Merge pull request #3574 from gab-k/support-nrf54lm20a

Add initial board support for nRF54LM20 DK

Author: hathach

README.rst

@@ -182,7 +182,9 @@ Supported CPUs
 +--------------+-----+-----------------------+--------+------+-----------+------------------------+--------------------+
 | MindMotion   | mm32                        | ✔      |      | ✖         | mm32f327x_otg          | ci_fs variant      |
 +--------------+-----+-----------------------+--------+------+-----------+------------------------+--------------------+
-| NordicSemi   | nRF 52833, 52840, 5340      | ✔      | ✖    | ✖         | nrf5x                  | only ep8 is ISO    |
+| NordicSemi   | nRF52, nRF53                | ✔      | ✖    | ✖         | nrf5x                  | only ep8 is ISO    |
+|              +-----------------------------+--------+------+-----------+------------------------+--------------------+
+|              | nRF54                       | ✔      | ✖    | ✔         | dwc2                   |                    |
 +--------------+-----------------------------+--------+------+-----------+------------------------+--------------------+
 | Nuvoton      | NUC120                      | ✔      | ✖    | ✖         | nuc120                 |                    |
 |              +-----------------------------+--------+------+-----------+------------------------+--------------------+

docs/reference/boards.rst

@@ -221,6 +221,7 @@ nrf52840dk                   Nordic nRF52840DK                      nrf       ht
 nrf52840dongle               Nordic nRF52840 Dongle                 nrf       https://www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF52840-Dongle
 nrf5340dk                    Nordic nRF5340 DK                      nrf       https://www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF5340-DK
 nrf54h20dk                   Nordic nRF54H20 DK                     nrf       https://www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF5340-DK
+nrf54lm20dk                  Nordic nRF54LM20 DK                    nrf       https://www.nordicsemi.com/Products/Development-hardware/nRF54LM20-DK
 ===========================  =====================================  ========  ==============================================================================  ======
 
 Raspberry Pi

hw/bsp/BoardPresets.json

@@ -470,6 +470,10 @@
       "name": "nrf54h20dk",
       "inherits": "default"
     },
+    {
+      "name": "nrf54lm20dk",
+      "inherits": "default"
+    },
     {
       "name": "nutiny_nuc126v",
       "inherits": "default"
@@ -1563,6 +1567,11 @@
       "description": "Build preset for the nrf54h20dk board",
       "configurePreset": "nrf54h20dk"
     },
+    {
+      "name": "nrf54lm20dk",
+      "description": "Build preset for the nrf54lm20dk board",
+      "configurePreset": "nrf54lm20dk"
+    },
     {
       "name": "nutiny_nuc126v",
       "description": "Build preset for the nutiny_nuc126v board",
@@ -3711,6 +3720,19 @@
         }
       ]
     },
+    {
+      "name": "nrf54lm20dk",
+      "steps": [
+        {
+          "type": "configure",
+          "name": "nrf54lm20dk"
+        },
+        {
+          "type": "build",
+          "name": "nrf54lm20dk"
+        }
+      ]
+    },
     {
       "name": "nutiny_nuc126v",
       "steps": [

hw/bsp/nrf/FreeRTOSConfig/FreeRTOSConfig.h

@@ -53,6 +53,12 @@
 #define configENABLE_TRUSTZONE                  0
 #define configMINIMAL_SECURE_STACK_SIZE         (1024)
 
+/* nRF54 runs entirely in Secure mode (SAU present but no SPE bootloader).
+ * Tell FreeRTOS CM33 NTZ port to use Secure-compatible EXC_RETURN values. */
+#if defined(NRF54H20_XXAA) || defined(NRF54LM20A_ENGA_XXAA)
+#define configRUN_FREERTOS_SECURE_ONLY          1
+#endif
+
 #define configUSE_PREEMPTION                    1
 #define configUSE_PORT_OPTIMISED_TASK_SELECTION 0
 #define configCPU_CLOCK_HZ                      SystemCoreClock

