/*
 * Copyright (c) 2011-12 The Chromium OS Authors.
 *
 * SPDX-License-Identifier:     GPL-2.0+
 *
 * This file is derived from the flashrom project.
 */

#include <common.h>
#include <dm.h>
#include <errno.h>
#include <malloc.h>
#include <spi.h>
#include <pci.h>
#include <pci_ids.h>
#include <asm/io.h>

#include "ich.h"

#define SPI_OPCODE_WREN      0x06
#define SPI_OPCODE_FAST_READ 0x0b

struct ich_spi_platdata {
        pci_dev_t dev;          /* PCI device number */
        int ich_version;        /* Controller version, 7 or 9 */
        bool use_sbase;         /* Use SBASE instead of RCB */
};

struct ich_spi_priv {
        int ichspi_lock;
        int locked;
        int opmenu;
        int menubytes;
        void *base;             /* Base of register set */
        int preop;
        int optype;
        int addr;
        int data;
        unsigned databytes;
        int status;
        int control;
        int bbar;
        uint32_t *pr;           /* only for ich9 */
        int speed;              /* pointer to speed control */
        ulong max_speed;        /* Maximum bus speed in MHz */
        ulong cur_speed;        /* Current bus speed */
        struct spi_trans trans; /* current transaction in progress */
};

static u8 ich_readb(struct ich_spi_priv *priv, int reg)
{
        u8 value = readb(priv->base + reg);

        debug("read %2.2x from %4.4x\n", value, reg);

        return value;
}

static u16 ich_readw(struct ich_spi_priv *priv, int reg)
{
        u16 value = readw(priv->base + reg);

        debug("read %4.4x from %4.4x\n", value, reg);

        return value;
}

static u32 ich_readl(struct ich_spi_priv *priv, int reg)
{
        u32 value = readl(priv->base + reg);

        debug("read %8.8x from %4.4x\n", value, reg);

        return value;
}

static void ich_writeb(struct ich_spi_priv *priv, u8 value, int reg)
{
        writeb(value, priv->base + reg);
        debug("wrote %2.2x to %4.4x\n", value, reg);
}

static void ich_writew(struct ich_spi_priv *priv, u16 value, int reg)
{
        writew(value, priv->base + reg);
        debug("wrote %4.4x to %4.4x\n", value, reg);
}

static void ich_writel(struct ich_spi_priv *priv, u32 value, int reg)
{
        writel(value, priv->base + reg);
        debug("wrote %8.8x to %4.4x\n", value, reg);
}

static void write_reg(struct ich_spi_priv *priv, const void *value,
                      int dest_reg, uint32_t size)
{
        memcpy_toio(priv->base + dest_reg, value, size);
}

static void read_reg(struct ich_spi_priv *priv, int src_reg, void *value,
                     uint32_t size)
{
        memcpy_fromio(value, priv->base + src_reg, size);
}

static void ich_set_bbar(struct ich_spi_priv *ctlr, uint32_t minaddr)
{
        const uint32_t bbar_mask = 0x00ffff00;
        uint32_t ichspi_bbar;

        minaddr &= bbar_mask;
        ichspi_bbar = ich_readl(ctlr, ctlr->bbar) & ~bbar_mask;
        ichspi_bbar |= minaddr;
        ich_writel(ctlr, ichspi_bbar, ctlr->bbar);
}

