reflow-oven-control-sw/stm-firmware/hw-version-detect.c

/* Reflow Oven Controller
 *
 * Copyright (C) 2021  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/>.
 */

/**
 * @addtogroup hw-version-detect
 * @{
 */

#include <reflow-controller/hw-version-detect.h>
#include <stm-periph/rcc-manager.h>
#include <stm32/stm32f4xx.h>

#if HW_REV_DETECT_PIN_LOW > HW_REV_DETECT_PIN_HIGH
#error Configuration error for Hardware derection pins. Lowest position must be less than the highest pin position.
#endif

enum hw_revision get_pcb_hardware_version(void)
{
	uint8_t current_pin;
	uint16_t port_bitmask = 0U; /* Use uint16_t because a port can have 16 IOs max. */
	const uint16_t highest_bit_mask = (1 << (HW_REV_DETECT_PIN_HIGH - HW_REV_DETECT_PIN_LOW));
	static enum hw_revision revision = HW_REV_NOT_DETECTED;

	/* If the revision has been previously detected,
	 * just return it and don't do the whole detection stuff
	 */
	if (revision != HW_REV_NOT_DETECTED)
		return revision;

	rcc_manager_enable_clock(&RCC->AHB1ENR, BITMASK_TO_BITNO(HW_REV_DETECT_RCC_FIELD));

	/* Setup the pins as input with pull up */
	for (current_pin = HW_REV_DETECT_PIN_LOW; current_pin <= HW_REV_DETECT_PIN_HIGH; current_pin++) {
		HW_REV_DETECT_GPIO->MODER &= MODER_DELETE(current_pin);
		HW_REV_DETECT_GPIO->PUPDR &= PUPDR_DELETE(current_pin);
		HW_REV_DETECT_GPIO->PUPDR |= PULLUP(current_pin);
	}

	/* Loop again and read in the pin mask.
	 * Because we use GND-Shorts on the pins to detect the version, the pins are read inverted.
	 */
	for (current_pin = HW_REV_DETECT_PIN_LOW; current_pin <= HW_REV_DETECT_PIN_HIGH; current_pin++) {
		port_bitmask >>= 1;
		port_bitmask |= (HW_REV_DETECT_GPIO->IDR & (1 << current_pin)) ? 0x0 : highest_bit_mask;
	}

	/* Resolve the read in bitmask to a hardware version */
	switch (port_bitmask) {
	case 0U:
		revision = HW_REV_V1_2;
		break;
	case 1U:
		revision = HW_REV_V1_3;
		break;
	case 2U:
		revision = HW_REV_V1_3_1;
		break;
	default:
		revision = HW_REV_ERROR;
	}

	rcc_manager_disable_clock(&RCC->AHB1ENR, BITMASK_TO_BITNO(HW_REV_DETECT_RCC_FIELD));

	return revision;
}

/** @} */