[PATCH net-next 0/10] pull-request: can-next 2025-06-18

[PATCH net-next 0/10] pull-request: can-next 2025-06-18

[Marc Kleine-Budde]

Hello netdev-team,

this is a pull request of 10 patches for net-next/main.

All 10 patches are by Geert Uytterhoeven, target the rcar_canfd
driver, first cleanup/refactor the driver and then add support for
Transceiver Delay Compensation.

regards,
Marc

---
The following changes since commit 6d4e01d29d87356924f1521ca6df7a364e948f13:

  net: Use dev_fwnode() (2025-06-12 18:46:37 -0700)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next.git tags/linux-can-next-for-6.17-20250618

for you to fetch changes up to 1fee0c61317272dd6807fb38a28ee85d00cd1cb4:

  Merge patch series "can: rcar_canfd: Add support for Transceiver Delay Compensation" (2025-06-13 09:34:11 +0200)

----------------------------------------------------------------
linux-can-next-for-6.17-20250618

----------------------------------------------------------------
Geert Uytterhoeven (10):
      can: rcar_canfd: Consistently use ndev for net_device pointers
      can: rcar_canfd: Remove bittiming debug prints
      can: rcar_canfd: Add helper variable ndev to rcar_canfd_rx_pkt()
      can: rcar_canfd: Add helper variable dev to rcar_canfd_reset_controller()
      can: rcar_canfd: Simplify data access in rcar_canfd_{ge,pu}t_data()
      can: rcar_canfd: Repurpose f_dcfg base for other registers
      can: rcar_canfd: Rename rcar_canfd_setrnc() to rcar_canfd_set_rnc()
      can: rcar_canfd: Share config code in rcar_canfd_set_bittiming()
      can: rcar_canfd: Return early in rcar_canfd_set_bittiming() when not FD
      can: rcar_canfd: Add support for Transceiver Delay Compensation

Marc Kleine-Budde (1):
      Merge patch series "can: rcar_canfd: Add support for Transceiver Delay Compensation"

 drivers/net/can/rcar/rcar_canfd.c | 232 ++++++++++++++++++++++++++------------
 1 file changed, 158 insertions(+), 74 deletions(-)

[PATCH net-next 01/10] can: rcar_canfd: Consistently use ndev for net_device pointers

[Marc Kleine-Budde]

From: Geert Uytterhoeven <geert+renesas@glider.be>

Most net_device pointers are named "ndev", but some are called "dev".
Increase uniformity by always using "ndev".

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://patch.msgid.link/7593bdd484a35999030865f90e4c9063b22d2a54.1749655315.git.geert+renesas@glider.be
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/rcar/rcar_canfd.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index 7f10213738e5..2174c9667cab 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -1436,9 +1436,9 @@ static irqreturn_t rcar_canfd_channel_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static void rcar_canfd_set_bittiming(struct net_device *dev)
+static void rcar_canfd_set_bittiming(struct net_device *ndev)
 {
-	struct rcar_canfd_channel *priv = netdev_priv(dev);
+	struct rcar_canfd_channel *priv = netdev_priv(ndev);
 	struct rcar_canfd_global *gpriv = priv->gpriv;
 	const struct can_bittiming *bt = &priv->can.bittiming;
 	const struct can_bittiming *dbt = &priv->can.fd.data_bittiming;
@@ -1818,10 +1818,10 @@ static int rcar_canfd_do_set_mode(struct net_device *ndev, enum can_mode mode)
 	}
 }
 
-static int rcar_canfd_get_berr_counter(const struct net_device *dev,
+static int rcar_canfd_get_berr_counter(const struct net_device *ndev,
 				       struct can_berr_counter *bec)
 {
-	struct rcar_canfd_channel *priv = netdev_priv(dev);
+	struct rcar_canfd_channel *priv = netdev_priv(ndev);
 	u32 val, ch = priv->channel;
 
 	/* Peripheral clock is already enabled in probe */

base-commit: 6d4e01d29d87356924f1521ca6df7a364e948f13
-- 
2.47.2

Re: [PATCH net-next 01/10] can: rcar_canfd: Consistently use ndev for net_device pointers

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Marc Kleine-Budde <mkl@pengutronix.de>:

On Wed, 18 Jun 2025 11:19:55 +0200 you wrote:
> From: Geert Uytterhoeven <geert+renesas@glider.be>
> 
> Most net_device pointers are named "ndev", but some are called "dev".
> Increase uniformity by always using "ndev".
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
> Link: https://patch.msgid.link/7593bdd484a35999030865f90e4c9063b22d2a54.1749655315.git.geert+renesas@glider.be
> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> 
> [...]

Here is the summary with links:
  - [net-next,01/10] can: rcar_canfd: Consistently use ndev for net_device pointers
    https://git.kernel.org/netdev/net-next/c/df6b192e25df
  - [net-next,02/10] can: rcar_canfd: Remove bittiming debug prints
    https://git.kernel.org/netdev/net-next/c/a62781343160
  - [net-next,03/10] can: rcar_canfd: Add helper variable ndev to rcar_canfd_rx_pkt()
    https://git.kernel.org/netdev/net-next/c/4e5974f5515b
  - [net-next,04/10] can: rcar_canfd: Add helper variable dev to rcar_canfd_reset_controller()
    https://git.kernel.org/netdev/net-next/c/1f9b5003d4ba
  - [net-next,05/10] can: rcar_canfd: Simplify data access in rcar_canfd_{ge,pu}t_data()
    https://git.kernel.org/netdev/net-next/c/f5e3150b1a0f
  - [net-next,06/10] can: rcar_canfd: Repurpose f_dcfg base for other registers
    https://git.kernel.org/netdev/net-next/c/e4d8eb97a469
  - [net-next,07/10] can: rcar_canfd: Rename rcar_canfd_setrnc() to rcar_canfd_set_rnc()
    https://git.kernel.org/netdev/net-next/c/1b76dca8fd89
  - [net-next,08/10] can: rcar_canfd: Share config code in rcar_canfd_set_bittiming()
    https://git.kernel.org/netdev/net-next/c/0a0c94c682fd
  - [net-next,09/10] can: rcar_canfd: Return early in rcar_canfd_set_bittiming() when not FD
    https://git.kernel.org/netdev/net-next/c/0acd46190ea2
  - [net-next,10/10] can: rcar_canfd: Add support for Transceiver Delay Compensation
    https://git.kernel.org/netdev/net-next/c/586d5eecdf14

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

[PATCH net-next 02/10] can: rcar_canfd: Remove bittiming debug prints

[Marc Kleine-Budde]

From: Geert Uytterhoeven <geert+renesas@glider.be>

There is no need to have debug code to print the bittiming values, as
the user can get all values through the netlink interface.

