Add submodule dependency filesHEADmaster

Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec

1 files changed, 2660 insertions, 0 deletions

diff --git a/roms/u-boot/drivers/mtd/spi/spi-nor-core.c b/roms/u-boot/drivers/mtd/spi/spi-nor-core.c
new file mode 100644
index 000000000..a6625535a
--- /dev/null
+++ b/roms/u-boot/drivers/mtd/spi/spi-nor-core.c
@@ -0,0 +1,2660 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Based on m25p80.c, by Mike Lavender (mike@steroidmicros.com), with
+ * influence from lart.c (Abraham Van Der Merwe) and mtd_dataflash.c
+ *
+ * Copyright (C) 2005, Intec Automation Inc.
+ * Copyright (C) 2014, Freescale Semiconductor, Inc.
+ *
+ * Synced from Linux v4.19
+ */
+
+#include <common.h>
+#include <log.h>
+#include <watchdog.h>
+#include <dm.h>
+#include <dm/device_compat.h>
+#include <dm/devres.h>
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/log2.h>
+#include <linux/math64.h>
+#include <linux/sizes.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/spi-nor.h>
+#include <spi-mem.h>
+#include <spi.h>
+
+#include "sf_internal.h"
+
+/* Define max times to check status register before we give up. */
+
+/*
+ * For everything but full-chip erase; probably could be much smaller, but kept
+ * around for safety for now
+ */
+
+#define HZ					CONFIG_SYS_HZ
+
+#define DEFAULT_READY_WAIT_JIFFIES		(40UL * HZ)
+
+static int spi_nor_read_write_reg(struct spi_nor *nor, struct spi_mem_op
+		*op, void *buf)
+{
+	if (op->data.dir == SPI_MEM_DATA_IN)
+		op->data.buf.in = buf;
+	else
+		op->data.buf.out = buf;
+	return spi_mem_exec_op(nor->spi, op);
+}
+
+static int spi_nor_read_reg(struct spi_nor *nor, u8 code, u8 *val, int len)
+{
+	struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(code, 1),
+					  SPI_MEM_OP_NO_ADDR,
+					  SPI_MEM_OP_NO_DUMMY,
+					  SPI_MEM_OP_DATA_IN(len, NULL, 1));
+	int ret;
+
+	ret = spi_nor_read_write_reg(nor, &op, val);
+	if (ret < 0)
+		dev_dbg(nor->dev, "error %d reading %x\n", ret, code);
+
+	return ret;
+}
+
+static int spi_nor_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
+{
+	struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(opcode, 1),
+					  SPI_MEM_OP_NO_ADDR,
+					  SPI_MEM_OP_NO_DUMMY,
+					  SPI_MEM_OP_DATA_OUT(len, NULL, 1));
+
+	return spi_nor_read_write_reg(nor, &op, buf);
+}
+
+static ssize_t spi_nor_read_data(struct spi_nor *nor, loff_t from, size_t len,
+				 u_char *buf)
+{
+	struct spi_mem_op op =
+			SPI_MEM_OP(SPI_MEM_OP_CMD(nor->read_opcode, 1),
+				   SPI_MEM_OP_ADDR(nor->addr_width, from, 1),
+				   SPI_MEM_OP_DUMMY(nor->read_dummy, 1),
+				   SPI_MEM_OP_DATA_IN(len, buf, 1));
+	size_t remaining = len;
+	int ret;
+
+	/* get transfer protocols. */
+	op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->read_proto);
+	op.addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->read_proto);
+	op.dummy.buswidth = op.addr.buswidth;
+	op.data.buswidth = spi_nor_get_protocol_data_nbits(nor->read_proto);
+
+	/* convert the dummy cycles to the number of bytes */
+	op.dummy.nbytes = (nor->read_dummy * op.dummy.buswidth) / 8;
+
+	while (remaining) {
+		op.data.nbytes = remaining < UINT_MAX ? remaining : UINT_MAX;
+		ret = spi_mem_adjust_op_size(nor->spi, &op);
+		if (ret)
+			return ret;
+
+		ret = spi_mem_exec_op(nor->spi, &op);
+		if (ret)
+			return ret;
+
+		op.addr.val += op.data.nbytes;
+		remaining -= op.data.nbytes;
+		op.data.buf.in += op.data.nbytes;
+	}
+
+	return len;
+}
+
+static ssize_t spi_nor_write_data(struct spi_nor *nor, loff_t to, size_t len,
+				  const u_char *buf)
+{
+	struct spi_mem_op op =
+			SPI_MEM_OP(SPI_MEM_OP_CMD(nor->program_opcode, 1),
+				   SPI_MEM_OP_ADDR(nor->addr_width, to, 1),
+				   SPI_MEM_OP_NO_DUMMY,
+				   SPI_MEM_OP_DATA_OUT(len, buf, 1));
+	int ret;
+
+	/* get transfer protocols. */
+	op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->write_proto);
+	op.addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->write_proto);
+	op.data.buswidth = spi_nor_get_protocol_data_nbits(nor->write_proto);
+
+	if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
+		op.addr.nbytes = 0;
+
+	ret = spi_mem_adjust_op_size(nor->spi, &op);
+	if (ret)
+		return ret;
+	op.data.nbytes = len < op.data.nbytes ? len : op.data.nbytes;
+
+	ret = spi_mem_exec_op(nor->spi, &op);
+	if (ret)
+		return ret;
+
+	return op.data.nbytes;
+}
+
+/*
+ * Read the status register, returning its value in the location
+ * Return the status register value.
+ * Returns negative if error occurred.
+ */
+static int read_sr(struct spi_nor *nor)
+{
+	int ret;
+	u8 val;
+
+	ret = nor->read_reg(nor, SPINOR_OP_RDSR, &val, 1);
+	if (ret < 0) {
+		pr_debug("error %d reading SR\n", (int)ret);
+		return ret;
+	}
+
+	return val;
+}
+
+/*
+ * Read the flag status register, returning its value in the location
+ * Return the status register value.
+ * Returns negative if error occurred.
+ */
+static int read_fsr(struct spi_nor *nor)
+{
+	int ret;
+	u8 val;
+
+	ret = nor->read_reg(nor, SPINOR_OP_RDFSR, &val, 1);
+	if (ret < 0) {
+		pr_debug("error %d reading FSR\n", ret);
+		return ret;
+	}
+
+	return val;
+}
+
+/*
+ * Read configuration register, returning its value in the
+ * location. Return the configuration register value.
+ * Returns negative if error occurred.
+ */
+#if defined(CONFIG_SPI_FLASH_SPANSION) || defined(CONFIG_SPI_FLASH_WINBOND)
+static int read_cr(struct spi_nor *nor)
+{
+	int ret;
+	u8 val;
+
+	ret = nor->read_reg(nor, SPINOR_OP_RDCR, &val, 1);
+	if (ret < 0) {
+		dev_dbg(nor->dev, "error %d reading CR\n", ret);
+		return ret;
+	}
+
+	return val;
+}
+#endif
+
+/*
+ * Write status register 1 byte
+ * Returns negative if error occurred.
+ */
+static int write_sr(struct spi_nor *nor, u8 val)
+{
+	nor->cmd_buf[0] = val;
+	return nor->write_reg(nor, SPINOR_OP_WRSR, nor->cmd_buf, 1);
+}
+
+/*
+ * Set write enable latch with Write Enable command.
+ * Returns negative if error occurred.
+ */
+static int write_enable(struct spi_nor *nor)
+{
+	return nor->write_reg(nor, SPINOR_OP_WREN, NULL, 0);
+}
+
+/*
+ * Send write disable instruction to the chip.
+ */
+static int write_disable(struct spi_nor *nor)
+{
+	return nor->write_reg(nor, SPINOR_OP_WRDI, NULL, 0);
+}
+
+static struct spi_nor *mtd_to_spi_nor(struct mtd_info *mtd)
+{
+	return mtd->priv;
+}
+
+#ifndef CONFIG_SPI_FLASH_BAR
+static u8 spi_nor_convert_opcode(u8 opcode, const u8 table[][2], size_t size)
+{
+	size_t i;
+
+	for (i = 0; i < size; i++)
+		if (table[i][0] == opcode)
+			return table[i][1];
+
+	/* No conversion found, keep input op code. */
+	return opcode;
+}
+
+static u8 spi_nor_convert_3to4_read(u8 opcode)
+{
+	static const u8 spi_nor_3to4_read[][2] = {
+		{ SPINOR_OP_READ,	SPINOR_OP_READ_4B },
+		{ SPINOR_OP_READ_FAST,	SPINOR_OP_READ_FAST_4B },
+		{ SPINOR_OP_READ_1_1_2,	SPINOR_OP_READ_1_1_2_4B },
+		{ SPINOR_OP_READ_1_2_2,	SPINOR_OP_READ_1_2_2_4B },
+		{ SPINOR_OP_READ_1_1_4,	SPINOR_OP_READ_1_1_4_4B },
+		{ SPINOR_OP_READ_1_4_4,	SPINOR_OP_READ_1_4_4_4B },
+		{ SPINOR_OP_READ_1_1_8,	SPINOR_OP_READ_1_1_8_4B },
+		{ SPINOR_OP_READ_1_8_8,	SPINOR_OP_READ_1_8_8_4B },
+
+		{ SPINOR_OP_READ_1_1_1_DTR,	SPINOR_OP_READ_1_1_1_DTR_4B },
+		{ SPINOR_OP_READ_1_2_2_DTR,	SPINOR_OP_READ_1_2_2_DTR_4B },
+		{ SPINOR_OP_READ_1_4_4_DTR,	SPINOR_OP_READ_1_4_4_DTR_4B },
+	};
+
+	return spi_nor_convert_opcode(opcode, spi_nor_3to4_read,
+				      ARRAY_SIZE(spi_nor_3to4_read));
+}
+
+static u8 spi_nor_convert_3to4_program(u8 opcode)
+{
+	static const u8 spi_nor_3to4_program[][2] = {
+		{ SPINOR_OP_PP,		SPINOR_OP_PP_4B },
+		{ SPINOR_OP_PP_1_1_4,	SPINOR_OP_PP_1_1_4_4B },
+		{ SPINOR_OP_PP_1_4_4,	SPINOR_OP_PP_1_4_4_4B },
+		{ SPINOR_OP_PP_1_1_8,	SPINOR_OP_PP_1_1_8_4B },
+		{ SPINOR_OP_PP_1_8_8,	SPINOR_OP_PP_1_8_8_4B },
+	};
+
+	return spi_nor_convert_opcode(opcode, spi_nor_3to4_program,
+				      ARRAY_SIZE(spi_nor_3to4_program));
+}
+
+static u8 spi_nor_convert_3to4_erase(u8 opcode)
+{
+	static const u8 spi_nor_3to4_erase[][2] = {
+		{ SPINOR_OP_BE_4K,	SPINOR_OP_BE_4K_4B },
+		{ SPINOR_OP_BE_32K,	SPINOR_OP_BE_32K_4B },
+		{ SPINOR_OP_SE,		SPINOR_OP_SE_4B },
+	};
+
+	return spi_nor_convert_opcode(opcode, spi_nor_3to4_erase,
+				      ARRAY_SIZE(spi_nor_3to4_erase));
+}
+
+static void spi_nor_set_4byte_opcodes(struct spi_nor *nor,
+				      const struct flash_info *info)
+{
+	/* Do some manufacturer fixups first */
+	switch (JEDEC_MFR(info)) {
+	case SNOR_MFR_SPANSION:
+		/* No small sector erase for 4-byte command set */
+		nor->erase_opcode = SPINOR_OP_SE;
+		nor->mtd.erasesize = info->sector_size;
+		break;
+
+	default:
+		break;
+	}
+
+	nor->read_opcode = spi_nor_convert_3to4_read(nor->read_opcode);
+	nor->program_opcode = spi_nor_convert_3to4_program(nor->program_opcode);
+	nor->erase_opcode = spi_nor_convert_3to4_erase(nor->erase_opcode);
+}
+#endif /* !CONFIG_SPI_FLASH_BAR */
+
+/* Enable/disable 4-byte addressing mode. */
+static int set_4byte(struct spi_nor *nor, const struct flash_info *info,
+		     int enable)
+{
+	int status;
+	bool need_wren = false;
+	u8 cmd;
+
+	switch (JEDEC_MFR(info)) {
+	case SNOR_MFR_ST:
+	case SNOR_MFR_MICRON:
+		/* Some Micron need WREN command; all will accept it */
+		need_wren = true;
+	case SNOR_MFR_ISSI:
+	case SNOR_MFR_MACRONIX:
+	case SNOR_MFR_WINBOND:
+		if (need_wren)
+			write_enable(nor);
+
+		cmd = enable ? SPINOR_OP_EN4B : SPINOR_OP_EX4B;
+		status = nor->write_reg(nor, cmd, NULL, 0);
+		if (need_wren)
+			write_disable(nor);
+
+		if (!status && !enable &&
+		    JEDEC_MFR(info) == SNOR_MFR_WINBOND) {
+			/*
+			 * On Winbond W25Q256FV, leaving 4byte mode causes
+			 * the Extended Address Register to be set to 1, so all
+			 * 3-byte-address reads come from the second 16M.
