Commit | Line | Data |
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14cf11af PM |
1 | /* |
2 | * Miscellaneous procedures for dealing with the PowerMac hardware. | |
3 | * Contains support for the backlight. | |
4 | * | |
5 | * Copyright (C) 2000 Benjamin Herrenschmidt | |
5474c120 | 6 | * Copyright (C) 2006 Michael Hanselmann <linux-kernel@hansmi.ch> |
14cf11af PM |
7 | * |
8 | */ | |
9 | ||
14cf11af | 10 | #include <linux/kernel.h> |
5474c120 MH |
11 | #include <linux/fb.h> |
12 | #include <linux/backlight.h> | |
4b755999 MH |
13 | #include <linux/adb.h> |
14 | #include <linux/pmu.h> | |
15 | #include <asm/atomic.h> | |
14cf11af | 16 | #include <asm/prom.h> |
14cf11af PM |
17 | #include <asm/backlight.h> |
18 | ||
5474c120 | 19 | #define OLD_BACKLIGHT_MAX 15 |
14cf11af | 20 | |
6d5aefb8 DH |
21 | static void pmac_backlight_key_worker(struct work_struct *work); |
22 | static void pmac_backlight_set_legacy_worker(struct work_struct *work); | |
4b755999 | 23 | |
6d5aefb8 DH |
24 | static DECLARE_WORK(pmac_backlight_key_work, pmac_backlight_key_worker); |
25 | static DECLARE_WORK(pmac_backlight_set_legacy_work, pmac_backlight_set_legacy_worker); | |
e01af038 | 26 | |
4b755999 MH |
27 | /* Although these variables are used in interrupt context, it makes no sense to |
28 | * protect them. No user is able to produce enough key events per second and | |
e01af038 MH |
29 | * notice the errors that might happen. |
30 | */ | |
31 | static int pmac_backlight_key_queued; | |
4b755999 MH |
32 | static int pmac_backlight_set_legacy_queued; |
33 | ||
34 | /* The via-pmu code allows the backlight to be grabbed, in which case the | |
35 | * in-kernel control of the brightness needs to be disabled. This should | |
36 | * only be used by really old PowerBooks. | |
37 | */ | |
38 | static atomic_t kernel_backlight_disabled = ATOMIC_INIT(0); | |
e01af038 | 39 | |
5474c120 MH |
40 | /* Protect the pmac_backlight variable */ |
41 | DEFINE_MUTEX(pmac_backlight_mutex); | |
14cf11af | 42 | |
5474c120 MH |
43 | /* Main backlight storage |
44 | * | |
45 | * Backlight drivers in this variable are required to have the "props" | |
46 | * attribute set and to have an update_status function. | |
47 | * | |
48 | * We can only store one backlight here, but since Apple laptops have only one | |
49 | * internal display, it doesn't matter. Other backlight drivers can be used | |
50 | * independently. | |
51 | * | |
52 | * Lock ordering: | |
53 | * pmac_backlight_mutex (global, main backlight) | |
54 | * pmac_backlight->sem (backlight class) | |
55 | */ | |
56 | struct backlight_device *pmac_backlight; | |
14cf11af | 57 | |
5474c120 | 58 | int pmac_has_backlight_type(const char *type) |
14cf11af | 59 | { |
5474c120 MH |
60 | struct device_node* bk_node = find_devices("backlight"); |
61 | ||
14cf11af | 62 | if (bk_node) { |
018a3d1d JK |
63 | const char *prop = get_property(bk_node, |
64 | "backlight-control", NULL); | |
5474c120 MH |
65 | if (prop && strncmp(prop, type, strlen(type)) == 0) |
66 | return 1; | |
14cf11af PM |
67 | } |
68 | ||
5474c120 | 69 | return 0; |
14cf11af | 70 | } |
14cf11af | 71 | |
5474c120 | 72 | int pmac_backlight_curve_lookup(struct fb_info *info, int value) |
14cf11af | 73 | { |
5474c120 MH |
74 | int level = (FB_BACKLIGHT_LEVELS - 1); |
75 | ||
76 | if (info && info->bl_dev) { | |
77 | int i, max = 0; | |
78 | ||
79 | /* Look for biggest value */ | |
80 | for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) | |
81 | max = max((int)info->bl_curve[i], max); | |
82 | ||
83 | /* Look for nearest value */ | |
84 | for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) { | |
85 | int diff = abs(info->bl_curve[i] - value); | |
86 | if (diff < max) { | |
87 | max = diff; | |
88 | level = i; | |
89 | } | |
90 | } | |
91 | ||
92 | } | |
93 | ||
94 | return level; | |
14cf11af | 95 | } |
14cf11af | 96 | |
6d5aefb8 | 97 | static void pmac_backlight_key_worker(struct work_struct *work) |
14cf11af | 98 | { |
4b755999 MH |
99 | if (atomic_read(&kernel_backlight_disabled)) |
100 | return; | |
101 | ||
5474c120 MH |
102 | mutex_lock(&pmac_backlight_mutex); |
103 | if (pmac_backlight) { | |
104 | struct backlight_properties *props; | |
