Andy Yan | 4fcd504 | 2016-07-06 21:27:26 +0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License as published by |
| 6 | * the Free Software Foundation; either version 2 of the License, or |
| 7 | * (at your option) any later version. |
| 8 | */ |
| 9 | |
| 10 | #include <linux/device.h> |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/of.h> |
| 15 | #include <linux/reboot.h> |
| 16 | #include "reboot-mode.h" |
| 17 | |
| 18 | #define PREFIX "mode-" |
| 19 | |
| 20 | struct mode_info { |
| 21 | const char *mode; |
| 22 | u32 magic; |
| 23 | struct list_head list; |
| 24 | }; |
| 25 | |
| 26 | static unsigned int get_reboot_mode_magic(struct reboot_mode_driver *reboot, |
| 27 | const char *cmd) |
| 28 | { |
| 29 | const char *normal = "normal"; |
| 30 | int magic = 0; |
| 31 | struct mode_info *info; |
| 32 | |
| 33 | if (!cmd) |
| 34 | cmd = normal; |
| 35 | |
| 36 | list_for_each_entry(info, &reboot->head, list) { |
| 37 | if (!strcmp(info->mode, cmd)) { |
| 38 | magic = info->magic; |
| 39 | break; |
| 40 | } |
| 41 | } |
| 42 | |
| 43 | return magic; |
| 44 | } |
| 45 | |
| 46 | static int reboot_mode_notify(struct notifier_block *this, |
| 47 | unsigned long mode, void *cmd) |
| 48 | { |
| 49 | struct reboot_mode_driver *reboot; |
| 50 | unsigned int magic; |
| 51 | |
| 52 | reboot = container_of(this, struct reboot_mode_driver, reboot_notifier); |
| 53 | magic = get_reboot_mode_magic(reboot, cmd); |
| 54 | if (magic) |
| 55 | reboot->write(reboot, magic); |
| 56 | |
| 57 | return NOTIFY_DONE; |
| 58 | } |
| 59 | |
| 60 | /** |
| 61 | * reboot_mode_register - register a reboot mode driver |
| 62 | * @reboot: reboot mode driver |
| 63 | * |
| 64 | * Returns: 0 on success or a negative error code on failure. |
| 65 | */ |
| 66 | int reboot_mode_register(struct reboot_mode_driver *reboot) |
| 67 | { |
| 68 | struct mode_info *info; |
| 69 | struct property *prop; |
| 70 | struct device_node *np = reboot->dev->of_node; |
| 71 | size_t len = strlen(PREFIX); |
| 72 | int ret; |
| 73 | |
| 74 | INIT_LIST_HEAD(&reboot->head); |
| 75 | |
| 76 | for_each_property_of_node(np, prop) { |
| 77 | if (strncmp(prop->name, PREFIX, len)) |
| 78 | continue; |
| 79 | |
| 80 | info = devm_kzalloc(reboot->dev, sizeof(*info), GFP_KERNEL); |
| 81 | if (!info) { |
| 82 | ret = -ENOMEM; |
| 83 | goto error; |
| 84 | } |
| 85 | |
| 86 | if (of_property_read_u32(np, prop->name, &info->magic)) { |
| 87 | dev_err(reboot->dev, "reboot mode %s without magic number\n", |
| 88 | info->mode); |
| 89 | devm_kfree(reboot->dev, info); |
| 90 | continue; |
| 91 | } |
| 92 | |
| 93 | info->mode = kstrdup_const(prop->name + len, GFP_KERNEL); |
| 94 | if (!info->mode) { |
| 95 | ret = -ENOMEM; |
| 96 | goto error; |
| 97 | } else if (info->mode[0] == '\0') { |
| 98 | kfree_const(info->mode); |
| 99 | ret = -EINVAL; |
| 100 | dev_err(reboot->dev, "invalid mode name(%s): too short!\n", |
| 101 | prop->name); |
| 102 | goto error; |
| 103 | } |
| 104 | |
| 105 | list_add_tail(&info->list, &reboot->head); |
| 106 | } |
| 107 | |
| 108 | reboot->reboot_notifier.notifier_call = reboot_mode_notify; |
| 109 | register_reboot_notifier(&reboot->reboot_notifier); |
| 110 | |
| 111 | return 0; |
| 112 | |
| 113 | error: |
| 114 | list_for_each_entry(info, &reboot->head, list) |
| 115 | kfree_const(info->mode); |
| 116 | |
| 117 | return ret; |
| 118 | } |
| 119 | EXPORT_SYMBOL_GPL(reboot_mode_register); |
| 120 | |
| 121 | /** |
| 122 | * reboot_mode_unregister - unregister a reboot mode driver |
| 123 | * @reboot: reboot mode driver |
| 124 | */ |
| 125 | int reboot_mode_unregister(struct reboot_mode_driver *reboot) |
| 126 | { |
| 127 | struct mode_info *info; |
| 128 | |
| 129 | unregister_reboot_notifier(&reboot->reboot_notifier); |
| 130 | |
| 131 | list_for_each_entry(info, &reboot->head, list) |
| 132 | kfree_const(info->mode); |
| 133 | |
| 134 | return 0; |
| 135 | } |
| 136 | EXPORT_SYMBOL_GPL(reboot_mode_unregister); |
| 137 | |
| 138 | MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com"); |
| 139 | MODULE_DESCRIPTION("System reboot mode core library"); |
| 140 | MODULE_LICENSE("GPL v2"); |