drivers/mtd/spi/sf_probe.c - platform/external/u-boot - Gitiles

 /*
  * SPI flash probing
  *
  * Copyright (C) 2008 Atmel Corporation
  * Copyright (C) 2010 Reinhard Meyer, EMK Elektronik
  * Copyright (C) 2013 Jagannadha Sutradharudu Teki, Xilinx Inc.
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */

 #include <common.h>
 #include <dm.h>
 #include <errno.h>
 #include <fdtdec.h>
 #include <malloc.h>
 #include <spi.h>
 #include <spi_flash.h>
 #include <asm/io.h>

 #include "sf_internal.h"

 DECLARE_GLOBAL_DATA_PTR;

 /* Read commands array */
 static u8 spi_read_cmds_array[] = {
 	CMD_READ_ARRAY_SLOW,
 	CMD_READ_DUAL_OUTPUT_FAST,
 	CMD_READ_DUAL_IO_FAST,
 	CMD_READ_QUAD_OUTPUT_FAST,
 	CMD_READ_QUAD_IO_FAST,
 };

 #ifdef CONFIG_SPI_FLASH_MACRONIX
 static int spi_flash_set_qeb_mxic(struct spi_flash *flash)
 {
 	u8 qeb_status;
 	int ret;

 	ret = spi_flash_cmd_read_status(flash, &qeb_status);
 	if (ret < 0)
 		return ret;

 	if (qeb_status & STATUS_QEB_MXIC) {
 		debug("SF: mxic: QEB is already set\n");
 	} else {
 		ret = spi_flash_cmd_write_status(flash, STATUS_QEB_MXIC);
 		if (ret < 0)
 			return ret;
 	}

 	return ret;
 }
 #endif

 #if defined(CONFIG_SPI_FLASH_SPANSION) || defined(CONFIG_SPI_FLASH_WINBOND)
 static int spi_flash_set_qeb_winspan(struct spi_flash *flash)
 {
 	u8 qeb_status;
 	int ret;

 	ret = spi_flash_cmd_read_config(flash, &qeb_status);
 	if (ret < 0)
 		return ret;

 	if (qeb_status & STATUS_QEB_WINSPAN) {
 		debug("SF: winspan: QEB is already set\n");
 	} else {
 		ret = spi_flash_cmd_write_config(flash, STATUS_QEB_WINSPAN);
 		if (ret < 0)
 			return ret;
 	}

 	return ret;
 }
 #endif

 static int spi_flash_set_qeb(struct spi_flash *flash, u8 idcode0)
 {
 	switch (idcode0) {
 #ifdef CONFIG_SPI_FLASH_MACRONIX
 	case SPI_FLASH_CFI_MFR_MACRONIX:
 		return spi_flash_set_qeb_mxic(flash);
 #endif
 #if defined(CONFIG_SPI_FLASH_SPANSION) || defined(CONFIG_SPI_FLASH_WINBOND)
 	case SPI_FLASH_CFI_MFR_SPANSION:
 	case SPI_FLASH_CFI_MFR_WINBOND:
 		return spi_flash_set_qeb_winspan(flash);
 #endif
 #ifdef CONFIG_SPI_FLASH_STMICRO
 	case SPI_FLASH_CFI_MFR_STMICRO:
 		debug("SF: QEB is volatile for %02x flash\n", idcode0);
 		return 0;
 #endif
 	default:
 		printf("SF: Need set QEB func for %02x flash\n", idcode0);
 		return -1;
 	}
 }

 static int spi_flash_validate_params(struct spi_slave *spi, u8 *idcode,
 				     struct spi_flash *flash)
 {
 	const struct spi_flash_params *params;
 	u8 cmd;
 	u16 jedec = idcode[1] << 8 | idcode[2];
 	u16 ext_jedec = idcode[3] << 8 | idcode[4];

 	/* Validate params from spi_flash_params table */
 	params = spi_flash_params_table;
 	for (; params->name != NULL; params++) {
 		if ((params->jedec >> 16) == idcode[0]) {
 			if ((params->jedec & 0xFFFF) == jedec) {
 				if (params->ext_jedec == 0)
 					break;
 				else if (params->ext_jedec == ext_jedec)
 					break;
 			}
 		}
 	}

 	if (!params->name) {
 		printf("SF: Unsupported flash IDs: ");
 		printf("manuf %02x, jedec %04x, ext_jedec %04x\n",
 		       idcode[0], jedec, ext_jedec);
 		return -EPROTONOSUPPORT;
 	}

