regmap: Add I2C bus support

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
This commit is contained in:
Mark Brown 2011-06-20 19:02:29 +01:00
parent b83a313bf2
commit 9943fa300a
4 changed files with 124 additions and 0 deletions

View file

@ -3,4 +3,8 @@
# subsystems should select the appropriate symbols.
config REGMAP
default y if REGMAP_I2C
bool
config REGMAP_I2C
tristate

View file

@ -1 +1,2 @@
obj-$(CONFIG_REGMAP) += regmap.o
obj-$(CONFIG_REGMAP_I2C) += regmap-i2c.o

View file

@ -0,0 +1,115 @@
/*
* 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 = {
.type = &i2c_bus_type,
.write = regmap_i2c_write,
.gather_write = regmap_i2c_gather_write,
.read = regmap_i2c_read,
.owner = THIS_MODULE,
};
/**
* 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, &regmap_i2c, config);
}
EXPORT_SYMBOL_GPL(regmap_init_i2c);

View file

@ -17,6 +17,8 @@
#include <linux/list.h>
#include <linux/module.h>
struct i2c_client;
struct regmap_config {
int reg_bits;
int val_bits;
@ -59,6 +61,8 @@ struct regmap_bus {
struct regmap *regmap_init(struct device *dev,
const struct regmap_bus *bus,
const struct regmap_config *config);
struct regmap *regmap_init_i2c(struct i2c_client *i2c,
const struct regmap_config *config);
void regmap_exit(struct regmap *map);
int regmap_write(struct regmap *map, unsigned int reg, unsigned int val);
int regmap_raw_write(struct regmap *map, unsigned int reg,