/*
 * Copyright (c) 2023 STMicroelectronics
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/kernel.h>
#include <zephyr/device.h>
#include <zephyr/init.h>
#include <zephyr/drivers/flash.h>

#define DT_DRV_COMPAT st_stm32wba_flash_controller

#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(flash_stm32wba, CONFIG_FLASH_LOG_LEVEL);

#include "flash_stm32.h"
#include "flash_manager.h"
#include "flash_driver.h"

/* Let's wait for double the max erase time to be sure that the operation is
 * completed.
 */
#define STM32_FLASH_TIMEOUT	\
	(2 * DT_PROP(DT_INST(0, st_stm32_nv_flash), max_erase_time))

extern struct k_work_q ble_ctlr_work_q;
struct k_work fm_work;

static const struct flash_parameters flash_stm32_parameters = {
	.write_block_size = FLASH_STM32_WRITE_BLOCK_SIZE,
	.erase_value = 0xff,
};

K_SEM_DEFINE(flash_busy, 0, 1);

static void flash_callback(FM_FlashOp_Status_t status)
{
	LOG_DBG("%d", status);

	k_sem_give(&flash_busy);
}

struct FM_CallbackNode cb_ptr = {
	.Callback = flash_callback
};

void FM_ProcessRequest(void)
{
	k_work_submit_to_queue(&ble_ctlr_work_q, &fm_work);
}

void FM_BackgroundProcess_Entry(struct k_work *work)
{
	ARG_UNUSED(work);

	FM_BackgroundProcess();
}

bool flash_stm32_valid_range(const struct device *dev, off_t offset,
				    uint32_t len, bool write)
{
	if (write && !flash_stm32_valid_write(offset, len)) {
		return false;
	}
	return flash_stm32_range_exists(dev, offset, len);
}


static inline void flash_stm32_sem_take(const struct device *dev)
{
	k_sem_take(&FLASH_STM32_PRIV(dev)->sem, K_FOREVER);
}

static inline void flash_stm32_sem_give(const struct device *dev)
{
	k_sem_give(&FLASH_STM32_PRIV(dev)->sem);
}

static int flash_stm32_read(const struct device *dev, off_t offset,
			    void *data,
			    size_t len)
{
	if (!flash_stm32_valid_range(dev, offset, len, false)) {
		LOG_ERR("Read range invalid. Offset: %p, len: %zu",
			(void *) offset, len);
		return -EINVAL;
	}

	if (!len) {
		return 0;
	}

	flash_stm32_sem_take(dev);

	memcpy(data, (uint8_t *) FLASH_STM32_BASE_ADDRESS + offset, len);

	flash_stm32_sem_give(dev);

	return 0;
}

static int flash_stm32_erase(const struct device *dev, off_t offset,
			     size_t len)
{
	int rc;
	int sect_num = (len / FLASH_PAGE_SIZE) + 1;

	if (!flash_stm32_valid_range(dev, offset, len, true)) {
		LOG_ERR("Erase range invalid. Offset: %p, len: %zu",
			(void *)offset, len);
		return -EINVAL;
	}

	if (!len) {
		return 0;
	}

	flash_stm32_sem_take(dev);

	LOG_DBG("Erase offset: %p, page: %ld, len: %zu, sect num: %d",
		(void *)offset, offset / FLASH_PAGE_SIZE, len, sect_num);

	rc = FM_Erase(offset / FLASH_PAGE_SIZE, sect_num, &cb_ptr);
	if (rc == 0) {
		k_sem_take(&flash_busy, K_FOREVER);
	} else {
		LOG_DBG("Erase operation rejected. err = %d", rc);
	}

	flash_stm32_sem_give(dev);

	return rc;
}

static int flash_stm32_write(const struct device *dev, off_t offset,
			     const void *data, size_t len)
{
	int rc;

	if (!flash_stm32_valid_range(dev, offset, len, true)) {
		LOG_ERR("Write range invalid. Offset: %p, len: %zu",
			(void *)offset, len);
		return -EINVAL;
	}

	if (!len) {
		return 0;
	}

	flash_stm32_sem_take(dev);

	LOG_DBG("Write offset: %p, len: %zu", (void *)offset, len);

	rc = FM_Write((uint32_t *)data,
		      (uint32_t *)(FLASH_STM32_BASE_ADDRESS + offset),
		      (int32_t)len/4, &cb_ptr);
	if (rc == 0) {
		k_sem_take(&flash_busy, K_FOREVER);
	} else {
		LOG_DBG("Write operation rejected. err = %d", rc);
	}

	flash_stm32_sem_give(dev);

	return rc;
}

static const struct flash_parameters *
			flash_stm32_get_parameters(const struct device *dev)
{
	ARG_UNUSED(dev);

	return &flash_stm32_parameters;
}

static struct flash_stm32_priv flash_data = {
	.regs = (FLASH_TypeDef *) DT_INST_REG_ADDR(0),
};

void flash_stm32wba_page_layout(const struct device *dev,
				const struct flash_pages_layout **layout,
				size_t *layout_size)
{
	static struct flash_pages_layout stm32wba_flash_layout = {
		.pages_count = 0,
		.pages_size = 0,
	};

	ARG_UNUSED(dev);

	if (stm32wba_flash_layout.pages_count == 0) {
		stm32wba_flash_layout.pages_count = FLASH_SIZE / FLASH_PAGE_SIZE;
		stm32wba_flash_layout.pages_size = FLASH_PAGE_SIZE;
	}

	*layout = &stm32wba_flash_layout;
	*layout_size = 1;
}

static const struct flash_driver_api flash_stm32_api = {
	.erase = flash_stm32_erase,
	.write = flash_stm32_write,
	.read = flash_stm32_read,
	.get_parameters = flash_stm32_get_parameters,
#ifdef CONFIG_FLASH_PAGE_LAYOUT
	.page_layout = flash_stm32wba_page_layout,
#endif
};

static int stm32_flash_init(const struct device *dev)
{
	k_sem_init(&FLASH_STM32_PRIV(dev)->sem, 1, 1);

	LOG_DBG("Flash initialized. BS: %zu",
		flash_stm32_parameters.write_block_size);

	k_work_init(&fm_work, &FM_BackgroundProcess_Entry);

	/* Enable flash driver system flag */
	FD_SetStatus(FD_FLASHACCESS_RFTS, LL_FLASH_DISABLE);
	FD_SetStatus(FD_FLASHACCESS_RFTS_BYPASS, LL_FLASH_ENABLE);
	FD_SetStatus(FD_FLASHACCESS_SYSTEM, LL_FLASH_ENABLE);

#if ((CONFIG_FLASH_LOG_LEVEL >= LOG_LEVEL_DBG) && CONFIG_FLASH_PAGE_LAYOUT)
	const struct flash_pages_layout *layout;
	size_t layout_size;

	flash_stm32wba_page_layout(dev, &layout, &layout_size);
	for (size_t i = 0; i < layout_size; i++) {
		LOG_DBG("Block %zu: bs: %zu count: %zu", i,
			layout[i].pages_size, layout[i].pages_count);
	}
#endif

	return 0;
}

DEVICE_DT_INST_DEFINE(0, stm32_flash_init, NULL,
		    &flash_data, NULL, POST_KERNEL,
		    CONFIG_FLASH_INIT_PRIORITY, &flash_stm32_api);