Commit f4715189 authored by Thomas Tuttle's avatar Thomas Tuttle Committed by Len Brown
Browse files

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: default avatarThomas Tuttle <linux-kernel@ttuttle.net>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 4afaf54b

drivers/acpi/video.c

+34 −7
Original line number Diff line number Diff line
@@ -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)
@@ -1509,9 +1510,35 @@ static int 
acpi_video_get_next_level(struct acpi_video_device *device,

			  u32 level_current, u32 event)

{

	/*Fix me */

	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

acpi_video_switch_brightness(struct acpi_video_device *device, int event)

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