Re: [PATCH 4/6] usb: xhci-mtk: add support runtime PM

[Ikjoon Jang]

On Thu, Apr 8, 2021 at 5:35 PM Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> wrote:
>
> A dedicated wakeup irq will be used to handle runtime suspend/resume,
> we use dev_pm_set_dedicated_wake_irq API to take care of requesting
> and attaching wakeup irq, then the suspend/resume framework will help
> to enable/disable wakeup irq.
>
> The runtime PM is default off since some platforms may not support it.
> users can enable it via power/control (set "auto") in sysfs.
>
> Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
> ---
>  drivers/usb/host/xhci-mtk.c | 140 +++++++++++++++++++++++++++++++-----
>  1 file changed, 124 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
> index a74764ab914a..30927f4064d4 100644
> --- a/drivers/usb/host/xhci-mtk.c
> +++ b/drivers/usb/host/xhci-mtk.c
> @@ -16,6 +16,7 @@
>  #include <linux/of.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/pm_wakeirq.h>
>  #include <linux/regmap.h>
>  #include <linux/regulator/consumer.h>
>
> @@ -358,7 +359,6 @@ static int usb_wakeup_of_property_parse(struct xhci_hcd_mtk *mtk,
>                         mtk->uwk_reg_base, mtk->uwk_vers);
>
>         return PTR_ERR_OR_ZERO(mtk->uwk);
> -
>  }
>
>  static void usb_wakeup_set(struct xhci_hcd_mtk *mtk, bool enable)
> @@ -458,6 +458,7 @@ static int xhci_mtk_probe(struct platform_device *pdev)
>         struct resource *res;
>         struct usb_hcd *hcd;
>         int ret = -ENODEV;
> +       int wakeup_irq;
>         int irq;
>
>         if (usb_disabled())
> @@ -485,6 +486,21 @@ static int xhci_mtk_probe(struct platform_device *pdev)
>         if (ret)
>                 return ret;
>
> +       irq = platform_get_irq_byname_optional(pdev, "host");
> +       if (irq < 0) {
> +               if (irq == -EPROBE_DEFER)
> +                       return irq;
> +
> +               /* for backward compatibility */
> +               irq = platform_get_irq(pdev, 0);
> +               if (irq < 0)
> +                       return irq;
> +       }
> +
> +       wakeup_irq = platform_get_irq_byname_optional(pdev, "wakeup");
> +       if (wakeup_irq == -EPROBE_DEFER)
> +               return wakeup_irq;
> +
>         mtk->lpm_support = of_property_read_bool(node, "usb3-lpm-capable");
>         /* optional property, ignore the error if it does not exist */
>         of_property_read_u32(node, "mediatek,u3p-dis-msk",
> @@ -496,9 +512,11 @@ static int xhci_mtk_probe(struct platform_device *pdev)
>                 return ret;
>         }
>
> +       pm_runtime_set_active(dev);
> +       pm_runtime_use_autosuspend(dev);
> +       pm_runtime_set_autosuspend_delay(dev, 4000);
>         pm_runtime_enable(dev);
>         pm_runtime_get_sync(dev);
> -       device_enable_async_suspend(dev);
>
>         ret = xhci_mtk_ldos_enable(mtk);
>         if (ret)
> @@ -508,12 +526,6 @@ static int xhci_mtk_probe(struct platform_device *pdev)
>         if (ret)
>                 goto disable_ldos;
>
> -       irq = platform_get_irq(pdev, 0);
> -       if (irq < 0) {
> -               ret = irq;
> -               goto disable_clk;
> -       }
> -
>         hcd = usb_create_hcd(driver, dev, dev_name(dev));
>         if (!hcd) {
>                 ret = -ENOMEM;
> @@ -579,8 +591,26 @@ static int xhci_mtk_probe(struct platform_device *pdev)
>         if (ret)
>                 goto dealloc_usb2_hcd;
>
> +       if (wakeup_irq > 0) {
> +               ret = dev_pm_set_dedicated_wake_irq(dev, wakeup_irq);
> +               if (ret) {
> +                       dev_err(dev, "set wakeup irq %d failed\n", wakeup_irq);
> +                       goto dealloc_usb3_hcd;
> +               }
> +               dev_info(dev, "wakeup irq %d\n", wakeup_irq);
> +       }
> +
> +       device_enable_async_suspend(dev);
> +       pm_runtime_mark_last_busy(dev);
> +       pm_runtime_put_autosuspend(dev);
> +       pm_runtime_forbid(dev);
> +
>         return 0;
>
> +dealloc_usb3_hcd:
> +       usb_remove_hcd(xhci->shared_hcd);
> +       xhci->shared_hcd = NULL;
> +
>  dealloc_usb2_hcd:
>         usb_remove_hcd(hcd);
>
> @@ -601,25 +631,26 @@ static int xhci_mtk_probe(struct platform_device *pdev)
>         xhci_mtk_ldos_disable(mtk);
>
>  disable_pm:
> -       pm_runtime_put_sync(dev);
> +       pm_runtime_put_sync_autosuspend(dev);
>         pm_runtime_disable(dev);
>         return ret;
>  }
>
> -static int xhci_mtk_remove(struct platform_device *dev)
> +static int xhci_mtk_remove(struct platform_device *pdev)
>  {
> -       struct xhci_hcd_mtk *mtk = platform_get_drvdata(dev);
> +       struct xhci_hcd_mtk *mtk = platform_get_drvdata(pdev);
>         struct usb_hcd  *hcd = mtk->hcd;
>         struct xhci_hcd *xhci = hcd_to_xhci(hcd);
>         struct usb_hcd  *shared_hcd = xhci->shared_hcd;
> +       struct device *dev = &pdev->dev;
>
> -       pm_runtime_put_noidle(&dev->dev);
> -       pm_runtime_disable(&dev->dev);
> +       pm_runtime_get_sync(dev);
> +       xhci->xhc_state |= XHCI_STATE_REMOVING;
> +       dev_pm_clear_wake_irq(dev);
> +       device_init_wakeup(dev, false);
>
>         usb_remove_hcd(shared_hcd);
>         xhci->shared_hcd = NULL;
> -       device_init_wakeup(&dev->dev, false);
> -
>         usb_remove_hcd(hcd);
>         usb_put_hcd(shared_hcd);
>         usb_put_hcd(hcd);
> @@ -627,6 +658,10 @@ static int xhci_mtk_remove(struct platform_device *dev)
>         xhci_mtk_clks_disable(mtk);
>         xhci_mtk_ldos_disable(mtk);
>
> +       pm_runtime_disable(dev);
> +       pm_runtime_put_noidle(dev);
> +       pm_runtime_set_suspended(dev);
> +
>         return 0;
>  }
>
> @@ -690,10 +725,83 @@ static int __maybe_unused xhci_mtk_resume(struct device *dev)
>         return ret;
>  }
>
> +static int check_rhub_status(struct xhci_hcd *xhci, struct xhci_hub *rhub)
> +{
> +       u32 suspended_ports;
> +       u32 status;
> +       int num_ports;
> +       int i;
> +
> +       num_ports = rhub->num_ports;
> +       suspended_ports = rhub->bus_state.suspended_ports;
> +       for (i = 0; i < num_ports; i++) {
> +               if (!(suspended_ports & BIT(i))) {
> +                       status = readl(rhub->ports[i]->addr);
> +                       if (status & PORT_CONNECT)

