-/*!
- * \file
- * <!--
- * Copyright 2003, 2004 Develer S.r.l. (http://www.develer.com/)
- * Copyright 2000 Bernardo Innocenti <bernie@develer.com>
- * This file is part of DevLib - See devlib/README for information.
- * -->
- *
- * \version $Id$
- *
- * \author Bernardo Innocenti <bernie@develer.com>
- *
- * \brief Low-level timer module for AVR
- */
-
-/*#*
- *#* $Log$
- *#* Revision 1.19 2004/10/19 08:56:41 bernie
- *#* TIMER_STROBE_ON, TIMER_STROBE_OFF, TIMER_STROBE_INIT: Move from timer_avr.h to timer.h, where they really belong.
- *#*
- *#* Revision 1.18 2004/09/20 03:31:03 bernie
- *#* Fix racy racy code.
- *#*
- *#* Revision 1.17 2004/09/14 21:07:09 bernie
- *#* Include hw.h explicitly.
- *#*
- *#* Revision 1.16 2004/09/06 21:49:26 bernie
- *#* CONFIG_TIMER_STROBE: be tolerant with missing optional macro.
- *#*
- *#* Revision 1.15 2004/08/25 14:12:08 rasky
- *#* Aggiornato il comment block dei log RCS
- *#*
- *#* Revision 1.14 2004/08/24 16:27:01 bernie
- *#* Add missing headers.
- *#*
- *#* Revision 1.13 2004/08/24 14:30:11 bernie
- *#* Use new-style config macros for drv/timer.c
- *#*
- *#* Revision 1.12 2004/08/10 06:59:45 bernie
- *#* CONFIG_TIMER_STROBE: Define no-op default macros.
- *#*
- *#* Revision 1.11 2004/08/03 15:53:17 aleph
- *#* Fix spacing
- *#*
- *#* Revision 1.10 2004/08/02 20:20:29 aleph
- *#* Merge from project_ks
- *#*
- *#* Revision 1.9 2004/07/22 02:01:14 bernie
- *#* Use TIMER_PRESCALER consistently.
- *#*/
-#ifndef DRV_TIMER_AVR_H
-#define DRV_TIMER_AVR_H
-
-#include <arch_config.h> // ARCH_BOARD_KC
-#include "hw.h"
-
-#include <avr/wdt.h>
-#include <avr/signal.h>
-
-#if defined(ARCH_BOARD_KC) && (ARCH & ARCH_BOARD_KC)
- #include <drv/adc.h>
-#endif
-
-
-/*!
- * Values for CONFIG_TIMER.
- *
- * Select which hardware timer interrupt to use for system clock and softtimers.
- * \note The timer 1 overflow mode set the timer as a 24 kHz PWM.
- */
-#define TIMER_ON_OUTPUT_COMPARE0 1
-#define TIMER_ON_OVERFLOW1 2
-#define TIMER_ON_OUTPUT_COMPARE2 3
-
-
-/* Not needed, IRQ timer flag cleared automatically */
-#define timer_hw_irq() do {} while (0)
-
-#define TIMER_PRESCALER 64
-
-/*!
- * System timer: additional division after the prescaler
- * 12288000 / 64 / 192 (0..191) = 1 ms
- */
-#define OCR_DIVISOR (CLOCK_FREQ / TIMER_PRESCALER / TICKS_PER_SEC - 1) /* 191 */
-
-/*! HW dependent timer initialization */
-#if (CONFIG_TIMER == TIMER_ON_OUTPUT_COMPARE0)
-
- //! Type of time expressed in ticks of the hardware high-precision timer
- typedef uint8_t hptime_t;
-
- static void timer_hw_init(void)
- {
- cpuflags_t flags;
- DISABLE_IRQSAVE(flags);
-
- /* Reset Timer flags */
- TIFR = BV(OCF0) | BV(TOV0);
-
- /* Setup Timer/Counter interrupt */
- ASSR = 0x00; /* Internal system clock */
- TCCR0 = BV(WGM01) /* Clear on Compare match */
- #if TIMER_PRESCALER == 64
- | BV(CS02)
- #else
- #error Unsupported value of TIMER_PRESCALER
- #endif
- ;
- TCNT0 = 0x00; /* Initialization of Timer/Counter */
- OCR0 = OCR_DIVISOR; /* Timer/Counter Output Compare Register */
-
- /* Enable timer interrupts: Timer/Counter2 Output Compare (OCIE2) */
- TIMSK &= ~BV(TOIE0);
- TIMSK |= BV(OCIE0);
-
- ENABLE_IRQRESTORE(flags);
- }
-
- //! Frequency of the hardware high precision timer
- #define TIMER_HW_HPTICKS_PER_SEC (CLOCK_FREQ / TIMER_PRESCALER)
-
- INLINE hptime_t timer_hw_hpread(void)
- {
- return TCNT0;
- }
-
-#elif (CONFIG_TIMER == TIMER_ON_OVERFLOW1)
-
- //! Type of time expressed in ticks of the hardware high precision timer
- typedef uint16_t hptime_t;
-
- static void timer_hw_init(void)
- {
- cpuflags_t flags;
- DISABLE_IRQSAVE(flags);
-
- /* Reset Timer overflow flag */
- TIFR |= BV(TOV1);
-
- /* Fast PWM mode, 9 bit, 24 kHz, no prescaling. When changing freq or
- resolution (top of TCNT), change TIMER_HW_HPTICKS_PER_SEC too */
- TCCR1A |= BV(WGM11);
- TCCR1A &= ~BV(WGM10);
- TCCR1B |= BV(WGM12) | BV(CS10);
- TCCR1B &= ~(BV(WGM13) | BV(CS11) | BV(CS12));
-
- TCNT1 = 0x00; /* initialization of Timer/Counter */
-
- /* Enable timer interrupt: Timer/Counter1 Overflow */
- TIMSK |= BV(TOIE1);
-
- ENABLE_IRQRESTORE(flags);
- }
-
- //! Frequency of the hardware high precision timer
- #define TIMER_HW_HPTICKS_PER_SEC (24000ul * 512)
-
- INLINE hptime_t timer_hw_hpread(void)
- {
- return TCNT1;
- }
-
-#elif (CONFIG_TIMER == TIMER_ON_OUTPUT_COMPARE2)
-
- //! Type of time expressed in ticks of the hardware high precision timer
- typedef uint8_t hptime_t;
-
- static void timer_hw_init(void)
- {
- cpuflags_t flags;
- DISABLE_IRQSAVE(flags);
-
- /* Reset Timer flags */
- TIFR = BV(OCF2) | BV(TOV2);
-
- /* Setup Timer/Counter interrupt */
- TCCR2 = BV(WGM21)
- #if TIMER_PRESCALER == 64
- | BV(CS21) | BV(CS20)
- #else
- #error Unsupported value of TIMER_PRESCALER
- #endif
- ;
- /* Clear on Compare match & prescaler = 64, internal sys clock.
