summaryrefslogtreecommitdiffstats
path: root/c/src/lib/libcpu/mips/clock/ckinit.c
blob: 60b3187223e65969124e81d86f4463d1a2f85807 (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
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249

/*  ckinit.c
 *
 *  This file contains the clock driver initialization for the IDT 4650.
 *
 *  Author:     Craig Lebakken <craigl@transition.com>
 *
 *  COPYRIGHT (c) 1996 by Transition Networks Inc.
 *
 *  To anyone who acknowledges that this file is provided "AS IS"
 *  without any express or implied warranty:
 *      permission to use, copy, modify, and distribute this file
 *      for any purpose is hereby granted without fee, provided that
 *      the above copyright notice and this notice appears in all
 *      copies, and that the name of Transition Networks not be used in
 *      advertising or publicity pertaining to distribution of the
 *      software without specific, written prior permission.
 *      Transition Networks makes no representations about the suitability
 *      of this software for any purpose.
 *
 *  Derived from c/src/lib/libbsp/no_cpu/no_bsp/clock/ckinit.c:
 *
 *  COPYRIGHT (c) 1989-1998.
 *  On-Line Applications Research Corporation (OAR).
 *  Copyright assigned to U.S. Government, 1994.
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.OARcorp.com/rtems/license.html.
 *
 *  $Id$
 */

/*
 *  Rather than deleting this, it is commented out to (hopefully) help
 *  the submitter send updates.
 *
 *  static char _sccsid[] = "@(#)ckinit.c 08/20/96     1.3\n";
 */


#include <stdlib.h>

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

#define EXT_INT5    0x8000  /* external interrupt 5 */

#include "clock.h"

#define CLOCKS_PER_MICROSECOND ( CPU_CLOCK_RATE_MHZ ) /* equivalent to CPU clock speed in MHz */

void Clock_exit( void );
rtems_isr Clock_isr( rtems_vector_number vector );


/*
 *  The interrupt vector number associated with the clock tick device
 *  driver.
 */

#define CLOCK_VECTOR_MASK    EXT_INT5
#define CLOCK_VECTOR         0x7

/*
 *  Clock_driver_ticks is a monotonically increasing counter of the
 *  number of clock ticks since the driver was initialized.
 */

volatile rtems_unsigned32 Clock_driver_ticks;

/*
 *  Clock_isrs is the number of clock ISRs until the next invocation of
 *  the RTEMS clock tick routine.  The clock tick device driver
 *  gets an interrupt once a millisecond and counts down until the
 *  length of time between the user configured microseconds per tick
 *  has passed.
 */

rtems_unsigned32 Clock_isrs;              /* ISRs until next tick */

/*
 * These are set by clock driver during its init
 */
 
rtems_device_major_number rtems_clock_major = ~0;
rtems_device_minor_number rtems_clock_minor;

/*
 *  The previous ISR on this clock tick interrupt vector.
 */

rtems_isr_entry  Old_ticker;

void Clock_exit( void );

static unsigned32 mips_timer_rate = 0;

/*
 *  Isr Handler
 */

rtems_isr Clock_isr(
  rtems_vector_number vector
)
{
/*
 * bump the number of clock driver ticks since initialization
 *
 * determine if it is time to announce the passing of tick as configured
 * to RTEMS through the rtems_clock_tick directive
 *
 * perform any timer dependent tasks
 */

  /* refresh the internal CPU timer */
  mips_set_timer( mips_timer_rate );

  Clock_driver_ticks += 1;

  rtems_clock_tick();
}

/* User callback shell (set from Clock_Control) */
static void (*user_callback)(void);

rtems_isr User_Clock_isr(
  rtems_vector_number vector
)
{
   /* refresh the internal CPU timer */
   mips_set_timer( mips_timer_rate );

   if (user_callback)
      user_callback();
}

/*
 *  Install_clock
 *
 *  Install a clock tick handleR and reprograms the chip.  This
 *  is used to initially establish the clock tick.
 */

void Install_clock(
  rtems_isr_entry clock_isr
)
{
  /*
   *  Initialize the clock tick device driver variables
   */

  Clock_driver_ticks = 0;
  Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000;

  /*
   *  If ticks_per_timeslice is configured as non-zero, then the user
   *  wants a clock tick.
   */

  if ( BSP_Configuration.ticks_per_timeslice ) {
    Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 );
    /*
     *  Hardware specific initialize goes here
     */

    mips_timer_rate = BSP_Configuration.microseconds_per_tick * CLOCKS_PER_MICROSECOND;
    mips_set_timer( mips_timer_rate );
    enable_int(CLOCK_VECTOR_MASK);
  }

  /*
   *  Schedule the clock cleanup routine to execute if the application exits.
   */

  atexit( Clock_exit );
}

/*
 *  Clean up before the application exits
 */

void Clock_exit( void )
{
  if ( BSP_Configuration.ticks_per_timeslice ) {

    /* mips: turn off the timer interrupts */
    disable_int(CLOCK_VECTOR_MASK);

  }
}

/*
 *  Clock_initialize
 *
 *  Device driver entry point for clock tick driver initialization.
 */

rtems_device_driver Clock_initialize(
  rtems_device_major_number major,
  rtems_device_minor_number minor,
  void *pargp
)
{
  Install_clock( 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_unsigned32 isrlevel;
    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(CLOCK_VECTOR);
    }
    else if (args->command == rtems_build_name('N', 'E', 'W', ' '))
    {
      rtems_interrupt_disable( isrlevel );
      user_callback = (void (*)(void))args->buffer;
      (void) set_vector( User_Clock_isr, CLOCK_VECTOR, 1 );
      rtems_interrupt_enable( isrlevel );
    }
 
done:
    return RTEMS_SUCCESSFUL;
}