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

 /*
  * Copyright (c) 2018 Savoir-Faire Linux.
  *
  * This driver is heavily inspired from the spi_flash_w25qxxdv.c SPI NOR driver.
  *
  * SPDX-License-Identifier: Apache-2.0
  */

 #include <errno.h>
 #include <drivers/flash.h>
 #include <drivers/spi.h>
 #include <init.h>
 #include <string.h>
 #include <logging/log.h>

 #include "spi_nor.h"
 #include "flash_priv.h"

 LOG_MODULE_REGISTER(spi_nor, CONFIG_FLASH_LOG_LEVEL);

 #define SPI_NOR_MAX_ADDR_WIDTH 4

 /**
  * struct spi_nor_data - Structure for defining the SPI NOR access
  * @spi: The SPI device
  * @spi_cfg: The SPI configuration
  * @cs_ctrl: The GPIO pin used to emulate the SPI CS if required
  * @sem: The semaphore to access to the flash
  */
 struct spi_nor_data {
 	struct device *spi;
 	struct spi_config spi_cfg;
 #ifdef DT_INST_0_JEDEC_SPI_NOR_CS_GPIOS_CONTROLLER
 	struct spi_cs_control cs_ctrl;
 #endif /* DT_INST_0_JEDEC_SPI_NOR_CS_GPIOS_CONTROLLER */
 	struct k_sem sem;
 };

 #if defined(CONFIG_MULTITHREADING)
 #define SYNC_INIT() k_sem_init(	\
 		&((struct spi_nor_data *)dev->driver_data)->sem, 1, UINT_MAX)
 #define SYNC_LOCK() k_sem_take(&driver_data->sem, K_FOREVER)
 #define SYNC_UNLOCK() k_sem_give(&driver_data->sem)
 #else
 #define SYNC_INIT()
 #define SYNC_LOCK()
 #define SYNC_UNLOCK()
 #endif

 /*
  * @brief Send an SPI command
  *
  * @param dev Device struct
  * @param opcode The command to send
  * @param is_addressed A flag to define if the command is addressed
  * @param addr The address to send
  * @param data The buffer to store or read the value
  * @param length The size of the buffer
  * @param is_write A flag to define if it's a read or a write command
  * @return 0 on success, negative errno code otherwise
  */
 static int spi_nor_access(const struct device *const dev,
 			  u8_t opcode, bool is_addressed, off_t addr,
 			  void *data, size_t length, bool is_write)
 {
 	struct spi_nor_data *const driver_data = dev->driver_data;

 	u8_t buf[4] = {
 		opcode,
 		(addr & 0xFF0000) >> 16,
 		(addr & 0xFF00) >> 8,
 		(addr & 0xFF),
 	};

 	struct spi_buf spi_buf[2] = {
 		{
 			.buf = buf,
 			.len = (is_addressed) ? 4 : 1,
 		},
 		{
 			.buf = data,
 			.len = length
 		}
 	};
 	const struct spi_buf_set tx_set = {
 		.buffers = spi_buf,
 		.count = (length) ? 2 : 1
 	};

 	const struct spi_buf_set rx_set = {
 		.buffers = spi_buf,
 		.count = 2
 	};

 	if (is_write) {
 		return spi_write(driver_data->spi,
 			&driver_data->spi_cfg, &tx_set);
 	}

 	return spi_transceive(driver_data->spi,
 		&driver_data->spi_cfg, &tx_set, &rx_set);
 }

 #define spi_nor_cmd_read(dev, opcode, dest, length) \
 	spi_nor_access(dev, opcode, false, 0, dest, length, false)
 #define spi_nor_cmd_addr_read(dev, opcode, addr, dest, length) \
 	spi_nor_access(dev, opcode, true, addr, dest, length, false)
 #define spi_nor_cmd_write(dev, opcode) \
 	spi_nor_access(dev, opcode, false, 0, NULL, 0, true)
 #define spi_nor_cmd_addr_write(dev, opcode, addr, src, length) \
 	spi_nor_access(dev, opcode, true, addr, (void *)src, length, true)

