Merge pull request #259 from majbthrd/nuc121

add Nuvoton NUC121/NUC125/NUC126

.gitmodules

@@ -19,3 +19,6 @@
 [submodule "hw/mcu/microchip"]
 	path = hw/mcu/microchip
 	url = https://github.com/hathach/microchip_driver.git
+[submodule "hw/mcu/nuvoton"]
+	path = hw/mcu/nuvoton
+	url = https://github.com/majbthrd/nuc_driver.git

CONTRIBUTORS.md

@@ -23,6 +23,10 @@
   * USBTMC class driver support with example
   * Various improvement e.g Zero-length packet, Lint setup 
   * Board support for STM32F070RB Nucleo, STM32F303 Discovery
+
+* **[Peter Lawrence](https://github.com/majbthrd)**
+  * Nuvoton NUC 121, 125, 126 device driver port
+  * Board support for NuTiny NUC121s, NUC125s, NUC126V
   
 * **[Scott Shawcroft](https://github.com/tannewt)**
   * SAMD21 and SAMD51 device driver port

README.md

@@ -38,6 +38,7 @@ The stack supports the following MCUs
 - **Sony:** CXD56
 - **ST:** STM32 series: L0, F0, F1, F2, F3, F4, F7, H7 (device only)
 - **[ValentyUSB](https://github.com/im-tomu/valentyusb)** eptri
+- **Nuvoton:** NUC121/NUC125, NUC126
 
 [Here is the list of supported Boards](docs/boards.md) that can be used with provided examples.
 

docs/boards.md

@@ -7,7 +7,7 @@ The board support code is only used for self-contained examples and testing. It
  
 ## Supported Boards
 
-This code base already had supported for a handful of following boards
+This code base already had supported for a handful of following boards (sorted alphabetically)
 
 ### MicroChip SAMD
 
@@ -26,6 +26,12 @@ This code base already had supported for a handful of following boards
 - [Nordic nRF52840 Dongle (aka pca10059)](https://www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF52840-Dongle)
 - [Nordic nRF52833 Development Kit (aka pca10100)](https://www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF52833-DK)
 
+### Nuvoton
+
+- [NuTiny NUC121S](https://direct.nuvoton.com/en/nutiny-nuc121s)
+- [NuTiny NUC125S](https://direct.nuvoton.com/en/nutiny-nuc125s)
+- [NuTiny NUC126V](https://direct.nuvoton.com/en/nutiny-nuc126v)
+
 ### NXP iMX RT
 
 - [MIMX RT1010 Evaluation Kit](https://www.nxp.com/design/development-boards/i.mx-evaluation-and-development-boards/i.mx-rt1010-evaluation-kit:MIMXRT1010-EVK)

hw/bsp/nutiny_nuc121s/board.mk

@@ -0,0 +1,55 @@
+CFLAGS += \
+  -flto \
+  -mthumb \
+  -mabi=aapcs-linux \
+  -mcpu=cortex-m0 \
+  -D__ARM_FEATURE_DSP=0 \
+  -DUSE_ASSERT=0 \
+  -DCFG_EXAMPLE_MSC_READONLY \
+  -DCFG_TUSB_MCU=OPT_MCU_NUC121
+
+# All source paths should be relative to the top level.
+LD_FILE = hw/bsp/nutiny_nuc121s/nuc121_flash.ld
+
+SRC_C += \
+  hw/mcu/nuvoton/nuc121_125/Device/Nuvoton/NUC121/Source/system_NUC121.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/adc.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/bpwm.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/clk.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/fmc.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/gpio.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/i2c.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/pdma.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/pwm.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/spi_i2s.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/sys.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/timer.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/uart.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/usbd.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/usci_i2c.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/usci_spi.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/usci_uart.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/wdt.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/wwdt.c
+
+SRC_S += \
+  hw/mcu/nuvoton/nuc121_125/Device/Nuvoton/NUC121/Source/GCC/startup_NUC121.S
+
+INC += \
+  $(TOP)/hw/mcu/nuvoton/nuc121_125/Device/Nuvoton/NUC121/Include \
+  $(TOP)/hw/mcu/nuvoton/nuc121_125/StdDriver/inc \
+  $(TOP)/hw/mcu/nuvoton/nuc121_125/CMSIS/Include
+
+# For TinyUSB port source
+VENDOR = nuvoton
+CHIP_FAMILY = nuc121
+
+# For freeRTOS port source
+FREERTOS_PORT = ARM_CM0
+
+# For flash-jlink target
+JLINK_DEVICE = NUC121SC2AE
+JLINK_IF = swd
+
+# flash using jlink
+flash: flash-jlink

