feat(us/host): set device cfg during enumeration

- user callback funciton to set device configuration
      as a part of usb_host_install
    - callback provides device descriptor of a device being enumerated
    - user can set which cfg descriptor the USB device will be set with
    - user can filter device enumeration
    - Kconfig menu to enable callback function
    - usb_host_lib example demonstration

components/usb/Kconfig

@@ -104,4 +104,15 @@ menu "USB-OTG"
         bool
         default y
 
+    config USB_HOST_ENABLE_ENUM_FILTER_CALLBACK
+        bool "Enable enumeration filter callback"
+        default n
+        help
+            The enumeration filter callback is called before enumeration of each newly attached device. This callback
+            allows users to control whether a device should be enumerated, and what configuration number to use when
+            enumerating a device.
+
+            If enabled, the enumeration filter callback can be set via 'usb_host_config_t' when calling
+            'usb_host_install()'.
+
 endmenu #USB-OTG

components/usb/hub.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -32,11 +32,15 @@ implement the bare minimum to control the root HCD port.
 #define HUB_ROOT_HCD_PORT_FIFO_BIAS                 HCD_PORT_FIFO_BIAS_BALANCED
 #endif
 
+#ifdef CONFIG_USB_HOST_ENABLE_ENUM_FILTER_CALLBACK
+#define ENABLE_ENUM_FILTER_CALLBACK
+#endif // CONFIG_USB_HOST_ENABLE_ENUM_FILTER_CALLBACK
+
 #define SET_ADDR_RECOVERY_INTERVAL_MS               CONFIG_USB_HOST_SET_ADDR_RECOVERY_MS
 
 #define ENUM_CTRL_TRANSFER_MAX_DATA_LEN             CONFIG_USB_HOST_CONTROL_TRANSFER_MAX_SIZE
 #define ENUM_DEV_ADDR                               1       // Device address used in enumeration
-#define ENUM_CONFIG_INDEX                           0       // Index used to get the first configuration descriptor of the device
+#define ENUM_CONFIG_INDEX_DEFAULT                   0       // Index used to get the first configuration descriptor of the device
 #define ENUM_SHORT_DESC_REQ_LEN                     8       // Number of bytes to request when getting a short descriptor (just enough to get bMaxPacketSize0 or wTotalLength)
 #define ENUM_WORST_CASE_MPS_LS                      8       // The worst case MPS of EP0 for a LS device
 #define ENUM_WORST_CASE_MPS_FS                      64      // The worst case MPS of EP0 for a FS device
@@ -165,6 +169,11 @@ typedef struct {
     uint8_t iSerialNumber;          /**< Index of the Serial Number string descriptor */
     uint8_t str_desc_bLength;       /**< Saved bLength from getting a short string descriptor */
     uint8_t bConfigurationValue;    /**< Device's current configuration number */
+    uint8_t enum_config_index;      /**< Configuration index used during enumeration */
+#ifdef ENABLE_ENUM_FILTER_CALLBACK
+    usb_host_enum_filter_cb_t enum_filter_cb;   /**< Set device configuration callback */
+    bool graceful_exit;                         /**< Exit enumeration by user's request from the callback function */
+#endif // ENABLE_ENUM_FILTER_CALLBACK
 } enum_ctrl_t;
 
 typedef struct {
@@ -280,6 +289,11 @@ static bool enum_stage_start(enum_ctrl_t *enum_ctrl)
     ESP_ERROR_CHECK(hcd_pipe_update_callback(enum_dflt_pipe_hdl, enum_dflt_pipe_callback, NULL));
     enum_ctrl->dev_hdl = enum_dev_hdl;
     enum_ctrl->pipe = enum_dflt_pipe_hdl;
+
+    // Flag to gracefully exit the enumeration process if requested by the user in the enumeration filter cb
+#ifdef ENABLE_ENUM_FILTER_CALLBACK
+    enum_ctrl->graceful_exit = false;
+#endif // ENABLE_ENUM_FILTER_CALLBACK
     return true;
 }
 
@@ -323,6 +337,39 @@ static void get_string_desc_index_and_langid(enum_ctrl_t *enum_ctrl, uint8_t *in
     }
 }
 
