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>
diff --git a/README b/README
index e58e9c0..a0646c3 100644
--- a/README
+++ b/README
@@ -423,6 +423,11 @@
CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
This value denotes start offset of DSP CCSR space.
+ CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
+ Single Source Clock is clocking mode present in some of FSL SoC's.
+ In this mode, a single differential clock is used to supply
+ clocks to the sysclock, ddrclock and usbclock.
+
- Generic CPU options:
CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN