neorv32/sw/lib/source/neorv32_wdt.c

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2024-02-24 08:25:27 +00:00
// #################################################################################################
// # << NEORV32: neorv32_wdt.c - Watchdog Timer (WDT) HW Driver >> #
// # ********************************************************************************************* #
// # BSD 3-Clause License #
// # #
// # Copyright (c) 2023, Stephan Nolting. All rights reserved. #
// # #
// # Redistribution and use in source and binary forms, with or without modification, are #
// # permitted provided that the following conditions are met: #
// # #
// # 1. Redistributions of source code must retain the above copyright notice, this list of #
// # conditions and the following disclaimer. #
// # #
// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of #
// # conditions and the following disclaimer in the documentation and/or other materials #
// # provided with the distribution. #
// # #
// # 3. Neither the name of the copyright holder nor the names of its contributors may be used to #
// # endorse or promote products derived from this software without specific prior written #
// # permission. #
// # #
// # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS #
// # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF #
// # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE #
// # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, #
// # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #
// # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED #
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// # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED #
// # OF THE POSSIBILITY OF SUCH DAMAGE. #
// # ********************************************************************************************* #
// # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting #
// #################################################################################################
/**********************************************************************//**
* @file neorv32_wdt.c
* @brief Watchdog Timer (WDT) HW driver source file.
*
* @note These functions should only be used if the WDT unit was synthesized (IO_WDT_EN = true).
**************************************************************************/
#include "neorv32.h"
#include "neorv32_wdt.h"
/**********************************************************************//**
* Check if WDT unit was synthesized.
*
* @return 0 if WDT was not synthesized, 1 if WDT is available.
**************************************************************************/
int neorv32_wdt_available(void) {
if (NEORV32_SYSINFO->SOC & (1 << SYSINFO_SOC_IO_WDT)) {
return 1;
}
else {
return 0;
}
}
/**********************************************************************//**
* Configure and enable watchdog timer. The WDT control register bits are listed in #NEORV32_WDT_CTRL_enum.
*
* @warning Once the lock bit is set it can only be removed by a hardware reset!
*
* @param[in] timeout 24-bit timeout value. A WDT IRQ is triggered when the internal counter reaches
* 'timeout/2'. A system hardware reset is triggered when the internal counter reaches 'timeout'.
* @param[in] lock Control register will be locked when 1 (until next reset).
* @param[in] debug_en Allow watchdog to continue operation even when CPU is in debug mode.
* @param[in] sleep_en Allow watchdog to continue operation even when CPU is in sleep mode.
* @param[in] strict Force hardware reset if reset password is incorrect.
**************************************************************************/
void neorv32_wdt_setup(uint32_t timeout, int lock, int debug_en, int sleep_en, int strict) {
NEORV32_WDT->CTRL = 0; // reset and disable
// update configuration
uint32_t ctrl = 0;
ctrl |= ((uint32_t)(1)) << WDT_CTRL_EN;
ctrl |= ((uint32_t)(timeout & 0xffffffU)) << WDT_CTRL_TIMEOUT_LSB;
ctrl |= ((uint32_t)(debug_en & 0x1U)) << WDT_CTRL_DBEN;
ctrl |= ((uint32_t)(sleep_en & 0x1U)) << WDT_CTRL_SEN;
ctrl |= ((uint32_t)(strict & 0x1U)) << WDT_CTRL_STRICT;
NEORV32_WDT->CTRL = ctrl;
// lock configuration?
if (lock) {
NEORV32_WDT->CTRL |= 1 << WDT_CTRL_LOCK;
}
}
/**********************************************************************//**
* Disable watchdog timer.
*
* @return Returns 0 if WDT is really deactivated, -1 otherwise.
**************************************************************************/
int neorv32_wdt_disable(void) {
const uint32_t en_mask_c = (uint32_t)(1 << WDT_CTRL_EN);
NEORV32_WDT->CTRL &= en_mask_c; // try to disable
// check if WDT is really off
if (NEORV32_WDT->CTRL & en_mask_c) {
return -1; // still active
}
else {
return 0; // WDT is disabled
}
}
/**********************************************************************//**
* Feed watchdog (reset timeout counter).
**************************************************************************/
void neorv32_wdt_feed(void) {
NEORV32_WDT->RESET = (uint32_t)WDT_PASSWORD;
}
/**********************************************************************//**
* Get cause of last system reset.
*
* @return Cause of last reset (0: external reset, 1: OCD reset, 2: WDT reset).
**************************************************************************/
int neorv32_wdt_get_cause(void) {
uint32_t tmp = NEORV32_WDT->CTRL;
tmp = tmp >> WDT_CTRL_RCAUSE_LO;
tmp = tmp & 3;
return tmp;
}