dcd: retire dcd_edpt_close() on the iso-migrated drivers

Now that ip3511, rusb2 and nrf5x are on ISO_ALLOC, the stack's usbd_edpt_close()
is a no-op for them, so dcd_edpt_close() is no longer a public DCD entry point.
Audit of the remaining callers:

- ip3511, nrf5x: dcd_edpt_close_all() does its own teardown and no longer calls
  dcd_edpt_close() -> it is dead code, removed.
- rusb2: dcd_edpt_close_all() still tears down each pipe via it -> kept but made
  a static internal helper (edpt_close), not a public dcd_ API.

Revert dcd.h to declaring dcd_edpt_close() only under TUP_DCD_EDPT_CLOSE_API (for
the remaining close-API MCUs); ISO_ALLOC IPs declare iso alloc/activate instead.

Behaviour-neutral (removed/renamed uncalled functions); dwc2 still builds and
nrf5x still passes bulk/iso/halt on hardware.

Co-Authored-By: Claude Fable 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01HeF2gZ1M7GWkz6Av4BpKPg

4 files changed, 11 insertions, 52 deletions

diff --git a/src/device/dcd.h b/src/device/dcd.h
index 8f980c11e..f861eb258 100644
--- a/src/device/dcd.h
+++ b/src/device/dcd.h
@@ -174,18 +174,19 @@ void dcd_edpt_stall           (uint8_t rhport, uint8_t ep_addr);
 // This API never calls with control endpoints, since it is auto cleared when receiving setup packet
 void dcd_edpt_clear_stall     (uint8_t rhport, uint8_t ep_addr);
 
-// Close an endpoint. On CLOSE_API IPs the stack calls this from usbd_edpt_close(); on ISO_ALLOC
-// IPs it is a no-op in the stack, but some drivers (rusb2, ip3511, nrf5x) still use it internally
-// from dcd_edpt_close_all(), so it is declared unconditionally.
+#ifdef TUP_DCD_EDPT_CLOSE_API
+// Close an endpoint.
 void dcd_edpt_close(uint8_t rhport, uint8_t ep_addr);
 
-#ifdef TUP_DCD_EDPT_ISO_ALLOC
+#else
+
 // Allocate packet buffer used by ISO endpoints
 // Some MCU need manual packet buffer allocation, we allocate the largest size to avoid clustering
 bool dcd_edpt_iso_alloc(uint8_t rhport, uint8_t ep_addr, uint16_t largest_packet_size);
 
 // Configure and enable an ISO endpoint according to descriptor
 bool dcd_edpt_iso_activate(uint8_t rhport, tusb_desc_endpoint_t const * desc_ep);
+
 #endif
 
 //--------------------------------------------------------------------+
diff --git a/src/portable/nordic/nrf5x/dcd_nrf5x.c b/src/portable/nordic/nrf5x/dcd_nrf5x.c
index 6c301e4b6..e0baa1f4a 100644
--- a/src/portable/nordic/nrf5x/dcd_nrf5x.c
+++ b/src/portable/nordic/nrf5x/dcd_nrf5x.c
@@ -396,43 +396,6 @@ void dcd_edpt_close_all(uint8_t rhport) {
   dcd_int_enable(rhport);
 }
 
