From: Douglas Anderson <dianders@chromium.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
John Youn <johnyoun@synopsys.com>, Felipe Balbi <balbi@ti.com>
Cc: linux-usb@vger.kernel.org, Chris Zhong <zyw@rock-chips.com>,
Heiko Stuebner <heiko@sntech.de>,
Julius Werner <jwerner@chromium.org>,
Andrew Bresticker <abrestic@chromium.org>,
Alexandru Stan <amstan@chromium.org>,
lyz@rock-chips.com, linux-rockchip@lists.infradead.org,
Douglas Anderson <dianders@chromium.org>,
linux-kernel@vger.kernel.org
Subject: [REPOST PATCH 3/3] USB: dwc2: Don't turn off the usbphy in suspend if wakeup is enabled
Date: Mon, 6 Jul 2015 11:27:04 -0700 [thread overview]
Message-ID: <1436207224-21849-4-git-send-email-dianders@chromium.org> (raw)
In-Reply-To: <1436207224-21849-1-git-send-email-dianders@chromium.org>
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
next prev parent reply other threads:[~2015-07-06 18:28 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-06 18:27 [REPOST PATCH 0/3] dwc2 patches to allow wakeup on Rockchip rk3288 Douglas Anderson
2015-07-06 18:27 ` [REPOST PATCH 1/3] USB: Export usb_wakeup_enabled_descendants() Douglas Anderson
2015-07-06 18:27 ` [REPOST PATCH 2/3] Documentation: dt-bindings: Add snps,need-phy-for-wake for dwc2 USB Douglas Anderson
2015-07-06 18:27 ` Douglas Anderson [this message]
2015-07-06 18:34 ` [REPOST PATCH 3/3] USB: dwc2: Don't turn off the usbphy in suspend if wakeup is enabled Felipe Balbi
2015-07-06 19:32 ` Doug Anderson
2015-07-06 19:35 ` Felipe Balbi
2015-07-06 18:58 ` Alan Stern
2015-07-06 19:02 ` Felipe Balbi
2015-07-06 19:39 ` Doug Anderson
2015-07-07 14:28 ` Alan Stern
2015-07-08 0:06 ` Julius Werner
2015-07-08 15:01 ` Alan Stern
2015-07-08 19:41 ` Julius Werner
2015-07-08 19:58 ` Alan Stern
2015-10-21 16:23 ` [REPOST PATCH 0/3] dwc2 patches to allow wakeup on Rockchip rk3288 Doug Anderson
2015-10-27 2:05 ` John Youn
2015-10-31 0:01 ` Doug Anderson
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