+			 * We must clear the register to enable normal behavior.
+			 */
+			write_enable(nor);
+			nor->cmd_buf[0] = 0;
+			nor->write_reg(nor, SPINOR_OP_WREAR, nor->cmd_buf, 1);
+			write_disable(nor);
+		}
+
+		return status;
+	default:
+		/* Spansion style */
+		nor->cmd_buf[0] = enable << 7;
+		return nor->write_reg(nor, SPINOR_OP_BRWR, nor->cmd_buf, 1);
+	}
+}
+
+static int spi_nor_sr_ready(struct spi_nor *nor)
+{
+	int sr = read_sr(nor);
+
+	if (sr < 0)
+		return sr;
+
+	if (nor->flags & SNOR_F_USE_CLSR && sr & (SR_E_ERR | SR_P_ERR)) {
+		if (sr & SR_E_ERR)
+			dev_dbg(nor->dev, "Erase Error occurred\n");
+		else
+			dev_dbg(nor->dev, "Programming Error occurred\n");
+
+		nor->write_reg(nor, SPINOR_OP_CLSR, NULL, 0);
+		return -EIO;
+	}
+
+	return !(sr & SR_WIP);
+}
+
+static int spi_nor_fsr_ready(struct spi_nor *nor)
+{
+	int fsr = read_fsr(nor);
+
+	if (fsr < 0)
+		return fsr;
+
+	if (fsr & (FSR_E_ERR | FSR_P_ERR)) {
+		if (fsr & FSR_E_ERR)
+			dev_err(nor->dev, "Erase operation failed.\n");
+		else
+			dev_err(nor->dev, "Program operation failed.\n");
+
+		if (fsr & FSR_PT_ERR)
+			dev_err(nor->dev,
+				"Attempted to modify a protected sector.\n");
+
+		nor->write_reg(nor, SPINOR_OP_CLFSR, NULL, 0);
+		return -EIO;
+	}
+
+	return fsr & FSR_READY;
+}
+
+static int spi_nor_ready(struct spi_nor *nor)
+{
+	int sr, fsr;
+
+	sr = spi_nor_sr_ready(nor);
+	if (sr < 0)
+		return sr;
+	fsr = nor->flags & SNOR_F_USE_FSR ? spi_nor_fsr_ready(nor) : 1;
+	if (fsr < 0)
+		return fsr;
+	return sr && fsr;
+}
+
+/*
+ * Service routine to read status register until ready, or timeout occurs.
+ * Returns non-zero if error.
+ */
+static int spi_nor_wait_till_ready_with_timeout(struct spi_nor *nor,
+						unsigned long timeout)
+{
+	unsigned long timebase;
+	int ret;
+
+	timebase = get_timer(0);
+
+	while (get_timer(timebase) < timeout) {
+		ret = spi_nor_ready(nor);
+		if (ret < 0)
+			return ret;
+		if (ret)
+			return 0;
+	}
+
+	dev_err(nor->dev, "flash operation timed out\n");
+
+	return -ETIMEDOUT;
+}
+
+static int spi_nor_wait_till_ready(struct spi_nor *nor)
+{
+	return spi_nor_wait_till_ready_with_timeout(nor,
+						    DEFAULT_READY_WAIT_JIFFIES);
+}
+
+#ifdef CONFIG_SPI_FLASH_BAR
+/*
+ * This "clean_bar" is necessary in a situation when one was accessing
+ * spi flash memory > 16 MiB by using Bank Address Register's BA24 bit.
+ *
+ * After it the BA24 bit shall be cleared to allow access to correct
+ * memory region after SW reset (by calling "reset" command).
+ *
+ * Otherwise, the BA24 bit may be left set and then after reset, the
+ * ROM would read/write/erase SPL from 16 MiB * bank_sel address.
+ */
+static int clean_bar(struct spi_nor *nor)
+{
+	u8 cmd, bank_sel = 0;
+
+	if (nor->bank_curr == 0)
+		return 0;
+	cmd = nor->bank_write_cmd;
+	nor->bank_curr = 0;
+	write_enable(nor);
+
+	return nor->write_reg(nor, cmd, &bank_sel, 1);
+}
+
+static int write_bar(struct spi_nor *nor, u32 offset)
+{
+	u8 cmd, bank_sel;
+	int ret;
+
+	bank_sel = offset / SZ_16M;
+	if (bank_sel == nor->bank_curr)
+		goto bar_end;
+
+	cmd = nor->bank_write_cmd;
+	write_enable(nor);
+	ret = nor->write_reg(nor, cmd, &bank_sel, 1);
+	if (ret < 0) {
+		debug("SF: fail to write bank register\n");
+		return ret;
+	}
+
+bar_end:
+	nor->bank_curr = bank_sel;
+	return nor->bank_curr;
+}
+
+static int read_bar(struct spi_nor *nor, const struct flash_info *info)
+{
+	u8 curr_bank = 0;
+	int ret;
+
+	switch (JEDEC_MFR(info)) {
+	case SNOR_MFR_SPANSION:
+		nor->bank_read_cmd = SPINOR_OP_BRRD;
+		nor->bank_write_cmd = SPINOR_OP_BRWR;
+		break;
+	default:
+		nor->bank_read_cmd = SPINOR_OP_RDEAR;
+		nor->bank_write_cmd = SPINOR_OP_WREAR;
+	}
+
+	ret = nor->read_reg(nor, nor->bank_read_cmd,
+				    &curr_bank, 1);
+	if (ret) {
+		debug("SF: fail to read bank addr register\n");
+		return ret;
+	}
+	nor->bank_curr = curr_bank;
+
+	return 0;
+}
+#endif
+
+/*
+ * Initiate the erasure of a single sector
+ */
+static int spi_nor_erase_sector(struct spi_nor *nor, u32 addr)
+{
+	struct spi_mem_op op =
+		SPI_MEM_OP(SPI_MEM_OP_CMD(nor->erase_opcode, 1),
+			   SPI_MEM_OP_ADDR(nor->addr_width, addr, 1),
+			   SPI_MEM_OP_NO_DUMMY,
+			   SPI_MEM_OP_NO_DATA);
+
+	if (nor->erase)
+		return nor->erase(nor, addr);
+
+	/*
+	 * Default implementation, if driver doesn't have a specialized HW
+	 * control
+	 */
+	return spi_mem_exec_op(nor->spi, &op);
+}
+
+/*
+ * Erase an address range on the nor chip.  The address range may extend
+ * one or more erase sectors.  Return an error is there is a problem erasing.
+ */
+static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct spi_nor *nor = mtd_to_spi_nor(mtd);
+	u32 addr, len, rem;
+	int ret;
+
+	dev_dbg(nor->dev, "at 0x%llx, len %lld\n", (long long)instr->addr,
+		(long long)instr->len);
+
+	if (!instr->len)
+		return 0;
+
+	div_u64_rem(instr->len, mtd->erasesize, &rem);
+	if (rem)
+		return -EINVAL;
+
+	addr = instr->addr;
+	len = instr->len;
+
+	while (len) {
+		WATCHDOG_RESET();
+#ifdef CONFIG_SPI_FLASH_BAR
+		ret = write_bar(nor, addr);
+		if (ret < 0)
+			return ret;
+#endif
+		write_enable(nor);
+
+		ret = spi_nor_erase_sector(nor, addr);
+		if (ret)
+			goto erase_err;
+
+		addr += mtd->erasesize;
+		len -= mtd->erasesize;
+
+		ret = spi_nor_wait_till_ready(nor);
+		if (ret)
+			goto erase_err;
+	}
+
+erase_err:
+#ifdef CONFIG_SPI_FLASH_BAR
+	ret = clean_bar(nor);
+#endif
+	write_disable(nor);
+
+	return ret;
+}
+
+#if defined(CONFIG_SPI_FLASH_STMICRO) || defined(CONFIG_SPI_FLASH_SST)
+/* Write status register and ensure bits in mask match written values */
+static int write_sr_and_check(struct spi_nor *nor, u8 status_new, u8 mask)
+{
+	int ret;
+
+	write_enable(nor);
+	ret = write_sr(nor, status_new);
+	if (ret)
+		return ret;
+
+	ret = spi_nor_wait_till_ready(nor);
+	if (ret)
+		return ret;
+
+	ret = read_sr(nor);
+	if (ret < 0)
+		return ret;
+
+	return ((ret & mask) != (status_new & mask)) ? -EIO : 0;
+}
+
+static void stm_get_locked_range(struct spi_nor *nor, u8 sr, loff_t *ofs,
+				 uint64_t *len)
+{
+	struct mtd_info *mtd = &nor->mtd;
+	u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
+	int shift = ffs(mask) - 1;
+	int pow;
+
+	if (!(sr & mask)) {
+		/* No protection */
+		*ofs = 0;
+		*len = 0;
+	} else {
+		pow = ((sr & mask) ^ mask) >> shift;
+		*len = mtd->size >> pow;
+		if (nor->flags & SNOR_F_HAS_SR_TB && sr & SR_TB)
+			*ofs = 0;
+		else
+			*ofs = mtd->size - *len;
+	}
+}
+
+/*
+ * Return 1 if the entire region is locked (if @locked is true) or unlocked (if
+ * @locked is false); 0 otherwise
+ */
+static int stm_check_lock_status_sr(struct spi_nor *nor, loff_t ofs, u64 len,
+				    u8 sr, bool locked)
+{
+	loff_t lock_offs;
+	uint64_t lock_len;
+
+	if (!len)
+		return 1;
+
+	stm_get_locked_range(nor, sr, &lock_offs, &lock_len);
+
+	if (locked)
+		/* Requested range is a sub-range of locked range */
+		return (ofs + len <= lock_offs + lock_len) && (ofs >= lock_offs);
+	else
+		/* Requested range does not overlap with locked range */
+		return (ofs >= lock_offs + lock_len) || (ofs + len <= lock_offs);
+}
+
+static int stm_is_locked_sr(struct spi_nor *nor, loff_t ofs, uint64_t len,
+			    u8 sr)
+{
+	return stm_check_lock_status_sr(nor, ofs, len, sr, true);
+}
+
+static int stm_is_unlocked_sr(struct spi_nor *nor, loff_t ofs, uint64_t len,
+			      u8 sr)
+{
+	return stm_check_lock_status_sr(nor, ofs, len, sr, false);
+}
+
+/*
+ * Lock a region of the flash. Compatible with ST Micro and similar flash.
+ * Supports the block protection bits BP{0,1,2} in the status register
+ * (SR). Does not support these features found in newer SR bitfields:
+ *   - SEC: sector/block protect - only handle SEC=0 (block protect)
+ *   - CMP: complement protect - only support CMP=0 (range is not complemented)
+ *
+ * Support for the following is provided conditionally for some flash:
+ *   - TB: top/bottom protect
+ *
+ * Sample table portion for 8MB flash (Winbond w25q64fw):
+ *
+ *   SEC  |  TB   |  BP2  |  BP1  |  BP0  |  Prot Length  | Protected Portion
+ *  --------------------------------------------------------------------------
+ *    X   |   X   |   0   |   0   |   0   |  NONE         | NONE
+ *    0   |   0   |   0   |   0   |   1   |  128 KB       | Upper 1/64
+ *    0   |   0   |   0   |   1   |   0   |  256 KB       | Upper 1/32
+ *    0   |   0   |   0   |   1   |   1   |  512 KB       | Upper 1/16
+ *    0   |   0   |   1   |   0   |   0   |  1 MB         | Upper 1/8
+ *    0   |   0   |   1   |   0   |   1   |  2 MB         | Upper 1/4
+ *    0   |   0   |   1   |   1   |   0   |  4 MB         | Upper 1/2
+ *    X   |   X   |   1   |   1   |   1   |  8 MB         | ALL
+ *  ------|-------|-------|-------|-------|---------------|-------------------
+ *    0   |   1   |   0   |   0   |   1   |  128 KB       | Lower 1/64
+ *    0   |   1   |   0   |   1   |   0   |  256 KB       | Lower 1/32
+ *    0   |   1   |   0   |   1   |   1   |  512 KB       | Lower 1/16
+ *    0   |   1   |   1   |   0   |   0   |  1 MB         | Lower 1/8
+ *    0   |   1   |   1   |   0   |   1   |  2 MB         | Lower 1/4
+ *    0   |   1   |   1   |   1   |   0   |  4 MB         | Lower 1/2
+ *
+ * Returns negative on errors, 0 on success.
