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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
parentpwm-backlight: Improve readability (diff)
downloadlinux-62b744a87c1170b339f993aa3cfb22465974816a.tar.xz
linux-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>
-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);