source: rtems/c/src/lib/libbsp/m68k/ods68302/clock/ckinit.c @ 34ef6c7

4.104.114.95
Last change on this file since 34ef6c7 was 34ef6c7, checked in by Joel Sherrill <joel.sherrill@…>, on Sep 5, 2008 at 10:06:51 PM

2008-09-05 Joel Sherrill <joel.sherrill@…>

  • clock/ckinit.c: The Shared Memory Driver no longer requires the special IOCTL in Clock_control. This was a hack which has existed since before the Classic API Timer Manager was implemented. All implementations of and references to Clock_control were removed.
  • Property mode set to 100644
File size: 2.9 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 <rtems/m68k/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 uint32_t         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 */
50uint32_t         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 = rtems_configuration_get_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
87  Clock_driver_ticks = 0;
88  Clock_isrs = rtems_configuration_get_microseconds_per_tick() / 1000;
89
90  set_vector( clock_isr, CLOCK_VECTOR, 1 );
91
92  m302.reg.trr1 = TRR1_VAL;             /* set timer reference register */
93  m302.reg.tmr1 = TMR1_VAL;             /* set timer mode register & enable */
94  /*
95   * Enable TIMER1 interrupts only.
96   */
97  m302.reg.imr |= RBIT_IMR_TIMER1;      /* set 68302 int-mask to allow ints */
98
99  atexit( Clock_exit );
100}
101
102void Clock_exit( void )
103{
104  /* TODO: figure out what to do here */
105  /* do not restore old vector */
106}
107
108rtems_device_driver Clock_initialize(
109  rtems_device_major_number major,
110  rtems_device_minor_number minor,
111  void *pargp
112)
113{
114  Install_clock( Clock_isr );
115
116  /*
117   * make major/minor avail to others such as shared memory driver
118   */
119
120  rtems_clock_major = major;
121  rtems_clock_minor = minor;
122
123  return RTEMS_SUCCESSFUL;
124}
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