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 - 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 */
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 * @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 */
38 struct 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 */
72 struct 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)
87 int reset_controller_register(struct reset_controller_dev *rcdev);
88 void reset_controller_unregister(struct reset_controller_dev *rcdev);
89
90 struct device;
91 int devm_reset_controller_register(struct device *dev,
92 struct reset_controller_dev *rcdev);
93
94 void reset_controller_add_lookup(struct reset_control_lookup *lookup,
95 unsigned int num_entries);
96 #else
97 static inline int reset_controller_register(struct reset_controller_dev *rcdev)
98 {
99 return 0;
100 }
101
102 static inline void reset_controller_unregister(struct reset_controller_dev *rcdev)
103 {
104 }
105
106 static inline int devm_reset_controller_register(struct device *dev,
107 struct reset_controller_dev *rcdev)
108 {
109 return 0;
110 }
111
112 static inline void reset_controller_add_lookup(struct reset_control_lookup *lookup,
113 unsigned int num_entries)
114 {
115 }
116 #endif
117
118 #endif
119
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