source: rtems/c/src/lib/libbsp/m68k/gen68302/clock/ckinit.c @ d6284ab

4.104.114.84.9
Last change on this file since d6284ab was d6284ab, checked in by Joel Sherrill <joel.sherrill@…>, on Sep 4, 2003 at 6:51:48 PM

2003-09-04 Joel Sherrill <joel@…>

  • clock/ckinit.c, console/console.c, include/bsp.h, include/coverhd.h, start/start.S, startup/bspclean.c, startup/bspstart.c, startup/linkcmds, timer/timer.c: URL for license changed.
  • Property mode set to 100644
File size: 3.6 KB
Line 
1/*  Clock_init()
2 *
3 *  This routine initializes Timer 1 for an MC68302.
4 *  The tick frequency is 1 millisecond.
5 *
6 *  Input parameters:  NONE
7 *
8 *  Output parameters:  NONE
9 *
10 *  COPYRIGHT (c) 1989-1999.
11 *  On-Line Applications Research Corporation (OAR).
12 *
13 *  The license and distribution terms for this file may be
14 *  found in the file LICENSE in this distribution or at
15 *  http://www.rtems.com/license/LICENSE.
16 *
17 *  $Id$
18 */
19
20#include <stdlib.h>                     /* for atexit() */
21
22#include <bsp.h>
23#include <rtems/libio.h>
24
25#include "m68302.h"
26
27#define CLOCK_VECTOR 137
28
29#define TMR1_VAL (  RBIT_TMR_RST        /* software reset the timer */\
30                  | RBIT_TMR_ICLK_MASTER16 /* master clock divided by 16 */\
31                  | RBIT_TMR_FRR        /* restart timer after ref reached */\
32                  | RBIT_TMR_ORI)       /* enable interrupt when ref reached */
33#define TRR1_VAL 1000                   /* 1000 ticks @ 16MHz/16
34                                         *    = 1 millisecond tick.
35                                         */
36
37/*
38 *  Clock_driver_ticks is a monotonically increasing counter of the
39 *  number of clock ticks since the driver was initialized.
40 */
41volatile rtems_unsigned32 Clock_driver_ticks;
42
43/*
44 *  Clock_isrs is the number of clock ISRs until the next invocation of
45 *  the RTEMS clock tick routine.  The clock tick device driver
46 *  gets an interrupt once a millisecond and counts down until the
47 *  length of time between the user configured microseconds per tick
48 *  has passed.
49 */
50rtems_unsigned32 Clock_isrs;
51
52void Clock_exit( void );
53 
54/*
55 * These are set by clock driver during its init
56 */
57 
58rtems_device_major_number rtems_clock_major = ~0;
59rtems_device_minor_number rtems_clock_minor;
60
61/*
62 *  ISR Handler
63 */
64
65rtems_isr Clock_isr(
66  rtems_vector_number vector
67)
68{
69  Clock_driver_ticks += 1;
70
71  m302.reg.isr  = RBIT_ISR_TIMER1;      /* clear in-service bit */
72  m302.reg.ter1 = (RBIT_TER_REF | RBIT_TER_CAP); /* clear timer intr request */
73
74  if ( Clock_isrs == 1 ) {
75    rtems_clock_tick();
76    Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000;
77  }
78  else
79    Clock_isrs -= 1;
80}
81
82void Install_clock(
83  rtems_isr_entry clock_isr
84)
85{
86  Clock_driver_ticks = 0;
87  Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000;
88
89  set_vector( clock_isr, CLOCK_VECTOR, 1 );
90
91  m302.reg.trr1 = TRR1_VAL;             /* set timer reference register */
92  m302.reg.tmr1 = TMR1_VAL;             /* set timer mode register & enable */
93  /*
94   * Enable TIMER1 interrupts only.
95   */
96  m302.reg.imr |= RBIT_IMR_TIMER1;      /* set 68302 int-mask to allow ints */
97
98  atexit( Clock_exit );
99}
100
101void Clock_exit( void )
102{
103  /* TODO: figure out what to do here */
104  /* do not restore old vector */
105}
106
107rtems_device_driver Clock_initialize(
108  rtems_device_major_number major,
109  rtems_device_minor_number minor,
110  void *pargp
111)
112{
113  Install_clock( Clock_isr );
114 
115  /*
116   * make major/minor avail to others such as shared memory driver
117   */
118 
119  rtems_clock_major = major;
120  rtems_clock_minor = minor;
121 
122  return RTEMS_SUCCESSFUL;
123}
124 
125rtems_device_driver Clock_control(
126  rtems_device_major_number major,
127  rtems_device_minor_number minor,
128  void *pargp
129)
130{
131    rtems_unsigned32 isrlevel;
132    rtems_libio_ioctl_args_t *args = pargp;
133 
134    if (args == 0)
135        goto done;
136 
137    /*
138     * This is hokey, but until we get a defined interface
139     * to do this, it will just be this simple...
140     */
141 
142    if (args->command == rtems_build_name('I', 'S', 'R', ' '))
143    {
144        Clock_isr( CLOCK_VECTOR);
145    }
146    else if (args->command == rtems_build_name('N', 'E', 'W', ' '))
147    {
148      rtems_interrupt_disable( isrlevel );
149       (void) set_vector( args->buffer, CLOCK_VECTOR, 1 );
150      rtems_interrupt_enable( isrlevel );
151    }
152 
153done:
154    return RTEMS_SUCCESSFUL;
155}
156
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