blob: 6c29fe727c0f4ea7ee30d1daac58dc5efc309fc6 [file] [log] [blame]
Michael Hanselmann5474c122006-06-25 05:47:08 -07001/*
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
Michael Hanselmann5474c122006-06-25 05:47:08 -070018static struct backlight_properties pmu_backlight_data;
David Woodhouse4efd5872006-09-29 01:58:37 -070019static DEFINE_SPINLOCK(pmu_backlight_lock);
Michael Hanselmann4b755992006-07-30 03:04:19 -070020static int sleeping;
Benjamin Herrenschmidtd565dd32006-08-31 21:27:49 -070021static u8 bl_curve[FB_BACKLIGHT_LEVELS];
Michael Hanselmann5474c122006-06-25 05:47:08 -070022
Benjamin Herrenschmidtd565dd32006-08-31 21:27:49 -070023static void pmu_backlight_init_curve(u8 off, u8 min, u8 max)
24{
25 unsigned 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
37static 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
57static int pmu_backlight_get_level_brightness(int level)
Michael Hanselmann5474c122006-06-25 05:47:08 -070058{
59 int pmulevel;
60
61 /* Get and convert the value */
Benjamin Herrenschmidtd565dd32006-08-31 21:27:49 -070062 pmulevel = bl_curve[level] * FB_BACKLIGHT_MAX / MAX_PMU_LEVEL;
Michael Hanselmann5474c122006-06-25 05:47:08 -070063 if (pmulevel < 0)
64 pmulevel = 0;
65 else if (pmulevel > MAX_PMU_LEVEL)
66 pmulevel = MAX_PMU_LEVEL;
67
68 return pmulevel;
69}
70
71static int pmu_backlight_update_status(struct backlight_device *bd)
72{
Michael Hanselmann5474c122006-06-25 05:47:08 -070073 struct adb_request req;
Michael Hanselmann4b755992006-07-30 03:04:19 -070074 unsigned long flags;
75 int level = bd->props->brightness;
Michael Hanselmann5474c122006-06-25 05:47:08 -070076
Michael Hanselmann4b755992006-07-30 03:04:19 -070077 spin_lock_irqsave(&pmu_backlight_lock, flags);
78
79 /* Don't update brightness when sleeping */
80 if (sleeping)
81 goto out;
Michael Hanselmann5474c122006-06-25 05:47:08 -070082
83 if (bd->props->power != FB_BLANK_UNBLANK ||
84 bd->props->fb_blank != FB_BLANK_UNBLANK)
85 level = 0;
86
Michael Hanselmann4b755992006-07-30 03:04:19 -070087 if (level > 0) {
Benjamin Herrenschmidtd565dd32006-08-31 21:27:49 -070088 int pmulevel = pmu_backlight_get_level_brightness(level);
Michael Hanselmann5474c122006-06-25 05:47:08 -070089
Michael Hanselmann4b755992006-07-30 03:04:19 -070090 pmu_request(&req, NULL, 2, PMU_BACKLIGHT_BRIGHT, pmulevel);
91 pmu_wait_complete(&req);
Michael Hanselmann5474c122006-06-25 05:47:08 -070092
Michael Hanselmann4b755992006-07-30 03:04:19 -070093 pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
94 PMU_POW_BACKLIGHT | PMU_POW_ON);
95 pmu_wait_complete(&req);
96 } else {
97 pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
98 PMU_POW_BACKLIGHT | PMU_POW_OFF);
99 pmu_wait_complete(&req);
100 }
101
102out:
103 spin_unlock_irqrestore(&pmu_backlight_lock, flags);
Michael Hanselmann5474c122006-06-25 05:47:08 -0700104
105 return 0;
106}
107
108static int pmu_backlight_get_brightness(struct backlight_device *bd)
109{
110 return bd->props->brightness;
111}
112
113static struct backlight_properties pmu_backlight_data = {
114 .owner = THIS_MODULE,
115 .get_brightness = pmu_backlight_get_brightness,
