boards/stm32f103-minimum: Add CAN bring-up, char/socket drivers, and defconfig

Add board support for on-chip bxCAN: stm32_can.c registers /dev/can0 via stm32_caninitialize() when CONFIG_STM32_CAN_CHARDRIVER is set; stm32_cansock.c calls stm32_cansockinitialize() for the socket-CAN path when CONFIG_STM32_CAN_SOCKET is set.

Signed-off-by: Alexey Matveev <tippet@yandex.ru>

Documentation/platforms/arm/stm32f1/boards/stm32f103-minimum/index.rst

@@ -599,6 +599,44 @@ firmware in the second board. Now you can start the both boards, run the
 "can" command in the Write-only board and then run the "can" command in the
 Read-only board. You should see the data coming.
 
+CAN support
+===========
+
+The STM32F103C8 has a on-chip bxCAN controller, then we can use it for
+CAN bus communication.
+It has limitations:
+
+- USB is not available together with on-chip CAN, because they share the SRAM
+  buffer (see the MCP2515 External Module section);
+- you need to use transceivers (SN65HVD230, ...) to connect the CAN bus;
+- you need a second device on the CAN bus to test the communication.
+
+If you want only to check the CAN bus, you can use mode 'loopback' in the CAN device.
+
+CAN PINS
+--------
+
+  ..
+     CAN1 (default pin mapping; ``CONFIG_STM32_CAN1_REMAP1`` is not set)
+       RX      PA11
+       TX      PA12
+
+     CAN1 (alternate mapping; enable ``CONFIG_STM32_CAN1_REMAP1``)
+       RX      PB8
+       TX      PB9
+
+  On STM32F103Cx in LQFP48, CAN1_REMAP2 is not available.
+
+Transceivers
+------------
+
+The MCU CAN peripheral only provides single-ended TTL-level ``CAN_RX`` / ``CAN_TX``
+lines. A CAN transceiver interfaces those to the differential **CANH** / **CANL**
+bus (dominant/recessive signaling), drives the correct line impedance, and
+typically adds short-circuit and ESD protection so the chip can safely connect
+to a real vehicle or bench network. Common parts include SN65HVD230, MCP2551,
+and TJA1050.
+
 STM32F103 Minimum - specific Configuration Options
 ==================================================
 
@@ -885,3 +923,14 @@ veml6070
 This is a config example to use the Vishay VEML6070 UV-A sensor. To use this
 sensor you need to connect PB6 (I2C1 CLK) to SCL; PB7 (I2C1 SDA) to SDA of
 sensor module. I used a GY-VEML6070 module to test this driver.
+
+can
+---
+
+This is a config example to use on-chip CAN1 and the CAN example application.
+Wire PA11 (CAN_RX) and PA12 (CAN_TX) to a CAN transceiver;
+connect the transceiver's CANH and CANL to the bus.
+See the 'CAN support' section above for pins, transceivers, and limitations.
+
+A UART adapter on USART1 (PA9/PA10) is required for the NSH console on a
+host PC.