 	/* Assign spi data */
 	flash->spi = spi;
 	flash->name = params->name;
 	flash->memory_map = spi->memory_map;
 	flash->dual_flash = flash->spi->option;

 	/* Assign spi_flash ops */
 #ifndef CONFIG_DM_SPI_FLASH
 	flash->write = spi_flash_cmd_write_ops;
 #if defined(CONFIG_SPI_FLASH_SST)
 	if (params->flags & SST_WP)
 		flash->write = sst_write_wp;
 #endif
 	flash->erase = spi_flash_cmd_erase_ops;
 	flash->read = spi_flash_cmd_read_ops;
 #endif

 	/* Compute the flash size */
 	flash->shift = (flash->dual_flash & SF_DUAL_PARALLEL_FLASH) ? 1 : 0;
 	/*
 	 * The Spansion S25FL032P and S25FL064P have 256b pages, yet use the
 	 * 0x4d00 Extended JEDEC code. The rest of the Spansion flashes with
 	 * the 0x4d00 Extended JEDEC code have 512b pages. All of the others
 	 * have 256b pages.
 	 */
 	if (ext_jedec == 0x4d00) {
 		if ((jedec == 0x0215) || (jedec == 0x216))
 			flash->page_size = 256;
 		else
 			flash->page_size = 512;
 	} else {
 		flash->page_size = 256;
 	}
 	flash->page_size <<= flash->shift;
 	flash->sector_size = params->sector_size << flash->shift;
 	flash->size = flash->sector_size * params->nr_sectors << flash->shift;
 #ifdef CONFIG_SF_DUAL_FLASH
 	if (flash->dual_flash & SF_DUAL_STACKED_FLASH)
 		flash->size <<= 1;
 #endif

 	/* Compute erase sector and command */
 	if (params->flags & SECT_4K) {
 		flash->erase_cmd = CMD_ERASE_4K;
 		flash->erase_size = 4096 << flash->shift;
 	} else if (params->flags & SECT_32K) {
 		flash->erase_cmd = CMD_ERASE_32K;
 		flash->erase_size = 32768 << flash->shift;
 	} else {
 		flash->erase_cmd = CMD_ERASE_64K;
 		flash->erase_size = flash->sector_size;
 	}

 	/* Look for the fastest read cmd */
 	cmd = fls(params->e_rd_cmd & flash->spi->op_mode_rx);
 	if (cmd) {
 		cmd = spi_read_cmds_array[cmd - 1];
 		flash->read_cmd = cmd;
 	} else {
 		/* Go for default supported read cmd */
 		flash->read_cmd = CMD_READ_ARRAY_FAST;
 	}

 	/* Not require to look for fastest only two write cmds yet */
 	if (params->flags & WR_QPP && flash->spi->op_mode_tx & SPI_OPM_TX_QPP)
 		flash->write_cmd = CMD_QUAD_PAGE_PROGRAM;
 	else
 		/* Go for default supported write cmd */
 		flash->write_cmd = CMD_PAGE_PROGRAM;

 	/* Read dummy_byte: dummy byte is determined based on the
 	 * dummy cycles of a particular command.
 	 * Fast commands - dummy_byte = dummy_cycles/8
 	 * I/O commands- dummy_byte = (dummy_cycles * no.of lines)/8
 	 * For I/O commands except cmd[0] everything goes on no.of lines
 	 * based on particular command but incase of fast commands except
 	 * data all go on single line irrespective of command.
 	 */
 	switch (flash->read_cmd) {
 	case CMD_READ_QUAD_IO_FAST:
 		flash->dummy_byte = 2;
 		break;
 	case CMD_READ_ARRAY_SLOW:
 		flash->dummy_byte = 0;
 		break;
 	default:
 		flash->dummy_byte = 1;
 	}

 	/* Poll cmd selection */
 	flash->poll_cmd = CMD_READ_STATUS;
 #ifdef CONFIG_SPI_FLASH_STMICRO
 	if (params->flags & E_FSR)
 		flash->poll_cmd = CMD_FLAG_STATUS;
 #endif

