[U-Boot] support all dataflash for at91sam9g20ek_2mmc

[John Stile <john@stilen.com>]

On Thu, 2013-02-14 at 07:20 -0800, John Stile wrote:
> I am using uboot-2013.01, with at91sam9g20ek_2mmc and I am trying to
> build for dataflash, using at91bootstrap-1.16, and buildroot-2011.11
> 
> Initially I built for nand flash, with a patch to boards.cfg and
> at91sam9260ek.c
> 
> This was fine if I used the reset button, but from a cold boot, startup
> stopped after after at91bootstrap-1.16, and uboot never starts.
> 
> Now I am trying to build uboot for all dataflash, but I still see the
> same behavior with uboot.
> 
> Uboot worked from dataflash when using uboot-1.3.6 (and patches from
> atmel), but much has changed since then, so it is hard to figure out if
> something from those patches is lost in the current uboot.  
> 
> What can I try next.
> 
I have gone over the patch list for uboot-1.3.6, and tracked down where
they are moved to in uboot-2013.01, and nothing is jumping out at me
yet, except these different:

uboot-1.3.6:
#define AT91_SLOW_CLOCK		32768	        /* slow clock */
#define AT91_MAIN_CLOCK		198656000	/* from 18.432 MHz crystal */
#define AT91_MASTER_CLOCK	99328000	/* peripheral = main / 2 */
#define CFG_HZ			1000000		/* 1us resolution */
#define CONFIG_SYS_SPI_WRITE_TOUT           (5*CONFIG_SYS_HZ)

uboot-2013.01:
#define CONFIG_SYS_AT91_SLOW_CLOCK	32768		/* slow clock xtal */
#define CONFIG_SYS_AT91_MAIN_CLOCK	18432000	/* main clock xtal */
#define CONFIG_SYS_HZ			1000
Though include/configs/cpuat91.h
#define AT91C_MASTER_CLOCK         (AT91C_MAIN_CLOCK / 3)
#define CFG_SPI_WRITE_TOUT           (5*CFG_HZ)


Q1: should I change Hz from 1000 to 1000000?
Q2: should I change MAIN_CLOCK from 18432000 to 198656000?
Q3: why is MASTER_CLOCK in old using divisor of 2, where new is using a
divisor of 3?