// SPDX-License-Identifier: GPL-2.0-only
/*
 * Intel PCH/PCU SPI flash driver.
 *
 * Copyright (C) 2016 - 2022, Intel Corporation
 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
 */

#include <linux/iopoll.h>
#include <linux/module.h>

#include <linux/mtd/partitions.h>
#include <linux/mtd/spi-nor.h>

#include <linux/spi/flash.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi-mem.h>

#include "spi-intel.h"

/* Offsets are from @ispi->base */
#define BFPREG                          0x00

#define HSFSTS_CTL                      0x04
#define HSFSTS_CTL_FSMIE                BIT(31)
#define HSFSTS_CTL_FDBC_SHIFT           24
#define HSFSTS_CTL_FDBC_MASK            (0x3f << HSFSTS_CTL_FDBC_SHIFT)

#define HSFSTS_CTL_FCYCLE_SHIFT         17
#define HSFSTS_CTL_FCYCLE_MASK          (0x0f << HSFSTS_CTL_FCYCLE_SHIFT)
/* HW sequencer opcodes */
#define HSFSTS_CTL_FCYCLE_READ          (0x00 << HSFSTS_CTL_FCYCLE_SHIFT)
#define HSFSTS_CTL_FCYCLE_WRITE         (0x02 << HSFSTS_CTL_FCYCLE_SHIFT)
#define HSFSTS_CTL_FCYCLE_ERASE         (0x03 << HSFSTS_CTL_FCYCLE_SHIFT)
#define HSFSTS_CTL_FCYCLE_ERASE_64K     (0x04 << HSFSTS_CTL_FCYCLE_SHIFT)
#define HSFSTS_CTL_FCYCLE_RDSFDP        (0x05 << HSFSTS_CTL_FCYCLE_SHIFT)
#define HSFSTS_CTL_FCYCLE_RDID          (0x06 << HSFSTS_CTL_FCYCLE_SHIFT)
#define HSFSTS_CTL_FCYCLE_WRSR          (0x07 << HSFSTS_CTL_FCYCLE_SHIFT)
#define HSFSTS_CTL_FCYCLE_RDSR          (0x08 << HSFSTS_CTL_FCYCLE_SHIFT)

#define HSFSTS_CTL_FGO                  BIT(16)
#define HSFSTS_CTL_FLOCKDN              BIT(15)
#define HSFSTS_CTL_FDV                  BIT(14)
#define HSFSTS_CTL_SCIP                 BIT(5)
#define HSFSTS_CTL_AEL                  BIT(2)
#define HSFSTS_CTL_FCERR                BIT(1)
#define HSFSTS_CTL_FDONE                BIT(0)

#define FADDR                           0x08
#define DLOCK                           0x0c
#define FDATA(n)                        (0x10 + ((n) * 4))

#define FRACC                           0x50

#define FREG(n)                         (0x54 + ((n) * 4))
#define FREG_BASE_MASK                  GENMASK(14, 0)
#define FREG_LIMIT_SHIFT                16
#define FREG_LIMIT_MASK                 GENMASK(30, 16)

/* Offset is from @ispi->pregs */
#define PR(n)                           ((n) * 4)
#define PR_WPE                          BIT(31)
#define PR_LIMIT_SHIFT                  16
#define PR_LIMIT_MASK                   GENMASK(30, 16)
#define PR_RPE                          BIT(15)
#define PR_BASE_MASK                    GENMASK(14, 0)

/* Offsets are from @ispi->sregs */
#define SSFSTS_CTL                      0x00
#define SSFSTS_CTL_FSMIE                BIT(23)
#define SSFSTS_CTL_DS                   BIT(22)
#define SSFSTS_CTL_DBC_SHIFT            16
#define SSFSTS_CTL_SPOP                 BIT(11)
#define SSFSTS_CTL_ACS                  BIT(10)
#define SSFSTS_CTL_SCGO                 BIT(9)
#define SSFSTS_CTL_COP_SHIFT            12
#define SSFSTS_CTL_FRS                  BIT(7)
#define SSFSTS_CTL_DOFRS                BIT(6)
#define SSFSTS_CTL_AEL                  BIT(4)
#define SSFSTS_CTL_FCERR                BIT(3)
#define SSFSTS_CTL_FDONE                BIT(2)
#define SSFSTS_CTL_SCIP                 BIT(0)

#define PREOP_OPTYPE                    0x04
#define OPMENU0                         0x08
#define OPMENU1                         0x0c

#define OPTYPE_READ_NO_ADDR             0
#define OPTYPE_WRITE_NO_ADDR            1
#define OPTYPE_READ_WITH_ADDR           2
#define OPTYPE_WRITE_WITH_ADDR          3

/* CPU specifics */
#define BYT_PR                          0x74
#define BYT_SSFSTS_CTL                  0x90
#define BYT_FREG_NUM                    5
#define BYT_PR_NUM                      5

#define LPT_PR                          0x74
#define LPT_SSFSTS_CTL                  0x90
#define LPT_FREG_NUM                    5
#define LPT_PR_NUM                      5

#define BXT_PR                          0x84
#define BXT_SSFSTS_CTL                  0xa0
#define BXT_FREG_NUM                    12
#define BXT_PR_NUM                      5

#define CNL_PR                          0x84
#define CNL_FREG_NUM                    6
#define CNL_PR_NUM                      5

#define LVSCC                           0xc4
#define UVSCC                           0xc8
#define ERASE_OPCODE_SHIFT              8
#define ERASE_OPCODE_MASK               (0xff << ERASE_OPCODE_SHIFT)
#define ERASE_64K_OPCODE_SHIFT          16
#define ERASE_64K_OPCODE_MASK           (0xff << ERASE_64K_OPCODE_SHIFT)

/* Flash descriptor fields */
#define FLVALSIG_MAGIC                  0x0ff0a55a
#define FLMAP0_NC_MASK                  GENMASK(9, 8)
#define FLMAP0_NC_SHIFT                 8
#define FLMAP0_FCBA_MASK                GENMASK(7, 0)

#define FLCOMP_C0DEN_MASK               GENMASK(3, 0)
#define FLCOMP_C0DEN_512K               0x00
#define FLCOMP_C0DEN_1M                 0x01
#define FLCOMP_C0DEN_2M                 0x02
#define FLCOMP_C0DEN_4M                 0x03
#define FLCOMP_C0DEN_8M                 0x04
#define FLCOMP_C0DEN_16M                0x05
#define FLCOMP_C0DEN_32M                0x06
#define FLCOMP_C0DEN_64M                0x07
#define FLCOMP_C0DEN_128M               0x08

#define INTEL_SPI_TIMEOUT               5000 /* ms */
#define INTEL_SPI_FIFO_SZ               64

