aboutsummaryrefslogtreecommitdiff
path: root/include/linux/nvmem-provider.h
blob: 6d6f8e5d24c97ca71bf7863fdf98c3bdb0ee9a2b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * nvmem framework provider.
 *
 * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
 * Copyright (C) 2013 Maxime Ripard <maxime.ripard@free-electrons.com>
 */

#ifndef _LINUX_NVMEM_PROVIDER_H
#define _LINUX_NVMEM_PROVIDER_H

#include <linux/err.h>
#include <linux/errno.h>
#include <linux/gpio/consumer.h>

struct nvmem_device;
struct nvmem_cell_info;
typedef int (*nvmem_reg_read_t)(void *priv, unsigned int offset,
				void *val, size_t bytes);
typedef int (*nvmem_reg_write_t)(void *priv, unsigned int offset,
				 void *val, size_t bytes);

enum nvmem_type {
	NVMEM_TYPE_UNKNOWN = 0,
	NVMEM_TYPE_EEPROM,
	NVMEM_TYPE_OTP,
	NVMEM_TYPE_BATTERY_BACKED,
};

/**
 * struct nvmem_config - NVMEM device configuration
 *
 * @dev:	Parent device.
 * @name:	Optional name.
 * @id:		Optional device ID used in full name. Ignored if name is NULL.
 * @owner:	Pointer to exporter module. Used for refcounting.
 * @cells:	Optional array of pre-defined NVMEM cells.
 * @ncells:	Number of elements in cells.
 * @type:	Type of the nvmem storage
 * @read_only:	Device is read-only.
 * @root_only:	Device is accessibly to root only.
 * @no_of_node:	Device should not use the parent's of_node even if it's !NULL.
 * @reg_read:	Callback to read data.
 * @reg_write:	Callback to write data.
 * @size:	Device size.
 * @word_size:	Minimum read/write access granularity.
 * @stride:	Minimum read/write access stride.
 * @priv:	User context passed to read/write callbacks.
 * @wp-gpio:   Write protect pin
 *
 * Note: A default "nvmem<id>" name will be assigned to the device if
 * no name is specified in its configuration. In such case "<id>" is
 * generated with ida_simple_get() and provided id field is ignored.
 *
 * Note: Specifying name and setting id to -1 implies a unique device
 * whose name is provided as-is (kept unaltered).
 */
struct nvmem_config {
	struct device		*dev;
	const char		*name;
	int			id;
	struct module		*owner;
	struct gpio_desc	*wp_gpio;
	const struct nvmem_cell_info	*cells;
	int			ncells;
	enum nvmem_type		type;
	bool			read_only;
	bool			root_only;
	bool			no_of_node;
	nvmem_reg_read_t	reg_read;
	nvmem_reg_write_t	reg_write;
	int	size;
	int	word_size;
	int	stride;
	void	*priv;
	/* To be only used by old driver/misc/eeprom drivers */
	bool			compat;
	struct device		*base_dev;
};

/**
 * struct nvmem_cell_table - NVMEM cell definitions for given provider
 *
 * @nvmem_name:		Provider name.
 * @cells:		Array of cell definitions.
 * @ncells:		Number of cell definitions in the array.
 * @node:		List node.
 *
 * This structure together with related helper functions is provided for users
 * that don't can't access the nvmem provided structure but wish to register
 * cell definitions for it e.g. board files registering an EEPROM device.
 */
struct nvmem_cell_table {
	const char		*nvmem_name;
	const struct nvmem_cell_info	*cells;
	size_t			ncells;
	struct list_head	node;
};

#if IS_ENABLED(CONFIG_NVMEM)

struct nvmem_device *nvmem_register(const struct nvmem_config *cfg);
void nvmem_unregister(struct nvmem_device *nvmem);

struct nvmem_device *devm_nvmem_register(struct device *dev,
					 const struct nvmem_config *cfg);

int devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem);

void nvmem_add_cell_table(struct nvmem_cell_table *table);
void nvmem_del_cell_table(struct nvmem_cell_table *table);

#else

static inline struct nvmem_device *nvmem_register(const struct nvmem_config *c)
{
	return ERR_PTR(-EOPNOTSUPP);
}

static inline void nvmem_unregister(struct nvmem_device *nvmem) {}

static inline struct nvmem_device *
devm_nvmem_register(struct device *dev, const struct nvmem_config *c)
{
	return nvmem_register(c);
}

static inline int
devm_nvmem_unregister(struct device *dev, struct nvmem_device *nvmem)
{
	return -EOPNOTSUPP;
}

static inline void nvmem_add_cell_table(struct nvmem_cell_table *table) {}
static inline void nvmem_del_cell_table(struct nvmem_cell_table *table) {}

#endif /* CONFIG_NVMEM */
#endif  /* ifndef _LINUX_NVMEM_PROVIDER_H */