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 <diand...@chromium.org> Signed-off-by: Chris Zhong <z...@rock-chips.com> --- For relevant prior discussion of this idea, see: https://lkml.kernel.org/r/1436207224-21849-4-git-send-email-diand...@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 152ac41dfb2d..73c1e998f27a 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 d10a7f8daec3..31be644d1273 100644 --- a/drivers/usb/dwc2/platform.c +++ b/drivers/usb/dwc2/platform.c @@ -47,7 +47,9 @@ #include <linux/phy/phy.h> #include <linux/platform_data/s3c-hsotg.h> #include <linux/reset.h> +#include <linux/usb.h> +#include <linux/usb/hcd.h> #include <linux/usb/of.h> #include "core.h" @@ -447,6 +449,10 @@ 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 +484,14 @@ 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"); @@ -513,6 +527,28 @@ 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); @@ -521,8 +557,10 @@ 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; } @@ -532,11 +570,12 @@ 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); -- 2.21.0.1020.gf2820cf01a-goog
