[PATCH 02/11] ARM: nomadik: initial devicetree support

[Mark Rutland]

On Fri, Jan 11, 2013 at 05:04:11PM +0000, Grant Likely wrote:
> On Tue, 8 Jan 2013 09:57:29 +0000, Mark Rutland <mark.rutland at arm.com> wrote:
> > Hi,
> > 
> > I have a couple of comments on the dts{,i} portion.
> > 
> > On Mon, Jan 07, 2013 at 10:55:59PM +0000, Linus Walleij wrote:
> > > Support basic device tree boot on the Nomadik. Implement the
> > > support in the cpu file with the intent of deleting the board
> > > files later. At this stage IRQ controllers, system timer,
> > > l2x0 cache, UARTs and thus console boot is fully functional.
> > > Patch out the code adding devices by initcalls for now so
> > > as not to disturb the boot.
> > > 
> > > Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
> > > ---
> > >  arch/arm/boot/dts/Makefile                 |  1 +
> > >  arch/arm/boot/dts/ste-nomadik-s8815.dts    | 18 ++++++
> > >  arch/arm/boot/dts/ste-nomadik-stn8815.dtsi | 77 +++++++++++++++++++++++++
> > >  arch/arm/mach-nomadik/board-nhk8815.c      |  4 ++
> > >  arch/arm/mach-nomadik/cpu-8815.c           | 90 ++++++++++++++++++++++++++++++
> > >  arch/arm/mach-nomadik/cpu-8815.h           |  1 +
> > >  arch/arm/mach-nomadik/i2c-8815nhk.c        |  5 ++
> > >  7 files changed, 196 insertions(+)
> > >  create mode 100644 arch/arm/boot/dts/ste-nomadik-s8815.dts
> > >  create mode 100644 arch/arm/boot/dts/ste-nomadik-stn8815.dtsi
> > > 
> > > diff --git a/arch/arm/boot/dts/Makefile b/arch/arm/boot/dts/Makefile
> > > index e44da40..7bc5ba73 100644
> > > --- a/arch/arm/boot/dts/Makefile
> > > +++ b/arch/arm/boot/dts/Makefile
> > > @@ -100,6 +100,7 @@ dtb-$(CONFIG_ARCH_MXS) += imx23-evk.dtb \
> > >  	imx28-m28evk.dtb \
> > >  	imx28-sps1.dtb \
> > >  	imx28-tx28.dtb
> > > +dtb-$(CONFIG_ARCH_NOMADIK) += ste-nomadik-s8815.dtb
> > >  dtb-$(CONFIG_ARCH_OMAP2PLUS) += omap2420-h4.dtb \
> > >  	omap3-beagle.dtb \
> > >  	omap3-beagle-xm.dtb \
> > > diff --git a/arch/arm/boot/dts/ste-nomadik-s8815.dts b/arch/arm/boot/dts/ste-nomadik-s8815.dts
> > > new file mode 100644
> > > index 0000000..b698bc2
> > > --- /dev/null
> > > +++ b/arch/arm/boot/dts/ste-nomadik-s8815.dts
> > > @@ -0,0 +1,18 @@
> > > +/*
> > > + * Device Tree for the ST-Ericsson Nomadik S8815 board
> > > + * Produced by Calao Systems
> > > + */
> > > +
> > > +/dts-v1/;
> > > +/include/ "ste-nomadik-stn8815.dtsi"
> > > +
> > > +/ {
> > > +	model = "ST-Ericsson Nomadik S8815";
> > > +	compatible = "stericsson,nomadik";
> > > +	#address-cells = <1>;
> > > +	#size-cells = <1>;
> > 
> > Given there are addresses and sizes in the dtsi (but none in the dts), should
> > #address-cells and #size-cells not be in the dtsi?
> > 
> > > +
> > > +	chosen {
> > > +		bootargs = "root=/dev/ram0 console=ttyAMA1,115200n8 earlyprintk";
> > > +	};
> > > +};
> > > diff --git a/arch/arm/boot/dts/ste-nomadik-stn8815.dtsi b/arch/arm/boot/dts/ste-nomadik-stn8815.dtsi
> > > new file mode 100644
> > > index 0000000..81284c5
> > > --- /dev/null
> > > +++ b/arch/arm/boot/dts/ste-nomadik-stn8815.dtsi
> > > @@ -0,0 +1,77 @@
> > > +/*
> > > + * Device Tree for the ST-Ericsson Nomadik 8815 STn8815 SoC
> > > + */
> > > +/include/ "skeleton.dtsi"
> > > +
> > > +/ {
> > > +	memory {
> > > +	       reg = <0x00000000 0x04000000>;
> > > +	       reg = <0x08000000 0x04000000>;
> > 
> > I believe that's not valid (duplicate property name).
> > 
> > Judging by other dts files under arch/arm/boot/dts, these should be two nodes,
> > with their unit addresses set (and possibly device_type, which I see is set for
> > some dts files, but not all).
> 
> One node should be just fine if the following form is used:
> 
> 	memory {
> 		reg = <0x00000000 0x04000000>,
> 		      <0x08000000 0x04000000>;
> 	};
> 

That also makes sense.

> > 
> > Maybe I've misunderstood how this is laid out, but I can't see where we get a
> > cpus node from in the board's dts. Has this just been forgotten?
> 
> A cpus node isn't required if it doesn't provide any non-discoverable
> information.
> 

Seeing the discussion around the Tegra #CPUs detection code, I'd think we
should have one:

http://lists.infradead.org/pipermail/linux-arm-kernel/2013-January/140209.html

Thanks,
Mark.