try adding a submodule?

.github/workflows/build.yml

@@ -266,6 +266,7 @@ jobs:
         - "monster_m4sk"
         - "ndgarage_ndbit6"
         - "ndgarage_ndbit6_v2"
+        - "neokey_trinkey_m0"
         - "neopixel_trinkey_m0"
         - "nfc_copy_cat"
         - "nice_nano"
@@ -315,6 +316,7 @@ jobs:
         - "shirtty"
         - "silicognition-m4-shim"
         - "simmel"
+        - "slide_trinkey_m0"
         - "snekboard"
         - "sparkfun_lumidrive"
         - "sparkfun_nrf52840_micromod"

.gitmodules

@@ -171,6 +171,9 @@
 [submodule "frozen/Adafruit_CircuitPython_LC709203F"]
 	path = frozen/Adafruit_CircuitPython_LC709203F
 	url = https://github.com/adafruit/Adafruit_CircuitPython_LC709203F
+[submodule "frozen/Adafruit_CircuitPython_SimpleMath"]
+	path = frozen/Adafruit_CircuitPython_SimpleMath
+	url = https://github.com/adafruit/Adafruit_CircuitPython_SimpleMath
 [submodule "ports/raspberrypi/sdk"]
 	path = ports/raspberrypi/sdk
 	url = https://github.com/adafruit/pico-sdk.git

ports/atmel-samd/boards/slide_trinkey_m0/board.c

@@ -0,0 +1,40 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
+ *
+ * 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 "supervisor/board.h"
+#include "common-hal/microcontroller/Pin.h"
+#include "supervisor/shared/board.h"
+#include "hal/include/hal_gpio.h"
+
+void board_init(void) {
+}
+
+bool board_requests_safe_mode(void) {
+    return false;
+}
+
+void reset_board(void) {
+}

ports/atmel-samd/boards/slide_trinkey_m0/mpconfigboard.h

@@ -0,0 +1,58 @@
+#define MICROPY_HW_BOARD_NAME "Adafruit NeoKey Trinkey M0"
+#define MICROPY_HW_MCU_NAME "samd21e18"
+
+#define MICROPY_HW_NEOPIXEL (&pin_PA06)
+
+#define MICROPY_PORT_A        (0)
+#define MICROPY_PORT_B        (0)
+#define MICROPY_PORT_C        (0)
+
+#define IGNORE_PIN_PA00     1
+#define IGNORE_PIN_PA01     1
+#define IGNORE_PIN_PA02     1
+#define IGNORE_PIN_PA03     1
+#define IGNORE_PIN_PA04     1
+#define IGNORE_PIN_PA05     1
+#define IGNORE_PIN_PA08     1
+#define IGNORE_PIN_PA09     1
+#define IGNORE_PIN_PA10     1
+#define IGNORE_PIN_PA11     1
+#define IGNORE_PIN_PA12     1
+#define IGNORE_PIN_PA13     1
+#define IGNORE_PIN_PA14     1
+#define IGNORE_PIN_PA15     1
+#define IGNORE_PIN_PA16     1
+#define IGNORE_PIN_PA17     1
+#define IGNORE_PIN_PA18     1
+#define IGNORE_PIN_PA19     1
+#define IGNORE_PIN_PA20     1
+#define IGNORE_PIN_PA21     1
+// USB is always used internally so skip the pin objects for it.
+#define IGNORE_PIN_PA24     1
+#define IGNORE_PIN_PA25     1
+#define IGNORE_PIN_PA27     1
+#define IGNORE_PIN_PA29     1
+#define IGNORE_PIN_PA30     1
+#define IGNORE_PIN_PA31     1
+#define IGNORE_PIN_PB00     1
+#define IGNORE_PIN_PB01     1
+#define IGNORE_PIN_PB02     1
+#define IGNORE_PIN_PB03     1
+#define IGNORE_PIN_PB04     1
+#define IGNORE_PIN_PB05     1
+#define IGNORE_PIN_PB06     1
+#define IGNORE_PIN_PB07     1
+#define IGNORE_PIN_PB08     1
+#define IGNORE_PIN_PB09     1
+#define IGNORE_PIN_PB10     1
+#define IGNORE_PIN_PB11     1
+#define IGNORE_PIN_PB12     1
+#define IGNORE_PIN_PB13     1
+#define IGNORE_PIN_PB14     1
+#define IGNORE_PIN_PB15     1
+#define IGNORE_PIN_PB16     1
+#define IGNORE_PIN_PB17     1
+#define IGNORE_PIN_PB22     1
+#define IGNORE_PIN_PB23     1
+#define IGNORE_PIN_PB30     1
+#define IGNORE_PIN_PB31     1

ports/atmel-samd/boards/slide_trinkey_m0/mpconfigboard.mk

@@ -0,0 +1,35 @@
+USB_VID = 0x239A
+USB_PID = 0x8101
+USB_PRODUCT = "Slide Trinkey M0"
+USB_MANUFACTURER = "Adafruit Industries LLC"
+
+CHIP_VARIANT = SAMD21E18A
+CHIP_FAMILY = samd21
+
+INTERNAL_FLASH_FILESYSTEM = 1
+LONGINT_IMPL = NONE
+
+CIRCUITPY_ANALOGIO = 1
+CIRCUITPY_ROTARYIO = 0
+CIRCUITPY_RTC = 0
+CIRCUITPY_SAMD = 0
+CIRCUITPY_PS2IO = 0
+CIRCUITPY_PULSEIO = 0
+CIRCUITPY_PWMIO = 0
+CIRCUITPY_AUDIOCORE = 0
+CIRCUITPY_BUSIO = 0
+CIRCUITPY_STORAGE = 0
+
+CIRCUITPY_MATH = 1
+CIRCUITPY_PIXELBUF = 1
+CIRCUITPY_USB_MIDI = 1
+CIRCUITPY_TOUCHIO = 1
+CIRCUITPY_FULL_BUILD = 0
+
+SUPEROPT_GC = 0
+SUPEROPT_VM = 0
+
+# Include these Python libraries in firmware.
+FROZEN_MPY_DIRS += $(TOP)/frozen/Adafruit_CircuitPython_SimpleMath
+FROZEN_MPY_DIRS += $(TOP)/frozen/Adafruit_CircuitPython_NeoPixel
+FROZEN_MPY_DIRS += $(TOP)/frozen/Adafruit_CircuitPython_HID

ports/atmel-samd/boards/slide_trinkey_m0/pins.c

@@ -0,0 +1,8 @@
+#include "shared-bindings/board/__init__.h"
+
+STATIC const mp_rom_map_elem_t board_global_dict_table[] = {
+    //{ MP_ROM_QSTR(MP_QSTR_TOUCH), MP_ROM_PTR(&pin_PA07) },
+    { MP_ROM_QSTR(MP_QSTR_NEOPIXEL), MP_ROM_PTR(&pin_PA06) },
+    { MP_ROM_QSTR(MP_QSTR_POTENTIOMETER), MP_ROM_PTR(&pin_PA07) },
+};
+MP_DEFINE_CONST_DICT(board_module_globals, board_global_dict_table);