/*
 * Check if this device ID matches one of supported Intel PCH devices.
 *
 * Return the ICH version if there is a match, or zero otherwise.
 */
static int get_ich_version(uint16_t device_id)
{
        if (device_id == PCI_DEVICE_ID_INTEL_TGP_LPC ||
            device_id == PCI_DEVICE_ID_INTEL_ITC_LPC ||
            device_id == PCI_DEVICE_ID_INTEL_QRK_ILB)
                return 7;

        if ((device_id >= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MIN &&
             device_id <= PCI_DEVICE_ID_INTEL_COUGARPOINT_LPC_MAX) ||
            (device_id >= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MIN &&
             device_id <= PCI_DEVICE_ID_INTEL_PANTHERPOINT_LPC_MAX) ||
            device_id == PCI_DEVICE_ID_INTEL_VALLEYVIEW_LPC ||
            device_id == PCI_DEVICE_ID_INTEL_LYNXPOINT_LPC)
                return 9;

        return 0;
}

/* @return 1 if the SPI flash supports the 33MHz speed */
static int ich9_can_do_33mhz(pci_dev_t dev)
{
        u32 fdod, speed;

        /* Observe SPI Descriptor Component Section 0 */
        pci_write_config_dword(dev, 0xb0, 0x1000);

        /* Extract the Write/Erase SPI Frequency from descriptor */
        pci_read_config_dword(dev, 0xb4, &fdod);

        /* Bits 23:21 have the fast read clock frequency, 0=20MHz, 1=33MHz */
        speed = (fdod >> 21) & 7;

        return speed == 1;
}

static int ich_find_spi_controller(struct ich_spi_platdata *ich)
{
        int last_bus = pci_last_busno();
        int bus;

        if (last_bus == -1) {
                debug("No PCI busses?\n");
                return -ENODEV;
        }

        for (bus = 0; bus <= last_bus; bus++) {
                uint16_t vendor_id, device_id;
                uint32_t ids;
                pci_dev_t dev;

                dev = PCI_BDF(bus, 31, 0);
                pci_read_config_dword(dev, 0, &ids);
                vendor_id = ids;
                device_id = ids >> 16;

                if (vendor_id == PCI_VENDOR_ID_INTEL) {
                        ich->dev = dev;
                        ich->ich_version = get_ich_version(device_id);
                        if (device_id == PCI_DEVICE_ID_INTEL_VALLEYVIEW_LPC)
                                ich->use_sbase = true;
                        return ich->ich_version == 0 ? -ENODEV : 0;
                }
        }

        debug("ICH SPI: No ICH found.\n");
        return -ENODEV;
}

static int ich_init_controller(struct ich_spi_platdata *plat,
                               struct ich_spi_priv *ctlr)
{
        uint8_t *rcrb; /* Root Complex Register Block */
        uint32_t rcba; /* Root Complex Base Address */
        uint32_t sbase_addr;
        uint8_t *sbase;

        pci_read_config_dword(plat->dev, 0xf0, &rcba);
        /* Bits 31-14 are the base address, 13-1 are reserved, 0 is enable. */
        rcrb = (uint8_t *)(rcba & 0xffffc000);

        /* SBASE is similar */
        pci_read_config_dword(plat->dev, 0x54, &sbase_addr);
        sbase = (uint8_t *)(sbase_addr & 0xfffffe00);

        if (plat->ich_version == 7) {
                struct ich7_spi_regs *ich7_spi;

                ich7_spi = (struct ich7_spi_regs *)(rcrb + 0x3020);
                ctlr->ichspi_lock = readw(&ich7_spi->spis) & SPIS_LOCK;
                ctlr->opmenu = offsetof(struct ich7_spi_regs, opmenu);
                ctlr->menubytes = sizeof(ich7_spi->opmenu);
                ctlr->optype = offsetof(struct ich7_spi_regs, optype);
                ctlr->addr = offsetof(struct ich7_spi_regs, spia);
                ctlr->data = offsetof(struct ich7_spi_regs, spid);
                ctlr->databytes = sizeof(ich7_spi->spid);
                ctlr->status = offsetof(struct ich7_spi_regs, spis);
                ctlr->control = offsetof(struct ich7_spi_regs, spic);
                ctlr->bbar = offsetof(struct ich7_spi_regs, bbar);
                ctlr->preop = offsetof(struct ich7_spi_regs, preop);
                ctlr->base = ich7_spi;
        } else if (plat->ich_version == 9) {
                struct ich9_spi_regs *ich9_spi;