+ */
+static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
+{
+	struct mtd_info *mtd = &nor->mtd;
+	int status_old, status_new;
+	u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
+	u8 shift = ffs(mask) - 1, pow, val;
+	loff_t lock_len;
+	bool can_be_top = true, can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB;
+	bool use_top;
+
+	status_old = read_sr(nor);
+	if (status_old < 0)
+		return status_old;
+
+	/* If nothing in our range is unlocked, we don't need to do anything */
+	if (stm_is_locked_sr(nor, ofs, len, status_old))
+		return 0;
+
+	/* If anything below us is unlocked, we can't use 'bottom' protection */
+	if (!stm_is_locked_sr(nor, 0, ofs, status_old))
+		can_be_bottom = false;
+
+	/* If anything above us is unlocked, we can't use 'top' protection */
+	if (!stm_is_locked_sr(nor, ofs + len, mtd->size - (ofs + len),
+			      status_old))
+		can_be_top = false;
+
+	if (!can_be_bottom && !can_be_top)
+		return -EINVAL;
+
+	/* Prefer top, if both are valid */
+	use_top = can_be_top;
+
+	/* lock_len: length of region that should end up locked */
+	if (use_top)
+		lock_len = mtd->size - ofs;
+	else
+		lock_len = ofs + len;
+
+	/*
+	 * Need smallest pow such that:
+	 *
+	 *   1 / (2^pow) <= (len / size)
+	 *
+	 * so (assuming power-of-2 size) we do:
+	 *
+	 *   pow = ceil(log2(size / len)) = log2(size) - floor(log2(len))
+	 */
+	pow = ilog2(mtd->size) - ilog2(lock_len);
+	val = mask - (pow << shift);
+	if (val & ~mask)
+		return -EINVAL;
+	/* Don't "lock" with no region! */
+	if (!(val & mask))
+		return -EINVAL;
+
+	status_new = (status_old & ~mask & ~SR_TB) | val;
+
+	/* Disallow further writes if WP pin is asserted */
+	status_new |= SR_SRWD;
+
+	if (!use_top)
+		status_new |= SR_TB;
+
+	/* Don't bother if they're the same */
+	if (status_new == status_old)
+		return 0;
+
+	/* Only modify protection if it will not unlock other areas */
+	if ((status_new & mask) < (status_old & mask))
+		return -EINVAL;
+
+	return write_sr_and_check(nor, status_new, mask);
+}
+
+/*
+ * Unlock a region of the flash. See stm_lock() for more info
+ *
+ * Returns negative on errors, 0 on success.
+ */
+static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
+{
+	struct mtd_info *mtd = &nor->mtd;
+	int status_old, status_new;
+	u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
+	u8 shift = ffs(mask) - 1, pow, val;
+	loff_t lock_len;
+	bool can_be_top = true, can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB;
+	bool use_top;
+
+	status_old = read_sr(nor);
+	if (status_old < 0)
+		return status_old;
+
+	/* If nothing in our range is locked, we don't need to do anything */
+	if (stm_is_unlocked_sr(nor, ofs, len, status_old))
+		return 0;
+
+	/* If anything below us is locked, we can't use 'top' protection */
+	if (!stm_is_unlocked_sr(nor, 0, ofs, status_old))
+		can_be_top = false;
+
+	/* If anything above us is locked, we can't use 'bottom' protection */
+	if (!stm_is_unlocked_sr(nor, ofs + len, mtd->size - (ofs + len),
+				status_old))
+		can_be_bottom = false;
+
+	if (!can_be_bottom && !can_be_top)
+		return -EINVAL;
+
+	/* Prefer top, if both are valid */
+	use_top = can_be_top;
+
+	/* lock_len: length of region that should remain locked */
+	if (use_top)
+		lock_len = mtd->size - (ofs + len);
+	else
+		lock_len = ofs;
+
+	/*
+	 * Need largest pow such that:
+	 *
+	 *   1 / (2^pow) >= (len / size)
+	 *
+	 * so (assuming power-of-2 size) we do:
+	 *
+	 *   pow = floor(log2(size / len)) = log2(size) - ceil(log2(len))
+	 */
+	pow = ilog2(mtd->size) - order_base_2(lock_len);
+	if (lock_len == 0) {
+		val = 0; /* fully unlocked */
+	} else {
+		val = mask - (pow << shift);
+		/* Some power-of-two sizes are not supported */
+		if (val & ~mask)
+			return -EINVAL;
+	}
+
+	status_new = (status_old & ~mask & ~SR_TB) | val;
+
+	/* Don't protect status register if we're fully unlocked */
+	if (lock_len == 0)
+		status_new &= ~SR_SRWD;
+
+	if (!use_top)
+		status_new |= SR_TB;
+
+	/* Don't bother if they're the same */
+	if (status_new == status_old)
+		return 0;
+
+	/* Only modify protection if it will not lock other areas */
+	if ((status_new & mask) > (status_old & mask))
+		return -EINVAL;
+
+	return write_sr_and_check(nor, status_new, mask);
+}
+
+/*
+ * Check if a region of the flash is (completely) locked. See stm_lock() for
+ * more info.
+ *
+ * Returns 1 if entire region is locked, 0 if any portion is unlocked, and
+ * negative on errors.
+ */
+static int stm_is_locked(struct spi_nor *nor, loff_t ofs, uint64_t len)
+{
+	int status;
+
+	status = read_sr(nor);
+	if (status < 0)
+		return status;
+
+	return stm_is_locked_sr(nor, ofs, len, status);
+}
+#endif /* CONFIG_SPI_FLASH_STMICRO */
+
+static const struct flash_info *spi_nor_read_id(struct spi_nor *nor)
+{
+	int			tmp;
+	u8			id[SPI_NOR_MAX_ID_LEN];
+	const struct flash_info	*info;
+
+	tmp = nor->read_reg(nor, SPINOR_OP_RDID, id, SPI_NOR_MAX_ID_LEN);
+	if (tmp < 0) {
+		dev_dbg(nor->dev, "error %d reading JEDEC ID\n", tmp);
+		return ERR_PTR(tmp);
+	}
+
+	info = spi_nor_ids;
+	for (; info->name; info++) {
+		if (info->id_len) {
+			if (!memcmp(info->id, id, info->id_len))
+				return info;
+		}
+	}
+
+	dev_err(nor->dev, "unrecognized JEDEC id bytes: %02x, %02x, %02x\n",
+		id[0], id[1], id[2]);
+	return ERR_PTR(-ENODEV);
+}
+
+static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, u_char *buf)
+{
+	struct spi_nor *nor = mtd_to_spi_nor(mtd);
+	int ret;
+
+	dev_dbg(nor->dev, "from 0x%08x, len %zd\n", (u32)from, len);
+
+	while (len) {
+		loff_t addr = from;
+		size_t read_len = len;
+
+#ifdef CONFIG_SPI_FLASH_BAR
+		u32 remain_len;
+
+		ret = write_bar(nor, addr);
+		if (ret < 0)
+			return log_ret(ret);
+		remain_len = (SZ_16M * (nor->bank_curr + 1)) - addr;
+
+		if (len < remain_len)
+			read_len = len;
+		else
+			read_len = remain_len;
+#endif
+
+		ret = nor->read(nor, addr, read_len, buf);
+		if (ret == 0) {
+			/* We shouldn't see 0-length reads */
+			ret = -EIO;
+			goto read_err;
+		}
+		if (ret < 0)
+			goto read_err;
+
+		*retlen += ret;
+		buf += ret;
+		from += ret;
+		len -= ret;
+	}
+	ret = 0;
+
+read_err:
+#ifdef CONFIG_SPI_FLASH_BAR
+	ret = clean_bar(nor);
+#endif
+	return ret;
+}
+
+#ifdef CONFIG_SPI_FLASH_SST
+/*
+ * sst26 flash series has its own block protection implementation:
+ * 4x   - 8  KByte blocks - read & write protection bits - upper addresses
+ * 1x   - 32 KByte blocks - write protection bits
+ * rest - 64 KByte blocks - write protection bits
+ * 1x   - 32 KByte blocks - write protection bits
+ * 4x   - 8  KByte blocks - read & write protection bits - lower addresses
+ *
+ * We'll support only per 64k lock/unlock so lower and upper 64 KByte region
+ * will be treated as single block.
+ */
+#define SST26_BPR_8K_NUM		4
+#define SST26_MAX_BPR_REG_LEN		(18 + 1)
+#define SST26_BOUND_REG_SIZE		((32 + SST26_BPR_8K_NUM * 8) * SZ_1K)
+
+enum lock_ctl {
+	SST26_CTL_LOCK,
+	SST26_CTL_UNLOCK,
+	SST26_CTL_CHECK
+};
+
+static bool sst26_process_bpr(u32 bpr_size, u8 *cmd, u32 bit, enum lock_ctl ctl)
+{
+	switch (ctl) {
+	case SST26_CTL_LOCK:
+		cmd[bpr_size - (bit / 8) - 1] |= BIT(bit % 8);
+		break;
+	case SST26_CTL_UNLOCK:
+		cmd[bpr_size - (bit / 8) - 1] &= ~BIT(bit % 8);
+		break;
+	case SST26_CTL_CHECK:
+		return !!(cmd[bpr_size - (bit / 8) - 1] & BIT(bit % 8));
+	}
+
+	return false;
+}
+
+/*
+ * Lock, unlock or check lock status of the flash region of the flash (depending
+ * on the lock_ctl value)
+ */
+static int sst26_lock_ctl(struct spi_nor *nor, loff_t ofs, uint64_t len, enum lock_ctl ctl)
+{
+	struct mtd_info *mtd = &nor->mtd;
+	u32 i, bpr_ptr, rptr_64k, lptr_64k, bpr_size;
+	bool lower_64k = false, upper_64k = false;
+	u8 bpr_buff[SST26_MAX_BPR_REG_LEN] = {};
+	int ret;
+
+	/* Check length and offset for 64k alignment */
+	if ((ofs & (SZ_64K - 1)) || (len & (SZ_64K - 1))) {
+		dev_err(nor->dev, "length or offset is not 64KiB allighned\n");
+		return -EINVAL;
+	}
+
+	if (ofs + len > mtd->size) {
+		dev_err(nor->dev, "range is more than device size: %#llx + %#llx > %#llx\n",
+			ofs, len, mtd->size);
+		return -EINVAL;
+	}
+
+	/* SST26 family has only 16 Mbit, 32 Mbit and 64 Mbit IC */
+	if (mtd->size != SZ_2M &&
+	    mtd->size != SZ_4M &&
+	    mtd->size != SZ_8M)
+		return -EINVAL;
+
+	bpr_size = 2 + (mtd->size / SZ_64K / 8);
+
+	ret = nor->read_reg(nor, SPINOR_OP_READ_BPR, bpr_buff, bpr_size);
+	if (ret < 0) {
+		dev_err(nor->dev, "fail to read block-protection register\n");
+		return ret;
+	}
+
+	rptr_64k = min_t(u32, ofs + len, mtd->size - SST26_BOUND_REG_SIZE);
+	lptr_64k = max_t(u32, ofs, SST26_BOUND_REG_SIZE);
+
+	upper_64k = ((ofs + len) > (mtd->size - SST26_BOUND_REG_SIZE));
+	lower_64k = (ofs < SST26_BOUND_REG_SIZE);
+
+	/* Lower bits in block-protection register are about 64k region */
+	bpr_ptr = lptr_64k / SZ_64K - 1;
+
+	/* Process 64K blocks region */
+	while (lptr_64k < rptr_64k) {
+		if (sst26_process_bpr(bpr_size, bpr_buff, bpr_ptr, ctl))
+			return EACCES;
+
+		bpr_ptr++;
+		lptr_64k += SZ_64K;
+	}
+
+	/* 32K and 8K region bits in BPR are after 64k region bits */
+	bpr_ptr = (mtd->size - 2 * SST26_BOUND_REG_SIZE) / SZ_64K;
+
+	/* Process lower 32K block region */
+	if (lower_64k)
+		if (sst26_process_bpr(bpr_size, bpr_buff, bpr_ptr, ctl))
+			return EACCES;
+
+	bpr_ptr++;
+
+	/* Process upper 32K block region */
+	if (upper_64k)
+		if (sst26_process_bpr(bpr_size, bpr_buff, bpr_ptr, ctl))
+			return EACCES;
+
+	bpr_ptr++;
+
+	/* Process lower 8K block regions */
+	for (i = 0; i < SST26_BPR_8K_NUM; i++) {
+		if (lower_64k)
+			if (sst26_process_bpr(bpr_size, bpr_buff, bpr_ptr, ctl))
+				return EACCES;
+
+		/* In 8K area BPR has both read and write protection bits */
+		bpr_ptr += 2;
+	}
+
+	/* Process upper 8K block regions */
+	for (i = 0; i < SST26_BPR_8K_NUM; i++) {
+		if (upper_64k)
+			if (sst26_process_bpr(bpr_size, bpr_buff, bpr_ptr, ctl))
+				return EACCES;
+
+		/* In 8K area BPR has both read and write protection bits */
+		bpr_ptr += 2;
+	}
+
+	/* If we check region status we don't need to write BPR back */
+	if (ctl == SST26_CTL_CHECK)
+		return 0;
+
+	ret = nor->write_reg(nor, SPINOR_OP_WRITE_BPR, bpr_buff, bpr_size);
+	if (ret < 0) {
+		dev_err(nor->dev, "fail to write block-protection register\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int sst26_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
+{
+	return sst26_lock_ctl(nor, ofs, len, SST26_CTL_UNLOCK);
+}
+
+static int sst26_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
+{
+	return sst26_lock_ctl(nor, ofs, len, SST26_CTL_LOCK);
+}
+
+/*
+ * Returns EACCES (positive value) if region is locked, 0 if region is unlocked,
+ * and negative on errors.
