Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Quan Nguyen <quan@os.amperecomputing.com>
To:     Corey Minyard <minyard@acm.org>, Rob Herring <robh+dt@kernel.org>,
        Joel Stanley <joel@jms.id.au>,
        Andrew Jeffery <andrew@aj.id.au>,
        Wolfram Sang <wsa@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        openipmi-developer@lists.sourceforge.net,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        linux-i2c@vger.kernel.org
Cc:     openbmc@lists.ozlabs.org,
        Open Source Submission <patches@amperecomputing.com>,
        Phong Vo <phong@os.amperecomputing.com>,
        "Thang Q . Nguyen" <thang@os.amperecomputing.com>
Subject: [PATCH v2 1/3] i2c: i2c-core-smbus: Expose PEC calculate function for generic use
Date:   Tue, 30 Mar 2021 21:10:27 +0700
Message-Id: <20210330141029.20412-2-quan@os.amperecomputing.com>
In-Reply-To: <20210330141029.20412-1-quan@os.amperecomputing.com>
References: <20210330141029.20412-1-quan@os.amperecomputing.com>
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
MIME-Version: 1.0
X-MS-Exchange-MessageSentRepresentingType: 1
Received: from hcm-sw-17.amperecomputing.com (118.69.219.201) by HK0PR03CA0120.apcprd03.prod.outlook.com (2603:1096:203:b0::36) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3977.29 via Frontend Transport; Tue, 30 Mar 2021 14:10:50 +0000
X-MS-PublicTrafficType: Email
X-MS-Office365-Filtering-Correlation-Id: 0915a22f-cb1c-4fc6-b4cf-08d8f385a1c7
X-MS-TrafficTypeDiagnostic: MW4PR01MB6338:
X-MS-Exchange-Transport-Forked: True
X-Microsoft-Antispam-PRVS: <MW4PR01MB63387E44D15A48DD708E073DF27D9@MW4PR01MB6338.prod.exchangelabs.com>
X-MS-Oob-TLC-OOBClassifiers: OLM:3968;
X-MS-Exchange-SenderADCheck: 1
X-Microsoft-Antispam: BCL:0;
X-Microsoft-Antispam-Message-Info: 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
X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:MW2PR0102MB3482.prod.exchangelabs.com;PTR:;CAT:NONE;SFS:(4636009)(366004)(2616005)(5660300002)(2906002)(956004)(186003)(16526019)(6512007)(66556008)(66476007)(6666004)(921005)(107886003)(52116002)(8676002)(7416002)(8936002)(86362001)(38100700001)(66946007)(110136005)(6506007)(83380400001)(498600001)(6486002)(4326008)(1076003)(26005)(54906003)(41533002);DIR:OUT;SFP:1102;
X-MS-Exchange-AntiSpam-MessageData: =?us-ascii?Q?CBHYV2yQ0q92bfTkMZg8G7STuaJM1Ob5oWxTRvT/+C20yDdxtfx6HKr3p6tL?=
 =?us-ascii?Q?H+5Oa6VnMYdMdmV+W+JImj4LGXgU+7Bg69O+GslEeiPqqe/Kb8SBUbnS3Rpz?=
 =?us-ascii?Q?btvElmsDdwmNUP8ONFbA7rmtow6wESC/MKrouR3ODMzj98nlc27dAMoVCj/M?=
 =?us-ascii?Q?CfSg37aere70tOltfgh1mGGZhNBangZNTuXoD4z0GV0xT73O7qf191OgjUPb?=
 =?us-ascii?Q?OLaQcN3KNDNCH4oNBQ5/eqjNdBlnyfgMp4/e/3rM6rxiNYfLYPfAoZ3qk0F2?=
 =?us-ascii?Q?E9i1cTVEKC+rKuzJsodepGAfXjxhQK0Mv+Yh/Sl2QiLWeJbAdCPAaQ/zS9rv?=
 =?us-ascii?Q?vm2wqYLizbNtyfF9hRQlpz8iRRRUFyo+xgQ9j2JZecrkiviG0jj1G+rSRZ2i?=
 =?us-ascii?Q?WMz85R2bfFCpMPSF81zjKXndQ9GTlPQmprZBjC7SRYVXkW/WBlTqUeuJ5xNA?=
 =?us-ascii?Q?FSxxIP2dhHE7eTDnBf1Tjr5wSxZX/0a0eidJE2UQmQXdUTZaNfPKYNeRLuK9?=
 =?us-ascii?Q?2QuVqMXLmh95O1wnLXZAysEIcmAua8h7YQtZBDTYMdzF/KIv2fn/IUDOhMw+?=
 =?us-ascii?Q?jEPUHymEAFNt4iAlNVOlxaWxDNHUYCJX6bejZzggs5dhmNhk6I81f4eKrgle?=
 =?us-ascii?Q?qRWpgaZxZ4nVw2/gSGI4Plj/GJM0hJzHCgjKZvVTuYgOrLHKZ0lHotI9xM/w?=
 =?us-ascii?Q?DH8v+YpFhukjCNBIWMfT3h9dQPCfyiewee0EX1DkgCuemzTyk0BLgu/j7QjX?=
 =?us-ascii?Q?5NHek8tjXzOYKPlVwnjiUGXSbFbU/pfq+Oi5BMxm/ulSIpTM0NCH8FPHW7Go?=
 =?us-ascii?Q?A8j2sy1pIgSFZrso3pcL2JB2bWZkPxGxNZncuoKxDilSxwhTFxRCKctmxNhv?=
 =?us-ascii?Q?2QAhMTuIy0f0phLsTloSYzAgTow0X3vJEd/NOUlfm+SRSAUDZTgTEWpsftxa?=
 =?us-ascii?Q?vV5pmfU0nA4Hv7OFZABMzW6m1NPLjO+TrXVXPf59jKi7pUNnc2RikNoVREaq?=
 =?us-ascii?Q?ZHAGgwfd4R0Hwepuo7ECdtdSDCWO8A40IRQSahXLIIkFWYxrzUINdid6qg3Q?=
 =?us-ascii?Q?ZXCdL+CS4ZTGLssAN5y5VvX9RgdZPNL5Jcw4jRYyFJSVpDtgZKXcI3b8tLNj?=
 =?us-ascii?Q?/5Gok92Vp4/kRtDI0j2xZn2oh2Bc95v85cSBoQf6a2RxSzsoMsbkQIajoN2T?=
 =?us-ascii?Q?+s4SrYktxS7JZoLXI+evMN0WLLLBjkI/Xf0hJZIcq/XO1ELWO8cFv4OVUHj8?=
 =?us-ascii?Q?eDlyRqDDgOdVI1CXiefH1t3vvoy349tMFEGiQnjhDTFGdVHkhYdOqvcZPPFq?=
 =?us-ascii?Q?ZNkQlzuyvi6ECELkm9DRkiJA?=
X-OriginatorOrg: os.amperecomputing.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 0915a22f-cb1c-4fc6-b4cf-08d8f385a1c7
X-MS-Exchange-CrossTenant-AuthSource: MW2PR0102MB3482.prod.exchangelabs.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Mar 2021 14:10:54.7752
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 3bc2b170-fd94-476d-b0ce-4229bdc904a7
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: VTiLY/qwMIT9qKH9qr1dkXfld33hyHg/9hK7w5koBwss2FybuIkd24Ib2GOa9pRq2cyC9UNB893r3HJHYktgr2XPwgEfntBP6VllJlx7aMo=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW4PR01MB6338
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Expose the PEC calculation i2c_smbus_pec() for generic use.

