drivers/flash/soc_flash_nrf.c - third_party/github/zephyrproject-rtos/zephyr - Git at Google

 /*
  * Copyright (c) 2017-2024 Nordic Semiconductor ASA
  * Copyright (c) 2016 Linaro Limited
  * Copyright (c) 2016 Intel Corporation
  *
  * SPDX-License-Identifier: Apache-2.0
  */

 #include <errno.h>

 #include <zephyr/kernel.h>
 #include <zephyr/device.h>
 #include <zephyr/init.h>
 #include <soc.h>
 #include <zephyr/drivers/flash.h>
 #include <string.h>
 #include <nrfx_nvmc.h>
 #include <nrf_erratas.h>

 #include "soc_flash_nrf.h"

 #define LOG_LEVEL CONFIG_FLASH_LOG_LEVEL
 #include <zephyr/logging/log.h>
 LOG_MODULE_REGISTER(flash_nrf);

 #if DT_NODE_HAS_STATUS_OKAY(DT_INST(0, nordic_nrf51_flash_controller))
 #define DT_DRV_COMPAT nordic_nrf51_flash_controller
 #elif DT_NODE_HAS_STATUS_OKAY(DT_INST(0, nordic_nrf52_flash_controller))
 #define DT_DRV_COMPAT nordic_nrf52_flash_controller
 #elif DT_NODE_HAS_STATUS_OKAY(DT_INST(0, nordic_nrf53_flash_controller))
 #define DT_DRV_COMPAT nordic_nrf53_flash_controller
 #elif DT_NODE_HAS_STATUS_OKAY(DT_INST(0, nordic_nrf91_flash_controller))
 #define DT_DRV_COMPAT nordic_nrf91_flash_controller
 #else
 #error No matching compatible for soc_flash_nrf.c
 #endif

 #define SOC_NV_FLASH_NODE DT_INST(0, soc_nv_flash)

 #ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
 #define FLASH_SLOT_WRITE     7500
 #if defined(CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE)
 #define FLASH_SLOT_ERASE (MAX(CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE_MS * 1000, \
 			      7500))
 #else
 #define FLASH_SLOT_ERASE FLASH_PAGE_ERASE_MAX_TIME_US
 #endif /* CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE */

 static int write_op(void *context); /* instance of flash_op_handler_t */
 static int write_synchronously(off_t addr, const void *data, size_t len);

 static int erase_op(void *context); /* instance of flash_op_handler_t */
 static int erase_synchronously(uint32_t addr, uint32_t size);
 #endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */

 static const struct flash_parameters flash_nrf_parameters = {
 #if defined(CONFIG_SOC_FLASH_NRF_EMULATE_ONE_BYTE_WRITE_ACCESS)
 	.write_block_size = 1,
 #else
 	.write_block_size = 4,
 #endif
 	.erase_value = 0xff,
 };

 #if defined(CONFIG_MULTITHREADING)
 /* semaphore for locking flash resources (tickers) */
 static struct k_sem sem_lock;
 #define SYNC_INIT() k_sem_init(&sem_lock, 1, 1)
 #define SYNC_LOCK() k_sem_take(&sem_lock, K_FOREVER)
 #define SYNC_UNLOCK() k_sem_give(&sem_lock)
 #else
 #define SYNC_INIT()
 #define SYNC_LOCK()
 #define SYNC_UNLOCK()
 #endif

 #if NRF52_ERRATA_242_PRESENT
 #include <hal/nrf_power.h>
 static int suspend_pofwarn(void);
 static void restore_pofwarn(void);

 #define SUSPEND_POFWARN() suspend_pofwarn()
 #define RESUME_POFWARN()  restore_pofwarn()
 #else
 #define SUSPEND_POFWARN() 0
 #define RESUME_POFWARN()
 #endif /* NRF52_ERRATA_242_PRESENT */

 static int write(off_t addr, const void *data, size_t len);
 static int erase(uint32_t addr, uint32_t size);

 static inline bool is_aligned_32(uint32_t data)
 {
 	return (data & 0x3) ? false : true;
 }

 static inline bool is_within_bounds(off_t addr, size_t len, off_t boundary_start,
 				    size_t boundary_size)
 {
 	return (addr >= boundary_start &&
 			(addr < (boundary_start + boundary_size)) &&
 			(len <= (boundary_start + boundary_size - addr)));
 }

 static inline bool is_regular_addr_valid(off_t addr, size_t len)
 {
 	return is_within_bounds(addr, len, 0, nrfx_nvmc_flash_size_get());
 }

 static inline bool is_uicr_addr_valid(off_t addr, size_t len)
 {
 #ifdef CONFIG_SOC_FLASH_NRF_UICR
 	return is_within_bounds(addr, len, (off_t)NRF_UICR, sizeof(*NRF_UICR));
 #else
 	return false;
 #endif /* CONFIG_SOC_FLASH_NRF_UICR */
 }

