summaryrefslogtreecommitdiffstats
path: root/drivers
diff options
context:
space:
mode:
authorThierry Reding <treding@nvidia.com>2013-10-07 11:32:02 +0200
committerThierry Reding <thierry.reding@gmail.com>2013-10-16 09:05:56 +0200
commit62b744a87c1170b339f993aa3cfb22465974816a (patch)
tree88a702d8c151b788eab8faeb9297d058ed9a628c /drivers
parent668e63c6701d486c68b49ffffc0e5b7de1a2e95c (diff)
downloadlinux-stable-62b744a87c1170b339f993aa3cfb22465974816a.tar.gz
linux-stable-62b744a87c1170b339f993aa3cfb22465974816a.tar.bz2
linux-stable-62b744a87c1170b339f993aa3cfb22465974816a.zip
pwm-backlight: Refactor backlight power on/off
In preparation for adding an optional regulator and enable GPIO to the driver, split the power on and power off sequences into separate functions to reduce code duplication at the multiple call sites. Signed-off-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/video/backlight/pwm_bl.c53
1 files changed, 31 insertions, 22 deletions
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 774bce38ba42..ab9d5e6012a4 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -35,6 +35,31 @@ struct pwm_bl_data {
void (*exit)(struct device *);
};
+static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness,
+ int max)
+{
+ int duty_cycle, err;
+
+ if (pb->levels) {
+ duty_cycle = pb->levels[brightness];
+ max = pb->levels[max];
+ } else {
+ duty_cycle = brightness;
+ }
+
+ duty_cycle = (duty_cycle * (pb->period - pb->lth_brightness) / max) +
+ pb->lth_brightness;
+
+ pwm_config(pb->pwm, duty_cycle, pb->period);
+ pwm_enable(pb->pwm);
+}
+
+static void pwm_backlight_power_off(struct pwm_bl_data *pb)
+{
+ pwm_config(pb->pwm, 0, pb->period);
+ pwm_disable(pb->pwm);
+}
+
static int pwm_backlight_update_status(struct backlight_device *bl)
{
struct pwm_bl_data *pb = bl_get_data(bl);
@@ -49,24 +74,10 @@ static int pwm_backlight_update_status(struct backlight_device *bl)
if (pb->notify)
brightness = pb->notify(pb->dev, brightness);
- if (brightness == 0) {
- pwm_config(pb->pwm, 0, pb->period);
- pwm_disable(pb->pwm);
- } else {
- int duty_cycle;
-
- if (pb->levels) {
- duty_cycle = pb->levels[brightness];
- max = pb->levels[max];
- } else {
- duty_cycle = brightness;
- }
-
- duty_cycle = pb->lth_brightness +
- (duty_cycle * (pb->period - pb->lth_brightness) / max);
- pwm_config(pb->pwm, duty_cycle, pb->period);
- pwm_enable(pb->pwm);
- }
+ if (brightness > 0)
+ pwm_backlight_power_on(pb, brightness, max);
+ else
+ pwm_backlight_power_off(pb);
if (pb->notify_after)
pb->notify_after(pb->dev, brightness);
@@ -267,8 +278,7 @@ static int pwm_backlight_remove(struct platform_device *pdev)
struct pwm_bl_data *pb = bl_get_data(bl);
backlight_device_unregister(bl);
- pwm_config(pb->pwm, 0, pb->period);
- pwm_disable(pb->pwm);
+ pwm_backlight_power_off(pb);
if (pb->exit)
pb->exit(&pdev->dev);
@@ -285,8 +295,7 @@ static int pwm_backlight_suspend(struct device *dev)
if (pb->notify)
pb->notify(pb->dev, 0);
- pwm_config(pb->pwm, 0, pb->period);
- pwm_disable(pb->pwm);
+ pwm_backlight_power_off(pb);
if (pb->notify_after)
pb->notify_after(pb->dev, 0);