From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3A80BC44508 for ; Wed, 15 Jul 2026 11:43:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date :Subject:Cc:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=4iI7cm50TUfbt29M1XzW54/S6U86vKbruO9GvSiUuH0=; b=aSAzKAFqYuaCVBsg68LmOzjxwp aamFLTSuB5yTDgK+1fkOBi+DEtmDYSz37U7sYqwFX4meIxQGlHIJc6qpJh5YT2+Ee1lbST42dr7K7 MaXbRf2vNPvhXMTwo+ssjqjuFkaoReJewTqpc9K/eMS8luSmswhEUuPcr2qJdUpr/dsgQu3sxYoT9 x8jC/0b9NNuGIG9sUyHGXC969QjxE5PvNe10wtavkR/3G4KDSCAFq6Yf+ajdAa6CNA6Gvkslx4NYV 3QxmvisbHjqSUIKpeGSijsciudnbTXYF7AVOl8/bnz4Y+7iueV/b9EIdI/3WjoDzanmZMT9hqBi5o GzVL4Gcg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wjy18-0000000EbtT-3HIk; Wed, 15 Jul 2026 11:43:10 +0000 Received: from gloria.sntech.de ([185.11.138.130]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wjy15-0000000EbsP-3R2H; Wed, 15 Jul 2026 11:43:09 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sntech.de; s=gloria202408; h=Content-Type:Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Reply-To; bh=4iI7cm50TUfbt29M1XzW54/S6U86vKbruO9GvSiUuH0=; b=sWAGpdJCjLiATuC2iZfg0E1iT8 5rxsKju5Y4nlh3QLn3hMx6qr69JvQ1H46Qx/HsW0jfcCJ9E1uEAmYxCjAQk2N1mtHLO9iWgx3hQs8 hURR00Tun5XOsU60sNFUfEPbTRh8BX9ZGBbA93gw79jfPTfSrl2OZEsjqWvI64QdLJvaUQ5Wx/+G5 KKAilP1EEdH8GzlFbgiWs3V+WrQiRkVrbjAZc+M5qkCbE2v7zdTBdvkCY5p0xCv7498A0R+kbF7Uu OXI6aZs476f1wARdihN6FYfJJSsSUK9FYe2uyZvk04uj3HRJz4PWbcZoATcASfIVPLNZLOCeHh7bx 6hx4xtyw==; From: Heiko =?UTF-8?B?U3TDvGJuZXI=?= To: srini@kernel.org, Hrushiraj Gandhi Cc: robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org, Hrushiraj Gandhi Subject: Re: [PATCH 1/2] dt-bindings: nvmem: rockchip-efuse: add rockchip,efuse-write-enable property Date: Wed, 15 Jul 2026 13:42:56 +0200 Message-ID: <2363663.KTMopqUuYO@diego> In-Reply-To: <20260715110107.409204-2-hrushirajg23@gmail.com> References: <20260715110107.409204-1-hrushirajg23@gmail.com> <20260715110107.409204-2-hrushirajg23@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260715_044307_909074_EB2E6104 X-CRM114-Status: GOOD ( 18.12 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Am Mittwoch, 15. Juli 2026, 13:01:06 Mitteleurop=C3=A4ische Sommerzeit schr= ieb Hrushiraj Gandhi: > Add an optional boolean property to explicitly opt in to write (OTP > programming) support. eFuse bits are one-time-programmable and > permanently set once written; write support must therefore not be > enabled by default on arbitrary boards. >=20 > Boards that intend to use software-initiated eFuse programming (e.g. > factory key provisioning) must declare this property and must ensure > the required VQPS programming supply (1.8V to 1.98V per RK3399 TRM) > is present and correctly sequenced during writes. >=20 > Signed-off-by: Hrushiraj Gandhi > --- > .../devicetree/bindings/nvmem/rockchip-efuse.yaml | 11 +++++++++++ > 1 file changed, 11 insertions(+) >=20 > diff --git a/Documentation/devicetree/bindings/nvmem/rockchip-efuse.yaml = b/Documentation/devicetree/bindings/nvmem/rockchip-efuse.yaml > index b80fd8d1ae5b..8a7195245c84 100644 > --- a/Documentation/devicetree/bindings/nvmem/rockchip-efuse.yaml > +++ b/Documentation/devicetree/bindings/nvmem/rockchip-efuse.yaml > @@ -46,6 +46,17 @@ properties: > this property is defined. > $ref: /schemas/types.yaml#/definitions/uint32 > =20 > + rockchip,efuse-write-enable: > + type: boolean > + description: > + Enable write (programming) support for this eFuse block. eFuse bits > + are one-time-programmable; setting a bit is permanent and cannot be > + undone. This property must only be set on boards where irreversible > + OTP programming from software is an intended use case (e.g. factory > + provisioning), and where the required VQPS programming voltage > + (1.8V to 1.98V per RK3399 TRM) is guaranteed to be present and > + correctly sequenced by the board's power design during writes. Devicetree is not a configuration space, and I think this really does count as configuration - as the efuse will be writeable on every board. You mention the VQPS voltage. If I'm reading schematics and application notes correctly, this is a separate input used solely for writing efuses and _needs_ to be 0V (off?) during reads. You mention "needs to be present and correctly sequenced", who is supposed to turn on/off that regulator? So you very likely need to define that regulator and can even use its absence as an indicator to disable writes. Heiko