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> | |
60063497 | 15 | #include <linux/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 | |
28ee086d RP |
40 | /* Protect the pmac_backlight variable below. |
41 | You should hold this lock when using the pmac_backlight pointer to | |
42 | prevent its potential removal. */ | |
5474c120 | 43 | DEFINE_MUTEX(pmac_backlight_mutex); |
14cf11af | 44 | |
5474c120 MH |
45 | /* Main backlight storage |
46 | * | |
599a52d1 | 47 | * Backlight drivers in this variable are required to have the "ops" |
5474c120 MH |
48 | * attribute set and to have an update_status function. |
49 | * | |
50 | * We can only store one backlight here, but since Apple laptops have only one | |
51 | * internal display, it doesn't matter. Other backlight drivers can be used | |
52 | * independently. | |
53 | * | |
5474c120 MH |
54 | */ |
55 | struct backlight_device *pmac_backlight; | |
14cf11af | 56 | |
5474c120 | 57 | int pmac_has_backlight_type(const char *type) |
14cf11af | 58 | { |
30686ba6 | 59 | struct device_node* bk_node = of_find_node_by_name(NULL, "backlight"); |
5474c120 | 60 | |
14cf11af | 61 | if (bk_node) { |
e2eb6392 | 62 | const char *prop = of_get_property(bk_node, |
018a3d1d | 63 | "backlight-control", NULL); |
30686ba6 SR |
64 | if (prop && strncmp(prop, type, strlen(type)) == 0) { |
65 | of_node_put(bk_node); | |
5474c120 | 66 | return 1; |
30686ba6 SR |
67 | } |
68 | of_node_put(bk_node); | |
14cf11af PM |
69 | } |
70 | ||
5474c120 | 71 | return 0; |
14cf11af | 72 | } |
14cf11af | 73 | |
5474c120 | 74 | int pmac_backlight_curve_lookup(struct fb_info *info, int value) |
14cf11af | 75 | { |
5474c120 MH |
76 | int level = (FB_BACKLIGHT_LEVELS - 1); |
77 | ||
78 | if (info && info->bl_dev) { | |
79 | int i, max = 0; | |
80 | ||
81 | /* Look for biggest value */ | |
82 | for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) | |
83 | max = max((int)info->bl_curve[i], max); | |
84 | ||
85 | /* Look for nearest value */ | |
86 | for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) { | |
87 | int diff = abs(info->bl_curve[i] - value); | |
88 | if (diff < max) { | |
89 | max = diff; | |
90 | level = i; | |
91 | } | |
92 | } | |
93 | ||
94 | } | |
95 | ||
96 | return level; | |
14cf11af | 97 | } |
14cf11af | 98 | |
6d5aefb8 | 99 | static void pmac_backlight_key_worker(struct work_struct *work) |
14cf11af | 100 | { |
4b755999 MH |
101 | if (atomic_read(&kernel_backlight_disabled)) |
102 | return; | |
103 | ||
5474c120 MH |
104 | mutex_lock(&pmac_backlight_mutex); |
105 | if (pmac_backlight) { | |
106 | struct backlight_properties *props; | |
107 | int brightness; | |
108 | ||
599a52d1 | 109 | props = &pmac_backlight->props; |
5474c120 MH |
110 | |
111 | brightness = props->brightness + | |
e01af038 MH |
112 | ((pmac_backlight_key_queued?-1:1) * |
113 | (props->max_brightness / 15)); | |
5474c120 MH |
114 | |
115 | if (brightness < 0) | |
116 | brightness = 0; | |
117 | else if (brightness > props->max_brightness) | |
118 | brightness = props->max_brightness; | |
119 | ||
120 | props->brightness = brightness; | |
28ee086d | 121 | backlight_update_status(pmac_backlight); |
5474c120 MH |
122 | } |
123 | mutex_unlock(&pmac_backlight_mutex); | |
14cf11af | 124 | } |
5474c120 | 125 | |
4b755999 | 126 | /* This function is called in interrupt context */ |
