root/drivers/input/misc/adxl34x-i2c.c
// 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;
        int error;

        error = i2c_check_functionality(client->adapter,
                        I2C_FUNC_SMBUS_BYTE_DATA);
        if (!error) {
                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))
                return PTR_ERR(ac);

        i2c_set_clientdata(client, ac);

        return 0;
}

static const struct i2c_device_id adxl34x_id[] = {
        { "adxl34x" },
        { }
};

MODULE_DEVICE_TABLE(i2c, adxl34x_id);

static const struct of_device_id adxl34x_of_id[] = {
        /*
         * The ADXL346 is backward-compatible with the ADXL345. Differences are
         * handled by runtime detection of the device model, there's thus no
         * need for listing the "adi,adxl346" compatible value explicitly.
         */
        { .compatible = "adi,adxl345", },
        /*
         * Deprecated, DT nodes should use one or more of the device-specific
         * compatible values "adi,adxl345" and "adi,adxl346".
         */
        { .compatible = "adi,adxl34x", },
        { }
};

MODULE_DEVICE_TABLE(of, adxl34x_of_id);

static struct i2c_driver adxl34x_driver = {
        .driver = {
                .name = "adxl34x",
                .dev_groups = adxl34x_groups,
                .pm = pm_sleep_ptr(&adxl34x_pm),
                .of_match_table = adxl34x_of_id,
        },
        .probe    = adxl34x_i2c_probe,
        .id_table = adxl34x_id,
};

module_i2c_driver(adxl34x_driver);

MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("ADXL345/346 Three-Axis Digital Accelerometer I2C Bus Driver");
MODULE_LICENSE("GPL");