 /**
  * @brief Retrieve the Flash JEDEC ID and compare it with the one expected
  *
  * @param dev The device structure
  * @param flash_id The flash info structure which contains the expected JEDEC ID
  * @return 0 on success, negative errno code otherwise
  */
 static inline int spi_nor_read_id(struct device *dev,
 				  const struct spi_nor_config *const flash_id)
 {
 	u8_t buf[SPI_NOR_MAX_ID_LEN];

 	if (spi_nor_cmd_read(dev, SPI_NOR_CMD_RDID, buf,
 	    SPI_NOR_MAX_ID_LEN) != 0) {
 		return -EIO;
 	}

 	if (memcmp(flash_id->id, buf, SPI_NOR_MAX_ID_LEN) != 0) {
 		return -ENODEV;
 	}

 	return 0;
 }

 /**
  * @brief Wait until the flash is ready
  *
  * @param dev The device structure
  * @return 0 on success, negative errno code otherwise
  */
 static int spi_nor_wait_until_ready(struct device *dev)
 {
 	int ret;
 	u8_t reg;

 	do {
 		ret = spi_nor_cmd_read(dev, SPI_NOR_CMD_RDSR, &reg, 1);
 	} while (!ret && (reg & SPI_NOR_WIP_BIT));

 	return ret;
 }

 static int spi_nor_read(struct device *dev, off_t addr, void *dest,
 			size_t size)
 {
 	struct spi_nor_data *const driver_data = dev->driver_data;
 	const struct spi_nor_config *params = dev->config->config_info;
 	int ret;

 	/* should be between 0 and flash size */
 	if ((addr < 0) || ((addr + size) > params->size)) {
 		return -EINVAL;
 	}

 	SYNC_LOCK();

 	spi_nor_wait_until_ready(dev);

 	ret = spi_nor_cmd_addr_read(dev, SPI_NOR_CMD_READ, addr, dest, size);

 	SYNC_UNLOCK();
 	return ret;
 }

 static int spi_nor_write(struct device *dev, off_t addr, const void *src,
 			 size_t size)
 {
 	struct spi_nor_data *const driver_data = dev->driver_data;
 	const struct spi_nor_config *params = dev->config->config_info;
 	int ret;

 	/* should be between 0 and flash size */
 	if ((addr < 0) || ((size + addr) > params->size)) {
 		return -EINVAL;
 	}

 	SYNC_LOCK();

 	while (size > 0) {
 		size_t to_write = size;

 		/* Don't write more than a page. */
 		if (to_write >= SPI_NOR_PAGE_SIZE) {
 			to_write = SPI_NOR_PAGE_SIZE;
 		}

 		/* Don't write across a page boundary */
 		if (((addr + to_write - 1U) / SPI_NOR_PAGE_SIZE)
 		    != (addr / SPI_NOR_PAGE_SIZE)) {
 			to_write = SPI_NOR_PAGE_SIZE - (addr % SPI_NOR_PAGE_SIZE);
 		}

 		spi_nor_cmd_write(dev, SPI_NOR_CMD_WREN);
 		ret = spi_nor_cmd_addr_write(dev, SPI_NOR_CMD_PP, addr,
 					     src, to_write);
 		if (ret != 0) {
 			SYNC_UNLOCK();
 			return ret;
 		}

 		size -= to_write;
 		src = (const u8_t *)src + to_write;
 		addr += to_write;

 		spi_nor_wait_until_ready(dev);
 	}

 	SYNC_UNLOCK();
 	return 0;
 }

 static int spi_nor_erase(struct device *dev, off_t addr, size_t size)
 {
 	struct spi_nor_data *const driver_data = dev->driver_data;
 	const struct spi_nor_config *params = dev->config->config_info;

 	/* should be between 0 and flash size */
 	if ((addr < 0) || ((size + addr) > params->size)) {
 		return -ENODEV;
 	}

 	SYNC_LOCK();

 	while (size) {
 		/* write enable */
 		spi_nor_cmd_write(dev, SPI_NOR_CMD_WREN);

