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> |
66b15db6 | 16 | #include <linux/export.h> |
14cf11af | 17 | #include <asm/prom.h> |
14cf11af PM |
18 | #include <asm/backlight.h> |
19 | ||
5474c120 | 20 | #define OLD_BACKLIGHT_MAX 15 |
14cf11af | 21 | |
6d5aefb8 DH |
22 | static void pmac_backlight_key_worker(struct work_struct *work); |
23 | static void pmac_backlight_set_legacy_worker(struct work_struct *work); | |
4b755999 | 24 | |
6d5aefb8 DH |
25 | static DECLARE_WORK(pmac_backlight_key_work, pmac_backlight_key_worker); |
26 | static DECLARE_WORK(pmac_backlight_set_legacy_work, pmac_backlight_set_legacy_worker); | |
e01af038 | 27 | |
4b755999 MH |
28 | /* Although these variables are used in interrupt context, it makes no sense to |
29 | * protect them. No user is able to produce enough key events per second and | |
e01af038 MH |
30 | * notice the errors that might happen. |
31 | */ | |
32 | static int pmac_backlight_key_queued; | |
4b755999 MH |
33 | static int pmac_backlight_set_legacy_queued; |
34 | ||
35 | /* The via-pmu code allows the backlight to be grabbed, in which case the | |
36 | * in-kernel control of the brightness needs to be disabled. This should | |
37 | * only be used by really old PowerBooks. | |
38 | */ | |
39 | static atomic_t kernel_backlight_disabled = ATOMIC_INIT(0); | |
e01af038 | 40 | |
28ee086d RP |
41 | /* Protect the pmac_backlight variable below. |
42 | You should hold this lock when using the pmac_backlight pointer to | |
43 | prevent its potential removal. */ | |
5474c120 | 44 | DEFINE_MUTEX(pmac_backlight_mutex); |
14cf11af | 45 | |
5474c120 MH |
46 | /* Main backlight storage |
47 | * | |
599a52d1 | 48 | * Backlight drivers in this variable are required to have the "ops" |
5474c120 MH |
49 | * attribute set and to have an update_status function. |
50 | * | |
51 | * We can only store one backlight here, but since Apple laptops have only one | |
52 | * internal display, it doesn't matter. Other backlight drivers can be used | |
53 | * independently. | |
54 | * | |
5474c120 MH |
55 | */ |
56 | struct backlight_device *pmac_backlight; | |
14cf11af | 57 | |
5474c120 | 58 | int pmac_has_backlight_type(const char *type) |
14cf11af | 59 | { |
30686ba6 | 60 | struct device_node* bk_node = of_find_node_by_name(NULL, "backlight"); |
5474c120 | 61 | |
14cf11af | 62 | if (bk_node) { |
e2eb6392 | 63 | const char *prop = of_get_property(bk_node, |
018a3d1d | 64 | "backlight-control", NULL); |
30686ba6 SR |
65 | if (prop && strncmp(prop, type, strlen(type)) == 0) { |
66 | of_node_put(bk_node); | |
5474c120 | 67 | return 1; |
30686ba6 SR |
68 | } |
69 | of_node_put(bk_node); | |
14cf11af PM |
70 | } |
71 | ||
5474c120 | 72 | return 0; |
14cf11af | 73 | } |
14cf11af | 74 | |
5474c120 | 75 | int pmac_backlight_curve_lookup(struct fb_info *info, int value) |
14cf11af | 76 | { |
5474c120 MH |
77 | int level = (FB_BACKLIGHT_LEVELS - 1); |
78 | ||
79 | if (info && info->bl_dev) { | |
80 | int i, max = 0; | |
81 | ||
82 | /* Look for biggest value */ | |
83 | for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) | |
84 | max = max((int)info->bl_curve[i], max); | |
85 | ||
86 | /* Look for nearest value */ | |
87 | for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) { | |
88 | int diff = abs(info->bl_curve[i] - value); | |
89 | if (diff < max) { | |
90 | max = diff; | |
91 | level = i; | |
92 | } | |
93 | } | |
94 | ||
95 | } | |
96 | ||
97 | return level; | |
14cf11af | 98 | } |
14cf11af | 99 | |