 	/* Configure the BAR - discover bank cmds and read current bank */
 #ifdef CONFIG_SPI_FLASH_BAR
 	u8 curr_bank = 0;
 	if (flash->size > SPI_FLASH_16MB_BOUN) {
 		int ret;

 		flash->bank_read_cmd = (idcode[0] == 0x01) ?
 					CMD_BANKADDR_BRRD : CMD_EXTNADDR_RDEAR;
 		flash->bank_write_cmd = (idcode[0] == 0x01) ?
 					CMD_BANKADDR_BRWR : CMD_EXTNADDR_WREAR;

 		ret = spi_flash_read_common(flash, &flash->bank_read_cmd, 1,
 					    &curr_bank, 1);
 		if (ret) {
 			debug("SF: fail to read bank addr register\n");
 			return ret;
 		}
 		flash->bank_curr = curr_bank;
 	} else {
 		flash->bank_curr = curr_bank;
 	}
 #endif

 	/* Flash powers up read-only, so clear BP# bits */
 #if defined(CONFIG_SPI_FLASH_ATMEL) || \
 	defined(CONFIG_SPI_FLASH_MACRONIX) || \
 	defined(CONFIG_SPI_FLASH_SST)
 		spi_flash_cmd_write_status(flash, 0);
 #endif

 	return 0;
 }

 #ifdef CONFIG_OF_CONTROL
 int spi_flash_decode_fdt(const void *blob, struct spi_flash *flash)
 {
 	fdt_addr_t addr;
 	fdt_size_t size;
 	int node;

 	/* If there is no node, do nothing */
 	node = fdtdec_next_compatible(blob, 0, COMPAT_GENERIC_SPI_FLASH);
 	if (node < 0)
 		return 0;

 	addr = fdtdec_get_addr_size(blob, node, "memory-map", &size);
 	if (addr == FDT_ADDR_T_NONE) {
 		debug("%s: Cannot decode address\n", __func__);
 		return 0;
 	}

 	if (flash->size != size) {
 		debug("%s: Memory map must cover entire device\n", __func__);
 		return -1;
 	}
 	flash->memory_map = map_sysmem(addr, size);

 	return 0;
 }
 #endif /* CONFIG_OF_CONTROL */

 #ifdef CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
 /* enable the W#/Vpp signal to disable writing to the status register */
 static int spi_enable_wp_pin(struct spi_flash *flash)
 {
 	u8 status;
 	int ret;

 	ret = spi_flash_cmd_read_status(flash, &status);
 	if (ret < 0)
 		return ret;

 	ret = spi_flash_cmd_write_status(flash, STATUS_SRWD);
 	if (ret < 0)
 		return ret;

 	ret = spi_flash_cmd_write_disable(flash);
 	if (ret < 0)
 		return ret;

 	return 0;
 }
 #else
 static int spi_enable_wp_pin(struct spi_flash *flash)
 {
 	return 0;
 }
 #endif

 /**
  * spi_flash_probe_slave() - Probe for a SPI flash device on a bus
  *
  * @spi: Bus to probe
  * @flashp: Pointer to place to put flash info, which may be NULL if the
  * space should be allocated
  */
 int spi_flash_probe_slave(struct spi_slave *spi, struct spi_flash *flash)
 {
 	u8 idcode[5];
 	int ret;

 	/* Setup spi_slave */
 	if (!spi) {
 		printf("SF: Failed to set up slave\n");
 		return -ENODEV;
 	}

 	/* Claim spi bus */
 	ret = spi_claim_bus(spi);
 	if (ret) {
 		debug("SF: Failed to claim SPI bus: %d\n", ret);
 		return ret;
 	}

 	/* Read the ID codes */
 	ret = spi_flash_cmd(spi, CMD_READ_ID, idcode, sizeof(idcode));
 	if (ret) {
 		printf("SF: Failed to get idcodes\n");
 		goto err_read_id;
 	}

 #ifdef DEBUG
 	printf("SF: Got idcodes\n");
 	print_buffer(0, idcode, 1, sizeof(idcode), 0);
 #endif

 	if (spi_flash_validate_params(spi, idcode, flash)) {
 		ret = -EINVAL;
 		goto err_read_id;
 	}

 	/* Set the quad enable bit - only for quad commands */
 	if ((flash->read_cmd == CMD_READ_QUAD_OUTPUT_FAST) ||
 	    (flash->read_cmd == CMD_READ_QUAD_IO_FAST) ||
 	    (flash->write_cmd == CMD_QUAD_PAGE_PROGRAM)) {
 		if (spi_flash_set_qeb(flash, idcode[0])) {
 			debug("SF: Fail to set QEB for %02x\n", idcode[0]);
 			ret = -EINVAL;
 			goto err_read_id;
 		}
 	}