hw/bsp/nutiny_nuc121s/nuc121_flash.ld

@@ -0,0 +1,195 @@
+/* Linker script to configure memory regions. */
+MEMORY
+{
+  FLASH (rx) : ORIGIN = 0x00000000, LENGTH = 0x8000    /* 32k */
+  RAM (rwx)  : ORIGIN = 0x20000000, LENGTH = 0x2000    /* 8k  */
+}
+
+/* Library configurations */
+GROUP(libgcc.a libc.a libm.a libnosys.a)
+
+/* Linker script to place sections and symbol values. Should be used together
+ * with other linker script that defines memory regions FLASH and RAM.
+ * It references following symbols, which must be defined in code:
+ *   Reset_Handler : Entry of reset handler
+ *
+ * It defines following symbols, which code can use without definition:
+ *   __exidx_start
+ *   __exidx_end
+ *   __copy_table_start__
+ *   __copy_table_end__
+ *   __zero_table_start__
+ *   __zero_table_end__
+ *   __etext
+ *   __data_start__
+ *   __preinit_array_start
+ *   __preinit_array_end
+ *   __init_array_start
+ *   __init_array_end
+ *   __fini_array_start
+ *   __fini_array_end
+ *   __data_end__
+ *   __bss_start__
+ *   __bss_end__
+ *   __end__
+ *   end
+ *   __HeapLimit
+ *   __StackLimit
+ *   __StackTop
+ *   __stack
+ *   __Vectors_End
+ *   __Vectors_Size
+ */
+ENTRY(Reset_Handler)
+
+SECTIONS
+{
+	.text :
+	{
+		KEEP(*(.vectors))
+		__Vectors_End = .;
+		__Vectors_Size = __Vectors_End - __Vectors;
+		__end__ = .;
+
+		*(.text*)
+
+		KEEP(*(.init))
+		KEEP(*(.fini))
+
+		/* .ctors */
+		*crtbegin.o(.ctors)
+		*crtbegin?.o(.ctors)
+		*(EXCLUDE_FILE(*crtend?.o *crtend.o) .ctors)
+		*(SORT(.ctors.*))
+		*(.ctors)
+
+		/* .dtors */
+ 		*crtbegin.o(.dtors)
+ 		*crtbegin?.o(.dtors)
+ 		*(EXCLUDE_FILE(*crtend?.o *crtend.o) .dtors)
+ 		*(SORT(.dtors.*))
+ 		*(.dtors)
+        
+		*(.rodata*)
+
+		KEEP(*(.eh_frame*))
+	} > FLASH
+
+	.ARM.extab :
+	{
+		*(.ARM.extab* .gnu.linkonce.armextab.*)
+	} > FLASH
+
+	__exidx_start = .;
+	.ARM.exidx :
+	{
+		*(.ARM.exidx* .gnu.linkonce.armexidx.*)
+	} > FLASH
+	__exidx_end = .;
+
+	/* To copy multiple ROM to RAM sections,
+	 * uncomment .copy.table section and,
+	 * define __STARTUP_COPY_MULTIPLE in startup_ARMCMx.S */
+	/*
+	.copy.table :
+	{
+		. = ALIGN(4);
+		__copy_table_start__ = .;
+		LONG (__etext)
+		LONG (__data_start__)
+		LONG (__data_end__ - __data_start__)
+		LONG (__etext2)
+		LONG (__data2_start__)
+		LONG (__data2_end__ - __data2_start__)
+		__copy_table_end__ = .;
+	} > FLASH
+	*/
+
+	/* To clear multiple BSS sections,
+	 * uncomment .zero.table section and,
+	 * define __STARTUP_CLEAR_BSS_MULTIPLE in startup_ARMCMx.S */
+	/*
+	.zero.table :
+	{
+		. = ALIGN(4);
+		__zero_table_start__ = .;
+		LONG (__bss_start__)
+		LONG (__bss_end__ - __bss_start__)
+		LONG (__bss2_start__)
+		LONG (__bss2_end__ - __bss2_start__)
+		__zero_table_end__ = .;
+	} > FLASH
+	*/
+
+	__etext = .;
+
+	.data : AT (__etext)
+	{
+		__data_start__ = .;
+		*(vtable)
+		*(.data*)
+
+		. = ALIGN(4);
+		/* preinit data */
+		PROVIDE_HIDDEN (__preinit_array_start = .);
+		KEEP(*(.preinit_array))
+		PROVIDE_HIDDEN (__preinit_array_end = .);
+
+		. = ALIGN(4);
+		/* init data */
+		PROVIDE_HIDDEN (__init_array_start = .);
+		KEEP(*(SORT(.init_array.*)))
+		KEEP(*(.init_array))
+		PROVIDE_HIDDEN (__init_array_end = .);
+
+
+		. = ALIGN(4);
+		/* finit data */
+		PROVIDE_HIDDEN (__fini_array_start = .);
+		KEEP(*(SORT(.fini_array.*)))
+		KEEP(*(.fini_array))
+		PROVIDE_HIDDEN (__fini_array_end = .);
+
+		KEEP(*(.jcr*))
+		. = ALIGN(4);
+		/* All data end */
+		__data_end__ = .;
+
+	} > RAM
+
+	.bss :
+	{
+		. = ALIGN(4);
+		__bss_start__ = .;
+		*(.bss*)
+		*(COMMON)
+		. = ALIGN(4);
+		__bss_end__ = .;
+	} > RAM
+
+	.heap (COPY):
+	{
+		__HeapBase = .;
+		__end__ = .;
+		end = __end__;
+		KEEP(*(.heap*))
+		__HeapLimit = .;
+	} > RAM
+
+	/* .stack_dummy section doesn't contains any symbols. It is only
+	 * used for linker to calculate size of stack sections, and assign
+	 * values to stack symbols later */
+	.stack_dummy (COPY):
+	{
+		KEEP(*(.stack*))
+	} > RAM
+
+	/* Set stack top to end of RAM, and stack limit move down by
+	 * size of stack_dummy section */
+	__StackTop = ORIGIN(RAM) + LENGTH(RAM);
+	__StackLimit = __StackTop - SIZEOF(.stack_dummy);
+	PROVIDE(__stack = __StackTop);
+
+	/* Check if data + heap + stack exceeds RAM limit */
+	ASSERT(__StackLimit >= __HeapLimit, "region RAM overflowed with stack")
+}

hw/bsp/nutiny_nuc121s/nutiny_nuc121.c

@@ -0,0 +1,102 @@
+/* 
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * 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.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#include "bsp/board.h"
+#include "NuMicro.h"
+#include "clk.h"
+#include "sys.h"
+
+void board_init(void)
+{
+  /* Unlock protected registers */
+  SYS_UnlockReg();
+
+  /*---------------------------------------------------------------------------------------------------------*/
+  /* Init System Clock                                                                                       */
+  /*---------------------------------------------------------------------------------------------------------*/
+
+  /* Enable Internal HIRC 48 MHz clock */
+  CLK_EnableXtalRC(CLK_PWRCTL_HIRCEN);
+
+  /* Waiting for Internal RC clock ready */
+  CLK_WaitClockReady(CLK_STATUS_HIRCSTB_Msk);
+
+  /* Switch HCLK clock source to Internal HIRC and HCLK source divide 1 */
+  CLK_SetHCLK(CLK_CLKSEL0_HCLKSEL_HIRC, CLK_CLKDIV0_HCLK(1));
+
+  /* Enable module clock */
+  CLK_EnableModuleClock(USBD_MODULE);
+
+  /* Select module clock source */
+  CLK_SetModuleClock(USBD_MODULE, CLK_CLKSEL3_USBDSEL_HIRC, CLK_CLKDIV0_USB(1));
+
+  /* Enable module clock */
+  CLK_EnableModuleClock(USBD_MODULE);
+
+#if CFG_TUSB_OS  == OPT_OS_NONE
+  // 1ms tick timer
+  SysTick_Config(48000000 / 1000);
+#endif
+}
+
+#if CFG_TUSB_OS  == OPT_OS_NONE
+volatile uint32_t system_ticks = 0;
+void SysTick_Handler (void)
+{
+  system_ticks++;
+}
+
+uint32_t board_millis(void)
+{
+  return system_ticks;
+}
+#endif
+
+//--------------------------------------------------------------------+
+// Board porting API
+//--------------------------------------------------------------------+
+
+void board_led_write(bool state)
+{
+  (void)(state);
+}
+
+uint32_t board_button_read(void)
+{
+  return 0;
+}
+
+int board_uart_read(uint8_t* buf, int len)
+{
+  (void) buf; (void) len;
+  return 0;
+}
+
+int board_uart_write(void const * buf, int len)
+{
+  (void) buf; (void) len;
+  return 0;
+}