Suggested-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://patch.msgid.link/a8b9f2c8938dc5e63b8faf1d0cdc91dadc12117e.1749655315.git.geert+renesas@glider.be
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/rcar/rcar_canfd.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index 2174c9667cab..b353168f75f2 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -1458,8 +1458,6 @@ static void rcar_canfd_set_bittiming(struct net_device *ndev)
 		       RCANFD_NCFG_NSJW(gpriv, sjw) | RCANFD_NCFG_NTSEG2(gpriv, tseg2));
 
 		rcar_canfd_write(priv->base, RCANFD_CCFG(ch), cfg);
-		netdev_dbg(priv->ndev, "nrate: brp %u, sjw %u, tseg1 %u, tseg2 %u\n",
-			   brp, sjw, tseg1, tseg2);
 
 		/* Data bit timing settings */
 		brp = dbt->brp - 1;
@@ -1471,8 +1469,6 @@ static void rcar_canfd_set_bittiming(struct net_device *ndev)
 		       RCANFD_DCFG_DSJW(gpriv, sjw) | RCANFD_DCFG_DTSEG2(gpriv, tseg2));
 
 		rcar_canfd_write(priv->base, RCANFD_F_DCFG(gpriv, ch), cfg);
-		netdev_dbg(priv->ndev, "drate: brp %u, sjw %u, tseg1 %u, tseg2 %u\n",
-			   brp, sjw, tseg1, tseg2);
 	} else {
 		/* Classical CAN only mode */
 		if (gpriv->info->shared_can_regs) {
@@ -1488,9 +1484,6 @@ static void rcar_canfd_set_bittiming(struct net_device *ndev)
 		}
 
 		rcar_canfd_write(priv->base, RCANFD_CCFG(ch), cfg);
-		netdev_dbg(priv->ndev,
-			   "rate: brp %u, sjw %u, tseg1 %u, tseg2 %u\n",
-			   brp, sjw, tseg1, tseg2);
 	}
 }
 
-- 
2.47.2

[PATCH net-next 03/10] can: rcar_canfd: Add helper variable ndev to rcar_canfd_rx_pkt()

[Marc Kleine-Budde]

From: Geert Uytterhoeven <geert+renesas@glider.be>

rcar_canfd_rx_pkt() has many users of "priv->ndev".  Introduce a
shorthand to simplify the code.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://patch.msgid.link/22afe32a65f7c3e64ce3917aec943ac24d6e185a.1749655315.git.geert+renesas@glider.be
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/rcar/rcar_canfd.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index b353168f75f2..ddf3b91d3d2b 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -1684,7 +1684,8 @@ static netdev_tx_t rcar_canfd_start_xmit(struct sk_buff *skb,
 
 static void rcar_canfd_rx_pkt(struct rcar_canfd_channel *priv)
 {
-	struct net_device_stats *stats = &priv->ndev->stats;
+	struct net_device *ndev = priv->ndev;
+	struct net_device_stats *stats = &ndev->stats;
 	struct rcar_canfd_global *gpriv = priv->gpriv;
 	struct canfd_frame *cf;
 	struct sk_buff *skb;
@@ -1700,14 +1701,13 @@ static void rcar_canfd_rx_pkt(struct rcar_canfd_channel *priv)
 
 		if ((priv->can.ctrlmode & CAN_CTRLMODE_FD) &&
 		    sts & RCANFD_RFFDSTS_RFFDF)
-			skb = alloc_canfd_skb(priv->ndev, &cf);
+			skb = alloc_canfd_skb(ndev, &cf);
 		else
-			skb = alloc_can_skb(priv->ndev,
-					    (struct can_frame **)&cf);
+			skb = alloc_can_skb(ndev, (struct can_frame **)&cf);
 	} else {
 		id = rcar_canfd_read(priv->base, RCANFD_C_RFID(ridx));
 		dlc = rcar_canfd_read(priv->base, RCANFD_C_RFPTR(ridx));
-		skb = alloc_can_skb(priv->ndev, (struct can_frame **)&cf);
+		skb = alloc_can_skb(ndev, (struct can_frame **)&cf);
 	}
 
 	if (!skb) {
@@ -1728,7 +1728,7 @@ static void rcar_canfd_rx_pkt(struct rcar_canfd_channel *priv)
 
 		if (sts & RCANFD_RFFDSTS_RFESI) {
 			cf->flags |= CANFD_ESI;
-			netdev_dbg(priv->ndev, "ESI Error\n");
+			netdev_dbg(ndev, "ESI Error\n");
 		}
 
 		if (!(sts & RCANFD_RFFDSTS_RFFDF) && (id & RCANFD_RFID_RFRTR)) {
-- 
2.47.2

[PATCH net-next 04/10] can: rcar_canfd: Add helper variable dev to rcar_canfd_reset_controller()

[Marc Kleine-Budde]

From: Geert Uytterhoeven <geert+renesas@glider.be>

rcar_canfd_reset_controller() has many users of "pdev->dev".  Introduce
a shorthand to simplify the code.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://patch.msgid.link/21e64816808eb3eba722f4c547f4f5112d5d62a6.1749655315.git.geert+renesas@glider.be
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/rcar/rcar_canfd.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index ddf3b91d3d2b..3244584a6ee5 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -841,6 +841,7 @@ static void rcar_canfd_set_mode(struct rcar_canfd_global *gpriv)
 
 static int rcar_canfd_reset_controller(struct rcar_canfd_global *gpriv)
 {
+	struct device *dev = &gpriv->pdev->dev;
 	u32 sts, ch;
 	int err;
 
@@ -850,7 +851,7 @@ static int rcar_canfd_reset_controller(struct rcar_canfd_global *gpriv)
 	err = readl_poll_timeout((gpriv->base + RCANFD_GSTS), sts,
 				 !(sts & RCANFD_GSTS_GRAMINIT), 2, 500000);
 	if (err) {
-		dev_dbg(&gpriv->pdev->dev, "global raminit failed\n");
+		dev_dbg(dev, "global raminit failed\n");
 		return err;
 	}
 
