This patch adds brightness sysfs support for acpi video driver
through backlight class. Any comments are appreciated.
--Luming
Kconfig | 2 +-
video.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 50 insertions(+), 2 deletions(-)
-- diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 56c5ba8..d5507ea 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -106,7 +106,7 @@ config ACPI_BUTTON
config ACPI_VIDEO
tristate "Video"
- depends on X86
+ depends on X86 && BACKLIGHT_DEVICE
help
This driver implement the ACPI Extensions For Display Adapters
for integrated graphics devices on motherboard, as specified in
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 56666a9..26f5225 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -30,6 +30,7 @@
#include <linux/list.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
+#include <linux/backlight.h>
#include <asm/uaccess.h>
@@ -141,11 +142,11 @@ struct acpi_video_device_cap {
u8 _ADR:1; /*Return the unique ID */
u8 _BCL:1; /*Query list of brightness control levels supported */
u8 _BCM:1; /*Set the brightness level */
+ u8 _BQC:1; /*Get current brightness level */
u8 _DDC:1; /*Return the EDID for this device */
u8 _DCS:1; /*Return status of output device */
u8 _DGS:1; /*Query graphics state */
u8 _DSS:1; /*Device state set */
- u8 _reserved:1;
};
struct acpi_video_device_brightness {
@@ -260,6 +261,34 @@ static int acpi_video_get_next_level(str
u32 level_current, u32 event);
static void acpi_video_switch_brightness(struct acpi_video_device *device,
int event);
+static int acpi_video_device_lcd_set_level(struct acpi_video_device *, int);
+static int acpi_video_device_lcd_get_level_current(struct acpi_video_device *,unsigned long *);
+/*backlight device sysfs support*/
+static int acpi_video_get_brightness(struct backlight_device *bd);
+static int acpi_video_set_brightness(struct backlight_device *bd);
+
+static struct backlight_device *acpi_video_backlight;
+static struct acpi_video_device *backlight_acpi_device;
+static struct backlight_properties acpi_video_data = {
+ .owner = THIS_MODULE,
+ .max_brightness = 0,
+ .get_brightness = acpi_video_get_brightness,
+ .update_status = acpi_video_set_brightness,
+};
+static int acpi_video_get_brightness(struct backlight_device *bd)
+{
+ unsigned long cur_level;
+ acpi_video_device_lcd_get_level_current(backlight_acpi_device, &cur_level);
+ return (int) cur_level;
+}
+
+static int acpi_video_set_brightness(struct backlight_device *bd)
+{
+ int request_level = bd->props->brightness;
+ acpi_video_device_lcd_set_level(backlight_acpi_device, request_level);
+ return 0;
+}
+
/* --------------------------------------------------------------------------
Video Management
@@ -498,6 +527,7 @@ static void acpi_video_device_find_cap(s
acpi_integer status;
acpi_handle h_dummy1;
int i;
+ u32 max_level = 0;
union acpi_object *obj = NULL;
struct acpi_video_device_brightness *br = NULL;
@@ -513,6 +543,9 @@ static void acpi_video_device_find_cap(s
if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_BCM", &h_dummy1))) {
device->cap._BCM = 1;
}
+ if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_BQC", &h_dummy1))) {
+ device->cap._BQC = 1;
+ }
if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_DDC", &h_dummy1))) {
device->cap._DDC = 1;
}
@@ -526,6 +559,7 @@ static void acpi_video_device_find_cap(s
device->cap._DSS = 1;
}
+
status = acpi_video_device_lcd_query_levels(device, &obj);
if (obj && obj->type == ACPI_TYPE_PACKAGE && obj->package.count >= 2) {
@@ -550,6 +584,8 @@ static void acpi_video_device_find_cap(s
continue;
}
br->levels[count] = (u32) o->integer.value;
+ if (br->levels[count] > max_level)
+ max_level = br->levels[count];
count++;
}
out:
@@ -568,6 +604,16 @@ static void acpi_video_device_find_cap(s
kfree(obj);
+ if (device->cap._BCL && device->cap._BCM && device->cap._BQC){
+ unsigned long tmp;
+ acpi_video_data.max_brightness = max_level;
+ acpi_video_device_lcd_get_level_current(device, &tmp);
+ acpi_video_data.brightness = tmp;
+ acpi_video_backlight = backlight_device_register("acpi-video",
+ NULL, &acpi_video_data);
+ backlight_acpi_device = device;
+ }
+
return;
}
@@ -1568,6 +1614,8 @@ static int acpi_video_bus_put_one_device
status = acpi_remove_notify_handler(device->dev->handle,
ACPI_DEVICE_NOTIFY,
acpi_video_device_notify);
+ if (device == backlight_acpi_device)
+ backlight_device_unregister(acpi_video_backlight);
return 0;
}
Thanks,
Luming
-
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