USB: Fix of_usb_get_dr_mode_by_phy with a shared phy block

Some SoCs have a single phy-hw-block with multiple phys, this is
modelled by a single phy dts node, so we end up with multiple
controller nodes with a phys property pointing to the phy-node
of the otg-phy.

Only one of these controllers typically is an otg controller, yet we
were checking the first controller who uses a phy from the block and
then end up looking for a dr_mode property in e.g. the ehci controller.

This commit fixes this by adding an arg0 parameter to
of_usb_get_dr_mode_by_phy and make of_usb_get_dr_mode_by_phy
check that this matches the phandle args[0] value when looking for
the otg controller.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

3 files changed, 23 insertions, 9 deletions

diff --git a/drivers/usb/common/common.c b/drivers/usb/common/common.c
index e3d01619d6b3..5ef8da6e67c3 100644
--- a/drivers/usb/common/common.c
+++ b/drivers/usb/common/common.c
@@ -131,15 +131,17 @@ EXPORT_SYMBOL_GPL(usb_get_dr_mode);
  * of_usb_get_dr_mode_by_phy - Get dual role mode for the controller device
  * which is associated with the given phy device_node
  * @np: Pointer to the given phy device_node
+ * @arg0: phandle args[0] for phy's with #phy-cells >= 1, or -1 for
+ *        phys which do not have phy-cells
  *
  * In dts a usb controller associates with phy devices.  The function gets
  * the string from property 'dr_mode' of the controller associated with the
  * given phy device node, and returns the correspondig enum usb_dr_mode.
  */
-enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *phy_np)
+enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
 {
         struct device_node *controller = NULL;
-        struct device_node *phy;
+        struct of_phandle_args args;
         const char *dr_mode;
         int index;
         int err;
@@ -148,12 +150,24 @@ enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *phy_np)
                 controller = of_find_node_with_property(controller, "phys");
                 index = 0;
                 do {
-                        phy = of_parse_phandle(controller, "phys", index);
-                        of_node_put(phy);
-                        if (phy == phy_np)
+                        if (arg0 == -1) {
+                                args.np = of_parse_phandle(controller, "phys",
+                                                        index);
+                                args.args_count = 0;
+                        } else {
+                                err = of_parse_phandle_with_args(controller,
+                                                        "phys", "#phy-cells",
+                                                        index, &args);
+                                if (err)
+                                        break;
+                        }
+
+                        of_node_put(args.np);
+                        if (args.np == np && (args.args_count == 0 ||
+                                              args.args[0] == arg0))
                                 goto finish;
                         index++;
-                } while (phy);
+                } while (args.np);
         } while (controller);
 
 finish:
diff --git a/drivers/usb/phy/phy-am335x.c b/drivers/usb/phy/phy-am335x.c
index a262a4343f29..7e5aece769da 100644
--- a/drivers/usb/phy/phy-am335x.c
+++ b/drivers/usb/phy/phy-am335x.c
@@ -54,7 +54,7 @@ static int am335x_phy_probe(struct platform_device *pdev)
                 return am_phy->id;
         }
 
-        am_phy->dr_mode = of_usb_get_dr_mode_by_phy(pdev->dev.of_node);
+        am_phy->dr_mode = of_usb_get_dr_mode_by_phy(pdev->dev.of_node, -1);
 
         ret = usb_phy_gen_create_phy(dev, &am_phy->usb_phy_gen, NULL);
         if (ret)
diff --git a/include/linux/usb/of.h b/include/linux/usb/of.h
index de3237fce6b2..5ff9032ee1b4 100644
--- a/include/linux/usb/of.h
+++ b/include/linux/usb/of.h
@@ -12,7 +12,7 @@
 #include <linux/usb/phy.h>
 
 #if IS_ENABLED(CONFIG_OF)
-enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *phy_np);
+enum usb_dr_mode of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0);
 bool of_usb_host_tpl_support(struct device_node *np);
 int of_usb_update_otg_caps(struct device_node *np,
                         struct usb_otg_caps *otg_caps);
@@ -20,7 +20,7 @@ struct device_node *usb_of_get_child_node(struct device_node *parent,
                         int portnum);
 #else
 static inline enum usb_dr_mode
-of_usb_get_dr_mode_by_phy(struct device_node *phy_np)
+of_usb_get_dr_mode_by_phy(struct device_node *np, int arg0)
 {
         return USB_DR_MODE_UNKNOWN;
 }