Implement functions to allow for DMA usage in audio driver.

- Add tud_audio_n_get_ep_out_ff(), tud_audio_n_get_ep_in_ff(),
tud_audio_n_get_rx_support_ff(), and tud_audio_n_get_tx_support_ff()
- Change get_linear_read/write_info() to return linear and wrapped part
at once
- Adjusted affected code in audio_device.c and tested with
audio_4_channel.

src/class/audio/audio_device.c

@@ -447,27 +447,39 @@ bool tud_audio_n_clear_ep_out_ff(uint8_t func_id)
   return tu_fifo_clear(&_audiod_fct[func_id].ep_out_ff);
 }
 
+tu_fifo_t* tud_audio_n_get_ep_out_ff(uint8_t func_id)
+{
+  if(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL) return &_audiod_fct[func_id].ep_out_ff;
+  return NULL;
+}
+
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_DECODING && CFG_TUD_AUDIO_ENABLE_EP_OUT
 // Delete all content in the support RX FIFOs
 bool tud_audio_n_clear_rx_support_ff(uint8_t func_id, uint8_t ff_idx)
 {
-  TU_VERIFY(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL, ff_idx < _audiod_fct[func_id].n_rx_supp_ff);
+  TU_VERIFY(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL && ff_idx < _audiod_fct[func_id].n_rx_supp_ff);
   return tu_fifo_clear(&_audiod_fct[func_id].rx_supp_ff[ff_idx]);
 }
 
 uint16_t tud_audio_n_available_support_ff(uint8_t func_id, uint8_t ff_idx)
 {
-  TU_VERIFY(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL, ff_idx < _audiod_fct[func_id].n_rx_supp_ff);
+  TU_VERIFY(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL && ff_idx < _audiod_fct[func_id].n_rx_supp_ff);
   return tu_fifo_count(&_audiod_fct[func_id].rx_supp_ff[ff_idx]);
 }
 
 uint16_t tud_audio_n_read_support_ff(uint8_t func_id, uint8_t ff_idx, void* buffer, uint16_t bufsize)
 {
-  TU_VERIFY(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL, ff_idx < _audiod_fct[func_id].n_rx_supp_ff);
+  TU_VERIFY(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL && ff_idx < _audiod_fct[func_id].n_rx_supp_ff);
   return tu_fifo_read_n(&_audiod_fct[func_id].rx_supp_ff[ff_idx], buffer, bufsize);
 }
+
+tu_fifo_t* tud_audio_n_get_rx_support_ff(uint8_t func_id, uint8_t ff_idx)
+{
+  if(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL && ff_idx < _audiod_fct[func_id].n_rx_supp_ff) return &_audiod_fct[func_id].rx_supp_ff[ff_idx];
+  return NULL;
+}
 #endif
 
 // This function is called once an audio packet is received by the USB and is responsible for putting data from USB memory into EP_OUT_FIFO (or support FIFOs + decoding of received stream into audio channels).
@@ -635,32 +647,26 @@ static bool audiod_decode_type_I_pcm(uint8_t rhport, audiod_function_t* audio, u
   uint8_t cnt_ff;
 
   // Decode
-  void * dst;
+  void * dst, * dst_wrap;
   uint8_t * src;
   uint8_t * dst_end;
-  uint16_t len;
+  uint16_t len, len_wrap;
 
   for (cnt_ff = 0; cnt_ff < n_ff_used; cnt_ff++)
   {
     src = &audio->lin_buf_out[cnt_ff*audio->n_channels_per_ff_rx * audio->n_bytes_per_sampe_rx];
-
+    len = tu_fifo_get_linear_write_info(&audio->rx_supp_ff[cnt_ff], 0, nBytesPerFFToRead, &dst, &len_wrap, &dst_wrap);
-    len = tu_fifo_get_linear_write_info(&audio->rx_supp_ff[cnt_ff], 0, &dst, nBytesPerFFToRead);
-    tu_fifo_advance_write_pointer(&audio->rx_supp_ff[cnt_ff], len);
 
     dst_end = dst + len;
-
     src = audiod_interleaved_copy_bytes_fast_decode(nBytesToCopy, dst, dst_end, src, n_ff_used);
 
