drivers/misc/tizen-inform-reboot.c

   1 /*
   2  * Tizen reboot parameter passing notifier
   3  *
   4  * Written by: Junghoon Kim <jhoon20.kim@samsung.com>
   5  *
   6  * Copyright (C) 2017 Samsung Electronics Co., Ltd.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/notifier.h>
  14 #include <linux/reboot.h>
  15 #include <linux/syscalls.h>
  16 #include <linux/file.h>
  17 #include <linux/fcntl.h>
  18 #include <linux/uaccess.h>
  19
  20 static int inform_reboot_notifier(struct notifier_block *nb,
  21                                                 unsigned long val, void *buf)
  22 {
  23         char *cmd = buf;
  24         char *filename = CONFIG_TIZEN_INFORM_PATH;
  25         struct file *file;
  26         loff_t pos = 0;
  27
  28         file = filp_open(filename, O_CREAT | O_WRONLY | O_TRUNC, 0644);
  29         if (!IS_ERR(file)) {
  30                 struct super_block *sb = file->f_path.dentry->d_sb;
  31
  32                 if (cmd) {
  33                         if (!strncmp(cmd, "fota", 4))
  34                                 cmd = "upgr";
  35                         else if (!strncmp(cmd, "recovery", 8))
  36                                 cmd = "rcvr";
  37                         else if (!strncmp(cmd, "download", 8))
  38                                 cmd = "dwnl";
  39                         else
  40                                 cmd = "ndef";
  41                 } else
  42                         cmd = "norm";
  43
  44                 vfs_write(file, cmd, strlen(cmd), &pos);
  45
  46                 down_read(&sb->s_umount);
  47                 sync_filesystem(sb);
  48                 up_read(&sb->s_umount);
  49
  50                 fput(file);
  51         } else {
  52                 pr_err("Reboot parameter passing is failed.\n"
  53                                 "Inform file path should be described correctly in config.\n");
  54         }
  55
  56         return NOTIFY_DONE;
  57 }
  58
  59 static struct notifier_block nb_inform_reboot_block = {
  60         .notifier_call = inform_reboot_notifier,
  61         .priority = 256,
  62 };
  63
  64 static int __init inform_reboot_init(void)
  65 {
  66         /* to support reboot parameter passing */
  67         register_reboot_notifier(&nb_inform_reboot_block);
  68         return 0;
  69 }
  70
  71 subsys_initcall(inform_reboot_init);