-void dcd_edpt_close(uint8_t rhport, uint8_t ep_addr) {
-  (void) rhport;
-
-  uint8_t const epnum = tu_edpt_number(ep_addr);
-  uint8_t const dir = tu_edpt_dir(ep_addr);
-
-  if (epnum != EP_ISO_NUM) {
-    // CBI
-    if (dir == TUSB_DIR_OUT) {
-      NRF_USBD->INTENCLR = TU_BIT(USBD_INTEN_ENDEPOUT0_Pos + epnum);
-      NRF_USBD->EPOUTEN &= ~TU_BIT(epnum);
-    } else {
-      NRF_USBD->INTENCLR = TU_BIT(USBD_INTEN_ENDEPIN0_Pos + epnum);
-      NRF_USBD->EPINEN &= ~TU_BIT(epnum);
-    }
-  } else {
-    _dcd.xfer[EP_ISO_NUM][dir].mps = 0;
-    // ISO
-    if (dir == TUSB_DIR_OUT) {
-      NRF_USBD->INTENCLR = USBD_INTENCLR_ENDISOOUT_Msk;
-      NRF_USBD->EPOUTEN &= ~USBD_EPOUTEN_ISOOUT_Msk;
-      NRF_USBD->EVENTS_ENDISOOUT = 0;
-    } else {
-      NRF_USBD->INTENCLR = USBD_INTENCLR_ENDISOIN_Msk;
-      NRF_USBD->EPINEN &= ~USBD_EPINEN_ISOIN_Msk;
-    }
-    // One of the ISO endpoints closed, no need to split buffers any more.
-    NRF_USBD->ISOSPLIT = USBD_ISOSPLIT_SPLIT_OneDir;
-    // When both ISO endpoint are close there is no need for SOF any more.
-    if (_dcd.xfer[EP_ISO_NUM][TUSB_DIR_IN].mps + _dcd.xfer[EP_ISO_NUM][TUSB_DIR_OUT].mps == 0)
-      NRF_USBD->INTENCLR = USBD_INTENCLR_SOF_Msk;
-  }
-  _dcd.xfer[epnum][dir].started = false;
-  __ISB();
-  __DSB();
-}
-
 bool dcd_edpt_iso_alloc(uint8_t rhport, uint8_t ep_addr, uint16_t largest_packet_size) {
   (void)rhport;
   (void)largest_packet_size;
diff --git a/src/portable/nxp/lpc_ip3511/dcd_lpc_ip3511.c b/src/portable/nxp/lpc_ip3511/dcd_lpc_ip3511.c
index 451b07e15..1b591cf99 100644
--- a/src/portable/nxp/lpc_ip3511/dcd_lpc_ip3511.c
+++ b/src/portable/nxp/lpc_ip3511/dcd_lpc_ip3511.c
@@ -423,15 +423,6 @@ void dcd_edpt_close_all (uint8_t rhport)
   }
 }
 
-void dcd_edpt_close(uint8_t rhport, uint8_t ep_addr)
-{
-  (void) rhport;
-
-  uint8_t ep_id = ep_addr2id(ep_addr);
-  _dcd.ep[ep_id][0].cmd_sts.active = _dcd.ep[ep_id][0].cmd_sts.active = 0; // TODO proper way is to EPSKIP then wait ep[][].active then write ep[][].disable (see table 778 in LPC55S69 Use Manual)
-  _dcd.ep[ep_id][0].cmd_sts.disable = _dcd.ep[ep_id][1].cmd_sts.disable = 1;
-}
-
 bool dcd_edpt_iso_alloc(uint8_t rhport, uint8_t ep_addr, uint16_t largest_packet_size) {
   (void) largest_packet_size;
   // Reserve the endpoint command/status entry once (persists across altsetting changes); the
diff --git a/src/portable/renesas/rusb2/dcd_rusb2.c b/src/portable/renesas/rusb2/dcd_rusb2.c
index ddd3fe0f2..0ef7661fe 100644
--- a/src/portable/renesas/rusb2/dcd_rusb2.c
+++ b/src/portable/renesas/rusb2/dcd_rusb2.c
@@ -766,6 +766,8 @@ bool dcd_edpt_open(uint8_t rhport, tusb_desc_endpoint_t const * ep_desc)
   return true;
 }
 
+static void edpt_close(uint8_t rhport, uint8_t ep_addr);
+
 void dcd_edpt_close_all(uint8_t rhport)
 {
   unsigned i = TU_ARRAY_SIZE(_dcd.pipe);
@@ -775,12 +777,14 @@ void dcd_edpt_close_all(uint8_t rhport)
     if (!ep_addr) {
       continue;
     }
-    dcd_edpt_close(rhport, (uint8_t)ep_addr);
+    edpt_close(rhport, (uint8_t)ep_addr);
   }
   dcd_int_enable(rhport);
 }
 
-void dcd_edpt_close(uint8_t rhport, uint8_t ep_addr)
+// Internal helper: on this (ISO_ALLOC) IP the stack no longer calls dcd_edpt_close(); only
+// dcd_edpt_close_all() uses it to tear down each pipe.
+static void edpt_close(uint8_t rhport, uint8_t ep_addr)
 {
   rusb2_reg_t * rusb = RUSB2_REG(rhport);
   const unsigned epn = tu_edpt_number(ep_addr);