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regmap: Add 1-Wire bus support

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Add basic support regmap (register map access) API for 1-Wire bus

Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Alex A. Mihaylov
2017-06-02 10:06:27 +03:00
committed by Mark Brown
parent 2ea659a9ef
commit cc5d0db390
4 changed files with 285 additions and 1 deletions
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245
drivers/base/regmap/regmap-w1.c Normal file
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/*
* Register map access API - W1 (1-Wire) support
*
* Copyright (C) 2017 OAO Radioavionica
* Author: Alex A. Mihaylov <minimumlaw@rambler.ru>
*
* 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/module.h>
#include "../../w1/w1.h"
#include "internal.h"
#define W1_CMD_READ_DATA 0x69
#define W1_CMD_WRITE_DATA 0x6C
/*
* 1-Wire slaves registers with addess 8 bit and data 8 bit
*/
static int w1_reg_a8_v8_read(void *context, unsigned int reg, unsigned int *val)
{
struct device *dev = context;
struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
int ret = 0;
if (reg > 255)
return -EINVAL;
mutex_lock(&sl->master->bus_mutex);
if (!w1_reset_select_slave(sl)) {
w1_write_8(sl->master, W1_CMD_READ_DATA);
w1_write_8(sl->master, reg);
*val = w1_read_8(sl->master);
} else {
ret = -ENODEV;
}
mutex_unlock(&sl->master->bus_mutex);
return ret;
}
static int w1_reg_a8_v8_write(void *context, unsigned int reg, unsigned int val)
{
struct device *dev = context;
struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
int ret = 0;
if (reg > 255)
return -EINVAL;
mutex_lock(&sl->master->bus_mutex);
if (!w1_reset_select_slave(sl)) {
w1_write_8(sl->master, W1_CMD_WRITE_DATA);
w1_write_8(sl->master, reg);
w1_write_8(sl->master, val);
} else {
ret = -ENODEV;
}
mutex_unlock(&sl->master->bus_mutex);
return ret;
}
/*
* 1-Wire slaves registers with addess 8 bit and data 16 bit
*/
static int w1_reg_a8_v16_read(void *context, unsigned int reg,
unsigned int *val)
{
struct device *dev = context;
struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
int ret = 0;
if (reg > 255)
return -EINVAL;
mutex_lock(&sl->master->bus_mutex);
if (!w1_reset_select_slave(sl)) {
w1_write_8(sl->master, W1_CMD_READ_DATA);
w1_write_8(sl->master, reg);
*val = w1_read_8(sl->master);
*val |= w1_read_8(sl->master)<<8;
} else {
ret = -ENODEV;
}
mutex_unlock(&sl->master->bus_mutex);
return ret;
}
static int w1_reg_a8_v16_write(void *context, unsigned int reg,
unsigned int val)
{
struct device *dev = context;
struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
int ret = 0;
if (reg > 255)
return -EINVAL;
mutex_lock(&sl->master->bus_mutex);
if (!w1_reset_select_slave(sl)) {
w1_write_8(sl->master, W1_CMD_WRITE_DATA);
w1_write_8(sl->master, reg);
w1_write_8(sl->master, val & 0x00FF);
w1_write_8(sl->master, val>>8 & 0x00FF);
} else {
ret = -ENODEV;
}
mutex_unlock(&sl->master->bus_mutex);
return ret;
}
/*
* 1-Wire slaves registers with addess 16 bit and data 16 bit
*/
static int w1_reg_a16_v16_read(void *context, unsigned int reg,
unsigned int *val)
{
struct device *dev = context;
struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
int ret = 0;
if (reg > 65535)
return -EINVAL;
mutex_lock(&sl->master->bus_mutex);
if (!w1_reset_select_slave(sl)) {
w1_write_8(sl->master, W1_CMD_READ_DATA);
w1_write_8(sl->master, reg & 0x00FF);
w1_write_8(sl->master, reg>>8 & 0x00FF);
*val = w1_read_8(sl->master);
*val |= w1_read_8(sl->master)<<8;
} else {
ret = -ENODEV;
}
mutex_unlock(&sl->master->bus_mutex);
return ret;
}
static int w1_reg_a16_v16_write(void *context, unsigned int reg,
unsigned int val)
{
struct device *dev = context;
struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
int ret = 0;
if (reg > 65535)
return -EINVAL;
mutex_lock(&sl->master->bus_mutex);
if (!w1_reset_select_slave(sl)) {
w1_write_8(sl->master, W1_CMD_WRITE_DATA);
w1_write_8(sl->master, reg & 0x00FF);
w1_write_8(sl->master, reg>>8 & 0x00FF);
w1_write_8(sl->master, val & 0x00FF);
w1_write_8(sl->master, val>>8 & 0x00FF);
} else {
ret = -ENODEV;
}
mutex_unlock(&sl->master->bus_mutex);
return ret;
}
/*
* Various types of supported bus addressing
*/
static struct regmap_bus regmap_w1_bus_a8_v8 = {
.reg_read = w1_reg_a8_v8_read,
.reg_write = w1_reg_a8_v8_write,
};
static struct regmap_bus regmap_w1_bus_a8_v16 = {
.reg_read = w1_reg_a8_v16_read,
.reg_write = w1_reg_a8_v16_write,
};
static struct regmap_bus regmap_w1_bus_a16_v16 = {
.reg_read = w1_reg_a16_v16_read,
.reg_write = w1_reg_a16_v16_write,
};
static const struct regmap_bus *regmap_get_w1_bus(struct device *w1_dev,
const struct regmap_config *config)
{
if (config->reg_bits == 8 && config->val_bits == 8)
return &regmap_w1_bus_a8_v8;
if (config->reg_bits == 8 && config->val_bits == 16)
return &regmap_w1_bus_a8_v16;
if (config->reg_bits == 16 && config->val_bits == 16)
return &regmap_w1_bus_a16_v16;
return ERR_PTR(-ENOTSUPP);
}
struct regmap *__regmap_init_w1(struct device *w1_dev,
const struct regmap_config *config,
struct lock_class_key *lock_key,
const char *lock_name)
{
const struct regmap_bus *bus = regmap_get_w1_bus(w1_dev, config);
if (IS_ERR(bus))
return ERR_CAST(bus);
return __regmap_init(w1_dev, bus, w1_dev, config,
lock_key, lock_name);
return NULL;
}
EXPORT_SYMBOL_GPL(__regmap_init_w1);
struct regmap *__devm_regmap_init_w1(struct device *w1_dev,
const struct regmap_config *config,
struct lock_class_key *lock_key,
const char *lock_name)
{
const struct regmap_bus *bus = regmap_get_w1_bus(w1_dev, config);
if (IS_ERR(bus))
return ERR_CAST(bus);
return __devm_regmap_init(w1_dev, bus, w1_dev, config,
lock_key, lock_name);
return NULL;
}
EXPORT_SYMBOL_GPL(__devm_regmap_init_w1);
MODULE_LICENSE("GPL");