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 E8426C6FA8F for ; Wed, 30 Aug 2023 13:05:29 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qbKsL-0005kF-WF; Wed, 30 Aug 2023 09:04:50 -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 1qbKsG-0005hC-AD; Wed, 30 Aug 2023 09:04:45 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qbKs9-0007Qj-EC; Wed, 30 Aug 2023 09:04:43 -0400 Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4RbPWg5GjTz6K6V0; Wed, 30 Aug 2023 20:59:27 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Wed, 30 Aug 2023 14:04:15 +0100 Date: Wed, 30 Aug 2023 14:04:14 +0100 To: Klaus Jensen CC: Corey Minyard , Paolo Bonzini , Peter Maydell , Jason Wang , Keith Busch , Lior Weintraub , Jeremy Kerr , Matt Johnston , Peter Delevoryas , , , , "Klaus Jensen" Subject: Re: [PATCH v4 1/3] hw/i2c: add smbus pec utility function Message-ID: <20230830140414.0000428b@Huawei.com> In-Reply-To: <20230823-nmi-i2c-v4-1-2b0f86e5be25@samsung.com> References: <20230823-nmi-i2c-v4-0-2b0f86e5be25@samsung.com> <20230823-nmi-i2c-v4-1-2b0f86e5be25@samsung.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml500001.china.huawei.com (7.191.163.213) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Received-SPF: pass client-ip=185.176.79.56; envelope-from=jonathan.cameron@huawei.com; helo=frasgout.his.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=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: , Reply-to: Jonathan Cameron From: Jonathan Cameron via Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, 23 Aug 2023 11:21:58 +0200 Klaus Jensen wrote: > From: Klaus Jensen > > Add i2c_smbus_pec() to calculate the SMBus Packet Error Code for a > message. > > Signed-off-by: Klaus Jensen Reviewed-by: Jonathan Cameron > --- > hw/i2c/smbus_master.c | 26 ++++++++++++++++++++++++++ > include/hw/i2c/smbus_master.h | 2 ++ > 2 files changed, 28 insertions(+) > > 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" > > +static uint8_t crc8(uint16_t data) > +{ > + int i; > + > + for (i = 0; i < 8; i++) { > + if (data & 0x8000) { > + data ^= 0x1070U << 3; > + } > + > + data <<= 1; > + } > + > + return (uint8_t)(data >> 8); > +} > + > +uint8_t i2c_smbus_pec(uint8_t crc, uint8_t *buf, size_t len) > +{ > + int i; > + > + for (i = 0; i < len; i++) { > + crc = 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 @@ > > #include "hw/i2c/i2c.h" > > +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); >