UPSTREAM: rockchip/rk3399: enable DPLL SSC for DDR EMI test on bob
Spread Spectrum Modulator (SSMOD) is a fully-digital circuit used to
modulate the frequency of the Silicon Creations Fractional PLL in order
to reduce EMI.
We need to turn the DPLL spread spectrum feature on to
reduce the EMI noise for DDR on bob.
BRANCH=none
BUG=b:37262721
TEST=mem checks the register value on bob.
localhost / # mem r 0xff76004c ---> 0x00000100
localhost / # mem r 0xff760050 ---> 0x00000860
TEST=Tested with memtester/s2r/reboot on bob.
Change-Id: I75461d4235bcf55324e6664a1220754e770b4786
Original-Change-Id: I75461d4235bcf55324e6664a1220754e770b4786
Original-Signed-off-by: Xing Zheng <zhengxing@rock-chips.com>
Original-Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Original-Reviewed-on: https://review.coreboot.org/19557
Original-Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/377691
Commit-Ready: Caesar Wang <wxt@rock-chips.com>
Tested-by: Caesar Wang <wxt@rock-chips.com>
Reviewed-by: Philip Chen <philipchen@chromium.org>
3 files changed
