mirror of
https://github.com/torvalds/linux.git
synced 2024-11-07 04:32:03 +00:00
14674e7011
Since there are uses for I2C_M_NOSTART which are much more sensible and standard than most of the protocol mangling functionality (the main one being gather writes to devices where something like a register address needs to be inserted before a block of data) create a new I2C_FUNC_NOSTART for this feature and update all the users to use it. Also strengthen the disrecommendation of the protocol mangling while we're at it. In the case of regmap-i2c we remove the requirement for mangling as I2C_M_NOSTART is the only mangling feature which is being used. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Jean Delvare <khali@linux-fr.org>
135 lines
3.2 KiB
C
135 lines
3.2 KiB
C
/*
|
|
* 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(void *context, const void *data, size_t count)
|
|
{
|
|
struct device *dev = context;
|
|
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(void *context,
|
|
const void *reg, size_t reg_size,
|
|
const void *val, size_t val_size)
|
|
{
|
|
struct device *dev = context;
|
|
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_NOSTART))
|
|
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(void *context,
|
|
const void *reg, size_t reg_size,
|
|
void *val, size_t val_size)
|
|
{
|
|
struct device *dev = context;
|
|
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, &i2c->dev, config);
|
|
}
|
|
EXPORT_SYMBOL_GPL(regmap_init_i2c);
|
|
|
|
/**
|
|
* devm_regmap_init_i2c(): Initialise managed 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. The regmap will be automatically freed by the
|
|
* device management code.
|
|
*/
|
|
struct regmap *devm_regmap_init_i2c(struct i2c_client *i2c,
|
|
const struct regmap_config *config)
|
|
{
|
|
return devm_regmap_init(&i2c->dev, ®map_i2c, &i2c->dev, config);
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_regmap_init_i2c);
|
|
|
|
MODULE_LICENSE("GPL");
|