/* ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010, 2011,2012 Giovanni Di Sirio. This file is part of ChibiOS/RT. ChibiOS/RT is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. ChibiOS/RT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ /** * @file chvt.h * @brief Time macros and structures. * * @addtogroup time * @{ */ #ifndef _CHVT_H_ #define _CHVT_H_ /** * @name Time conversion utilities * @{ */ /** * @brief Seconds to system ticks. * @details Converts from seconds to system ticks number. * @note The result is rounded upward to the next tick boundary. * * @param[in] sec number of seconds * @return The number of ticks. * * @api */ #define S2ST(sec) ((systime_t)((sec) * CH_FREQUENCY)) /** * @brief Milliseconds to system ticks. * @details Converts from milliseconds to system ticks number. * @note The result is rounded upward to the next tick boundary. * * @param[in] msec number of milliseconds * @return The number of ticks. * * @api */ #define MS2ST(msec) ((systime_t)(((((msec) - 1L) * CH_FREQUENCY) / \ 1000L) + 1L)) /** * @brief Microseconds to system ticks. * @details Converts from microseconds to system ticks number. * @note The result is rounded upward to the next tick boundary. * * @param[in] usec number of microseconds * @return The number of ticks. * * @api */ #define US2ST(usec) ((systime_t)(((((usec) - 1L) * CH_FREQUENCY) / \ 1000000L) + 1L)) /** @} */ /** * @brief Virtual Timer callback function. */ typedef void (*vtfunc_t)(void *); /** * @brief Virtual Timer structure type. */ typedef struct VirtualTimer VirtualTimer; /** * @extends DeltaList * * @brief Virtual Timer descriptor structure. */ struct VirtualTimer { VirtualTimer *vt_next; /**< @brief Next timer in the delta list. */ VirtualTimer *vt_prev; /**< @brief Previous timer in the delta list. */ systime_t vt_time; /**< @brief Time delta before timeout. */ vtfunc_t vt_func; /**< @brief Timer callback function pointer. */ void *vt_par; /**< @brief Timer callback function parameter. */ }; /** * @brief Virtual timers list header. * @note The delta list is implemented as a double link bidirectional list * in order to make the unlink time constant, the reset of a virtual * timer is often used in the code. */ typedef struct { VirtualTimer *vt_next; /**< @brief Next timer in the delta list. */ VirtualTimer *vt_prev; /**< @brief Last timer in the delta list. */ systime_t vt_time; /**< @brief Must be initialized to -1. */ volatile systime_t vt_systime; /**< @brief System Time counter. */ } VTList; /** * @name Macro Functions * @{ */ /** * @brief Virtual timers ticker. * @note The system lock is released before entering the callback and * re-acquired immediately after. It is callback's responsibility * to acquire the lock if needed. This is done in order to reduce * interrupts jitter when many timers are in use. * * @iclass */ #define chVTDoTickI() { \ vtlist.vt_systime++; \ if (&vtlist != (VTList *)vtlist.vt_next) { \ VirtualTimer *vtp; \ \ --vtlist.vt_next->vt_time; \ while (!(vtp = vtlist.vt_next)->vt_time) { \ vtfunc_t fn = vtp->vt_func; \ vtp->vt_func = (vtfunc_t)NULL; \ vtp->vt_next->vt_prev = (void *)&vtlist; \ (&vtlist)->vt_next = vtp->vt_next; \ chSysUnlockFromIsr(); \ fn(vtp->vt_par); \ chSysLockFromIsr(); \ } \ } \ } /** * @brief Returns @p TRUE if the specified timer is armed. * * @iclass */ #define chVTIsArmedI(vtp) ((vtp)->vt_func != NULL) /** * @brief Enables a virtual timer. * @note The associated function is invoked from interrupt context. * * @param[out] vtp the @p VirtualTimer structure pointer * @param[in] time the number of ticks before the operation timeouts, the * special values are handled as follow: * - @a TIME_INFINITE is allowed but interpreted as a * normal time specification. * - @a TIME_IMMEDIATE this value is not allowed. * . * @param[in] vtfunc the timer callback function. After invoking the * callback the timer is disabled and the structure can * be disposed or reused. * @param[in] par a parameter that will be passed to the callback * function * * @api */ #define chVTSet(vtp, time, vtfunc, par) { \ chSysLock(); \ chVTSetI(vtp, time, vtfunc, par); \ chSysUnlock(); \ } /** * @brief Disables a Virtual Timer. * @note The timer is first checked and disabled only if armed. * * @param[in] vtp the @p VirtualTimer structure pointer * * @api */ #define chVTReset(vtp) { \ chSysLock(); \ if (chVTIsArmedI(vtp)) \ chVTResetI(vtp); \ chSysUnlock(); \ } /** * @brief Current system time. * @details Returns the number of system ticks since the @p chSysInit() * invocation. * @note The counter can reach its maximum and then restart from zero. * @note This function is designed to work with the @p chThdSleepUntil(). * * @return The system time in ticks. * * @api */ #define chTimeNow() (vtlist.vt_systime) /** @} */ extern VTList vtlist; /* * Virtual Timers APIs. */ #ifdef __cplusplus extern "C" { #endif void _vt_init(void); void chVTSetI(VirtualTimer *vtp, systime_t time, vtfunc_t vtfunc, void *par); void chVTResetI(VirtualTimer *vtp); bool_t chTimeIsWithin(systime_t start, systime_t end); #ifdef __cplusplus } #endif #endif /* _CHVT_H_ */ /** @} */