linux驱动通过smbus block write read读取某设备温度 实例
时间: 2024-01-04 20:03:11 浏览: 215
好的,以下是一个通过smbus block write/read读取设备温度的Linux驱动示例代码:
```c
#include <linux/i2c.h>
#include <linux/i2c-dev.h>
static int device_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
int ret;
char buf[4] = {0};
// 发送block write指令,写入指令码0x01和寄存器地址0x00
buf[0] = 0x01;
buf[1] = 0x00;
ret = i2c_master_send(client, buf, 2);
if (ret != 2) {
dev_err(&client->dev, "Failed to write to the i2c bus. Error code: %d\n", ret);
return ret;
}
// 发送block read指令,读取2字节温度值
ret = i2c_master_recv(client, buf, 2);
if (ret != 2) {
dev_err(&client->dev, "Failed to read from the i2c bus. Error code: %d\n", ret);
return ret;
}
// 将读取到的2字节温度值转换为摄氏度,并打印
int temp = (buf[0] << 8) | buf[1];
dev_info(&client->dev, "Temperature: %.2f℃\n", temp * 0.0625);
return 0;
}
static const struct i2c_device_id device_id[] = {
{ "my_device", 0 }, // 设备ID和设备名,可以根据实际情况修改
{ }
};
MODULE_DEVICE_TABLE(i2c, device_id);
static struct i2c_driver device_driver = {
.probe = device_probe,
.id_table = device_id,
.driver = {
.name = "my_device_driver", // 驱动名,可以根据实际情况修改
.owner = THIS_MODULE,
},
};
static int __init device_init(void)
{
return i2c_add_driver(&device_driver);
}
static void __exit device_exit(void)
{
i2c_del_driver(&device_driver);
}
module_init(device_init);
module_exit(device_exit);
MODULE_AUTHOR("Your Name");
MODULE_DESCRIPTION("Driver for my_device");
MODULE_LICENSE("GPL");
```
这里假设设备地址为0x4c,要读取的温度值存储在寄存器地址0x00中,每个温度单位占据2字节,且是以补码形式存储的。在probe函数中,通过发送block write指令写入指令码0x01和寄存器地址0x00,再发送block read指令读取2字节温度值,最后将读取到的温度值转换为摄氏度并打印。设备名为"my_device",驱动名为"my_device_driver",可以根据实际情况修改。
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