mtd: spi: spi-nor-core: Add 4 Byte addressing support

[platform/kernel/u-boot.git] / drivers / mtd / spi / spi-nor-core.c

// 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 <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>

/* 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)

#define SPI_NOR_MAX_ID_LEN      6
#define SPI_NOR_MAX_ADDR_WIDTH  4

struct flash_info {
        char            *name;

        /*
         * This array stores the ID bytes.
         * The first three bytes are the JEDIC ID.
         * JEDEC ID zero means "no ID" (mostly older chips).
         */
        u8              id[SPI_NOR_MAX_ID_LEN];
        u8              id_len;

        /* The size listed here is what works with SPINOR_OP_SE, which isn't
         * necessarily called a "sector" by the vendor.
         */
        unsigned int    sector_size;
        u16             n_sectors;

        u16             page_size;
        u16             addr_width;

        u16             flags;
#define SECT_4K                 BIT(0)  /* SPINOR_OP_BE_4K works uniformly */
#define SPI_NOR_NO_ERASE        BIT(1)  /* No erase command needed */
#define SST_WRITE               BIT(2)  /* use SST byte programming */
#define SPI_NOR_NO_FR           BIT(3)  /* Can't do fastread */
#define SECT_4K_PMC             BIT(4)  /* SPINOR_OP_BE_4K_PMC works uniformly */
#define SPI_NOR_DUAL_READ       BIT(5)  /* Flash supports Dual Read */
#define SPI_NOR_QUAD_READ       BIT(6)  /* Flash supports Quad Read */
#define USE_FSR                 BIT(7)  /* use flag status register */
#define SPI_NOR_HAS_LOCK        BIT(8)  /* Flash supports lock/unlock via SR */
#define SPI_NOR_HAS_TB          BIT(9)  /*
                                         * Flash SR has Top/Bottom (TB) protect
                                         * bit. Must be used with
                                         * SPI_NOR_HAS_LOCK.
                                         */
#define SPI_S3AN                BIT(10) /*
                                         * Xilinx Spartan 3AN In-System Flash
                                         * (MFR cannot be used for probing
                                         * because it has the same value as
                                         * ATMEL flashes)
                                         */
#define SPI_NOR_4B_OPCODES      BIT(11) /*
                                         * Use dedicated 4byte address op codes
                                         * to support memory size above 128Mib.
                                         */
#define NO_CHIP_ERASE           BIT(12) /* Chip does not support chip erase */
#define USE_CLSR                BIT(14) /* use CLSR command */

        int     (*quad_enable)(struct spi_nor *nor);
};

#define JEDEC_MFR(info) ((info)->id[0])

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(&flash->spimem->spi->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));
        size_t remaining = len;
        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;

        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.out += op.data.nbytes;
        }

        return len;
}

/*
 * 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;
}

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_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 },
        };

        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);
}

/* 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_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_dbg(nor->dev, "Erase operation failed.\n");
                else
                        dev_dbg(nor->dev, "Program operation failed.\n");

                if (fsr & FSR_PT_ERR)
                        dev_dbg(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);
}

/*
 * Initiate the erasure of a single sector
 */
static int spi_nor_erase_sector(struct spi_nor *nor, u32 addr)
{
        u8 buf[SPI_NOR_MAX_ADDR_WIDTH];
        int i;

        if (nor->erase)
                return nor->erase(nor, addr);

        /*
         * Default implementation, if driver doesn't have a specialized HW
         * control
         */
        for (i = nor->addr_width - 1; i >= 0; i--) {
                buf[i] = addr & 0xff;
                addr >>= 8;
        }

        return nor->write_reg(nor, nor->erase_opcode, buf, nor->addr_width);
}

/*
 * 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);

        div_u64_rem(instr->len, mtd->erasesize, &rem);
        if (rem)
                return -EINVAL;

        addr = instr->addr;
        len = instr->len;

        while (len) {
                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;
        }

        write_disable(nor);

erase_err:
        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 */

/* Used when the "_ext_id" is two bytes at most */
#define INFO(_jedec_id, _ext_id, _sector_size, _n_sectors, _flags)      \
                .id = {                                                 \
                        ((_jedec_id) >> 16) & 0xff,                     \
                        ((_jedec_id) >> 8) & 0xff,                      \
                        (_jedec_id) & 0xff,                             \
                        ((_ext_id) >> 8) & 0xff,                        \
                        (_ext_id) & 0xff,                               \
                        },                                              \
                .id_len = (!(_jedec_id) ? 0 : (3 + ((_ext_id) ? 2 : 0))),       \
                .sector_size = (_sector_size),                          \
                .n_sectors = (_n_sectors),                              \
                .page_size = 256,                                       \
                .flags = (_flags),