+static bool set_config_index(enum_ctrl_t *enum_ctrl, const usb_device_desc_t *device_desc)
+{
+#ifdef ENABLE_ENUM_FILTER_CALLBACK
+    // Callback enabled in the menuncofig, but the callback function was not defined
+    if (enum_ctrl->enum_filter_cb == NULL) {
+        enum_ctrl->enum_config_index = ENUM_CONFIG_INDEX_DEFAULT;
+        return true;
+    }
+
+    uint8_t enum_config_index;
+    const bool enum_continue = enum_ctrl->enum_filter_cb(device_desc, &enum_config_index);
+
+    // User's request NOT to enumerate the USB device
+    if (!enum_continue) {
+        ESP_LOGW(HUB_DRIVER_TAG, "USB device (PID = 0x%x, VID = 0x%x) will not be enumerated", device_desc->idProduct, device_desc->idVendor);
+        enum_ctrl->graceful_exit = true;
+        return false;
+    }
+
+    // Set configuration descriptor
+    if ((enum_config_index == 0) || (enum_config_index > device_desc->bNumConfigurations)) {
+        ESP_LOGW(HUB_DRIVER_TAG, "bConfigurationValue %d provided by user, device will be configured with configuration descriptor 1", enum_config_index);
+        enum_ctrl->enum_config_index = ENUM_CONFIG_INDEX_DEFAULT;
+    } else {
+        enum_ctrl->enum_config_index = enum_config_index - 1;
+    }
+#else // ENABLE_ENUM_FILTER_CALLBACK
+    enum_ctrl->enum_config_index = ENUM_CONFIG_INDEX_DEFAULT;
+#endif // ENABLE_ENUM_FILTER_CALLBACK
+
+    return true;
+}
+
 static bool enum_stage_transfer(enum_ctrl_t *enum_ctrl)
 {
     usb_transfer_t *transfer = &enum_ctrl->urb->transfer;
@@ -351,7 +398,7 @@ static bool enum_stage_transfer(enum_ctrl_t *enum_ctrl)
     }
     case ENUM_STAGE_GET_SHORT_CONFIG_DESC: {
         // Get a short config descriptor at index 0
-        USB_SETUP_PACKET_INIT_GET_CONFIG_DESC((usb_setup_packet_t *)transfer->data_buffer, ENUM_CONFIG_INDEX, ENUM_SHORT_DESC_REQ_LEN);
+        USB_SETUP_PACKET_INIT_GET_CONFIG_DESC((usb_setup_packet_t *)transfer->data_buffer, enum_ctrl->enum_config_index, ENUM_SHORT_DESC_REQ_LEN);
         transfer->num_bytes = sizeof(usb_setup_packet_t) + usb_round_up_to_mps(ENUM_SHORT_DESC_REQ_LEN, enum_ctrl->bMaxPacketSize0);
         // IN data stage should return exactly ENUM_SHORT_DESC_REQ_LEN bytes
         enum_ctrl->expect_num_bytes = sizeof(usb_setup_packet_t) + ENUM_SHORT_DESC_REQ_LEN;
@@ -359,7 +406,7 @@ static bool enum_stage_transfer(enum_ctrl_t *enum_ctrl)
     }
     case ENUM_STAGE_GET_FULL_CONFIG_DESC: {
         // Get the full configuration descriptor at index 0, requesting its exact length.
-        USB_SETUP_PACKET_INIT_GET_CONFIG_DESC((usb_setup_packet_t *)transfer->data_buffer, ENUM_CONFIG_INDEX, enum_ctrl->wTotalLength);
+        USB_SETUP_PACKET_INIT_GET_CONFIG_DESC((usb_setup_packet_t *)transfer->data_buffer, enum_ctrl->enum_config_index, enum_ctrl->wTotalLength);
         transfer->num_bytes = sizeof(usb_setup_packet_t) + usb_round_up_to_mps(enum_ctrl->wTotalLength, enum_ctrl->bMaxPacketSize0);
         // IN data stage should return exactly wTotalLength bytes
         enum_ctrl->expect_num_bytes = sizeof(usb_setup_packet_t) + enum_ctrl->wTotalLength;
@@ -497,7 +544,7 @@ static bool enum_stage_transfer_check(enum_ctrl_t *enum_ctrl)
         enum_ctrl->iManufacturer = device_desc->iManufacturer;
         enum_ctrl->iProduct = device_desc->iProduct;
         enum_ctrl->iSerialNumber = device_desc->iSerialNumber;
-        ret = true;
+        ret = set_config_index(enum_ctrl, device_desc);
         break;
     }
     case ENUM_STAGE_CHECK_SHORT_CONFIG_DESC: {
@@ -924,7 +971,15 @@ static void enum_handle_events(void)
     if (stage_pass) {
         ESP_LOGD(HUB_DRIVER_TAG, "Stage done: %s", enum_stage_strings[enum_ctrl->stage]);
     } else {
-        ESP_LOGE(HUB_DRIVER_TAG, "Stage failed: %s", enum_stage_strings[enum_ctrl->stage]);
+#ifdef ENABLE_ENUM_FILTER_CALLBACK
+        if (!enum_ctrl->graceful_exit) {
+            ESP_LOGE(HUB_DRIVER_TAG, "Stage failed: %s", enum_stage_strings[enum_ctrl->stage]);
+        } else {
+            ESP_LOGD(HUB_DRIVER_TAG, "Stage done: %s", enum_stage_strings[enum_ctrl->stage]);
+        }
+#else // ENABLE_ENUM_FILTER_CALLBACK
+            ESP_LOGE(HUB_DRIVER_TAG, "Stage failed: %s", enum_stage_strings[enum_ctrl->stage]);
+#endif // ENABLE_ENUM_FILTER_CALLBACK
     }
     enum_set_next_stage(enum_ctrl, stage_pass);
 }
@@ -959,9 +1014,13 @@ esp_err_t hub_install(hub_config_t *hub_config)
     hub_driver_obj->dynamic.driver_state = HUB_DRIVER_STATE_INSTALLED;
     hub_driver_obj->single_thread.enum_ctrl.stage = ENUM_STAGE_NONE;
     hub_driver_obj->single_thread.enum_ctrl.urb = enum_urb;
+#ifdef ENABLE_ENUM_FILTER_CALLBACK
+    hub_driver_obj->single_thread.enum_ctrl.enum_filter_cb = hub_config->enum_filter_cb;
+#endif // ENABLE_ENUM_FILTER_CALLBACK
     hub_driver_obj->constant.root_port_hdl = port_hdl;
     hub_driver_obj->constant.proc_req_cb = hub_config->proc_req_cb;
     hub_driver_obj->constant.proc_req_cb_arg = hub_config->proc_req_cb_arg;
+
     HUB_DRIVER_ENTER_CRITICAL();
     if (p_hub_driver_obj != NULL) {
         HUB_DRIVER_EXIT_CRITICAL();