 #if CONFIG_SOC_FLASH_NRF_UICR && IS_ENABLED(NRF91_ERRATA_7_ENABLE_WORKAROUND)
 static inline void nrf91_errata_7_enter(void)
 {
 	__disable_irq();
 }

 static inline void nrf91_errata_7_exit(void)
 {
 	__DSB();
 	__enable_irq();
 }

 static void nrf_buffer_read_91_uicr(void *data, off_t addr, size_t len)
 {
 	nrf91_errata_7_enter();
 	nrf_nvmc_buffer_read(data, (uint32_t)addr, len);
 	nrf91_errata_7_exit();
 }
 #endif

 static void nvmc_wait_ready(void)
 {
 	while (!nrfx_nvmc_write_done_check()) {
 	}
 }

 static int flash_nrf_read(const struct device *dev, off_t addr,
 			    void *data, size_t len)
 {
 	const bool within_uicr = is_uicr_addr_valid(addr, len);

 	if (is_regular_addr_valid(addr, len)) {
 		addr += DT_REG_ADDR(SOC_NV_FLASH_NODE);
 	} else if (!within_uicr) {
 		LOG_ERR("invalid address: 0x%08lx:%zu",
 				(unsigned long)addr, len);
 		return -EINVAL;
 	}

 	if (!len) {
 		return 0;
 	}

 #if CONFIG_SOC_FLASH_NRF_UICR && IS_ENABLED(NRF91_ERRATA_7_ENABLE_WORKAROUND)
 	if (within_uicr) {
 		nrf_buffer_read_91_uicr(data, (uint32_t)addr, len);
 		return 0;
 	}
 #endif

 	nrf_nvmc_buffer_read(data, (uint32_t)addr, len);

 	return 0;
 }

 static int flash_nrf_write(const struct device *dev, off_t addr,
 			     const void *data, size_t len)
 {
 	int ret;

 	if (is_regular_addr_valid(addr, len)) {
 		addr += DT_REG_ADDR(SOC_NV_FLASH_NODE);
 	} else if (!is_uicr_addr_valid(addr, len)) {
 		LOG_ERR("invalid address: 0x%08lx:%zu",
 				(unsigned long)addr, len);
 		return -EINVAL;
 	}

 #if !defined(CONFIG_SOC_FLASH_NRF_EMULATE_ONE_BYTE_WRITE_ACCESS)
 	if (!is_aligned_32(addr) || (len % sizeof(uint32_t))) {
 		LOG_ERR("not word-aligned: 0x%08lx:%zu",
 				(unsigned long)addr, len);
 		return -EINVAL;
 	}
 #endif

 	if (!len) {
 		return 0;
 	}

 	SYNC_LOCK();

 #ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
 	if (nrf_flash_sync_is_required()) {
 		ret = write_synchronously(addr, data, len);
 	} else
 #endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */
 	{
 		ret = write(addr, data, len);
 	}

 	SYNC_UNLOCK();

 	return ret;
 }

 static int flash_nrf_erase(const struct device *dev, off_t addr, size_t size)
 {
 	uint32_t pg_size = nrfx_nvmc_flash_page_size_get();
 	uint32_t n_pages = size / pg_size;
 	int ret;

 	if (is_regular_addr_valid(addr, size)) {
 		/* Erase can only be done per page */
 		if (((addr % pg_size) != 0) || ((size % pg_size) != 0)) {
 			LOG_ERR("unaligned address: 0x%08lx:%zu",
 					(unsigned long)addr, size);
 			return -EINVAL;
 		}

 		if (!n_pages) {
 			return 0;
 		}

 		addr += DT_REG_ADDR(SOC_NV_FLASH_NODE);
 #ifdef CONFIG_SOC_FLASH_NRF_UICR
 	} else if (addr != (off_t)NRF_UICR || size != sizeof(*NRF_UICR)) {
 		LOG_ERR("invalid address: 0x%08lx:%zu",
 				(unsigned long)addr, size);
 		return -EINVAL;
 	}
 #else
 	} else {
 		LOG_ERR("invalid address: 0x%08lx:%zu",
 				(unsigned long)addr, size);
 		return -EINVAL;
 	}
 #endif /* CONFIG_SOC_FLASH_NRF_UICR */

 	SYNC_LOCK();

 #ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
 	if (nrf_flash_sync_is_required()) {
 		ret = erase_synchronously(addr, size);
 	} else
 #endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */
 	{
 		ret = erase(addr, size);
 	}

