simplify TUD_DFU_DESCRIPTOR with alternate count

remove CFG_TUD_DFU_ALT_COUNT since there is only one DFU functional
descriptor

examples/device/dfu/src/main.c

@@ -154,8 +154,9 @@ bool tud_dfu_device_data_done_check_cb(uint8_t alt)
   return true;
 }
 
-void tud_dfu_abort_cb(void)
+void tud_dfu_abort_cb(uint8_t alt)
 {
+  (void) alt;
   printf("    Host aborted transfer\r\n");
 }
 

examples/device/dfu/src/tusb_config.h

@@ -81,8 +81,6 @@
 #define CFG_TUD_DFU_RUNTIME 0
 #define CFG_TUD_DFU_MODE    1
 
-// Count of all alt settings, typically it's the partition count (Flash, EEPROM, etc.)
-#define CFG_TUD_DFU_ALT_COUNT               2
 // DFU buffer size, it has to be set to the buffer size used in TUD_DFU_DESCRIPTOR
 #define CFG_TUD_DFU_TRANSFER_BUFFER_SIZE    4096
 

examples/device/dfu/src/usb_descriptors.c

@@ -81,13 +81,16 @@ uint8_t const * tud_descriptor_device_cb(void)
 // Configuration Descriptor
 //--------------------------------------------------------------------+
 
+// Number of Alternate Interface (each for 1 flash partition)
+#define ALT_COUNT   2
+
 enum
 {
   ITF_NUM_DFU_MODE,
   ITF_NUM_TOTAL
 };
 
-#define CONFIG_TOTAL_LEN    (TUD_CONFIG_DESC_LEN + TUD_DFU_MODE_DESC_LEN)
+#define CONFIG_TOTAL_LEN    (TUD_CONFIG_DESC_LEN + TUD_DFU_DESC_LEN(ALT_COUNT))
 
 #define FUNC_ATTRS (DFU_FUNC_ATTR_CAN_UPLOAD_BITMASK | DFU_FUNC_ATTR_CAN_DOWNLOAD_BITMASK)
 
@@ -96,8 +99,8 @@ uint8_t const desc_configuration[] =
   // Config number, interface count, string index, total length, attribute, power in mA
   TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP, 100),
 
-  // Interface number, attributes, detach timeout, transfer size, string index 0, [string index 1 ... string index n]
-  TUD_DFU_DESCRIPTOR(ITF_NUM_DFU_MODE, FUNC_ATTRS, 1000, CFG_TUD_DFU_TRANSFER_BUFFER_SIZE, 4, 5),
+  // Interface number, Alternate count, starting string index, attributes, detach timeout, transfer size
+  TUD_DFU_DESCRIPTOR(ITF_NUM_DFU_MODE, ALT_COUNT, 4, FUNC_ATTRS, 1000, CFG_TUD_DFU_TRANSFER_BUFFER_SIZE),
 };
 
 // Invoked when received GET CONFIGURATION DESCRIPTOR

src/device/usbd.h

@@ -605,50 +605,51 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
   /* Function */ \
   9, DFU_DESC_FUNCTIONAL, _attr, U16_TO_U8S_LE(_timeout), U16_TO_U8S_LE(_xfer_size), U16_TO_U8S_LE(0x0101)
 
-// Maximum alternate settings (used for different partitons) supported
-#ifndef CFG_TUD_DFU_ALT_COUNT
-#define CFG_TUD_DFU_ALT_COUNT 1
-#endif
-
-// Length of template descriptor: 18 bytes + number of alternatives * 9
-#define TUD_DFU_MODE_DESC_LEN (9 + (CFG_TUD_DFU_ALT_COUNT) * 9)
+// Length of template descriptor: 9 bytes + number of alternatives * 9
+#define TUD_DFU_DESC_LEN(_alt_count)    (9 + (_alt_count) * 9)
 
-/* Primary Interface */
-#define TUD_DFU_MODE_FUNC(_attr, _timeout, _xfer_size) \
+// Interface number, Alternate count, starting string index, attributes, detach timeout, transfer size
+// Note: Alternate count must be numberic or macro, string index is increased by one for each Alt interface
+#define TUD_DFU_DESCRIPTOR(_itfnum, _alt_count, _stridx, _attr, _timeout, _xfer_size) \
+  TU_XSTRCAT(_TUD_DFU_ALT_,_alt_count)(_itfnum, 0, _stridx), \
   /* Function */ \
   9, DFU_DESC_FUNCTIONAL, _attr, U16_TO_U8S_LE(_timeout), U16_TO_U8S_LE(_xfer_size), U16_TO_U8S_LE(0x0101)
 