@@ -863,7 +864,7 @@ static int rcar_canfd_reset_controller(struct rcar_canfd_global *gpriv)
 	err = readl_poll_timeout((gpriv->base + RCANFD_GSTS), sts,
 				 (sts & RCANFD_GSTS_GRSTSTS), 2, 500000);
 	if (err) {
-		dev_dbg(&gpriv->pdev->dev, "global reset failed\n");
+		dev_dbg(dev, "global reset failed\n");
 		return err;
 	}
 
@@ -887,8 +888,7 @@ static int rcar_canfd_reset_controller(struct rcar_canfd_global *gpriv)
 					 (sts & RCANFD_CSTS_CRSTSTS),
 					 2, 500000);
 		if (err) {
-			dev_dbg(&gpriv->pdev->dev,
-				"channel %u reset failed\n", ch);
+			dev_dbg(dev, "channel %u reset failed\n", ch);
 			return err;
 		}
 	}
-- 
2.47.2

[PATCH net-next 05/10] can: rcar_canfd: Simplify data access in rcar_canfd_{ge,pu}t_data()

[Marc Kleine-Budde]

From: Geert Uytterhoeven <geert+renesas@glider.be>

Replace the repeated casts, pointer additions, and pointer dereferences
by array accesses to improve readability.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://patch.msgid.link/4f43f44dcfda13d48a2c502648833934a51d9d6c.1749655315.git.geert+renesas@glider.be
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/rcar/rcar_canfd.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index 3244584a6ee5..dded509793bb 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -781,23 +781,23 @@ static void rcar_canfd_update_bit(void __iomem *base, u32 reg,
 static void rcar_canfd_get_data(struct rcar_canfd_channel *priv,
 				struct canfd_frame *cf, u32 off)
 {
+	u32 *data = (u32 *)cf->data;
 	u32 i, lwords;
 
 	lwords = DIV_ROUND_UP(cf->len, sizeof(u32));
 	for (i = 0; i < lwords; i++)
-		*((u32 *)cf->data + i) =
-			rcar_canfd_read(priv->base, off + i * sizeof(u32));
+		data[i] = rcar_canfd_read(priv->base, off + i * sizeof(u32));
 }
 
 static void rcar_canfd_put_data(struct rcar_canfd_channel *priv,
 				struct canfd_frame *cf, u32 off)
 {
+	const u32 *data = (u32 *)cf->data;
 	u32 i, lwords;
 
 	lwords = DIV_ROUND_UP(cf->len, sizeof(u32));
 	for (i = 0; i < lwords; i++)
-		rcar_canfd_write(priv->base, off + i * sizeof(u32),
-				 *((u32 *)cf->data + i));
+		rcar_canfd_write(priv->base, off + i * sizeof(u32), data[i]);
 }
 
 static void rcar_canfd_tx_failure_cleanup(struct net_device *ndev)
-- 
2.47.2

[PATCH net-next 06/10] can: rcar_canfd: Repurpose f_dcfg base for other registers

[Marc Kleine-Budde]

From: Geert Uytterhoeven <geert+renesas@glider.be>

Reuse the existing Channel Data Bitrate Configuration Register offset
member in the register configuration as the base offset for all related
channel-specific registers.
Rename the member and update the (incorrect) comment to reflect this.
Replace the function-like channel-specific register offset macros by
inline functions.

This fixes the offsets of all other (currently unused) channel-specific
registers on R-Car Gen4 and RZ/G3E, and allows us to replace
RCANFD_GEN4_FDCFG() by the more generic rcar_canfd_f_cfdcfg().

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://patch.msgid.link/75c8197c849fc9e360a75d4fa55bc01c1d850433.1749655315.git.geert+renesas@glider.be
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/rcar/rcar_canfd.c | 52 ++++++++++++++++++++++---------
 1 file changed, 37 insertions(+), 15 deletions(-)

diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index dded509793bb..8baf8a928da7 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -425,19 +425,10 @@
 #define RCANFD_C_RPGACC(r)		(0x1900 + (0x04 * (r)))
 
 /* R-Car Gen4 Classical and CAN FD mode specific register map */
-#define RCANFD_GEN4_FDCFG(m)		(0x1404 + (0x20 * (m)))
-
 #define RCANFD_GEN4_GAFL_OFFSET		(0x1800)
 
 /* CAN FD mode specific register map */
 
-/* RSCFDnCFDCmXXX -> RCANFD_F_XXX(m) */
-#define RCANFD_F_DCFG(gpriv, m)		((gpriv)->info->regs->f_dcfg + (0x20 * (m)))
-#define RCANFD_F_CFDCFG(m)		(0x0504 + (0x20 * (m)))
-#define RCANFD_F_CFDCTR(m)		(0x0508 + (0x20 * (m)))
-#define RCANFD_F_CFDSTS(m)		(0x050c + (0x20 * (m)))
-#define RCANFD_F_CFDCRC(m)		(0x0510 + (0x20 * (m)))
-
 /* RSCFDnCFDGAFLXXXj offset */
 #define RCANFD_F_GAFL_OFFSET		(0x1000)
 
@@ -510,7 +501,7 @@ struct rcar_canfd_regs {
 	u16 cfcc;	/* Common FIFO Configuration/Control Register */
 	u16 cfsts;	/* Common FIFO Status Register */
 	u16 cfpctr;	/* Common FIFO Pointer Control Register */
-	u16 f_dcfg;	/* Global FD Configuration Register */
+	u16 coffset;	/* Channel Data Bitrate Configuration Register */
 	u16 rfoffset;	/* Receive FIFO buffer access ID register */
 	u16 cfoffset;	/* Transmit/receive FIFO buffer access ID register */
 };
@@ -641,7 +632,7 @@ static const struct rcar_canfd_regs rcar_gen3_regs = {
 	.cfcc = 0x0118,
 	.cfsts = 0x0178,
 	.cfpctr = 0x01d8,
-	.f_dcfg = 0x0500,
+	.coffset = 0x0500,
 	.rfoffset = 0x3000,
 	.cfoffset = 0x3400,
 };
@@ -651,7 +642,7 @@ static const struct rcar_canfd_regs rcar_gen4_regs = {
 	.cfcc = 0x0120,
 	.cfsts = 0x01e0,
 	.cfpctr = 0x0240,
-	.f_dcfg = 0x1400,
+	.coffset = 0x1400,
 	.rfoffset = 0x6000,
 	.cfoffset = 0x6400,
 };
@@ -800,6 +791,37 @@ static void rcar_canfd_put_data(struct rcar_canfd_channel *priv,
 		rcar_canfd_write(priv->base, off + i * sizeof(u32), data[i]);
 }
 
