[PATCH 2/2] ARM: dts: imx6q: add Novena board

Lucas Stach
2015-11-18T11:25:58Z

Am Mittwoch, den 18.11.2015, 11:35 +0100 schrieb Marek Vasut:
> On Wednesday, November 18, 2015 at 11:10:12 AM, Lucas Stach wrote:
> > Hi Marek,
>
> Hi!
>
> > some comments below.
>
> Thanks!
>
> [...]
>
> > > + regulators {
> > > + compatible = "simple-bus";
> > > + #address-cells = <1>;
> > > + #size-cells = <0>;
> > > +
> >
> > Remove this simple bus. It's not there in hardware, regulators are board
> > level components just like the nodes below.
>
> This is surprising to me, since all the boards I checked use this /regulators
> simple bus to contain all the regulators. Is this going to change now ?

Yes, there are a lot of bad examples out there, mainly because people
wanted to logically group the regulators together. But as it isn't
representing any real hardware we should really try to move away from
this practice.

> [...]
>
> > > +&ecspi3 {
> > > + pinctrl-names = "default";
> > > + pinctrl-0 = <&pinctrl_ecspi3_novena>;
> > > + fsl,spi-num-chipselects = <3>;
> > > + status = "okay";
> > > +
> > > + spidev at 0 {
> > > + compatible = "spidev";
> >
> > This will explode on a new kernel. Specifying spidev without using a
> > more specific compatible will trigger a WARN_ON(), as it's considered
> > bad style.
>
> Oh, looks like imx_v6_v7_defconfig didn't have SPIDEV active, which is
> why I didn't catch it during my last test, dang.
>
> This SPI interface is routed into the FPGA, so what do you suggest I put
> in the compatible string? There is no other sensible driver for the peripheral,
> since the peripheral can be anything.
>
I'm not really the right person to ask for that, but I would guess that
inventing a "novena,fpga-spi" compatible or something like that and
adding it to the spidev driver would be the right thing to do.

Regards,
Lucas

--
Pengutronix e.K. | Lucas Stach |
Industrial Linux Solutions | http://www.pengutronix.de/ |