[PATCH v2 1/2] ASoC: rockchip-i2s: dt: add an optional property "i2s_clk_out"

[Jianqun Xu]

Add an property "i2s_clk_out", which enables to output clock to outside
of rockchip SoCs. Let's make it optional since not each board needs it.

Signed-off-by: Jianqun Xu <jay.xu at rock-chips.com>
---
changes since v1:
- make "i2s_clk_out" optional, suggested by Sonny

 Documentation/devicetree/bindings/sound/rockchip-i2s.txt | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/sound/rockchip-i2s.txt b/Documentation/devicetree/bindings/sound/rockchip-i2s.txt
index 9b82c20..6dedd0d 100644
--- a/Documentation/devicetree/bindings/sound/rockchip-i2s.txt
+++ b/Documentation/devicetree/bindings/sound/rockchip-i2s.txt
@@ -22,6 +22,10 @@ Required properties:
    - "i2s_hclk": clock for I2S BUS
    - "i2s_clk" : clock for I2S controller
 
+Optional property:
+   - "i2s_clk_out" : clock output to outside of chip, usally as master clock for audio
+   codec chip
+
 Example for rk3288 I2S controller:
 
 i2s at ff890000 {
@@ -32,6 +36,6 @@ i2s at ff890000 {
 	#size-cells = <0>;
 	dmas = <&pdma1 0>, <&pdma1 1>;
 	dma-names = "tx", "rx";
-	clock-names = "i2s_hclk", "i2s_clk";
-	clocks = <&cru HCLK_I2S0>, <&cru SCLK_I2S0>;
+	clock-names = "i2s_hclk", "i2s_clk", "i2s_clk_out";
+	clocks = <&cru HCLK_I2S0>, <&cru SCLK_I2S0>, <&cru SCLK_I2S0_CLKOUT>;
 };
-- 
1.9.1