 		if (size == params->size) {
 			/* chip erase */
 			spi_nor_cmd_write(dev, SPI_NOR_CMD_CE);
 			size -= params->size;
 		} else if ((size >= SPI_NOR_BLOCK_SIZE)
 			   && SPI_NOR_IS_BLOCK_ALIGNED(addr)) {
 			/* 64 KiB block erase */
 			spi_nor_cmd_addr_write(dev, SPI_NOR_CMD_BE, addr,
 			NULL, 0);
 			addr += SPI_NOR_BLOCK_SIZE;
 			size -= SPI_NOR_BLOCK_SIZE;
 		} else if ((size >= SPI_NOR_BLOCK32_SIZE)
 			   && SPI_NOR_IS_BLOCK32_ALIGNED(addr)) {
 			/* 32 KiB block erase */
 			spi_nor_cmd_addr_write(dev, SPI_NOR_CMD_BE_32K, addr,
 					       NULL, 0);
 			addr += SPI_NOR_BLOCK32_SIZE;
 			size -= SPI_NOR_BLOCK32_SIZE;
 		} else if ((size >= SPI_NOR_SECTOR_SIZE)
 			   && SPI_NOR_IS_SECTOR_ALIGNED(addr)) {
 			/* sector erase */
 			spi_nor_cmd_addr_write(dev, SPI_NOR_CMD_SE, addr,
 					       NULL, 0);
 			addr += SPI_NOR_SECTOR_SIZE;
 			size -= SPI_NOR_SECTOR_SIZE;
 		} else {
 			/* minimal erase size is at least a sector size */
 			SYNC_UNLOCK();
 			LOG_DBG("unsupported at 0x%lx size %zu", (long)addr,
 				size);
 			return -EINVAL;
 		}

 		spi_nor_wait_until_ready(dev);
 	}

 	SYNC_UNLOCK();

 	return 0;
 }

 static int spi_nor_write_protection_set(struct device *dev, bool write_protect)
 {
 	struct spi_nor_data *const driver_data = dev->driver_data;
 	int ret;

 	SYNC_LOCK();

 	spi_nor_wait_until_ready(dev);

 	ret = spi_nor_cmd_write(dev, (write_protect) ?
 	      SPI_NOR_CMD_WRDI : SPI_NOR_CMD_WREN);

 #if DT_INST_0_JEDEC_SPI_NOR_JEDEC_ID_0 == 0xbf && DT_INST_0_JEDEC_SPI_NOR_JEDEC_ID_1 == 0x26
 	if (ret == 0 && !write_protect) {
 		ret = spi_nor_cmd_write(dev, SPI_NOR_CMD_MCHP_UNLOCK);
 	}
 #endif

 	SYNC_UNLOCK();

 	return ret;
 }

 /**
  * @brief Configure the flash
  *
  * @param dev The flash device structure
  * @param info The flash info structure
  * @return 0 on success, negative errno code otherwise
  */
 static int spi_nor_configure(struct device *dev)
 {
 	struct spi_nor_data *data = dev->driver_data;
 	const struct spi_nor_config *params = dev->config->config_info;

 	data->spi = device_get_binding(DT_INST_0_JEDEC_SPI_NOR_BUS_NAME);
 	if (!data->spi) {
 		return -EINVAL;
 	}

 	data->spi_cfg.frequency = DT_INST_0_JEDEC_SPI_NOR_SPI_MAX_FREQUENCY;
 	data->spi_cfg.operation = SPI_WORD_SET(8);
 	data->spi_cfg.slave = DT_INST_0_JEDEC_SPI_NOR_BASE_ADDRESS;

 #ifdef DT_INST_0_JEDEC_SPI_NOR_CS_GPIOS_CONTROLLER
 	data->cs_ctrl.gpio_dev =
 		device_get_binding(DT_INST_0_JEDEC_SPI_NOR_CS_GPIOS_CONTROLLER);
 	if (!data->cs_ctrl.gpio_dev) {
 		return -ENODEV;
 	}

 	data->cs_ctrl.gpio_pin = DT_INST_0_JEDEC_SPI_NOR_CS_GPIOS_PIN;
 	data->cs_ctrl.delay = CONFIG_SPI_NOR_CS_WAIT_DELAY;

 	data->spi_cfg.cs = &data->cs_ctrl;
 #endif /* DT_INST_0_JEDEC_SPI_NOR_CS_GPIOS_CONTROLLER */

 	/* now the spi bus is configured, we can verify the flash id */
 	if (spi_nor_read_id(dev, params) != 0) {
 		return -ENODEV;
 	}


 	return 0;
 }

 /**
  * @brief Initialize and configure the flash
  *
  * @param name The flash name
  * @return 0 on success, negative errno code otherwise
  */
 static int spi_nor_init(struct device *dev)
 {
 	SYNC_INIT();

 	return spi_nor_configure(dev);
 }

 #if defined(CONFIG_FLASH_PAGE_LAYOUT)

