rt-thread/bsp/efm32/Libraries/emlib/src/em_letimer.c

534 lines
16 KiB
C

/***************************************************************************//**
* @file
* @brief Low Energy Timer (LETIMER) Peripheral API
* @author Energy Micro AS
* @version 3.0.0
*******************************************************************************
* @section License
* <b>(C) Copyright 2012 Energy Micro AS, http://www.energymicro.com</b>
*******************************************************************************
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*
* DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Energy Micro AS has no
* obligation to support this Software. Energy Micro AS is providing the
* Software "AS IS", with no express or implied warranties of any kind,
* including, but not limited to, any implied warranties of merchantability
* or fitness for any particular purpose or warranties against infringement
* of any proprietary rights of a third party.
*
* Energy Micro AS will not be liable for any consequential, incidental, or
* special damages, or any other relief, or for any claim by any third party,
* arising from your use of this Software.
*
******************************************************************************/
#include "em_letimer.h"
#include "em_cmu.h"
#include "em_assert.h"
/***************************************************************************//**
* @addtogroup EM_Library
* @{
******************************************************************************/
/***************************************************************************//**
* @addtogroup LETIMER
* @brief Low Energy Timer (LETIMER) Peripheral API
* @{
******************************************************************************/
/*******************************************************************************
******************************* DEFINES ***********************************
******************************************************************************/
/** @cond DO_NOT_INCLUDE_WITH_DOXYGEN */
/** Validation of valid comparator register for assert statements. */
#define LETIMER_COMP_REG_VALID(reg) (((reg) <= 1))
/** Validation of LETIMER register block pointer reference for assert statements. */
#define LETIMER_REF_VALID(ref) ((ref) == LETIMER0)
/** Validation of valid repeat counter register for assert statements. */
#define LETIMER_REP_REG_VALID(reg) (((reg) <= 1))
/** @endcond */
/*******************************************************************************
************************** LOCAL FUNCTIONS ********************************
******************************************************************************/
/** @cond DO_NOT_INCLUDE_WITH_DOXYGEN */
#if defined(_EFM32_GECKO_FAMILY)
/***************************************************************************//**
* @brief
* Wait for ongoing sync of register(s) to low frequency domain to complete.
*
* @note
* This only applies to the Gecko Family, see the reference manual
* chapter about Access to Low Energy Peripherals (Asynchronos Registers)
* for details.
*
* @param[in] letimer
* Pointer to LETIMER peripheral register block
*
* @param[in] mask
* Bitmask corresponding to SYNCBUSY register defined bits, indicating
* registers that must complete any ongoing synchronization.
******************************************************************************/
__STATIC_INLINE void LETIMER_Sync(LETIMER_TypeDef *letimer, uint32_t mask)
{
/* Avoid deadlock if modifying the same register twice when freeze mode is */
/* activated. */
if (letimer->FREEZE & LETIMER_FREEZE_REGFREEZE)
return;
/* Wait for any pending previous write operation to have been completed */
/* in low frequency domain, only required for Gecko Family of devices */
while (letimer->SYNCBUSY & mask)
;
}
#endif
/** @endcond */
/*******************************************************************************
************************** GLOBAL FUNCTIONS *******************************
******************************************************************************/
/***************************************************************************//**
* @brief
* Get LETIMER compare register value.
*
* @param[in] letimer
* Pointer to LETIMER peripheral register block
*
* @param[in] comp
* Compare register to get, either 0 or 1
*
* @return
* Compare register value, 0 if invalid register selected.
******************************************************************************/
uint32_t LETIMER_CompareGet(LETIMER_TypeDef *letimer, unsigned int comp)
{
uint32_t ret;
EFM_ASSERT(LETIMER_REF_VALID(letimer) && LETIMER_COMP_REG_VALID(comp));
/* Initialize selected compare value */
switch (comp)
{
case 0:
ret = letimer->COMP0;
break;
case 1:
ret = letimer->COMP1;
break;
default:
/* Unknown compare register selected */
ret = 0;
break;
}
return(ret);
}
/***************************************************************************//**
* @brief
* Set LETIMER compare register value.
