diff options
| author | Hans de Goede <hdegoede@redhat.com> | 2018-06-10 17:01:21 +0300 |
|---|---|---|
| committer | Felipe Balbi <felipe.balbi@linux.intel.com> | 2018-07-26 13:54:21 +0300 |
| commit | 7740d04d901db7fe631b89dc4f695093327e2124 (patch) | |
| tree | 126c22e14df016007374c019a3c7f2a9a185db99 /drivers/usb | |
| parent | 5741022cbdf3616a9def13b15ab5667a36c65706 (diff) | |
| download | linux-7740d04d901db7fe631b89dc4f695093327e2124.tar.xz | |
usb: dwc3: pci: Enable ULPI Refclk on platforms where the firmware does not
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>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/dwc3/dwc3-pci.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/drivers/usb/dwc3/dwc3-pci.c b/drivers/usb/dwc3/dwc3-pci.c index 5c175f839efd..26829b299482 100644 --- a/drivers/usb/dwc3/dwc3-pci.c +++ b/drivers/usb/dwc3/dwc3-pci.c @@ -39,6 +39,10 @@ #define PCI_INTEL_BXT_STATE_D0 0 #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 * @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) { 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) { 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, acpi_dwc3_byt_gpios); if (ret) |