#define INFO6(_jedec_id, _ext_id, _sector_size, _n_sectors, _flags)     \
                .id = {                                                 \
                        ((_jedec_id) >> 16) & 0xff,                     \
                        ((_jedec_id) >> 8) & 0xff,                      \
                        (_jedec_id) & 0xff,                             \
                        ((_ext_id) >> 16) & 0xff,                       \
                        ((_ext_id) >> 8) & 0xff,                        \
                        (_ext_id) & 0xff,                               \
                        },                                              \
                .id_len = 6,                                            \
                .sector_size = (_sector_size),                          \
                .n_sectors = (_n_sectors),                              \
                .page_size = 256,                                       \
                .flags = (_flags),

/* NOTE: double check command sets and memory organization when you add
 * more nor chips.  This current list focusses on newer chips, which
 * have been converging on command sets which including JEDEC ID.
 *
 * All newly added entries should describe *hardware* and should use SECT_4K
 * (or SECT_4K_PMC) if hardware supports erasing 4 KiB sectors. For usage
 * scenarios excluding small sectors there is config option that can be
 * disabled: CONFIG_MTD_SPI_NOR_USE_4K_SECTORS.
 * For historical (and compatibility) reasons (before we got above config) some
 * old entries may be missing 4K flag.
 */
const struct flash_info spi_nor_ids[] = {
#ifdef CONFIG_SPI_FLASH_ATMEL           /* ATMEL */
        /* Atmel -- some are (confusingly) marketed as "DataFlash" */
        { "at26df321",  INFO(0x1f4700, 0, 64 * 1024, 64, SECT_4K) },
        { "at25df321a", INFO(0x1f4701, 0, 64 * 1024, 64, SECT_4K) },