*
* @note
* The setting of a compare register requires synchronization into the
* low frequency domain. If the same register is modified before a previous
* update has completed, this function will stall until the previous
* synchronization has completed. This only applies to the Gecko Family, see
* comment in the LETIMER_Sync() internal function call.
*
* @param[in] letimer
* Pointer to LETIMER peripheral register block
*
* @param[in] comp
* Compare register to set, either 0 or 1
*
* @param[in] value
* Initialization value (<= 0x0000ffff)
******************************************************************************/
void LETIMER_CompareSet(LETIMER_TypeDef *letimer,
unsigned int comp,
uint32_t value)
{
volatile uint32_t *compReg;
uint32_t syncbusy;
EFM_ASSERT(LETIMER_REF_VALID(letimer) &&
LETIMER_COMP_REG_VALID(comp) &&
((value & ~(_LETIMER_COMP0_COMP0_MASK >> _LETIMER_COMP0_COMP0_SHIFT)) == 0));
/* Initialize selected compare value */
switch (comp)
{
case 0:
compReg = &(letimer->COMP0);
syncbusy = LETIMER_SYNCBUSY_COMP0;
break;
case 1:
compReg = &(letimer->COMP1);
syncbusy = LETIMER_SYNCBUSY_COMP1;
break;
default:
/* Unknown compare register selected, abort */
return;
}
#if defined(_EFM32_GECKO_FAMILY)
/* LF register about to be modified require sync. busy check */
LETIMER_Sync(letimer, syncbusy);
#endif
*compReg = value;
}
/***************************************************************************//**
* @brief
* Start/stop LETIMER.
*
* @note
* The enabling/disabling of the LETIMER modifies the LETIMER CMD register
* which requires synchronization into the low frequency domain. If this
* register is modified before a previous update to the same register has
* completed, this function will stall until the previous synchronization has
* completed. This only applies to the Gecko Family, see comment in the
* LETIMER_Sync() internal function call.
*
* @param[in] letimer
* Pointer to LETIMER peripheral register block.
*
* @param[in] enable
* true to enable counting, false to disable.
******************************************************************************/
void LETIMER_Enable(LETIMER_TypeDef *letimer, bool enable)
{
EFM_ASSERT(LETIMER_REF_VALID(letimer));
#if defined(_EFM32_GECKO_FAMILY)
/* LF register about to be modified require sync. busy check */
LETIMER_Sync(letimer, LETIMER_SYNCBUSY_CMD);
#endif
if (enable)
{
letimer->CMD = LETIMER_CMD_START;
}
else
{
letimer->CMD = LETIMER_CMD_STOP;
}
}
/***************************************************************************//**
* @brief
* LETIMER register synchronization freeze control.
*
* @details
* Some LETIMER registers require synchronization into the low frequency (LF)
* domain. The freeze feature allows for several such registers to be
* modified before passing them to the LF domain simultaneously (which
* takes place when the freeze mode is disabled).
*
* @note
* When enabling freeze mode, this function will wait for all current
* ongoing LETIMER synchronization to LF domain to complete (Normally
* synchronization will not be in progress.) However for this reason, when
* using freeze mode, modifications of registers requiring LF synchronization
* should be done within one freeze enable/disable block to avoid unecessary
* stalling.
*
* @param[in] letimer
* Pointer to LETIMER peripheral register block.
*
* @param[in] enable
* @li true - enable freeze, modified registers are not propagated to the
* LF domain
* @li false - disables freeze, modified registers are propagated to LF
* domain
******************************************************************************/
void LETIMER_FreezeEnable(LETIMER_TypeDef *letimer, bool enable)
{
if (enable)
{
/*
* Wait for any ongoing LF synchronization to complete. This is just to
* protect against the rare case when a user
* - modifies a register requiring LF sync
* - then enables freeze before LF sync completed
* - then modifies the same register again
* since modifying a register while it is in sync progress should be
* avoided.
