ASoC: max98090: read micbias from device property

This patch reads max98090 micbias from acpi or dt

Signed-off-by: Fang, Yang A <yang.a.fang@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

2 files changed, 18 insertions, 1 deletions

diff --git a/Documentation/devicetree/bindings/sound/max98090.txt b/Documentation/devicetree/bindings/sound/max98090.txt
index aa802a274520..4e3be6682c98 100644
--- a/Documentation/devicetree/bindings/sound/max98090.txt
+++ b/Documentation/devicetree/bindings/sound/max98090.txt
@@ -18,6 +18,12 @@ Optional properties:
 
 - maxim,dmic-freq: Frequency at which to clock DMIC
 
+- maxim,micbias: Micbias voltage applies to the analog mic, valid voltages value are:
+        0 - 2.2v
+        1 - 2.55v
+        2 - 2.4v
+        3 - 2.8v
+
 Pins on the device (for linking into audio routes):
 
   * MIC1
diff --git a/sound/soc/codecs/max98090.c b/sound/soc/codecs/max98090.c
index 3e33ef2acf3c..9d80c68abdd5 100644
--- a/sound/soc/codecs/max98090.c
+++ b/sound/soc/codecs/max98090.c
@@ -2422,6 +2422,8 @@ static int max98090_probe(struct snd_soc_codec *codec)
         struct max98090_cdata *cdata;
         enum max98090_type devtype;
         int ret = 0;
+        int err;
+        unsigned int micbias;
 
         dev_dbg(codec->dev, "max98090_probe\n");
 
@@ -2506,8 +2508,17 @@ static int max98090_probe(struct snd_soc_codec *codec)
         snd_soc_write(codec, M98090_REG_BIAS_CONTROL,
                 M98090_VCM_MODE_MASK);
 
+        err = device_property_read_u32(codec->dev, "maxim,micbias", &micbias);
+        if (err) {
+                micbias = M98090_MBVSEL_2V8;
+                dev_info(codec->dev, "use default 2.8v micbias\n");
+        } else if (micbias < M98090_MBVSEL_2V2 || micbias > M98090_MBVSEL_2V8) {
+                dev_err(codec->dev, "micbias out of range 0x%x\n", micbias);
+                micbias = M98090_MBVSEL_2V8;
+        }
+
         snd_soc_update_bits(codec, M98090_REG_MIC_BIAS_VOLTAGE,
-                M98090_MBVSEL_MASK, M98090_MBVSEL_2V8);
+                M98090_MBVSEL_MASK, micbias);
 
         max98090_add_widgets(codec);