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Commit 1a7c618a authored by Zhang Rui's avatar Zhang Rui Committed by Len Brown
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ACPI video: support _BQC/_BCL/_BCM methods that use index values 

The input/output of _BQC/_BCL/_BCM control methods should be represented
by a number between 0 and 100, and can be thought of as a percentage.
But some buggy _BQC/_BCL/_BCM methods use the index values instead.
http://bugzilla.kernel.org/show_bug.cgi?id=12302
http://bugzilla.kernel.org/show_bug.cgi?id=12249
http://bugzilla.kernel.org/show_bug.cgi?id=12037



Add the functionality to support such kind of BIOSes in ACPI video driver.

Signed-off-by: default avatarZhang Rui <rui.zhang@intel.com>
Acked-by: default avatarMatthew Garrett <mjg59@srcf.ucam.org>
Acked-by: default avatarThomas Renninger <trenn@suse.de>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent d80fb99f

drivers/acpi/video.c

+70 −21
Original line number Diff line number Diff line
@@ -171,6 +171,9 @@ struct acpi_video_device_cap { 
struct acpi_video_brightness_flags {

	u8 _BCL_no_ac_battery_levels:1;	/* no AC/Battery levels in _BCL */

	u8 _BCL_reversed:1;		/* _BCL package is in a reversed order*/

	u8 _BCL_use_index:1;		/* levels in _BCL are index values */

	u8 _BCM_use_index:1;		/* input of _BCM is an index value */

	u8 _BQC_use_index:1;		/* _BQC returns an index value */

};



struct acpi_video_device_brightness {
@@ -505,6 +508,7 @@ acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level) 
	device->brightness->curr = level;

	for (state = 2; state < device->brightness->count; state++)

		if (level == device->brightness->levels[state]) {

			if (device->backlight)

				device->backlight->props.brightness = state - 2;

			return 0;

		}
@@ -523,6 +527,13 @@ acpi_video_device_lcd_get_level_current(struct acpi_video_device *device, 
		status = acpi_evaluate_integer(device->dev->handle, "_BQC",

						NULL, level);

		if (ACPI_SUCCESS(status)) {

			if (device->brightness->flags._BQC_use_index) {

				if (device->brightness->flags._BCL_reversed)

					*level = device->brightness->count

								 - 3 - (*level);

				*level = device->brightness->levels[*level + 2];



			}

			device->brightness->curr = *level;

			return 0;

		} else {
@@ -689,8 +700,10 @@ acpi_video_init_brightness(struct acpi_video_device *device) 
{

	union acpi_object *obj = NULL;

	int i, max_level = 0, count = 0, level_ac_battery = 0;

	unsigned long long level, level_old;

	union acpi_object *o;

	struct acpi_video_device_brightness *br = NULL;

	int result = -EINVAL;



	if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) {

		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
@@ -704,13 +717,16 @@ acpi_video_init_brightness(struct acpi_video_device *device) 
	br = kzalloc(sizeof(*br), GFP_KERNEL);

	if (!br) {

		printk(KERN_ERR "can't allocate memory\n");

		result = -ENOMEM;

		goto out;

	}



	br->levels = kmalloc((obj->package.count + 2) * sizeof *(br->levels),

				GFP_KERNEL);

	if (!br->levels)

	if (!br->levels) {

		result = -ENOMEM;

		goto out_free;

	}



	for (i = 0; i < obj->package.count; i++) {

		o = (union acpi_object *)&obj->package.elements[i];
@@ -756,10 +772,55 @@ acpi_video_init_brightness(struct acpi_video_device *device) 


	br->count = count;

	device->brightness = br;



	/* Check the input/output of _BQC/_BCL/_BCM */

	if ((max_level < 100) && (max_level <= (count - 2)))

		br->flags._BCL_use_index = 1;



	/*

	 * _BCM is always consistent with _BCL,

	 * at least for all the laptops we have ever seen.

	 */

	br->flags._BCM_use_index = br->flags._BCL_use_index;



	/* _BQC uses INDEX while _BCL uses VALUE in some laptops */

	br->curr = max_level;

	result = acpi_video_device_lcd_get_level_current(device, &level_old);

	if (result)

		goto out_free_levels;



	result = acpi_video_device_lcd_set_level(device, br->curr);

	if (result)

		goto out_free_levels;



	result = acpi_video_device_lcd_get_level_current(device, &level);

	if (result)

		goto out_free_levels;



	if ((level != level_old) && !br->flags._BCM_use_index) {

		/* Note:

		 * This piece of code does not work correctly if the current

		 * brightness levels is 0.

		 * But I guess boxes that boot with such a dark screen are rare

		 * and no more code is needed to cover this specifial case.

		 */



		if (level_ac_battery != 2) {

			/*

			 * For now, we don't support the _BCL like this:

			 * 16, 15, 0, 1, 2, 3, ..., 14, 15, 16

			 * because we may mess up the index returned by _BQC.

			 * Plus: we have not got a box like this.

			 */

			ACPI_ERROR((AE_INFO, "_BCL not supported\n"));

		}

		br->flags._BQC_use_index = 1;

	}



	ACPI_DEBUG_PRINT((ACPI_DB_INFO,

			  "found %d brightness levels\n", count - 2));

	kfree(obj);

	return max_level;

	return result;



out_free_levels:

	kfree(br->levels);
@@ -768,7 +829,7 @@ acpi_video_init_brightness(struct acpi_video_device *device) 
out:

	device->brightness = NULL;

	kfree(obj);

	return 0;

	return result;

}



/*
@@ -785,7 +846,6 @@ acpi_video_init_brightness(struct acpi_video_device *device) 
static void acpi_video_device_find_cap(struct acpi_video_device *device)

{

	acpi_handle h_dummy1;

	u32 max_level = 0;





	memset(&device->cap, 0, sizeof(device->cap));
@@ -814,13 +874,14 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device) 
		device->cap._DSS = 1;

	}



	if (acpi_video_backlight_support())

		max_level = acpi_video_init_brightness(device);



	if (device->cap._BCL && device->cap._BCM && max_level > 0) {

	if (acpi_video_backlight_support()) {

		int result;

		static int count = 0;

		char *name;



		result = acpi_video_init_brightness(device);

		if (result)

			return;

		name = kzalloc(MAX_NAME_LEN, GFP_KERNEL);

		if (!name)

			return;
@@ -829,18 +890,6 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device) 
		device->backlight = backlight_device_register(name,

			NULL, device, &acpi_backlight_ops);

		device->backlight->props.max_brightness = device->brightness->count-3;

		/*

		 * If there exists the _BQC object, the _BQC object will be

		 * called to get the current backlight brightness. Otherwise

		 * the brightness will be set to the maximum.

		 */

		if (device->cap._BQC)

			device->backlight->props.brightness =

				acpi_video_get_brightness(device->backlight);

		else

			device->backlight->props.brightness =

				device->backlight->props.max_brightness;

		backlight_update_status(device->backlight);

		kfree(name);



		device->cdev = thermal_cooling_device_register("LCD",