regmap() 通过SMBUS协议中 block write-block read process call命令格式读取设备温度 其中写block count为2 读block count为4 command code为0想2 block实例
时间: 2024-02-17 12:01:39 浏览: 129
好的,以下是一个使用regmap()通过SMBUS协议中block write-block read process call命令格式读取设备温度的示例,其中写block count为2,读block count为4,command code为0想2 block:
假设设备地址为0x50,温度寄存器地址为0x10,温度寄存器格式为16位有符号整数。
```
// 初始化regmap
struct device *dev;
struct regmap *map;
struct i2c_client *client;
dev = &client->dev;
map = devm_regmap_init_i2c(client, &my_regmap_config);
// 构造写block
u8 cmd_write[] = { 0x10, 0x00 };
struct i2c_msg msgs_write[] = {
{
.addr = client->addr,
.flags = 0,
.len = sizeof(cmd_write),
.buf = cmd_write,
}
};
// 构造读block
u8 buf[4];
struct i2c_msg msgs_read[] = {
{
.addr = client->addr,
.flags = I2C_M_RD,
.len = sizeof(buf),
.buf = buf,
}
};
// 发送block write-block read process call命令
struct i2c_rdwr_ioctl_data rdwr = {
.msgs = msgs_write,
.nmsgs = ARRAY_SIZE(msgs_write),
};
int ret = ioctl(client->adapter->dev.parent->fd, I2C_RDWR, &rdwr);
if (ret < 0) {
// 错误处理
}
rdwr.msgs = msgs_read;
rdwr.nmsgs = ARRAY_SIZE(msgs_read);
ret = ioctl(client->adapter->dev.parent->fd, I2C_RDWR, &rdwr);
if (ret < 0) {
// 错误处理
}
// 解析温度
int16_t temperature = (buf[2] << 8) | buf[3];
```
在上面的示例中,使用了ioctl()函数向设备发送block write-block read process call命令,其中写block count为2,读block count为4,command code为0想2 block。需要注意的是,在构造写block和读block时,需要保证写block和读block的长度和设备协议一致。另外,读取到的温度值需要根据设备的温度寄存器格式进行转换。
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