1 /*
2 * nvmem framework provider.
3 *
4 * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
5 * Copyright (C) 2013 Maxime Ripard <maxime.ripard@free-electrons.com>
6 *
7 * This file is licensed under the terms of the GNU General Public
8 * License version 2. This program is licensed "as is" without any
9 * warranty of any kind, whether express or implied.
10 */
11
12 #ifndef _LINUX_NVMEM_PROVIDER_H
13 #define _LINUX_NVMEM_PROVIDER_H
14
15 #include <linux/err.h>
16 #include <linux/errno.h>
17
18 struct nvmem_device;
19 struct nvmem_cell_info;
20 typedef int (*nvmem_reg_read_t)(void *priv, unsigned int offset,
21 void *val, size_t bytes);
22 typedef int (*nvmem_reg_write_t)(void *priv, unsigned int offset,
23 void *val, size_t bytes);
24
25 /**
26 * struct nvmem_config - NVMEM device configuration
27 *
28 * @dev: Parent device.
29 * @name: Optional name.
30 * @id: Optional device ID used in full name. Ignored if name is NULL.
31 * @owner: Pointer to exporter module. Used for refcounting.
32 * @cells: Optional array of pre-defined NVMEM cells.
33 * @ncells: Number of elements in cells.
34 * @read_only: Device is read-only.
35 * @root_only: Device is accessibly to root only.
36 * @reg_read: Callback to read data.
37 * @reg_write: Callback to write data.
38 * @size: Device size.
39 * @word_size: Minimum read/write access granularity.
40 * @stride: Minimum read/write access stride.
41 * @priv: User context passed to read/write callbacks.
42 *
43 * Note: A default "nvmem<id>" name will be assigned to the device if
44 * no name is specified in its configuration. In such case "<id>" is
45 * generated with ida_simple_get() and provided id field is ignored.
46 *
47 * Note: Specifying name and setting id to -1 implies a unique device
48 * whose name is provided as-is (kept unaltered).
49 */
50 struct nvmem_config {
51 struct device *dev;
52 const char *name;
53 int id;
54 struct module *owner;
55 const struct nvmem_cell_info *cells;
56 int ncells;
57 bool read_only;
58 bool root_only;
59 nvmem_reg_read_t reg_read;
60 nvmem_reg_write_t reg_write;
61 int size;
62 int word_size;
63 int stride;
64 void *priv;
65 /* To be only used by old driver/misc/eeprom drivers */
66 bool compat;
67 struct device *base_dev;
68 };
69
70 #if IS_ENABLED(CONFIG_NVMEM)
71
72 struct nvmem_device *nvmem_register(const struct nvmem_config *cfg);
73 int nvmem_unregister(struct nvmem_device *nvmem);
74
75 struct nvmem_device *devm_nvmem_register(struct device *dev,
76 const struct nvmem_config *cfg);
77
78 int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem);
79
80 int nvmem_add_cells(struct nvmem_device *nvmem,
81 const struct nvmem_cell_info *info,
82 int ncells);
83 #else
84
nvmem_register(const struct nvmem_config * c)85 static inline struct nvmem_device *nvmem_register(const struct nvmem_config *c)
86 {
87 return ERR_PTR(-ENOSYS);
88 }
89
nvmem_unregister(struct nvmem_device * nvmem)90 static inline int nvmem_unregister(struct nvmem_device *nvmem)
91 {
92 return -ENOSYS;
93 }
94
95 static inline struct nvmem_device *
devm_nvmem_register(struct device * dev,const struct nvmem_config * c)96 devm_nvmem_register(struct device *dev, const struct nvmem_config *c)
97 {
98 return nvmem_register(c);
99 }
100
101 static inline int
devm_nvmem_unregister(struct device * dev,struct nvmem_device * nvmem)102 devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem)
103 {
104 return nvmem_unregister(nvmem);
105
106 }
107
nvmem_add_cells(struct nvmem_device * nvmem,const struct nvmem_cell_info * info,int ncells)108 static inline int nvmem_add_cells(struct nvmem_device *nvmem,
109 const struct nvmem_cell_info *info,
110 int ncells)
111 {
112 return -ENOSYS;
113 }
114
115 #endif /* CONFIG_NVMEM */
116 #endif /* ifndef _LINUX_NVMEM_PROVIDER_H */
117