ia64/linux-2.6.18-xen.hg

view drivers/macintosh/via-pmu-backlight.c @ 893:f994bfe9b93b

linux/blktap2: reduce TLB flush scope

c/s 885 added very coarse TLB flushing. Since these flushes always
follow single page updates, single page flushes (when available) are
sufficient.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Jun 04 10:32:57 2009 +0100 (2009-06-04)
parents 3e8752eb6d9c
children
line source
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 */
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>
16 #define MAX_PMU_LEVEL 0xFF
18 static struct backlight_properties pmu_backlight_data;
19 static DEFINE_SPINLOCK(pmu_backlight_lock);
20 static int sleeping;
21 static u8 bl_curve[FB_BACKLIGHT_LEVELS];
23 static void pmu_backlight_init_curve(u8 off, u8 min, u8 max)
24 {
25 unsigned int i, flat, count, range = (max - min);
27 bl_curve[0] = off;
29 for (flat = 1; flat < (FB_BACKLIGHT_LEVELS / 16); ++flat)
30 bl_curve[flat] = min;
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 }
37 static int pmu_backlight_curve_lookup(int value)
38 {
39 int level = (FB_BACKLIGHT_LEVELS - 1);
40 int i, max = 0;
42 /* Look for biggest value */
43 for (i = 0; i < FB_BACKLIGHT_LEVELS; i++)
44 max = max((int)bl_curve[i], max);
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 }
57 static int pmu_backlight_get_level_brightness(int level)
58 {
59 int pmulevel;
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;
68 return pmulevel;
69 }
71 static int pmu_backlight_update_status(struct backlight_device *bd)
72 {
73 struct adb_request req;
74 unsigned long flags;
75 int level = bd->props->brightness;
77 spin_lock_irqsave(&pmu_backlight_lock, flags);
79 /* Don't update brightness when sleeping */
80 if (sleeping)
81 goto out;
83 if (bd->props->power != FB_BLANK_UNBLANK ||
84 bd->props->fb_blank != FB_BLANK_UNBLANK)
85 level = 0;
87 if (level > 0) {
88 int pmulevel = pmu_backlight_get_level_brightness(level);
90 pmu_request(&req, NULL, 2, PMU_BACKLIGHT_BRIGHT, pmulevel);
91 pmu_wait_complete(&req);
93 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 }
102 out:
103 spin_unlock_irqrestore(&pmu_backlight_lock, flags);
105 return 0;
106 }
108 static int pmu_backlight_get_brightness(struct backlight_device *bd)
109 {
110 return bd->props->brightness;
111 }
113 static 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 };
120 #ifdef CONFIG_PM
121 void pmu_backlight_set_sleep(int sleep)
122 {
123 unsigned long flags;
125 spin_lock_irqsave(&pmu_backlight_lock, flags);
126 sleeping = sleep;
127 spin_unlock_irqrestore(&pmu_backlight_lock, flags);
128 }
129 #endif /* CONFIG_PM */
131 void __init pmu_backlight_init()
132 {
133 struct backlight_device *bd;
134 char name[10];
135 int level, autosave;
137 /* 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");
142 if (!autosave &&
143 !pmac_has_backlight_type("pmu") &&
144 !machine_is_compatible("AAPL,PowerBook1998") &&
145 !machine_is_compatible("PowerBook1,1"))
146 return;
148 snprintf(name, sizeof(name), "pmubl");
150 bd = backlight_device_register(name, NULL, &pmu_backlight_data);
151 if (IS_ERR(bd)) {
152 printk("pmubl: Backlight registration failed\n");
153 goto error;
154 }
155 pmu_backlight_init_curve(0x7F, 0x46, 0x0E);
157 level = pmu_backlight_data.max_brightness;
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);
165 level = pmu_backlight_curve_lookup(
166 (req.reply[0] >> 4) *
167 pmu_backlight_data.max_brightness / 15);
168 }
170 down(&bd->sem);
171 bd->props->brightness = level;
172 bd->props->power = FB_BLANK_UNBLANK;
173 bd->props->update_status(bd);
174 up(&bd->sem);
176 mutex_lock(&pmac_backlight_mutex);
177 if (!pmac_backlight)
178 pmac_backlight = bd;
179 mutex_unlock(&pmac_backlight_mutex);
181 printk("pmubl: Backlight initialized (%s)\n", name);
183 return;
185 error:
186 return;
187 }