/**
 * struct intel_spi - Driver private data
 * @dev: Device pointer
 * @info: Pointer to board specific info
 * @base: Beginning of MMIO space
 * @pregs: Start of protection registers
 * @sregs: Start of software sequencer registers
 * @host: Pointer to the SPI controller structure
 * @nregions: Maximum number of regions
 * @pr_num: Maximum number of protected range registers
 * @chip0_size: Size of the first flash chip in bytes
 * @locked: Is SPI setting locked
 * @protected: Whether the regions are write protected
 * @bios_locked: Is BIOS region locked
 * @swseq_reg: Use SW sequencer in register reads/writes
 * @swseq_erase: Use SW sequencer in erase operation
 * @atomic_preopcode: Holds preopcode when atomic sequence is requested
 * @opcodes: Opcodes which are supported. This are programmed by BIOS
 *           before it locks down the controller.
 * @mem_ops: Pointer to SPI MEM ops supported by the controller
 */
struct intel_spi {
        struct device *dev;
        const struct intel_spi_boardinfo *info;
        void __iomem *base;
        void __iomem *pregs;
        void __iomem *sregs;
        struct spi_controller *host;
        size_t nregions;
        size_t pr_num;
        size_t chip0_size;
        bool locked;
        bool protected;
        bool bios_locked;
        bool swseq_reg;
        bool swseq_erase;
        u8 atomic_preopcode;
        u8 opcodes[8];
        const struct intel_spi_mem_op *mem_ops;
};

struct intel_spi_mem_op {
        struct spi_mem_op mem_op;
        u32 replacement_op;
        int (*exec_op)(struct intel_spi *ispi,
                       const struct spi_mem *mem,
                       const struct intel_spi_mem_op *iop,
                       const struct spi_mem_op *op);
};

static bool writeable;
module_param(writeable, bool, 0);
MODULE_PARM_DESC(writeable, "Enable write access to SPI flash chip (default=0)");
static bool ignore_protection_status;
module_param(ignore_protection_status, bool, 0);
MODULE_PARM_DESC(
        ignore_protection_status,
        "Do not block SPI flash chip write access even if it is write-protected (default=0)");

static void intel_spi_dump_regs(struct intel_spi *ispi)
{
        u32 value;
        int i;

        dev_dbg(ispi->dev, "BFPREG=0x%08x\n", readl(ispi->base + BFPREG));

        value = readl(ispi->base + HSFSTS_CTL);
        dev_dbg(ispi->dev, "HSFSTS_CTL=0x%08x\n", value);
        if (value & HSFSTS_CTL_FLOCKDN)
                dev_dbg(ispi->dev, "-> Locked\n");

        dev_dbg(ispi->dev, "FADDR=0x%08x\n", readl(ispi->base + FADDR));
        dev_dbg(ispi->dev, "DLOCK=0x%08x\n", readl(ispi->base + DLOCK));

        for (i = 0; i < 16; i++)
                dev_dbg(ispi->dev, "FDATA(%d)=0x%08x\n",
                        i, readl(ispi->base + FDATA(i)));

        dev_dbg(ispi->dev, "FRACC=0x%08x\n", readl(ispi->base + FRACC));

        for (i = 0; i < ispi->nregions; i++)
                dev_dbg(ispi->dev, "FREG(%d)=0x%08x\n", i,
                        readl(ispi->base + FREG(i)));
        for (i = 0; i < ispi->pr_num; i++)
                dev_dbg(ispi->dev, "PR(%d)=0x%08x\n", i,
                        readl(ispi->pregs + PR(i)));

        if (ispi->sregs) {
                value = readl(ispi->sregs + SSFSTS_CTL);
                dev_dbg(ispi->dev, "SSFSTS_CTL=0x%08x\n", value);
                dev_dbg(ispi->dev, "PREOP_OPTYPE=0x%08x\n",
                        readl(ispi->sregs + PREOP_OPTYPE));
                dev_dbg(ispi->dev, "OPMENU0=0x%08x\n",
                        readl(ispi->sregs + OPMENU0));
                dev_dbg(ispi->dev, "OPMENU1=0x%08x\n",
                        readl(ispi->sregs + OPMENU1));
        }

        dev_dbg(ispi->dev, "LVSCC=0x%08x\n", readl(ispi->base + LVSCC));
        dev_dbg(ispi->dev, "UVSCC=0x%08x\n", readl(ispi->base + UVSCC));

        dev_dbg(ispi->dev, "Protected regions:\n");
        for (i = 0; i < ispi->pr_num; i++) {
                u32 base, limit;

                value = readl(ispi->pregs + PR(i));
                if (!(value & (PR_WPE | PR_RPE)))
                        continue;

                limit = (value & PR_LIMIT_MASK) >> PR_LIMIT_SHIFT;
                base = value & PR_BASE_MASK;

                dev_dbg(ispi->dev, " %02d base: 0x%08x limit: 0x%08x [%c%c]\n",
                        i, base << 12, (limit << 12) | 0xfff,
                        value & PR_WPE ? 'W' : '.', value & PR_RPE ? 'R' : '.');
        }

        dev_dbg(ispi->dev, "Flash regions:\n");
        for (i = 0; i < ispi->nregions; i++) {
                u32 region, base, limit;

                region = readl(ispi->base + FREG(i));
                base = region & FREG_BASE_MASK;
                limit = (region & FREG_LIMIT_MASK) >> FREG_LIMIT_SHIFT;

                if (base >= limit || (i > 0 && limit == 0))
                        dev_dbg(ispi->dev, " %02d disabled\n", i);
                else
                        dev_dbg(ispi->dev, " %02d base: 0x%08x limit: 0x%08x\n",
                                i, base << 12, (limit << 12) | 0xfff);
        }

        dev_dbg(ispi->dev, "Using %cW sequencer for register access\n",
                ispi->swseq_reg ? 'S' : 'H');
        dev_dbg(ispi->dev, "Using %cW sequencer for erase operation\n",
                ispi->swseq_erase ? 'S' : 'H');
}

/* Reads max INTEL_SPI_FIFO_SZ bytes from the device fifo */
static int intel_spi_read_block(struct intel_spi *ispi, void *buf, size_t size)
{
        size_t bytes;
        int i = 0;

        if (size > INTEL_SPI_FIFO_SZ)
                return -EINVAL;

        while (size > 0) {
                bytes = min_t(size_t, size, 4);
                memcpy_fromio(buf, ispi->base + FDATA(i), bytes);
                size -= bytes;
                buf += bytes;
                i++;
        }

        return 0;
}

/* Writes max INTEL_SPI_FIFO_SZ bytes to the device fifo */
static int intel_spi_write_block(struct intel_spi *ispi, const void *buf,
                                 size_t size)
{
        size_t bytes;
        int i = 0;

        if (size > INTEL_SPI_FIFO_SZ)
                return -EINVAL;

        while (size > 0) {
                bytes = min_t(size_t, size, 4);
                memcpy_toio(ispi->base + FDATA(i), buf, bytes);
                size -= bytes;
                buf += bytes;
                i++;
        }

        return 0;
}

static int intel_spi_wait_hw_busy(struct intel_spi *ispi)
{
        u32 val;

        return readl_poll_timeout(ispi->base + HSFSTS_CTL, val,
                                  !(val & HSFSTS_CTL_SCIP), 0,
                                  INTEL_SPI_TIMEOUT * 1000);
}

static int intel_spi_wait_sw_busy(struct intel_spi *ispi)
{
        u32 val;

