Linux 2.6.20.7

[linux/fpc-iii.git] / drivers / net / sk98lin / skvpd.c

/******************************************************************************
 *
 * Name:        skvpd.c
 * Project:     GEnesis, PCI Gigabit Ethernet Adapter
 * Version:     $Revision: 1.37 $
 * Date:        $Date: 2003/01/13 10:42:45 $
 * Purpose:     Shared software to read and write VPD data
 *
 ******************************************************************************/

/******************************************************************************
 *
 *      (C)Copyright 1998-2003 SysKonnect GmbH.
 *
 *      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.
 *
 *      The information in this file is provided "AS IS" without warranty.
 *
 ******************************************************************************/

/*
        Please refer skvpd.txt for information how to include this module
 */
static const char SysKonnectFileId[] =
        "@(#)$Id: skvpd.c,v 1.37 2003/01/13 10:42:45 rschmidt Exp $ (C) SK";

#include "h/skdrv1st.h"
#include "h/sktypes.h"
#include "h/skdebug.h"
#include "h/skdrv2nd.h"

/*
 * Static functions
 */
#ifndef SK_KR_PROTO
static SK_VPD_PARA      *vpd_find_para(
        SK_AC   *pAC,
        const char      *key,
        SK_VPD_PARA *p);
#else   /* SK_KR_PROTO */
static SK_VPD_PARA      *vpd_find_para();
#endif  /* SK_KR_PROTO */

/*
 * waits for a completion of a VPD transfer
 * The VPD transfer must complete within SK_TICKS_PER_SEC/16
 *
 * returns      0:      success, transfer completes
 *              error   exit(9) with a error message
 */
static int VpdWait(
SK_AC   *pAC,   /* Adapters context */
SK_IOC  IoC,    /* IO Context */
int             event)  /* event to wait for (VPD_READ / VPD_write) completion*/
{
        SK_U64  start_time;
        SK_U16  state;

        SK_DBG_MSG(pAC,SK_DBGMOD_VPD, SK_DBGCAT_CTRL,
                ("VPD wait for %s\n", event?"Write":"Read"));
        start_time = SkOsGetTime(pAC);
        do {
                if (SkOsGetTime(pAC) - start_time > SK_TICKS_PER_SEC) {

                        /* Bug fix AF: Thu Mar 28 2002
                         * Do not call: VPD_STOP(pAC, IoC);
                         * A pending VPD read cycle can not be aborted by writing
                         * VPD_WRITE to the PCI_VPD_ADR_REG (VPD address register).
                         * Although the write threshold in the OUR-register protects
                         * VPD read only space from being overwritten this does not
                         * protect a VPD read from being `converted` into a VPD write
                         * operation (on the fly). As a consequence the VPD_STOP would
                         * delete VPD read only data. In case of any problems with the
                         * I2C bus we exit the loop here. The I2C read operation can
                         * not be aborted except by a reset (->LR).
                         */
                        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_FATAL | SK_DBGCAT_ERR,
                                ("ERROR:VPD wait timeout\n"));
                        return(1);
                }
                
                VPD_IN16(pAC, IoC, PCI_VPD_ADR_REG, &state);
                
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_CTRL,
                        ("state = %x, event %x\n",state,event));
        } while((int)(state & PCI_VPD_FLAG) == event);

        return(0);
}

#ifdef SKDIAG

/*
 * Read the dword at address 'addr' from the VPD EEPROM.
 *
 * Needed Time: MIN 1,3 ms      MAX 2,6 ms
 *
 * Note: The DWord is returned in the endianess of the machine the routine
 *       is running on.
 *
 * Returns the data read.
 */
SK_U32 VpdReadDWord(
SK_AC   *pAC,   /* Adapters context */
SK_IOC  IoC,    /* IO Context */
int             addr)   /* VPD address */
{
        SK_U32  Rtv;

        /* start VPD read */
        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_CTRL,
                ("VPD read dword at 0x%x\n",addr));
        addr &= ~VPD_WRITE;             /* ensure the R/W bit is set to read */

        VPD_OUT16(pAC, IoC, PCI_VPD_ADR_REG, (SK_U16)addr);

