diff mbox series

[06/12] usb: dwc3: qcom: Add dwc3 core reference in driver state

Message ID 20231016-dwc3-refactor-v1-6-ab4a84165470@quicinc.com
State New
Headers show
Series usb: dwc3: qcom: Flatten dwc3 structure | expand

Commit Message

Bjorn Andersson Oct. 17, 2023, 3:11 a.m. UTC 
In the coming changes the Qualcomm DWC3 glue will be able to either
manage the DWC3 core as a child platform_device, or directly instantiate
it within its own context.

Introduce a reference to the dwc3 core state and make the driver
reference the dwc3 core either the child device or this new reference.

As the new member isn't assigned, and qcom->dwc_dev is assigned in all
current cases, the change should have no functional impact.

Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
---
 drivers/usb/dwc3/dwc3-qcom.c | 100 +++++++++++++++++++++++++++++++++++--------
 1 file changed, 83 insertions(+), 17 deletions(-)

Comments

Bjorn Andersson Jan. 8, 2024, 6:02 p.m. UTC | #1 
On Wed, Nov 22, 2023 at 01:18:33PM +0100, Johan Hovold wrote:
> On Mon, Oct 16, 2023 at 08:11:14PM -0700, Bjorn Andersson wrote:
> > In the coming changes the Qualcomm DWC3 glue will be able to either
> > manage the DWC3 core as a child platform_device, or directly instantiate
> > it within its own context.
> > 
> > Introduce a reference to the dwc3 core state and make the driver
> > reference the dwc3 core either the child device or this new reference.
> > 
> > As the new member isn't assigned, and qcom->dwc_dev is assigned in all
> > current cases, the change should have no functional impact.
> > 
> > Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
> > ---
> >  drivers/usb/dwc3/dwc3-qcom.c | 100 +++++++++++++++++++++++++++++++++++--------
> >  1 file changed, 83 insertions(+), 17 deletions(-)
> > 
> > diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> > index 7c810712d246..901e5050363b 100644
> > --- a/drivers/usb/dwc3/dwc3-qcom.c
> > +++ b/drivers/usb/dwc3/dwc3-qcom.c
> > @@ -67,7 +67,8 @@ struct dwc3_acpi_pdata {
> >  struct dwc3_qcom {
> >  	struct device		*dev;
> >  	void __iomem		*qscratch_base;
> > -	struct platform_device	*dwc_dev;
> > +	struct platform_device	*dwc_dev; /* only used when core is separate device */
> > +	struct dwc3		*dwc; /* not used when core is separate device */
> 
> Hmm. This quickly become really messy and hard to maintain. It may be
> fine as an intermediate step as part of this series, but why can't you
> do the conversion fully so that the Qualcomm glue driver never registers
> a core platform device? Is it just about where the core driver looks for
> DT properties?
> 

In the new driver model, pdev->dev.of_node needs to contain the
resources for both the glue and the core. For most of the information,
that's a matter of copying properties and child nodes from the child
of_node, but e.g. reg and interrupts needs to be merged.

As mentioned in my other reply, extcon is serviced to both nodes, so
without the callbacks that will break, at least - and I'd have to check
to see if the of_graphs can be handled...


That said, part of the reason for doing this shuffle is to make sure
that dwc is always a valid pointer, and while keeping this scheme of two
modes we will not be able to assume this anywhere in the code - and
hence continue to rely on luck.

One way around this would be to follow the of_platform_populate() with a
check to see if the core was registered and if so grab the dwc pointer,
otherwise of_platform_depopulate() the core again and probe defer.

It will come with a penalty for devices running on the old binding, and
we don't protect ourselves from the core being unbound while we're
holding a pointer to its internal data. But it looks like a much better
position to me.