                if (plat->use_sbase)
                        ich9_spi = (struct ich9_spi_regs *)sbase;
                else
                        ich9_spi = (struct ich9_spi_regs *)(rcrb + 0x3800);
                ctlr->ichspi_lock = readw(&ich9_spi->hsfs) & HSFS_FLOCKDN;
                ctlr->opmenu = offsetof(struct ich9_spi_regs, opmenu);
                ctlr->menubytes = sizeof(ich9_spi->opmenu);
                ctlr->optype = offsetof(struct ich9_spi_regs, optype);
                ctlr->addr = offsetof(struct ich9_spi_regs, faddr);
                ctlr->data = offsetof(struct ich9_spi_regs, fdata);
                ctlr->databytes = sizeof(ich9_spi->fdata);
                ctlr->status = offsetof(struct ich9_spi_regs, ssfs);
                ctlr->control = offsetof(struct ich9_spi_regs, ssfc);
                ctlr->speed = ctlr->control + 2;
                ctlr->bbar = offsetof(struct ich9_spi_regs, bbar);
                ctlr->preop = offsetof(struct ich9_spi_regs, preop);
                ctlr->pr = &ich9_spi->pr[0];
                ctlr->base = ich9_spi;
        } else {
                debug("ICH SPI: Unrecognised ICH version %d\n",
                      plat->ich_version);
                return -EINVAL;
        }

        /* Work out the maximum speed we can support */
        ctlr->max_speed = 20000000;
        if (plat->ich_version == 9 && ich9_can_do_33mhz(plat->dev))
                ctlr->max_speed = 33000000;
        debug("ICH SPI: Version %d detected at %p, speed %ld\n",
              plat->ich_version, ctlr->base, ctlr->max_speed);

        ich_set_bbar(ctlr, 0);

        return 0;
}

static inline void spi_use_out(struct spi_trans *trans, unsigned bytes)
{
        trans->out += bytes;
        trans->bytesout -= bytes;
}

static inline void spi_use_in(struct spi_trans *trans, unsigned bytes)
{
        trans->in += bytes;
        trans->bytesin -= bytes;
}

static void spi_setup_type(struct spi_trans *trans, int data_bytes)
{
        trans->type = 0xFF;

        /* Try to guess spi type from read/write sizes. */
        if (trans->bytesin == 0) {
                if (trans->bytesout + data_bytes > 4)
                        /*
                         * If bytesin = 0 and bytesout > 4, we presume this is
                         * a write data operation, which is accompanied by an
                         * address.
                         */
                        trans->type = SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS;
                else
                        trans->type = SPI_OPCODE_TYPE_WRITE_NO_ADDRESS;
                return;
        }

        if (trans->bytesout == 1) {     /* and bytesin is > 0 */
                trans->type = SPI_OPCODE_TYPE_READ_NO_ADDRESS;
                return;
        }

        if (trans->bytesout == 4)       /* and bytesin is > 0 */
                trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;

        /* Fast read command is called with 5 bytes instead of 4 */
        if (trans->out[0] == SPI_OPCODE_FAST_READ && trans->bytesout == 5) {
                trans->type = SPI_OPCODE_TYPE_READ_WITH_ADDRESS;
                --trans->bytesout;
        }
}

static int spi_setup_opcode(struct ich_spi_priv *ctlr, struct spi_trans *trans)
{
        uint16_t optypes;
        uint8_t opmenu[ctlr->menubytes];

        trans->opcode = trans->out[0];
        spi_use_out(trans, 1);
        if (!ctlr->ichspi_lock) {
                /* The lock is off, so just use index 0. */
                ich_writeb(ctlr, trans->opcode, ctlr->opmenu);
                optypes = ich_readw(ctlr, ctlr->optype);
                optypes = (optypes & 0xfffc) | (trans->type & 0x3);
                ich_writew(ctlr, optypes, ctlr->optype);
                return 0;
        } else {
                /* The lock is on. See if what we need is on the menu. */
                uint8_t optype;
                uint16_t opcode_index;