*/
while (letimer->SYNCBUSY)
;
letimer->FREEZE = LETIMER_FREEZE_REGFREEZE;
}
else
{
letimer->FREEZE = 0;
}
}
/***************************************************************************//**
* @brief
* Initialize LETIMER.
*
* @details
* Note that the compare/repeat values must be set separately with
* LETIMER_CompareSet() and LETIMER_RepeatSet(). That should probably be done
* prior to the use of this function if configuring the LETIMER to start when
* initialization is completed.
*
* @note
* The initialization of the LETIMER modifies the LETIMER CTRL/CMD registers
* which require synchronization into the low frequency domain. If any of those
* registers are modified before a previous update to the same register has
* completed, this function will stall until the previous synchronization has
* completed. This only applies to the Gecko Family, see comment in the
* LETIMER_Sync() internal function call.
*
* @param[in] letimer
* Pointer to LETIMER peripheral register block.
*
* @param[in] init
* Pointer to LETIMER initialization structure.
******************************************************************************/
void LETIMER_Init(LETIMER_TypeDef *letimer, const LETIMER_Init_TypeDef *init)
{
uint32_t tmp = 0;
EFM_ASSERT(LETIMER_REF_VALID(letimer));
/* Stop timer if specified to be disabled and running */
if (!(init->enable) && (letimer->STATUS & LETIMER_STATUS_RUNNING))
{
#if defined(_EFM32_GECKO_FAMILY)
/* LF register about to be modified require sync. busy check */
LETIMER_Sync(letimer, LETIMER_SYNCBUSY_CMD);
#endif
letimer->CMD = LETIMER_CMD_STOP;
}
/* Configure DEBUGRUN flag, sets whether or not counter should be
* updated when debugger is active */
if (init->debugRun)
{
tmp |= LETIMER_CTRL_DEBUGRUN;
}
if (init->rtcComp0Enable)
{
tmp |= LETIMER_CTRL_RTCC0TEN;
}
if (init->rtcComp1Enable)
{
tmp |= LETIMER_CTRL_RTCC1TEN;
}
if (init->comp0Top)
{
tmp |= LETIMER_CTRL_COMP0TOP;
}
if (init->bufTop)
{
tmp |= LETIMER_CTRL_BUFTOP;
}
if (init->out0Pol)
{
tmp |= LETIMER_CTRL_OPOL0;
}
if (init->out1Pol)
{
tmp |= LETIMER_CTRL_OPOL1;
}
tmp |= init->ufoa0 << _LETIMER_CTRL_UFOA0_SHIFT;
tmp |= init->ufoa1 << _LETIMER_CTRL_UFOA1_SHIFT;
tmp |= init->repMode << _LETIMER_CTRL_REPMODE_SHIFT;
#if defined(_EFM32_GECKO_FAMILY)
/* LF register about to be modified require sync. busy check */
LETIMER_Sync(letimer, LETIMER_SYNCBUSY_CTRL);
#endif
letimer->CTRL = tmp;
/* Start timer if specified to be enabled and not already running */
if (init->enable && !(letimer->STATUS & LETIMER_STATUS_RUNNING))
{
#if defined(_EFM32_GECKO_FAMILY)
/* LF register about to be modified require sync. busy check */
LETIMER_Sync(letimer, LETIMER_SYNCBUSY_CMD);
#endif
letimer->CMD = LETIMER_CMD_START;
}
}
/***************************************************************************//**
* @brief
* Get LETIMER repeat register value.
*
* @param[in] letimer
* Pointer to LETIMER peripheral register block
*
* @param[in] rep
* Repeat register to get, either 0 or 1
*
* @return
* Repeat register value, 0 if invalid register selected.
