Commit d485ef43 authored by Dmitry Frank's avatar Dmitry Frank Committed by Rafael J. Wysocki
Browse files

ACPI / video: get rid of magic numbers and use enum instead 



The first two items in the _BCL method response are special:

  - Level when machine has full power
  - Level when machine is on batteries
  - .... actual supported levels go there ....

So this commits adds an enum and uses its descriptive elements
throughout the code, instead of magic numbers.

Signed-off-by: default avatarDmitry Frank <mail@dmitryfrank.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 4f7d029b

drivers/acpi/acpi_video.c

+66 −44
Original line number Diff line number Diff line
@@ -88,6 +88,18 @@ static int acpi_video_bus_remove(struct acpi_device *device); 
static void acpi_video_bus_notify(struct acpi_device *device, u32 event);

void acpi_video_detect_exit(void);



/*

 * Indices in the _BCL method response: the first two items are special,

 * the rest are all supported levels.

 *

 * See page 575 of the ACPI spec 3.0

 */

enum acpi_video_level_idx {

	ACPI_VIDEO_AC_LEVEL,		/* level when machine has full power */

	ACPI_VIDEO_BATTERY_LEVEL,	/* level when machine is on batteries */

	ACPI_VIDEO_FIRST_LEVEL,		/* actual supported levels begin here */

};



static const struct acpi_device_id video_device_ids[] = {

	{ACPI_VIDEO_HID, 0},

	{"", 0},
@@ -217,20 +229,16 @@ static int acpi_video_get_brightness(struct backlight_device *bd) 


	if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))

		return -EINVAL;

	for (i = 2; i < vd->brightness->count; i++) {

	for (i = ACPI_VIDEO_FIRST_LEVEL; 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 i - ACPI_VIDEO_FIRST_LEVEL;

	}

	return 0;

}



static int acpi_video_set_brightness(struct backlight_device *bd)

{

	int request_level = bd->props.brightness + 2;

	int request_level = bd->props.brightness + ACPI_VIDEO_FIRST_LEVEL;

	struct acpi_video_device *vd = bl_get_data(bd);



	cancel_delayed_work(&vd->switch_brightness_work);
@@ -244,18 +252,18 @@ static const struct backlight_ops acpi_backlight_ops = { 
};



/* thermal cooling device callbacks */

static int video_get_max_state(struct thermal_cooling_device *cooling_dev, unsigned

			       long *state)

static int video_get_max_state(struct thermal_cooling_device *cooling_dev,

			       unsigned long *state)

{

	struct acpi_device *device = cooling_dev->devdata;

	struct acpi_video_device *video = acpi_driver_data(device);



	*state = video->brightness->count - 3;

	*state = video->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;

	return 0;

}



static int video_get_cur_state(struct thermal_cooling_device *cooling_dev, unsigned

			       long *state)

static int video_get_cur_state(struct thermal_cooling_device *cooling_dev,

			       unsigned long *state)

{

	struct acpi_device *device = cooling_dev->devdata;

	struct acpi_video_device *video = acpi_driver_data(device);
@@ -264,7 +272,8 @@ static int video_get_cur_state(struct thermal_cooling_device *cooling_dev, unsig 


	if (acpi_video_device_lcd_get_level_current(video, &level, false))

		return -EINVAL;

	for (offset = 2; offset < video->brightness->count; offset++)

	for (offset = ACPI_VIDEO_FIRST_LEVEL; offset < video->brightness->count;

	     offset++)

		if (level == video->brightness->levels[offset]) {

			*state = video->brightness->count - offset - 1;

			return 0;
@@ -280,7 +289,7 @@ video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long st 
	struct acpi_video_device *video = acpi_driver_data(device);

	int level;



	if (state >= video->brightness->count - 2)

	if (state >= video->brightness->count - ACPI_VIDEO_FIRST_LEVEL)

		return -EINVAL;



	state = video->brightness->count - state;
@@ -345,10 +354,12 @@ 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++)

	for (state = ACPI_VIDEO_FIRST_LEVEL; state < device->brightness->count;

	     state++)

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

			if (device->backlight)

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

				device->backlight->props.brightness =

					state - ACPI_VIDEO_FIRST_LEVEL;

			return 0;

		}
@@ -530,14 +541,16 @@ acpi_video_bqc_value_to_level(struct acpi_video_device *device, 


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

		/*

		 * _BQC returns an index that doesn't account for

		 * the first 2 items with special meaning, so we need

		 * to compensate for that by offsetting ourselves

		 * _BQC returns an index that doesn't account for the first 2

		 * items with special meaning (see enum acpi_video_level_idx),

		 * so we need to compensate for that by offsetting ourselves

		 */

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

			bqc_value = device->brightness->count - 3 - bqc_value;

			bqc_value = device->brightness->count -

				ACPI_VIDEO_FIRST_LEVEL - 1 - bqc_value;



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

		level = device->brightness->levels[bqc_value +

		                                   ACPI_VIDEO_FIRST_LEVEL];

	} else {

		level = bqc_value;

	}
@@ -571,7 +584,8 @@ acpi_video_device_lcd_get_level_current(struct acpi_video_device *device, 


			*level = acpi_video_bqc_value_to_level(device, *level);



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

			for (i = ACPI_VIDEO_FIRST_LEVEL;

			     i < device->brightness->count; i++)

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

					device->brightness->curr = *level;

					return 0;
@@ -716,7 +730,9 @@ static int acpi_video_bqc_quirk(struct acpi_video_device *device, 
	 * Some systems always report current brightness level as maximum

	 * through _BQC, we need to test another value for them.

