Re: [virtio-comment] Re: [PATCH] [PATCH v5] virtio-spi: add the device specification

[Haixu Cui <quic_haixcui@quicinc.com>]

On 11/27/2023 10:33 PM, Cornelia Huck wrote:
> On Mon, Nov 27 2023, Cornelia Huck <cohuck@redhat.com> wrote:
>
> > On Mon, Nov 27 2023, Haixu Cui <quic_haixcui@quicinc.com> wrote:
> >
> > > On 11/24/2023 11:46 PM, Cornelia Huck wrote:
> > > > On Fri, Nov 24 2023, Haixu Cui <quic_haixcui@quicinc.com> wrote:
> > > > > +The \field{chip_select_max_number} is the maximum number of chipselect the host SPI controller supports.
> > > >
> > > > "chipselect" is probably a known term for people familiar with SPI -- is
> > > > there any definition of those terms that the spec can point to?
> > >
> > > Just as Mark said, there is no formal spec for SPI, so no standard spec
> > > for such terms referring to. The same for CPHA/CPOL/LSB/MSB, please see
> > > below.
> >
> > If we have nothing to point to, it is probably best to simply
> > expand/explain the terms on their first usage.
> >
> > > > Can we point to some documentation that explains CPHA and CPOL?
> > >
> > > Here. No standard SPI spec to point to. CPOL/CPHA have definitions in
> > > wikipedia(Clock polarity and phase chapter):
> > >
> > > https://en.wikipedia.org/wiki/Serial_Peripheral_Interface
> > >
> > > How about copying some concise information from wikipedia as Note? Or is
> > > referring to such webpage acceptable in this spec.
> >
> > Not sure if we can do an outright copy (licence compatibility), but
> > paraphrasing should be fine. (I'd rather not directly reference the
> > site, because the content is not guaranteed to be stable, but we could
> > maybe add it as "further reading".)
>
> Looking again, the kernel doc referenced by Mark
> (https://www.kernel.org/doc/html/v6.6/driver-api/spi.html) might also be
> a good candidate, especially as we can refer to a specific version.
This Linux doc is a good Normative References, but it doesn't have 
definitions of the terms, like chipselect, CPOA, LSB...

I will add some concise descriptions on their first usage.

Best Regards
Thanks

Haixu Cui