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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 870FFCD5BD4 for ; Thu, 21 Sep 2023 07:12:27 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qjDqo-0003q6-OT; Thu, 21 Sep 2023 03:11:50 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qjDqm-0003oy-1i; Thu, 21 Sep 2023 03:11:48 -0400 Received: from pi.codeconstruct.com.au ([203.29.241.158] helo=codeconstruct.com.au) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qjDqk-0001Qd-AH; Thu, 21 Sep 2023 03:11:47 -0400 Received: from [192.168.68.112] (ppp14-2-88-115.adl-apt-pir-bras31.tpg.internode.on.net [14.2.88.115]) by mail.codeconstruct.com.au (Postfix) with ESMTPSA id 585F320034; Thu, 21 Sep 2023 15:11:42 +0800 (AWST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=codeconstruct.com.au; s=2022a; t=1695280303; bh=YEOfyYBMEjXEsSB5+ijTzjaH2UDhyoRDH9AI+T7kK6M=; h=Subject:From:To:Cc:Date:In-Reply-To:References; b=msqie3g4wS3arYEbDG/rS4za+LctZfSTsUec879NwNX4MFdcQdZObj6NT4781QFoP Df6MXJkbIM5RJr1+wK+VzTUh+qBHTXs+1cgu47C50lRNkN4J3T6W3G0W6zdY/15Pud AVEdK4uTsbCd5yWQab+CENuWtSnnSvws6tjunDPzNqL3W5z+GZO9yTKn7v0/ifTxEq QFnykFznh4old/RqfvEukrQ8WQ8LzUfdGdIMdG6sTBRvwZQHs0gOIw9QtF/XlviVtB Anyg57GAT1O0T5w58ESAFn3a47an10iQVM0v/6Cb3QXnzMDOSbH8WChnHyXKVtowPZ A4DtRXCIM6c0Q== Message-ID: <8c281addd173112061e9de7a3916c01493d138a0.camel@codeconstruct.com.au> Subject: Re: [PATCH v6 1/3] hw/i2c: add smbus pec utility function From: Andrew Jeffery To: Klaus Jensen , Corey Minyard , Paolo Bonzini , Peter Maydell , Jason Wang , Keith Busch Cc: Lior Weintraub , Jeremy Kerr , Matt Johnston , Peter Delevoryas , Jonathan Cameron , qemu-devel@nongnu.org, qemu-arm@nongnu.org, qemu-block@nongnu.org, Klaus Jensen Date: Thu, 21 Sep 2023 16:41:41 +0930 In-Reply-To: <20230914-nmi-i2c-v6-1-11bbb4f74d18@samsung.com> References: <20230914-nmi-i2c-v6-0-11bbb4f74d18@samsung.com> <20230914-nmi-i2c-v6-1-11bbb4f74d18@samsung.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.46.4-2 MIME-Version: 1.0 Received-SPF: pass client-ip=203.29.241.158; envelope-from=andrew@codeconstruct.com.au; helo=codeconstruct.com.au X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Thu, 2023-09-14 at 11:53 +0200, Klaus Jensen wrote: > From: Klaus Jensen >=20 > Add i2c_smbus_pec() to calculate the SMBus Packet Error Code for a > message. >=20 > Reviewed-by: Jonathan Cameron > Signed-off-by: Klaus Jensen It at least looks a lot like the linux implementation :) Reviewed-by: Andrew Jeffery > --- > hw/i2c/smbus_master.c | 26 ++++++++++++++++++++++++++ > include/hw/i2c/smbus_master.h | 2 ++ > 2 files changed, 28 insertions(+) >=20 > diff --git a/hw/i2c/smbus_master.c b/hw/i2c/smbus_master.c > index 6a53c34e70b7..01a8e4700222 100644 > --- a/hw/i2c/smbus_master.c > +++ b/hw/i2c/smbus_master.c > @@ -15,6 +15,32 @@ > #include "hw/i2c/i2c.h" > #include "hw/i2c/smbus_master.h" > =20 > +static uint8_t crc8(uint16_t data) > +{ > + int i; > + > + for (i =3D 0; i < 8; i++) { > + if (data & 0x8000) { > + data ^=3D 0x1070U << 3; > + } > + > + data <<=3D 1; > + } > + > + return (uint8_t)(data >> 8); > +} > + > +uint8_t i2c_smbus_pec(uint8_t crc, uint8_t *buf, size_t len) > +{ > + int i; > + > + for (i =3D 0; i < len; i++) { > + crc =3D crc8((crc ^ buf[i]) << 8); > + } > + > + return crc; > +} > + > /* Master device commands. */ > int smbus_quick_command(I2CBus *bus, uint8_t addr, int read) > { > diff --git a/include/hw/i2c/smbus_master.h b/include/hw/i2c/smbus_master.= h > index bb13bc423c22..d90f81767d86 100644 > --- a/include/hw/i2c/smbus_master.h > +++ b/include/hw/i2c/smbus_master.h > @@ -27,6 +27,8 @@ > =20 > #include "hw/i2c/i2c.h" > =20 > +uint8_t i2c_smbus_pec(uint8_t crc, uint8_t *buf, size_t len); > + > /* Master device commands. */ > int smbus_quick_command(I2CBus *bus, uint8_t addr, int read); > int smbus_receive_byte(I2CBus *bus, uint8_t addr); >=20