diff options
| author | Torin Cooper-Bennun <torin@maxiluxsystems.com> | 2021-03-08 10:24:27 +0000 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2021-03-30 11:14:48 +0200 |
| commit | df06fd678260bca919ea894281ec54ce10e45ce6 (patch) | |
| tree | f8d97c3f0b5ccf562fa43d4ef3b88957506fea4c | |
| parent | 17447f08202d7599a61bc218343b8e7da0a23fa6 (diff) | |
can: m_can: m_can_chip_config(): enable and configure internal timestamps
This is a prerequisite for transitioning the m_can driver to rx-offload,
which works best with TX and RX timestamps.
The timestamps provided by M_CAN are 16-bit, timed according to the
nominal bit timing, and may be prescaled by a multiplier up to 16. We
choose the highest prescalar so that the timestamp wraps every 2^20 bit
times, or 209 ms at a bus speed of 5 Mbit/s. Timestamps will have a
precision of 16 bit times.
Link: https://lore.kernel.org/r/20210308102427.63916-3-torin@maxiluxsystems.com
Signed-off-by: Torin Cooper-Bennun <torin@maxiluxsystems.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
| -rw-r--r-- | drivers/net/can/m_can/m_can.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index 9f7cfe91f7ff..7df81e38b043 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -1135,6 +1135,7 @@ static int m_can_set_bittiming(struct net_device *dev) * - >= v3.1.x: TX FIFO is used * - configure mode * - setup bittiming + * - configure timestamp generation */ static void m_can_chip_config(struct net_device *dev) { @@ -1246,6 +1247,10 @@ static void m_can_chip_config(struct net_device *dev) /* set bittiming params */ m_can_set_bittiming(dev); + /* enable internal timestamp generation, with a prescalar of 16. The + * prescalar is applied to the nominal bit timing */ + m_can_write(cdev, M_CAN_TSCC, FIELD_PREP(TSCC_TCP_MASK, 0xf)); + m_can_config_endisable(cdev, false); if (cdev->ops->init) |