board/stm32f401rc-rs485: Add USB console support

This commit adds support to use NSH over USB without
connecting an external USB/Serial adapter.

Signed-off-by: Rodrigo Sim <rcsim10@gmail.com>

Documentation/platforms/arm/stm32f4/boards/stm32f401rc-rs485/index.rst

@@ -224,6 +224,27 @@ nsh
 Configures the NuttShell (nsh) located at apps/examples/nsh. This
 configuration enables a serial console on USART6.
 
+
+usbnsh
+------
+
+Configures the NuttShell (nsh) located at apps/examples/nsh. This
+configuration enables a serial console over USB.
+
+After flasing and reboot your board you should see in your dmesg logs::
+
+       [ 2638.948089] usb 1-1.4: new full-speed USB device number 16 using xhci_hcd
+       [ 2639.054432] usb 1-1.4: New USB device found, idVendor=0525, idProduct=a4a7, bcdDevice= 1.01
+       [ 2639.054437] usb 1-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
+       [ 2639.054438] usb 1-1.4: Product: CDC/ACM Serial
+       [ 2639.054440] usb 1-1.4: Manufacturer: NuttX
+       [ 2639.054441] usb 1-1.4: SerialNumber: 0
+       [ 2639.074861] cdc_acm 1-1.4:1.0: ttyACM0: USB ACM device
+       [ 2639.074886] usbcore: registered new interface driver cdc_acm
+       [ 2639.074887] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters
+
+You may need to press **ENTER** 3 times before the NSH show up.
+
 sdcard
 ------
 

boards/arm/stm32/stm32f401rc-rs485/configs/usbnsh/defconfig

@@ -0,0 +1,62 @@
+#
+# 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_NSH_ARGCAT is not set
+# CONFIG_NSH_CMDOPT_HEXDUMP is not set
+# CONFIG_NSH_DISABLE_IFCONFIG is not set
+# CONFIG_NSH_DISABLE_PS is not set
+CONFIG_ARCH="arm"
+CONFIG_ARCH_BOARD="stm32f401rc-rs485"
+CONFIG_ARCH_BOARD_STM32F401RC_RS485=y
+CONFIG_ARCH_BUTTONS=y
+CONFIG_ARCH_CHIP="stm32"
+CONFIG_ARCH_CHIP_STM32=y
+CONFIG_ARCH_CHIP_STM32F401RC=y
+CONFIG_ARCH_INTERRUPTSTACK=2048
+CONFIG_ARCH_IRQBUTTONS=y
+CONFIG_ARCH_STACKDUMP=y
+CONFIG_BOARDCTL_USBDEVCTRL=y
+CONFIG_BOARD_LOOPSPERMSEC=8499
+CONFIG_BUILTIN=y
+CONFIG_CDCACM=y
+CONFIG_CDCACM_CONSOLE=y
+CONFIG_EXAMPLES_BUTTONS=y
+CONFIG_EXAMPLES_BUTTONS_NAME0="SW3"
+CONFIG_EXAMPLES_BUTTONS_NAME1="SW4"
+CONFIG_EXAMPLES_BUTTONS_NAME2="SW5"
+CONFIG_EXAMPLES_BUTTONS_NAMES=y
+CONFIG_EXAMPLES_BUTTONS_QTD=3
+CONFIG_HAVE_CXX=y
+CONFIG_HAVE_CXXINITIALIZE=y
+CONFIG_INIT_ENTRYPOINT="nsh_main"
+CONFIG_INPUT=y
+CONFIG_INPUT_BUTTONS=y
+CONFIG_INPUT_BUTTONS_LOWER=y
+CONFIG_INTELHEX_BINARY=y
+CONFIG_NSH_ARCHINIT=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=98304
+CONFIG_RAM_START=0x20000000
+CONFIG_RAW_BINARY=y
+CONFIG_RR_INTERVAL=200
+CONFIG_SCHED_WAITPID=y
+CONFIG_SPI=y
+CONFIG_START_DAY=5
+CONFIG_START_MONTH=5
+CONFIG_START_YEAR=2014
+CONFIG_STM32_JTAG_SW_ENABLE=y
+CONFIG_STM32_OTGFS=y
+CONFIG_STM32_PWR=y
+CONFIG_STM32_USART6=y
+CONFIG_SYSTEM_NSH=y
+CONFIG_TASK_NAME_SIZE=0
+CONFIG_USBDEV=y

boards/arm/stm32/stm32f401rc-rs485/src/CMakeLists.txt

@@ -40,6 +40,10 @@ if(CONFIG_STM32_SDIO)
   list(APPEND SRCS stm32_sdio.c)
 endif()
 
+if(CONFIG_STM32_OTGFS)
+  list(APPEND SRCS stm32_usb.c)
+endif()
+
 if(CONFIG_STM32_CONFIG_I2C_EE_24XXEEPROM)
   list(APPEND SRCS stm32_at24.c)
 endif()

boards/arm/stm32/stm32f401rc-rs485/src/Make.defs

@@ -43,6 +43,10 @@ ifeq ($(CONFIG_STM32_SDIO),y)
 CSRCS += stm32_sdio.c
 endif
 
+ifeq ($(CONFIG_STM32_OTGFS),y)
+CSRCS += stm32_usb.c
+endif
+
 ifeq ($(CONFIG_I2C_EE_24XX),y)
 CSRCS += stm32_at24.c
 endif

boards/arm/stm32/stm32f401rc-rs485/src/stm32_usb.c

@@ -0,0 +1,92 @@
+/****************************************************************************
+ * boards/arm/stm32/stm32f401rc-rs485/src/stm32_usb.c
+ *
+ * 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 <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <debug.h>
+
+#include "stm32_otgfs.h"
+#include "stm32_gpio.h"
+#include "stm32f401rc-rs485.h"
+
+#ifdef CONFIG_STM32_OTGFS
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#ifdef CONFIG_USBDEV
+#  define HAVE_USB 1
+#else
+#  warning "CONFIG_STM32_OTGFS is enabled but CONFIG_USBDEV is not"
+#  undef HAVE_USB
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: stm32_usb_configure
+ *
+ * Description:
+ *   Called from stm32_boardinitialize very early in inialization to setup
+ *   USB-related GPIO pins for the Olimex STM32 P407 board.
+ *
+ ****************************************************************************/
+
+void stm32_usb_configure(void)
+{
+#ifdef CONFIG_STM32_OTGFS
+  /* The OTG FS has an internal soft pull-up.
+   * No GPIO configuration is required
+   */
+
+  /* We don´t have the OTG FS VBUS sensing GPIO */
+#endif
+}
+
+/****************************************************************************
+ * Name:  stm32_usbsuspend
+ *
+ * Description:
+ *   Board logic must provide the stm32_usbsuspend logic if the USBDEV
+ *   driver is used.  This function is called whenever the USB enters or
+ *   leaves suspend mode.
+ *   This is an opportunity for the board logic to shutdown clocks, power,
+ *   etc. while the USB is suspended.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_USBDEV
+void stm32_usbsuspend(struct usbdev_s *dev, bool resume)
+{
+  uinfo("resume: %d\n", resume);
+}
+#endif
+
+#endif /* CONFIG_STM32_OTGFS */