1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
|
/*
* Backlight Driver for Intel-based Apples
*
* Copyright (c) Red Hat <mjg@redhat.com>
* Based on code from Pommed:
* Copyright (C) 2006 Nicolas Boichat <nicolas @boichat.ch>
* Copyright (C) 2006 Felipe Alfaro Solana <felipe_alfaro @linuxmail.org>
* Copyright (C) 2007 Julien BLACHE <jb@jblache.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This driver triggers SMIs which cause the firmware to change the
* backlight brightness. This is icky in many ways, but it's impractical to
* get at the firmware code in order to figure out what it's actually doing.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/backlight.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/atomic.h>
#include <linux/apple_bl.h>
static struct backlight_device *apple_backlight_device;
struct hw_data {
/* I/O resource to allocate. */
unsigned long iostart;
unsigned long iolen;
/* Backlight operations structure. */
const struct backlight_ops backlight_ops;
void (*set_brightness)(int);
};
static const struct hw_data *hw_data;
/* Module parameters. */
static int debug;
module_param_named(debug, debug, int, 0644);
MODULE_PARM_DESC(debug, "Set to one to enable debugging messages.");
/*
* Implementation for machines with Intel chipset.
*/
static void intel_chipset_set_brightness(int intensity)
{
outb(0x04 | (intensity << 4), 0xb3);
outb(0xbf, 0xb2);
}
static int intel_chipset_send_intensity(struct backlight_device *bd)
{
int intensity = bd->props.brightness;
if (debug)
pr_debug("setting brightness to %d\n", intensity);
intel_chipset_set_brightness(intensity);
return 0;
}
static int intel_chipset_get_intensity(struct backlight_device *bd)
{
int intensity;
outb(0x03, 0xb3);
outb(0xbf, 0xb2);
intensity = inb(0xb3) >> 4;
if (debug)
pr_debug("read brightness of %d\n", intensity);
return intensity;
}
static const struct hw_data intel_chipset_data = {
.iostart = 0xb2,
.iolen = 2,
.backlight_ops = {
.options = BL_CORE_SUSPENDRESUME,
.get_brightness = intel_chipset_get_intensity,
.update_status = intel_chipset_send_intensity,
},
.set_brightness = intel_chipset_set_brightness,
};
/*
* Implementation for machines with Nvidia chipset.
*/
static void nvidia_chipset_set_brightness(int intensity)
{
outb(0x04 | (intensity << 4), 0x52f);
outb(0xbf, 0x52e);
}
static int nvidia_chipset_send_intensity(struct backlight_device *bd)
{
int intensity = bd->props.brightness;
if (debug)
pr_debug("setting brightness to %d\n", intensity);
nvidia_chipset_set_brightness(intensity);
return 0;
}
static int nvidia_chipset_get_intensity(struct backlight_device *bd)
{
int intensity;
outb(0x03, 0x52f);
outb(0xbf, 0x52e);
intensity = inb(0x52f) >> 4;
if (debug)
pr_debug("read brightness of %d\n", intensity);
return intensity;
}
static const struct hw_data nvidia_chipset_data = {
.iostart = 0x52e,
.iolen = 2,
.backlight_ops = {
.options = BL_CORE_SUSPENDRESUME,
.get_brightness = nvidia_chipset_get_intensity,
.update_status = nvidia_chipset_send_intensity
},
.set_brightness = nvidia_chipset_set_brightness,
};
static int apple_bl_add(struct acpi_device *dev)
{
struct backlight_properties props;
struct pci_dev *host;
int intensity;
host = pci_get_domain_bus_and_slot(0, 0, 0);
if (!host) {
pr_err("unable to find PCI host\n");
return -ENODEV;
}
if (host->vendor == PCI_VENDOR_ID_INTEL)
hw_data = &intel_chipset_data;
else if (host->vendor == PCI_VENDOR_ID_NVIDIA)
hw_data = &nvidia_chipset_data;
pci_dev_put(host);
if (!hw_data) {
pr_err("unknown hardware\n");
return -ENODEV;
}
/* Check that the hardware responds - this may not work under EFI */
intensity = hw_data->backlight_ops.get_brightness(NULL);
if (!intensity) {
hw_data->set_brightness(1);
if (!hw_data->backlight_ops.get_brightness(NULL))
return -ENODEV;
hw_data->set_brightness(0);
}
if (!request_region(hw_data->iostart, hw_data->iolen,
"Apple backlight"))
return -ENXIO;
memset(&props, 0, sizeof(struct backlight_properties));
props.type = BACKLIGHT_PLATFORM;
props.max_brightness = 15;
apple_backlight_device = backlight_device_register("apple_backlight",
NULL, NULL, &hw_data->backlight_ops, &props);
if (IS_ERR(apple_backlight_device)) {
release_region(hw_data->iostart, hw_data->iolen);
return PTR_ERR(apple_backlight_device);
}
apple_backlight_device->props.brightness =
hw_data->backlight_ops.get_brightness(apple_backlight_device);
backlight_update_status(apple_backlight_device);
return 0;
}
static int apple_bl_remove(struct acpi_device *dev)
{
backlight_device_unregister(apple_backlight_device);
release_region(hw_data->iostart, hw_data->iolen);
hw_data = NULL;
return 0;
}
static const struct acpi_device_id apple_bl_ids[] = {
{"APP0002", 0},
{"", 0},
};
static struct acpi_driver apple_bl_driver = {
.name = "Apple backlight",
.ids = apple_bl_ids,
.ops = {
.add = apple_bl_add,
.remove = apple_bl_remove,
},
};
static atomic_t apple_bl_registered = ATOMIC_INIT(0);
int apple_bl_register(void)
{
if (atomic_xchg(&apple_bl_registered, 1) == 0)
return acpi_bus_register_driver(&apple_bl_driver);
return 0;
}
EXPORT_SYMBOL_GPL(apple_bl_register);
void apple_bl_unregister(void)
{
if (atomic_xchg(&apple_bl_registered, 0) == 1)
acpi_bus_unregister_driver(&apple_bl_driver);
}
EXPORT_SYMBOL_GPL(apple_bl_unregister);
static int __init apple_bl_init(void)
{
return apple_bl_register();
}
static void __exit apple_bl_exit(void)
{
apple_bl_unregister();
}
module_init(apple_bl_init);
module_exit(apple_bl_exit);
MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
MODULE_DESCRIPTION("Apple Backlight Driver");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(acpi, apple_bl_ids);
MODULE_ALIAS("mbp_nvidia_bl");
|