                /* Write Enable is handled as atomic prefix */
                if (trans->opcode == SPI_OPCODE_WREN)
                        return 0;

                read_reg(ctlr, ctlr->opmenu, opmenu, sizeof(opmenu));
                for (opcode_index = 0; opcode_index < ctlr->menubytes;
                                opcode_index++) {
                        if (opmenu[opcode_index] == trans->opcode)
                                break;
                }

                if (opcode_index == ctlr->menubytes) {
                        printf("ICH SPI: Opcode %x not found\n",
                               trans->opcode);
                        return -EINVAL;
                }

                optypes = ich_readw(ctlr, ctlr->optype);
                optype = (optypes >> (opcode_index * 2)) & 0x3;
                if (trans->type == SPI_OPCODE_TYPE_WRITE_NO_ADDRESS &&
                    optype == SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS &&
                    trans->bytesout >= 3) {
                        /* We guessed wrong earlier. Fix it up. */
                        trans->type = optype;
                }
                if (optype != trans->type) {
                        printf("ICH SPI: Transaction doesn't fit type %d\n",
                               optype);
                        return -ENOSPC;
                }
                return opcode_index;
        }
}

static int spi_setup_offset(struct spi_trans *trans)
{
        /* Separate the SPI address and data. */
        switch (trans->type) {
        case SPI_OPCODE_TYPE_READ_NO_ADDRESS:
        case SPI_OPCODE_TYPE_WRITE_NO_ADDRESS:
                return 0;
        case SPI_OPCODE_TYPE_READ_WITH_ADDRESS:
        case SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS:
                trans->offset = ((uint32_t)trans->out[0] << 16) |
                                ((uint32_t)trans->out[1] << 8) |
                                ((uint32_t)trans->out[2] << 0);
                spi_use_out(trans, 3);
                return 1;
        default:
                printf("Unrecognized SPI transaction type %#x\n", trans->type);
                return -EPROTO;
        }
}

/*
 * Wait for up to 6s til status register bit(s) turn 1 (in case wait_til_set
 * below is true) or 0. In case the wait was for the bit(s) to set - write
 * those bits back, which would cause resetting them.
 *
 * Return the last read status value on success or -1 on failure.
 */
static int ich_status_poll(struct ich_spi_priv *ctlr, u16 bitmask,
                           int wait_til_set)
{
        int timeout = 600000; /* This will result in 6s */
        u16 status = 0;

        while (timeout--) {
                status = ich_readw(ctlr, ctlr->status);
                if (wait_til_set ^ ((status & bitmask) == 0)) {
                        if (wait_til_set) {
                                ich_writew(ctlr, status & bitmask,
                                           ctlr->status);
                        }
                        return status;
                }
                udelay(10);
        }

        printf("ICH SPI: SCIP timeout, read %x, expected %x\n",
               status, bitmask);
        return -ETIMEDOUT;
}

static int ich_spi_xfer(struct udevice *dev, unsigned int bitlen,
                        const void *dout, void *din, unsigned long flags)
{
        struct udevice *bus = dev_get_parent(dev);
        struct ich_spi_priv *ctlr = dev_get_priv(bus);
        uint16_t control;
        int16_t opcode_index;
        int with_address;
        int status;
        int bytes = bitlen / 8;
        struct spi_trans *trans = &ctlr->trans;
        unsigned type = flags & (SPI_XFER_BEGIN | SPI_XFER_END);
        int using_cmd = 0;
        int ret;

        /* Ee don't support writing partial bytes. */
        if (bitlen % 8) {
                debug("ICH SPI: Accessing partial bytes not supported\n");
                return -EPROTONOSUPPORT;
        }