 #ifdef CONFIG_OF_CONTROL
 	if (spi_flash_decode_fdt(gd->fdt_blob, flash)) {
 		debug("SF: FDT decode error\n");
 		ret = -EINVAL;
 		goto err_read_id;
 	}
 #endif
 #ifndef CONFIG_SPL_BUILD
 	printf("SF: Detected %s with page size ", flash->name);
 	print_size(flash->page_size, ", erase size ");
 	print_size(flash->erase_size, ", total ");
 	print_size(flash->size, "");
 	if (flash->memory_map)
 		printf(", mapped at %p", flash->memory_map);
 	puts("\n");
 #endif
 #ifndef CONFIG_SPI_FLASH_BAR
 	if (((flash->dual_flash == SF_SINGLE_FLASH) &&
 	     (flash->size > SPI_FLASH_16MB_BOUN)) ||
 	     ((flash->dual_flash > SF_SINGLE_FLASH) &&
 	     (flash->size > SPI_FLASH_16MB_BOUN << 1))) {
 		puts("SF: Warning - Only lower 16MiB accessible,");
 		puts(" Full access #define CONFIG_SPI_FLASH_BAR\n");
 	}
 #endif
 	if (spi_enable_wp_pin(flash))
 		puts("Enable WP pin failed\n");

 	/* Release spi bus */
 	spi_release_bus(spi);

 	return 0;

 err_read_id:
 	spi_release_bus(spi);
 	return ret;
 }

 #ifndef CONFIG_DM_SPI_FLASH
 struct spi_flash *spi_flash_probe_tail(struct spi_slave *bus)
 {
 	struct spi_flash *flash;

 	/* Allocate space if needed (not used by sf-uclass */
 	flash = calloc(1, sizeof(*flash));
 	if (!flash) {
 		debug("SF: Failed to allocate spi_flash\n");
 		return NULL;
 	}

 	if (spi_flash_probe_slave(bus, flash)) {
 		spi_free_slave(bus);
 		free(flash);
 		return NULL;
 	}

 	return flash;
 }

 struct spi_flash *spi_flash_probe(unsigned int busnum, unsigned int cs,
 		unsigned int max_hz, unsigned int spi_mode)
 {
 	struct spi_slave *bus;

 	bus = spi_setup_slave(busnum, cs, max_hz, spi_mode);
 	return spi_flash_probe_tail(bus);
 }

 #ifdef CONFIG_OF_SPI_FLASH
 struct spi_flash *spi_flash_probe_fdt(const void *blob, int slave_node,
 				      int spi_node)
 {
 	struct spi_slave *bus;

 	bus = spi_setup_slave_fdt(blob, slave_node, spi_node);
 	return spi_flash_probe_tail(bus);
 }
 #endif

 void spi_flash_free(struct spi_flash *flash)
 {
 	spi_free_slave(flash->spi);
 	free(flash);
 }

 #else /* defined CONFIG_DM_SPI_FLASH */

 static int spi_flash_std_read(struct udevice *dev, u32 offset, size_t len,
 			      void *buf)
 {
 	struct spi_flash *flash = dev->uclass_priv;

 	return spi_flash_cmd_read_ops(flash, offset, len, buf);
 }

 int spi_flash_std_write(struct udevice *dev, u32 offset, size_t len,
 			const void *buf)
 {
 	struct spi_flash *flash = dev->uclass_priv;

 	return spi_flash_cmd_write_ops(flash, offset, len, buf);
 }

 int spi_flash_std_erase(struct udevice *dev, u32 offset, size_t len)
 {
 	struct spi_flash *flash = dev->uclass_priv;

 	return spi_flash_cmd_erase_ops(flash, offset, len);
 }

 int spi_flash_std_probe(struct udevice *dev)
 {
 	struct spi_slave *slave = dev_get_parentdata(dev);
 	struct spi_flash *flash;

 	flash = dev->uclass_priv;
 	flash->dev = dev;
 	debug("%s: slave=%p, cs=%d\n", __func__, slave, slave->cs);
 	return spi_flash_probe_slave(slave, flash);
 }

 static const struct dm_spi_flash_ops spi_flash_std_ops = {
 	.read = spi_flash_std_read,
 	.write = spi_flash_std_write,
 	.erase = spi_flash_std_erase,
 };

 static const struct udevice_id spi_flash_std_ids[] = {
 	{ .compatible = "spi-flash" },
 	{ }
 };

