1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
|
/* Clock_initialize
*
* This routine initializes the Motorola MFP 68901 on the
* FORCE CPU386 board. The tick frequency is 1 millisecond.
*
* Input parameters: NONE
*
* Output parameters: NONE
*
* COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
* On-Line Applications Research Corporation (OAR).
* All rights assigned to U.S. Government, 1994.
*
* This material may be reproduced by or for the U.S. Government pursuant
* to the copyright license under the clause at DFARS 252.227-7013. This
* notice must appear in all copies of this file and its derivatives.
*
* $Id$
*/
#include <bsp.h>
#include <clockdrv.h>
#include <stdlib.h>
volatile rtems_unsigned32 Clock_driver_ticks;
rtems_unsigned32 Clock_isrs; /* ISRs until next tick */
rtems_isr_entry Old_ticker;
rtems_device_driver Clock_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp,
rtems_id tid,
rtems_unsigned32 *rval
)
{
Install_clock( Clock_isr );
}
void ReInstall_clock(
rtems_isr_entry clock_isr
)
{
rtems_unsigned32 isrlevel = 0;
rtems_interrupt_disable( isrlevel );
(void) set_vector( clock_isr, 0x38, 1 );
rtems_interrupt_enable( isrlevel );
}
void Install_clock(
rtems_isr_entry clock_isr
)
{
Clock_driver_ticks = 0;
Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000;
if ( BSP_Configuration.ticks_per_timeslice ) {
Old_ticker = ( rtems_isr_entry ) set_vector( clock_isr, 0x38, 1 );
outport_byte( TBCR, 0x14 ); /* reset it, delay mode, 50X */
outport_byte( TBDR, 0x50 ); /* 1 millisecond */
outport_byte( IERA, 0x41 ); /* enable interrupt for B */
}
atexit( Clock_exit );
}
void Clock_exit( void )
{
if ( BSP_Configuration.ticks_per_timeslice ) {
outport_byte( TBCR, 0x00 ); /* initial value */
outport_byte( IERA, 0x40 ); /* disable interrupt */
/* ??? Is "do not restore old vector" causing problems? */
}
}
|