        return readl_poll_timeout(ispi->sregs + SSFSTS_CTL, val,
                                  !(val & SSFSTS_CTL_SCIP), 0,
                                  INTEL_SPI_TIMEOUT * 1000);
}

static bool intel_spi_set_writeable(struct intel_spi *ispi)
{
        if (!ispi->info->set_writeable)
                return false;

        return ispi->info->set_writeable(ispi->base, ispi->info->data);
}

static int intel_spi_opcode_index(struct intel_spi *ispi, u8 opcode, int optype)
{
        int i;
        int preop;

        if (ispi->locked) {
                for (i = 0; i < ARRAY_SIZE(ispi->opcodes); i++)
                        if (ispi->opcodes[i] == opcode)
                                return i;

                return -EINVAL;
        }

        /* The lock is off, so just use index 0 */
        writel(opcode, ispi->sregs + OPMENU0);
        preop = readw(ispi->sregs + PREOP_OPTYPE);
        writel(optype << 16 | preop, ispi->sregs + PREOP_OPTYPE);

        return 0;
}

static int intel_spi_hw_cycle(struct intel_spi *ispi,
                              const struct intel_spi_mem_op *iop, size_t len)
{
        u32 val, status;
        int ret;

        if (!iop->replacement_op)
                return -EINVAL;

        val = readl(ispi->base + HSFSTS_CTL);
        val &= ~(HSFSTS_CTL_FCYCLE_MASK | HSFSTS_CTL_FDBC_MASK);
        val |= (len - 1) << HSFSTS_CTL_FDBC_SHIFT;
        val |= HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
        val |= HSFSTS_CTL_FGO;
        val |= iop->replacement_op;
        writel(val, ispi->base + HSFSTS_CTL);

        ret = intel_spi_wait_hw_busy(ispi);
        if (ret)
                return ret;

        status = readl(ispi->base + HSFSTS_CTL);
        if (status & HSFSTS_CTL_FCERR)
                return -EIO;
        else if (status & HSFSTS_CTL_AEL)
                return -EACCES;

        return 0;
}

static int intel_spi_sw_cycle(struct intel_spi *ispi, u8 opcode, size_t len,
                              int optype)
{
        u32 val = 0, status;
        u8 atomic_preopcode;
        int ret;

        ret = intel_spi_opcode_index(ispi, opcode, optype);
        if (ret < 0)
                return ret;

        /*
         * Always clear it after each SW sequencer operation regardless
         * of whether it is successful or not.
         */
        atomic_preopcode = ispi->atomic_preopcode;
        ispi->atomic_preopcode = 0;

        /* Only mark 'Data Cycle' bit when there is data to be transferred */
        if (len > 0)
                val = ((len - 1) << SSFSTS_CTL_DBC_SHIFT) | SSFSTS_CTL_DS;
        val |= ret << SSFSTS_CTL_COP_SHIFT;
        val |= SSFSTS_CTL_FCERR | SSFSTS_CTL_FDONE;
        val |= SSFSTS_CTL_SCGO;
        if (atomic_preopcode) {
                u16 preop;

                switch (optype) {
                case OPTYPE_WRITE_NO_ADDR:
                case OPTYPE_WRITE_WITH_ADDR:
                        /* Pick matching preopcode for the atomic sequence */
                        preop = readw(ispi->sregs + PREOP_OPTYPE);
                        if ((preop & 0xff) == atomic_preopcode)
                                ; /* Do nothing */
                        else if ((preop >> 8) == atomic_preopcode)
                                val |= SSFSTS_CTL_SPOP;
                        else
                                return -EINVAL;

                        /* Enable atomic sequence */
                        val |= SSFSTS_CTL_ACS;
                        break;

                default:
                        return -EINVAL;
                }
        }
        writel(val, ispi->sregs + SSFSTS_CTL);

        ret = intel_spi_wait_sw_busy(ispi);
        if (ret)
                return ret;

        status = readl(ispi->sregs + SSFSTS_CTL);
        if (status & SSFSTS_CTL_FCERR)
                return -EIO;
        else if (status & SSFSTS_CTL_AEL)
                return -EACCES;

        return 0;
}

static u32 intel_spi_chip_addr(const struct intel_spi *ispi,
                               const struct spi_mem *mem)
{
        /* Pick up the correct start address */
        if (!mem)
                return 0;
        return (spi_get_chipselect(mem->spi, 0) == 1) ? ispi->chip0_size : 0;
}

static int intel_spi_read_reg(struct intel_spi *ispi, const struct spi_mem *mem,
                              const struct intel_spi_mem_op *iop,
                              const struct spi_mem_op *op)
{
        u32 addr = intel_spi_chip_addr(ispi, mem) + op->addr.val;
        size_t nbytes = op->data.nbytes;
        u8 opcode = op->cmd.opcode;
        int ret;

        writel(addr, ispi->base + FADDR);

        if (ispi->swseq_reg)
                ret = intel_spi_sw_cycle(ispi, opcode, nbytes,
                                         OPTYPE_READ_NO_ADDR);
        else
                ret = intel_spi_hw_cycle(ispi, iop, nbytes);

        if (ret)
                return ret;

        return intel_spi_read_block(ispi, op->data.buf.in, nbytes);
}

static int intel_spi_write_reg(struct intel_spi *ispi, const struct spi_mem *mem,
                               const struct intel_spi_mem_op *iop,
                               const struct spi_mem_op *op)
{
        u32 addr = intel_spi_chip_addr(ispi, mem) + op->addr.val;
        size_t nbytes = op->data.nbytes;
        u8 opcode = op->cmd.opcode;
        int ret;

        /*
         * This is handled with atomic operation and preop code in Intel
         * controller so we only verify that it is available. If the
         * controller is not locked, program the opcode to the PREOP
         * register for later use.
         *
         * When hardware sequencer is used there is no need to program
         * any opcodes (it handles them automatically as part of a command).
         */
        if (opcode == SPINOR_OP_WREN) {
                u16 preop;

                if (!ispi->swseq_reg)
                        return 0;

                preop = readw(ispi->sregs + PREOP_OPTYPE);
                if ((preop & 0xff) != opcode && (preop >> 8) != opcode) {
                        if (ispi->locked)
                                return -EINVAL;
                        writel(opcode, ispi->sregs + PREOP_OPTYPE);
                }

                /*
                 * This enables atomic sequence on next SW sycle. Will
                 * be cleared after next operation.
                 */
                ispi->atomic_preopcode = opcode;
                return 0;
        }

        /*
         * We hope that HW sequencer will do the right thing automatically and
         * with the SW sequencer we cannot use preopcode anyway, so just ignore
         * the Write Disable operation and pretend it was completed
         * successfully.
         */
        if (opcode == SPINOR_OP_WRDI)
                return 0;

        writel(addr, ispi->base + FADDR);

        /* Write the value beforehand */
        ret = intel_spi_write_block(ispi, op->data.buf.out, nbytes);
        if (ret)
                return ret;

        if (ispi->swseq_reg)
                return intel_spi_sw_cycle(ispi, opcode, nbytes,
                                          OPTYPE_WRITE_NO_ADDR);
        return intel_spi_hw_cycle(ispi, iop, nbytes);
}

static int intel_spi_read(struct intel_spi *ispi, const struct spi_mem *mem,
                          const struct intel_spi_mem_op *iop,
                          const struct spi_mem_op *op)
{
        u32 addr = intel_spi_chip_addr(ispi, mem) + op->addr.val;
        size_t block_size, nbytes = op->data.nbytes;
        void *read_buf = op->data.buf.in;
        u32 val, status;
        int ret;