        /* An empty end transaction can be ignored */
        if (type == SPI_XFER_END && !dout && !din)
                return 0;

        if (type & SPI_XFER_BEGIN)
                memset(trans, '\0', sizeof(*trans));

        /* Dp we need to come back later to finish it? */
        if (dout && type == SPI_XFER_BEGIN) {
                if (bytes > ICH_MAX_CMD_LEN) {
                        debug("ICH SPI: Command length limit exceeded\n");
                        return -ENOSPC;
                }
                memcpy(trans->cmd, dout, bytes);
                trans->cmd_len = bytes;
                debug("ICH SPI: Saved %d bytes\n", bytes);
                return 0;
        }

        /*
         * We process a 'middle' spi_xfer() call, which has no
         * SPI_XFER_BEGIN/END, as an independent transaction as if it had
         * an end. We therefore repeat the command. This is because ICH
         * seems to have no support for this, or because interest (in digging
         * out the details and creating a special case in the code) is low.
         */
        if (trans->cmd_len) {
                trans->out = trans->cmd;
                trans->bytesout = trans->cmd_len;
                using_cmd = 1;
                debug("ICH SPI: Using %d bytes\n", trans->cmd_len);
        } else {
                trans->out = dout;
                trans->bytesout = dout ? bytes : 0;
        }

        trans->in = din;
        trans->bytesin = din ? bytes : 0;

        /* There has to always at least be an opcode. */
        if (!trans->bytesout) {
                debug("ICH SPI: No opcode for transfer\n");
                return -EPROTO;
        }

        ret = ich_status_poll(ctlr, SPIS_SCIP, 0);
        if (ret < 0)
                return ret;

        ich_writew(ctlr, SPIS_CDS | SPIS_FCERR, ctlr->status);

        spi_setup_type(trans, using_cmd ? bytes : 0);
        opcode_index = spi_setup_opcode(ctlr, trans);
        if (opcode_index < 0)
                return -EINVAL;
        with_address = spi_setup_offset(trans);
        if (with_address < 0)
                return -EINVAL;

        if (trans->opcode == SPI_OPCODE_WREN) {
                /*
                 * Treat Write Enable as Atomic Pre-Op if possible
                 * in order to prevent the Management Engine from
                 * issuing a transaction between WREN and DATA.
                 */
                if (!ctlr->ichspi_lock)
                        ich_writew(ctlr, trans->opcode, ctlr->preop);
                return 0;
        }

        if (ctlr->speed && ctlr->max_speed >= 33000000) {
                int byte;

                byte = ich_readb(ctlr, ctlr->speed);
                if (ctlr->cur_speed >= 33000000)
                        byte |= SSFC_SCF_33MHZ;
                else
                        byte &= ~SSFC_SCF_33MHZ;
                ich_writeb(ctlr, byte, ctlr->speed);
        }

        /* See if we have used up the command data */
        if (using_cmd && dout && bytes) {
                trans->out = dout;
                trans->bytesout = bytes;
                debug("ICH SPI: Moving to data, %d bytes\n", bytes);
        }

        /* Preset control fields */
        control = ich_readw(ctlr, ctlr->control);
        control &= ~SSFC_RESERVED;
        control = SPIC_SCGO | ((opcode_index & 0x07) << 4);

        /* Issue atomic preop cycle if needed */
        if (ich_readw(ctlr, ctlr->preop))
                control |= SPIC_ACS;

        if (!trans->bytesout && !trans->bytesin) {
                /* SPI addresses are 24 bit only */
                if (with_address) {
                        ich_writel(ctlr, trans->offset & 0x00FFFFFF,
                                   ctlr->addr);
                }
                /*
                 * This is a 'no data' command (like Write Enable), its
                 * bitesout size was 1, decremented to zero while executing
                 * spi_setup_opcode() above. Tell the chip to send the
                 * command.
                 */
                ich_writew(ctlr, control, ctlr->control);

