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/***************************************************************************
* z16f/z16f_timerisr.c
*
* Copyright (C) 2008-2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
***************************************************************************/
/***************************************************************************
* Included Files
***************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <debug.h>
#include <nuttx/arch.h>
#include "chip/chip.h"
#include "clock_internal.h"
#include "up_internal.h"
/***************************************************************************
* Definitions
***************************************************************************/
/* System clock frequency value from ZDS target settings */
extern _Erom unsigned long SYS_CLK_FREQ;
#define _DEFCLK ((unsigned long)&SYS_CLK_FREQ)
/***************************************************************************
* Private Types
***************************************************************************/
/***************************************************************************
* Private Function Prototypes
***************************************************************************/
/***************************************************************************
* Global Functions
***************************************************************************/
/***************************************************************************
* Function: up_timerisr
*
* Description:
* The timer ISR will perform a variety of services for various portions
* of the system.
*
***************************************************************************/
int up_timerisr(int irq, uint32_t *regs)
{
/* Process timer interrupt */
sched_process_timer();
return 0;
}
/***************************************************************************
* Function: up_timerinit
*
* Description:
* This function is called during start-up to initialize
* the timer interrupt.
*
***************************************************************************/
void up_timerinit(void)
{
up_disable_irq(Z16F_IRQ_SYSTIMER);
/* Disable the timer and configure for divide by 1 and continuous mode. */
putreg8( Z16F_TIMERSCTL1_DIV1 | Z16F_TIMERSCTL1_CONT, Z16F_TIMER0_CTL1);
/* Assign an intial timer value */
putreg16(0x0001, Z16F_TIMER0_HL);
/* Set the timer reload value.
*
* In continuous mode:
*
* timer_frequency = system_clock_freqency / divisor / reload_value
* or
* reload_value = (system_clock_frequency / timer_frequency / divisor
*
* For system_clock_frequency=200MHz, timer_frequency=100KHz, and divisor=1,
* this yields 200.
*/
putreg16(((uint32_t)_DEFCLK / 100000), Z16F_TIMER0_R);
/* Enable the timer */
putreg8((getreg8(Z16F_TIMER0_CTL1) | Z16F_TIMERCTL1_TEN), Z16F_TIMER0_CTL1);
/* Set the timer priority */
/* Attach and enable the timer interrupt (leaving at priority 0 */
irq_attach(Z16F_IRQ_SYSTIMER, (xcpt_t)up_timerisr);
up_enable_irq(Z16F_IRQ_SYSTIMER);
}
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