drivers/input/misc/adxl34x-i2c.c

Source file repositories/reference/linux-study-clean/drivers/input/misc/adxl34x-i2c.c

File Facts

System
Linux kernel
Corpus path
drivers/input/misc/adxl34x-i2c.c
Extension
.c
Size
3362 bytes
Lines
138
Domain
Driver Families
Bucket
drivers/input
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-or-later
/*
 * ADLX345/346 Three-Axis Digital Accelerometers (I2C Interface)
 *
 * Enter bugs at http://blackfin.uclinux.org/
 *
 * Copyright (C) 2009 Michael Hennerich, Analog Devices Inc.
 */

#include <linux/input.h>	/* BUS_I2C */
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/types.h>
#include <linux/pm.h>
#include "adxl34x.h"

static int adxl34x_smbus_read(struct device *dev, unsigned char reg)
{
	struct i2c_client *client = to_i2c_client(dev);

	return i2c_smbus_read_byte_data(client, reg);
}

static int adxl34x_smbus_write(struct device *dev,
			       unsigned char reg, unsigned char val)
{
	struct i2c_client *client = to_i2c_client(dev);

	return i2c_smbus_write_byte_data(client, reg, val);
}

static int adxl34x_smbus_read_block(struct device *dev,
				    unsigned char reg, int count,
				    void *buf)
{
	struct i2c_client *client = to_i2c_client(dev);

	return i2c_smbus_read_i2c_block_data(client, reg, count, buf);
}

static int adxl34x_i2c_read_block(struct device *dev,
				  unsigned char reg, int count,
				  void *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	int ret;

	ret = i2c_master_send(client, &reg, 1);
	if (ret < 0)
		return ret;

	ret = i2c_master_recv(client, buf, count);
	if (ret < 0)
		return ret;

	if (ret != count)
		return -EIO;

	return 0;
}

static const struct adxl34x_bus_ops adxl34x_smbus_bops = {
	.bustype	= BUS_I2C,
	.write		= adxl34x_smbus_write,
	.read		= adxl34x_smbus_read,
	.read_block	= adxl34x_smbus_read_block,
};

static const struct adxl34x_bus_ops adxl34x_i2c_bops = {
	.bustype	= BUS_I2C,
	.write		= adxl34x_smbus_write,
	.read		= adxl34x_smbus_read,
	.read_block	= adxl34x_i2c_read_block,
};

static int adxl34x_i2c_probe(struct i2c_client *client)
{
	struct adxl34x *ac;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
		dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
		return -EIO;
	}

	ac = adxl34x_probe(&client->dev, client->irq, false,
			   i2c_check_functionality(client->adapter,
						   I2C_FUNC_SMBUS_READ_I2C_BLOCK) ?
				&adxl34x_smbus_bops : &adxl34x_i2c_bops);
	if (IS_ERR(ac))

Annotation

Implementation Notes