From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 0F3C61C1F2F; Tue, 1 Apr 2025 11:09:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743505776; cv=none; b=YwUaP+2Bmlr1COYfI1CPSLcL7ztfH19xj4cT5C7hG9XhAU2ieTa0emmVouGhoP7rD0RNS1BZUv7ZYKochnjBz7KXbXO3SI+lc4tSuvYKBMh/VaeOxL2jevQKwGOvaYpa8LZTtINL5Wmi6UBSyMGgVQ2iD1Vh15wpQzNHADXjxOQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743505776; c=relaxed/simple; bh=PPv3xZIaLfz6iEjfD3QWE/BzXA85IVTbjNSjcOtzP7U=; h=MIME-Version:Date:From:To:Cc:Subject:In-Reply-To:References: Message-ID:Content-Type; b=OqGURePjnag0aVhjHSPNRbC3/ey9C3MAv2ie/y5Z9rLrPl4qy1gYJ8XDwTn4MB/g4SKfOUIDTO3LmFZDm4xyU34TKfagsY+iCi8djWsg+lD2iuMaV0mOQ08bLZ4EkUx2WWSUCQ+qYnEr5/G9SJJ6lh0s2O5IVTvWt1SeHgElM7g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HIRt8ESx; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HIRt8ESx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4D57DC4CEE8; Tue, 1 Apr 2025 11:09:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743505775; bh=PPv3xZIaLfz6iEjfD3QWE/BzXA85IVTbjNSjcOtzP7U=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=HIRt8ESxjaNP4dTFe9O3bTFy/yc4Vu8mZMdpmsTV1O+ZEF+LbVTvmeTdNe5uqlEy8 umJiahRypk/xeeWaVMe4va3ULlpaUeYCFlqqL1U4f0cXbqv6v6f3Q4XI5Yygk3r1Wp cEy2UJ7XqYXnGLNXHgSzbpnSZ5OKYv2vUIy/28pHniQp9deAa+5cpxWxPHtDU11q3K zU/WCCttTgF72QlRDoFjFyMmobHsBJ7GMIYVWTjvb/jnBwa8qgAD6BRJfmrJ+eAW5a RlFDzk77WkXP5nhXHns+2iFJ8bEfZyUeOhKnTWLR3Z6IOreQmYw1rAjnvBm14JnHV1 lfJAt5Bi2TZhw== Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Date: Tue, 01 Apr 2025 13:09:30 +0200 From: Michael Walle To: "Kumar, Udit" Cc: Nishanth Menon , Vignesh Raghavendra , Tero Kristo , Rob Herring , Krzysztof Kozlowski , Conor Dooley , linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm64: dts: ti: k3-am62p-j722s: add rng node In-Reply-To: References: <20250313144155.2382316-1-mwalle@kernel.org> <837cba5f-f49e-4cbf-9cbe-2b25f7c9d4b8@ti.com> <1ad2d8c2-6a0d-419d-984d-4974adb0e1f0@ti.com> Message-ID: X-Sender: mwalle@kernel.org Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hi Udit, >>>>>> --- 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? -michael