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//==========================================================================
//
// hal_intr.c
//
// PowerPC interrupt handlers
//
//==========================================================================
// ####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
//
// eCos is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 or (at your option) any later
// version.
//
// eCos 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. See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License
// along with eCos; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// As a special exception, if other files instantiate templates or use
// macros or inline functions from this file, or you compile this file
// and link it with other works to produce a work based on this file,
// this file does not by itself cause the resulting work to be covered by
// the GNU General Public License. However the source code for this file
// must still be made available in accordance with section (3) of the GNU
// General Public License v2.
//
// This exception does not invalidate any other reasons why a work based
// on this file might be covered by the GNU General Public License.
// -------------------------------------------
// ####ECOSGPLCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s): jskov
// Contributors: jskov
// Date: 1999-02-20
// Purpose: PowerPC interrupt handlers
// Description: This file contains code to handle interrupt related issues
// on the PowerPC.
//
//####DESCRIPTIONEND####
//
//==========================================================================
#include <pkgconf/hal.h>
#include <cyg/hal/hal_intr.h>
static unsigned long ticks_per_us;
externC void
hal_IRQ_init(void)
{
// No architecture general initialization, but the variant may have
// provided some.
hal_variant_IRQ_init();
// Initialize real-time clock (for delays, etc, even if kernel doesn't use it)
HAL_CLOCK_INITIALIZE(CYGNUM_HAL_RTC_PERIOD);
// Pre-calculate this factor to avoid the extra calculations on each delay
ticks_per_us = ((long long)1 * (CYGNUM_HAL_RTC_PERIOD * 100)) / 1000000;
}
// Delay for some number of useconds.
externC void
hal_delay_us(int us)
{
cyg_int32 old_dec, new_dec;
long ticks;
int diff;
// Note: the system constant CYGNUM_HAL_RTC_PERIOD corresponds to 10,000us
// Scale the desired number of microseconds to be a number of decrementer ticks
if (ticks_per_us > 0) {
ticks = us * ticks_per_us;
} else {
ticks = ((long long)us * (CYGNUM_HAL_RTC_PERIOD * 100)) / 1000000;
}
asm volatile("mfdec %0;" : "=r"(old_dec) : );
while (ticks > 0) {
do {
asm volatile("mfdec %0;" : "=r"(new_dec) : );
} while (old_dec == new_dec);
if (new_dec < 0) {
HAL_CLOCK_RESET(0, CYGNUM_HAL_RTC_PERIOD);
}
diff = (old_dec - new_dec);
if (diff < 1) diff = 1;
old_dec = new_dec;
ticks -= diff;
}
}
// -------------------------------------------------------------------------
// EOF hal_intr.c
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