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ASoC: tas5086: add support for pwm start mode config

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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: Daniel Mack <zonque@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
This commit is contained in:
Daniel Mack 2013-06-24 16:25:32 +02:00 committed by Mark Brown
parent 18710acdee
commit 79b23b5640
2 changed files with 33 additions and 0 deletions
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11
Documentation/devicetree/bindings/sound/ti,tas5086.txt
View file

@ -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 {

22
sound/soc/codecs/tas5086.c
View file

@ -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
*/
@ -717,13 +721,31 @@ 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) {
regmap_write(priv->regmap, TAS5086_SPLIT_CAP_CHARGE, 0);