 	SYNC_UNLOCK();

 	return ret;
 }

 #if defined(CONFIG_FLASH_PAGE_LAYOUT)
 static struct flash_pages_layout dev_layout;

 static void flash_nrf_pages_layout(const struct device *dev,
 				     const struct flash_pages_layout **layout,
 				     size_t *layout_size)
 {
 	*layout = &dev_layout;
 	*layout_size = 1;
 }
 #endif /* CONFIG_FLASH_PAGE_LAYOUT */

 static const struct flash_parameters *
 flash_nrf_get_parameters(const struct device *dev)
 {
 	ARG_UNUSED(dev);

 	return &flash_nrf_parameters;
 }

 static const struct flash_driver_api flash_nrf_api = {
 	.read = flash_nrf_read,
 	.write = flash_nrf_write,
 	.erase = flash_nrf_erase,
 	.get_parameters = flash_nrf_get_parameters,
 #if defined(CONFIG_FLASH_PAGE_LAYOUT)
 	.page_layout = flash_nrf_pages_layout,
 #endif
 };

 static int nrf_flash_init(const struct device *dev)
 {
 	SYNC_INIT();

 #ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
 	nrf_flash_sync_init();
 #endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */

 #if defined(CONFIG_FLASH_PAGE_LAYOUT)
 	dev_layout.pages_count = nrfx_nvmc_flash_page_count_get();
 	dev_layout.pages_size = nrfx_nvmc_flash_page_size_get();
 #endif

 	return 0;
 }

 DEVICE_DT_INST_DEFINE(0, nrf_flash_init, NULL,
 		 NULL, NULL,
 		 POST_KERNEL, CONFIG_FLASH_INIT_PRIORITY,
 		 &flash_nrf_api);

 #ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE

 static int erase_synchronously(uint32_t addr, uint32_t size)
 {
 	struct flash_context context = {
 		.flash_addr = addr,
 		.len = size,
 		.enable_time_limit = 1, /* enable time limit */
 #if defined(CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE)
 		.flash_addr_next = addr
 #endif
 	};

 	struct flash_op_desc flash_op_desc = {
 		.handler = erase_op,
 		.context = &context
 	};

 	nrf_flash_sync_set_context(FLASH_SLOT_ERASE);
 	return nrf_flash_sync_exe(&flash_op_desc);
 }

 static int write_synchronously(off_t addr, const void *data, size_t len)
 {
 	struct flash_context context = {
 		.data_addr = (uint32_t) data,
 		.flash_addr = addr,
 		.len = len,
 		.enable_time_limit = 1 /* enable time limit */
 	};

 	struct flash_op_desc flash_op_desc = {
 		.handler = write_op,
 		.context = &context
 	};

 	nrf_flash_sync_set_context(FLASH_SLOT_WRITE);
 	return nrf_flash_sync_exe(&flash_op_desc);
 }

 #endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */

 static int erase_op(void *context)
 {
 	uint32_t pg_size = nrfx_nvmc_flash_page_size_get();
 	struct flash_context *e_ctx = context;

 #ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
 	uint32_t i = 0U;

 	if (e_ctx->enable_time_limit) {
 		nrf_flash_sync_get_timestamp_begin();
 	}
 #endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */

 #ifdef CONFIG_SOC_FLASH_NRF_UICR
 	if (e_ctx->flash_addr == (off_t)NRF_UICR) {
 		if (SUSPEND_POFWARN()) {
 			return -ECANCELED;
 		}

 		(void)nrfx_nvmc_uicr_erase();
 		RESUME_POFWARN();
 		return FLASH_OP_DONE;
 	}
 #endif

 	do {
 		if (SUSPEND_POFWARN()) {
 			return -ECANCELED;
 		}

 #if defined(CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE)
 		if (e_ctx->flash_addr == e_ctx->flash_addr_next) {
 			nrfx_nvmc_page_partial_erase_init(e_ctx->flash_addr,
 				CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE_MS);
 			e_ctx->flash_addr_next += pg_size;
 		}

 		if (nrfx_nvmc_page_partial_erase_continue()) {
 			e_ctx->len -= pg_size;
 			e_ctx->flash_addr += pg_size;
 		}
 #else
 		(void)nrfx_nvmc_page_erase(e_ctx->flash_addr);
 		e_ctx->len -= pg_size;
 		e_ctx->flash_addr += pg_size;
 #endif /* CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE */

 		RESUME_POFWARN();

 #ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
 		i++;

 		if (e_ctx->enable_time_limit) {
 			if (nrf_flash_sync_check_time_limit(i)) {
 				break;
 			}

 		}
 #endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */

 	} while (e_ctx->len > 0);

 	return (e_ctx->len > 0) ? FLASH_OP_ONGOING : FLASH_OP_DONE;
 }

 static void shift_write_context(uint32_t shift, struct flash_context *w_ctx)
 {
 	w_ctx->flash_addr += shift;
 	w_ctx->data_addr += shift;
 	w_ctx->len -= shift;
 }

 static int write_op(void *context)
 {
 	struct flash_context *w_ctx = context;

