/*
 * Copyright (c) 2012 Intel Corporation. All rights reserved.
 * Copyright (c) 2006 - 2012 QLogic Corporation. All rights reserved.
 * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/vmalloc.h>

#include "qib.h"

/*
 * Functions specific to the serial EEPROM on cards handled by ib_qib.
 * The actual serail interface code is in qib_twsi.c. This file is a client
 */

/**
 * qib_eeprom_read - receives bytes from the eeprom via I2C
 * @dd: the qlogic_ib device
 * @eeprom_offset: address to read from
 * @buffer: where to store result
 * @len: number of bytes to receive
 */
int qib_eeprom_read(struct qib_devdata *dd, u8 eeprom_offset,
                    void *buff, int len)
{
        int ret;

        ret = mutex_lock_interruptible(&dd->eep_lock);
        if (!ret) {
                ret = qib_twsi_reset(dd);
                if (ret)
                        qib_dev_err(dd, "EEPROM Reset for read failed\n");
                else
                        ret = qib_twsi_blk_rd(dd, dd->twsi_eeprom_dev,
                                              eeprom_offset, buff, len);
                mutex_unlock(&dd->eep_lock);
        }

        return ret;
}

/*
 * Actually update the eeprom, first doing write enable if
 * needed, then restoring write enable state.
 * Must be called with eep_lock held
 */
static int eeprom_write_with_enable(struct qib_devdata *dd, u8 offset,
                     const void *buf, int len)
{
        int ret, pwen;

        pwen = dd->f_eeprom_wen(dd, 1);
        ret = qib_twsi_reset(dd);
        if (ret)
                qib_dev_err(dd, "EEPROM Reset for write failed\n");
        else
                ret = qib_twsi_blk_wr(dd, dd->twsi_eeprom_dev,
                                      offset, buf, len);
        dd->f_eeprom_wen(dd, pwen);
        return ret;
}

/**
 * qib_eeprom_write - writes data to the eeprom via I2C
 * @dd: the qlogic_ib device
 * @eeprom_offset: where to place data
 * @buffer: data to write
 * @len: number of bytes to write
 */
int qib_eeprom_write(struct qib_devdata *dd, u8 eeprom_offset,
                     const void *buff, int len)
{
        int ret;

        ret = mutex_lock_interruptible(&dd->eep_lock);
        if (!ret) {
                ret = eeprom_write_with_enable(dd, eeprom_offset, buff, len);
                mutex_unlock(&dd->eep_lock);
        }

        return ret;
}

static u8 flash_csum(struct qib_flash *ifp, int adjust)
{
        u8 *ip = (u8 *) ifp;
        u8 csum = 0, len;

        /*
         * Limit length checksummed to max length of actual data.
         * Checksum of erased eeprom will still be bad, but we avoid
         * reading past the end of the buffer we were passed.
         */
        len = ifp->if_length;
        if (len > sizeof(struct qib_flash))
                len = sizeof(struct qib_flash);
        while (len--)
                csum += *ip++;
        csum -= ifp->if_csum;
        csum = ~csum;
        if (adjust)
                ifp->if_csum = csum;

        return csum;
}

/**
 * qib_get_eeprom_info- get the GUID et al. from the TSWI EEPROM device
 * @dd: the qlogic_ib device
 *
 * We have the capability to use the nguid field, and get
 * the guid from the first chip's flash, to use for all of them.
 */
void qib_get_eeprom_info(struct qib_devdata *dd)
{
        void *buf;
        struct qib_flash *ifp;
        __be64 guid;
        int len, eep_stat;
        u8 csum, *bguid;
        int t = dd->unit;
        struct qib_devdata *dd0 = qib_lookup(0);

        if (t && dd0->nguid > 1 && t <= dd0->nguid) {
                u8 oguid;

                dd->base_guid = dd0->base_guid;
                bguid = (u8 *) &dd->base_guid;

                oguid = bguid[7];
                bguid[7] += t;
                if (oguid > bguid[7]) {
                        if (bguid[6] == 0xff) {
                                if (bguid[5] == 0xff) {
                                        qib_dev_err(dd,
                                                    "Can't set GUID from base, wraps to OUI!\n");
                                        dd->base_guid = 0;
                                        goto bail;
                                }
                                bguid[5]++;
                        }
                        bguid[6]++;
                }
                dd->nguid = 1;
                goto bail;
        }

