[U-Boot] setup of PEX_GCLK_RATIO in E500 CPUs(P2010) missing ?
York Sun
york.sun at nxp.com
Tue Aug 29 14:59:37 UTC 2017
On 08/29/2017 03:47 AM, Joakim Tjernlund wrote:
> As we are looking at PCI stuff ATM I would like to ask
> about PEX_GCLK_RATIO in E500 CPUs. I cannot find this is setup
> at all for E500 but I THINK this is required.
>
> In 83xx one do:
> get_clocks();
> /* Configure the PCIE controller core clock ratio */
> out_le32(hose_cfg_base + PEX_GCLK_RATIO,
> (((bus ? gd->arch.pciexp2_clk : gd->arch.pciexp1_clk)
> / 1000000) * 16) / 333);
> udelay(1000000);
>
> Any clues?
>
Jocke,
P2010 has SerDes. With PCIe, SerDes uses 100MHz reference clock. Please
see reference manual "SerDes reference clock configuration".
York
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