diff options
author | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
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committer | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-22 10:38:37 -0500 |
commit | fcc9d2e5a6c89d22b8b773a64fb4ad21ac318446 (patch) | |
tree | a57612d1888735a2ec7972891b68c1ac5ec8faea /kernel/power/fbearlysuspend.c | |
parent | 8dea78da5cee153b8af9c07a2745f6c55057fe12 (diff) |
Diffstat (limited to 'kernel/power/fbearlysuspend.c')
-rw-r--r-- | kernel/power/fbearlysuspend.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/kernel/power/fbearlysuspend.c b/kernel/power/fbearlysuspend.c new file mode 100644 index 00000000000..15137650149 --- /dev/null +++ b/kernel/power/fbearlysuspend.c | |||
@@ -0,0 +1,153 @@ | |||
1 | /* kernel/power/fbearlysuspend.c | ||
2 | * | ||
3 | * Copyright (C) 2005-2008 Google, Inc. | ||
4 | * | ||
5 | * This software is licensed under the terms of the GNU General Public | ||
6 | * License version 2, as published by the Free Software Foundation, and | ||
7 | * may be copied, distributed, and modified under those terms. | ||
8 | * | ||
9 | * This program is distributed in the hope that it will be useful, | ||
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
12 | * GNU General Public License for more details. | ||
13 | * | ||
14 | */ | ||
15 | |||
16 | #include <linux/earlysuspend.h> | ||
17 | #include <linux/module.h> | ||
18 | #include <linux/wait.h> | ||
19 | |||
20 | #include "power.h" | ||
21 | |||
22 | static wait_queue_head_t fb_state_wq; | ||
23 | static DEFINE_SPINLOCK(fb_state_lock); | ||
24 | static enum { | ||
25 | FB_STATE_STOPPED_DRAWING, | ||
26 | FB_STATE_REQUEST_STOP_DRAWING, | ||
27 | FB_STATE_DRAWING_OK, | ||
28 | } fb_state; | ||
29 | |||
30 | /* tell userspace to stop drawing, wait for it to stop */ | ||
31 | static void stop_drawing_early_suspend(struct early_suspend *h) | ||
32 | { | ||
33 | int ret; | ||
34 | unsigned long irq_flags; | ||
35 | |||
36 | spin_lock_irqsave(&fb_state_lock, irq_flags); | ||
37 | fb_state = FB_STATE_REQUEST_STOP_DRAWING; | ||
38 | spin_unlock_irqrestore(&fb_state_lock, irq_flags); | ||
39 | |||
40 | wake_up_all(&fb_state_wq); | ||
41 | ret = wait_event_timeout(fb_state_wq, | ||
42 | fb_state == FB_STATE_STOPPED_DRAWING, | ||
43 | HZ); | ||
44 | if (unlikely(fb_state != FB_STATE_STOPPED_DRAWING)) | ||
45 | pr_warning("stop_drawing_early_suspend: timeout waiting for " | ||
46 | "userspace to stop drawing\n"); | ||
47 | } | ||
48 | |||
49 | /* tell userspace to start drawing */ | ||
50 | static void start_drawing_late_resume(struct early_suspend *h) | ||
51 | { | ||
52 | unsigned long irq_flags; | ||
53 | |||
54 | spin_lock_irqsave(&fb_state_lock, irq_flags); | ||
55 | fb_state = FB_STATE_DRAWING_OK; | ||
56 | spin_unlock_irqrestore(&fb_state_lock, irq_flags); | ||
57 | wake_up(&fb_state_wq); | ||
58 | } | ||
59 | |||
60 | static struct early_suspend stop_drawing_early_suspend_desc = { | ||
61 | .level = EARLY_SUSPEND_LEVEL_STOP_DRAWING, | ||
62 | .suspend = stop_drawing_early_suspend, | ||
63 | .resume = start_drawing_late_resume, | ||
64 | }; | ||
65 | |||
66 | static ssize_t wait_for_fb_sleep_show(struct kobject *kobj, | ||
67 | struct kobj_attribute *attr, char *buf) | ||
68 | { | ||
69 | char *s = buf; | ||
70 | int ret; | ||
71 | |||
72 | ret = wait_event_interruptible(fb_state_wq, | ||
73 | fb_state != FB_STATE_DRAWING_OK); | ||
74 | if (ret && fb_state == FB_STATE_DRAWING_OK) | ||
75 | return ret; | ||
76 | else | ||
77 | s += sprintf(buf, "sleeping"); | ||
78 | return s - buf; | ||
79 | } | ||
80 | |||
81 | static ssize_t wait_for_fb_wake_show(struct kobject *kobj, | ||
82 | struct kobj_attribute *attr, char *buf) | ||
83 | { | ||
84 | char *s = buf; | ||
85 | int ret; | ||
86 | unsigned long irq_flags; | ||
87 | |||
88 | spin_lock_irqsave(&fb_state_lock, irq_flags); | ||
89 | if (fb_state == FB_STATE_REQUEST_STOP_DRAWING) { | ||
90 | fb_state = FB_STATE_STOPPED_DRAWING; | ||
91 | wake_up(&fb_state_wq); | ||
92 | } | ||
93 | spin_unlock_irqrestore(&fb_state_lock, irq_flags); | ||
94 | |||
95 | ret = wait_event_interruptible(fb_state_wq, | ||
96 | fb_state == FB_STATE_DRAWING_OK); | ||
97 | if (ret && fb_state != FB_STATE_DRAWING_OK) | ||
98 | return ret; | ||
99 | else | ||
100 | s += sprintf(buf, "awake"); | ||
101 | |||
102 | return s - buf; | ||
103 | } | ||
104 | |||
105 | #define power_ro_attr(_name) \ | ||
106 | static struct kobj_attribute _name##_attr = { \ | ||
107 | .attr = { \ | ||
108 | .name = __stringify(_name), \ | ||
109 | .mode = 0444, \ | ||
110 | }, \ | ||
111 | .show = _name##_show, \ | ||
112 | .store = NULL, \ | ||
113 | } | ||
114 | |||
115 | power_ro_attr(wait_for_fb_sleep); | ||
116 | power_ro_attr(wait_for_fb_wake); | ||
117 | |||
118 | static struct attribute *g[] = { | ||
119 | &wait_for_fb_sleep_attr.attr, | ||
120 | &wait_for_fb_wake_attr.attr, | ||
121 | NULL, | ||
122 | }; | ||
123 | |||
124 | static struct attribute_group attr_group = { | ||
125 | .attrs = g, | ||
126 | }; | ||
127 | |||
128 | static int __init android_power_init(void) | ||
129 | { | ||
130 | int ret; | ||
131 | |||
132 | init_waitqueue_head(&fb_state_wq); | ||
133 | fb_state = FB_STATE_DRAWING_OK; | ||
134 | |||
135 | ret = sysfs_create_group(power_kobj, &attr_group); | ||
136 | if (ret) { | ||
137 | pr_err("android_power_init: sysfs_create_group failed\n"); | ||
138 | return ret; | ||
139 | } | ||
140 | |||
141 | register_early_suspend(&stop_drawing_early_suspend_desc); | ||
142 | return 0; | ||
143 | } | ||
144 | |||
145 | static void __exit android_power_exit(void) | ||
146 | { | ||
147 | unregister_early_suspend(&stop_drawing_early_suspend_desc); | ||
148 | sysfs_remove_group(power_kobj, &attr_group); | ||
149 | } | ||
150 | |||
151 | module_init(android_power_init); | ||
152 | module_exit(android_power_exit); | ||
153 | |||