add support for seeeduino xiao

4 files changed, 335 insertions, 0 deletions

diff --git a/docs/boards.md b/docs/boards.md
index 9667f6944..abf914aaa 100644
--- a/docs/boards.md
+++ b/docs/boards.md
@@ -18,6 +18,7 @@ This code base already had supported for a handful of following boards (sorted a
 - [Adafruit ItsyBitsy M4 Express](https://www.adafruit.com/product/3800)
 - [Adafruit Metro M0 Express](https://www.adafruit.com/product/3505)
 - [Adafruit Metro M4 Express](https://www.adafruit.com/product/3382)
+- [Seeeduino Xiao](https://www.seeedstudio.com/Seeeduino-XIAO-Arduino-Microcontroller-SAMD21-Cortex-M0+-p-4426.html)
 
 ### Nordic nRF5x
 
diff --git a/hw/bsp/seeeduino_xiao/board.mk b/hw/bsp/seeeduino_xiao/board.mk
new file mode 100644
index 000000000..d762c4eca
--- /dev/null
+++ b/hw/bsp/seeeduino_xiao/board.mk
@@ -0,0 +1,45 @@
+CFLAGS += \
+  -flto \
+  -mthumb \
+  -mabi=aapcs-linux \
+  -mcpu=cortex-m0plus \
+  -nostdlib -nostartfiles \
+  -D__SAMD21G18A__ \
+  -DCONF_DFLL_OVERWRITE_CALIBRATION=0 \
+  -DCFG_TUSB_MCU=OPT_MCU_SAMD21
+
+# All source paths should be relative to the top level.
+LD_FILE = hw/bsp/$(BOARD)/samd21g18a_flash.ld
+
+SRC_C += \
+	hw/mcu/microchip/samd/asf4/samd21/gcc/gcc/startup_samd21.c \
+	hw/mcu/microchip/samd/asf4/samd21/gcc/system_samd21.c \
+	hw/mcu/microchip/samd/asf4/samd21/hpl/gclk/hpl_gclk.c \
+	hw/mcu/microchip/samd/asf4/samd21/hpl/pm/hpl_pm.c \
+	hw/mcu/microchip/samd/asf4/samd21/hpl/sysctrl/hpl_sysctrl.c \
+	hw/mcu/microchip/samd/asf4/samd21/hal/src/hal_atomic.c
+
+INC += \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd21/ \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd21/config \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd21/include \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd21/hal/include \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd21/hal/utils/include \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd21/hpl/pm/ \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd21/hpl/port \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd21/hri \
+	$(TOP)/hw/mcu/microchip/samd/asf4/samd21/CMSIS/Include
+
+# For TinyUSB port source 
+VENDOR = microchip
+CHIP_FAMILY = samd
+
+# For freeRTOS port source
+FREERTOS_PORT = ARM_CM0
+
+# For flash-jlink target
+JLINK_DEVICE = ATSAMD21G18
+JLINK_IF = swd
+
+# flash using jlink
+flash: flash-jlink
diff --git a/hw/bsp/seeeduino_xiao/samd21g18a_flash.ld b/hw/bsp/seeeduino_xiao/samd21g18a_flash.ld
new file mode 100644
index 000000000..bae38a881
--- /dev/null
+++ b/hw/bsp/seeeduino_xiao/samd21g18a_flash.ld
@@ -0,0 +1,147 @@
+/**
+ * \file
+ *
+ * \brief Linker script for running in internal FLASH on the SAMD21G18A
+ *
+ * Copyright (c) 2017 Microchip Technology Inc.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed 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 Licence 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.
+ *
+ * \asf_license_stop
+ *
+ */
+
+
+OUTPUT_FORMAT("elf32-littlearm", "elf32-littlearm", "elf32-littlearm")
+OUTPUT_ARCH(arm)
+SEARCH_DIR(.)
