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@xxxxxxxxxxxxxxx>
---
drivers/acpi/acpi_video.c | 110 +++++++++++++++++++++++++++-------------------
1 file changed, 66 insertions(+), 44 deletions(-)
diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c
index d00bc0ef87a6..9a607af971e7 100644
--- a/drivers/acpi/acpi_video.c
+++ b/drivers/acpi/acpi_video.c
@@ -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,
--
2.11.0
--
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