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path: root/drivers/video/backlight/pwm_bl.c
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Diffstat (limited to 'drivers/video/backlight/pwm_bl.c')
-rw-r--r--drivers/video/backlight/pwm_bl.c29
1 files changed, 15 insertions, 14 deletions
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index eec6c98527f9..32e96e3525a1 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -34,6 +34,7 @@ struct pwm_bl_data {
struct regulator *power_supply;
int enable_gpio;
unsigned long enable_gpio_flags;
+ unsigned int scale;
int (*notify)(struct device *,
int brightness);
void (*notify_after)(struct device *,
@@ -42,23 +43,20 @@ struct pwm_bl_data {
void (*exit)(struct device *);
};
-static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness,
- int max)
+static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness)
{
+ unsigned int lth = pb->lth_brightness;
int duty_cycle, err;
if (pb->enabled)
return;
- if (pb->levels) {
+ if (pb->levels)
duty_cycle = pb->levels[brightness];
- max = pb->levels[max];
- } else {
+ else
duty_cycle = brightness;
- }
- duty_cycle = (duty_cycle * (pb->period - pb->lth_brightness) / max) +
- pb->lth_brightness;
+ duty_cycle = (duty_cycle * (pb->period - lth) / pb->scale) + lth;
pwm_config(pb->pwm, duty_cycle, pb->period);
@@ -100,7 +98,6 @@ static int pwm_backlight_update_status(struct backlight_device *bl)
{
struct pwm_bl_data *pb = bl_get_data(bl);
int brightness = bl->props.brightness;
- int max = bl->props.max_brightness;
if (bl->props.power != FB_BLANK_UNBLANK ||
bl->props.fb_blank != FB_BLANK_UNBLANK ||
@@ -111,7 +108,7 @@ static int pwm_backlight_update_status(struct backlight_device *bl)
brightness = pb->notify(pb->dev, brightness);
if (brightness > 0)
- pwm_backlight_power_on(pb, brightness, max);
+ pwm_backlight_power_on(pb, brightness);
else
pwm_backlight_power_off(pb);
@@ -218,7 +215,6 @@ static int pwm_backlight_probe(struct platform_device *pdev)
struct backlight_properties props;
struct backlight_device *bl;
struct pwm_bl_data *pb;
- unsigned int max;
int ret;
if (!data) {
@@ -245,10 +241,15 @@ static int pwm_backlight_probe(struct platform_device *pdev)
}
if (data->levels) {
- max = data->levels[data->max_brightness];
+ unsigned int i;
+
+ for (i = 0; i <= data->max_brightness; i++)
+ if (data->levels[i] > pb->scale)
+ pb->scale = data->levels[i];
+
pb->levels = data->levels;
} else
- max = data->max_brightness;
+ pb->scale = data->max_brightness;
pb->enable_gpio = data->enable_gpio;
pb->enable_gpio_flags = data->enable_gpio_flags;
@@ -304,7 +305,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
pwm_set_period(pb->pwm, data->pwm_period_ns);
pb->period = pwm_get_period(pb->pwm);
- pb->lth_brightness = data->lth_brightness * (pb->period / max);
+ pb->lth_brightness = data->lth_brightness * (pb->period / pb->scale);
memset(&props, 0, sizeof(struct backlight_properties));
props.type = BACKLIGHT_RAW;