reflow-oven-control-sw/stm-firmware/safety/fault.c

/* Reflow Oven Controller
 *
 * Copyright (C) 2020  Mario Hüttel <mario.huettel@gmx.net>
 *
 * This file is part of the Reflow Oven Controller Project.
 *
 * The reflow oven controller is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * The Reflow Oven Control Firmware 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 the reflow oven controller project.
 * If not, see <http://www.gnu.org/licenses/>.
 */

#include <reflow-controller/oven-driver.h>
#include <reflow-controller/digio.h>
#include <reflow-controller/safety/fault.h>
#include <reflow-controller/safety/safety-memory.h>
#include <helper-macros/helper-macros.h>

/**
 * @brief Handler for hard faults.
 *
 * This hard fault handler will turn of the oven output and go to panic mode.
 * @note Depending on the fault condition some of the things done here could fail.
 */
void HardFault_Handler(void)
{
	/* This is a non recoverable fault. Stop the oven */
	oven_driver_set_power(0);
	oven_driver_apply_power_level();

	/* Set the error led */
	led_set(0, 1);

	/* Try the real panic mode */
	panic_mode();
}

/* Overwrite default handler. Go to panic mode */
/**
 * @brief Default interrupt handler. This will trigger a panic.
 * @note This function should never be called during normal operation.
 */
void __int_default_handler(void)
{
	panic_mode();
}

/**
 * @brief Put the device into panic mode.
 *
 * This function can be used when a irrecoverable error is encountered.
 * The function will:
 *  - Disable the oven output
 *  - Set the panic flag in the safety memory
 *  - Hang and wait for the watchdog to trigger a system reset.
 *
 *  The panic state will be entered after the reset due to the set panic flag in the safety memory
 */
void panic_mode(void)
{
	/* This variable is static, because I don't want it to be on the stack */
	static struct safety_memory_boot_status IN_SECTION(.ccm.bss) boot_status;

	oven_driver_set_power(0);
	oven_driver_apply_power_level();

	if (!safety_memory_get_boot_status(&boot_status)) {
		boot_status.reset_from_panic = 0xFFFFFFFF;
		(void)safety_memory_set_boot_status(&boot_status);
	}

	/* Let the watchdog do the rest */
	while (1)
		;
}