cdc_uart: add RTS and DTR pins

A 128K reservation on a device with 256K of RAM is a bit demanding.
Shrink to fix a link error in a DebugRel build.

pico_sdk_import.cmake

@@ -3,8 +3,6 @@
 # This can be dropped into an external project to help locate this SDK
 # It should be include()ed prior to project()
 
-# todo document
-
 if (DEFINED ENV{PICO_SDK_PATH} AND (NOT PICO_SDK_PATH))
     set(PICO_SDK_PATH $ENV{PICO_SDK_PATH})
     message("Using PICO_SDK_PATH from environment ('${PICO_SDK_PATH}')")
@@ -20,8 +18,8 @@ if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT_PATH} AND (NOT PICO_SDK_FETCH_FROM_GIT_P
     message("Using PICO_SDK_FETCH_FROM_GIT_PATH from environment ('${PICO_SDK_FETCH_FROM_GIT_PATH}')")
 endif ()
 
-set(PICO_SDK_PATH "${PICO_SDK_PATH}" CACHE PATH "Path to the PICO SDK")
-set(PICO_SDK_FETCH_FROM_GIT "${PICO_SDK_FETCH_FROM_GIT}" CACHE BOOL "Set to ON to fetch copy of PICO SDK from git if not otherwise locatable")
+set(PICO_SDK_PATH "${PICO_SDK_PATH}" CACHE PATH "Path to the Raspberry Pi Pico SDK")
+set(PICO_SDK_FETCH_FROM_GIT "${PICO_SDK_FETCH_FROM_GIT}" CACHE BOOL "Set to ON to fetch copy of SDK from git if not otherwise locatable")
 set(PICO_SDK_FETCH_FROM_GIT_PATH "${PICO_SDK_FETCH_FROM_GIT_PATH}" CACHE FILEPATH "location to download SDK")
 
 if (NOT PICO_SDK_PATH)
@@ -31,20 +29,31 @@ if (NOT PICO_SDK_PATH)
         if (PICO_SDK_FETCH_FROM_GIT_PATH)
             get_filename_component(FETCHCONTENT_BASE_DIR "${PICO_SDK_FETCH_FROM_GIT_PATH}" REALPATH BASE_DIR "${CMAKE_SOURCE_DIR}")
         endif ()
-        FetchContent_Declare(
-                pico_sdk
-                GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
-                GIT_TAG master
-        )
+        # GIT_SUBMODULES_RECURSE was added in 3.17
+        if (${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.17.0")
+            FetchContent_Declare(
+                    pico_sdk
+                    GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
+                    GIT_TAG master
+                    GIT_SUBMODULES_RECURSE FALSE
+            )
+        else ()
+            FetchContent_Declare(
+                    pico_sdk
+                    GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
+                    GIT_TAG master
+            )
+        endif ()
+
         if (NOT pico_sdk)
-            message("Downloading PICO SDK")
+            message("Downloading Raspberry Pi Pico SDK")
             FetchContent_Populate(pico_sdk)
             set(PICO_SDK_PATH ${pico_sdk_SOURCE_DIR})
         endif ()
         set(FETCHCONTENT_BASE_DIR ${FETCHCONTENT_BASE_DIR_SAVE})
     else ()
         message(FATAL_ERROR
-                "PICO SDK location was not specified. Please set PICO_SDK_PATH or set PICO_SDK_FETCH_FROM_GIT to on to fetch from git."
+                "SDK location was not specified. Please set PICO_SDK_PATH or set PICO_SDK_FETCH_FROM_GIT to on to fetch from git."
                 )
     endif ()
 endif ()
@@ -56,9 +65,9 @@ endif ()
 
 set(PICO_SDK_INIT_CMAKE_FILE ${PICO_SDK_PATH}/pico_sdk_init.cmake)
 if (NOT EXISTS ${PICO_SDK_INIT_CMAKE_FILE})
-    message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' does not appear to contain the PICO SDK")
+    message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' does not appear to contain the Raspberry Pi Pico SDK")
 endif ()
 
