From mboxrd@z Thu Jan 1 00:00:00 1970 From: Douglas Anderson Subject: [PATCH v2 4/5] USB: dwc2: Don't turn off the usbphy in suspend if wakeup is enabled Date: Wed, 17 Apr 2019 17:13:55 -0700 Message-ID: <20190418001356.124334-5-dianders@chromium.org> References: <20190418001356.124334-1-dianders@chromium.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190418001356.124334-1-dianders@chromium.org> Sender: linux-kernel-owner@vger.kernel.org To: Minas Harutyunyan , Felipe Balbi , heiko@sntech.de Cc: Alan Stern , Artur Petrosyan , amstan@chromium.org, linux-rockchip@lists.infradead.org, William Wu , linux-usb@vger.kernel.org, Stefan Wahren , Randy Li , zyw@rock-chips.com, mka@chromium.org, ryandcase@chromium.org, Amelie Delaunay , jwerner@chromium.org, dinguyen@opensource.altera.com, Elaine Zhang , Douglas Anderson , Greg Kroah-Hartman , linux-kernel@vger.kernel.org List-Id: linux-rockchip.vger.kernel.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: Douglas Anderson Signed-off-by: Chris Zhong --- For relevant prior discussion of this idea, see: https://lkml.kernel.org/r/1436207224-21849-4-git-send-email-dianders@chromium.org If I'm reading all the responses correctly folks were of the opinion that this patch is still the right way to go. Changes in v2: - Rebased to mainline atop rk3288 remote wake quirk series. drivers/usb/dwc2/core.h | 5 +++++ drivers/usb/dwc2/platform.c | 43 +++++++++++++++++++++++++++++++++++-- 2 files changed, 46 insertions(+), 2 deletions(-) diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h index f30748f4fe7e..a99fe7851352 100644 --- a/drivers/usb/dwc2/core.h +++ b/drivers/usb/dwc2/core.h @@ -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; diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c index 9b65b766e0b9..6f0271c5d163 100644 --- a/drivers/usb/dwc2/platform.c +++ b/drivers/usb/dwc2/platform.c @@ -47,7 +47,9 @@ #include #include #include +#include +#include #include #include "core.h" @@ -450,6 +452,10 @@ 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. @@ -481,6 +487,14 @@ 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"); @@ -516,6 +530,28 @@ 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->ll_hw_enabled) + 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); @@ -524,8 +560,10 @@ static int __maybe_unused dwc2_suspend(struct device *dev) if (dwc2_is_device_mode(dwc2)) dwc2_hsotg_suspend(dwc2); - if (dwc2->ll_hw_enabled) + if (dwc2_can_poweroff_phy(dwc2)) { ret = __dwc2_lowlevel_hw_disable(dwc2); + dwc2->phy_off_for_suspend = true; + } return ret; } @@ -535,11 +573,12 @@ 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); -- 2.21.0.593.g511ec345e18-goog