+/* RSCFDnCFDCmXXX -> rcar_canfd_f_xxx(gpriv, ch) */
+static inline unsigned int rcar_canfd_f_dcfg(struct rcar_canfd_global *gpriv,
+					     unsigned int ch)
+{
+	return gpriv->info->regs->coffset + 0x00 + 0x20 * ch;
+}
+
+static inline unsigned int rcar_canfd_f_cfdcfg(struct rcar_canfd_global *gpriv,
+					       unsigned int ch)
+{
+	return gpriv->info->regs->coffset + 0x04 + 0x20 * ch;
+}
+
+static inline unsigned int rcar_canfd_f_cfdctr(struct rcar_canfd_global *gpriv,
+					       unsigned int ch)
+{
+	return gpriv->info->regs->coffset + 0x08 + 0x20 * ch;
+}
+
+static inline unsigned int rcar_canfd_f_cfdsts(struct rcar_canfd_global *gpriv,
+					       unsigned int ch)
+{
+	return gpriv->info->regs->coffset + 0x0c + 0x20 * ch;
+}
+
+static inline unsigned int rcar_canfd_f_cfdcrc(struct rcar_canfd_global *gpriv,
+					       unsigned int ch)
+{
+	return gpriv->info->regs->coffset + 0x10 + 0x20 * ch;
+}
+
 static void rcar_canfd_tx_failure_cleanup(struct net_device *ndev)
 {
 	u32 i;
@@ -827,8 +849,8 @@ static void rcar_canfd_set_mode(struct rcar_canfd_global *gpriv)
 
 		for_each_set_bit(ch, &gpriv->channels_mask,
 				 gpriv->info->max_channels)
-			rcar_canfd_set_bit(gpriv->base, RCANFD_GEN4_FDCFG(ch),
-					   val);
+			rcar_canfd_set_bit(gpriv->base,
+					   rcar_canfd_f_cfdcfg(gpriv, ch), val);
 	} else {
 		if (gpriv->fdmode)
 			rcar_canfd_set_bit(gpriv->base, RCANFD_GRMCFG,
@@ -1468,7 +1490,7 @@ static void rcar_canfd_set_bittiming(struct net_device *ndev)
 		cfg = (RCANFD_DCFG_DTSEG1(gpriv, tseg1) | RCANFD_DCFG_DBRP(brp) |
 		       RCANFD_DCFG_DSJW(gpriv, sjw) | RCANFD_DCFG_DTSEG2(gpriv, tseg2));
 
-		rcar_canfd_write(priv->base, RCANFD_F_DCFG(gpriv, ch), cfg);
+		rcar_canfd_write(priv->base, rcar_canfd_f_dcfg(gpriv, ch), cfg);
 	} else {
 		/* Classical CAN only mode */
 		if (gpriv->info->shared_can_regs) {
-- 
2.47.2

Re: [PATCH net-next 06/10] can: rcar_canfd: Repurpose f_dcfg base for other registers

[Jakub Kicinski]

On Wed, 18 Jun 2025 11:20:00 +0200 Marc Kleine-Budde wrote:
> +static inline unsigned int rcar_canfd_f_dcfg(struct rcar_canfd_global *gpriv,
> +					     unsigned int ch)
> +{
> +	return gpriv->info->regs->coffset + 0x00 + 0x20 * ch;
> +}
> +
> +static inline unsigned int rcar_canfd_f_cfdcfg(struct rcar_canfd_global *gpriv,
> +					       unsigned int ch)
> +{
> +	return gpriv->info->regs->coffset + 0x04 + 0x20 * ch;
> +}
> +
> +static inline unsigned int rcar_canfd_f_cfdctr(struct rcar_canfd_global *gpriv,
> +					       unsigned int ch)
> +{
> +	return gpriv->info->regs->coffset + 0x08 + 0x20 * ch;
> +}
> +
> +static inline unsigned int rcar_canfd_f_cfdsts(struct rcar_canfd_global *gpriv,
> +					       unsigned int ch)
> +{
> +	return gpriv->info->regs->coffset + 0x0c + 0x20 * ch;
> +}
> +
> +static inline unsigned int rcar_canfd_f_cfdcrc(struct rcar_canfd_global *gpriv,
> +					       unsigned int ch)
> +{
> +	return gpriv->info->regs->coffset + 0x10 + 0x20 * ch;
> +}

clang is no longer fooled by static inline, it identifies that 4 out of
these functions are never called. I think one ends up getting used in
patch 10 (just looking at warning counts), but the other 3 remain dead
code. Geert, do you have a strong attachment to having all helpers
defined or can we trim this, please?

Re: [PATCH net-next 06/10] can: rcar_canfd: Repurpose f_dcfg base for other registers

[Vincent Mailhol]

Hi Jakub,

On Thu. 19 Jun. 2025 at 10:38, Jakub Kicinski <kuba@kernel.org> wrote:
> On Wed, 18 Jun 2025 11:20:00 +0200 Marc Kleine-Budde wrote:
> > +static inline unsigned int rcar_canfd_f_dcfg(struct rcar_canfd_global *gpriv,
> > +                                          unsigned int ch)
> > +{
> > +     return gpriv->info->regs->coffset + 0x00 + 0x20 * ch;
> > +}
> > +
> > +static inline unsigned int rcar_canfd_f_cfdcfg(struct rcar_canfd_global *gpriv,
> > +                                            unsigned int ch)
> > +{
> > +     return gpriv->info->regs->coffset + 0x04 + 0x20 * ch;
> > +}
> > +
> > +static inline unsigned int rcar_canfd_f_cfdctr(struct rcar_canfd_global *gpriv,
> > +                                            unsigned int ch)
> > +{
> > +     return gpriv->info->regs->coffset + 0x08 + 0x20 * ch;
> > +}
> > +
> > +static inline unsigned int rcar_canfd_f_cfdsts(struct rcar_canfd_global *gpriv,
> > +                                            unsigned int ch)
> > +{
> > +     return gpriv->info->regs->coffset + 0x0c + 0x20 * ch;
> > +}
> > +
> > +static inline unsigned int rcar_canfd_f_cfdcrc(struct rcar_canfd_global *gpriv,
> > +                                            unsigned int ch)
> > +{
> > +     return gpriv->info->regs->coffset + 0x10 + 0x20 * ch;
> > +}
>
> clang is no longer fooled by static inline, it identifies that 4 out of
> these functions are never called. I think one ends up getting used in
> patch 10 (just looking at warning counts), but the other 3 remain dead
> code. Geert, do you have a strong attachment to having all helpers
> defined or can we trim this, please?

