include/bsp/clock-armv7m.h

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup RTEMSDriverClockArmv7MSysTick
0007  *
0008  * @brief This header file provides support for Armv7-M clock drivers.
0009  */
0010
0011 /*
0012  * Copyright (C) 2024 embedded brains GmbH & Co. KG
0013  * Copyright (C) 2011, 2018 Sebastian Huber
0014  *
0015  * Redistribution and use in source and binary forms, with or without
0016  * modification, are permitted provided that the following conditions
0017  * are met:
0018  * 1. Redistributions of source code must retain the above copyright
0019  *    notice, this list of conditions and the following disclaimer.
0020  * 2. Redistributions in binary form must reproduce the above copyright
0021  *    notice, this list of conditions and the following disclaimer in the
0022  *    documentation and/or other materials provided with the distribution.
0023  *
0024  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0025  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0026  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0027  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0028  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0029  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0030  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0031  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0032  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0033  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0034  * POSSIBILITY OF SUCH DAMAGE.
0035  */
0036
0037 #ifndef BSP_CLOCK_ARMV7M_H
0038 #define BSP_CLOCK_ARMV7M_H
0039
0040 #include <rtems/score/armv7m.h>
0041 #include <rtems/timecounter.h>
0042
0043 #include <bsp.h>
0044
0045 #ifdef __cplusplus
0046 extern "C" {
0047 #endif /* __cplusplus */
0048
0049 /**
0050  * @defgroup RTEMSDriverClockArmv7MSysTick Armv7-M SysTick Clock Driver
0051  *
0052  * @ingroup RTEMSDriverClockImpl
0053  *
0054  * @brief This group contains the Armv7-M SysTick support and Clock Driver
0055  *   implementation.
0056  *
0057  * @{
0058  */
0059
0060 #ifdef ARM_MULTILIB_ARCH_V7M
0061
0062 typedef struct {
0063   struct timecounter base;
0064   uint32_t ticks;
0065 } ARMV7M_Timecounter;
0066
0067 extern ARMV7M_Timecounter _ARMV7M_TC;
0068
0069 static inline uint32_t _ARMV7M_Clock_frequency(void)
0070 {
0071 #ifdef BSP_ARMV7M_SYSTICK_FREQUENCY
0072   return BSP_ARMV7M_SYSTICK_FREQUENCY;
0073 #else
0074   volatile ARMV7M_Systick *systick = _ARMV7M_Systick;
0075   return ARMV7M_SYSTICK_CALIB_TENMS_GET(systick->calib) * 100;
0076 #endif
0077 }
0078
0079 static uint32_t _ARMV7M_Clock_counter(ARMV7M_Timecounter *tc)
0080 {
0081   volatile ARMV7M_Systick *systick;
0082   rtems_interrupt_level level;
0083   uint32_t interval;
0084   uint32_t counter;
0085   uint32_t ticks;
0086   uint32_t csr;
0087
0088   rtems_interrupt_disable(level);
0089   systick = _ARMV7M_Systick;
0090   counter = systick->cvr;
0091   csr = systick->csr;
0092   interval = systick->rvr;
0093   ticks = tc->ticks;
0094
0095   if (RTEMS_PREDICT_FALSE((csr & ARMV7M_SYSTICK_CSR_COUNTFLAG) != 0)) {
0096     counter = systick->cvr;
0097     ticks += interval;
0098     tc->ticks = ticks;
0099   }
0100
0101   counter = interval - counter + ticks;
0102   rtems_interrupt_enable(level);
0103
0104   return counter;
0105 }
0106
0107 #endif /* ARM_MULTILIB_ARCH_V7M */
0108
0109 /** @} */
0110
0111 #ifdef __cplusplus
0112 }
0113 #endif /* __cplusplus */
0114
0115 #endif /* BSP_CLOCK_ARMV7M_H */