components/usb/include/usb/usb_host.h

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -106,6 +106,8 @@ typedef struct {
                                      set this if they want to use an external USB PHY. Otherwise, the USB Host Library
                                      will automatically configure the internal USB PHY */
     int intr_flags;             /**< Interrupt flags for the underlying ISR used by the USB Host stack */
+    usb_host_enum_filter_cb_t enum_filter_cb; /**< Enumeration filter callback. Enable CONFIG_USB_HOST_ENABLE_ENUM_FILTER_CALLBACK
+                                                   to use this feature. Set to NULL otherwise. */
 } usb_host_config_t;
 
 /**

components/usb/include/usb/usb_types_stack.h

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -10,6 +10,7 @@ Warning: The USB Host Library API is still a beta version and may be subject to
 
 #pragma once
 
+#include <stdbool.h>
 #include "usb/usb_types_ch9.h"
 
 #ifdef __cplusplus
@@ -46,6 +47,29 @@ typedef enum {
  */
 typedef struct usb_device_handle_s *usb_device_handle_t;
 
+/**
+ * @brief Enumeration filter callback
+ *
+ * This callback is called at the beginning of the enumeration process for a newly attached device.
+ * Through this callback, users are able to:
+ *
+ * - filter which devices should be enumerated
+ * - select the configuration number to use when enumerating the device
+ *
+ * The device descriptor is passed to this callback to allow users to filter devices based on
+ * Vendor ID, Product ID, and class code.
+ *
+ * @attention This callback must be non-blocking
+ * @attention This callback must not submit any USB transfers
+ * @param[in] dev_desc Device descriptor of the device to enumerate
+ * @param[out] bConfigurationValue Configuration number to use when enumerating the device (starts with 1)
+ *
+ * @return bool
+ *  - true:  USB device will be enumerated
+ *  - false: USB device will not be enumerated
+ */
+typedef bool (*usb_host_enum_filter_cb_t)(const usb_device_desc_t *dev_desc, uint8_t *bConfigurationValue);
+
 /**
  * @brief Basic information of an enumerated device
  */

components/usb/private_include/hub.h

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2021 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -8,6 +8,7 @@
 
 #include <stdlib.h>
 #include <stdint.h>
+#include "sdkconfig.h"
 #include "esp_err.h"
 #include "usb_private.h"
 #include "usbh.h"
@@ -22,8 +23,11 @@ extern "C" {
  * @brief Hub driver configuration
  */
 typedef struct {
-    usb_proc_req_cb_t proc_req_cb;      /**< Processing request callback */
-    void *proc_req_cb_arg;              /**< Processing request callback argument */
+    usb_proc_req_cb_t proc_req_cb;                  /**< Processing request callback */
+    void *proc_req_cb_arg;                          /**< Processing request callback argument */
+#ifdef CONFIG_USB_HOST_ENABLE_ENUM_FILTER_CALLBACK
+    usb_host_enum_filter_cb_t enum_filter_cb;       /**< Set device configuration callback */
+#endif // CONFIG_USB_HOST_ENABLE_ENUM_FILTER_CALLBACK
 } hub_config_t;
 
