1 /******************************************************************************
2 *  Filename:       aon_rtc.c
3 *  Revised:        2015-06-24 13:36:23 +0200 (Wed, 24 Jun 2015)
4 *  Revision:       44023
5 *
6 *  Description:    Driver for the AON RTC.
7 *
8 *  Copyright (c) 2015, 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 <driverlib/aon_rtc.h>
40 #include <driverlib/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  AONRTCCurrentCompareValueGet
50     #define AONRTCCurrentCompareValueGet    NOROM_AONRTCCurrentCompareValueGet
51     #undef  AONRTCCurrent64BitValueGet
52     #define AONRTCCurrent64BitValueGet      NOROM_AONRTCCurrent64BitValueGet
53 #endif
54 
55 
56 //*****************************************************************************
57 //
58 // Get the current value of the RTC counter in a format compatible to the compare registers.
59 //
60 //*****************************************************************************
61 uint32_t
AONRTCCurrentCompareValueGet(void)62 AONRTCCurrentCompareValueGet( void )
63 {
64     uint32_t   ui32CurrentSec    ;
65     uint32_t   ui32CurrentSubSec ;
66     uint32_t   ui32SecondSecRead ;
67 
68     //
69     // Reading SEC both before and after SUBSEC in order to detect if SEC incremented while reading SUBSEC
70     // If SEC incremented, we can�t be sure which SEC the SUBSEC belongs to, so repeating the sequence then.
71     //
72     do {
73         ui32CurrentSec    = HWREG( AON_RTC_BASE + AON_RTC_O_SEC    );
74         ui32CurrentSubSec = HWREG( AON_RTC_BASE + AON_RTC_O_SUBSEC );
75         ui32SecondSecRead = HWREG( AON_RTC_BASE + AON_RTC_O_SEC    );
76     } while ( ui32CurrentSec != ui32SecondSecRead );
77 
78     return (( ui32CurrentSec << 16 ) | ( ui32CurrentSubSec >> 16 ));
79 }
80 
81 //*****************************************************************************
82 //
83 // Get the current 64-bit value of the RTC counter.
84 //
85 //*****************************************************************************
86 uint64_t
AONRTCCurrent64BitValueGet(void)87 AONRTCCurrent64BitValueGet( void )
88 {
89     union {
90         uint64_t  returnValue       ;
91         uint32_t  secAndSubSec[ 2 ] ;
92     } currentRtc                    ;
93     uint32_t      ui32SecondSecRead ;
94 
95     //
96     // Reading SEC both before and after SUBSEC in order to detect if SEC incremented while reading SUBSEC
97     // If SEC incremented, we can�t be sure which SEC the SUBSEC belongs to, so repeating the sequence then.
98     //
99     do {
100         currentRtc.secAndSubSec[ 1 ] = HWREG( AON_RTC_BASE + AON_RTC_O_SEC    );
101         currentRtc.secAndSubSec[ 0 ] = HWREG( AON_RTC_BASE + AON_RTC_O_SUBSEC );
102         ui32SecondSecRead            = HWREG( AON_RTC_BASE + AON_RTC_O_SEC    );
103     } while ( currentRtc.secAndSubSec[ 1 ] != ui32SecondSecRead );
104 
105     return ( currentRtc.returnValue );
106 }
107