source: rtems/c/src/lib/libbsp/i386/i386ex/clock/ckinit.c @ 6ff7e2c

4.104.114.84.95
Last change on this file since 6ff7e2c was 6ff7e2c, checked in by Joel Sherrill <joel.sherrill@…>, on Sep 4, 2003 at 6:51:20 PM

2003-09-04 Joel Sherrill <joel@…>

  • clock/ckinit.c, console/console.c, include/bsp.h, include/coverhd.h, start/80386ex.h, start/80386ex.inc, start/macros.inc, start/start.S, startup/bspstart.c, startup/linkcmds, startup/setvec.c, timer/timer.c, timer/timerisr.S: URL for license changed.
  • Property mode set to 100644
File size: 3.9 KB
Line 
1/*  Clock_initialize
2 *
3 *  This routine initializes the Timer/Counter on the Intel
4 *  386ex evaluation board.
5 *
6 *  The tick frequency is 1 millisecond.
7 *
8 *  Input parameters:  NONE
9 *
10 *  Output parameters:  NONE
11 *
12 *  COPYRIGHT (c) 1989-1999.
13 *  On-Line Applications Research Corporation (OAR).
14 *
15 *  The license and distribution terms for this file may be
16 *  found in the file LICENSE in this distribution or at
17 *  http://www.rtems.com/license/LICENSE.
18 *
19 *  $Id$
20 */
21#define TMR0      0xF040
22#define TMR1      0xF041
23#define TMR2      0xF042
24#define TMRCON    0xF043
25#define TMRCFG    0xF834
26
27#include <bsp.h>
28#include <irq.h>
29
30#include <rtems/libio.h>
31
32#include <stdlib.h>
33
34rtems_unsigned32 Clock_isrs;              /* ISRs until next tick */
35static rtems_unsigned32 Clock_initial_isr_value;
36
37volatile rtems_unsigned32 Clock_driver_ticks;
38
39void Clock_exit( void );
40
41/*
42 * These are set by clock driver during its init
43 */
44 
45rtems_device_major_number rtems_clock_major = ~0;
46rtems_device_major_number rtems_clock_minor = 0;
47
48/*
49 *  This is the ISR handler.
50 */
51
52void Clock_isr()
53{
54  /* enable_tracing(); */
55  Clock_driver_ticks += 1;
56  if ( Clock_isrs == 1 ) {
57    rtems_clock_tick();
58    Clock_isrs = Clock_initial_isr_value; /* BSP_Configuration.microseconds_per_tick / 1000;*/
59  }
60  else
61    Clock_isrs -= 1;
62}
63
64void ClockOff(const rtems_irq_connect_data* unused)
65{
66  outport_byte  ( TMRCFG , 0x80 ); /* disable the counter timer */
67}
68
69void ClockOn(const rtems_irq_connect_data* unused)
70{
71  outport_byte    ( TMRCFG , 0x00 ); /* enable the counter timer */
72}
73
74int ClockIsOn(const rtems_irq_connect_data* unused)
75{
76  return ((i8259s_cache & 0x1) == 0);
77}
78
79static rtems_irq_connect_data clockIrqData = {BSP_PERIODIC_TIMER,
80                                              Clock_isr,
81                                              ClockOn,
82                                              ClockOff,
83                                              ClockIsOn};
84
85
86rtems_device_driver Clock_initialize(
87  rtems_device_major_number major,
88  rtems_device_minor_number minor,
89  void *pargp
90)
91{
92  unsigned timer_counter_init_value;
93  unsigned char clock_lsb, clock_msb;
94 
95  Clock_driver_ticks = 0;
96
97  Clock_isrs = 
98    Clock_initial_isr_value = 
99    BSP_Configuration.microseconds_per_tick / 1000; /* ticks per clock_isr */
100 
101  /*
102   * configure the counter timer ( should be based on microsecs/tick )
103   * NB. The divisor(Clock_isrs) resolves the  is the same number that appears in confdefs.h
104   * when setting the microseconds_per_tick value.
105   */
106  ClockOff      ( &clockIrqData );
107 
108  timer_counter_init_value  =  BSP_Configuration.microseconds_per_tick / Clock_isrs;
109  clock_lsb = (unsigned char)timer_counter_init_value;
110  clock_msb = timer_counter_init_value >> 8;
111 
112  outport_byte  ( TMRCON , 0x34 ); 
113  outport_byte  ( TMR0   , clock_lsb );       /* load LSB first */
114  outport_byte  ( TMR0   , clock_msb );  /* then MSB       */
115 
116  if (!BSP_install_rtems_irq_handler (&clockIrqData)) {
117    printk("Unable to initialize system clock\n");
118    rtems_fatal_error_occurred(1);
119  }
120
121  /*
122   * make major/minor avail to others such as shared memory driver
123   */
124 
125  rtems_clock_major = major;
126  rtems_clock_minor = minor;
127 
128  return RTEMS_SUCCESSFUL;
129}
130
131rtems_device_driver Clock_control(
132  rtems_device_major_number major,
133  rtems_device_minor_number minor,
134  void *pargp
135)
136{
137    rtems_libio_ioctl_args_t *args = pargp;
138 
139    if (args == 0)
140        goto done;
141 
142    /*
143     * This is hokey, but until we get a defined interface
144     * to do this, it will just be this simple...
145     */
146 
147    if (args->command == rtems_build_name('I', 'S', 'R', ' '))
148    {
149        Clock_isr();
150    }
151    else if (args->command == rtems_build_name('N', 'E', 'W', ' '))
152    {
153      if (!BSP_install_rtems_irq_handler (&clockIrqData)) {
154        printk("Error installing clock interrupt handler!\n");
155        rtems_fatal_error_occurred(1);
156      }
157#ifdef DEBUG
158      else
159        printk("Clock installed AGAIN\n");
160#endif
161    }
162 
163done:
164    return RTEMS_SUCCESSFUL;
165}
166
167void Clock_exit()
168{
169  ClockOff(&clockIrqData); 
170  BSP_remove_rtems_irq_handler (&clockIrqData);
171}
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