I had a discussion with Geert on these functions here:

https://lore.kernel.org/linux-can/20250613-misty-amethyst-swine-7bd775-mkl@pengutronix.de/t/#mef5cb235313c5f0c4910d5571b052eb5e9ada92e

in which I made a suggestion to reword these. That suggestion would
actually resolve your concerns. Geert was OK with the suggestion but
we agreed to move on as-is and make those changes later on.

If temporarily having those static inline functions unused is not a
big blocker for you, can we just have this merged and wait for the
bigger refactor which is on Geert TODO’s list?


Yours sincerely,
Vincent Mailhol

Re: [PATCH net-next 06/10] can: rcar_canfd: Repurpose f_dcfg base for other registers

[Geert Uytterhoeven]

Hi Vincent, Jakub,

On Thu, 19 Jun 2025 at 06:43, Vincent Mailhol
<mailhol.vincent@wanadoo.fr> wrote:
> On Thu. 19 Jun. 2025 at 10:38, Jakub Kicinski <kuba@kernel.org> wrote:
> > On Wed, 18 Jun 2025 11:20:00 +0200 Marc Kleine-Budde wrote:
> > > +static inline unsigned int rcar_canfd_f_dcfg(struct rcar_canfd_global *gpriv,
> > > +                                          unsigned int ch)
> > > +{
> > > +     return gpriv->info->regs->coffset + 0x00 + 0x20 * ch;
> > > +}
> > > +
> > > +static inline unsigned int rcar_canfd_f_cfdcfg(struct rcar_canfd_global *gpriv,
> > > +                                            unsigned int ch)
> > > +{
> > > +     return gpriv->info->regs->coffset + 0x04 + 0x20 * ch;
> > > +}
> > > +
> > > +static inline unsigned int rcar_canfd_f_cfdctr(struct rcar_canfd_global *gpriv,
> > > +                                            unsigned int ch)
> > > +{
> > > +     return gpriv->info->regs->coffset + 0x08 + 0x20 * ch;
> > > +}
> > > +
> > > +static inline unsigned int rcar_canfd_f_cfdsts(struct rcar_canfd_global *gpriv,
> > > +                                            unsigned int ch)
> > > +{
> > > +     return gpriv->info->regs->coffset + 0x0c + 0x20 * ch;
> > > +}
> > > +
> > > +static inline unsigned int rcar_canfd_f_cfdcrc(struct rcar_canfd_global *gpriv,
> > > +                                            unsigned int ch)
> > > +{
> > > +     return gpriv->info->regs->coffset + 0x10 + 0x20 * ch;
> > > +}
> >
> > clang is no longer fooled by static inline, it identifies that 4 out of

Oh well, that explains why someone pointed to a CI log showing more
unused functions in a different driver.  I hope it only does that
for unused functions in .c files, not in header files?

> > these functions are never called. I think one ends up getting used in
> > patch 10 (just looking at warning counts), but the other 3 remain dead
> > code. Geert, do you have a strong attachment to having all helpers
> > defined or can we trim this, please?

I would like to keep them (or at least the information), as it serves
as register documentation, just like the macros they replaced....

> I had a discussion with Geert on these functions here:
>
> https://lore.kernel.org/linux-can/20250613-misty-amethyst-swine-7bd775-mkl@pengutronix.de/t/#mef5cb235313c5f0c4910d5571b052eb5e9ada92e
>
> in which I made a suggestion to reword these. That suggestion would
> actually resolve your concerns. Geert was OK with the suggestion but
> we agreed to move on as-is and make those changes later on.
>
> If temporarily having those static inline functions unused is not a
> big blocker for you, can we just have this merged and wait for the
> bigger refactor which is on Geert TODO’s list?

I am still working on converting more ugly macros (while increasing
functionality, and fixing bugs ^-).  But given the clang warnings,
I agree it would be good to fast-track the first conversion.

Patch sent: "[PATCH] can: rcar_canfd: Describe channel-specific FD
registers using C struct"
https://lore.kernel.org/292b75b3bc8dd95f805f0223f606737071c8cf86.1750327217.git.geert+renesas@glider.be

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH net-next 06/10] can: rcar_canfd: Repurpose f_dcfg base for other registers

[Jakub Kicinski]

On Thu, 19 Jun 2025 12:16:00 +0200 Geert Uytterhoeven wrote:
> On Thu, 19 Jun 2025 at 06:43, Vincent Mailhol <mailhol.vincent@wanadoo.fr> wrote:
> > On Thu. 19 Jun. 2025 at 10:38, Jakub Kicinski <kuba@kernel.org> wrote:  
> > > On Wed, 18 Jun 2025 11:20:00 +0200 Marc Kleine-Budde wrote:  
> > > > +static inline unsigned int rcar_canfd_f_cfdcrc(struct rcar_canfd_global *gpriv,
> > > > +                                            unsigned int ch)
> > > > +{
> > > > +     return gpriv->info->regs->coffset + 0x10 + 0x20 * ch;
> > > > +}  
> > >
> > > clang is no longer fooled by static inline, it identifies that 4 out of  
> 
> Oh well, that explains why someone pointed to a CI log showing more
> unused functions in a different driver.  I hope it only does that
> for unused functions in .c files, not in header files?

Yes, AFAIU it's clever enough to distinguish what came in from 
the headers.

