Eric Lee / linux-smarc-t335x-v3.2

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Commit ad241528c4919505afccb022acbab3eeb0db4d80

Authored by Jan Nikitenko
Committed by Linus Torvalds
1 parent c06e677aed
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

CRC7 support 

Add CRC7 routines, used for example in MMC over SPI communication.
Kerneldoc updates

[akpm@linux-foundation.org: fix funny mix of const and non-const]
Signed-off-by: Jan Nikitenko <jan.nikitenko@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 5 changed files with 94 additions and 1 deletions Side-by-side Diff

Documentation/DocBook/kernel-api.tmpl
Diff comments   View file @ ad24152
... ... @@ -139,8 +139,10 @@
139 139 !Elib/cmdline.c
140 140 </sect1>
141 141  
142   - <sect1><title>CRC Functions</title>
  142 + <sect1 id="crc"><title>CRC Functions</title>
  143 +!Elib/crc7.c
143 144 !Elib/crc16.c
  145 +!Elib/crc-itu-t.c
144 146 !Elib/crc32.c
145 147 !Elib/crc-ccitt.c
146 148 </sect1>
include/linux/crc7.h
Diff comments   View file @ ad24152
  1 +#ifndef _LINUX_CRC7_H
  2 +#define _LINUX_CRC7_H
  3 +#include <linux/types.h>
  4 +
  5 +extern const u8 crc7_syndrome_table[256];
  6 +
  7 +static inline u8 crc7_byte(u8 crc, u8 data)
  8 +{
  9 + return crc7_syndrome_table[(crc << 1) ^ data];
  10 +}
  11 +
  12 +extern u8 crc7(u8 crc, const u8 *buffer, size_t len);
  13 +
  14 +#endif
... ... @@ -41,6 +41,14 @@
41 41 kernel tree does. Such modules that use library CRC32 functions
42 42 require M here.
43 43  
  44 +config CRC7
  45 + tristate "CRC7 functions"
  46 + help
  47 + This option is provided for the case where no in-kernel-tree
  48 + modules require CRC7 functions, but a module built outside
  49 + the kernel tree does. Such modules that use library CRC7
  50 + functions require M here.
  51 +
44 52 config LIBCRC32C
45 53 tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
46 54 help
... ... @@ -43,6 +43,7 @@
43 43 obj-$(CONFIG_CRC16) += crc16.o
44 44 obj-$(CONFIG_CRC_ITU_T) += crc-itu-t.o
45 45 obj-$(CONFIG_CRC32) += crc32.o
  46 +obj-$(CONFIG_CRC7) += crc7.o
46 47 obj-$(CONFIG_LIBCRC32C) += libcrc32c.o
47 48 obj-$(CONFIG_GENERIC_ALLOCATOR) += genalloc.o
48 49  
  1 +/*
  2 + * crc7.c
  3 + *
  4 + * This source code is licensed under the GNU General Public License,
  5 + * Version 2. See the file COPYING for more details.
  6 + */
  7 +
  8 +#include <linux/types.h>
  9 +#include <linux/module.h>
  10 +#include <linux/crc7.h>