        /*
         * Read full flash, not just currently used part, since it may have
         * been written with a newer definition.
         * */
        len = sizeof(struct qib_flash);
        buf = vmalloc(len);
        if (!buf)
                goto bail;

        /*
         * Use "public" eeprom read function, which does locking and
         * figures out device. This will migrate to chip-specific.
         */
        eep_stat = qib_eeprom_read(dd, 0, buf, len);

        if (eep_stat) {
                qib_dev_err(dd, "Failed reading GUID from eeprom\n");
                goto done;
        }
        ifp = (struct qib_flash *)buf;

        csum = flash_csum(ifp, 0);
        if (csum != ifp->if_csum) {
                qib_devinfo(dd->pcidev,
                        "Bad I2C flash checksum: 0x%x, not 0x%x\n",
                        csum, ifp->if_csum);
                goto done;
        }
        if (*(__be64 *) ifp->if_guid == cpu_to_be64(0) ||
            *(__be64 *) ifp->if_guid == ~cpu_to_be64(0)) {
                qib_dev_err(dd,
                        "Invalid GUID %llx from flash; ignoring\n",
                        *(unsigned long long *) ifp->if_guid);
                /* don't allow GUID if all 0 or all 1's */
                goto done;
        }

        /* complain, but allow it */
        if (*(u64 *) ifp->if_guid == 0x100007511000000ULL)
                qib_devinfo(dd->pcidev,
                        "Warning, GUID %llx is default, probably not correct!\n",
                        *(unsigned long long *) ifp->if_guid);

        bguid = ifp->if_guid;
        if (!bguid[0] && !bguid[1] && !bguid[2]) {
                /*
                 * Original incorrect GUID format in flash; fix in
                 * core copy, by shifting up 2 octets; don't need to
                 * change top octet, since both it and shifted are 0.
                 */
                bguid[1] = bguid[3];
                bguid[2] = bguid[4];
                bguid[3] = 0;
                bguid[4] = 0;
                guid = *(__be64 *) ifp->if_guid;
        } else
                guid = *(__be64 *) ifp->if_guid;
        dd->base_guid = guid;
        dd->nguid = ifp->if_numguid;
        /*
         * Things are slightly complicated by the desire to transparently
         * support both the Pathscale 10-digit serial number and the QLogic
         * 13-character version.
         */
        if ((ifp->if_fversion > 1) && ifp->if_sprefix[0] &&
            ((u8 *) ifp->if_sprefix)[0] != 0xFF) {
                char *snp = dd->serial;

                /*
                 * This board has a Serial-prefix, which is stored
                 * elsewhere for backward-compatibility.
                 */
                memcpy(snp, ifp->if_sprefix, sizeof(ifp->if_sprefix));
                snp[sizeof(ifp->if_sprefix)] = '\0';
                len = strlen(snp);
                snp += len;
                len = sizeof(dd->serial) - len;
                if (len > sizeof(ifp->if_serial))
                        len = sizeof(ifp->if_serial);
                memcpy(snp, ifp->if_serial, len);
        } else {
                memcpy(dd->serial, ifp->if_serial, sizeof(ifp->if_serial));
        }
        if (!strstr(ifp->if_comment, "Tested successfully"))
                qib_dev_err(dd,
                        "Board SN %s did not pass functional test: %s\n",
                        dd->serial, ifp->if_comment);

done:
        vfree(buf);

bail:;
}