From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lelvem-ot01.ext.ti.com (lelvem-ot01.ext.ti.com [198.47.23.234]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 39E7F2853E1; Thu, 10 Apr 2025 13:20:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.47.23.234 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744291238; cv=none; b=PaO8jyv94N++kZhp4xikd5uPjf59ZJXhcTSDr/2sKt9U6DYIUsUlG9t32DXmQen5+mYosFxGhD4dsY7uuudnpwxE1hI2LqcWS7ynq3XhNqVD53xTF4MfTAMxfATVpFO/vSzucOBGEBIdT1oyLdCos171YtYm4waLffjNZqkTi0Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744291238; c=relaxed/simple; bh=UtA5gEjIdlbSvKgOUXHBQThchBGfso4/X0OKyeayV/w=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=sDZEHbPJXyn+pH0t7/PIgSbNAkuX5G6EajjB+vrXveXFeWhldPHxM6ZQuCQCOZc7jdC3pIy4wu6DpAw1B8z2kX/1cRmmgGvJXxlK/YgpzL7uqvwyvCiLEXoYAp6GvWR33EGXHheaPQDG+iXMirpCzUyIjOHRfyIiYxQ2BYSvNLc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com; spf=pass smtp.mailfrom=ti.com; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b=OuKGFnMM; arc=none smtp.client-ip=198.47.23.234 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ti.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="OuKGFnMM" Received: from lelv0266.itg.ti.com ([10.180.67.225]) by lelvem-ot01.ext.ti.com (8.15.2/8.15.2) with ESMTPS id 53ADKRQo1297586 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 10 Apr 2025 08:20:27 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1744291227; bh=UtA5gEjIdlbSvKgOUXHBQThchBGfso4/X0OKyeayV/w=; h=Date:Subject:To:CC:References:From:In-Reply-To; b=OuKGFnMMx+MGvEHE8CmdC489iJJG7mN1JssoJ3A6Ftsa1C46guZVqrplScEry3sZ+ WV6gHSc4YDhfyhpYR4RMQv1vHqnLs4/PpxH2vWGi+iZ/P6opqIhfbJVofEKKnFdW91 67pce3rXPZgG3jXXfI+1U4MLYMck6OvLWw2VU/WY= Received: from DLEE103.ent.ti.com (dlee103.ent.ti.com [157.170.170.33]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 53ADKRAK029560 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 10 Apr 2025 08:20:27 -0500 Received: from DLEE100.ent.ti.com (157.170.170.30) by DLEE103.ent.ti.com (157.170.170.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Thu, 10 Apr 2025 08:20:26 -0500 Received: from lelvsmtp6.itg.ti.com (10.180.75.249) by DLEE100.ent.ti.com (157.170.170.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Thu, 10 Apr 2025 08:20:26 -0500 Received: from [10.249.141.75] ([10.249.141.75]) by lelvsmtp6.itg.ti.com (8.15.2/8.15.2) with ESMTP id 53ADKMAE056004; Thu, 10 Apr 2025 08:20:23 -0500 Message-ID: Date: Thu, 10 Apr 2025 18:50:22 +0530 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] arm64: dts: ti: k3-am62p-j722s: add rng node To: Michael Walle , Manorit Chawdhry CC: Nishanth Menon , Vignesh Raghavendra , Tero Kristo , Rob Herring , Krzysztof Kozlowski , Conor Dooley , , , References: <20250313144155.2382316-1-mwalle@kernel.org> <837cba5f-f49e-4cbf-9cbe-2b25f7c9d4b8@ti.com> <1ad2d8c2-6a0d-419d-984d-4974adb0e1f0@ti.com> <20250409103303.dkrrvp7mdctx32pd@uda0497581-HP> Content-Language: en-US From: "Kumar, Udit" In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-C2ProcessedOrg: 333ef613-75bf-4e12-a4b1-8e3623f5dcea Hi Michael, On 4/10/2025 4:56 PM, Michael Walle wrote: > Hi Manorit, > >>>>>>>>> --- a/arch/arm64/boot/dts/ti/k3-am62p-j722s-common-main.dtsi >>>>>>>>> [..] >>>>>>>> For completeness , this is ok to add this node but >>>>>>>> should be kept disabled >>>>>>> Shouldn't it be "reserved" then, see [1]. >>>>>> yes, should be reserved. >>>>>> >>>>>> With marking status as reserved. >>>>>> >>>>>> Please use Reviewed-by: Udit Kumar >>>>> Thanks. >>>>> >>>>>>>> similar to >>>>>>>> >>>>>>>> https://github.com/torvalds/linux/blob/master/arch/arm64/boot/dts/ti/k3-j7200-mcu-wakeup.dtsi#L662 >>>>>>> j784s4, j721e and j721s2 have them enabled. What is the rule here? >>>>>> J784s4, j721e and j721s2 SOCs has two TRNG blocks, >>>>>> >>>>>> example for j721e, one is used by kernel [0] and another by >>>>>> optee [1]. >>>>>> >>>>>> >>>>>>> You also disable the hwrng in optee in your evm according to [2]: >>>>>>> CFG_WITH_SOFTWARE_PRNG=y >>>>>> We are planning to use this hardware block by secure firmware. >>>>>> >>>>>> Therefore request not to use by optee as well >>>>> How will you be able to access the RNG from linux and u-boot? I'm >>>>> asking because I'll need it in u-boot for the lwip stack and the >>>>> HTTPS protocol. >>>> For now,  If you need TRNG then I can suggest to use optee TRNG (ie >>>> build >>>> optee with HW TRNG). >>> I'll be using an uboot TRNG driver. But how will that work in >>> the future if the RNG is used by the secure firmware? >> Wondering if this would be of interest to you [0]. I think since this >> device only has one TRNG, there has to be a master around and we can >> mitigate that from OP-TEE as of now, incase anything changes in future >> then the communication channel between OP-TEE and the secure firmware >> can be established but currently it's still at work. I think the best >> way to go forward is to get the numbers from OP-TEE atm IMHO. > I saw the optee rng. But as of now, the instructions are to use a > software PRNG for optee. Thus, if someone compiles optee by > following the instructions, it's unlikely to work. > > Would TI willing to agree to change the building docs and enable the > TRNG in optee and then work on moving the TRNG into the secure > firmware and build a channel between optee and that firmware? Right > now, the TRNG seems pretty useless as we cannot use it neither from > u-boot or linux (and being future proof). Thanks for note, I agree to update doc two times 1) with current state ie use optee based trng 2) When fw based trng is available, > > -michael