diff options
| author | Florian Vaussard <florian.vaussard@epfl.ch> | 2013-01-28 06:00:59 -0800 |
|---|---|---|
| committer | Bryan Wu <cooloney@gmail.com> | 2013-04-01 11:04:50 -0700 |
| commit | c971ff185f6443e834686f140ba6d6e341ced600 (patch) | |
| tree | fef36e139acb29b2797c94861ee763817440b8dd /drivers/leds | |
| parent | 24d321284745cbc593fba8115585329d48703704 (diff) | |
leds: leds-pwm: Defer led_pwm_set() if PWM can sleep
Call to led_pwm_set() can happen inside atomic context, like triggers.
If the PWM call can sleep, defer using a worker.
Signed-off-by: Florian Vaussard <florian.vaussard@epfl.ch>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Diffstat (limited to 'drivers/leds')
| -rw-r--r-- | drivers/leds/leds-pwm.c | 50 |
1 files changed, 42 insertions, 8 deletions
diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c index a1ea5f6a8d39..faf52c005e8c 100644 --- a/drivers/leds/leds-pwm.c +++ b/drivers/leds/leds-pwm.c @@ -23,12 +23,16 @@ #include <linux/pwm.h> #include <linux/leds_pwm.h> #include <linux/slab.h> +#include <linux/workqueue.h> struct led_pwm_data { struct led_classdev cdev; struct pwm_device *pwm; + struct work_struct work; unsigned int active_low; unsigned int period; + int duty; + bool can_sleep; }; struct led_pwm_priv { @@ -36,6 +40,26 @@ struct led_pwm_priv { struct led_pwm_data leds[0]; }; +static void __led_pwm_set(struct led_pwm_data *led_dat) +{ + int new_duty = led_dat->duty; + + pwm_config(led_dat->pwm, new_duty, led_dat->period); + + if (new_duty == 0) + pwm_disable(led_dat->pwm); + else + pwm_enable(led_dat->pwm); +} + +static void led_pwm_work(struct work_struct *work) +{ + struct led_pwm_data *led_dat = + container_of(work, struct led_pwm_data, work); + + __led_pwm_set(led_dat); +} + static void led_pwm_set(struct led_classdev *led_cdev, enum led_brightness brightness) { @@ -44,13 +68,12 @@ static void led_pwm_set(struct led_classdev *led_cdev, unsigned int max = led_dat->cdev.max_brightness; unsigned int period = led_dat->period; - if (brightness == 0) { - pwm_config(led_dat->pwm, 0, period); - pwm_disable(led_dat->pwm); - } else { - pwm_config(led_dat->pwm, brightness * period / max, period); - pwm_enable(led_dat->pwm); - } + led_dat->duty = brightness * period / max; + + if (led_dat->can_sleep) + schedule_work(&led_dat->work); + else + __led_pwm_set(led_dat); } static inline size_t sizeof_pwm_leds_priv(int num_leds) @@ -100,6 +123,10 @@ static struct led_pwm_priv *led_pwm_create_of(struct platform_device *pdev) led_dat->cdev.brightness = LED_OFF; led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; + led_dat->can_sleep = pwm_can_sleep(led_dat->pwm); + if (led_dat->can_sleep) + INIT_WORK(&led_dat->work, led_pwm_work); + ret = led_classdev_register(&pdev->dev, &led_dat->cdev); if (ret < 0) { dev_err(&pdev->dev, "failed to register for %s\n", @@ -153,6 +180,10 @@ static int led_pwm_probe(struct platform_device *pdev) led_dat->cdev.max_brightness = cur_led->max_brightness; led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME; + led_dat->can_sleep = pwm_can_sleep(led_dat->pwm); + if (led_dat->can_sleep) + INIT_WORK(&led_dat->work, led_pwm_work); + ret = led_classdev_register(&pdev->dev, &led_dat->cdev); if (ret < 0) goto err; @@ -180,8 +211,11 @@ static int led_pwm_remove(struct platform_device *pdev) struct led_pwm_priv *priv = platform_get_drvdata(pdev); int i; - for (i = 0; i < priv->num_leds; i++) + for (i = 0; i < priv->num_leds; i++) { led_classdev_unregister(&priv->leds[i].cdev); + if (priv->leds[i].can_sleep) + cancel_work_sync(&priv->leds[i].work); + } return 0; } |