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/time.h> 23 24 #include "timekeeping_internal.h" 25 26 #define NUM_BINS 32 27 28 static unsigned int sleep_time_bin[NUM_BINS] = {0}; 29 tk_debug_show_sleep_time(struct seq_file * s,void * data)30 static int tk_debug_show_sleep_time(struct seq_file *s, void *data) 31 { 32 unsigned int bin; 33 seq_puts(s, " time (secs) count\n"); 34 seq_puts(s, "------------------------------\n"); 35 for (bin = 0; bin < 32; bin++) { 36 if (sleep_time_bin[bin] == 0) 37 continue; 38 seq_printf(s, "%10u - %-10u %4u\n", 39 bin ? 1 << (bin - 1) : 0, 1 << bin, 40 sleep_time_bin[bin]); 41 } 42 return 0; 43 } 44 tk_debug_sleep_time_open(struct inode * inode,struct file * file)45 static int tk_debug_sleep_time_open(struct inode *inode, struct file *file) 46 { 47 return single_open(file, tk_debug_show_sleep_time, NULL); 48 } 49 50 static const struct file_operations tk_debug_sleep_time_fops = { 51 .open = tk_debug_sleep_time_open, 52 .read = seq_read, 53 .llseek = seq_lseek, 54 .release = single_release, 55 }; 56 tk_debug_sleep_time_init(void)57 static int __init tk_debug_sleep_time_init(void) 58 { 59 struct dentry *d; 60 61 d = debugfs_create_file("sleep_time", 0444, NULL, NULL, 62 &tk_debug_sleep_time_fops); 63 if (!d) { 64 pr_err("Failed to create sleep_time debug file\n"); 65 return -ENOMEM; 66 } 67 68 return 0; 69 } 70 late_initcall(tk_debug_sleep_time_init); 71 tk_debug_account_sleep_time(struct timespec64 * t)72 void tk_debug_account_sleep_time(struct timespec64 *t) 73 { 74 /* Cap bin index so we don't overflow the array */ 75 int bin = min(fls(t->tv_sec), NUM_BINS-1); 76 77 sleep_time_bin[bin]++; 78 printk_deferred(KERN_INFO "Suspended for %lld.%03lu seconds\n", 79 (s64)t->tv_sec, t->tv_nsec / NSEC_PER_MSEC); 80 } 81 82