 /* instance 0 size in bytes */
 #define INST_0_BYTES (DT_INST_0_JEDEC_SPI_NOR_SIZE / 8)

 /* instance 0 page count */
 #define LAYOUT_PAGES_COUNT (INST_0_BYTES / CONFIG_SPI_NOR_FLASH_LAYOUT_PAGE_SIZE)

 BUILD_ASSERT_MSG((CONFIG_SPI_NOR_FLASH_LAYOUT_PAGE_SIZE * LAYOUT_PAGES_COUNT)
 		 == INST_0_BYTES,
 		 "SPI_NOR_FLASH_LAYOUT_PAGE_SIZE incompatible with flash size");

 static const struct flash_pages_layout dev_layout = {
 	.pages_count = LAYOUT_PAGES_COUNT,
 	.pages_size = CONFIG_SPI_NOR_FLASH_LAYOUT_PAGE_SIZE,
 };
 #undef LAYOUT_PAGES_COUNT

 static void spi_nor_pages_layout(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_driver_api spi_nor_api = {
 	.read = spi_nor_read,
 	.write = spi_nor_write,
 	.erase = spi_nor_erase,
 	.write_protection = spi_nor_write_protection_set,
 #if defined(CONFIG_FLASH_PAGE_LAYOUT)
 	.page_layout = spi_nor_pages_layout,
 #endif
 	.write_block_size = 1,
 };

 static const struct spi_nor_config flash_id = {
 	.id = DT_INST_0_JEDEC_SPI_NOR_JEDEC_ID,
 #ifdef DT_INST_0_JEDEC_SPI_NOR_HAS_BE32K
 	.has_be32k = true,
 #endif /* DT_INST_0_JEDEC_SPI_NOR_HAS_BE32K */
 	.size = DT_INST_0_JEDEC_SPI_NOR_SIZE / 8,
 };

 static struct spi_nor_data spi_nor_memory_data;

 DEVICE_AND_API_INIT(spi_flash_memory, DT_INST_0_JEDEC_SPI_NOR_LABEL,
 		    &spi_nor_init, &spi_nor_memory_data,
 		    &flash_id, POST_KERNEL, CONFIG_SPI_NOR_INIT_PRIORITY,
 		    &spi_nor_api);
	/*
	* Copyright (c) 2018 Savoir-Faire Linux.
	*
	* This driver is heavily inspired from the spi_flash_w25qxxdv.c SPI NOR driver.
	*
	* SPDX-License-Identifier: Apache-2.0
	*/

	#include <errno.h>
	#include <drivers/flash.h>
	#include <drivers/spi.h>
	#include <init.h>
	#include <string.h>
	#include <logging/log.h>

	#include "spi_nor.h"
	#include "flash_priv.h"

	LOG_MODULE_REGISTER(spi_nor, CONFIG_FLASH_LOG_LEVEL);

	#define SPI_NOR_MAX_ADDR_WIDTH 4

	/**
	* struct spi_nor_data - Structure for defining the SPI NOR access
	* @spi: The SPI device
	* @spi_cfg: The SPI configuration
	* @cs_ctrl: The GPIO pin used to emulate the SPI CS if required
	* @sem: The semaphore to access to the flash
	*/
	struct spi_nor_data {
	struct device *spi;
	struct spi_config spi_cfg;
	#ifdef DT_INST_0_JEDEC_SPI_NOR_CS_GPIOS_CONTROLLER
	struct spi_cs_control cs_ctrl;
	#endif /* DT_INST_0_JEDEC_SPI_NOR_CS_GPIOS_CONTROLLER */
	struct k_sem sem;
	};

	#if defined(CONFIG_MULTITHREADING)
	#define SYNC_INIT() k_sem_init( \
	&((struct spi_nor_data *)dev->driver_data)->sem, 1, UINT_MAX)
	#define SYNC_LOCK() k_sem_take(&driver_data->sem, K_FOREVER)
	#define SYNC_UNLOCK() k_sem_give(&driver_data->sem)
	#else
	#define SYNC_INIT()
	#define SYNC_LOCK()
	#define SYNC_UNLOCK()
	#endif

