Currently, disabling a pwm channel clears the OFF registers, which resets the configured duty cycle. Therefore, after a disable/enable sequence, the pwm state is not in the same state as it was before. As a workaround, the user had to do a config call after disable/enable.
Fix it by only toggling the "full-off" bit in disable/enable and no longer use the "full-on" / "full-off" bits in config. >From now on, the "full-on" bit is only used in GPIO mode and the "full-off" bit is only used in disable/enable, which also reduces complexity in the driver. Signed-off-by: Clemens Gruber <[email protected]> --- drivers/pwm/pwm-pca9685.c | 83 +++++---------------------------------- 1 file changed, 9 insertions(+), 74 deletions(-) diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c index 4a55dc18656c..df214758256e 100644 --- a/drivers/pwm/pwm-pca9685.c +++ b/drivers/pwm/pwm-pca9685.c @@ -283,45 +283,7 @@ static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, } } - if (duty_ns < 1) { - if (pwm->hwpwm >= PCA9685_MAXCHAN) - reg = PCA9685_ALL_LED_OFF_H; - else - reg = LED_N_OFF_H(pwm->hwpwm); - - regmap_write(pca->regmap, reg, LED_FULL); - - return 0; - } - - if (duty_ns == period_ns) { - /* Clear both OFF registers */ - if (pwm->hwpwm >= PCA9685_MAXCHAN) - reg = PCA9685_ALL_LED_OFF_L; - else - reg = LED_N_OFF_L(pwm->hwpwm); - - regmap_write(pca->regmap, reg, 0x0); - - if (pwm->hwpwm >= PCA9685_MAXCHAN) - reg = PCA9685_ALL_LED_OFF_H; - else - reg = LED_N_OFF_H(pwm->hwpwm); - - regmap_write(pca->regmap, reg, 0x0); - - /* Set the full ON bit */ - if (pwm->hwpwm >= PCA9685_MAXCHAN) - reg = PCA9685_ALL_LED_ON_H; - else - reg = LED_N_ON_H(pwm->hwpwm); - - regmap_write(pca->regmap, reg, LED_FULL); - - return 0; - } - - duty = PCA9685_COUNTER_RANGE * (unsigned long long)duty_ns; + duty = (PCA9685_COUNTER_RANGE - 1) * (unsigned long long)duty_ns; duty = DIV_ROUND_UP_ULL(duty, period_ns); if (pwm->hwpwm >= PCA9685_MAXCHAN) @@ -338,14 +300,6 @@ static int pca9685_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, regmap_write(pca->regmap, reg, ((int)duty >> 8) & 0xf); - /* Clear the full ON bit, otherwise the set OFF time has no effect */ - if (pwm->hwpwm >= PCA9685_MAXCHAN) - reg = PCA9685_ALL_LED_ON_H; - else - reg = LED_N_ON_H(pwm->hwpwm); - - regmap_write(pca->regmap, reg, 0); - return 0; } @@ -354,24 +308,6 @@ static int pca9685_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) struct pca9685 *pca = to_pca(chip); unsigned int reg; - /* - * The PWM subsystem does not support a pre-delay. - * So, set the ON-timeout to 0 - */ - if (pwm->hwpwm >= PCA9685_MAXCHAN) - reg = PCA9685_ALL_LED_ON_L; - else - reg = LED_N_ON_L(pwm->hwpwm); - - regmap_write(pca->regmap, reg, 0); - - if (pwm->hwpwm >= PCA9685_MAXCHAN) - reg = PCA9685_ALL_LED_ON_H; - else - reg = LED_N_ON_H(pwm->hwpwm); - - regmap_write(pca->regmap, reg, 0); - /* * Clear the full-off bit. * It has precedence over the others and must be off. @@ -391,20 +327,16 @@ static void pca9685_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) struct pca9685 *pca = to_pca(chip); unsigned int reg; + /* + * Set the full-off bit. + * It has precedence over the others. + */ if (pwm->hwpwm >= PCA9685_MAXCHAN) reg = PCA9685_ALL_LED_OFF_H; else reg = LED_N_OFF_H(pwm->hwpwm); - regmap_write(pca->regmap, reg, LED_FULL); - - /* Clear the LED_OFF counter. */ - if (pwm->hwpwm >= PCA9685_MAXCHAN) - reg = PCA9685_ALL_LED_OFF_L; - else - reg = LED_N_OFF_L(pwm->hwpwm); - - regmap_write(pca->regmap, reg, 0x0); + regmap_update_bits(pca->regmap, reg, LED_FULL, LED_FULL); } static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) @@ -487,6 +419,9 @@ static int pca9685_pwm_probe(struct i2c_client *client, /* Clear all "full off" bits */ regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0); regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0); + /* Clear all "on" regs */ + regmap_write(pca->regmap, PCA9685_ALL_LED_ON_L, 0); + regmap_write(pca->regmap, PCA9685_ALL_LED_ON_H, 0); pca->chip.ops = &pca9685_pwm_ops; /* Add an extra channel for ALL_LED */ -- 2.29.2
