[Letux-kernel] [OpenOCD-devel] [PATCH]: d86217d board: add Skytone Alpha 400

[Paul Boddie]

On Tuesday, 3 November 2020 20:52:07 CET Riccardo Mottola wrote:
> 
> Paul Boddie wrote:
> > 
> > Let's not forget the documentation area, too:
> > 
> > https://projects.goldelico.com/p/letux400/doc/
> > 
> > I could probably add more details to that, given that there has been some
> > effort to formulate how the hardware works in connection with modernising
> > those patches.
> 
> Please do!

I've started adding some notes to those pages, and I've made some new pages:

https://projects.goldelico.com/p/letux400/page/I2C/
https://projects.goldelico.com/p/letux400/page/Power/
https://projects.goldelico.com/p/letux400/page/PWM/

It becomes difficult to remember all the details, however, so some of the 
notes will not be complete. The updated drivers in the letux-kernel repository 
should also encode much of the knowledge, but since I don't agree with the 
practice of having terse code as the oracle with regard to how something 
works, the idea is to make sure that the documentation describes what is 
really being done and why.

Some other things that will get some documentation include the LCD peripheral, 
which is pretty well understood, plus the MMC, DMA, RTC, USB, I2S (audio) and 
Ethernet peripherals, and the interrupt controller. Although mainline Linux 
may provide built-in support for some of these things, it is still worth 
describing them, I think.

Nikolaus and I have investigated the JZ4780 RTC peripheral before now (with 
some advice and insights from Zhou), and I expect the JZ4730 RTC to have 
similar limitations (with the PCF8563T being used here as a companion chip), 
and the power management details might also be worth figuring out, just as 
they are with the JZ4780 on the CI20.

Paul