clk: add gpio gated clock

The added gpio-gate-clock is a basic clock that can be enabled and
disabled trough a gpio output. The DT binding document for the clock
is also added. For EPROBE_DEFER handling the registering of the clock
has to be delayed until of_clk_get() call time.

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

1 files changed, 21 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/clock/gpio-gate-clock.txt b/Documentation/devicetree/bindings/clock/gpio-gate-clock.txt
new file mode 100644
index 000000000000..d3379ff9b84b
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/gpio-gate-clock.txt
@@ -0,0 +1,21 @@
+Binding for simple gpio gated clock.
+
+This binding uses the common clock binding[1].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible : shall be "gpio-gate-clock".
+- #clock-cells : from common clock binding; shall be set to 0.
+- enable-gpios : GPIO reference for enabling and disabling the clock.
+
+Optional properties:
+- clocks: Maximum of one parent clock is supported.
+
+Example:
+	clock {
+		compatible = "gpio-gate-clock";
+		clocks = <&parentclk>;
+		#clock-cells = <0>;
+		enable-gpios = <&gpio 1 GPIO_ACTIVE_HIGH>;
+	};