diff options
Diffstat (limited to 'os/hal/ports/AVR/TINY/TIMv1/hal_st_lld.c')
| -rw-r--r-- | os/hal/ports/AVR/TINY/TIMv1/hal_st_lld.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/os/hal/ports/AVR/TINY/TIMv1/hal_st_lld.c b/os/hal/ports/AVR/TINY/TIMv1/hal_st_lld.c new file mode 100644 index 000000000..4732ec7dd --- /dev/null +++ b/os/hal/ports/AVR/TINY/TIMv1/hal_st_lld.c @@ -0,0 +1,253 @@ +/*
+ ChibiOS - Copyright (C) 2006..2016 Giovanni Di Sirio
+
+ Licensed 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.
+*/
+
+/**
+ * @file hal_st_lld.c
+ * @brief AVR ST subsystem low level driver source.
+ *
+ * @addtogroup ST
+ * @{
+ */
+
+#include "hal.h"
+
+#if (OSAL_ST_MODE != OSAL_ST_MODE_NONE) || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Driver local definitions. */
+/*===========================================================================*/
+
+/**
+ * @brief Timer maximum value
+ */
+#define AVR_TIMER_COUNTER_MAX 255
+
+/*===========================================================================*/
+/* Driver exported variables. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local types. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local variables and types. */
+/*===========================================================================*/
+
+#if (OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC) || defined(__DOXYGEN__)
+
+/* Work out what the timer interrupt is called on this MCU */
+#ifdef TIMER0_COMPA_vect
+ #define AVR_TIMER_VECT TIMER0_COMPA_vect
+#elif defined(TIMER_COMPA_vect)
+ #define AVR_TIMER_VECT TIMER_COMPA_vect
+#elif defined(TIMER0_COMP_vect)
+ #define AVR_TIMER_VECT TIMER0_COMP_vect
+#else
+ #error "Cannot find interrupt vector name for timer"
+#endif
+
+/* Find the most suitable prescaler setting for the desired OSAL_ST_FREQUENCY */
+#if ((F_CPU / OSAL_ST_FREQUENCY) <= AVR_TIMER_COUNTER_MAX)
+
+ #define AVR_TIMER_PRESCALER 1
+ #define AVR_TIMER_PRESCALER_BITS ((0<<CS02)|(0<<CS01)|(1<<CS00)) /* CLK */
+
+#elif ((F_CPU / OSAL_ST_FREQUENCY / 8) <= AVR_TIMER_COUNTER_MAX)
+
+ #define AVR_TIMER_PRESCALER 8
+ #define AVR_TIMER_PRESCALER_BITS ((0<<CS02)|(1<<CS01)|(0<<CS00)) /* CLK/8 */
+
+#elif ((F_CPU / OSAL_ST_FREQUENCY / 64) <= AVR_TIMER_COUNTER_MAX)
+
+ #define AVR_TIMER_PRESCALER 64
+
+ #ifdef __AVR_ATmega128__
+ #define AVR_TIMER_PRESCALER_BITS ((1<<CS02)|(0<<CS01)|(0<<CS00)) /* CLK/64 */
+ #else
+ #define AVR_TIMER_PRESCALER_BITS ((0<<CS02)|(1<<CS01)|(1<<CS00)) /* CLK/64 */
+ #endif
+
+#elif ((F_CPU / OSAL_ST_FREQUENCY / 256) <= AVR_TIMER_COUNTER_MAX)
+
+ #define AVR_TIMER_PRESCALER 256
+
+ #ifdef __AVR_ATmega128__
+ #define AVR_TIMER_PRESCALER_BITS ((1<<CS02)|(1<<CS01)|(0<<CS00)) /* CLK/256 */
+ #else
+ #define AVR_TIMER_PRESCALER_BITS ((1<<CS02)|(0<<CS01)|(0<<CS00)) /* CLK/256 */
+ #endif
+
+#elif ((F_CPU / OSAL_ST_FREQUENCY / 1024) <= AVR_TIMER_COUNTER_MAX)
+
+ #define AVR_TIMER_PRESCALER 1024
+
+ #ifdef __AVR_ATmega128__
+ #define AVR_TIMER_PRESCALER_BITS (1<<CS02)|(1<<CS01)|(1<<CS00); /* CLK/1024 */
+ #else
+ #define AVR_TIMER_PRESCALER_BITS (1<<CS02)|(0<<CS01)|(1<<CS00); /* CLK/1024 */
+ #endif
+
+#else
+ #error "Frequency too low for timer, please set OSAL_ST_FREQUENCY to a higher value"
+#endif
+
+#define AVR_TIMER_COUNTER (F_CPU / OSAL_ST_FREQUENCY / AVR_TIMER_PRESCALER)
+
+/* Test if OSAL_ST_FREQUENCY can be matched exactly using this timer */
+#define F_CPU_ (AVR_TIMER_COUNTER * AVR_TIMER_PRESCALER * OSAL_ST_FREQUENCY)
+#if (F_CPU_ != F_CPU)
+ #warning "OSAL_ST_FREQUENCY cannot be generated exactly using timer"
+#endif
+#undef F_CPU_
+
+#endif /* OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC */
+
+#if (OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING) || defined(__DOXYGEN__)
+
+/* FIXME: Prescaler is now fixed in 1024.
