2 files changed, 92 insertions, 19 deletions

diff --git a/Documentation/devicetree/bindings/sound/sgtl5000.txt b/Documentation/devicetree/bindings/sound/sgtl5000.txt
index d556dcb8816b..0e5e4eb3ef1b 100644
--- a/Documentation/devicetree/bindings/sound/sgtl5000.txt
+++ b/Documentation/devicetree/bindings/sound/sgtl5000.txt
@@ -7,6 +7,17 @@ Required properties:
 
 - clocks : the clock provider of SYS_MCLK
 
+- micbias-resistor-k-ohms : the bias resistor to be used in kOmhs
+        The resistor can take values of 2k, 4k or 8k.
+        If set to 0 it will be off.
+        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.
+
 - VDDA-supply : the regulator provider of VDDA
 
 - VDDIO-supply: the regulator provider of VDDIO
@@ -21,6 +32,8 @@ codec: sgtl5000@0a {
         compatible = "fsl,sgtl5000";
         reg = <0x0a>;
         clocks = <&clks 150>;
+        micbias-resistor-k-ohms = <2>;
+        micbias-voltage-m-volts = <2250>;
         VDDA-supply = <&reg_3p3v>;
         VDDIO-supply = <&reg_3p3v>;
 };
diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c
index 6bb77d76561b..490404c6b4d8 100644
--- a/sound/soc/codecs/sgtl5000.c
+++ b/sound/soc/codecs/sgtl5000.c
@@ -16,6 +16,7 @@
 #include <linux/pm.h>
 #include <linux/i2c.h>
 #include <linux/clk.h>
+#include <linux/log2.h>
 #include <linux/regmap.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
@@ -121,6 +122,13 @@ struct ldo_regulator {
         bool enabled;
 };
 
+enum sgtl5000_micbias_resistor {
+        SGTL5000_MICBIAS_OFF = 0,
+        SGTL5000_MICBIAS_2K = 2,
+        SGTL5000_MICBIAS_4K = 4,
+        SGTL5000_MICBIAS_8K = 8,
+};
+
 /* sgtl5000 private structure in codec */
 struct sgtl5000_priv {
         int sysclk;     /* sysclk rate */
@@ -131,6 +139,8 @@ struct sgtl5000_priv {
         struct regmap *regmap;
         struct clk *mclk;
         int revision;
+        u8 micbias_resistor;
+        u8 micbias_voltage;
 };
 
 /*
@@ -145,12 +155,14 @@ struct sgtl5000_priv {
 static int mic_bias_event(struct snd_soc_dapm_widget *w,
         struct snd_kcontrol *kcontrol, int event)
 {
+        struct sgtl5000_priv *sgtl5000 = snd_soc_codec_get_drvdata(w->codec);
+
         switch (event) {
         case SND_SOC_DAPM_POST_PMU:
-                /* change mic bias resistor to 4Kohm */
+                /* change mic bias resistor */
                 snd_soc_update_bits(w->codec, SGTL5000_CHIP_MIC_CTRL,
-                                SGTL5000_BIAS_R_MASK,
-                                SGTL5000_BIAS_R_4k << SGTL5000_BIAS_R_SHIFT);
+                        SGTL5000_BIAS_R_MASK,
+                        sgtl5000->micbias_resistor << SGTL5000_BIAS_R_SHIFT);
                 break;
 
         case SND_SOC_DAPM_PRE_PMD:
@@ -530,16 +542,16 @@ static int sgtl5000_set_dai_sysclk(struct snd_soc_dai *codec_dai,
 
 /*
  * set clock according to i2s frame clock,
- * sgtl5000 provide 2 clock sources.
- * 1. sys_mclk. sample freq can only configure to
+ * sgtl5000 provides 2 clock sources:
+ * 1. sys_mclk: sample freq can only be configured to
  *      1/256, 1/384, 1/512 of sys_mclk.
- * 2. pll. can derive any audio clocks.
+ * 2. pll: can derive any audio clocks.
  *
  * clock setting rules:
- * 1. in slave mode, only sys_mclk can use.
- * 2. as constraint by sys_mclk, sample freq should
- *      set to 32k, 44.1k and above.
- * 3. using sys_mclk prefer to pll to save power.
+ * 1. in slave mode, only sys_mclk can be used
+ * 2. as constraint by sys_mclk, sample freq should be set to 32 kHz, 44.1 kHz
+ * and above.
+ * 3. usage of sys_mclk is preferred over pll to save power.
  */
 static int sgtl5000_set_clock(struct snd_soc_codec *codec, int frame_rate)
 {
@@ -549,8 +561,8 @@ static int sgtl5000_set_clock(struct snd_soc_codec *codec, int frame_rate)
 
