linux iic驱动例子

i2c@13860000 {
    compatible = "nxp,pca9548";
    reg = <0x13860000 0x100>;
    #address-cells = <1>;
    #size-cells = <0>;

    i2c@0 {
        compatible = "maxim,max31855";
        reg = <0x0>;
    };
};

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/err.h>

#define MAX31855_REG_CONFIG 0x00
#define MAX31855_REG_CR0 0x01
#define MAX31855_REG_CR1 0x02
#define MAX31855_REG_SR 0x03
#define MAX31855_REG_DR 0x04

struct max31855_data {
    struct i2c_client *client;
};

static int max31855_read_reg(struct i2c_client *client, u8 reg, u8 *val)
{
    return i2c_smbus_read_byte_data(client, reg);
}

static int max31855_write_reg(struct i2c_client *client, u8 reg, u8 val)
{
    return i2c_smbus_write_byte_data(client, reg, val);
}

static int max31855_probe(struct i2c_client *client,
                           const struct i2c_device_id *id)
{
    struct max31855_data *data;

    data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
    if (!data)
        return -ENOMEM;

    data->client = client;
    i2c_set_clientdata(client, data);

    // 初始化设备配置
    max31855_write_reg(client, MAX31855_REG_CONFIG, 0x80);

    return 0;
}

static int max31855_remove(struct i2c_client *client)
{
    return 0;
}

static const struct i2c_device_id max31855_id[] = {
    { "max31855", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, max31855_id);

static struct i2c_driver max31855_driver = {
    .driver = {
        .name = "max31855",
    },
    .probe = max31855_probe,
    .remove = max31855_remove,
    .id_table = max31855_id,
};

module_i2c_driver(max31855_driver);

MODULE_AUTHOR("Your Name");
MODULE_DESCRIPTION("MAX31855 I2C driver");
MODULE_LICENSE("GPL");