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6fa3eb70 S |
1 | /* |
2 | * debugfs file to track time spent in suspend | |
3 | * | |
4 | * Copyright (c) 2011, Google, Inc. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
14 | * more details. | |
15 | */ | |
16 | ||
17 | #include <linux/debugfs.h> | |
18 | #include <linux/err.h> | |
19 | #include <linux/init.h> | |
20 | #include <linux/kernel.h> | |
21 | #include <linux/seq_file.h> | |
22 | #include <linux/syscore_ops.h> | |
23 | #include <linux/time.h> | |
24 | ||
25 | static struct timespec suspend_time_before; | |
26 | static unsigned int time_in_suspend_bins[32]; | |
27 | ||
28 | #ifdef CONFIG_DEBUG_FS | |
29 | static int suspend_time_debug_show(struct seq_file *s, void *data) | |
30 | { | |
31 | int bin; | |
32 | seq_printf(s, "time (secs) count\n"); | |
33 | seq_printf(s, "------------------\n"); | |
34 | for (bin = 0; bin < 32; bin++) { | |
35 | if (time_in_suspend_bins[bin] == 0) | |
36 | continue; | |
37 | seq_printf(s, "%4d - %4d %4u\n", | |
38 | bin ? 1 << (bin - 1) : 0, 1 << bin, | |
39 | time_in_suspend_bins[bin]); | |
40 | } | |
41 | return 0; | |
42 | } | |
43 | ||
44 | static int suspend_time_debug_open(struct inode *inode, struct file *file) | |
45 | { | |
46 | return single_open(file, suspend_time_debug_show, NULL); | |
47 | } | |
48 | ||
49 | static const struct file_operations suspend_time_debug_fops = { | |
50 | .open = suspend_time_debug_open, | |
51 | .read = seq_read, | |
52 | .llseek = seq_lseek, | |
53 | .release = single_release, | |
54 | }; | |
55 | ||
56 | static int __init suspend_time_debug_init(void) | |
57 | { | |
58 | struct dentry *d; | |
59 | ||
60 | d = debugfs_create_file("suspend_time", 0755, NULL, NULL, | |
61 | &suspend_time_debug_fops); | |
62 | if (!d) { | |
63 | pr_err("Failed to create suspend_time debug file\n"); | |
64 | return -ENOMEM; | |
65 | } | |
66 | ||
67 | return 0; | |
68 | } | |
69 | ||
70 | late_initcall(suspend_time_debug_init); | |
71 | #endif | |
72 | ||
73 | static int suspend_time_syscore_suspend(void) | |
74 | { | |
75 | read_persistent_clock(&suspend_time_before); | |
76 | ||
77 | return 0; | |
78 | } | |
79 | ||
80 | static void suspend_time_syscore_resume(void) | |
81 | { | |
82 | struct timespec after; | |
83 | ||
84 | read_persistent_clock(&after); | |
85 | ||
86 | after = timespec_sub(after, suspend_time_before); | |
87 | ||
88 | time_in_suspend_bins[fls(after.tv_sec)]++; | |
89 | ||
90 | pr_info("Suspended for %lu.%03lu seconds\n", after.tv_sec, | |
91 | after.tv_nsec / NSEC_PER_MSEC); | |
92 | } | |
93 | ||
94 | static struct syscore_ops suspend_time_syscore_ops = { | |
95 | .suspend = suspend_time_syscore_suspend, | |
96 | .resume = suspend_time_syscore_resume, | |
97 | }; | |
98 | ||
99 | static int suspend_time_syscore_init(void) | |
100 | { | |
101 | register_syscore_ops(&suspend_time_syscore_ops); | |
102 | ||
103 | return 0; | |
104 | } | |
105 | ||
106 | static void suspend_time_syscore_exit(void) | |
107 | { | |
108 | unregister_syscore_ops(&suspend_time_syscore_ops); | |
109 | } | |
110 | module_init(suspend_time_syscore_init); | |
111 | module_exit(suspend_time_syscore_exit); |