kernel.git/drivers/net/can/dev/bittiming.c, branch linux-5.14.yHosts the 0x221E linux distro kernel.
https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-5.14.y2021-11-17T10:03:54Zcan: bittiming: can_fixup_bittiming(): change type of tseg1 and alltseg to unsigned int2021-11-17T10:03:54ZMarc Kleine-Budde2021-10-13T13:00:10Zurn:sha1:b108a79345c388f167f131b9a80f24dc4f7d27ae
[ Upstream commit e346290439609a8ac67122418ca2efbad8d0a7e7 ]
All timing calculation is done with unsigned integers, so change type
of tseg1 and alltseg to unsigned int, too.
Link: https://lore.kernel.org/all/20211013130653.1513627-1-mkl@pengutronix.de
Link: https://github.com/linux-can/can-utils/pull/314
Reported-by: Gary Bisson <bisson.gary@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
can: bittiming: add CAN_KBPS, CAN_MBPS and CAN_MHZ macros2021-03-30T09:14:45ZVincent Mailhol2021-03-06T05:40:40Zurn:sha1:1d7750760b70ba8b0e641146eee1b3a343d1b292
Add three macro to simplify the readability of big bit timing numbers:
- CAN_KBPS: kilobits per second (one thousand)
- CAN_MBPS: megabits per second (one million)
- CAN_MHZ: megahertz per second (one million)
Example:
u32 bitrate_max = 8 * CAN_MBPS;
struct can_clock clock = {.freq = 80 * CAN_MHZ};
instead of:
u32 bitrate_max = 8000000;
struct can_clock clock = {.freq = 80000000};
Apply the new macro to driver/net/can/dev/bittiming.c.
Link: https://lore.kernel.org/r/20210306054040.76483-1-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
can: bittiming: add calculation for CAN FD Transmitter Delay Compensation (TDC)2021-03-30T09:14:45ZVincent Mailhol2021-02-24T00:20:08Zurn:sha1:c25cc7993243fdc00ab7e608e3764819538015ab
The logic for the tdco calculation is to just reuse the normal sample
point: tdco = sp. Because the sample point is expressed in tenth of
percent and the tdco is expressed in time quanta, a conversion is
needed.
At the end,
ssp = tdcv + tdco
= tdcv + sp.
Another popular method is to set tdco to the middle of the bit:
tdc->tdco = can_bit_time(dbt) / 2
During benchmark tests, we could not find a clear advantages for one
of the two methods.
The tdco calculation is triggered each time the data_bittiming is
changed so that users relying on automated calculation can use the
netlink interface the exact same way without need of new parameters.
For example, a command such as:
ip link set canX type can bitrate 500000 dbitrate 4000000 fd on
would trigger the calculation.
The user using CONFIG_CAN_CALC_BITTIMING who does not want automated
calculation needs to manually set tdco to zero.
For example with:
ip link set canX type can tdco 0 bitrate 500000 dbitrate 4000000 fd on
(if the tdco parameter is provided in a previous command, it will be
overwritten).
If tdcv is set to zero (default), it is automatically calculated by
the transiver for each frame. As such, there is no code in the kernel
to calculate it.
tdcf has no automated calculation functions because we could not
figure out a formula for this parameter.
Link: https://lore.kernel.org/r/20210224002008.4158-6-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
can: dev: move bittiming related code into seperate file2021-01-13T08:42:58ZMarc Kleine-Budde2021-01-11T14:19:18Zurn:sha1:5a9d5ecd69ed65fc2d49cdecfc1c1ab1e4d7af34
This patch moves the bittiming related code of the CAN device infrastructure
into a separate file.
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20210111141930.693847-4-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>