[PATCH v2 2/3] ASoC: sun50i-codec-analog: Add support for internal bias

From: Samuel Holland
Date: Mon Jun 20 2022 - 23:55:09 EST


From: Arnaud Ferraris <arnaud.ferraris@xxxxxxxxxxxxx>

In order to properly bias headset microphones, there should be a pull-up
resistor between pins HBIAS and MIC2P. This can be an external resistor,
but the codec also provides an internal 2.2K resistor which is enabled
by a register.

This patch enables or disables the internal bias resistor based on a
device tree property.

Signed-off-by: Arnaud Ferraris <arnaud.ferraris@xxxxxxxxxxxxx>
[Samuel: split binding and implementation; move to device probe]
Signed-off-by: Samuel Holland <samuel@xxxxxxxxxxxx>
---

Changes in v2:
- Move register update from component probe to device probe

sound/soc/sunxi/sun50i-codec-analog.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/sound/soc/sunxi/sun50i-codec-analog.c b/sound/soc/sunxi/sun50i-codec-analog.c
index a41e25ad0aaf..e1e5e8de0130 100644
--- a/sound/soc/sunxi/sun50i-codec-analog.c
+++ b/sound/soc/sunxi/sun50i-codec-analog.c
@@ -117,6 +117,7 @@
#define SUN50I_ADDA_HS_MBIAS_CTRL_MMICBIASEN 7

#define SUN50I_ADDA_JACK_MIC_CTRL 0x1d
+#define SUN50I_ADDA_JACK_MIC_CTRL_INNERRESEN 6
#define SUN50I_ADDA_JACK_MIC_CTRL_HMICBIASEN 5

/* mixer controls */
@@ -507,6 +508,7 @@ static int sun50i_codec_analog_probe(struct platform_device *pdev)
{
struct regmap *regmap;
void __iomem *base;
+ bool enable;

base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base)) {
@@ -520,6 +522,12 @@ static int sun50i_codec_analog_probe(struct platform_device *pdev)
return PTR_ERR(regmap);
}

+ enable = device_property_read_bool(&pdev->dev,
+ "allwinner,internal-bias-resistor");
+ regmap_update_bits(regmap, SUN50I_ADDA_JACK_MIC_CTRL,
+ BIT(SUN50I_ADDA_JACK_MIC_CTRL_INNERRESEN),
+ enable << SUN50I_ADDA_JACK_MIC_CTRL_INNERRESEN);
+
return devm_snd_soc_register_component(&pdev->dev,
&sun50i_codec_analog_cmpnt_drv,
NULL, 0);
--
2.35.1