Some systems may require a different resistor than the default one (4K).
This adds a property in sgtl5000 codec.
It keeps the default of 4K when nothing is specified so it does not break
existing code.
Signed-off-by: Jean-Michel Hautbois <jean-michel.hautbois@xxxxxxxxxxx>
---
.../devicetree/bindings/sound/sgtl5000.txt | 8 ++++
sound/soc/codecs/sgtl5000.c | 55 ++++++++++++++++++++--
2 files changed, 59 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/sound/sgtl5000.txt b/Documentation/devicetree/bindings/sound/sgtl5000.txt
index 955df60..d6ec927 100644
--- a/Documentation/devicetree/bindings/sound/sgtl5000.txt
+++ b/Documentation/devicetree/bindings/sound/sgtl5000.txt
@@ -7,10 +7,18 @@ 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.
+
+
Example:
codec: sgtl5000@0a {
compatible = "fsl,sgtl5000";
reg = <0x0a>;
clocks = <&clks 150>;
+ sgtl5000-micbias-resistor = <1>;
};
diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c
index 6bb77d7..f0b40a6 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 +139,7 @@ struct sgtl5000_priv {
struct regmap *regmap;
struct clk *mclk;
int revision;
+ u8 micbias_resistor;
};
/*
@@ -145,12 +154,14 @@ 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:
@@ -1326,7 +1337,9 @@ 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);
/*
* disable DAP
@@ -1418,6 +1431,8 @@ 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);
@@ -1470,6 +1485,38 @@ 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_2K:
+ sgtl5000->micbias_resistor = 2;
+ break;
+ case SGTL5000_MICBIAS_2K:
+ 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;
+ }
+ dev_err(&client->dev,
+ "Unsuitable MicBias resistor\n");
+ }
+ } else {
+ }
+ }
+
i2c_set_clientdata(client, sgtl5000);
/* Ensure sgtl5000 will start with sane register values */
--
2.1.1
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