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