1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * debugfs file to track time spent in suspend
4  *
5  * Copyright (c) 2011, Google, Inc.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15  * more details.
16  */
17 
18 #include <linux/debugfs.h>
19 #include <linux/err.h>
20 #include <linux/init.h>
21 #include <linux/kernel.h>
22 #include <linux/seq_file.h>
23 #include <linux/suspend.h>
24 #include <linux/time.h>
25 
26 #include "timekeeping_internal.h"
27 
28 #define NUM_BINS 32
29 
30 static unsigned int sleep_time_bin[NUM_BINS] = {0};
31 
32 static int tk_debug_show_sleep_time(struct seq_file *s, void *data)
33 {
34 	unsigned int bin;
35 	seq_puts(s, "      time (secs)        count\n");
36 	seq_puts(s, "------------------------------\n");
37 	for (bin = 0; bin < 32; bin++) {
38 		if (sleep_time_bin[bin] == 0)
39 			continue;
40 		seq_printf(s, "%10u - %-10u %4u\n",
41 			bin ? 1 << (bin - 1) : 0, 1 << bin,
42 				sleep_time_bin[bin]);
43 	}
44 	return 0;
45 }
46 
47 static int tk_debug_sleep_time_open(struct inode *inode, struct file *file)
48 {
49 	return single_open(file, tk_debug_show_sleep_time, NULL);
50 }
51 
52 static const struct file_operations tk_debug_sleep_time_fops = {
53 	.open		= tk_debug_sleep_time_open,
54 	.read		= seq_read,
55 	.llseek		= seq_lseek,
56 	.release	= single_release,
57 };
58 
59 static int __init tk_debug_sleep_time_init(void)
60 {
61 	struct dentry *d;
62 
63 	d = debugfs_create_file("sleep_time", 0444, NULL, NULL,
64 		&tk_debug_sleep_time_fops);
65 	if (!d) {
66 		pr_err("Failed to create sleep_time debug file\n");
67 		return -ENOMEM;
68 	}
69 
70 	return 0;
71 }
72 late_initcall(tk_debug_sleep_time_init);
73 
74 void tk_debug_account_sleep_time(const struct timespec64 *t)
75 {
76 	/* Cap bin index so we don't overflow the array */
77 	int bin = min(fls(t->tv_sec), NUM_BINS-1);
78 
79 	sleep_time_bin[bin]++;
80 	pm_deferred_pr_dbg("Timekeeping suspended for %lld.%03lu seconds\n",
81 			   (s64)t->tv_sec, t->tv_nsec / NSEC_PER_MSEC);
82 }
83 
84