3 files changed, 71 insertions, 0 deletions
diff --git a/src/device/usbd.c b/src/device/usbd.c
index 791d533ae..55e76bb66 100644
--- a/src/device/usbd.c
+++ b/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;
diff --git a/src/device/usbd_pvt.h b/src/device/usbd_pvt.h
index 212c3a202..de2f37281 100644
--- a/src/device/usbd_pvt.h
+++ b/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);
diff --git a/src/portable/st/synopsys/dcd_synopsys.c b/src/portable/st/synopsys/dcd_synopsys.c
index 35c814460..0aee6a919 100644
--- a/src/portable/st/synopsys/dcd_synopsys.c
+++ b/src/portable/st/synopsys/dcd_synopsys.c
@@ -28,6 +28,7 @@
  */
 
 #include "tusb_option.h"
+#include "tusb_fifo.h"
 
 // Since TinyUSB doesn't use SOF for now, and this interrupt too often (1ms interval)
 // We disable SOF for now until needed later on
@@ -134,6 +135,7 @@ static TU_ATTR_ALIGNED(4) uint32_t _setup_packet[2];
 
 typedef struct {
   uint8_t * buffer;
+  tu_fifo_t * ff;
   uint16_t total_len;
   uint16_t max_size;
   uint8_t interval;
@@ -659,6 +661,38 @@ bool dcd_edpt_xfer (uint8_t rhport, uint8_t ep_addr, uint8_t * buffer, uint16_t
   return true;
 }
 
+bool dcd_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);
+
+  xfer_ctl_t * xfer = XFER_CTL_BASE(epnum, dir);
+  xfer->buffer      = NULL;                                 // Indicates a FIFO shall be used
+  xfer->ff          = ff;
+  xfer->total_len   = total_bytes;
+
+  // EP0 can only handle one packet
+  if(epnum == 0) {
+    ep0_pending[dir] = total_bytes;
+    // Schedule the first transaction for EP0 transfer
+    edpt_schedule_packets(rhport, epnum, dir, 1, ep0_pending[dir]);
+    return true;
+  }
+
+  uint16_t num_packets = (total_bytes / xfer->max_size);
+  uint8_t const short_packet_size = total_bytes % xfer->max_size;
+
+  // Zero-size packet is special case.
+  if(short_packet_size > 0 || (total_bytes == 0)) {
+    num_packets++;
+  }
+
+  // Schedule packets to be sent within interrupt
+  edpt_schedule_packets(rhport, epnum, dir, num_packets, total_bytes);
+
+  return true;
+}
+
 static void dcd_edpt_disable (uint8_t rhport, uint8_t ep_addr, bool stall)
 {
   (void) rhport;
@@ -849,6 +883,9 @@ static void handle_rxflvl_ints(uint8_t rhport, USB_OTG_OUTEndpointTypeDef * out_
     {
       xfer_ctl_t * xfer = XFER_CTL_BASE(epnum, TUSB_DIR_OUT);
 
+
+      // TODO: TAKE CARE OF ISO FIFO!
+
       // Read packet off RxFIFO
       read_fifo_packet(rhport, xfer->buffer, bcnt);
 
@@ -960,6 +997,8 @@ static void handle_epin_ints(uint8_t rhport, USB_OTG_DeviceTypeDef * dev, USB_OT
             break;
           }
 
+          // TODO: TAKE CARE OF ISO FIFO!
+
           // Push packet to Tx-FIFO
           write_fifo_packet(rhport, n, xfer->buffer, packet_size);