+ */
+static int sst26_is_locked(struct spi_nor *nor, loff_t ofs, uint64_t len)
+{
+	/*
+	 * is_locked function is used for check before reading or erasing flash
+	 * region, so offset and length might be not 64k allighned, so adjust
+	 * them to be 64k allighned as sst26_lock_ctl works only with 64k
+	 * allighned regions.
+	 */
+	ofs -= ofs & (SZ_64K - 1);
+	len = len & (SZ_64K - 1) ? (len & ~(SZ_64K - 1)) + SZ_64K : len;
+
+	return sst26_lock_ctl(nor, ofs, len, SST26_CTL_CHECK);
+}
+
+static int sst_write_byteprogram(struct spi_nor *nor, loff_t to, size_t len,
+				 size_t *retlen, const u_char *buf)
+{
+	size_t actual;
+	int ret = 0;
+
+	for (actual = 0; actual < len; actual++) {
+		nor->program_opcode = SPINOR_OP_BP;
+
+		write_enable(nor);
+		/* write one byte. */
+		ret = nor->write(nor, to, 1, buf + actual);
+		if (ret < 0)
+			goto sst_write_err;
+		ret = spi_nor_wait_till_ready(nor);
+		if (ret)
+			goto sst_write_err;
+		to++;
+	}
+
+sst_write_err:
+	write_disable(nor);
+	return ret;
+}
+
+static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
+		     size_t *retlen, const u_char *buf)
+{
+	struct spi_nor *nor = mtd_to_spi_nor(mtd);
+	struct spi_slave *spi = nor->spi;
+	size_t actual;
+	int ret;
+
+	dev_dbg(nor->dev, "to 0x%08x, len %zd\n", (u32)to, len);
+	if (spi->mode & SPI_TX_BYTE)
+		return sst_write_byteprogram(nor, to, len, retlen, buf);
+
+	write_enable(nor);
+
+	nor->sst_write_second = false;
+
+	actual = to % 2;
+	/* Start write from odd address. */
+	if (actual) {
+		nor->program_opcode = SPINOR_OP_BP;
+
+		/* write one byte. */
+		ret = nor->write(nor, to, 1, buf);
+		if (ret < 0)
+			goto sst_write_err;
+		ret = spi_nor_wait_till_ready(nor);
+		if (ret)
+			goto sst_write_err;
+	}
+	to += actual;
+
+	/* Write out most of the data here. */
+	for (; actual < len - 1; actual += 2) {
+		nor->program_opcode = SPINOR_OP_AAI_WP;
+
+		/* write two bytes. */
+		ret = nor->write(nor, to, 2, buf + actual);
+		if (ret < 0)
+			goto sst_write_err;
+		ret = spi_nor_wait_till_ready(nor);
+		if (ret)
+			goto sst_write_err;
+		to += 2;
+		nor->sst_write_second = true;
+	}
+	nor->sst_write_second = false;
+
+	write_disable(nor);
+	ret = spi_nor_wait_till_ready(nor);
+	if (ret)
+		goto sst_write_err;
+
+	/* Write out trailing byte if it exists. */
+	if (actual != len) {
+		write_enable(nor);
+
+		nor->program_opcode = SPINOR_OP_BP;
+		ret = nor->write(nor, to, 1, buf + actual);
+		if (ret < 0)
+			goto sst_write_err;
+		ret = spi_nor_wait_till_ready(nor);
+		if (ret)
+			goto sst_write_err;
+		write_disable(nor);
+		actual += 1;
+	}
+sst_write_err:
+	*retlen += actual;
+	return ret;
+}
+#endif
+/*
+ * Write an address range to the nor chip.  Data must be written in
+ * FLASH_PAGESIZE chunks.  The address range may be any size provided
+ * it is within the physical boundaries.
+ */
+static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
+	size_t *retlen, const u_char *buf)
+{
+	struct spi_nor *nor = mtd_to_spi_nor(mtd);
+	size_t page_offset, page_remain, i;
+	ssize_t ret;
+
+#ifdef CONFIG_SPI_FLASH_SST
+	/* sst nor chips use AAI word program */
+	if (nor->info->flags & SST_WRITE)
+		return sst_write(mtd, to, len, retlen, buf);
+#endif
+
+	dev_dbg(nor->dev, "to 0x%08x, len %zd\n", (u32)to, len);
+
+	if (!len)
+		return 0;
+
+	for (i = 0; i < len; ) {
+		ssize_t written;
+		loff_t addr = to + i;
+		WATCHDOG_RESET();
+
+		/*
+		 * If page_size is a power of two, the offset can be quickly
+		 * calculated with an AND operation. On the other cases we
+		 * need to do a modulus operation (more expensive).
+		 */
+		if (is_power_of_2(nor->page_size)) {
+			page_offset = addr & (nor->page_size - 1);
+		} else {
+			u64 aux = addr;
+
+			page_offset = do_div(aux, nor->page_size);
+		}
+		/* the size of data remaining on the first page */
+		page_remain = min_t(size_t,
+				    nor->page_size - page_offset, len - i);
+
+#ifdef CONFIG_SPI_FLASH_BAR
+		ret = write_bar(nor, addr);
+		if (ret < 0)
+			return ret;
+#endif
+		write_enable(nor);
+		ret = nor->write(nor, addr, page_remain, buf + i);
+		if (ret < 0)
+			goto write_err;
+		written = ret;
+
+		ret = spi_nor_wait_till_ready(nor);
+		if (ret)
+			goto write_err;
+		*retlen += written;
+		i += written;
+	}
+
+write_err:
+#ifdef CONFIG_SPI_FLASH_BAR
+	ret = clean_bar(nor);
+#endif
+	return ret;
+}
+
+#if defined(CONFIG_SPI_FLASH_MACRONIX) || defined(CONFIG_SPI_FLASH_ISSI)
+/**
+ * macronix_quad_enable() - set QE bit in Status Register.
+ * @nor:	pointer to a 'struct spi_nor'
+ *
+ * Set the Quad Enable (QE) bit in the Status Register.
+ *
+ * bit 6 of the Status Register is the QE bit for Macronix like QSPI memories.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int macronix_quad_enable(struct spi_nor *nor)
+{
+	int ret, val;
+
+	val = read_sr(nor);
+	if (val < 0)
+		return val;
+	if (val & SR_QUAD_EN_MX)
+		return 0;
+
+	write_enable(nor);
+
+	write_sr(nor, val | SR_QUAD_EN_MX);
+
+	ret = spi_nor_wait_till_ready(nor);
+	if (ret)
+		return ret;
+
+	ret = read_sr(nor);
+	if (!(ret > 0 && (ret & SR_QUAD_EN_MX))) {
+		dev_err(nor->dev, "Macronix Quad bit not set\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+#endif
+
+#if defined(CONFIG_SPI_FLASH_SPANSION) || defined(CONFIG_SPI_FLASH_WINBOND)
+/*
+ * Write status Register and configuration register with 2 bytes
+ * The first byte will be written to the status register, while the
+ * second byte will be written to the configuration register.
+ * Return negative if error occurred.
+ */
+static int write_sr_cr(struct spi_nor *nor, u8 *sr_cr)
+{
+	int ret;
+
+	write_enable(nor);
+
+	ret = nor->write_reg(nor, SPINOR_OP_WRSR, sr_cr, 2);
+	if (ret < 0) {
+		dev_dbg(nor->dev,
+			"error while writing configuration register\n");
+		return -EINVAL;
+	}
+
+	ret = spi_nor_wait_till_ready(nor);
+	if (ret) {
+		dev_dbg(nor->dev,
+			"timeout while writing configuration register\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * spansion_read_cr_quad_enable() - set QE bit in Configuration Register.
+ * @nor:	pointer to a 'struct spi_nor'
+ *
+ * Set the Quad Enable (QE) bit in the Configuration Register.
+ * This function should be used with QSPI memories supporting the Read
+ * Configuration Register (35h) instruction.
+ *
+ * bit 1 of the Configuration Register is the QE bit for Spansion like QSPI
+ * memories.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int spansion_read_cr_quad_enable(struct spi_nor *nor)
+{
+	u8 sr_cr[2];
+	int ret;
+
+	/* Check current Quad Enable bit value. */
+	ret = read_cr(nor);
+	if (ret < 0) {
+		dev_dbg(nor->dev,
+			"error while reading configuration register\n");
+		return -EINVAL;
+	}
+
+	if (ret & CR_QUAD_EN_SPAN)
+		return 0;
+
+	sr_cr[1] = ret | CR_QUAD_EN_SPAN;
+
+	/* Keep the current value of the Status Register. */
+	ret = read_sr(nor);
+	if (ret < 0) {
+		dev_dbg(nor->dev, "error while reading status register\n");
+		return -EINVAL;
+	}
+	sr_cr[0] = ret;
+
+	ret = write_sr_cr(nor, sr_cr);
+	if (ret)
+		return ret;
+
+	/* Read back and check it. */
+	ret = read_cr(nor);
+	if (!(ret > 0 && (ret & CR_QUAD_EN_SPAN))) {
+		dev_dbg(nor->dev, "Spansion Quad bit not set\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+#if CONFIG_IS_ENABLED(SPI_FLASH_SFDP_SUPPORT)
+/**
+ * spansion_no_read_cr_quad_enable() - set QE bit in Configuration Register.
+ * @nor:	pointer to a 'struct spi_nor'
+ *
+ * Set the Quad Enable (QE) bit in the Configuration Register.
+ * This function should be used with QSPI memories not supporting the Read
+ * Configuration Register (35h) instruction.
