path: root/drivers/reset/core.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Reset Controller framework
 *
 * Copyright 2013 Philipp Zabel, Pengutronix
 */
#include <linux/atomic.h>
#include <linux/cleanup.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
#include <linux/idr.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/acpi.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/reset-controller.h>
#include <linux/slab.h>

static DEFINE_MUTEX(reset_list_mutex);
static LIST_HEAD(reset_controller_list);

static DEFINE_MUTEX(reset_lookup_mutex);
static LIST_HEAD(reset_lookup_list);

/* Protects reset_gpio_lookup_list */
static DEFINE_MUTEX(reset_gpio_lookup_mutex);
static LIST_HEAD(reset_gpio_lookup_list);
static DEFINE_IDA(reset_gpio_ida);

/**
 * struct reset_control - a reset control
 * @rcdev: a pointer to the reset controller device
 *         this reset control belongs to
 * @list: list entry for the rcdev's reset controller list
 * @id: ID of the reset controller in the reset
 *      controller device
 * @refcnt: Number of gets of this reset_control
 * @acquired: Only one reset_control may be acquired for a given rcdev and id.
 * @shared: Is this a shared (1), or an exclusive (0) reset_control?
 * @array: Is this an array of reset controls (1)?
 * @deassert_count: Number of times this reset line has been deasserted
 * @triggered_count: Number of times this reset line has been reset. Currently
 *                   only used for shared resets, which means that the value
 *                   will be either 0 or 1.
 */
struct reset_control {
	struct reset_controller_dev *rcdev;
	struct list_head list;
	unsigned int id;
	struct kref refcnt;
	bool acquired;
	bool shared;
	bool array;
	atomic_t deassert_count;
	atomic_t tr