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@xxxxxx>
---
.../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) {
--
2.7.4
--
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