summaryrefslogtreecommitdiffstats
path: root/drivers/video/backlight/backlight.c
diff options
context:
space:
mode:
authorRichard Purdie <rpurdie@rpsys.net>2006-03-31 02:31:49 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-31 12:19:00 -0800
commit6ca017658b1f902c9bba2cc1017e301581f7728d (patch)
tree9180b3923d4f6ef09c11d7f7386024f391508759 /drivers/video/backlight/backlight.c
parent9b0e1c5dd2941aec566047e10a5cc929ca7f7d4f (diff)
downloadblackbird-op-linux-6ca017658b1f902c9bba2cc1017e301581f7728d.tar.gz
blackbird-op-linux-6ca017658b1f902c9bba2cc1017e301581f7728d.zip
[PATCH] backlight: Backlight Class Improvements
Backlight class attributes are currently easy to implement incorrectly. Moving certain handling into the backlight core prevents this whilst at the same time makes the drivers simpler and consistent. The following changes are included: The brightness attribute only sets and reads the brightness variable in the backlight_properties structure. The power attribute only sets and reads the power variable in the backlight_properties structure. Any framebuffer blanking events change a variable fb_blank in the backlight_properties structure. The backlight driver has only two functions to implement. One function is called when any of the above properties change (to update the backlight brightness), the second is called to return the current backlight brightness value. A new attribute "actual_brightness" is added to return this brightness as determined by the driver having combined all the above factors (and any driver/device specific factors). Additionally, the backlight core takes care of checking the maximum brightness is not exceeded and of turning off the backlight before device removal. The corgi backlight driver is updated to reflect these changes. Signed-off-by: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Antonino Daplas <adaplas@pol.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/video/backlight/backlight.c')
-rw-r--r--drivers/video/backlight/backlight.c84
1 files changed, 56 insertions, 28 deletions
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 151fda8dded0..334b1db1bd7c 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -16,14 +16,12 @@
static ssize_t backlight_show_power(struct class_device *cdev, char *buf)
{
- int rc;
+ int rc = -ENXIO;
struct backlight_device *bd = to_backlight_device(cdev);
down(&bd->sem);
- if (likely(bd->props && bd->props->get_power))
- rc = sprintf(buf, "%d\n", bd->props->get_power(bd));
- else
- rc = -ENXIO;
+ if (likely(bd->props))
+ rc = sprintf(buf, "%d\n", bd->props->power);
up(&bd->sem);
return rc;
@@ -31,7 +29,7 @@ static ssize_t backlight_show_power(struct class_device *cdev, char *buf)
static ssize_t backlight_store_power(struct class_device *cdev, const char *buf, size_t count)
{
- int rc, power;
+ int rc = -ENXIO, power;
char *endp;
struct backlight_device *bd = to_backlight_device(cdev);
@@ -40,12 +38,13 @@ static ssize_t backlight_store_power(struct class_device *cdev, const char *buf,
return -EINVAL;
down(&bd->sem);
- if (likely(bd->props && bd->props->set_power)) {
+ if (likely(bd->props)) {
pr_debug("backlight: set power to %d\n", power);
- bd->props->set_power(bd, power);
+ bd->props->power = power;
+ if (likely(bd->props->update_status))
+ bd->props->update_status(bd);
rc = count;
- } else
- rc = -ENXIO;
+ }
up(&bd->sem);
return rc;
@@ -53,14 +52,12 @@ static ssize_t backlight_store_power(struct class_device *cdev, const char *buf,
