Reset the prescale and ON/OFF registers to their POR default state in the probe function. Otherwise, the PWMs could still be active after a watchdog reset and reboot, etc.
Signed-off-by: Clemens Gruber <[email protected]> --- drivers/pwm/pwm-pca9685.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c index 7b14447f3c05..38aadaf50996 100644 --- a/drivers/pwm/pwm-pca9685.c +++ b/drivers/pwm/pwm-pca9685.c @@ -47,6 +47,7 @@ #define PCA9685_ALL_LED_OFF_H 0xFD #define PCA9685_PRESCALE 0xFE +#define PCA9685_PRESCALE_DEF 0x1E /* => default frequency of ~200 Hz */ #define PCA9685_PRESCALE_MIN 0x03 /* => max. frequency of 1526 Hz */ #define PCA9685_PRESCALE_MAX 0xFF /* => min. frequency of 24 Hz */ @@ -446,9 +447,11 @@ static int pca9685_pwm_probe(struct i2c_client *client, reg &= ~(MODE1_ALLCALL | MODE1_SUB1 | MODE1_SUB2 | MODE1_SUB3); regmap_write(pca->regmap, PCA9685_MODE1, reg); - /* Clear all "full off" bits */ + /* Reset ON/OFF registers to HW defaults (only full OFF bit is set) */ + regmap_write(pca->regmap, PCA9685_ALL_LED_ON_L, 0); + regmap_write(pca->regmap, PCA9685_ALL_LED_ON_H, 0); regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0); - regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0); + regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, LED_FULL); pca->chip.ops = &pca9685_pwm_ops; /* Add an extra channel for ALL_LED */ @@ -470,8 +473,10 @@ static int pca9685_pwm_probe(struct i2c_client *client, /* * The chip comes out of power-up in the sleep state, * but force it to sleep in case it was woken up before + * and set the default prescale value */ pca9685_set_sleep_mode(pca, true); + regmap_write(pca->regmap, PCA9685_PRESCALE, PCA9685_PRESCALE_DEF); pm_runtime_set_suspended(&client->dev); pm_runtime_enable(&client->dev); -- 2.29.2