So this pm_runtime support is activated only when there's no devices
connected at all?
I think this will always return -EBUSY with my board having an on-board hub
connected to both rhubs.

> +                               return -EBUSY;
> +               }
> +       }
> +
> +       return 0;
> +}
> +
> +/*
> + * check the bus whether it could suspend or not
> + * the bus will suspend if the downstream ports are already suspended,
> + * or no devices connected.
> + */
> +static int check_bus_status(struct xhci_hcd *xhci)
> +{
> +       int ret;
> +
> +       ret = check_rhub_status(xhci, &xhci->usb3_rhub);
> +       if (ret)
> +               return ret;
> +
> +       return check_rhub_status(xhci, &xhci->usb2_rhub);
> +}
> +
> +static int __maybe_unused xhci_mtk_runtime_suspend(struct device *dev)
> +{
> +       struct xhci_hcd_mtk  *mtk = dev_get_drvdata(dev);
> +       struct xhci_hcd *xhci = hcd_to_xhci(mtk->hcd);
> +       int ret = 0;
> +
> +       if (xhci->xhc_state)
> +               return -ESHUTDOWN;
> +
> +       if (device_may_wakeup(dev)) {
> +               ret = check_bus_status(xhci);
> +               if (!ret)
> +                       ret = xhci_mtk_suspend(dev);
> +       }
> +
> +       /* -EBUSY: let PM automatically reschedule another autosuspend */
> +       return ret ? -EBUSY : 0;
> +}
> +
> +static int __maybe_unused xhci_mtk_runtime_resume(struct device *dev)
> +{
> +       struct xhci_hcd_mtk  *mtk = dev_get_drvdata(dev);
> +       struct xhci_hcd *xhci = hcd_to_xhci(mtk->hcd);
> +       int ret = 0;
> +
> +       if (xhci->xhc_state)
> +               return -ESHUTDOWN;
> +
> +       if (device_may_wakeup(dev))
> +               ret = xhci_mtk_resume(dev);
> +
> +       return ret;
> +}
> +
>  static const struct dev_pm_ops xhci_mtk_pm_ops = {
>         SET_SYSTEM_SLEEP_PM_OPS(xhci_mtk_suspend, xhci_mtk_resume)
> +       SET_RUNTIME_PM_OPS(xhci_mtk_runtime_suspend,
> +                          xhci_mtk_runtime_resume, NULL)
>  };
> -#define DEV_PM_OPS IS_ENABLED(CONFIG_PM) ? &xhci_mtk_pm_ops : NULL
> +
> +#define DEV_PM_OPS (IS_ENABLED(CONFIG_PM) ? &xhci_mtk_pm_ops : NULL)
>
>  static const struct of_device_id mtk_xhci_of_match[] = {
>         { .compatible = "mediatek,mt8173-xhci"},
> --
> 2.18.0
>