module_platform_driver(rockchip_usb_driver);

>  

> +#ifndef MODULE

> +static int __init rockchip_init_usb_uart(void)

> +{

> +	const struct of_device_id *match;

> +	const struct rockchip_usb_phy_pdata *data;

> +	struct device_node *np;

> +	struct regmap *grf;

> +	int ret;

> +

> +	if (!enable_usb_uart)

> +		return 0;

> +

> +	np = of_find_matching_node_and_match(NULL, rockchip_usb_phy_dt_ids,

> +					     &match);

> +	if (!np) {

> +		pr_err("%s: failed to find usbphy node\n", __func__);

> +		return -ENOTSUPP;

> +	}

> +

> +	pr_debug("%s: using settings for %s\n", __func__, match->compatible);

> +	data = match->data;

> +

> +	if (!data->init_usb_uart) {

> +		pr_err("%s: usb-uart not available on %s\n",

> +		       __func__, match->compatible);

> +		return -ENOTSUPP;

> +	}

> +

> +	grf = syscon_regmap_lookup_by_phandle(np, "rockchip,grf");

> +	if (IS_ERR(grf)) {

> +		pr_err("%s: Missing rockchip,grf property, %lu\n",

> +		       __func__, PTR_ERR(grf));

> +		return PTR_ERR(grf);

> +	}

> +

> +	ret = data->init_usb_uart(grf);

> +	if (ret) {

> +		pr_err("%s: could not init usb_uart, %d\n", __func__, ret);

> +		enable_usb_uart = 0;

> +		return ret;

> +	}

> +

> +	return 0;

> +}

> +early_initcall(rockchip_init_usb_uart);

> +

> +static int __init rockchip_usb_uart(char *buf)

> +{

> +	enable_usb_uart = true;

> +	return 0;

> +}

> +early_param("rockchip.usb_uart", rockchip_usb_uart);

> +#endif

> +

>  MODULE_AUTHOR("Yunzhi Li <lyz@rock-chips.com>");

>  MODULE_DESCRIPTION("Rockchip USB 2.0 PHY driver");

>  MODULE_LICENSE("GPL v2");

>
diff mbox

Patch

diff --git a/drivers/phy/phy-rockchip-usb.c b/drivers/phy/phy-rockchip-usb.=
c
index 33a80eb..f62d899 100644
--- a/drivers/phy/phy-rockchip-usb.c
+++ b/drivers/phy/phy-rockchip-usb.c
@@ -30,21 +30,23 @@ 
 #include <linux/regmap.h>
 #include <linux/mfd/syscon.h>
=20
-/*
- * The higher 16-bit of this register is used for write protection
- * only if BIT(13 + 16) set to 1 the BIT(13) can be written.
- */
-#define SIDDQ_WRITE_ENA        BIT(29)
-#define SIDDQ_ON               BIT(13)
-#define SIDDQ_OFF              (0 << 13)
+static int enable_usb_uart;
+
+#define HIWORD_UPDATE(val, mask) \
+               ((val) | (mask) << 16)
+
+#define UOC_CON0_SIDDQ BIT(13)
=20
 struct rockchip_usb_phys {
        int reg;
        const char *pll_name;
 };
=20
<snip>
.
.

I didn't see this problem with the other patches I applied today.

Thanks
Kishon