drivers/iio/dac/ad5593r.c

Source file repositories/reference/linux-study-clean/drivers/iio/dac/ad5593r.c

File Facts

System
Linux kernel
Corpus path
drivers/iio/dac/ad5593r.c
Extension
.c
Size
3638 bytes
Lines
151
Domain
Driver Families
Bucket
drivers/iio
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * AD5593R Digital <-> Analog converters driver
 *
 * Copyright 2015-2016 Analog Devices Inc.
 * Author: Paul Cercueil <paul.cercueil@analog.com>
 */

#include "ad5592r-base.h"

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

#include <linux/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;

Annotation

Implementation Notes