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>

1 files changed, 14 insertions, 0 deletions

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 @@
+#ifndef _LINUX_CRC7_H
+#define _LINUX_CRC7_H
+#include <linux/types.h>
+
+extern const u8 crc7_syndrome_table[256];
+
+static inline u8 crc7_byte(u8 crc, u8 data)
+{
+        return crc7_syndrome_table[(crc << 1) ^ data];
+}
+
+extern u8 crc7(u8 crc, const u8 *buffer, size_t len);
+
+#endif