+/// $Id$
+
+/*
+ * Copyright (c) 2004-2005 Crossbow Technology, Inc. All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation for any purpose, without fee, and without written agreement is
+ * hereby granted, provided that the above copyright notice, the following
+ * two paragraphs and the author appear in all copies of this software.
+ *
+ * IN NO EVENT SHALL CROSSBOW TECHNOLOGY OR ANY OF ITS LICENSORS BE LIABLE TO
+ * ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
+ * DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF CROSSBOW OR ITS LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * CROSSBOW TECHNOLOGY AND ITS LICENSORS SPECIFICALLY DISCLAIM ALL WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND NEITHER CROSSBOW NOR ANY LICENSOR HAS ANY
+ * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR
+ * MODIFICATIONS.
+ */
+
+/**
+ * HPL interface to Atmega128 timer 0 in ASYNC mode. This is a specialised
+ * HPL component that assumes that timer 0 is used in ASYNC mode and
+ * includes some workarounds for some of the weirdnesses (delayed overflow
+ * interrupt) of that mode.
+ *
+ * @author Martin Turon <mturon@xbow.com>
+ * @author David Gay <dgay@intel-research.net>
+ */
+
+#include <Atm128Timer.h>
+
+module HplAtm128Timer0AsyncP {
+ provides {
+ interface Init @atleastonce();
+ // 8-bit Timers
+ interface HplAtm128Timer<uint8_t> as Timer;
+ interface HplAtm128TimerCtrl8 as TimerCtrl;
+ interface HplAtm128Compare<uint8_t> as Compare;
+ interface McuPowerOverride;
+ }
+}
+implementation
+{
+ command error_t Init.init() {
+ SET_BIT(ASSR, AS0); // set Timer/Counter0 to asynchronous mode
+ return SUCCESS;
+ }
+
+ //=== Read the current timer value. ===================================
+ async command uint8_t Timer.get() { return TCNT0; }
+
+ //=== Set/clear the current timer value. ==============================
+ async command void Timer.set(uint8_t t) {
+ while (ASSR & 1 << TCN0UB)
+ ;
+ TCNT0 = t;
+ }
+
+ //=== Read the current timer scale. ===================================
+ async command uint8_t Timer.getScale() { return TCCR0 & 0x7; }
+
+ //=== Turn off the timers. ============================================
+ async command void Timer.off() { call Timer.setScale(AVR_CLOCK_OFF); }
+
+ //=== Write a new timer scale. ========================================
+ async command void Timer.setScale(uint8_t s) {
+ Atm128TimerControl_t x = call TimerCtrl.getControl();
+ x.bits.cs = s;
+ call TimerCtrl.setControl(x);
+ }
+
+ //=== Read the control registers. =====================================
+ async command Atm128TimerControl_t TimerCtrl.getControl() {
+ return *(Atm128TimerControl_t*)&TCCR0;
+ }
+
+ //=== Write the control registers. ====================================
+ async command void TimerCtrl.setControl( Atm128TimerControl_t x ) {
+ while (ASSR & 1 << TCR0UB)
+ ;
+ TCCR0 = x.flat;
+ }
+
+ //=== Read the interrupt mask. =====================================
+ async command Atm128_TIMSK_t TimerCtrl.getInterruptMask() {
+ return *(Atm128_TIMSK_t*)&TIMSK;
+ }
+
+ //=== Write the interrupt mask. ====================================
+ DEFINE_UNION_CAST(TimerMask8_2int, Atm128_TIMSK_t, uint8_t);
+ DEFINE_UNION_CAST(TimerMask16_2int, Atm128_ETIMSK_t, uint8_t);
+
+ async command void TimerCtrl.setInterruptMask( Atm128_TIMSK_t x ) {
+ TIMSK = TimerMask8_2int(x);
+ }
+
