Add support for MTP device class

examples/device/mtp/CMakeLists.txt

@@ -0,0 +1,39 @@
+cmake_minimum_required(VERSION 3.20)
+
+include(${CMAKE_CURRENT_SOURCE_DIR}/../../../hw/bsp/family_support.cmake)
+
+# gets PROJECT name for the example (e.g. <BOARD>-<DIR_NAME>)
+family_get_project_name(PROJECT ${CMAKE_CURRENT_LIST_DIR})
+
+project(${PROJECT} C CXX ASM)
+
+# Checks this example is valid for the family and initializes the project
+family_initialize_project(${PROJECT} ${CMAKE_CURRENT_LIST_DIR})
+
+# Espressif has its own cmake build system
+if(FAMILY STREQUAL "espressif")
+  return()
+endif()
+
+if (RTOS STREQUAL zephyr)
+  set(EXE_NAME app)
+else()
+  set(EXE_NAME ${PROJECT})
+  add_executable(${EXE_NAME})
+endif()
+
+# Example source
+target_sources(${EXE_NAME} PRIVATE
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/main.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/mtp_fs_example.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/usb_descriptors.c
+  )
+
+# Example include
+target_include_directories(${EXE_NAME} PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}/src
+  )
+
+# Configure compilation flags and libraries for the example without RTOS.
+# See the corresponding function in hw/bsp/FAMILY/family.cmake for details.
+family_configure_device_example(${EXE_NAME} ${RTOS})

examples/device/mtp/CMakePresets.json

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+{
+  "version": 6,
+  "include": [
+    "../../../hw/bsp/BoardPresets.json"
+  ]
+}

examples/device/mtp/Makefile

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+include ../../build_system/make/make.mk
+
+INC += \
+  src \
+  $(TOP)/hw \
+
+# Example source
+EXAMPLE_SOURCE += $(wildcard src/*.c)
+SRC_C += $(addprefix $(CURRENT_PATH)/, $(EXAMPLE_SOURCE))
+
+include ../../build_system/make/rules.mk

examples/device/mtp/prj.conf

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+CONFIG_GPIO=y
+CONFIG_FPU=y
+CONFIG_NO_OPTIMIZATIONS=y
+CONFIG_UART_INTERRUPT_DRIVEN=y
+CONFIG_NRFX_POWER=y
+CONFIG_NRFX_UARTE0=y

examples/device/mtp/src/main.c

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+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2025 Ennebi Elettronica (https://ennebielettronica.com)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "bsp/board_api.h"
+#include "tusb.h"
+
+//--------------------------------------------------------------------+
+// MACRO CONSTANT TYPEDEF PROTYPES
+//--------------------------------------------------------------------+
+
+/* Blink pattern
+ * - 250 ms  : device not mounted
+ * - 1000 ms : device mounted
+ * - 2500 ms : device is suspended
+ */
+enum {
+  BLINK_NOT_MOUNTED = 250,
+  BLINK_MOUNTED = 1000,
+  BLINK_SUSPENDED = 2500,
+};
+
+static uint32_t blink_interval_ms = BLINK_NOT_MOUNTED;
+
+void led_blinking_task(void);
+
+/*------------- MAIN -------------*/
+int main(void) {
+  board_init();
+
+  // init device stack on configured roothub port
+  tusb_rhport_init_t dev_init = {
+    .role = TUSB_ROLE_DEVICE,
+    .speed = TUSB_SPEED_AUTO
+  };
+  tusb_init(BOARD_TUD_RHPORT, &dev_init);
+
+  if (board_init_after_tusb) {
+    board_init_after_tusb();
+  }
+
+  while (1) {
+    tud_task(); // tinyusb device task
+    led_blinking_task();
+  }
+}
+
+//--------------------------------------------------------------------+
+// Device callbacks
+//--------------------------------------------------------------------+
+
+// Invoked when device is mounted
+void tud_mount_cb(void) {
+  blink_interval_ms = BLINK_MOUNTED;
+}
+
+// Invoked when device is unmounted
+void tud_umount_cb(void) {
+  blink_interval_ms = BLINK_NOT_MOUNTED;
+}
+
+// Invoked when usb bus is suspended
+// remote_wakeup_en : if host allow us  to perform remote wakeup
+// Within 7ms, device must draw an average of current less than 2.5 mA from bus
+void tud_suspend_cb(bool remote_wakeup_en) {
+  (void) remote_wakeup_en;
+  blink_interval_ms = BLINK_SUSPENDED;
+}
+
+// Invoked when usb bus is resumed
+void tud_resume_cb(void) {
+  blink_interval_ms = tud_mounted() ? BLINK_MOUNTED : BLINK_NOT_MOUNTED;
+}
+
+//--------------------------------------------------------------------+
+// BLINKING TASK
+//--------------------------------------------------------------------+
+void led_blinking_task(void) {
+  static uint32_t start_ms = 0;
+  static bool led_state = false;
+
+  // Blink every interval ms
+  if (board_millis() - start_ms < blink_interval_ms) return; // not enough time
+  start_ms += blink_interval_ms;
+
+  board_led_write(led_state);
+  led_state = 1 - led_state; // toggle
+}