        { "at45db011d", INFO(0x1f2200, 0, 64 * 1024,   4, SECT_4K) },
        { "at45db021d", INFO(0x1f2300, 0, 64 * 1024,   8, SECT_4K) },
        { "at45db041d", INFO(0x1f2400, 0, 64 * 1024,   8, SECT_4K) },
        { "at45db081d", INFO(0x1f2500, 0, 64 * 1024,  16, SECT_4K) },
        { "at45db161d", INFO(0x1f2600, 0, 64 * 1024,  32, SECT_4K) },
        { "at45db321d", INFO(0x1f2700, 0, 64 * 1024,  64, SECT_4K) },
        { "at45db641d", INFO(0x1f2800, 0, 64 * 1024, 128, SECT_4K) },
        { "at26df081a", INFO(0x1f4501, 0, 64 * 1024,  16, SECT_4K) },
#endif
#ifdef CONFIG_SPI_FLASH_EON             /* EON */
        /* EON -- en25xxx */
        { "en25q32b",   INFO(0x1c3016, 0, 64 * 1024,   64, 0) },
        { "en25q64",    INFO(0x1c3017, 0, 64 * 1024,  128, SECT_4K) },
        { "en25qh128",  INFO(0x1c7018, 0, 64 * 1024,  256, 0) },
        { "en25s64",    INFO(0x1c3817, 0, 64 * 1024,  128, SECT_4K) },
#endif
#ifdef CONFIG_SPI_FLASH_GIGADEVICE      /* GIGADEVICE */
        /* GigaDevice */
        {
                "gd25q16", INFO(0xc84015, 0, 64 * 1024,  32,
                        SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
                        SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB)
        },
        {
                "gd25q32", INFO(0xc84016, 0, 64 * 1024,  64,
                        SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
                        SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB)
        },
        {
                "gd25lq32", INFO(0xc86016, 0, 64 * 1024, 64,
                        SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
                        SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB)
        },
        {
                "gd25q64", INFO(0xc84017, 0, 64 * 1024, 128,
                        SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
                        SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB)
        },
#endif
#ifdef CONFIG_SPI_FLASH_ISSI            /* ISSI */
        /* ISSI */
        { "is25lq040b", INFO(0x9d4013, 0, 64 * 1024,   8,
                        SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
        { "is25lp032",  INFO(0x9d6016, 0, 64 * 1024,  64, 0) },
        { "is25lp064",  INFO(0x9d6017, 0, 64 * 1024, 128, 0) },
        { "is25lp128",  INFO(0x9d6018, 0, 64 * 1024, 256,
                        SECT_4K | SPI_NOR_DUAL_READ) },
        { "is25lp256",  INFO(0x9d6019, 0, 64 * 1024, 512,
                        SECT_4K | SPI_NOR_DUAL_READ) },
        { "is25wp032",  INFO(0x9d7016, 0, 64 * 1024,  64,
                        SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
        { "is25wp064",  INFO(0x9d7017, 0, 64 * 1024, 128,
                        SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
        { "is25wp128",  INFO(0x9d7018, 0, 64 * 1024, 256,
                        SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
#endif
#ifdef CONFIG_SPI_FLASH_MACRONIX        /* MACRONIX */
        /* Macronix */
        { "mx25l2005a",  INFO(0xc22012, 0, 64 * 1024,   4, SECT_4K) },
        { "mx25l4005a",  INFO(0xc22013, 0, 64 * 1024,   8, SECT_4K) },
        { "mx25l8005",   INFO(0xc22014, 0, 64 * 1024,  16, 0) },
        { "mx25l1606e",  INFO(0xc22015, 0, 64 * 1024,  32, SECT_4K) },
        { "mx25l3205d",  INFO(0xc22016, 0, 64 * 1024,  64, SECT_4K) },
        { "mx25l6405d",  INFO(0xc22017, 0, 64 * 1024, 128, SECT_4K) },
        { "mx25u2033e",  INFO(0xc22532, 0, 64 * 1024,   4, SECT_4K) },
        { "mx25u1635e",  INFO(0xc22535, 0, 64 * 1024,  32, SECT_4K) },
        { "mx25u6435f",  INFO(0xc22537, 0, 64 * 1024, 128, SECT_4K) },
        { "mx25l12805d", INFO(0xc22018, 0, 64 * 1024, 256, 0) },
        { "mx25l12855e", INFO(0xc22618, 0, 64 * 1024, 256, 0) },
        { "mx25l25635e", INFO(0xc22019, 0, 64 * 1024, 512, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
        { "mx25u25635f", INFO(0xc22539, 0, 64 * 1024, 512, SECT_4K | SPI_NOR_4B_OPCODES) },
        { "mx25l25655e", INFO(0xc22619, 0, 64 * 1024, 512, 0) },
        { "mx66l51235l", INFO(0xc2201a, 0, 64 * 1024, 1024, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ | SPI_NOR_4B_OPCODES) },
        { "mx66u51235f", INFO(0xc2253a, 0, 64 * 1024, 1024, SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ | SPI_NOR_4B_OPCODES) },
        { "mx66l1g45g",  INFO(0xc2201b, 0, 64 * 1024, 2048, SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
        { "mx25l1633e",  INFO(0xc22415, 0, 64 * 1024,   32, SPI_NOR_QUAD_READ | SPI_NOR_4B_OPCODES | SECT_4K) },
#endif

