diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index fe1ecae73086..3e9515073e05 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -594,6 +594,27 @@ static void dwc3_core_exit(struct dwc3 *dwc) phy_power_off(dwc->usb3_generic_phy); } +static bool dwc3_core_is_valid(struct dwc3 *dwc) +{ + u32 reg; + + reg = dwc3_readl(dwc->regs, DWC3_GSNPSID); + + /* This should read as U3 followed by revision number */ + if ((reg & DWC3_GSNPSID_MASK) == 0x55330000) { + /* Detected DWC_usb3 IP */ + dwc->revision = reg; + } else if ((reg & DWC3_GSNPSID_MASK) == 0x33310000) { + /* Detected DWC_usb31 IP */ + dwc->revision = dwc3_readl(dwc->regs, DWC3_VER_NUMBER); + dwc->revision |= DWC3_REVISION_IS_DWC31; + } else { + return false; + } + + return true; +} + /** * dwc3_core_init - Low-level initialization of DWC3 Core * @dwc: Pointer to our controller context structure @@ -606,16 +627,7 @@ static int dwc3_core_init(struct dwc3 *dwc) u32 reg; int ret; - reg = dwc3_readl(dwc->regs, DWC3_GSNPSID); - /* This should read as U3 followed by revision number */ - if ((reg & DWC3_GSNPSID_MASK) == 0x55330000) { - /* Detected DWC_usb3 IP */ - dwc->revision = reg; - } else if ((reg & DWC3_GSNPSID_MASK) == 0x33310000) { - /* Detected DWC_usb31 IP */ - dwc->revision = dwc3_readl(dwc->regs, DWC3_VER_NUMBER); - dwc->revision |= DWC3_REVISION_IS_DWC31; - } else { + if (!dwc3_core_is_valid(dwc)) { dev_err(dwc->dev, "this is not a DesignWare USB3 DRD Core\n"); ret = -ENODEV; goto err0;