1 /**************************************************************************/ 2 /* */ 3 /* Copyright (c) Microsoft Corporation. All rights reserved. */ 4 /* */ 5 /* This software is licensed under the Microsoft Software License */ 6 /* Terms for Microsoft Azure RTOS. Full text of the license can be */ 7 /* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */ 8 /* and in the root directory of this software. */ 9 /* */ 10 /**************************************************************************/ 11 12 13 /**************************************************************************/ 14 /**************************************************************************/ 15 /** */ 16 /** USBX Component */ 17 /** */ 18 /** OHCI Controller Driver */ 19 /** */ 20 /**************************************************************************/ 21 /**************************************************************************/ 22 23 24 /* Include necessary system files. */ 25 26 #define UX_SOURCE_CODE 27 28 #include "ux_api.h" 29 #include "ux_hcd_ohci.h" 30 #include "ux_host_stack.h" 31 32 33 /**************************************************************************/ 34 /* */ 35 /* FUNCTION RELEASE */ 36 /* */ 37 /* _ux_hcd_ohci_regular_td_obtain PORTABLE C */ 38 /* 6.1.11 */ 39 /* AUTHOR */ 40 /* */ 41 /* Chaoqiong Xiao, Microsoft Corporation */ 42 /* */ 43 /* DESCRIPTION */ 44 /* */ 45 /* This function obtains a free TD from the regular TD list. */ 46 /* */ 47 /* INPUT */ 48 /* */ 49 /* hcd_ohci Pointer to OHCI controller */ 50 /* */ 51 /* OUTPUT */ 52 /* */ 53 /* *UX_OHCI_TD Regular TD pointer */ 54 /* */ 55 /* CALLS */ 56 /* */ 57 /* _ux_utility_memory_set Set memory block */ 58 /* _ux_host_mutex_on Get protection mutex */ 59 /* _ux_host_mutex_off Release protection mutex */ 60 /* */ 61 /* CALLED BY */ 62 /* */ 63 /* OHCI Controller Driver */ 64 /* */ 65 /* RELEASE HISTORY */ 66 /* */ 67 /* DATE NAME DESCRIPTION */ 68 /* */ 69 /* 05-19-2020 Chaoqiong Xiao Initial Version 6.0 */ 70 /* 09-30-2020 Chaoqiong Xiao Modified comment(s), */ 71 /* verified memset and memcpy */ 72 /* cases, */ 73 /* resulting in version 6.1 */ 74 /* 04-25-2022 Chaoqiong Xiao Modified comment(s), */ 75 /* fixed standalone compile, */ 76 /* resulting in version 6.1.11 */ 77 /* */ 78 /**************************************************************************/ _ux_hcd_ohci_regular_td_obtain(UX_HCD_OHCI * hcd_ohci)79UX_OHCI_TD *_ux_hcd_ohci_regular_td_obtain(UX_HCD_OHCI *hcd_ohci) 80 { 81 82 UX_OHCI_TD *td; 83 ULONG td_index; 84 85 86 /* Set the Mutex as this is a critical section. */ 87 _ux_host_mutex_on(&_ux_system -> ux_system_mutex); 88 89 /* Start the search from the beginning of the regular TD list. */ 90 td = hcd_ohci -> ux_hcd_ohci_td_list; 91 92 for (td_index = 0; td_index < _ux_system_host -> ux_system_host_max_td; td_index++) 93 { 94 95 /* Check the TD status, a free TD is marked with the UNUSED flag. */ 96 if (td -> ux_ohci_td_status == UX_UNUSED) 97 { 98 99 /* The TD may have been used, so we reset all fields. */ 100 _ux_utility_memory_set(td, 0, sizeof(UX_OHCI_TD)); /* Use case of memset is verified. */ 101 102 /* This TD is now marked as USED. */ 103 td -> ux_ohci_td_status = UX_USED; 104 105 /* Release the protection. */ 106 _ux_host_mutex_off(&_ux_system -> ux_system_mutex); 107 108 /* Return TD pointer - success! */ 109 return(td); 110 } 111 112 /* Move to the next TD. */ 113 td++; 114 } 115 116 /* There is no available TD in the TD list. */ 117 118 /* Release protection. */ 119 _ux_host_mutex_off(&_ux_system -> ux_system_mutex); 120 121 /* Return NULL to caller. */ 122 return(UX_NULL); 123 } 124 125
