/************************************************************************
* up_timerisr.c
*
* Copyright (C) 2007, 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 <8052.h>
#include "clock_internal.h"
#include "up_internal.h"
/************************************************************************
* Definitions
************************************************************************/
/************************************************************************
* 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 systems.
*
************************************************************************/
int up_timerisr(int irq, FAR uint8_t *frame)
{
/* 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)
{
#ifdef CONFIG_8052_TIMER2
up_disable_irq(TIMER2_IRQ);
/* Set up timer 2 -- See pjrc.h for details */
T2MOD = 0;
/* Set up the capture count to generate 100Hz system
* interrupts.
*/
RCAP2L = TIMER2_CAPTURE_LOW;
RCAP2H = TIMER2_CAPTURE_HIGH;
TL2 = TIMER2_CAPTURE_LOW;
TH2 = TIMER2_CAPTURE_HIGH;
/* Configure for interrupts */
T2CON = 0x04;
/* Attach and enable the timer interrupt */
irq_attach(TIMER2_IRQ, (xcpt_t)up_timerisr);
up_enable_irq(TIMER2_IRQ);
#else
/* Timer 0, mode 0 can be used as a system timer. In that mode, the
* 1.8432 MHz clock is divided by 32. A single 8-bit value is incremented
* at 57600 Hz, which results in 225 Timer 0 overflow interrupts per
* second.
*/
up_disable_irq(TIMER0_IRQ);
/* Initialize timer 0 */
TR0 = 0; /* Make sure timer 0 is stopped */
TF0 = 0; /* Clear the overflow flag */
TMOD &= 0xF0; /* Set to mode 0 (without changing timer1) */
TL0 = 0; /* Clear timer 0 value */
TH0 = 0;
/* Attach and enable the timer interrupt */
irq_attach(TIMER0_IRQ, (xcpt_t)up_timerisr);
TR0 = 1; /* Start the timer */
up_enable_irq(TIMER0_IRQ);
#endif
}