         /*
          * sample freq should be divided by frame clock,
-         * if frame clock lower than 44.1khz, sample feq should set to
-         * 32khz or 44.1khz.
+         * if frame clock is lower than 44.1 kHz, sample freq should be set to
+         * 32 kHz or 44.1 kHz.
          */
         switch (frame_rate) {
         case 8000:
@@ -603,7 +615,8 @@ static int sgtl5000_set_clock(struct snd_soc_codec *codec, int frame_rate)
 
         /*
          * calculate the divider of mclk/sample_freq,
-         * factor of freq =96k can only be 256, since mclk in range (12m,27m)
+         * factor of freq = 96 kHz can only be 256, since mclk is in the range
+         * of 8 MHz - 27 MHz
          */
         switch (sgtl5000->sysclk / sys_fs) {
         case 256:
@@ -619,7 +632,7 @@ static int sgtl5000_set_clock(struct snd_soc_codec *codec, int frame_rate)
                         SGTL5000_MCLK_FREQ_SHIFT;
                 break;
         default:
-                /* if mclk not satisify the divider, use pll */
+                /* if mclk does not satisfy the divider, use pll */
                 if (sgtl5000->master) {
                         clk_ctl |= SGTL5000_MCLK_FREQ_PLL <<
                                 SGTL5000_MCLK_FREQ_SHIFT;
@@ -795,7 +808,7 @@ static int ldo_regulator_enable(struct regulator_dev *dev)
                                 SGTL5000_LINEREG_D_POWERUP,
                                 SGTL5000_LINEREG_D_POWERUP);
 
-        /* when internal ldo enabled, simple digital power can be disabled */
+        /* when internal ldo is enabled, simple digital power can be disabled */
         snd_soc_update_bits(codec, SGTL5000_CHIP_ANA_POWER,
                                 SGTL5000_LINREG_SIMPLE_POWERUP,
                                 0);
@@ -1079,7 +1092,7 @@ static bool sgtl5000_readable(struct device *dev, unsigned int reg)
 /*
  * sgtl5000 has 3 internal power supplies:
  * 1. VAG, normally set to vdda/2
- * 2. chargepump, set to different value
+ * 2. charge pump, set to different value
  *      according to voltage of vdda and vddio
  * 3. line out VAG, normally set to vddio/2
  *
@@ -1326,8 +1339,13 @@ static int sgtl5000_probe(struct snd_soc_codec *codec)
                         SGTL5000_HP_ZCD_EN |
                         SGTL5000_ADC_ZCD_EN);
 
-        snd_soc_write(codec, SGTL5000_CHIP_MIC_CTRL, 2);
+        snd_soc_update_bits(codec, SGTL5000_CHIP_MIC_CTRL,
+                        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:
@@ -1418,9 +1436,10 @@ static int sgtl5000_i2c_probe(struct i2c_client *client,
         struct sgtl5000_priv *sgtl5000;
         int ret, reg, rev;
         unsigned int mclk;
+        struct device_node *np = client->dev.of_node;
+        u32 value;
 
-        sgtl5000 = devm_kzalloc(&client->dev, sizeof(struct sgtl5000_priv),
-                                                                GFP_KERNEL);
+        sgtl5000 = devm_kzalloc(&client->dev, sizeof(*sgtl5000), GFP_KERNEL);
         if (!sgtl5000)
                 return -ENOMEM;
 
@@ -1470,6 +1489,47 @@ static int sgtl5000_i2c_probe(struct i2c_client *client,
         dev_info(&client->dev, "sgtl5000 revision 0x%x\n", rev);
         sgtl5000->revision = rev;
 
+        if (np) {
+                if (!of_property_read_u32(np,
+                        "micbias-resistor-k-ohms", &value)) {
+                        switch (value) {
+                        case SGTL5000_MICBIAS_OFF:
+                                sgtl5000->micbias_resistor = 0;
+                                break;
+                        case SGTL5000_MICBIAS_2K:
+                                sgtl5000->micbias_resistor = 1;
+                                break;
+                        case SGTL5000_MICBIAS_4K:
+                                sgtl5000->micbias_resistor = 2;
+                                break;
+                        case SGTL5000_MICBIAS_8K:
+                                sgtl5000->micbias_resistor = 3;
+                                break;
+                        default:
+                                sgtl5000->micbias_resistor = 2;
+                                dev_err(&client->dev,
+                                        "Unsuitable MicBias resistor\n");
+                        }
+                } else {
+                        /* 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;
+                }
+        }
+
         i2c_set_clientdata(client, sgtl5000);
 
         /* Ensure sgtl5000 will start with sane register values */