usb: dwc3: apple: Configure USB2 PHY earlier

Signed-off-by: Sven Peter <[email protected]>

Author: svenpeter42

drivers/usb/dwc3/dwc3-apple.c

@@ -218,25 +218,30 @@ static int dwc3_apple_core_init(struct dwc3_apple *appledwc)
 	return ret;
 }
 
-static void dwc3_apple_phy_set_mode(struct dwc3_apple *appledwc, enum phy_mode mode)
-{
-	lockdep_assert_held(&appledwc->lock);
-
-	/*
-	 * This platform requires SUSPHY to be enabled here already in order to properly configure
-	 * the PHY and switch dwc3's PIPE interface to USB3 PHY.
-	 */
-	dwc3_enable_susphy(&appledwc->dwc, true);
-	phy_set_mode(appledwc->dwc.usb2_generic_phy[0], mode);
-	phy_set_mode(appledwc->dwc.usb3_generic_phy[0], mode);
-}
-
 static int dwc3_apple_init(struct dwc3_apple *appledwc, enum dwc3_apple_state state)
 {
 	int ret, ret_reset;
 
 	lockdep_assert_held(&appledwc->lock);
 
+	/*
+	 * The USB2 PHY on this platform must be configured for host or device mode while it is
+	 * still powered off and before dwc3 tries to access it. Otherwise the new configuration
+	 * will only take affect during the *next* time dwc3 is brought up.
+	 */
+	switch (state) {
+	case DWC3_APPLE_HOST:
+		phy_set_mode(appledwc->dwc.usb2_generic_phy[0], PHY_MODE_USB_HOST);
+		break;
+	case DWC3_APPLE_DEVICE:
+		phy_set_mode(appledwc->dwc.usb2_generic_phy[0], PHY_MODE_USB_DEVICE);
+		break;
+	default:
+		/* Unreachable unless there's a bug in this driver */
+		WARN_ON_ONCE(1);
+		return -EINVAL;
+	}
+
 	ret = reset_control_deassert(appledwc->reset);
 	if (ret) {
 		dev_err(appledwc->dev, "Failed to deassert reset, err=%d\n", ret);
@@ -257,7 +262,13 @@ static int dwc3_apple_init(struct dwc3_apple *appledwc, enum dwc3_apple_state st
 	case DWC3_APPLE_HOST:
 		appledwc->dwc.dr_mode = USB_DR_MODE_HOST;
 		dwc3_apple_set_ptrcap(appledwc, DWC3_GCTL_PRTCAP_HOST);
-		dwc3_apple_phy_set_mode(appledwc, PHY_MODE_USB_HOST);
+		/*
+		 * This platform requires SUSPHY to be enabled here already in order to properly configure
+		 * the PHY and switch dwc3's PIPE interface to USB3 PHY. The USB2 PHY has already been
+		 * configured to the correct mode earlier.
+		 */
+		dwc3_enable_susphy(&appledwc->dwc, true);
+		phy_set_mode(appledwc->dwc.usb3_generic_phy[0], PHY_MODE_USB_HOST);
 		ret = dwc3_host_init(&appledwc->dwc);
 		if (ret) {
 			dev_err(appledwc->dev, "Failed to initialize host, ret=%d\n", ret);
@@ -268,7 +279,13 @@ static int dwc3_apple_init(struct dwc3_apple *appledwc, enum dwc3_apple_state st
 	case DWC3_APPLE_DEVICE:
 		appledwc->dwc.dr_mode = USB_DR_MODE_PERIPHERAL;
 		dwc3_apple_set_ptrcap(appledwc, DWC3_GCTL_PRTCAP_DEVICE);
-		dwc3_apple_phy_set_mode(appledwc, PHY_MODE_USB_DEVICE);
+		/*
+		 * This platform requires SUSPHY to be enabled here already in order to properly configure
+		 * the PHY and switch dwc3's PIPE interface to USB3 PHY. The USB2 PHY has already been
+		 * configured to the correct mode earlier.
+		 */
+		dwc3_enable_susphy(&appledwc->dwc, true);
+		phy_set_mode(appledwc->dwc.usb3_generic_phy[0], PHY_MODE_USB_DEVICE);
 		ret = dwc3_gadget_init(&appledwc->dwc);
 		if (ret) {
 			dev_err(appledwc->dev, "Failed to initialize gadget, ret=%d\n", ret);