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 --- .../devicetree/bindings/sound/ti,tas5086.txt | 11 +++++++++++ sound/soc/codecs/tas5086.c | 22 ++++++++++++++++++++++ 2 files changed, 33 insertions(+)
diff --git a/Documentation/devicetree/bindings/sound/ti,tas5086.txt b/Documentation/devicetree/bindings/sound/ti,tas5086.txt index e8310f1..f199f7d 100644 --- a/Documentation/devicetree/bindings/sound/ti,tas5086.txt +++ b/Documentation/devicetree/bindings/sound/ti,tas5086.txt @@ -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 { diff --git a/sound/soc/codecs/tas5086.c b/sound/soc/codecs/tas5086.c index 99e190d..fec9a28 100644 --- a/sound/soc/codecs/tas5086.c +++ b/sound/soc/codecs/tas5086.c @@ -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);