 #ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
 	uint32_t i = 1U;

 	if (w_ctx->enable_time_limit) {
 		nrf_flash_sync_get_timestamp_begin();
 	}
 #endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */
 #if defined(CONFIG_SOC_FLASH_NRF_EMULATE_ONE_BYTE_WRITE_ACCESS)
 	/* If not aligned, write unaligned beginning */
 	if (!is_aligned_32(w_ctx->flash_addr)) {
 		uint32_t count = sizeof(uint32_t) - (w_ctx->flash_addr & 0x3);

 		if (count > w_ctx->len) {
 			count = w_ctx->len;
 		}

 		if (SUSPEND_POFWARN()) {
 			return -ECANCELED;
 		}

 		nrfx_nvmc_bytes_write(w_ctx->flash_addr,
 				      (const void *)w_ctx->data_addr,
 				      count);

 		RESUME_POFWARN();
 		shift_write_context(count, w_ctx);

 #ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
 		if (w_ctx->enable_time_limit) {
 			if (nrf_flash_sync_check_time_limit(1)) {
 				nvmc_wait_ready();
 				return FLASH_OP_ONGOING;
 			}
 		}
 #endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */
 	}
 #endif /* CONFIG_SOC_FLASH_NRF_EMULATE_ONE_BYTE_WRITE_ACCESS */
 	/* Write all the 4-byte aligned data */
 	while (w_ctx->len >= sizeof(uint32_t)) {
 		if (SUSPEND_POFWARN()) {
 			return -ECANCELED;
 		}

 		nrfx_nvmc_word_write(w_ctx->flash_addr,
 				     UNALIGNED_GET((uint32_t *)w_ctx->data_addr));
 		RESUME_POFWARN();
 		shift_write_context(sizeof(uint32_t), w_ctx);

 #ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
 		i++;

 		if (w_ctx->enable_time_limit) {
 			if (nrf_flash_sync_check_time_limit(i)) {
 				nvmc_wait_ready();
 				return FLASH_OP_ONGOING;
 			}
 		}
 #endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */
 	}
 #if defined(CONFIG_SOC_FLASH_NRF_EMULATE_ONE_BYTE_WRITE_ACCESS)
 	/* Write remaining unaligned data */
 	if (w_ctx->len) {
 		if (SUSPEND_POFWARN()) {
 			return -ECANCELED;
 		}

 		nrfx_nvmc_bytes_write(w_ctx->flash_addr,
 				      (const void *)w_ctx->data_addr,
 				      w_ctx->len);
 		RESUME_POFWARN();
 		shift_write_context(w_ctx->len, w_ctx);
 	}
 #endif /* CONFIG_SOC_FLASH_NRF_EMULATE_ONE_BYTE_WRITE_ACCESS */
 	nvmc_wait_ready();

 	return FLASH_OP_DONE;
 }

 static int erase(uint32_t addr, uint32_t size)
 {
 	struct flash_context context = {
 		.flash_addr = addr,
 		.len = size,
 #ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
 		.enable_time_limit = 0, /* disable time limit */
 #endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */
 #if defined(CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE)
 		.flash_addr_next = addr
 #endif
 	};

 	return	erase_op(&context);
 }

 static int write(off_t addr, const void *data, size_t len)
 {
 	struct flash_context context = {
 		.data_addr = (uint32_t) data,
 		.flash_addr = addr,
 		.len = len,
 #ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
 		.enable_time_limit = 0 /* disable time limit */
 #endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */
 	};

 	return write_op(&context);
 }

 #if NRF52_ERRATA_242_PRESENT
 /* Disable POFWARN by writing POFCON before a write or erase operation.
  * Do not attempt to write or erase if EVENTS_POFWARN is already asserted.
  */
 static bool pofcon_enabled;

 static int suspend_pofwarn(void)
 {
 	if (!nrf52_errata_242()) {
 		return 0;
 	}

 	bool enabled;
 	nrf_power_pof_thr_t pof_thr;

 	pof_thr = nrf_power_pofcon_get(NRF_POWER, &enabled);

 	if (enabled) {
 		nrf_power_pofcon_set(NRF_POWER, false, pof_thr);

