Toggle reset line in max98927_i2c_probe. Use a list to store max98927 instances so we do not toggle reset line again if more than one instances share the same reset line.
Signed-off-by: Cheng-Yi Chiang cychiang@chromium.org --- sound/soc/codecs/max98927.c | 78 +++++++++++++++++++++++++++++++++++++++++++++ sound/soc/codecs/max98927.h | 2 ++ 2 files changed, 80 insertions(+)
diff --git a/sound/soc/codecs/max98927.c b/sound/soc/codecs/max98927.c index 941712058a8f5..789b27cdfd9e0 100644 --- a/sound/soc/codecs/max98927.c +++ b/sound/soc/codecs/max98927.c @@ -11,6 +11,7 @@ */
#include <linux/acpi.h> +#include <linux/delay.h> #include <linux/i2c.h> #include <linux/module.h> #include <linux/regmap.h> @@ -24,6 +25,11 @@ #include <sound/tlv.h> #include "max98927.h"
+#define MAX98927_MIN_RESET_US 1 +#define MAX98927_RELEASE_RESET_DELAY_US 500 + +static LIST_HEAD(reset_list); + static struct reg_default max98927_reg[] = { {MAX98927_R0001_INT_RAW1, 0x00}, {MAX98927_R0002_INT_RAW2, 0x00}, @@ -877,6 +883,54 @@ static void max98927_slot_config(struct i2c_client *i2c, max98927->i_l_slot = 1; }
+static int max98927_i2c_toggle_reset(struct device *dev, + struct max98927_priv *max98927) +{ + /* + * If we do not have reset gpio, assume platform firmware + * controls the regulator and toggles it for us. + */ + if (!max98927->reset_gpio) + return 0; + + gpiod_set_value_cansleep(max98927->reset_gpio, 1); + + /* + * We need to wait a bit before we are allowed to release reset GPIO. + */ + usleep_range(MAX98927_MIN_RESET_US, MAX98927_MIN_RESET_US + 5); + + gpiod_set_value_cansleep(max98927->reset_gpio, 0); + + /* + * We need to wait a bit before I2C communication is available. + */ + usleep_range(MAX98927_RELEASE_RESET_DELAY_US, + MAX98927_RELEASE_RESET_DELAY_US + 5); + + /* + * Release reset GPIO because we are not going to use it. + */ + devm_gpiod_put(dev, max98927->reset_gpio); + + return 0; +} + +static bool max98927_is_first_to_reset(struct max98927_priv *max98927) +{ + struct max98927_priv *p; + + if (!max98927->reset_gpio) + return false; + + list_for_each_entry(p, &reset_list, list) { + if (max98927->reset_gpio == p->reset_gpio) + return false; + } + + return true; +} + static int max98927_i2c_probe(struct i2c_client *i2c, const struct i2c_device_id *id) { @@ -904,6 +958,28 @@ static int max98927_i2c_probe(struct i2c_client *i2c, } else max98927->interleave_mode = 0;
+ /* Gets optional GPIO for reset line. */ + max98927->reset_gpio = devm_gpiod_get_optional( + &i2c->dev, "reset", GPIOD_OUT_LOW); + if (IS_ERR(max98927->reset_gpio)) { + ret = PTR_ERR(max98927->reset_gpio); + dev_err(&i2c->dev, "error getting reset gpio: %d\n", ret); + return ret; + } + + /* + * Only toggle reset line for the first instance when the + * reset line is shared among instances. For example, + * left and right amplifier share the same reset line, and + * we should only toggle the reset line once. + */ + if (max98927_is_first_to_reset(max98927)) { + dev_info(&i2c->dev, "%s: toggle reset line\n", __func__); + ret = max98927_i2c_toggle_reset(&i2c->dev, max98927); + if (ret) + return ret; + } + /* regmap initialization */ max98927->regmap = devm_regmap_init_i2c(i2c, &max98927_regmap); @@ -934,6 +1010,8 @@ static int max98927_i2c_probe(struct i2c_client *i2c, if (ret < 0) dev_err(&i2c->dev, "Failed to register component: %d\n", ret);
+ list_add(&max98927->list, &reset_list); + return ret; }
diff --git a/sound/soc/codecs/max98927.h b/sound/soc/codecs/max98927.h index 538992a238b28..d48f61f6c3ba5 100644 --- a/sound/soc/codecs/max98927.h +++ b/sound/soc/codecs/max98927.h @@ -275,5 +275,7 @@ struct max98927_priv { unsigned int master; unsigned int digital_gain; bool tdm_mode; + struct gpio_desc *reset_gpio; + struct list_head list; }; #endif