summaryrefslogtreecommitdiffstats
path: root/firmware/drivers/rtc/rtc_pcf50605.c
blob: 93fa391ae3e6f0c04e5d7b5af9336f9280c95064 (plain)
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
/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2002 by Linus Nielsen Feltzing, Uwe Freese, Laurent Baum
 *
 * All files in this archive are subject to the GNU General Public License.
 * See the file COPYING in the source tree root for full license agreement.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/
#include "config.h"
#include "i2c.h"
#include "rtc.h"
#include "kernel.h"
#include "system.h"
#include "pcf50605.h"
#include <stdbool.h>

/* Values which each disable one alarm time register */
static const char alarm_disable[] = {
    0x7f, 0x7f, 0x3f, 0x07, 0x3f, 0x1f, 0xff
};

void rtc_init(void)
{
    rtc_check_alarm_started(false);
}

int rtc_read_datetime(unsigned char* buf)
{
    return pcf50605_read_multiple(0x0a, buf, 7);
}

int rtc_write_datetime(unsigned char* buf)
{
    pcf50605_write_multiple(0x0a, buf, 7);
    return 1;
}

/**
 * Checks the PCF interrupt 1 register bit 7 to see if an alarm interrupt has
 * triggered since last we checked.
 */
bool rtc_check_alarm_flag(void) 
{
    return pcf50605_read(0x02) & 0x80;
}

/**
 * Enables or disables the alarm.
 * The Ipod bootloader clears all PCF interrupt registers and always enables
 * the "wake on RTC" bit on OOCC1, so we have to rely on other means to find
 * out if we just woke from an alarm.
 * Return value is always false for us. 
 */
bool rtc_enable_alarm(bool enable)
{
    if (enable) {
        /* Tell the PCF to ignore everything but second, minute and hour, so
         * that an alarm will trigger the next time the alarm time occurs.
         */
        pcf50605_write_multiple(0x14, alarm_disable + 3, 4);
        /* Unmask the alarm interrupt (might be unneeded) */
        pcf50605_write(0x5, pcf50605_read(0x5) & ~0x80);
        /* Make sure wake on RTC is set when shutting down */
        pcf50605_wakeup_flags |= 0x10;
    } else {
        /* We use this year to indicate a disabled alarm. If you happen to live
         * around this time and are annoyed by this, feel free to seek out my
         * grave and do something nasty to it.
         */
        pcf50605_write(0x17, 0x99);
        /* Make sure we don't wake on RTC after shutting down */
        pcf50605_wakeup_flags &= ~0x10;
    }
    return false;
}

/**
 * Check if alarm caused unit to start.
 */
bool rtc_check_alarm_started(bool release_alarm)
{
    static bool run_before = false, alarm_state;
    bool rc;

    if (run_before) { 
        rc = alarm_state;
        alarm_state &= ~release_alarm;
    } else {
        char rt[3], at[3];
        /* The Ipod bootloader seems to read (and thus clear) the PCF interrupt
         * registers, so we need to find some other way to detect if an alarm
         * just happened
         */
        pcf50605_read_multiple(0x0a, rt, 3);
        pcf50605_read_multiple(0x11, at, 3);

        /* If alarm time and real time match within 10 seconds of each other, we
         * assume an alarm just triggered
         */
        rc = alarm_state = rt[1] == at[1] && rt[2] == at[2]
                           && (rt[0] - at[0]) <= 10;
        run_before = true;
    }
    return rc;
}

void rtc_set_alarm(int h, int m)
{
    /* Set us to wake at the first second of the specified time */
    pcf50605_write(0x11, 0);
    /* Convert to BCD */
    pcf50605_write(0x12, ((m/10) << 4) | m%10);
    pcf50605_write(0x13, ((h/10) << 4) | h%10);
}

void rtc_get_alarm(int *h, int *m)
{
    char buf[2];

    pcf50605_read_multiple(0x12, buf, 2);
    /* Convert from BCD */
    *m = ((buf[0] >> 4) & 0x7)*10 + (buf[0] & 0x0f);
    *h = ((buf[1] >> 4) & 0x3)*10 + (buf[1] & 0x0f);
}