From: Mike Willard mwillard@izotope.com
commit ccfc531695f3a4aada042f6bdb33ac6be24e1aec upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- sound/soc/codecs/cs4270.c | 40 +++++++++++++++++++++++++++++++++++----- 1 file changed, 35 insertions(+), 5 deletions(-)
--- a/sound/soc/codecs/cs4270.c +++ b/sound/soc/codecs/cs4270.c @@ -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[] = { @@ -649,6 +652,22 @@ static const struct regmap_config cs4270 };
/** + * 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 * @id: the I2C device ID (ignored) @@ -660,7 +679,6 @@ static int cs4270_i2c_probe(struct i2c_c 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_c 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_driv }, .id_table = cs4270_id, .probe = cs4270_i2c_probe, + .remove = cs4270_i2c_remove, };
module_i2c_driver(cs4270_i2c_driver);