Re: [PATCH 1/6] ARM: dts: rockchip: add basic dtsi file for RK3229 SoC

[Frank Wang]

Hi Heiko,

On 2017/6/19 20:30, Heiko StÃbner wrote:
> Hi Frank,
>
> Am Montag, 19. Juni 2017, 18:34:27 CEST schrieb Frank Wang:
> > On 2017/6/18 2:12, Heiko Stuebner wrote:
> > > Am Donnerstag, 15. Juni 2017, 15:16:15 CEST schrieb Frank Wang:
> > > > Due to some tiny differences between RK3228 and RK3229, this patch
> > > > adds a basic dtsi file which includes a new CPU opp table and PSCI
> > > > brought up support for RK3229.
> > > >
> > > > Signed-off-by: Frank Wang<frank.wang@xxxxxxxxxxxxxx>
> [...]
>
> > > > +	psci {
> > > > +		compatible = "arm,psci-1.0", "arm,psci-0.2";
> > > > +		method = "smc";
> > > > +	};
> > > > +};
> > > > +
> > > > +&cpu0 {
> > > > +	enable-method = "psci";
> > > > +};
> > > Hmm, I don't really understand this.
> > > What method of core-bringup does the rk3228 use? In the current
> > > rk322x.dtsi there is no enable-method at all defined.
> > For non-security, the same with rk3036 SoC, we use rk3036-smp method to
> > bring-up cores, and for security, we use arm-psci method.
> > As security become more and more important and required, we would prefer
> > using arm-psci method, and it is also an easy way to use.
> >
> > > So is the rk3228 firmware using a different method than the rk3229?
> > No, they are the same. How about I move these changes to rk322x.dtsi?
> yep, that is what I was getting at with my question ;-)
>
>
> > > And out of curiosity as this is a arm32 without atf, is the psci
> > > implementation (for uboot?) you're using available somewhere?
> > Ah, it is included in op-tee :-)
> Is that super secret or will this be part of the official op-tee [0]
> at some point (Similar to the ATF stuff on arm64)?

Hmm, the op-tee itself must keep secure, but the psci part in it can be 
extracted to public, although it may have a bit of secure risk.
Due to Rockchip have amended the frame of op-tee to support psci, we can 
try to upstream these changes to official op-tee or push them to source 
codes of Rockchip in git-hub.


BR.
Frank

> Heiko
>
> [0]https://github.com/OP-TEE/optee_os/tree/master/core/arch/arm