回覆: 回覆: [net-next 4/4] net: ftgmac100: add RGMII delay for AST2600

Jacky Chou <jacky_chou@xxxxxxxxxxxxxx> · Tue, 18 Mar 2025 05:34:08 +0000

Hi Andrew,

Thank you for your reply.

> > The RGMII delay of AST2600 has a lot of steps can be configured.
> 
> Are they uniformly space? Then it should be a simple formula to calculate? Or
> a lookup table?

There are fixed delay values by step. I list below.
AST2600 MAC0/1 one step delay = 45 ps
AST2600 MAC2/3 one step delay = 250 ps
I calculate all step and emulate them.
The dt-binding will be like below.
rx-internal-delay-ps:
    description:
      Setting this property to a non-zero number sets the RX internal delay
      for the MAC. ... skip ...
    enum:
      [45, 90, 135, 180, 225, 250, 270, 315, 360, 405, 450, 495, 500, 540, 585, 630, 675, 
       720, 750, 765, 810, 855, 900, 945, 990, 1000, 1035, 1080, 1125, 1170, 1215, 1250, 
       1260, 1305, 1350, 1395, 1440, 1500, 1750, 2000, 2250, 2500, 2750, 3000, 3250, 3500, 
       3750, 4000, 4250, 4500, 4750, 5000, 5250, 5500, 5750, 6000, 6250, 6500, 6750, 7000, 
       7250, 7500, 7750, 8000]

I will modify using calculating delay value in next version.

Thanks,
Jacky