phy: rockchip-usb: should be a child device of the GRF

The usb-phy is fully enclosed in the general register files (GRF).
Therefore as seen from the device-tree it shouldn't be a separate
platform-device but instead a sub-device of the GRF - using the
simply-mfd mechanism.

As the usb-phy is part of the kernel for some releases now, we keep
the old (and now deprecated) binding for compatibility purposes.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Documentation/devicetree/bindings/phy/rockchip-usb-phy.txt

@@ -5,11 +5,13 @@ Required properties:
      "rockchip,rk3066a-usb-phy"
      "rockchip,rk3188-usb-phy"
      "rockchip,rk3288-usb-phy"
- - rockchip,grf : phandle to the syscon managing the "general
-   register files"
  - #address-cells: should be 1
  - #size-cells: should be 0
 
+Deprecated properties:
+ - rockchip,grf : phandle to the syscon managing the "general
+   register files" - phy should be a child of the GRF instead
+
 Sub-nodes:
 Each PHY should be represented as a sub-node.
 
@@ -28,14 +30,19 @@ Optional Properties:
 
 Example:
 
-usbphy: phy {
-	compatible = "rockchip,rk3288-usb-phy";
-	rockchip,grf = <&grf>;
-	#address-cells = <1>;
-	#size-cells = <0>;
+grf: syscon@ff770000 {
+	compatible = "rockchip,rk3288-grf", "syscon", "simple-mfd";
+
+...
+
+	usbphy: phy {
+		compatible = "rockchip,rk3288-usb-phy";
+		#address-cells = <1>;
+		#size-cells = <0>;
 
-	usbphy0: usb-phy0 {
-		#phy-cells = <0>;
-		reg = <0x320>;
+		usbphy0: usb-phy0 {
+			#phy-cells = <0>;
+			reg = <0x320>;
+		};
 	};
 };

drivers/phy/phy-rockchip-usb.c

@@ -397,8 +397,13 @@ static int rockchip_usb_phy_probe(struct platform_device *pdev)
 	phy_base->pdata = match->data;
 
 	phy_base->dev = dev;
-	phy_base->reg_base = syscon_regmap_lookup_by_phandle(dev->of_node,
-							     "rockchip,grf");
+	phy_base->reg_base = ERR_PTR(-ENODEV);
+	if (dev->parent && dev->parent->of_node)
+		phy_base->reg_base = syscon_node_to_regmap(
+						dev->parent->of_node);
+	if (IS_ERR(phy_base->reg_base))
+		phy_base->reg_base = syscon_regmap_lookup_by_phandle(
+						dev->of_node, "rockchip,grf");
 	if (IS_ERR(phy_base->reg_base)) {
 		dev_err(&pdev->dev, "Missing rockchip,grf property\n");
 		return PTR_ERR(phy_base->reg_base);
@@ -463,7 +468,11 @@ static int __init rockchip_init_usb_uart(void)
 		return -ENOTSUPP;
 	}
 
-	grf = syscon_regmap_lookup_by_phandle(np, "rockchip,grf");
+	grf = ERR_PTR(-ENODEV);
+	if (np->parent)
+		grf = syscon_node_to_regmap(np->parent);
+	if (IS_ERR(grf))
+		grf = syscon_regmap_lookup_by_phandle(np, "rockchip,grf");
 	if (IS_ERR(grf)) {
 		pr_err("%s: Missing rockchip,grf property, %lu\n",
 		       __func__, PTR_ERR(grf));