 		/* This check need to be reworked once POFWARN event will be
 		 * served by zephyr.
 		 */
 		if (nrf_power_event_check(NRF_POWER, NRF_POWER_EVENT_POFWARN)) {
 			nrf_power_pofcon_set(NRF_POWER, true, pof_thr);
 			return -ECANCELED;
 		}

 		pofcon_enabled = enabled;
 	}

 	return 0;
 }

 static void restore_pofwarn(void)
 {
 	nrf_power_pof_thr_t pof_thr;

 	if (pofcon_enabled) {
 		pof_thr = nrf_power_pofcon_get(NRF_POWER, NULL);

 		nrf_power_pofcon_set(NRF_POWER, true, pof_thr);
 		pofcon_enabled = false;
 	}
 }
 #endif  /* NRF52_ERRATA_242_PRESENT */
	/*
	* Copyright (c) 2017-2024 Nordic Semiconductor ASA
	* Copyright (c) 2016 Linaro Limited
	* Copyright (c) 2016 Intel Corporation
	*
	* SPDX-License-Identifier: Apache-2.0
	*/

	#include <errno.h>

	#include <zephyr/kernel.h>
	#include <zephyr/device.h>
	#include <zephyr/init.h>
	#include <soc.h>
	#include <zephyr/drivers/flash.h>
	#include <string.h>
	#include <nrfx_nvmc.h>
	#include <nrf_erratas.h>

	#include "soc_flash_nrf.h"

	#define LOG_LEVEL CONFIG_FLASH_LOG_LEVEL
	#include <zephyr/logging/log.h>
	LOG_MODULE_REGISTER(flash_nrf);

	#if DT_NODE_HAS_STATUS_OKAY(DT_INST(0, nordic_nrf51_flash_controller))
	#define DT_DRV_COMPAT nordic_nrf51_flash_controller
	#elif DT_NODE_HAS_STATUS_OKAY(DT_INST(0, nordic_nrf52_flash_controller))
	#define DT_DRV_COMPAT nordic_nrf52_flash_controller
	#elif DT_NODE_HAS_STATUS_OKAY(DT_INST(0, nordic_nrf53_flash_controller))
	#define DT_DRV_COMPAT nordic_nrf53_flash_controller
	#elif DT_NODE_HAS_STATUS_OKAY(DT_INST(0, nordic_nrf91_flash_controller))
	#define DT_DRV_COMPAT nordic_nrf91_flash_controller
	#else
	#error No matching compatible for soc_flash_nrf.c
	#endif

	#define SOC_NV_FLASH_NODE DT_INST(0, soc_nv_flash)

	#ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
	#define FLASH_SLOT_WRITE 7500
	#if defined(CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE)
	#define FLASH_SLOT_ERASE (MAX(CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE_MS * 1000, \
	7500))
	#else
	#define FLASH_SLOT_ERASE FLASH_PAGE_ERASE_MAX_TIME_US
	#endif /* CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE */

	static int write_op(void context); / instance of flash_op_handler_t */
	static int write_synchronously(off_t addr, const void *data, size_t len);

	static int erase_op(void context); / instance of flash_op_handler_t */
	static int erase_synchronously(uint32_t addr, uint32_t size);
	#endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */

	static const struct flash_parameters flash_nrf_parameters = {
	#if defined(CONFIG_SOC_FLASH_NRF_EMULATE_ONE_BYTE_WRITE_ACCESS)
	.write_block_size = 1,
	#else
	.write_block_size = 4,
	#endif
	.erase_value = 0xff,
	};

	#if defined(CONFIG_MULTITHREADING)
	/* semaphore for locking flash resources (tickers) */
	static struct k_sem sem_lock;
	#define SYNC_INIT() k_sem_init(&sem_lock, 1, 1)
	#define SYNC_LOCK() k_sem_take(&sem_lock, K_FOREVER)
	#define SYNC_UNLOCK() k_sem_give(&sem_lock)
	#else
	#define SYNC_INIT()
	#define SYNC_LOCK()
	#define SYNC_UNLOCK()
	#endif

	#if NRF52_ERRATA_242_PRESENT
	#include <hal/nrf_power.h>
	static int suspend_pofwarn(void);
	static void restore_pofwarn(void);

	#define SUSPEND_POFWARN() suspend_pofwarn()
	#define RESUME_POFWARN() restore_pofwarn()
	#else
	#define SUSPEND_POFWARN() 0
	#define RESUME_POFWARN()
	#endif /* NRF52_ERRATA_242_PRESENT */

	static int write(off_t addr, const void *data, size_t len);
	static int erase(uint32_t addr, uint32_t size);

	static inline bool is_aligned_32(uint32_t data)
	{
	return (data & 0x3) ? false : true;
	}

	static inline bool is_within_bounds(off_t addr, size_t len, off_t boundary_start,
	size_t boundary_size)
	{
	return (addr >= boundary_start &&
	(addr < (boundary_start + boundary_size)) &&
	(len <= (boundary_start + boundary_size - addr)));
	}

	static inline bool is_regular_addr_valid(off_t addr, size_t len)
	{
	return is_within_bounds(addr, len, 0, nrfx_nvmc_flash_size_get());
	}

	static inline bool is_uicr_addr_valid(off_t addr, size_t len)
	{
	#ifdef CONFIG_SOC_FLASH_NRF_UICR
	return is_within_bounds(addr, len, (off_t)NRF_UICR, sizeof(*NRF_UICR));
	#else
	return false;
	#endif /* CONFIG_SOC_FLASH_NRF_UICR */
	}

