From 87fe0e6072bb6797e20f5f12599f5a4c6a1506bf Mon Sep 17 00:00:00 2001
From: "Alan C. Assis" <acassis@gmail.com>
Date: Sun, 4 Apr 2021 16:11:10 -0300
Subject: [PATCH] stm32f4discovery: Add Modbus Slave example

---
 .../configs/modbus_slave/defconfig            | 65 +++++++++++++++++++
 .../stm32/stm32f4discovery/include/board.h    | 15 +++++
 2 files changed, 80 insertions(+)
 create mode 100644 boards/arm/stm32/stm32f4discovery/configs/modbus_slave/defconfig

diff --git a/boards/arm/stm32/stm32f4discovery/configs/modbus_slave/defconfig b/boards/arm/stm32/stm32f4discovery/configs/modbus_slave/defconfig
new file mode 100644
index 0000000000..ffc1a97565
--- /dev/null
+++ b/boards/arm/stm32/stm32f4discovery/configs/modbus_slave/defconfig
@@ -0,0 +1,65 @@
+#
+# 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_ARCH_FPU is not set
+# CONFIG_MB_TCP_ENABLED is not set
+# CONFIG_NSH_ARGCAT is not set
+# CONFIG_NSH_CMDOPT_HEXDUMP is not set
+# CONFIG_NSH_CMDPARMS is not set
+# CONFIG_NSH_DISABLE_MB is not set
+# CONFIG_NSH_DISABLE_MH is not set
+# CONFIG_NSH_DISABLE_MW is not set
+CONFIG_ARCH="arm"
+CONFIG_ARCH_BOARD="stm32f4discovery"
+CONFIG_ARCH_BOARD_STM32F4_DISCOVERY=y
+CONFIG_ARCH_BUTTONS=y
+CONFIG_ARCH_CHIP="stm32"
+CONFIG_ARCH_CHIP_STM32=y
+CONFIG_ARCH_CHIP_STM32F407VG=y
+CONFIG_ARCH_STACKDUMP=y
+CONFIG_BOARD_LATE_INITIALIZE=y
+CONFIG_BOARD_LOOPSPERMSEC=16717
+CONFIG_BUILTIN=y
+CONFIG_EXAMPLES_HELLO=y
+CONFIG_EXAMPLES_MODBUS=y
+CONFIG_EXAMPLES_MODBUS_PORT=1
+CONFIG_FS_PROCFS=y
+CONFIG_HAVE_CXX=y
+CONFIG_HAVE_CXXINITIALIZE=y
+CONFIG_INTELHEX_BINARY=y
+CONFIG_MAX_TASKS=16
+CONFIG_MM_REGIONS=2
+CONFIG_MODBUS=y
+CONFIG_MODBUS_SLAVE=y
+CONFIG_NSH_BUILTIN_APPS=y
+CONFIG_NSH_FILEIOSIZE=512
+CONFIG_NSH_LINELEN=64
+CONFIG_NSH_READLINE=y
+CONFIG_PREALLOC_TIMERS=4
+CONFIG_RAM_SIZE=114688
+CONFIG_RAM_START=0x20000000
+CONFIG_RAW_BINARY=y
+CONFIG_RR_INTERVAL=200
+CONFIG_SCHED_WAITPID=y
+CONFIG_SDCLONE_DISABLE=y
+CONFIG_SERIAL_TERMIOS=y
+CONFIG_START_DAY=6
+CONFIG_START_MONTH=12
+CONFIG_START_YEAR=2011
+CONFIG_STM32_JTAG_SW_ENABLE=y
+CONFIG_STM32_PWR=y
+CONFIG_STM32_SPI1=y
+CONFIG_STM32_USART1=y
+CONFIG_STM32_USART2=y
+CONFIG_SYSTEM_NSH=y
+CONFIG_USART1_BAUD=38400
+CONFIG_USART1_PARITY=2
+CONFIG_USART1_RS485=y
+CONFIG_USART2_RXBUFSIZE=128
+CONFIG_USART2_SERIAL_CONSOLE=y
+CONFIG_USART2_TXBUFSIZE=128
+CONFIG_USER_ENTRYPOINT="nsh_main"
diff --git a/boards/arm/stm32/stm32f4discovery/include/board.h b/boards/arm/stm32/stm32f4discovery/include/board.h
index 2bdb08f8fb..63177e5815 100644
--- a/boards/arm/stm32/stm32f4discovery/include/board.h
+++ b/boards/arm/stm32/stm32f4discovery/include/board.h
@@ -241,6 +241,21 @@
 #  define GPIO_CAN2_TX GPIO_CAN2_TX_1
 #endif
 
+/* USART1 */
+
+#ifdef CONFIG_USART1_RS485
+  /* Lets use for RS485 on pins: PB6 and PB7 */
+
+#  define GPIO_USART1_TX        GPIO_USART1_TX_2
+#  define GPIO_USART1_RX        GPIO_USART1_RX_2
+
+  /* RS485 DIR pin: PA15 */
+
+#  define GPIO_USART1_RS485_DIR (GPIO_OUTPUT | GPIO_PUSHPULL | GPIO_SPEED_50MHz |\
+                               GPIO_OUTPUT_CLEAR | GPIO_PORTA | GPIO_PIN15)
+
+#endif
+
 /* USART2:
  *
  * The STM32F4 Discovery has no on-board serial devices, but the console is