hw/bsp/nutiny_nuc125s/board.mk

@@ -0,0 +1,38 @@
+CFLAGS += \
+  -flto \
+  -mthumb \
+  -mabi=aapcs-linux \
+  -mcpu=cortex-m0 \
+  -D__ARM_FEATURE_DSP=0 \
+  -DUSE_ASSERT=0 \
+  -DCFG_EXAMPLE_MSC_READONLY \
+  -DCFG_TUSB_MCU=OPT_MCU_NUC121
+
+# All source paths should be relative to the top level.
+LD_FILE = hw/bsp/nutiny_nuc125s/nuc125_flash.ld
+
+SRC_C += \
+  hw/mcu/nuvoton/nuc121_125/Device/Nuvoton/NUC121/Source/system_NUC121.c \
+  hw/mcu/nuvoton/nuc121_125/StdDriver/src/clk.c
+
+SRC_S += \
+  hw/mcu/nuvoton/nuc121_125/Device/Nuvoton/NUC121/Source/GCC/startup_NUC121.S
+
+INC += \
+  $(TOP)/hw/mcu/nuvoton/nuc121_125/Device/Nuvoton/NUC121/Include \
+  $(TOP)/hw/mcu/nuvoton/nuc121_125/StdDriver/inc \
+  $(TOP)/hw/mcu/nuvoton/nuc121_125/CMSIS/Include
+
+# For TinyUSB port source
+VENDOR = nuvoton
+CHIP_FAMILY = nuc121
+
+# For freeRTOS port source
+FREERTOS_PORT = ARM_CM0
+
+# For flash-jlink target
+JLINK_DEVICE = NUC125SC2AE
+JLINK_IF = swd
+
+# flash using jlink
+flash: flash-jlink

hw/bsp/nutiny_nuc125s/nuc125_flash.ld

@@ -0,0 +1,195 @@
+/* Linker script to configure memory regions. */
+MEMORY
+{
+  FLASH (rx) : ORIGIN = 0x00000000, LENGTH = 0x8000    /* 32k */
+  RAM (rwx)  : ORIGIN = 0x20000000, LENGTH = 0x2000    /* 8k  */
+}
+
+/* Library configurations */
+GROUP(libgcc.a libc.a libm.a libnosys.a)
+
+/* Linker script to place sections and symbol values. Should be used together
+ * with other linker script that defines memory regions FLASH and RAM.
+ * It references following symbols, which must be defined in code:
+ *   Reset_Handler : Entry of reset handler
+ *
+ * It defines following symbols, which code can use without definition:
+ *   __exidx_start
+ *   __exidx_end
+ *   __copy_table_start__
+ *   __copy_table_end__
+ *   __zero_table_start__
+ *   __zero_table_end__
+ *   __etext
+ *   __data_start__
+ *   __preinit_array_start
+ *   __preinit_array_end
+ *   __init_array_start
+ *   __init_array_end
+ *   __fini_array_start
+ *   __fini_array_end
+ *   __data_end__
+ *   __bss_start__
+ *   __bss_end__
+ *   __end__
+ *   end
+ *   __HeapLimit
+ *   __StackLimit
+ *   __StackTop
+ *   __stack
+ *   __Vectors_End
+ *   __Vectors_Size
+ */
+ENTRY(Reset_Handler)
+
+SECTIONS
+{
+	.text :
+	{
+		KEEP(*(.vectors))
+		__Vectors_End = .;
+		__Vectors_Size = __Vectors_End - __Vectors;
+		__end__ = .;
+
+		*(.text*)
+
+		KEEP(*(.init))
+		KEEP(*(.fini))
+
+		/* .ctors */
+		*crtbegin.o(.ctors)
+		*crtbegin?.o(.ctors)
+		*(EXCLUDE_FILE(*crtend?.o *crtend.o) .ctors)
+		*(SORT(.ctors.*))
+		*(.ctors)
+
+		/* .dtors */
+ 		*crtbegin.o(.dtors)
+ 		*crtbegin?.o(.dtors)
+ 		*(EXCLUDE_FILE(*crtend?.o *crtend.o) .dtors)
+ 		*(SORT(.dtors.*))
+ 		*(.dtors)
+        
+		*(.rodata*)
+
+		KEEP(*(.eh_frame*))
+	} > FLASH
+
+	.ARM.extab :
+	{
+		*(.ARM.extab* .gnu.linkonce.armextab.*)
+	} > FLASH
+
+	__exidx_start = .;
+	.ARM.exidx :
+	{
+		*(.ARM.exidx* .gnu.linkonce.armexidx.*)
+	} > FLASH
+	__exidx_end = .;
+
+	/* To copy multiple ROM to RAM sections,
+	 * uncomment .copy.table section and,
+	 * define __STARTUP_COPY_MULTIPLE in startup_ARMCMx.S */
+	/*
+	.copy.table :
+	{
+		. = ALIGN(4);
+		__copy_table_start__ = .;
+		LONG (__etext)
+		LONG (__data_start__)
+		LONG (__data_end__ - __data_start__)
+		LONG (__etext2)
+		LONG (__data2_start__)
+		LONG (__data2_end__ - __data2_start__)
+		__copy_table_end__ = .;
+	} > FLASH
+	*/
+
+	/* To clear multiple BSS sections,
+	 * uncomment .zero.table section and,
+	 * define __STARTUP_CLEAR_BSS_MULTIPLE in startup_ARMCMx.S */
+	/*
+	.zero.table :
+	{
+		. = ALIGN(4);
+		__zero_table_start__ = .;
+		LONG (__bss_start__)
+		LONG (__bss_end__ - __bss_start__)
+		LONG (__bss2_start__)
+		LONG (__bss2_end__ - __bss2_start__)
+		__zero_table_end__ = .;
+	} > FLASH
+	*/
+
+	__etext = .;
+
+	.data : AT (__etext)
+	{
+		__data_start__ = .;
+		*(vtable)
+		*(.data*)
+
+		. = ALIGN(4);
+		/* preinit data */
+		PROVIDE_HIDDEN (__preinit_array_start = .);
+		KEEP(*(.preinit_array))
+		PROVIDE_HIDDEN (__preinit_array_end = .);
+
+		. = ALIGN(4);
+		/* init data */
+		PROVIDE_HIDDEN (__init_array_start = .);
+		KEEP(*(SORT(.init_array.*)))
+		KEEP(*(.init_array))
+		PROVIDE_HIDDEN (__init_array_end = .);
+
+
+		. = ALIGN(4);
+		/* finit data */
+		PROVIDE_HIDDEN (__fini_array_start = .);
+		KEEP(*(SORT(.fini_array.*)))
+		KEEP(*(.fini_array))
+		PROVIDE_HIDDEN (__fini_array_end = .);
+
+		KEEP(*(.jcr*))
+		. = ALIGN(4);
+		/* All data end */
+		__data_end__ = .;
+
+	} > RAM
+
+	.bss :
+	{
+		. = ALIGN(4);
+		__bss_start__ = .;
+		*(.bss*)
+		*(COMMON)
+		. = ALIGN(4);
+		__bss_end__ = .;
+	} > RAM
+
+	.heap (COPY):
+	{
+		__HeapBase = .;
+		__end__ = .;
+		end = __end__;
+		KEEP(*(.heap*))
+		__HeapLimit = .;
+	} > RAM
+
+	/* .stack_dummy section doesn't contains any symbols. It is only
+	 * used for linker to calculate size of stack sections, and assign
+	 * values to stack symbols later */
+	.stack_dummy (COPY):
+	{
+		KEEP(*(.stack*))
+	} > RAM
+
+	/* Set stack top to end of RAM, and stack limit move down by
+	 * size of stack_dummy section */
+	__StackTop = ORIGIN(RAM) + LENGTH(RAM);
+	__StackLimit = __StackTop - SIZEOF(.stack_dummy);
+	PROVIDE(__stack = __StackTop);
+
+	/* Check if data + heap + stack exceeds RAM limit */
+	ASSERT(__StackLimit >= __HeapLimit, "region RAM overflowed with stack")
+}