(In this case I think dwc_dev becomes a local variable using during
probe, and the rest of the code would operate on dwc)

Regards,
Bjorn
diff mbox series

Patch

diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
index 7c810712d246..901e5050363b 100644
--- a/drivers/usb/dwc3/dwc3-qcom.c
+++ b/drivers/usb/dwc3/dwc3-qcom.c
@@ -67,7 +67,8 @@  struct dwc3_acpi_pdata {
 struct dwc3_qcom {
 	struct device		*dev;
 	void __iomem		*qscratch_base;
-	struct platform_device	*dwc_dev;
+	struct platform_device	*dwc_dev; /* only used when core is separate device */
+	struct dwc3		*dwc; /* not used when core is separate device */
 	struct clk		**clks;
 	int			num_clocks;
 	struct reset_control	*resets;
@@ -263,7 +264,11 @@  static int dwc3_qcom_interconnect_init(struct dwc3_qcom *qcom)
 		goto put_path_ddr;
 	}
 
-	max_speed = usb_get_maximum_speed(&qcom->dwc_dev->dev);
+	if (qcom->dwc_dev)
+		max_speed = usb_get_maximum_speed(&qcom->dwc_dev->dev);
+	else
+		max_speed = usb_get_maximum_speed(qcom->dev);
+
 	if (max_speed >= USB_SPEED_SUPER || max_speed == USB_SPEED_UNKNOWN) {
 		ret = icc_set_bw(qcom->icc_path_ddr,
 				USB_MEMORY_AVG_SS_BW, USB_MEMORY_PEAK_SS_BW);
@@ -311,7 +316,10 @@  static bool dwc3_qcom_is_host(struct dwc3_qcom *qcom)
 	/*
 	 * FIXME: Fix this layering violation.
 	 */
-	dwc = platform_get_drvdata(qcom->dwc_dev);
+	if (qcom->dwc_dev)
+		dwc = platform_get_drvdata(qcom->dwc_dev);
+	else
+		dwc = qcom->dwc;
 
 	/* Core driver may not have probed yet. */
 	if (!dwc)
@@ -322,10 +330,14 @@  static bool dwc3_qcom_is_host(struct dwc3_qcom *qcom)
 
 static enum usb_device_speed dwc3_qcom_read_usb2_speed(struct dwc3_qcom *qcom)
 {
-	struct dwc3 *dwc = platform_get_drvdata(qcom->dwc_dev);
 	struct usb_device *udev;
 	struct usb_hcd __maybe_unused *hcd;
+	struct dwc3 *dwc;
 
+	if (qcom->dwc_dev)
+		dwc = platform_get_drvdata(qcom->dwc_dev);
+	else
+		dwc = qcom->dwc;
 	/*
 	 * FIXME: Fix this layering violation.
 	 */
@@ -485,12 +497,17 @@  static int dwc3_qcom_resume(struct dwc3_qcom *qcom, bool wakeup)
 static irqreturn_t qcom_dwc3_resume_irq(int irq, void *data)
 {
 	struct dwc3_qcom *qcom = data;
-	struct dwc3	*dwc = platform_get_drvdata(qcom->dwc_dev);
+	struct dwc3	*dwc;
 
 	/* If pm_suspended then let pm_resume take care of resuming h/w */
 	if (qcom->pm_suspended)
 		return IRQ_HANDLED;
 
+	if (qcom->dwc_dev)
+		dwc = platform_get_drvdata(qcom->dwc_dev);
+	else
+		dwc = qcom->dwc;
+
 	/*
 	 * This is safe as role switching is done from a freezable workqueue
 	 * and the wakeup interrupts are disabled as part of resume.
@@ -936,25 +953,33 @@  static int dwc3_qcom_probe(struct platform_device *pdev)
 	if (ret)
 		goto depopulate;
 
-	qcom->mode = usb_get_dr_mode(&qcom->dwc_dev->dev);
+	if (qcom->dwc_dev)
+		qcom->mode = usb_get_dr_mode(&qcom->dwc_dev->dev);
+	else
+		qcom->mode = usb_get_dr_mode(dev);
 
 	/* enable vbus override for device mode */
 	if (qcom->mode != USB_DR_MODE_HOST)
 		dwc3_qcom_vbus_override_enable(qcom, true);
 