#ifdef CONFIG_SPI_FLASH_STMICRO         /* STMICRO */
        /* Micron */
        { "n25q016a",    INFO(0x20bb15, 0, 64 * 1024,   32, SECT_4K | SPI_NOR_QUAD_READ) },
        { "n25q032",     INFO(0x20ba16, 0, 64 * 1024,   64, SPI_NOR_QUAD_READ) },
        { "n25q032a",    INFO(0x20bb16, 0, 64 * 1024,   64, SPI_NOR_QUAD_READ) },
        { "n25q064",     INFO(0x20ba17, 0, 64 * 1024,  128, SECT_4K | SPI_NOR_QUAD_READ) },
        { "n25q064a",    INFO(0x20bb17, 0, 64 * 1024,  128, SECT_4K | SPI_NOR_QUAD_READ) },
        { "n25q128a11",  INFO(0x20bb18, 0, 64 * 1024,  256, SECT_4K | SPI_NOR_QUAD_READ) },
        { "n25q128a13",  INFO(0x20ba18, 0, 64 * 1024,  256, SECT_4K | SPI_NOR_QUAD_READ) },
        { "n25q256a",    INFO(0x20ba19, 0, 64 * 1024,  512, SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
        { "n25q256ax1",  INFO(0x20bb19, 0, 64 * 1024,  512, SECT_4K | SPI_NOR_QUAD_READ) },
        { "n25q512a",    INFO(0x20bb20, 0, 64 * 1024, 1024, SECT_4K | USE_FSR | SPI_NOR_QUAD_READ) },
        { "n25q512ax3",  INFO(0x20ba20, 0, 64 * 1024, 1024, SECT_4K | USE_FSR | SPI_NOR_QUAD_READ) },
        { "n25q00",      INFO(0x20ba21, 0, 64 * 1024, 2048, SECT_4K | USE_FSR | SPI_NOR_QUAD_READ | NO_CHIP_ERASE) },
        { "n25q00a",     INFO(0x20bb21, 0, 64 * 1024, 2048, SECT_4K | USE_FSR | SPI_NOR_QUAD_READ | NO_CHIP_ERASE) },
        { "mt25qu02g",   INFO(0x20bb22, 0, 64 * 1024, 4096, SECT_4K | USE_FSR | SPI_NOR_QUAD_READ | NO_CHIP_ERASE) },
#endif
#ifdef CONFIG_SPI_FLASH_SPANSION        /* SPANSION */
        /* Spansion/Cypress -- single (large) sector size only, at least
         * for the chips listed here (without boot sectors).
         */
        { "s25sl032p",  INFO(0x010215, 0x4d00,  64 * 1024,  64, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
        { "s25sl064p",  INFO(0x010216, 0x4d00,  64 * 1024, 128, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
        { "s25fl256s0", INFO(0x010219, 0x4d00, 256 * 1024, 128, USE_CLSR) },
        { "s25fl256s1", INFO(0x010219, 0x4d01,  64 * 1024, 512, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ | USE_CLSR) },
        { "s25fl512s",  INFO6(0x010220, 0x4d0081, 256 * 1024, 256, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ | USE_CLSR) },
        { "s25fl512s_256k",  INFO(0x010220, 0x4d00, 256 * 1024, 256, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ | USE_CLSR) },
        { "s25fl512s_64k",  INFO(0x010220, 0x4d01, 64 * 1024, 1024, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ | USE_CLSR) },
        { "s25fl512s_512k",  INFO(0x010220, 0x4f00, 256 * 1024, 256, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ | USE_CLSR) },
        { "s25sl12800", INFO(0x012018, 0x0300, 256 * 1024,  64, 0) },
        { "s25sl12801", INFO(0x012018, 0x0301,  64 * 1024, 256, 0) },
        { "s25fl128s",  INFO6(0x012018, 0x4d0180, 64 * 1024, 256, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ | USE_CLSR) },
        { "s25fl129p0", INFO(0x012018, 0x4d00, 256 * 1024,  64, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ | USE_CLSR) },
        { "s25fl129p1", INFO(0x012018, 0x4d01,  64 * 1024, 256, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ | USE_CLSR) },
        { "s25sl008a",  INFO(0x010213,      0,  64 * 1024,  16, 0) },
        { "s25sl016a",  INFO(0x010214,      0,  64 * 1024,  32, 0) },
        { "s25sl032a",  INFO(0x010215,      0,  64 * 1024,  64, 0) },
        { "s25sl064a",  INFO(0x010216,      0,  64 * 1024, 128, 0) },
        { "s25fl116k",  INFO(0x014015,      0,  64 * 1024,  32, SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
        { "s25fl164k",  INFO(0x014017,      0,  64 * 1024, 128, SECT_4K) },
        { "s25fl208k",  INFO(0x014014,      0,  64 * 1024,  16, SECT_4K | SPI_NOR_DUAL_READ) },
        { "s25fl128l",  INFO(0x016018,      0,  64 * 1024, 256, SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ | SPI_NOR_4B_OPCODES) },
#endif
#ifdef CONFIG_SPI_FLASH_SST             /* SST */
        /* SST -- large erase sizes are "overlays", "sectors" are 4K */
        { "sst25vf040b", INFO(0xbf258d, 0, 64 * 1024,  8, SECT_4K | SST_WRITE) },
        { "sst25vf080b", INFO(0xbf258e, 0, 64 * 1024, 16, SECT_4K | SST_WRITE) },
        { "sst25vf016b", INFO(0xbf2541, 0, 64 * 1024, 32, SECT_4K | SST_WRITE) },
        { "sst25vf032b", INFO(0xbf254a, 0, 64 * 1024, 64, SECT_4K | SST_WRITE) },
        { "sst25vf064c", INFO(0xbf254b, 0, 64 * 1024, 128, SECT_4K) },
        { "sst25wf512",  INFO(0xbf2501, 0, 64 * 1024,  1, SECT_4K | SST_WRITE) },
        { "sst25wf010",  INFO(0xbf2502, 0, 64 * 1024,  2, SECT_4K | SST_WRITE) },
