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
28 static struct backlight_device *mbp_backlight_device;
29
30 static 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
mbp_send_intensity(struct backlight_device * bd)55 static 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
mbp_get_intensity(struct backlight_device * bd)65 static int mbp_get_intensity(struct backlight_device *bd)
66 {
67 outb(0x03, 0xb3);
68 outb(0xbf, 0xb2);
69 return inb(0xb3) >> 4;
70 }
71
72 static struct backlight_ops mbp_ops = {
73 .options = BL_CORE_SUSPENDRESUME,
74 .get_brightness = mbp_get_intensity,
75 .update_status = mbp_send_intensity,
76 };
77
mbp_init(void)78 static int __init mbp_init(void)
79 {
80 if (!dmi_check_system(mbp_device_table))
81 return -ENODEV;
82
83 if (!request_region(0xb2, 2, "Macbook Pro backlight"))
84 return -ENXIO;
85
86 mbp_backlight_device = backlight_device_register("mbp_backlight",
87 NULL, NULL,
88 &mbp_ops);
89 if (IS_ERR(mbp_backlight_device)) {
90 release_region(0xb2, 2);
91 return PTR_ERR(mbp_backlight_device);
92 }
93
94 mbp_backlight_device->props.max_brightness = 15;
95 mbp_backlight_device->props.brightness =
96 mbp_get_intensity(mbp_backlight_device);
97 backlight_update_status(mbp_backlight_device);
98
99 return 0;
100 }
101
mbp_exit(void)102 static void __exit mbp_exit(void)
103 {
104 backlight_device_unregister(mbp_backlight_device);
105
106 release_region(0xb2, 2);
107 }
108
109 module_init(mbp_init);
110 module_exit(mbp_exit);
111
112 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
113 MODULE_DESCRIPTION("Nvidia-based Macbook Pro Backlight Driver");
114 MODULE_LICENSE("GPL");
115 MODULE_DEVICE_TABLE(dmi, mbp_device_table);
116