Re: Different nand interface

[Alice Hennessy <ahennessy@mvista.com>]

David Woodhouse wrote:

> On Thu, 2003-10-23 at 14:33 -0700, Alice Hennessy wrote:
> > Hi,
> >
> > I need some advice on how to support a board that has a hardware state
> > machine that creates a parallel bus style interface to the NAND chip.
> > It is totally different from the standard 8 IO signal controls.   It
> > can do write_byte and read_byte put requires the offset into the flash
> > as a parameter.    nand.c is fairly modular, allowing several
> > functions to be coded in the hardware file but there is no current
> > method of passing an offset into, say, read_byte and write_byte unless
> > the nand_chip priv field
> > can be used (via mtd->priv).   Do you think the standard nand.c can be
> > used in this case or should I create a specific one for this board?
>
> S'difficult to say without knowing more details of the hardware in
> question. What does it _do_ with the address lines in question? Are you
> at least looking at the current code which has read_buf() functions?
>
> Even the DiskOnChip isn't this bizarre :)
>
> --
> dwmw2

Yes, I am looking at the current code which is more modular so it gives me
hope.
There are 2 nand chips on the board.  If you want to read from the 0x100th
byte
on chip 1 you need to do readb(chip1_base + 0x100);  if you want to write
the 0x10000th byte on chip 2 you need to do writeb(chip2_base +
0x10000,bytedata).
The chips are 16M X 8 bit and  are mapped in a contiguous 32 M byte memory
space
with 0-16M for chip1 and 16-32M for chip2.

Alice