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ASoC: cs4270: pull reset GPIO low then high

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Pull the RST line low then high when initializing the driver,
in order to force a reset of the chip.
Previously, the line was not pulled low, which could result in
the chip registers not resetting to their default values on boot.

Signed-off-by: Mike Willard <mwillard@izotope.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200401205454.79792-1-mwillard@izotope.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Mike Willard 2020-04-01 20:54:54 +00:00 committed by Mark Brown
parent 4146575eb0
commit ccfc531695
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 35 additions and 5 deletions
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40
sound/soc/codecs/cs4270.c
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@ -137,6 +137,9 @@ struct cs4270_private {
/* power domain regulators */
struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)];
/* reset gpio */
struct gpio_desc *reset_gpio;
};
static const struct snd_soc_dapm_widget cs4270_dapm_widgets[] = {
@ -648,6 +651,22 @@ static const struct regmap_config cs4270_regmap = {
.volatile_reg = cs4270_reg_is_volatile,
};
/**
* cs4270_i2c_remove - deinitialize the I2C interface of the CS4270
* @i2c_client: the I2C client object
*
* This function puts the chip into low power mode when the i2c device
* is removed.
*/
static int cs4270_i2c_remove(struct i2c_client *i2c_client)
{
struct cs4270_private *cs4270 = i2c_get_clientdata(i2c_client);
gpiod_set_value_cansleep(cs4270->reset_gpio, 0);
return 0;
}
/**
* cs4270_i2c_probe - initialize the I2C interface of the CS4270
* @i2c_client: the I2C client object
@ -660,7 +679,6 @@ static int cs4270_i2c_probe(struct i2c_client *i2c_client,
const struct i2c_device_id *id)
{
struct cs4270_private *cs4270;
struct gpio_desc *reset_gpiod;
unsigned int val;
int ret, i;
@ -679,10 +697,21 @@ static int cs4270_i2c_probe(struct i2c_client *i2c_client,
if (ret < 0)
return ret;
reset_gpiod = devm_gpiod_get_optional(&i2c_client->dev, "reset",
GPIOD_OUT_HIGH);
if (PTR_ERR(reset_gpiod) == -EPROBE_DEFER)
return -EPROBE_DEFER;
/* reset the device */
cs4270->reset_gpio = devm_gpiod_get_optional(&i2c_client->dev, "reset",
GPIOD_OUT_LOW);
if (IS_ERR(cs4270->reset_gpio)) {
dev_dbg(&i2c_client->dev, "Error getting CS4270 reset GPIO\n");
return PTR_ERR(cs4270->reset_gpio);
}
if (cs4270->reset_gpio) {
dev_dbg(&i2c_client->dev, "Found reset GPIO\n");
gpiod_set_value_cansleep(cs4270->reset_gpio, 1);
}
/* Sleep 500ns before i2c communications */
ndelay(500);
cs4270->regmap = devm_regmap_init_i2c(i2c_client, &cs4270_regmap);
if (IS_ERR(cs4270->regmap))
@ -735,6 +764,7 @@ static struct i2c_driver cs4270_i2c_driver = {
},
.id_table = cs4270_id,
.probe = cs4270_i2c_probe,
.remove = cs4270_i2c_remove,
};
module_i2c_driver(cs4270_i2c_driver);