驱动怎么拿到设备树中iic地址

在设备树中，I2C设备节点通常会定义一个属性 `reg`，该属性的值指定了I2C设备在总线上的地址信息。对于I2C设备而言，`reg` 属性通常包含两个值，第一个值是设备在I2C总线上的地址，第二个值是设备的寄存器地址。例如，下面是一个示例设备树节点：

i2c_device@50 {
  compatible = "vendor,device";
  reg = <0x50 0x00>;
};

在这个示例中，设备节点的名称是 `i2c_device`，它的I2C地址是 `0x50`，寄存器地址是 `0x00`。因此，在驱动程序中，可以通过调用 `devm_i2c_new_device()` 函数来注册I2C设备，并传递设备树节点中的 `reg` 属性值。

static const struct of_device_id i2c_device_of_match[] = {
    { .compatible = "vendor,device" },
    { },
};

static int i2c_device_probe(struct i2c_client *client,
			    const struct i2c_device_id *id)
{
    /* 读取设备树中的I2C地址信息 */
    struct device_node *np = client->dev.of_node;
    u32 reg[2];
    int ret;

    ret = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg));
    if (ret < 0) {
        dev_err(&client->dev, "failed to read I2C address\n");
        return ret;
    }

    /* 注册I2C设备 */
    struct i2c_board_info board_info = {
        .type = "i2c_device",
        .addr = reg[0],
    };

    struct device *dev = &client->dev;
    struct i2c_adapter *adapter = client->adapter;
    struct i2c_client *new_client;

    new_client = i2c_new_device(adapter, &board_info);
    if (!new_client) {
        dev_err(dev, "failed to register I2C device\n");
        return -ENODEV;
    }

    /* 存储设备信息 */
    struct i2c_device_data *data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
    if (!data) {
        dev_err(dev, "failed to allocate memory\n");
        return -ENOMEM;
    }
    data->i2c_client = new_client;
    data->reg_addr = reg[1];

    /* 存储设备数据 */
    i2c_set_clientdata(new_client, data);

    /* 配置设备 */
    i2c_device_setup(new_client);

    dev_info(dev, "I2C device registered: %s\n", new_client->name);
    return 0;
}

static struct i2c_driver i2c_device_driver = {
    .driver = {
        .name = "i2c_device",
        .of_match_table = i2c_device_of_match,
    },
    .probe = i2c_device_probe,
    .remove = i2c_device_remove,
    .id_table = i2c_device_id,
};