hibernate.c

Luminary coxter_M3 内核的遥控源代码

//*****************************************************************************
//
// hibernate.c - Driver for the Hibernation module
//
// Copyright (c) 2007 Luminary Micro, Inc.  All rights reserved.
// 
// Software License Agreement
// 
// Luminary Micro, Inc. (LMI) is supplying this software for use solely and
// exclusively on LMI's microcontroller products.
// 
// The software is owned by LMI and/or its suppliers, and is protected under
// applicable copyright laws.  All rights are reserved.  You may not combine
// this software with "viral" open-source software in order to form a larger
// program.  Any use in violation of the foregoing restrictions may subject
// the user to criminal sanctions under applicable laws, as well as to civil
// liability for the breach of the terms and conditions of this license.
// 
// THIS SOFTWARE IS PROVIDED "AS IS".  NO WARRANTIES, WHETHER EXPRESS, IMPLIED
// OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
// LMI SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR
// CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
// 
// This is part of revision 1928 of the Stellaris Peripheral Driver Library.
//
//*****************************************************************************

//*****************************************************************************
//
//! \addtogroup hibernate_api
//! @{
//
//*****************************************************************************

#include "../hw_memmap.h"
#include "../hw_types.h"
#include "../hw_ints.h"
#include "../hw_hibernate.h"
#include "sysctl.h"
#include "interrupt.h"
#include "hibernate.h"
#include "debug.h"

//*****************************************************************************
//
// The delay in microseconds for writing to the Hibernation module registers.
//
//*****************************************************************************
#define DELAY_USECS             95

//*****************************************************************************
//
// The number of processor cycles to execute one pass of the delay loop.
//
//*****************************************************************************
#define LOOP_CYCLES             3

//*****************************************************************************
//
// The calculated number of delay loops to achieve the write delay.
//
//*****************************************************************************
static unsigned long g_ulWriteDelay;

//*****************************************************************************
//
//! \internal
//!
//! Provides a small delay.
//!
//! \param ulCount is the number of delay loop iterations to perform.
//!
//! Since the Hibernation module needs a delay between words written to it,
//! this function provides a means of generating that delay.  It is written in
//! assembly to keep the delay consistent across tool chains, avoiding the need
//! to tune the delay based on the tool chain in use.
//!
//! The loop below in theory takes 4 cycles/loop.
//!
//! \return None.
//
//*****************************************************************************
#if defined(ewarm)
static void
HibernateWriteDelay(unsigned long ulCount)
{
    __asm("    subs    r0, #1\n"
          "    bne.n   HibernateWriteDelay\n"
          "    bx      lr");
}
#endif
#if defined(gcc) || defined(sourcerygxx)
static void __attribute__((naked))
HibernateWriteDelay(unsigned long ulCount)
{
    __asm("    subs    r0, #1\n"
          "    bne     HibernateWriteDelay\n"
          "    bx      lr");
}
#endif
#if defined(rvmdk) || defined(__ARMCC_VERSION)
__asm void
HibernateWriteDelay(unsigned long ulCount)
{
    subs    r0, #1;
    bne     HibernateWriteDelay;
    bx      lr;
}
#endif

//*****************************************************************************
//
//! Enables the Hibernation module for operation.
//!
//! \param ulHibClk is the rate of the clock supplied to the Hibernation
//! module.
//!
//! Enables the Hibernation module for operation.  This function should be
//! called before any of the Hibernation module features are used.
//!
//! The peripheral clock will be the same as the processor clock.  This will be
//! the value returned by SysCtlClockGet(), or it can be explicitly hard-coded
//! if it is constant and known (to save the code/execution overhead of a call
//! to SysCtlClockGet()).
//!
//! This function replaces the original HibernateEnable() API and performs the
//! same actions.  A macro is provided in <tt>hibernate.h</tt> to map the
//! original API to this API.
//!
//! \return None.
//
//*****************************************************************************
void
HibernateEnableExpClk(unsigned long ulHibClk)
{
    //
    // Turn on the clock enable bit.
    //
    HWREG(HIB_CTL) |= HIB_CTL_CLK32EN;

    //
    // Compute the number of delay loops that must be used to achieve the
    // desired delay for writes to the hibernation registers.  This value
    // will be used in calls to HibernateWriteDelay().
    //
    g_ulWriteDelay = ((ulHibClk / 1000) * DELAY_USECS) / (1000L * LOOP_CYCLES);
    g_ulWriteDelay++;
}