        /*
         * Atomic sequence is not expected with HW sequencer reads. Make
         * sure it is cleared regardless.
         */
        if (WARN_ON_ONCE(ispi->atomic_preopcode))
                ispi->atomic_preopcode = 0;

        while (nbytes > 0) {
                block_size = min_t(size_t, nbytes, INTEL_SPI_FIFO_SZ);

                /* Read cannot cross 4K boundary */
                block_size = min_t(loff_t, addr + block_size,
                                   round_up(addr + 1, SZ_4K)) - addr;

                writel(addr, ispi->base + FADDR);

                val = readl(ispi->base + HSFSTS_CTL);
                val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
                val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
                val |= (block_size - 1) << HSFSTS_CTL_FDBC_SHIFT;
                val |= HSFSTS_CTL_FCYCLE_READ;
                val |= HSFSTS_CTL_FGO;
                writel(val, ispi->base + HSFSTS_CTL);

                ret = intel_spi_wait_hw_busy(ispi);
                if (ret)
                        return ret;

                status = readl(ispi->base + HSFSTS_CTL);
                if (status & HSFSTS_CTL_FCERR)
                        ret = -EIO;
                else if (status & HSFSTS_CTL_AEL)
                        ret = -EACCES;

                if (ret < 0) {
                        dev_err(ispi->dev, "read error: %x: %#x\n", addr, status);
                        return ret;
                }

                ret = intel_spi_read_block(ispi, read_buf, block_size);
                if (ret)
                        return ret;

                nbytes -= block_size;
                addr += block_size;
                read_buf += block_size;
        }

        return 0;
}

static int intel_spi_write(struct intel_spi *ispi, const struct spi_mem *mem,
                           const struct intel_spi_mem_op *iop,
                           const struct spi_mem_op *op)
{
        u32 addr = intel_spi_chip_addr(ispi, mem) + op->addr.val;
        size_t block_size, nbytes = op->data.nbytes;
        const void *write_buf = op->data.buf.out;
        u32 val, status;
        int ret;

        /* Not needed with HW sequencer write, make sure it is cleared */
        ispi->atomic_preopcode = 0;

        while (nbytes > 0) {
                block_size = min_t(size_t, nbytes, INTEL_SPI_FIFO_SZ);

                /* Write cannot cross 4K boundary */
                block_size = min_t(loff_t, addr + block_size,
                                   round_up(addr + 1, SZ_4K)) - addr;

                writel(addr, ispi->base + FADDR);

                val = readl(ispi->base + HSFSTS_CTL);
                val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
                val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
                val |= (block_size - 1) << HSFSTS_CTL_FDBC_SHIFT;
                val |= HSFSTS_CTL_FCYCLE_WRITE;

                ret = intel_spi_write_block(ispi, write_buf, block_size);
                if (ret) {
                        dev_err(ispi->dev, "failed to write block\n");
                        return ret;
                }

                /* Start the write now */
                val |= HSFSTS_CTL_FGO;
                writel(val, ispi->base + HSFSTS_CTL);

                ret = intel_spi_wait_hw_busy(ispi);
                if (ret) {
                        dev_err(ispi->dev, "timeout\n");
                        return ret;
                }

                status = readl(ispi->base + HSFSTS_CTL);
                if (status & HSFSTS_CTL_FCERR)
                        ret = -EIO;
                else if (status & HSFSTS_CTL_AEL)
                        ret = -EACCES;

                if (ret < 0) {
                        dev_err(ispi->dev, "write error: %x: %#x\n", addr, status);
                        return ret;
                }

                nbytes -= block_size;
                addr += block_size;
                write_buf += block_size;
        }

        return 0;
}

static int intel_spi_erase(struct intel_spi *ispi, const struct spi_mem *mem,
                           const struct intel_spi_mem_op *iop,
                           const struct spi_mem_op *op)
{
        u32 addr = intel_spi_chip_addr(ispi, mem) + op->addr.val;
        u8 opcode = op->cmd.opcode;
        u32 val, status;
        int ret;

        writel(addr, ispi->base + FADDR);

        if (ispi->swseq_erase)
                return intel_spi_sw_cycle(ispi, opcode, 0,
                                          OPTYPE_WRITE_WITH_ADDR);

        /* Not needed with HW sequencer erase, make sure it is cleared */
        ispi->atomic_preopcode = 0;

        val = readl(ispi->base + HSFSTS_CTL);
        val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
        val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
        val |= HSFSTS_CTL_FGO;
        val |= iop->replacement_op;
        writel(val, ispi->base + HSFSTS_CTL);

        ret = intel_spi_wait_hw_busy(ispi);
        if (ret)
                return ret;

        status = readl(ispi->base + HSFSTS_CTL);
        if (status & HSFSTS_CTL_FCERR)
                return -EIO;
        if (status & HSFSTS_CTL_AEL)
                return -EACCES;

        return 0;
}

static int intel_spi_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
{
        op->data.nbytes = clamp_val(op->data.nbytes, 0, INTEL_SPI_FIFO_SZ);
        return 0;
}

static bool intel_spi_cmp_mem_op(const struct intel_spi_mem_op *iop,
                                 const struct spi_mem_op *op)
{
        if (iop->mem_op.cmd.nbytes != op->cmd.nbytes ||
            iop->mem_op.cmd.buswidth != op->cmd.buswidth ||
            iop->mem_op.cmd.dtr != op->cmd.dtr)
                return false;

        if (iop->mem_op.addr.nbytes != op->addr.nbytes ||
            iop->mem_op.addr.dtr != op->addr.dtr)
                return false;

        if (iop->mem_op.data.dir != op->data.dir ||
            iop->mem_op.data.dtr != op->data.dtr)
                return false;

        if (iop->mem_op.data.dir != SPI_MEM_NO_DATA) {
                if (iop->mem_op.data.buswidth != op->data.buswidth)
                        return false;
        }

        return true;
}

static const struct intel_spi_mem_op *
intel_spi_match_mem_op(struct intel_spi *ispi, const struct spi_mem_op *op)
{
        const struct intel_spi_mem_op *iop;

        for (iop = ispi->mem_ops; iop->mem_op.cmd.opcode; iop++) {
                if (iop->mem_op.cmd.opcode == op->cmd.opcode &&
                    intel_spi_cmp_mem_op(iop, op))
                        return iop;
        }

        return NULL;
}

static bool intel_spi_supports_mem_op(struct spi_mem *mem,
                                      const struct spi_mem_op *op)
{
        struct intel_spi *ispi = spi_controller_get_devdata(mem->spi->controller);
        const struct intel_spi_mem_op *iop;

        iop = intel_spi_match_mem_op(ispi, op);
        if (!iop) {
                dev_dbg(ispi->dev, "%#x not supported\n", op->cmd.opcode);
                return false;
        }

