ACPI: Adds backlight sysfs support for acpi video driver.

Adds backlight sysfs support for acpi video driver.

signed-off-by: Luming Yu <Luming.yu@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

2 files changed, 70 insertions, 3 deletions

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 6f8c50ea54e1..e3f77e2ce25f 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_CLASS_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 9200a46c38bd..4b09a021b434 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -32,6 +32,7 @@
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 
+#include <linux/backlight.h>
 #include <asm/uaccess.h>
 
 #include <acpi/acpi_bus.h>
@@ -56,6 +57,7 @@
 
 #define ACPI_VIDEO_HEAD_INVALID         (~0u - 1)
 #define ACPI_VIDEO_HEAD_END             (~0u)
+#define MAX_NAME_LEN    20
 
 #define _COMPONENT              ACPI_VIDEO_COMPONENT
 ACPI_MODULE_NAME("acpi_video")
@@ -142,11 +144,11 @@ 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 {
@@ -163,6 +165,8 @@ struct acpi_video_device {
         struct acpi_video_bus *video;
         struct acpi_device *dev;
         struct acpi_video_device_brightness *brightness;
+        struct backlight_device *backlight;
+        struct backlight_properties *data;
 };
 
 /* bus */
@@ -257,11 +261,35 @@ static void acpi_video_device_bind(struct acpi_video_bus *video,
                                    struct acpi_video_device *device);
 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
 static int acpi_video_switch_output(struct acpi_video_bus *video, int event);
+static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
+                        int level);
+static int acpi_video_device_lcd_get_level_current(
+                        struct acpi_video_device *device,
+                        unsigned long *level);
 static int acpi_video_get_next_level(struct acpi_video_device *device,
                                      u32 level_current, u32 event);
 static void acpi_video_switch_brightness(struct acpi_video_device *device,
                                          int event);
 
+/*backlight device sysfs support*/
+static int acpi_video_get_brightness(struct backlight_device *bd)
+{
+        unsigned long cur_level;
+        struct acpi_video_device *vd =
+                (struct acpi_video_device *)class_get_devdata(&bd->class_dev);
+        acpi_video_device_lcd_get_level_current(vd, &cur_level);
+        return (int) cur_level;
+}
+
+static int acpi_video_set_brightness(struct backlight_device *bd)
+{
+        int request_level = bd->props->brightness;
+        struct acpi_video_device *vd =
+                (struct acpi_video_device *)class_get_devdata(&bd->class_dev);
+        acpi_video_device_lcd_set_level(vd, request_level);
+        return 0;
+}
+
 /* --------------------------------------------------------------------------
                                Video Management
    -------------------------------------------------------------------------- */
@@ -499,6 +527,7 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
         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;
 
@@ -514,6 +543,8 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
         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;
         }
@@ -551,6 +582,8 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
                                         continue;
                                 }
                                 br->levels[count] = (u32) o->integer.value;
+                                if (br->levels[count] > max_level)
+                                        max_level = br->levels[count];
                                 count++;
                         }
                       out:
@@ -569,6 +602,37 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
 
         kfree(obj);
 
+        if (device->cap._BCL && device->cap._BCM && device->cap._BQC){
+                unsigned long tmp;
+                static int count = 0;
+                char *name;
+                struct backlight_properties *acpi_video_data;
+
+                name = kzalloc(MAX_NAME_LEN, GFP_KERNEL);
+                if (!name)
+                        return;
+
+                acpi_video_data = kzalloc(
+                        sizeof(struct backlight_properties),
+                        GFP_KERNEL);
+                if (!acpi_video_data){
+                        kfree(name);
+                        return;
+                }
+                acpi_video_data->owner = THIS_MODULE;
+                acpi_video_data->get_brightness =
+                        acpi_video_get_brightness;
+                acpi_video_data->update_status =
+                        acpi_video_set_brightness;
+                sprintf(name, "acpi_video%d", count++);
+                device->data = acpi_video_data;
+                acpi_video_data->max_brightness = max_level;
+                acpi_video_device_lcd_get_level_current(device, &tmp);
+                acpi_video_data->brightness = (int)tmp;
+                device->backlight = backlight_device_register(name,
+                        NULL, device, acpi_video_data);
+                kfree(name);
+        }
         return;
 }
 
@@ -1595,7 +1659,10 @@ static int acpi_video_bus_put_one_device(struct acpi_video_device *device)
         status = acpi_remove_notify_handler(device->dev->handle,
                                             ACPI_DEVICE_NOTIFY,
                                             acpi_video_device_notify);
-
+        if (device->backlight){
+                backlight_device_unregister(device->backlight);
+                kfree(device->data);
+        }
         return 0;
 }