1 /******************************************************************************
2 * Filename: aon_rtc.c
3 * Revised: 2020-02-14 11:30:20 +0100 (Fri, 14 Feb 2020)
4 * Revision: 56760
5 *
6 * Description: Driver for the AON RTC.
7 *
8 * Copyright (c) 2015 - 2020, Texas Instruments Incorporated
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions are met:
13 *
14 * 1) Redistributions of source code must retain the above copyright notice,
15 * this list of conditions and the following disclaimer.
16 *
17 * 2) Redistributions in binary form must reproduce the above copyright notice,
18 * this list of conditions and the following disclaimer in the documentation
19 * and/or other materials provided with the distribution.
20 *
21 * 3) Neither the name of the ORGANIZATION nor the names of its contributors may
22 * be used to endorse or promote products derived from this software without
23 * specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
26 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
29 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 *
37 ******************************************************************************/
38
39 #include "aon_rtc.h"
40 #include "cpu.h"
41
42 //*****************************************************************************
43 //
44 // Handle support for DriverLib in ROM:
45 // This section will undo prototype renaming made in the header file
46 //
47 //*****************************************************************************
48 #if !defined(DOXYGEN)
49 #undef AONRTCCurrent64BitValueGet
50 #define AONRTCCurrent64BitValueGet NOROM_AONRTCCurrent64BitValueGet
51 #endif
52
53
54 //*****************************************************************************
55 //
56 // Get the current 64-bit value of the RTC counter.
57 //
58 //*****************************************************************************
59 uint64_t
AONRTCCurrent64BitValueGet(void)60 AONRTCCurrent64BitValueGet( void )
61 {
62 union {
63 uint64_t returnValue ;
64 uint32_t secAndSubSec[ 2 ] ;
65 } currentRtc ;
66 uint32_t ui32SecondSecRead ;
67
68 // Reading SEC both before and after SUBSEC in order to detect if SEC incremented while reading SUBSEC
69 // If SEC incremented, we can't be sure which SEC the SUBSEC belongs to, so repeating the sequence then.
70 do {
71 currentRtc.secAndSubSec[ 1 ] = HWREG( AON_RTC_BASE + AON_RTC_O_SEC );
72 currentRtc.secAndSubSec[ 0 ] = HWREG( AON_RTC_BASE + AON_RTC_O_SUBSEC );
73 ui32SecondSecRead = HWREG( AON_RTC_BASE + AON_RTC_O_SEC );
74 } while ( currentRtc.secAndSubSec[ 1 ] != ui32SecondSecRead );
75
76 return ( currentRtc.returnValue );
77 }
78
