linux-imx

#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.

 * @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)

{