drivers: can: Add Renesas R-Car driver

This driver is for classic CAN, it makes use of CAN interface
in FIFO mode.

This driver support Standard ID as well as Extended ID.

Tested on H3ULCB, Ebisu platform, with external adapter and
in loopback mode.

Signed-off-by: Julien Massot <julien.massot@iot.bzh>

drivers/can/CMakeLists.txt

@@ -7,6 +7,7 @@ zephyr_sources_ifdef(CONFIG_CAN_STM32        can_stm32.c)
 zephyr_sources_ifdef(CONFIG_CAN_STM32FD      can_stm32fd.c)
 zephyr_sources_ifdef(CONFIG_CAN_MCAN         can_mcan.c)
 zephyr_sources_ifdef(CONFIG_CAN_MCUX_FLEXCAN can_mcux_flexcan.c)
+zephyr_sources_ifdef(CONFIG_CAN_RCAR         can_rcar.c)
 
 zephyr_sources_ifdef(CONFIG_USERSPACE        can_handlers.c)
 zephyr_sources_ifdef(CONFIG_CAN_SHELL        can_shell.c)

drivers/can/Kconfig

@@ -86,6 +86,7 @@ source "drivers/can/Kconfig.stm32fd"
 source "drivers/can/Kconfig.mcux"
 source "drivers/can/Kconfig.mcp2515"
 source "drivers/can/Kconfig.mcan"
+source "drivers/can/Kconfig.rcar"
 source "drivers/can/Kconfig.loopback"
 source "drivers/can/Kconfig.net"
 

drivers/can/Kconfig.rcar

@@ -0,0 +1,18 @@
+# Reneas R-Car CAN configuration options
+
+# Copyright (c) 2021 IoT.bzh
+# SPDX-License-Identifier: Apache-2.0
+
+config CAN_RCAR
+	bool "Renesas R-Car CAN Driver"
+	depends on SOC_FAMILY_RCAR
+	help
+	  Enable Renesas R-Car CAN Driver.
+
+config CAN_RCAR_MAX_FILTER
+	int "Maximum number of concurrent active filters"
+	default 5
+	range 1 32
+	help
+	  Defines the array size of the callback/msgq pointers.
+	  Must be at least the size of concurrent reads.