/*
 * Copyright (c) 2011-12 The Chromium OS Authors.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but without any warranty; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 *
 * This file is derived from the flashrom project.
 */

#include <common.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_ctlr {
        pci_dev_t dev;          /* PCI device number */
        int ich_version;        /* Controller version, 7 or 9 */
        int ichspi_lock;
        int locked;
        uint8_t *opmenu;
        int menubytes;
        void *base;             /* Base of register set */
        uint16_t *preop;
        uint16_t *optype;
        uint32_t *addr;
        uint8_t *data;
        unsigned databytes;
        uint8_t *status;
        uint16_t *control;
        uint32_t *bbar;
        uint32_t *pr;           /* only for ich9 */
        uint8_t *speed;         /* pointer to speed control */
        ulong max_speed;        /* Maximum bus speed in MHz */
};

struct ich_ctlr ctlr;

static inline struct ich_spi_slave *to_ich_spi(struct spi_slave *slave)
{
        return container_of(slave, struct ich_spi_slave, slave);
}

static unsigned int ich_reg(const void *addr)
{
        return (unsigned)(addr - ctlr.base) & 0xffff;
}

static u8 ich_readb(const void *addr)
{
        u8 value = readb(addr);

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

        return value;
}

static u16 ich_readw(const void *addr)
{
        u16 value = readw(addr);

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

        return value;
}

static u32 ich_readl(const void *addr)
{
        u32 value = readl(addr);

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

        return value;
}

static void ich_writeb(u8 value, void *addr)
{
        writeb(value, addr);
        debug("wrote %2.2x to %4.4x\n", value, ich_reg(addr));
}

static void ich_writew(u16 value, void *addr)
{
        writew(value, addr);
        debug("wrote %4.4x to %4.4x\n", value, ich_reg(addr));
}

static void ich_writel(u32 value, void *addr)
{
        writel(value, addr);
        debug("wrote %8.8x to %4.4x\n", value, ich_reg(addr));
}

static void write_reg(const void *value, void *dest, uint32_t size)
{
        memcpy_toio(dest, value, size);
}

static void read_reg(const void *src, void *value, uint32_t size)
{
        memcpy_fromio(value, src, size);
}

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

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

int spi_cs_is_valid(unsigned int bus, unsigned int cs)
{
        puts("spi_cs_is_valid used but not implemented\n");
        return 0;
}

struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
                unsigned int max_hz, unsigned int mode)
{
        struct ich_spi_slave *ich;

        ich = spi_alloc_slave(struct ich_spi_slave, bus, cs);
        if (!ich) {
                puts("ICH SPI: Out of memory\n");
                return NULL;
        }

        /*
         * Yes this controller can only write a small number of bytes at
         * once! The limit is typically 64 bytes.
         */
        ich->slave.max_write_size = ctlr.databytes;
        ich->speed = max_hz;

        return &ich->slave;
}

void spi_free_slave(struct spi_slave *slave)
{
        struct ich_spi_slave *ich = to_ich_spi(slave);

        free(ich);
}

/*
 * 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)
                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))
                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(pci_dev_t *devp, int *ich_versionp)
{
        int last_bus = pci_last_busno();
        int bus;

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

        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) {
                        *devp = dev;
                        *ich_versionp = get_ich_version(device_id);
                        return 0;
                }
        }

        debug("ICH SPI: No ICH found.\n");
        return -1;
}

static int ich_init_controller(struct ich_ctlr *ctlr)
{
        uint8_t *rcrb; /* Root Complex Register Block */
        uint32_t rcba; /* Root Complex Base Address */

        pci_read_config_dword(ctlr->dev, 0xf0, &rcba);
        /* Bits 31-14 are the base address, 13-1 are reserved, 0 is enable. */
        rcrb = (uint8_t *)(rcba & 0xffffc000);
        if (ctlr->ich_version == 7) {
                struct ich7_spi_regs *ich7_spi;

                ich7_spi = (struct ich7_spi_regs *)(rcrb + 0x3020);
                ctlr->ichspi_lock = ich_readw(&ich7_spi->spis) & SPIS_LOCK;
                ctlr->opmenu = ich7_spi->opmenu;
                ctlr->menubytes = sizeof(ich7_spi->opmenu);
                ctlr->optype = &ich7_spi->optype;
                ctlr->addr = &ich7_spi->spia;
                ctlr->data = (uint8_t *)ich7_spi->spid;
                ctlr->databytes = sizeof(ich7_spi->spid);
                ctlr->status = (uint8_t *)&ich7_spi->spis;
                ctlr->control = &ich7_spi->spic;
                ctlr->bbar = &ich7_spi->bbar;
                ctlr->preop = &ich7_spi->preop;
                ctlr->base = ich7_spi;
        } else if (ctlr->ich_version == 9) {
                struct ich9_spi_regs *ich9_spi;

                ich9_spi = (struct ich9_spi_regs *)(rcrb + 0x3800);
                ctlr->ichspi_lock = ich_readw(&ich9_spi->hsfs) & HSFS_FLOCKDN;
                ctlr->opmenu = ich9_spi->opmenu;
                ctlr->menubytes = sizeof(ich9_spi->opmenu);
                ctlr->optype = &ich9_spi->optype;
                ctlr->addr = &ich9_spi->faddr;
                ctlr->data = (uint8_t *)ich9_spi->fdata;
                ctlr->databytes = sizeof(ich9_spi->fdata);
                ctlr->status = &ich9_spi->ssfs;
                ctlr->control = (uint16_t *)ich9_spi->ssfc;
                ctlr->speed = ich9_spi->ssfc + 2;
                ctlr->bbar = &ich9_spi->bbar;
                ctlr->preop = &ich9_spi->preop;
                ctlr->pr = &ich9_spi->pr[0];
                ctlr->base = ich9_spi;
        } else {
                debug("ICH SPI: Unrecognized ICH version %d.\n",
                      ctlr->ich_version);
                return -1;
        }
        debug("ICH SPI: Version %d detected\n", ctlr->ich_version);