	 */

	test_level = current_level == max_level ? br->levels[3] : max_level;

	test_level = current_level == max_level

		? br->levels[ACPI_VIDEO_FIRST_LEVEL + 1]

		: max_level;



	result = acpi_video_device_lcd_set_level(device, test_level);

	if (result)
@@ -730,8 +746,8 @@ static int acpi_video_bqc_quirk(struct acpi_video_device *device, 
		/* buggy _BQC found, need to find out if it uses index */

		if (level < br->count) {

			if (br->flags._BCL_reversed)

				level = br->count - 3 - level;

			if (br->levels[level + 2] == test_level)

				level = br->count - ACPI_VIDEO_FIRST_LEVEL - 1 - level;

			if (br->levels[level + ACPI_VIDEO_FIRST_LEVEL] == test_level)

				br->flags._BQC_use_index = 1;

		}
@@ -761,7 +777,7 @@ int acpi_video_get_levels(struct acpi_device *device, 
		goto out;

	}



	if (obj->package.count < 2) {

	if (obj->package.count < ACPI_VIDEO_FIRST_LEVEL) {

		result = -EINVAL;

		goto out;

	}
@@ -773,8 +789,8 @@ int acpi_video_get_levels(struct acpi_device *device, 
		goto out;

	}



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

				GFP_KERNEL);

	br->levels = kmalloc((obj->package.count + ACPI_VIDEO_FIRST_LEVEL) *

	                     sizeof(*br->levels), GFP_KERNEL);

	if (!br->levels) {

		result = -ENOMEM;

		goto out_free;
@@ -788,7 +804,8 @@ int acpi_video_get_levels(struct acpi_device *device, 
		}

		value = (u32) o->integer.value;

		/* Skip duplicate entries */

		if (count > 2 && br->levels[count - 1] == value)

		if (count > ACPI_VIDEO_FIRST_LEVEL

		    && br->levels[count - 1] == value)

			continue;



		br->levels[count] = value;
@@ -804,26 +821,29 @@ int acpi_video_get_levels(struct acpi_device *device, 
	 * In this case, the first two elements in _BCL packages

	 * are also supported brightness levels that OS should take care of.

	 */

	for (i = 2; i < count; i++) {

		if (br->levels[i] == br->levels[0])

	for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {

		if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])

			level_ac_battery++;

		if (br->levels[i] == br->levels[1])

		if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])

			level_ac_battery++;

	}



	if (level_ac_battery < 2) {

		level_ac_battery = 2 - level_ac_battery;

	if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {

		level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;

		br->flags._BCL_no_ac_battery_levels = 1;

		for (i = (count - 1 + level_ac_battery); i >= 2; i--)

		for (i = (count - 1 + level_ac_battery);

		     i >= ACPI_VIDEO_FIRST_LEVEL; i--)

			br->levels[i] = br->levels[i - level_ac_battery];

		count += level_ac_battery;

	} else if (level_ac_battery > 2)

	} else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)

		ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));



	/* Check if the _BCL package is in a reversed order */

	if (max_level == br->levels[2]) {

	if (max_level == br->levels[ACPI_VIDEO_FIRST_LEVEL]) {

		br->flags._BCL_reversed = 1;

		sort(&br->levels[2], count - 2, sizeof(br->levels[2]),

		sort(&br->levels[ACPI_VIDEO_FIRST_LEVEL],

		     count - ACPI_VIDEO_FIRST_LEVEL,

		     sizeof(br->levels[ACPI_VIDEO_FIRST_LEVEL]),

		     acpi_video_cmp_level, NULL);

	} else if (max_level != br->levels[count - 1])

		ACPI_ERROR((AE_INFO,
@@ -894,7 +914,7 @@ acpi_video_init_brightness(struct acpi_video_device *device) 
	 * level_old is invalid (no matter whether it's a level

	 * or an index). Set the backlight to max_level in this case.

	 */

	for (i = 2; i < br->count; i++)

	for (i = ACPI_VIDEO_FIRST_LEVEL; i < br->count; i++)

		if (level == br->levels[i])

			break;

	if (i == br->count || !level)
@@ -906,7 +926,8 @@ set_level: 
		goto out_free_levels;



	ACPI_DEBUG_PRINT((ACPI_DB_INFO,

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

	                  "found %d brightness levels\n",

	                  br->count - ACPI_VIDEO_FIRST_LEVEL));

	return 0;



out_free_levels:
@@ -1297,7 +1318,7 @@ acpi_video_get_next_level(struct acpi_video_device *device, 
	max = max_below = 0;

	min = min_above = 255;

	/* Find closest level to level_current */

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

	for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {

		l = device->brightness->levels[i];

		if (abs(l - level_current) < abs(delta)) {

			delta = l - level_current;
@@ -1307,7 +1328,7 @@ acpi_video_get_next_level(struct acpi_video_device *device, 
	}

	/* Ajust level_current to closest available level */

	level_current += delta;

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

	for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {

		l = device->brightness->levels[i];

		if (l < min)

			min = l;
@@ -1680,7 +1701,8 @@ static void acpi_video_dev_register_backlight(struct acpi_video_device *device) 


	memset(&props, 0, sizeof(struct backlight_properties));

	props.type = BACKLIGHT_FIRMWARE;

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

	props.max_brightness =

		device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;

	device->backlight = backlight_device_register(name,

						      parent,

						      device,

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