diff options
| author | Fabio Estevam <fabio.estevam@nxp.com> | 2017-04-05 11:32:34 -0300 |
|---|---|---|
| committer | Max Krummenacher <max.krummenacher@toradex.com> | 2017-04-05 19:29:29 +0200 |
| commit | 56b32850e08f94d5a5db28454ffce7aeb4ca6be9 (patch) | |
| tree | fe69e597e5c1492a2c5e0ae0faed4f2ecd7caaa6 | |
| parent | bad77047b191c7d62ce1f3e0762f775c5e256d7f (diff) | |
ASoC: sgtl5000: Allow LRCLK pad drive strength to be changed
Introduce the "lrclk-strength" property to allow LRCLK pad drive strength
to be changed via device tree.
When running a stress playback loop test on a mx6dl wandboard channel
swap can be noticed on about 10% of the times.
While debugging this issue I noticed that when probing the SGTL5000
LRCLK pin with the scope the swap did not happen. After removing
the probe the swap started to happen again.
After changing the LRCLK pad drive strength to the maximum value the
issue is gone.
Same fix works on a mx6dl Colibri board as well.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Backport from http://mailman.alsa-project.org/pipermail/alsa-devel/2017-April/119525.html
Conflicts:
Documentation/devicetree/bindings/sound/sgtl5000.txt
sound/soc/codecs/sgtl5000.c
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
| -rw-r--r-- | Documentation/devicetree/bindings/sound/sgtl5000.txt | 9 | ||||
| -rw-r--r-- | sound/soc/codecs/sgtl5000.c | 19 |
2 files changed, 27 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/sound/sgtl5000.txt b/Documentation/devicetree/bindings/sound/sgtl5000.txt index 0e5e4eb3ef1b..62d9465c6c4c 100644 --- a/Documentation/devicetree/bindings/sound/sgtl5000.txt +++ b/Documentation/devicetree/bindings/sound/sgtl5000.txt @@ -26,6 +26,15 @@ Optional properties: - VDDD-supply : the regulator provider of VDDD +- lrclk-strength: the LRCLK pad strength. Possible values are: +0, 1, 2 and 3 as per the table below: + +VDDIO 1.8V 2.5V 3.3V +0 = Disable +1 = 1.66 mA 2.87 mA 4.02 mA +2 = 3.33 mA 5.74 mA 8.03 mA +3 = 4.99 mA 8.61 mA 12.05 mA + Example: codec: sgtl5000@0a { diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c index 3fe5da7ce497..1b15540a11b1 100644 --- a/sound/soc/codecs/sgtl5000.c +++ b/sound/soc/codecs/sgtl5000.c @@ -129,6 +129,13 @@ enum sgtl5000_micbias_resistor { SGTL5000_MICBIAS_8K = 8, }; +enum { + I2S_LRCLK_STRENGTH_DISABLE, + I2S_LRCLK_STRENGTH_LOW, + I2S_LRCLK_STRENGTH_MEDIUM, + I2S_LRCLK_STRENGTH_HIGH, +}; + /* sgtl5000 private structure in codec */ struct sgtl5000_priv { int sysclk; /* sysclk rate */ @@ -141,6 +148,7 @@ struct sgtl5000_priv { int revision; u8 micbias_resistor; u8 micbias_voltage; + u8 lrclk_strength; }; /* @@ -1303,6 +1311,7 @@ err_ldo_remove: static int sgtl5000_probe(struct snd_soc_codec *codec) { int ret; + u16 reg; struct sgtl5000_priv *sgtl5000 = snd_soc_codec_get_drvdata(codec); ret = sgtl5000_enable_regulators(codec); @@ -1336,7 +1345,8 @@ static int sgtl5000_probe(struct snd_soc_codec *codec) SGTL5000_DAC_MUTE_RIGHT | SGTL5000_DAC_MUTE_LEFT); - snd_soc_write(codec, SGTL5000_CHIP_PAD_STRENGTH, 0x015f); + reg = ((sgtl5000->lrclk_strength) << SGTL5000_PAD_I2S_LRCLK_SHIFT | 0x5f); + snd_soc_write(codec, SGTL5000_CHIP_PAD_STRENGTH, reg); snd_soc_write(codec, SGTL5000_CHIP_ANA_CTRL, SGTL5000_HP_ZCD_EN | @@ -1527,6 +1537,13 @@ static int sgtl5000_i2c_probe(struct i2c_client *client, } } + sgtl5000->lrclk_strength = I2S_LRCLK_STRENGTH_LOW; + if (!of_property_read_u32(np, "lrclk-strength", &value)) { + if (value > I2S_LRCLK_STRENGTH_HIGH) + value = I2S_LRCLK_STRENGTH_LOW; + sgtl5000->lrclk_strength = value; + } + i2c_set_clientdata(client, sgtl5000); /* Ensure sgtl5000 will start with sane register values */ |