usb: dwc3: core: support optional PHYs

Since PHYs for dwc3 is optional (not all SoCs having PHYs for DWC3
should be programmed), do not return from probe if the USB PHY library
returns -ENODEV as that indicates the platform does not have a
programmable PHY.

While this can be considered as a temporary fix, a long term solution
would be to add 'nop' PHY for platforms that does not have programmable
PHY.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Reviewed-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 14 insertions, 20 deletions

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 8c627c9a5130..c89570cc0689 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -534,32 +534,26 @@ static int dwc3_probe(struct platform_device *pdev)
 
         if (IS_ERR(dwc->usb2_phy)) {
                 ret = PTR_ERR(dwc->usb2_phy);
-
-                /*
-                 * if -ENXIO is returned, it means PHY layer wasn't
-                 * enabled, so it makes no sense to return -EPROBE_DEFER
-                 * in that case, since no PHY driver will ever probe.
-                 */
-                if (ret == -ENXIO)
+                if (ret == -ENXIO || ret == -ENODEV) {
+                        dwc->usb2_phy = NULL;
+                } else if (ret == -EPROBE_DEFER) {
                         return ret;
-
-                dev_err(dev, "no usb2 phy configured\n");
-                return -EPROBE_DEFER;
+                } else {
+                        dev_err(dev, "no usb2 phy configured\n");
+                        return ret;
+                }
         }
 
         if (IS_ERR(dwc->usb3_phy)) {
                 ret = PTR_ERR(dwc->usb3_phy);
-
-                /*
-                 * if -ENXIO is returned, it means PHY layer wasn't
-                 * enabled, so it makes no sense to return -EPROBE_DEFER
-                 * in that case, since no PHY driver will ever probe.
-                 */
-                if (ret == -ENXIO)
+                if (ret == -ENXIO || ret == -ENODEV) {
+                        dwc->usb3_phy = NULL;
+                } else if (ret == -EPROBE_DEFER) {
                         return ret;
-
-                dev_err(dev, "no usb3 phy configured\n");
-                return -EPROBE_DEFER;
+                } else {
+                        dev_err(dev, "no usb3 phy configured\n");
+                        return ret;
+                }
         }
 
         dwc->xhci_resources[0].start = res->start;