Re: [PATCH v2 1/2] usb: core: phy: add support for PHY calibration

[Anand Moon <linux.amoon@gmail.com>]

Hi Marek,

On Fri, 19 Jul 2019 at 13:43, Marek Szyprowski <m.szyprowski@samsung.com> wrote:
>
> Some PHYs (for example Exynos5 USB3.0 DRD PHY) require calibration to be
> done after every USB HCD reset. Generic PHY framework has been already
> extended with phy_calibrate() function in commit 36914111e682 ("drivers:
> phy: add calibrate method"). This patch adds support for it to generic
> PHY handling code in USB HCD core.
>

Tested on my XU3 / XU4 / HC1
Tested-by: Anand Moon <linux.amoon@gmail.com>


> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>  drivers/usb/core/hcd.c |  7 +++++++
>  drivers/usb/core/phy.c | 21 +++++++++++++++++++++
>  drivers/usb/core/phy.h |  1 +
>  3 files changed, 29 insertions(+)
>
> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index 88533938ce19..b89936c1df23 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -2291,6 +2291,9 @@ int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
>         hcd->state = HC_STATE_RESUMING;
>         status = hcd->driver->bus_resume(hcd);
>         clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
> +       if (status == 0)
> +               status = usb_phy_roothub_calibrate(hcd->phy_roothub);
> +
>         if (status == 0) {
>                 struct usb_device *udev;
>                 int port1;
> @@ -2864,6 +2867,10 @@ int usb_add_hcd(struct usb_hcd *hcd,
>         }
>         hcd->rh_pollable = 1;
>
> +       retval = usb_phy_roothub_calibrate(hcd->phy_roothub);
> +       if (retval)
> +               goto err_hcd_driver_setup;
> +
>         /* NOTE: root hub and controller capabilities may not be the same */
>         if (device_can_wakeup(hcd->self.controller)
>                         && device_can_wakeup(&hcd->self.root_hub->dev))
> diff --git a/drivers/usb/core/phy.c b/drivers/usb/core/phy.c
> index 7580493b867a..fb1588e7c282 100644
> --- a/drivers/usb/core/phy.c
> +++ b/drivers/usb/core/phy.c
> @@ -151,6 +151,27 @@ int usb_phy_roothub_set_mode(struct usb_phy_roothub *phy_roothub,
>  }
>  EXPORT_SYMBOL_GPL(usb_phy_roothub_set_mode);
>
> +int usb_phy_roothub_calibrate(struct usb_phy_roothub *phy_roothub)
> +{
> +       struct usb_phy_roothub *roothub_entry;
> +       struct list_head *head;
> +       int err;
> +
> +       if (!phy_roothub)
> +               return 0;
> +
> +       head = &phy_roothub->list;
> +
> +       list_for_each_entry(roothub_entry, head, list) {
> +               err = phy_calibrate(roothub_entry->phy);
> +               if (err)
> +                       return err;
> +       }
> +
> +       return 0;
> +}
> +EXPORT_SYMBOL_GPL(usb_phy_roothub_calibrate);
> +
>  int usb_phy_roothub_power_on(struct usb_phy_roothub *phy_roothub)
>  {
>         struct usb_phy_roothub *roothub_entry;
> diff --git a/drivers/usb/core/phy.h b/drivers/usb/core/phy.h
> index dad564e2d2d4..20a267cd986b 100644
> --- a/drivers/usb/core/phy.h
> +++ b/drivers/usb/core/phy.h
> @@ -18,6 +18,7 @@ int usb_phy_roothub_exit(struct usb_phy_roothub *phy_roothub);
>
>  int usb_phy_roothub_set_mode(struct usb_phy_roothub *phy_roothub,
>                              enum phy_mode mode);
> +int usb_phy_roothub_calibrate(struct usb_phy_roothub *phy_roothub);
>  int usb_phy_roothub_power_on(struct usb_phy_roothub *phy_roothub);
>  void usb_phy_roothub_power_off(struct usb_phy_roothub *phy_roothub);
>
> --
> 2.17.1
>