hw/bsp/nrf/boards/nrf54lm20dk/board.cmake

@@ -0,0 +1,8 @@
+set(MCU_VARIANT nrf54lm20a_enga)
+set(JLINK_DEVICE NRF54LM20A_M33)
+
+function(update_board TARGET)
+  target_compile_definitions(${TARGET} PUBLIC
+    CFG_EXAMPLE_VIDEO_READONLY
+    )
+endfunction()

hw/bsp/nrf/boards/nrf54lm20dk/board.h

@@ -0,0 +1,58 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020, Ha Thach (tinyusb.org)
+ * Copyright (c) 2026, Gabriel Koppenstein
+ *
+ * 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.
+ */
+
+/* metadata:
+   name: Nordic nRF54LM20 DK
+   url: https://www.nordicsemi.com/Products/Development-hardware/nRF54LM20-DK
+*/
+
+#ifndef BOARD_H_
+#define BOARD_H_
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+#define _PINNUM(port, pin)    ((port)*32 + (pin))
+
+// LED0 active high (MOSFET-driven)
+#define LED_PIN               _PINNUM(1, 22)
+#define LED_STATE_ON          1
+
+// Button0 active low
+#define BUTTON_PIN            _PINNUM(1, 26)
+#define BUTTON_STATE_ACTIVE   0
+
+// UART20 (VCOM via debugger)
+#define UART_TX_PIN           _PINNUM(1, 16)
+#define UART_RX_PIN           _PINNUM(1, 17)
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif /* BOARD_H_ */

hw/bsp/nrf/boards/nrf54lm20dk/board.mk

@@ -0,0 +1,6 @@
+MCU_VARIANT = nrf54lm20a_enga
+CFLAGS += -DNRF54LM20A_ENGA_XXAA
+
+# flash using jlink
+JLINK_DEVICE = NRF54LM20A_M33
+flash: flash-jlink

hw/bsp/nrf/family.c

@@ -2,6 +2,7 @@
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ * Copyright (c) 2026, Gabriel Koppenstein
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -45,7 +46,7 @@
 #include "nrfx.h"
 #include "hal/nrf_gpio.h"
 #include "nrfx_gpiote.h"
-#if !defined(NRF54H20_XXAA)
+#if !defined(NRF54H20_XXAA) && !defined(NRF54LM20A_ENGA_XXAA)
 #include "nrfx_power.h"
 #endif
 #include "nrfx_uarte.h"
@@ -79,42 +80,74 @@ enum {
 };
 
 // Forward USB interrupt events to TinyUSB IRQ Handler
-#if defined(NRF54H20_XXAA)
-#define USBD_IRQn  USBHS_IRQn
+#if defined(NRF54H20_XXAA) || defined(NRF54LM20A_ENGA_XXAA)
+  #define USBD_IRQn USBHS_IRQn
 void USBHS_IRQHandler(void) {
   tusb_int_handler(0, true);
 }
 
+  #if defined(NRF54LM20A_ENGA_XXAA)
+static nrfx_uarte_t _uart_id = NRFX_UARTE_INSTANCE(20);
+  #else
 static nrfx_uarte_t _uart_id = NRFX_UARTE_INSTANCE(120);
+  #endif
 
 #else
+  #ifdef NRF5340_XXAA
+    #define LFCLK_SRC_RC   CLOCK_LFCLKSRC_SRC_LFRC
+    #define VBUSDETECT_Msk USBREG_USBREGSTATUS_VBUSDETECT_Msk
+    #define OUTPUTRDY_Msk  USBREG_USBREGSTATUS_OUTPUTRDY_Msk
+    #define GPIOTE_IRQn    GPIOTE1_IRQn
+  #else
+    #define LFCLK_SRC_RC   CLOCK_LFCLKSRC_SRC_RC
+    #define VBUSDETECT_Msk POWER_USBREGSTATUS_VBUSDETECT_Msk
+    #define OUTPUTRDY_Msk  POWER_USBREGSTATUS_OUTPUTRDY_Msk
+  #endif
 
