From e085a8a359a82bce204fe15325e1aead53aa3edd Mon Sep 17 00:00:00 2001 From: Caesar Wang Date: Thu, 4 May 2017 09:24:23 +0800 Subject: rockchip/rk3399: enable DPLL SSC for DDR EMI test on bob MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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. Change-Id: I75461d4235bcf55324e6664a1220754e770b4786 Signed-off-by: Xing Zheng Signed-off-by: Caesar Wang Reviewed-on: https://review.coreboot.org/19557 Tested-by: build bot (Jenkins) Reviewed-by: Julius Werner --- src/soc/rockchip/rk3399/Kconfig | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'src/soc/rockchip/rk3399/Kconfig') diff --git a/src/soc/rockchip/rk3399/Kconfig b/src/soc/rockchip/rk3399/Kconfig index 65b31d523e..ff857c022c 100644 --- a/src/soc/rockchip/rk3399/Kconfig +++ b/src/soc/rockchip/rk3399/Kconfig @@ -24,4 +24,12 @@ config PMIC_BUS int default -1 +config RK3399_SPREAD_SPECTRUM_DDR + bool "Spread-spectrum DDR clock" + default n + help + Select 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. + endif -- cgit v1.2.3