add CFG_TUD_VENDOR_RX_MANUAL_XFER per suggestion

Author: hathach

src/class/vendor/vendor_device.c

@@ -136,6 +136,15 @@ void tud_vendor_n_read_flush(uint8_t idx) {
 }
 #endif
 
+#if CFG_TUD_VENDOR_RX_MANUAL_XFER
+bool tud_vendor_n_read_xfer(uint8_t idx) {
+  TU_VERIFY(idx < CFG_TUD_VENDOR);
+  vendord_interface_t *p_itf = &_vendord_itf[idx];
+  return tu_edpt_stream_read_xfer(p_itf->rhport, &p_itf->stream.rx);
+}
+#endif
+
+
 //--------------------------------------------------------------------+
 // Write API
 //--------------------------------------------------------------------+
@@ -274,7 +283,9 @@ uint16_t vendord_open(uint8_t rhport, const tusb_desc_interface_t *desc_itf, uin
         tu_edpt_stream_t *stream_rx = &p_vendor->stream.rx;
         if (stream_rx->ep_addr == 0) {
           tu_edpt_stream_open(stream_rx, desc_ep);
+  #if CFG_TUD_VENDOR_RX_MANUAL_XFER
           TU_ASSERT(tu_edpt_stream_read_xfer(rhport, stream_rx) > 0, 0); // prepare for incoming data
+  #endif
         }
       }
     }
@@ -302,7 +313,9 @@ bool vendord_xfer_cb(uint8_t rhport, uint8_t ep_addr, xfer_result_t result, uint
     tud_vendor_rx_cb(idx, NULL, 0);
   #endif
 
+  #if CFG_TUD_VENDOR_RX_MANUAL_XFER
     tu_edpt_stream_read_xfer(rhport, &p_vendor->stream.rx); // prepare next data
+  #endif
   } else if (ep_addr == p_vendor->stream.tx.ep_addr) {
     // Send complete
     tud_vendor_tx_cb(idx, (uint16_t)xferred_bytes);

src/class/vendor/vendor_device.h

@@ -27,8 +27,15 @@
 #ifndef TUSB_VENDOR_DEVICE_H_
 #define TUSB_VENDOR_DEVICE_H_
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include "common/tusb_common.h"
 
+//--------------------------------------------------------------------+
+// Configuration
+//--------------------------------------------------------------------+
 #ifndef CFG_TUD_VENDOR_EPSIZE
   #define CFG_TUD_VENDOR_EPSIZE 64
 #endif
@@ -43,30 +50,53 @@
   #define CFG_TUD_VENDOR_TX_BUFSIZE 64
 #endif
 
-#ifdef __cplusplus
-extern "C" {
+// Application will manually schedule RX transfer. This can be useful when using with non-fifo (buffered) mode
+// i.e. CFG_TUD_VENDOR_RX_BUFSIZE = 0
+#ifndef CFG_TUD_VENDOR_RX_MANUAL_XFER
+  #define CFG_TUD_VENDOR_RX_MANUAL_XFER 0
 #endif
 
 //--------------------------------------------------------------------+
 // Application API (Multiple Interfaces) i.e CFG_TUD_VENDOR > 1
 //--------------------------------------------------------------------+
-bool     tud_vendor_n_mounted(uint8_t idx);
+
+// Return whether the vendor interface is mounted
+bool tud_vendor_n_mounted(uint8_t idx);
 
 #if CFG_TUD_VENDOR_RX_BUFSIZE > 0
+// Return number of available bytes for reading
 uint32_t tud_vendor_n_available(uint8_t idx);
-bool     tud_vendor_n_peek(uint8_t idx, uint8_t *ui8);
+
+// Peek a byte from RX buffer
+bool tud_vendor_n_peek(uint8_t idx, uint8_t *ui8);
+
+// Read from RX FIFO
 uint32_t tud_vendor_n_read(uint8_t idx, void *buffer, uint32_t bufsize);
+
+// Discard count bytes in RX FIFO
 uint32_t tud_vendor_n_read_discard(uint8_t idx, uint32_t count);
-void     tud_vendor_n_read_flush(uint8_t idx);
+
+// Flush (clear) RX FIFO
+void tud_vendor_n_read_flush(uint8_t idx);
+#endif
+
+#if CFG_TUD_VENDOR_RX_MANUAL_XFER
+// Start a new RX transfer to fill the RX FIFO, return false if previous transfer is still ongoing
+bool tud_vendor_n_read_xfer(uint8_t idx);
 #endif
 
+// Write to TX FIFO. This can be buffered and not sent immediately unless buffered bytes >= USB endpoint size
 uint32_t tud_vendor_n_write(uint8_t idx, const void *buffer, uint32_t bufsize);
 
 #if CFG_TUD_VENDOR_TX_BUFSIZE > 0
+// Force sending buffered data, return number of bytes sent
 uint32_t tud_vendor_n_write_flush(uint8_t idx);
+
+// Return number of bytes available for writing in TX FIFO
 uint32_t tud_vendor_n_write_available(uint8_t idx);
 #endif
 
+// Write a null-terminated string to TX FIFO
 TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_vendor_n_write_str(uint8_t idx, const char *str) {
   return tud_vendor_n_write(idx, str, strlen(str));
 }
@@ -103,6 +133,12 @@ TU_ATTR_ALWAYS_INLINE static inline void tud_vendor_read_flush(void) {
 }
 #endif
 
+#if CFG_TUD_VENDOR_RX_MANUAL_XFER
+TU_ATTR_ALWAYS_INLINE static inline bool tud_vendor_read_xfer(void) {
+  return tud_vendor_n_read_xfer(0);
+}
+#endif
+
 TU_ATTR_ALWAYS_INLINE static inline uint32_t tud_vendor_write(const void *buffer, uint32_t bufsize) {
   return tud_vendor_n_write(0, buffer, bufsize);
 }