> > > these functions are never called. I think one ends up getting used in
> > > patch 10 (just looking at warning counts), but the other 3 remain dead
> > > code. Geert, do you have a strong attachment to having all helpers
> > > defined or can we trim this, please?  
> 
> I would like to keep them (or at least the information), as it serves
> as register documentation, just like the macros they replaced....

Okay, we'll pull, but we really should try to keep the tree free of W=1
warnings. The CI can deal with existing warnings but they will annoy
humans doing development. Maybe there is a way to disable the warning
selectively for rcar if you find it unhelpful? And then we'll see if
some well meaning code janitor sends a patch to delete them anyway ;)

[PATCH net-next 07/10] can: rcar_canfd: Rename rcar_canfd_setrnc() to rcar_canfd_set_rnc()

[Marc Kleine-Budde]

From: Geert Uytterhoeven <geert+renesas@glider.be>

Insert an underscore in the function's name, for consistency with other
getter and setter helper functions.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://patch.msgid.link/9fdc2584ce27b2784ecea76390d2a81eab289d0d.1749655315.git.geert+renesas@glider.be
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/rcar/rcar_canfd.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index 8baf8a928da7..c292694ae4d2 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -830,8 +830,8 @@ static void rcar_canfd_tx_failure_cleanup(struct net_device *ndev)
 		can_free_echo_skb(ndev, i, NULL);
 }
 
-static void rcar_canfd_setrnc(struct rcar_canfd_global *gpriv, unsigned int ch,
-			      unsigned int num_rules)
+static void rcar_canfd_set_rnc(struct rcar_canfd_global *gpriv, unsigned int ch,
+			       unsigned int num_rules)
 {
 	unsigned int rnc_stride = 32 / gpriv->info->rnc_field_width;
 	unsigned int shift = 32 - (ch % rnc_stride + 1) * gpriv->info->rnc_field_width;
@@ -960,7 +960,7 @@ static void rcar_canfd_configure_afl_rules(struct rcar_canfd_global *gpriv,
 			    RCANFD_GAFLECTR_AFLDAE));
 
 	/* Write number of rules for channel */
-	rcar_canfd_setrnc(gpriv, ch, num_rules);
+	rcar_canfd_set_rnc(gpriv, ch, num_rules);
 	if (gpriv->info->shared_can_regs)
 		offset = RCANFD_GEN4_GAFL_OFFSET;
 	else if (gpriv->fdmode)
-- 
2.47.2

[PATCH net-next 08/10] can: rcar_canfd: Share config code in rcar_canfd_set_bittiming()

[Marc Kleine-Budde]

From: Geert Uytterhoeven <geert+renesas@glider.be>

The configuration register format for nominal bit timings in CAN-FD mode
and the format for bit timings in CAN mode on CAN-FD controllers with
shared Classical CAN registers are the same.

Restructure the code to make this clear, also reducing kernel size by 80
bytes.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://patch.msgid.link/b7643a3c49777989d02145a85b85cf773ec2123f.1749655315.git.geert+renesas@glider.be
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/rcar/rcar_canfd.c | 25 +++++++------------------
 1 file changed, 7 insertions(+), 18 deletions(-)

diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index c292694ae4d2..9ee49ef57e4f 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -1474,13 +1474,17 @@ static void rcar_canfd_set_bittiming(struct net_device *ndev)
 	tseg1 = bt->prop_seg + bt->phase_seg1 - 1;
 	tseg2 = bt->phase_seg2 - 1;
 
-	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
-		/* CAN FD only mode */
+	if ((priv->can.ctrlmode & CAN_CTRLMODE_FD) || gpriv->info->shared_can_regs) {
 		cfg = (RCANFD_NCFG_NTSEG1(gpriv, tseg1) | RCANFD_NCFG_NBRP(brp) |
 		       RCANFD_NCFG_NSJW(gpriv, sjw) | RCANFD_NCFG_NTSEG2(gpriv, tseg2));
+	} else {
+		cfg = (RCANFD_CFG_TSEG1(tseg1) | RCANFD_CFG_BRP(brp) |
+		       RCANFD_CFG_SJW(sjw) | RCANFD_CFG_TSEG2(tseg2));
+	}
 
-		rcar_canfd_write(priv->base, RCANFD_CCFG(ch), cfg);
+	rcar_canfd_write(priv->base, RCANFD_CCFG(ch), cfg);
 
+	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
 		/* Data bit timing settings */
 		brp = dbt->brp - 1;
 		sjw = dbt->sjw - 1;
@@ -1491,21 +1495,6 @@ static void rcar_canfd_set_bittiming(struct net_device *ndev)
 		       RCANFD_DCFG_DSJW(gpriv, sjw) | RCANFD_DCFG_DTSEG2(gpriv, tseg2));
 
 		rcar_canfd_write(priv->base, rcar_canfd_f_dcfg(gpriv, ch), cfg);
-	} else {
-		/* Classical CAN only mode */
-		if (gpriv->info->shared_can_regs) {
-			cfg = (RCANFD_NCFG_NTSEG1(gpriv, tseg1) |
-			       RCANFD_NCFG_NBRP(brp) |
-			       RCANFD_NCFG_NSJW(gpriv, sjw) |
-			       RCANFD_NCFG_NTSEG2(gpriv, tseg2));
-		} else {
-			cfg = (RCANFD_CFG_TSEG1(tseg1) |
-			       RCANFD_CFG_BRP(brp) |
-			       RCANFD_CFG_SJW(sjw) |
-			       RCANFD_CFG_TSEG2(tseg2));
-		}
-
-		rcar_canfd_write(priv->base, RCANFD_CCFG(ch), cfg);
 	}
 }
 
-- 
2.47.2

[PATCH net-next 09/10] can: rcar_canfd: Return early in rcar_canfd_set_bittiming() when not FD

[Marc Kleine-Budde]

From: Geert Uytterhoeven <geert+renesas@glider.be>

Return early after completing all setup for non-FD mode in
rcar_canfd_set_bittiming(), to prepare for the advent of more FD-only
setup.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://patch.msgid.link/35fcdcad026cfdd0fd361637f065842d99a6c19d.1749655315.git.geert+renesas@glider.be
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/rcar/rcar_canfd.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index 9ee49ef57e4f..3340ae75bbec 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -1484,18 +1484,19 @@ static void rcar_canfd_set_bittiming(struct net_device *ndev)
 
 	rcar_canfd_write(priv->base, RCANFD_CCFG(ch), cfg);
 
