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/* clock.c
*
* This routine initializes the PIT on the MPC8xx.
* The tick frequency is specified by the bsp.
*
* Author: Jay Monkman (jmonkman@frasca.com)
* Copyright (C) 1998 by Frasca International, Inc.
*
* Derived from c/src/lib/libcpu/ppc/ppc403/clock/clock.c:
*
* Author: Andrew Bray <andy@i-cubed.co.uk>
*
* COPYRIGHT (c) 1995 by i-cubed ltd.
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of i-cubed limited not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* i-cubed limited makes no representations about the suitability
* of this software for any purpose.
*
* Derived from c/src/lib/libcpu/hppa1_1/clock/clock.c:
*
* COPYRIGHT (c) 1989-1998.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*
* $Id$
*/
#include <rtems.h>
#include <rtems/clockdrv.h>
#include <rtems/libio.h>
#include <stdlib.h> /* for atexit() */
#include <mpc8260.h>
#include <bsp/irq.h>
volatile uint32_t Clock_driver_ticks;
extern int BSP_get_clock_irq_level();
extern int BSP_connect_clock_handler(rtems_isr_entry);
extern int BSP_disconnect_clock_handler();
void Clock_exit( void );
uint32_t decrementer_value;
volatile int ClockInitialised = 0;
/*
* These are set by clock driver during its init
*/
rtems_device_major_number rtems_clock_major = ~0;
rtems_device_minor_number rtems_clock_minor;
/*
* ISR Handler
*/
rtems_isr Clock_isr(rtems_vector_number vector)
{
int clicks;
if( ClockInitialised ) {
PPC_Get_decrementer( clicks );
do {
clicks += decrementer_value;
PPC_Set_decrementer( clicks );
Clock_driver_ticks++;
rtems_clock_tick();
} while( clicks < 100 );
}
#if 0
m8260.piscr |= M8260_PISCR_PS;
Clock_driver_ticks++;
rtems_clock_tick();
#endif
}
void clockOn(void* unused)
{
decrementer_value = rtems_configuration_get_microseconds_per_tick() *
rtems_cpu_configuration_get_clicks_per_usec() - 1;
PPC_Set_decrementer( decrementer_value );
Clock_driver_ticks = 0;
ClockInitialised = 1;
#if 0
unsigned desiredLevel;
uint32_t pit_value;
pit_value = (rtems_configuration_get_microseconds_per_tick() *
rtems_cpu_configuration_get_clicks_per_usec()) - 1 ;
if (pit_value > 0xffff) { /* pit is only 16 bits long */
rtems_fatal_error_occurred(-1);
}
m8260.sccr &= ~(1<<24);
m8260.pitc = pit_value;
desiredLevel = BSP_get_clock_irq_level();
/* set PIT irq level, enable PIT, PIT interrupts */
/* and clear int. status */
m8260.piscr = /*M8260_PISCR_PIRQ(desiredLevel) |*/
M8260_PISCR_PTE | M8260_PISCR_PS | M8260_PISCR_PIE;
#endif
}
/*
* Called via atexit()
* Remove the clock interrupt handler by setting handler to NULL
*/
void
clockOff(void* unused)
{
#if 0
/* disable PIT and PIT interrupts */
m8260.piscr &= ~(M8260_PISCR_PTE | M8260_PISCR_PIE);
#endif
ClockInitialised = 0;
}
int clockIsOn(void* unused)
{
return ClockInitialised;
#if 0
if (m8260.piscr & M8260_PISCR_PIE) return 1;
return 0;
#endif
}
/*
* Called via atexit()
* Remove the clock interrupt handler by setting handler to NULL
*/
void
Clock_exit(void)
{
(void) BSP_disconnect_clock_handler ();
}
void Install_clock(rtems_isr_entry clock_isr)
{
Clock_driver_ticks = 0;
decrementer_value = rtems_configuration_get_microseconds_per_tick() *
rtems_cpu_configuration_get_clicks_per_usec() - 1;
PPC_Set_decrementer( decrementer_value );
BSP_connect_clock_handler (clock_isr);
ClockInitialised = 1;
atexit(Clock_exit);
}
void
ReInstall_clock(rtems_isr_entry new_clock_isr)
{
BSP_connect_clock_handler (new_clock_isr);
}
rtems_device_driver Clock_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp
)
{
Install_clock( Clock_isr );
/*
* make major/minor avail to others such as shared memory driver
*/
rtems_clock_major = major;
rtems_clock_minor = minor;
return RTEMS_SUCCESSFUL;
}
rtems_device_driver Clock_control(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp
)
{
rtems_libio_ioctl_args_t *args = pargp;
if (args == 0)
goto done;
/*
* This is hokey, but until we get a defined interface
* to do this, it will just be this simple...
*/
if (args->command == rtems_build_name('I', 'S', 'R', ' ')) {
Clock_isr(BSP_PERIODIC_TIMER);
}
else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) {
ReInstall_clock(args->buffer);
}
done:
return RTEMS_SUCCESSFUL;
}
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