Re: [PATCH v4 5/5] dt-bindings: clock: ast2600: Add reset config for I3C

[Jeremy Kerr <jk@codeconstruct.com.au>]

Hi Joel,

> > So I'm not sure what that comment is supposed to signify as to what
> > qualifies as a "gate" in the context of a reset...
> 
> This is poor documentation from the author of the clock driver,

Hah, not that guy again!

> which is me.

oh.

> We only expose the reset lines in the device tree for resets that are
> not associated with a clock line.
> 
> This is done because the aspeed docs specify we do a dance when
> enabling an IP:
> 
>  1. Place IP in reset
>  2. Enable clock
>  3. Delay
>  4. Release reset
> 
> So we do this with the aspeed_g6_gates array. The rule is: any gate
> with a number in the rst column doesn't have that reset line exposed.
> That's what this cryptic comment in the header is warning about.

That makes sense, and means I can drop the explicit reset control from
the DTS, and then we don't need these definitions.

> This was documented to some extent in the original commit message for
> the 2400/2500 driver:
> 
>  https://git.kernel.org/torvalds/c/15ed8ce5f84e2b
> 
> We could hoist that out and put it in the source file(s).

Awesome, thanks for the explanation - I'll add a patch to do so.

Cheers,


Jeremy