stm32: Add support for STM32N6xx MCUs.

This commit adds preliminary support for ST's new STM32N6xx MCUs.

Supported features of this MCU so far are:
- basic clock tree initialisation, running at 800MHz
- fully working USB
- XSPI in memory-mapped mode
- machine.Pin
- machine.UART
- RTC and deepsleep support
- SD card
- filesystem
- ROMFS
- WiFi and BLE via cyw43-driver (SDIO backend)

Note that the N6 does not have internal flash, and has some tricky boot
sequence, so using a custom bootloader (mboot) is almost a necessity.

Signed-off-by: Damien George <damien@micropython.org>

1 files changed, 22 insertions, 5 deletions

diff --git a/ports/stm32/stm32_it.c b/ports/stm32/stm32_it.c
index 4bf509bb9..3639e2f04 100644
--- a/ports/stm32/stm32_it.c
+++ b/ports/stm32/stm32_it.c
@@ -343,14 +343,22 @@ void OTG_FS_IRQHandler(void) {
 }
 #endif
 #if MICROPY_HW_USB_HS
+#if defined(STM32N6)
+void USB1_OTG_HS_IRQHandler(void) {
+    IRQ_ENTER(USB1_OTG_HS_IRQn);
+    HAL_PCD_IRQHandler(&pcd_hs_handle);
+    IRQ_EXIT(USB1_OTG_HS_IRQn);
+}
+#else
 void OTG_HS_IRQHandler(void) {
     IRQ_ENTER(OTG_HS_IRQn);
     HAL_PCD_IRQHandler(&pcd_hs_handle);
     IRQ_EXIT(OTG_HS_IRQn);
 }
 #endif
+#endif
 
-#if MICROPY_HW_USB_FS || MICROPY_HW_USB_HS
+#if (MICROPY_HW_USB_FS || MICROPY_HW_USB_HS) && !defined(STM32N6)
 /**
   * @brief  This function handles USB OTG Common FS/HS Wakeup functions.
   * @param  *pcd_handle for FS or HS
@@ -421,7 +429,7 @@ void OTG_FS_WKUP_IRQHandler(void) {
 }
 #endif
 
-#if MICROPY_HW_USB_HS
+#if MICROPY_HW_USB_HS && !defined(STM32N6)
 /**
   * @brief  This function handles USB OTG HS Wakeup IRQ Handler.
   * @param  None
@@ -480,7 +488,7 @@ void ETH_WKUP_IRQHandler(void) {
 }
 #endif
 
-#if defined(STM32H5)
+#if defined(STM32H5) || defined(STM32N6)
 void TAMP_IRQHandler(void) {
     IRQ_ENTER(TAMP_IRQn);
     Handle_EXTI_Irq(EXTI_RTC_TAMP);
@@ -502,6 +510,9 @@ void TAMP_STAMP_IRQHandler(void) {
 
 #if defined(STM32H5)
 void RTC_IRQHandler(void)
+#elif defined(STM32N6)
+#define RTC_WKUP_IRQn RTC_S_IRQn
+void RTC_S_IRQHandler(void)
 #else
 void RTC_WKUP_IRQHandler(void)
 #endif
@@ -509,8 +520,8 @@ void RTC_WKUP_IRQHandler(void)
     IRQ_ENTER(RTC_WKUP_IRQn);
     #if defined(STM32G0) || defined(STM32G4) || defined(STM32WL)
     RTC->MISR &= ~RTC_MISR_WUTMF; // clear wakeup interrupt flag
-    #elif defined(STM32H5)
-    RTC->SCR = RTC_SCR_CWUTF; // clear wakeup interrupt flag
+    #elif defined(STM32H5) || defined(STM32N6)
+    LL_RTC_ClearFlag_WUT(RTC);
     #elif defined(STM32H7A3xx) || defined(STM32H7A3xxQ) || defined(STM32H7B3xx) || defined(STM32H7B3xxQ)
     RTC->SR &= ~RTC_SR_WUTF; // clear wakeup interrupt flag
     #else
@@ -520,6 +531,12 @@ void RTC_WKUP_IRQHandler(void)
     IRQ_EXIT(RTC_WKUP_IRQn);
 }
 
+#if defined(STM32N6)
+void RTC_IRQHandler(void) {
+    RTC_S_IRQHandler();
+}
+#endif
+
 #if defined(STM32F0) || defined(STM32G0) || defined(STM32L0)
 
 #if defined(STM32G0)