+ *
+ * bit 1 of the Configuration Register is the QE bit for Spansion like QSPI
+ * memories.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int spansion_no_read_cr_quad_enable(struct spi_nor *nor)
+{
+	u8 sr_cr[2];
+	int ret;
+
+	/* Keep the current value of the Status Register. */
+	ret = read_sr(nor);
+	if (ret < 0) {
+		dev_dbg(nor->dev, "error while reading status register\n");
+		return -EINVAL;
+	}
+	sr_cr[0] = ret;
+	sr_cr[1] = CR_QUAD_EN_SPAN;
+
+	return write_sr_cr(nor, sr_cr);
+}
+
+#endif /* CONFIG_SPI_FLASH_SFDP_SUPPORT */
+#endif /* CONFIG_SPI_FLASH_SPANSION */
+
+struct spi_nor_read_command {
+	u8			num_mode_clocks;
+	u8			num_wait_states;
+	u8			opcode;
+	enum spi_nor_protocol	proto;
+};
+
+struct spi_nor_pp_command {
+	u8			opcode;
+	enum spi_nor_protocol	proto;
+};
+
+enum spi_nor_read_command_index {
+	SNOR_CMD_READ,
+	SNOR_CMD_READ_FAST,
+	SNOR_CMD_READ_1_1_1_DTR,
+
+	/* Dual SPI */
+	SNOR_CMD_READ_1_1_2,
+	SNOR_CMD_READ_1_2_2,
+	SNOR_CMD_READ_2_2_2,
+	SNOR_CMD_READ_1_2_2_DTR,
+
+	/* Quad SPI */
+	SNOR_CMD_READ_1_1_4,
+	SNOR_CMD_READ_1_4_4,
+	SNOR_CMD_READ_4_4_4,
+	SNOR_CMD_READ_1_4_4_DTR,
+
+	/* Octo SPI */
+	SNOR_CMD_READ_1_1_8,
+	SNOR_CMD_READ_1_8_8,
+	SNOR_CMD_READ_8_8_8,
+	SNOR_CMD_READ_1_8_8_DTR,
+
+	SNOR_CMD_READ_MAX
+};
+
+enum spi_nor_pp_command_index {
+	SNOR_CMD_PP,
+
+	/* Quad SPI */
+	SNOR_CMD_PP_1_1_4,
+	SNOR_CMD_PP_1_4_4,
+	SNOR_CMD_PP_4_4_4,
+
+	/* Octo SPI */
+	SNOR_CMD_PP_1_1_8,
+	SNOR_CMD_PP_1_8_8,
+	SNOR_CMD_PP_8_8_8,
+
+	SNOR_CMD_PP_MAX
+};
+
+struct spi_nor_flash_parameter {
+	u64				size;
+	u32				page_size;
+
+	struct spi_nor_hwcaps		hwcaps;
+	struct spi_nor_read_command	reads[SNOR_CMD_READ_MAX];
+	struct spi_nor_pp_command	page_programs[SNOR_CMD_PP_MAX];
+
+	int (*quad_enable)(struct spi_nor *nor);
+};
+
+static void
+spi_nor_set_read_settings(struct spi_nor_read_command *read,
+			  u8 num_mode_clocks,
+			  u8 num_wait_states,
+			  u8 opcode,
+			  enum spi_nor_protocol proto)
+{
+	read->num_mode_clocks = num_mode_clocks;
+	read->num_wait_states = num_wait_states;
+	read->opcode = opcode;
+	read->proto = proto;
+}
+
+static void
+spi_nor_set_pp_settings(struct spi_nor_pp_command *pp,
+			u8 opcode,
+			enum spi_nor_protocol proto)
+{
+	pp->opcode = opcode;
+	pp->proto = proto;
+}
+
+#if CONFIG_IS_ENABLED(SPI_FLASH_SFDP_SUPPORT)
+/*
+ * Serial Flash Discoverable Parameters (SFDP) parsing.
+ */
+
+/**
+ * spi_nor_read_sfdp() - read Serial Flash Discoverable Parameters.
+ * @nor:	pointer to a 'struct spi_nor'
+ * @addr:	offset in the SFDP area to start reading data from
+ * @len:	number of bytes to read
+ * @buf:	buffer where the SFDP data are copied into (dma-safe memory)
+ *
+ * Whatever the actual numbers of bytes for address and dummy cycles are
+ * for (Fast) Read commands, the Read SFDP (5Ah) instruction is always
+ * followed by a 3-byte address and 8 dummy clock cycles.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int spi_nor_read_sfdp(struct spi_nor *nor, u32 addr,
+			     size_t len, void *buf)
+{
+	u8 addr_width, read_opcode, read_dummy;
+	int ret;
+
+	read_opcode = nor->read_opcode;
+	addr_width = nor->addr_width;
+	read_dummy = nor->read_dummy;
+
+	nor->read_opcode = SPINOR_OP_RDSFDP;
+	nor->addr_width = 3;
+	nor->read_dummy = 8;
+
+	while (len) {
+		ret = nor->read(nor, addr, len, (u8 *)buf);
+		if (!ret || ret > len) {
+			ret = -EIO;
+			goto read_err;
+		}
+		if (ret < 0)
+			goto read_err;
+
+		buf += ret;
+		addr += ret;
+		len -= ret;
+	}
+	ret = 0;
+
+read_err:
+	nor->read_opcode = read_opcode;
+	nor->addr_width = addr_width;
+	nor->read_dummy = read_dummy;
+
+	return ret;
+}
+
+struct sfdp_parameter_header {
+	u8		id_lsb;
+	u8		minor;
+	u8		major;
+	u8		length; /* in double words */
+	u8		parameter_table_pointer[3]; /* byte address */
+	u8		id_msb;
+};
+
+#define SFDP_PARAM_HEADER_ID(p)	(((p)->id_msb << 8) | (p)->id_lsb)
+#define SFDP_PARAM_HEADER_PTP(p) \
+	(((p)->parameter_table_pointer[2] << 16) | \
+	 ((p)->parameter_table_pointer[1] <<  8) | \
+	 ((p)->parameter_table_pointer[0] <<  0))
+
+#define SFDP_BFPT_ID		0xff00	/* Basic Flash Parameter Table */
+#define SFDP_SECTOR_MAP_ID	0xff81	/* Sector Map Table */
+#define SFDP_SST_ID		0x01bf	/* Manufacturer specific Table */
+
+#define SFDP_SIGNATURE		0x50444653U
+#define SFDP_JESD216_MAJOR	1
+#define SFDP_JESD216_MINOR	0
+#define SFDP_JESD216A_MINOR	5
+#define SFDP_JESD216B_MINOR	6
+
+struct sfdp_header {
+	u32		signature; /* Ox50444653U <=> "SFDP" */
+	u8		minor;
+	u8		major;
+	u8		nph; /* 0-base number of parameter headers */
+	u8		unused;
+
+	/* Basic Flash Parameter Table. */
+	struct sfdp_parameter_header	bfpt_header;
+};
+
+/* Basic Flash Parameter Table */
+
+/*
+ * JESD216 rev B defines a Basic Flash Parameter Table of 16 DWORDs.
+ * They are indexed from 1 but C arrays are indexed from 0.
+ */
+#define BFPT_DWORD(i)		((i) - 1)
+#define BFPT_DWORD_MAX		16
+
+/* The first version of JESB216 defined only 9 DWORDs. */
+#define BFPT_DWORD_MAX_JESD216			9
+
+/* 1st DWORD. */
+#define BFPT_DWORD1_FAST_READ_1_1_2		BIT(16)
+#define BFPT_DWORD1_ADDRESS_BYTES_MASK		GENMASK(18, 17)
+#define BFPT_DWORD1_ADDRESS_BYTES_3_ONLY	(0x0UL << 17)
+#define BFPT_DWORD1_ADDRESS_BYTES_3_OR_4	(0x1UL << 17)
+#define BFPT_DWORD1_ADDRESS_BYTES_4_ONLY	(0x2UL << 17)
+#define BFPT_DWORD1_DTR				BIT(19)
+#define BFPT_DWORD1_FAST_READ_1_2_2		BIT(20)
+#define BFPT_DWORD1_FAST_READ_1_4_4		BIT(21)
+#define BFPT_DWORD1_FAST_READ_1_1_4		BIT(22)
+
+/* 5th DWORD. */
+#define BFPT_DWORD5_FAST_READ_2_2_2		BIT(0)
+#define BFPT_DWORD5_FAST_READ_4_4_4		BIT(4)
+
+/* 11th DWORD. */
+#define BFPT_DWORD11_PAGE_SIZE_SHIFT		4
+#define BFPT_DWORD11_PAGE_SIZE_MASK		GENMASK(7, 4)
+
+/* 15th DWORD. */
+
+/*
+ * (from JESD216 rev B)
+ * Quad Enable Requirements (QER):
+ * - 000b: Device does not have a QE bit. Device detects 1-1-4 and 1-4-4
+ *         reads based on instruction. DQ3/HOLD# functions are hold during
+ *         instruction phase.
+ * - 001b: QE is bit 1 of status register 2. It is set via Write Status with
+ *         two data bytes where bit 1 of the second byte is one.
+ *         [...]
+ *         Writing only one byte to the status register has the side-effect of
+ *         clearing status register 2, including the QE bit. The 100b code is
+ *         used if writing one byte to the status register does not modify
+ *         status register 2.
+ * - 010b: QE is bit 6 of status register 1. It is set via Write Status with
+ *         one data byte where bit 6 is one.
+ *         [...]
+ * - 011b: QE is bit 7 of status register 2. It is set via Write status
+ *         register 2 instruction 3Eh with one data byte where bit 7 is one.
+ *         [...]
+ *         The status register 2 is read using instruction 3Fh.
+ * - 100b: QE is bit 1 of status register 2. It is set via Write Status with
+ *         two data bytes where bit 1 of the second byte is one.
+ *         [...]
+ *         In contrast to the 001b code, writing one byte to the status
+ *         register does not modify status register 2.
+ * - 101b: QE is bit 1 of status register 2. Status register 1 is read using
+ *         Read Status instruction 05h. Status register2 is read using
+ *         instruction 35h. QE is set via Writ Status instruction 01h with
+ *         two data bytes where bit 1 of the second byte is one.
+ *         [...]
+ */
+#define BFPT_DWORD15_QER_MASK			GENMASK(22, 20)
+#define BFPT_DWORD15_QER_NONE			(0x0UL << 20) /* Micron */
+#define BFPT_DWORD15_QER_SR2_BIT1_BUGGY		(0x1UL << 20)
+#define BFPT_DWORD15_QER_SR1_BIT6		(0x2UL << 20) /* Macronix */
+#define BFPT_DWORD15_QER_SR2_BIT7		(0x3UL << 20)
+#define BFPT_DWORD15_QER_SR2_BIT1_NO_RD		(0x4UL << 20)
+#define BFPT_DWORD15_QER_SR2_BIT1		(0x5UL << 20) /* Spansion */
+
+struct sfdp_bfpt {
+	u32	dwords[BFPT_DWORD_MAX];
+};
+
+/* Fast Read settings. */
+
+static void
+spi_nor_set_read_settings_from_bfpt(struct spi_nor_read_command *read,
+				    u16 half,
+				    enum spi_nor_protocol proto)
+{
+	read->num_mode_clocks = (half >> 5) & 0x07;
+	read->num_wait_states = (half >> 0) & 0x1f;
+	read->opcode = (half >> 8) & 0xff;
+	read->proto = proto;
+}
+
+struct sfdp_bfpt_read {
+	/* The Fast Read x-y-z hardware capability in params->hwcaps.mask. */
+	u32			hwcaps;
+
+	/*
+	 * The <supported_bit> bit in <supported_dword> BFPT DWORD tells us
+	 * whether the Fast Read x-y-z command is supported.
+	 */
+	u32			supported_dword;
+	u32			supported_bit;
+
+	/*
+	 * The half-word at offset <setting_shift> in <setting_dword> BFPT DWORD
+	 * encodes the op code, the number of mode clocks and the number of wait
+	 * states to be used by Fast Read x-y-z command.
