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| author | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2013-07-27 18:11:16 +0000 |
|---|---|---|
| committer | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2013-07-27 18:11:16 +0000 |
| commit | cea523fdb0cad1ec6422a9b4ea13ba08da0932a1 (patch) | |
| tree | 9c0267d48de82f4923dbf5425d53a902fd0d53b7 /os/kernel/include/chrt.h | |
| parent | 2f46bd9742047fac9ed3d139396b112120e2eada (diff) | |
| download | ChibiOS-cea523fdb0cad1ec6422a9b4ea13ba08da0932a1.tar.gz ChibiOS-cea523fdb0cad1ec6422a9b4ea13ba08da0932a1.tar.bz2 ChibiOS-cea523fdb0cad1ec6422a9b4ea13ba08da0932a1.zip | |
git-svn-id: svn://svn.code.sf.net/p/chibios/svn/branches/kernel_3_dev@6035 35acf78f-673a-0410-8e92-d51de3d6d3f4
Diffstat (limited to 'os/kernel/include/chrt.h')
| -rw-r--r-- | os/kernel/include/chrt.h | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/os/kernel/include/chrt.h b/os/kernel/include/chrt.h new file mode 100644 index 000000000..bac5635dc --- /dev/null +++ b/os/kernel/include/chrt.h @@ -0,0 +1,231 @@ +/*
+ ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
+ 2011,2012,2013 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 <http://www.gnu.org/licenses/>.
+*/
+
+/**
+ * @file chrt.h
+ * @brief Real Time Counter and Measurement module macros and structures.
+ *
+ * @addtogroup rt_measurement
+ * @{
+ */
+
+#ifndef _CHRT_H_
+#define _CHRT_H_
+
+#if CH_CFG_USE_RT || defined(__DOXYGEN__)
+
+#define port_rt_get_counter_value() 0
+
+/*===========================================================================*/
+/* Module constants. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module pre-compile time settings. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Derived constants and error checks. */
+/*===========================================================================*/
+
+#if !CH_PORT_SUPPORTS_RT
+#error "the port layer does not support the realtime counter functionality"
+#endif
+
+/*===========================================================================*/
+/* Module data structures and types. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module macros. */
+/*===========================================================================*/
+/**
+ * @name Time conversion utilities for the realtime counter
+ * @{
+ */
+/**
+ * @brief Seconds to realtime counter.
+ * @details Converts from seconds to realtime counter cycles.
+ * @note The result is rounded upward to the next tick boundary.
+ *
+ * @param[in] sec number of seconds
+ * @return The number of cycles.
+ *
+ * @api
+ */
+#define S2RTV(freq, sec) ((freq) * (sec))
+
+/**
+ * @brief Milliseconds to realtime counter.
+ * @details Converts from milliseconds to realtime counter cycles.
+ * @note The result is rounded upward to the next tick boundary.
+ *
+ * @param[in] msec number of milliseconds
+ * @return The number of cycles.
+ *
+ * @api
+ */
+#define MS2RTC(freq, msec) (rtcnt_t)((((freq) + 999UL) / 1000UL) * (msec))
+
+/**
+ * @brief Microseconds to realtime counter.
+ * @details Converts from microseconds to realtime counter cycles.
+ * @note The result is rounded upward to the next tick boundary.
+ *
+ * @param[in] usec number of microseconds
+ * @return The number of cycles.
+ *
+ * @api
+ */
+#define US2RTC(freq, usec) (rtcnt_t)((((freq) + 999999UL) / 1000000UL) * (usec))
+
+/**
+ * @brief Realtime counter cycles to seconds.
+ * @details Converts from realtime counter cycles number to seconds.
+ *
+ * @param[in] n number of cycles
+ * @return The number of seconds.
+ *
+ * @api
+ */
+#define RTC2S(freq, n) (rtcnt_t)((n) / (freq))
+
+/**
+ * @brief Realtime counter cycles to milliseconds.
+ * @details Converts from realtime counter cycles number to milliseconds.
+ *
+ * @param[in] n number of cycles
+ * @return The number of milliseconds.
+ *
+ * @api
+ */
+#define RTC2MS(freq, n) ((n) / ((freq) / 1000UL))
+
+/**
+ * @brief Realtime counter cycles to microseconds.
+ * @details Converts from realtime counter cycles number to microseconds.
+ *
+ * @param[in] n number of cycles
+ * @return The number of microseconds.
+ *
+ * @api
+ */
+#define RTC2US(freq, n) ((n) / ((freq) / 1000000UL))
+/** @} */
+
+/*===========================================================================*/
+/* External declarations. */
+/*===========================================================================*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+#ifdef __cplusplus
+}
+#endif
+
+/*===========================================================================*/
+/* Module inline functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Returns the current value of the system real time counter.
+ * @note This function can be called from any context.
+ *
+ * @return The value of the system free running counter of
+ * type rtcnt_t.
+ *
+ * @special
+ */
+static inline rtcnt_t chRTGetCounterValue(void) {
+
+ return port_rt_get_counter_value();
+}
+
+/**
+ * @brief Realtime window test.
+ * @details This function verifies if the current realtime counter value
+ * lies within the specified range or not. The test takes care
+ * of the realtime counter wrapping to zero on overflow.
+ * @note When start==end then the function returns always true because the
+ * whole time range is specified.
+ * @note This function can be called from any context.
+ *
+ * @par Example 1
+ * Example of a guarded loop using the realtime counter. The loop implements
+ * a timeout after one second.
+ * @code
+ * rtcnt_t start = chRTGetCounterValue();
+ * rtcnt_t timeout = start + S2RTC(1);
+ * while (my_condition) {
+ * if (!chRTIsCounterWithin(start, timeout)
+ * return TIMEOUT;
+ * // Do something.
+ * }
+ * // Continue.
+ * @endcode
+ *
+ * @par Example 2
+ * Example of a loop that lasts exactly 50 microseconds.
+ * @code
+ * rtcnt_t start = chRTGetCounterValue();
+ * rtcnt_t timeout = start + US2RTC(50);
+ * while (chRTIsCounterWithin(start, timeout)) {
+ * // Do something.
+ * }
+ * // Continue.
+ * @endcode
+ *
+ * @param[in] start the start of the time window (inclusive)
+ * @param[in] end the end of the time window (non inclusive)
+ * @retval true current time within the specified time window.
+ * @retval false current time not within the specified time window.
+ *
+ * @special
+ */
+static inline bool chRTIsCounterWithin(rtcnt_t start, rtcnt_t end) {
+ rtcnt_t now = chRTGetCounterValue();
+
+ return end > start ? (now >= start) && (now < end) :
+ (now >= start) || (now < end);
+}
+
+/**
+ * @brief Polled delay.
+ * @note The real delay is always few cycles in excess of the specified
+ * value.
+ * @note This function can be called from any context.
+ *
+ * @param[in] ticks number of ticks
+ *
+ * @special
+ */
+static inline void chRTPolledDelay(rtcnt_t ticks) {
+ rtcnt_t start = chRTGetCounterValue();
+ rtcnt_t timeout = start + (ticks);
+ while (chRTIsCounterWithin(start, timeout))
+ ;
+}
+
+#endif /* CH_CFG_USE_RT */
+
+#endif /* _CHRT_H_ */
+
+/** @} */
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