ASoC: sgtl5000: Add MicBias voltage support

Some systems may require to specify a bias different than default (1.25V).
This adds a property in sgtl5000 codec.
The property is specified in milli-volts so that it is coherent with datasheet.

Signed-off-by: Jean-Michel Hautbois <jean-michel.hautbois@vodalys.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/Documentation/devicetree/bindings/sound/sgtl5000.txt b/Documentation/devicetree/bindings/sound/sgtl5000.txt
index d6ec92707d81..1aab40339617 100644
--- a/Documentation/devicetree/bindings/sound/sgtl5000.txt
+++ b/Documentation/devicetree/bindings/sound/sgtl5000.txt
@@ -13,6 +13,10 @@ Required properties:
         If this node is not mentioned or if the value is unknown, then
         micbias resistor is set to 4K.
 
+- micbias-voltage-m-volts : the bias voltage to be used in mVolts
+        The voltage can take values from 1.25V to 3V by 250mV steps
+        If this node is not mentionned or the value is unknown, then
+        the value is set to 1.25V.
 
 Example:
 
@@ -20,5 +24,6 @@ codec: sgtl5000@0a {
         compatible = "fsl,sgtl5000";
         reg = <0x0a>;
         clocks = <&clks 150>;
-        sgtl5000-micbias-resistor = <1>;
+        micbias-resistor-k-ohms = <2>;
+        micbias-voltage-m-volts = <2250>;
 };