can: Add Nuvoton NCT6694 CANFD support

This driver supports Socket CANFD functionality for NCT6694 MFD
device based on USB interface.

Reviewed-by: Marc Kleine-Budde <mkl@pengutronix.de>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Ming Yu <a0282524688@gmail.com>
Link: https://lore.kernel.org/r/20250912091952.1169369-5-a0282524688@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>

Author: m1ng1109

MAINTAINERS

@@ -18088,6 +18088,7 @@ S:	Supported
 F:	drivers/gpio/gpio-nct6694.c
 F:	drivers/i2c/busses/i2c-nct6694.c
 F:	drivers/mfd/nct6694.c
+F:	drivers/net/can/usb/nct6694_canfd.c
 F:	include/linux/mfd/nct6694.h
 
 NUVOTON NCT7201 IIO DRIVER

drivers/net/can/usb/Kconfig

@@ -134,6 +134,17 @@ config CAN_MCBA_USB
 	  This driver supports the CAN BUS Analyzer interface
 	  from Microchip (http://www.microchip.com/development-tools/).
 
+config CAN_NCT6694
+	tristate "Nuvoton NCT6694 Socket CANfd support"
+	depends on MFD_NCT6694
+	select CAN_RX_OFFLOAD
+	help
+	  If you say yes to this option, support will be included for Nuvoton
+	  NCT6694, a USB device to socket CANfd controller.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called nct6694_canfd.
+
 config CAN_PEAK_USB
 	tristate "PEAK PCAN-USB/USB Pro interfaces for CAN 2.0b/CAN-FD"
 	help

drivers/net/can/usb/Makefile

@@ -11,5 +11,6 @@ obj-$(CONFIG_CAN_F81604) += f81604.o
 obj-$(CONFIG_CAN_GS_USB) += gs_usb.o
 obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb/
 obj-$(CONFIG_CAN_MCBA_USB) += mcba_usb.o
+obj-$(CONFIG_CAN_NCT6694) += nct6694_canfd.o
 obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
 obj-$(CONFIG_CAN_UCAN) += ucan.o