[v17,2/5] usb: dwc3: core: Host wake up support from system suspend

From: Sandeep Maheswaram <quic_c_sanm@quicinc.com>

Check wakeup-source property for dwc3 core node to set the
wakeup capability. Drop the device_init_wakeup call from
runtime suspend and resume.

If the dwc3 is wakeup capable, don't power down the USB PHY(s).
The glue drivers are expected to take care of configuring the
additional wakeup settings if needed based on the dwc3 wakeup
capability status. In some SOC designs, powering off the PHY is
resulting in higher leakage, so this patch save power on such boards.

Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
---
 drivers/usb/dwc3/core.c | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

On Tue, May 24, 2022 at 03:43:45PM +0530, Krishna Kurapati wrote:
> From: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> 
> Check wakeup-source property for dwc3 core node to set the
> wakeup capability. Drop the device_init_wakeup call from
> runtime suspend and resume.
> 
> If the dwc3 is wakeup capable, don't power down the USB PHY(s).
> The glue drivers are expected to take care of configuring the
> additional wakeup settings if needed based on the dwc3 wakeup
> capability status. In some SOC designs, powering off the PHY is
> resulting in higher leakage, so this patch save power on such boards.
> 
> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
> ---
>  drivers/usb/dwc3/core.c | 26 ++++++++++++--------------
>  1 file changed, 12 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 5734219..4a7c82e 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1782,6 +1782,7 @@ static int dwc3_probe(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, dwc);
>  	dwc3_cache_hwparams(dwc);
> +	device_init_wakeup(&pdev->dev, of_property_read_bool(dev->of_node, "wakeup-source"));
>  
>  	spin_lock_init(&dwc->lock);
>  	mutex_init(&dwc->mutex);
> @@ -1943,11 +1944,6 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
>  		dwc3_core_exit(dwc);
>  		break;
>  	case DWC3_GCTL_PRTCAP_HOST:
> -		if (!PMSG_IS_AUTO(msg)) {
> -			dwc3_core_exit(dwc);
> -			break;
> -		}
> -
>  		/* Let controller to suspend HSPHY before PHY driver suspends */
>  		if (dwc->dis_u2_susphy_quirk ||
>  		    dwc->dis_enblslpm_quirk) {
> @@ -1962,6 +1958,11 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
>  
>  		phy_pm_runtime_put_sync(dwc->usb2_generic_phy);
>  		phy_pm_runtime_put_sync(dwc->usb3_generic_phy);
> +
> +		if (!PMSG_IS_AUTO(msg)) {
> +			if (!device_can_wakeup(dwc->dev))
> +				dwc3_core_exit(dwc);
> +		}
>  		break;
>  	case DWC3_GCTL_PRTCAP_OTG:
>  		/* do nothing during runtime_suspend */
> @@ -2005,11 +2006,12 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
>  		break;
>  	case DWC3_GCTL_PRTCAP_HOST:
>  		if (!PMSG_IS_AUTO(msg)) {
> -			ret = dwc3_core_init_for_resume(dwc);
> -			if (ret)
> -				return ret;
> -			dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
> -			break;
> +			if (!device_can_wakeup(dwc->dev)) {
> +				ret = dwc3_core_init_for_resume(dwc);
> +				if (ret)
> +					return ret;
> +				dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
> +			}
>  		}
>  		/* Restore GUSB2PHYCFG bits that were modified in suspend */
>  		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
> @@ -2081,8 +2083,6 @@ static int dwc3_runtime_suspend(struct device *dev)
>  	if (ret)
>  		return ret;
>  
> -	device_init_wakeup(dev, true);
> -
>  	return 0;
>  }
>  
> @@ -2091,8 +2091,6 @@ static int dwc3_runtime_resume(struct device *dev)
>  	struct dwc3     *dwc = dev_get_drvdata(dev);
>  	int		ret;
>  
> -	device_init_wakeup(dev, false);
> -
>  	ret = dwc3_resume_common(dwc, PMSG_AUTO_RESUME);
>  	if (ret)
>  		return ret;
> -- 
> 2.7.4
> 

Looks good to me. Feel free to add

Reviewed-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>

Thanks,
Pavan

On Tue, May 24, 2022 at 03:43:45PM +0530, Krishna Kurapati wrote:
> From: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> 
> Check wakeup-source property for dwc3 core node to set the
> wakeup capability. Drop the device_init_wakeup call from
> runtime suspend and resume.
> 
> If the dwc3 is wakeup capable, don't power down the USB PHY(s).
> The glue drivers are expected to take care of configuring the
> additional wakeup settings if needed based on the dwc3 wakeup
> capability status. In some SOC designs, powering off the PHY is
> resulting in higher leakage, so this patch save power on such boards.
> 
> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>