hw/bsp/nutiny_nuc125s/nutiny_nuc125.c

@@ -0,0 +1,102 @@
+/* 
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * 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.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#include "bsp/board.h"
+#include "NuMicro.h"
+#include "clk.h"
+#include "sys.h"
+
+void board_init(void)
+{
+  /* Unlock protected registers */
+  SYS_UnlockReg();
+
+  /*---------------------------------------------------------------------------------------------------------*/
+  /* Init System Clock                                                                                       */
+  /*---------------------------------------------------------------------------------------------------------*/
+
+  /* Enable Internal HIRC 48 MHz clock */
+  CLK_EnableXtalRC(CLK_PWRCTL_HIRCEN);
+
+  /* Waiting for Internal RC clock ready */
+  CLK_WaitClockReady(CLK_STATUS_HIRCSTB_Msk);
+
+  /* Switch HCLK clock source to Internal HIRC and HCLK source divide 1 */
+  CLK_SetHCLK(CLK_CLKSEL0_HCLKSEL_HIRC, CLK_CLKDIV0_HCLK(1));
+
+  /* Enable module clock */
+  CLK_EnableModuleClock(USBD_MODULE);
+
+  /* Select module clock source */
+  CLK_SetModuleClock(USBD_MODULE, CLK_CLKSEL3_USBDSEL_HIRC, CLK_CLKDIV0_USB(1));
+
+  /* Enable module clock */
+  CLK_EnableModuleClock(USBD_MODULE);
+
+#if CFG_TUSB_OS  == OPT_OS_NONE
+  // 1ms tick timer
+  SysTick_Config(48000000 / 1000);
+#endif
+}
+
+#if CFG_TUSB_OS  == OPT_OS_NONE
+volatile uint32_t system_ticks = 0;
+void SysTick_Handler (void)
+{
+  system_ticks++;
+}
+
+uint32_t board_millis(void)
+{
+  return system_ticks;
+}
+#endif
+
+//--------------------------------------------------------------------+
+// Board porting API
+//--------------------------------------------------------------------+
+
+void board_led_write(bool state)
+{
+  (void)(state);
+}
+
+uint32_t board_button_read(void)
+{
+  return 0;
+}
+
+int board_uart_read(uint8_t* buf, int len)
+{
+  (void) buf; (void) len;
+  return 0;
+}
+
+int board_uart_write(void const * buf, int len)
+{
+  (void) buf; (void) len;
+  return 0;
+}

hw/bsp/nutiny_nuc126v/board.mk

@@ -0,0 +1,59 @@
+CFLAGS += \
+  -flto \
+  -mthumb \
+  -mabi=aapcs-linux \
+  -mcpu=cortex-m0 \
+  -D__ARM_FEATURE_DSP=0 \
+  -DUSE_ASSERT=0 \
+  -D__CORTEX_SC=0 \
+  -DCFG_TUSB_MCU=OPT_MCU_NUC126
+
+# All source paths should be relative to the top level.
+LD_FILE = hw/bsp/nutiny_nuc126v/nuc126_flash.ld
+
+SRC_C += \
+  hw/mcu/nuvoton/nuc126/Device/Nuvoton/NUC126/Source/system_NUC126.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/acmp.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/adc.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/clk.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/crc.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/ebi.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/fmc.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/gpio.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/pdma.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/pwm.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/rtc.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/sc.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/scuart.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/spi.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/sys.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/timer.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/timer_pwm.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/uart.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/usbd.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/usci_spi.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/usci_uart.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/wdt.c \
+  hw/mcu/nuvoton/nuc126/StdDriver/src/wwdt.c
+
+SRC_S += \
+  hw/mcu/nuvoton/nuc126/Device/Nuvoton/NUC126/Source/GCC/startup_NUC126.S
+
+INC += \
+  $(TOP)/hw/mcu/nuvoton/nuc126/Device/Nuvoton/NUC126/Include \
+  $(TOP)/hw/mcu/nuvoton/nuc126/StdDriver/inc \
+  $(TOP)/hw/mcu/nuvoton/nuc126/CMSIS/Include
+
+# For TinyUSB port source
+VENDOR = nuvoton
+CHIP_FAMILY = nuc121
+
+# For freeRTOS port source
+FREERTOS_PORT = ARM_CM0
+
+# For flash-jlink target
+JLINK_DEVICE = NUC126VG4AE
+JLINK_IF = swd
+
+# flash using jlink
+flash: flash-jlink

