ACPI: Implement acpi_video_get_next_level()
acpi_video_get_next_level was supposed to implement an algorithm to select
a new brightness level based on the old brightness level of an ACPI video
device, but it simply says "/* Fix me */" and returns the current
brightness.
This patch implements acpi_video_get_next_level properly. It had to change
a few constants at the top of the file because they were (apparently)
wrong, but it appears to work on my Dell Inspiron e1405 (with BIOS A05
only--BIOS A04 doesn't seem to send ACPI video hotkey events).
[akpm@osdl.org: cleanups]
Signed-off-by: Thomas Tuttle <linux-kernel@ttuttle.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 56666a9..9200a46 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -3,6 +3,7 @@
*
* Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
* Copyright (C) 2004 Bruno Ducrot <ducrot@poupinou.org>
+ * Copyright (C) 2006 Thomas Tuttle <linux-kernel@ttuttle.net>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
@@ -47,11 +48,11 @@
#define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT 0x83
#define ACPI_VIDEO_NOTIFY_PREV_OUTPUT 0x84
-#define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS 0x82
-#define ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS 0x83
-#define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS 0x84
-#define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS 0x85
-#define ACPI_VIDEO_NOTIFY_DISPLAY_OFF 0x86
+#define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS 0x85
+#define ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS 0x86
+#define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS 0x87
+#define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS 0x88
+#define ACPI_VIDEO_NOTIFY_DISPLAY_OFF 0x89
#define ACPI_VIDEO_HEAD_INVALID (~0u - 1)
#define ACPI_VIDEO_HEAD_END (~0u)
@@ -1509,8 +1510,34 @@
acpi_video_get_next_level(struct acpi_video_device *device,
u32 level_current, u32 event)
{
- /*Fix me */
- return level_current;
+ int min, max, min_above, max_below, i, l;
+ max = max_below = 0;
+ min = min_above = 255;
+ for (i = 0; i < device->brightness->count; i++) {
+ l = device->brightness->levels[i];
+ if (l < min)
+ min = l;
+ if (l > max)
+ max = l;
+ if (l < min_above && l > level_current)
+ min_above = l;
+ if (l > max_below && l < level_current)
+ max_below = l;
+ }
+
+ switch (event) {
+ case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
+ return (level_current < max) ? min_above : min;
+ case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
+ return (level_current < max) ? min_above : max;
+ case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
+ return (level_current > min) ? max_below : min;
+ case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
+ case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
+ return 0;
+ default:
+ return level_current;
+ }
}
static void