[RFC PATCH 06/10] hwspinlock: OMAP4: Add spinlock support in DT
Arnd Bergmann
arnd at arndb.de
Thu Sep 8 10:47:55 EDT 2011
On Thursday 08 September 2011, Ohad Ben-Cohen wrote:
> On Thu, Sep 8, 2011 at 11:07 AM, Cousson, Benoit <b-cousson at ti.com> wrote:
> > The (small) issue for my point of view is that the #hwspinlock is already
> > encoded in the IP itself. So adding a baseid directly in DT will look like
> > duplicating indirectly something that is already there in the HW.
> > That being said, since we cannot rely on the order, we will not be able to
> > get the proper baseid until the driver probe every hwspinlock devices :-(
> > So baseid might be a easier choice.
>
> Sounds good. Thanks a lot !
I think a number would work here but is not optimal for the device tree
representation. I think a better binding would be to encode it like
interrupt numbers, where every device that uses a hwspinlock will describe
that as a combination of phandle to the hwspinlock controller and
identifier to be used by that controller, e.g.
spinlock1 {
compatible = "ti,omap-spinlock";
regs = ...
interrupts = <42>;
interrupt-parent = &irq-controller;
};
dsp {
compatible = ...
regs = ...
spinlocks = <23>; // local number withing &spinlock1;
spinlock-controller = &spinlock1;
};
or possibly shorter
spinlocks = <&spinlock1 23>;
Arnd
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