[PATCH] Initial DT support for SIMpad devices.
Jamie Iles
jamie at jamieiles.com
Mon Nov 21 09:47:46 EST 2011
Hi Jochen,
On Mon, Nov 21, 2011 at 03:32:56PM +0100, Jochen Friedrich wrote:
> >>+ localbus {
> >>+ compatible = "intel,sa1110-localbus";
> >
> >Could this claim compatibility with simple-bus?
>
> I wasn't sure about this. I took a look in the powerpc DTS files for reference and they used
> some kind of <chip>-localbus compatible entries. So I took the same approach here.
Hmm, I haven't seen any of the ARM platforms doing this, and unless the
sa1110 bus has some extra knobs that need tweaking, then simple-bus
should be fine.
> >>+ uart2: serial at 0x80050000 {
> >>+ compatible = "intel,sa1100-uart";
> >>+ reg =<0x80050000 0x24>;
> >>+ interrupts =<17>;
> >>+ status = "disabled";
> >
> >Hmm, I couldn't see status defined in the UART binding or where it was
> >used... Is this required?
>
> status is a global property and it's being used in drivers/of/base.c, of_device_is_available().
> It is used in other dtsi files like e.g. at91sam9g45.dtsi as well to define optional nodes.
Ahh, I wasn't aware of that one - thanks!
> >>+/ {
> >>+ model = "SIEMENS, SIMpad";
> >>+ compatible = "siemens,simpad";
> >
> >It may be worth adding the SoC compatible string after the board one for
> >completeness.
>
> Do you mean something like this?
>
> compatible = "siemens,simpad", "intel,sa1100";
Yup, that looks about right.
> >>+ chosen {
> >>+ bootargs = "console=ttySA0";
> >
> >It is preferred for the bootloader to set these up rather than having
> >them statically in the DTS if at all possible.
>
> Yes, my boot loader does this, but simpad support is not in official U-BOOT yet.
> This allows testing with a different boot loader like the hh.org one and a Linux
> binary with DTB appended.
OK, I guess that's fair enough, though I certainly shouldn't be
considered an authoritative source on this!
Jamie
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