     // Handle wrapped part of FIFO
-    if (len < nBytesPerFFToRead)
+    if (len_wrap != 0)
     {
-      len = tu_fifo_get_linear_write_info(&audio->rx_supp_ff[cnt_ff], 0, &dst, nBytesPerFFToRead - len);
+      dst_end = dst_wrap + len_wrap;
-      tu_fifo_advance_write_pointer(&audio->rx_supp_ff[cnt_ff], len);
+      audiod_interleaved_copy_bytes_fast_decode(nBytesToCopy, dst_wrap, dst_end, src, n_ff_used);
-
-      dst_end = dst + len;
-
-      audiod_interleaved_copy_bytes_fast_decode(nBytesToCopy, dst, dst_end, src, n_ff_used);
     }
+    tu_fifo_advance_write_pointer(&audio->rx_supp_ff[cnt_ff], len + len_wrap);
   }
 
   // Number of bytes should be a multiple of CFG_TUD_AUDIO_N_BYTES_PER_SAMPLE_RX * CFG_TUD_AUDIO_N_CHANNELS_RX but checking makes no sense - no way to correct it
@@ -699,9 +705,16 @@ bool tud_audio_n_clear_ep_in_ff(uint8_t func_id)                          // Del
   return tu_fifo_clear(&_audiod_fct[func_id].ep_in_ff);
 }
 
+tu_fifo_t* tud_audio_n_get_ep_in_ff(uint8_t func_id)
+{
+  if(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL) return &_audiod_fct[func_id].ep_in_ff;
+  return NULL;
+}
+
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_ENCODING && CFG_TUD_AUDIO_ENABLE_EP_IN
+
 uint16_t tud_audio_n_flush_tx_support_ff(uint8_t func_id)                 // Force all content in the support TX FIFOs to be written into linear buffer and schedule a transmit
 {
   TU_VERIFY(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL);
@@ -719,15 +732,22 @@ uint16_t tud_audio_n_flush_tx_support_ff(uint8_t func_id)                 // For
 
 bool tud_audio_n_clear_tx_support_ff(uint8_t func_id, uint8_t ff_idx)
 {
-  TU_VERIFY(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL, ff_idx < _audiod_fct[func_id].n_tx_supp_ff);
+  TU_VERIFY(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL && ff_idx < _audiod_fct[func_id].n_tx_supp_ff);
   return tu_fifo_clear(&_audiod_fct[func_id].tx_supp_ff[ff_idx]);
 }
 
 uint16_t tud_audio_n_write_support_ff(uint8_t func_id, uint8_t ff_idx, const void * data, uint16_t len)
 {
-  TU_VERIFY(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL, ff_idx < _audiod_fct[func_id].n_tx_supp_ff);
+  TU_VERIFY(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL && ff_idx < _audiod_fct[func_id].n_tx_supp_ff);
   return tu_fifo_write_n(&_audiod_fct[func_id].tx_supp_ff[ff_idx], data, len);
 }
+
+tu_fifo_t* tud_audio_n_get_tx_support_ff(uint8_t func_id, uint8_t ff_idx)
+{
+  if(func_id < CFG_TUD_AUDIO && _audiod_fct[func_id].p_desc != NULL && ff_idx < _audiod_fct[func_id].n_tx_supp_ff) return &_audiod_fct[func_id].tx_supp_ff[ff_idx];
+  return NULL;
+}
+
 #endif
 
 
@@ -751,6 +771,7 @@ uint16_t tud_audio_int_ctr_n_write(uint8_t func_id, uint8_t const* buffer, uint1
 
   return true;
 }
+
 #endif
 
 
@@ -952,32 +973,28 @@ static uint16_t audiod_encode_type_I_pcm(uint8_t rhport, audiod_function_t* audi
   nBytesPerFFToSend = (nBytesPerFFToSend / nBytesToCopy) * nBytesToCopy;
 
   // Encode
-  void * src;
+  void * src, * src_wrap;
   uint8_t * dst;
   uint8_t * src_end;
-  uint16_t len;
+  uint16_t len, len_wrap;
 
   for (cnt_ff = 0; cnt_ff < n_ff_used; cnt_ff++)
   {
     dst = &audio->lin_buf_in[cnt_ff*audio->n_channels_per_ff_tx*audio->n_bytes_per_sampe_tx];
 
-    len = tu_fifo_get_linear_read_info(&audio->tx_supp_ff[cnt_ff], 0, &src, nBytesPerFFToSend);
+    len = tu_fifo_get_linear_read_info(&audio->tx_supp_ff[cnt_ff], 0, nBytesPerFFToSend, &src, &len_wrap, &src_wrap);
-    tu_fifo_advance_read_pointer(&audio->tx_supp_ff[cnt_ff], len);
 
     src_end = src + len;
-
     dst = audiod_interleaved_copy_bytes_fast_encode(nBytesToCopy, src, src_end, dst, n_ff_used);
 