        /*
         * For software sequencer check that the opcode is actually
         * present in the opmenu if it is locked.
         */
        if (ispi->swseq_reg && ispi->locked) {
                int i;

                /* Check if it is in the locked opcodes list */
                for (i = 0; i < ARRAY_SIZE(ispi->opcodes); i++) {
                        if (ispi->opcodes[i] == op->cmd.opcode)
                                return true;
                }

                dev_dbg(ispi->dev, "%#x not supported\n", op->cmd.opcode);
                return false;
        }

        return true;
}

static int intel_spi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
{
        struct intel_spi *ispi = spi_controller_get_devdata(mem->spi->controller);
        const struct intel_spi_mem_op *iop;

        iop = intel_spi_match_mem_op(ispi, op);
        if (!iop)
                return -EOPNOTSUPP;

        return iop->exec_op(ispi, mem, iop, op);
}

static const char *intel_spi_get_name(struct spi_mem *mem)
{
        const struct intel_spi *ispi = spi_controller_get_devdata(mem->spi->controller);

        /*
         * Return name of the flash controller device to be compatible
         * with the MTD version.
         */
        return dev_name(ispi->dev);
}

static int intel_spi_dirmap_create(struct spi_mem_dirmap_desc *desc)
{
        struct intel_spi *ispi = spi_controller_get_devdata(desc->mem->spi->controller);
        const struct intel_spi_mem_op *iop;

        iop = intel_spi_match_mem_op(ispi, &desc->info.op_tmpl);
        if (!iop)
                return -EOPNOTSUPP;

        desc->priv = (void *)iop;
        return 0;
}

static ssize_t intel_spi_dirmap_read(struct spi_mem_dirmap_desc *desc, u64 offs,
                                     size_t len, void *buf)
{
        struct intel_spi *ispi = spi_controller_get_devdata(desc->mem->spi->controller);
        const struct intel_spi_mem_op *iop = desc->priv;
        struct spi_mem_op op = desc->info.op_tmpl;
        int ret;

        /* Fill in the gaps */
        op.addr.val = offs;
        op.data.nbytes = len;
        op.data.buf.in = buf;

        ret = iop->exec_op(ispi, desc->mem, iop, &op);
        return ret ? ret : len;
}

static ssize_t intel_spi_dirmap_write(struct spi_mem_dirmap_desc *desc, u64 offs,
                                      size_t len, const void *buf)
{
        struct intel_spi *ispi = spi_controller_get_devdata(desc->mem->spi->controller);
        const struct intel_spi_mem_op *iop = desc->priv;
        struct spi_mem_op op = desc->info.op_tmpl;
        int ret;

        op.addr.val = offs;
        op.data.nbytes = len;
        op.data.buf.out = buf;

        ret = iop->exec_op(ispi, desc->mem, iop, &op);
        return ret ? ret : len;
}

static const struct spi_controller_mem_ops intel_spi_mem_ops = {
        .adjust_op_size = intel_spi_adjust_op_size,
        .supports_op = intel_spi_supports_mem_op,
        .exec_op = intel_spi_exec_mem_op,
        .get_name = intel_spi_get_name,
        .dirmap_create = intel_spi_dirmap_create,
        .dirmap_read = intel_spi_dirmap_read,
        .dirmap_write = intel_spi_dirmap_write,
};

#define INTEL_SPI_OP_ADDR(__nbytes)                                     \
        {                                                               \
                .nbytes = __nbytes,                                     \
        }

#define INTEL_SPI_OP_NO_DATA                                            \
        {                                                               \
                .dir = SPI_MEM_NO_DATA,                                 \
        }

#define INTEL_SPI_OP_DATA_IN(__buswidth)                                \
        {                                                               \
                .dir = SPI_MEM_DATA_IN,                                 \
                .buswidth = __buswidth,                                 \
        }

#define INTEL_SPI_OP_DATA_OUT(__buswidth)                               \
        {                                                               \
                .dir = SPI_MEM_DATA_OUT,                                \
                .buswidth = __buswidth,                                 \
        }

#define INTEL_SPI_MEM_OP(__cmd, __addr, __data, __exec_op)              \
        {                                                               \
                .mem_op = {                                             \
                        .cmd = __cmd,                                   \
                        .addr = __addr,                                 \
                        .data = __data,                                 \
                },                                                      \
                .exec_op = __exec_op,                                   \
        }

#define INTEL_SPI_MEM_OP_REPL(__cmd, __addr, __data, __exec_op, __repl) \
        {                                                               \
                .mem_op = {                                             \
                        .cmd = __cmd,                                   \
                        .addr = __addr,                                 \
                        .data = __data,                                 \
                },                                                      \
                .exec_op = __exec_op,                                   \
                .replacement_op = __repl,                               \
        }

