-- Antoniu Miclăuş > -----Original Message----- > From: Krzysztof Kozlowski <krzk@xxxxxxxxxx> > Sent: Monday, January 13, 2025 1:24 PM > To: Nuno Sá <noname.nuno@xxxxxxxxx>; Miclaus, Antoniu > <Antoniu.Miclaus@xxxxxxxxxx> > Cc: jic23@xxxxxxxxxx; robh@xxxxxxxxxx; conor+dt@xxxxxxxxxx; linux- > iio@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > linux-pwm@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v4 1/3] dt-bindings: iio: adf4371: add refin mode > > [External] > > On 13/01/2025 12:17, Nuno Sá wrote: > > On Mon, 2025-01-13 at 11:21 +0100, Krzysztof Kozlowski wrote: > >> On 13/01/2025 10:55, Nuno Sá wrote: > >>> On Mon, 2025-01-13 at 09:37 +0100, Krzysztof Kozlowski wrote: > >>>> On Thu, Jan 09, 2025 at 03:37:05PM +0200, Antoniu Miclaus wrote: > >>>>> clock-names: > >>>>> description: > >>>>> - Must be "clkin" > >>>>> - maxItems: 1 > >>>>> + Must be "clkin" if the input reference is single ended or "clkin- > >>>>> diff" > >>>>> + if the input reference is differential. By default single ended > >>>>> input > >>>>> is > >>>>> + applied. > >>>>> + enum: [clkin, clkin-diff] > >>>>> + default: clkin > >>>> > >>>> Which pins are these? I went through adf4371 datasheet and no > reference > >>>> on clock inputs like clkin or clkin-diff. > >>>> > >>>> > >>> > >>> Hmm, I guess we should call this 'refp' and 'refp-n' then (the latter seems > >>> a > >>> bit more odd)? Or just 'ref' and 'ref-diff'? > >> > >> That mistake was done at the beginning - the "clkin" is just useless > >> name. It cannot be "clkout" and it cannot be anything else than clk, so > >> it is 100% redundant. > >> > > > > Oh sure... Makes sense and I forgot that the property is not new... > > > >> But looking for pins brought second point - here you claim these are > >> mutually exclusive while datasheet suggests that both inputs can be > >> connected. Unless they come from the same source always? > >> > > > > If you have a single ended input then only one pin (the positive one) will be > > used. If the input signal is differential, then both pins will be used. So they > > But the clocks describe input pins, at least in typical case, so that's > my question: how many clock sources do you have here? One or two? > > > are mutually exclusive... You either have single ended or a differential input. > > And depending on the input type, the limit of the input frequency varies. > > Based on this, this is the same clock, so using "diff" is not a property > of "clocks". Look at other bindings how they encode differential choice > for some signals - usually bool property, but not always - see other > adi/admv devices. This approach that you suggest was implemented in patch series v1 (as boolean) / v3 (as enum). Based on feedback in v3 received from Jonathan I switched to this. Should I revert it? > Best regards, > Krzysztof
