1 /* 2 * Copyright (c) 2009-2022 Huawei Technologies Co., Ltd. All rights reserved. 3 * 4 * UniProton is licensed under Mulan PSL v2. 5 * You can use this software according to the terms and conditions of the Mulan PSL v2. 6 * You may obtain a copy of Mulan PSL v2 at: 7 * http://license.coscl.org.cn/MulanPSL2 8 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, 9 * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, 10 * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE. 11 * See the Mulan PSL v2 for more details. 12 * Create: 2009-12-22 13 * Description: 硬件tick模块的C文件。 14 */ 15 #include "prt_hw_tick_internal.h" 16 17 /* 18 * 描述：CycleUpdate内部函数，该接口必须关中断情况下调用 19 */ OsCycleUpdate(void)20OS_SEC_L2_TEXT void OsCycleUpdate(void) 21 { 22 U32 hwCycleFirst; /* PosA */ 23 U32 hwCycleCtrl; /* PosB */ 24 U32 hwCycleSecond; /* PosC */ 25 /* 26 * 此处关中断后SysTick 中断上报会发生在以上四个时机 27 * 1), Before PosA then CONTROL_COUNTFLAG will be set and hwCycleFirst >= hwCycleSecond 28 * 2), Between PosA and PosB then CONTROL_COUNTFLAG will be set and hwCycleFirst < hwCycleSecond 29 * 3), Between PosB and PosC then CONTROL_COUNTFLAG will be clear and hwCycleFirst < hwCycleSecond 30 * 4), After PosC we'll see it next time 31 */ 32 hwCycleFirst = *(volatile U32 *)OS_SYSTICK_CURRENT_REG; 33 hwCycleCtrl = *(volatile U32 *)OS_SYSTICK_CONTROL_REG; 34 hwCycleSecond = *(volatile U32 *)OS_SYSTICK_CURRENT_REG; 35 36 /* 如果1、装载值前一次比后一次小 或 2、OS_SYSTICK_CONTROL_COUNTFLAG 已经SET， */ 37 /* 则 说明tick反转，需要手动补偿一个周期 */ 38 if (((hwCycleCtrl & OS_SYSTICK_CONTROL_COUNTFLAG_MSK) != 0) || (hwCycleFirst < hwCycleSecond)) { 39 g_cycleByTickNow += OsGetCyclePerTick(); 40 /* 再一次读时钟定时器，读清COUNTFLAG位 */ 41 /* COUNTFLAG位(bit16)：Returns 1 If Timer Counted To 0 Since Last Time This Was Read */ 42 (void)*(volatile U32 *)OS_SYSTICK_CONTROL_REG; 43 } 44 g_cycleNow = (g_cycleByTickNow + (OsGetCyclePerTick() - hwCycleSecond)); 45 } 46 PRT_ClkGetCycleCount64(void)47OS_SEC_L2_TEXT U64 PRT_ClkGetCycleCount64(void) 48 { 49 U64 cycle; 50 uintptr_t intSave; 51 intSave = PRT_HwiLock(); 52 OsCycleUpdate(); 53 cycle = g_cycleNow; 54 PRT_HwiRestore(intSave); 55 return cycle; 56 } 57