        /* ignore return code here */
        (void)VpdWait(pAC, IoC, VPD_READ);

        /* Don't swap here, it's a data stream of bytes */
        Rtv = 0;

        VPD_IN32(pAC, IoC, PCI_VPD_DAT_REG, &Rtv);
        
        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_CTRL,
                ("VPD read dword data = 0x%x\n",Rtv));
        return(Rtv);
}

#endif  /* SKDIAG */

/*
 *      Read one Stream of 'len' bytes of VPD data, starting at 'addr' from
 *      or to the I2C EEPROM.
 *
 * Returns number of bytes read / written.
 */
static int VpdWriteStream(
SK_AC   *pAC,   /* Adapters context */
SK_IOC  IoC,    /* IO Context */
char    *buf,   /* data buffer */
int             Addr,   /* VPD start address */
int             Len)    /* number of bytes to read / to write */
{
        int             i;
        int             j;
        SK_U16  AdrReg;
        int             Rtv;
        SK_U8   * pComp;        /* Compare pointer */
        SK_U8   Data;           /* Input Data for Compare */

        /* Init Compare Pointer */
        pComp = (SK_U8 *) buf;

        for (i = 0; i < Len; i++, buf++) {
                if ((i%sizeof(SK_U32)) == 0) {
                        /*
                         * At the begin of each cycle read the Data Reg
                         * So it is initialized even if only a few bytes
                         * are written.
                         */
                        AdrReg = (SK_U16) Addr;
                        AdrReg &= ~VPD_WRITE;   /* READ operation */

                        VPD_OUT16(pAC, IoC, PCI_VPD_ADR_REG, AdrReg);

                        /* Wait for termination */
                        Rtv = VpdWait(pAC, IoC, VPD_READ);
                        if (Rtv != 0) {
                                return(i);
                        }
                }

                /* Write current Byte */
                VPD_OUT8(pAC, IoC, PCI_VPD_DAT_REG + (i%sizeof(SK_U32)),
                                *(SK_U8*)buf);

                if (((i%sizeof(SK_U32)) == 3) || (i == (Len - 1))) {
                        /* New Address needs to be written to VPD_ADDR reg */
                        AdrReg = (SK_U16) Addr;
                        Addr += sizeof(SK_U32);
                        AdrReg |= VPD_WRITE;    /* WRITE operation */

                        VPD_OUT16(pAC, IoC, PCI_VPD_ADR_REG, AdrReg);

                        /* Wait for termination */
                        Rtv = VpdWait(pAC, IoC, VPD_WRITE);
                        if (Rtv != 0) {
                                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                                        ("Write Timed Out\n"));
                                return(i - (i%sizeof(SK_U32)));
                        }

                        /*
                         * Now re-read to verify
                         */
                        AdrReg &= ~VPD_WRITE;   /* READ operation */

                        VPD_OUT16(pAC, IoC, PCI_VPD_ADR_REG, AdrReg);

                        /* Wait for termination */
                        Rtv = VpdWait(pAC, IoC, VPD_READ);
                        if (Rtv != 0) {
                                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                                        ("Verify Timed Out\n"));
                                return(i - (i%sizeof(SK_U32)));
                        }

                        for (j = 0; j <= (int)(i%sizeof(SK_U32)); j++, pComp++) {
                                
                                VPD_IN8(pAC, IoC, PCI_VPD_DAT_REG + j, &Data);
                                
                                if (Data != *pComp) {
                                        /* Verify Error */
                                        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                                                ("WriteStream Verify Error\n"));
                                        return(i - (i%sizeof(SK_U32)) + j);
                                }
                        }
                }
        }

        return(Len);
}
        

/*
 *      Read one Stream of 'len' bytes of VPD data, starting at 'addr' from
 *      or to the I2C EEPROM.
 *
 * Returns number of bytes read / written.
 */
static int VpdReadStream(
SK_AC   *pAC,   /* Adapters context */
SK_IOC  IoC,    /* IO Context */
char    *buf,   /* data buffer */
int             Addr,   /* VPD start address */
int             Len)    /* number of bytes to read / to write */
{
        int             i;
        SK_U16  AdrReg;
        int             Rtv;

        for (i = 0; i < Len; i++, buf++) {
                if ((i%sizeof(SK_U32)) == 0) {
                        /* New Address needs to be written to VPD_ADDR reg */
                        AdrReg = (SK_U16) Addr;
                        Addr += sizeof(SK_U32);
                        AdrReg &= ~VPD_WRITE;   /* READ operation */