	#if CONFIG_SOC_FLASH_NRF_UICR && IS_ENABLED(NRF91_ERRATA_7_ENABLE_WORKAROUND)
	static inline void nrf91_errata_7_enter(void)
	{
	__disable_irq();
	}

	static inline void nrf91_errata_7_exit(void)
	{
	__DSB();
	__enable_irq();
	}

	static void nrf_buffer_read_91_uicr(void *data, off_t addr, size_t len)
	{
	nrf91_errata_7_enter();
	nrf_nvmc_buffer_read(data, (uint32_t)addr, len);
	nrf91_errata_7_exit();
	}
	#endif

	static void nvmc_wait_ready(void)
	{
	while (!nrfx_nvmc_write_done_check()) {
	}
	}

	static int flash_nrf_read(const struct device *dev, off_t addr,
	void *data, size_t len)
	{
	const bool within_uicr = is_uicr_addr_valid(addr, len);

	if (is_regular_addr_valid(addr, len)) {
	addr += DT_REG_ADDR(SOC_NV_FLASH_NODE);
	} else if (!within_uicr) {
	LOG_ERR("invalid address: 0x%08lx:%zu",
	(unsigned long)addr, len);
	return -EINVAL;
	}

	if (!len) {
	return 0;
	}

	#if CONFIG_SOC_FLASH_NRF_UICR && IS_ENABLED(NRF91_ERRATA_7_ENABLE_WORKAROUND)
	if (within_uicr) {
	nrf_buffer_read_91_uicr(data, (uint32_t)addr, len);
	return 0;
	}
	#endif

	nrf_nvmc_buffer_read(data, (uint32_t)addr, len);

	return 0;
	}

	static int flash_nrf_write(const struct device *dev, off_t addr,
	const void *data, size_t len)
	{
	int ret;

	if (is_regular_addr_valid(addr, len)) {
	addr += DT_REG_ADDR(SOC_NV_FLASH_NODE);
	} else if (!is_uicr_addr_valid(addr, len)) {
	LOG_ERR("invalid address: 0x%08lx:%zu",
	(unsigned long)addr, len);
	return -EINVAL;
	}

	#if !defined(CONFIG_SOC_FLASH_NRF_EMULATE_ONE_BYTE_WRITE_ACCESS)
	if (!is_aligned_32(addr) \|\| (len % sizeof(uint32_t))) {
	LOG_ERR("not word-aligned: 0x%08lx:%zu",
	(unsigned long)addr, len);
	return -EINVAL;
	}
	#endif

	if (!len) {
	return 0;
	}

	SYNC_LOCK();

	#ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
	if (nrf_flash_sync_is_required()) {
	ret = write_synchronously(addr, data, len);
	} else
	#endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */
	{
	ret = write(addr, data, len);
	}

	SYNC_UNLOCK();

	return ret;
	}

	static int flash_nrf_erase(const struct device *dev, off_t addr, size_t size)
	{
	uint32_t pg_size = nrfx_nvmc_flash_page_size_get();
	uint32_t n_pages = size / pg_size;
	int ret;

	if (is_regular_addr_valid(addr, size)) {
	/* Erase can only be done per page */
	if (((addr % pg_size) != 0) \|\| ((size % pg_size) != 0)) {
	LOG_ERR("unaligned address: 0x%08lx:%zu",
	(unsigned long)addr, size);
	return -EINVAL;
	}

	if (!n_pages) {
	return 0;
	}

	addr += DT_REG_ADDR(SOC_NV_FLASH_NODE);
	#ifdef CONFIG_SOC_FLASH_NRF_UICR
	} else if (addr != (off_t)NRF_UICR \|\| size != sizeof(*NRF_UICR)) {
	LOG_ERR("invalid address: 0x%08lx:%zu",
	(unsigned long)addr, size);
	return -EINVAL;
	}
	#else
	} else {
	LOG_ERR("invalid address: 0x%08lx:%zu",
	(unsigned long)addr, size);
	return -EINVAL;
	}
	#endif /* CONFIG_SOC_FLASH_NRF_UICR */

	SYNC_LOCK();

	#ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
	if (nrf_flash_sync_is_required()) {
	ret = erase_synchronously(addr, size);
	} else
	#endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */
	{
	ret = erase(addr, size);
	}

