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

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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: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Chris Zhong <zyw@rock-chips.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
Douglas Anderson 2019-05-20 10:56:04 -07:00 committed by Felipe Balbi
parent 1d390437f6
commit c846b03ff7
3 changed files with 47 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/usb/dwc2/core.h
View File

@ -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

19
drivers/usb/dwc2/hcd.c
View File

@ -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;
}

23
drivers/usb/dwc2/platform.c
View File

@ -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);