include/bsp/watchdog.h

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup RTEMSBSPsAArch64RaspberryPi
0007  *
0008  * @brief API of the Watchdog driver for the raspberrypi4 bsp in RTEMS.
0009  */
0010
0011 /*
0012  * Copyright (C) 2024 Ning Yang
0013  *
0014  * Redistribution and use in source and binary forms, with or without
0015  * modification, are permitted provided that the following conditions
0016  * are met:
0017  * 1. Redistributions of source code must retain the above copyright
0018  *    notice, this list of conditions and the following disclaimer.
0019  * 2. Redistributions in binary form must reproduce the above copyright
0020  *    notice, this list of conditions and the following disclaimer in the
0021  *    documentation and/or other materials provided with the distribution.
0022  *
0023  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0024  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0025  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0026  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0027  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0028  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0029  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0030  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0031  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0032  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0033  * POSSIBILITY OF SUCH DAMAGE.
0034  */
0035
0036 #ifndef LIBBSP_AARCH64_RASPBERRYPI_BSP_RPI_WATCHDOG_H
0037 #define LIBBSP_AARCH64_RASPBERRYPI_BSP_RPI_WATCHDOG_H
0038
0039 #ifdef __cplusplus
0040 extern "C" {
0041 #endif
0042
0043 /**
0044  * @note a brief example of expected usage.
0045  *
0046  * void raspberrypi_watchdog_example()
0047  * {
0048  *  raspberrypi_watchdog_init();
0049  *  raspberrypi_watchdog_start(15000);
0050  *
0051  *  raspberrypi_watchdog_reload();
0052  *  ...
0053  *  raspberrypi_watchdog_reload();
0054  *
0055  *  raspberrypi_watchdog_stop();
0056  * }
0057  *
0058  */
0059
0060 /**
0061  * @brief Initialize BSP watchdog routines.
0062  */
0063 void raspberrypi_watchdog_init(void);
0064
0065 /**
0066  * @brief Turn on the watchdog / begin the counter at the desired value.
0067  *
0068  * @param timeout Watchdog timeout value in ms.
0069  *                The watchdog device has 20 bits of timeout, so it only
0070  *                supports a maximum of 15999 ms for its timeout.
0071  *                This value should be between 0 and 15999.
0072  */
0073 void raspberrypi_watchdog_start(uint32_t timeout_ms);
0074
0075 /**
0076  * @brief Turn off the watchdog.
0077  */
0078 void raspberrypi_watchdog_stop(void);
0079
0080 /**
0081  * @brief Reload watchdog.
0082  */
0083 void raspberrypi_watchdog_reload(void);
0084
0085 /**
0086  * @brief Get the remaining time of the watchdog.
0087  *        The return value is still valid when the watchdog has been stopped.
0088  *
0089  * @retval Watchdog remaining time in ms.
0090  */
0091 uint32_t raspberrypi_watchdog_get_remaining_time(void);
0092
0093 #ifdef __cplusplus
0094 }
0095 #endif
0096
0097 #endif