linux驱动如何注册两个I2C适配器
时间: 2024-01-10 22:03:05 浏览: 40
在Linux内核中,I2C适配器是通过i2c_add_adapter()函数进行注册的。要注册两个I2C适配器,可以按照以下步骤进行操作:
1. 在驱动程序中定义两个i2c_adapter结构体变量,例如:
static struct i2c_adapter i2c_adapter1 = {
.owner = THIS_MODULE,
.class = I2C_CLASS_HWMON,
.algo = &i2c_algorithm,
.name = "i2c_adapter1",
};
static struct i2c_adapter i2c_adapter2 = {
.owner = THIS_MODULE,
.class = I2C_CLASS_HWMON,
.algo = &i2c_algorithm,
.name = "i2c_adapter2",
};
2. 在驱动程序的probe函数中,调用i2c_add_adapter()函数,将两个i2c_adapter结构体变量注册为I2C适配器。例如:
static int my_driver_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
int ret;
/* Register i2c_adapter1 */
ret = i2c_add_adapter(&i2c_adapter1);
if (ret)
return ret;
/* Register i2c_adapter2 */
ret = i2c_add_adapter(&i2c_adapter2);
if (ret)
goto error_unregister_adapter1;
/* Do other initialization */
return 0;
error_unregister_adapter1:
i2c_del_adapter(&i2c_adapter1);
return ret;
}
3. 在驱动程序的remove函数中,调用i2c_del_adapter()函数,注销已注册的I2C适配器。例如:
static int my_driver_remove(struct i2c_client *client)
{
/* Do cleanup */
/* Unregister i2c_adapter2 */
i2c_del_adapter(&i2c_adapter2);
/* Unregister i2c_adapter1 */
i2c_del_adapter(&i2c_adapter1);
return 0;
}
注意,如果两个I2C适配器共享同一个I2C控制器,需要在i2c_algorithm中实现多主机协议(Multi-Master Protocol)来保证通信的正确性。