                /* wait for the result */
                status = ich_status_poll(ctlr, SPIS_CDS | SPIS_FCERR, 1);
                if (status < 0)
                        return status;

                if (status & SPIS_FCERR) {
                        debug("ICH SPI: Command transaction error\n");
                        return -EIO;
                }

                return 0;
        }

        /*
         * Check if this is a write command atempting to transfer more bytes
         * than the controller can handle. Iterations for writes are not
         * supported here because each SPI write command needs to be preceded
         * and followed by other SPI commands, and this sequence is controlled
         * by the SPI chip driver.
         */
        if (trans->bytesout > ctlr->databytes) {
                debug("ICH SPI: Too much to write. This should be prevented by the driver's max_write_size?\n");
                return -EPROTO;
        }

        /*
         * Read or write up to databytes bytes at a time until everything has
         * been sent.
         */
        while (trans->bytesout || trans->bytesin) {
                uint32_t data_length;

                /* SPI addresses are 24 bit only */
                ich_writel(ctlr, trans->offset & 0x00FFFFFF, ctlr->addr);

                if (trans->bytesout)
                        data_length = min(trans->bytesout, ctlr->databytes);
                else
                        data_length = min(trans->bytesin, ctlr->databytes);

                /* Program data into FDATA0 to N */
                if (trans->bytesout) {
                        write_reg(ctlr, trans->out, ctlr->data, data_length);
                        spi_use_out(trans, data_length);
                        if (with_address)
                                trans->offset += data_length;
                }

                /* Add proper control fields' values */
                control &= ~((ctlr->databytes - 1) << 8);
                control |= SPIC_DS;
                control |= (data_length - 1) << 8;

                /* write it */
                ich_writew(ctlr, control, ctlr->control);

                /* Wait for Cycle Done Status or Flash Cycle Error. */
                status = ich_status_poll(ctlr, SPIS_CDS | SPIS_FCERR, 1);
                if (status < 0)
                        return status;

                if (status & SPIS_FCERR) {
                        debug("ICH SPI: Data transaction error\n");
                        return -EIO;
                }

                if (trans->bytesin) {
                        read_reg(ctlr, ctlr->data, trans->in, data_length);
                        spi_use_in(trans, data_length);
                        if (with_address)
                                trans->offset += data_length;
                }
        }

        /* Clear atomic preop now that xfer is done */
        ich_writew(ctlr, 0, ctlr->preop);

        return 0;
}


/*
 * This uses the SPI controller from the Intel Cougar Point and Panther Point
 * PCH to write-protect portions of the SPI flash until reboot. The changes
 * don't actually take effect until the HSFS[FLOCKDN] bit is set, but that's
 * done elsewhere.
 */
int spi_write_protect_region(struct udevice *dev, uint32_t lower_limit,
                             uint32_t length, int hint)
{
        struct udevice *bus = dev->parent;
        struct ich_spi_priv *ctlr = dev_get_priv(bus);
        uint32_t tmplong;
        uint32_t upper_limit;

        if (!ctlr->pr) {
                printf("%s: operation not supported on this chipset\n",
                       __func__);
                return -ENOSYS;
        }

        if (length == 0 ||
            lower_limit > (0xFFFFFFFFUL - length) + 1 ||
            hint < 0 || hint > 4) {
                printf("%s(0x%x, 0x%x, %d): invalid args\n", __func__,
                       lower_limit, length, hint);
                return -EPERM;
        }

        upper_limit = lower_limit + length - 1;

