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usb: dwc3: pci: Enable ULPI Refclk on platforms where the firmware does not

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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>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
Hans de Goede 2018-06-10 16:01:21 +02:00 committed by Felipe Balbi
parent 5741022cbd
commit 7740d04d90
1 changed files with 31 additions and 0 deletions
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31
drivers/usb/dwc3/dwc3-pci.c
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@ -39,6 +39,10 @@
#define PCI_INTEL_BXT_STATE_D0 0 #define PCI_INTEL_BXT_STATE_D0 0
#define PCI_INTEL_BXT_STATE_D3 3 #define PCI_INTEL_BXT_STATE_D3 3
#define GP_RWBAR 1
#define GP_RWREG1 0xa0
#define GP_RWREG1_ULPI_REFCLK_DISABLE (1 << 17)
/** /**
* struct dwc3_pci - Driver private structure * struct dwc3_pci - Driver private structure
* @dwc3: child dwc3 platform_device * @dwc3: child dwc3 platform_device
@ -74,6 +78,28 @@ static struct gpiod_lookup_table platform_bytcr_gpios = {
}, },
}; };
static int dwc3_byt_enable_ulpi_refclock(struct pci_dev *pci)
{
void __iomem *reg;
u32 value;
reg = pcim_iomap(pci, GP_RWBAR, 0);
if (IS_ERR(reg))
return PTR_ERR(reg);
value = readl(reg + GP_RWREG1);
if (!(value & GP_RWREG1_ULPI_REFCLK_DISABLE))
goto unmap; /* ULPI refclk already enabled */
value &= ~GP_RWREG1_ULPI_REFCLK_DISABLE;
writel(value, reg + GP_RWREG1);
/* This comes from the Intel Android x86 tree w/o any explanation */
msleep(100);
unmap:
pcim_iounmap(pci, reg);
return 0;
}
static int dwc3_pci_quirks(struct dwc3_pci *dwc) static int dwc3_pci_quirks(struct dwc3_pci *dwc)
{ {
struct platform_device *dwc3 = dwc->dwc3; struct platform_device *dwc3 = dwc->dwc3;
@ -129,6 +155,11 @@ static int dwc3_pci_quirks(struct dwc3_pci *dwc)
if (pdev->device == PCI_DEVICE_ID_INTEL_BYT) { if (pdev->device == PCI_DEVICE_ID_INTEL_BYT) {
struct gpio_desc *gpio; struct gpio_desc *gpio;
/* On BYT the FW does not always enable the refclock */
ret = dwc3_byt_enable_ulpi_refclock(pdev);
if (ret)
return ret;
ret = devm_acpi_dev_add_driver_gpios(&pdev->dev, ret = devm_acpi_dev_add_driver_gpios(&pdev->dev,
acpi_dwc3_byt_gpios); acpi_dwc3_byt_gpios);
if (ret) if (ret)