[RFC] onenand detect logic

[Nishanth Menon <menon.nishanth@gmail.com>]

Hi Folks,
as a disclaimer, the following discussion is entirely a thought
experiment ;)

While discussing with Rohit C on supporting a different onenand on git
kernel, he enlightened me that the GPMC tracking and detecting onenand
CS based address is flaky.
Current Logic (with a highly deserving HACK alert comment) does this:
for each CS(){
   if (CONFIG_7 reg  ==0x20000000)
	then assume it is onenand.
}

Here is a alternative proposal (majority from Rohit):

for each CS(){
	if (configured as a NOR type memory){
		write 0x90 to CONFIG_7 0x0 offset /* 0x90 0r 0x98 CFI command will
ensure that the memory is in non-read state, but in onenand it is a
readonly location */
		read  manu id and device id from onenand regs offsets from CONFIG_7
		if matched as that for onenand, select same
	}
}
Caveat: does not detect 2 onenands..

Question: Any better way of doing this dynamically and a bit more elegantly?

Regards,
Nishanth Menon