clk: add gpio controlled clock multiplexer

Add a common clock driver for basic gpio controlled clock multiplexers.
This driver can be used for devices like 5V41068A or 831721I from IDT
or for discrete multiplexer circuits. The 'select' pin selects one of
two parent clocks.

Cc: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Sergej Sawazki <ce3a@gmx.de>
[sboyd@codeaurora.org: Fix error paths to free memory and do it
in the correct order]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/clock/gpio-mux-clock.txt b/Documentation/devicetree/bindings/clock/gpio-mux-clock.txt
new file mode 100644
index 000000000000..2be1e038ca62
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/gpio-mux-clock.txt
@@ -0,0 +1,19 @@
+Binding for simple gpio clock multiplexer.
+
+This binding uses the common clock binding[1].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible : shall be "gpio-mux-clock".
+- clocks: list of two references to parent clocks.
+- #clock-cells : from common clock binding; shall be set to 0.
+- select-gpios : GPIO reference for selecting the parent clock.
+
+Example:
+	clock {
+		compatible = "gpio-mux-clock";
+		clocks = <&parentclk1>, <&parentclk2>;
+		#clock-cells = <0>;
+		select-gpios = <&gpio 1 GPIO_ACTIVE_HIGH>;
+	};