+	 */
+	u32			settings_dword;
+	u32			settings_shift;
+
+	/* The SPI protocol for this Fast Read x-y-z command. */
+	enum spi_nor_protocol	proto;
+};
+
+static const struct sfdp_bfpt_read sfdp_bfpt_reads[] = {
+	/* Fast Read 1-1-2 */
+	{
+		SNOR_HWCAPS_READ_1_1_2,
+		BFPT_DWORD(1), BIT(16),	/* Supported bit */
+		BFPT_DWORD(4), 0,	/* Settings */
+		SNOR_PROTO_1_1_2,
+	},
+
+	/* Fast Read 1-2-2 */
+	{
+		SNOR_HWCAPS_READ_1_2_2,
+		BFPT_DWORD(1), BIT(20),	/* Supported bit */
+		BFPT_DWORD(4), 16,	/* Settings */
+		SNOR_PROTO_1_2_2,
+	},
+
+	/* Fast Read 2-2-2 */
+	{
+		SNOR_HWCAPS_READ_2_2_2,
+		BFPT_DWORD(5),  BIT(0),	/* Supported bit */
+		BFPT_DWORD(6), 16,	/* Settings */
+		SNOR_PROTO_2_2_2,
+	},
+
+	/* Fast Read 1-1-4 */
+	{
+		SNOR_HWCAPS_READ_1_1_4,
+		BFPT_DWORD(1), BIT(22),	/* Supported bit */
+		BFPT_DWORD(3), 16,	/* Settings */
+		SNOR_PROTO_1_1_4,
+	},
+
+	/* Fast Read 1-4-4 */
+	{
+		SNOR_HWCAPS_READ_1_4_4,
+		BFPT_DWORD(1), BIT(21),	/* Supported bit */
+		BFPT_DWORD(3), 0,	/* Settings */
+		SNOR_PROTO_1_4_4,
+	},
+
+	/* Fast Read 4-4-4 */
+	{
+		SNOR_HWCAPS_READ_4_4_4,
+		BFPT_DWORD(5), BIT(4),	/* Supported bit */
+		BFPT_DWORD(7), 16,	/* Settings */
+		SNOR_PROTO_4_4_4,
+	},
+};
+
+struct sfdp_bfpt_erase {
+	/*
+	 * The half-word at offset <shift> in DWORD <dwoard> encodes the
+	 * op code and erase sector size to be used by Sector Erase commands.
+	 */
+	u32			dword;
+	u32			shift;
+};
+
+static const struct sfdp_bfpt_erase sfdp_bfpt_erases[] = {
+	/* Erase Type 1 in DWORD8 bits[15:0] */
+	{BFPT_DWORD(8), 0},
+
+	/* Erase Type 2 in DWORD8 bits[31:16] */
+	{BFPT_DWORD(8), 16},
+
+	/* Erase Type 3 in DWORD9 bits[15:0] */
+	{BFPT_DWORD(9), 0},
+
+	/* Erase Type 4 in DWORD9 bits[31:16] */
+	{BFPT_DWORD(9), 16},
+};
+
+static int spi_nor_hwcaps_read2cmd(u32 hwcaps);
+
+/**
+ * spi_nor_parse_bfpt() - read and parse the Basic Flash Parameter Table.
+ * @nor:		pointer to a 'struct spi_nor'
+ * @bfpt_header:	pointer to the 'struct sfdp_parameter_header' describing
+ *			the Basic Flash Parameter Table length and version
+ * @params:		pointer to the 'struct spi_nor_flash_parameter' to be
+ *			filled
+ *
+ * The Basic Flash Parameter Table is the main and only mandatory table as
+ * defined by the SFDP (JESD216) specification.
+ * It provides us with the total size (memory density) of the data array and
+ * the number of address bytes for Fast Read, Page Program and Sector Erase
+ * commands.
+ * For Fast READ commands, it also gives the number of mode clock cycles and
+ * wait states (regrouped in the number of dummy clock cycles) for each
+ * supported instruction op code.
+ * For Page Program, the page size is now available since JESD216 rev A, however
+ * the supported instruction op codes are still not provided.
+ * For Sector Erase commands, this table stores the supported instruction op
+ * codes and the associated sector sizes.
+ * Finally, the Quad Enable Requirements (QER) are also available since JESD216
+ * rev A. The QER bits encode the manufacturer dependent procedure to be
+ * executed to set the Quad Enable (QE) bit in some internal register of the
+ * Quad SPI memory. Indeed the QE bit, when it exists, must be set before
+ * sending any Quad SPI command to the memory. Actually, setting the QE bit
+ * tells the memory to reassign its WP# and HOLD#/RESET# pins to functions IO2
+ * and IO3 hence enabling 4 (Quad) I/O lines.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int spi_nor_parse_bfpt(struct spi_nor *nor,
+			      const struct sfdp_parameter_header *bfpt_header,
+			      struct spi_nor_flash_parameter *params)
+{
+	struct mtd_info *mtd = &nor->mtd;
+	struct sfdp_bfpt bfpt;
+	size_t len;
+	int i, cmd, err;
+	u32 addr;
+	u16 half;
+
+	/* JESD216 Basic Flash Parameter Table length is at least 9 DWORDs. */
+	if (bfpt_header->length < BFPT_DWORD_MAX_JESD216)
+		return -EINVAL;
+
+	/* Read the Basic Flash Parameter Table. */
+	len = min_t(size_t, sizeof(bfpt),
+		    bfpt_header->length * sizeof(u32));
+	addr = SFDP_PARAM_HEADER_PTP(bfpt_header);
+	memset(&bfpt, 0, sizeof(bfpt));
+	err = spi_nor_read_sfdp(nor,  addr, len, &bfpt);
+	if (err < 0)
+		return err;
+
+	/* Fix endianness of the BFPT DWORDs. */
+	for (i = 0; i < BFPT_DWORD_MAX; i++)
+		bfpt.dwords[i] = le32_to_cpu(bfpt.dwords[i]);
+
+	/* Number of address bytes. */
+	switch (bfpt.dwords[BFPT_DWORD(1)] & BFPT_DWORD1_ADDRESS_BYTES_MASK) {
+	case BFPT_DWORD1_ADDRESS_BYTES_3_ONLY:
+		nor->addr_width = 3;
+		break;
+
+	case BFPT_DWORD1_ADDRESS_BYTES_4_ONLY:
+		nor->addr_width = 4;
+		break;
+
+	default:
+		break;
+	}
+
+	/* Flash Memory Density (in bits). */
+	params->size = bfpt.dwords[BFPT_DWORD(2)];
+	if (params->size & BIT(31)) {
+		params->size &= ~BIT(31);
+
+		/*
+		 * Prevent overflows on params->size. Anyway, a NOR of 2^64
+		 * bits is unlikely to exist so this error probably means
+		 * the BFPT we are reading is corrupted/wrong.
+		 */
+		if (params->size > 63)
+			return -EINVAL;
+
+		params->size = 1ULL << params->size;
+	} else {
+		params->size++;
+	}
+	params->size >>= 3; /* Convert to bytes. */
+
+	/* Fast Read settings. */
+	for (i = 0; i < ARRAY_SIZE(sfdp_bfpt_reads); i++) {
+		const struct sfdp_bfpt_read *rd = &sfdp_bfpt_reads[i];
+		struct spi_nor_read_command *read;
+
+		if (!(bfpt.dwords[rd->supported_dword] & rd->supported_bit)) {
+			params->hwcaps.mask &= ~rd->hwcaps;
+			continue;
+		}
+
+		params->hwcaps.mask |= rd->hwcaps;
+		cmd = spi_nor_hwcaps_read2cmd(rd->hwcaps);
+		read = &params->reads[cmd];
+		half = bfpt.dwords[rd->settings_dword] >> rd->settings_shift;
+		spi_nor_set_read_settings_from_bfpt(read, half, rd->proto);
+	}
+
+	/* Sector Erase settings. */
+	for (i = 0; i < ARRAY_SIZE(sfdp_bfpt_erases); i++) {
+		const struct sfdp_bfpt_erase *er = &sfdp_bfpt_erases[i];
+		u32 erasesize;
+		u8 opcode;
+
+		half = bfpt.dwords[er->dword] >> er->shift;
+		erasesize = half & 0xff;
+
+		/* erasesize == 0 means this Erase Type is not supported. */
+		if (!erasesize)
+			continue;
+
+		erasesize = 1U << erasesize;
+		opcode = (half >> 8) & 0xff;
+#ifdef CONFIG_SPI_FLASH_USE_4K_SECTORS
+		if (erasesize == SZ_4K) {
+			nor->erase_opcode = opcode;
+			mtd->erasesize = erasesize;
+			break;
+		}
+#endif
+		if (!mtd->erasesize || mtd->erasesize < erasesize) {
+			nor->erase_opcode = opcode;
+			mtd->erasesize = erasesize;
+		}
+	}
+
+	/* Stop here if not JESD216 rev A or later. */
+	if (bfpt_header->length < BFPT_DWORD_MAX)
+		return 0;
+
+	/* Page size: this field specifies 'N' so the page size = 2^N bytes. */
+	params->page_size = bfpt.dwords[BFPT_DWORD(11)];
+	params->page_size &= BFPT_DWORD11_PAGE_SIZE_MASK;
+	params->page_size >>= BFPT_DWORD11_PAGE_SIZE_SHIFT;
+	params->page_size = 1U << params->page_size;
+
+	/* Quad Enable Requirements. */
+	switch (bfpt.dwords[BFPT_DWORD(15)] & BFPT_DWORD15_QER_MASK) {
+	case BFPT_DWORD15_QER_NONE:
+		params->quad_enable = NULL;
+		break;
+#if defined(CONFIG_SPI_FLASH_SPANSION) || defined(CONFIG_SPI_FLASH_WINBOND)
+	case BFPT_DWORD15_QER_SR2_BIT1_BUGGY:
+	case BFPT_DWORD15_QER_SR2_BIT1_NO_RD:
+		params->quad_enable = spansion_no_read_cr_quad_enable;
+		break;
+#endif
+#if defined(CONFIG_SPI_FLASH_MACRONIX) || defined(CONFIG_SPI_FLASH_ISSI)
+	case BFPT_DWORD15_QER_SR1_BIT6:
+		params->quad_enable = macronix_quad_enable;
+		break;
+#endif
+#if defined(CONFIG_SPI_FLASH_SPANSION) || defined(CONFIG_SPI_FLASH_WINBOND)
+	case BFPT_DWORD15_QER_SR2_BIT1:
+		params->quad_enable = spansion_read_cr_quad_enable;
+		break;
+#endif
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * spi_nor_parse_microchip_sfdp() - parse the Microchip manufacturer specific
+ * SFDP table.
+ * @nor:		pointer to a 'struct spi_nor'.
+ * @param_header:	pointer to the SFDP parameter header.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int
+spi_nor_parse_microchip_sfdp(struct spi_nor *nor,
+			     const struct sfdp_parameter_header *param_header)
+{
+	size_t size;
+	u32 addr;
+	int ret;
+
+	size = param_header->length * sizeof(u32);
+	addr = SFDP_PARAM_HEADER_PTP(param_header);
+
+	nor->manufacturer_sfdp = devm_kmalloc(nor->dev, size, GFP_KERNEL);
+	if (!nor->manufacturer_sfdp)
+		return -ENOMEM;
+
+	ret = spi_nor_read_sfdp(nor, addr, size, nor->manufacturer_sfdp);
+
+	return ret;
+}
+
+/**
+ * spi_nor_parse_sfdp() - parse the Serial Flash Discoverable Parameters.
+ * @nor:		pointer to a 'struct spi_nor'
+ * @params:		pointer to the 'struct spi_nor_flash_parameter' to be
+ *			filled
+ *
+ * The Serial Flash Discoverable Parameters are described by the JEDEC JESD216
+ * specification. This is a standard which tends to supported by almost all
+ * (Q)SPI memory manufacturers. Those hard-coded tables allow us to learn at
+ * runtime the main parameters needed to perform basic SPI flash operations such
+ * as Fast Read, Page Program or Sector Erase commands.
+ *
+ * Return: 0 on success, -errno otherwise.
+ */
+static int spi_nor_parse_sfdp(struct spi_nor *nor,
+			      struct spi_nor_flash_parameter *params)
+{
+	const struct sfdp_parameter_header *param_header, *bfpt_header;
+	struct sfdp_parameter_header *param_headers = NULL;
+	struct sfdp_header header;
+	size_t psize;
+	int i, err;
+
+	/* Get the SFDP header. */
+	err = spi_nor_read_sfdp(nor, 0, sizeof(header), &header);
+	if (err < 0)
+		return err;
+
+	/* Check the SFDP header version. */
+	if (le32_to_cpu(header.signature) != SFDP_SIGNATURE ||
+	    header.major != SFDP_JESD216_MAJOR)
+		return -EINVAL;
+
+	/*
+	 * Verify that the first and only mandatory parameter header is a
+	 * Basic Flash Parameter Table header as specified in JESD216.
+	 */
+	bfpt_header = &header.bfpt_header;
+	if (SFDP_PARAM_HEADER_ID(bfpt_header) != SFDP_BFPT_ID ||
+	    bfpt_header->major != SFDP_JESD216_MAJOR)
+		return -EINVAL;
+
+	/*
+	 * Allocate memory then read all parameter headers with a single
+	 * Read SFDP command. These parameter headers will actually be parsed
+	 * twice: a first time to get the latest revision of the basic flash
+	 * parameter table, then a second time to handle the supported optional
+	 * tables.
