Re: [PATCH v7 1/2] usb: host: xhci-plat: Get PHYs for xhci's hcds

[Vivek Gautam]

Hi Felipe,



On Fri, Oct 31, 2014 at 6:56 PM, Vivek Gautam <gautam.vivek@xxxxxxxxxxx> wrote:
> The host controller by itself may sometimes need to handle PHY
> and re-initialize it to re-configure some of the PHY parameters
> to get full support out of the PHY controller.
> Therefore, facilitate getting the two possible PHYs, viz.
> USB 2.0 type (UTMI+) and USB 3.0 type (PIPE3), and initialize them.
>
> Signed-off-by: Vivek Gautam <gautam.vivek@xxxxxxxxxxx>
> ---
>  drivers/usb/host/xhci-plat.c |   74 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 74 insertions(+)
>
> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> index 3d78b0c..5207d5b 100644
> --- a/drivers/usb/host/xhci-plat.c
> +++ b/drivers/usb/host/xhci-plat.c
> @@ -16,6 +16,7 @@
>  #include <linux/module.h>
>  #include <linux/of.h>
>  #include <linux/platform_device.h>
> +#include <linux/phy/phy.h>
>  #include <linux/slab.h>
>  #include <linux/usb/xhci_pdriver.h>
>
> @@ -129,10 +130,41 @@ static int xhci_plat_probe(struct platform_device *pdev)
>                         goto put_hcd;
>         }
>
> +       /* Get possile USB 2.0 type PHY (UTMI+) available with xhci */
> +       hcd->phy = devm_phy_get(&pdev->dev, "usb2-phy");
> +       if (IS_ERR(hcd->phy)) {
> +               ret = PTR_ERR(hcd->phy);
> +               if (ret == -EPROBE_DEFER) {
> +                       goto disable_clk;
> +               } else if (ret != -ENOSYS && ret != -ENODEV) {
> +                       hcd->phy = NULL;
> +                       dev_warn(&pdev->dev,
> +                                "Error retrieving usb2 phy: %d\n", ret);
> +               }
> +       }
> +
>         ret = usb_add_hcd(hcd, irq, IRQF_SHARED);
>         if (ret)
>                 goto disable_clk;
>
> +       /*
> +        * Initialize and power-on USB 2.0 PHY
> +        * FIXME: Isn't this a hacky way of initializing the PHY again ?
> +        * xhci's parent would have already initialized the PHY, but we
> +        * wanna do it again.
> +        */

Does this change looks anywhere close to what you suggested to
re-initialize PHYs in XHCI even after DWC3 has initialized them once,
in order to avoid adding phy_calibration() callback ? ;-)

> +       hcd->phy->init_count = 0;
> +       ret = phy_init(hcd->phy);
> +       if (ret)
> +               goto dealloc_usb2_hcd;
> +
> +       hcd->phy->power_count = 0;
> +       ret = phy_power_on(hcd->phy);
> +       if (ret) {
> +               phy_exit(hcd->phy);
> +               goto dealloc_usb2_hcd;
> +       }
> +
>         device_wakeup_enable(hcd->self.controller);
>
>         /* USB 2.0 roothub is stored in the platform_device now. */
> @@ -158,12 +190,41 @@ static int xhci_plat_probe(struct platform_device *pdev)
>         if (HCC_MAX_PSA(xhci->hcc_params) >= 4)
>                 xhci->shared_hcd->can_do_streams = 1;
>
> +       /* Get possile USB 3.0 type PHY (PIPE3) available with xhci */
> +       xhci->shared_hcd->phy = devm_phy_get(&pdev->dev, "usb3-phy");
> +       if (IS_ERR(xhci->shared_hcd->phy)) {
> +               ret = PTR_ERR(xhci->shared_hcd->phy);
> +               if (ret == -EPROBE_DEFER) {
> +                       goto put_usb3_hcd;
> +               } else if (ret != -ENOSYS && ret != -ENODEV) {
> +                       xhci->shared_hcd->phy = NULL;
> +                       dev_warn(&pdev->dev,
> +                                "Error retrieving usb3 phy: %d\n", ret);
> +               }
> +       }
> +
>         ret = usb_add_hcd(xhci->shared_hcd, irq, IRQF_SHARED);
>         if (ret)
>                 goto put_usb3_hcd;
>
> +       /* Initialize and power-on USB 3.0 PHY */
> +       xhci->shared_hcd->phy->init_count = 0;
> +       ret = phy_init(xhci->shared_hcd->phy);
> +       if (ret)
> +               goto dealloc_usb3_hcd;
> +
> +       xhci->shared_hcd->phy->power_count = 0;
> +       ret = phy_power_on(xhci->shared_hcd->phy);
> +       if (ret) {
> +               phy_exit(xhci->shared_hcd->phy);
> +               goto dealloc_usb3_hcd;
> +       }
> +
>         return 0;
>
> +dealloc_usb3_hcd:
> +       usb_remove_hcd(xhci->shared_hcd);
> +
>  put_usb3_hcd:
>         usb_put_hcd(xhci->shared_hcd);
>
> @@ -186,9 +247,15 @@ static int xhci_plat_remove(struct platform_device *dev)
>         struct xhci_hcd *xhci = hcd_to_xhci(hcd);
>         struct clk *clk = xhci->clk;
>
> +       phy_power_off(xhci->shared_hcd->phy);
> +       phy_exit(xhci->shared_hcd->phy);
> +
>         usb_remove_hcd(xhci->shared_hcd);
>         usb_put_hcd(xhci->shared_hcd);
>
> +       phy_power_off(hcd->phy);
> +       phy_exit(hcd->phy);
> +
>         usb_remove_hcd(hcd);
>         if (!IS_ERR(clk))
>                 clk_disable_unprepare(clk);
> @@ -204,6 +271,8 @@ static int xhci_plat_suspend(struct device *dev)
>         struct usb_hcd  *hcd = dev_get_drvdata(dev);
>         struct xhci_hcd *xhci = hcd_to_xhci(hcd);
>
> +       phy_exit(hcd->phy);
> +
>         return xhci_suspend(xhci);
>  }
>
> @@ -211,6 +280,11 @@ static int xhci_plat_resume(struct device *dev)
>  {
>         struct usb_hcd  *hcd = dev_get_drvdata(dev);
>         struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> +       int ret;
> +
> +       ret = phy_init(hcd->phy);
> +       if (ret)
> +               return ret;
>
>         return xhci_resume(xhci, 0);
>  }
> --
> 1.7.10.4
>



-- 
Best Regards
Vivek Gautam
Samsung R&D Institute, Bangalore
India
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