Implement dcd_edpt_iso_xfer() for dcd_esp32s2.c

src/portable/espressif/esp32s2/dcd_esp32s2.c

@@ -27,6 +27,7 @@
  */
 
 #include "tusb_option.h"
+#include "common/tusb_fifo.h"
 
 #if CFG_TUSB_MCU == OPT_MCU_ESP32S2 && TUSB_OPT_DEVICE_ENABLED
 
@@ -59,6 +60,7 @@
 
 typedef struct {
     uint8_t *buffer;
+    tu_fifo_t * ff;
     uint16_t total_len;
     uint16_t queued_len;
     uint16_t max_size;
@@ -354,6 +356,64 @@ bool dcd_edpt_xfer(uint8_t rhport, uint8_t ep_addr, uint8_t *buffer, uint16_t to
   return true;
 }
 
+bool dcd_edpt_iso_xfer (uint8_t rhport, uint8_t ep_addr, tu_fifo_t * ff, uint16_t total_bytes)
+{
+  (void)rhport;
+
+  // USB buffers always work in bytes so to avoid unnecessary divisions we demand item_size = 1
+  TU_ASSERT(ff->item_size == 1);
+
+  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;
+  xfer->ff           = ff;
+  xfer->total_len    = total_bytes;
+  xfer->queued_len   = 0;
+  xfer->short_packet = false;
+
+  uint16_t num_packets = (total_bytes / xfer->max_size);
+  uint8_t short_packet_size = total_bytes % xfer->max_size;
+
+  // Zero-size packet is special case.
+  if (short_packet_size > 0 || (total_bytes == 0)) {
+    num_packets++;
+  }
+
+  // Set copy mode to constant address - required since data copied to or from the hardware USB FIFO needs to be written at a constant address
+  if (dir == TUSB_DIR_IN)
+  {
+    tu_fifo_set_copy_mode_write(ff, TU_FIFO_COPY_CST);
+  }
+  else
+  {
+    tu_fifo_set_copy_mode_read(ff, TU_FIFO_COPY_CST);
+  }
+
+  ESP_LOGV(TAG, "Transfer <-> EP%i, %s, pkgs: %i, bytes: %i",
+           epnum, ((dir == TUSB_DIR_IN) ? "USB0.HOST (in)" : "HOST->DEV (out)"),
+           num_packets, total_bytes);
+
+  // IN and OUT endpoint xfers are interrupt-driven, we just schedule them
+  // here.
+  if (dir == TUSB_DIR_IN) {
+    // A full IN transfer (multiple packets, possibly) triggers XFRC.
+    USB0.in_ep_reg[epnum].dieptsiz = (num_packets << USB_D_PKTCNT0_S) | total_bytes;
+    USB0.in_ep_reg[epnum].diepctl |= USB_D_EPENA1_M | USB_D_CNAK1_M; // Enable | CNAK
+
+    // Enable fifo empty interrupt only if there are something to put in the fifo.
+    if(total_bytes != 0) {
+      USB0.dtknqr4_fifoemptymsk |= (1 << epnum);
+    }
+  } else {
+    // Each complete packet for OUT xfers triggers XFRC.
+    USB0.out_ep_reg[epnum].doeptsiz |= USB_PKTCNT0_M | ((xfer->max_size & USB_XFERSIZE0_V) << USB_XFERSIZE0_S);
+    USB0.out_ep_reg[epnum].doepctl  |= USB_EPENA0_M | USB_CNAK0_M;
+  }
+  return true;
+}
+
 void dcd_edpt_stall(uint8_t rhport, uint8_t ep_addr)
 {
   (void)rhport;
@@ -462,6 +522,9 @@ static void receive_packet(xfer_ctl_t *xfer, /* usb_out_endpoint_t * out_ep, */
     to_recv_size = (xfer_size > xfer->max_size) ? xfer->max_size : xfer_size;
   }
 
+  // Common buffer read
+  if (xfer->buffer)
+  {
     uint8_t to_recv_rem = to_recv_size % 4;
     uint16_t to_recv_size_aligned = to_recv_size - to_recv_rem;
 
@@ -494,6 +557,13 @@ static void receive_packet(xfer_ctl_t *xfer, /* usb_out_endpoint_t * out_ep, */
       }
     }
 
+  }
+  else
+  {
+    // Ring buffer
+    tu_fifo_write_n(xfer->ff, (const void *) rx_fifo, to_recv_size);
+  }
+
   xfer->queued_len += xfer_size;
 
   // Per USB spec, a short OUT packet (including length 0) is always
@@ -510,6 +580,9 @@ static void transmit_packet(xfer_ctl_t *xfer, volatile usb_in_endpoint_t *in_ep,
   xfer->queued_len = xfer->total_len - remaining;
 
   uint16_t to_xfer_size = (remaining > xfer->max_size) ? xfer->max_size : remaining;
+
+  if (xfer->buffer)
+  {
     uint8_t to_xfer_rem = to_xfer_size % 4;
     uint16_t to_xfer_size_aligned = to_xfer_size - to_xfer_rem;
 
@@ -542,6 +615,11 @@ static void transmit_packet(xfer_ctl_t *xfer, volatile usb_in_endpoint_t *in_ep,
 
       (*tx_fifo) = tmp;
     }
+  }
+  else
+  {
+    tu_fifo_read_n(xfer->ff, (void *) tx_fifo, to_xfer_size);
+  }
 }
 
 static void read_rx_fifo(void)