Hello!

On 06/07/2018 01:38 PM, Hans de Goede wrote:

> On some Bay Trail (BYT) systems the firmware does not enable the
> ULPI Refclk.
> 
> This commit adds a helper which checks and if necessary enabled the Refclk
> and calls this helper for BYT machines.
> 
> Signed-off-by: Hans de Goede <hdego...@redhat.com>
> ---
>  drivers/usb/dwc3/dwc3-pci.c | 34 ++++++++++++++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/dwc3-pci.c b/drivers/usb/dwc3/dwc3-pci.c
> index 34b84d3bc7cf..65bc110388f3 100644
> --- a/drivers/usb/dwc3/dwc3-pci.c
> +++ b/drivers/usb/dwc3/dwc3-pci.c
[...]
> @@ -78,6 +81,34 @@ static struct gpiod_lookup_table platform_bytcr_gpios = {
>       },
>  };
>  
> +static void dwc3_pci_enable_ulpi_refclock(struct pci_dev *pci)
> +{
> +     void __iomem    *reg;
> +     struct resource res;
> +     struct device   *dev = &pci->dev;
> +     u32             value;
> +
> +     res.start       = pci_resource_start(pci, 1);
> +     res.end         = pci_resource_end(pci, 1);
> +     res.name        = "dwc_usb3_bar1";
> +     res.flags       = IORESOURCE_MEM;
> +
> +     reg = devm_ioremap_resource(dev, &res);
> +     if (IS_ERR(reg)) {
> +             dev_err(dev, "cannot check GP_RWREG1 to assert ulpi 
> refclock\n");

   Eh?
   BTW, devm_ioremap_resource() prints the error cause already...

> +             return;
> +     }
> +
> +     value = readl(reg + GP_RWREG1);
> +     if (!(value & GP_RWREG1_ULPI_REFCLK_DISABLE))

   I guess that dev_err() belongs here...

> +             return; /* ULPI refclk already enabled */
> +
> +     dev_warn(dev, "ULPI refclock is disabled from the BIOS, enabling it\n");
> +     value &= ~GP_RWREG1_ULPI_REFCLK_DISABLE;
> +     writel(value, reg + GP_RWREG1);
> +     msleep(100);
> +}
> +
>  static int dwc3_pci_quirks(struct dwc3_pci *dwc)
>  {
>       struct platform_device          *dwc3 = dwc->dwc3;
[...]

MBR, Sergei
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