-#ifdef NRF5340_XXAA
-#define LFCLK_SRC_RC CLOCK_LFCLKSRC_SRC_LFRC
-#define VBUSDETECT_Msk USBREG_USBREGSTATUS_VBUSDETECT_Msk
-#define OUTPUTRDY_Msk USBREG_USBREGSTATUS_OUTPUTRDY_Msk
-#define GPIOTE_IRQn GPIOTE1_IRQn
-#else
-#define LFCLK_SRC_RC CLOCK_LFCLKSRC_SRC_RC
-#define VBUSDETECT_Msk POWER_USBREGSTATUS_VBUSDETECT_Msk
-#define OUTPUTRDY_Msk POWER_USBREGSTATUS_OUTPUTRDY_Msk
-#endif
-
-#if CFG_TUSB_OS != OPT_OS_ZEPHYR
+  #if CFG_TUSB_OS != OPT_OS_ZEPHYR
 static nrfx_uarte_t _uart_id = NRFX_UARTE_INSTANCE(0);
-#endif
+  #endif
 
 void USBD_IRQHandler(void) {
-  tud_int_handler(0);
+  tusb_int_handler(0, true);
 }
 #endif
 
+//--------------------------------------------------------------------+
+// UART RX ring buffer and event handler
+//--------------------------------------------------------------------+
+#if CFG_TUSB_OS != OPT_OS_ZEPHYR
+
+#define UART_RX_BUFSIZE 64
+
+static uint8_t rx_fifo[UART_RX_BUFSIZE];
+static volatile uint16_t rx_fifo_head = 0;
+static volatile uint16_t rx_fifo_tail = 0;
+
+static uint8_t rx_dma_buf[1]; // 1-byte DMA target for continuous RX
+
+static void uart_event_handler(nrfx_uarte_event_t const* p_event, void* p_context) {
+  (void) p_context;
+  if (p_event->type == NRFX_UARTE_EVT_RX_DONE) {
+    for (size_t i = 0; i < p_event->data.rx.length; i++) {
+      uint16_t next_head = (rx_fifo_head + 1) & (UART_RX_BUFSIZE - 1);
+      if (next_head != rx_fifo_tail) {
+        rx_fifo[rx_fifo_head] = p_event->data.rx.p_buffer[i];
+        rx_fifo_head = next_head;
+      }
+    }
+    // re-arm 1-byte RX
+    nrfx_uarte_rx(&_uart_id, rx_dma_buf, sizeof(rx_dma_buf));
+  }
+}
+
+#endif
 
 // tinyusb function that handles power event (detected, ready, removed)
 // We must call it within SD's SOC event handler, or set it as power event handler if SD is not enabled.
 extern void tusb_hal_nrf_power_event(uint32_t event);
 
-#if !defined(NRF54H20_XXAA)
+#if !defined(NRF54H20_XXAA) && !defined(NRF54LM20A_ENGA_XXAA)
 // nrf power callback, could be unused if SD is enabled or usb is disabled (board_test example)
 TU_ATTR_UNUSED static void power_event_handler(nrfx_power_usb_evt_t event) {
   tusb_hal_nrf_power_event((uint32_t) event);
@@ -131,9 +164,8 @@ static nrfx_gpiote_t _gpiote = NRFX_GPIOTE_INSTANCE(0);
 //--------------------------------------------------------------------+
 //
 //--------------------------------------------------------------------+
-
 void board_init(void) {
-#if !defined(NRF54H20_XXAA)
+#if !defined(NRF54H20_XXAA) && !defined(NRF54LM20A_ENGA_XXAA)
   // stop LF clock just in case we jump from application without reset
   NRF_CLOCK->TASKS_LFCLKSTOP = 1UL;
 
