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>

diff --git a/Documentation/devicetree/bindings/sound/sgtl5000.txt b/Documentation/devicetree/bindings/sound/sgtl5000.txt
index d6ec927..1aab403 100644 (file)
--- 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>;
 };

diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c
index c417b4a..59336f6 100644 (file)
--- a/sound/soc/codecs/sgtl5000.c
+++ b/sound/soc/codecs/sgtl5000.c
@@ -140,6 +140,7 @@ struct sgtl5000_priv {
        struct clk *mclk;
        int revision;
        u8 micbias_resistor;
+       u8 micbias_voltage;
 };
 
 /*
@@ -1342,6 +1343,9 @@ static int sgtl5000_probe(struct snd_soc_codec *codec)
                        SGTL5000_BIAS_R_MASK,
                        sgtl5000->micbias_resistor << SGTL5000_BIAS_R_SHIFT);
 
+       snd_soc_update_bits(codec, SGTL5000_CHIP_MIC_CTRL,
+                       SGTL5000_BIAS_R_MASK,
+                       sgtl5000->micbias_voltage << SGTL5000_BIAS_R_SHIFT);
        /*
         * disable DAP
         * TODO:
@@ -1511,10 +1515,19 @@ static int sgtl5000_i2c_probe(struct i2c_client *client,
                        /* default is 4Kohms */
                        sgtl5000->micbias_resistor = 2;
                }
+               if (!of_property_read_u32(np,
+                       "micbias-voltage-m-volts", &value)) {
+                       /* 1250mV => 0 */
+                       /* steps of 250mV */
+                       if ((value >= 1250) && (value <= 3000))
+                               sgtl5000->micbias_voltage = (value / 250) - 5;
+                       else {
+                               sgtl5000->micbias_voltage = 0;
                                dev_err(&client->dev,
                                        "Unsuitable MicBias resistor\n");
                        }
                } else {
+                       sgtl5000->micbias_voltage = 0;
                }
        }