105 | int brightness; | |
106 | ||
107 | down(&pmac_backlight->sem); | |
108 | props = pmac_backlight->props; | |
109 | ||
110 | brightness = props->brightness + | |
e01af038 MH |
111 | ((pmac_backlight_key_queued?-1:1) * |
112 | (props->max_brightness / 15)); | |
5474c120 MH |
113 | |
114 | if (brightness < 0) | |
115 | brightness = 0; | |
116 | else if (brightness > props->max_brightness) | |
117 | brightness = props->max_brightness; | |
118 | ||
119 | props->brightness = brightness; | |
120 | props->update_status(pmac_backlight); | |
121 | ||
122 | up(&pmac_backlight->sem); | |
123 | } | |
124 | mutex_unlock(&pmac_backlight_mutex); | |
14cf11af | 125 | } |
5474c120 | 126 | |
4b755999 | 127 | /* This function is called in interrupt context */ |
e01af038 | 128 | void pmac_backlight_key(int direction) |
14cf11af | 129 | { |
4b755999 MH |
130 | if (atomic_read(&kernel_backlight_disabled)) |
131 | return; | |
132 | ||
e01af038 MH |
133 | /* we can receive multiple interrupts here, but the scheduled work |
134 | * will run only once, with the last value | |
135 | */ | |
136 | pmac_backlight_key_queued = direction; | |
137 | schedule_work(&pmac_backlight_key_work); | |
14cf11af PM |
138 | } |
139 | ||
4b755999 | 140 | static int __pmac_backlight_set_legacy_brightness(int brightness) |
14cf11af | 141 | { |
5474c120 MH |
142 | int error = -ENXIO; |
143 | ||
144 | mutex_lock(&pmac_backlight_mutex); | |
145 | if (pmac_backlight) { | |
146 | struct backlight_properties *props; | |
147 | ||
148 | down(&pmac_backlight->sem); | |
149 | props = pmac_backlight->props; | |
150 | props->brightness = brightness * | |
cab267c6 MH |
151 | (props->max_brightness + 1) / |
152 | (OLD_BACKLIGHT_MAX + 1); | |
153 | ||
154 | if (props->brightness > props->max_brightness) | |
155 | props->brightness = props->max_brightness; | |
156 | else if (props->brightness < 0) | |
157 | props->brightness = 0; | |
158 | ||
5474c120 MH |
159 | props->update_status(pmac_backlight); |
160 | up(&pmac_backlight->sem); | |
161 | ||
162 | error = 0; | |
14cf11af | 163 | } |
5474c120 MH |
164 | mutex_unlock(&pmac_backlight_mutex); |
165 | ||
166 | return error; | |
14cf11af | 167 | } |
5474c120 | 168 | |
6d5aefb8 | 169 | static void pmac_backlight_set_legacy_worker(struct work_struct *work) |
4b755999 MH |
170 | { |
171 | if (atomic_read(&kernel_backlight_disabled)) | |
172 | return; | |
173 | ||
174 | __pmac_backlight_set_legacy_brightness(pmac_backlight_set_legacy_queued); | |
175 | } | |
176 | ||
177 | /* This function is called in interrupt context */ | |
178 | void pmac_backlight_set_legacy_brightness_pmu(int brightness) { | |
179 | if (atomic_read(&kernel_backlight_disabled)) | |
180 | return; | |
181 | ||
182 | pmac_backlight_set_legacy_queued = brightness; | |
183 | schedule_work(&pmac_backlight_set_legacy_work); | |
184 | } | |
185 | ||
186 | int pmac_backlight_set_legacy_brightness(int brightness) | |
187 | { | |
188 | return __pmac_backlight_set_legacy_brightness(brightness); | |
189 | } | |
190 | ||
5474c120 | 191 | int pmac_backlight_get_legacy_brightness() |
14cf11af | 192 | { |
5474c120 | 193 | int result = -ENXIO; |
14cf11af | 194 | |
5474c120 MH |
195 | mutex_lock(&pmac_backlight_mutex); |
196 | if (pmac_backlight) { | |
197 | struct backlight_properties *props; | |
14cf11af | 198 | |
5474c120 MH |
199 | down(&pmac_backlight->sem); |
200 | props = pmac_backlight->props; | |
cab267c6 | 201 | |
5474c120 | 202 | result = props->brightness * |
cab267c6 MH |
203 | (OLD_BACKLIGHT_MAX + 1) / |
204 | (props->max_brightness + 1); | |
205 | ||
5474c120 MH |
206 | up(&pmac_backlight->sem); |
207 | } | |
208 | mutex_unlock(&pmac_backlight_mutex); | |
14cf11af | 209 | |
5474c120 | 210 | return result; |
14cf11af | 211 | } |
e01af038 | 212 | |
4b755999 MH |
213 | void pmac_backlight_disable() |
214 | { | |
215 | atomic_inc(&kernel_backlight_disabled); | |
216 | } | |
217 | ||
218 | void pmac_backlight_enable() | |
219 | { | |
220 | atomic_dec(&kernel_backlight_disabled); | |
221 | } | |
222 | ||
e01af038 MH |
223 | EXPORT_SYMBOL_GPL(pmac_backlight); |
224 | EXPORT_SYMBOL_GPL(pmac_backlight_mutex); | |
225 | EXPORT_SYMBOL_GPL(pmac_has_backlight_type); |