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/suspend.h> 23 #include <linux/time.h> 24 25 #include "timekeeping_internal.h" 26 27 #define NUM_BINS 32 28 29 static unsigned int sleep_time_bin[NUM_BINS] = {0}; 30 31 static int tk_debug_show_sleep_time(struct seq_file *s, void *data) 32 { 33 unsigned int bin; 34 seq_puts(s, " time (secs) count\n"); 35 seq_puts(s, "------------------------------\n"); 36 for (bin = 0; bin < 32; bin++) { 37 if (sleep_time_bin[bin] == 0) 38 continue; 39 seq_printf(s, "%10u - %-10u %4u\n", 40 bin ? 1 << (bin - 1) : 0, 1 << bin, 41 sleep_time_bin[bin]); 42 } 43 return 0; 44 } 45 46 static int tk_debug_sleep_time_open(struct inode *inode, struct file *file) 47 { 48 return single_open(file, tk_debug_show_sleep_time, NULL); 49 } 50 51 static const struct file_operations tk_debug_sleep_time_fops = { 52 .open = tk_debug_sleep_time_open, 53 .read = seq_read, 54 .llseek = seq_lseek, 55 .release = single_release, 56 }; 57 58 static int __init tk_debug_sleep_time_init(void) 59 { 60 struct dentry *d; 61 62 d = debugfs_create_file("sleep_time", 0444, NULL, NULL, 63 &tk_debug_sleep_time_fops); 64 if (!d) { 65 pr_err("Failed to create sleep_time debug file\n"); 66 return -ENOMEM; 67 } 68 69 return 0; 70 } 71 late_initcall(tk_debug_sleep_time_init); 72 73 void tk_debug_account_sleep_time(struct timespec64 *t) 74 { 75 /* Cap bin index so we don't overflow the array */ 76 int bin = min(fls(t->tv_sec), NUM_BINS-1); 77 78 sleep_time_bin[bin]++; 79 pm_deferred_pr_dbg("Timekeeping suspended for %lld.%03lu seconds\n", 80 (s64)t->tv_sec, t->tv_nsec / NSEC_PER_MSEC); 81 } 82 83