 U_BOOT_DRIVER(spi_flash_std) = {
 	.name		= "spi_flash_std",
 	.id		= UCLASS_SPI_FLASH,
 	.of_match	= spi_flash_std_ids,
 	.probe		= spi_flash_std_probe,
 	.priv_auto_alloc_size = sizeof(struct spi_flash),
 	.ops		= &spi_flash_std_ops,
 };

 #endif /* CONFIG_DM_SPI_FLASH */
	/*
	* SPI flash probing
	*
	* Copyright (C) 2008 Atmel Corporation
	* Copyright (C) 2010 Reinhard Meyer, EMK Elektronik
	* Copyright (C) 2013 Jagannadha Sutradharudu Teki, Xilinx Inc.
	*
	* SPDX-License-Identifier: GPL-2.0+
	*/

	#include <common.h>
	#include <dm.h>
	#include <errno.h>
	#include <fdtdec.h>
	#include <malloc.h>
	#include <spi.h>
	#include <spi_flash.h>
	#include <asm/io.h>

	#include "sf_internal.h"

	DECLARE_GLOBAL_DATA_PTR;

	/* Read commands array */
	static u8 spi_read_cmds_array[] = {
	CMD_READ_ARRAY_SLOW,
	CMD_READ_DUAL_OUTPUT_FAST,
	CMD_READ_DUAL_IO_FAST,
	CMD_READ_QUAD_OUTPUT_FAST,
	CMD_READ_QUAD_IO_FAST,
	};

	#ifdef CONFIG_SPI_FLASH_MACRONIX
	static int spi_flash_set_qeb_mxic(struct spi_flash *flash)
	{
	u8 qeb_status;
	int ret;

	ret = spi_flash_cmd_read_status(flash, &qeb_status);
	if (ret < 0)
	return ret;

	if (qeb_status & STATUS_QEB_MXIC) {
	debug("SF: mxic: QEB is already set\n");
	} else {
	ret = spi_flash_cmd_write_status(flash, STATUS_QEB_MXIC);
	if (ret < 0)
	return ret;
	}

	return ret;
	}
	#endif

	#if defined(CONFIG_SPI_FLASH_SPANSION) \|\| defined(CONFIG_SPI_FLASH_WINBOND)
	static int spi_flash_set_qeb_winspan(struct spi_flash *flash)
	{
	u8 qeb_status;
	int ret;

	ret = spi_flash_cmd_read_config(flash, &qeb_status);
	if (ret < 0)
	return ret;

	if (qeb_status & STATUS_QEB_WINSPAN) {
	debug("SF: winspan: QEB is already set\n");
	} else {
	ret = spi_flash_cmd_write_config(flash, STATUS_QEB_WINSPAN);
	if (ret < 0)
	return ret;
	}

	return ret;
	}
	#endif

	static int spi_flash_set_qeb(struct spi_flash *flash, u8 idcode0)
	{
	switch (idcode0) {
	#ifdef CONFIG_SPI_FLASH_MACRONIX
	case SPI_FLASH_CFI_MFR_MACRONIX:
	return spi_flash_set_qeb_mxic(flash);
	#endif
	#if defined(CONFIG_SPI_FLASH_SPANSION) \|\| defined(CONFIG_SPI_FLASH_WINBOND)
	case SPI_FLASH_CFI_MFR_SPANSION:
	case SPI_FLASH_CFI_MFR_WINBOND:
	return spi_flash_set_qeb_winspan(flash);
	#endif
	#ifdef CONFIG_SPI_FLASH_STMICRO
	case SPI_FLASH_CFI_MFR_STMICRO:
	debug("SF: QEB is volatile for %02x flash\n", idcode0);
	return 0;
	#endif
	default:
	printf("SF: Need set QEB func for %02x flash\n", idcode0);
	return -1;
	}
	}

	static int spi_flash_validate_params(struct spi_slave spi, u8 idcode,
	struct spi_flash *flash)
	{
	const struct spi_flash_params *params;
	u8 cmd;
	u16 jedec = idcode[1] << 8 \| idcode[2];
	u16 ext_jedec = idcode[3] << 8 \| idcode[4];

	/* Validate params from spi_flash_params table */
	params = spi_flash_params_table;
	for (; params->name != NULL; params++) {
	if ((params->jedec >> 16) == idcode[0]) {
	if ((params->jedec & 0xFFFF) == jedec) {
	if (params->ext_jedec == 0)
	break;
	else if (params->ext_jedec == ext_jedec)
	break;
	}
	}
	}

	if (!params->name) {
	printf("SF: Unsupported flash IDs: ");
	printf("manuf %02x, jedec %04x, ext_jedec %04x\n",
	idcode[0], jedec, ext_jedec);
	return -EPROTONOSUPPORT;
	}

