All of lore.kernel.org
 help / color / mirror / Atom feed
From: Marc Kleine-Budde <mkl@pengutronix.de>
To: linux-can@vger.kernel.org
Cc: kernel@pengutronix.de, michael@walle.cc, qiangqing.zhang@nxp.com,
	Marc Kleine-Budde <mkl@pengutronix.de>
Subject: [PATCH 18/20] can: flexcan: add Transceiver Delay Compensation support
Date: Tue, 22 Sep 2020 16:44:27 +0200	[thread overview]
Message-ID: <20200922144429.2613631-19-mkl@pengutronix.de> (raw)
In-Reply-To: <20200922144429.2613631-1-mkl@pengutronix.de>

From: Joakim Zhang <qiangqing.zhang@nxp.com>

The CAN-FD protocol allows the transmission and reception of data at a
higher bit rate than the nominal rate used in the arbitration phase when
the message's BRS bit is set.

The TDC mechanism is effective only during the data phase of FD frames
having BRS bit set. It has no effect either on non-FD frames, or on FD
frames transmitted at normal bit rate.

Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Link: https://lore.kernel.org/r/20190712075926.7357-7-qiangqing.zhang@nxp.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/flexcan.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index fc0e9d5fd02b..fc98b5d521f2 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -156,6 +156,10 @@
 #define FLEXCAN_FDCTRL_MBDSR_12		0x1
 #define FLEXCAN_FDCTRL_MBDSR_32		0x2
 #define FLEXCAN_FDCTRL_MBDSR_64		0x3
+#define FLEXCAN_FDCTRL_TDCEN		BIT(15)
+#define FLEXCAN_FDCTRL_TDCFAIL		BIT(14)
+#define FLEXCAN_FDCTRL_TDCOFF		GENMASK(12, 8)
+#define FLEXCAN_FDCTRL_TDCVAL		GENMASK(5, 0)
 
 /* FLEXCAN FD Bit Timing register (FDCBT) bits */
 #define FLEXCAN_FDCBT_FPRESDIV_MASK	GENMASK(29, 20)
@@ -1220,11 +1224,24 @@ static void flexcan_set_bittiming_cbt(const struct net_device *dev)
 
 	/* FDCTRL */
 	reg_fdctrl = priv->read(&regs->fdctrl);
-	reg_fdctrl &= ~FLEXCAN_FDCTRL_FDRATE;
+	reg_fdctrl &= ~(FLEXCAN_FDCTRL_FDRATE |
+			FIELD_PREP(FLEXCAN_FDCTRL_TDCOFF, 0x1f));
 
-	if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
+	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
 		reg_fdctrl |= FLEXCAN_FDCTRL_FDRATE;
 
+		if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
+			/* TDC must be disabled for Loop Back mode */
+			reg_fdctrl &= ~FLEXCAN_FDCTRL_TDCEN;
+		} else {
+			reg_fdctrl |= FLEXCAN_FDCTRL_TDCEN |
+				FIELD_PREP(FLEXCAN_FDCTRL_TDCOFF,
+					   ((dbt->phase_seg1 - 1) +
+					    dbt->prop_seg + 2) *
+					   ((dbt->brp - 1 ) + 1));
+		}
+	}
+
 	netdev_dbg(dev, "writing fdctrl=0x%08x\n", reg_fdctrl);
 	priv->write(reg_fdctrl, &regs->fdctrl);
 
-- 
2.28.0


  parent reply	other threads:[~2020-09-22 14:44 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-22 14:44 [RFC]: flexcan FD support - can-next 2020-09-22 Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 01/20] can: flexcan: sort include files alphabetically Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 02/20] can: flexcan: flexcan_exit_stop_mode(): remove stray empty line Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 03/20] can: flexcan: more register names Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 04/20] can: flexcan: struct flexcan_regs: document registers not affected by soft reset Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 05/20] can: flexcan: quirks: get rid of long lines Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 06/20] can: flexcan: Ack wakeup interrupt separately Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 07/20] can: flexcan: flexcan_probe(): make regulator xceiver optional Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 08/20] can: flexcan: Add check for transceiver maximum bitrate limitation Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 09/20] can: flexcan: add correctable errors correction when HW supports ECC Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 10/20] can: flexcan: flexcan_chip_stop(): add error handling and propagate error value Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 11/20] can: flexcan: disable clocks during stop mode Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 12/20] can: flexcan: add LPSR mode support Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 13/20] can: flexcan: flexcan_set_bittiming(): move setup of CAN-2.0 bitiming into separate function Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 14/20] can: flexcan: use struct canfd_frame for CAN classic frame Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 15/20] can: flexcan: add CAN-FD mode support Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 16/20] can: flexcan: add ISO CAN FD feature support Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 17/20] can: flexcan: add CAN FD BRS support Marc Kleine-Budde
2020-09-22 14:44 ` Marc Kleine-Budde [this message]
2020-09-22 14:44 ` [PATCH 19/20] can: flexcan: add imx8qm support Marc Kleine-Budde
2020-09-22 14:44 ` [PATCH 20/20] can: flexcan: add lx2160ar1 support Marc Kleine-Budde
2020-09-23  7:45   ` Michael Walle
2020-09-23  7:54     ` Marc Kleine-Budde
2020-09-23  8:02       ` Michael Walle
2020-09-23  8:10         ` Marc Kleine-Budde
2020-09-23  8:31           ` Joakim Zhang
2020-09-23  8:58             ` Marc Kleine-Budde
2020-09-23  9:38               ` Michael Walle
2020-09-23  9:50               ` Joakim Zhang
2020-09-23  8:53 pull-request: can-next 2020-09-23 Marc Kleine-Budde
2020-09-23  8:54 ` [PATCH 18/20] can: flexcan: add Transceiver Delay Compensation support Marc Kleine-Budde

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200922144429.2613631-19-mkl@pengutronix.de \
    --to=mkl@pengutronix.de \
    --cc=kernel@pengutronix.de \
    --cc=linux-can@vger.kernel.org \
    --cc=michael@walle.cc \
    --cc=qiangqing.zhang@nxp.com \
    --subject='Re: [PATCH 18/20] can: flexcan: add Transceiver Delay Compensation support' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.