add usb serial for debug firmware

Code by gpt5.5-xhigh

CMakeLists.txt

@@ -28,6 +28,13 @@ set(PICO_BOARD pico2_w CACHE STRING "Board type")
 #set(PICO_CYW43_SUPPORTED 1)
 #set(PICO_CYW43_ARCH_THREADSAFE_BACKGROUND 1)
 
+option(ENABLE_SERIAL "Enable USB CDC serial printf output" OFF)
+if (ENABLE_SERIAL)
+        set(ENABLE_SERIAL_VALUE 1)
+else ()
+        set(ENABLE_SERIAL_VALUE 0)
+endif ()
+
 # Pull in Raspberry Pi Pico SDK (must be before project)
 include(pico_sdk_import.cmake)
 
@@ -67,9 +74,13 @@ target_compile_definitions(wdl_resampler PRIVATE
 )
 target_compile_definitions(ds5-bridge PRIVATE
         CYW43_LWIP=0
+        ENABLE_SERIAL=${ENABLE_SERIAL_VALUE}
         PICO_FLASH_ASSUME_CORE1_SAFE=1
         WDL_RESAMPLE_TYPE=float
         CYW43_PIO_CLOCK_DIV_INT=5
+        PICO_STDIO_USB_USE_DEFAULT_DESCRIPTORS=0
+        PICO_STDIO_USB_ENABLE_RESET_VIA_BAUD_RATE=0
+        PICO_STDIO_USB_ENABLE_RESET_VIA_VENDOR_INTERFACE=0
 )
 
 pico_set_program_name(ds5-bridge "ds5-bridge")
@@ -77,7 +88,7 @@ pico_set_program_version(ds5-bridge "0.5.3")
 
 # Modify the below lines to enable/disable output over UART/USB
 pico_enable_stdio_uart(ds5-bridge 1)
-pico_enable_stdio_usb(ds5-bridge 0)
+pico_enable_stdio_usb(ds5-bridge ${ENABLE_SERIAL_VALUE})
 
 # Add the standard include files to the build
 #target_include_directories(ds5-bridge PRIVATE

src/bt.cpp

@@ -298,7 +298,9 @@ static void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *p
         }
 
         case HCI_EVENT_DISCONNECTION_COMPLETE: {
+#ifndef ENABLE_SERIAL
             tud_disconnect();
+#endif
             gap_connectable_control(1);
             gap_discoverable_control(1);
             const uint8_t reason = hci_event_disconnection_complete_get_reason(packet);
@@ -345,7 +347,9 @@ static void l2cap_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t
                 }else if (size > 1){
                     is_dse = true;
                 }
+#ifndef ENABLE_SERIAL
                 tud_connect();
+#endif
             }
             if (packet[0] == 0xA3) {
                 uint8_t report_id = packet[1];

src/main.cpp

@@ -12,6 +12,9 @@
 #include "hardware/vreg.h"
 #include "hardware/watchdog.h"
 #include "pico/cyw43_arch.h"
+#if ENABLE_SERIAL
+#include "pico/stdio_usb.h"
+#endif
 #include "config.h"
 #include "cmd.h"
 
@@ -175,8 +178,13 @@ int main() {
         .speed = TUSB_SPEED_FULL
     };
     tusb_init(BOARD_TUD_RHPORT, &dev_init);
+#ifndef ENABLE_SERIAL
     tud_disconnect();
+#endif
     board_init_after_tusb();
+#if ENABLE_SERIAL
+    stdio_usb_init();
+#endif
 
     if (cyw43_arch_init()) {
         printf("Failed to initialize CYW43\n");

src/tusb_config.h

@@ -30,6 +30,10 @@
  extern "C" {
 #endif
 
+#ifndef ENABLE_SERIAL
+#define ENABLE_SERIAL 0
+#endif
+
 //--------------------------------------------------------------------+
 // Board Specific Configuration
 //--------------------------------------------------------------------+
@@ -93,7 +97,7 @@
 //------------- CLASS -------------//
 #define CFG_TUD_AUDIO             1
 #define CFG_TUD_HID               1
-#define CFG_TUD_CDC               1
+#define CFG_TUD_CDC               ENABLE_SERIAL
 #define CFG_TUD_MSC               0
 #define CFG_TUD_MIDI              0
 #define CFG_TUD_VENDOR            0

src/usb_descriptors.cpp

@@ -27,6 +27,10 @@
 #include "tusb.h"
 #include "config.h"
 
+#ifndef ENABLE_SERIAL
+#define ENABLE_SERIAL 0
+#endif
+
 bool ds_mode() {
     if (get_config().controller_mode == 2) {
         return !is_dse;
@@ -34,6 +38,41 @@ bool ds_mode() {
     return get_config().controller_mode == 0;
 }
 