	/* Assign spi data */
	flash->spi = spi;
	flash->name = params->name;
	flash->memory_map = spi->memory_map;
	flash->dual_flash = flash->spi->option;

	/* Assign spi_flash ops */
	#ifndef CONFIG_DM_SPI_FLASH
	flash->write = spi_flash_cmd_write_ops;
	#if defined(CONFIG_SPI_FLASH_SST)
	if (params->flags & SST_WP)
	flash->write = sst_write_wp;
	#endif
	flash->erase = spi_flash_cmd_erase_ops;
	flash->read = spi_flash_cmd_read_ops;
	#endif

	/* Compute the flash size */
	flash->shift = (flash->dual_flash & SF_DUAL_PARALLEL_FLASH) ? 1 : 0;
	/*
	* The Spansion S25FL032P and S25FL064P have 256b pages, yet use the
	* 0x4d00 Extended JEDEC code. The rest of the Spansion flashes with
	* the 0x4d00 Extended JEDEC code have 512b pages. All of the others
	* have 256b pages.
	*/
	if (ext_jedec == 0x4d00) {
	if ((jedec == 0x0215) \|\| (jedec == 0x216))
	flash->page_size = 256;
	else
	flash->page_size = 512;
	} else {
	flash->page_size = 256;
	}
	flash->page_size <<= flash->shift;
	flash->sector_size = params->sector_size << flash->shift;
	flash->size = flash->sector_size * params->nr_sectors << flash->shift;
	#ifdef CONFIG_SF_DUAL_FLASH
	if (flash->dual_flash & SF_DUAL_STACKED_FLASH)
	flash->size <<= 1;
	#endif

	/* Compute erase sector and command */
	if (params->flags & SECT_4K) {
	flash->erase_cmd = CMD_ERASE_4K;
	flash->erase_size = 4096 << flash->shift;
	} else if (params->flags & SECT_32K) {
	flash->erase_cmd = CMD_ERASE_32K;
	flash->erase_size = 32768 << flash->shift;
	} else {
	flash->erase_cmd = CMD_ERASE_64K;
	flash->erase_size = flash->sector_size;
	}

	/* Look for the fastest read cmd */
	cmd = fls(params->e_rd_cmd & flash->spi->op_mode_rx);
	if (cmd) {
	cmd = spi_read_cmds_array[cmd - 1];
	flash->read_cmd = cmd;
	} else {
	/* Go for default supported read cmd */
	flash->read_cmd = CMD_READ_ARRAY_FAST;
	}

	/* Not require to look for fastest only two write cmds yet */
	if (params->flags & WR_QPP && flash->spi->op_mode_tx & SPI_OPM_TX_QPP)
	flash->write_cmd = CMD_QUAD_PAGE_PROGRAM;
	else
	/* Go for default supported write cmd */
	flash->write_cmd = CMD_PAGE_PROGRAM;

	/* Read dummy_byte: dummy byte is determined based on the
	* dummy cycles of a particular command.
	* Fast commands - dummy_byte = dummy_cycles/8
	* I/O commands- dummy_byte = (dummy_cycles * no.of lines)/8
	* For I/O commands except cmd[0] everything goes on no.of lines
	* based on particular command but incase of fast commands except
	* data all go on single line irrespective of command.
	*/
	switch (flash->read_cmd) {
	case CMD_READ_QUAD_IO_FAST:
	flash->dummy_byte = 2;
	break;
	case CMD_READ_ARRAY_SLOW:
	flash->dummy_byte = 0;
	break;
	default:
	flash->dummy_byte = 1;
	}

	/* Poll cmd selection */
	flash->poll_cmd = CMD_READ_STATUS;
	#ifdef CONFIG_SPI_FLASH_STMICRO
	if (params->flags & E_FSR)
	flash->poll_cmd = CMD_FLAG_STATUS;
	#endif

