tree 8969fd749e188219c441fa104bd6240e9f3e6b81
parent 7e0464ddaf405ebe013a8a24541fd02ffaa10d71
author Priyanka Jain <Priyanka.Jain@freescale.com> 1387270552 +0530
committer York Sun <yorksun@freescale.com> 1388700613 -0800

powerpc/mpc85xx: Add support for single source clocking

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>