boards/arm/stm32/stm32f103-minimum/configs/can/defconfig

@@ -0,0 +1,74 @@
+#
+# This file is autogenerated: PLEASE DO NOT EDIT IT.
+#
+# You can use "make menuconfig" to make any modifications to the installed .config file.
+# You can then do "make savedefconfig" to generate a new defconfig file that includes your
+# modifications.
+#
+# CONFIG_DISABLE_OS_API is not set
+# CONFIG_NSH_DISABLESCRIPT is not set
+# CONFIG_NSH_DISABLE_CAT is not set
+# CONFIG_NSH_DISABLE_CD is not set
+# CONFIG_NSH_DISABLE_CP is not set
+# CONFIG_NSH_DISABLE_ECHO is not set
+# CONFIG_NSH_DISABLE_EXEC is not set
+# CONFIG_NSH_DISABLE_EXIT is not set
+# CONFIG_NSH_DISABLE_FREE is not set
+# CONFIG_NSH_DISABLE_GET is not set
+# CONFIG_NSH_DISABLE_HEXDUMP is not set
+# CONFIG_NSH_DISABLE_LS is not set
+# CONFIG_NSH_DISABLE_MKDIR is not set
+# CONFIG_NSH_DISABLE_MOUNT is not set
+# CONFIG_NSH_DISABLE_PS is not set
+# CONFIG_NSH_DISABLE_PUT is not set
+# CONFIG_NSH_DISABLE_PWD is not set
+# CONFIG_NSH_DISABLE_RM is not set
+# CONFIG_NSH_DISABLE_SLEEP is not set
+# CONFIG_NSH_DISABLE_TEST is not set
+# CONFIG_NSH_DISABLE_UMOUNT is not set
+# CONFIG_NSH_DISABLE_UNAME is not set
+# CONFIG_NSH_DISABLE_WGET is not set
+# CONFIG_NSH_DISABLE_XD is not set
+CONFIG_ARCH="arm"
+CONFIG_ARCH_BOARD="stm32f103-minimum"
+CONFIG_ARCH_BOARD_COMMON=y
+CONFIG_ARCH_BOARD_STM32F103_MINIMUM=y
+CONFIG_ARCH_CHIP="stm32"
+CONFIG_ARCH_CHIP_STM32=y
+CONFIG_ARCH_CHIP_STM32F103C8=y
+CONFIG_ARCH_STACKDUMP=y
+CONFIG_BOARD_LOOPSPERMSEC=5483
+CONFIG_BUILTIN=y
+CONFIG_CAN_ERRORS=y
+CONFIG_CAN_EXTID=y
+CONFIG_DEFAULT_SMALL=y
+CONFIG_EXAMPLES_CAN=y
+CONFIG_EXAMPLES_CAN_NMSGS=4
+CONFIG_EXAMPLES_CAN_WRITE=y
+CONFIG_HOST_MACOS=y
+CONFIG_INIT_ENTRYPOINT="nsh_main"
+CONFIG_LINE_MAX=80
+CONFIG_NSH_ARCHINIT=y
+CONFIG_NSH_BUILTIN_APPS=y
+CONFIG_NSH_FILEIOSIZE=1024
+CONFIG_RAM_SIZE=20480
+CONFIG_RAM_START=0x20000000
+CONFIG_RAW_BINARY=y
+CONFIG_RR_INTERVAL=200
+CONFIG_SCHED_HPWORK=y
+CONFIG_SCHED_HPWORKPRIORITY=192
+CONFIG_SCHED_WAITPID=y
+CONFIG_SERIAL_TERMIOS=y
+CONFIG_START_DAY=5
+CONFIG_START_MONTH=7
+CONFIG_START_YEAR=2011
+CONFIG_STM32_CAN1=y
+CONFIG_STM32_CAN_TSEG1=13
+CONFIG_STM32_CAN_TSEG2=2
+CONFIG_STM32_DISABLE_IDLE_SLEEP_DURING_DEBUG=y
+CONFIG_STM32_JTAG_FULL_ENABLE=y
+CONFIG_STM32_USART1=y
+CONFIG_SYMTAB_ORDEREDBYNAME=y
+CONFIG_SYSTEM_NSH=y
+CONFIG_TASK_NAME_SIZE=0
+CONFIG_USART1_SERIAL_CONSOLE=y

boards/arm/stm32/stm32f103-minimum/src/CMakeLists.txt

@@ -109,6 +109,15 @@ if(CONFIG_USBMSC)
   list(APPEND SRCS stm32_usbmsc.c)
 endif()
 
+if(CONFIG_STM32_CAN)
+  if(CONFIG_STM32_CAN_CHARDRIVER)
+    list(APPEND SRCS stm32_can.c)
+  endif()
+  if(CONFIG_STM32_CAN_SOCKET)
+    list(APPEND SRCS stm32_cansock.c)
+  endif()
+endif()
+
 target_sources(board PRIVATE ${SRCS})
 
 set_property(GLOBAL PROPERTY LD_SCRIPT "${NUTTX_BOARD_DIR}/scripts/ld.script")

