[PATCH v3 6/8] phy: miphy28lp: Add SSC support for PCIE

Valdis.Kletnieks at vt.edu Valdis.Kletnieks at vt.edu
Mon Sep 29 12:19:28 PDT 2014


On Fri, 26 Sep 2014 10:54:15 +0200, Gabriel FERNANDEZ said:
> SSC is the technique of modulating the operating frequency of a signal
> slightly to spread its radiated emissions over a range of frequencies.
> This reduction in the maximum emission for a given frequency helps meet
> radiated emission requirements.
> These settings are applicable for PCIE with Internal clock.

> +		writeb_relaxed(0x69, miphy_phy->base + MIPHY_PLL_SBR_3);
> +		writeb_relaxed(0x21, miphy_phy->base + MIPHY_PLL_SBR_4);
> +		writeb_relaxed(0x3c, miphy_phy->base + MIPHY_PLL_SBR_2);
> +		writeb_relaxed(0x21, miphy_phy->base + MIPHY_PLL_SBR_4);
> +		writeb_relaxed(0x00, miphy_phy->base + MIPHY_PLL_SBR_1);
> +		writeb_relaxed(0x02, miphy_phy->base + MIPHY_PLL_SBR_1);
> +		writeb_relaxed(0x00, miphy_phy->base + MIPHY_PLL_SBR_1);

I'd feel a lot better about all these magic numbers (and the triple write
to SBR_1) if the Changelog or something referenced where they came from....
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