Driver development based on I2C protocol

1、linux Under the I2C Agreement framework

commonly i2c_adapter The following specific adapter hardware related operation codes are developed by the chip manufacturer . Just finish in I2C Secondary development based on the agreement , For example, based on I2C The protocol realizes the transmission of network data , perhaps I2C Control of peripheral devices , perhaps blalalala

2、I2C Read and write sequence diagram of the Protocol

I2C Device mount I2C After bus ,I2C The device address of the device is determined by the hardware . Same article I2C Differences on the bus I2C The device address of the device is different .I2C The unit of protocol transmission is a byte .

Write timing

  once I2C The write operation of includes device address + Write operations ; Register address , data .

Every time CPU After sending a byte of data ,I2C Equipment handle DATA Line pull down , do ACK

Reading sequence

  Reading sequence is slightly more complex than writing sequence . In two parts , The first step is to write , tell I2C The device needs to read the address of the register . Step 2 read operation , Second send I2C Device address , wait for I2C equipment ACK after , Complete data reading .【 here CPU Become the receiving end , After reading one byte of data ,CPU Can send ACK. If there is ACK, The slave device will continue to send register data （ Most of the I2C The device supports multi address reading , Send a register address , Continue the next multiple register data ）; If NOACK,I2C The device stops sending data 】

3、 The code framework

To be added