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/*
* Register map access API - I2C support
*
* Copyright 2011 Wolfson Microelectronics plc
*
* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/regmap.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/init.h>
static int regmap_i2c_write(struct device *dev, const void *data, size_t count)
{
struct i2c_client *i2c = to_i2c_client(dev);
int ret;
ret = i2c_master_send(i2c, data, count);
if (ret == count)
return 0;
else if (ret < 0)
return ret;
else
return -EIO;
}
static int regmap_i2c_gather_write(struct device *dev,
const void *reg, size_t reg_size,
const void *val, size_t val_size)
{
struct i2c_client *i2c = to_i2c_client(dev);
struct i2c_msg xfer[2];
int ret;
/* If the I2C controller can't do a gather tell the core, it
* will substitute in a linear write for us.
*/
if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_PROTOCOL_MANGLING))
return -ENOTSUPP;
xfer[0].addr = i2c->addr;
xfer[0].flags = 0;
xfer[0].len = reg_size;
xfer[0].buf = (void *)reg;
xfer[1].addr = i2c->addr;
xfer[1].flags = I2C_M_NOSTART;
xfer[1].len = val_size;
xfer[1].buf = (void *)val;
ret = i2c_transfer(i2c->adapter, xfer, 2);
if (ret == 2)
return 0;
if (ret < 0)
return ret;
else
return -EIO;
}
static int regmap_i2c_read(struct device *dev,
const void *reg, size_t reg_size,
void *val, size_t val_size)
{
struct i2c_client *i2c = to_i2c_client(dev);
struct i2c_msg xfer[2];
int ret;
xfer[0].addr = i2c->addr;
xfer[0].flags = 0;
xfer[0].len = reg_size;
xfer[0].buf = (void *)reg;
xfer[1].addr = i2c->addr;
xfer[1].flags = I2C_M_RD;
xfer[1].len = val_size;
xfer[1].buf = val;
ret = i2c_transfer(i2c->adapter, xfer, 2);
if (ret == 2)
return 0;
else if (ret < 0)
return ret;
else
return -EIO;
}
static struct regmap_bus regmap_i2c = {
.write = regmap_i2c_write,
.gather_write = regmap_i2c_gather_write,
.read = regmap_i2c_read,
};
/**
* regmap_init_i2c(): Initialise register map
*
* @i2c: Device that will be interacted with
* @config: Configuration for register map
*
* The return value will be an ERR_PTR() on error or a valid pointer to
* a struct regmap.
*/
struct regmap *regmap_init_i2c(struct i2c_client *i2c,
const struct regmap_config *config)
{
return regmap_init(&i2c->dev, ®map_i2c, config);
}
EXPORT_SYMBOL_GPL(regmap_init_i2c);
MODULE_LICENSE("GPL");
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