116 .update_status = pmu_backlight_update_status,
117 .max_brightness = (FB_BACKLIGHT_LEVELS - 1),
118};
119
Michael Hanselmann4b755992006-07-30 03:04:19 -0700120#ifdef CONFIG_PM
Benjamin Herrenschmidtd565dd32006-08-31 21:27:49 -0700121void pmu_backlight_set_sleep(int sleep)
Michael Hanselmann4b755992006-07-30 03:04:19 -0700122{
123 unsigned long flags;
124
125 spin_lock_irqsave(&pmu_backlight_lock, flags);
Benjamin Herrenschmidtd565dd32006-08-31 21:27:49 -0700126 sleeping = sleep;
Michael Hanselmann4b755992006-07-30 03:04:19 -0700127 spin_unlock_irqrestore(&pmu_backlight_lock, flags);
Michael Hanselmann4b755992006-07-30 03:04:19 -0700128}
Benjamin Herrenschmidtd565dd32006-08-31 21:27:49 -0700129#endif /* CONFIG_PM */
Michael Hanselmann4b755992006-07-30 03:04:19 -0700130
131void __init pmu_backlight_init()
Michael Hanselmann5474c122006-06-25 05:47:08 -0700132{
133 struct backlight_device *bd;
Michael Hanselmann5474c122006-06-25 05:47:08 -0700134 char name[10];
135 int level, autosave;
136
Michael Hanselmann5474c122006-06-25 05:47:08 -0700137 /* Special case for the old PowerBook since I can't test on it */
138 autosave =
139 machine_is_compatible("AAPL,3400/2400") ||
140 machine_is_compatible("AAPL,3500");
141
142 if (!autosave &&
143 !pmac_has_backlight_type("pmu") &&
144 !machine_is_compatible("AAPL,PowerBook1998") &&
145 !machine_is_compatible("PowerBook1,1"))
146 return;
147
Benjamin Herrenschmidtd565dd32006-08-31 21:27:49 -0700148 snprintf(name, sizeof(name), "pmubl");
Michael Hanselmann5474c122006-06-25 05:47:08 -0700149
Benjamin Herrenschmidtd565dd32006-08-31 21:27:49 -0700150 bd = backlight_device_register(name, NULL, &pmu_backlight_data);
Michael Hanselmann5474c122006-06-25 05:47:08 -0700151 if (IS_ERR(bd)) {
152 printk("pmubl: Backlight registration failed\n");
153 goto error;
154 }
Benjamin Herrenschmidtd565dd32006-08-31 21:27:49 -0700155 pmu_backlight_init_curve(0x7F, 0x46, 0x0E);
Michael Hanselmann5474c122006-06-25 05:47:08 -0700156
157 level = pmu_backlight_data.max_brightness;
158
159 if (autosave) {
160 /* read autosaved value if available */
161 struct adb_request req;
162 pmu_request(&req, NULL, 2, 0xd9, 0);
163 pmu_wait_complete(&req);
164
Benjamin Herrenschmidtd565dd32006-08-31 21:27:49 -0700165 level = pmu_backlight_curve_lookup(
Michael Hanselmann5474c122006-06-25 05:47:08 -0700166 (req.reply[0] >> 4) *
167 pmu_backlight_data.max_brightness / 15);
Michael Hanselmann5474c122006-06-25 05:47:08 -0700168 }
169
Benjamin Herrenschmidta9303632006-08-31 21:27:54 -0700170 down(&bd->sem);
Michael Hanselmann5474c122006-06-25 05:47:08 -0700171 bd->props->brightness = level;
172 bd->props->power = FB_BLANK_UNBLANK;
173 bd->props->update_status(bd);
Benjamin Herrenschmidta9303632006-08-31 21:27:54 -0700174 up(&bd->sem);
Michael Hanselmann5474c122006-06-25 05:47:08 -0700175
176 mutex_lock(&pmac_backlight_mutex);
177 if (!pmac_backlight)
178 pmac_backlight = bd;
179 mutex_unlock(&pmac_backlight_mutex);
180
Michael Hanselmann5474c122006-06-25 05:47:08 -0700181 printk("pmubl: Backlight initialized (%s)\n", name);
182
183 return;
184
185error:
186 return;
187}