/****************************************************************************
* arch/arm/src/lpc2378/lpc23xx_timerisr.c
*
* Copyright (C) 2010 Rommel Marcelo. All rights reserved.
* Author: Rommel Marcelo
*
* This file is part of the NuttX RTOS and based on the lpc2148 port:
*
* Copyright (C) 2010 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 <sys/types.h>
#include <debug.h>
#include <nuttx/arch.h>
#include <arch/board/board.h>
#include "clock_internal.h"
#include "internal.h"
#include "up_arch.h"
#include "lpc23xx_scb.h"
#include "lpc23xx_vic.h"
#include "lpc23xx_timer.h"
/****************************************************************************
* Definitions
****************************************************************************/
/* T0_PCLKDIV valid values are 1,2,4 */
#define T0_PCLK_DIV 1
/* PCKLSEL0 bits 3:2, 00=CCLK/4, 01=CCLK/1 , 10=CCLK/2 */
#ifdef T0_PCLK_DIV
# if T0_PCLK_DIV == 1
# define TIMER0_PCLKSEL (0x00000004)
# elif T0_PCLK_DIV == 2
# define TIMER0_PCLKSEL (0x00000008)
# elif T0_PCLK_DIV == 4
# define TIMER0_PCLKSEL (0x00000000)
# endif
#endif
#define T0_PCLKSEL_MASK (0x0000000C)
#define T0_TICKS_COUNT ( (CCLK / T0_PCLK_DIV ) / TICK_PER_SEC )
/****************************************************************************
* 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.
*
****************************************************************************/
#ifdef CONFIG_VECTORED_INTERRUPTS
int up_timerisr(uint32_t * regs)
#else
int up_timerisr(int irq, uint32_t * regs)
#endif
{
static uint32_t tick;
/* Process timer interrupt */
sched_process_timer();
/* Clear the MR0 match interrupt */
tmr_putreg8(TMR_IR_MR0I, TMR_IR_OFFSET);
/* Reset the VIC as well */
#ifdef CONFIG_VECTORED_INTERRUPTS
/* write any value to VICAddress to acknowledge the interrupt */
vic_putreg(0, VIC_ADDRESS_OFFSET);
#endif
if (tick++ > 100)
{
tick = 0;
up_statledoff();
}
else
up_statledon();
return 0;
}
/****************************************************************************
* Function: up_timerinit
*
* Description:
* This function is called during start-up to initialize
* the system timer interrupt.
*
****************************************************************************/
void up_timerinit(void)
{
uint16_t mcr;
/* Power up Timer0 */
SCB_PCONP |= PCTIM0;
/* Timer0 clock input frequency = CCLK / TO_PCLKDIV */
SCB_PCLKSEL0 = (SCB_PCLKSEL0 & ~T0_PCLKSEL_MASK) | TIMER0_PCLKSEL;
/* Clear all match and capture event interrupts */
tmr_putreg8(TMR_IR_ALLI, TMR_IR_OFFSET);
/* Clear the timer counter */
tmr_putreg32(0, TMR_TC_OFFSET);
/* No pre-scaler */
tmr_putreg32(0, TMR_PR_OFFSET);
tmr_putreg32(0, TMR_PC_OFFSET);
/* Set timer match register to get a TICK_PER_SEC rate See arch/board.h and
* sched/os_internal.h
*/
tmr_putreg32(T0_TICKS_COUNT, TMR_MR0_OFFSET); /* 10ms Intterrupt */
/* Reset timer counter register and interrupt on match */
mcr = tmr_getreg16(TMR_MCR_OFFSET);
mcr &= ~TMR_MCR_MR1I;
mcr |= (TMR_MCR_MR0I | TMR_MCR_MR0R);
tmr_putreg16(mcr, TMR_MCR_OFFSET); /* -- bit 0=1 -int on MR0, bit 1=1 - Reset on MR0 */
/* Enable counting */
/* ~ tmr_putreg32(1, TMR_TCR_OFFSET); */
tmr_putreg8(TMR_CR_ENABLE, TMR_TCR_OFFSET);
/* Attach the timer interrupt vector */
#ifdef CONFIG_VECTORED_INTERRUPTS
up_attach_vector(IRQ_SYSTIMER, PRIORITY_HIGHEST, (vic_vector_t) up_timerisr);
#else
(void)irq_attach(IRQ_SYSTIMER, (xcpt_t) up_timerisr);
up_prioritize_irq(IRQ_SYSTIMER, PRIORITY_HIGHEST);
#endif
/* And enable the system timer interrupt */
up_enable_irq(IRQ_SYSTIMER);
}