+	 * Hence we read the parameter headers once for all to reduce the
+	 * processing time. Also we use kmalloc() instead of devm_kmalloc()
+	 * because we don't need to keep these parameter headers: the allocated
+	 * memory is always released with kfree() before exiting this function.
+	 */
+	if (header.nph) {
+		psize = header.nph * sizeof(*param_headers);
+
+		param_headers = kmalloc(psize, GFP_KERNEL);
+		if (!param_headers)
+			return -ENOMEM;
+
+		err = spi_nor_read_sfdp(nor, sizeof(header),
+					psize, param_headers);
+		if (err < 0) {
+			dev_err(nor->dev,
+				"failed to read SFDP parameter headers\n");
+			goto exit;
+		}
+	}
+
+	/*
+	 * Check other parameter headers to get the latest revision of
+	 * the basic flash parameter table.
+	 */
+	for (i = 0; i < header.nph; i++) {
+		param_header = &param_headers[i];
+
+		if (SFDP_PARAM_HEADER_ID(param_header) == SFDP_BFPT_ID &&
+		    param_header->major == SFDP_JESD216_MAJOR &&
+		    (param_header->minor > bfpt_header->minor ||
+		     (param_header->minor == bfpt_header->minor &&
+		      param_header->length > bfpt_header->length)))
+			bfpt_header = param_header;
+	}
+
+	err = spi_nor_parse_bfpt(nor, bfpt_header, params);
+	if (err)
+		goto exit;
+
+	/* Parse other parameter headers. */
+	for (i = 0; i < header.nph; i++) {
+		param_header = &param_headers[i];
+
+		switch (SFDP_PARAM_HEADER_ID(param_header)) {
+		case SFDP_SECTOR_MAP_ID:
+			dev_info(nor->dev,
+				 "non-uniform erase sector maps are not supported yet.\n");
+			break;
+
+		case SFDP_SST_ID:
+			err = spi_nor_parse_microchip_sfdp(nor, param_header);
+			break;
+
+		default:
+			break;
+		}
+
+		if (err) {
+			dev_warn(nor->dev,
+				 "Failed to parse optional parameter table: %04x\n",
+				 SFDP_PARAM_HEADER_ID(param_header));
+			/*
+			 * Let's not drop all information we extracted so far
+			 * if optional table parsers fail. In case of failing,
+			 * each optional parser is responsible to roll back to
+			 * the previously known spi_nor data.
+			 */
+			err = 0;
+		}
+	}
+
+exit:
+	kfree(param_headers);
+	return err;
+}
+#else
+static int spi_nor_parse_sfdp(struct spi_nor *nor,
+			      struct spi_nor_flash_parameter *params)
+{
+	return -EINVAL;
+}
+#endif /* SPI_FLASH_SFDP_SUPPORT */
+
+static int spi_nor_init_params(struct spi_nor *nor,
+			       const struct flash_info *info,
+			       struct spi_nor_flash_parameter *params)
+{
+	/* Set legacy flash parameters as default. */
+	memset(params, 0, sizeof(*params));
+
+	/* Set SPI NOR sizes. */
+	params->size = info->sector_size * info->n_sectors;
+	params->page_size = info->page_size;
+
+	/* (Fast) Read settings. */
+	params->hwcaps.mask |= SNOR_HWCAPS_READ;
+	spi_nor_set_read_settings(&params->reads[SNOR_CMD_READ],
+				  0, 0, SPINOR_OP_READ,
+				  SNOR_PROTO_1_1_1);
+
+	if (!(info->flags & SPI_NOR_NO_FR)) {
+		params->hwcaps.mask |= SNOR_HWCAPS_READ_FAST;
+		spi_nor_set_read_settings(&params->reads[SNOR_CMD_READ_FAST],
+					  0, 8, SPINOR_OP_READ_FAST,
+					  SNOR_PROTO_1_1_1);
+	}
+
+	if (info->flags & SPI_NOR_DUAL_READ) {
+		params->hwcaps.mask |= SNOR_HWCAPS_READ_1_1_2;
+		spi_nor_set_read_settings(&params->reads[SNOR_CMD_READ_1_1_2],
+					  0, 8, SPINOR_OP_READ_1_1_2,
+					  SNOR_PROTO_1_1_2);
+	}
+
+	if (info->flags & SPI_NOR_QUAD_READ) {
+		params->hwcaps.mask |= SNOR_HWCAPS_READ_1_1_4;
+		spi_nor_set_read_settings(&params->reads[SNOR_CMD_READ_1_1_4],
+					  0, 8, SPINOR_OP_READ_1_1_4,
+					  SNOR_PROTO_1_1_4);
+	}
+
+	if (info->flags & SPI_NOR_OCTAL_READ) {
+		params->hwcaps.mask |= SNOR_HWCAPS_READ_1_1_8;
+		spi_nor_set_read_settings(&params->reads[SNOR_CMD_READ_1_1_8],
+					  0, 8, SPINOR_OP_READ_1_1_8,
+					  SNOR_PROTO_1_1_8);
+	}
+
+	/* Page Program settings. */
+	params->hwcaps.mask |= SNOR_HWCAPS_PP;
+	spi_nor_set_pp_settings(&params->page_programs[SNOR_CMD_PP],
+				SPINOR_OP_PP, SNOR_PROTO_1_1_1);
+
+	if (info->flags & SPI_NOR_QUAD_READ) {
+		params->hwcaps.mask |= SNOR_HWCAPS_PP_1_1_4;
+		spi_nor_set_pp_settings(&params->page_programs[SNOR_CMD_PP_1_1_4],
+					SPINOR_OP_PP_1_1_4, SNOR_PROTO_1_1_4);
+	}
+
+	/* Select the procedure to set the Quad Enable bit. */
+	if (params->hwcaps.mask & (SNOR_HWCAPS_READ_QUAD |
+				   SNOR_HWCAPS_PP_QUAD)) {
+		switch (JEDEC_MFR(info)) {
+#if defined(CONFIG_SPI_FLASH_MACRONIX) || defined(CONFIG_SPI_FLASH_ISSI)
+		case SNOR_MFR_MACRONIX:
+		case SNOR_MFR_ISSI:
+			params->quad_enable = macronix_quad_enable;
+			break;
+#endif
+		case SNOR_MFR_ST:
+		case SNOR_MFR_MICRON:
+			break;
+
+		default:
+#if defined(CONFIG_SPI_FLASH_SPANSION) || defined(CONFIG_SPI_FLASH_WINBOND)
+			/* Kept only for backward compatibility purpose. */
+			params->quad_enable = spansion_read_cr_quad_enable;
+#endif
+			break;
+		}
+	}
+
+	/* Override the parameters with data read from SFDP tables. */
+	nor->addr_width = 0;
+	nor->mtd.erasesize = 0;
+	if ((info->flags & (SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)) &&
+	    !(info->flags & SPI_NOR_SKIP_SFDP)) {
+		struct spi_nor_flash_parameter sfdp_params;
+
+		memcpy(&sfdp_params, params, sizeof(sfdp_params));
+		if (spi_nor_parse_sfdp(nor, &sfdp_params)) {
+			nor->addr_width = 0;
+			nor->mtd.erasesize = 0;
+		} else {
+			memcpy(params, &sfdp_params, sizeof(*params));
+		}
+	}
+
+	return 0;
+}
+
+static int spi_nor_hwcaps2cmd(u32 hwcaps, const int table[][2], size_t size)
+{
+	size_t i;
+
+	for (i = 0; i < size; i++)
+		if (table[i][0] == (int)hwcaps)
+			return table[i][1];
+
+	return -EINVAL;
+}
+
+static int spi_nor_hwcaps_read2cmd(u32 hwcaps)
+{
+	static const int hwcaps_read2cmd[][2] = {
+		{ SNOR_HWCAPS_READ,		SNOR_CMD_READ },
+		{ SNOR_HWCAPS_READ_FAST,	SNOR_CMD_READ_FAST },
+		{ SNOR_HWCAPS_READ_1_1_1_DTR,	SNOR_CMD_READ_1_1_1_DTR },
+		{ SNOR_HWCAPS_READ_1_1_2,	SNOR_CMD_READ_1_1_2 },
+		{ SNOR_HWCAPS_READ_1_2_2,	SNOR_CMD_READ_1_2_2 },
+		{ SNOR_HWCAPS_READ_2_2_2,	SNOR_CMD_READ_2_2_2 },
+		{ SNOR_HWCAPS_READ_1_2_2_DTR,	SNOR_CMD_READ_1_2_2_DTR },
+		{ SNOR_HWCAPS_READ_1_1_4,	SNOR_CMD_READ_1_1_4 },
+		{ SNOR_HWCAPS_READ_1_4_4,	SNOR_CMD_READ_1_4_4 },
+		{ SNOR_HWCAPS_READ_4_4_4,	SNOR_CMD_READ_4_4_4 },
+		{ SNOR_HWCAPS_READ_1_4_4_DTR,	SNOR_CMD_READ_1_4_4_DTR },
+		{ SNOR_HWCAPS_READ_1_1_8,	SNOR_CMD_READ_1_1_8 },
+		{ SNOR_HWCAPS_READ_1_8_8,	SNOR_CMD_READ_1_8_8 },
+		{ SNOR_HWCAPS_READ_8_8_8,	SNOR_CMD_READ_8_8_8 },
+		{ SNOR_HWCAPS_READ_1_8_8_DTR,	SNOR_CMD_READ_1_8_8_DTR },
+	};
+
+	return spi_nor_hwcaps2cmd(hwcaps, hwcaps_read2cmd,
+				  ARRAY_SIZE(hwcaps_read2cmd));
+}
+
+static int spi_nor_hwcaps_pp2cmd(u32 hwcaps)
+{
+	static const int hwcaps_pp2cmd[][2] = {
+		{ SNOR_HWCAPS_PP,		SNOR_CMD_PP },
+		{ SNOR_HWCAPS_PP_1_1_4,		SNOR_CMD_PP_1_1_4 },
+		{ SNOR_HWCAPS_PP_1_4_4,		SNOR_CMD_PP_1_4_4 },
+		{ SNOR_HWCAPS_PP_4_4_4,		SNOR_CMD_PP_4_4_4 },
+		{ SNOR_HWCAPS_PP_1_1_8,		SNOR_CMD_PP_1_1_8 },
+		{ SNOR_HWCAPS_PP_1_8_8,		SNOR_CMD_PP_1_8_8 },
+		{ SNOR_HWCAPS_PP_8_8_8,		SNOR_CMD_PP_8_8_8 },
+	};
+
+	return spi_nor_hwcaps2cmd(hwcaps, hwcaps_pp2cmd,
+				  ARRAY_SIZE(hwcaps_pp2cmd));
+}
+
+static int spi_nor_select_read(struct spi_nor *nor,
+			       const struct spi_nor_flash_parameter *params,
+			       u32 shared_hwcaps)
+{
+	int cmd, best_match = fls(shared_hwcaps & SNOR_HWCAPS_READ_MASK) - 1;
+	const struct spi_nor_read_command *read;
+
+	if (best_match < 0)
+		return -EINVAL;
+
+	cmd = spi_nor_hwcaps_read2cmd(BIT(best_match));
+	if (cmd < 0)
+		return -EINVAL;
+
+	read = &params->reads[cmd];
+	nor->read_opcode = read->opcode;
+	nor->read_proto = read->proto;
+
+	/*
+	 * In the spi-nor framework, we don't need to make the difference
+	 * between mode clock cycles and wait state clock cycles.
+	 * Indeed, the value of the mode clock cycles is used by a QSPI
+	 * flash memory to know whether it should enter or leave its 0-4-4
+	 * (Continuous Read / XIP) mode.
+	 * eXecution In Place is out of the scope of the mtd sub-system.
+	 * Hence we choose to merge both mode and wait state clock cycles
+	 * into the so called dummy clock cycles.
