how to use amd_flash.c

how to use amd_flash.c

[Steve Tsai]

I'd want to use mtd and jffs2 in our ARM7  board.  The flash is MX29LV160B/T
and it is similar to am29LV160, but it does not support CFI. How many files
do I to modify or add to mtd tree? It seems I can modify amd_flash.c to fit
my flash, but I can not probe the chip at booting time. Does anyone know how
to use amd_flash.c? thanks.


Steve Tsai

how to use amd_flash.c

[Steve Tsai]

I'd want to use mtd and jffs2 in our ARM7  board.  The flash is MX29LV160B/T
and it is similar to am29LV160, but it does not support CFI. How many files
do I to modify or add to mtd tree? It seems I can modify amd_flash.c to fit
my flash, but I can not probe the chip at booting time. Does anyone know how
to use amd_flash.c? thanks.


Steve Tsai

Re: how to use amd_flash.c

[Jonas Holmberg]

On Thu, 2002-04-04 at 09:07, Steve Tsai wrote:
> I'd want to use mtd and jffs2 in our ARM7  board.  The flash is MX29LV160B/T
> and it is similar to am29LV160, but it does not support CFI. How many files
> do I to modify or add to mtd tree? It seems I can modify amd_flash.c to fit
> my flash, but I can not probe the chip at booting time. Does anyone know how
> to use amd_flash.c? thanks.

You need to find out the manufacturer ID and device ID for your chip. It
can usually be found in some datasheet at the manufacurer's site. Then
add an element to the amd_flash_info table[] in amd_flash_probe().

But the amd_flash driver is obsolete and you should use jedec_probe
instead. It works about the same way as amd_flash_probe. The only thing
that amd_flash does better than jedec_probe + CFI-driver is that it
handles different types of chips in the same map. But with the new MTD
concat layer you don't need to use amd_flash in that case either.

/Jonas

Re: how to use amd_flash.c

[Steve Tsai]

Hi Jonas,

Thanks. I know how to add codes to amd_flash.c, but I can not make kernel
run amd_flash_probe(). I used jffs1 and flash.c on my board from AXIS before
and it works fine. Now I want ot port uClinux 2.4.17 to my board and I plan
to use jffs2 and mtd, but I found it is more complicated.  The flash I use
is not CFI compliance, so I am not sure I can use jedec_probe + CFI-driver.
I modified amd_flash.c already, but the kernal can not probe the flash at
start time. Should I call do_map_probe in somewhere to find out the flash?

Steve


> On Thu, 2002-04-04 at 09:07, Steve Tsai wrote:
> > I'd want to use mtd and jffs2 in our ARM7  board.  The flash is
MX29LV160B/T
> > and it is similar to am29LV160, but it does not support CFI. How many
files
> > do I to modify or add to mtd tree? It seems I can modify amd_flash.c to
fit
> > my flash, but I can not probe the chip at booting time. Does anyone know
how
> > to use amd_flash.c? thanks.
>
> You need to find out the manufacturer ID and device ID for your chip. It
> can usually be found in some datasheet at the manufacurer's site. Then
> add an element to the amd_flash_info table[] in amd_flash_probe().
>
> But the amd_flash driver is obsolete and you should use jedec_probe
> instead. It works about the same way as amd_flash_probe. The only thing
> that amd_flash does better than jedec_probe + CFI-driver is that it
> handles different types of chips in the same map. But with the new MTD
> concat layer you don't need to use amd_flash in that case either.
>
> /Jonas
>
>
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/

Re: how to use amd_flash.c

[Jonas Holmberg]

On Thu, 2002-04-04 at 09:41, Steve Tsai wrote:
> Hi Jonas,
> 
> Thanks. I know how to add codes to amd_flash.c, but I can not make kernel
> run amd_flash_probe(). I used jffs1 and flash.c on my board from AXIS before
> and it works fine. Now I want ot port uClinux 2.4.17 to my board and I plan
> to use jffs2 and mtd, but I found it is more complicated.  The flash I use
> is not CFI compliance, so I am not sure I can use jedec_probe + CFI-driver.

The jedec_probe sets things up so that the CFI-drivers can be used with
non-CFI chips.

> I modified amd_flash.c already, but the kernal can not probe the flash at
> start time. Should I call do_map_probe in somewhere to find out the flash?

Yes, you need to write a map driver that calls do_map_probe. You can
look at arch/cris/drivers/axisflashmap.c for inspiration.

/Jonas