From: Frank Wang <frank.wang@rock-chips.com>
Subject: Re: [PATCH 1/6] ARM: dts: rockchip: add basic dtsi file for RK3229
 SoC
To: =?UTF-8?Q?Heiko_St=c3=bcbner?= <heiko@sntech.de>
Cc: robh+dt@kernel.org, ulf.hansson@linaro.org, mark.rutland@arm.com,
        linux-arm-kernel@lists.infradead.org,
        linux-rockchip@lists.infradead.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org,
        charles.chen@rock-chips.com, kevan.lan@rock-chips.com,
        huangtao@rock-chips.com, wmc@rock-chips.com,
        =?UTF-8?B?6ZmI5YGl5rSq?= <chenjh@rock-chips.com>,
        Kever Yang <kever.yang@rock-chips.com>
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Date: Tue, 20 Jun 2017 15:13:00 +0800
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Hi Heiko,

On 2017/6/19 20:30, Heiko Stübner 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@rock-chips.com>
> [...]
>
>>>> +	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
>
>