Commit 79b23b56 authored by Daniel Mack's avatar Daniel Mack Committed by Mark Brown
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ASoC: tas5086: add support for pwm start mode config 



The TAS5086 has two alternative modes to start its PWM channels, Mid-Z
and Low-Z. Which one to use depends on how the PWM power stages are
connected to the TAS5086.

This patch adds 6 optional boolean properties to the DT bindings of the
driver which allow the user to configure each individual channel to the
Mid-Z scheme, and leaves all the others to the default (Low-Z).

Signed-off-by: default avatarDaniel Mack <zonque@gmail.com>
Signed-off-by: default avatarMark Brown <broonie@linaro.org>
parent 18710acd

Documentation/devicetree/bindings/sound/ti,tas5086.txt

+11 −0
Original line number Diff line number Diff line
@@ -20,6 +20,17 @@ Optional properties: 
			When not specified, the hardware default of 1300ms

			is retained.



 - ti,mid-z-channel-X:	Boolean properties, X being a number from 1 to 6.

			If given, channel X will start with the Mid-Z start

			sequence, otherwise the default Low-Z scheme is used.



			The correct configuration depends on how the power

			stages connected to the PWM output pins work. Not all

			power stages are compatible to Mid-Z - please refer

			to the datasheets for more details.



			Most systems should not set any of these properties.



Examples:



	i2c_bus {

sound/soc/codecs/tas5086.c

+22 −0
Original line number Diff line number Diff line
@@ -88,6 +88,10 @@ 


#define TAS5086_MAX_REGISTER		TAS5086_PWM_OUTPUT_MUX



#define TAS5086_PWM_START_MIDZ_FOR_START_1	(1 << 7)

#define TAS5086_PWM_START_MIDZ_FOR_START_2	(1 << 6)

#define TAS5086_PWM_START_CHANNEL_MASK		(0x3f)



/*

 * Default TAS5086 power-up configuration

 */
@@ -717,12 +721,30 @@ static int tas5086_probe(struct snd_soc_codec *codec) 
{

	struct tas5086_private *priv = snd_soc_codec_get_drvdata(codec);

	int charge_period = 1300000; /* hardware default is 1300 ms */

	u8 pwm_start = TAS5086_PWM_START_CHANNEL_MASK;

	int i, ret;



	if (of_match_device(of_match_ptr(tas5086_dt_ids), codec->dev)) {

		struct device_node *of_node = codec->dev->of_node;

		of_property_read_u32(of_node, "ti,charge-period", &charge_period);



		for (i = 0; i < 6; i++) {

			char name[25];



			snprintf(name, sizeof(name),

				 "ti,mid-z-channel-%d", i + 1);



			if (of_get_property(of_node, name, NULL) != NULL)

				pwm_start &= ~(1 << i);

		}

	}



	/*

	 * Configure 'part 2' of the PWM starts to always use MID-Z, and tell

	 * all configured mid-z channels to start start under 'part 2'.

	 */

	regmap_write(priv->regmap, TAS5086_PWM_START,

		     TAS5086_PWM_START_MIDZ_FOR_START_2 | pwm_start);



	/* lookup and set split-capacitor charge period */

	if (charge_period == 0) {

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