Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc
[linux-2.6.git] / drivers / macintosh / via-pmu-backlight.c
1 /*
2  * Backlight code for via-pmu
3  *
4  * Copyright (C) 1998 Paul Mackerras and Fabio Riccardi.
5  * Copyright (C) 2001-2002 Benjamin Herrenschmidt
6  * Copyright (C) 2006      Michael Hanselmann <linux-kernel@hansmi.ch>
7  *
8  */
9
10 #include <asm/ptrace.h>
11 #include <linux/adb.h>
12 #include <linux/pmu.h>
13 #include <asm/backlight.h>
14 #include <asm/prom.h>
15
16 #define MAX_PMU_LEVEL 0xFF
17
18 static const struct backlight_ops pmu_backlight_data;
19 static DEFINE_SPINLOCK(pmu_backlight_lock);
20 static int sleeping, uses_pmu_bl;
21 static u8 bl_curve[FB_BACKLIGHT_LEVELS];
22
23 static void pmu_backlight_init_curve(u8 off, u8 min, u8 max)
24 {
25         int i, flat, count, range = (max - min);
26
27         bl_curve[0] = off;
28
29         for (flat = 1; flat < (FB_BACKLIGHT_LEVELS / 16); ++flat)
30                 bl_curve[flat] = min;
31
32         count = FB_BACKLIGHT_LEVELS * 15 / 16;
33         for (i = 0; i < count; ++i)
34                 bl_curve[flat + i] = min + (range * (i + 1) / count);
35 }
36
37 static int pmu_backlight_curve_lookup(int value)
38 {
39         int level = (FB_BACKLIGHT_LEVELS - 1);
40         int i, max = 0;
41
42         /* Look for biggest value */
43         for (i = 0; i < FB_BACKLIGHT_LEVELS; i++)
44                 max = max((int)bl_curve[i], max);
45
46         /* Look for nearest value */
47         for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) {
48                 int diff = abs(bl_curve[i] - value);
49                 if (diff < max) {
50                         max = diff;
51                         level = i;
52                 }
53         }
54         return level;
55 }
56
57 static int pmu_backlight_get_level_brightness(int level)
58 {
59         int pmulevel;
60
61         /* Get and convert the value */
62         pmulevel = bl_curve[level] * FB_BACKLIGHT_MAX / MAX_PMU_LEVEL;
63         if (pmulevel < 0)
64                 pmulevel = 0;
65         else if (pmulevel > MAX_PMU_LEVEL)
66                 pmulevel = MAX_PMU_LEVEL;
67
68         return pmulevel;
69 }
70
71 static int __pmu_backlight_update_status(struct backlight_device *bd)
72 {
73         struct adb_request req;
74         int level = bd->props.brightness;
75
76
77         if (bd->props.power != FB_BLANK_UNBLANK ||
78             bd->props.fb_blank != FB_BLANK_UNBLANK)
79                 level = 0;
80
81         if (level > 0) {
82                 int pmulevel = pmu_backlight_get_level_brightness(level);
83
84                 pmu_request(&req, NULL, 2, PMU_BACKLIGHT_BRIGHT, pmulevel);
85                 pmu_wait_complete(&req);
86
87                 pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
88                         PMU_POW_BACKLIGHT | PMU_POW_ON);
89                 pmu_wait_complete(&req);
90         } else {
91                 pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
92                         PMU_POW_BACKLIGHT | PMU_POW_OFF);
93                 pmu_wait_complete(&req);
94         }
95
96         return 0;
97 }
98
99 static int pmu_backlight_update_status(struct backlight_device *bd)
100 {
101         unsigned long flags;
102         int rc = 0;
103
104         spin_lock_irqsave(&pmu_backlight_lock, flags);
105         /* Don't update brightness when sleeping */
106         if (!sleeping)
107                 rc = __pmu_backlight_update_status(bd);
108         spin_unlock_irqrestore(&pmu_backlight_lock, flags);
109         return rc;
110 }
111
112
113 static int pmu_backlight_get_brightness(struct backlight_device *bd)
114 {
115         return bd->props.brightness;
116 }
117
118 static const struct backlight_ops pmu_backlight_data = {
119         .get_brightness = pmu_backlight_get_brightness,
120         .update_status  = pmu_backlight_update_status,
121
122 };
123
124 #ifdef CONFIG_PM
125 void pmu_backlight_set_sleep(int sleep)
126 {
127         unsigned long flags;
128
129         spin_lock_irqsave(&pmu_backlight_lock, flags);
130         sleeping = sleep;
131         if (pmac_backlight && uses_pmu_bl) {
132                 if (sleep) {
133                         struct adb_request req;
134
135                         pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
136                                     PMU_POW_BACKLIGHT | PMU_POW_OFF);
137                         pmu_wait_complete(&req);
138                 } else
139                         __pmu_backlight_update_status(pmac_backlight);
140         }
141         spin_unlock_irqrestore(&pmu_backlight_lock, flags);
142 }
143 #endif /* CONFIG_PM */
144
145 void __init pmu_backlight_init()
146 {
147         struct backlight_properties props;
148         struct backlight_device *bd;
149         char name[10];
150         int level, autosave;
151
152         /* Special case for the old PowerBook since I can't test on it */
153         autosave =
154                 of_machine_is_compatible("AAPL,3400/2400") ||
155                 of_machine_is_compatible("AAPL,3500");
156
157         if (!autosave &&
158             !pmac_has_backlight_type("pmu") &&
159             !of_machine_is_compatible("AAPL,PowerBook1998") &&
160             !of_machine_is_compatible("PowerBook1,1"))
161                 return;
162
163         snprintf(name, sizeof(name), "pmubl");
164
165         memset(&props, 0, sizeof(struct backlight_properties));
166         props.type = BACKLIGHT_PLATFORM;
167         props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
168         bd = backlight_device_register(name, NULL, NULL, &pmu_backlight_data,
169                                        &props);
170         if (IS_ERR(bd)) {
171                 printk(KERN_ERR "PMU Backlight registration failed\n");
172                 return;
173         }
174         uses_pmu_bl = 1;
175         pmu_backlight_init_curve(0x7F, 0x46, 0x0E);
176
177         level = bd->props.max_brightness;
178
179         if (autosave) {
180                 /* read autosaved value if available */
181                 struct adb_request req;
182                 pmu_request(&req, NULL, 2, 0xd9, 0);
183                 pmu_wait_complete(&req);
184
185                 level = pmu_backlight_curve_lookup(
186                                 (req.reply[0] >> 4) *
187                                 bd->props.max_brightness / 15);
188         }
189
190         bd->props.brightness = level;
191         bd->props.power = FB_BLANK_UNBLANK;
192         backlight_update_status(bd);
193
194         printk(KERN_INFO "PMU Backlight initialized (%s)\n", name);
195 }