-set(PICO_SDK_PATH ${PICO_SDK_PATH} CACHE PATH "Path to the PICO SDK" FORCE)
+set(PICO_SDK_PATH ${PICO_SDK_PATH} CACHE PATH "Path to the Raspberry Pi Pico SDK" FORCE)
 
 include(${PICO_SDK_INIT_CMAKE_FILE})

src/FreeRTOSConfig.h

@@ -71,7 +71,7 @@
 /* Memory allocation related definitions. */
 #define configSUPPORT_STATIC_ALLOCATION         0
 #define configSUPPORT_DYNAMIC_ALLOCATION        1
-#define configTOTAL_HEAP_SIZE                   (128*1024)
+#define configTOTAL_HEAP_SIZE                   (64*1024)
 #define configAPPLICATION_ALLOCATED_HEAP        0
 
 /* Hook function related definitions. */

src/cdc_uart.c

@@ -43,6 +43,13 @@ void cdc_uart_init(void) {
     gpio_set_pulls(PICOPROBE_UART_TX, 1, 0);
     gpio_set_pulls(PICOPROBE_UART_RX, 1, 0);
     uart_init(PICOPROBE_UART_INTERFACE, PICOPROBE_UART_BAUDRATE);
+
+    gpio_init(PICOPROBE_UART_DTR);
+    gpio_init(PICOPROBE_UART_RTS);
+    gpio_set_dir(PICOPROBE_UART_DTR, GPIO_OUT);
+    gpio_set_dir(PICOPROBE_UART_RTS, GPIO_OUT);
+    gpio_put(PICOPROBE_UART_DTR, 1);
+    gpio_put(PICOPROBE_UART_RTS, 1);
 }
 
 void cdc_task(void)
@@ -117,6 +124,9 @@ void tud_cdc_line_coding_cb(uint8_t itf, cdc_line_coding_t const* line_coding)
 
 void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts)
 {
+  gpio_put(PICOPROBE_UART_DTR, !dtr);
+  gpio_put(PICOPROBE_UART_RTS, !rts);
+
   /* CDC drivers use linestate as a bodge to activate/deactivate the interface.
    * Resume our UART polling on activate, stop on deactivate */
   if (!dtr && !rts)

src/main.c

@@ -64,6 +64,11 @@ void usb_thread(void *ptr)
     } while (1);
 }
 
+// Workaround API change in 0.13
+#if (TUSB_VERSION_MAJOR == 0) && (TUSB_VERSION_MINOR <= 12)
+#define tud_vendor_flush(x) ((void)0)
+#endif
+
 void dap_thread(void *ptr)
 {
     uint32_t resp_len;
@@ -72,6 +77,7 @@ void dap_thread(void *ptr)
             tud_vendor_read(RxDataBuffer, sizeof(RxDataBuffer));
             resp_len = DAP_ProcessCommand(RxDataBuffer, TxDataBuffer);
             tud_vendor_write(TxDataBuffer, resp_len);
+            tud_vendor_flush();
         } else {
             // Trivial delay to save power
             vTaskDelay(2);

src/picoprobe_config.h

@@ -58,6 +58,8 @@
 // UART config
 #define PICOPROBE_UART_TX 4
 #define PICOPROBE_UART_RX 5
+#define PICOPROBE_UART_RTS 7
+#define PICOPROBE_UART_DTR 8
 #define PICOPROBE_UART_INTERFACE uart1
 #define PICOPROBE_UART_BAUDRATE 115200
 

src/tusb_config.h

@@ -74,6 +74,10 @@
 #define CFG_TUD_VENDOR_RX_BUFSIZE 8192
 #define CFG_TUD_VENDOR_TX_BUFSIZE 8192
 
+#ifndef TUD_OPT_RP2040_USB_DEVICE_UFRAME_FIX
+#define TUD_OPT_RP2040_USB_DEVICE_UFRAME_FIX 1
+#endif
+
 #ifdef __cplusplus
  }
 #endif