/*
 * The controller handles pretty much everything internally based on the
 * SFDP data but we want to make sure we only support the operations
 * actually possible. Only check buswidth and transfer direction, the
 * core validates data.
 */
#define INTEL_SPI_GENERIC_OPS                                           \
        /* Status register operations */                                \
        INTEL_SPI_MEM_OP_REPL(SPI_MEM_OP_CMD(SPINOR_OP_RDID, 1),        \
                              SPI_MEM_OP_NO_ADDR,                       \
                              INTEL_SPI_OP_DATA_IN(1),                  \
                              intel_spi_read_reg,                       \
                              HSFSTS_CTL_FCYCLE_RDID),                  \
        INTEL_SPI_MEM_OP_REPL(SPI_MEM_OP_CMD(SPINOR_OP_RDSR, 1),        \
                              SPI_MEM_OP_NO_ADDR,                       \
                              INTEL_SPI_OP_DATA_IN(1),                  \
                              intel_spi_read_reg,                       \
                              HSFSTS_CTL_FCYCLE_RDSR),                  \
        INTEL_SPI_MEM_OP_REPL(SPI_MEM_OP_CMD(SPINOR_OP_WRSR, 1),        \
                              SPI_MEM_OP_NO_ADDR,                       \
                              INTEL_SPI_OP_DATA_OUT(1),                 \
                              intel_spi_write_reg,                      \
                              HSFSTS_CTL_FCYCLE_WRSR),                  \
        INTEL_SPI_MEM_OP_REPL(SPI_MEM_OP_CMD(SPINOR_OP_RDSFDP, 1),      \
                              INTEL_SPI_OP_ADDR(3),                     \
                              INTEL_SPI_OP_DATA_IN(1),                  \
                              intel_spi_read_reg,                       \
                              HSFSTS_CTL_FCYCLE_RDSFDP),                \
        /* Normal read */                                               \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ, 1),             \
                         INTEL_SPI_OP_ADDR(3),                          \
                         INTEL_SPI_OP_DATA_IN(1),                       \
                         intel_spi_read),                               \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ, 1),             \
                         INTEL_SPI_OP_ADDR(3),                          \
                         INTEL_SPI_OP_DATA_IN(2),                       \
                         intel_spi_read),                               \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ, 1),             \
                         INTEL_SPI_OP_ADDR(3),                          \
                         INTEL_SPI_OP_DATA_IN(4),                       \
                         intel_spi_read),                               \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ, 1),             \
                         INTEL_SPI_OP_ADDR(4),                          \
                         INTEL_SPI_OP_DATA_IN(1),                       \
                         intel_spi_read),                               \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ, 1),             \
                         INTEL_SPI_OP_ADDR(4),                          \
                         INTEL_SPI_OP_DATA_IN(2),                       \
                         intel_spi_read),                               \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ, 1),             \
                         INTEL_SPI_OP_ADDR(4),                          \
                         INTEL_SPI_OP_DATA_IN(4),                       \
                         intel_spi_read),                               \
        /* Fast read */                                                 \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ_FAST, 1),        \
                         INTEL_SPI_OP_ADDR(3),                          \
                         INTEL_SPI_OP_DATA_IN(1),                       \
                         intel_spi_read),                               \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ_FAST, 1),        \
                         INTEL_SPI_OP_ADDR(3),                          \
                         INTEL_SPI_OP_DATA_IN(2),                       \
                         intel_spi_read),                               \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ_FAST, 1),        \
                         INTEL_SPI_OP_ADDR(3),                          \
                         INTEL_SPI_OP_DATA_IN(4),                       \
                         intel_spi_read),                               \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ_FAST, 1),        \
                         INTEL_SPI_OP_ADDR(4),                          \
                         INTEL_SPI_OP_DATA_IN(1),                       \
                         intel_spi_read),                               \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ_FAST, 1),        \
                         INTEL_SPI_OP_ADDR(4),                          \
                         INTEL_SPI_OP_DATA_IN(2),                       \
                         intel_spi_read),                               \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ_FAST, 1),        \
                         INTEL_SPI_OP_ADDR(4),                          \
                         INTEL_SPI_OP_DATA_IN(4),                       \
                         intel_spi_read),                               \
        /* Read with 4-byte address opcode */                           \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ_4B, 1),          \
                         INTEL_SPI_OP_ADDR(4),                          \
                         INTEL_SPI_OP_DATA_IN(1),                       \
                         intel_spi_read),                               \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ_4B, 1),          \
                         INTEL_SPI_OP_ADDR(4),                          \
                         INTEL_SPI_OP_DATA_IN(2),                       \
                         intel_spi_read),                               \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ_4B, 1),          \
                         INTEL_SPI_OP_ADDR(4),                          \
                         INTEL_SPI_OP_DATA_IN(4),                       \
                         intel_spi_read),                               \
        /* Fast read with 4-byte address opcode */                      \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ_FAST_4B, 1),     \
                         INTEL_SPI_OP_ADDR(4),                          \
                         INTEL_SPI_OP_DATA_IN(1),                       \
                         intel_spi_read),                               \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ_FAST_4B, 1),     \
                         INTEL_SPI_OP_ADDR(4),                          \
                         INTEL_SPI_OP_DATA_IN(2),                       \
                         intel_spi_read),                               \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ_FAST_4B, 1),     \
                         INTEL_SPI_OP_ADDR(4),                          \
                         INTEL_SPI_OP_DATA_IN(4),                       \
                         intel_spi_read),                               \
        /* Write operations */                                          \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_PP, 1),               \
                         INTEL_SPI_OP_ADDR(3),                          \
                         INTEL_SPI_OP_DATA_OUT(1),                      \
                         intel_spi_write),                              \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_PP, 1),               \
                         INTEL_SPI_OP_ADDR(4),                          \
                         INTEL_SPI_OP_DATA_OUT(1),                      \
                         intel_spi_write),                              \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_PP_4B, 1),            \
                         INTEL_SPI_OP_ADDR(4),                          \
                         INTEL_SPI_OP_DATA_OUT(1),                      \
                         intel_spi_write),                              \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_WREN, 1),             \
                         SPI_MEM_OP_NO_ADDR,                            \
                         SPI_MEM_OP_NO_DATA,                            \
                         intel_spi_write_reg),                          \
        INTEL_SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_WRDI, 1),             \
                         SPI_MEM_OP_NO_ADDR,                            \
                         SPI_MEM_OP_NO_DATA,                            \
                         intel_spi_write_reg),                          \
        /* Erase operations */                                          \
        INTEL_SPI_MEM_OP_REPL(SPI_MEM_OP_CMD(SPINOR_OP_BE_4K, 1),       \
                              INTEL_SPI_OP_ADDR(3),                     \
                              SPI_MEM_OP_NO_DATA,                       \
                              intel_spi_erase,                          \
                              HSFSTS_CTL_FCYCLE_ERASE),                 \
        INTEL_SPI_MEM_OP_REPL(SPI_MEM_OP_CMD(SPINOR_OP_BE_4K, 1),       \
                              INTEL_SPI_OP_ADDR(4),                     \
                              SPI_MEM_OP_NO_DATA,                       \
                              intel_spi_erase,                          \
                              HSFSTS_CTL_FCYCLE_ERASE),                 \
        INTEL_SPI_MEM_OP_REPL(SPI_MEM_OP_CMD(SPINOR_OP_BE_4K_4B, 1),    \
                              INTEL_SPI_OP_ADDR(4),                     \
                              SPI_MEM_OP_NO_DATA,                       \
                              intel_spi_erase,                          \
                              HSFSTS_CTL_FCYCLE_ERASE)                  \

static const struct intel_spi_mem_op generic_mem_ops[] = {
        INTEL_SPI_GENERIC_OPS,
        { },
};

static const struct intel_spi_mem_op erase_64k_mem_ops[] = {
        INTEL_SPI_GENERIC_OPS,
        /* 64k sector erase operations */
        INTEL_SPI_MEM_OP_REPL(SPI_MEM_OP_CMD(SPINOR_OP_SE, 1),
                              INTEL_SPI_OP_ADDR(3),
                              SPI_MEM_OP_NO_DATA,
                              intel_spi_erase,
                              HSFSTS_CTL_FCYCLE_ERASE_64K),
        INTEL_SPI_MEM_OP_REPL(SPI_MEM_OP_CMD(SPINOR_OP_SE, 1),
                              INTEL_SPI_OP_ADDR(4),
                              SPI_MEM_OP_NO_DATA,
                              intel_spi_erase,
                              HSFSTS_CTL_FCYCLE_ERASE_64K),
        INTEL_SPI_MEM_OP_REPL(SPI_MEM_OP_CMD(SPINOR_OP_SE_4B, 1),
                              INTEL_SPI_OP_ADDR(4),
                              SPI_MEM_OP_NO_DATA,
                              intel_spi_erase,
                              HSFSTS_CTL_FCYCLE_ERASE_64K),
        { },
};

static int intel_spi_init(struct intel_spi *ispi)
{
        u32 opmenu0, opmenu1, lvscc, uvscc, val;
        bool erase_64k = false;
        int i;

        switch (ispi->info->type) {
        case INTEL_SPI_BYT:
                ispi->sregs = ispi->base + BYT_SSFSTS_CTL;
                ispi->pregs = ispi->base + BYT_PR;
                ispi->nregions = BYT_FREG_NUM;
                ispi->pr_num = BYT_PR_NUM;
                ispi->swseq_reg = true;
                break;

