feature(dcd): Check avaliable endpoints:

            - Check if endpoint is avaliable while opening it
            - Release endponint once is closed

src/portable/synopsys/dwc2/dcd_dwc2.c

@@ -630,6 +630,48 @@ void dcd_sof_enable(uint8_t rhport, bool en)
 /* DCD Endpoint port
  *------------------------------------------------------------------*/
 
+#if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3, OPT_MCU_ESP32P4)
+
+// Check if IN/OUT endpoint is avaliable before opening it
+static bool dcd_edpt_available(uint8_t rhport, uint8_t dir) 
+{
+    // Verify that we have a vacant EP
+    if ((dwc_ep_config[rhport].in_ep + dwc_ep_config[rhport].out_ep) > (dwc_ep_config[rhport].ep_max_count - 1)) {
+        return false;
+    }
+    // Get the ep_count amount at the moment as a temporal variable and update it
+    uint8_t new_ep_count = (dir) ? dwc_ep_config[rhport].in_ep : dwc_ep_config[rhport].out_ep;
+    new_ep_count++;
+
+    // Verify overflow for IN EP ESP32Sx
+ #if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
+     // ESP32Sx has 6 endpoints, from which only 5 can be confiugred as IN
+     if ((dir) && (new_ep_count > (dwc_ep_config[rhport].ep_max_count - 1))) {
+         return false;
+     }
+ #endif // TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3)
+    // Write new value back
+    if(dir) {
+        dwc_ep_config[rhport].in_ep = new_ep_count;
+    } else {
+        dwc_ep_config[rhport].out_ep = new_ep_count;
+    }
+    return true; 
+}
+
+// Release an endpoint.
+static void dcd_edpt_release(uint8_t rhport, uint8_t dir)
+{
+  if (dir) {
+    TU_ASSERT(dwc_ep_config[rhport].in_ep == 0);    // Check if number of opened EPs is not zero
+    dwc_ep_config[rhport].in_ep--;                  // Release in_ep
+  } else {
+    TU_ASSERT(dwc_ep_config[rhport].out_ep == 0);
+    dwc_ep_config[rhport].out_ep--;
+  }
+}
+#endif
+
 bool dcd_edpt_open (uint8_t rhport, tusb_desc_endpoint_t const * desc_edpt)
 {
   (void) rhport;
@@ -640,7 +682,12 @@ bool dcd_edpt_open (uint8_t rhport, tusb_desc_endpoint_t const * desc_edpt)
   uint8_t const epnum = tu_edpt_number(desc_edpt->bEndpointAddress);
   uint8_t const dir   = tu_edpt_dir(desc_edpt->bEndpointAddress);
 
-  TU_ASSERT(epnum < ep_count);
+  #if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3, OPT_MCU_ESP32P4)
+  if (!dcd_edpt_available(rhport, dir)) {
+    TU_LOG(1, "No endpoints available (ep_max=%d) \r\n", dwc_ep_config[rhport].ep_max_count);
+    return false;
+  }
+  #endif
 
   xfer_ctl_t * xfer = XFER_CTL_BASE(epnum, dir);
   xfer->max_size = tu_edpt_packet_size(desc_edpt);
@@ -721,6 +768,11 @@ void dcd_edpt_close_all (uint8_t rhport)
   dwc2_regs_t * dwc2     = DWC2_REG(rhport);
   uint8_t const ep_count = _dwc2_controller[rhport].ep_count;
 
+  #if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3, OPT_MCU_ESP32P4)
+  dwc_ep_config[rhport].in_ep = 0;
+  dwc_ep_config[rhport].out_ep = 0;
+  #endif
+
   // Disable non-control interrupt
   dwc2->daintmsk = (1 << DAINTMSK_OEPM_Pos) | (1 << DAINTMSK_IEPM_Pos);
 
@@ -878,6 +930,13 @@ void dcd_edpt_close (uint8_t rhport, uint8_t ep_addr)
 
   dcd_edpt_disable(rhport, ep_addr, false);
 
+  #if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3, OPT_MCU_ESP32P4)
+  // Release an endpoint if it is not the 0 EP
+  if (epnum) {
+    dcd_edpt_release(rhport, dir);
+  }
+  #endif
+
   // Update max_size
   xfer_status[epnum][dir].max_size = 0;  // max_size = 0 marks a disabled EP - required for changing FIFO allocation
 

src/portable/synopsys/dwc2/dwc2_esp32.h

@@ -55,7 +55,7 @@
 #endif
 
 #if DWC2_FS_PERIPH_BASE
-  #define DWC2_FS_EP_MAX       6             // USB_OUT_EP_NUM. TODO ESP32Sx only has 5 tx fifo (5 endpoint IN)
+  #define DWC2_FS_EP_MAX       6             // USB_OUT_EP_NUM
   #define DWC2_FS_EP_FIFO_SIZE 1024
 #endif
 
@@ -82,6 +82,16 @@ static const dwc2_controller_t _dwc2_controller[] =
 #endif
 };
 
+static dwc_ep_config_t dwc_ep_config[] = 
+{
+#ifdef DWC2_FS_PERIPH_BASE
+  { .out_ep = 0, .in_ep = 0, .ep_max_count = DWC2_FS_EP_MAX },
+#endif
+#ifdef DWC2_HS_PERIPH_BASE
+  { .out_ep = 0, .in_ep = 0, .ep_max_count = DWC2_HS_EP_MAX },
+#endif
+};
+
 static intr_handle_t usb_ih[DWC2_PERIPH_COUNT];
 
 static void dcd_int_handler_wrap(void* arg)

src/portable/synopsys/dwc2/dwc2_type.h

@@ -32,6 +32,14 @@ typedef struct
   uint32_t  ep_fifo_size;
 }dwc2_controller_t;
 
+#if TU_CHECK_MCU(OPT_MCU_ESP32S2, OPT_MCU_ESP32S3, OPT_MCU_ESP32P4)
+typedef struct {
+    uint8_t out_ep;
+    uint8_t in_ep;
+    const uint8_t ep_max_count;
+}dwc_ep_config_t;
+#endif
+
 /* DWC OTG HW Release versions */
 #define DWC2_CORE_REV_2_71a   0x4f54271a
 #define DWC2_CORE_REV_2_72a   0x4f54272a