[PATCH 06/14] ARM: kirkwood: convert uart0 to devicetree.
Grant Likely
grant.likely at secretlab.ca
Fri Mar 9 08:31:39 EST 2012
On Wed, Mar 07, 2012 at 02:27:23PM -0500, Jason wrote:
> On Wed, Mar 07, 2012 at 06:31:31PM +0000, Arnd Bergmann wrote:
> > On Wednesday 07 March 2012, Jason Cooper wrote:
> > > + serial at f1012000 {
> > > + compatible = "ns16550a";
> > > + reg = <0xf1012000 0xff>;
> > > + reg-shift = <2>;
> > > + interrupts = <33>;
> > > + clock-frequency = <200000000>;
> > > + };
> >
> > I just noticed that the length here should be inclusive, i.e. 0x100 not 0xff.
> > This is different from the way we define resources in Linux.
>
> Grrr. Now I'm getting frustrated. I'm trying to boot without
> earlyprintk. Evidently, something is wrong with the above, because the
> device boots all the way up (blinky lights come on), but I get no
> messages after the usual "Uncompressing Linux... done, booting the
> kernel."
>
> Here's my most recent attempt:
>
I see that you've resolved your problem, but some comments below on the
device node:
> serial at f1012000 {
> device_type = "serial";
Never use device_type. It should only ever appear in the memory node, and
I plan to remove it from there too.
> compatible = "ns16550a";
> reg = <0xf1012000 0x100>; /*phys addr*/
> virt-reg = <0xfed12000>; /*virt addr*/
Don't use virt-reg. Nothing in the kernel uses it and the kernel will
make it's own decision about virtual address mapping.
> reg-shift = <2>;
> reg-io-width = <1>;
1 is the default for reg-io-width. No need to have this property. It
should only be used if the device requires 32 bit accesses.
> interrupts = <33>;
> current-speed = <115200>;
> interrupt-parent = <&intc>;
> clock-frequency = <200000000>;
> };
>
g.
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