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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: Dmitry Frank <mail@dmitryfrank.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Dmitry Frank 2017-04-19 12:48:07 +03:00 committed by Rafael J. Wysocki
parent 4f7d029b9b
commit d485ef4307
1 changed files with 66 additions and 44 deletions
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110
drivers/acpi/acpi_video.c
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@ -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;
@ -804,27 +821,30 @@ 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]),
acpi_video_cmp_level, NULL);
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,
"Found unordered _BCL package"));
@ -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 @@ acpi_video_init_brightness(struct acpi_video_device *device)
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,