        /* Work out the maximum speed we can support */
        ctlr->max_speed = 20000000;
        if (ctlr->ich_version == 9 && ich9_can_do_33mhz(ctlr->dev))
                ctlr->max_speed = 33000000;

        ich_set_bbar(ctlr, 0);

        return 0;
}

void spi_init(void)
{
        uint8_t bios_cntl;

        if (ich_find_spi_controller(&ctlr.dev, &ctlr.ich_version)) {
                printf("ICH SPI: Cannot find device\n");
                return;
        }

        if (ich_init_controller(&ctlr)) {
                printf("ICH SPI: Cannot setup controller\n");
                return;
        }

        /*
         * Disable the BIOS write protect so write commands are allowed.  On
         * v9, deassert SMM BIOS Write Protect Disable.
         */
        pci_read_config_byte(ctlr.dev, 0xdc, &bios_cntl);
        if (ctlr.ich_version == 9)
                bios_cntl &= ~(1 << 5);
        pci_write_config_byte(ctlr.dev, 0xdc, bios_cntl | 0x1);
}

int spi_claim_bus(struct spi_slave *slave)
{
        /* Handled by ICH automatically. */
        return 0;
}

void spi_release_bus(struct spi_slave *slave)
{
        /* Handled by ICH automatically. */
}

void spi_cs_activate(struct spi_slave *slave)
{
        /* Handled by ICH automatically. */
}

void spi_cs_deactivate(struct spi_slave *slave)
{
        /* Handled by ICH automatically. */
}

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 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(trans->opcode, ctlr.opmenu);
                optypes = ich_readw(ctlr.optype);
                optypes = (optypes & 0xfffc) | (trans->type & 0x3);
                ich_writew(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.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 -1;
                }

                optypes = ich_readw(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 -1;
                }
                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 -1;
        }
}

/*
 * 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(u16 bitmask, int wait_til_set)
{
        int timeout = 600000; /* This will result in 6s */
        u16 status = 0;

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

        printf("ICH SPI: SCIP timeout, read %x, expected %x\n",
               status, bitmask);
        return -1;
}

/*
int spi_xfer(struct spi_slave *slave, const void *dout,
                unsigned int bitsout, void *din, unsigned int bitsin)
*/
int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
                void *din, unsigned long flags)
{
        struct ich_spi_slave *ich = to_ich_spi(slave);
        uint16_t control;
        int16_t opcode_index;
        int with_address;
        int status;
        int bytes = bitlen / 8;
        struct spi_trans *trans = &ich->trans;
        unsigned type = flags & (SPI_XFER_BEGIN | SPI_XFER_END);
        int using_cmd = 0;
        /* Align read transactions to 64-byte boundaries */
        char buff[ctlr.databytes];

        /* Ee don't support writing partial bytes. */
        if (bitlen % 8) {
                debug("ICH SPI: Accessing partial bytes not supported\n");
                return -1;
        }

        /* 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 -1;
                }
                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 -1;
        }

        if (ich_status_poll(SPIS_SCIP, 0) == -1)
                return -1;

        ich_writew(SPIS_CDS | SPIS_FCERR, ctlr.status);

        spi_setup_type(trans, using_cmd ? bytes : 0);
        opcode_index = spi_setup_opcode(trans);
        if (opcode_index < 0)
                return -1;
        with_address = spi_setup_offset(trans);
        if (with_address < 0)
                return -1;

        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(trans->opcode, ctlr.preop);
                return 0;
        }

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

                byte = ich_readb(ctlr.speed);
                if (ich->speed >= 33000000)
                        byte |= SSFC_SCF_33MHZ;
                else
                        byte &= ~SSFC_SCF_33MHZ;
                ich_writeb(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.control);
        control &= ~SSFC_RESERVED;
        control = SPIC_SCGO | ((opcode_index & 0x07) << 4);

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

        if (!trans->bytesout && !trans->bytesin) {
                /* SPI addresses are 24 bit only */
                if (with_address)
                        ich_writel(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(control, ctlr.control);

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

                if (status & SPIS_FCERR) {
                        debug("ICH SPI: Command transaction error\n");
                        return -1;
                }

                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 -1;
        }

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

                aligned_offset = trans->offset & ~(ctlr.databytes - 1);
                diff = trans->offset - aligned_offset;

                /* SPI addresses are 24 bit only */
                ich_writel(aligned_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(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(control, ctlr.control);

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

                if (status & SPIS_FCERR) {
                        debug("ICH SPI: Data transaction error\n");
                        return -1;
                }

                if (trans->bytesin) {
                        if (diff) {
                                data_length -= diff;
                                read_reg(ctlr.data, buff, ctlr.databytes);
                                memcpy(trans->in, buff + diff, data_length);
                        } else {
                                read_reg(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(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(uint32_t lower_limit, uint32_t length, int hint)
{
        uint32_t tmplong;
        uint32_t upper_limit;

        if (!ctlr.pr) {
                printf("%s: operation not supported on this chipset\n",
                       __func__);
                return -1;
        }

        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 -1;
        }

        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;
}