[PATCH v2 08/10] can: grcan: Add saving and restoring of CAN FD baud-rate registers

From: Arun Muthusamy

Date: Tue Dec 23 2025 - 05:56:38 EST


From: Daniel Hellstrom <daniel@xxxxxxxxxxx>

While reset the GRCAN baud-rates are preserved, since GRCANFD has the
baud-rate in different registers we need to add saving of those
registers too.

Signed-off-by: Daniel Hellstrom <daniel@xxxxxxxxxxx>
Signed-off-by: Arun Muthusamy <arun.muthusamy@xxxxxxxxxxx>
---
drivers/net/can/grcan.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/net/can/grcan.c b/drivers/net/can/grcan.c
index cdb9498cf783..dc14b3145e73 100644
--- a/drivers/net/can/grcan.c
+++ b/drivers/net/can/grcan.c
@@ -520,15 +520,27 @@ static void grcan_reset(struct net_device *dev)
struct grcan_priv *priv = netdev_priv(dev);
struct grcan_registers __iomem *regs = priv->regs;
u32 config = grcan_read_reg(&regs->conf);
+ u32 nbtr, fdbtr;
+
+ if (priv->hwcap->fd) {
+ nbtr = grcan_read_reg(&regs->nbtr);
+ fdbtr = grcan_read_reg(&regs->fdbtr);
+ }

grcan_set_bits(&regs->ctrl, GRCAN_CTRL_RESET);
grcan_write_reg(&regs->conf, config);
+ if (priv->hwcap->fd) {
+ grcan_write_reg(&regs->nbtr, nbtr);
+ grcan_write_reg(&regs->fdbtr, fdbtr);
+ }

priv->eskbp = grcan_read_reg(&regs->txrd);
priv->can.state = CAN_STATE_STOPPED;

/* Turn off hardware filtering - regs->rxcode set to 0 by reset */
grcan_write_reg(&regs->rxmask, 0);
+
+ priv->hwcap->set_bittiming(dev);
}

/* stop device without changing any configurations */
--
2.51.0