+
+/* Memory Spaces Definitions */
+MEMORY
+{
+  rom      (rx)  : ORIGIN = 0x00000000 + 8K, LENGTH = 0x00040000 - 8K  /* 8K offset to preserve bootloader */
+  ram      (rwx) : ORIGIN = 0x20000000, LENGTH = 0x00008000
+}
+
+/* The stack size used by the application. NOTE: you need to adjust according to your application. */
+STACK_SIZE = DEFINED(STACK_SIZE) ? STACK_SIZE : DEFINED(__stack_size__) ? __stack_size__ : 0x2000;
+
+ENTRY(Reset_Handler)
+
+/* Section Definitions */
+SECTIONS
+{
+    .text :
+    {
+        . = ALIGN(4);
+        _sfixed = .;
+        KEEP(*(.vectors .vectors.*))
+        *(.text*)
+	*(.gnu.linkonce.t.*)
+        *(.glue_7t) *(.glue_7)
+        *(.rodata .rodata* .gnu.linkonce.r.*)
+        *(.ARM.extab* .gnu.linkonce.armextab.*)
+
+        /* Support C constructors, and C destructors in both user code
+           and the C library. This also provides support for C++ code. */
+        . = ALIGN(4);
+        KEEP(*(.init))
+        . = ALIGN(4);
+        __preinit_array_start = .;
+        KEEP (*(.preinit_array))
+        __preinit_array_end = .;
+
+        . = ALIGN(4);
+        __init_array_start = .;
+        KEEP (*(SORT(.init_array.*)))
+        KEEP (*(.init_array))
+        __init_array_end = .;
+
+        . = ALIGN(4);
+        KEEP (*crtbegin.o(.ctors))
+        KEEP (*(EXCLUDE_FILE (*crtend.o) .ctors))
+        KEEP (*(SORT(.ctors.*)))
+        KEEP (*crtend.o(.ctors))
+
+        . = ALIGN(4);
+        KEEP(*(.fini))
+
+        . = ALIGN(4);
+        __fini_array_start = .;
+        KEEP (*(.fini_array))
+        KEEP (*(SORT(.fini_array.*)))
+        __fini_array_end = .;
+
+        KEEP (*crtbegin.o(.dtors))
+        KEEP (*(EXCLUDE_FILE (*crtend.o) .dtors))
+        KEEP (*(SORT(.dtors.*)))
+        KEEP (*crtend.o(.dtors))
+
+        . = ALIGN(4);
+        _efixed = .;            /* End of text section */
+    } > rom
+
+    /* .ARM.exidx is sorted, so has to go in its own output section.  */
+    PROVIDE_HIDDEN (__exidx_start = .);
+    .ARM.exidx :
+    {
+      *(.ARM.exidx* .gnu.linkonce.armexidx.*)
+    } > rom
+    PROVIDE_HIDDEN (__exidx_end = .);
+
+    . = ALIGN(4);
+    _etext = .;
+
+    .relocate : AT (_etext)
+    {
+        . = ALIGN(4);
+        _srelocate = .;
+        *(.ramfunc .ramfunc.*);
+        *(.data .data.*);
+        . = ALIGN(4);
+        _erelocate = .;
+    } > ram
+
+    /* .bss section which is used for uninitialized data */
+    .bss (NOLOAD) :
+    {
+        . = ALIGN(4);
+        _sbss = . ;
+        _szero = .;
+        *(.bss .bss.*)
+        *(COMMON)
+        . = ALIGN(4);
+        _ebss = . ;
+        _ezero = .;
+        end = .;
+    } > ram
+
+    /* stack section */
+    .stack (NOLOAD):
+    {
+        . = ALIGN(8);
+        _sstack = .;
+        . = . + STACK_SIZE;
+        . = ALIGN(8);
+        _estack = .;
+    } > ram
+
+    . = ALIGN(4);
+    _end = . ;
+}
diff --git a/hw/bsp/seeeduino_xiao/seeeduino_xiao.c b/hw/bsp/seeeduino_xiao/seeeduino_xiao.c
new file mode 100644
index 000000000..a3602d66e
--- /dev/null
+++ b/hw/bsp/seeeduino_xiao/seeeduino_xiao.c