	SYNC_UNLOCK();

	return ret;
	}

	#if defined(CONFIG_FLASH_PAGE_LAYOUT)
	static struct flash_pages_layout dev_layout;

	static void flash_nrf_pages_layout(const struct device *dev,
	const struct flash_pages_layout **layout,
	size_t *layout_size)
	{
	*layout = &dev_layout;
	*layout_size = 1;
	}
	#endif /* CONFIG_FLASH_PAGE_LAYOUT */

	static const struct flash_parameters *
	flash_nrf_get_parameters(const struct device *dev)
	{
	ARG_UNUSED(dev);

	return &flash_nrf_parameters;
	}

	static const struct flash_driver_api flash_nrf_api = {
	.read = flash_nrf_read,
	.write = flash_nrf_write,
	.erase = flash_nrf_erase,
	.get_parameters = flash_nrf_get_parameters,
	#if defined(CONFIG_FLASH_PAGE_LAYOUT)
	.page_layout = flash_nrf_pages_layout,
	#endif
	};

	static int nrf_flash_init(const struct device *dev)
	{
	SYNC_INIT();

	#ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
	nrf_flash_sync_init();
	#endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */

	#if defined(CONFIG_FLASH_PAGE_LAYOUT)
	dev_layout.pages_count = nrfx_nvmc_flash_page_count_get();
	dev_layout.pages_size = nrfx_nvmc_flash_page_size_get();
	#endif

	return 0;
	}

	DEVICE_DT_INST_DEFINE(0, nrf_flash_init, NULL,
	NULL, NULL,
	POST_KERNEL, CONFIG_FLASH_INIT_PRIORITY,
	&flash_nrf_api);

	#ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE

	static int erase_synchronously(uint32_t addr, uint32_t size)
	{
	struct flash_context context = {
	.flash_addr = addr,
	.len = size,
	.enable_time_limit = 1, /* enable time limit */
	#if defined(CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE)
	.flash_addr_next = addr
	#endif
	};

	struct flash_op_desc flash_op_desc = {
	.handler = erase_op,
	.context = &context
	};

	nrf_flash_sync_set_context(FLASH_SLOT_ERASE);
	return nrf_flash_sync_exe(&flash_op_desc);
	}

	static int write_synchronously(off_t addr, const void *data, size_t len)
	{
	struct flash_context context = {
	.data_addr = (uint32_t) data,
	.flash_addr = addr,
	.len = len,
	.enable_time_limit = 1 /* enable time limit */
	};

	struct flash_op_desc flash_op_desc = {
	.handler = write_op,
	.context = &context
	};

	nrf_flash_sync_set_context(FLASH_SLOT_WRITE);
	return nrf_flash_sync_exe(&flash_op_desc);
	}

	#endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */

	static int erase_op(void *context)
	{
	uint32_t pg_size = nrfx_nvmc_flash_page_size_get();
	struct flash_context *e_ctx = context;

	#ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
	uint32_t i = 0U;

	if (e_ctx->enable_time_limit) {
	nrf_flash_sync_get_timestamp_begin();
	}
	#endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */

	#ifdef CONFIG_SOC_FLASH_NRF_UICR
	if (e_ctx->flash_addr == (off_t)NRF_UICR) {
	if (SUSPEND_POFWARN()) {
	return -ECANCELED;
	}

	(void)nrfx_nvmc_uicr_erase();
	RESUME_POFWARN();
	return FLASH_OP_DONE;
	}
	#endif

	do {
	if (SUSPEND_POFWARN()) {
	return -ECANCELED;
	}

	#if defined(CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE)
	if (e_ctx->flash_addr == e_ctx->flash_addr_next) {
	nrfx_nvmc_page_partial_erase_init(e_ctx->flash_addr,
	CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE_MS);
	e_ctx->flash_addr_next += pg_size;
	}

	if (nrfx_nvmc_page_partial_erase_continue()) {
	e_ctx->len -= pg_size;
	e_ctx->flash_addr += pg_size;
	}
	#else
	(void)nrfx_nvmc_page_erase(e_ctx->flash_addr);
	e_ctx->len -= pg_size;
	e_ctx->flash_addr += pg_size;
	#endif /* CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE */

	RESUME_POFWARN();

	#ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
	i++;

	if (e_ctx->enable_time_limit) {
	if (nrf_flash_sync_check_time_limit(i)) {
	break;
	}

	}
	#endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */

	} while (e_ctx->len > 0);

	return (e_ctx->len > 0) ? FLASH_OP_ONGOING : FLASH_OP_DONE;
	}

	static void shift_write_context(uint32_t shift, struct flash_context *w_ctx)
	{
	w_ctx->flash_addr += shift;
	w_ctx->data_addr += shift;
	w_ctx->len -= shift;
	}

	static int write_op(void *context)
	{
	struct flash_context *w_ctx = context;