e01af038 | 127 | void pmac_backlight_key(int direction) |
14cf11af | 128 | { |
4b755999 MH |
129 | if (atomic_read(&kernel_backlight_disabled)) |
130 | return; | |
131 | ||
e01af038 MH |
132 | /* we can receive multiple interrupts here, but the scheduled work |
133 | * will run only once, with the last value | |
134 | */ | |
135 | pmac_backlight_key_queued = direction; | |
136 | schedule_work(&pmac_backlight_key_work); | |
14cf11af PM |
137 | } |
138 | ||
4b755999 | 139 | static int __pmac_backlight_set_legacy_brightness(int brightness) |
14cf11af | 140 | { |
5474c120 MH |
141 | int error = -ENXIO; |
142 | ||
143 | mutex_lock(&pmac_backlight_mutex); | |
144 | if (pmac_backlight) { | |
145 | struct backlight_properties *props; | |
146 | ||
599a52d1 | 147 | props = &pmac_backlight->props; |
5474c120 | 148 | props->brightness = brightness * |
cab267c6 MH |
149 | (props->max_brightness + 1) / |
150 | (OLD_BACKLIGHT_MAX + 1); | |
151 | ||
152 | if (props->brightness > props->max_brightness) | |
153 | props->brightness = props->max_brightness; | |
154 | else if (props->brightness < 0) | |
155 | props->brightness = 0; | |
156 | ||
28ee086d | 157 | backlight_update_status(pmac_backlight); |
5474c120 MH |
158 | |
159 | error = 0; | |
14cf11af | 160 | } |
5474c120 MH |
161 | mutex_unlock(&pmac_backlight_mutex); |
162 | ||
163 | return error; | |
14cf11af | 164 | } |
5474c120 | 165 | |
6d5aefb8 | 166 | static void pmac_backlight_set_legacy_worker(struct work_struct *work) |
4b755999 MH |
167 | { |
168 | if (atomic_read(&kernel_backlight_disabled)) | |
169 | return; | |
170 | ||
171 | __pmac_backlight_set_legacy_brightness(pmac_backlight_set_legacy_queued); | |
172 | } | |
173 | ||
174 | /* This function is called in interrupt context */ | |
175 | void pmac_backlight_set_legacy_brightness_pmu(int brightness) { | |
176 | if (atomic_read(&kernel_backlight_disabled)) | |
177 | return; | |
178 | ||
179 | pmac_backlight_set_legacy_queued = brightness; | |
180 | schedule_work(&pmac_backlight_set_legacy_work); | |
181 | } | |
182 | ||
183 | int pmac_backlight_set_legacy_brightness(int brightness) | |
184 | { | |
185 | return __pmac_backlight_set_legacy_brightness(brightness); | |
186 | } | |
187 | ||
5474c120 | 188 | int pmac_backlight_get_legacy_brightness() |
14cf11af | 189 | { |
5474c120 | 190 | int result = -ENXIO; |
14cf11af | 191 | |
5474c120 MH |
192 | mutex_lock(&pmac_backlight_mutex); |
193 | if (pmac_backlight) { | |
194 | struct backlight_properties *props; | |
14cf11af | 195 | |
599a52d1 | 196 | props = &pmac_backlight->props; |
cab267c6 | 197 | |
5474c120 | 198 | result = props->brightness * |
cab267c6 MH |
199 | (OLD_BACKLIGHT_MAX + 1) / |
200 | (props->max_brightness + 1); | |
5474c120 MH |
201 | } |
202 | mutex_unlock(&pmac_backlight_mutex); | |
14cf11af | 203 | |
5474c120 | 204 | return result; |
14cf11af | 205 | } |
e01af038 | 206 | |
4b755999 MH |
207 | void pmac_backlight_disable() |
208 | { | |
209 | atomic_inc(&kernel_backlight_disabled); | |
210 | } | |
211 | ||
212 | void pmac_backlight_enable() | |
213 | { | |
214 | atomic_dec(&kernel_backlight_disabled); | |
215 | } | |
216 | ||
e01af038 MH |
217 | EXPORT_SYMBOL_GPL(pmac_backlight); |
218 | EXPORT_SYMBOL_GPL(pmac_backlight_mutex); | |
219 | EXPORT_SYMBOL_GPL(pmac_has_backlight_type); |