Re: [PATCH 13/15] MTD: add few workarounds to nand system for SmartMedia/xD chips.

Maxim Levitsky
2010-02-22T21:33:32Z

On Mon, 2010-02-22 at 22:25 +0100, Thomas Gleixner wrote:
> On Mon, 22 Feb 2010, Maxim Levitsky wrote:
>
> > * Add an option NAND_SMARTMEDIA that can be set by nand driver
> > If set, it will cause separate ID table to be used, which includes
> > mask rom devices and new xD cards
>
> Why that option ? We can just extend the existing ids table and be
> done. No extra magic needed.
>

Two reasons.

First of all several xD chips (I belive the Type M) have exactly same
IDs like normal nand chips. However they don't report capabilities about
pagesize, blocksize, etc.

I am confident that these cards have an internal FTL and controller, and
just 'emulate' that nand interface.

Also, my card reports write protect, although, xD cards don't have any
'switch' to make them protected.
Even if there were readonly ROM xD cards (the odds of this are virtually
zero), these won't just expose this in WP bit.

Best regards,
Maxim Levitsky