Commit c846b03f authored by Douglas Anderson's avatar Douglas Anderson Committed by Felipe Balbi
Browse files

USB: dwc2: Don't turn off the usbphy in suspend if wakeup is enabled 



If the 'snps,need-phy-for-wake' is set in the device tree then:

- We know that we can wakeup, so call device_set_wakeup_capable().
  The USB core will use this knowledge to enable wakeup by default.
- We know that we should keep the PHY on during suspend if something
  on our root hub needs remote wakeup.  This requires the patch (USB:
  Export usb_wakeup_enabled_descendants()).  Note that we don't keep
  the PHY on at suspend time if it's not needed because it would be a
  power draw.

If we later find some users of dwc2 that can support wakeup without
keeping the PHY on we may want to add a way to call
device_set_wakeup_capable() without keeping the PHY on at suspend
time.

Signed-off-by: default avatarDouglas Anderson <dianders@chromium.org>
Signed-off-by: default avatarChris Zhong <zyw@rock-chips.com>
Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
parent 1d390437

drivers/usb/dwc2/core.h

+8 −0
Original line number Diff line number Diff line
@@ -861,6 +861,9 @@ struct dwc2_hregs_backup { 
 * @hibernated:		True if core is hibernated

 * @reset_phy_on_wake:	Quirk saying that we should assert PHY reset on a

 *			remote wakeup.

 * @phy_off_for_suspend: Status of whether we turned the PHY off at suspend.

 * @need_phy_for_wake:	Quirk saying that we should keep the PHY on at

 *			suspend if we need USB to wake us up.

 * @frame_number:       Frame number read from the core. For both device

 *			and host modes. The value ranges are from 0

 *			to HFNUM_MAX_FRNUM.
@@ -1049,6 +1052,8 @@ struct dwc2_hsotg { 
	unsigned int ll_hw_enabled:1;

	unsigned int hibernated:1;

	unsigned int reset_phy_on_wake:1;

	unsigned int need_phy_for_wake:1;

	unsigned int phy_off_for_suspend:1;

	u16 frame_number;



	struct phy *phy;
@@ -1438,6 +1443,7 @@ int dwc2_restore_host_registers(struct dwc2_hsotg *hsotg); 
int dwc2_host_enter_hibernation(struct dwc2_hsotg *hsotg);

int dwc2_host_exit_hibernation(struct dwc2_hsotg *hsotg,

			       int rem_wakeup, int reset);

bool dwc2_host_can_poweroff_phy(struct dwc2_hsotg *dwc2);

static inline void dwc2_host_schedule_phy_reset(struct dwc2_hsotg *hsotg)

{ schedule_work(&hsotg->phy_reset_work); }

#else
@@ -1463,6 +1469,8 @@ static inline int dwc2_host_enter_hibernation(struct dwc2_hsotg *hsotg) 
static inline int dwc2_host_exit_hibernation(struct dwc2_hsotg *hsotg,

					     int rem_wakeup, int reset)

{ return 0; }

static inline bool dwc2_host_can_poweroff_phy(struct dwc2_hsotg *dwc2)

{ return false; }

static inline void dwc2_host_schedule_phy_reset(struct dwc2_hsotg *hsotg) {}



#endif

drivers/usb/dwc2/hcd.c

+19 −0
Original line number Diff line number Diff line
@@ -5587,3 +5587,22 @@ int dwc2_host_exit_hibernation(struct dwc2_hsotg *hsotg, int rem_wakeup, 
	dev_dbg(hsotg->dev, "Host hibernation restore complete\n");

	return ret;

}



bool dwc2_host_can_poweroff_phy(struct dwc2_hsotg *dwc2)

{

	struct usb_device *root_hub = dwc2_hsotg_to_hcd(dwc2)->self.root_hub;



	/* If the controller isn't allowed to wakeup then we can power off. */

	if (!device_may_wakeup(dwc2->dev))

		return true;



	/*

	 * We don't want to power off the PHY if something under the

	 * root hub has wakeup enabled.

	 */

	if (usb_wakeup_enabled_descendants(root_hub))

		return false;



	/* No reason to keep the PHY powered, so allow poweroff */

	return true;

}

drivers/usb/dwc2/platform.c

+20 −3
Original line number Diff line number Diff line
@@ -447,6 +447,10 @@ static int dwc2_driver_probe(struct platform_device *dev) 
	if (retval)

		goto error;



	hsotg->need_phy_for_wake =

		of_property_read_bool(dev->dev.of_node,

				      "snps,need-phy-for-wake");



	/*

	 * Reset before dwc2_get_hwparams() then it could get power-on real

	 * reset value form registers.
@@ -478,6 +482,14 @@ static int dwc2_driver_probe(struct platform_device *dev) 
		hsotg->gadget_enabled = 1;

	}



	/*

	 * If we need PHY for wakeup we must be wakeup capable.

	 * When we have a device that can wake without the PHY we

	 * can adjust this condition.

	 */

	if (hsotg->need_phy_for_wake)

		device_set_wakeup_capable(&dev->dev, true);



	hsotg->reset_phy_on_wake =

		of_property_read_bool(dev->dev.of_node,

				      "snps,reset-phy-on-wake");
@@ -516,13 +528,17 @@ error: 
static int __maybe_unused dwc2_suspend(struct device *dev)

{

	struct dwc2_hsotg *dwc2 = dev_get_drvdata(dev);

	bool is_device_mode = dwc2_is_device_mode(dwc2);

	int ret = 0;



	if (dwc2_is_device_mode(dwc2))

	if (is_device_mode)

		dwc2_hsotg_suspend(dwc2);



	if (dwc2->ll_hw_enabled)

	if (dwc2->ll_hw_enabled &&

	    (is_device_mode || dwc2_host_can_poweroff_phy(dwc2))) {

		ret = __dwc2_lowlevel_hw_disable(dwc2);

		dwc2->phy_off_for_suspend = true;

	}



	return ret;

}
@@ -532,11 +548,12 @@ static int __maybe_unused dwc2_resume(struct device *dev) 
	struct dwc2_hsotg *dwc2 = dev_get_drvdata(dev);

	int ret = 0;



	if (dwc2->ll_hw_enabled) {

	if (dwc2->phy_off_for_suspend && dwc2->ll_hw_enabled) {

		ret = __dwc2_lowlevel_hw_enable(dwc2);

		if (ret)

			return ret;

	}

	dwc2->phy_off_for_suspend = false;



	if (dwc2_is_device_mode(dwc2))

		ret = dwc2_hsotg_resume(dwc2);

CRA Git | Maintained and supported by SUSTech CRA and CCSE