A lower duty cycle may be less jarring to hear, so give users the possibility to control it via device parameter attached to the PWM beeper device.
Signed-off-by: Ahmad Fatoum <[email protected]> --- drivers/sound/pwm-beeper.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/drivers/sound/pwm-beeper.c b/drivers/sound/pwm-beeper.c index 94b27359c1c3..5e29e953ddc8 100644 --- a/drivers/sound/pwm-beeper.c +++ b/drivers/sound/pwm-beeper.c @@ -14,6 +14,7 @@ struct pwm_beeper { struct pwm_device *pwm; struct regulator *amplifier; struct sound_card card; + u32 duty_cycle; }; #define HZ_TO_NANOSECONDS(x) (1000000000UL/(x)) @@ -33,7 +34,7 @@ static int pwm_beeper_beep(struct sound_card *card, unsigned freq, unsigned dura state.enabled = true; state.period = HZ_TO_NANOSECONDS(freq); - pwm_set_relative_duty_cycle(&state, 50, 100); + pwm_set_relative_duty_cycle(&state, beeper->duty_cycle, 100); error = pwm_apply_state(beeper->pwm, &state); if (error) @@ -49,6 +50,22 @@ static int pwm_beeper_beep(struct sound_card *card, unsigned freq, unsigned dura return error; } +static int pwm_beeper_apply_params(struct param_d *p, void *priv) +{ + struct pwm_beeper *beeper = priv; + struct pwm_state state; + + if (beeper->duty_cycle > 100) + return -EINVAL; + + pwm_get_state(beeper->pwm, &state); + if (!state.enabled) + return 0; + + pwm_set_relative_duty_cycle(&state, beeper->duty_cycle, 100); + return pwm_apply_state(beeper->pwm, &state); +} + static int pwm_beeper_probe(struct device *dev) { struct pwm_beeper *beeper; @@ -74,6 +91,7 @@ static int pwm_beeper_probe(struct device *dev) return error; } + beeper->duty_cycle = 50; beeper->amplifier = regulator_get(dev, "amp"); if (IS_ERR(beeper->amplifier)) return dev_errp_probe(dev, beeper->amplifier, "getting 'amp' regulator\n"); @@ -91,6 +109,9 @@ static int pwm_beeper_probe(struct device *dev) card->bell_frequency = bell_frequency; card->beep = pwm_beeper_beep; + dev_add_param_uint32(dev, "duty_cycle", pwm_beeper_apply_params, + NULL, &beeper->duty_cycle, "%u%", beeper); + return sound_card_register(card); } -- 2.47.3