        case INTEL_SPI_LPT:
                ispi->sregs = ispi->base + LPT_SSFSTS_CTL;
                ispi->pregs = ispi->base + LPT_PR;
                ispi->nregions = LPT_FREG_NUM;
                ispi->pr_num = LPT_PR_NUM;
                ispi->swseq_reg = true;
                break;

        case INTEL_SPI_BXT:
                ispi->sregs = ispi->base + BXT_SSFSTS_CTL;
                ispi->pregs = ispi->base + BXT_PR;
                ispi->nregions = BXT_FREG_NUM;
                ispi->pr_num = BXT_PR_NUM;
                erase_64k = true;
                break;

        case INTEL_SPI_CNL:
                ispi->sregs = NULL;
                ispi->pregs = ispi->base + CNL_PR;
                ispi->nregions = CNL_FREG_NUM;
                ispi->pr_num = CNL_PR_NUM;
                erase_64k = true;
                break;

        default:
                return -EINVAL;
        }

        ispi->bios_locked = true;
        /* Try to disable BIOS write protection if user asked to do so */
        if (writeable) {
                if (intel_spi_set_writeable(ispi))
                        ispi->bios_locked = false;
                else
                        dev_warn(ispi->dev, "can't disable chip write protection\n");
        }

        /* Disable #SMI generation from HW sequencer */
        val = readl(ispi->base + HSFSTS_CTL);
        val &= ~HSFSTS_CTL_FSMIE;
        writel(val, ispi->base + HSFSTS_CTL);

        /*
         * Determine whether erase operation should use HW or SW sequencer.
         *
         * The HW sequencer has a predefined list of opcodes, with only the
         * erase opcode being programmable in LVSCC and UVSCC registers.
         * If these registers don't contain a valid erase opcode, erase
         * cannot be done using HW sequencer.
         */
        lvscc = readl(ispi->base + LVSCC);
        uvscc = readl(ispi->base + UVSCC);
        if (!(lvscc & ERASE_OPCODE_MASK) || !(uvscc & ERASE_OPCODE_MASK))
                ispi->swseq_erase = true;
        /* SPI controller on Intel BXT supports 64K erase opcode */
        if (ispi->info->type == INTEL_SPI_BXT && !ispi->swseq_erase)
                if (!(lvscc & ERASE_64K_OPCODE_MASK) ||
                    !(uvscc & ERASE_64K_OPCODE_MASK))
                        erase_64k = false;

        if (!ispi->sregs && (ispi->swseq_reg || ispi->swseq_erase)) {
                dev_err(ispi->dev, "software sequencer not supported, but required\n");
                return -EINVAL;
        }

        /*
         * Some controllers can only do basic operations using hardware
         * sequencer. All other operations are supposed to be carried out
         * using software sequencer.
         */
        if (ispi->swseq_reg) {
                /* Disable #SMI generation from SW sequencer */
                val = readl(ispi->sregs + SSFSTS_CTL);
                val &= ~SSFSTS_CTL_FSMIE;
                writel(val, ispi->sregs + SSFSTS_CTL);
        }

        /* Check controller's lock status */
        val = readl(ispi->base + HSFSTS_CTL);
        ispi->locked = !!(val & HSFSTS_CTL_FLOCKDN);

        if (ispi->locked && ispi->sregs) {
                /*
                 * BIOS programs allowed opcodes and then locks down the
                 * register. So read back what opcodes it decided to support.
                 * That's the set we are going to support as well.
                 */
                opmenu0 = readl(ispi->sregs + OPMENU0);
                opmenu1 = readl(ispi->sregs + OPMENU1);

                if (opmenu0 && opmenu1) {
                        for (i = 0; i < ARRAY_SIZE(ispi->opcodes) / 2; i++) {
                                ispi->opcodes[i] = opmenu0 >> i * 8;
                                ispi->opcodes[i + 4] = opmenu1 >> i * 8;
                        }
                }
        }

        if (erase_64k) {
                dev_dbg(ispi->dev, "Using erase_64k memory operations");
                ispi->mem_ops = erase_64k_mem_ops;
        } else {
                dev_dbg(ispi->dev, "Using generic memory operations");
                ispi->mem_ops = generic_mem_ops;
        }

        intel_spi_dump_regs(ispi);
        return 0;
}

static bool intel_spi_is_protected(const struct intel_spi *ispi,
                                   unsigned int base, unsigned int limit)
{
        int i;

        for (i = 0; i < ispi->pr_num; i++) {
                u32 pr_base, pr_limit, pr_value;

                pr_value = readl(ispi->pregs + PR(i));
                if (!(pr_value & (PR_WPE | PR_RPE)))
                        continue;

                pr_limit = (pr_value & PR_LIMIT_MASK) >> PR_LIMIT_SHIFT;
                pr_base = pr_value & PR_BASE_MASK;

                if (pr_base >= base && pr_limit <= limit)
                        return true;
        }

        return false;
}

/*
 * There will be a single partition holding all enabled flash regions. We
 * call this "BIOS".
 */
static void intel_spi_fill_partition(struct intel_spi *ispi,
                                     struct mtd_partition *part)
{
        u64 end;
        int i;

        memset(part, 0, sizeof(*part));

        /* Start from the mandatory descriptor region */
        part->size = 4096;
        part->name = "BIOS";

        /*
         * Now try to find where this partition ends based on the flash
         * region registers.
         */
        for (i = 1; i < ispi->nregions; i++) {
                u32 region, base, limit;

                region = readl(ispi->base + FREG(i));
                base = region & FREG_BASE_MASK;
                limit = (region & FREG_LIMIT_MASK) >> FREG_LIMIT_SHIFT;

                if (base >= limit || limit == 0)
                        continue;

                /*
                 * If any of the regions have protection bits set and
                 * the ignore protection status parameter is not set,
                 * make the whole partition read-only to be on the safe side.
                 *
                 * Also if the user did not ask the chip to be writeable
                 * mask the bit too.
                 */
                if (!writeable || (!ignore_protection_status &&
                                   intel_spi_is_protected(ispi, base, limit))) {
                        part->mask_flags |= MTD_WRITEABLE;
                        ispi->protected = true;
                }

                end = (limit << 12) + 4096;
                if (end > part->size)
                        part->size = end;
        }