 // ---------------------------------------------- Hub Driver Functions -------------------------------------------------

components/usb/usb_host.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -10,6 +10,7 @@ Warning: The USB Host Library API is still a beta version and may be subject to
 
 #include <stdlib.h>
 #include <stdint.h>
+#include "sdkconfig.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 #include "freertos/queue.h"
@@ -47,6 +48,10 @@ static portMUX_TYPE host_lock = portMUX_INITIALIZER_UNLOCKED;
 #define PROCESS_REQUEST_PENDING_FLAG_USBH       0x01
 #define PROCESS_REQUEST_PENDING_FLAG_HUB        0x02
 
+#ifdef CONFIG_USB_HOST_ENABLE_ENUM_FILTER_CALLBACK
+#define ENABLE_ENUM_FILTER_CALLBACK
+#endif // CONFIG_USB_HOST_ENABLE_ENUM_FILTER_CALLBACK
+
 typedef struct ep_wrapper_s ep_wrapper_t;
 typedef struct interface_s interface_t;
 typedef struct client_s client_t;
@@ -404,10 +409,18 @@ esp_err_t usb_host_install(const usb_host_config_t *config)
         goto usbh_err;
     }
 
+#ifdef ENABLE_ENUM_FILTER_CALLBACK
+    if (config->enum_filter_cb == NULL) {
+        ESP_LOGW(USB_HOST_TAG, "User callback to set USB device configuration is enabled, but not used");
+    }
+#endif // ENABLE_ENUM_FILTER_CALLBACK
     // Install Hub
     hub_config_t hub_config = {
         .proc_req_cb = proc_req_callback,
         .proc_req_cb_arg = NULL,
+#ifdef ENABLE_ENUM_FILTER_CALLBACK
+        .enum_filter_cb = config->enum_filter_cb,
+#endif // ENABLE_ENUM_FILTER_CALLBACK
     };
     ret = hub_install(&hub_config);
     if (ret != ESP_OK) {

examples/peripherals/usb/host/cdc/cdc_acm_vcp/main/CMakeLists.txt

@@ -2,3 +2,5 @@ idf_component_register(
     SRCS "cdc_acm_vcp_example_main.cpp"
     INCLUDE_DIRS "."
     )
+
+target_compile_options(${COMPONENT_LIB} PRIVATE "-Wno-missing-field-initializers")

examples/peripherals/usb/host/usb_host_lib/main/usb_host_lib_main.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2021-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Unlicense OR CC0-1.0
  */
@@ -14,10 +14,43 @@
 #define DAEMON_TASK_PRIORITY    2
 #define CLASS_TASK_PRIORITY     3
 
+#ifdef CONFIG_USB_HOST_ENABLE_ENUM_FILTER_CALLBACK
+#define ENABLE_ENUM_FILTER_CALLBACK
+#endif // CONFIG_USB_HOST_ENABLE_ENUM_FILTER_CALLBACK
+
 extern void class_driver_task(void *arg);
 
 static const char *TAG = "DAEMON";
 
+/**
+ * @brief Set configuration callback
+ *
+ * Set the USB device configuration during the enumeration process, must be enabled in the menuconfig
+
+ * @note bConfigurationValue starts at index 1
+ *
+ * @param[in] dev_desc device descriptor of the USB device currently being enumerated
+ * @param[out] bConfigurationValue configuration descriptor index, that will be user for enumeration
+ *
+ * @return bool
+ * - true:  USB device will be enumerated
+ * - false: USB device will not be enumerated
+ */
+#ifdef ENABLE_ENUM_FILTER_CALLBACK
+static bool set_config_cb(const usb_device_desc_t *dev_desc, uint8_t *bConfigurationValue)
+{
+    // If the USB device has more than one configuration, set the second configuration
+    if (dev_desc->bNumConfigurations > 1) {
+        *bConfigurationValue = 2;
+    } else {
+        *bConfigurationValue = 1;
+    }
+
+    // Return true to enumerate the USB device
+    return true;
+}
+#endif // ENABLE_ENUM_FILTER_CALLBACK
+
 static void host_lib_daemon_task(void *arg)
 {
     SemaphoreHandle_t signaling_sem = (SemaphoreHandle_t)arg;
@@ -26,6 +59,9 @@ static void host_lib_daemon_task(void *arg)
     usb_host_config_t host_config = {
         .skip_phy_setup = false,
         .intr_flags = ESP_INTR_FLAG_LEVEL1,
+# ifdef ENABLE_ENUM_FILTER_CALLBACK
+        .enum_filter_cb = set_config_cb,
+# endif // ENABLE_ENUM_FILTER_CALLBACK
     };
     ESP_ERROR_CHECK(usb_host_install(&host_config));