On Sun, Oct 12, 2014 at 10:39:11PM +0100, Jean-Michel Hautbois wrote:
> 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.
>
> v2: modify the default case on DT parsing
>
> Signed-off-by: Jean-Michel Hautbois <[email protected]>
> ---
> .../devicetree/bindings/sound/sgtl5000.txt | 10 ++++
> sound/soc/codecs/sgtl5000.c | 60
> ++++++++++++++++++++--
> 2 files changed, 66 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/sound/sgtl5000.txt
> b/Documentation/devicetree/bindings/sound/sgtl5000.txt
> index 955df60..dd38f84 100644
> --- a/Documentation/devicetree/bindings/sound/sgtl5000.txt
> +++ b/Documentation/devicetree/bindings/sound/sgtl5000.txt
> @@ -7,10 +7,20 @@ Required properties:
>
> - clocks : the clock provider of SYS_MCLK
>
> +- sgtl5000-micbias-resistor : the bias resistor to be used
> + 1 or SGTL5000_MICBIAS_2K - MICBIAS resistor is set to 2K
> + 2 or SGTL5000_MICBIAS_4K - MICBIAS resistor is set to 4K
> + 3 or SGTL5000_MICBIAS_8K - MICBIAS resistor is set to 8K
> + 0 or SGTL5000_MICBIAS_OFF - MICBIAS resistor is not used
> + If this node is not mentioned or if the value is unknown, then
> + micbias resistor is set to 4K.
The SGTL5000_MICBIAS_* constants aren't in a DT header, so shouldn't be
referenced here.
Why not have mcbias-resistor-k-ohms as 2, 4, 8, or 0?
That would be much easier to read as a human.
Thanks,
Mark.
> +
> +
> 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..a255754 100644
> --- a/sound/soc/codecs/sgtl5000.c
> +++ b/sound/soc/codecs/sgtl5000.c
> @@ -121,6 +121,13 @@ struct ldo_regulator {
> bool enabled;
> };
>
> +enum sgtl5000_micbias_resistor {
> + SGTL5000_MICBIAS_OFF = 0,
> + SGTL5000_MICBIAS_2K = 1,
> + SGTL5000_MICBIAS_4K = 2,
> + SGTL5000_MICBIAS_8K = 3,
> +};
> +
> /* sgtl5000 private structure in codec */
> struct sgtl5000_priv {
> int sysclk; /* sysclk rate */
> @@ -131,6 +138,7 @@ struct sgtl5000_priv {
> struct regmap *regmap;
> struct clk *mclk;
> int revision;
> + enum sgtl5000_micbias_resistor micbias_resistor;
> };
>
> /*
> @@ -145,12 +153,14 @@ 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 +1336,16 @@ 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);
> + switch (sgtl5000->micbias_resistor) {
> + case SGTL5000_MICBIAS_2K:
> + case SGTL5000_MICBIAS_4K:
> + case SGTL5000_MICBIAS_8K:
> + snd_soc_update_bits(codec, SGTL5000_CHIP_MIC_CTRL,
> + SGTL5000_BIAS_R_MASK,
> + sgtl5000->micbias_resistor << SGTL5000_BIAS_R_SHIFT);
> + default:
> + break;
> + }
>
> /*
> * disable DAP
> @@ -1418,6 +1437,8 @@ 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 +1491,37 @@ 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,
> + "sgtl5000-micbias-resistor", &value)) {
> + switch (value) {
> + case 0:
> + sgtl5000->micbias_resistor =
> + SGTL5000_MICBIAS_OFF;
> + break;
> + case 1:
> + sgtl5000->micbias_resistor =
> + SGTL5000_MICBIAS_2K;
> + break;
> + case 2:
> + sgtl5000->micbias_resistor =
> + SGTL5000_MICBIAS_4K;
> + break;
> + case 3:
> + sgtl5000->micbias_resistor =
> + SGTL5000_MICBIAS_8K;
> + break;
> + default:
> + sgtl5000->micbias_resistor =
> + SGTL5000_MICBIAS_4K;
> + dev_err(&client->dev,
> + "Unsuitable MicBias resistor\n");
> + }
> + } else {
> + sgtl5000->micbias_resistor = SGTL5000_MICBIAS_4K;
> + }
> + }
> +
> i2c_set_clientdata(client, sgtl5000);
>
> /* Ensure sgtl5000 will start with sane register values */
> --
> 2.1.1
>
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