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
|
/*
* Miscellaneous procedures for dealing with the PowerMac hardware.
* Contains support for the backlight.
*
* Copyright (C) 2000 Benjamin Herrenschmidt
* Copyright (C) 2006 Michael Hanselmann <linux-kernel@hansmi.ch>
*
*/
#include <linux/kernel.h>
#include <linux/fb.h>
#include <linux/backlight.h>
#include <linux/adb.h>
#include <linux/pmu.h>
#include <asm/atomic.h>
#include <asm/prom.h>
#include <asm/backlight.h>
#define OLD_BACKLIGHT_MAX 15
static void pmac_backlight_key_worker(struct work_struct *work);
static void pmac_backlight_set_legacy_worker(struct work_struct *work);
static DECLARE_WORK(pmac_backlight_key_work, pmac_backlight_key_worker);
static DECLARE_WORK(pmac_backlight_set_legacy_work, pmac_backlight_set_legacy_worker);
/* Although these variables are used in interrupt context, it makes no sense to
* protect them. No user is able to produce enough key events per second and
* notice the errors that might happen.
*/
static int pmac_backlight_key_queued;
static int pmac_backlight_set_legacy_queued;
/* The via-pmu code allows the backlight to be grabbed, in which case the
* in-kernel control of the brightness needs to be disabled. This should
* only be used by really old PowerBooks.
*/
static atomic_t kernel_backlight_disabled = ATOMIC_INIT(0);
/* Protect the pmac_backlight variable below.
You should hold this lock when using the pmac_backlight pointer to
prevent its potential removal. */
DEFINE_MUTEX(pmac_backlight_mutex);
/* Main backlight storage
*
* Backlight drivers in this variable are required to have the "ops"
* attribute set and to have an update_status function.
*
* We can only store one backlight here, but since Apple laptops have only one
* internal display, it doesn't matter. Other backlight drivers can be used
* independently.
*
*/
struct backlight_device *pmac_backlight;
int pmac_has_backlight_type(const char *type)
{
struct device_node* bk_node = find_devices("backlight");
if (bk_node) {
const char *prop = get_property(bk_node,
"backlight-control", NULL);
if (prop && strncmp(prop, type, strlen(type)) == 0)
return 1;
}
return 0;
}
int pmac_backlight_curve_lookup(struct fb_info *info, int value)
{
int level = (FB_BACKLIGHT_LEVELS - 1);
if (info && info->bl_dev) {
int i, max = 0;
/* Look for biggest value */
for (i = 0; i < FB_BACKLIGHT_LEVELS; i++)
max = max((int)info->bl_curve[i], max);
/* Look for nearest value */
for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) {
int diff = abs(info->bl_curve[i] - value);
if (diff < max) {
max = diff;
level = i;
}
}
}
return level;
}
static void pmac_backlight_key_worker(struct work_struct *work)
{
if (atomic_read(&kernel_backlight_disabled))
return;
mutex_lock(&pmac_backlight_mutex);
if (pmac_backlight) {
struct backlight_properties *props;
int brightness;
props = &pmac_backlight->props;
brightness = props->brightness +
((pmac_backlight_key_queued?-1:1) *
(props->max_brightness / 15));
if (brightness < 0)
brightness = 0;
else if (brightness > props->max_brightness)
brightness = props->max_brightness;
props->brightness = brightness;
backlight_update_status(pmac_backlight);
}
mutex_unlock(&pmac_backlight_mutex);
}
/* This function is called in interrupt context */
void pmac_backlight_key(int direction)
{
if (atomic_read(&kernel_backlight_disabled))
return;
/* we can receive multiple interrupts here, but the scheduled work
* will run only once, with the last value
*/
pmac_backlight_key_queued = direction;
schedule_work(&pmac_backlight_key_work);
}
static int __pmac_backlight_set_legacy_brightness(int brightness)
{
int error = -ENXIO;
mutex_lock(&pmac_backlight_mutex);
if (pmac_backlight) {
struct backlight_properties *props;
props = &pmac_backlight->props;
props->brightness = brightness *
(props->max_brightness + 1) /
(OLD_BACKLIGHT_MAX + 1);
if (props->brightness > props->max_brightness)
props->brightness = props->max_brightness;
else if (props->brightness < 0)
props->brightness = 0;
backlight_update_status(pmac_backlight);
error = 0;
}
mutex_unlock(&pmac_backlight_mutex);
return error;
}
static void pmac_backlight_set_legacy_worker(struct work_struct *work)
{
if (atomic_read(&kernel_backlight_disabled))
return;
__pmac_backlight_set_legacy_brightness(pmac_backlight_set_legacy_queued);
}
/* This function is called in interrupt context */
void pmac_backlight_set_legacy_brightness_pmu(int brightness) {
if (atomic_read(&kernel_backlight_disabled))
return;
pmac_backlight_set_legacy_queued = brightness;
schedule_work(&pmac_backlight_set_legacy_work);
}
int pmac_backlight_set_legacy_brightness(int brightness)
{
return __pmac_backlight_set_legacy_brightness(brightness);
}
int pmac_backlight_get_legacy_brightness()
{
int result = -ENXIO;
mutex_lock(&pmac_backlight_mutex);
if (pmac_backlight) {
struct backlight_properties *props;
props = &pmac_backlight->props;
result = props->brightness *
(OLD_BACKLIGHT_MAX + 1) /
(props->max_brightness + 1);
}
mutex_unlock(&pmac_backlight_mutex);
return result;
}
void pmac_backlight_disable()
{
atomic_inc(&kernel_backlight_disabled);
}
void pmac_backlight_enable()
{
atomic_dec(&kernel_backlight_disabled);
}
EXPORT_SYMBOL_GPL(pmac_backlight);
EXPORT_SYMBOL_GPL(pmac_backlight_mutex);
EXPORT_SYMBOL_GPL(pmac_has_backlight_type);
|