@@ -167,12 +199,14 @@ void board_init(void) {
 
 #if CFG_TUSB_OS != OPT_OS_ZEPHYR
   // UART
+  static uint8_t uart_tx_cache[64];
   nrfx_uarte_config_t uart_cfg = {
       .txd_pin   = UART_TX_PIN,
       .rxd_pin   = UART_RX_PIN,
       .rts_pin   = NRF_UARTE_PSEL_DISCONNECTED,
       .cts_pin   = NRF_UARTE_PSEL_DISCONNECTED,
       .p_context = NULL,
+      .tx_cache  = { .p_buffer = uart_tx_cache, .length = sizeof(uart_tx_cache) },
       .baudrate  = NRF_UARTE_BAUDRATE_115200, // CFG_BOARD_UART_BAUDRATE
       .interrupt_priority = 7,
       .config = {
@@ -181,16 +215,26 @@ void board_init(void) {
       }
   };
 
-  nrfx_uarte_init(&_uart_id, &uart_cfg, NULL);
+  nrfx_uarte_init(&_uart_id, &uart_cfg, uart_event_handler);
+  // start continuous 1-byte RX
+  nrfx_uarte_rx(&_uart_id, rx_dma_buf, sizeof(rx_dma_buf));
 #endif
 
   //------------- USB -------------//
 #if CFG_TUD_ENABLED
+
+#if defined(NRF54LM20A_ENGA_XXAA)
+  // Request HFXO crystal clock for PCLK24M (required by USBHS core)
+  NRF_CLOCK->TASKS_XO24MSTART = CLOCK_TASKS_XO24MSTART_TASKS_XO24MSTART_Trigger;
+  while (!NRF_CLOCK->EVENTS_XO24MSTARTED) {}
+  NRF_CLOCK->EVENTS_XO24MSTARTED = 0;
+#endif
+
   // Priorities 0, 1, 4 (nRF52) are reserved for SoftDevice
   // 2 is highest for application
   NVIC_SetPriority(USBD_IRQn, 2);
 
-#if !defined(NRF54H20_XXAA)
+#if !defined(NRF54H20_XXAA) && !defined(NRF54LM20A_ENGA_XXAA)
   // USB power may already be ready at this time -> no event generated
   // We need to invoke the handler based on the status initially
   uint32_t usb_reg;
@@ -258,7 +302,7 @@ size_t board_get_unique_id(uint8_t id[], size_t max_len) {
 
 #if defined(NRF54H20_XXAA)
   uintptr_t did_addr = (uintptr_t) NRF_FICR->BLE.ADDR;
-#elif defined(NRF5340_XXAA)
+#elif defined(NRF54LM20A_ENGA_XXAA) || defined(NRF5340_XXAA)
   uintptr_t did_addr = (uintptr_t) NRF_FICR->INFO.DEVICEID;
 #else
   uintptr_t did_addr = (uintptr_t) NRF_FICR->DEVICEID;
@@ -272,19 +316,29 @@ size_t board_get_unique_id(uint8_t id[], size_t max_len) {
 }
 
 int board_uart_read(uint8_t* buf, int len) {
+#if CFG_TUSB_OS == OPT_OS_ZEPHYR
   (void) buf;
   (void) len;
   return -1;
-//  nrfx_err_t err = nrfx_uarte_rx(&_uart_id, buf, (size_t) len);
-//  return NRFX_SUCCESS == err ? len : 0;
+#else
+  int count = 0;
+  while (count < len && rx_fifo_tail != rx_fifo_head) {
+    buf[count++] = rx_fifo[rx_fifo_tail];
+    rx_fifo_tail = (rx_fifo_tail + 1) & (UART_RX_BUFSIZE - 1);
+  }
+  return count;
+#endif
 }
 
 int board_uart_write(void const* buf, int len) {
 #if CFG_TUSB_OS == OPT_OS_ZEPHYR
   (void) buf;
   return len;
 #else
-  nrfx_err_t err = nrfx_uarte_tx(&_uart_id, (uint8_t const*) buf, (size_t) len ,0);
+  if (nrfx_uarte_tx_in_progress(&_uart_id)) {
+    return 0;
+  }
+  nrfx_err_t err = nrfx_uarte_tx(&_uart_id, (uint8_t const*) buf, (size_t) len, 0);
   return (NRFX_SUCCESS == err) ? len : 0;
 #endif
 }