	/* Configure the BAR - discover bank cmds and read current bank */
	#ifdef CONFIG_SPI_FLASH_BAR
	u8 curr_bank = 0;
	if (flash->size > SPI_FLASH_16MB_BOUN) {
	int ret;

	flash->bank_read_cmd = (idcode[0] == 0x01) ?
	CMD_BANKADDR_BRRD : CMD_EXTNADDR_RDEAR;
	flash->bank_write_cmd = (idcode[0] == 0x01) ?
	CMD_BANKADDR_BRWR : CMD_EXTNADDR_WREAR;

	ret = spi_flash_read_common(flash, &flash->bank_read_cmd, 1,
	&curr_bank, 1);
	if (ret) {
	debug("SF: fail to read bank addr register\n");
	return ret;
	}
	flash->bank_curr = curr_bank;
	} else {
	flash->bank_curr = curr_bank;
	}
	#endif

	/* Flash powers up read-only, so clear BP# bits */
	#if defined(CONFIG_SPI_FLASH_ATMEL) \|\| \
	defined(CONFIG_SPI_FLASH_MACRONIX) \|\| \
	defined(CONFIG_SPI_FLASH_SST)
	spi_flash_cmd_write_status(flash, 0);
	#endif

	return 0;
	}

	#ifdef CONFIG_OF_CONTROL
	int spi_flash_decode_fdt(const void blob, struct spi_flash flash)
	{
	fdt_addr_t addr;
	fdt_size_t size;
	int node;

	/* If there is no node, do nothing */
	node = fdtdec_next_compatible(blob, 0, COMPAT_GENERIC_SPI_FLASH);
	if (node < 0)
	return 0;

	addr = fdtdec_get_addr_size(blob, node, "memory-map", &size);
	if (addr == FDT_ADDR_T_NONE) {
	debug("%s: Cannot decode address\n", __func__);
	return 0;
	}

	if (flash->size != size) {
	debug("%s: Memory map must cover entire device\n", __func__);
	return -1;
	}
	flash->memory_map = map_sysmem(addr, size);

	return 0;
	}
	#endif /* CONFIG_OF_CONTROL */

	#ifdef CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
	/* enable the W#/Vpp signal to disable writing to the status register */
	static int spi_enable_wp_pin(struct spi_flash *flash)
	{
	u8 status;
	int ret;

	ret = spi_flash_cmd_read_status(flash, &status);
	if (ret < 0)
	return ret;

	ret = spi_flash_cmd_write_status(flash, STATUS_SRWD);
	if (ret < 0)
	return ret;

	ret = spi_flash_cmd_write_disable(flash);
	if (ret < 0)
	return ret;

	return 0;
	}
	#else
	static int spi_enable_wp_pin(struct spi_flash *flash)
	{
	return 0;
	}
	#endif

	/**
	* spi_flash_probe_slave() - Probe for a SPI flash device on a bus
	*
	* @spi: Bus to probe
	* @flashp: Pointer to place to put flash info, which may be NULL if the
	* space should be allocated
	*/
	int spi_flash_probe_slave(struct spi_slave spi, struct spi_flash flash)
	{
	u8 idcode[5];
	int ret;

	/* Setup spi_slave */
	if (!spi) {
	printf("SF: Failed to set up slave\n");
	return -ENODEV;
	}

	/* Claim spi bus */
	ret = spi_claim_bus(spi);
	if (ret) {
	debug("SF: Failed to claim SPI bus: %d\n", ret);
	return ret;
	}

	/* Read the ID codes */
	ret = spi_flash_cmd(spi, CMD_READ_ID, idcode, sizeof(idcode));
	if (ret) {
	printf("SF: Failed to get idcodes\n");
	goto err_read_id;
	}

	#ifdef DEBUG
	printf("SF: Got idcodes\n");
	print_buffer(0, idcode, 1, sizeof(idcode), 0);
	#endif

	if (spi_flash_validate_params(spi, idcode, flash)) {
	ret = -EINVAL;
	goto err_read_id;
	}

	/* Set the quad enable bit - only for quad commands */
	if ((flash->read_cmd == CMD_READ_QUAD_OUTPUT_FAST) \|\|
	(flash->read_cmd == CMD_READ_QUAD_IO_FAST) \|\|
	(flash->write_cmd == CMD_QUAD_PAGE_PROGRAM)) {
	if (spi_flash_set_qeb(flash, idcode[0])) {
	debug("SF: Fail to set QEB for %02x\n", idcode[0]);
	ret = -EINVAL;
	goto err_read_id;
	}
	}

