Re: [PATCH 05/10] usb: chipidea: msm: support the HSIC asynchronous wakeup interrupt

On 26-08-10 18:42:09, Dmitry Baryshkov wrote:
> The HSIC instances of the chipidea controller runtime-suspend with
> their clocks gated whenever the bus is empty. HSIC has no VBUS-style
> connect detection: a device (such as an onboard hub coming out of
> reset) signals a single connect event, and if the controller is
> suspended at that moment the connect is never noticed and the device
> never enumerates.
> 
> The hardware provides an asynchronous wakeup interrupt that fires on
> HSIC bus activity while the controller is in low power mode. Pick it
> up as an optional second interrupt and attach it as a dedicated wake
> irq of the core device, so the PM core arms it over runtime suspend
> and resumes the controller when the bus reports activity.
> 
> Assisted-by: Claude:claude-fable-5
> Signed-off-by: Dmitry Baryshkov <[email protected]>
> ---
>  drivers/usb/chipidea/ci_hdrc_msm.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/drivers/usb/chipidea/ci_hdrc_msm.c b/drivers/usb/chipidea/ci_hdrc_msm.c
> index 3ab3daa78e34..e28ea87f9898 100644
> --- a/drivers/usb/chipidea/ci_hdrc_msm.c
> +++ b/drivers/usb/chipidea/ci_hdrc_msm.c
> @@ -4,6 +4,7 @@
>  #include <linux/module.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/pm_wakeirq.h>
>  #include <linux/usb/chipidea.h>
>  #include <linux/clk.h>
>  #include <linux/reset.h>
> @@ -173,6 +174,7 @@ static int ci_hdrc_msm_probe(struct platform_device *pdev)
>  {
>  	struct ci_hdrc_msm *ci;
>  	struct platform_device *plat_ci;
> +	int wake_irq;
>  	struct clk *clk;
>  	struct reset_control *reset;
>  	int ret;
> @@ -261,6 +263,19 @@ static int ci_hdrc_msm_probe(struct platform_device *pdev)
>  
>  	ci->ci = plat_ci;
>  
> +	/*
> +	 * The optional second interrupt is the asynchronous wakeup interrupt
> +	 * of the HSIC instances: without it a bus connect arriving while the
> +	 * runtime-suspended controller has its clocks gated is never seen.
> +	 */
> +	wake_irq = platform_get_irq_optional(pdev, 1);

You may need to consider error case:

https://lore.kernel.org/all/[email protected]/

> +	if (wake_irq > 0) {
> +		device_init_wakeup(&plat_ci->dev, true);

USB wakeup may NOT the same with system wakeup, the user may don't want
USB event wake system up from suspend. You may consider the solution at:
see data->wakeup_irq at drivers/usb/chipidea/ci_hdrc_imx.c. 

Peter

> +		ret = dev_pm_set_dedicated_wake_irq(&plat_ci->dev, wake_irq);
> +		if (ret)
> +			dev_warn(&pdev->dev, "no wakeup interrupt: %d\n", ret);
> +	}
> +
>  	pm_runtime_set_active(&pdev->dev);
>  	pm_runtime_no_callbacks(&pdev->dev);
>  	pm_runtime_enable(&pdev->dev);
> @@ -279,6 +294,7 @@ static void ci_hdrc_msm_remove(struct platform_device *pdev)
>  	struct ci_hdrc_msm *ci = platform_get_drvdata(pdev);
>  
>  	pm_runtime_disable(&pdev->dev);
> +	dev_pm_clear_wake_irq(&ci->ci->dev);
>  	ci_hdrc_remove_device(ci->ci);
>  	clk_disable_unprepare(ci->iface_clk);
>  	clk_disable_unprepare(ci->core_clk);
> 
> -- 
> 2.47.3
> 

-- 

Thanks,
Peter Chen

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