diff options
Diffstat (limited to 'drivers/pwm/pwm-pca9685.c')
| -rw-r--r-- | drivers/pwm/pwm-pca9685.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c index b740b824bda9..5db62e5af518 100644 --- a/drivers/pwm/pwm-pca9685.c +++ b/drivers/pwm/pwm-pca9685.c @@ -331,6 +331,41 @@ static int pca9685_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, return 0; } +static void pca9685_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) +{ + struct pca9685 *pca = to_pca(chip); + unsigned long long duty; + unsigned int val = 0; + + /* Calculate (chip-wide) period from prescale value */ + regmap_read(pca->regmap, PCA9685_PRESCALE, &val); + /* + * PCA9685_OSC_CLOCK_MHZ is 25, i.e. an integer divider of 1000. + * The following calculation is therefore only a multiplication + * and we are not losing precision. + */ + state->period = (PCA9685_COUNTER_RANGE * 1000 / PCA9685_OSC_CLOCK_MHZ) * + (val + 1); + + /* The (per-channel) polarity is fixed */ + state->polarity = PWM_POLARITY_NORMAL; + + if (pwm->hwpwm >= PCA9685_MAXCHAN) { + /* + * The "all LEDs" channel does not support HW readout + * Return 0 and disabled for backwards compatibility + */ + state->duty_cycle = 0; + state->enabled = false; + return; + } + + state->enabled = true; + duty = pca9685_pwm_get_duty(pca, pwm->hwpwm); + state->duty_cycle = DIV_ROUND_DOWN_ULL(duty * state->period, PCA9685_COUNTER_RANGE); +} + static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) { struct pca9685 *pca = to_pca(chip); @@ -353,6 +388,7 @@ static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) static const struct pwm_ops pca9685_pwm_ops = { .apply = pca9685_pwm_apply, + .get_state = pca9685_pwm_get_state, .request = pca9685_pwm_request, .free = pca9685_pwm_free, .owner = THIS_MODULE, |