-#define TUD_DFU_MODE_ALT(_itfnum, _alt, _stridx) \
+#define _TUD_DFU_ALT(_itfnum, _alt, _stridx) \
   /* Interface */ \
-  9, TUSB_DESC_INTERFACE, _itfnum, _alt, 0, TUD_DFU_APP_CLASS, TUD_DFU_APP_SUBCLASS, DFU_PROTOCOL_DFU, _stridx, \
-
-#define _TUD_DFU_FIRST(a, ...) a
-#define _TUD_DFU_REST(a, ...) __VA_ARGS__
-#define _TUD_DFU_COMBINE(...) __VA_ARGS__
-
-#define TUD_DFU_MODE_ALT_1(_itfnum, ...) TUD_DFU_MODE_ALT(_itfnum, (CFG_TUD_DFU_ALT_COUNT) - 1, _TUD_DFU_FIRST(__VA_ARGS__))
-#define TUD_DFU_MODE_ALT_2(_itfnum, ...) TUD_DFU_MODE_ALT(_itfnum, (CFG_TUD_DFU_ALT_COUNT) - 2, _TUD_DFU_FIRST(__VA_ARGS__)) \
-  TUD_DFU_MODE_ALT_1(_itfnum, _TUD_DFU_REST(__VA_ARGS__))
-#define TUD_DFU_MODE_ALT_3(_itfnum, ...) TUD_DFU_MODE_ALT(_itfnum, (CFG_TUD_DFU_ALT_COUNT) - 3, _TUD_DFU_FIRST(__VA_ARGS__)) \
-  TUD_DFU_MODE_ALT_2(_itfnum, _TUD_DFU_REST(__VA_ARGS__))
-#define TUD_DFU_MODE_ALT_4(_itfnum, ...) TUD_DFU_MODE_ALT(_itfnum, (CFG_TUD_DFU_ALT_COUNT) - 4, _TUD_DFU_FIRST(__VA_ARGS__)) \
-  TUD_DFU_MODE_ALT_3(_itfnum, _TUD_DFU_REST(__VA_ARGS__))
-#define TUD_DFU_MODE_ALT_5(_itfnum, ...) TUD_DFU_MODE_ALT(_itfnum, (CFG_TUD_DFU_ALT_COUNT) - 5, _TUD_DFU_FIRST(__VA_ARGS__)) \
-  TUD_DFU_MODE_ALT_4(_itfnum, _TUD_DFU_REST(__VA_ARGS__))
-#define TUD_DFU_MODE_ALT_6(_itfnum, ...) TUD_DFU_MODE_ALT(_itfnum, (CFG_TUD_DFU_ALT_COUNT) - 6, _TUD_DFU_FIRST(__VA_ARGS__)) \
-  TUD_DFU_MODE_ALT_5(_itfnum, _TUD_DFU_REST(__VA_ARGS__))
-#define TUD_DFU_MODE_ALT_7(_itfnum, ...) TUD_DFU_MODE_ALT(_itfnum, (CFG_TUD_DFU_ALT_COUNT) - 7, _TUD_DFU_FIRST(__VA_ARGS__)) \
-  TUD_DFU_MODE_ALT_6(_itfnum, _TUD_DFU_REST(__VA_ARGS__))
-#define TUD_DFU_MODE_ALT_8(_itfnum, ...) TUD_DFU_MODE_ALT(_itfnum, (CFG_TUD_DFU_ALT_COUNT) - 8, _TUD_DFU_FIRST(__VA_ARGS__)) \
-  TUD_DFU_MODE_ALT_7(_itfnum, _TUD_DFU_REST(__VA_ARGS__))
-
-#define TUD_DFU_MODE_ALTS(_itfnum, ...) \
-  TU_XSTRCAT(TUD_DFU_MODE_ALT_, CFG_TUD_DFU_ALT_COUNT)(_itfnum, __VA_ARGS__)
-
-// Interface number, attributes, detach timeout, transfer size, string index 0, [string index 1, string index n]
-#define TUD_DFU_DESCRIPTOR(_itfnum, _attr, _timeout, _xfer_size, _stridx, ...) \
-  TUD_DFU_MODE_ALTS(_itfnum, _TUD_DFU_COMBINE(_stridx, __VA_ARGS__)) \
-  TUD_DFU_MODE_FUNC(_attr, _timeout, _xfer_size)
+  9, TUSB_DESC_INTERFACE, _itfnum, _alt, 0, TUD_DFU_APP_CLASS, TUD_DFU_APP_SUBCLASS, DFU_PROTOCOL_DFU, _stridx
+
+#define _TUD_DFU_ALT_1(_itfnum, _alt_count, _stridx) \
+  _TUD_DFU_ALT(_itfnum, _alt_count, _stridx)
+
+#define _TUD_DFU_ALT_2(_itfnum, _alt_count, _stridx) \
+  _TUD_DFU_ALT(_itfnum, _alt_count, _stridx),      \
+  _TUD_DFU_ALT_1(_itfnum, _alt_count+1, _stridx+1)
+
+#define _TUD_DFU_ALT_3(_itfnum, _alt_count, _stridx) \
+  _TUD_DFU_ALT(_itfnum, _alt_count, _stridx),      \
+  _TUD_DFU_ALT_2(_itfnum, _alt_count+1, _stridx+1)
+
+#define _TUD_DFU_ALT_4(_itfnum, _alt_count, _stridx) \
+  _TUD_DFU_ALT(_itfnum, _alt_count, _stridx),      \
+  _TUD_DFU_ALT_3(_itfnum, _alt_count+1, _stridx+1)
+
+#define _TUD_DFU_ALT_5(_itfnum, _alt_count, _stridx) \
+  _TUD_DFU_ALT(_itfnum, _alt_count, _stridx),      \
+  _TUD_DFU_ALT_4(_itfnum, _alt_count+1, _stridx+1)
+
+#define _TUD_DFU_ALT_6(_itfnum, _alt_count, _stridx) \
+  _TUD_DFU_ALT(_itfnum, _alt_count, _stridx),      \
+  _TUD_DFU_ALT_5(_itfnum, _alt_count+1, _stridx+1)
+
+#define _TUD_DFU_ALT_7(_itfnum, _alt_count, _stridx) \
+  _TUD_DFU_ALT(_itfnum, _alt_count, _stridx),      \
+  _TUD_DFU_ALT_6(_itfnum, _alt_count+1, _stridx+1)
+
+#define _TUD_DFU_ALT_8(_itfnum, _alt_count, _stridx) \
+  _TUD_DFU_ALT(_itfnum, _alt_count, _stridx),      \
+  _TUD_DFU_ALT_7(_itfnum, _alt_count+1, _stridx+1)
+
 
 //------------- CDC-ECM -------------//