f2f0193960
Gregory Nutt has submitted the SGA and we can migrate the licenses to Apache. Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
161 lines
5.1 KiB
C
161 lines
5.1 KiB
C
/****************************************************************************
|
|
* arch/arm/src/xmc4/xmc4_timerisr.c
|
|
*
|
|
* Licensed to the Apache Software Foundation (ASF) under one or more
|
|
* contributor license agreements. See the NOTICE file distributed with
|
|
* this work for additional information regarding copyright ownership. The
|
|
* ASF licenses this file to you under the Apache License, Version 2.0 (the
|
|
* "License"); you may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
* License for the specific language governing permissions and limitations
|
|
* under the License.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <stdint.h>
|
|
#include <time.h>
|
|
#include <debug.h>
|
|
|
|
#include <nuttx/arch.h>
|
|
#include <arch/board/board.h>
|
|
|
|
#include "nvic.h"
|
|
#include "clock/clock.h"
|
|
#include "arm_internal.h"
|
|
#include "arm_arch.h"
|
|
|
|
#include "chip.h"
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
/* The SysTick counter runs on the clock selected by SYST_CSR.CLKSOURCE.
|
|
* That selection may be either:
|
|
*
|
|
* CLKSOURCE=0: fSTDBY / 2
|
|
* CLKSOURCE=1: fCPU
|
|
*
|
|
* In the first case, the SysTick counter would run at 16.384Khz. The most
|
|
* common system clock of 10 msec/tick cannot be exactly represented with
|
|
* that value.
|
|
*
|
|
* In the second case, the SysTick counter may run too rapidly to support
|
|
* longer timer tick intervals. For example, if the CPU clock is 144Mhz,
|
|
* then that 10 msec interval would correspond to a reload value of 1,440,000
|
|
* or 0x0015f900.
|
|
*/
|
|
|
|
/* The desired timer interrupt frequency is provided by the definition
|
|
* CLK_TCK (see include/time.h). CLK_TCK defines the desired number of
|
|
* system clock ticks per second. That value is a user configurable setting
|
|
* that defaults to 100 (100 ticks per second = 10 MS interval).
|
|
*
|
|
* Lets try fCPU first:
|
|
*/
|
|
|
|
#define SYSTICK_RELOAD ((BOARD_CPU_FREQUENCY / CLK_TCK) - 1)
|
|
#undef USE_STDBY_CLOCK
|
|
|
|
/* Verify that the reload value will fit in the reload register. */
|
|
|
|
#if SYSTICK_RELOAD > 0x00ffffff
|
|
/* No, then revert to fSTDBY */
|
|
|
|
# undef SYSTICK_RELOAD
|
|
# define SYSTICK_RELOAD ((BOARD_STDBY_FREQUENCY / CLK_TCK) - 1)
|
|
# define USE_STDBY_CLOCK 1
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Function: xmc4_timerisr
|
|
*
|
|
* Description:
|
|
* The timer ISR will perform a variety of services for various portions
|
|
* of the systems.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int xmc4_timerisr(int irq, uint32_t *regs, FAR void *arg)
|
|
{
|
|
/* Process timer interrupt */
|
|
|
|
nxsched_process_timer();
|
|
return 0;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Function: up_timer_initialize
|
|
*
|
|
* Description:
|
|
* This function is called during start-up to initialize
|
|
* the timer interrupt.
|
|
*
|
|
****************************************************************************/
|
|
|
|
void up_timer_initialize(void)
|
|
{
|
|
uint32_t regval;
|
|
|
|
/* Set the SysTick interrupt to the default priority */
|
|
|
|
regval = getreg32(NVIC_SYSH12_15_PRIORITY);
|
|
regval &= ~NVIC_SYSH_PRIORITY_PR15_MASK;
|
|
regval |= (NVIC_SYSH_PRIORITY_DEFAULT << NVIC_SYSH_PRIORITY_PR15_SHIFT);
|
|
putreg32(regval, NVIC_SYSH12_15_PRIORITY);
|
|
|
|
#ifndef USE_STDBY_CLOCK
|
|
/* Note that it should not be necessary to set the SYSTICK clock source:
|
|
* "The CLKSOURCE bit in SysTick Control and Status register is always set
|
|
* to select the core clock."
|
|
*
|
|
* For the XMC4xx, fhat selection may be either:
|
|
*
|
|
* CLKSOURCE=0: fSTDBY / 2
|
|
* CLKSOURCE=1: fCPU
|
|
*/
|
|
|
|
regval = getreg32(NVIC_SYSTICK_CTRL);
|
|
regval |= NVIC_SYSTICK_CTRL_CLKSOURCE;
|
|
putreg32(regval, NVIC_SYSTICK_CTRL);
|
|
#endif
|
|
|
|
/* Configure SysTick to interrupt at the requested rate */
|
|
|
|
putreg32(SYSTICK_RELOAD, NVIC_SYSTICK_RELOAD);
|
|
|
|
/* Attach the timer interrupt vector */
|
|
|
|
irq_attach(XMC4_IRQ_SYSTICK, (xcpt_t)xmc4_timerisr, NULL);
|
|
|
|
/* Enable SysTick interrupts */
|
|
|
|
putreg32((NVIC_SYSTICK_CTRL_CLKSOURCE | NVIC_SYSTICK_CTRL_TICKINT |
|
|
NVIC_SYSTICK_CTRL_ENABLE),
|
|
NVIC_SYSTICK_CTRL);
|
|
|
|
/* And enable the timer interrupt */
|
|
|
|
up_enable_irq(XMC4_IRQ_SYSTICK);
|
|
}
|