-	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
-		/* Data bit timing settings */
-		brp = dbt->brp - 1;
-		sjw = dbt->sjw - 1;
-		tseg1 = dbt->prop_seg + dbt->phase_seg1 - 1;
-		tseg2 = dbt->phase_seg2 - 1;
+	if (!(priv->can.ctrlmode & CAN_CTRLMODE_FD))
+		return;
 
-		cfg = (RCANFD_DCFG_DTSEG1(gpriv, tseg1) | RCANFD_DCFG_DBRP(brp) |
-		       RCANFD_DCFG_DSJW(gpriv, sjw) | RCANFD_DCFG_DTSEG2(gpriv, tseg2));
+	/* Data bit timing settings */
+	brp = dbt->brp - 1;
+	sjw = dbt->sjw - 1;
+	tseg1 = dbt->prop_seg + dbt->phase_seg1 - 1;
+	tseg2 = dbt->phase_seg2 - 1;
 
-		rcar_canfd_write(priv->base, rcar_canfd_f_dcfg(gpriv, ch), cfg);
-	}
+	cfg = (RCANFD_DCFG_DTSEG1(gpriv, tseg1) | RCANFD_DCFG_DBRP(brp) |
+	       RCANFD_DCFG_DSJW(gpriv, sjw) | RCANFD_DCFG_DTSEG2(gpriv, tseg2));
+
+	rcar_canfd_write(priv->base, rcar_canfd_f_dcfg(gpriv, ch), cfg);
 }
 
 static int rcar_canfd_start(struct net_device *ndev)
-- 
2.47.2

[PATCH net-next 10/10] can: rcar_canfd: Add support for Transceiver Delay Compensation

[Marc Kleine-Budde]

From: Geert Uytterhoeven <geert+renesas@glider.be>

The Renesas CAN-FD hardware block supports configuring Transceiver Delay
Compensation, and reading back the Transceiver Delay Compensation
Result, which is needed to support high transfer rates like 8 Mbps.
The Secondary Sample Point is either the measured delay plus the
configured offset, or just the configured offset.

Fix the existing RCANFD_FDCFG_TDCO() macro for the intended use case
(writing instead of reading the field).  Add register definition bits
for the Channel n CAN-FD Status Register.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://patch.msgid.link/69db727d5f728d679ba691d20854e7d963d0f323.1749655315.git.geert+renesas@glider.be
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/rcar/rcar_canfd.c | 85 +++++++++++++++++++++++++++++--
 1 file changed, 82 insertions(+), 3 deletions(-)

diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index 3340ae75bbec..1e559c0ff038 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -191,9 +191,19 @@
 /* RSCFDnCFDCmFDCFG */
 #define RCANFD_GEN4_FDCFG_CLOE		BIT(30)
 #define RCANFD_GEN4_FDCFG_FDOE		BIT(28)
+#define RCANFD_FDCFG_TDCO		GENMASK(23, 16)
 #define RCANFD_FDCFG_TDCE		BIT(9)
 #define RCANFD_FDCFG_TDCOC		BIT(8)
-#define RCANFD_FDCFG_TDCO(x)		(((x) & 0x7f) >> 16)
+
+/* RSCFDnCFDCmFDSTS */
+#define RCANFD_FDSTS_SOC		GENMASK(31, 24)
+#define RCANFD_FDSTS_EOC		GENMASK(23, 16)
+#define RCANFD_GEN4_FDSTS_TDCVF		BIT(15)
+#define RCANFD_GEN4_FDSTS_PNSTS		GENMASK(13, 12)
+#define RCANFD_FDSTS_SOCO		BIT(9)
+#define RCANFD_FDSTS_EOCO		BIT(8)
+#define RCANFD_FDSTS_TDCVF		BIT(7)
+#define RCANFD_FDSTS_TDCR		GENMASK(7, 0)
 
 /* RSCFDnCFDRFCCx */
 #define RCANFD_RFCC_RFIM		BIT(12)
@@ -520,6 +530,7 @@ struct rcar_canfd_shift_data {
 struct rcar_canfd_hw_info {
 	const struct can_bittiming_const *nom_bittiming;
 	const struct can_bittiming_const *data_bittiming;
+	const struct can_tdc_const *tdc_const;
 	const struct rcar_canfd_regs *regs;
 	const struct rcar_canfd_shift_data *sh;
 	u8 rnc_field_width;
@@ -627,6 +638,25 @@ static const struct can_bittiming_const rcar_canfd_bittiming_const = {
 	.brp_inc = 1,
 };
 
