2 * Register map access API - I2C support
4 * Copyright 2011 Wolfson Microelectronics plc
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/regmap.h>
14 #include <linux/i2c.h>
15 #include <linux/module.h>
18 static int regmap_smbus_byte_reg_read(void *context
, unsigned int reg
,
21 struct device
*dev
= context
;
22 struct i2c_client
*i2c
= to_i2c_client(dev
);
28 ret
= i2c_smbus_read_byte_data(i2c
, reg
);
37 static int regmap_smbus_byte_reg_write(void *context
, unsigned int reg
,
40 struct device
*dev
= context
;
41 struct i2c_client
*i2c
= to_i2c_client(dev
);
43 if (val
> 0xff || reg
> 0xff)
46 return i2c_smbus_write_byte_data(i2c
, reg
, val
);
49 static struct regmap_bus regmap_smbus_byte
= {
50 .reg_write
= regmap_smbus_byte_reg_write
,
51 .reg_read
= regmap_smbus_byte_reg_read
,
54 static int regmap_smbus_word_reg_read(void *context
, unsigned int reg
,
57 struct device
*dev
= context
;
58 struct i2c_client
*i2c
= to_i2c_client(dev
);
64 ret
= i2c_smbus_read_word_data(i2c
, reg
);
73 static int regmap_smbus_word_reg_write(void *context
, unsigned int reg
,
76 struct device
*dev
= context
;
77 struct i2c_client
*i2c
= to_i2c_client(dev
);
79 if (val
> 0xffff || reg
> 0xff)
82 return i2c_smbus_write_word_data(i2c
, reg
, val
);
85 static struct regmap_bus regmap_smbus_word
= {
86 .reg_write
= regmap_smbus_word_reg_write
,
87 .reg_read
= regmap_smbus_word_reg_read
,
90 static int regmap_i2c_write(void *context
, const void *data
, size_t count
)
92 struct device
*dev
= context
;
93 struct i2c_client
*i2c
= to_i2c_client(dev
);
96 ret
= i2c_master_send(i2c
, data
, count
);
105 static int regmap_i2c_gather_write(void *context
,
106 const void *reg
, size_t reg_size
,
107 const void *val
, size_t val_size
)
109 struct device
*dev
= context
;
110 struct i2c_client
*i2c
= to_i2c_client(dev
);
111 struct i2c_msg xfer
[2];
114 /* If the I2C controller can't do a gather tell the core, it
115 * will substitute in a linear write for us.
117 if (!i2c_check_functionality(i2c
->adapter
, I2C_FUNC_NOSTART
))
120 xfer
[0].addr
= i2c
->addr
;
122 xfer
[0].len
= reg_size
;
123 xfer
[0].buf
= (void *)reg
;
125 xfer
[1].addr
= i2c
->addr
;
126 xfer
[1].flags
= I2C_M_NOSTART
;
127 xfer
[1].len
= val_size
;
128 xfer
[1].buf
= (void *)val
;
130 ret
= i2c_transfer(i2c
->adapter
, xfer
, 2);
139 static int regmap_i2c_read(void *context
,
140 const void *reg
, size_t reg_size
,
141 void *val
, size_t val_size
)
143 struct device
*dev
= context
;
144 struct i2c_client
*i2c
= to_i2c_client(dev
);
145 struct i2c_msg xfer
[2];
148 xfer
[0].addr
= i2c
->addr
;
150 xfer
[0].len
= reg_size
;
151 xfer
[0].buf
= (void *)reg
;
153 xfer
[1].addr
= i2c
->addr
;
154 xfer
[1].flags
= I2C_M_RD
;
155 xfer
[1].len
= val_size
;
158 ret
= i2c_transfer(i2c
->adapter
, xfer
, 2);
167 static struct regmap_bus regmap_i2c
= {
168 .write
= regmap_i2c_write
,
169 .gather_write
= regmap_i2c_gather_write
,
170 .read
= regmap_i2c_read
,
173 static const struct regmap_bus
*regmap_get_i2c_bus(struct i2c_client
*i2c
,
174 const struct regmap_config
*config
)
176 if (i2c_check_functionality(i2c
->adapter
, I2C_FUNC_I2C
))
178 else if (config
->val_bits
== 16 && config
->reg_bits
== 8 &&
179 i2c_check_functionality(i2c
->adapter
,
180 I2C_FUNC_SMBUS_WORD_DATA
))
181 return ®map_smbus_word
;
182 else if (config
->val_bits
== 8 && config
->reg_bits
== 8 &&
183 i2c_check_functionality(i2c
->adapter
,
184 I2C_FUNC_SMBUS_BYTE_DATA
))
185 return ®map_smbus_byte
;
187 return ERR_PTR(-ENOTSUPP
);
191 * regmap_init_i2c(): Initialise register map
193 * @i2c: Device that will be interacted with
194 * @config: Configuration for register map
196 * The return value will be an ERR_PTR() on error or a valid pointer to
199 struct regmap
*regmap_init_i2c(struct i2c_client
*i2c
,
200 const struct regmap_config
*config
)
202 const struct regmap_bus
*bus
= regmap_get_i2c_bus(i2c
, config
);
205 return ERR_CAST(bus
);
207 return regmap_init(&i2c
->dev
, bus
, &i2c
->dev
, config
);
209 EXPORT_SYMBOL_GPL(regmap_init_i2c
);
212 * devm_regmap_init_i2c(): Initialise managed register map
214 * @i2c: Device that will be interacted with
215 * @config: Configuration for register map
217 * The return value will be an ERR_PTR() on error or a valid pointer
218 * to a struct regmap. The regmap will be automatically freed by the
219 * device management code.
221 struct regmap
*devm_regmap_init_i2c(struct i2c_client
*i2c
,
222 const struct regmap_config
*config
)
224 const struct regmap_bus
*bus
= regmap_get_i2c_bus(i2c
, config
);
227 return ERR_CAST(bus
);
229 return devm_regmap_init(&i2c
->dev
, bus
, &i2c
->dev
, config
);
231 EXPORT_SYMBOL_GPL(devm_regmap_init_i2c
);
233 MODULE_LICENSE("GPL");