1 /* 2 * Copyright (c) 2020-2022 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16 /** 17 * @addtogroup USB 18 * @{ 19 * 20 * @brief Declares USB-related APIs, including the custom data types and functions used to obtain descriptors, 21 * interface objects, and request objects, and to submit requests. 22 * 23 * @since 1.0 24 * @version 1.0 25 */ 26 27 /** 28 * @file usb_session.h 29 * 30 * @brief Defines the session context data. 31 * 32 * @since 1.0 33 * @version 1.0 34 */ 35 #ifndef USB_SESSION_H 36 #define USB_SESSION_H 37 38 #include "usb_object.h" 39 40 #ifdef __cplusplus 41 extern "C" { 42 #endif 43 44 /** 45 * @brief Defines a session context object. 46 * 47 * A session context object allows a program to use the driver development kit (DDK) independently. This can prevent 48 * interference between users of a single DDK. Such a session can be initiated by using <b>UsbInitHostSdk()</b> or 49 * <b>UsbRawInit()</b> and destroyed by using <b>UsbExitHostSdk()</b> or <b>UsbRawExit()</b>. 50 * If a program has only one user, you can ignore the session context. You just need to pass <b>NULL</b> in each 51 * function call that requires context, and the default session context will be used. 52 */ 53 struct UsbSession { 54 /** Device linked list */ 55 struct HdfSList usbDevs; 56 /** Interface object pool linked list */ 57 struct DListHead ifacePoolList; 58 /** Mutex used for operations on the device linked list and interface object pool linked list */ 59 struct OsalMutex lock; 60 /** Number of references to session context objects */ 61 OsalAtomic refCount; 62 }; 63 64 #ifdef __cplusplus 65 } 66 #endif 67 68 #endif /* USB_SESSION_H */ 69 /** @} */