hw/bsp/nutiny_nuc126v/nuc126_flash.ld

@@ -0,0 +1,195 @@
+/* Linker script to configure memory regions. */
+MEMORY
+{
+  FLASH (rx) : ORIGIN = 0x00000000, LENGTH = 0x40000   /* 256k */
+  RAM (rwx)  : ORIGIN = 0x20000000, LENGTH = 0x5000    /*  20k */
+}
+
+/* Library configurations */
+GROUP(libgcc.a libc.a libm.a libnosys.a)
+
+/* Linker script to place sections and symbol values. Should be used together
+ * with other linker script that defines memory regions FLASH and RAM.
+ * It references following symbols, which must be defined in code:
+ *   Reset_Handler : Entry of reset handler
+ *
+ * It defines following symbols, which code can use without definition:
+ *   __exidx_start
+ *   __exidx_end
+ *   __copy_table_start__
+ *   __copy_table_end__
+ *   __zero_table_start__
+ *   __zero_table_end__
+ *   __etext
+ *   __data_start__
+ *   __preinit_array_start
+ *   __preinit_array_end
+ *   __init_array_start
+ *   __init_array_end
+ *   __fini_array_start
+ *   __fini_array_end
+ *   __data_end__
+ *   __bss_start__
+ *   __bss_end__
+ *   __end__
+ *   end
+ *   __HeapLimit
+ *   __StackLimit
+ *   __StackTop
+ *   __stack
+ *   __Vectors_End
+ *   __Vectors_Size
+ */
+ENTRY(Reset_Handler)
+
+SECTIONS
+{
+	.text :
+	{
+		KEEP(*(.vectors))
+		__Vectors_End = .;
+		__Vectors_Size = __Vectors_End - __Vectors;
+		__end__ = .;
+
+		*(.text*)
+
+		KEEP(*(.init))
+		KEEP(*(.fini))
+
+		/* .ctors */
+		*crtbegin.o(.ctors)
+		*crtbegin?.o(.ctors)
+		*(EXCLUDE_FILE(*crtend?.o *crtend.o) .ctors)
+		*(SORT(.ctors.*))
+		*(.ctors)
+
+		/* .dtors */
+ 		*crtbegin.o(.dtors)
+ 		*crtbegin?.o(.dtors)
+ 		*(EXCLUDE_FILE(*crtend?.o *crtend.o) .dtors)
+ 		*(SORT(.dtors.*))
+ 		*(.dtors)
+
+		*(.rodata*)
+
+		KEEP(*(.eh_frame*))
+	} > FLASH
+
+	.ARM.extab :
+	{
+		*(.ARM.extab* .gnu.linkonce.armextab.*)
+	} > FLASH
+
+	__exidx_start = .;
+	.ARM.exidx :
+	{
+		*(.ARM.exidx* .gnu.linkonce.armexidx.*)
+	} > FLASH
+	__exidx_end = .;
+
+	/* To copy multiple ROM to RAM sections,
+	 * uncomment .copy.table section and,
+	 * define __STARTUP_COPY_MULTIPLE in startup_ARMCMx.S */
+	/*
+	.copy.table :
+	{
+		. = ALIGN(4);
+		__copy_table_start__ = .;
+		LONG (__etext)
+		LONG (__data_start__)
+		LONG (__data_end__ - __data_start__)
+		LONG (__etext2)
+		LONG (__data2_start__)
+		LONG (__data2_end__ - __data2_start__)
+		__copy_table_end__ = .;
+	} > FLASH
+	*/
+
+	/* To clear multiple BSS sections,
+	 * uncomment .zero.table section and,
+	 * define __STARTUP_CLEAR_BSS_MULTIPLE in startup_ARMCMx.S */
+	/*
+	.zero.table :
+	{
+		. = ALIGN(4);
+		__zero_table_start__ = .;
+		LONG (__bss_start__)
+		LONG (__bss_end__ - __bss_start__)
+		LONG (__bss2_start__)
+		LONG (__bss2_end__ - __bss2_start__)
+		__zero_table_end__ = .;
+	} > FLASH
+	*/
+
+	__etext = .;
+
+	.data : AT (__etext)
+	{
+		__data_start__ = .;
+		*(vtable)
+		*(.data*)
+
+		. = ALIGN(4);
+		/* preinit data */
+		PROVIDE_HIDDEN (__preinit_array_start = .);
+		KEEP(*(.preinit_array))
+		PROVIDE_HIDDEN (__preinit_array_end = .);
+
+		. = ALIGN(4);
+		/* init data */
+		PROVIDE_HIDDEN (__init_array_start = .);
+		KEEP(*(SORT(.init_array.*)))
+		KEEP(*(.init_array))
+		PROVIDE_HIDDEN (__init_array_end = .);
+
+
+		. = ALIGN(4);
+		/* finit data */
+		PROVIDE_HIDDEN (__fini_array_start = .);
+		KEEP(*(SORT(.fini_array.*)))
+		KEEP(*(.fini_array))
+		PROVIDE_HIDDEN (__fini_array_end = .);
+
+		KEEP(*(.jcr*))
+		. = ALIGN(4);
+		/* All data end */
+		__data_end__ = .;
+
+	} > RAM
+
+	.bss :
+	{
+		. = ALIGN(4);
+		__bss_start__ = .;
+		*(.bss*)
+		*(COMMON)
+		. = ALIGN(4);
+		__bss_end__ = .;
+	} > RAM
+
+	.heap (COPY):
+	{
+		__HeapBase = .;
+		__end__ = .;
+		end = __end__;
+		KEEP(*(.heap*))
+		__HeapLimit = .;
+	} > RAM
+
+	/* .stack_dummy section doesn't contains any symbols. It is only
+	 * used for linker to calculate size of stack sections, and assign
+	 * values to stack symbols later */
+	.stack_dummy (COPY):
+	{
+		KEEP(*(.stack*))
+	} > RAM
+
+	/* Set stack top to end of RAM, and stack limit move down by
+	 * size of stack_dummy section */
+	__StackTop = ORIGIN(RAM) + LENGTH(RAM);
+	__StackLimit = __StackTop - SIZEOF(.stack_dummy);
+	PROVIDE(__stack = __StackTop);
+
+	/* Check if data + heap + stack exceeds RAM limit */
+	ASSERT(__StackLimit >= __HeapLimit, "region RAM overflowed with stack")
+}

hw/bsp/nutiny_nuc126v/nutiny_nuc126.c

@@ -0,0 +1,133 @@
+/* 
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * 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.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+#include "bsp/board.h"
+#include "NuMicro.h"
+#include "clk.h"
+#include "sys.h"
+
+#define CRYSTAL_LESS /* system will be 48MHz when defined, otherwise, system is 72MHz */
+#define HIRC48_AUTO_TRIM    SYS_IRCTCTL1_REFCKSEL_Msk | (1UL << SYS_IRCTCTL1_LOOPSEL_Pos) | (2UL << SYS_IRCTCTL1_FREQSEL_Pos)
+#define TRIM_INIT           (SYS_BASE+0x118)
+
+void board_init(void)
+{
+  /* Unlock protected registers */
+  SYS_UnlockReg();
+
+  /*---------------------------------------------------------------------------------------------------------*/
+  /* Init System Clock                                                                                       */
+  /*---------------------------------------------------------------------------------------------------------*/
+
+  /* Enable Internal RC 22.1184 MHz clock */
+  CLK_EnableXtalRC(CLK_PWRCTL_HIRCEN_Msk);
+
+  /* Waiting for Internal RC clock ready */
+  CLK_WaitClockReady(CLK_STATUS_HIRCSTB_Msk);
+
+  /* Switch HCLK clock source to Internal RC and HCLK source divide 1 */
+  CLK_SetHCLK(CLK_CLKSEL0_HCLKSEL_HIRC, CLK_CLKDIV0_HCLK(1));
+
+#ifndef CRYSTAL_LESS
+  /* Enable external XTAL 12 MHz clock */
+  CLK_EnableXtalRC(CLK_PWRCTL_HXTEN_Msk);
+
+  /* Waiting for external XTAL clock ready */
+  CLK_WaitClockReady(CLK_STATUS_HXTSTB_Msk);
+
+  /* Set core clock */
+  CLK_SetCoreClock(72000000);
+
+  /* Use HIRC as UART clock source */
+  CLK_SetModuleClock(UART0_MODULE, CLK_CLKSEL1_UARTSEL_HIRC, CLK_CLKDIV0_UART(1));
+
+  /* Use PLL as USB clock source */
+  CLK_SetModuleClock(USBD_MODULE, CLK_CLKSEL3_USBDSEL_PLL, CLK_CLKDIV0_USB(3));
+
+#else
+  /* Enable Internal RC 48MHz clock */
+  CLK_EnableXtalRC(CLK_PWRCTL_HIRC48EN_Msk);
+
+  /* Waiting for Internal RC clock ready */
+  CLK_WaitClockReady(CLK_STATUS_HIRC48STB_Msk);
+
+  /* Switch HCLK clock source to Internal RC and HCLK source divide 1 */
+  CLK_SetHCLK(CLK_CLKSEL0_HCLKSEL_HIRC48, CLK_CLKDIV0_HCLK(1));
+
+  /* Use HIRC as UART clock source */
+  CLK_SetModuleClock(UART0_MODULE, CLK_CLKSEL1_UARTSEL_HIRC, CLK_CLKDIV0_UART(1));
+
+  /* Use HIRC48 as USB clock source */
+  CLK_SetModuleClock(USBD_MODULE, CLK_CLKSEL3_USBDSEL_HIRC48, CLK_CLKDIV0_USB(1));
+#endif
+
+  /* Enable module clock */
+  CLK_EnableModuleClock(USBD_MODULE);
+
+#if CFG_TUSB_OS  == OPT_OS_NONE
+  // 1ms tick timer
+  SysTick_Config(48000000 / 1000);
+#endif
+}
+
+#if CFG_TUSB_OS  == OPT_OS_NONE
+volatile uint32_t system_ticks = 0;
+void SysTick_Handler (void)
+{
+  system_ticks++;
+}
+
+uint32_t board_millis(void)
+{
+  return system_ticks;
+}
+#endif
+
+//--------------------------------------------------------------------+
+// Board porting API
+//--------------------------------------------------------------------+
+
+void board_led_write(bool state)
+{
+  (void)(state);
+}
+
+uint32_t board_button_read(void)
+{
+  return 0;
+}
+
+int board_uart_read(uint8_t* buf, int len)
+{
+  (void) buf; (void) len;
+  return 0;
+}
+
+int board_uart_write(void const * buf, int len)
+{
+  (void) buf; (void) len;
+  return 0;
+}