        { "sst25wf020",  INFO(0xbf2503, 0, 64 * 1024,  4, SECT_4K | SST_WRITE) },
        { "sst25wf020a", INFO(0x621612, 0, 64 * 1024,  4, SECT_4K) },
        { "sst25wf040b", INFO(0x621613, 0, 64 * 1024,  8, SECT_4K) },
        { "sst25wf040",  INFO(0xbf2504, 0, 64 * 1024,  8, SECT_4K | SST_WRITE) },
        { "sst25wf080",  INFO(0xbf2505, 0, 64 * 1024, 16, SECT_4K | SST_WRITE) },
        { "sst26vf064b", INFO(0xbf2643, 0, 64 * 1024, 128, SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
        { "sst26wf016",  INFO(0xbf2651, 0, 64 * 1024,  32, SECT_4K) },
        { "sst26wf032",  INFO(0xbf2622, 0, 64 * 1024,  64, SECT_4K) },
        { "sst26wf064",  INFO(0xbf2643, 0, 64 * 1024, 128, SECT_4K) },
#endif
#ifdef CONFIG_SPI_FLASH_STMICRO         /* STMICRO */
        /* ST Microelectronics -- newer production may have feature updates */
        { "m25p10",  INFO(0x202011,  0,  32 * 1024,   4, 0) },
        { "m25p20",  INFO(0x202012,  0,  64 * 1024,   4, 0) },
        { "m25p40",  INFO(0x202013,  0,  64 * 1024,   8, 0) },
        { "m25p80",  INFO(0x202014,  0,  64 * 1024,  16, 0) },
        { "m25p16",  INFO(0x202015,  0,  64 * 1024,  32, 0) },
        { "m25p32",  INFO(0x202016,  0,  64 * 1024,  64, 0) },
        { "m25p64",  INFO(0x202017,  0,  64 * 1024, 128, 0) },
        { "m25p128", INFO(0x202018,  0, 256 * 1024,  64, 0) },
        { "m25pe16", INFO(0x208015,  0, 64 * 1024, 32, SECT_4K) },
        { "m25px16",    INFO(0x207115,  0, 64 * 1024, 32, SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
        { "m25px64",    INFO(0x207117,  0, 64 * 1024, 128, 0) },
#endif
#ifdef CONFIG_SPI_FLASH_WINBOND         /* WINBOND */
        /* Winbond -- w25x "blocks" are 64K, "sectors" are 4KiB */
        { "w25x05", INFO(0xef3010, 0, 64 * 1024,  1,  SECT_4K) },
        { "w25x10", INFO(0xef3011, 0, 64 * 1024,  2,  SECT_4K) },
        { "w25x20", INFO(0xef3012, 0, 64 * 1024,  4,  SECT_4K) },
        { "w25x40", INFO(0xef3013, 0, 64 * 1024,  8,  SECT_4K) },
        { "w25x80", INFO(0xef3014, 0, 64 * 1024,  16, SECT_4K) },
        { "w25x16", INFO(0xef3015, 0, 64 * 1024,  32, SECT_4K) },
        {
                "w25q16dw", INFO(0xef6015, 0, 64 * 1024,  32,
                        SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
                        SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB)
        },
        { "w25x32", INFO(0xef3016, 0, 64 * 1024,  64, SECT_4K) },
        { "w25q20cl", INFO(0xef4012, 0, 64 * 1024,  4, SECT_4K) },
        { "w25q20bw", INFO(0xef5012, 0, 64 * 1024,  4, SECT_4K) },
        { "w25q20ew", INFO(0xef6012, 0, 64 * 1024,  4, SECT_4K) },
        { "w25q32", INFO(0xef4016, 0, 64 * 1024,  64, SECT_4K) },
        {
                "w25q32dw", INFO(0xef6016, 0, 64 * 1024,  64,
                        SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
                        SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB)
        },
        {
                "w25q32jv", INFO(0xef7016, 0, 64 * 1024,  64,
                        SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
                        SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB)
        },
        { "w25x64", INFO(0xef3017, 0, 64 * 1024, 128, SECT_4K) },
        { "w25q64", INFO(0xef4017, 0, 64 * 1024, 128, SECT_4K) },
        {
                "w25q64dw", INFO(0xef6017, 0, 64 * 1024, 128,
                        SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
                        SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB)
        },
        {
                "w25q128fw", INFO(0xef6018, 0, 64 * 1024, 256,
                        SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
                        SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB)
        },
        { "w25q80", INFO(0xef5014, 0, 64 * 1024,  16, SECT_4K) },
        { "w25q80bl", INFO(0xef4014, 0, 64 * 1024,  16, SECT_4K) },
        { "w25q128", INFO(0xef4018, 0, 64 * 1024, 256, SECT_4K) },
        { "w25q256", INFO(0xef4019, 0, 64 * 1024, 512, SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
        { "w25m512jv", INFO(0xef7119, 0, 64 * 1024, 1024,
                        SECT_4K | SPI_NOR_QUAD_READ | SPI_NOR_DUAL_READ) },
#endif
#ifdef CONFIG_SPI_FLASH_XMC
        /* XMC (Wuhan Xinxin Semiconductor Manufacturing Corp.) */
        { "XM25QH64A", INFO(0x207017, 0, 64 * 1024, 128, SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
        { "XM25QH128A", INFO(0x207018, 0, 64 * 1024, 256, SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
#endif
        { },
};

