4 * This file is part of BeRTOS.
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12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
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18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * As a special exception, you may use this file as part of a free software
21 * library without restriction. Specifically, if other files instantiate
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24 * file does not by itself cause the resulting executable to be covered by
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29 * Copyright 2007 Develer S.r.l. (http://www.develer.com/)
33 * \author Francesco Sacchi <batt@develer.com>
35 * \brief Low-level timer module for Atmel AT91 (interface).
38 #ifndef DRV_AT91_TIMER_H
39 #define DRV_AT91_TIMER_H
41 #include <hw/hw_cpufreq.h> /* CPU_FREQ */
43 #include "cfg/cfg_timer.h" /* CONFIG_TIMER */
44 #include <cfg/compiler.h> /* uint8_t */
45 #include <cfg/macros.h> /* BV */
50 * \name Values for CONFIG_TIMER.
52 * Select which hardware timer interrupt to use for system clock and softtimers.
54 * $WIZ$ timer_select = "TIMER_ON_PIT", "TIMER_DEFAULT"
56 #define TIMER_ON_PIT 1 ///< System timer on Periodic interval timer
58 #define TIMER_DEFAULT TIMER_ON_PIT ///< Default system timer
61 * Hardware dependent timer initialization.
63 #if (CONFIG_TIMER == TIMER_ON_PIT)
66 * On ARM all system IRQs are handled by the sysirq_dispatcher, so the actual
67 * timer handler can be treated like any other normal routine.
69 #define DEFINE_TIMER_ISR void timer_handler(void); \
70 void timer_handler(void)
72 #define TIMER_TICKS_PER_SEC 1000
73 #define TIMER_HW_CNT (CPU_FREQ / (16 * TIMER_TICKS_PER_SEC) - 1)
75 /** Frequency of the hardware high-precision timer. */
76 #define TIMER_HW_HPTICKS_PER_SEC (CPU_FREQ / 16)
78 /** Type of time expressed in ticks of the hardware high-precision timer */
79 typedef uint32_t hptime_t;
80 #define SIZEOF_HPTIME_T 4
82 INLINE void timer_hw_irq(void)
84 /* Reset counters, this is needed to reset timer and interrupt flags */
85 uint32_t dummy = PIVR;
89 INLINE bool timer_hw_triggered(void)
91 return PIT_SR & BV(PITS);
94 INLINE hptime_t timer_hw_hpread(void)
96 /* In the upper part of PIT_PIIR there is unused data */
97 return PIIR & CPIV_MASK;
102 #error Unimplemented value for CONFIG_TIMER
103 #endif /* CONFIG_TIMER */
105 void timer_hw_init(void);
108 #endif /* DRV_TIMER_AT91_H */