     // Handle wrapped part of FIFO
-    if (len < nBytesPerFFToSend)
+    if (len_wrap != 0)
     {
-      len = tu_fifo_get_linear_read_info(&audio->tx_supp_ff[cnt_ff], 0, &src, nBytesPerFFToSend - len);
+      src_end = src_wrap + len_wrap;
-      tu_fifo_advance_read_pointer(&audio->tx_supp_ff[cnt_ff], len);
+      audiod_interleaved_copy_bytes_fast_encode(nBytesToCopy, src_wrap, src_end, dst, n_ff_used);
-
-      src_end = src + len;
-
-      audiod_interleaved_copy_bytes_fast_encode(nBytesToCopy, src, src_end, dst, n_ff_used);
     }
+
+    tu_fifo_advance_read_pointer(&audio->tx_supp_ff[cnt_ff], len + len_wrap);
   }
 
   return nBytesPerFFToSend * n_ff_used;

src/class/audio/audio_device.h

@@ -33,6 +33,7 @@
 #include "device/usbd.h"
 
 #include "audio.h"
+#include "tusb_fifo.h"
 
 //--------------------------------------------------------------------+
 // Class Driver Configuration
@@ -364,23 +365,27 @@ bool     tud_audio_n_mounted    (uint8_t func_id);
 uint16_t tud_audio_n_available                    (uint8_t func_id);
 uint16_t tud_audio_n_read                         (uint8_t func_id, void* buffer, uint16_t bufsize);
 bool     tud_audio_n_clear_ep_out_ff              (uint8_t func_id);                          // Delete all content in the EP OUT FIFO
+tu_fifo_t*   tud_audio_n_get_ep_out_ff            (uint8_t func_id);
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_DECODING
 bool     tud_audio_n_clear_rx_support_ff          (uint8_t func_id, uint8_t ff_idx);       // Delete all content in the support RX FIFOs
 uint16_t tud_audio_n_available_support_ff         (uint8_t func_id, uint8_t ff_idx);
 uint16_t tud_audio_n_read_support_ff              (uint8_t func_id, uint8_t ff_idx, void* buffer, uint16_t bufsize);
+tu_fifo_t* tud_audio_n_get_rx_support_ff          (uint8_t func_id, uint8_t ff_idx);
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_IN && !CFG_TUD_AUDIO_ENABLE_ENCODING
 uint16_t tud_audio_n_write                        (uint8_t func_id, const void * data, uint16_t len);
 bool     tud_audio_n_clear_ep_in_ff               (uint8_t func_id);                          // Delete all content in the EP IN FIFO
+tu_fifo_t*   tud_audio_n_get_ep_in_ff             (uint8_t func_id);
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_ENABLE_ENCODING
 uint16_t tud_audio_n_flush_tx_support_ff          (uint8_t func_id);      // Force all content in the support TX FIFOs to be written into EP SW FIFO
 bool     tud_audio_n_clear_tx_support_ff          (uint8_t func_id, uint8_t ff_idx);
 uint16_t tud_audio_n_write_support_ff             (uint8_t func_id, uint8_t ff_idx, const void * data, uint16_t len);
+tu_fifo_t* tud_audio_n_get_tx_support_ff          (uint8_t func_id, uint8_t ff_idx);
 #endif
 
 #if CFG_TUD_AUDIO_INT_CTR_EPSIZE_IN
@@ -399,12 +404,14 @@ static inline bool         tud_audio_mounted                (void);
 static inline uint16_t     tud_audio_available              (void);
 static inline bool         tud_audio_clear_ep_out_ff        (void);                       // Delete all content in the EP OUT FIFO
 static inline uint16_t     tud_audio_read                   (void* buffer, uint16_t bufsize);
+static inline tu_fifo_t*   tud_audio_get_ep_out_ff          (void);
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_DECODING
 static inline bool     tud_audio_clear_rx_support_ff        (uint8_t ff_idx);
 static inline uint16_t tud_audio_available_support_ff       (uint8_t ff_idx);
 static inline uint16_t tud_audio_read_support_ff            (uint8_t ff_idx, void* buffer, uint16_t bufsize);
+static inline tu_fifo_t* tud_audio_get_rx_support_ff        (uint8_t ff_idx);
 #endif
 
