Merge branch 'misc' of master.kernel.org:/pub/scm/linux/kernel/git/galak/powerpc...
[linux-2.6] / arch / powerpc / platforms / powermac / backlight.c
1 /*
2  * Miscellaneous procedures for dealing with the PowerMac hardware.
3  * Contains support for the backlight.
4  *
5  *   Copyright (C) 2000 Benjamin Herrenschmidt
6  *
7  */
8
9 #include <linux/config.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/stddef.h>
13 #include <linux/reboot.h>
14 #include <linux/nvram.h>
15 #include <linux/console.h>
16 #include <asm/sections.h>
17 #include <asm/ptrace.h>
18 #include <asm/io.h>
19 #include <asm/pgtable.h>
20 #include <asm/system.h>
21 #include <asm/prom.h>
22 #include <asm/machdep.h>
23 #include <asm/nvram.h>
24 #include <asm/backlight.h>
25
26 #include <linux/adb.h>
27 #include <linux/pmu.h>
28
29 static struct backlight_controller *backlighter;
30 static void* backlighter_data;
31 static int backlight_autosave;
32 static int backlight_level = BACKLIGHT_MAX;
33 static int backlight_enabled = 1;
34 static int backlight_req_level = -1;
35 static int backlight_req_enable = -1;
36
37 static void backlight_callback(void *);
38 static DECLARE_WORK(backlight_work, backlight_callback, NULL);
39
40 void register_backlight_controller(struct backlight_controller *ctrler,
41                                           void *data, char *type)
42 {
43         struct device_node* bk_node;
44         char *prop;
45         int valid = 0;
46
47         /* There's already a matching controller, bail out */
48         if (backlighter != NULL)
49                 return;
50
51         bk_node = find_devices("backlight");
52
53 #ifdef CONFIG_ADB_PMU
54         /* Special case for the old PowerBook since I can't test on it */
55         backlight_autosave = machine_is_compatible("AAPL,3400/2400")
56                 || machine_is_compatible("AAPL,3500");
57         if ((backlight_autosave
58              || machine_is_compatible("AAPL,PowerBook1998")
59              || machine_is_compatible("PowerBook1,1"))
60             && !strcmp(type, "pmu"))
61                 valid = 1;
62 #endif
63         if (bk_node) {
64                 prop = get_property(bk_node, "backlight-control", NULL);
65                 if (prop && !strncmp(prop, type, strlen(type)))
66                         valid = 1;
67         }
68         if (!valid)
69                 return;
70         backlighter = ctrler;
71         backlighter_data = data;
72
73         if (bk_node && !backlight_autosave)
74                 prop = get_property(bk_node, "bklt", NULL);
75         else
76                 prop = NULL;
77         if (prop) {
78                 backlight_level = ((*prop)+1) >> 1;
79                 if (backlight_level > BACKLIGHT_MAX)
80                         backlight_level = BACKLIGHT_MAX;
81         }
82
83 #ifdef CONFIG_ADB_PMU
84         if (backlight_autosave) {
85                 struct adb_request req;
86                 pmu_request(&req, NULL, 2, 0xd9, 0);
87                 while (!req.complete)
88                         pmu_poll();
89                 backlight_level = req.reply[0] >> 4;
90         }
91 #endif
92         acquire_console_sem();
93         if (!backlighter->set_enable(1, backlight_level, data))
94                 backlight_enabled = 1;
95         release_console_sem();
96
97         printk(KERN_INFO "Registered \"%s\" backlight controller,"
98                "level: %d/15\n", type, backlight_level);
99 }
100 EXPORT_SYMBOL(register_backlight_controller);
101
102 void unregister_backlight_controller(struct backlight_controller
103                                             *ctrler, void *data)
104 {
105         /* We keep the current backlight level (for now) */
106         if (ctrler == backlighter && data == backlighter_data)
107                 backlighter = NULL;
108 }
109 EXPORT_SYMBOL(unregister_backlight_controller);
110
111 static int __set_backlight_enable(int enable)
112 {
113         int rc;
114
115         if (!backlighter)
116                 return -ENODEV;
117         acquire_console_sem();
118         rc = backlighter->set_enable(enable, backlight_level,
119                                      backlighter_data);
120         if (!rc)
121                 backlight_enabled = enable;
122         release_console_sem();
123         return rc;
124 }
125 int set_backlight_enable(int enable)
126 {
127         if (!backlighter)
128                 return -ENODEV;
129         backlight_req_enable = enable;
130         schedule_work(&backlight_work);
131         return 0;
132 }
133
134 EXPORT_SYMBOL(set_backlight_enable);
135
136 int get_backlight_enable(void)
137 {
138         if (!backlighter)
139                 return -ENODEV;
140         return backlight_enabled;
141 }
142 EXPORT_SYMBOL(get_backlight_enable);
143
144 static int __set_backlight_level(int level)
145 {
146         int rc = 0;
147
148         if (!backlighter)
149                 return -ENODEV;
150         if (level < BACKLIGHT_MIN)
151                 level = BACKLIGHT_OFF;
152         if (level > BACKLIGHT_MAX)
153                 level = BACKLIGHT_MAX;
154         acquire_console_sem();
155         if (backlight_enabled)
156                 rc = backlighter->set_level(level, backlighter_data);
157         if (!rc)
158                 backlight_level = level;
159         release_console_sem();
160         if (!rc && !backlight_autosave) {
161                 level <<=1;
162                 if (level & 0x10)
163                         level |= 0x01;
164                 // -- todo: save to property "bklt"
165         }
166         return rc;
167 }
168 int set_backlight_level(int level)
169 {
170         if (!backlighter)
171                 return -ENODEV;
172         backlight_req_level = level;
173         schedule_work(&backlight_work);
174         return 0;
175 }
176
177 EXPORT_SYMBOL(set_backlight_level);
178
179 int get_backlight_level(void)
180 {
181         if (!backlighter)
182                 return -ENODEV;
183         return backlight_level;
184 }
185 EXPORT_SYMBOL(get_backlight_level);
186
187 static void backlight_callback(void *dummy)
188 {
189         int level, enable;
190
191         do {
192                 level = backlight_req_level;
193                 enable = backlight_req_enable;
194                 mb();
195
196                 if (level >= 0)
197                         __set_backlight_level(level);
198                 if (enable >= 0)
199                         __set_backlight_enable(enable);
200         } while(cmpxchg(&backlight_req_level, level, -1) != level ||
201                 cmpxchg(&backlight_req_enable, enable, -1) != enable);
202 }