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 
7 struct reset_controller_dev;
8 
9 /**
10  * struct reset_control_ops
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  */
18 struct 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 
25 struct module;
26 struct device_node;
27 struct 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  * @rcdev: 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  */
38 struct reset_control_lookup {
39 	struct list_head list;
40 	struct reset_controller_dev *rcdev;
41 	unsigned int index;
42 	const char *dev_id;
43 	const char *con_id;
44 };
45 
46 #define RESET_LOOKUP(_dev_id, _con_id, _index)				\
47 	{								\
48 		.dev_id = _dev_id,					\
49 		.con_id = _con_id,					\
50 		.index = _index,					\
51 	}
52 
53 /**
54  * struct reset_controller_dev - reset controller entity that might
55  *                               provide multiple reset controls
56  * @ops: a pointer to device specific struct reset_control_ops
57  * @owner: kernel module of the reset controller driver
58  * @list: internal list of reset controller devices
59  * @reset_control_head: head of internal list of requested reset controls
60  * @of_node: corresponding device tree node as phandle target
61  * @of_reset_n_cells: number of cells in reset line specifiers
62  * @of_xlate: translation function to translate from specifier as found in the
63  *            device tree to id as given to the reset control ops
64  * @nr_resets: number of reset controls in this reset controller device
65  */
66 struct reset_controller_dev {
67 	const struct reset_control_ops *ops;
68 	struct module *owner;
69 	struct list_head list;
70 	struct list_head reset_control_head;
71 	struct device_node *of_node;
72 	int of_reset_n_cells;
73 	int (*of_xlate)(struct reset_controller_dev *rcdev,
74 			const struct of_phandle_args *reset_spec);
75 	unsigned int nr_resets;
76 };
77 
78 int reset_controller_register(struct reset_controller_dev *rcdev);
79 void reset_controller_unregister(struct reset_controller_dev *rcdev);
80 
81 struct device;
82 int devm_reset_controller_register(struct device *dev,
83 				   struct reset_controller_dev *rcdev);
84 
85 void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
86 				 struct reset_control_lookup *lookup,
87 				 unsigned int num_entries);
88 
89 #endif
90