+ * Should add support for calculating best value according to
+ * user requested configuration.
+ */
+#define PRESCALER (_BV(CS12) | _BV(CS10))
+
+#endif /* OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING */
+
+/*===========================================================================*/
+/* Driver local functions. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver interrupt handlers. */
+/*===========================================================================*/
+
+#if (OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC) || defined(__DOXYGEN__)
+
+/**
+ * @brief Timer handler for periodic mode.
+ */
+OSAL_IRQ_HANDLER(AVR_TIMER_VECT) {
+
+ OSAL_IRQ_PROLOGUE();
+
+ osalSysLockFromISR();
+ osalOsTimerHandlerI();
+ osalSysUnlockFromISR();
+
+ OSAL_IRQ_EPILOGUE();
+}
+
+#endif /* OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC */
+
+#if (OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING) || defined(__DOXYGEN__)
+
+/**
+ * @brief Timer handler for free running mode.
+ */
+OSAL_IRQ_HANDLER(TIMER1_COMPA_vect) {
+
+ OSAL_IRQ_PROLOGUE();
+
+ // TODO: reset status if required
+
+ osalSysLockFromISR();
+ osalOsTimerHandlerI();
+ osalSysUnlockFromISR();
+
+ OSAL_IRQ_EPILOGUE();
+}
+
+#endif /* OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING */
+
+/*===========================================================================*/
+/* Driver exported functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Low level ST driver initialization.
+ *
+ * @notapi
+ */
+void st_lld_init(void) {
+
+#if (OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING) || defined(__DOXYGEN__)
+
+ /*
+ * Periodic mode uses Timer 1 (16 bit).
+ */
+
+ /* CTC mode, no clock source */
+ TCCR1A = 0;
+ TCCR1B = _BV(WGM12);
+
+ /* start disabled */
+ TCCR1C = 0;
+ OCR1A = 0;
+ TCNT1 = 0;
+ TIFR_REG = _BV(OCF1A); /* Reset pending. */
+ TIMSK_REG = 0;
+ TCCR1B = PRESCALER;
+
+#endif /* OSAL_ST_MODE == OSAL_ST_MODE_FREERUNNING */
+
+#if (OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC) || defined(__DOXYGEN__)
+
+ /*
+ * Periodic mode uses Timer 0 (8 bit).
+ */
+#if defined(TCCR0B) /* Timer has multiple output comparators */
+ TCCR0A = (1 << WGM01) | (0 << WGM00) | /* CTC mode. */
+ (0 << COM0A1) | (0 << COM0A0); /* OC0A disabled. */
+ //(0 << COM0B1) | (0 << COM0B0); /* OC0B disabled. */
+ // FIXME: See if the line bellow must be delate or recoded.
+ //TCCR0B = (0 << WGM02) | AVR_TIMER_PRESCALER_BITS; /* CTC mode. */
+ OCR0A = AVR_TIMER_COUNTER - 1;
+ TCNT0 = 0; /* Reset counter. */
+#if defined(__AVR_ATtiny85__)
+ TIFR = (1 << OCF0A); /* Reset pending. */
+ TIMSK = (1 << OCIE0A); /* IRQ on compare. */
+#else
+ TIFR0 = (1 << OCF0A); /* Reset pending. */
+ TIMSK0 = (1 << OCIE0A); /* IRQ on compare. */
+#endif
+
+#elif defined(TCCR0A) /* AT90CAN doesn't have TCCR0B and slightly different TCCR0A */
+ TCCR0A = (1 << WGM01) | (0 << WGM00) | /* CTC mode. */
+ (0 << COM0A1) | (0 << COM0A0); /* OC0A disabled. */
+ OCR0A = AVR_TIMER_COUNTER - 1;
+ TCNT0 = 0; /* Reset counter. */
+ TIFR0 = (1 << OCF0A); /* Reset pending. */
+ TIMSK0 = (1 << OCIE0A); /* IRQ on compare. */
+
+#elif defined(TCCR0) /* Timer has single output comparator */
+ TCCR0 = (1 << WGM01) | (0 << WGM00) | /* CTC mode. */
+ (0 << COM01) | (0 << COM00) | /* OC0A disabled. */
+ AVR_TIMER_PRESCALER_BITS;
+ OCR0 = AVR_TIMER_COUNTER - 1;
+ TCNT0 = 0; /* Reset counter. */
+ TIFR = (1 << OCF0); /* Reset pending. */
+ TIMSK = (1 << OCIE0); /* IRQ on compare. */
+#else
+ #error "Neither TCCR0A nor TCCR0 registers are defined"
+#endif
+
+#endif /* OSAL_ST_MODE == OSAL_ST_MODE_PERIODIC */
+
+}
+
+#endif /* OSAL_ST_MODE != OSAL_ST_MODE_NONE */
+
+/** @} */
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