+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction. Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License. This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2003, 2004, 2005 Develer S.r.l. (http://www.develer.com/)
+ * Copyright 2000 Bernardo Innocenti <bernie@develer.com>
+ *
+ * -->
+ *
+ * \version $Id$
+ *
+ * \author Bernardo Innocenti <bernie@develer.com>
+ * \author Francesco Sacchi <batt@develer.com>
+ *
+ * \brief Low-level timer module for AVR (interface).
+ */
+
+/*#*
+ *#* $Log$
+ *#* Revision 1.32 2007/10/08 12:14:32 batt
+ *#* Fix some review issues.
+ *#*
+ *#* Revision 1.31 2007/10/07 12:30:55 batt
+ *#* Add default timer for AVR.
+ *#*
+ *#* Revision 1.30 2007/06/07 14:35:12 batt
+ *#* Merge from project_ks.
+ *#*
+ *#* Revision 1.29 2007/03/21 11:01:36 batt
+ *#* Add missing support for ATMega1281.
+ *#*
+ *#* Revision 1.28 2006/07/19 12:56:26 bernie
+ *#* Convert to new Doxygen style.
+ *#*
+ *#* Revision 1.27 2006/05/18 00:38:24 bernie
+ *#* Use hw_cpu.h instead of ubiquitous hw.h.
+ *#*
+ *#* Revision 1.26 2006/02/21 21:28:02 bernie
+ *#* New time handling based on TIMER_TICKS_PER_SEC to support slow timers with ticks longer than 1ms.
+ *#*
+ *#* Revision 1.25 2005/07/19 07:26:37 bernie
+ *#* Refactor to decouple timer ticks from milliseconds.
+ *#*
+ *#* Revision 1.24 2005/04/11 19:10:28 bernie
+ *#* Include top-level headers from cfg/ subdir.
+ *#*
+ *#* Revision 1.23 2005/03/01 23:24:51 bernie
+ *#* Tweaks for avr-libc 1.2.x.
+ *#*
+ *#* Revision 1.21 2004/12/13 12:07:06 bernie
+ *#* DISABLE_IRQSAVE/ENABLE_IRQRESTORE: Convert to IRQ_SAVE_DISABLE/IRQ_RESTORE.
+ *#*
+ *#* Revision 1.20 2004/11/16 20:59:46 bernie
+ *#* Include <avr/io.h> explicitly.
+ *#*
+ *#* 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.
+ *#*/
+#ifndef DRV_TIMER_AVR_H
+#define DRV_TIMER_AVR_H
+
+#include <appconfig.h> /* CONFIG_TIMER */
+#include <cfg/compiler.h> /* uint8_t */
+#include <hw_cpu.h> /* CLOCK_FREQ */
+
+/**
+ * \name 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
+#define TIMER_ON_OVERFLOW3 4
+
+#define TIMER_DEFAULT TIMER_ON_OUTPUT_COMPARE0 ///< Default system timer
+/* \} */
+
+/*
+ * Hardware dependent timer initialization.
+ */
+#if (CONFIG_TIMER == TIMER_ON_OUTPUT_COMPARE0)
+
+ #define TIMER_PRESCALER 64
+ #define TIMER_HW_BITS 8
+ #define DEFINE_TIMER_ISR SIGNAL(SIG_OUTPUT_COMPARE0)
+ #define TIMER_TICKS_PER_SEC 1000
+ #define TIMER_HW_CNT OCR_DIVISOR
+
+ /// Type of time expressed in ticks of the hardware high-precision timer
+ typedef uint8_t hptime_t;
+
+#elif (CONFIG_TIMER == TIMER_ON_OVERFLOW1)
+
+ #define TIMER_PRESCALER 1
+ #define TIMER_HW_BITS 8
+ /** This value is the maximum in overflow based timers. */
+ #define TIMER_HW_CNT (1 << TIMER_HW_BITS)
+ #define DEFINE_TIMER_ISR SIGNAL(SIG_OVERFLOW1)
+ #define TIMER_TICKS_PER_SEC ((TIMER_HW_HPTICKS_PER_SEC + TIMER_HW_CNT / 2) / TIMER_HW_CNT)
+
+ /// Type of time expressed in ticks of the hardware high precision timer
+ typedef uint16_t hptime_t;
+
+#elif (CONFIG_TIMER == TIMER_ON_OUTPUT_COMPARE2)
+
+ #define TIMER_PRESCALER 64
+ #define TIMER_HW_BITS 8
+ #if CPU_AVR_ATMEGA1281 || CPU_AVR_ATMEGA168
+ #define DEFINE_TIMER_ISR SIGNAL(SIG_OUTPUT_COMPARE2A)
+ #else
+ #define DEFINE_TIMER_ISR SIGNAL(SIG_OUTPUT_COMPARE2)
+ #endif
+ #define TIMER_TICKS_PER_SEC 1000
+ /** Value for OCR register in output-compare based timers. */
+ #define TIMER_HW_CNT OCR_DIVISOR
+
+
+ /// Type of time expressed in ticks of the hardware high precision timer
+ typedef uint8_t hptime_t;
+
+#elif (CONFIG_TIMER == TIMER_ON_OVERFLOW3)
+
+ #define TIMER_PRESCALER 1
+ #define TIMER_HW_BITS 8
+ /** This value is the maximum in overflow based timers. */
+ #define TIMER_HW_CNT (1 << TIMER_HW_BITS)
+ #define DEFINE_TIMER_ISR SIGNAL(SIG_OVERFLOW3)
+ #define TIMER_TICKS_PER_SEC ((TIMER_HW_HPTICKS_PER_SEC + TIMER_HW_CNT / 2) / TIMER_HW_CNT)
+
+ /// Type of time expressed in ticks of the hardware high precision timer
+ typedef uint16_t hptime_t;
+#else
+
+ #error Unimplemented value for CONFIG_TIMER
+#endif /* CONFIG_TIMER */
+
+
+/** Frequency of the hardware high precision timer. */
+#define TIMER_HW_HPTICKS_PER_SEC ((CLOCK_FREQ + TIMER_PRESCALER / 2) / TIMER_PRESCALER)
+
+/**
+ * System timer: additional division after the prescaler
+ * 12288000 / 64 / 192 (0..191) = 1 ms
+ */
+#define OCR_DIVISOR (((CLOCK_FREQ + TIMER_PRESCALER / 2) / TIMER_PRESCALER + TIMER_TICKS_PER_SEC / 2) / TIMER_TICKS_PER_SEC - 1)
+
+/** Not needed, IRQ timer flag cleared automatically */
+#define timer_hw_irq() do {} while (0)
+
+/** Not needed, timer IRQ handler called only for timer source */
+#define timer_hw_triggered() (true)
+
+
+#endif /* DRV_TIMER_AVR_H */