boards/arm/stm32/stm32f103-minimum/src/Make.defs

@@ -111,6 +111,15 @@ ifeq ($(CONFIG_USBMSC),y)
 CSRCS += stm32_usbmsc.c
 endif
 
+ifeq ($(CONFIG_STM32_CAN),y)
+ifeq ($(CONFIG_STM32_CAN_CHARDRIVER),y)
+CSRCS += stm32_can.c
+endif
+ifeq ($(CONFIG_STM32_CAN_SOCKET),y)
+CSRCS += stm32_cansock.c
+endif
+endif
+
 DEPPATH += --dep-path board
 VPATH += :board
 CFLAGS += ${INCDIR_PREFIX}$(TOPDIR)$(DELIM)arch$(DELIM)$(CONFIG_ARCH)$(DELIM)src$(DELIM)board$(DELIM)board

boards/arm/stm32/stm32f103-minimum/src/stm32_bringup.c

@@ -578,5 +578,29 @@ int stm32_bringup(void)
   usbdev_adb_initialize();
 #endif
 
+#ifdef CONFIG_STM32_CAN_CHARDRIVER
+  /* Initialize CAN and register the CAN driver. */
+
+  ret = stm32_can_setup();
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "ERROR: stm32_can_setup failed: %d\n", ret);
+    }
+#endif
+
+#ifdef CONFIG_STM32_CAN_SOCKET
+  /* Initialize CAN socket interface */
+
+  /* STM32F103C8 may not have enough Flash for SocketCAN; use a part with
+   * more Flash (e.g. STM32F103CB).
+   */
+
+  ret = stm32_cansock_setup();
+  if (ret < 0)
+    {
+      syslog(LOG_ERR, "ERROR: stm32_cansock_setup failed: %d\n", ret);
+    }
+#endif
+
   return ret;
 }

boards/arm/stm32/stm32f103-minimum/src/stm32_can.c

@@ -0,0 +1,69 @@
+/****************************************************************************
+ * boards/arm/stm32/stm32f103-minimum/src/stm32_can.c
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <errno.h>
+#include <nuttx/debug.h>
+
+#include <nuttx/can/can.h>
+
+#include "stm32.h"
+#include "stm32_can.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_can_setup
+ *
+ * Description:
+ *  Initialize CAN and register the CAN device
+ *
+ ****************************************************************************/
+
+int stm32_can_setup(void)
+{
+  struct can_dev_s *can;
+  int ret;
+
+  can = stm32_caninitialize(1);
+  if (can == NULL)
+    {
+      canerr("ERROR:  Failed to get CAN interface\n");
+      return -ENODEV;
+    }
+
+  ret = can_register("/dev/can0", can);
+  if (ret < 0)
+    {
+      canerr("ERROR: can_register failed: %d\n", ret);
+      return ret;
+    }
+
+  return OK;
+}

boards/arm/stm32/stm32f103-minimum/src/stm32_cansock.c

@@ -0,0 +1,59 @@
+/****************************************************************************
+ * boards/arm/stm32/stm32f103-minimum/src/stm32_cansock.c
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <nuttx/debug.h>
+
+#include "stm32_can.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_cansock_setup
+ *
+ * Description:
+ *  Initialize CAN socket interface
+ *
+ ****************************************************************************/
+
+int stm32_cansock_setup(void)
+{
+  int ret;
+
+  /* Call stm32_cansockinitialize() to register the CAN network device */
+
+  ret = stm32_cansockinitialize(1);
+  if (ret < 0)
+    {
+      canerr("ERROR:  Failed to get CAN interface %d\n", ret);
+      return ret;
+    }
+
+  return OK;
+}

boards/arm/stm32/stm32f103-minimum/src/stm32f103_minimum.h

@@ -374,5 +374,29 @@ int stm32_hyt271initialize(int devno);
 int stm32_ds18b20initialize(int devno);
 #endif
 
+/****************************************************************************
+ * Name: stm32_can_setup
+ *
+ * Description:
+ *  Initialize CAN and register the CAN device
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_STM32_CAN_CHARDRIVER
+int stm32_can_setup(void);
+#endif
+
+/****************************************************************************
+ * Name: stm32_cansock_setup
+ *
+ * Description:
+ *  Initialize CAN socket interface
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_STM32_CAN_SOCKET
+int stm32_cansock_setup(void);
+#endif
+
 #endif /* __ASSEMBLY__ */
 #endif /* __BOARDS_ARM_STM32_STM32F103_MINIMUM_SRC_STM32F103_MINIMUM_H */