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RIOT/cpu/stm32f3/periph/timer.c
Hauke Petersen e7fbaf3815 cpu: removed NAKED attribute from ISRs
- removed the __attribute__((naked)) from ISRs
- removed ISR_ENTER() and ISR_EXIT() macros

Rationale: Cortex-Mx MCUs save registers R0-R4 automatically
on calling ISRs. The naked attribute tells the compiler not
to save any other registers. This is fine, as long as the
code in the ISR is not nested. If nested, it will use also
R4 and R5, which will then lead to currupted registers on
exit of the ISR. Removing the naked will fix this.
2014-10-30 19:33:32 +01:00

277 lines
5.5 KiB
C

/*
* Copyright (C) 2014 Freie Universität Berlin
*
* This file is subject to the terms and conditions of the GNU Lesser General
* Public License v2.1. See the file LICENSE in the top level directory for more
* details.
*/
/**
* @ingroup cpu_stm32f3
* @{
*
* @file
* @brief Low-level timer driver implementation
*
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
*
* @}
*/
#include <stdlib.h>
#include "cpu.h"
#include "board.h"
#include "sched.h"
#include "thread.h"
#include "periph_conf.h"
#include "periph/timer.h"
/** Unified IRQ handler for all timers */
static inline void irq_handler(tim_t timer, TIM_TypeDef *dev);
/** Type for timer state */
typedef struct {
void (*cb)(int);
} timer_conf_t;
/** Timer state memory */
timer_conf_t config[TIMER_NUMOF];
int timer_init(tim_t dev, unsigned int ticks_per_us, void (*callback)(int))
{
TIM_TypeDef *timer;
switch (dev) {
#if TIMER_0_EN
case TIMER_0:
/* enable timer peripheral clock */
TIMER_0_CLKEN();
/* set timer's IRQ priority */
NVIC_SetPriority(TIMER_0_IRQ_CHAN, TIMER_IRQ_PRIO);
/* select timer */
timer = TIMER_0_DEV;
break;
#endif
case TIMER_UNDEFINED:
default:
return -1;
}
/* set callback function */
config[dev].cb = callback;
/* set timer to run in counter mode */
timer->CR1 = 0;
timer->CR2 = 0;
/* set auto-reload and prescaler values and load new values */
timer->PSC = TIMER_0_PRESCALER * ticks_per_us;
timer->EGR |= TIM_EGR_UG;
/* enable the timer's interrupt */
timer_irq_enable(dev);
/* start the timer */
timer_start(dev);
return 0;
}
int timer_set(tim_t dev, int channel, unsigned int timeout)
{
int now = timer_read(dev);
return timer_set_absolute(dev, channel, now + timeout - 1);
}
int timer_set_absolute(tim_t dev, int channel, unsigned int value)
{
TIM_TypeDef *timer;
switch (dev) {
#if TIMER_0_EN
case TIMER_0:
timer = TIMER_0_DEV;
break;
#endif
default:
return -1;
}
switch (channel) {
case 0:
timer->CCR1 = value;
timer->SR &= ~TIM_SR_CC1IF;
timer->DIER |= TIM_DIER_CC1IE;
break;
case 1:
timer->CCR2 = value;
timer->SR &= ~TIM_SR_CC2IF;
timer->DIER |= TIM_DIER_CC2IE;
break;
case 2:
timer->CCR3 = value;
timer->SR &= ~TIM_SR_CC3IF;
timer->DIER |= TIM_DIER_CC3IE;
break;
case 3:
timer->CCR4 = value;
timer->SR &= ~TIM_SR_CC4IF;
timer->DIER |= TIM_DIER_CC4IE;
break;
default:
return -1;
}
return 0;
}
int timer_clear(tim_t dev, int channel)
{
TIM_TypeDef *timer;
switch (dev) {
#if TIMER_0_EN
case TIMER_0:
timer = TIMER_0_DEV;
break;
#endif
case TIMER_UNDEFINED:
default:
return -1;
}
switch (channel) {
case 0:
timer->DIER &= ~TIM_DIER_CC1IE;
break;
case 1:
timer->DIER &= ~TIM_DIER_CC2IE;
break;
case 2:
timer->DIER &= ~TIM_DIER_CC3IE;
break;
case 3:
timer->DIER &= ~TIM_DIER_CC4IE;
break;
default:
return -1;
}
return 0;
}
unsigned int timer_read(tim_t dev)
{
switch (dev) {
#if TIMER_0_EN
case TIMER_0:
return TIMER_0_DEV->CNT;
break;
#endif
case TIMER_UNDEFINED:
default:
return 0;
}
}
void timer_start(tim_t dev)
{
switch (dev) {
#if TIMER_0_EN
case TIMER_0:
TIMER_0_DEV->CR1 |= TIM_CR1_CEN;
break;
#endif
case TIMER_UNDEFINED:
break;
}
}
void timer_stop(tim_t dev)
{
switch (dev) {
#if TIMER_0_EN
case TIMER_0:
TIMER_0_DEV->CR1 &= ~TIM_CR1_CEN;
break;
#endif
case TIMER_UNDEFINED:
break;
}
}
void timer_irq_enable(tim_t dev)
{
switch (dev) {
#if TIMER_0_EN
case TIMER_0:
NVIC_EnableIRQ(TIMER_0_IRQ_CHAN);
break;
#endif
case TIMER_UNDEFINED:
break;
}
}
void timer_irq_disable(tim_t dev)
{
switch (dev) {
#if TIMER_0_EN
case TIMER_0:
NVIC_DisableIRQ(TIMER_0_IRQ_CHAN);
break;
#endif
case TIMER_UNDEFINED:
break;
}
}
void timer_reset(tim_t dev)
{
switch (dev) {
#if TIMER_0_EN
case TIMER_0:
TIMER_0_DEV->CNT = 0;
break;
#endif
case TIMER_UNDEFINED:
break;
}
}
#if TIMER_0_EN
void TIMER_0_ISR(void)
{
irq_handler(TIMER_0, TIMER_0_DEV);
}
#endif
static inline void irq_handler(tim_t timer, TIM_TypeDef *dev)
{
if (dev->SR & TIM_SR_CC1IF) {
dev->DIER &= ~TIM_DIER_CC1IE;
dev->SR &= ~TIM_SR_CC1IF;
config[timer].cb(0);
}
else if (dev->SR & TIM_SR_CC2IF) {
dev->DIER &= ~TIM_DIER_CC2IE;
dev->SR &= ~TIM_SR_CC2IF;
config[timer].cb(1);
}
else if (dev->SR & TIM_SR_CC3IF) {
dev->DIER &= ~TIM_DIER_CC3IE;
dev->SR &= ~TIM_SR_CC3IF;
config[timer].cb(2);
}
else if (dev->SR & TIM_SR_CC4IF) {
dev->DIER &= ~TIM_DIER_CC4IE;
dev->SR &= ~TIM_SR_CC4IF;
config[timer].cb(3);
}
if (sched_context_switch_request) {
thread_yield();
}
}