[PATCH 4/6] arm64: Add DTS support for FSL's LS2085A SoC

[bhupesh.sharma at freescale.com]

> -----Original Message-----
> From: Catalin Marinas [mailto:catalin.marinas at arm.com]
> Sent: Friday, August 15, 2014 6:40 PM
> To: Yoder Stuart-B08248
> Cc: Sharma Bhupesh-B45370; devicetree-discuss at lists.ozlabs.org; Will
> Deacon; arnd at arndb.de; grant.likely at secretlab.ca; linux-arm-
> kernel at lists.infradead.org; Basu Arnab-B45036
> Subject: Re: [PATCH 4/6] arm64: Add DTS support for FSL's LS2085A SoC
> 
> On Fri, Aug 15, 2014 at 01:53:13PM +0100, Stuart Yoder wrote:
> > > On Fri, Aug 15, 2014 at 10:49:13AM +0100, Bhupesh Sharma wrote:
> > > > +	cpus {
> > > > +		#address-cells = <2>;
> > > > +		#size-cells = <0>;
> > > > +
> > > > +		/* We have 4 clusters having 2 Cortex-A57 cores each */
> > > > +		cpu at 0 {
> > > > +			device_type = "cpu";
> > > > +			compatible = "arm,cortex-a57";
> > > > +			reg = <0x0 0x0>;
> > > > +			enable-method = "spin-table";
> > > > +			cpu-release-addr = <0x0 0x8000fff8>;
> > > > +		};
> > >
> > > Why not PSCI?
> >
> > It simply is where we are today-- we don't have functioning PSCI yet
> > but plan to get there over time.
> 
> Thanks for clarification.
> 
> > All the existing device trees
> > in arch/arm64 use "spin-table", so it seems that other platforms are
> > in the same situation:
> >    apm-storm.dtsi
> 
> Not possible because there is no EL3 mode on the CPU implementation.
> 
> >    foundation-v8.dts
> >    rtsm_ve-aemv8a.dts
> 
> These work with the latest boot wrapper (which overrides the DT nodes and
> passes the PSCI information).

Right. We are working on our PSCI handler implementation in EL3 and the spin-table
approach it something we are currently supporting on the simulator model using
u-boot bootloader setting up the spin-tables.

Our patches for implementing spin-table approach in armv8 u-boot are already under
review and corresponding rework [1].

[1] http://lists.denx.de/pipermail/u-boot/2014-July/183692.html

Regards,
Bhupesh