- When changing prescaler change TIMER_HW_HPTICKS_PER_SEC too */
- TCNT2 = 0x00; /* initialization of Timer/Counter */
- OCR2 = OCR_DIVISOR; /* Timer/Counter Output Compare Register */
-
- /* Enable timer interrupts: Timer/Counter2 Output Compare (OCIE2) */
- TIMSK &= ~BV(TOIE2);
- TIMSK |= BV(OCIE2);
-
- ENABLE_IRQRESTORE(flags);
- }
-
- //! Frequency of the hardware high precision timer
- #define TIMER_HW_HPTICKS_PER_SEC (CLOCK_FREQ / TIMER_PRESCALER)
-
- INLINE hptime_t timer_hw_hpread(void)
- {
- return TCNT2;
- }
-
-#else
- #error Unimplemented value for CONFIG_TIMER
-#endif /* CONFIG_TIMER */
-
-
-#if (CONFIG_TIMER == TIMER_ON_OVERFLOW1)
-
- #define DEFINE_TIMER_ISR \
- static void timer_handler(void)
-
- DEFINE_TIMER_ISR;
-
- /*
- * Timer 1 overflow irq handler. It's called at the frequency of the timer 1
- * PWM (should be 24 kHz). It's too much for timer purposes, so the interrupt
- * handler is really a counter that call the true handler in timer.c
- * every 1 ms.
- */
- SIGNAL(SIG_OVERFLOW1)
- {
- #if (ARCH & ARCH_BOARD_KC)
- /*
- * Super-optimization-hack: switch CPU ADC mux here, ASAP after the start
- * of conversion (auto-triggered with timer 1 overflow).
- * The switch can be done 2 ADC cycles after start of conversion.
- * The handler prologue takes a little more than 32 CPU cycles: with
- * the prescaler at 1/16 the timing should be correct even at the start
- * of the handler.
- *
- * The switch is synchronized with the ADC handler using _adc_trigger_lock.
- *
- * Mel (A Real Programmer)
- */
- extern uint8_t _adc_idx_next;
- extern bool _adc_trigger_lock;
-
- if (!_adc_trigger_lock)
- {
- /*
- * Disable free-running mode to avoid starting a
- * new conversion before the ADC handler has read
- * the ongoing one. This condition could occur
- * under very high interrupt load and would have the
- * unwanted effect of reading from the wrong ADC
- * channel.
- *
- * NOTE: writing 0 to ADSC and ADIF has no effect.
- */
- ADCSRA = ADCSRA & ~(BV(ADFR) | BV(ADIF) | BV(ADSC));
-
- ADC_SETCHN(_adc_idx_next);
- _adc_trigger_lock = true;
- }
- #endif // ARCH_BOARD_KC
-
- /*!
- * How many timer overflows we must count before calling the real
- * timer handler.
- * When the timer is programmed to overflow at 24 kHz, a value of
- * 24 will result in 1ms between each call.
- */
- #define TIMER1_OVF_COUNT 24
- //#warning TIMER1_OVF_COUNT for timer at 12 kHz
- //#define TIMER1_OVF_COUNT 12
-
- static uint8_t count = TIMER1_OVF_COUNT;
-
- count--;
- if (!count)
- {
- timer_handler();
- count = TIMER1_OVF_COUNT;
- }
- }
-
-#elif (CONFIG_TIMER == TIMER_ON_OUTPUT_COMPARE0)
-
- #define DEFINE_TIMER_ISR \
- SIGNAL(SIG_OUTPUT_COMPARE0)
-
-#elif (CONFIG_TIMER == TIMER_ON_OUTPUT_COMPARE2)
-
- #define DEFINE_TIMER_ISR \
- SIGNAL(SIG_OUTPUT_COMPARE2)
-
-#else
- #error Unimplemented value for CONFIG_TIMER
-#endif /* CONFIG_TIMER */
-
-#endif /* DRV_TIMER_AVR_H */