6d5aefb8 | 100 | static void pmac_backlight_key_worker(struct work_struct *work) |
14cf11af | 101 | { |
4b755999 MH |
102 | if (atomic_read(&kernel_backlight_disabled)) |
103 | return; | |
104 | ||
5474c120 MH |
105 | mutex_lock(&pmac_backlight_mutex); |
106 | if (pmac_backlight) { | |
107 | struct backlight_properties *props; | |
108 | int brightness; | |
109 | ||
599a52d1 | 110 | props = &pmac_backlight->props; |
5474c120 MH |
111 | |
112 | brightness = props->brightness + | |
e01af038 MH |
113 | ((pmac_backlight_key_queued?-1:1) * |
114 | (props->max_brightness / 15)); | |
5474c120 MH |
115 | |
116 | if (brightness < 0) | |
117 | brightness = 0; | |
118 | else if (brightness > props->max_brightness) | |
119 | brightness = props->max_brightness; | |
120 | ||
121 | props->brightness = brightness; | |
28ee086d | 122 | backlight_update_status(pmac_backlight); |
5474c120 MH |
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 | ||
599a52d1 | 148 | props = &pmac_backlight->props; |
5474c120 | 149 | props->brightness = brightness * |
cab267c6 MH |
150 | (props->max_brightness + 1) / |
151 | (OLD_BACKLIGHT_MAX + 1); | |
152 | ||
153 | if (props->brightness > props->max_brightness) | |
154 | props->brightness = props->max_brightness; | |
155 | else if (props->brightness < 0) | |
156 | props->brightness = 0; | |
157 | ||
28ee086d | 158 | backlight_update_status(pmac_backlight); |
5474c120 MH |
159 | |
160 | error = 0; | |
14cf11af | 161 | } |
5474c120 MH |
162 | mutex_unlock(&pmac_backlight_mutex); |
163 | ||
164 | return error; | |
14cf11af | 165 | } |
5474c120 | 166 | |
6d5aefb8 | 167 | static void pmac_backlight_set_legacy_worker(struct work_struct *work) |
4b755999 MH |
168 | { |
169 | if (atomic_read(&kernel_backlight_disabled)) | |
170 | return; | |
171 | ||
172 | __pmac_backlight_set_legacy_brightness(pmac_backlight_set_legacy_queued); | |
173 | } | |
174 | ||
175 | /* This function is called in interrupt context */ | |
176 | void pmac_backlight_set_legacy_brightness_pmu(int brightness) { | |
177 | if (atomic_read(&kernel_backlight_disabled)) | |
178 | return; | |
179 | ||
180 | pmac_backlight_set_legacy_queued = brightness; | |
181 | schedule_work(&pmac_backlight_set_legacy_work); | |
182 | } | |
183 | ||
184 | int pmac_backlight_set_legacy_brightness(int brightness) | |
185 | { | |
186 | return __pmac_backlight_set_legacy_brightness(brightness); | |
187 | } | |
188 | ||
4a7b8a49 | 189 | int pmac_backlight_get_legacy_brightness(void) |
14cf11af | 190 | { |
5474c120 | 191 | int result = -ENXIO; |
14cf11af | 192 | |
5474c120 MH |
193 | mutex_lock(&pmac_backlight_mutex); |
194 | if (pmac_backlight) { | |
195 | struct backlight_properties *props; | |
14cf11af | 196 | |
599a52d1 | 197 | props = &pmac_backlight->props; |
cab267c6 | 198 | |
5474c120 | 199 | result = props->brightness * |
cab267c6 MH |
200 | (OLD_BACKLIGHT_MAX + 1) / |
201 | (props->max_brightness + 1); | |
5474c120 MH |
202 | } |
203 | mutex_unlock(&pmac_backlight_mutex); | |
14cf11af | 204 | |
5474c120 | 205 | return result; |
14cf11af | 206 | } |
e01af038 | 207 | |
4a7b8a49 | 208 | void pmac_backlight_disable(void) |
4b755999 MH |
209 | { |
210 | atomic_inc(&kernel_backlight_disabled); | |
211 | } | |
212 | ||
4a7b8a49 | 213 | void pmac_backlight_enable(void) |
4b755999 MH |
214 | { |
215 | atomic_dec(&kernel_backlight_disabled); | |
216 | } | |
217 | ||
e01af038 MH |
218 | EXPORT_SYMBOL_GPL(pmac_backlight); |
219 | EXPORT_SYMBOL_GPL(pmac_backlight_mutex); | |
220 | EXPORT_SYMBOL_GPL(pmac_has_backlight_type); |