Merge pull request #3565 from Precidata/driver-init

Make driver init() function optional

Author: HiFiPhile

docs/reference/architecture.rst

@@ -189,13 +189,13 @@ Class Driver Interface
 See ``usbd.c``.
 
 **Required Functions**:
-- ``init()``: Initialize class driver
 - ``reset()``: Reset class state
 - ``open()``: Configure class endpoints
 - ``control_xfer_cb()``: Handle control requests
 - ``xfer_cb()``: Handle data transfer completion
 
 **Optional Functions**:
+- ``init()``: Initialize class driver
 - ``close()``: Clean up class resources
 - ``deinit()``: Deinitialize class driver
 - ``sof()``: Start-of-frame processing

src/device/usbd.c

@@ -572,9 +572,10 @@ bool tud_rhport_init(uint8_t rhport, const tusb_rhport_init_t* rh_init) {
   // Init class drivers
   for (uint8_t i = 0; i < TOTAL_DRIVER_COUNT; i++) {
     usbd_class_driver_t const* driver = get_driver(i);
-    TU_ASSERT(driver && driver->init);
-    TU_LOG_USBD("%s init\r\n", driver->name);
-    driver->init();
+    if (driver && driver->init) {
+      TU_LOG_USBD("%s init\r\n", driver->name);
+      driver->init();
+    }
   }
 
   _usbd_rhport = rhport;

src/host/usbh.c

@@ -544,7 +544,7 @@ bool tuh_rhport_init(uint8_t rhport, const tusb_rhport_init_t* rh_init) {
     // Class drivers
     for (uint8_t drv_id = 0; drv_id < TOTAL_DRIVER_COUNT; drv_id++) {
       usbh_class_driver_t const* driver = get_driver(drv_id);
-      if (driver != NULL) {
+      if (driver && driver->init) {
         TU_LOG_USBH("%s init\r\n", driver->name);
         driver->init();
       }