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: Chris Zhong <zyw@xxxxxxxxxxxxxx>
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---
drivers/usb/dwc2/core.h | 2 ++
drivers/usb/dwc2/platform.c | 45 +++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 45 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index 53b8de0..b60a1e8 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -687,6 +687,8 @@ struct dwc2_hsotg {
enum usb_dr_mode dr_mode;
unsigned int hcd_enabled:1;
unsigned int gadget_enabled:1;
+ unsigned int need_phy_for_wake:1;
+ unsigned int phy_off_for_suspend:1;
struct phy *phy;
struct usb_phy *uphy;
diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 9093530..38fce75 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -42,7 +42,9 @@
#include <linux/of_device.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
#include <linux/usb/of.h>
#include "core.h"
@@ -222,6 +224,10 @@ static int dwc2_driver_probe(struct platform_device *dev)
hsotg->dr_mode = of_usb_get_dr_mode(dev->dev.of_node);
+ hsotg->need_phy_for_wake =
+ of_property_read_bool(dev->dev.of_node,
+ "snps,need-phy-for-wake");
+
/*
* Attempt to find a generic PHY, then look for an old style
* USB PHY
@@ -265,6 +271,14 @@ 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);
+
if (hsotg->dr_mode != USB_DR_MODE_PERIPHERAL) {
retval = dwc2_hcd_init(hsotg, irq);
if (retval) {
@@ -282,6 +296,28 @@ static int dwc2_driver_probe(struct platform_device *dev)
return retval;
}
+static bool __maybe_unused dwc2_can_poweroff_phy(struct dwc2_hsotg *dwc2)
+{
+ struct usb_device *root_hub = dwc2_hsotg_to_hcd(dwc2)->self.root_hub;
+
+ if (dwc2->lx_state == DWC2_L0)
+ return false;
+
+ /* 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;
+}
+
static int __maybe_unused dwc2_suspend(struct device *dev)
{
struct dwc2_hsotg *dwc2 = dev_get_drvdata(dev);
@@ -290,8 +326,10 @@ static int __maybe_unused dwc2_suspend(struct device *dev)
if (dwc2_is_device_mode(dwc2)) {
ret = s3c_hsotg_suspend(dwc2);
} else {
- if (dwc2->lx_state == DWC2_L0)
+ if (!dwc2_can_poweroff_phy(dwc2))
return 0;
+
+ dwc2->phy_off_for_suspend = true;
phy_exit(dwc2->phy);
phy_power_off(dwc2->phy);
@@ -307,9 +345,12 @@ static int __maybe_unused dwc2_resume(struct device *dev)
if (dwc2_is_device_mode(dwc2)) {
ret = s3c_hsotg_resume(dwc2);
} else {
+ if (!dwc2->phy_off_for_suspend)
+ return ret;
+
phy_power_on(dwc2->phy);
phy_init(dwc2->phy);
-
+ dwc2->phy_off_for_suspend = false;
}
return ret;
}
--
2.4.3.573.g4eafbef
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