                        VPD_OUT16(pAC, IoC, PCI_VPD_ADR_REG, AdrReg);

                        /* Wait for termination */
                        Rtv = VpdWait(pAC, IoC, VPD_READ);
                        if (Rtv != 0) {
                                return(i);
                        }
                }
                VPD_IN8(pAC, IoC, PCI_VPD_DAT_REG + (i%sizeof(SK_U32)),
                        (SK_U8 *)buf);
        }

        return(Len);
}

/*
 *      Read ore writes 'len' bytes of VPD data, starting at 'addr' from
 *      or to the I2C EEPROM.
 *
 * Returns number of bytes read / written.
 */
static int VpdTransferBlock(
SK_AC   *pAC,   /* Adapters context */
SK_IOC  IoC,    /* IO Context */
char    *buf,   /* data buffer */
int             addr,   /* VPD start address */
int             len,    /* number of bytes to read / to write */
int             dir)    /* transfer direction may be VPD_READ or VPD_WRITE */
{
        int             Rtv;    /* Return value */
        int             vpd_rom_size;

        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_CTRL,
                ("VPD %s block, addr = 0x%x, len = %d\n",
                dir ? "write" : "read", addr, len));

        if (len == 0)
                return(0);

        vpd_rom_size = pAC->vpd.rom_size;
        
        if (addr > vpd_rom_size - 4) {
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR | SK_DBGCAT_FATAL,
                        ("Address error: 0x%x, exp. < 0x%x\n",
                        addr, vpd_rom_size - 4));
                return(0);
        }
        
        if (addr + len > vpd_rom_size) {
                len = vpd_rom_size - addr;
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                        ("Warning: len was cut to %d\n", len));
        }

        if (dir == VPD_READ) {
                Rtv = VpdReadStream(pAC, IoC, buf, addr, len);
        }
        else {
                Rtv = VpdWriteStream(pAC, IoC, buf, addr, len);
        }

        return(Rtv);
}

#ifdef SKDIAG

/*
 *      Read 'len' bytes of VPD data, starting at 'addr'.
 *
 * Returns number of bytes read.
 */
int VpdReadBlock(
SK_AC   *pAC,   /* pAC pointer */
SK_IOC  IoC,    /* IO Context */
char    *buf,   /* buffer were the data should be stored */
int             addr,   /* start reading at the VPD address */
int             len)    /* number of bytes to read */
{
        return(VpdTransferBlock(pAC, IoC, buf, addr, len, VPD_READ));
}

/*
 *      Write 'len' bytes of *but to the VPD EEPROM, starting at 'addr'.
 *
 * Returns number of bytes writes.
 */
int VpdWriteBlock(
SK_AC   *pAC,   /* pAC pointer */
SK_IOC  IoC,    /* IO Context */
char    *buf,   /* buffer, holds the data to write */
int             addr,   /* start writing at the VPD address */
int             len)    /* number of bytes to write */
{
        return(VpdTransferBlock(pAC, IoC, buf, addr, len, VPD_WRITE));
}
#endif  /* SKDIAG */

/*
 * (re)initialize the VPD buffer
 *
 * Reads the VPD data from the EEPROM into the VPD buffer.
 * Get the remaining read only and read / write space.
 *
 * return       0:      success
 *              1:      fatal VPD error
 */
static int VpdInit(
SK_AC   *pAC,   /* Adapters context */
SK_IOC  IoC)    /* IO Context */
{
        SK_VPD_PARA *r, rp;     /* RW or RV */
        int             i;
        unsigned char   x;
        int             vpd_size;
        SK_U16  dev_id;
        SK_U32  our_reg2;

        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_INIT, ("VpdInit .. "));
        
        VPD_IN16(pAC, IoC, PCI_DEVICE_ID, &dev_id);
        