  11 +
  12 +
  13 +/* Table for CRC-7 (polynomial x^7 + x^3 + 1) */
  14 +const u8 crc7_syndrome_table[256] = {
  15 + 0x00, 0x09, 0x12, 0x1b, 0x24, 0x2d, 0x36, 0x3f,
  16 + 0x48, 0x41, 0x5a, 0x53, 0x6c, 0x65, 0x7e, 0x77,
  17 + 0x19, 0x10, 0x0b, 0x02, 0x3d, 0x34, 0x2f, 0x26,
  18 + 0x51, 0x58, 0x43, 0x4a, 0x75, 0x7c, 0x67, 0x6e,
  19 + 0x32, 0x3b, 0x20, 0x29, 0x16, 0x1f, 0x04, 0x0d,
  20 + 0x7a, 0x73, 0x68, 0x61, 0x5e, 0x57, 0x4c, 0x45,
  21 + 0x2b, 0x22, 0x39, 0x30, 0x0f, 0x06, 0x1d, 0x14,
  22 + 0x63, 0x6a, 0x71, 0x78, 0x47, 0x4e, 0x55, 0x5c,
  23 + 0x64, 0x6d, 0x76, 0x7f, 0x40, 0x49, 0x52, 0x5b,
  24 + 0x2c, 0x25, 0x3e, 0x37, 0x08, 0x01, 0x1a, 0x13,
  25 + 0x7d, 0x74, 0x6f, 0x66, 0x59, 0x50, 0x4b, 0x42,
  26 + 0x35, 0x3c, 0x27, 0x2e, 0x11, 0x18, 0x03, 0x0a,
  27 + 0x56, 0x5f, 0x44, 0x4d, 0x72, 0x7b, 0x60, 0x69,
  28 + 0x1e, 0x17, 0x0c, 0x05, 0x3a, 0x33, 0x28, 0x21,
  29 + 0x4f, 0x46, 0x5d, 0x54, 0x6b, 0x62, 0x79, 0x70,
  30 + 0x07, 0x0e, 0x15, 0x1c, 0x23, 0x2a, 0x31, 0x38,
  31 + 0x41, 0x48, 0x53, 0x5a, 0x65, 0x6c, 0x77, 0x7e,
  32 + 0x09, 0x00, 0x1b, 0x12, 0x2d, 0x24, 0x3f, 0x36,
  33 + 0x58, 0x51, 0x4a, 0x43, 0x7c, 0x75, 0x6e, 0x67,
  34 + 0x10, 0x19, 0x02, 0x0b, 0x34, 0x3d, 0x26, 0x2f,
  35 + 0x73, 0x7a, 0x61, 0x68, 0x57, 0x5e, 0x45, 0x4c,
  36 + 0x3b, 0x32, 0x29, 0x20, 0x1f, 0x16, 0x0d, 0x04,
  37 + 0x6a, 0x63, 0x78, 0x71, 0x4e, 0x47, 0x5c, 0x55,
  38 + 0x22, 0x2b, 0x30, 0x39, 0x06, 0x0f, 0x14, 0x1d,
  39 + 0x25, 0x2c, 0x37, 0x3e, 0x01, 0x08, 0x13, 0x1a,
  40 + 0x6d, 0x64, 0x7f, 0x76, 0x49, 0x40, 0x5b, 0x52,
  41 + 0x3c, 0x35, 0x2e, 0x27, 0x18, 0x11, 0x0a, 0x03,
  42 + 0x74, 0x7d, 0x66, 0x6f, 0x50, 0x59, 0x42, 0x4b,
  43 + 0x17, 0x1e, 0x05, 0x0c, 0x33, 0x3a, 0x21, 0x28,
  44 + 0x5f, 0x56, 0x4d, 0x44, 0x7b, 0x72, 0x69, 0x60,
  45 + 0x0e, 0x07, 0x1c, 0x15, 0x2a, 0x23, 0x38, 0x31,
  46 + 0x46, 0x4f, 0x54, 0x5d, 0x62, 0x6b, 0x70, 0x79
  47 +};
  48 +EXPORT_SYMBOL(crc7_syndrome_table);
  49 +
  50 +/**
  51 + * crc7 - update the CRC7 for the data buffer
  52 + * @crc: previous CRC7 value
  53 + * @buffer: data pointer
  54 + * @len: number of bytes in the buffer
  55 + * Context: any
  56 + *
  57 + * Returns the updated CRC7 value.
  58 + */
  59 +u8 crc7(u8 crc, const u8 *buffer, size_t len)
  60 +{
  61 + while (len--)
  62 + crc = crc7_byte(crc, *buffer++);
  63 + return crc;
  64 +}
  65 +EXPORT_SYMBOL(crc7);
  66 +
  67 +MODULE_DESCRIPTION("CRC7 calculations");
  68 +MODULE_LICENSE("GPL");