+	 */
+	nor->read_dummy = read->num_mode_clocks + read->num_wait_states;
+	return 0;
+}
+
+static int spi_nor_select_pp(struct spi_nor *nor,
+			     const struct spi_nor_flash_parameter *params,
+			     u32 shared_hwcaps)
+{
+	int cmd, best_match = fls(shared_hwcaps & SNOR_HWCAPS_PP_MASK) - 1;
+	const struct spi_nor_pp_command *pp;
+
+	if (best_match < 0)
+		return -EINVAL;
+
+	cmd = spi_nor_hwcaps_pp2cmd(BIT(best_match));
+	if (cmd < 0)
+		return -EINVAL;
+
+	pp = &params->page_programs[cmd];
+	nor->program_opcode = pp->opcode;
+	nor->write_proto = pp->proto;
+	return 0;
+}
+
+static int spi_nor_select_erase(struct spi_nor *nor,
+				const struct flash_info *info)
+{
+	struct mtd_info *mtd = &nor->mtd;
+
+	/* Do nothing if already configured from SFDP. */
+	if (mtd->erasesize)
+		return 0;
+
+#ifdef CONFIG_SPI_FLASH_USE_4K_SECTORS
+	/* prefer "small sector" erase if possible */
+	if (info->flags & SECT_4K) {
+		nor->erase_opcode = SPINOR_OP_BE_4K;
+		mtd->erasesize = 4096;
+	} else if (info->flags & SECT_4K_PMC) {
+		nor->erase_opcode = SPINOR_OP_BE_4K_PMC;
+		mtd->erasesize = 4096;
+	} else
+#endif
+	{
+		nor->erase_opcode = SPINOR_OP_SE;
+		mtd->erasesize = info->sector_size;
+	}
+	return 0;
+}
+
+static int spi_nor_setup(struct spi_nor *nor, const struct flash_info *info,
+			 const struct spi_nor_flash_parameter *params,
+			 const struct spi_nor_hwcaps *hwcaps)
+{
+	u32 ignored_mask, shared_mask;
+	bool enable_quad_io;
+	int err;
+
+	/*
+	 * Keep only the hardware capabilities supported by both the SPI
+	 * controller and the SPI flash memory.
+	 */
+	shared_mask = hwcaps->mask & params->hwcaps.mask;
+
+	/* SPI n-n-n protocols are not supported yet. */
+	ignored_mask = (SNOR_HWCAPS_READ_2_2_2 |
+			SNOR_HWCAPS_READ_4_4_4 |
+			SNOR_HWCAPS_READ_8_8_8 |
+			SNOR_HWCAPS_PP_4_4_4 |
+			SNOR_HWCAPS_PP_8_8_8);
+	if (shared_mask & ignored_mask) {
+		dev_dbg(nor->dev,
+			"SPI n-n-n protocols are not supported yet.\n");
+		shared_mask &= ~ignored_mask;
+	}
+
+	/* Select the (Fast) Read command. */
+	err = spi_nor_select_read(nor, params, shared_mask);
+	if (err) {
+		dev_dbg(nor->dev,
+			"can't select read settings supported by both the SPI controller and memory.\n");
+		return err;
+	}
+
+	/* Select the Page Program command. */
+	err = spi_nor_select_pp(nor, params, shared_mask);
+	if (err) {
+		dev_dbg(nor->dev,
+			"can't select write settings supported by both the SPI controller and memory.\n");
+		return err;
+	}
+
+	/* Select the Sector Erase command. */
+	err = spi_nor_select_erase(nor, info);
+	if (err) {
+		dev_dbg(nor->dev,
+			"can't select erase settings supported by both the SPI controller and memory.\n");
+		return err;
+	}
+
+	/* Enable Quad I/O if needed. */
+	enable_quad_io = (spi_nor_get_protocol_width(nor->read_proto) == 4 ||
+			  spi_nor_get_protocol_width(nor->write_proto) == 4);
+	if (enable_quad_io && params->quad_enable)
+		nor->quad_enable = params->quad_enable;
+	else
+		nor->quad_enable = NULL;
+
+	return 0;
+}
+
+static int spi_nor_init(struct spi_nor *nor)
+{
+	int err;
+
+	/*
+	 * Atmel, SST, Intel/Numonyx, and others serial NOR tend to power up
+	 * with the software protection bits set
+	 */
+	if (IS_ENABLED(CONFIG_SPI_FLASH_UNLOCK_ALL) &&
+	    (JEDEC_MFR(nor->info) == SNOR_MFR_ATMEL ||
+	     JEDEC_MFR(nor->info) == SNOR_MFR_INTEL ||
+	     JEDEC_MFR(nor->info) == SNOR_MFR_SST ||
+	     nor->info->flags & SPI_NOR_HAS_LOCK)) {
+		write_enable(nor);
+		write_sr(nor, 0);
+		spi_nor_wait_till_ready(nor);
+	}
+
+	if (nor->quad_enable) {
+		err = nor->quad_enable(nor);
+		if (err) {
+			dev_dbg(nor->dev, "quad mode not supported\n");
+			return err;
+		}
+	}
+
+	if (nor->addr_width == 4 &&
+	    (JEDEC_MFR(nor->info) != SNOR_MFR_SPANSION) &&
+	    !(nor->info->flags & SPI_NOR_4B_OPCODES)) {
+		/*
+		 * If the RESET# pin isn't hooked up properly, or the system
+		 * otherwise doesn't perform a reset command in the boot
+		 * sequence, it's impossible to 100% protect against unexpected
+		 * reboots (e.g., crashes). Warn the user (or hopefully, system
+		 * designer) that this is bad.
+		 */
+		if (nor->flags & SNOR_F_BROKEN_RESET)
+			debug("enabling reset hack; may not recover from unexpected reboots\n");
+		set_4byte(nor, nor->info, 1);
+	}
+
+	return 0;
+}
+
+int spi_nor_scan(struct spi_nor *nor)
+{
+	struct spi_nor_flash_parameter params;
+	const struct flash_info *info = NULL;
+	struct mtd_info *mtd = &nor->mtd;
+	struct spi_nor_hwcaps hwcaps = {
+		.mask = SNOR_HWCAPS_READ |
+			SNOR_HWCAPS_READ_FAST |
+			SNOR_HWCAPS_PP,
+	};
+	struct spi_slave *spi = nor->spi;
+	int ret;
+
+	/* Reset SPI protocol for all commands. */
+	nor->reg_proto = SNOR_PROTO_1_1_1;
+	nor->read_proto = SNOR_PROTO_1_1_1;
+	nor->write_proto = SNOR_PROTO_1_1_1;
+	nor->read = spi_nor_read_data;
+	nor->write = spi_nor_write_data;
+	nor->read_reg = spi_nor_read_reg;
+	nor->write_reg = spi_nor_write_reg;
+
+	if (spi->mode & SPI_RX_OCTAL) {
+		hwcaps.mask |= SNOR_HWCAPS_READ_1_1_8;
+
+		if (spi->mode & SPI_TX_OCTAL)
+			hwcaps.mask |= (SNOR_HWCAPS_READ_1_8_8 |
+					SNOR_HWCAPS_PP_1_1_8 |
+					SNOR_HWCAPS_PP_1_8_8);
+	} else if (spi->mode & SPI_RX_QUAD) {
+		hwcaps.mask |= SNOR_HWCAPS_READ_1_1_4;
+
+		if (spi->mode & SPI_TX_QUAD)
+			hwcaps.mask |= (SNOR_HWCAPS_READ_1_4_4 |
+					SNOR_HWCAPS_PP_1_1_4 |
+					SNOR_HWCAPS_PP_1_4_4);
+	} else if (spi->mode & SPI_RX_DUAL) {
+		hwcaps.mask |= SNOR_HWCAPS_READ_1_1_2;
+
+		if (spi->mode & SPI_TX_DUAL)
+			hwcaps.mask |= SNOR_HWCAPS_READ_1_2_2;
+	}
+
+	info = spi_nor_read_id(nor);
+	if (IS_ERR_OR_NULL(info))
+		return -ENOENT;
+	/* Parse the Serial Flash Discoverable Parameters table. */
+	ret = spi_nor_init_params(nor, info, &params);
+	if (ret)
+		return ret;
+
+	if (!mtd->name)
+		mtd->name = info->name;
+	mtd->priv = nor;
+	mtd->type = MTD_NORFLASH;
+	mtd->writesize = 1;
+	mtd->flags = MTD_CAP_NORFLASH;
+	mtd->size = params.size;
+	mtd->_erase = spi_nor_erase;
+	mtd->_read = spi_nor_read;
+	mtd->_write = spi_nor_write;
+
+#if defined(CONFIG_SPI_FLASH_STMICRO) || defined(CONFIG_SPI_FLASH_SST)
+	/* NOR protection support for STmicro/Micron chips and similar */
+	if (JEDEC_MFR(info) == SNOR_MFR_ST ||
+	    JEDEC_MFR(info) == SNOR_MFR_MICRON ||
+	    JEDEC_MFR(info) == SNOR_MFR_SST ||
+			info->flags & SPI_NOR_HAS_LOCK) {
+		nor->flash_lock = stm_lock;
+		nor->flash_unlock = stm_unlock;
+		nor->flash_is_locked = stm_is_locked;
+	}
+#endif
+
+#ifdef CONFIG_SPI_FLASH_SST
+	/*
+	 * sst26 series block protection implementation differs from other
+	 * series.
+	 */
+	if (info->flags & SPI_NOR_HAS_SST26LOCK) {
+		nor->flash_lock = sst26_lock;
+		nor->flash_unlock = sst26_unlock;
+		nor->flash_is_locked = sst26_is_locked;
+	}
+#endif
+
+	if (info->flags & USE_FSR)
+		nor->flags |= SNOR_F_USE_FSR;
+	if (info->flags & SPI_NOR_HAS_TB)
+		nor->flags |= SNOR_F_HAS_SR_TB;
+	if (info->flags & NO_CHIP_ERASE)
+		nor->flags |= SNOR_F_NO_OP_CHIP_ERASE;
+	if (info->flags & USE_CLSR)
+		nor->flags |= SNOR_F_USE_CLSR;
+
+	if (info->flags & SPI_NOR_NO_ERASE)
+		mtd->flags |= MTD_NO_ERASE;
+
+	nor->page_size = params.page_size;
+	mtd->writebufsize = nor->page_size;
+
+	/* Some devices cannot do fast-read, no matter what DT tells us */
+	if ((info->flags & SPI_NOR_NO_FR) || (spi->mode & SPI_RX_SLOW))
+		params.hwcaps.mask &= ~SNOR_HWCAPS_READ_FAST;
+
+	/*
+	 * Configure the SPI memory:
+	 * - select op codes for (Fast) Read, Page Program and Sector Erase.
+	 * - set the number of dummy cycles (mode cycles + wait states).
+	 * - set the SPI protocols for register and memory accesses.
+	 * - set the Quad Enable bit if needed (required by SPI x-y-4 protos).
+	 */
+	ret = spi_nor_setup(nor, info, &params, &hwcaps);
+	if (ret)
+		return ret;
+
+	if (nor->addr_width) {
+		/* already configured from SFDP */
+	} else if (info->addr_width) {
+		nor->addr_width = info->addr_width;
+	} else if (mtd->size > SZ_16M) {
+#ifndef CONFIG_SPI_FLASH_BAR
+		/* enable 4-byte addressing if the device exceeds 16MiB */
+		nor->addr_width = 4;
+		if (JEDEC_MFR(info) == SNOR_MFR_SPANSION ||
+		    info->flags & SPI_NOR_4B_OPCODES)
+			spi_nor_set_4byte_opcodes(nor, info);
+#else
+	/* Configure the BAR - discover bank cmds and read current bank */
+	nor->addr_width = 3;
+	ret = read_bar(nor, info);
+	if (ret < 0)
+		return ret;
+#endif
+	} else {
+		nor->addr_width = 3;
+	}
+
+	if (nor->addr_width > SPI_NOR_MAX_ADDR_WIDTH) {
+		dev_dbg(nor->dev, "address width is too large: %u\n",
+			nor->addr_width);
+		return -EINVAL;
+	}
+
+	/* Send all the required SPI flash commands to initialize device */
+	nor->info = info;
+	ret = spi_nor_init(nor);
+	if (ret)
+		return ret;
+
+	nor->name = mtd->name;
+	nor->size = mtd->size;
+	nor->erase_size = mtd->erasesize;
+	nor->sector_size = mtd->erasesize;
+
+#ifndef CONFIG_SPL_BUILD
+	printf("SF: Detected %s with page size ", nor->name);
+	print_size(nor->page_size, ", erase size ");
+	print_size(nor->erase_size, ", total ");
+	print_size(nor->size, "");
+	puts("\n");
+#endif
+
+	return 0;
+}
+
+/* U-Boot specific functions, need to extend MTD to support these */
+int spi_flash_cmd_get_sw_write_prot(struct spi_nor *nor)
+{
+	int sr = read_sr(nor);
+
+	if (sr < 0)
+		return sr;
+
+	return (sr >> 2) & 7;
+}