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1#ifndef __LINUX_REGMAP_H
2#define __LINUX_REGMAP_H
3
4/*
5 * Register map access API
6 *
7 * Copyright 2011 Wolfson Microelectronics plc
8 *
9 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15
16#include <linux/device.h>
17#include <linux/list.h>
18
19struct module;
20struct i2c_client;
21struct spi_device;
22
23/* An enum of all the supported cache types */
24enum regcache_type {
25 REGCACHE_NONE,
26 REGCACHE_INDEXED,
27 REGCACHE_RBTREE,
28 REGCACHE_LZO
29};
30
31/**
32 * Default value for a register. We use an array of structs rather
33 * than a simple array as many modern devices have very sparse
34 * register maps.
35 *
36 * @reg: Register address.
37 * @def: Register default value.
38 */
39struct reg_default {
40 unsigned int reg;
41 unsigned int def;
42};
43
44/**
45 * Configuration for the register map of a device.
46 *
47 * @reg_bits: Number of bits in a register address, mandatory.
48 * @val_bits: Number of bits in a register value, mandatory.
49 *
50 * @writeable_reg: Optional callback returning true if the register
51 * can be written to.
52 * @readable_reg: Optional callback returning true if the register
53 * can be read from.
54 * @volatile_reg: Optional callback returning true if the register
55 * value can't be cached.
56 * @precious_reg: Optional callback returning true if the rgister
57 * should not be read outside of a call from the driver
58 * (eg, a clear on read interrupt status register).
59 *
60 * @max_register: Optional, specifies the maximum valid register index.
61 * @reg_defaults: Power on reset values for registers (for use with
62 * register cache support).
63 * @num_reg_defaults: Number of elements in reg_defaults.
64 *
65 * @read_flag_mask: Mask to be set in the top byte of the register when doing
66 * a read.
67 * @write_flag_mask: Mask to be set in the top byte of the register when doing
68 * a write. If both read_flag_mask and write_flag_mask are
69 * empty the regmap_bus default masks are used.
70 *
71 * @cache_type: The actual cache type.
72 * @reg_defaults_raw: Power on reset values for registers (for use with
73 * register cache support).
74 * @num_reg_defaults_raw: Number of elements in reg_defaults_raw.
75 */
76struct regmap_config {
77 int reg_bits;
78 int val_bits;
79
80 bool (*writeable_reg)(struct device *dev, unsigned int reg);
81 bool (*readable_reg)(struct device *dev, unsigned int reg);
82 bool (*volatile_reg)(struct device *dev, unsigned int reg);
83 bool (*precious_reg)(struct device *dev, unsigned int reg);
84
85 unsigned int max_register;
86 struct reg_default *reg_defaults;
87 unsigned int num_reg_defaults;
88 enum regcache_type cache_type;
89 const void *reg_defaults_raw;
90 unsigned int num_reg_defaults_raw;
91
92 u8 read_flag_mask;
93 u8 write_flag_mask;
94};
95
96typedef int (*regmap_hw_write)(struct device *dev, const void *data,
97 size_t count);
98typedef int (*regmap_hw_gather_write)(struct device *dev,
99 const void *reg, size_t reg_len,
100 const void *val, size_t val_len);
101typedef int (*regmap_hw_read)(struct device *dev,
102 const void *reg_buf, size_t reg_size,
103 void *val_buf, size_t val_size);
104
105/**
106 * Description of a hardware bus for the register map infrastructure.
107 *
108 * @write: Write operation.
109 * @gather_write: Write operation with split register/value, return -ENOTSUPP
110 * if not implemented on a given device.
111 * @read: Read operation. Data is returned in the buffer used to transmit
112 * data.
113 * @read_flag_mask: Mask to be set in the top byte of the register when doing
114 * a read.
115 */
116struct regmap_bus {
117 regmap_hw_write write;
118 regmap_hw_gather_write gather_write;
119 regmap_hw_read read;
120 u8 read_flag_mask;
121};
122
123struct regmap *regmap_init(struct device *dev,
124 const struct regmap_bus *bus,
125 const struct regmap_config *config);
126struct regmap *regmap_init_i2c(struct i2c_client *i2c,
127 const struct regmap_config *config);
128struct regmap *regmap_init_spi(struct spi_device *dev,
129 const struct regmap_config *config);
130
131void regmap_exit(struct regmap *map);
132int regmap_write(struct regmap *map, unsigned int reg, unsigned int val);
133int regmap_raw_write(struct regmap *map, unsigned int reg,
134 const void *val, size_t val_len);
135int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val);
136int regmap_raw_read(struct regmap *map, unsigned int reg,
137 void *val, size_t val_len);
138int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
139 size_t val_count);
140int regmap_update_bits(struct regmap *map, unsigned int reg,
141 unsigned int mask, unsigned int val);
142
143int regcache_sync(struct regmap *map);
144void regcache_cache_only(struct regmap *map, bool enable);
145void regcache_cache_bypass(struct regmap *map, bool enable);
146
147#endif