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_next_td_clean PORTABLE C */ 38 /* 6.1 */ 39 /* AUTHOR */ 40 /* */ 41 /* Chaoqiong Xiao, Microsoft Corporation */ 42 /* */ 43 /* DESCRIPTION */ 44 /* */ 45 /* This function cleans all the tds attached to a ED. The end of the */ 46 /* TD chain is pointed by the tail TD. */ 47 /* */ 48 /* INPUT */ 49 /* */ 50 /* td Pointer to OHCI TD */ 51 /* */ 52 /* OUTPUT */ 53 /* */ 54 /* None */ 55 /* */ 56 /* CALLS */ 57 /* */ 58 /* _ux_utility_physical_address Get physical address */ 59 /* _ux_utility_virtual_address Get virtual address */ 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 /* fixed physical and virtual */ 72 /* address conversion, */ 73 /* resulting in version 6.1 */ 74 /* */ 75 /**************************************************************************/ _ux_hcd_ohci_next_td_clean(UX_OHCI_TD * td)76VOID _ux_hcd_ohci_next_td_clean(UX_OHCI_TD *td) 77 { 78 79 UX_OHCI_ED *ed; 80 UX_OHCI_TD *head_td; 81 UX_OHCI_TD *tail_td; 82 ULONG value_td; 83 ULONG value_carry; 84 85 86 /* Obtain the pointer to the ED from the TD. */ 87 ed = td -> ux_ohci_td_ed; 88 89 /* Ensure that the potential Carry bit is maintained in the head ED. */ 90 value_carry = (ULONG)(ed -> ux_ohci_ed_head_td) & UX_OHCI_ED_TOGGLE_CARRY; 91 92 /* Ensure that the potential Halt bit is removed in the head ED. */ 93 value_td = (ULONG) _ux_utility_virtual_address(ed -> ux_ohci_ed_head_td) & UX_OHCI_ED_MASK_TD; 94 head_td = (UX_OHCI_TD *)value_td; 95 96 /* Remove all the tds from this ED and leave the head and tail pointing 97 to the dummy TD. */ 98 tail_td = _ux_utility_virtual_address(ed -> ux_ohci_ed_tail_td); 99 100 /* Free all tds attached to the ED. */ 101 while (head_td != tail_td) 102 { 103 104 /* Mark the current head_td as free. */ 105 head_td -> ux_ohci_td_status = UX_UNUSED; 106 107 /* Update the head TD with the next TD. */ 108 ed -> ux_ohci_ed_head_td = head_td -> ux_ohci_td_next_td; 109 110 /* Now the new head_td is the next TD in the chain. */ 111 head_td = _ux_utility_virtual_address(ed -> ux_ohci_ed_head_td); 112 } 113 114 /* Restore the value carry for next transfers. */ 115 value_td = (ULONG) ed -> ux_ohci_ed_head_td; 116 value_td |= value_carry; 117 ed -> ux_ohci_ed_head_td = (UX_OHCI_TD *) value_td; 118 119 /* Return to caller. */ 120 return; 121 } 122 123
