[U-Boot-Users] AMD29LV800T in 16bit mode x4 devices (64bit bus)

[U-Boot-Users] AMD29LV800T in 16bit mode x4 devices (64bit bus)

[Richard Danter]

Hi,

Is there a driver that supports this flash within U-Boot? I can't see 
one, but want to make sure I didn't miss it before I reinvent the wheel!

Thanks
Rich

[U-Boot-Users] AMD29LV800T in 16bit mode x4 devices (64bit bus)

[Wolfgang Denk]

In message <42D2DC59.6090507@ntlworld.com> you wrote:
> 
> Is there a driver that supports this flash within U-Boot? I can't see 
> one, but want to make sure I didn't miss it before I reinvent the wheel!

Why can't you see one? How did you search?

There are several. First, there is the general CFI driver,  and  then
there are several board specific drivers like board/tqm8260/flash.c


Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Intuition, however illogical, is recognized as a command prerogative.
	-- Kirk, "Obsession", stardate 3620.7

[U-Boot-Users] AMD29LV800T in 16bit mode x4 devices (64bit bus)

[Richard Danter]

Wolfgang Denk wrote:
> In message <42D2DC59.6090507@ntlworld.com> you wrote:
> 
>>Is there a driver that supports this flash within U-Boot? I can't see 
>>one, but want to make sure I didn't miss it before I reinvent the wheel!

> 
> There are several. First, there is the general CFI driver,  and  then
> there are several board specific drivers like board/tqm8260/flash.c

I have tried both of the suggested drivers with neither working for me.

I have spent more time looking at the tqm8260/flash.c and have managed 
to make some improvements. Initially it was unable to even read back the 
device type but I noticed that if I single stepped (using JTAG) the 
flash_get_size() function then it _was_ able to correctly read the 
device type.

This sounded like a timing issue until someone suggested that between 
the writes and reads I should have "sync" and/or "eieio" to ensure the 
CPU (MPC7400) does not execute them out of sequence. This certainly 
fixed the flash_get_size() function, but I am still unable to write to 
the flash (eg using saveenv). Though again I do see some data written if 
I am single-stepping the write_dword() function.

Reading data from the flash works just fine.

Any suggestions?

Thanks
Rich

[U-Boot-Users] AMD29LV800T in 16bit mode x4 devices (64bit bus) - Fixed

[Richard Danter]

Richard Danter wrote:
> Wolfgang Denk wrote:
> 
>> In message <42D2DC59.6090507@ntlworld.com> you wrote:
>>
>>> Is there a driver that supports this flash within U-Boot? I can't see 
>>> one, but want to make sure I didn't miss it before I reinvent the wheel!
> 
> 
>>
>> There are several. First, there is the general CFI driver,  and  then
>> there are several board specific drivers like board/tqm8260/flash.c
> 
> 
> I have tried both of the suggested drivers with neither working for me.
> 
> I have spent more time looking at the tqm8260/flash.c and have managed 
> to make some improvements. Initially it was unable to even read back the 
> device type but I noticed that if I single stepped (using JTAG) the 
> flash_get_size() function then it _was_ able to correctly read the 
> device type.

It seems with my board I _have_ to write data 64-bits at a time. Writing 
the lower 32-bits and then the upper 32-bits does not work.

I'm using the FP registers now and all works fine.

Rich