 // TX API
@@ -412,12 +419,14 @@ static inline uint16_t tud_audio_read_support_ff            (uint8_t ff_idx, voi
 #if CFG_TUD_AUDIO_ENABLE_EP_IN && !CFG_TUD_AUDIO_ENABLE_ENCODING
 static inline uint16_t tud_audio_write                      (const void * data, uint16_t len);
 static inline bool 	   tud_audio_clear_ep_in_ff             (void);
+static inline tu_fifo_t* tud_audio_get_ep_in_ff             (void);
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_ENABLE_ENCODING
 static inline uint16_t tud_audio_flush_tx_support_ff        (void);
 static inline uint16_t tud_audio_clear_tx_support_ff        (uint8_t ff_idx);
 static inline uint16_t tud_audio_write_support_ff           (uint8_t ff_idx, const void * data, uint16_t len);
+static inline tu_fifo_t* tud_audio_get_tx_support_ff        (uint8_t ff_idx);
 #endif
 
 // INT CTR API
@@ -514,6 +523,11 @@ static inline bool tud_audio_clear_ep_out_ff(void)
   return tud_audio_n_clear_ep_out_ff(0);
 }
 
+static inline tu_fifo_t* tud_audio_get_ep_out_ff(void)
+{
+  return tud_audio_n_get_ep_out_ff(0);
+}
+
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_DECODING
@@ -533,6 +547,11 @@ static inline uint16_t tud_audio_read_support_ff(uint8_t ff_idx, void* buffer, u
   return tud_audio_n_read_support_ff(0, ff_idx, buffer, bufsize);
 }
 
+static inline tu_fifo_t* tud_audio_get_rx_support_ff(uint8_t ff_idx)
+{
+  return tud_audio_n_get_rx_support_ff(0, ff_idx);
+}
+
 #endif
 
 // TX API
@@ -549,6 +568,11 @@ static inline bool tud_audio_clear_ep_in_ff(void)
   return tud_audio_n_clear_ep_in_ff(0);
 }
 
+static inline tu_fifo_t* tud_audio_get_ep_in_ff(void)
+{
+  return tud_audio_n_get_ep_in_ff(0);
+}
+
 #endif
 
 #if CFG_TUD_AUDIO_ENABLE_EP_IN && CFG_TUD_AUDIO_ENABLE_ENCODING
@@ -568,6 +592,11 @@ static inline uint16_t tud_audio_write_support_ff(uint8_t ff_idx, const void * d
   return tud_audio_n_write_support_ff(0, ff_idx, data, len);
 }
 
+static inline tu_fifo_t* tud_audio_get_tx_support_ff(uint8_t ff_idx)
+{
+  return tud_audio_n_get_tx_support_ff(0, ff_idx);
+}
+
 #endif
 
 #if CFG_TUD_AUDIO_INT_CTR_EPSIZE_IN

src/common/tusb_fifo.c

@@ -905,7 +905,7 @@ void tu_fifo_advance_read_pointer(tu_fifo_t *f, uint16_t n)
                     Length of linear part IN ITEMS, if zero corresponding pointer ptr is invalid
  */
 /******************************************************************************/
-uint16_t tu_fifo_get_linear_read_info(tu_fifo_t *f, uint16_t offset, void **ptr, uint16_t n)
+uint16_t tu_fifo_get_linear_read_info(tu_fifo_t *f, uint16_t offset, uint16_t n, void **ptr_lin, uint16_t *len_wrap, void **ptr_wrap)
 {
   // Operate on temporary values in case they change in between
   uint16_t w = f->wr_idx, r = f->rd_idx;
@@ -933,23 +933,26 @@ uint16_t tu_fifo_get_linear_read_info(tu_fifo_t *f, uint16_t offset, void **ptr,
   w = get_relative_pointer(f, w, 0);
   r = get_relative_pointer(f, r, offset);
 
+  // Copy pointer to buffer to start reading from
+  *ptr_lin = &f->buffer[r];
+  *ptr_wrap = f->buffer;
+
   // Check if there is a wrap around necessary
   uint16_t len;
 
   if (w > r) {
+    // Non wrapping case
     len = w - r;
+    len = tu_min16(n, len);     // Limit to required length
+    *len_wrap = 0;
   }
   else
   {
     len = f->depth - r;       // Also the case if FIFO was full
+    len = tu_min16(n, len);
+    *len_wrap = n-len;        // n was already limited to what is available
   }
 
-  // Limit to required length
-  len = tu_min16(n, len);
-
-  // Copy pointer to buffer to start reading from
-  *ptr = &f->buffer[r];
-
   return len;
 }
 
