pbio/drv/usb_simulation: Add virtual hub driver.

This will help prepare the common USB driver code, and test USB and BLE both enabled.

Author: laurensvalk

.vscode/launch.json

@@ -66,7 +66,7 @@
             "request": "launch",
             "program": "${workspaceFolder}/bricks/virtualhub/build-debug/firmware.elf",
             "args": [
-                "${workspaceFolder}/tests/virtualhub/motor/car.py",
+                "${workspaceFolder}/tests/virtualhub/basics/hello.py",
             ],
             "stopAtEntry": false,
             "cwd": "${workspaceFolder}",

bricks/_common/sources.mk

@@ -188,9 +188,11 @@ PBIO_SRC_C = $(addprefix lib/pbio/,\
 	drv/uart/uart_stm32f0.c \
 	drv/uart/uart_stm32f4_ll_irq.c \
 	drv/uart/uart_stm32l4_ll_dma.c \
+	drv/usb/usb.c \
 	drv/usb/usb_common_desc.c \
 	drv/usb/usb_ev3.c \
 	drv/usb/usb_nxt.c \
+	drv/usb/usb_simulation.c \
 	drv/usb/usb_stm32.c \
 	drv/watchdog/watchdog_ev3.c \
 	drv/watchdog/watchdog_stm32.c \

lib/pbio/drv/usb/usb.c

@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2025 The Pybricks Authors
+
+#include <pbdrv/config.h>
+
+#if PBDRV_CONFIG_USB_SIMULATION
+
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "usb.h"
+#include <pbdrv/usb.h>
+
+#include <pbio/error.h>
+#include <pbio/os.h>
+
+void pbdrv_usb_set_receive_handler(pbdrv_usb_receive_handler_t handler) {
+}
+
+void pbdrv_usb_schedule_status_update(const uint8_t *status_msg) {
+}
+
+pbio_error_t pbdrv_usb_stdout_tx(const uint8_t *data, uint32_t *size) {
+    return PBIO_SUCCESS;
+}
+
+uint32_t pbdrv_usb_stdout_tx_available(void) {
+    return UINT32_MAX;
+}
+
+bool pbdrv_usb_stdout_tx_is_idle(void) {
+    return true;
+}
+
+bool pbdrv_usb_connection_is_active(void) {
+    return false;
+}
+
+void pbdrv_usb_init(void) {
+    pbdrv_usb_init_device();
+}
+
+void pbdrv_usb_deinit(void) {
+}
+
+#endif // PBDRV_CONFIG_USB_SIMULATION

lib/pbio/drv/usb/usb.h

@@ -15,15 +15,27 @@
  */
 void pbdrv_usb_init(void);
 
+/**
+ * Platform specific device initialization.
+ */
+void pbdrv_usb_init_device(void);
+
 /**
  * De-initializes the USB driver for data transfers on soft-poweroff. Keeps charging if supported.
  */
 void pbdrv_usb_deinit(void);
 
 #else // PBDRV_CONFIG_USB
 
-#define pbdrv_usb_init()
-#define pbdrv_usb_deinit()
+static inline void pbdrv_usb_init(void) {
+}
+
+static inline void pbdrv_usb_deinit(void) {
+}
+
+static inline void pbdrv_usb_init_device(void) {
+}
+
 
 #endif // PBDRV_CONFIG_USB
 

lib/pbio/drv/usb/usb_simulation.c

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2025 The Pybricks Authors
+
+#include <pbdrv/config.h>
+
+#if PBDRV_CONFIG_USB_SIMULATION
+
+#include <pbdrv/usb.h>
+
+#include <pbio/error.h>
+#include <pbio/os.h>
+
+pbdrv_usb_bcd_t pbdrv_usb_get_bcd(void) {
+    return PBDRV_USB_BCD_NONE;
+}
+
+void pbdrv_usb_init_device(void) {
+}
+
+#endif // PBDRV_CONFIG_USB_SIMULATION

lib/pbio/platform/virtual_hub/pbdrvconfig.h

@@ -40,3 +40,8 @@
 #define PBDRV_CONFIG_HAS_PORT_E (1)
 #define PBDRV_CONFIG_HAS_PORT_F (1)
 #define PBDRV_CONFIG_HAS_PORT_VCC_CONTROL                   (1)
+
+#define PBDRV_CONFIG_USB                                    (0)
+#define PBDRV_CONFIG_USB_SIMULATION                         (0)
+#define PBDRV_CONFIG_USB_MFG_STR                            u"Pybricks"
+#define PBDRV_CONFIG_USB_PROD_STR                           u"Virtual Hub"