From patchwork Mon Jan 20 15:01:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oscar A Perez X-Patchwork-Id: 11342431 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D709913A4 for ; Mon, 20 Jan 2020 15:11:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B4BA222314 for ; Mon, 20 Jan 2020 15:11:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=neuralgames.com header.i=@neuralgames.com header.b="kY+GPOBB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729165AbgATPLr (ORCPT ); Mon, 20 Jan 2020 10:11:47 -0500 Received: from kross.rwserver.com ([69.13.37.146]:37040 "EHLO kross2019.rwserver.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728783AbgATPLr (ORCPT ); Mon, 20 Jan 2020 10:11:47 -0500 Received: from localhost (localhost [127.0.0.1]) by kross2019.rwserver.com (Postfix) with ESMTP id 3E1EBB3629; Mon, 20 Jan 2020 09:01:33 -0600 (CST) Authentication-Results: kross2019.rwserver.com (amavisd-new); dkim=pass (1024-bit key) reason="pass (just generated, assumed good)" header.d=neuralgames.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=neuralgames.com; h=x-mailer:message-id:date:date:subject:subject:from:from; s= default; t=1579532490; x=1581346891; bh=dshgkKumJVS0zAqIIrcV+cw7 enEW8iyIBXeKU3OU9w4=; b=kY+GPOBBbjAO2SEjaQm70ehoBqYzhl9zuqJcDvf9 rZjYn0c8QmwPVNoZ13ejhQEWEEnhy4Kh5ot8OLH+v4A4uxbzILR/GUZ+2SXAfMJp Ie2Jt9n13YD3PsTv8s1wVAI0BzbzOf1+onms+kCrTQTe3ti050chJ2HoYxhOJn6F Yyg= X-Virus-Scanned: Debian amavisd-new at kross2019.rwserver.com Received: from kross2019.rwserver.com ([127.0.0.1]) by localhost (kross2019.rwserver.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 5l7g2zoo_9du; Mon, 20 Jan 2020 09:01:30 -0600 (CST) Received: from localhost (ZT-GROUP-IN.bear1.Houston1.Level3.net [4.14.58.158]) (Authenticated sender: linux@neuralgames.com) by kross2019.rwserver.com (Postfix) with ESMTPSA id 9F147B3628; Mon, 20 Jan 2020 09:01:30 -0600 (CST) From: Oscar A Perez To: Matt Mackall , Herbert Xu , Rob Herring , Mark Rutland , Joel Stanley , Andrew Jeffery , Oscar A Perez , linux-crypto@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] hwrng: Add support for ASPEED RNG Date: Mon, 20 Jan 2020 15:01:08 +0000 Message-Id: <20200120150113.2565-1-linux@neuralgames.com> X-Mailer: git-send-email 2.17.1 Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org This minimal driver adds support for the Hardware Random Number Generator that comes with the AST2400/AST2500/AST2600 SOCs from AspeedTech. The HRNG on these SOCs uses Ring Oscillators working together to generate a stream of random bits that can be read by the platform via a 32bit data register. Signed-off-by: Oscar A Perez --- .../devicetree/bindings/rng/aspeed-rng.yaml | 90 +++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 Documentation/devicetree/bindings/rng/aspeed-rng.yaml diff --git a/Documentation/devicetree/bindings/rng/aspeed-rng.yaml b/Documentation/devicetree/bindings/rng/aspeed-rng.yaml new file mode 100644 index 000000000000..06070ebe1c33 --- /dev/null +++ b/Documentation/devicetree/bindings/rng/aspeed-rng.yaml @@ -0,0 +1,90 @@ +# SPDX-License-Identifier: GPL-2.0 +%YAML 1.2 +--- +$id: "http://devicetree.org/schemas/rng/aspeed-rng.yaml#" +$schema: "http://devicetree.org/meta-schemas/core.yaml#" + + +title: Bindings for Aspeed Hardware Random Number Generator + + +maintainers: + - Oscar A Perez + + +description: | + The HRNG on the AST2400/AST2500/AST2600 SOCs from AspeedTech uses four Ring + Oscillators working together to generate a stream of random bits that can be + read by the platform via a 32bit data register every one microsecond. + All the platform has to do is to provide to the driver the 'quality' entropy + value, the 'mode' in which the combining ROs will generate the stream of + random bits and, the 'period' value that is used as a wait-time between reads + from the 32bit data register. + + +properties: + compatible: + oneOf: + - items: + - enum: + - aspeed,ast2400-rng + - aspeed,ast2500-rng + - aspeed,ast2600-rng + + + reg: + description: + Base address and length of the register set of this block. + Currently 'reg' must be eight bytes wide and 32-bit aligned. + + maxItems: 1 + + + period: + description: + Wait time in microseconds to be used between reads. + The RNG on these Aspeed SOCs generates 32bit of random data + every one microsecond. Choose between 1 and n microseconds. + + maxItems: 1 + + + mode: + description: + One of the eight modes in which the four internal ROs (Ring + Oscillators) are combined to generate a stream of random + bits. The default mode is seven which is the default method + of combining RO random bits on these Aspeed SOCs. + + maxItems: 1 + + + quality: + description: + Estimated number of bits of entropy per 1024 bits read from + the RNG. Note that the default quality is zero which stops + this HRNG from automatically filling the kernel's entropy + pool with data. + + maxItems: 1 + + +required: + - compatible + - reg + - period + - quality + + +examples: + - | + rng: hwrng@1e6e2074 { + compatible = "aspeed,ast2500-rng"; + reg = <0x1e6e2074 0x8>; + period = <4>; + quality = <128>; + mode = <0x7>; + }; + + +...