//*****************************************************************************
//
//! Disables the Hibernation module for operation.
//!
//! Disables the Hibernation module for operation.  After this function is
//! called, none of the Hibernation module features are available.
//!
//! \return None.
//
//*****************************************************************************
void
HibernateDisable(void)
{
    //
    // Turn off the clock enable bit.
    //
    HWREG(HIB_CTL) &= ~HIB_CTL_CLK32EN;
}

//*****************************************************************************
//
//! Selects the clock input for the Hibernation module.
//!
//! \param ulClockInput specifies the clock input.
//!
//! Configures the clock input for the Hibernation module.  The configuration
//! option chosen depends entirely on hardware design.  The clock input for the
//! module will either be a 32.768 kHz oscillator or a 4.194304 MHz crystal.
//! The parameter \e ulClockFlags must be one of the following:
//!
//! - \b HIBERNATE_CLOCK_SEL_RAW - use the raw signal from a 32.768 kHz
//! oscillator.
//! - \b HIBERNATE_CLOCK_SEL_DIV128 - use the crystal input, divided by 128.
//!
//! \return None.
//
//*****************************************************************************
void
HibernateClockSelect(unsigned long ulClockInput)
{
    //
    // Check the arguments.
    //
    ASSERT((ulClockInput == HIBERNATE_CLOCK_SEL_RAW) ||
           (ulClockInput == HIBERNATE_CLOCK_SEL_DIV128));

    //
    // Set the clock selection bit according to the parameter.
    //
    HWREG(HIB_CTL) = ulClockInput | (HWREG(HIB_CTL) & ~HIB_CTL_CLKSEL);
}

//*****************************************************************************
//
//! Enables the RTC feature of the Hibernation module.
//!
//! Enables the RTC in the Hibernation module.  The RTC can be used to wake the
//! processor from hibernation at a certain time, or to generate interrupts at
//! certain times.  This function must be called before using any of the RTC
//! features of the Hibernation module.
//!
//! \return None.
//
//*****************************************************************************
void
HibernateRTCEnable(void)
{
    //
    // Turn on the RTC enable bit.
    //
    HWREG(HIB_CTL) |= HIB_CTL_RTCEN;
}

//*****************************************************************************
//
//! Disables the RTC feature of the Hibernation module.
//!
//! Disables the RTC in the Hibernation module.  After calling this function
//! the RTC features of the Hibernation module will not be available.
//!
//! \return None.
//
//*****************************************************************************
void
HibernateRTCDisable(void)
{
    //
    // Turn off the RTC enable bit.
    //
    HWREG(HIB_CTL) &= ~HIB_CTL_RTCEN;
}

//*****************************************************************************
//
//! Configures the wake conditions for the Hibernation module.
//!
//! \param ulWakeFlags specifies which conditions should be used for waking.
//!
//! Enables the conditions under which the Hibernation module will wake.  The
//! \e ulWakeFlags parameter is the logical OR of any combination of the
//! following:
//!
//! - \b HIBERNATE_WAKE_PIN - wake when the external wake pin is asserted.
//! - \b HIBERNATE_WAKE_RTC - wake when one of the RTC matches occurs.
//!
//! \return None.
//
//*****************************************************************************
void
HibernateWakeSet(unsigned long ulWakeFlags)
{
    //
    // Check the arguments.
    //
    ASSERT(!(ulWakeFlags & ~(HIBERNATE_WAKE_PIN | HIBERNATE_WAKE_RTC)));

    //
    // Set the specified wake flags in the control register.
    //
    HWREG(HIB_CTL) = (ulWakeFlags |
                      (HWREG(HIB_CTL) &
                       ~(HIBERNATE_WAKE_PIN | HIBERNATE_WAKE_RTC)));
}

//*****************************************************************************
//
//! Gets the currently configured wake conditions for the Hibernation module.
//!
//! Returns the flags representing the wake configuration for the Hibernation
//! module.  The return value will be a combination of the following flags:
//!
//! - \b HIBERNATE_WAKE_PIN - wake when the external wake pin is asserted.
//! - \b HIBERNATE_WAKE_RTC - wake when one of the RTC matches occurs.
//!
//! \return Returns flags indicating the configured wake conditions.
//
//*****************************************************************************
unsigned long
HibernateWakeGet(void)
{
    //
    // Read the wake bits from the control register and return
    // those bits to the caller.
    //
    return(HWREG(HIB_CTL) & (HIBERNATE_WAKE_PIN | HIBERNATE_WAKE_RTC));
}

//*****************************************************************************
//
//! Configures the low battery detection.
//!
//! \param ulLowBatFlags specifies behavior of low battery detection.
//!