Re: [PATCH v2 6/6] i2c: spacemit: introduce pio for k1

Yixun Lan
2025-09-27T10:17:00Z

Hi Troy,

On 12:04 Sat 27 Sep , Troy Mitchell wrote:
> On Sat, Sep 27, 2025 at 09:45:47AM +0800, Yixun Lan wrote:
> > Hi Troy,
> >
> > On 10:02 Thu 25 Sep , Troy Mitchell wrote:
> > > This patch introduces I2C PIO functionality for the Spacemit K1 SoC,
> > > enabling the use of I2C with interrupts disabled.
> > I feel it's more proper to say
> > s/with interrupts disabled/in atomic context/
> Good point.
>
> >
> > I've noticed that K1 I2C controller support three different transmission mode:
> > non-fifo, fifo mode, dma mode
> >
> > while you are trying to implement pio support, I'd suggest to think one
> > further step in the long run - support more fifo/dma + normal/atomic features,
> I understand your concern, but I have reviewed the code structure,
> and adding FIFO support would not significantly affect the current PIO implementation.
we will see..

>
> >
> > Personally, I'd like to see fifo mode implemented before adding pio
> > support, as it will bring quite significant code changes, require heavy
> > code review effort. And yes, this will put more demanding work on your side
> > and may slow things a bit..
> That said, we don’t have any plans to support FIFO at this point,
> and PIO functionality is something we need urgently.
> So I will continue to push this patch (tomorrow).
please do not flush the mailing list and give people some time, I haven't seen
enough reviews coming, please wait for ~one week before sending next version,
or make sure you've accumulated enough changes..

> Thanks for your understanding. For details on the code changes, please see above.
>
> In addition, if anyone is interested in adding FIFO support, I’d be happy to help.
>
do you want to push the work (support fifo mode) to community?

--
Yixun Lan (dlan)