1 /******************************************************************************
2 * Filename: aon_rtc.c
3 *
4 * Description: Driver for the AON RTC.
5 *
6 * Copyright (c) 2015 - 2022, Texas Instruments Incorporated
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions are met:
11 *
12 * 1) Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 *
15 * 2) Redistributions in binary form must reproduce the above copyright notice,
16 * this list of conditions and the following disclaimer in the documentation
17 * and/or other materials provided with the distribution.
18 *
19 * 3) Neither the name of the ORGANIZATION nor the names of its contributors may
20 * be used to endorse or promote products derived from this software without
21 * specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
24 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
27 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33 * POSSIBILITY OF SUCH DAMAGE.
34 *
35 ******************************************************************************/
36
37 #include "aon_rtc.h"
38 #include "cpu.h"
39 #include "../inc/hw_memmap_common.h"
40
41 //*****************************************************************************
42 //
43 // Handle support for DriverLib in ROM:
44 // This section will undo prototype renaming made in the header file
45 //
46 //*****************************************************************************
47 #if !defined(DOXYGEN)
48 #undef AONRTCCurrent64BitValueGet
49 #define AONRTCCurrent64BitValueGet NOROM_AONRTCCurrent64BitValueGet
50 #endif
51
52 //*****************************************************************************
53 //
54 // Get the current 64-bit value of the RTC counter.
55 //
56 //*****************************************************************************
57 uint64_t
AONRTCCurrent64BitValueGet(void)58 AONRTCCurrent64BitValueGet( void )
59 {
60 union {
61 uint64_t returnValue ;
62 uint32_t secAndSubSec[ 2 ] ;
63 } currentRtc ;
64 uint32_t ui32SecondSecRead ;
65
66 // Reading SEC both before and after SUBSEC in order to detect if SEC incremented while reading SUBSEC
67 // If SEC incremented, we can't be sure which SEC the SUBSEC belongs to, so repeating the sequence then.
68 do {
69 currentRtc.secAndSubSec[ 1 ] = HWREG( AON_RTC_BASE + NONSECURE_OFFSET + AON_RTC_O_SEC );
70 currentRtc.secAndSubSec[ 0 ] = HWREG( AON_RTC_BASE + NONSECURE_OFFSET + AON_RTC_O_SUBSEC );
71 ui32SecondSecRead = HWREG( AON_RTC_BASE + NONSECURE_OFFSET + AON_RTC_O_SEC );
72 } while ( currentRtc.secAndSubSec[ 1 ] != ui32SecondSecRead );
73
74 return ( currentRtc.returnValue );
75 }
76