hw/mcu/nuvoton

@@ -0,0 +1 @@
+Subproject commit dc96fff794d14818c93ea1d4d760d51a014d70c5

src/portable/nuvoton/nuc121/dcd_nuc121.c

@@ -0,0 +1,434 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Peter Lawrence
+ *
+ * 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.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+/*
+  Theory of operation:
+
+  The NUC121/NUC125/NUC126 USBD peripheral has eight "EP"s, but each is simplex, 
+  so two collectively (peripheral nomenclature of "EP0" and "EP1") are needed to 
+  implement USB EP0.  PERIPH_EP0 and PERIPH_EP1 are used by this driver for 
+  EP0_IN and EP0_OUT respectively.  This leaves up to six for user usage.
+*/
+
+#include "tusb_option.h"
+
+#if TUSB_OPT_DEVICE_ENABLED && ( (CFG_TUSB_MCU == OPT_MCU_NUC121) || (CFG_TUSB_MCU == OPT_MCU_NUC126) )
+
+#include "device/dcd.h"
+#include "NuMicro.h"
+
+/* allocation of USBD RAM for Setup, EP0_IN, and and EP_OUT */
+#define PERIPH_SETUP_BUF_BASE  0
+#define PERIPH_SETUP_BUF_LEN   8
+#define PERIPH_EP0_BUF_BASE    (PERIPH_SETUP_BUF_BASE + PERIPH_SETUP_BUF_LEN)
+#define PERIPH_EP0_BUF_LEN     CFG_TUD_ENDPOINT0_SIZE
+#define PERIPH_EP1_BUF_BASE    (PERIPH_EP0_BUF_BASE + PERIPH_EP0_BUF_LEN)
+#define PERIPH_EP1_BUF_LEN     CFG_TUD_ENDPOINT0_SIZE
+#define PERIPH_EP2_BUF_BASE    (PERIPH_EP1_BUF_BASE + PERIPH_EP1_BUF_LEN)
+
+/* rather important info unfortunately not provided by device include files: how much there is */
+#define USBD_BUF_SIZE          ((CFG_TUSB_MCU == OPT_MCU_NUC121) ? 768 : 512)
+
+enum ep_enum
+{
+  PERIPH_EP0 = 0,
+  PERIPH_EP1 = 1,
+  PERIPH_EP2 = 2,
+  PERIPH_EP3 = 3,
+  PERIPH_EP4 = 4,
+  PERIPH_EP5 = 5,
+  PERIPH_EP6 = 6,
+  PERIPH_EP7 = 7,
+  PERIPH_MAX_EP,
+};
+
+/* set by dcd_set_address() */
+static volatile uint8_t assigned_address;
+
+/* reset by dcd_init(), this is used by dcd_edpt_open() to assign USBD peripheral buffer addresses */
+static uint32_t bufseg_addr;
+
+/* used by dcd_edpt_xfer() and the ISR to reset the data sync (DATA0/DATA1) in an EP0_IN transfer */
+static bool active_ep0_xfer;
+
+/* RAM table needed to track ongoing transfers performed by dcd_edpt_xfer(), dcd_in_xfer(), and the ISR */
+static struct xfer_ctl_t
+{
+  uint8_t *data_ptr;         /* collectively, data_ptr and remaining_bytes track progress of endpoint transfers */
+  uint16_t remaining_bytes;
+  uint16_t max_packet_size;  /* needed since device driver only finds out this at runtime */
+  uint16_t total_bytes;      /* quantity needed to pass as argument to dcd_event_xfer_complete() (for IN endpoints) */
+} xfer_table[PERIPH_MAX_EP];
+
+/*
+  local helper functions
+*/
+
+static void usb_attach(void)
+{
+  USBD->SE0 &= ~USBD_SE0_SE0_Msk;
+}
+
+static void usb_detach(void)
+{
+  USBD->SE0 |= USBD_SE0_SE0_Msk;
+}
+
+static void usb_control_send_zlp(void)
+{
+  USBD->EP[PERIPH_EP0].CFG |= USBD_CFG_DSQSYNC_Msk;
+  USBD->EP[PERIPH_EP0].MXPLD = 0;
+}
+
+/* reconstruct ep_addr from particular USB Configuration Register */
+static uint8_t decode_ep_addr(USBD_EP_T *ep)
+{
+  uint8_t ep_addr = ep->CFG & USBD_CFG_EPNUM_Msk;
+  if ( USBD_CFG_EPMODE_IN == (ep->CFG & USBD_CFG_STATE_Msk) )
+    ep_addr |= TUSB_DIR_IN_MASK;
+  return ep_addr;
+}
+
+/* map 8-bit ep_addr into peripheral endpoint index (PERIPH_EP0...) */
+static USBD_EP_T *ep_entry(uint8_t ep_addr, bool add)
+{
+  USBD_EP_T *ep;
+  enum ep_enum ep_index;
+
+  for (ep_index = PERIPH_EP0, ep = USBD->EP; ep_index < PERIPH_MAX_EP; ep_index++, ep++)
+  {
+    if (add)
+    {
+      /* take first peripheral endpoint that is unused */
+      if (0 == (ep->CFG & USBD_CFG_STATE_Msk)) return ep;
+    }
+    else
+    {
+      /* find a peripheral endpoint that matches ep_addr */
+      uint8_t candidate_ep_addr = decode_ep_addr(ep);
+      if (candidate_ep_addr == ep_addr) return ep;
+    }
+  }
+
+  return NULL;
+}
+
+/* perform an IN endpoint transfer; this is called by dcd_edpt_xfer() and the ISR  */
+static void dcd_in_xfer(struct xfer_ctl_t *xfer, USBD_EP_T *ep)
+{
+  uint16_t bytes_now = tu_min16(xfer->remaining_bytes, xfer->max_packet_size);
+
+  memcpy((uint8_t *)(USBD_BUF_BASE + ep->BUFSEG), xfer->data_ptr, bytes_now);
+  ep->MXPLD = bytes_now;
+}
+
+/* centralized location for USBD interrupt enable bit mask */
