tos/chips/msp430/McuSleepC.nc

   1 /*
   2  * "Copyright (c) 2005 Stanford University. All rights reserved.
   3  *
   4  * Permission to use, copy, modify, and distribute this software and
   5  * its documentation for any purpose, without fee, and without written
   6  * agreement is hereby granted, provided that the above copyright
   7  * notice, the following two paragraphs and the author appear in all
   8  * copies of this software.
   9  *
  10  * IN NO EVENT SHALL STANFORD UNIVERSITY BE LIABLE TO ANY PARTY FOR
  11  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  12  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  13  * IF STANFORD UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  14  * DAMAGE.
  15  *
  16  * STANFORD UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
  17  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE
  19  * PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND STANFORD UNIVERSITY
  20  * HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
  21  * ENHANCEMENTS, OR MODIFICATIONS."
  22  *
  23  */
  24
  25 /**
  26  * Implementation of TEP 112 (Microcontroller Power Management) for
  27  * the MSP430. Code for low power calculation copied from older
  28  * msp430hardware.h by Vlado Handziski, Joe Polastre, and Cory Sharp.
  29  *
  30  *
  31  * @author Philip Levis
  32  * @author Vlado Handziski
  33  * @author Joe Polastre
  34  * @author Cory Sharp
  35  * @date   October 26, 2005
  36  * @see  Please refer to TEP 112 for more information about this component and its
  37  *          intended use.
  38  *
  39  */
  40
  41 module McuSleepC @safe() {
  42   provides {
  43     interface McuSleep;
  44     interface McuPowerState;
  45   }
  46   uses {
  47     interface McuPowerOverride;
  48   }
  49 }
  50 implementation {
  51   bool dirty = TRUE;
  52   mcu_power_t powerState = MSP430_POWER_ACTIVE;
  53
  54   /* Note that the power values are maintained in an order
  55    * based on their active components, NOT on their values.*/
  56   // NOTE: This table should be in progmem.
  57   const uint16_t msp430PowerBits[MSP430_POWER_LPM4 + 1] = {
  58     0,                                       // ACTIVE
  59     SR_CPUOFF,                               // LPM0
  60     SR_SCG0+SR_CPUOFF,                       // LPM1
  61     SR_SCG1+SR_CPUOFF,                       // LPM2
  62     SR_SCG1+SR_SCG0+SR_CPUOFF,               // LPM3
  63     SR_SCG1+SR_SCG0+SR_OSCOFF+SR_CPUOFF,     // LPM4
  64   };
  65
  66   mcu_power_t getPowerState() {
  67     mcu_power_t pState = MSP430_POWER_LPM3;
  68     // TimerA, USART0, USART1 check
  69     if ((((TACCTL0 & CCIE) ||
  70           (TACCTL1 & CCIE) ||
  71           (TACCTL2 & CCIE)) &&
  72          ((TACTL & TASSEL_3) == TASSEL_2))
  73 #ifdef __MSP430_HAS_UART0__
  74         || ((ME1 & (UTXE0 | URXE0)) && (U0TCTL & SSEL1))
  75 #endif
  76 #ifdef __MSP430_HAS_UART1__
  77         || ((ME2 & (UTXE1 | URXE1)) && (U1TCTL & SSEL1))
  78 #endif
  79 #ifdef __MSP430_HAS_I2C__
  80          // registers end in "nr" to prevent nesC race condition detection
  81         || ((U0CTLnr & I2CEN) && (I2CTCTLnr & SSEL1) &&
  82              (I2CDCTLnr & I2CBUSY) && (U0CTLnr & SYNC) && (U0CTLnr & I2C))
  83 #endif
  84         )
  85       pState = MSP430_POWER_LPM1;
  86
  87 #ifdef __MSP430_HAS_ADC12
  88     // ADC12 check, pre-condition: pState != MSP430_POWER_ACTIVE
  89     if (ADC12CTL0 & ADC12ON){
  90       if (ADC12CTL1 & ADC12SSEL_2){
  91         // sample or conversion operation with MCLK or SMCLK
  92         if (ADC12CTL1 & ADC12SSEL_1)
  93           pState = MSP430_POWER_LPM1;
  94         else
  95           pState = MSP430_POWER_ACTIVE;
  96       } else if ((ADC12CTL1 & SHS0) && ((TACTL & TASSEL_3) == TASSEL_2)){
  97         // Timer A is used as sample-and-hold source and SMCLK sources Timer A
  98         // (Timer A interrupts are always disabled when it is used by the
  99         // ADC subsystem, that's why the Timer check above is not enough)
 100               pState = MSP430_POWER_LPM1;
 101       }
 102     }
 103 #endif
 104
 105     return pState;
 106   }
 107
 108   void computePowerState() {
 109     powerState = mcombine(getPowerState(),
 110                           call McuPowerOverride.lowestState());
 111   }
 112
 113   async command void McuSleep.sleep() {
 114     uint16_t temp;
 115     if (dirty) {
 116       computePowerState();
 117       //dirty = 0;
 118     }
 119     temp = msp430PowerBits[powerState] | SR_GIE;
 120     __asm__ __volatile__( "bis  %0, r2" : : "m" (temp) );
 121     // All of memory may change at this point...
 122     asm volatile ("" : : : "memory");
 123     __nesc_disable_interrupt();
 124   }
 125
 126   async command void McuPowerState.update() {
 127     atomic dirty = 1;
 128   }
 129
 130  default async command mcu_power_t McuPowerOverride.lowestState() {
 131    return MSP430_POWER_LPM4;
 132  }
 133
 134 }