[U-Boot] [PATCH 3/6] Davinci: ea20: Add NAND support

[Stefano Babic]

On 04/11/2011 03:05 PM, Ben Gardiner wrote:

Hi Ben,

> 
>> [...]
>> @@ -143,20 +144,20 @@ int board_init(void)
>>        irq_init();
>>  #endif
>>
>> -#ifdef CONFIG_NAND_DAVINCI
>>        /*
>>         * NAND CS setup - cycle counts based on da850evm NAND timings in the
>>         * Linux kernel @ 25MHz EMIFA
>>         */
>> +#ifdef CONFIG_NAND_DAVINCI
>>        writel((DAVINCI_ABCR_WSETUP(0) |
>> -               DAVINCI_ABCR_WSTROBE(0) |
>> +               DAVINCI_ABCR_WSTROBE(1) |
> 
> If WSTROBE is modified then the timings are no longer solely based on
> the NAND timings in arch/arm/mach-davinci/board-da850-evm.c in the
> Linux kernel. Can you add an amendment to the comment describing the
> motivation for the extra WSTROBE cycle?

Really this board will not use at all the board-da850-evm.c, but (no
patches are yet pushed) it will have its own board configuration file
(something like arch/arm/mach-davinci/ea20.c). I understand that if no
timing structure is set into the davinci_nand_pdata in Linux, values set
by the bootloader are not overwritten (this is the case for this board
at the moment). Regarding setting the WSTROBE, I understood from manual
(EMIFA) that WSTROBE and RSTROBE cannot be set to zero if the EMA_WAIT
pin is used, as on this board.

Best regards,
Stefano

-- 
=====================================================================
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80  Email: office at denx.de
=====================================================================