/**
* @defgroup timer Timer Library
* @code #include <drivers/timer/timer.h> @endcode
*
* @brief Functions for simple and advanced timer usage.
*
* Timer software module. Utilizes a hardware timer to provide a number of
* software timers to the application. Each timer can be set to either one-shot
* or free-running mode. Timer events can be defined by polling or callbacks.
*
* @author Andreas Fritiofson
* @date 2007-07-13
*/
/**@{*/
#ifndef TIMER_H_
#define TIMER_H_
/*-----------------------------------------------------------------------------
* Includes
*---------------------------------------------------------------------------*/
#include <inttypes.h>
/*-----------------------------------------------------------------------------
* Defines
*---------------------------------------------------------------------------*/
/**
* @brief Definitions for timer types
*
* TimerTypeOneShot: When passed as the type argument to timerSetTimeout, the
* timer will trigger only once and then disable itself.
* TimerTypeFreeRunning: When passed as the type argument to timerSetTimeout,
* the timer will reload itself at every expiration and trigger periodically.
*/
#define TimerTypeOneShot 0
#define TimerTypeFreeRunning 1
/*-----------------------------------------------------------------------------
* Public Types
*---------------------------------------------------------------------------*/
/**
* @brief Type of the callback function pointer
*/
typedef void (*timerCallback_t)(uint8_t);
/*-----------------------------------------------------------------------------
* Public Function Prototypes
*---------------------------------------------------------------------------*/
/**
* @brief Initialize timer engine
*
* Initializes the timer engine. The hardware timer interrupt source will be
* enabled, but global interrupts need to be enabled by the application.
*/
void Timer_Init(void);
/**
* @brief Get current timer value
*
* @retval
* The current time in ticks. The tick count wraps around after 2^32
* ticks without any notification.
*/
uint32_t Timer_GetTicks(void);
/**
* @brief Initializes a software timer and starts it.
*
* @param timer
* The timer.
* @param timeout
* The timeout in ticks. Passing zero disables a running timer. A timeout
* value of X ticks gives an actual timeout of between (X-1) and X ticks,
* not including the time it takes for the application to check the
* expiration status of the timer.
* @param type
* TimerTypeOneShot or TimerTypeFreeRunning.
* @param callback
* Pointer to optional callback function on the form
* void callback(uint8_t timer). The callback function is called with the
* timer number as the argument whenever the timer expires. It is called
* from the interrupt handler and must be very short. Null if not used.
*/
void Timer_SetTimeout(uint8_t timer, uint16_t timeout, uint8_t type, timerCallback_t callback);
/**
* @brief Timer expired.
*
* Checks if a timer has expired, should be used for polling a timer event if callback
* is not used. The timer will only signal its expiration at
* the first call to this function after a timeout period, even if multiple
* timeout periods have elapsed since the previous call.
*
* @param timer
* The timer (0<=timer<TIMER_NUM_TIMERS).
* @return
* Non-zero if timer has expired since the previous check.
*/
uint8_t Timer_Expired(uint8_t timer);
/**@}*/
#endif /*TIMER_H_*/