Re: [PATCH 07/12] dt-bindings: net: Add StarFive JH7100 SoC

Cristian Ciocaltea
2023-02-15T00:34:31Z

On 2/11/23 18:01, Andrew Lunn wrote:
>> + starfive,gtxclk-dlychain:
>> + $ref: /schemas/types.yaml#/definitions/uint32
>> + description: GTX clock delay chain setting
>
> Please could you add more details to this. Is this controlling the
> RGMII delays? 0ns or 2ns?

This is what gets written to JH7100_SYSMAIN_REGISTER49 and it's
currently set to 4 in patch 12/12. As already mentioned, I don't have
the register information in the datasheet, but I'll update this as soon
as we get some details.

>> + gmac: ethernet@10020000 {
>> + compatible = "starfive,jh7100-dwmac", "snps,dwmac";
>> + reg = <0x0 0x10020000 0x0 0x10000>;
>> + clocks = <&clkgen JH7100_CLK_GMAC_ROOT_DIV>,
>> + <&clkgen JH7100_CLK_GMAC_AHB>,
>> + <&clkgen JH7100_CLK_GMAC_PTP_REF>,
>> + <&clkgen JH7100_CLK_GMAC_GTX>,
>> + <&clkgen JH7100_CLK_GMAC_TX_INV>;
>> + clock-names = "stmmaceth", "pclk", "ptp_ref", "gtxc", "tx";
>> + resets = <&rstgen JH7100_RSTN_GMAC_AHB>;
>> + reset-names = "ahb";
>> + interrupts = <6>, <7>;
>> + interrupt-names = "macirq", "eth_wake_irq";
>> + max-frame-size = <9000>;
>> + phy-mode = "rgmii-txid";
>
> This is unusual. Does your board have a really long RX clock line to
> insert the 2ns delay needed on the RX side?

Just tested with "rgmii" and didn't notice any issues. If I'm not
missing anything, I'll do the change in the next revision.

> Andrew

Thanks,
Cristian