diff options
Diffstat (limited to 'drivers/power/reset/reboot-mode.c')
| -rw-r--r-- | drivers/power/reset/reboot-mode.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset/reboot-mode.c new file mode 100644 index 0000000000..b4076b10b8 --- /dev/null +++ b/drivers/power/reset/reboot-mode.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd + */ + +#include <linux/device.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/reboot.h> +#include <linux/reboot-mode.h> + +#define PREFIX "mode-" + +struct mode_info { + const char *mode; + u32 magic; + struct list_head list; +}; + +static unsigned int get_reboot_mode_magic(struct reboot_mode_driver *reboot, + const char *cmd) +{ + const char *normal = "normal"; + int magic = 0; + struct mode_info *info; + + if (!cmd) + cmd = normal; + + list_for_each_entry(info, &reboot->head, list) { + if (!strcmp(info->mode, cmd)) { + magic = info->magic; + break; + } + } + + return magic; +} + +static int reboot_mode_notify(struct notifier_block *this, + unsigned long mode, void *cmd) +{ + struct reboot_mode_driver *reboot; + unsigned int magic; + + reboot = container_of(this, struct reboot_mode_driver, reboot_notifier); + magic = get_reboot_mode_magic(reboot, cmd); + if (magic) + reboot->write(reboot, magic); + + return NOTIFY_DONE; +} + +/** + * reboot_mode_register - register a reboot mode driver + * @reboot: reboot mode driver + * + * Returns: 0 on success or a negative error code on failure. + */ +int reboot_mode_register(struct reboot_mode_driver *reboot) +{ + struct mode_info *info; + struct property *prop; + struct device_node *np = reboot->dev->of_node; + size_t len = strlen(PREFIX); + int ret; + + INIT_LIST_HEAD(&reboot->head); + + for_each_property_of_node(np, prop) { + if (strncmp(prop->name, PREFIX, len)) + continue; + + info = devm_kzalloc(reboot->dev, sizeof(*info), GFP_KERNEL); + if (!info) { + ret = -ENOMEM; + goto error; + } + + if (of_property_read_u32(np, prop->name, &info->magic)) { + dev_err(reboot->dev, "reboot mode %s without magic number\n", + info->mode); + devm_kfree(reboot->dev, info); + continue; + } + + info->mode = kstrdup_const(prop->name + len, GFP_KERNEL); + if (!info->mode) { + ret = -ENOMEM; + goto error; + } else if (info->mode[0] == '\0') { + kfree_const(info->mode); + ret = -EINVAL; + dev_err(reboot->dev, "invalid mode name(%s): too short!\n", + prop->name); + goto error; + } + + list_add_tail(&info->list, &reboot->head); + } + + reboot->reboot_notifier.notifier_call = reboot_mode_notify; + register_reboot_notifier(&reboot->reboot_notifier); + + return 0; + +error: + list_for_each_entry(info, &reboot->head, list) + kfree_const(info->mode); + + return ret; +} +EXPORT_SYMBOL_GPL(reboot_mode_register); + +/** + * reboot_mode_unregister - unregister a reboot mode driver + * @reboot: reboot mode driver + */ +int reboot_mode_unregister(struct reboot_mode_driver *reboot) +{ + struct mode_info *info; + + unregister_reboot_notifier(&reboot->reboot_notifier); + + list_for_each_entry(info, &reboot->head, list) + kfree_const(info->mode); + + return 0; +} +EXPORT_SYMBOL_GPL(reboot_mode_unregister); + +static void devm_reboot_mode_release(struct device *dev, void *res) +{ + reboot_mode_unregister(*(struct reboot_mode_driver **)res); +} + +/** + * devm_reboot_mode_register() - resource managed reboot_mode_register() + * @dev: device to associate this resource with + * @reboot: reboot mode driver + * + * Returns: 0 on success or a negative error code on failure. + */ +int devm_reboot_mode_register(struct device *dev, + struct reboot_mode_driver *reboot) +{ + struct reboot_mode_driver **dr; + int rc; + + dr = devres_alloc(devm_reboot_mode_release, sizeof(*dr), GFP_KERNEL); + if (!dr) + return -ENOMEM; + + rc = reboot_mode_register(reboot); + if (rc) { + devres_free(dr); + return rc; + } + + *dr = reboot; + devres_add(dev, dr); + + return 0; +} +EXPORT_SYMBOL_GPL(devm_reboot_mode_register); + +static int devm_reboot_mode_match(struct device *dev, void *res, void *data) +{ + struct reboot_mode_driver **p = res; + + if (WARN_ON(!p || !*p)) + return 0; + + return *p == data; +} + +/** + * devm_reboot_mode_unregister() - resource managed reboot_mode_unregister() + * @dev: device to associate this resource with + * @reboot: reboot mode driver + */ +void devm_reboot_mode_unregister(struct device *dev, + struct reboot_mode_driver *reboot) +{ + WARN_ON(devres_release(dev, + devm_reboot_mode_release, + devm_reboot_mode_match, reboot)); +} +EXPORT_SYMBOL_GPL(devm_reboot_mode_unregister); + +MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com>"); +MODULE_DESCRIPTION("System reboot mode core library"); +MODULE_LICENSE("GPL v2"); |