MODULE: i2c-stubDESCRIPTION:This module is a very simple fake I2C/SMBus driver. It implements fourtypes of SMBus commands: write quick, (r/w) byte, (r/w) byte data, and(r/w) word data.No hardware is needed nor associated with this module. It will accept writequick commands to all addresses; it will respond to the other commands (alsoto all addresses) by reading from or writing to an array in memory. It willalso spam the kernel logs for every command it handles.A pointer register with auto-increment is implemented for all byteoperations. This allows for continuous byte reads like those supported byEEPROMs, among others.The typical use-case is like this: 1. load this module 2. use i2cset (from lm_sensors project) to pre-load some data 3. load the target sensors chip driver module 4. observe its behavior in the kernel logCAVEATS:There are independent arrays for byte/data and word/data commands. Dependingon if/how a target driver mixes them, you'll need to be careful.If your target driver polls some byte or word waiting for it to change, thestub could lock it up. Use i2cset to unlock it.If the hardware for your driver has banked registers (e.g. Winbond sensorschips) this module will not work well - although it could be extended tosupport that pretty easily.If you spam it hard enough, printk can be lossy. This module really wantssomething like relayfs.
