summaryrefslogtreecommitdiffstats
path: root/bsps/arm/lpc32xx/rtc/rtc-config.c
blob: 484c23f6f44724a1f722e85c176102a42b7f5220 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
/* SPDX-License-Identifier: BSD-2-Clause */

/**
 * @file
 *
 * @ingroup RTEMSBSPsARMLPC32XX
 *
 * @brief RTC configuration.
 */

/*
 * Copyright (c) 2009-2011 embedded brains GmbH.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <libchip/rtc.h>

#include <bsp.h>
#include <bsp/lpc32xx.h>
#include <rtems/rtems/clockimpl.h>

#include <time.h>

#define LPC32XX_RTC_COUNT 1U

#define LPC32XX_RTC_COUNTER_DELTA 0xfffffffeU

#define LPC32XX_RTC_KEY 0xb5c13f27U

#define LPC32XX_RTC_CTRL_FORCE_ONSW (1U << 7)
#define LPC32XX_RTC_CTRL_STOP (1U << 6)
#define LPC32XX_RTC_CTRL_RESET (1U << 4)
#define LPC32XX_RTC_CTRL_MATCH_1_ONSW (1U << 3)
#define LPC32XX_RTC_CTRL_MATCH_0_ONSW (1U << 2)
#define LPC32XX_RTC_CTRL_MATCH_1_INTR (1U << 1)
#define LPC32XX_RTC_CTRL_MATCH_0_INTR (1U << 0)

static void lpc32xx_rtc_set(uint32_t val)
{
  unsigned i = lpc32xx_arm_clk() / LPC32XX_OSCILLATOR_RTC;

  lpc32xx.rtc.ctrl |= LPC32XX_RTC_CTRL_STOP;
  lpc32xx.rtc.ucount = val;
  lpc32xx.rtc.dcount = LPC32XX_RTC_COUNTER_DELTA - val;
  lpc32xx.rtc.ctrl &= ~LPC32XX_RTC_CTRL_STOP;

  /* It needs some time before we can read the values back */
  while (i != 0) {
    __asm__ volatile ("nop");
    --i;
  }
}

static void lpc32xx_rtc_reset(void)
{
  lpc32xx.rtc.ctrl = LPC32XX_RTC_CTRL_RESET;
  lpc32xx.rtc.ctrl = 0;
  lpc32xx.rtc.key = LPC32XX_RTC_KEY;
  lpc32xx_rtc_set(0);
}

static void lpc32xx_rtc_initialize(int minor)
{
  uint32_t up_first = 0;
  uint32_t up_second = 0;
  uint32_t down_first = 0;
  uint32_t down_second = 0;

  if (lpc32xx.rtc.key != LPC32XX_RTC_KEY) {
    lpc32xx_rtc_reset();
  }

  do {
    up_first = lpc32xx.rtc.ucount;
    down_first = lpc32xx.rtc.dcount;
    up_second = lpc32xx.rtc.ucount;
    down_second = lpc32xx.rtc.dcount;
  } while (up_first != up_second || down_first != down_second);

  if (up_first + down_first != LPC32XX_RTC_COUNTER_DELTA) {
    lpc32xx_rtc_reset();
  }
}

static int lpc32xx_rtc_get_time(int minor, rtems_time_of_day *tod)
{
  struct timeval now = {
    .tv_sec = lpc32xx.rtc.ucount,
    .tv_usec = 0
  };
  struct tm time;

  gmtime_r(&now.tv_sec, &time);

  tod->year   = time.tm_year + 1900;
  tod->month  = time.tm_mon + 1;
  tod->day    = time.tm_mday;
  tod->hour   = time.tm_hour;
  tod->minute = time.tm_min;
  tod->second = time.tm_sec;
  tod->ticks  = 0;

  return RTEMS_SUCCESSFUL;
}

static int lpc32xx_rtc_set_time(int minor, const rtems_time_of_day *tod)
{
  lpc32xx_rtc_set(_TOD_To_seconds(tod));

  return 0;
}

static bool lpc32xx_rtc_probe(int minor)
{
  return true;
}

const rtc_fns lpc32xx_rtc_ops = {
  .deviceInitialize = lpc32xx_rtc_initialize,
  .deviceGetTime = lpc32xx_rtc_get_time,
  .deviceSetTime = lpc32xx_rtc_set_time
};

size_t RTC_Count = LPC32XX_RTC_COUNT;

rtc_tbl	RTC_Table [LPC32XX_RTC_COUNT] = {
  {
    .sDeviceName = "/dev/rtc",
    .deviceType = RTC_CUSTOM,
    .pDeviceFns = &lpc32xx_rtc_ops,
    .deviceProbe = lpc32xx_rtc_probe,
    .pDeviceParams = NULL,
    .ulCtrlPort1 = 0,
    .ulDataPort = 0,
    .getRegister = NULL,
    .setRegister = NULL
  }
};