-	/* register extcon to override sw_vbus on Vbus change later */
-	ret = dwc3_qcom_register_extcon(qcom);
-	if (ret)
-		goto interconnect_exit;
+	if (qcom->dwc_dev) {
+		/* register extcon to override sw_vbus on Vbus change later */
+		ret = dwc3_qcom_register_extcon(qcom);
+		if (ret)
+			goto interconnect_exit;
+	}
 
 	wakeup_source = of_property_read_bool(dev->of_node, "wakeup-source");
 	device_init_wakeup(&pdev->dev, wakeup_source);
-	device_init_wakeup(&qcom->dwc_dev->dev, wakeup_source);
+	if (qcom->dwc_dev)
+		device_init_wakeup(&qcom->dwc_dev->dev, wakeup_source);
 
 	qcom->is_suspended = false;
-	pm_runtime_set_active(dev);
-	pm_runtime_enable(dev);
-	pm_runtime_forbid(dev);
+	if (qcom->dwc_dev) {
+		pm_runtime_set_active(dev);
+		pm_runtime_enable(dev);
+		pm_runtime_forbid(dev);
+	}
 
 	return 0;
 
@@ -983,6 +1008,9 @@  static void dwc3_qcom_remove(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	int i;
 
+	if (qcom->dwc)
+		dwc3_remove(qcom->dwc);
+
 	device_remove_software_node(&qcom->dwc_dev->dev);
 	if (np)
 		of_platform_depopulate(&pdev->dev);
@@ -998,8 +1026,10 @@  static void dwc3_qcom_remove(struct platform_device *pdev)
 	dwc3_qcom_interconnect_exit(qcom);
 	reset_control_assert(qcom->resets);
 
-	pm_runtime_allow(dev);
-	pm_runtime_disable(dev);
+	if (qcom->dwc_dev) {
+		pm_runtime_allow(dev);
+		pm_runtime_disable(dev);
+	}
 }
 
 static int __maybe_unused dwc3_qcom_pm_suspend(struct device *dev)
@@ -1008,6 +1038,12 @@  static int __maybe_unused dwc3_qcom_pm_suspend(struct device *dev)
 	bool wakeup = device_may_wakeup(dev);
 	int ret;
 
+	if (qcom->dwc) {
+		ret = dwc3_suspend(qcom->dwc);
+		if (ret)
+			return ret;
+	}
+
 	ret = dwc3_qcom_suspend(qcom, wakeup);
 	if (ret)
 		return ret;
@@ -1029,12 +1065,33 @@  static int __maybe_unused dwc3_qcom_pm_resume(struct device *dev)
 
 	qcom->pm_suspended = false;
 
+	if (qcom->dwc) {
+		ret = dwc3_resume(qcom->dwc);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 
+static void dwc3_qcom_complete(struct device *dev)
+{
+	struct dwc3_qcom *qcom = dev_get_drvdata(dev);
+
+	if (qcom->dwc)
+		dwc3_complete(qcom->dwc);
+}
+
 static int __maybe_unused dwc3_qcom_runtime_suspend(struct device *dev)
 {
 	struct dwc3_qcom *qcom = dev_get_drvdata(dev);
+	int ret;
+
+	if (qcom->dwc) {
+		ret = dwc3_runtime_suspend(qcom->dwc);
+		if (ret)
+			return ret;
+	}
 
 	return dwc3_qcom_suspend(qcom, true);
 }
@@ -1042,12 +1099,21 @@  static int __maybe_unused dwc3_qcom_runtime_suspend(struct device *dev)
 static int __maybe_unused dwc3_qcom_runtime_resume(struct device *dev)
 {
 	struct dwc3_qcom *qcom = dev_get_drvdata(dev);
+	int ret;
+
+	ret = dwc3_qcom_resume(qcom, true);
+	if (ret)
+		return ret;
 
-	return dwc3_qcom_resume(qcom, true);
+	if (qcom->dwc)
+		return dwc3_runtime_resume(qcom->dwc);
+
+	return 0;
 }
 
 static const struct dev_pm_ops dwc3_qcom_dev_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(dwc3_qcom_pm_suspend, dwc3_qcom_pm_resume)
+	.complete = dwc3_qcom_complete,
 	SET_RUNTIME_PM_OPS(dwc3_qcom_runtime_suspend, dwc3_qcom_runtime_resume,
 			   NULL)
 };