+static const uint32_t enabled_irqs = USBD_INTSTS_VBDETIF_Msk | USBD_INTSTS_BUSIF_Msk | USBD_INTSTS_SETUP_Msk | USBD_INTSTS_USBIF_Msk | USBD_INTSTS_SOFIF_Msk;
+
+/*
+  NUC121/NUC125/NUC126 TinyUSB API driver implementation
+*/
+
+void dcd_init(uint8_t rhport)
+{
+  (void) rhport;
+
+#ifdef SUPPORT_LPM
+  USBD->ATTR = 0x7D0 | USBD_LPMACK;
+#else
+  USBD->ATTR = 0x7D0;
+#endif
+
+  usb_detach();
+
+  USBD->STBUFSEG = PERIPH_SETUP_BUF_BASE;
+
+  for (enum ep_enum ep_index = PERIPH_EP0; ep_index < PERIPH_MAX_EP; ep_index++)
+  {
+    USBD->EP[ep_index].CFGP &= ~USBD_CFG_STATE_Msk;
+  }
+
+  /* allocate the default EP0 endpoints */
+
+  USBD->EP[PERIPH_EP0].CFG = USBD_CFG_CSTALL_Msk | USBD_CFG_EPMODE_IN;
+  USBD->EP[PERIPH_EP0].BUFSEG = PERIPH_EP0_BUF_BASE;
+  xfer_table[PERIPH_EP0].max_packet_size = PERIPH_EP0_BUF_LEN;
+
+  USBD->EP[PERIPH_EP1].CFG = USBD_CFG_CSTALL_Msk | USBD_CFG_EPMODE_OUT;
+  USBD->EP[PERIPH_EP1].BUFSEG = PERIPH_EP1_BUF_BASE;
+  xfer_table[PERIPH_EP1].max_packet_size = PERIPH_EP1_BUF_LEN;
+
+  /* USB RAM beyond what we've allocated above is available to the user */
+  bufseg_addr = PERIPH_EP2_BUF_BASE;
+
+  usb_attach();
+
+  USBD->INTSTS = enabled_irqs;
+  USBD->INTEN  = enabled_irqs;
+}
+
+void dcd_int_enable(uint8_t rhport)
+{
+  (void) rhport;
+  NVIC_EnableIRQ(USBD_IRQn);
+}
+
+void dcd_int_disable(uint8_t rhport)
+{
+  (void) rhport;
+  NVIC_DisableIRQ(USBD_IRQn);
+}
+
+void dcd_set_address(uint8_t rhport, uint8_t dev_addr)
+{
+  (void) rhport;
+  usb_control_send_zlp(); /* SET_ADDRESS is the one exception where TinyUSB doesn't use dcd_edpt_xfer() to generate a ZLP */
+  assigned_address = dev_addr;
+}
+
+void dcd_set_config(uint8_t rhport, uint8_t config_num)
+{
+  (void) rhport;
+  (void) config_num;
+}
+
+void dcd_remote_wakeup(uint8_t rhport)
+{
+  (void) rhport;
+  USBD->ATTR = USBD_ATTR_RWAKEUP_Msk;
+}
+
+bool dcd_edpt_open(uint8_t rhport, tusb_desc_endpoint_t const * p_endpoint_desc)
+{
+  (void) rhport;
+
+  USBD_EP_T *ep = ep_entry(p_endpoint_desc->bEndpointAddress, true);
+  TU_ASSERT(ep);
+
+  /* mine the data for the information we need */
+  int const dir = tu_edpt_dir(p_endpoint_desc->bEndpointAddress);
+  int const size = p_endpoint_desc->wMaxPacketSize.size;
+  tusb_xfer_type_t const type = p_endpoint_desc->bmAttributes.xfer;
+  struct xfer_ctl_t *xfer = &xfer_table[ep - USBD->EP];
+
+  /* allocate buffer from USB RAM */
+  ep->BUFSEG = bufseg_addr;
+  bufseg_addr += size;
+  TU_ASSERT(bufseg_addr <= USBD_BUF_SIZE);
+
+  /* construct USB Configuration Register value and then write it */
+  uint32_t cfg = tu_edpt_number(p_endpoint_desc->bEndpointAddress);
+  cfg |= (TUSB_DIR_IN == dir) ? USBD_CFG_EPMODE_IN : USBD_CFG_EPMODE_OUT;
+  if (TUSB_XFER_ISOCHRONOUS == type)
+    cfg |= USBD_CFG_TYPE_ISO;
+  ep->CFG = cfg;
+
+  /* make a note of the endpoint size */
+  xfer->max_packet_size = size;
+
+  return true;
+}
+
+bool dcd_edpt_xfer(uint8_t rhport, uint8_t ep_addr, uint8_t *buffer, uint16_t total_bytes)
+{
+  (void) rhport;
+
+  /* mine the data for the information we need */
+  tusb_dir_t dir = tu_edpt_dir(ep_addr);
+  USBD_EP_T *ep = ep_entry(ep_addr, false);
+  struct xfer_ctl_t *xfer = &xfer_table[ep - USBD->EP];
+
+  /* store away the information we'll needing now and later */
+  xfer->data_ptr = buffer;
+  xfer->remaining_bytes = total_bytes;
+  xfer->total_bytes = total_bytes;
+
+  /* for the first of one or more EP0_IN packets in a message, the first must be DATA1 */
+  if ( (0x80 == ep_addr) && !active_ep0_xfer ) ep->CFG |= USBD_CFG_DSQSYNC_Msk;
+
+  if (TUSB_DIR_IN == dir)
+    dcd_in_xfer(xfer, ep);
+  else
+    ep->MXPLD = xfer->max_packet_size;
+
+  return true;
+}
+
+void dcd_edpt_stall(uint8_t rhport, uint8_t ep_addr)
+{
+  (void) rhport;
+  USBD_EP_T *ep = ep_entry(ep_addr, false);
+  ep->CFGP |= USBD_CFGP_SSTALL_Msk;
+}
+
+void dcd_edpt_clear_stall(uint8_t rhport, uint8_t ep_addr)
+{
+  (void) rhport;
+  USBD_EP_T *ep = ep_entry(ep_addr, false);
+  ep->CFG |= USBD_CFG_CSTALL_Msk;
+}
+
+void USBD_IRQHandler(void)
+{
+  uint32_t status = USBD->INTSTS;
+#ifdef SUPPORT_LPM
+  uint32_t state = USBD->ATTR & 0x300f;
+#else
+  uint32_t state = USBD->ATTR & 0xf;
+#endif
+
+  if(status & USBD_INTSTS_VBDETIF_Msk)
+  {
+    if(USBD->VBUSDET & USBD_VBUSDET_VBUSDET_Msk)
+    {
+      /* USB connect */
