From: Marc Kleine-Budde <mkl@pengutronix.de>
To: linux-can@vger.kernel.org
Cc: Thomas Kopp <thomas.kopp@microchip.com>,
kernel@pengutronix.de,
Vincent Mailhol <vincent.mailhol@gmail.com>,
Mark Bath <mark@baggywrinkle.co.uk>,
Marc Kleine-Budde <mkl@pengutronix.de>
Subject: [PATCH v2 03/17] can: bittiming: can_fixup_bittiming(): set effective tq
Date: Thu, 2 Feb 2023 12:08:40 +0100 [thread overview]
Message-ID: <20230202110854.2318594-4-mkl@pengutronix.de> (raw)
In-Reply-To: <20230202110854.2318594-1-mkl@pengutronix.de>
The can_fixup_bittiming() function is used to validate the
user-supplied low-level bit timing parameters and calculate the
bitrate prescaler (brp) from the requested time quanta (tq) and the
CAN clock of the controller.
can_fixup_bittiming() selects the best matching integer bit rate
prescaler, which may result in a different time quantum than the value
specified by the user.
Calculate the resulting time quantum and assign it so that the user
sees the effective time quantum.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
drivers/net/can/dev/bittiming.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/net/can/dev/bittiming.c b/drivers/net/can/dev/bittiming.c
index 5e111dbbe090..e4917c2f34d3 100644
--- a/drivers/net/can/dev/bittiming.c
+++ b/drivers/net/can/dev/bittiming.c
@@ -40,6 +40,8 @@ static int can_fixup_bittiming(const struct net_device *dev, struct can_bittimin
bt->bitrate = priv->clock.freq / (bt->brp * can_bit_time(bt));
bt->sample_point = ((CAN_SYNC_SEG + tseg1) * 1000) / can_bit_time(bt);
+ bt->tq = DIV_U64_ROUND_CLOSEST(mul_u32_u32(bt->brp, NSEC_PER_SEC),
+ priv->clock.freq);
return 0;
}
--
2.39.1
next prev parent reply other threads:[~2023-02-02 11:09 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-02 11:08 [PATCH v2 00/17] can: bittiming: cleanups and rework SJW handling Marc Kleine-Budde
2023-02-02 11:08 ` [PATCH v2 01/17] can: bittiming(): replace open coded variants of can_bit_time() Marc Kleine-Budde
2023-02-02 11:08 ` [PATCH v2 02/17] can: bittiming: can_fixup_bittiming(): use CAN_SYNC_SEG instead of 1 Marc Kleine-Budde
2023-02-02 11:08 ` Marc Kleine-Budde [this message]
2023-02-02 11:08 ` [PATCH v2 04/17] can: bittiming: can_get_bittiming(): use direct return and remove unneeded else Marc Kleine-Budde
2023-02-02 11:08 ` [PATCH v2 05/17] can: dev: register_candev(): ensure that bittiming const are valid Marc Kleine-Budde
2023-02-02 11:08 ` [PATCH v2 06/17] can: dev: register_candev(): bail out if both fixed bit rates and bit timing constants are provided Marc Kleine-Budde
2023-02-02 11:08 ` [PATCH v2 07/17] can: netlink: can_validate(): validate sample point for CAN and CAN-FD Marc Kleine-Budde
2023-02-02 11:08 ` [PATCH v2 08/17] can: netlink: can_changelink(): convert from netdev_err() to NL_SET_ERR_MSG_FMT() Marc Kleine-Budde
2023-02-02 11:08 ` [PATCH v2 09/17] can: bittiming: can_changelink() pass extack down callstack Marc Kleine-Budde
2023-02-02 11:08 ` [PATCH v2 10/17] can: bittiming: factor out can_sjw_set_default() and can_sjw_check() Marc Kleine-Budde
2023-02-02 11:51 ` Vincent Mailhol
2023-02-02 11:53 ` Marc Kleine-Budde
2023-02-02 12:04 ` Vincent Mailhol
2023-02-02 11:08 ` [PATCH v2 11/17] can: bittiming: can_fixup_bittiming(): report error via netlink and harmonize error value Marc Kleine-Budde
2023-02-02 11:08 ` [PATCH v2 12/17] can: bittiming: can_sjw_check(): " Marc Kleine-Budde
2023-02-02 11:08 ` [PATCH v2 13/17] can: bittiming: can_sjw_check(): check that SJW is not longer than either Phase Buffer Segment Marc Kleine-Budde
2023-02-02 11:08 ` [PATCH v2 14/17] can: bittiming: can_sjw_set_default(): use Phase Seg2 / 2 as default for SJW Marc Kleine-Budde
2023-02-02 11:57 ` Vincent Mailhol
2023-02-02 12:07 ` Marc Kleine-Budde
2023-02-06 13:01 ` Marc Kleine-Budde
2023-02-02 11:08 ` [PATCH v2 15/17] can: bittiming: can_calc_bittiming(): clean up SJW handling Marc Kleine-Budde
2023-02-02 11:08 ` [PATCH v2 16/17] can: bittiming: can_calc_bittiming(): convert from netdev_err() to NL_SET_ERR_MSG_FMT() Marc Kleine-Budde
2023-02-02 11:08 ` [PATCH v2 17/17] can: bittiming: can_validate_bitrate(): report error via netlink Marc Kleine-Budde
2023-02-02 12:05 ` [PATCH v2 00/17] can: bittiming: cleanups and rework SJW handling Vincent Mailhol
2023-02-02 12:17 ` Marc Kleine-Budde
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