phy: rcar-gen3-usb2: Add R-Car Gen3 USB2 PHY driver

This patch adds support for R-Car generation 3 USB2 PHY driver.
This SoC has 3 EHCI/OHCI channels, and the channel 0 is shared
with the HSUSB (USB2.0 peripheral) device. And each channel has
independent registers about the PHYs.

So, the purpose of this driver is:
 1) initializes some registers of SoC specific to use the
    {ehci,ohci}-platform driver.

 2) detects id pin to select host or peripheral on the channel 0.

For now, this driver only supports 1) above.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/phy/rcar-gen3-phy-usb2.txt b/Documentation/devicetree/bindings/phy/rcar-gen3-phy-usb2.txt
new file mode 100644
index 000000000000..affa0f72658b
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/rcar-gen3-phy-usb2.txt
@@ -0,0 +1,37 @@
+* Renesas R-Car generation 3 USB 2.0 PHY
+
+This file provides information on what the device node for the R-Car generation
+3 USB 2.0 PHY contains.
+
+Required properties:
+- compatible: "renesas,usb2-phy-r8a7795" if the device is a part of an R8A7795
+	      SoC.
+- reg: offset and length of the partial USB 2.0 Host register block.
+- reg-names: must be "usb2_host".
+- clocks: clock phandle and specifier pair(s).
+- #phy-cells: see phy-bindings.txt in the same directory, must be <0>.
+
+Optional properties:
+To use a USB channel where USB 2.0 Host and HSUSB (USB 2.0 Peripheral) are
+combined, the device tree node should set HSUSB properties to reg and reg-names
+properties. This is because HSUSB has registers to select USB 2.0 host or
+peripheral at that channel:
+- reg: offset and length of the partial HSUSB register block.
+- reg-names: must be "hsusb".
+
+Example (R-Car H3):
+
+	usb-phy@ee080200 {
+		compatible = "renesas,usb2-phy-r8a7795";
+		reg = <0 0xee080200 0 0x700>, <0 0xe6590100 0 0x100>;
+		reg-names = "usb2_host", "hsusb";
+		clocks = <&mstp7_clks R8A7795_CLK_EHCI0>,
+			 <&mstp7_clks R8A7795_CLK_HSUSB>;
+	};
+
+	usb-phy@ee0a0200 {
+		compatible = "renesas,usb2-phy-r8a7795";
+		reg = <0 0xee0a0200 0 0x700>;
+		reg-names = "usb2_host";
+		clocks = <&mstp7_clks R8A7795_CLK_EHCI0>;
+	};