static ssize_t backlight_show_brightness(struct class_device *cdev, char *buf)
{
- int rc;
+ int rc = -ENXIO;
struct backlight_device *bd = to_backlight_device(cdev);
down(&bd->sem);
- if (likely(bd->props && bd->props->get_brightness))
- rc = sprintf(buf, "%d\n", bd->props->get_brightness(bd));
- else
- rc = -ENXIO;
+ if (likely(bd->props))
+ rc = sprintf(buf, "%d\n", bd->props->brightness);
up(&bd->sem);
return rc;
@@ -68,7 +65,7 @@ static ssize_t backlight_show_brightness(struct class_device *cdev, char *buf)
static ssize_t backlight_store_brightness(struct class_device *cdev, const char *buf, size_t count)
{
- int rc, brightness;
+ int rc = -ENXIO, brightness;
char *endp;
struct backlight_device *bd = to_backlight_device(cdev);
@@ -77,12 +74,18 @@ static ssize_t backlight_store_brightness(struct class_device *cdev, const char
return -EINVAL;
down(&bd->sem);
- if (likely(bd->props && bd->props->set_brightness)) {
- pr_debug("backlight: set brightness to %d\n", brightness);
- bd->props->set_brightness(bd, brightness);
- rc = count;
- } else
- rc = -ENXIO;
+ if (likely(bd->props)) {
+ if (brightness > bd->props->max_brightness)
+ rc = -EINVAL;
+ else {
+ pr_debug("backlight: set brightness to %d\n",
+ brightness);
+ bd->props->brightness = brightness;
+ if (likely(bd->props->update_status))
+ bd->props->update_status(bd);
+ rc = count;
+ }
+ }
up(&bd->sem);
return rc;
@@ -90,14 +93,26 @@ static ssize_t backlight_store_brightness(struct class_device *cdev, const char
static ssize_t backlight_show_max_brightness(struct class_device *cdev, char *buf)
{
- int rc;
+ int rc = -ENXIO;
struct backlight_device *bd = to_backlight_device(cdev);
down(&bd->sem);
if (likely(bd->props))
rc = sprintf(buf, "%d\n", bd->props->max_brightness);
- else
- rc = -ENXIO;
+ up(&bd->sem);
+
+ return rc;
+}
+
+static ssize_t backlight_show_actual_brightness(struct class_device *cdev,
+ char *buf)
+{
+ int rc = -ENXIO;
+ struct backlight_device *bd = to_backlight_device(cdev);
+
+ down(&bd->sem);
+ if (likely(bd->props && bd->props->get_brightness))
+ rc = sprintf(buf, "%d\n", bd->props->get_brightness(bd));
up(&bd->sem);
return rc;
@@ -123,7 +138,10 @@ static struct class backlight_class = {
static struct class_device_attribute bl_class_device_attributes[] = {
DECLARE_ATTR(power, 0644, backlight_show_power, backlight_store_power),
- DECLARE_ATTR(brightness, 0644, backlight_show_brightness, backlight_store_brightness),
+ DECLARE_ATTR(brightness, 0644, backlight_show_brightness,
+ backlight_store_brightness),
+ DECLARE_ATTR(actual_brightness, 0444, backlight_show_actual_brightness,
+ NULL),
DECLARE_ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL),
};
@@ -144,8 +162,12 @@ static int fb_notifier_callback(struct notifier_block *self,
bd = container_of(self, struct backlight_device, fb_notif);
down(&bd->sem);
if (bd->props)
- if (!bd->props->check_fb || bd->props->check_fb(evdata->info))
- bd->props->set_power(bd, *(int *)evdata->data);
+ if (!bd->props->check_fb ||
+ bd->props->check_fb(evdata->info)) {
+ bd->props->fb_blank = *(int *)evdata->data;
+ if (likely(bd->props && bd->props->update_status))
+ bd->props->update_status(bd);
+ }
up(&bd->sem);
return 0;
}
@@ -231,6 +253,12 @@ void backlight_device_unregister(struct backlight_device *bd)
&bl_class_device_attributes[i]);
down(&bd->sem);
+ if (likely(bd->props && bd->props->update_status)) {
+ bd->props->brightness = 0;
+ bd->props->power = 0;
+ bd->props->update_status(bd);
+ }
+
bd->props = NULL;
up(&bd->sem);
OpenPOWER on IntegriCloud