stm32duino · cumin777 · Aug 27, 2026
diff --git a/libraries/SrcWrapper/inc/stm32_def.h b/libraries/SrcWrapper/inc/stm32_def.h
@@ -203,11 +203,13 @@ __STATIC_INLINE void LL_RTC_SetBinMixBCDU(RTC_TypeDef *RTCx, uint32_t BinMixBcdU
 }
 #endif // STM32U0xx
 
-/* STM32G0xx, STM32U0xx and some STM32U5xx defined USB_DRD_FS */
+/* Some STM32 series define USB_DRD_FS instead of the legacy USB instance. */
 #if !defined(USB) && defined(USB_DRD_FS)
   #define USB USB_DRD_FS
   #define PinMap_USB PinMap_USB_DRD_FS
-  #if defined(STM32H5xx) || defined(STM32U0xx) ||\
+  #if defined(STM32C5xx)
+    #define USB_BASE USB_DRD_FS_BASE
+  #elif defined(STM32H5xx) || defined(STM32U0xx) ||\
     defined(STM32U3xx) || defined(STM32U5xx)
     #define USB_BASE USB_DRD_BASE
     #if !defined(__HAL_RCC_USB_CLK_ENABLE)

diff --git a/libraries/USBDevice/inc/usbd_cdc_if.h b/libraries/USBDevice/inc/usbd_cdc_if.h
@@ -59,6 +59,9 @@ uint8_t  CDC_getStopBits(void);
 uint8_t  CDC_getParity(void);
 uint8_t  CDC_getDataBits(void);
 
+/* Optional board hook invoked after the host changes the CDC line coding. */
+void CDC_LineCodingChanged(uint32_t bitrate);
+
 #ifdef __cplusplus
 }
 #endif

diff --git a/libraries/USBDevice/inc/usbd_conf.h b/libraries/USBDevice/inc/usbd_conf.h
@@ -30,8 +30,16 @@ extern "C" {
 #include "stm32_def.h"
 
 #if defined(USE_HALV2_DRIVER)
-#error "USB library is not yet compatible with HALv2 driver."
-#else
+#if !defined(STM32C5xx)
+#warning "USB device support is currently implemented only for STM32C5xx HAL v2."
+#endif
+#endif
+
+#if defined(STM32C5xx)
+#define PCD_SNG_BUF HAL_PCD_SNG_BUF
+#define PCD_DBL_BUF HAL_PCD_DBL_BUF
+#endif
+
 #if !defined(USB_BASE) && !defined(USB_OTG_DEVICE_BASE)
 #error "This board does not support USB! Select 'None' in the 'Tools->USB interface' menu"
 #endif
@@ -40,8 +48,6 @@ extern "C" {
 #endif
 #if !defined(USB_BASE) && !defined(USB_OTG_FS) && defined(USB_OTG_HS) && !defined(USE_USB_HS)
 #error "This board support only USB High Speed! Select 'High Speed' or 'High Speed in Full Speed mode' in the 'Tools->USB interface' menu"
-#endif
-
 #endif
 #include <stdio.h>
 #include <stdlib.h>
@@ -77,7 +83,7 @@ extern "C" {
 #elif defined(STM32G0B1xx) || defined(STM32G0C1xx)
 #define USB_IRQn USB_UCPD1_2_IRQn
 #define USB_IRQHandler USB_UCPD1_2_IRQHandler
-#elif defined(STM32C0xx) || defined(STM32H5xx) || defined(STM32U0xx)
+#elif defined(STM32C0xx) || defined(STM32C5xx) || defined(STM32H5xx) || defined(STM32U0xx)
 #define USB_IRQn USB_DRD_FS_IRQn
 #define USB_IRQHandler USB_DRD_FS_IRQHandler
 #elif defined(STM32U5xx) && !defined(USB_DRD_FS)

diff --git a/libraries/USBDevice/inc/usbd_ep_conf.h b/libraries/USBDevice/inc/usbd_ep_conf.h
@@ -69,10 +69,21 @@ typedef struct {
 
 #ifdef USBD_USE_CDC
 #define PMA_CDC_OUT_BASE    (PMA_EP0_IN_ADDR + USB_MAX_EP0_SIZE)
+#if defined(STM32C5xx)
+/*
+ * The C5 USB DRD FS peripheral is used with bulk double buffering disabled.
+ * Keep each CDC endpoint in its own 64-byte PMA area; in particular, the
+ * interrupt IN endpoint must not overlap the bulk IN data buffer.
+ */
+#define PMA_CDC_OUT_ADDR    PMA_CDC_OUT_BASE
+#define PMA_CDC_IN_ADDR     (PMA_CDC_OUT_BASE + USB_FS_MAX_PACKET_SIZE)
+#define PMA_CDC_CMD_ADDR    (PMA_CDC_IN_ADDR + USB_FS_MAX_PACKET_SIZE)
+#else
 #define PMA_CDC_OUT_ADDR    ((PMA_CDC_OUT_BASE + USB_FS_MAX_PACKET_SIZE) | \
                             (PMA_CDC_OUT_BASE << 16U))
 #define PMA_CDC_IN_ADDR     (PMA_CDC_OUT_BASE + USB_FS_MAX_PACKET_SIZE * 2)
 #define PMA_CDC_CMD_ADDR    (PMA_CDC_IN_ADDR + CDC_CMD_PACKET_SIZE)
+#endif
 #endif /* USBD_USE_CDC */
 #ifdef USBD_USE_HID_COMPOSITE
   #define PMA_MOUSE_IN_ADDR   (PMA_EP0_IN_ADDR + HID_MOUSE_EPIN_SIZE)
@@ -86,4 +97,4 @@ extern const ep_desc_t ep_def[DEV_NUM_EP + 1];
 #endif /* USBCON */
 #endif /* __USBD_EP_CONF_H */
 
