/*
* This file contains the clock driver the Hitachi SH 703X
*
* Authors: Ralf Corsepius (corsepiu@faw.uni-ulm.de) and
* Bernd Becker (becker@faw.uni-ulm.de)
*
* COPYRIGHT (c) 1997-1998, FAW Ulm, Germany
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
*
* COPYRIGHT (c) 1998.
* On-Line Applications Research Corporation (OAR).
* Copyright assigned to U.S. Government, 1994.
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.OARcorp.com/rtems/license.html.
*
* $Id$
*/
#include <bsp.h>
#include <stdlib.h>
#include <rtems/libio.h>
#include <rtems/score/sh_io.h>
#include <rtems/score/sh.h>
#include <rtems/score/cpu_isps.h>
#include <rtems/score/iosh7030.h>
#define _ITU_COUNTER0_MICROSECOND (MHZ/4)
#ifndef CLOCKPRIO
#define CLOCKPRIO 10
#endif
#define ITU0_STARTMASK 0xfe
#define ITU0_SYNCMASK 0xfe
#define ITU0_MODEMASK 0xfe
#define ITU0_TCRMASK 0x22
#define ITU_STAT_MASK 0xf8
#define ITU0_IRQMASK 0xfe
#define ITU0_TIERMASK 0x01
#define IPRC_ITU0_MASK 0xff0f
#define ITU0_TIORVAL 0x08
/*
* The interrupt vector number associated with the clock tick device
* driver.
*/
#define CLOCK_VECTOR IMIA0_ISP_V
/*
* Clock_driver_ticks is a monotonically increasing counter of the
* number of clock ticks since the driver was initialized.
*/
volatile rtems_unsigned32 Clock_driver_ticks;
static void Clock_exit( void );
static rtems_isr Clock_isr( rtems_vector_number vector );
/*
* Clock_isrs is the number of clock ISRs until the next invocation of
* the RTEMS clock tick routine. The clock tick device driver
* gets an interrupt once a millisecond and counts down until the
* length of time between the user configured microseconds per tick
* has passed.
*/
rtems_unsigned32 Clock_isrs; /* ISRs until next tick */
static rtems_unsigned32 Clock_isrs_const; /* only calculated once */
/*
* These are set by clock driver during its init
*/
rtems_device_major_number rtems_clock_major = ~0;
rtems_device_minor_number rtems_clock_minor;
/*
* The previous ISR on this clock tick interrupt vector.
*/
rtems_isr_entry Old_ticker;
/*
* Isr Handler
*/
rtems_isr Clock_isr(
rtems_vector_number vector
)
{
/*
* bump the number of clock driver ticks since initialization
*
* determine if it is time to announce the passing of tick as configured
* to RTEMS through the rtems_clock_tick directive
*
* perform any timer dependent tasks
*/
unsigned8 temp;
/* reset the flags of the status register */
temp = read8( ITU_TSR0) & ITU_STAT_MASK;
write8( temp, ITU_TSR0);
Clock_driver_ticks++ ;
if( Clock_isrs == 1)
{
rtems_clock_tick();
Clock_isrs = Clock_isrs_const;
}
else
{
Clock_isrs-- ;
}
}
/*
* Install_clock
*
* Install a clock tick handler and reprograms the chip. This
* is used to initially establish the clock tick.
*/
void Install_clock(
rtems_isr_entry clock_isr
)
{
unsigned8 temp8 = 0;
/*
* Initialize the clock tick device driver variables
*/
Clock_driver_ticks = 0;
Clock_isrs_const = BSP_Configuration.microseconds_per_tick / 10000;
Clock_isrs = Clock_isrs_const;
/*
* If ticks_per_timeslice is configured as non-zero, then the user
* wants a clock tick.
*/
if ( BSP_Configuration.ticks_per_timeslice ) {
rtems_interrupt_catch( Clock_isr, CLOCK_VECTOR, &Old_ticker );
/*
* Hardware specific initialize goes here
*/
/* stop Timer 0 */
temp8 = read8( ITU_TSTR) & ITU0_STARTMASK;
write8( temp8, ITU_TSTR);
/* set initial counter value to 0 */
write16( 0, ITU_TCNT0);
/* Timer 0 runs independent */
temp8 = read8( ITU_TSNC) & ITU0_SYNCMASK;
write8( temp8, ITU_TSNC);
/* Timer 0 normal mode */
temp8 = read8( ITU_TMDR) & ITU0_MODEMASK;
write8( temp8, ITU_TMDR);
/* TCNT is cleared by GRA ; internal clock /4 */
write8( ITU0_TCRMASK , ITU_TCR0);
/* use GRA without I/O - pins */
write8( ITU0_TIORVAL, ITU_TIOR0);
/* reset flags of the status register */
temp8 = read8( ITU_TSR0) & ITU_STAT_MASK;
write8( temp8, ITU_TSR0);
/* Irq if is equal GRA */
temp8 = read8( ITU_TIER0) | ITU0_TIERMASK;
write8( temp8, ITU_TIER0);
/* set interrupt priority */
if( sh_set_irq_priority( CLOCK_VECTOR, CLOCKPRIO ) != RTEMS_SUCCESSFUL)
rtems_fatal_error_occurred( RTEMS_NOT_CONFIGURED);
/* set counter limits */
write16( _ITU_COUNTER0_MICROSECOND * BSP_Configuration.microseconds_per_tick,
ITU_GRA0);
/* start counter */
temp8 = read8( ITU_TSTR) |~ITU0_STARTMASK;
write8( temp8, ITU_TSTR);
}
/*
* Schedule the clock cleanup routine to execute if the application exits.
*/
atexit( Clock_exit );
}
/*
* Clean up before the application exits
*/
void Clock_exit( void )
{
unsigned8 temp8 = 0;
if ( BSP_Configuration.ticks_per_timeslice ) {
/* turn off the timer interrupts */
/* set interrupt priority to 0 */
if( sh_set_irq_priority( CLOCK_VECTOR, 0 ) != RTEMS_SUCCESSFUL)
rtems_fatal_error_occurred( RTEMS_UNSATISFIED);
/*
* temp16 = read16( ITU_TIER0) & IPRC_ITU0_IRQMASK;
* write16( temp16, ITU_TIER0);
*/
/* stop counter */
temp8 = read8( ITU_TSTR) & ITU0_STARTMASK;
write8( temp8, ITU_TSTR);
/* old vector shall not be installed */
}
}
/*
* Clock_initialize
*
* Device driver entry point for clock tick driver initialization.
*/
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_unsigned32 isrlevel;
rtems_libio_ioctl_args_t *args = pargp;
if (args != 0)
{
/*
* 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(CLOCK_VECTOR);
}
else if (args->command == rtems_build_name('N', 'E', 'W', ' '))
{
rtems_isr_entry ignored ;
rtems_interrupt_disable( isrlevel );
rtems_interrupt_catch( args->buffer, CLOCK_VECTOR, &ignored );
rtems_interrupt_enable( isrlevel );
}
}
return RTEMS_SUCCESSFUL;
}
