soc/arm/st_stm32/stm32g4/soc.c

/*
 * Copyright (c) 2019 Richard Osterloh <richard.osterloh@gmail.com>
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * @file
 * @brief System/hardware module for STM32G4 processor
 */

#include <zephyr/device.h>
#include <zephyr/init.h>
#include <stm32_ll_system.h>
#include <zephyr/arch/cpu.h>
#include <zephyr/arch/arm/aarch32/cortex_m/cmsis.h>

#if defined(PWR_CR3_UCPD_DBDIS)
#include <stm32_ll_bus.h>
#include <stm32_ll_pwr.h>
#endif /* PWR_CR3_UCPD_DBDIS */

/**
 * @brief Perform basic hardware initialization at boot.
 *
 * This needs to be run from the very beginning.
 * So the init priority has to be 0 (zero).
 *
 * @return 0
 */
static int stm32g4_init(const struct device *arg)
{
	uint32_t key;

	ARG_UNUSED(arg);

	key = irq_lock();

	/* Install default handler that simply resets the CPU
	 * if configured in the kernel, NOP otherwise
	 */
	NMI_INIT();

	irq_unlock(key);

	/* Update CMSIS SystemCoreClock variable (HCLK) */
	/* At reset, system core clock is set to 16 MHz from HSI */
	SystemCoreClock = 16000000;

	/* allow reflashing board */
	LL_DBGMCU_EnableDBGSleepMode();

#if defined(PWR_CR3_UCPD_DBDIS)
	/* Disable USB Type-C dead battery pull-down behavior */
	LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_PWR);
	LL_PWR_DisableUCPDDeadBattery();
#endif /* PWR_CR3_UCPD_DBDIS */
	return 0;
}

SYS_INIT(stm32g4_init, PRE_KERNEL_1, 0);