-/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
+/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
diff --git a/libraries/USBDevice/src/cdc/cdc_queue.c b/libraries/USBDevice/src/cdc/cdc_queue.c
@@ -85,6 +85,11 @@ uint8_t *CDC_TransmitQueue_ReadBlock(CDC_TransmitQueue_TypeDef *queue,
   } else {
     *size = CDC_TRANSMIT_QUEUE_BUFFER_SIZE - queue->read;
   }
+
+  /* Limit the queued transaction to one endpoint packet. */
+  if (*size > CDC_QUEUE_MAX_PACKET_SIZE) {
+    *size = CDC_QUEUE_MAX_PACKET_SIZE;
+  }
   queue->reserved = *size;
   return &queue->buffer[queue->read];
 }

diff --git a/libraries/USBDevice/src/cdc/usbd_cdc.c b/libraries/USBDevice/src/cdc/usbd_cdc.c
@@ -701,7 +701,11 @@ static uint8_t USBD_CDC_Setup(USBD_HandleTypeDef *pdev,
 static uint8_t USBD_CDC_DataIn(USBD_HandleTypeDef *pdev, uint8_t epnum)
 {
   USBD_CDC_HandleTypeDef *hcdc;
+#if defined(USE_HALV2_DRIVER)
+  hal_pcd_handle_t *hpcd = (hal_pcd_handle_t *)pdev->pData;
+#else
   PCD_HandleTypeDef *hpcd = (PCD_HandleTypeDef *)pdev->pData;
+#endif
 
   if (pdev->pClassDataCmsit[pdev->classId] == NULL) {
     return (uint8_t)USBD_FAIL;
@@ -710,7 +714,13 @@ static uint8_t USBD_CDC_DataIn(USBD_HandleTypeDef *pdev, uint8_t epnum)
   hcdc = (USBD_CDC_HandleTypeDef *)pdev->pClassDataCmsit[pdev->classId];
 
   if ((pdev->ep_in[epnum & 0xFU].total_length > 0U) &&
-      ((pdev->ep_in[epnum & 0xFU].total_length % hpcd->IN_ep[epnum & 0xFU].maxpacket) == 0U)) {
+      ((pdev->ep_in[epnum & 0xFU].total_length %
+#if defined(USE_HALV2_DRIVER)
+        hpcd->in_ep[epnum & 0xFU].max_packet
+#else
+        hpcd->IN_ep[epnum & 0xFU].maxpacket
+#endif
+       ) == 0U)) {
     /* Update the packet total length */
     pdev->ep_in[epnum & 0xFU].total_length = 0U;
 

diff --git a/libraries/USBDevice/src/cdc/usbd_cdc_if.c b/libraries/USBDevice/src/cdc/usbd_cdc_if.c
@@ -89,6 +89,12 @@ USBD_CDC_LineCodingTypeDef linecoding = {
   0x08    /* nb. of bits 8*/
 };
 
+/* Boards that need a CDC line-coding side effect can override this hook. */
+WEAK void CDC_LineCodingChanged(uint32_t bitrate)
+{
+  (void)bitrate;
+}
+
 /* Private functions ---------------------------------------------------------*/
 
 /**
@@ -175,6 +181,7 @@ static int8_t USBD_CDC_Control(uint8_t cmd, uint8_t *pbuf, uint16_t length)
       linecoding.format     = pbuf[4];
       linecoding.paritytype = pbuf[5];
       linecoding.datatype   = pbuf[6];
+      CDC_LineCodingChanged(linecoding.bitrate);
       break;
 
     case CDC_GET_LINE_CODING:
@@ -406,4 +413,3 @@ uint8_t  CDC_getDataBits(void)
 #endif /* USBD_USE_CDC */
 #endif /* USBCON */
 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
-
diff --git a/libraries/USBDevice/src/usbd_conf.c b/libraries/USBDevice/src/usbd_conf.c
@@ -16,7 +16,7 @@
   *
   ******************************************************************************
   */
-#ifdef USBCON
+#if defined(USBCON) && !defined(USE_HALV2_DRIVER)
 /* Includes ------------------------------------------------------------------*/
 #include "usbd_core.h"
 #include "usbd_if.h"
@@ -718,6 +718,5 @@ void USBD_LL_Delay(uint32_t Delay)
   HAL_Delay(Delay);
 }
 #endif /* HAL_PCD_MODULE_ENABLED */
-#endif /* USBCON */
+#endif /* USBCON && !USE_HALV2_DRIVER */
 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
-