******************************************************************************/
uint32_t LETIMER_RepeatGet(LETIMER_TypeDef *letimer, unsigned int rep)
{
uint32_t ret;
EFM_ASSERT(LETIMER_REF_VALID(letimer) && LETIMER_REP_REG_VALID(rep));
/* Initialize selected compare value */
switch (rep)
{
case 0:
ret = letimer->REP0;
break;
case 1:
ret = letimer->REP1;
break;
default:
/* Unknown compare register selected */
ret = 0;
break;
}
return(ret);
}
/***************************************************************************//**
* @brief
* Set LETIMER repeat counter register value.
*
* @note
* The setting of a repeat counter register requires synchronization into the
* low frequency domain. If the same register is modified before a previous
* update has completed, this function will stall until the previous
* synchronization has completed. This only applies to the Gecko Family, see
* comment in the LETIMER_Sync() internal function call.
*
* @param[in] letimer
* Pointer to LETIMER peripheral register block
*
* @param[in] rep
* Repeat counter register to set, either 0 or 1
*
* @param[in] value
* Initialization value (<= 0x0000ffff)
******************************************************************************/
void LETIMER_RepeatSet(LETIMER_TypeDef *letimer,
unsigned int rep,
uint32_t value)
{
volatile uint32_t *repReg;
#if defined(_EFM32_GECKO_FAMILY)
uint32_t syncbusy;
#endif
EFM_ASSERT(LETIMER_REF_VALID(letimer) &&
LETIMER_REP_REG_VALID(rep) &&
((value & ~(_LETIMER_REP0_REP0_MASK >> _LETIMER_REP0_REP0_SHIFT)) == 0));
/* Initialize selected compare value */
switch (rep)
{
case 0:
repReg = &(letimer->REP0);
#if defined(_EFM32_GECKO_FAMILY)
syncbusy = LETIMER_SYNCBUSY_REP0;
#endif
break;
case 1:
repReg = &(letimer->REP1);
#if defined(_EFM32_GECKO_FAMILY)
syncbusy = LETIMER_SYNCBUSY_REP1;
#endif
break;
default:
/* Unknown compare register selected, abort */
return;
}
#if defined(_EFM32_GECKO_FAMILY)
/* LF register about to be modified require sync. busy check */
LETIMER_Sync(letimer, syncbusy);
#endif
*repReg = value;
}
/***************************************************************************//**
* @brief
* Reset LETIMER to same state as after a HW reset.
*
* @note
* The ROUTE register is NOT reset by this function, in order to allow for
* centralized setup of this feature.
*
* @param[in] letimer
* Pointer to LETIMER peripheral register block.
******************************************************************************/
void LETIMER_Reset(LETIMER_TypeDef *letimer)
{
/* Freeze registers to avoid stalling for LF synchronization */
LETIMER_FreezeEnable(letimer, true);
/* Make sure disabled first, before resetting other registers */
letimer->CMD = LETIMER_CMD_STOP | LETIMER_CMD_CLEAR |
LETIMER_CMD_CTO0 | LETIMER_CMD_CTO1;
letimer->CTRL = _LETIMER_CTRL_RESETVALUE;
letimer->COMP0 = _LETIMER_COMP0_RESETVALUE;
letimer->COMP1 = _LETIMER_COMP1_RESETVALUE;
letimer->REP0 = _LETIMER_REP0_RESETVALUE;
letimer->REP1 = _LETIMER_REP1_RESETVALUE;
letimer->IEN = _LETIMER_IEN_RESETVALUE;
letimer->IFC = _LETIMER_IFC_MASK;
/* Do not reset route register, setting should be done independently */
/* Unfreeze registers, pass new settings on to LETIMER */
LETIMER_FreezeEnable(letimer, false);
}
/** @} (end addtogroup LETIMER) */
/** @} (end addtogroup EM_Library) */