	/*
	* @brief Send an SPI command
	*
	* @param dev Device struct
	* @param opcode The command to send
	* @param is_addressed A flag to define if the command is addressed
	* @param addr The address to send
	* @param data The buffer to store or read the value
	* @param length The size of the buffer
	* @param is_write A flag to define if it's a read or a write command
	* @return 0 on success, negative errno code otherwise
	*/
	static int spi_nor_access(const struct device *const dev,
	u8_t opcode, bool is_addressed, off_t addr,
	void *data, size_t length, bool is_write)
	{
	struct spi_nor_data *const driver_data = dev->driver_data;

	u8_t buf[4] = {
	opcode,
	(addr & 0xFF0000) >> 16,
	(addr & 0xFF00) >> 8,
	(addr & 0xFF),
	};

	struct spi_buf spi_buf[2] = {
	{
	.buf = buf,
	.len = (is_addressed) ? 4 : 1,
	},
	{
	.buf = data,
	.len = length
	}
	};
	const struct spi_buf_set tx_set = {
	.buffers = spi_buf,
	.count = (length) ? 2 : 1
	};

	const struct spi_buf_set rx_set = {
	.buffers = spi_buf,
	.count = 2
	};

	if (is_write) {
	return spi_write(driver_data->spi,
	&driver_data->spi_cfg, &tx_set);
	}

	return spi_transceive(driver_data->spi,
	&driver_data->spi_cfg, &tx_set, &rx_set);
	}

	#define spi_nor_cmd_read(dev, opcode, dest, length) \
	spi_nor_access(dev, opcode, false, 0, dest, length, false)
	#define spi_nor_cmd_addr_read(dev, opcode, addr, dest, length) \
	spi_nor_access(dev, opcode, true, addr, dest, length, false)
	#define spi_nor_cmd_write(dev, opcode) \
	spi_nor_access(dev, opcode, false, 0, NULL, 0, true)
	#define spi_nor_cmd_addr_write(dev, opcode, addr, src, length) \
	spi_nor_access(dev, opcode, true, addr, (void *)src, length, true)

	/**
	* @brief Retrieve the Flash JEDEC ID and compare it with the one expected
	*
	* @param dev The device structure
	* @param flash_id The flash info structure which contains the expected JEDEC ID
	* @return 0 on success, negative errno code otherwise
	*/
	static inline int spi_nor_read_id(struct device *dev,
	const struct spi_nor_config *const flash_id)
	{
	u8_t buf[SPI_NOR_MAX_ID_LEN];

	if (spi_nor_cmd_read(dev, SPI_NOR_CMD_RDID, buf,
	SPI_NOR_MAX_ID_LEN) != 0) {
	return -EIO;
	}

	if (memcmp(flash_id->id, buf, SPI_NOR_MAX_ID_LEN) != 0) {
	return -ENODEV;
	}

	return 0;
	}

	/**
	* @brief Wait until the flash is ready
	*
	* @param dev The device structure
	* @return 0 on success, negative errno code otherwise
	*/
	static int spi_nor_wait_until_ready(struct device *dev)
	{
	int ret;
	u8_t reg;

	do {
	ret = spi_nor_cmd_read(dev, SPI_NOR_CMD_RDSR, &reg, 1);
	} while (!ret && (reg & SPI_NOR_WIP_BIT));

	return ret;
	}

	static int spi_nor_read(struct device dev, off_t addr, void dest,
	size_t size)
	{
	struct spi_nor_data *const driver_data = dev->driver_data;
	const struct spi_nor_config *params = dev->config->config_info;
	int ret;

	/* should be between 0 and flash size */
	if ((addr < 0) \|\| ((addr + size) > params->size)) {
	return -EINVAL;
	}

	SYNC_LOCK();

	spi_nor_wait_until_ready(dev);

	ret = spi_nor_cmd_addr_read(dev, SPI_NOR_CMD_READ, addr, dest, size);

	SYNC_UNLOCK();
	return ret;
	}

	static int spi_nor_write(struct device dev, off_t addr, const void src,
	size_t size)
	{
	struct spi_nor_data *const driver_data = dev->driver_data;
	const struct spi_nor_config *params = dev->config->config_info;
	int ret;

	/* should be between 0 and flash size */
	if ((addr < 0) \|\| ((size + addr) > params->size)) {
	return -EINVAL;
	}

