M4OSA_Clock.c revision aa382f3637a68361989d5b70e3184bddcc472d3d 
1/*
2 * Copyright (C) 2004-2011 NXP Software
3 * Copyright (C) 2011 The Android Open Source Project
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 *      http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18
19/**
20 ************************************************************************
21 * @file         M4OSA_Clock.c
22 * @brief        Clock related functions
23 * @note         This file implements functions to manipulate clock
24 ************************************************************************
25*/
26
27#include <sys/time.h>
28#include <time.h>
29
30#include "M4OSA_Debug.h"
31#include "M4OSA_Clock.h"
32#include "M4OSA_Memory.h"
33#include "M4OSA_Types.h"
34
35
36
37
38/**
39 ************************************************************************
40 * @brief      This function gets an absolute time to an unknown reference with
41 *             a high precision.
42 * @note       It means it can only be used to get a relative time by computing
43 *             differences between to times.
44 *             It is to the caller to allocate time. Time is expressed in
45 *             timescale unit.
46 *             M4OSA_ROLLOVER_CLOCK in M4OSA_Types.h must be configured with the rollover
47 *             offset of this function.
48 * @param      time: (IN/OUT) time
49 * @param      timescale: (IN) The timescale (time unit per second)
50 * @return     M4NO_ERROR: there is no error
51 * @return     M4ERR_PARAMETER: at least one parameter is NULL
52 * @return     M4WAR_TIMESCALE_TOO_BIG: the precision of the system clock is
53 *             not
54 *             compliant with the input timescale
55 ************************************************************************
56*/
57M4OSA_ERR M4OSA_clockGetTime(M4OSA_Time* pTime, M4OSA_UInt32 timescale)
58{
59    struct timeval tv;
60    struct timezone tz;
61    M4OSA_UInt32 u32_time = 0;
62    M4OSA_UInt32 u32_time_hi;
63    M4OSA_UInt32 u32_time_lo;
64    M4OSA_UInt32 u32_time_lh;
65    M4OSA_UInt32 factor;
66
67    M4OSA_TRACE1_2("M4OSA_clockGetTime\t\tM4OSA_Time* 0x%x\tM4OSA_UInt32 %d",
68                                                              pTime, timescale);
69
70    M4OSA_DEBUG_IF2(M4OSA_NULL == pTime, M4ERR_PARAMETER,
71                                     "M4OSA_clockGetTime: pTime is M4OSA_NULL");
72    M4OSA_DEBUG_IF2(0 == timescale, M4ERR_PARAMETER,
73                                          "M4OSA_clockGetTime: timescale is 0");
74
75    factor = 1000000 / timescale;
76
77    if(gettimeofday(&tv, &tz) == 0)
78    {
79        u32_time_lo = (tv.tv_sec & 0xFFFF) * timescale;
80        u32_time_hi = (((tv.tv_sec >> 16) & 0xFFFF) * timescale) + ((u32_time_lo >> 16) & 0xFFFF);
81        u32_time_lo &= 0xFFFF;
82        u32_time_lo += tv.tv_usec / factor;
83        u32_time_hi += ((u32_time_lo >> 16) & 0xFFFF);
84        u32_time_lo &= 0xFFFF;
85        u32_time = ((u32_time_hi & 0x7FFF) << 16) | u32_time_lo;
86    }
87
88    /* M4OSA_Time is signed, so we need to check the max value*/
89    if (u32_time > M4OSA_INT32_MAX)
90    {
91        u32_time = u32_time - M4OSA_INT32_MAX;
92    }
93
94    *pTime = (M4OSA_Time)u32_time;
95
96    if( timescale > 10000 )
97    {
98        return M4WAR_TIMESCALE_TOO_BIG;
99    }
100
101    return M4NO_ERROR;
102}
103