^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * Copyright (c) 2011 Broadcom Corporation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * Permission to use, copy, modify, and/or distribute this software for any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * purpose with or without fee is hereby granted, provided that the above
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * copyright notice and this permission notice appear in all copies.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/crc8.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/printk.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * crc8_populate_msb - fill crc table for given polynomial in reverse bit order.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * @table: table to be filled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * @polynomial: polynomial for which table is to be filled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) void crc8_populate_msb(u8 table[CRC8_TABLE_SIZE], u8 polynomial)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) int i, j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) const u8 msbit = 0x80;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) u8 t = msbit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) table[0] = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) for (i = 1; i < CRC8_TABLE_SIZE; i *= 2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) t = (t << 1) ^ (t & msbit ? polynomial : 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) for (j = 0; j < i; j++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) table[i+j] = table[j] ^ t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) EXPORT_SYMBOL(crc8_populate_msb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) * crc8_populate_lsb - fill crc table for given polynomial in regular bit order.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) * @table: table to be filled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) * @polynomial: polynomial for which table is to be filled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) void crc8_populate_lsb(u8 table[CRC8_TABLE_SIZE], u8 polynomial)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) int i, j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) u8 t = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) table[0] = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) for (i = (CRC8_TABLE_SIZE >> 1); i; i >>= 1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) t = (t >> 1) ^ (t & 1 ? polynomial : 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) for (j = 0; j < CRC8_TABLE_SIZE; j += 2*i)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) table[i+j] = table[j] ^ t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) EXPORT_SYMBOL(crc8_populate_lsb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) * crc8 - calculate a crc8 over the given input data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) * @table: crc table used for calculation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) * @pdata: pointer to data buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) * @nbytes: number of bytes in data buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) * @crc: previous returned crc8 value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) u8 crc8(const u8 table[CRC8_TABLE_SIZE], u8 *pdata, size_t nbytes, u8 crc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) /* loop over the buffer data */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) while (nbytes-- > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) crc = table[(crc ^ *pdata++) & 0xff];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) return crc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) EXPORT_SYMBOL(crc8);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) MODULE_DESCRIPTION("CRC8 (by Williams, Ross N.) function");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) MODULE_AUTHOR("Broadcom Corporation");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) MODULE_LICENSE("Dual BSD/GPL");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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