The standby pin can be connected to a GPIO. In that case we have to drive it to the correct values for the TAS6424 to operate properly.
Signed-off-by: Jean-Jacques Hiblot jjhiblot@ti.com --- .../devicetree/bindings/sound/ti,tas6424.txt | 1 + sound/soc/codecs/tas6424.c | 22 ++++++++++++++++++++++ 2 files changed, 23 insertions(+)
diff --git a/Documentation/devicetree/bindings/sound/ti,tas6424.txt b/Documentation/devicetree/bindings/sound/ti,tas6424.txt index 1c4ada0..df71e41 100644 --- a/Documentation/devicetree/bindings/sound/ti,tas6424.txt +++ b/Documentation/devicetree/bindings/sound/ti,tas6424.txt @@ -6,6 +6,7 @@ Required properties: - compatible: "ti,tas6424" - TAS6424 - reg: I2C slave address - sound-dai-cells: must be equal to 0 + - standby-gpios: GPIO used to shut the TAS6424 down.
Example:
diff --git a/sound/soc/codecs/tas6424.c b/sound/soc/codecs/tas6424.c index 4f3a16c..5abb17f 100644 --- a/sound/soc/codecs/tas6424.c +++ b/sound/soc/codecs/tas6424.c @@ -16,6 +16,7 @@ #include <linux/slab.h> #include <linux/regulator/consumer.h> #include <linux/delay.h> +#include <linux/gpio/consumer.h>
#include <sound/pcm.h> #include <sound/pcm_params.h> @@ -43,6 +44,7 @@ struct tas6424_data { unsigned int last_fault1; unsigned int last_fault2; unsigned int last_warn; + struct gpio_desc *standby_gpio; };
/* @@ -627,6 +629,22 @@ static int tas6424_i2c_probe(struct i2c_client *client, return ret; }
+ /* + * Get control of the standby pin and set it LOW to take the codec + * out of the stand-by mode. + * Note: The actual pin polarity is taken care of in the GPIO lib + * according the polarity specified in the DTS. + */ + tas6424->standby_gpio = devm_gpiod_get_optional(dev, "standby", + GPIOD_OUT_LOW); + if (IS_ERR(tas6424->standby_gpio)) { + if (PTR_ERR(tas6424->standby_gpio) == -EPROBE_DEFER) + return -EPROBE_DEFER; + dev_info(dev, "failed to get standby GPIO: %ld\n", + PTR_ERR(tas6424->standby_gpio)); + tas6424->standby_gpio = NULL; + } + for (i = 0; i < ARRAY_SIZE(tas6424->supplies); i++) tas6424->supplies[i].supply = tas6424_supply_names[i]; ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(tas6424->supplies), @@ -671,6 +689,10 @@ static int tas6424_i2c_remove(struct i2c_client *client)
cancel_delayed_work_sync(&tas6424->fault_check_work);
+ /* put the codec in stand-by */ + if (tas6424->standby_gpio) + gpiod_set_value_cansleep(tas6424->standby_gpio, 1); + ret = regulator_bulk_disable(ARRAY_SIZE(tas6424->supplies), tas6424->supplies); if (ret < 0) {