Commit 87357797 authored by Jean-Michel Hautbois's avatar Jean-Michel Hautbois Committed by Mark Brown
Browse files

ASoC: sgtl5000: Add MicBias voltage support 



Some systems may require to specify a bias different than default (1.25V).
This adds a property in sgtl5000 codec.
The property is specified in milli-volts so that it is coherent with datasheet.

Signed-off-by: default avatarJean-Michel Hautbois <jean-michel.hautbois@vodalys.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent bd0593f5

Documentation/devicetree/bindings/sound/sgtl5000.txt

+6 −1
Original line number Diff line number Diff line
@@ -13,6 +13,10 @@ Required properties: 
	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.



Example:
@@ -20,5 +24,6 @@ codec: sgtl5000@0a { 
	compatible = "fsl,sgtl5000";

	reg = <0x0a>;

	clocks = <&clks 150>;

	sgtl5000-micbias-resistor = <1>;

	micbias-resistor-k-ohms = <2>;

	micbias-voltage-m-volts = <2250>;

};

sound/soc/codecs/sgtl5000.c

+13 −0
Original line number Diff line number Diff line
@@ -140,6 +140,7 @@ struct sgtl5000_priv { 
	struct clk *mclk;

	int revision;

	u8 micbias_resistor;

	u8 micbias_voltage;

};



/*
@@ -1342,6 +1343,9 @@ static int sgtl5000_probe(struct snd_soc_codec *codec) 
			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:
@@ -1511,10 +1515,19 @@ static int sgtl5000_i2c_probe(struct i2c_client *client, 
			/* 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;

		}

	}

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