tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Backlight Driver for Nvidia 8600 in Macbook Pro
3 *
4 * Copyright (c) Red Hat <mjg@redhat.com>
5 * Based on code from Pommed:
6 * Copyright (C) 2006 Nicolas Boichat <nicolas @boichat.ch>
7 * Copyright (C) 2006 Felipe Alfaro Solana <felipe_alfaro @linuxmail.org>
8 * Copyright (C) 2007 Julien BLACHE <jb@jblache.org>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 *
14 * This driver triggers SMIs which cause the firmware to change the
15 * backlight brightness. This is icky in many ways, but it's impractical to
16 * get at the firmware code in order to figure out what it's actually doing.
17 */
18
19#include <linux/module.h>
20#include <linux/kernel.h>
21#include <linux/init.h>
22#include <linux/platform_device.h>
23#include <linux/backlight.h>
24#include <linux/err.h>
25#include <linux/dmi.h>
26#include <linux/io.h>
27
28static struct backlight_device *mbp_backlight_device;
29
30static struct dmi_system_id __initdata mbp_device_table[] = {
31 {
32 .ident = "3,1",
33 .matches = {
34 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
35 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro3,1"),
36 },
37 },
38 {
39 .ident = "3,2",
40 .matches = {
41 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
42 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro3,2"),
43 },
44 },
45 {
46 .ident = "4,1",
47 .matches = {
48 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
49 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro4,1"),
50 },
51 },
52 { }
53};
54
55static int mbp_send_intensity(struct backlight_device *bd)
56{
57 int intensity = bd->props.brightness;
58
59 outb(0x04 | (intensity << 4), 0xb3);
60 outb(0xbf, 0xb2);
61
62 return 0;
63}
64
65static int mbp_get_intensity(struct backlight_device *bd)
66{
67 outb(0x03, 0xb3);
68 outb(0xbf, 0xb2);
69 return inb(0xb3) >> 4;
70}
71
72static struct backlight_ops mbp_ops = {
73 .get_brightness = mbp_get_intensity,
74 .update_status = mbp_send_intensity,
75};
76
77static int __init mbp_init(void)
78{
79 if (!dmi_check_system(mbp_device_table))
80 return -ENODEV;
81
82 if (!request_region(0xb2, 2, "Macbook Pro backlight"))
83 return -ENXIO;
84
85 mbp_backlight_device = backlight_device_register("mbp_backlight",
86 NULL, NULL,
87 &mbp_ops);
88 if (IS_ERR(mbp_backlight_device)) {
89 release_region(0xb2, 2);
90 return PTR_ERR(mbp_backlight_device);
91 }
92
93 mbp_backlight_device->props.max_brightness = 15;
94 mbp_backlight_device->props.brightness =
95 mbp_get_intensity(mbp_backlight_device);
96 backlight_update_status(mbp_backlight_device);
97
98 return 0;
99}
100
101static void __exit mbp_exit(void)
102{
103 backlight_device_unregister(mbp_backlight_device);
104
105 release_region(0xb2, 2);
106}
107
108module_init(mbp_init);
109module_exit(mbp_exit);
110
111MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
112MODULE_DESCRIPTION("Nvidia-based Macbook Pro Backlight Driver");
113MODULE_LICENSE("GPL");
114MODULE_DEVICE_TABLE(dmi, mbp_device_table);