source: rtems/c/src/lib/libcpu/powerpc/mpc5xx/clock/clock.c @ 297d99b1

4.104.114.84.95
Last change on this file since 297d99b1 was 297d99b1, checked in by Ralf Corsepius <ralf.corsepius@…>, on Apr 13, 2004 at 2:58:07 PM

2004-04-13 Ralf Corsepius <ralf_corsepius@…>

  • mpc5xx/clock/clock.c, mpc5xx/irq/irq_asm.S, mpc5xx/vectors/vectors.S: Reflect new locations of cpukit headers.
  • Property mode set to 100644
File size: 4.8 KB
Line 
1/* clock.c
2 *
3 *  This routine initializes the PIT on the MPC5xx.
4 *  The tick frequency is specified by the bsp.
5 *
6 *
7 *  MPC5xx port sponsored by Defence Research and Development Canada - Suffield
8 *  Copyright (C) 2004, Real-Time Systems Inc. (querbach@realtime.bc.ca)
9 *
10 *  Derived from c/src/lib/libcpu/powerpc/mpc8xx/clock/clock.c:
11 *
12 *  Author: Jay Monkman (jmonkman@frasca.com)
13 *  Copyright (C) 1998 by Frasca International, Inc.
14 *
15 *  Derived from c/src/lib/libcpu/ppc/ppc403/clock/clock.c:
16 *
17 *  Author: Andrew Bray <andy@i-cubed.co.uk>
18 *
19 *  COPYRIGHT (c) 1995 by i-cubed ltd.
20 *
21 *  To anyone who acknowledges that this file is provided "AS IS"
22 *  without any express or implied warranty:
23 *      permission to use, copy, modify, and distribute this file
24 *      for any purpose is hereby granted without fee, provided that
25 *      the above copyright notice and this notice appears in all
26 *      copies, and that the name of i-cubed limited not be used in
27 *      advertising or publicity pertaining to distribution of the
28 *      software without specific, written prior permission.
29 *      i-cubed limited makes no representations about the suitability
30 *      of this software for any purpose.
31 *
32 *  Derived from c/src/lib/libcpu/hppa1_1/clock/clock.c:
33 *
34 *  COPYRIGHT (c) 1989-1998.
35 *  On-Line Applications Research Corporation (OAR).
36 *
37 *  The license and distribution terms for this file may be
38 *  found in the file LICENSE in this distribution or at
39 *  http://www.rtems.com/license/LICENSE.
40 *
41 *  $Id$
42 */
43
44#include <rtems.h>
45#include <rtems/clockdrv.h>
46#include <rtems/libio.h>
47#include <libcpu/irq.h>
48
49#include <stdlib.h>                     /* for atexit() */
50#include <mpc5xx.h>
51
52volatile rtems_unsigned32 Clock_driver_ticks;
53extern int BSP_connect_clock_handler(rtems_isr_entry);
54extern int BSP_disconnect_clock_handler();
55
56void Clock_exit( void );
57
58/*
59 * These are set by clock driver during its init
60 */
61 
62rtems_device_major_number rtems_clock_major = ~0;
63rtems_device_minor_number rtems_clock_minor;
64 
65/*
66 *  ISR Handler
67 */
68rtems_isr Clock_isr(rtems_vector_number vector)
69{
70  usiu.piscrk = USIU_UNLOCK_KEY;
71  usiu.piscr |= USIU_PISCR_PS;                  /* acknowledge interrupt */
72  usiu.piscrk = 0;
73 
74  Clock_driver_ticks++;
75  rtems_clock_tick();
76}
77
78void clockOn(void* unused)
79{
80  unsigned desiredLevel;
81  rtems_unsigned32 pit_value;
82
83  /* calculate and set modulus */ 
84  pit_value = (rtems_configuration_get_microseconds_per_tick() *
85               rtems_cpu_configuration_get_clicks_per_usec()) - 1 ;
86 
87  if (pit_value > 0xffff) {           /* pit is only 16 bits long */
88    rtems_fatal_error_occurred(-1);
89  }
90  usiu.sccrk = USIU_UNLOCK_KEY;
91  usiu.sccr &= ~USIU_SCCR_RTDIV;        /* RTC and PIT clock is divided by 4 */
92  usiu.sccrk = 0;
93
94  usiu.pitck = USIU_UNLOCK_KEY;
95  usiu.pitc = pit_value;
96  usiu.pitck = 0;
97
98  /* set PIT irq level, enable PIT, PIT interrupts */
99  /*  and clear int. status */
100  desiredLevel = CPU_irq_level_from_symbolic_name(CPU_PERIODIC_TIMER);
101
102  usiu.piscrk = USIU_UNLOCK_KEY;
103  usiu.piscr = USIU_PISCR_PIRQ(desiredLevel)    /* set interrupt priority */
104             | USIU_PISCR_PS                    /* acknowledge interrupt */
105             | USIU_PISCR_PIE                   /* enable interrupt */
106             | USIU_PISCR_PITF                  /* freeze during debug */
107             | USIU_PISCR_PTE;                  /* enable timer */
108  usiu.piscrk = 0;
109}
110
111void
112clockOff(void* unused)
113{
114  /* disable PIT and PIT interrupts */
115  usiu.piscrk = USIU_UNLOCK_KEY;
116  usiu.piscr &= ~(USIU_PISCR_PTE | USIU_PISCR_PIE); 
117  usiu.piscrk = 0;
118}
119
120int clockIsOn(void* unused)
121{
122  if (usiu.piscr & USIU_PISCR_PIE) 
123    return 1;
124  return 0;
125}
126
127/*
128 * Called via atexit()
129 * Remove the clock interrupt handler by setting handler to NULL
130 */
131void
132Clock_exit(void)
133{
134  (void) BSP_disconnect_clock_handler ();
135}
136
137void Install_clock(rtems_isr_entry clock_isr)
138{
139  Clock_driver_ticks = 0;
140
141  BSP_connect_clock_handler (clock_isr);
142  atexit(Clock_exit);
143}
144
145void
146ReInstall_clock(rtems_isr_entry new_clock_isr)
147{
148  BSP_connect_clock_handler (new_clock_isr);
149}
150
151
152rtems_device_driver Clock_initialize(
153  rtems_device_major_number major,
154  rtems_device_minor_number minor,
155  void *pargp
156)
157{
158  Install_clock( Clock_isr );
159 
160  /*
161   * make major/minor avail to others such as shared memory driver
162   */
163 
164  rtems_clock_major = major;
165  rtems_clock_minor = minor;
166 
167  return RTEMS_SUCCESSFUL;
168}
169 
170rtems_device_driver Clock_control(
171  rtems_device_major_number major,
172  rtems_device_minor_number minor,
173  void *pargp
174)
175{
176  rtems_libio_ioctl_args_t *args = pargp;
177 
178  if (args == 0)
179    goto done;
180 
181  /*
182   * This is hokey, but until we get a defined interface
183   * to do this, it will just be this simple...
184   */
185 
186  if (args->command == rtems_build_name('I', 'S', 'R', ' ')) {
187    Clock_isr(0);               /* vector number ignored */
188  }
189  else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) {
190    ReInstall_clock(args->buffer);
191  }
192 
193 done:
194  return RTEMS_SUCCESSFUL;
195}
196
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