[U-Boot] [PATCH][v4] powerpc/mpc85xx: Add support for single source clocking

[York Sun <yorksun@freescale.com>]

On 12/17/2013 12:55 AM, Priyanka Jain wrote:
> Single-source clocking is new feature introduced in T1040.
> In this mode, a single differential clock is supplied to the
> DIFF_SYSCLK_P/N inputs to the processor, which in turn is
> used to supply clocks to the sysclock, ddrclock and usbclock.
> 
> So, both ddrclock and syclock are driven by same differential
> sysclock in single-source clocking mode whereas in normal clocking
> mode, generally separate DDRCLK and SYSCLK pins provides
> reference clock for sysclock and ddrclock
> 
> DDR_REFCLK_SEL rcw bit is used to determine DDR clock source
> -If DDR_REFCLK_SEL rcw bit is 0, then DDR PLLs are driven in
>  normal clocking mode by DDR_Reference clock
> 
> -If DDR_REFCLK_SEL rcw bit is 1, then DDR PLLs are driven in
>  single source clocking mode by DIFF_SYSCLK
> 
> Add code to determine ddrclock based on DDR_REFCLK_SEL rcw bit.
> 
> Signed-off-by: Poonam Aggrwal <poonam.aggrwal@freescale.com>
> Signed-off-by: Priyanka Jain <Priyanka.Jain@freescale.com>
> ---
> Changes for v4:
> 	Updated README with CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
> 	description.
> 
> Changes for v3:
> 	Incorporated York's comment to move declaration to
> 	beginning of function.
> 
> Changes for v2:
> 	Incorporated York's comment to separate out
> 	DDR_CLK_FREQ and SINGLE_SOURCE_CLK code
> 

Applied to u-boot-mpc85xx/master. Thanks.

York