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| author | Vincent Mailhol <mailhol.vincent@wanadoo.fr> | 2020-10-02 18:41:49 +0300 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2020-10-08 00:17:45 +0300 |
| commit | 1c47fa6b31c2683f03bc2f9174902bb7dcd35d83 (patch) | |
| tree | 6b23951a7d08219521f24875aaa6fc1f843f6bb3 /include/linux | |
| parent | f55a52bb2cdbc5a92ca209d0ada90a490a188f58 (diff) | |
| download | linux-1c47fa6b31c2683f03bc2f9174902bb7dcd35d83.tar.xz | |
can: dev: add a helper function to calculate the duration of one bit
Rename macro CAN_CALC_SYNC_SEG to CAN_SYNC_SEG and make it available
through include/linux/can/dev.h
Add an helper function can_bit_time() which returns the duration (in
time quanta) of one CAN bit.
Rationale for this patch: the sync segment and the bit time are two
concepts which are defined in the CAN ISO standard. Device drivers for
CAN might need those.
Please refer to ISO 11898-1:2015, section 11.3.1.1 "Bit time" for
additional information.
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20201002154219.4887-6-mailhol.vincent@wanadoo.fr
[mkl: Let can_bit_time() return an unsinged int, make argument const]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/can/dev.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h index f8975d0b90bb..41ff31795320 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -82,6 +82,21 @@ struct can_priv { #endif }; +#define CAN_SYNC_SEG 1 + +/* + * can_bit_time() - Duration of one bit + * + * Please refer to ISO 11898-1:2015, section 11.3.1.1 "Bit time" for + * additional information. + * + * Return: the number of time quanta in one bit. + */ +static inline unsigned int can_bit_time(const struct can_bittiming *bt) +{ + return CAN_SYNC_SEG + bt->prop_seg + bt->phase_seg1 + bt->phase_seg2; +} + /* * get_can_dlc(value) - helper macro to cast a given data length code (dlc) * to u8 and ensure the dlc value to be max. 8 bytes. |