diff options
Diffstat (limited to 'drivers/net/can/dev.c')
| -rw-r--r-- | drivers/net/can/dev.c | 35 |
1 files changed, 34 insertions, 1 deletions
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c index f03d7a48..239e4dd 100644 --- a/drivers/net/can/dev.c +++ b/drivers/net/can/dev.c @@ -33,6 +33,39 @@ MODULE_DESCRIPTION(MOD_DESC); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); +/* 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 can_dlc with sanitized can_dlc */ +u8 can_dlc2len(u8 can_dlc) +{ + return dlc2len[can_dlc & 0x0F]; +} +EXPORT_SYMBOL_GPL(can_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_len2dlc(u8 len) +{ + if (unlikely(len > 64)) + return 0xF; + + return len2dlc[len]; +} +EXPORT_SYMBOL_GPL(can_len2dlc); + #ifdef CONFIG_CAN_CALC_BITTIMING #define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */ @@ -454,7 +487,7 @@ EXPORT_SYMBOL_GPL(can_bus_off); static void can_setup(struct net_device *dev) { dev->type = ARPHRD_CAN; - dev->mtu = sizeof(struct can_frame); + dev->mtu = CAN_MTU; dev->hard_header_len = 0; dev->addr_len = 0; dev->tx_queue_len = 10; |
