phy: bcm-ns-usb2: new driver for USB 2.0 PHY on Northstar

Northstar is a family of SoCs used in home routers. They have USB 2.0
and 3.0 controllers with PHYs that need to be properly initialized.
This driver provides PHY init support in a generic way and can be bound
with an EHCI controller driver.
There are (just a few) registers being defined in bcma header. It's
because DMU/CRU registers will be also needed in other drivers. We will
need them e.g. in PCIe controller/PHY driver and at some point probably
in clock driver for BCM53573 chipset. By using include/linux/bcma/ we
avoid code duplication.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/phy/bcm-ns-usb2-phy.txt b/Documentation/devicetree/bindings/phy/bcm-ns-usb2-phy.txt
new file mode 100644
index 000000000000..a7aee9ea8926
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/bcm-ns-usb2-phy.txt
@@ -0,0 +1,21 @@
+Driver for Broadcom Northstar USB 2.0 PHY
+
+Required properties:
+- compatible: brcm,ns-usb2-phy
+- reg: iomem address range of DMU (Device Management Unit)
+- reg-names: "dmu", the only needed & supported reg right now
+- clocks: USB PHY reference clock
+- clock-names: "phy-ref-clk", the only needed & supported clock right now
+
+To initialize USB 2.0 PHY driver needs to setup PLL correctly. To do this it
+requires passing phandle to the USB PHY reference clock.
+
+Example:
+	usb2-phy {
+		compatible = "brcm,ns-usb2-phy";
+		reg = <0x1800c000 0x1000>;
+		reg-names = "dmu";
+		#phy-cells = <0>;
+		clocks = <&genpll BCM_NSP_GENPLL_USB_PHY_REF_CLK>;
+		clock-names = "phy-ref-clk";
+	};