diff options
Diffstat (limited to 'drivers/leds/leds-pwm.c')
-rw-r--r-- | drivers/leds/leds-pwm.c | 61 |
1 files changed, 60 insertions, 1 deletions
diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c index 3ed92f34bd4..9c5f7136b37 100644 --- a/drivers/leds/leds-pwm.c +++ b/drivers/leds/leds-pwm.c @@ -27,9 +27,60 @@ struct led_pwm_data { struct led_classdev cdev; struct pwm_device *pwm; unsigned int active_low; + unsigned int lth_brightness; unsigned int period; + unsigned int dutycycle_steps; + unsigned int period_steps; }; +static int led_pwm_blink_set(struct led_classdev *led_cdev, + unsigned long *delay_on, unsigned long *delay_off) +{ + struct led_pwm_data *led_dat = + container_of(led_cdev, struct led_pwm_data, cdev); + int dutycycle_ms, period_sec; + int dutycycle, period; + /* + * If both the delays are zero set some sensible delay + */ + if (*delay_on == 0 && *delay_off == 0) { + *delay_on = 500; + *delay_off = 500; + } + /* + * calculate the duty cycle from on and off time + */ + dutycycle_ms = ((*delay_on * 1000)/(*delay_on + *delay_off)); + /* + * convert calculated value to write into the PWM out register + */ + if (led_dat->dutycycle_steps) + dutycycle = ((dutycycle_ms * led_dat->dutycycle_steps)/1000); + else + dutycycle = (dutycycle_ms/1000); + /* + * calculate period from on and off time(msec) + */ + period_sec = ((*delay_on + *delay_off)/1000); + /* + * convert calculated value to write into the PWM out register + */ + if (led_dat->period_steps) { + if ((*delay_on + *delay_off) == 500) + period = led_dat->period_steps; + else + period = led_dat->period_steps - period_sec; + } + else + period = period_sec; + /* + * configure the PWM registers and enable blink functionality + */ + pwm_config_blink(led_dat->pwm, dutycycle, period); + pwm_blink_ctrl(led_dat->pwm, 1); + return 0; +} + static void led_pwm_set(struct led_classdev *led_cdev, enum led_brightness brightness) { @@ -42,7 +93,10 @@ static void led_pwm_set(struct led_classdev *led_cdev, pwm_config(led_dat->pwm, 0, period); pwm_disable(led_dat->pwm); } else { - pwm_config(led_dat->pwm, brightness * period / max, period); + brightness = led_dat->lth_brightness + (brightness * + (led_dat->period - led_dat->lth_brightness) / max); + pwm_config(led_dat->pwm, brightness, led_dat->period); + pwm_enable(led_dat->pwm); } } @@ -79,8 +133,13 @@ static int led_pwm_probe(struct platform_device *pdev) led_dat->cdev.default_trigger = cur_led->default_trigger; led_dat->active_low = cur_led->active_low; led_dat->period = cur_led->pwm_period_ns; + led_dat->lth_brightness = cur_led->lth_brightness * + (cur_led->pwm_period_ns / cur_led->max_brightness); + led_dat->dutycycle_steps = cur_led->dutycycle_steps; + led_dat->period_steps = cur_led->period_steps; led_dat->cdev.brightness_set = led_pwm_set; led_dat->cdev.brightness = LED_OFF; + led_dat->cdev.blink_set = led_pwm_blink_set; led_dat->cdev.max_brightness = cur_led->max_brightness; led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; |