	SYNC_LOCK();

	while (size > 0) {
	size_t to_write = size;

	/* Don't write more than a page. */
	if (to_write >= SPI_NOR_PAGE_SIZE) {
	to_write = SPI_NOR_PAGE_SIZE;
	}

	/* Don't write across a page boundary */
	if (((addr + to_write - 1U) / SPI_NOR_PAGE_SIZE)
	!= (addr / SPI_NOR_PAGE_SIZE)) {
	to_write = SPI_NOR_PAGE_SIZE - (addr % SPI_NOR_PAGE_SIZE);
	}

	spi_nor_cmd_write(dev, SPI_NOR_CMD_WREN);
	ret = spi_nor_cmd_addr_write(dev, SPI_NOR_CMD_PP, addr,
	src, to_write);
	if (ret != 0) {
	SYNC_UNLOCK();
	return ret;
	}

	size -= to_write;
	src = (const u8_t *)src + to_write;
	addr += to_write;

	spi_nor_wait_until_ready(dev);
	}

	SYNC_UNLOCK();
	return 0;
	}

	static int spi_nor_erase(struct device *dev, off_t addr, size_t size)
	{
	struct spi_nor_data *const driver_data = dev->driver_data;
	const struct spi_nor_config *params = dev->config->config_info;

	/* should be between 0 and flash size */
	if ((addr < 0) \|\| ((size + addr) > params->size)) {
	return -ENODEV;
	}

	SYNC_LOCK();

	while (size) {
	/* write enable */
	spi_nor_cmd_write(dev, SPI_NOR_CMD_WREN);

	if (size == params->size) {
	/* chip erase */
	spi_nor_cmd_write(dev, SPI_NOR_CMD_CE);
	size -= params->size;
	} else if ((size >= SPI_NOR_BLOCK_SIZE)
	&& SPI_NOR_IS_BLOCK_ALIGNED(addr)) {
	/* 64 KiB block erase */
	spi_nor_cmd_addr_write(dev, SPI_NOR_CMD_BE, addr,
	NULL, 0);
	addr += SPI_NOR_BLOCK_SIZE;
	size -= SPI_NOR_BLOCK_SIZE;
	} else if ((size >= SPI_NOR_BLOCK32_SIZE)
	&& SPI_NOR_IS_BLOCK32_ALIGNED(addr)) {
	/* 32 KiB block erase */
	spi_nor_cmd_addr_write(dev, SPI_NOR_CMD_BE_32K, addr,
	NULL, 0);
	addr += SPI_NOR_BLOCK32_SIZE;
	size -= SPI_NOR_BLOCK32_SIZE;
	} else if ((size >= SPI_NOR_SECTOR_SIZE)
	&& SPI_NOR_IS_SECTOR_ALIGNED(addr)) {
	/* sector erase */
	spi_nor_cmd_addr_write(dev, SPI_NOR_CMD_SE, addr,
	NULL, 0);
	addr += SPI_NOR_SECTOR_SIZE;
	size -= SPI_NOR_SECTOR_SIZE;
	} else {
	/* minimal erase size is at least a sector size */
	SYNC_UNLOCK();
	LOG_DBG("unsupported at 0x%lx size %zu", (long)addr,
	size);
	return -EINVAL;
	}

	spi_nor_wait_until_ready(dev);
	}

	SYNC_UNLOCK();

	return 0;
	}

	static int spi_nor_write_protection_set(struct device *dev, bool write_protect)
	{
	struct spi_nor_data *const driver_data = dev->driver_data;
	int ret;

	SYNC_LOCK();

	spi_nor_wait_until_ready(dev);

	ret = spi_nor_cmd_write(dev, (write_protect) ?
	SPI_NOR_CMD_WRDI : SPI_NOR_CMD_WREN);

	#if DT_INST_0_JEDEC_SPI_NOR_JEDEC_ID_0 == 0xbf && DT_INST_0_JEDEC_SPI_NOR_JEDEC_ID_1 == 0x26
	if (ret == 0 && !write_protect) {
	ret = spi_nor_cmd_write(dev, SPI_NOR_CMD_MCHP_UNLOCK);
	}
	#endif

