| Tom Rini | 83d290c | 2018-05-06 17:58:06 -0400 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
| Simon Glass | 60d18d3 | 2013-11-10 10:26:47 -0700 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (c) 2013 Google, Inc |
| Simon Glass | 60d18d3 | 2013-11-10 10:26:47 -0700 | [diff] [blame] | 4 | */ |
| 5 | |
| 6 | #include "linux/crc8.h" |
| 7 | |
| Stefan Roese | 456ecd0 | 2016-04-08 15:56:29 +0200 | [diff] [blame] | 8 | #define POLY (0x1070U << 3) |
| Simon Glass | 60d18d3 | 2013-11-10 10:26:47 -0700 | [diff] [blame] | 9 | |
| Stefan Roese | 456ecd0 | 2016-04-08 15:56:29 +0200 | [diff] [blame] | 10 | static unsigned char _crc8(unsigned short data) |
| 11 | { |
| 12 | int i; |
| 13 | |
| 14 | for (i = 0; i < 8; i++) { |
| 15 | if (data & 0x8000) |
| 16 | data = data ^ POLY; |
| 17 | data = data << 1; |
| Simon Glass | 60d18d3 | 2013-11-10 10:26:47 -0700 | [diff] [blame] | 18 | } |
| 19 | |
| Stefan Roese | 456ecd0 | 2016-04-08 15:56:29 +0200 | [diff] [blame] | 20 | return (unsigned char)(data >> 8); |
| 21 | } |
| 22 | |
| 23 | unsigned int crc8(unsigned int crc, const unsigned char *vptr, int len) |
| 24 | { |
| 25 | int i; |
| 26 | |
| 27 | for (i = 0; i < len; i++) |
| 28 | crc = _crc8((crc ^ vptr[i]) << 8); |
| 29 | |
| 30 | return crc; |
| Simon Glass | 60d18d3 | 2013-11-10 10:26:47 -0700 | [diff] [blame] | 31 | } |