diff options
Diffstat (limited to 'drivers/net/can/dev/length.c')
| -rw-r--r-- | drivers/net/can/dev/length.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/drivers/net/can/dev/length.c b/drivers/net/can/dev/length.c new file mode 100644 index 000000000000..6fe18aa23ec9 --- /dev/null +++ b/drivers/net/can/dev/length.c @@ -0,0 +1,38 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (C) 2012, 2020 Oliver Hartkopp <socketcan@hartkopp.net> + */ + +#include <linux/can/dev.h> + +/* CAN DLC to real data length conversion helpers */ + +static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7, + 8, 12, 16, 20, 24, 32, 48, 64}; + +/* get data length from raw data length code (DLC) */ +u8 can_fd_dlc2len(u8 dlc) +{ + return dlc2len[dlc & 0x0F]; +} +EXPORT_SYMBOL_GPL(can_fd_dlc2len); + +static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, /* 0 - 8 */ + 9, 9, 9, 9, /* 9 - 12 */ + 10, 10, 10, 10, /* 13 - 16 */ + 11, 11, 11, 11, /* 17 - 20 */ + 12, 12, 12, 12, /* 21 - 24 */ + 13, 13, 13, 13, 13, 13, 13, 13, /* 25 - 32 */ + 14, 14, 14, 14, 14, 14, 14, 14, /* 33 - 40 */ + 14, 14, 14, 14, 14, 14, 14, 14, /* 41 - 48 */ + 15, 15, 15, 15, 15, 15, 15, 15, /* 49 - 56 */ + 15, 15, 15, 15, 15, 15, 15, 15}; /* 57 - 64 */ + +/* map the sanitized data length to an appropriate data length code */ +u8 can_fd_len2dlc(u8 len) +{ + if (unlikely(len > 64)) + return 0xF; + + return len2dlc[len]; +} +EXPORT_SYMBOL_GPL(can_fd_len2dlc); |