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[PATCH 0/3] dwc2 patches to allow wakeup on Rockchip rk3288

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  [PATCH 0/3] dwc2 patches to allow wakeup on Rockchip rk3288 Douglas Anderson <dianders@chromium.org> - 2015-06-23 02:00 +0200
    [PATCH 3/3] USB: dwc2: Don't turn off the usbphy in suspend if wakeup is enabled Douglas Anderson <dianders@chromium.org> - 2015-06-23 02:00 +0200
    [PATCH 2/3] Documentation: dt-bindings: Add snps,need-phy-for-wake for dwc2 USB Douglas Anderson <dianders@chromium.org> - 2015-06-23 02:00 +0200
    [PATCH 1/3] USB: Export usb_wakeup_enabled_descendants() Douglas Anderson <dianders@chromium.org> - 2015-06-23 02:00 +0200

#1170297 — [PATCH 0/3] dwc2 patches to allow wakeup on Rockchip rk3288

This series of patches, together with
<https://patchwork.kernel.org/patch/6652341/> from Chris Zhong and a
dts change allow us to wake up from a USB device on rk3288 boards.
The patches were tested on rk3288-jerry in the chromeos-3.14 kernel.
The chromeos-3.14 kernel tested included a full set of dwc2 backports
from upstream, so this is expected to function upstream once we get
everything setup there.


Douglas Anderson (3):
  USB: Export usb_wakeup_enabled_descendants()
  Documentation: dt-bindings: Add snps,need-phy-for-wake for dwc2 USB
  USB: dwc2: Don't turn off the usbphy in suspend if wakeup is enabled

 Documentation/devicetree/bindings/usb/dwc2.txt |  4 +++
 drivers/usb/core/hub.c                         |  7 ++--
 drivers/usb/dwc2/core.h                        |  2 ++
 drivers/usb/dwc2/platform.c                    | 45 ++++++++++++++++++++++++--
 include/linux/usb/hcd.h                        |  5 +++
 5 files changed, 58 insertions(+), 5 deletions(-)

-- 
2.4.3.573.g4eafbef

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#1170298 — [PATCH 3/3] 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: Chris Zhong <zyw@rock-chips.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
 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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#1170300 — [PATCH 2/3] Documentation: dt-bindings: Add snps,need-phy-for-wake for dwc2 USB

Some SoCs with a dwc2 USB controller may need to keep the PHY on to
support remote wakeup.  Allow specifying this as a device tree
property.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
 Documentation/devicetree/bindings/usb/dwc2.txt | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/dwc2.txt b/Documentation/devicetree/bindings/usb/dwc2.txt
index fd132cb..84d258d 100644
--- a/Documentation/devicetree/bindings/usb/dwc2.txt
+++ b/Documentation/devicetree/bindings/usb/dwc2.txt
@@ -17,6 +17,9 @@ Refer to clk/clock-bindings.txt for generic clock consumer properties
 Optional properties:
 - phys: phy provider specifier
 - phy-names: shall be "usb2-phy"
+- snps,need-phy-for-wake: if present indicates that the phy needs to be left
+  on for remote wakeup during suspend.
+
 Refer to phy/phy-bindings.txt for generic phy consumer properties
 - dr_mode: shall be one of "host", "peripheral" and "otg"
   Refer to usb/generic.txt
@@ -35,4 +38,5 @@ Example:
 		clock-names = "otg";
 		phys = <&usbphy>;
 		phy-names = "usb2-phy";
+		snps,need-phy-for-wake;
         };
-- 
2.4.3.573.g4eafbef

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#1170303 — [PATCH 1/3] USB: Export usb_wakeup_enabled_descendants()

In (e583d9d USB: global suspend and remote wakeup don't mix) we
introduced wakeup_enabled_descendants() as a static function.  We'd
like to use this function in USB controller drivers to know if we
should keep the controller on during suspend time, since doing so has
a power impact.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
 drivers/usb/core/hub.c  | 7 ++++---
 include/linux/usb/hcd.h | 5 +++++
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 43cb2f2..fdc59db 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3034,13 +3034,14 @@ static int usb_disable_remote_wakeup(struct usb_device *udev)
 }
 
 /* Count of wakeup-enabled devices at or below udev */
-static unsigned wakeup_enabled_descendants(struct usb_device *udev)
+unsigned usb_wakeup_enabled_descendants(struct usb_device *udev)
 {
 	struct usb_hub *hub = usb_hub_to_struct_hub(udev);
 
 	return udev->do_remote_wakeup +
 			(hub ? hub->wakeup_enabled_descendants : 0);
 }
+EXPORT_SYMBOL_GPL(usb_wakeup_enabled_descendants);
 
 /*
  * usb_port_suspend - suspend a usb device's upstream port
@@ -3149,7 +3150,7 @@ int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 	 * Therefore we will turn on the suspend feature if udev or any of its
 	 * descendants is enabled for remote wakeup.
 	 */
-	else if (PMSG_IS_AUTO(msg) || wakeup_enabled_descendants(udev) > 0)
+	else if (PMSG_IS_AUTO(msg) || usb_wakeup_enabled_descendants(udev) > 0)
 		status = set_port_feature(hub->hdev, port1,
 				USB_PORT_FEAT_SUSPEND);
 	else {
@@ -3548,7 +3549,7 @@ static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
 		}
 		if (udev)
 			hub->wakeup_enabled_descendants +=
-					wakeup_enabled_descendants(udev);
+					usb_wakeup_enabled_descendants(udev);
 	}
 
 	if (hdev->do_remote_wakeup && hub->quirk_check_port_auto_suspend) {
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index c9aa779..30d74c9 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -626,11 +626,16 @@ extern wait_queue_head_t usb_kill_urb_queue;
 #define usb_endpoint_out(ep_dir)	(!((ep_dir) & USB_DIR_IN))
 
 #ifdef CONFIG_PM
+extern unsigned usb_wakeup_enabled_descendants(struct usb_device *udev);
 extern void usb_root_hub_lost_power(struct usb_device *rhdev);
 extern int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg);
 extern int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg);
 extern void usb_hcd_resume_root_hub(struct usb_hcd *hcd);
 #else
+static inline unsigned usb_wakeup_enabled_descendants(struct usb_device *udev)
+{
+	return 0;
+}
 static inline void usb_hcd_resume_root_hub(struct usb_hcd *hcd)
 {
 	return;
-- 
2.4.3.573.g4eafbef

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