// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
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*/
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#include <linux/device.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/kobject.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/reboot.h>
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#include <linux/reboot-mode.h>
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#include <linux/sysfs.h>
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#define PREFIX "mode-"
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struct mode_info {
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const char *mode;
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u32 magic;
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struct list_head list;
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};
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static const char *boot_mode = "coldboot";
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static ssize_t boot_mode_show(struct kobject *kobj, struct kobj_attribute *attr,
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char *buf)
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{
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return scnprintf(buf, PAGE_SIZE, "%s\n", boot_mode);
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}
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static struct kobj_attribute kobj_boot_mode = __ATTR_RO(boot_mode);
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static int get_reboot_mode_magic(struct reboot_mode_driver *reboot,
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const char *cmd)
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{
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const char *normal = "normal";
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int magic = 0;
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struct mode_info *info;
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if (!cmd || !cmd[0])
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cmd = normal;
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list_for_each_entry(info, &reboot->head, list) {
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if (!strcmp(info->mode, cmd)) {
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magic = info->magic;
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break;
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}
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}
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return magic;
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}
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static int last_magic;
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static void reboot_mode_write(struct reboot_mode_driver *reboot,
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const void *cmd)
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{
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int magic;
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magic = get_reboot_mode_magic(reboot, cmd);
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if (!magic)
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magic = get_reboot_mode_magic(reboot, NULL);
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if (magic) {
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reboot->write(reboot, magic);
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last_magic = magic;
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}
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}
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static int reboot_mode_notify(struct notifier_block *this,
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unsigned long mode, void *cmd)
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{
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struct reboot_mode_driver *reboot;
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reboot = container_of(this, struct reboot_mode_driver, reboot_notifier);
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reboot_mode_write(reboot, cmd);
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return NOTIFY_DONE;
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}
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static int reboot_mode_pre_restart_notify(struct notifier_block *this,
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unsigned long mode, void *cmd)
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{
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struct reboot_mode_driver *reboot;
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reboot = container_of(this, struct reboot_mode_driver, pre_restart_notifier);
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if (cmd || !last_magic)
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reboot_mode_write(reboot, cmd);
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return NOTIFY_DONE;
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}
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static int reboot_mode_panic_notify(struct notifier_block *this,
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unsigned long ev, void *ptr)
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{
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struct reboot_mode_driver *reboot;
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const char *cmd = "panic";
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reboot = container_of(this, struct reboot_mode_driver, panic_notifier);
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reboot_mode_write(reboot, cmd);
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return NOTIFY_DONE;
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}
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static int boot_mode_parse(struct reboot_mode_driver *reboot)
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{
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struct mode_info *info;
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unsigned int magic = reboot->read(reboot);
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list_for_each_entry(info, &reboot->head, list) {
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if (info->magic == magic) {
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boot_mode = info->mode;
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break;
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}
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}
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return 0;
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}
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/**
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* reboot_mode_register - register a reboot mode driver
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* @reboot: reboot mode driver
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*
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* Returns: 0 on success or a negative error code on failure.
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*/
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int reboot_mode_register(struct reboot_mode_driver *reboot)
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{
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struct mode_info *info;
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struct property *prop;
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struct device_node *np = reboot->dev->of_node;
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size_t len = strlen(PREFIX);
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int ret;
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INIT_LIST_HEAD(&reboot->head);
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for_each_property_of_node(np, prop) {
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if (strncmp(prop->name, PREFIX, len))
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continue;
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info = devm_kzalloc(reboot->dev, sizeof(*info), GFP_KERNEL);
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if (!info) {
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ret = -ENOMEM;
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goto error;
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}
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if (of_property_read_u32(np, prop->name, &info->magic)) {
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dev_err(reboot->dev, "reboot mode %s without magic number\n",
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info->mode);
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devm_kfree(reboot->dev, info);
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continue;
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}
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info->mode = kstrdup_const(prop->name + len, GFP_KERNEL);
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if (!info->mode) {
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ret = -ENOMEM;
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goto error;
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} else if (info->mode[0] == '\0') {
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kfree_const(info->mode);
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ret = -EINVAL;
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dev_err(reboot->dev, "invalid mode name(%s): too short!\n",
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prop->name);
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goto error;
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}
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list_add_tail(&info->list, &reboot->head);
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}
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boot_mode_parse(reboot);
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reboot->reboot_notifier.notifier_call = reboot_mode_notify;
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reboot->pre_restart_notifier.notifier_call = reboot_mode_pre_restart_notify;
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reboot->panic_notifier.notifier_call = reboot_mode_panic_notify;
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register_reboot_notifier(&reboot->reboot_notifier);
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register_pre_restart_handler(&reboot->pre_restart_notifier);
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atomic_notifier_chain_register(&panic_notifier_list,
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&reboot->panic_notifier);
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ret = sysfs_create_file(kernel_kobj, &kobj_boot_mode.attr);
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return ret;
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error:
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list_for_each_entry(info, &reboot->head, list)
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kfree_const(info->mode);
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return ret;
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}
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EXPORT_SYMBOL_GPL(reboot_mode_register);
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/**
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* reboot_mode_unregister - unregister a reboot mode driver
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* @reboot: reboot mode driver
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*/
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int reboot_mode_unregister(struct reboot_mode_driver *reboot)
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{
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struct mode_info *info;
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unregister_reboot_notifier(&reboot->reboot_notifier);
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list_for_each_entry(info, &reboot->head, list)
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kfree_const(info->mode);
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return 0;
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}
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EXPORT_SYMBOL_GPL(reboot_mode_unregister);
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static void devm_reboot_mode_release(struct device *dev, void *res)
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{
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reboot_mode_unregister(*(struct reboot_mode_driver **)res);
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}
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/**
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* devm_reboot_mode_register() - resource managed reboot_mode_register()
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* @dev: device to associate this resource with
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* @reboot: reboot mode driver
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*
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* Returns: 0 on success or a negative error code on failure.
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*/
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int devm_reboot_mode_register(struct device *dev,
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struct reboot_mode_driver *reboot)
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{
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struct reboot_mode_driver **dr;
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int rc;
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dr = devres_alloc(devm_reboot_mode_release, sizeof(*dr), GFP_KERNEL);
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if (!dr)
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return -ENOMEM;
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rc = reboot_mode_register(reboot);
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if (rc) {
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devres_free(dr);
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return rc;
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}
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*dr = reboot;
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devres_add(dev, dr);
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return 0;
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}
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EXPORT_SYMBOL_GPL(devm_reboot_mode_register);
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static int devm_reboot_mode_match(struct device *dev, void *res, void *data)
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{
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struct reboot_mode_driver **p = res;
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if (WARN_ON(!p || !*p))
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return 0;
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return *p == data;
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}
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/**
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* devm_reboot_mode_unregister() - resource managed reboot_mode_unregister()
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* @dev: device to associate this resource with
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* @reboot: reboot mode driver
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*/
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void devm_reboot_mode_unregister(struct device *dev,
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struct reboot_mode_driver *reboot)
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{
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WARN_ON(devres_release(dev,
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devm_reboot_mode_release,
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devm_reboot_mode_match, reboot));
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}
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EXPORT_SYMBOL_GPL(devm_reboot_mode_unregister);
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MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com>");
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MODULE_DESCRIPTION("System reboot mode core library");
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MODULE_LICENSE("GPL v2");
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