        /*
         * Determine bits to write, as follows:
         *  31     Write-protection enable (includes erase operation)
         *  30:29  reserved
         *  28:16  Upper Limit (FLA address bits 24:12, with 11:0 == 0xfff)
         *  15     Read-protection enable
         *  14:13  reserved
         *  12:0   Lower Limit (FLA address bits 24:12, with 11:0 == 0x000)
         */
        tmplong = 0x80000000 |
                ((upper_limit & 0x01fff000) << 4) |
                ((lower_limit & 0x01fff000) >> 12);

        printf("%s: writing 0x%08x to %p\n", __func__, tmplong,
               &ctlr->pr[hint]);
        ctlr->pr[hint] = tmplong;

        return 0;
}

static int ich_spi_probe(struct udevice *bus)
{
        struct ich_spi_platdata *plat = dev_get_platdata(bus);
        struct ich_spi_priv *priv = dev_get_priv(bus);
        uint8_t bios_cntl;
        int ret;

        ret = ich_init_controller(plat, priv);
        if (ret)
                return ret;
        /*
         * Disable the BIOS write protect so write commands are allowed.  On
         * v9, deassert SMM BIOS Write Protect Disable.
         */
        if (plat->use_sbase) {
                struct ich9_spi_regs *ich9_spi;

                ich9_spi = priv->base;
                bios_cntl = ich_readb(priv, ich9_spi->bcr);
                bios_cntl &= ~(1 << 5); /* clear Enable InSMM_STS (EISS) */
                bios_cntl |= 1;         /* Write Protect Disable (WPD) */
                ich_writeb(priv, bios_cntl, ich9_spi->bcr);
        } else {
                pci_read_config_byte(plat->dev, 0xdc, &bios_cntl);
                if (plat->ich_version == 9)
                        bios_cntl &= ~(1 << 5);
                pci_write_config_byte(plat->dev, 0xdc, bios_cntl | 0x1);
        }

        priv->cur_speed = priv->max_speed;

        return 0;
}

static int ich_spi_ofdata_to_platdata(struct udevice *bus)
{
        struct ich_spi_platdata *plat = dev_get_platdata(bus);
        int ret;

        ret = ich_find_spi_controller(plat);
        if (ret)
                return ret;

        return 0;
}

static int ich_spi_set_speed(struct udevice *bus, uint speed)
{
        struct ich_spi_priv *priv = dev_get_priv(bus);

        priv->cur_speed = speed;

        return 0;
}

static int ich_spi_set_mode(struct udevice *bus, uint mode)
{
        debug("%s: mode=%d\n", __func__, mode);

        return 0;
}

static int ich_spi_child_pre_probe(struct udevice *dev)
{
        struct udevice *bus = dev_get_parent(dev);
        struct ich_spi_platdata *plat = dev_get_platdata(bus);
        struct ich_spi_priv *priv = dev_get_priv(bus);
        struct spi_slave *slave = dev_get_parentdata(dev);

        /*
         * Yes this controller can only write a small number of bytes at
         * once! The limit is typically 64 bytes.
         */
        slave->max_write_size = priv->databytes;
        /*
         * ICH 7 SPI controller only supports array read command
         * and byte program command for SST flash
         */
        if (plat->ich_version == 7) {
                slave->op_mode_rx = SPI_OPM_RX_AS;
                slave->op_mode_tx = SPI_OPM_TX_BP;
        }

        return 0;
}

static const struct dm_spi_ops ich_spi_ops = {
        .xfer           = ich_spi_xfer,
        .set_speed      = ich_spi_set_speed,
        .set_mode       = ich_spi_set_mode,
        /*
         * cs_info is not needed, since we require all chip selects to be
         * in the device tree explicitly
         */
};

static const struct udevice_id ich_spi_ids[] = {
        { .compatible = "intel,ich-spi" },
        { }
};

U_BOOT_DRIVER(ich_spi) = {
        .name   = "ich_spi",
        .id     = UCLASS_SPI,
        .of_match = ich_spi_ids,
        .ops    = &ich_spi_ops,
        .ofdata_to_platdata = ich_spi_ofdata_to_platdata,
        .platdata_auto_alloc_size = sizeof(struct ich_spi_platdata),
        .priv_auto_alloc_size = sizeof(struct ich_spi_priv),
        .child_pre_probe = ich_spi_child_pre_probe,
        .probe  = ich_spi_probe,
};