3 files changed, 34 insertions, 9 deletions
diff --git a/examples/device/usbtest/src/main.c b/examples/device/usbtest/src/main.c
index 78575ac9b..e57a90161 100644
--- a/examples/device/usbtest/src/main.c
+++ b/examples/device/usbtest/src/main.c
@@ -61,7 +61,9 @@ static uint32_t blink_interval_ms = BLINK_NOT_MOUNTED;
 // unintended short packet or ZLP.
 static uint8_t const tx_chunk[CFG_TUD_VENDOR_TX_EPSIZE];
 static uint8_t const int_tx_chunk[USBTEST_INT_EP_MPS];
+#if USBTEST_TIER >= 4
 static uint8_t const iso_tx_chunk[USBTEST_ISO_EP_MPS];
+#endif
 
 // Interrupt/iso submit one packet per (micro)frame, sized to the NEGOTIATED speed's mps — a
 // high-speed build enumerated at full speed must submit the FS length, not the HS-capacity buffer
@@ -69,9 +71,11 @@ static uint8_t const iso_tx_chunk[USBTEST_ISO_EP_MPS];
 static inline uint16_t usbtest_int_len(void) {
   return (tud_speed_get() == TUSB_SPEED_HIGH) ? USBTEST_INT_EP_MPS_HS : USBTEST_INT_EP_MPS_FS;
 }
+#if USBTEST_TIER >= 4
 static inline uint16_t usbtest_iso_len(void) {
   return (tud_speed_get() == TUSB_SPEED_HIGH) ? USBTEST_ISO_EP_MPS_HS : USBTEST_ISO_EP_MPS_FS;
 }
+#endif
 
 //------------- prototypes -------------//
 void led_blinking_task(void* param);
@@ -125,10 +129,12 @@ static void usbtest_pump(void) {
       tud_vendor_int_write(int_tx_chunk, usbtest_int_len());
     }
 
+#if USBTEST_TIER >= 4
     tud_vendor_iso_read_xfer(); // isochronous sink
     if (tud_vendor_iso_write_available()) {
       tud_vendor_iso_write(iso_tx_chunk, usbtest_iso_len());
     }
+#endif
   }
 }
 
@@ -175,6 +181,7 @@ void tud_vendor_int_tx_cb(uint8_t idx, uint32_t sent_bytes) {
 
 // Isochronous pair: same discard/refill pumps; a completion may be a missed
 // frame, re-arm regardless
+#if USBTEST_TIER >= 4
 void tud_vendor_iso_rx_cb(uint8_t idx, const uint8_t* buffer, uint32_t bufsize) {
   (void) idx;
   (void) buffer;
@@ -187,6 +194,7 @@ void tud_vendor_iso_tx_cb(uint8_t idx, uint32_t sent_bytes) {
   (void) sent_bytes;
   tud_vendor_iso_write(iso_tx_chunk, usbtest_iso_len());
 }
+#endif
 
 //--------------------------------------------------------------------+
 // Vendor control requests (EP0)
diff --git a/examples/device/usbtest/src/usb_descriptors.c b/examples/device/usbtest/src/usb_descriptors.c
index 24efef453..b4f46adb8 100644
--- a/examples/device/usbtest/src/usb_descriptors.c
+++ b/examples/device/usbtest/src/usb_descriptors.c
@@ -67,21 +67,29 @@ enum {
 
