Re: [PATCH v2 06/16] dt-bindings: timer: add Canaan k210 to Synopsys DesignWare timer

[Conor Dooley]

On 27/06/2022 22:13, Serge Semin wrote:
> On Mon, Jun 27, 2022 at 08:39:54PM +0100, Conor Dooley wrote:
>> From: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>>
>> The Canaan k210 apparently has a Sysnopsys Designware timer but
>> according to the documentation & devicetree it has 2 interrupts rather
>> than the standard one. Add a custom compatible that supports the 2
>> interrupt configuration and falls back to the standard binding (which
>> is currently the one in use in the devicetree entry).
>>
> 
>> Link: https://canaan-creative.com/wp-content/uploads/2020/03/kendryte_standalone_programming_guide_20190311144158_en.pdf #Page 58
> 
> Firstly, it's page 51 in the framework of the document pages
> enumeration.

Ah yes, sorry about that.

> 
> Judging by the comment in the document above and what the HW reference
> manual says regarding the IRQ signals, what you really have on K210 is
> the DW APB Timer IP-cores each configured with two embedded timers.
> It's done by the IP-core synthesize parameter NUM_TIMERS={1..8}, which
> in your case equals to 2. A similar situation is on our SoC and, for
> instance, here:
> 
> arch/arm/boot/dts/berlin2q.dtsi
> arch/arm/boot/dts/berlin2.dtsi
> arch/arm/boot/dts/berlin2cd.dtsi
> (Though the Berlin2 APB Timer have been configured with 8 timers.)
> 
> So the correct modification would be:
> 1. Split up the nodes into two ones with one IRQ per each node.
> 2. Make sure I was right by testing the new dts out.
> 3. Update the DT-node only and leave the DT-bindings as is.

Hmm, sounds good. Will give that a whirl tomorrow.
Thanks for the info/suggestions Sergey.