source: rtems/c/src/lib/libbsp/m68k/idp/clock/ckinit.c @ ac7d5ef0

4.104.114.84.95
Last change on this file since ac7d5ef0 was ac7d5ef0, checked in by Joel Sherrill <joel.sherrill@…>, on May 11, 1995 at 5:39:37 PM

Initial revision

  • Property mode set to 100644
File size: 3.2 KB
Line 
1/*  Clock_init()
2 *
3 *
4 *  This is modified by Doug McBride to get it to work for the MC68EC040
5 *  IDP board.  The below comments are kept to show that some prior work
6 *  was done in the area and the modifications performed was application
7 *  specific for the IDP board to port it to.
8 *
9 *  This routine initializes the mc68230 on the MC68EC040 board.
10 *  The tick frequency is 40 milliseconds.
11 *
12 *  Input parameters:  NONE
13 *
14 *  Output parameters:  NONE
15 *
16 *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
17 *  On-Line Applications Research Corporation (OAR).
18 *  All rights assigned to U.S. Government, 1994.
19 *
20 *  This material may be reproduced by or for the U.S. Government pursuant
21 *  to the copyright license under the clause at DFARS 252.227-7013.  This
22 *  notice must appear in all copies of this file and its derivatives.
23 *
24 *  $Id$
25 */
26
27#include <stdlib.h>
28
29#include "rtems.h"
30#include "clockdrv.h"
31#include "bsp.h"
32#include "cpu.h"
33
34rtems_unsigned32 Clock_isrs;        /* ISRs until next tick */
35volatile rtems_unsigned32 Clock_driver_ticks;
36                                    /* ticks since initialization */
37rtems_isr_entry  Old_ticker;
38
39extern rtems_configuration_table Configuration;
40extern void led_putnum();
41void Disable_clock();
42
43#define TIMER_VECTOR 0x4D
44
45rtems_device_driver Clock_initialize( 
46  rtems_device_major_number major,
47  rtems_device_minor_number minor,
48  void *pargp,
49  rtems_id tid,
50  rtems_unsigned32 *rval
51)
52{
53  Install_clock( Clock_isr );
54}
55
56void ReInstall_clock( clock_isr )
57rtems_isr_entry clock_isr;
58{
59  rtems_unsigned32 isrlevel = 0 ;
60
61  rtems_interrupt_disable( isrlevel );
62   (void) set_vector( clock_isr, TIMER_VECTOR, 1 );
63  rtems_interrupt_enable( isrlevel );
64}
65
66/* The following was added for debugging purposes */
67void Disable_clock()
68{
69        /* Disable timer */
70        MC68230_WRITE (TCR, 0x00);
71}
72
73void Install_clock( clock_isr )
74rtems_isr_entry clock_isr;
75{
76  Clock_driver_ticks = 0;
77  Clock_isrs = (int)(Configuration.microseconds_per_tick / 1000);
78
79  if ( Configuration.ticks_per_timeslice ) {
80/*    led_putnum('c'); * for debugging purposes */
81    Old_ticker = (rtems_isr_entry) set_vector( clock_isr, TIMER_VECTOR, 1 );
82
83        /* Disable timer for initialization */
84        MC68230_WRITE (TCR, 0x00);
85
86        /* some PI/T initialization stuff here -- see comment in the ckisr.c
87           file in this directory to understand why I use the values that I do */
88        /* Set up the interrupt vector on the MC68230 chip:
89                TIVR = TIMER_VECTOR; */
90        MC68230_WRITE (TIVR, TIMER_VECTOR);
91
92        /* Set CPRH through CPRL to 193 (not 203) decimal for countdown--see ckisr.c
93                CPRH = 0x00;
94                CPRM = 0x00;
95                CPRL = 0xC1; */
96        MC68230_WRITE (CPRH, 0x00);
97        MC68230_WRITE (CPRM, 0x00);
98        MC68230_WRITE (CPRL, 0xC1);
99
100        /* Enable timer and use it as an external periodic interrupt generator
101                TCR = 0xA1; */
102/*    led_putnum('a'); * for debugging purposes */
103        MC68230_WRITE (TCR, 0xA1);
104
105        /*
106         *  Schedule the clock cleanup routine to execute if the application exits.
107         */
108    atexit( Clock_exit );
109  } 
110}
111
112void Clock_exit( void )
113{
114  rtems_unsigned8 data;
115
116  if ( Configuration.ticks_per_timeslice ) {
117
118        /* disable timer
119                data = TCR;
120                TCR = (data & 0xFE); */
121        MC68230_READ (TCR, data);
122        MC68230_WRITE (TCR, (data & 0xFE));
123
124    /* do not restore old vector */
125  }
126}
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