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authorMatthew Garrett <mjg59@srcf.ucam.org>2007-12-26 02:03:26 +0000
committerLen Brown <len.brown@intel.com>2008-02-01 22:43:31 -0500
commit38531e6fe51ad5c7dfe72e0e066b5f54bc1921cd (patch)
tree84d20e98033a647569b751aa43419d166f587c6d
parentaa6299926950c8dfe2fea638276cad6def092bc9 (diff)
ACPI: video: Rationalise ACPI backlight implementation
The sysfs backlight class provides no mechanism for querying the acceptable brightness for a backlight. The ACPI spec states that values are only valid if they are reported as available by the firmware. Since we can't provide that information to userspace, instead collapse the range to the number of actual values that can be set. http://bugzilla.kernel.org/show_bug.cgi?id=9277 Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org> Acked-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
-rw-r--r--drivers/acpi/video.c20
1 files changed, 13 insertions, 7 deletions
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index bd77e81e81c1..59639c9c6666 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -292,18 +292,26 @@ static int acpi_video_device_set_state(struct acpi_video_device *device, int sta
static int acpi_video_get_brightness(struct backlight_device *bd)
{
unsigned long cur_level;
+ int i;
struct acpi_video_device *vd =
(struct acpi_video_device *)bl_get_data(bd);
acpi_video_device_lcd_get_level_current(vd, &cur_level);
- return (int) cur_level;
+ for (i = 2; i < vd->brightness->count; i++) {
+ if (vd->brightness->levels[i] == cur_level)
+ /* The first two entries are special - see page 575
+ of the ACPI spec 3.0 */
+ return i-2;
+ }
+ return 0;
}
static int acpi_video_set_brightness(struct backlight_device *bd)
{
- int request_level = bd->props.brightness;
+ int request_level = bd->props.brightness+2;
struct acpi_video_device *vd =
(struct acpi_video_device *)bl_get_data(bd);
- acpi_video_device_lcd_set_level(vd, request_level);
+ acpi_video_device_lcd_set_level(vd,
+ vd->brightness->levels[request_level]);
return 0;
}
@@ -652,7 +660,6 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
kfree(obj);
if (device->cap._BCL && device->cap._BCM && device->cap._BQC && max_level > 0){
- unsigned long tmp;
static int count = 0;
char *name;
name = kzalloc(MAX_NAME_LEN, GFP_KERNEL);
@@ -660,11 +667,10 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
return;
sprintf(name, "acpi_video%d", count++);
- acpi_video_device_lcd_get_level_current(device, &tmp);
device->backlight = backlight_device_register(name,
NULL, device, &acpi_backlight_ops);
- device->backlight->props.max_brightness = max_level;
- device->backlight->props.brightness = (int)tmp;
+ device->backlight->props.max_brightness = device->brightness->count-3;
+ device->backlight->props.brightness = acpi_video_get_brightness(device->backlight);
backlight_update_status(device->backlight);
kfree(name);