	SYNC_UNLOCK();

	return ret;
	}

	/**
	* @brief Configure the flash
	*
	* @param dev The flash device structure
	* @param info The flash info structure
	* @return 0 on success, negative errno code otherwise
	*/
	static int spi_nor_configure(struct device *dev)
	{
	struct spi_nor_data *data = dev->driver_data;
	const struct spi_nor_config *params = dev->config->config_info;

	data->spi = device_get_binding(DT_INST_0_JEDEC_SPI_NOR_BUS_NAME);
	if (!data->spi) {
	return -EINVAL;
	}

	data->spi_cfg.frequency = DT_INST_0_JEDEC_SPI_NOR_SPI_MAX_FREQUENCY;
	data->spi_cfg.operation = SPI_WORD_SET(8);
	data->spi_cfg.slave = DT_INST_0_JEDEC_SPI_NOR_BASE_ADDRESS;

	#ifdef DT_INST_0_JEDEC_SPI_NOR_CS_GPIOS_CONTROLLER
	data->cs_ctrl.gpio_dev =
	device_get_binding(DT_INST_0_JEDEC_SPI_NOR_CS_GPIOS_CONTROLLER);
	if (!data->cs_ctrl.gpio_dev) {
	return -ENODEV;
	}

	data->cs_ctrl.gpio_pin = DT_INST_0_JEDEC_SPI_NOR_CS_GPIOS_PIN;
	data->cs_ctrl.delay = CONFIG_SPI_NOR_CS_WAIT_DELAY;

	data->spi_cfg.cs = &data->cs_ctrl;
	#endif /* DT_INST_0_JEDEC_SPI_NOR_CS_GPIOS_CONTROLLER */

	/* now the spi bus is configured, we can verify the flash id */
	if (spi_nor_read_id(dev, params) != 0) {
	return -ENODEV;
	}


	return 0;
	}

	/**
	* @brief Initialize and configure the flash
	*
	* @param name The flash name
	* @return 0 on success, negative errno code otherwise
	*/
	static int spi_nor_init(struct device *dev)
	{
	SYNC_INIT();

	return spi_nor_configure(dev);
	}

	#if defined(CONFIG_FLASH_PAGE_LAYOUT)

	/* instance 0 size in bytes */
	#define INST_0_BYTES (DT_INST_0_JEDEC_SPI_NOR_SIZE / 8)

	/* instance 0 page count */
	#define LAYOUT_PAGES_COUNT (INST_0_BYTES / CONFIG_SPI_NOR_FLASH_LAYOUT_PAGE_SIZE)

	BUILD_ASSERT_MSG((CONFIG_SPI_NOR_FLASH_LAYOUT_PAGE_SIZE * LAYOUT_PAGES_COUNT)
	== INST_0_BYTES,
	"SPI_NOR_FLASH_LAYOUT_PAGE_SIZE incompatible with flash size");

	static const struct flash_pages_layout dev_layout = {
	.pages_count = LAYOUT_PAGES_COUNT,
	.pages_size = CONFIG_SPI_NOR_FLASH_LAYOUT_PAGE_SIZE,
	};
	#undef LAYOUT_PAGES_COUNT

	static void spi_nor_pages_layout(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_driver_api spi_nor_api = {
	.read = spi_nor_read,
	.write = spi_nor_write,
	.erase = spi_nor_erase,
	.write_protection = spi_nor_write_protection_set,
	#if defined(CONFIG_FLASH_PAGE_LAYOUT)
	.page_layout = spi_nor_pages_layout,
	#endif
	.write_block_size = 1,
	};

	static const struct spi_nor_config flash_id = {
	.id = DT_INST_0_JEDEC_SPI_NOR_JEDEC_ID,
	#ifdef DT_INST_0_JEDEC_SPI_NOR_HAS_BE32K
	.has_be32k = true,
	#endif /* DT_INST_0_JEDEC_SPI_NOR_HAS_BE32K */
	.size = DT_INST_0_JEDEC_SPI_NOR_SIZE / 8,
	};

	static struct spi_nor_data spi_nor_memory_data;

	DEVICE_AND_API_INIT(spi_flash_memory, DT_INST_0_JEDEC_SPI_NOR_LABEL,
	&spi_nor_init, &spi_nor_memory_data,
	&flash_id, POST_KERNEL, CONFIG_SPI_NOR_INIT_PRIORITY,
	&spi_nor_api);