i2c通信的协议原理:
可参考博客:https://blog.youkuaiyun.com/pengliang528/article/details/79522644
I2C通信内核中操作方法
#define I2C_BUS_ID (2) //设备挂载在i2c总线的ID
#define I2C_SLAVE_ADDR (0x68) //high 7bits 从设备地址,第一个字节的高7位,后一位是读写位
/*
addr 需要操作的从设备 寄存器,16位
value 写入的值,32位
*/
int i2c_write_a16_d32(unsigned short addr,unsigned long value)
{
struct i2c_msg msg;
unsigned char data[6];
int ret;
struct i2c_adapter *adap;
adap = i2c_get_adapter(I2C_BUS_ID);
data[0] = (addr & 0xff00) >> 8;
data[1] = (addr & 0x00ff);
data[2] = (value & 0x000000ff);
data[3] = (value & 0x0000ff00) >> 8;
data[4] = (value & 0x00ff0000) >> 16;
data[5] = (value & 0xff000000) >> 24;
msg.addr = I2C_SLAVE_ADDR;
msg.flags = 0;
msg.len = 6;
msg.buf = data;
ret = i2c_transfer(adap, &msg, 1);
printk(