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;

        if (!ARRAY_SIZE(spi_nor_ids))
                return ERR_PTR(-ENODEV);

        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);
        }

        for (tmp = 0; tmp < ARRAY_SIZE(spi_nor_ids) - 1; tmp++) {
                info = &spi_nor_ids[tmp];
                if (info->id_len) {
                        if (!memcmp(info->id, id, info->id_len))
                                return &spi_nor_ids[tmp];
                }
        }
        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;

                ret = nor->read(nor, addr, 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:
        return ret;
}

#ifdef CONFIG_SPI_FLASH_SST
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);
        size_t actual;
        int ret;

        dev_dbg(nor->dev, "to 0x%08x, len %zd\n", (u32)to, len);

        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;

        dev_dbg(nor->dev, "to 0x%08x, len %zd\n", (u32)to, len);

        for (i = 0; i < len; ) {
                ssize_t written;
                loff_t addr = to + i;

                /*
                 * 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).
                 * Power of two numbers have only one bit set and we can use
                 * the instruction hweight32 to detect if we need to do a
                 * modulus (do_div()) or not.
                 */
                if (hweight32(nor->page_size) == 1) {
                        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);

                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;
                if (written != page_remain) {
                        ret = -EIO;
                        goto write_err;
                }
        }

write_err:
        return ret;
}

#ifdef CONFIG_SPI_FLASH_MACRONIX
/**
 * 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(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(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;
}
#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;
}

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);
        }

        /* 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)) {
#ifdef CONFIG_SPI_FLASH_MACRONIX
                case SNOR_MFR_MACRONIX:
                        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;
                }
        }
}

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;

#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 (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)
                        printf("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_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;

        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;

#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
        /* sst nor chips use AAI word program */
        if (info->flags & SST_WRITE)
                mtd->_write = sst_write;
        else
#endif
                mtd->_write = spi_nor_write;

        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 (info->addr_width) {
                nor->addr_width = info->addr_width;
        } else if (mtd->size > 0x1000000) {
                /* 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 {
                nor->addr_width = 3;
        }

        if (nor->addr_width > SPI_NOR_MAX_ADDR_WIDTH) {
                dev_dbg(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;
}