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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
18static const struct backlight_ops pmu_backlight_data;
19static DEFINE_SPINLOCK(pmu_backlight_lock);
20static int sleeping, uses_pmu_bl;
21static u8 bl_curve[FB_BACKLIGHT_LEVELS];
22
23static 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
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)
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
71static 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
99static 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
113static int pmu_backlight_get_brightness(struct backlight_device *bd)
114{
115 return bd->props.brightness;
116}
117
118static 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
125void 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
145void __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}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Backlight code for via-pmu
4 *
5 * Copyright (C) 1998 Paul Mackerras and Fabio Riccardi.
6 * Copyright (C) 2001-2002 Benjamin Herrenschmidt
7 * Copyright (C) 2006 Michael Hanselmann <linux-kernel@hansmi.ch>
8 *
9 */
10
11#include <asm/ptrace.h>
12#include <linux/adb.h>
13#include <linux/backlight.h>
14#include <linux/pmu.h>
15#include <asm/backlight.h>
16
17#define MAX_PMU_LEVEL 0xFF
18
19static const struct backlight_ops pmu_backlight_data;
20static DEFINE_SPINLOCK(pmu_backlight_lock);
21static int sleeping, uses_pmu_bl;
22static u8 bl_curve[FB_BACKLIGHT_LEVELS];
23
24static void pmu_backlight_init_curve(u8 off, u8 min, u8 max)
25{
26 int i, flat, count, range = (max - min);
27
28 bl_curve[0] = off;
29
30 for (flat = 1; flat < (FB_BACKLIGHT_LEVELS / 16); ++flat)
31 bl_curve[flat] = min;
32
33 count = FB_BACKLIGHT_LEVELS * 15 / 16;
34 for (i = 0; i < count; ++i)
35 bl_curve[flat + i] = min + (range * (i + 1) / count);
36}
37
38static int pmu_backlight_curve_lookup(int value)
39{
40 int level = (FB_BACKLIGHT_LEVELS - 1);
41 int i, max = 0;
42
43 /* Look for biggest value */
44 for (i = 0; i < FB_BACKLIGHT_LEVELS; i++)
45 max = max((int)bl_curve[i], max);
46
47 /* Look for nearest value */
48 for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) {
49 int diff = abs(bl_curve[i] - value);
50 if (diff < max) {
51 max = diff;
52 level = i;
53 }
54 }
55 return level;
56}
57
58static int pmu_backlight_get_level_brightness(int level)
59{
60 int pmulevel;
61
62 /* Get and convert the value */
63 pmulevel = bl_curve[level] * FB_BACKLIGHT_MAX / MAX_PMU_LEVEL;
64 if (pmulevel < 0)
65 pmulevel = 0;
66 else if (pmulevel > MAX_PMU_LEVEL)
67 pmulevel = MAX_PMU_LEVEL;
68
69 return pmulevel;
70}
71
72static int __pmu_backlight_update_status(struct backlight_device *bd)
73{
74 struct adb_request req;
75 int level = backlight_get_brightness(bd);
76
77 if (level > 0) {
78 int pmulevel = pmu_backlight_get_level_brightness(level);
79
80 pmu_request(&req, NULL, 2, PMU_BACKLIGHT_BRIGHT, pmulevel);
81 pmu_wait_complete(&req);
82
83 pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
84 PMU_POW_BACKLIGHT | PMU_POW_ON);
85 pmu_wait_complete(&req);
86 } else {
87 pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
88 PMU_POW_BACKLIGHT | PMU_POW_OFF);
89 pmu_wait_complete(&req);
90 }
91
92 return 0;
93}
94
95static int pmu_backlight_update_status(struct backlight_device *bd)
96{
97 unsigned long flags;
98 int rc = 0;
99
100 spin_lock_irqsave(&pmu_backlight_lock, flags);
101 /* Don't update brightness when sleeping */
102 if (!sleeping)
103 rc = __pmu_backlight_update_status(bd);
104 spin_unlock_irqrestore(&pmu_backlight_lock, flags);
105 return rc;
106}
107
108
109static const struct backlight_ops pmu_backlight_data = {
110 .update_status = pmu_backlight_update_status,
111
112};
113
114#ifdef CONFIG_PM
115void pmu_backlight_set_sleep(int sleep)
116{
117 unsigned long flags;
118
119 spin_lock_irqsave(&pmu_backlight_lock, flags);
120 sleeping = sleep;
121 if (pmac_backlight && uses_pmu_bl) {
122 if (sleep) {
123 struct adb_request req;
124
125 pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
126 PMU_POW_BACKLIGHT | PMU_POW_OFF);
127 pmu_wait_complete(&req);
128 } else
129 __pmu_backlight_update_status(pmac_backlight);
130 }
131 spin_unlock_irqrestore(&pmu_backlight_lock, flags);
132}
133#endif /* CONFIG_PM */
134
135void __init pmu_backlight_init(void)
136{
137 struct backlight_properties props;
138 struct backlight_device *bd;
139 char name[10];
140 int level, autosave;
141
142 /* Special case for the old PowerBook since I can't test on it */
143 autosave =
144 of_machine_is_compatible("AAPL,3400/2400") ||
145 of_machine_is_compatible("AAPL,3500");
146
147 if (!autosave &&
148 !pmac_has_backlight_type("pmu") &&
149 !of_machine_is_compatible("AAPL,PowerBook1998") &&
150 !of_machine_is_compatible("PowerBook1,1"))
151 return;
152
153 snprintf(name, sizeof(name), "pmubl");
154
155 memset(&props, 0, sizeof(struct backlight_properties));
156 props.type = BACKLIGHT_PLATFORM;
157 props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
158 bd = backlight_device_register(name, NULL, NULL, &pmu_backlight_data,
159 &props);
160 if (IS_ERR(bd)) {
161 printk(KERN_ERR "PMU Backlight registration failed\n");
162 return;
163 }
164 uses_pmu_bl = 1;
165 pmu_backlight_init_curve(0x7F, 0x46, 0x0E);
166
167 level = bd->props.max_brightness;
168
169 if (autosave) {
170 /* read autosaved value if available */
171 struct adb_request req;
172 pmu_request(&req, NULL, 2, 0xd9, 0);
173 pmu_wait_complete(&req);
174
175 level = pmu_backlight_curve_lookup(
176 (req.reply[0] >> 4) *
177 bd->props.max_brightness / 15);
178 }
179
180 bd->props.brightness = level;
181 bd->props.power = BACKLIGHT_POWER_ON;
182 backlight_update_status(bd);
183
184 printk(KERN_INFO "PMU Backlight initialized (%s)\n", name);
185}