summaryrefslogtreecommitdiffstats
path: root/c/src/lib/libbsp/unix/posix/clock/clock.c
blob: 7b2242425168bc286f4ada5dfb1d8466f297b3d5 (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
159
160
161
162
/*  Clock
 *
 *  This routine generates clock ticks using standard POSIX services.
 *  The tick frequency is specified by the bsp.
 *
 *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
 *  On-Line Applications Research Corporation (OAR).
 *  All rights assigned to U.S. Government, 1994.
 *
 *  This material may be reproduced by or for the U.S. Government pursuant
 *  to the copyright license under the clause at DFARS 252.227-7013.  This
 *  notice must appear in all copies of this file and its derivatives.
 *
 *  $Id$
 */

#include <rtems.h>
#include <rtems/libio.h>
#include <bsp.h>

/*
 *  In order to get the types and prototypes used in this file under
 *  Solaris 2.3, it is necessary to pull the following magic.
 */
 
#if defined(solaris)
#warning "Ignore the undefining __STDC__ warning"
#undef __STDC__
#define __STDC__ 0
#undef  _POSIX_C_SOURCE
#endif
 
#include <stdlib.h>
#include <stdio.h>
#include <signal.h>
#include <time.h>

extern rtems_configuration_table Configuration;

void Clock_exit(void);

volatile rtems_unsigned32 Clock_driver_ticks;

/*
 * These are set by clock driver during its init
 */

rtems_device_major_number rtems_clock_major = ~0;
rtems_device_minor_number rtems_clock_minor;

void
Install_clock(rtems_isr_entry clock_isr)
{
    struct itimerval  new;

    Clock_driver_ticks = 0;

    new.it_value.tv_sec = 0;
    new.it_value.tv_usec = Configuration.microseconds_per_tick;
    new.it_interval.tv_sec = 0;
    new.it_interval.tv_usec = Configuration.microseconds_per_tick;

    (void)set_vector(clock_isr, SIGALRM, 1);

    setitimer(ITIMER_REAL, &new, 0);

    atexit(Clock_exit);
}

void
ReInstall_clock(rtems_isr_entry new_clock_isr)
{
    rtems_unsigned32  isrlevel = 0;

    rtems_interrupt_disable(isrlevel);
    (void)set_vector(new_clock_isr, SIGALRM, 1);
    rtems_interrupt_enable(isrlevel);
}

void
Clock_isr(int vector)
{
    Clock_driver_ticks++;
    rtems_clock_tick();
}

/*
 * Called via atexit()
 * Remove the clock signal
 */

void
Clock_exit(void)
{
    struct itimerval  new;
     struct sigaction  act;

     /*
      * Set the SIGALRM signal to ignore any last
      * signals that might come in while we are
      * disarming the timer and removing the interrupt
      * vector.
      */

     act.sa_handler = SIG_IGN;

     sigaction(SIGALRM, &act, 0);

    new.it_value.tv_sec = 0;
    new.it_value.tv_usec = 0;

    setitimer(ITIMER_REAL, &new, 0);

    (void)set_vector(0, SIGALRM, 1);
}

rtems_device_driver
Clock_initialize(
  rtems_device_major_number major,
  rtems_device_minor_number minor,
  void *pargp
)
{
    Install_clock((rtems_isr_entry) Clock_isr);

    /*
     * make major/minor avail to others such as shared memory driver
     */
    rtems_clock_major = major;
    rtems_clock_minor = minor;

    return RTEMS_SUCCESSFUL;
}

rtems_device_driver Clock_control(
  rtems_device_major_number major,
  rtems_device_minor_number minor,
  void *pargp
)
{
    rtems_libio_ioctl_args_t *args = pargp;

    if (args == 0)
        goto done;

    /*
     * This is hokey, but until we get a defined interface
     * to do this, it will just be this simple...
     */

    if (args->command == rtems_build_name('I', 'S', 'R', ' '))
    {
        Clock_isr(SIGALRM);
    }
    else if (args->command == rtems_build_name('N', 'E', 'W', ' '))
    {
        ReInstall_clock(args->buffer);
    }
    
done:
    return RTEMS_SUCCESSFUL;
}