diff options
author | Jan Nikitenko <jan.nikitenko@gmail.com> | 2007-07-17 07:04:03 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-17 13:23:04 -0400 |
commit | ad241528c4919505afccb022acbab3eeb0db4d80 (patch) | |
tree | ec3a2a65707ca032eab973f98aa568ed007389f1 | |
parent | c06e677aed0c86480b01faa894967daa8aa3568a (diff) |
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>
-rw-r--r-- | Documentation/DocBook/kernel-api.tmpl | 4 | ||||
-rw-r--r-- | include/linux/crc7.h | 14 | ||||
-rw-r--r-- | lib/Kconfig | 8 | ||||
-rw-r--r-- | lib/Makefile | 1 | ||||
-rw-r--r-- | lib/crc7.c | 68 |
5 files changed, 94 insertions, 1 deletions
diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl index 46bcff2849bd..fd2ef4d29b6d 100644 --- a/Documentation/DocBook/kernel-api.tmpl +++ b/Documentation/DocBook/kernel-api.tmpl | |||
@@ -139,8 +139,10 @@ X!Ilib/string.c | |||
139 | !Elib/cmdline.c | 139 | !Elib/cmdline.c |
140 | </sect1> | 140 | </sect1> |
141 | 141 | ||
142 | <sect1><title>CRC Functions</title> | 142 | <sect1 id="crc"><title>CRC Functions</title> |
143 | !Elib/crc7.c | ||
143 | !Elib/crc16.c | 144 | !Elib/crc16.c |
145 | !Elib/crc-itu-t.c | ||
144 | !Elib/crc32.c | 146 | !Elib/crc32.c |
145 | !Elib/crc-ccitt.c | 147 | !Elib/crc-ccitt.c |
146 | </sect1> | 148 | </sect1> |
diff --git a/include/linux/crc7.h b/include/linux/crc7.h new file mode 100644 index 000000000000..1786e772d5c6 --- /dev/null +++ b/include/linux/crc7.h | |||
@@ -0,0 +1,14 @@ | |||
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 | ||
diff --git a/lib/Kconfig b/lib/Kconfig index 3eb29d5dc4f5..e5c2c514174a 100644 --- a/lib/Kconfig +++ b/lib/Kconfig | |||
@@ -41,6 +41,14 @@ config CRC32 | |||
41 | kernel tree does. Such modules that use library CRC32 functions | 41 | kernel tree does. Such modules that use library CRC32 functions |
42 | require M here. | 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 | config LIBCRC32C | 52 | config LIBCRC32C |
45 | tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check" | 53 | tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check" |
46 | help | 54 | help |
diff --git a/lib/Makefile b/lib/Makefile index 8363b60be9dd..da68b2ca0606 100644 --- a/lib/Makefile +++ b/lib/Makefile | |||
@@ -43,6 +43,7 @@ obj-$(CONFIG_CRC_CCITT) += crc-ccitt.o | |||
43 | obj-$(CONFIG_CRC16) += crc16.o | 43 | obj-$(CONFIG_CRC16) += crc16.o |
44 | obj-$(CONFIG_CRC_ITU_T) += crc-itu-t.o | 44 | obj-$(CONFIG_CRC_ITU_T) += crc-itu-t.o |
45 | obj-$(CONFIG_CRC32) += crc32.o | 45 | obj-$(CONFIG_CRC32) += crc32.o |
46 | obj-$(CONFIG_CRC7) += crc7.o | ||
46 | obj-$(CONFIG_LIBCRC32C) += libcrc32c.o | 47 | obj-$(CONFIG_LIBCRC32C) += libcrc32c.o |
47 | obj-$(CONFIG_GENERIC_ALLOCATOR) += genalloc.o | 48 | obj-$(CONFIG_GENERIC_ALLOCATOR) += genalloc.o |
48 | 49 | ||
diff --git a/lib/crc7.c b/lib/crc7.c new file mode 100644 index 000000000000..f1c3a144cec1 --- /dev/null +++ b/lib/crc7.c | |||
@@ -0,0 +1,68 @@ | |||
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"); | ||