Signed-off-by: Quan Nguyen <quan@os.amperecomputing.com>
---
 drivers/i2c/i2c-core-smbus.c | 12 ++++++++++--
 include/linux/i2c.h          |  1 +
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c
index d2d32c0fd8c3..e5b2d1465e7e 100644
--- a/drivers/i2c/i2c-core-smbus.c
+++ b/drivers/i2c/i2c-core-smbus.c
@@ -37,8 +37,15 @@ static u8 crc8(u16 data)
 	return (u8)(data >> 8);
 }
 
-/* Incremental CRC8 over count bytes in the array pointed to by p */
-static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
+/**
+ * i2c_smbus_pec - Incremental CRC8 over the given input data array
+ * @crc: previous return crc8 value
+ * @p: pointer to data buffer.
+ * @count: number of bytes in data buffer.
+ *
+ * Incremental CRC8 over count bytes in the array pointed to by p
+ */
+u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
 {
 	int i;
 
@@ -46,6 +53,7 @@ static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
 		crc = crc8((crc ^ p[i]) << 8);
 	return crc;
 }
+EXPORT_SYMBOL(i2c_smbus_pec);
 
 /* Assume a 7-bit address, which is reasonable for SMBus */
 static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg)
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 56622658b215..0d75e5bcdde6 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -144,6 +144,7 @@ s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
 /* Now follow the 'nice' access routines. These also document the calling
    conventions of i2c_smbus_xfer. */
 
+u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count);
 s32 i2c_smbus_read_byte(const struct i2c_client *client);
 s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
 s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command);
-- 
2.28.0