1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_RESET_CONTROLLER_H_
3#define _LINUX_RESET_CONTROLLER_H_
4
5#include <linux/list.h>
6
7struct reset_controller_dev;
8
9/**
10 * struct reset_control_ops - reset controller driver callbacks
11 *
12 * @reset: for self-deasserting resets, does all necessary
13 *         things to reset the device
14 * @assert: manually assert the reset line, if supported
15 * @deassert: manually deassert the reset line, if supported
16 * @status: return the status of the reset line, if supported
17 */
18struct reset_control_ops {
19	int (*reset)(struct reset_controller_dev *rcdev, unsigned long id);
20	int (*assert)(struct reset_controller_dev *rcdev, unsigned long id);
21	int (*deassert)(struct reset_controller_dev *rcdev, unsigned long id);
22	int (*status)(struct reset_controller_dev *rcdev, unsigned long id);
23};
24
25struct module;
26struct device_node;
27struct of_phandle_args;
28
29/**
30 * struct reset_control_lookup - represents a single lookup entry
31 *
32 * @list: internal list of all reset lookup entries
33 * @provider: name of the reset controller device controlling this reset line
34 * @index: ID of the reset controller in the reset controller device
35 * @dev_id: name of the device associated with this reset line
36 * @con_id: name of the reset line (can be NULL)
37 */
38struct reset_control_lookup {
39	struct list_head list;
40	const char *provider;
41	unsigned int index;
42	const char *dev_id;
43	const char *con_id;
44};
45
46#define RESET_LOOKUP(_provider, _index, _dev_id, _con_id)		\
47	{								\
48		.provider = _provider,					\
49		.index = _index,					\
50		.dev_id = _dev_id,					\
51		.con_id = _con_id,					\
52	}
53
54/**
55 * struct reset_controller_dev - reset controller entity that might
56 *                               provide multiple reset controls
57 * @ops: a pointer to device specific struct reset_control_ops
58 * @owner: kernel module of the reset controller driver
59 * @list: internal list of reset controller devices
60 * @reset_control_head: head of internal list of requested reset controls
61 * @dev: corresponding driver model device struct
62 * @of_node: corresponding device tree node as phandle target
63 * @of_args: for reset-gpios controllers: corresponding phandle args with
64 *           of_node and GPIO number complementing of_node; either this or
65 *           of_node should be present
66 * @of_reset_n_cells: number of cells in reset line specifiers
67 * @of_xlate: translation function to translate from specifier as found in the
68 *            device tree to id as given to the reset control ops, defaults
69 *            to :c:func:`of_reset_simple_xlate`.
70 * @nr_resets: number of reset controls in this reset controller device
71 */
72struct reset_controller_dev {
73	const struct reset_control_ops *ops;
74	struct module *owner;
75	struct list_head list;
76	struct list_head reset_control_head;
77	struct device *dev;
78	struct device_node *of_node;
79	const struct of_phandle_args *of_args;
80	int of_reset_n_cells;
81	int (*of_xlate)(struct reset_controller_dev *rcdev,
82			const struct of_phandle_args *reset_spec);
83	unsigned int nr_resets;
84};
85
86#if IS_ENABLED(CONFIG_RESET_CONTROLLER)
87int reset_controller_register(struct reset_controller_dev *rcdev);
88void reset_controller_unregister(struct reset_controller_dev *rcdev);
89
90struct device;
91int devm_reset_controller_register(struct device *dev,
92				   struct reset_controller_dev *rcdev);
93
94void reset_controller_add_lookup(struct reset_control_lookup *lookup,
95				 unsigned int num_entries);
96#else
97static inline int reset_controller_register(struct reset_controller_dev *rcdev)
98{
99	return 0;
100}
101
102static inline void reset_controller_unregister(struct reset_controller_dev *rcdev)
103{
104}
105
106static inline int devm_reset_controller_register(struct device *dev,
107						 struct reset_controller_dev *rcdev)
108{
109	return 0;
110}
111
112static inline void reset_controller_add_lookup(struct reset_control_lookup *lookup,
113					       unsigned int num_entries)
114{
115}
116#endif
117
118#endif
119