+ //=== Read the interrupt flags. =====================================
+ async command Atm128_TIFR_t TimerCtrl.getInterruptFlag() {
+ return *(Atm128_TIFR_t*)&TIFR;
+ }
+
+ //=== Write the interrupt flags. ====================================
+ DEFINE_UNION_CAST(TimerFlags8_2int, Atm128_TIFR_t, uint8_t);
+ DEFINE_UNION_CAST(TimerFlags16_2int, Atm128_ETIFR_t, uint8_t);
+
+ async command void TimerCtrl.setInterruptFlag( Atm128_TIFR_t x ) {
+ TIFR = TimerFlags8_2int(x);
+ }
+
+ //=== Timer 8-bit implementation. ====================================
+ async command void Timer.reset() { TIFR = 1 << TOV0; }
+ async command void Timer.start() { SET_BIT(TIMSK, TOIE0); }
+ async command void Timer.stop() { CLR_BIT(TIMSK, TOIE0); }
+
+ bool overflowed() {
+ return (call TimerCtrl.getInterruptFlag()).bits.tov0;
+ }
+
+ async command bool Timer.test() {
+ return overflowed();
+ }
+ async command bool Timer.isOn() {
+ return (call TimerCtrl.getInterruptMask()).bits.toie0;
+ }
+ async command void Compare.reset() { TIFR = 1 << OCF0; }
+ async command void Compare.start() { SET_BIT(TIMSK,OCIE0); }
+ async command void Compare.stop() { CLR_BIT(TIMSK,OCIE0); }
+ async command bool Compare.test() {
+ return (call TimerCtrl.getInterruptFlag()).bits.ocf0;
+ }
+ async command bool Compare.isOn() {
+ return (call TimerCtrl.getInterruptMask()).bits.ocie0;
+ }
+
+ //=== Read the compare registers. =====================================
+ async command uint8_t Compare.get() { return OCR0; }
+
+ //=== Write the compare registers. ====================================
+ async command void Compare.set(uint8_t t) {
+ atomic
+ {
+ while (ASSR & 1 << OCR0UB)
+ ;
+ OCR0 = t;
+ }
+ }
+
+ //=== Timer interrupts signals ========================================
+ void stabiliseTimer0() {
+ TCCR0 = TCCR0;
+ while (ASSR & 1 << TCR0UB)
+ ;
+ }
+
+ /**
+ * On the atm128, there is a small latency when waking up from
+ * POWER_SAVE mode. So if a timer is going to go off very soon, it's
+ * better to drop down until EXT_STANDBY, which has a 6 cycle wakeup
+ * latency. This function calculates whether staying in EXT_STANDBY
+ * is needed. If the timer is not running it returns POWER_DOWN.
+ * Please refer to TEP 112 and the atm128 datasheet for details.
+ */
+
+ async command mcu_power_t McuPowerOverride.lowestState() {
+ uint8_t diff;
+ // We need to make sure that the sleep wakeup latency will not
+ // cause us to miss a timer. POWER_SAVE
+ if (TIMSK & (1 << OCIE0 | 1 << TOIE0)) {
+ // need to wait for timer 0 updates propagate before sleeping
+ // (we don't need to worry about reentering sleep mode too early,
+ // as the wake ups from timer0 wait at least one TOSC1 cycle
+ // anyway - see the stabiliseTimer0 function in HplAtm128Timer0AsyncC)
+ while (ASSR & (1 << TCN0UB | 1 << OCR0UB | 1 << TCR0UB))
+ ;
+ diff = OCR0 - TCNT0;
+ if (diff < EXT_STANDBY_T0_THRESHOLD ||
+ TCNT0 > 256 - EXT_STANDBY_T0_THRESHOLD)
+ return ATM128_POWER_EXT_STANDBY;
+ return ATM128_POWER_SAVE;
+ }
+ else {
+ return ATM128_POWER_DOWN;
+ }
+ }
+
+ default async event void Compare.fired() { }
+ AVR_ATOMIC_HANDLER(SIG_OUTPUT_COMPARE0) {
+ stabiliseTimer0();
+ signal Compare.fired();
+ }
+
+ default async event void Timer.overflow() { }
+ AVR_ATOMIC_HANDLER(SIG_OVERFLOW0) {
+ stabiliseTimer0();
+ signal Timer.overflow();
+ }
+}
projects / tinyos-2.x.git / commitdiff