	#ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
	uint32_t i = 1U;

	if (w_ctx->enable_time_limit) {
	nrf_flash_sync_get_timestamp_begin();
	}
	#endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */
	#if defined(CONFIG_SOC_FLASH_NRF_EMULATE_ONE_BYTE_WRITE_ACCESS)
	/* If not aligned, write unaligned beginning */
	if (!is_aligned_32(w_ctx->flash_addr)) {
	uint32_t count = sizeof(uint32_t) - (w_ctx->flash_addr & 0x3);

	if (count > w_ctx->len) {
	count = w_ctx->len;
	}

	if (SUSPEND_POFWARN()) {
	return -ECANCELED;
	}

	nrfx_nvmc_bytes_write(w_ctx->flash_addr,
	(const void *)w_ctx->data_addr,
	count);

	RESUME_POFWARN();
	shift_write_context(count, w_ctx);

	#ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
	if (w_ctx->enable_time_limit) {
	if (nrf_flash_sync_check_time_limit(1)) {
	nvmc_wait_ready();
	return FLASH_OP_ONGOING;
	}
	}
	#endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */
	}
	#endif /* CONFIG_SOC_FLASH_NRF_EMULATE_ONE_BYTE_WRITE_ACCESS */
	/* Write all the 4-byte aligned data */
	while (w_ctx->len >= sizeof(uint32_t)) {
	if (SUSPEND_POFWARN()) {
	return -ECANCELED;
	}

	nrfx_nvmc_word_write(w_ctx->flash_addr,
	UNALIGNED_GET((uint32_t *)w_ctx->data_addr));
	RESUME_POFWARN();
	shift_write_context(sizeof(uint32_t), w_ctx);

	#ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
	i++;

	if (w_ctx->enable_time_limit) {
	if (nrf_flash_sync_check_time_limit(i)) {
	nvmc_wait_ready();
	return FLASH_OP_ONGOING;
	}
	}
	#endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */
	}
	#if defined(CONFIG_SOC_FLASH_NRF_EMULATE_ONE_BYTE_WRITE_ACCESS)
	/* Write remaining unaligned data */
	if (w_ctx->len) {
	if (SUSPEND_POFWARN()) {
	return -ECANCELED;
	}

	nrfx_nvmc_bytes_write(w_ctx->flash_addr,
	(const void *)w_ctx->data_addr,
	w_ctx->len);
	RESUME_POFWARN();
	shift_write_context(w_ctx->len, w_ctx);
	}
	#endif /* CONFIG_SOC_FLASH_NRF_EMULATE_ONE_BYTE_WRITE_ACCESS */
	nvmc_wait_ready();

	return FLASH_OP_DONE;
	}

	static int erase(uint32_t addr, uint32_t size)
	{
	struct flash_context context = {
	.flash_addr = addr,
	.len = size,
	#ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
	.enable_time_limit = 0, /* disable time limit */
	#endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */
	#if defined(CONFIG_SOC_FLASH_NRF_PARTIAL_ERASE)
	.flash_addr_next = addr
	#endif
	};

	return erase_op(&context);
	}

	static int write(off_t addr, const void *data, size_t len)
	{
	struct flash_context context = {
	.data_addr = (uint32_t) data,
	.flash_addr = addr,
	.len = len,
	#ifndef CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE
	.enable_time_limit = 0 /* disable time limit */
	#endif /* !CONFIG_SOC_FLASH_NRF_RADIO_SYNC_NONE */
	};

	return write_op(&context);
	}

	#if NRF52_ERRATA_242_PRESENT
	/* Disable POFWARN by writing POFCON before a write or erase operation.
	* Do not attempt to write or erase if EVENTS_POFWARN is already asserted.
	*/
	static bool pofcon_enabled;

	static int suspend_pofwarn(void)
	{
	if (!nrf52_errata_242()) {
	return 0;
	}

	bool enabled;
	nrf_power_pof_thr_t pof_thr;

	pof_thr = nrf_power_pofcon_get(NRF_POWER, &enabled);

	if (enabled) {
	nrf_power_pofcon_set(NRF_POWER, false, pof_thr);

	/* This check need to be reworked once POFWARN event will be
	* served by zephyr.
	*/
	if (nrf_power_event_check(NRF_POWER, NRF_POWER_EVENT_POFWARN)) {
	nrf_power_pofcon_set(NRF_POWER, true, pof_thr);
	return -ECANCELED;
	}

	pofcon_enabled = enabled;
	}

	return 0;
	}

	static void restore_pofwarn(void)
	{
	nrf_power_pof_thr_t pof_thr;

	if (pofcon_enabled) {
	pof_thr = nrf_power_pofcon_get(NRF_POWER, NULL);

	nrf_power_pofcon_set(NRF_POWER, true, pof_thr);
	pofcon_enabled = false;
	}
	}
	#endif /* NRF52_ERRATA_242_PRESENT */