Start changes - not yet finished

src/device/usbd.c

@@ -1188,6 +1188,35 @@ bool usbd_edpt_xfer(uint8_t rhport, uint8_t ep_addr, uint8_t * buffer, uint16_t
   }
 }
 
+bool usbd_edpt_ISO_xfer(uint8_t rhport, uint8_t ep_addr, tu_fifo_t * ff, uint16_t total_bytes)
+{
+  uint8_t const epnum = tu_edpt_number(ep_addr);
+  uint8_t const dir   = tu_edpt_dir(ep_addr);
+
+  TU_LOG2("  Queue ISO EP %02X with %u bytes ... ", ep_addr, total_bytes);
+
+  // Attempt to transfer on a busy endpoint, sound like an race condition !
+  TU_ASSERT(_usbd_dev.ep_status[epnum][dir].busy == 0);
+
+  // Set busy first since the actual transfer can be complete before dcd_edpt_xfer() could return
+  // and usbd task can preempt and clear the busy
+  _usbd_dev.ep_status[epnum][dir].busy = true;
+
+  if ( dcd_edpt_ISO_xfer(rhport, ep_addr, ff, total_bytes) )
+  {
+    TU_LOG2("OK\r\n");
+    return true;
+  }else
+  {
+    // DCD error, mark endpoint as ready to allow next transfer
+    _usbd_dev.ep_status[epnum][dir].busy = false;
+    _usbd_dev.ep_status[epnum][dir].claimed = 0;
+    TU_LOG2("failed\r\n");
+    TU_BREAKPOINT();
+    return false;
+  }
+}
+
 bool usbd_edpt_busy(uint8_t rhport, uint8_t ep_addr)
 {
   (void) rhport;

src/device/usbd_pvt.h

@@ -72,6 +72,9 @@ void usbd_edpt_close(uint8_t rhport, uint8_t ep_addr);
 // Submit a usb transfer
 bool usbd_edpt_xfer(uint8_t rhport, uint8_t ep_addr, uint8_t * buffer, uint16_t total_bytes);
 
+// Submit a usb ISO transfer by use of a FIFO (ring buffer)
+bool usbd_edpt_ISO_xfer(uint8_t rhport, uint8_t ep_addr, tu_fifo_t * ff, uint16_t total_bytes);
+
 // Claim an endpoint before submitting a transfer.
 // If caller does not make any transfer, it must release endpoint for others.
 bool usbd_edpt_claim(uint8_t rhport, uint8_t ep_addr);