source: rtems/c/src/lib/libbsp/m68k/mvme162/clock/ckinit.c @ e4c07444

4.104.114.84.95
Last change on this file since e4c07444 was 0dd1d44, checked in by Joel Sherrill <joel.sherrill@…>, on Jan 11, 2000 at 5:34:20 PM

Removed old hack of using Configuration Table entry ticks_per_timeslice
being set to 0 to indicate that there should be no Clock Tick. This
was used by the Timing Tests to avoid clock tick overhead perturbing
execution times. Now the Timing Tests simply leave the Clock Tick
Driver out of the Device Driver Table.

  • Property mode set to 100644
File size: 3.5 KB
Line 
1/*  Clock_init()
2 *
3 *  This routine initializes the Tick Timer 2 on the MVME162 board.
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.OARcorp.com/rtems/license.html.
16 *
17 *  Modifications of respective RTEMS file: COPYRIGHT (c) 1994.
18 *  EISCAT Scientific Association. M.Savitski
19 *
20 *  This material is a part of the MVME162 Board Support Package
21 *  for the RTEMS executive. Its licensing policies are those of the
22 *  RTEMS above.
23 *
24 *  $Id$
25 */
26
27#include <stdlib.h>
28
29#include <bsp.h>
30#include <rtems/libio.h>
31
32#define MS_COUNT          1000            /* T2's countdown constant (1 ms) */
33#define CLOCK_INT_LEVEL   6               /* T2's interrupt level */
34
35rtems_unsigned32 Clock_isrs;                  /* ISRs until next tick */
36volatile rtems_unsigned32 Clock_driver_ticks; /* ticks since initialization */
37rtems_isr_entry  Old_ticker;
38
39void Clock_exit( void );
40 
41#define CLOCK_VECTOR (VBR0 * 0x10 + 0x9)
42/*
43 * These are set by clock driver during its init
44 */
45 
46rtems_device_major_number rtems_clock_major = ~0;
47rtems_device_minor_number rtems_clock_minor;
48 
49
50/*
51 *  ISR Handler
52 */
53
54rtems_isr Clock_isr(rtems_vector_number vector)
55{
56  Clock_driver_ticks += 1;
57  lcsr->timer_cnt_2 = 0;            /* clear counter */
58  lcsr->intr_clear |= 0x02000000;
59
60  if ( Clock_isrs == 1 ) {
61    rtems_clock_tick();
62    Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000;
63  }
64  else 
65    Clock_isrs -= 1;
66}
67
68void Install_clock(rtems_isr_entry clock_isr )
69{
70
71  Clock_driver_ticks = 0;
72  Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000;
73
74  Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 );
75  lcsr->vector_base |= MASK_INT;   /* unmask VMEchip2 interrupts */
76  lcsr->to_ctl = 0xE7;             /* prescaler to 1 MHz (see Appendix A1) */
77  lcsr->timer_cmp_2 = MS_COUNT;
78  lcsr->timer_cnt_2 = 0;           /* clear counter */
79  lcsr->board_ctl |= 0x700;        /* increment, reset-on-compare, and */
80                                   /*   clear-overflow-cnt */
81
82  lcsr->intr_level[0] |= CLOCK_INT_LEVEL * 0x10;      /* set int level */
83  lcsr->intr_ena |= 0x02000000;       /* enable tick timer 2 interrupt */
84
85  atexit( Clock_exit );
86}
87
88void Clock_exit( void )
89{
90/* Dummy for now. See other m68k BSP's for code examples */
91}
92
93rtems_device_driver Clock_initialize(
94  rtems_device_major_number major,
95  rtems_device_minor_number minor,
96  void *pargp
97)
98{
99  Install_clock( Clock_isr );
100 
101  /*
102   * make major/minor avail to others such as shared memory driver
103   */
104 
105  rtems_clock_major = major;
106  rtems_clock_minor = minor;
107 
108  return RTEMS_SUCCESSFUL;
109}
110 
111rtems_device_driver Clock_control(
112  rtems_device_major_number major,
113  rtems_device_minor_number minor,
114  void *pargp
115)
116{
117    rtems_unsigned32 isrlevel;
118    rtems_libio_ioctl_args_t *args = pargp;
119 
120    if (args == 0)
121        goto done;
122 
123    /*
124     * This is hokey, but until we get a defined interface
125     * to do this, it will just be this simple...
126     */
127 
128    if (args->command == rtems_build_name('I', 'S', 'R', ' '))
129    {
130        Clock_isr(CLOCK_VECTOR);
131    }
132    else if (args->command == rtems_build_name('N', 'E', 'W', ' '))
133    {
134      rtems_interrupt_disable( isrlevel );
135       (void) set_vector( args->buffer, CLOCK_VECTOR, 1 );
136      rtems_interrupt_enable( isrlevel );
137    }
138 
139done:
140    return RTEMS_SUCCESSFUL;
141}
142
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