 // Vendor interface, Gadget-Zero style altsettings: alt 0 carries no endpoints (an
 // isochronous endpoint must not claim bandwidth in the default altsetting, USB 2.0
-// 5.6.3), alt 1 carries bulk + interrupt + isochronous IN/OUT. The host usbtest
-// driver skips altsettings without pipes and selects alt 1 itself. No TUD_ macro
-// covers this layout, hand-rolled.
-#define USBTEST_DESC_LEN  (9 + 9 + 6*7)
+// 5.6.3), alt 1 carries bulk + interrupt (+ isochronous IN/OUT at tier 4). The host
+// usbtest driver skips altsettings without pipes and selects alt 1 itself. No TUD_
+// macro covers this layout, hand-rolled.
+#if USBTEST_TIER >= 4
+  #define USBTEST_EP_COUNT  6
+  #define USBTEST_ISO_EPS(_isoout, _isoin, _iso_mps, _iso_interval) \
+    ,7, TUSB_DESC_ENDPOINT, _isoout, (uint8_t)(TUSB_XFER_ISOCHRONOUS | (uint8_t)(TUSB_ISO_EP_ATT_ASYNCHRONOUS)), U16_TO_U8S_LE(_iso_mps), _iso_interval,\
+    7, TUSB_DESC_ENDPOINT, _isoin, (uint8_t)(TUSB_XFER_ISOCHRONOUS | (uint8_t)(TUSB_ISO_EP_ATT_ASYNCHRONOUS)), U16_TO_U8S_LE(_iso_mps), _iso_interval
+#else
+  #define USBTEST_EP_COUNT  4
+  #define USBTEST_ISO_EPS(_isoout, _isoin, _iso_mps, _iso_interval)
+#endif
+#define USBTEST_DESC_LEN  (9 + 9 + USBTEST_EP_COUNT*7)
 #define USBTEST_DESCRIPTOR(_itfnum, _stridx, _epout, _epin, _bulk_mps, _intout, _intin, _int_mps, _int_interval, _isoout, _isoin, _iso_mps, _iso_interval) \
   /* alt 0: zero bandwidth, no endpoints */\
   9, TUSB_DESC_INTERFACE, _itfnum, 0, 0, TUSB_CLASS_VENDOR_SPECIFIC, 0x00, 0x00, _stridx,\
   /* alt 1: full source/sink set */\
-  9, TUSB_DESC_INTERFACE, _itfnum, 1, 6, TUSB_CLASS_VENDOR_SPECIFIC, 0x00, 0x00, _stridx,\
+  9, TUSB_DESC_INTERFACE, _itfnum, 1, USBTEST_EP_COUNT, TUSB_CLASS_VENDOR_SPECIFIC, 0x00, 0x00, _stridx,\
   7, TUSB_DESC_ENDPOINT, _epout, TUSB_XFER_BULK, U16_TO_U8S_LE(_bulk_mps), 0,\
   7, TUSB_DESC_ENDPOINT, _epin, TUSB_XFER_BULK, U16_TO_U8S_LE(_bulk_mps), 0,\
   7, TUSB_DESC_ENDPOINT, _intout, TUSB_XFER_INTERRUPT, U16_TO_U8S_LE(_int_mps), _int_interval,\
-  7, TUSB_DESC_ENDPOINT, _intin, TUSB_XFER_INTERRUPT, U16_TO_U8S_LE(_int_mps), _int_interval,\
-  7, TUSB_DESC_ENDPOINT, _isoout, (uint8_t)(TUSB_XFER_ISOCHRONOUS | (uint8_t)(TUSB_ISO_EP_ATT_ASYNCHRONOUS)), U16_TO_U8S_LE(_iso_mps), _iso_interval,\
-  7, TUSB_DESC_ENDPOINT, _isoin, (uint8_t)(TUSB_XFER_ISOCHRONOUS | (uint8_t)(TUSB_ISO_EP_ATT_ASYNCHRONOUS)), U16_TO_U8S_LE(_iso_mps), _iso_interval
+  7, TUSB_DESC_ENDPOINT, _intin, TUSB_XFER_INTERRUPT, U16_TO_U8S_LE(_int_mps), _int_interval\
+  USBTEST_ISO_EPS(_isoout, _isoin, _iso_mps, _iso_interval)
 
 #define CONFIG_TOTAL_LEN    (TUD_CONFIG_DESC_LEN + USBTEST_DESC_LEN)
 
diff --git a/examples/device/usbtest/src/usb_descriptors.h b/examples/device/usbtest/src/usb_descriptors.h
index 61b931bd0..bcf8b5ec4 100644
--- a/examples/device/usbtest/src/usb_descriptors.h
+++ b/examples/device/usbtest/src/usb_descriptors.h
@@ -32,7 +32,16 @@
 //   2: + vendor control 0x5b/0x5c (ctrl_out)
 //   3: + interrupt source/sink
 //   4: + isochronous source/sink
-#define USBTEST_TIER  4
+// Default is the full tier 4; a board whose DCD cannot serve a tier lowers it here
+// (BOARD_<NAME> is defined by both build systems) and the host battery follows.
+#ifndef USBTEST_TIER
+  #if defined(BOARD_RA2A1_EK)
+    // RA2A1's RUSB2 instance has no isochronous pipe (other RA parts have pipes 1-2)
+    #define USBTEST_TIER  3
+  #else
+    #define USBTEST_TIER  4
+  #endif
+#endif
 
 // Interrupt/isochronous endpoint max packet sizes, must match the configuration descriptor.
 // TUD_OPT_HIGH_SPEED is a compile-time capability flag, NOT the live bus speed, so the full-speed