[2/3] usb: dwc3: pci: Enable ULPI Refclk on platforms where the firmware doesnot

From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
To: Hans de Goede <hdegoede@redhat.com>,
	Felipe Balbi <balbi@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Subject: [2/3] usb: dwc3: pci: Enable ULPI Refclk on platforms where the firmware doesnot
Date: Thu, 7 Jun 2018 19:43:56 +0300	[thread overview]
Message-ID: <a21bdc3f-aa61-0b78-ab21-fbb19db0373f@cogentembedded.com> (raw)

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 <hdegoede@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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