Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932919Ab1EYQnR (ORCPT ); Wed, 25 May 2011 12:43:17 -0400 Received: from oproxy3-pub.bluehost.com ([69.89.21.8]:53588 "HELO oproxy3-pub.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1757457Ab1EYQnP (ORCPT ); Wed, 25 May 2011 12:43:15 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=default; d=xenotime.net; h=Received:Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References:Organization:X-Mailer:Mime-Version:Content-Type:Content-Transfer-Encoding:X-Identified-User; b=LfgxiARImz5NPXXJXElhlz6q/2yDN0Z4jhOiNMl8bjZM1RWtjGSlCjRpb1QpkiGW1RDoXK1eQ/ay0/F4/06ybS8NBcL4PWe9arTqgnQnUr38Zv1Ly716oyDpkklLhgHN; Date: Wed, 25 May 2011 09:43:04 -0700 From: Randy Dunlap To: "Arend van Spriel" Cc: "Andrew Morton" , linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, "John W. Linville" , "David S. Miller" , "Dan Carpenter" , "George Spelvin" Subject: Re: [RFC V4] lib: crc8: add new library module providing crc8 algorithm Message-Id: <20110525094304.0769a189.rdunlap@xenotime.net> In-Reply-To: <1306320099-17970-1-git-send-email-arend@broadcom.com> References: <1306320099-17970-1-git-send-email-arend@broadcom.com> Organization: YPO4 X-Mailer: Sylpheed 2.7.1 (GTK+ 2.16.6; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Identified-User: {1807:box742.bluehost.com:xenotime:xenotime.net} {sentby:smtp auth 50.53.38.135 authed with rdunlap@xenotime.net} Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3739 Lines: 120 On Wed, 25 May 2011 12:41:39 +0200 Arend van Spriel wrote: > include/linux/crc8.h | 101 ++++++++++++++++++++++++++++++++++++++++++++++++++ > lib/Kconfig | 7 +++ > lib/Makefile | 1 + > lib/crc8.c | 84 +++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 193 insertions(+), 0 deletions(-) > create mode 100644 include/linux/crc8.h > create mode 100644 lib/crc8.c [snip] > diff --git a/lib/crc8.c b/lib/crc8.c > new file mode 100644 > index 0000000..0ce4238 > --- /dev/null > +++ b/lib/crc8.c > @@ -0,0 +1,84 @@ > +/* > + * Copyright (c) 2011 Broadcom Corporation > + * > + * Permission to use, copy, modify, and/or distribute this software for any > + * purpose with or without fee is hereby granted, provided that the above > + * copyright notice and this permission notice appear in all copies. > + * > + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES > + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF > + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY > + * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES > + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION > + * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN > + * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. > + */ insert blank line here, please. > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > +#include > +#include > +#include > + > +/* > + * crc8_populate_msb - fill crc table for given polynomial in reverse bit order. > + * > + * table: table to be filled. > + * polynomial: polynomial for which table is to be filled. > + */ Please convert all of these function comments to kernel-doc, like the header file has. > +void crc8_populate_msb(u8 table[CRC8_TABLE_SIZE], u8 polynomial) > +{ > + int i, j; > + const u8 msbit = 0x80; > + u8 t = msbit; > + > + table[0] = 0; > + > + for (i = 1; i < CRC8_TABLE_SIZE; i *= 2) { > + t = (t << 1) ^ (t & msbit ? polynomial : 0); > + for (j = 0; j < i; j++) > + table[i+j] = table[j] ^ t; > + } > +} > +EXPORT_SYMBOL(crc8_populate_msb); > + > +/* > + * crc8_populate_lsb - fill crc table for given polynomial in regular bit order. > + * > + * table: table to be filled. > + * polynomial: polynomial for which table is to be filled. > + */ > +void crc8_populate_lsb(u8 table[CRC8_TABLE_SIZE], u8 polynomial) > +{ > + int i, j; > + u8 t = 1; > + > + table[0] = 0; > + > + for (i = (CRC8_TABLE_SIZE >> 1); i; i >>= 1) { > + t = (t >> 1) ^ (t & 1 ? polynomial : 0); > + for (j = 0; j < CRC8_TABLE_SIZE; j += 2*i) > + table[i+j] = table[j] ^ t; > + } > +} > +EXPORT_SYMBOL(crc8_populate_lsb); > + > +/* > + * crc8 - calculate a crc8 over the given input data. > + * > + * table: crc table used for calculation. > + * pdata: pointer to data buffer. > + * nbytes: number of bytes in data buffer. > + * crc: previous returned crc8 value. > + */ > +u8 crc8(const u8 table[CRC8_TABLE_SIZE], u8 *pdata, size_t nbytes, u8 crc) > +{ > + /* loop over the buffer data */ > + while (nbytes-- > 0) > + crc = table[(crc ^ *pdata++) & 0xff]; > + > + return crc; > +} > +EXPORT_SYMBOL(crc8); > + > +MODULE_DESCRIPTION("CRC8 (by Williams, Ross N.) function"); > +MODULE_AUTHOR("Broadcom Corporation"); > +MODULE_LICENSE("Dual BSD/GPL"); > -- --- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code *** -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/