+      USBD->ATTR |= USBD_ATTR_USBEN_Msk | USBD_ATTR_PHYEN_Msk;
+    }
+    else
+    {
+      /* USB disconnect */
+      USBD->ATTR &= ~USBD_ATTR_USBEN_Msk;
+    }
+  }
+
+  if(status & USBD_INTSTS_BUSIF_Msk)
+  {
+    if(state & USBD_ATTR_USBRST_Msk)
+    {
+      /* USB bus reset */
+      USBD->ATTR |= USBD_ATTR_USBEN_Msk | USBD_ATTR_PHYEN_Msk;
+
+      /* Reset all endpoints to DATA0 */
+      for(enum ep_enum ep_index = PERIPH_EP0; ep_index < PERIPH_MAX_EP; ep_index++)
+        USBD->EP[ep_index].CFG &= ~USBD_CFG_DSQSYNC_Msk;
+
+      /* Reset USB device address */
+      USBD->FADDR = 0;
+
+      /* reset EP0_IN flag */
+      active_ep0_xfer = false;
+
+      dcd_event_bus_signal(0, DCD_EVENT_BUS_RESET, true);
+    }
+
+    if(state & USBD_ATTR_SUSPEND_Msk)
+    {
+      /* Enable USB but disable PHY */
+      USBD->ATTR &= ~USBD_ATTR_PHYEN_Msk;
+      dcd_event_bus_signal(0, DCD_EVENT_SUSPEND, true);
+    }
+
+    if(state & USBD_ATTR_RESUME_Msk)
+    {
+      /* Enable USB and enable PHY */
+      USBD->ATTR |= USBD_ATTR_USBEN_Msk | USBD_ATTR_PHYEN_Msk;
+      dcd_event_bus_signal(0, DCD_EVENT_RESUME, true);
+    }
+  }
+
+  if(status & USBD_INTSTS_SETUP_Msk)
+  {
+    /* clear the data ready flag of control endpoints */
+    USBD->EP[PERIPH_EP0].CFGP |= USBD_CFGP_CLRRDY_Msk;
+    USBD->EP[PERIPH_EP1].CFGP |= USBD_CFGP_CLRRDY_Msk;
+
+    /* get SETUP packet from USB buffer */
+    dcd_event_setup_received(0, (uint8_t *)USBD_BUF_BASE, true);
+  }
+
+  if(status & USBD_INTSTS_USBIF_Msk)
+  {
+    if (status & USBD_INTSTS_EPEVT0_Msk) /* PERIPH_EP0 (EP0_IN) event: this is treated separately from the rest */
+    {
+      /* given ACK from host has happened, we can now set the address (if not already done) */
+      if((USBD->FADDR != assigned_address) && (USBD->FADDR == 0)) USBD->FADDR = assigned_address;
+
+      uint16_t const available_bytes = USBD->EP[PERIPH_EP0].MXPLD;
+
+      active_ep0_xfer = (available_bytes == xfer_table[PERIPH_EP0].max_packet_size);
+
+      dcd_event_xfer_complete(0, 0x80, available_bytes, XFER_RESULT_SUCCESS, true);
+    }
+
+    /* service PERIPH_EP1 through PERIPH_EP7 */
+    enum ep_enum ep_index;
+    uint32_t mask;
+    struct xfer_ctl_t *xfer;
+    USBD_EP_T *ep;
+    for (ep_index = PERIPH_EP1, mask = USBD_INTSTS_EPEVT1_Msk, xfer = &xfer_table[PERIPH_EP1], ep = &USBD->EP[PERIPH_EP1]; ep_index <= PERIPH_EP7; ep_index++, mask <<= 1, xfer++, ep++)
+    {
+      if(status & mask)
+      {
+        USBD->INTSTS = mask;
+
+        uint16_t const available_bytes = ep->MXPLD;
+        uint8_t const ep_addr = decode_ep_addr(ep);
+        bool const out_ep = !(ep_addr & TUSB_DIR_IN_MASK);
+
+        if (out_ep)
+        {
+          /* copy the data from the PC to the previously provided buffer */
+          memcpy(xfer->data_ptr, (uint8_t *)(USBD_BUF_BASE + ep->BUFSEG), available_bytes);
+          xfer->remaining_bytes -= available_bytes;
+          xfer->data_ptr += available_bytes;
+
+          /* when the transfer is finished, alert TinyUSB */
+          if ( (0 == xfer->remaining_bytes) || (available_bytes < xfer->max_packet_size) )
+            dcd_event_xfer_complete(0, ep_addr, available_bytes, XFER_RESULT_SUCCESS, true);
+        }
+        else
+        {
+          /* update the bookkeeping to reflect the data that has now been sent to the PC */
+          xfer->remaining_bytes -= available_bytes;
+          xfer->data_ptr += available_bytes;
+
+          /* if more data to send, send it; otherwise, alert TinyUSB that we've finished */
+          if (xfer->remaining_bytes)
+            dcd_in_xfer(xfer, ep);
+          else
+            dcd_event_xfer_complete(0, ep_addr, xfer->total_bytes, XFER_RESULT_SUCCESS, true);
+        }
+      }
+    }
+  }
+
+  if(status & USBD_INTSTS_SOFIF_Msk)
+  {
+    /* Start-Of-Frame event */
+    dcd_event_bus_signal(0, DCD_EVENT_SOF, true);
+  }
+
+  /* acknowledge all interrupts */
+  USBD->INTSTS = status & enabled_irqs;
+}
+
+void dcd_isr(uint8_t rhport)
+{
+  (void) rhport;
+  USBD_IRQHandler();
+}
+
+#endif

src/tusb_option.h

@@ -77,6 +77,9 @@
 
 #define OPT_MCU_MIMXRT10XX        700 ///< NXP iMX RT10xx
 
+#define OPT_MCU_NUC121            800
+#define OPT_MCU_NUC126            801
+
 /** @} */
 
 /** \defgroup group_supported_os Supported RTOS