[PATCH v2 5/5] board: add support for Schneider HMIBSC board

[Sumit Garg]

On Wed, 13 Mar 2024 at 16:59, Stephan Gerhold <stephan at gerhold.net> wrote:
>
> On Wed, Mar 13, 2024 at 12:08:58PM +0530, Sumit Garg wrote:
> > On Mon, 11 Mar 2024 at 20:07, Stephan Gerhold <stephan at gerhold.net> wrote:
> > > On Mon, Mar 11, 2024 at 04:40:26PM +0530, Sumit Garg wrote:
> > > > Support for Schneider Electric HMIBSC. Features:
> > > > - Qualcomm Snapdragon 410C SoC - APQ8016 (4xCortex A53, Adreno 306)
> > > > - 2GiB RAM
> > > > - 64GiB eMMC, SD slot
> > > > - WiFi and Bluetooth
> > > > - 2x Host, 1x Device USB port
> > > > - HDMI
> > > > - Discrete TPM2 chip over SPI
> > > >
> > > > Features enabled in U-Boot:
> > > > - RAUC updates
> > > > - Environment protection
> > > > - USB based ethernet adaptors
> > > >
> > > > Signed-off-by: Sumit Garg <sumit.garg at linaro.org>
> > >
> > [...]
> > > > +     gpio_rs232_high: gpio_rs232_high {
> > >
> > > Pretty sure DT schema checks would complain about this node name (need
> > > -state suffix, no underscores).
> >
> > We have the dtbs_check in U-Boot too. I will use that before posting
> > the next version.
> >
> > >
> > > > +             bootph-all;
> > > > +             pins = "gpio99";
> > > > +             function = "gpio";
> > > > +
> > > > +             drive-strength = <16>;
> > > > +             bias-disable;
> > > > +             output-high;
> > > > +     };
> > > > +
> > > > +     gpio_rs232_low: gpio_rs232_low {
> > >
> > > Same here.
> > >
> > > Also, since I'm looking at this a bit more closely now, are there maybe
> > > more clear label/node names you could use here, or a comment you could
> > > add what exactly these pins do? I guess this enables something about
> > > RS232 but it's not clear what exactly.
> >
> > Actually these GPIOs are a mux to select among different UART modes
> > (RS232/422/485). This configuration allows you to select RS232 mode.
> > How about following label/node names?
> >
> > uart1_mux0_rs232_high: uart1-mux0-rs232-state
> >
> > uart1_mux1_rs232_low: uart1-mux1-rs232-state
> >
>
> Hm, is it a 2 bit mux selector like
>
>         gpio99  gpio100 UART mode
>         0       0       ?
>         0       1       ?
>         1       0       RS232
>         1       1       ?
>
> and the others are RS422 and RS485?

Yeah, just to complete that table:

         gpio100  gpio99 UART mode
         0             0            loopback
         0             1            RS-232
         1             0            RS-485
         1             1            RS-422

> If yes, a comment with the table of
> the function assignments would help a lot for clarity.

Sure I will add that.

> With that,
> precise naming would not be that important anymore. :-)
>

I will keep the updated naming too.

-Sumit

> Thanks,
> Stephan