diff options
| author | Thierry Reding <treding@nvidia.com> | 2013-10-02 20:01:02 +0400 |
|---|---|---|
| committer | Thierry Reding <thierry.reding@gmail.com> | 2013-10-16 11:05:57 +0400 |
| commit | 97c38437115aa0c3fb2d50c488814b503ba529e0 (patch) | |
| tree | f7afc5b092a60ff9e7b7973f15ee9b550e9ab659 /drivers/video/backlight/pwm_bl.c | |
| parent | 62b744a87c1170b339f993aa3cfb22465974816a (diff) | |
| download | linux-97c38437115aa0c3fb2d50c488814b503ba529e0.tar.xz | |
pwm-backlight: Track enable state
Follow up patches will add support for more complex means of powering
the backlight on and off such as using a regulator. To prevent calls to
the regulator API from becoming unbalanced, keep track of the enabled
state internally.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'drivers/video/backlight/pwm_bl.c')
| -rw-r--r-- | drivers/video/backlight/pwm_bl.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index ab9d5e6012a4..4053efbe5edb 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -27,6 +27,7 @@ struct pwm_bl_data { unsigned int period; unsigned int lth_brightness; unsigned int *levels; + bool enabled; int (*notify)(struct device *, int brightness); void (*notify_after)(struct device *, @@ -40,6 +41,9 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness, { int duty_cycle, err; + if (pb->enabled) + return; + if (pb->levels) { duty_cycle = pb->levels[brightness]; max = pb->levels[max]; @@ -52,12 +56,18 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness, pwm_config(pb->pwm, duty_cycle, pb->period); pwm_enable(pb->pwm); + pb->enabled = true; } static void pwm_backlight_power_off(struct pwm_bl_data *pb) { + if (!pb->enabled) + return; + pwm_config(pb->pwm, 0, pb->period); pwm_disable(pb->pwm); + + pb->enabled = false; } static int pwm_backlight_update_status(struct backlight_device *bl) @@ -216,6 +226,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) pb->check_fb = data->check_fb; pb->exit = data->exit; pb->dev = &pdev->dev; + pb->enabled = false; pb->pwm = devm_pwm_get(&pdev->dev, NULL); if (IS_ERR(pb->pwm)) { |