nuttx/arch/arm/src/stm32/stm32_timerisr.c
Alin Jerpelea 6ff1648b4f arch: arm: stm: Author Gregory Nutt: update licenses to Apache
Gregory Nutt has submitted the SGA and we can migrate the licenses
 to Apache.

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2021-03-31 00:59:15 -05:00

155 lines
5.1 KiB
C

/****************************************************************************
* arch/arm/src/stm32/stm32_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 <nuttx/timers/arch_timer.h>
#include <arch/board/board.h>
#include "nvic.h"
#include "clock/clock.h"
#include "arm_internal.h"
#include "arm_arch.h"
#include "systick.h"
#include "chip.h"
#include "stm32.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* 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).
*
* The RCC feeds the Cortex System Timer (SysTick) with the AHB clock (HCLK)
* divided by 8. The SysTick can work either with this clock or with the
* Cortex clock (HCLK), configurable in the SysTick Control and Status
* register.
*/
#undef CONFIG_STM32_SYSTICK_HCLKd8 /* Power up default is HCLK, not HCLK/8 */
/* And I don't know now to re-configure it yet */
#ifdef CONFIG_STM32_SYSTICK_HCLKd8
# define SYSTICK_RELOAD ((STM32_HCLK_FREQUENCY / 8 / CLK_TCK) - 1)
#else
# define SYSTICK_RELOAD ((STM32_HCLK_FREQUENCY / CLK_TCK) - 1)
#endif
/* The size of the reload field is 24 bits. Verify that the reload value
* will fit in the reload register.
*/
#if SYSTICK_RELOAD > 0x00ffffff
# error SYSTICK_RELOAD exceeds the range of the RELOAD register
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Function: stm32_timerisr
*
* Description:
* The timer ISR will perform a variety of services for various portions
* of the systems.
*
****************************************************************************/
#if !defined(CONFIG_ARMV7M_SYSTICK) && !defined(CONFIG_TIMER_ARCH)
static int stm32_timerisr(int irq, uint32_t *regs, void *arg)
{
/* Process timer interrupt */
nxsched_process_timer();
return 0;
}
#endif
/****************************************************************************
* 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);
/* Make sure that the SYSTICK clock source is set correctly */
#if 0 /* Does not work. Comes up with HCLK source and I can't change it */
regval = getreg32(NVIC_SYSTICK_CTRL);
#ifdef CONFIG_STM32_SYSTICK_HCLKd8
regval &= ~NVIC_SYSTICK_CTRL_CLKSOURCE;
#else
regval |= NVIC_SYSTICK_CTRL_CLKSOURCE;
#endif
putreg32(regval, NVIC_SYSTICK_CTRL);
#endif
#if defined(CONFIG_ARMV7M_SYSTICK) && defined(CONFIG_TIMER_ARCH)
up_timer_set_lowerhalf(systick_initialize(true, STM32_HCLK_FREQUENCY, -1));
#else
/* Configure SysTick to interrupt at the requested rate */
putreg32(SYSTICK_RELOAD, NVIC_SYSTICK_RELOAD);
/* Attach the timer interrupt vector */
irq_attach(STM32_IRQ_SYSTICK, (xcpt_t)stm32_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(STM32_IRQ_SYSTICK);
#endif
}