clk: ti: add composite clock support

This is a multipurpose clock node, which contains support for multiple
sub-clocks. Uses basic composite clock type to implement the actual
functionality, and TI specific gate, mux and divider clocks.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

1 files changed, 54 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/clock/ti/composite.txt b/Documentation/devicetree/bindings/clock/ti/composite.txt
new file mode 100644
index 000000000000..5f43c4706b09
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/ti/composite.txt
@@ -0,0 +1,54 @@
+Binding for TI composite clock.
+
+Binding status: Unstable - ABI compatibility may be broken in the future
+
+This binding uses the common clock binding[1]. It assumes a
+register-mapped composite clock with multiple different sub-types;
+
+a multiplexer clock with multiple input clock signals or parents, one
+of which can be selected as output, this behaves exactly as [2]
+
+an adjustable clock rate divider, this behaves exactly as [3]
+
+a gating function which can be used to enable and disable the output
+clock, this behaves exactly as [4]
+
+The binding must provide a list of the component clocks that shall be
+merged to this clock. The component clocks shall be of one of the
+"ti,*composite*-clock" types.
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+[2] Documentation/devicetree/bindings/clock/ti/mux.txt
+[3] Documentation/devicetree/bindings/clock/ti/divider.txt
+[4] Documentation/devicetree/bindings/clock/ti/gate.txt
+
+Required properties:
+- compatible : shall be: "ti,composite-clock"
+- clocks : link phandles of component clocks
+- #clock-cells : from common clock binding; shall be set to 0.
+
+Examples:
+
+usb_l4_gate_ick: usb_l4_gate_ick {
+	#clock-cells = <0>;
+	compatible = "ti,composite-interface-clock";
+	clocks = <&l4_ick>;
+	ti,bit-shift = <5>;
+	reg = <0x0a10>;
+};
+
+usb_l4_div_ick: usb_l4_div_ick {
+	#clock-cells = <0>;
+	compatible = "ti,composite-divider-clock";
+	clocks = <&l4_ick>;
+	ti,bit-shift = <4>;
+	ti,max-div = <1>;
+	reg = <0x0a40>;
+	ti,index-starts-at-one;
+};
+
+usb_l4_ick: usb_l4_ick {
+	#clock-cells = <0>;
+	compatible = "ti,composite-clock";
+	clocks = <&usb_l4_gate_ick>, <&usb_l4_div_ick>;
+};