drivers/iio/dac/ad5593r.c

/*
 * AD5593R Digital <-> Analog converters driver
 *
 * Copyright 2015-2016 Analog Devices Inc.
 * Author: Paul Cercueil <paul.cercueil@analog.com>
 *
 * Licensed under the GPL-2.
 */

#include "ad5592r-base.h"

#include <linux/bitops.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of.h>

#include <asm/unaligned.h>

#define AD5593R_MODE_CONF		(0 << 4)
#define AD5593R_MODE_DAC_WRITE		(1 << 4)
#define AD5593R_MODE_ADC_READBACK	(4 << 4)
#define AD5593R_MODE_DAC_READBACK	(5 << 4)
#define AD5593R_MODE_GPIO_READBACK	(6 << 4)
#define AD5593R_MODE_REG_READBACK	(7 << 4)

static int ad5593r_read_word(struct i2c_client *i2c, u8 reg, u16 *value)
{
	int ret;
	u8 buf[2];

	ret = i2c_smbus_write_byte(i2c, reg);
	if (ret < 0)
		return ret;

	ret = i2c_master_recv(i2c, buf, sizeof(buf));
	if (ret < 0)
		return ret;

	*value = get_unaligned_be16(buf);

	return 0;
}

static int ad5593r_write_dac(struct ad5592r_state *st, unsigned chan, u16 value)
{
	struct i2c_client *i2c = to_i2c_client(st->dev);

	return i2c_smbus_write_word_swapped(i2c,
			AD5593R_MODE_DAC_WRITE | chan, value);
}

static int ad5593r_read_adc(struct ad5592r_state *st, unsigned chan, u16 *value)
{
	struct i2c_client *i2c = to_i2c_client(st->dev);
	s32 val;

	val = i2c_smbus_write_word_swapped(i2c,
			AD5593R_MODE_CONF | AD5592R_REG_ADC_SEQ, BIT(chan));
	if (val < 0)
		return (int) val;

	return ad5593r_read_word(i2c, AD5593R_MODE_ADC_READBACK, value);
}

static int ad5593r_reg_write(struct ad5592r_state *st, u8 reg, u16 value)
{
	struct i2c_client *i2c = to_i2c_client(st->dev);

	return i2c_smbus_write_word_swapped(i2c,
			AD5593R_MODE_CONF | reg, value);
}

static int ad5593r_reg_read(struct ad5592r_state *st, u8 reg, u16 *value)
{
	struct i2c_client *i2c = to_i2c_client(st->dev);

	return ad5593r_read_word(i2c, AD5593R_MODE_REG_READBACK | reg, value);
}

static int ad5593r_gpio_read(struct ad5592r_state *st, u8 *value)
{
	struct i2c_client *i2c = to_i2c_client(st->dev);
	u16 val;
	int ret;

	ret = ad5593r_read_word(i2c, AD5593R_MODE_GPIO_READBACK, &val);
	if (ret)
		return ret;

	*value = (u8) val;

	return 0;
}

static const struct ad5592r_rw_ops ad5593r_rw_ops = {
	.write_dac = ad5593r_write_dac,
	.read_adc = ad5593r_read_adc,
	.reg_write = ad5593r_reg_write,
	.reg_read = ad5593r_reg_read,
	.gpio_read = ad5593r_gpio_read,
};

static int ad5593r_i2c_probe(struct i2c_client *i2c,
		const struct i2c_device_id *id)
{
	return ad5592r_probe(&i2c->dev, id->name, &ad5593r_rw_ops);
}

static int ad5593r_i2c_remove(struct i2c_client *i2c)
{
	return ad5592r_remove(&i2c->dev);
}

static const struct i2c_device_id ad5593r_i2c_ids[] = {
	{ .name = "ad5593r", },
	{},
};
MODULE_DEVICE_TABLE(i2c, ad5593r_i2c_ids);

static const struct of_device_id ad5593r_of_match[] = {
	{ .compatible = "adi,ad5593r", },
	{},
};
MODULE_DEVICE_TABLE(of, ad5593r_of_match);

static struct i2c_driver ad5593r_driver = {
	.driver = {
		.name = "ad5593r",
		.of_match_table = of_match_ptr(ad5593r_of_match),
	},
	.probe = ad5593r_i2c_probe,
	.remove = ad5593r_i2c_remove,
	.id_table = ad5593r_i2c_ids,
};
module_i2c_driver(ad5593r_driver);

MODULE_AUTHOR("Paul Cercueil <paul.cercueil@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD5592R multi-channel converters");
MODULE_LICENSE("GPL v2");