+enum {
+    ITF_NUM_AUDIO_CONTROL = 0,
+    ITF_NUM_AUDIO_STREAMING_OUT,
+    ITF_NUM_AUDIO_STREAMING_IN,
+    ITF_NUM_HID,
+#if ENABLE_SERIAL
+    ITF_NUM_CDC,
+    ITF_NUM_CDC_DATA,
+#endif
+    ITF_NUM_TOTAL,
+
+    CONFIG_DESC_LEN_AUDIO_IAD =
+#if ENABLE_SERIAL
+        8,
+#else
+        0,
+#endif
+    CONFIG_DESC_LEN_BASE = 0x00E3 + CONFIG_DESC_LEN_AUDIO_IAD,
+    CONFIG_DESC_LEN_TOTAL = CONFIG_DESC_LEN_BASE
+#if ENABLE_SERIAL
+        + TUD_CDC_DESC_LEN
+#endif
+};
+
+// String Descriptor Index
+enum {
+    STRID_LANGID = 0,
+    STRID_MANUFACTURER,
+    STRID_PRODUCT,
+    STRID_SERIAL,
+#if ENABLE_SERIAL
+    STRID_CDC,
+#endif
+};
+
 //--------------------------------------------------------------------+
 // Device Descriptors
 //--------------------------------------------------------------------+
@@ -45,12 +84,15 @@ tusb_desc_device_t desc_device =
 
     // Use Interface Association Descriptor (IAD) for Audio
     // As required by USB Specs IAD's subclass must be common class (2) and protocol must be IAD (1)
-    /*.bDeviceClass = TUSB_CLASS_MISC,
+#if ENABLE_SERIAL
+    .bDeviceClass = TUSB_CLASS_MISC,
     .bDeviceSubClass = MISC_SUBCLASS_COMMON,
-    .bDeviceProtocol = MISC_PROTOCOL_IAD,*/
+    .bDeviceProtocol = MISC_PROTOCOL_IAD,
+#else
     .bDeviceClass = 0x00,
     .bDeviceSubClass = 0x00,
     .bDeviceProtocol = 0x00,
+#endif
     .bMaxPacketSize0 = CFG_TUD_ENDPOINT0_SIZE,
 
     .idVendor = 0x054C,
@@ -79,13 +121,25 @@ uint8_t descriptor_configuration[] = {
     // --- CONFIGURATION DESCRIPTOR ---
     0x09, // bLength
     0x02, // bDescriptorType (CONFIGURATION)
-    0xE3, 0x00, // wTotalLength: 227
+    U16_TO_U8S_LE(CONFIG_DESC_LEN_TOTAL), // wTotalLength
-    0x04, // bNumInterfaces: 4
+    ITF_NUM_TOTAL, // bNumInterfaces
     0x01, // bConfigurationValue: 1
     0x00, // iConfiguration: 0
     0xC0, // bmAttributes: SELF-POWERED, NO REMOTE-WAKEUP
     0xFA, // bMaxPower: 500mA (250 * 2mA)
 
+#if ENABLE_SERIAL
+    // --- INTERFACE ASSOCIATION DESCRIPTOR: Audio function (interfaces 0-2) ---
+    0x08, // bLength
+    TUSB_DESC_INTERFACE_ASSOCIATION, // bDescriptorType
+    ITF_NUM_AUDIO_CONTROL, // bFirstInterface
+    0x03, // bInterfaceCount
+    0x01, // bFunctionClass: Audio
+    0x01, // bFunctionSubClass: Audio Control
+    0x00, // bFunctionProtocol
+    0x00, // iFunction
+
+#endif
     // --- INTERFACE DESCRIPTOR (0.0): Audio Control ---
     0x09, // bLength
     0x04, // bDescriptorType (INTERFACE)
@@ -326,6 +380,11 @@ uint8_t descriptor_configuration[] = {
     0x03, // bmAttributes: Interrupt
     0x40, 0x00, // wMaxPacketSize: 64
     0x01, // bInterval: 1 (polling every 4ms -> 1ms)
+
+#if ENABLE_SERIAL
+    // --- CDC ACM (USB Serial) ---
+    TUD_CDC_DESCRIPTOR(ITF_NUM_CDC, STRID_CDC, 0x85, 0x08, 0x06, 0x86, 0x40),
+#endif
 };
 
 // Invoked when received GET CONFIGURATION DESCRIPTOR
@@ -345,7 +404,7 @@ uint8_t const *tud_descriptor_configuration_cb(uint8_t index) {
             bInterval = 0x01;
             break;
     }
-    constexpr auto offset = sizeof(descriptor_configuration);
+    constexpr auto offset = CONFIG_DESC_LEN_BASE;
     descriptor_configuration[offset - 1] = bInterval;
     descriptor_configuration[offset - 8] = bInterval;
     if (ds_mode()) {
@@ -741,14 +800,6 @@ uint8_t const *tud_hid_descriptor_report_cb(uint8_t itf) {
 // String Descriptors
 //--------------------------------------------------------------------+
 
-// String Descriptor Index
-enum {
-    STRID_LANGID = 0,
-    STRID_MANUFACTURER,
-    STRID_PRODUCT,
-    STRID_SERIAL,
-};
-
 // array of pointer to string descriptors
 static char const *string_desc_arr[] =
 {
@@ -756,6 +807,9 @@ static char const *string_desc_arr[] =
     "Sony Interactive Entertainment", // 1: Manufacturer
     NULL, // 2: Product
     NULL, // 3: Serials will use unique ID if possible
+#if ENABLE_SERIAL
+    "USB Serial", // 4: CDC interface
+#endif
 };
 
 static uint16_t _desc_str[60 + 1];