@@ -976,7 +979,7 @@ uint16_t tu_fifo_get_linear_read_info(tu_fifo_t *f, uint16_t offset, void **ptr,
                     Length of linear part IN ITEMS, if zero corresponding pointer ptr is invalid
  */
 /******************************************************************************/
-uint16_t tu_fifo_get_linear_write_info(tu_fifo_t *f, uint16_t offset, void **ptr, uint16_t n)
+uint16_t tu_fifo_get_linear_write_info(tu_fifo_t *f, uint16_t offset, uint16_t n, void **ptr_lin, uint16_t *len_wrap, void **ptr_wrap)
 {
   uint16_t w = f->wr_idx, r = f->rd_idx;
   uint16_t free = _tu_fifo_remaining(f, w, r);
@@ -1004,22 +1007,26 @@ uint16_t tu_fifo_get_linear_write_info(tu_fifo_t *f, uint16_t offset, void **ptr
   // Get relative pointers
   w = get_relative_pointer(f, w, offset);
   r = get_relative_pointer(f, r, 0);
+
+  // Copy pointer to buffer to start writing to
+  *ptr_lin = &f->buffer[w];
+  *ptr_wrap = f->buffer;      // Always start of buffer
+
   uint16_t len;
 
   if (w < r)
   {
+    // Non wrapping case
     len = r-w;
+    len = tu_min16(n, len);   // Limit to required length
+    *len_wrap = 0;
   }
   else
   {
     len = f->depth - w;
+    len = tu_min16(n, len);   // Limit to required length
+    *len_wrap = n-len;        // Remaining length - n already was limited to free or FIFO depth
   }
 
-  // Limit to required length
-  len = tu_min16(n, len);
-
-  // Copy pointer to buffer to start reading from
-  *ptr = &f->buffer[w];
-
   return len;
 }

src/common/tusb_fifo.h

@@ -134,8 +134,10 @@ void     tu_fifo_advance_read_pointer   (tu_fifo_t *f, uint16_t n);
 // This functions deliver a pointer to start reading/writing from/to and a valid linear length along which no wrap occurs.
 // In case not all of your data is available within one read/write, update the read/write pointer by
 // tu_fifo_advance_read_pointer()/tu_fifo_advance_write_pointer and conduct a second read/write operation
-uint16_t tu_fifo_get_linear_read_info   (tu_fifo_t *f, uint16_t offset, void **ptr, uint16_t n);
+// TODO - update comments
-uint16_t tu_fifo_get_linear_write_info  (tu_fifo_t *f, uint16_t offset, void **ptr, uint16_t n);
+
+uint16_t tu_fifo_get_linear_read_info(tu_fifo_t *f, uint16_t offset, uint16_t n, void **ptr_lin, uint16_t *len_wrap, void **ptr_wrap);
+uint16_t tu_fifo_get_linear_write_info(tu_fifo_t *f, uint16_t offset, uint16_t n, void **ptr_lin, uint16_t *len_wrap, void **ptr_wrap);
 
 static inline bool tu_fifo_peek(tu_fifo_t* f, void * p_buffer)
 {

src/portable/st/stm32_fsdev/dcd_stm32_fsdev.c

@@ -993,7 +993,7 @@ static bool dcd_write_packet_memory_ff(tu_fifo_t * ff, uint16_t dst, uint16_t wN
   // Since we copy from a ring buffer FIFO, a wrap might occur making it necessary to conduct two copies
   // Check for first linear part
   void * src;
-  uint16_t len = tu_fifo_get_linear_read_info(ff, 0, &src, wNBytes);  // We want to read from the FIFO
+  uint16_t len = tu_fifo_get_linear_read_info(ff, 0, &src, wNBytes);  // We want to read from the FIFO        - THIS FUNCTION CHANGED!!!
   TU_VERIFY(len && dcd_write_packet_memory(dst, src, len));           // and write it into the PMA
   tu_fifo_advance_read_pointer(ff, len);
 
@@ -1075,7 +1075,7 @@ static bool dcd_read_packet_memory_ff(tu_fifo_t * ff, uint16_t src, uint16_t wNB
   // Since we copy into a ring buffer FIFO, a wrap might occur making it necessary to conduct two copies
   // Check for first linear part
   void * dst;
-  uint16_t len = tu_fifo_get_linear_write_info(ff, 0, &dst, wNBytes);
+  uint16_t len = tu_fifo_get_linear_write_info(ff, 0, &dst, wNBytes);           // THIS FUNCTION CHANGED!!!!
   TU_VERIFY(len && dcd_read_packet_memory(dst, src, len));
   tu_fifo_advance_write_pointer(ff, len);