Hi Rob! Sorry about the delay in response, the mail got lost in the sheer volume of the devicetree list. I appreciate your response, see below. ---Lars > -----Original Message----- > From: Rob Herring <robh@xxxxxxxxxx> > Sent: Friday, December 7, 2018 14:54 > To: Linus Walleij <linus.walleij@xxxxxxxxxx>; Lars Povlsen - M31675 > <Lars.Povlsen@xxxxxxxxxxxxx> > Cc: devicetree@xxxxxxxxxxxxxxx; Gregory CLEMENT > <gregory.clement@xxxxxxxxxxx> > Subject: Re: [PATCH] mips: gpio: mscc_sgpio: Add DT bindings > documentation > > On Fri, Dec 7, 2018 at 3:43 AM Linus Walleij <linus.walleij@xxxxxxxxxx> > wrote: > > > > Hi Lars, > > > > thanks for your patch! > > > > On Mon, Nov 26, 2018 at 1:22 PM Lars Povlsen > <lars.povlsen@xxxxxxxxxxxxx> wrote: > > > > > +MSCC Serial GPIO driver > > > > Expand the acronym please, if IIUC this is > > "Microsemi Corporation (MSCC) Serial GPIO driver" > > > > > +- mscc,sgpio-frequency: The frequency at which the serial bitstream > is > > > + generated and sampled. Default: 12500000 (Hz). > > > > Uhm what is a serial bitstream in this context, I am lost. > > Please elaborate. > > Is this SGPIO as in this[1]? If so, then I don't think using the GPIO > binding is appropriate here. SGPIO is pretty fixed use. There is a > bitbanged SGPIO implementation in the Calxeda SATA driver BTW. > I was not aware of this [1] interface for HDD attachment. There is some similarity in the electrical interface, but this device is specifically for extending GPIO capacity on a SOC which is pin-limited. So I insist that the GPIO binding is highly appropriate here. > Rob > > [1] https://en.wikipedia.org/wiki/SGPIO
