diff options
Diffstat (limited to 'lib/crc4.c')
| -rw-r--r-- | lib/crc4.c | 44 |
1 files changed, 0 insertions, 44 deletions
diff --git a/lib/crc4.c b/lib/crc4.c deleted file mode 100644 index e7e1779c67d9..000000000000 --- a/lib/crc4.c +++ /dev/null @@ -1,44 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * crc4.c - simple crc-4 calculations. - */ - -#include <linux/crc4.h> -#include <linux/module.h> - -static const uint8_t crc4_tab[] = { - 0x0, 0x7, 0xe, 0x9, 0xb, 0xc, 0x5, 0x2, - 0x1, 0x6, 0xf, 0x8, 0xa, 0xd, 0x4, 0x3, -}; - -/** - * crc4 - calculate the 4-bit crc of a value. - * @c: starting crc4 - * @x: value to checksum - * @bits: number of bits in @x to checksum - * - * Returns the crc4 value of @x, using polynomial 0b10111. - * - * The @x value is treated as left-aligned, and bits above @bits are ignored - * in the crc calculations. - */ -uint8_t crc4(uint8_t c, uint64_t x, int bits) -{ - int i; - - /* mask off anything above the top bit */ - x &= (1ull << bits) - 1; - - /* Align to 4-bits */ - bits = (bits + 3) & ~0x3; - - /* Calculate crc4 over four-bit nibbles, starting at the MSbit */ - for (i = bits - 4; i >= 0; i -= 4) - c = crc4_tab[c ^ ((x >> i) & 0xf)]; - - return c; -} -EXPORT_SYMBOL_GPL(crc4); - -MODULE_DESCRIPTION("CRC4 calculations"); -MODULE_LICENSE("GPL"); |
