From d485ef43072e543e81c08276999987039dfa2755 Mon Sep 17 00:00:00 2001 From: Dmitry Frank Date: Wed, 19 Apr 2017 12:48:07 +0300 Subject: [PATCH] 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 Signed-off-by: Rafael J. Wysocki --- 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 @@ 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, -- 2.30.2