Contiki-Inga 3.x
watchdog.c
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1 /*
2  * Copyright (c) 2012, Texas Instruments Incorporated - http://www.ti.com/
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  * notice, this list of conditions and the following disclaimer in the
12  * documentation and/or other materials provided with the distribution.
13  *
14  * 3. Neither the name of the copyright holder nor the names of its
15  * contributors may be used to endorse or promote products derived
16  * from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22  * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
27  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
29  * OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 /**
32  * \addtogroup cc2538
33  * @{
34  *
35  * \defgroup cc2538-wdt cc2538 watchdog timer driver
36  *
37  * Driver for the cc2538 Watchdog Timer
38  * @{
39  *
40  * \file
41  * Implementation of the cc2538 watchdog driver. The peripheral runs in
42  * watchdog mode.
43  */
44 #include "contiki.h"
45 #include "reg.h"
46 #include "cpu.h"
47 #include "dev/smwdthrosc.h"
48 /*---------------------------------------------------------------------------*/
49 /** \brief Initialisation function for the WDT. Currently simply explicitly
50  * sets the WDT interval to max interval */
51 void
52 watchdog_init(void)
53 {
54  /* Max interval, don't enable yet */
55  REG(SMWDTHROSC_WDCTL) = 0;
56 }
57 /*---------------------------------------------------------------------------*/
58 /** \brief Starts the WDT in watchdog mode, maximum interval */
59 void
60 watchdog_start(void)
61 {
62  /* Max interval (32768), watchdog mode, Enable */
63  REG(SMWDTHROSC_WDCTL) = SMWDTHROSC_WDCTL_EN;
64 }
65 /*---------------------------------------------------------------------------*/
66 /** \brief Writes the WDT clear sequence. This function assumes that we are
67  * in watchdog mode and that interval bits (bits [1:0]) are 00 */
68 void
69 watchdog_periodic(void)
70 {
71  /* Safe to write to bits [3:0] since EN is 1 */
72  REG(SMWDTHROSC_WDCTL) = (SMWDTHROSC_WDCTL_CLR_3 | SMWDTHROSC_WDCTL_CLR_1);
73  REG(SMWDTHROSC_WDCTL) = (SMWDTHROSC_WDCTL_CLR_2 | SMWDTHROSC_WDCTL_CLR_0);
74 }
75 /*---------------------------------------------------------------------------*/
76 /** \brief In watchdog mode, the WDT can not be stopped. This function is
77  * defined here to satisfy API requirements.
78  */
79 void
80 watchdog_stop(void)
81 {
82  return;
83 }
84 /*---------------------------------------------------------------------------*/
85 /** \brief Keeps control until the WDT throws a reset signal */
86 void
87 watchdog_reboot(void)
88 {
89  INTERRUPTS_DISABLE();
90  while(1);
91 }
92 /**
93  * @}
94  * @}
95  */
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