Hi,
On Wed, Dec 18, 2013 at 06:52:09PM +0530, George Cherian wrote:
> USB remote wakeup using PHY wakeup is supported only in standby mode.
> Enabling the PHY_WKUP will break DS0 mode of system suspend.
> If the same is enabled while entering DS0, AM33xx never stays in DS0,
> it returns immediately from DS0. By default make the PHY wakeup
> disabled, using sysfs entry enable the same manually to get
> the remote wakeup working from standby.
>
> echo enabled > /sys/bus/platform/device/<usb phy id>/power/wakeup
> This will enable the PHY wakeup while going to standby.
>
> PHY wakeup feature is required to wakeup the system from standby
> state. Since AM33xx has a bug in which PHY wakeup should not
> be enabled while entering DS0, disable the same by default.
> A user wishing to use USB wakeup from standby mode need to enable
> the same using the sysfs entries.
>
> Also remove am335x_phy_runtime_(suspend/resume) this driver doesnot really
> enable/disable the clocks to the PHY.
> Add am335x_phy_(suspend/resume) and use the same for enabling the PHY_WKUP.
>
> Signed-off-by: George Cherian <george.cherian@xxxxxx>
> ---
> drivers/usb/phy/phy-am335x.c | 46 +++++++++++++++++++++++++++++++++-----------
> 1 file changed, 35 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/usb/phy/phy-am335x.c b/drivers/usb/phy/phy-am335x.c
> index 6370e50..3f78eaf 100644
> --- a/drivers/usb/phy/phy-am335x.c
> +++ b/drivers/usb/phy/phy-am335x.c
> @@ -64,6 +64,19 @@ static int am335x_phy_probe(struct platform_device *pdev)
> am_phy->usb_phy_gen.phy.shutdown = am335x_shutdown;
>
> platform_set_drvdata(pdev, am_phy);
> + device_init_wakeup(dev, true);
> +
> + /*
> + * If we leave PHY wakeup enabled then AM33XX wakes up
> + * immediately from DS0. To avoid this we mark dev->power.can_wakeup
> + * to false. The same is checked in suspend routine to decide
> + * on whether to enable PHY wakeup or not.
> + * PHY wakeup works fine in standby mode, there by allowing us to
> + * handle remote wakeup, wakeup on disconnect and connect.
> + */
> +
> + device_set_wakeup_enable(dev, false);
> + phy_ctrl_power(am_phy->phy_ctrl, am_phy->id, false);
>
> return 0;
>
> @@ -78,40 +91,51 @@ static int am335x_phy_remove(struct platform_device *pdev)
> return 0;
> }
>
> -#ifdef CONFIG_PM_RUNTIME
> -
> -static int am335x_phy_runtime_suspend(struct device *dev)
> +#ifdef CONFIG_PM_SLEEP
> +static int am335x_phy_suspend(struct device *dev)
> {
> struct platform_device *pdev = to_platform_device(dev);
> struct am335x_phy *am_phy = platform_get_drvdata(pdev);
>
> + /*
> + * Enable phy wakeup only if dev->power.can_wakeup is true.
> + * Make sure to enable wakeup to support remote wakeup in
> + * standby mode ( same is not supported in OFF(DS0) mode).
> + * Enable it by doing
> + * echo enabled > /sys/bus/platform/devices/<usb-phy-id>/power/wakeup
> + */
Alan, any suggestions on how to handle wakeup correctly ? I mean, it
should be enabled by default during runtime PM and disabled during
system sleep. But when it comes to default state of can_wakeup field,
what should we do ? Should the driver be fiddling with that ? Leave it
to the bus driver ? Any tips ?
cheers
--
balbi
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