        /*
         * Regions can refer to the second chip too so in this case we
         * just make the BIOS partition to occupy the whole chip.
         */
        if (ispi->chip0_size && part->size > ispi->chip0_size)
                part->size = MTDPART_SIZ_FULL;
}

static int intel_spi_read_desc(struct intel_spi *ispi)
{
        struct spi_mem_op op =
                SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ, 0),
                           SPI_MEM_OP_ADDR(3, 0, 0),
                           SPI_MEM_OP_NO_DUMMY,
                           SPI_MEM_OP_DATA_IN(0, NULL, 0));
        u32 buf[2], nc, fcba, flcomp;
        ssize_t ret;

        op.addr.val = 0x10;
        op.data.buf.in = buf;
        op.data.nbytes = sizeof(buf);

        ret = intel_spi_read(ispi, NULL, NULL, &op);
        if (ret) {
                dev_warn(ispi->dev, "failed to read descriptor\n");
                return ret;
        }

        dev_dbg(ispi->dev, "FLVALSIG=0x%08x\n", buf[0]);
        dev_dbg(ispi->dev, "FLMAP0=0x%08x\n", buf[1]);

        if (buf[0] != FLVALSIG_MAGIC) {
                dev_warn(ispi->dev, "descriptor signature not valid\n");
                return -ENODEV;
        }

        fcba = (buf[1] & FLMAP0_FCBA_MASK) << 4;
        dev_dbg(ispi->dev, "FCBA=%#x\n", fcba);

        op.addr.val = fcba;
        op.data.buf.in = &flcomp;
        op.data.nbytes = sizeof(flcomp);

        ret = intel_spi_read(ispi, NULL, NULL, &op);
        if (ret) {
                dev_warn(ispi->dev, "failed to read FLCOMP\n");
                return -ENODEV;
        }

        dev_dbg(ispi->dev, "FLCOMP=0x%08x\n", flcomp);

        switch (flcomp & FLCOMP_C0DEN_MASK) {
        case FLCOMP_C0DEN_512K:
                ispi->chip0_size = SZ_512K;
                break;
        case FLCOMP_C0DEN_1M:
                ispi->chip0_size = SZ_1M;
                break;
        case FLCOMP_C0DEN_2M:
                ispi->chip0_size = SZ_2M;
                break;
        case FLCOMP_C0DEN_4M:
                ispi->chip0_size = SZ_4M;
                break;
        case FLCOMP_C0DEN_8M:
                ispi->chip0_size = SZ_8M;
                break;
        case FLCOMP_C0DEN_16M:
                ispi->chip0_size = SZ_16M;
                break;
        case FLCOMP_C0DEN_32M:
                ispi->chip0_size = SZ_32M;
                break;
        case FLCOMP_C0DEN_64M:
                ispi->chip0_size = SZ_64M;
                break;
        case FLCOMP_C0DEN_128M:
                ispi->chip0_size = SZ_128M;
                break;
        default:
                dev_warn(ispi->dev, "unsupported C0DEN: %#lx\n",
                         flcomp & FLCOMP_C0DEN_MASK);
                return -EINVAL;
        }

        dev_dbg(ispi->dev, "chip0 size %zd KB\n", ispi->chip0_size / SZ_1K);

        nc = (buf[1] & FLMAP0_NC_MASK) >> FLMAP0_NC_SHIFT;
        if (!nc)
                ispi->host->num_chipselect = 1;
        else if (nc == 1)
                ispi->host->num_chipselect = 2;
        else
                return -EINVAL;

        dev_dbg(ispi->dev, "%u flash components found\n",
                ispi->host->num_chipselect);
        return 0;
}

static int intel_spi_populate_chip(struct intel_spi *ispi)
{
        struct flash_platform_data *pdata;
        struct mtd_partition *parts;
        struct spi_board_info chip;
        int ret;

        ret = intel_spi_read_desc(ispi);
        if (ret)
                return ret;

        pdata = devm_kzalloc(ispi->dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return -ENOMEM;

        pdata->nr_parts = 1;
        pdata->parts = devm_kcalloc(ispi->dev, pdata->nr_parts,
                                    sizeof(*pdata->parts), GFP_KERNEL);
        if (!pdata->parts)
                return -ENOMEM;

        intel_spi_fill_partition(ispi, pdata->parts);

        memset(&chip, 0, sizeof(chip));
        snprintf(chip.modalias, 8, "spi-nor");
        chip.platform_data = pdata;

        if (!spi_new_device(ispi->host, &chip))
                return -ENODEV;

        /* Add the second chip if present */
        if (ispi->host->num_chipselect < 2)
                return 0;

        pdata = devm_kzalloc(ispi->dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return -ENOMEM;

        pdata->name = devm_kasprintf(ispi->dev, GFP_KERNEL, "%s-chip1",
                                     dev_name(ispi->dev));
        if (!pdata->name)
                return -ENOMEM;

        pdata->nr_parts = 1;
        parts = devm_kcalloc(ispi->dev, pdata->nr_parts, sizeof(*parts),
                             GFP_KERNEL);
        if (!parts)
                return -ENOMEM;

        parts[0].size = MTDPART_SIZ_FULL;
        parts[0].name = "BIOS1";
        pdata->parts = parts;

        chip.platform_data = pdata;
        chip.chip_select = 1;

        if (!spi_new_device(ispi->host, &chip))
                return -ENODEV;
        return 0;
}

static ssize_t intel_spi_protected_show(struct device *dev,
                                        struct device_attribute *attr, char *buf)
{
        struct intel_spi *ispi = dev_get_drvdata(dev);

        return sysfs_emit(buf, "%d\n", ispi->protected);
}
static DEVICE_ATTR_ADMIN_RO(intel_spi_protected);

static ssize_t intel_spi_locked_show(struct device *dev,
                                     struct device_attribute *attr, char *buf)
{
        struct intel_spi *ispi = dev_get_drvdata(dev);

        return sysfs_emit(buf, "%d\n", ispi->locked);
}
static DEVICE_ATTR_ADMIN_RO(intel_spi_locked);

static ssize_t intel_spi_bios_locked_show(struct device *dev,
                                          struct device_attribute *attr, char *buf)
{
        struct intel_spi *ispi = dev_get_drvdata(dev);

        return sysfs_emit(buf, "%d\n", ispi->bios_locked);
}
static DEVICE_ATTR_ADMIN_RO(intel_spi_bios_locked);

static struct attribute *intel_spi_attrs[] = {
        &dev_attr_intel_spi_protected.attr,
        &dev_attr_intel_spi_locked.attr,
        &dev_attr_intel_spi_bios_locked.attr,
        NULL
};

static const struct attribute_group intel_spi_attr_group = {
        .attrs = intel_spi_attrs,
};

const struct attribute_group *intel_spi_groups[] = {
        &intel_spi_attr_group,
        NULL
};
EXPORT_SYMBOL_GPL(intel_spi_groups);

/**
 * intel_spi_probe() - Probe the Intel SPI flash controller
 * @dev: Pointer to the parent device
 * @base: iomapped MMIO resource
 * @info: Platform specific information
 *
 * Probes Intel SPI flash controller and creates the flash chip device.
 * Returns %0 on success and negative errno in case of failure.
 */
int intel_spi_probe(struct device *dev, void __iomem *base,
                    const struct intel_spi_boardinfo *info)
{
        struct spi_controller *host;
        struct intel_spi *ispi;
        int ret;

        host = devm_spi_alloc_host(dev, sizeof(*ispi));
        if (!host)
                return -ENOMEM;

        host->mem_ops = &intel_spi_mem_ops;

        ispi = spi_controller_get_devdata(host);

        ispi->base = base;
        ispi->dev = dev;
        ispi->host = host;
        ispi->info = info;

        ret = intel_spi_init(ispi);
        if (ret)
                return ret;

        ret = devm_spi_register_controller(dev, host);
        if (ret)
                return ret;

        dev_set_drvdata(dev, ispi);
        return intel_spi_populate_chip(ispi);
}
EXPORT_SYMBOL_GPL(intel_spi_probe);

MODULE_DESCRIPTION("Intel PCH/PCU SPI flash core driver");
MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
MODULE_LICENSE("GPL v2");