@@ -0,0 +1,142 @@
+/* 
+ * 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 "sam.h"
+#include "bsp/board.h"
+
+#include "hal/include/hal_gpio.h"
+#include "hal/include/hal_init.h"
+#include "hri/hri_nvmctrl_d21.h"
+
+#include "hpl/gclk/hpl_gclk_base.h"
+#include "hpl_pm_config.h"
+#include "hpl/pm/hpl_pm_base.h"
+
+//--------------------------------------------------------------------+
+// MACRO TYPEDEF CONSTANT ENUM DECLARATION
+//--------------------------------------------------------------------+
+#define LED_PIN      26
+#define BUTTON_PIN   9 // PA4, pin D1 on seeed pinout
+
+/* Referenced GCLKs, should be initialized firstly */
+#define _GCLK_INIT_1ST (1 << 0 | 1 << 1)
+
+/* Not referenced GCLKs, initialized last */
+#define _GCLK_INIT_LAST (~_GCLK_INIT_1ST)
+
+void board_init(void)
+{
+  // Clock init ( follow hpl_init.c )
+  hri_nvmctrl_set_CTRLB_RWS_bf(NVMCTRL, 2);
+
+  _pm_init();
+  _sysctrl_init_sources();
+#if _GCLK_INIT_1ST
+  _gclk_init_generators_by_fref(_GCLK_INIT_1ST);
+#endif
+  _sysctrl_init_referenced_generators();
+  _gclk_init_generators_by_fref(_GCLK_INIT_LAST);
+
+  // Update SystemCoreClock since it is hard coded with asf4 and not correct
+  // Init 1ms tick timer (samd SystemCoreClock may not correct)
+  SystemCoreClock = CONF_CPU_FREQUENCY;
+  SysTick_Config(CONF_CPU_FREQUENCY / 1000);
+
+  // Led init
+  gpio_set_pin_direction(LED_PIN, GPIO_DIRECTION_OUT);
+  gpio_set_pin_level(LED_PIN, 0);
+
+  // Button init
+  gpio_set_pin_direction(BUTTON_PIN, GPIO_DIRECTION_IN);
+  gpio_set_pin_pull_mode(BUTTON_PIN, GPIO_PULL_UP);
+
+#if CFG_TUSB_OS  == OPT_OS_FREERTOS
+  // If freeRTOS is used, IRQ priority is limit by max syscall ( smaller is higher )
+  NVIC_SetPriority(USB_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY);
+#endif
+
+  /* USB Clock init
+   * The USB module requires a GCLK_USB of 48 MHz ~ 0.25% clock
+   * for low speed and full speed operation. */
+  _pm_enable_bus_clock(PM_BUS_APBB, USB);
+  _pm_enable_bus_clock(PM_BUS_AHB, USB);
+  _gclk_enable_channel(USB_GCLK_ID, GCLK_CLKCTRL_GEN_GCLK0_Val);
+
+  // USB Pin Init
+  gpio_set_pin_direction(PIN_PA24, GPIO_DIRECTION_OUT);
+  gpio_set_pin_level(PIN_PA24, false);
+  gpio_set_pin_pull_mode(PIN_PA24, GPIO_PULL_OFF);
+  gpio_set_pin_direction(PIN_PA25, GPIO_DIRECTION_OUT);
+  gpio_set_pin_level(PIN_PA25, false);
+  gpio_set_pin_pull_mode(PIN_PA25, GPIO_PULL_OFF);
+
+  gpio_set_pin_function(PIN_PA24, PINMUX_PA24G_USB_DM);
+  gpio_set_pin_function(PIN_PA25, PINMUX_PA25G_USB_DP);
+}
+
+//--------------------------------------------------------------------+
+// Board porting API
+//--------------------------------------------------------------------+
+
+void board_led_write(bool state)
+{
+  gpio_set_pin_level(LED_PIN, state);
+}
+
+uint32_t board_button_read(void)
+{
+  // button is active low
+  return gpio_get_pin_level(BUTTON_PIN) ? 0 : 1;
+}
+
+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;
+}
+
+#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
+
+void HardFault_Handler(void) {
+	while(1);
+}