Fix bug where the EPREGs were not being initialized as expected.

src/portable/st/stm32_fsdev/dcd_stm32_fsdev.c

@@ -216,10 +216,11 @@ void dcd_init (uint8_t rhport)
 
   USB->ISTR &= ~(USB_ISTR_ALL_EVENTS); // Clear pending interrupts
 
-  // Clear all EPREG
-  for(uint16_t i=0; i<8; i++)
+  // Reset endpoints to disabled
+  for(uint i=0; i<STFSDEV_EP_COUNT; i++)
   {
-    EPREG(0) = 0u;
+    // This doesn't clear all bits since some bits are "toggle", but does set the type to DISABLED.
+    PCD_GET_ENDPOINT(USB,i) = 0u;
   }
 
   // Initialize the BTABLE for EP0 at this point (though setting up the EP0R is unneeded)
@@ -327,9 +328,9 @@ static void dcd_handle_bus_reset(void)
   USB->DADDR = 0u; // disable USB peripheral by clearing the EF flag
 
   // Clear all EPREG (or maybe this is automatic? I'm not sure)
-  for(uint16_t i=0; i<8; i++)
+  for(uint i=0; i<STFSDEV_EP_COUNT; i++)
   {
-    EPREG(0) = 0u;
+    PCD_GET_ENDPOINT(USB,i) = 0u;
   }
 
   ep_buf_ptr = DCD_STM32_BTABLE_BASE + 8*MAX_EP_COUNT; // 8 bytes per endpoint (two TX and two RX words, each)

src/portable/st/stm32_fsdev/dcd_stm32_fsdev_pvt_st.h

@@ -271,9 +271,6 @@ static __IO uint16_t * const pma = (__IO uint16_t*)USB_PMAADDR;
 #define PCD_CLEAR_EP_KIND(USBx, bEpNum)  (PCD_SET_ENDPOINT((USBx), (bEpNum), \
                                 (USB_EP_CTR_RX|USB_EP_CTR_TX|((((uint32_t)(PCD_GET_ENDPOINT((USBx), (bEpNum)))) & USB_EPKIND_MASK)))))
 
-
-#define EPREG(n) (((__IO uint16_t*)USB_BASE)[n*2])
-
 // This checks if the device has "LPM"
 #if defined(USB_ISTR_L1REQ)
 #define USB_ISTR_L1REQ_FORCED (USB_ISTR_L1REQ)
@@ -284,5 +281,7 @@ static __IO uint16_t * const pma = (__IO uint16_t*)USB_PMAADDR;
 #define USB_ISTR_ALL_EVENTS (USB_ISTR_PMAOVR | USB_ISTR_ERR | USB_ISTR_WKUP | USB_ISTR_SUSP | \
      USB_ISTR_RESET | USB_ISTR_SOF | USB_ISTR_ESOF | USB_ISTR_L1REQ_FORCED )
 
+// Number of endpoints in hardware
+#define STFSDEV_EP_COUNT (8)
 
 #endif /* PORTABLE_ST_STM32F0_DCD_STM32F0_FSDEV_PVT_ST_H_ */