+/* CAN FD Transmission Delay Compensation constants */
+static const struct can_tdc_const rcar_canfd_gen3_tdc_const = {
+	.tdcv_min = 1,
+	.tdcv_max = 128,
+	.tdco_min = 1,
+	.tdco_max = 128,
+	.tdcf_min = 0,	/* Filter window not supported */
+	.tdcf_max = 0,
+};
+
+static const struct can_tdc_const rcar_canfd_gen4_tdc_const = {
+	.tdcv_min = 1,
+	.tdcv_max = 256,
+	.tdco_min = 1,
+	.tdco_max = 256,
+	.tdcf_min = 0,	/* Filter window not supported */
+	.tdcf_max = 0,
+};
+
 static const struct rcar_canfd_regs rcar_gen3_regs = {
 	.rfcc = 0x00b8,
 	.cfcc = 0x0118,
@@ -672,6 +702,7 @@ static const struct rcar_canfd_shift_data rcar_gen4_shift_data = {
 static const struct rcar_canfd_hw_info rcar_gen3_hw_info = {
 	.nom_bittiming = &rcar_canfd_gen3_nom_bittiming_const,
 	.data_bittiming = &rcar_canfd_gen3_data_bittiming_const,
+	.tdc_const = &rcar_canfd_gen3_tdc_const,
 	.regs = &rcar_gen3_regs,
 	.sh = &rcar_gen3_shift_data,
 	.rnc_field_width = 8,
@@ -688,6 +719,7 @@ static const struct rcar_canfd_hw_info rcar_gen3_hw_info = {
 static const struct rcar_canfd_hw_info rcar_gen4_hw_info = {
 	.nom_bittiming = &rcar_canfd_gen4_nom_bittiming_const,
 	.data_bittiming = &rcar_canfd_gen4_data_bittiming_const,
+	.tdc_const = &rcar_canfd_gen4_tdc_const,
 	.regs = &rcar_gen4_regs,
 	.sh = &rcar_gen4_shift_data,
 	.rnc_field_width = 16,
@@ -704,6 +736,7 @@ static const struct rcar_canfd_hw_info rcar_gen4_hw_info = {
 static const struct rcar_canfd_hw_info rzg2l_hw_info = {
 	.nom_bittiming = &rcar_canfd_gen3_nom_bittiming_const,
 	.data_bittiming = &rcar_canfd_gen3_data_bittiming_const,
+	.tdc_const = &rcar_canfd_gen3_tdc_const,
 	.regs = &rcar_gen3_regs,
 	.sh = &rcar_gen3_shift_data,
 	.rnc_field_width = 8,
@@ -720,6 +753,7 @@ static const struct rcar_canfd_hw_info rzg2l_hw_info = {
 static const struct rcar_canfd_hw_info r9a09g047_hw_info = {
 	.nom_bittiming = &rcar_canfd_gen4_nom_bittiming_const,
 	.data_bittiming = &rcar_canfd_gen4_data_bittiming_const,
+	.tdc_const = &rcar_canfd_gen4_tdc_const,
 	.regs = &rcar_gen4_regs,
 	.sh = &rcar_gen4_shift_data,
 	.rnc_field_width = 16,
@@ -1460,12 +1494,15 @@ static irqreturn_t rcar_canfd_channel_interrupt(int irq, void *dev_id)
 
 static void rcar_canfd_set_bittiming(struct net_device *ndev)
 {
+	u32 mask = RCANFD_FDCFG_TDCO | RCANFD_FDCFG_TDCE | RCANFD_FDCFG_TDCOC;
 	struct rcar_canfd_channel *priv = netdev_priv(ndev);
 	struct rcar_canfd_global *gpriv = priv->gpriv;
 	const struct can_bittiming *bt = &priv->can.bittiming;
 	const struct can_bittiming *dbt = &priv->can.fd.data_bittiming;
+	const struct can_tdc_const *tdc_const = priv->can.fd.tdc_const;
+	const struct can_tdc *tdc = &priv->can.fd.tdc;
+	u32 cfg, tdcmode = 0, tdco = 0;
 	u16 brp, sjw, tseg1, tseg2;
-	u32 cfg;
 	u32 ch = priv->channel;
 
 	/* Nominal bit timing settings */
@@ -1497,6 +1534,20 @@ static void rcar_canfd_set_bittiming(struct net_device *ndev)
 	       RCANFD_DCFG_DSJW(gpriv, sjw) | RCANFD_DCFG_DTSEG2(gpriv, tseg2));
 
 	rcar_canfd_write(priv->base, rcar_canfd_f_dcfg(gpriv, ch), cfg);
+
+	/* Transceiver Delay Compensation */
+	if (priv->can.ctrlmode & CAN_CTRLMODE_TDC_AUTO) {
+		/* TDC enabled, measured + offset */
+		tdcmode = RCANFD_FDCFG_TDCE;
+		tdco = tdc->tdco - 1;
+	} else if (priv->can.ctrlmode & CAN_CTRLMODE_TDC_MANUAL) {
+		/* TDC enabled, offset only */
+		tdcmode = RCANFD_FDCFG_TDCE | RCANFD_FDCFG_TDCOC;
+		tdco = min(tdc->tdcv + tdc->tdco, tdc_const->tdco_max) - 1;
+	}
+
+	rcar_canfd_update_bit(gpriv->base, rcar_canfd_f_cfdcfg(gpriv, ch), mask,
+			      tdcmode | FIELD_PREP(RCANFD_FDCFG_TDCO, tdco));
 }
 
 static int rcar_canfd_start(struct net_device *ndev)
@@ -1807,6 +1858,29 @@ static int rcar_canfd_rx_poll(struct napi_struct *napi, int quota)
 	return num_pkts;
 }
 
+static unsigned int rcar_canfd_get_tdcr(struct rcar_canfd_global *gpriv,
+					unsigned int ch)
+{
+	u32 sts = rcar_canfd_read(gpriv->base, rcar_canfd_f_cfdsts(gpriv, ch));
+	u32 tdcr = FIELD_GET(RCANFD_FDSTS_TDCR, sts);
+
+	return tdcr & (gpriv->info->tdc_const->tdcv_max - 1);
+}
+
+static int rcar_canfd_get_auto_tdcv(const struct net_device *ndev, u32 *tdcv)
+{
+	struct rcar_canfd_channel *priv = netdev_priv(ndev);
+	u32 tdco = priv->can.fd.tdc.tdco;
+	u32 tdcr;
+
+	/* Transceiver Delay Compensation Result */
+	tdcr = rcar_canfd_get_tdcr(priv->gpriv, priv->channel) + 1;
+
+	*tdcv = tdcr < tdco ? 0 : tdcr - tdco;
+
+	return 0;
+}
+
 static int rcar_canfd_do_set_mode(struct net_device *ndev, enum can_mode mode)
 {
 	int err;
@@ -1929,12 +2003,17 @@ static int rcar_canfd_channel_probe(struct rcar_canfd_global *gpriv, u32 ch,
 	if (gpriv->fdmode) {
 		priv->can.bittiming_const = gpriv->info->nom_bittiming;
 		priv->can.fd.data_bittiming_const = gpriv->info->data_bittiming;
+		priv->can.fd.tdc_const = gpriv->info->tdc_const;
 
 		/* Controller starts in CAN FD only mode */
 		err = can_set_static_ctrlmode(ndev, CAN_CTRLMODE_FD);
 		if (err)
 			goto fail;
-		priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING;
+
+		priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING |
+					       CAN_CTRLMODE_TDC_AUTO |
+					       CAN_CTRLMODE_TDC_MANUAL;
+		priv->can.fd.do_get_auto_tdcv = rcar_canfd_get_auto_tdcv;
 	} else {
 		/* Controller starts in Classical CAN only mode */
 		priv->can.bittiming_const = &rcar_canfd_bittiming_const;
-- 
2.47.2