	#ifdef CONFIG_OF_CONTROL
	if (spi_flash_decode_fdt(gd->fdt_blob, flash)) {
	debug("SF: FDT decode error\n");
	ret = -EINVAL;
	goto err_read_id;
	}
	#endif
	#ifndef CONFIG_SPL_BUILD
	printf("SF: Detected %s with page size ", flash->name);
	print_size(flash->page_size, ", erase size ");
	print_size(flash->erase_size, ", total ");
	print_size(flash->size, "");
	if (flash->memory_map)
	printf(", mapped at %p", flash->memory_map);
	puts("\n");
	#endif
	#ifndef CONFIG_SPI_FLASH_BAR
	if (((flash->dual_flash == SF_SINGLE_FLASH) &&
	(flash->size > SPI_FLASH_16MB_BOUN)) \|\|
	((flash->dual_flash > SF_SINGLE_FLASH) &&
	(flash->size > SPI_FLASH_16MB_BOUN << 1))) {
	puts("SF: Warning - Only lower 16MiB accessible,");
	puts(" Full access #define CONFIG_SPI_FLASH_BAR\n");
	}
	#endif
	if (spi_enable_wp_pin(flash))
	puts("Enable WP pin failed\n");

	/* Release spi bus */
	spi_release_bus(spi);

	return 0;

	err_read_id:
	spi_release_bus(spi);
	return ret;
	}

	#ifndef CONFIG_DM_SPI_FLASH
	struct spi_flash spi_flash_probe_tail(struct spi_slave bus)
	{
	struct spi_flash *flash;

	/* Allocate space if needed (not used by sf-uclass */
	flash = calloc(1, sizeof(*flash));
	if (!flash) {
	debug("SF: Failed to allocate spi_flash\n");
	return NULL;
	}

	if (spi_flash_probe_slave(bus, flash)) {
	spi_free_slave(bus);
	free(flash);
	return NULL;
	}

	return flash;
	}

	struct spi_flash *spi_flash_probe(unsigned int busnum, unsigned int cs,
	unsigned int max_hz, unsigned int spi_mode)
	{
	struct spi_slave *bus;

	bus = spi_setup_slave(busnum, cs, max_hz, spi_mode);
	return spi_flash_probe_tail(bus);
	}

	#ifdef CONFIG_OF_SPI_FLASH
	struct spi_flash spi_flash_probe_fdt(const void blob, int slave_node,
	int spi_node)
	{
	struct spi_slave *bus;

	bus = spi_setup_slave_fdt(blob, slave_node, spi_node);
	return spi_flash_probe_tail(bus);
	}
	#endif

	void spi_flash_free(struct spi_flash *flash)
	{
	spi_free_slave(flash->spi);
	free(flash);
	}

	#else /* defined CONFIG_DM_SPI_FLASH */

	static int spi_flash_std_read(struct udevice *dev, u32 offset, size_t len,
	void *buf)
	{
	struct spi_flash *flash = dev->uclass_priv;

	return spi_flash_cmd_read_ops(flash, offset, len, buf);
	}

	int spi_flash_std_write(struct udevice *dev, u32 offset, size_t len,
	const void *buf)
	{
	struct spi_flash *flash = dev->uclass_priv;

	return spi_flash_cmd_write_ops(flash, offset, len, buf);
	}

	int spi_flash_std_erase(struct udevice *dev, u32 offset, size_t len)
	{
	struct spi_flash *flash = dev->uclass_priv;

	return spi_flash_cmd_erase_ops(flash, offset, len);
	}

	int spi_flash_std_probe(struct udevice *dev)
	{
	struct spi_slave *slave = dev_get_parentdata(dev);
	struct spi_flash *flash;

	flash = dev->uclass_priv;
	flash->dev = dev;
	debug("%s: slave=%p, cs=%d\n", __func__, slave, slave->cs);
	return spi_flash_probe_slave(slave, flash);
	}

	static const struct dm_spi_flash_ops spi_flash_std_ops = {
	.read = spi_flash_std_read,
	.write = spi_flash_std_write,
	.erase = spi_flash_std_erase,
	};

	static const struct udevice_id spi_flash_std_ids[] = {
	{ .compatible = "spi-flash" },
	{ }
	};

	U_BOOT_DRIVER(spi_flash_std) = {
	.name = "spi_flash_std",
	.id = UCLASS_SPI_FLASH,
	.of_match = spi_flash_std_ids,
	.probe = spi_flash_std_probe,
	.priv_auto_alloc_size = sizeof(struct spi_flash),
	.ops = &spi_flash_std_ops,
	};

	#endif /* CONFIG_DM_SPI_FLASH */