        VPD_IN32(pAC, IoC, PCI_OUR_REG_2, &our_reg2);
        
        pAC->vpd.rom_size = 256 << ((our_reg2 & PCI_VPD_ROM_SZ) >> 14);
        
        /*
         * this function might get used before the hardware is initialized
         * therefore we cannot always trust in GIChipId
         */
        if (((pAC->vpd.v.vpd_status & VPD_VALID) == 0 &&
                dev_id != VPD_DEV_ID_GENESIS) ||
                ((pAC->vpd.v.vpd_status & VPD_VALID) != 0 &&
                !pAC->GIni.GIGenesis)) {

                /* for Yukon the VPD size is always 256 */
                vpd_size = VPD_SIZE_YUKON;
        }
        else {
                /* Genesis uses the maximum ROM size up to 512 for VPD */
                if (pAC->vpd.rom_size > VPD_SIZE_GENESIS) {
                        vpd_size = VPD_SIZE_GENESIS;
                }
                else {
                        vpd_size = pAC->vpd.rom_size;
                }
        }

        /* read the VPD data into the VPD buffer */
        if (VpdTransferBlock(pAC, IoC, pAC->vpd.vpd_buf, 0, vpd_size, VPD_READ)
                != vpd_size) {

                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                        ("Block Read Error\n"));
                return(1);
        }
        
        pAC->vpd.vpd_size = vpd_size;

        /* Asus K8V Se Deluxe bugfix. Correct VPD content */
        /* MBo April 2004 */
        if (((unsigned char)pAC->vpd.vpd_buf[0x3f] == 0x38) &&
            ((unsigned char)pAC->vpd.vpd_buf[0x40] == 0x3c) &&
            ((unsigned char)pAC->vpd.vpd_buf[0x41] == 0x45)) {
                printk("sk98lin: Asus mainboard with buggy VPD? "
                                "Correcting data.\n");
                pAC->vpd.vpd_buf[0x40] = 0x38;
        }


        /* find the end tag of the RO area */
        if (!(r = vpd_find_para(pAC, VPD_RV, &rp))) {
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR | SK_DBGCAT_FATAL,
                        ("Encoding Error: RV Tag not found\n"));
                return(1);
        }
        
        if (r->p_val + r->p_len > pAC->vpd.vpd_buf + vpd_size/2) {
                SK_DBG_MSG(pAC,SK_DBGMOD_VPD,SK_DBGCAT_ERR | SK_DBGCAT_FATAL,
                        ("Encoding Error: Invalid VPD struct size\n"));
                return(1);
        }
        pAC->vpd.v.vpd_free_ro = r->p_len - 1;

        /* test the checksum */
        for (i = 0, x = 0; (unsigned)i <= (unsigned)vpd_size/2 - r->p_len; i++) {
                x += pAC->vpd.vpd_buf[i];
        }
        
        if (x != 0) {
                /* checksum error */
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR | SK_DBGCAT_FATAL,
                        ("VPD Checksum Error\n"));
                return(1);
        }

        /* find and check the end tag of the RW area */
        if (!(r = vpd_find_para(pAC, VPD_RW, &rp))) {
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR | SK_DBGCAT_FATAL,
                        ("Encoding Error: RV Tag not found\n"));
                return(1);
        }
        
        if (r->p_val < pAC->vpd.vpd_buf + vpd_size/2) {
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR | SK_DBGCAT_FATAL,
                        ("Encoding Error: Invalid VPD struct size\n"));
                return(1);
        }
        pAC->vpd.v.vpd_free_rw = r->p_len;

        /* everything seems to be ok */
        if (pAC->GIni.GIChipId != 0) {
                pAC->vpd.v.vpd_status |= VPD_VALID;
        }

        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_INIT,
                ("done. Free RO = %d, Free RW = %d\n",
                pAC->vpd.v.vpd_free_ro, pAC->vpd.v.vpd_free_rw));

        return(0);
}

/*
 *      find the Keyword 'key' in the VPD buffer and fills the
 *      parameter struct 'p' with it's values
 *
 * returns      *p      success
 *              0:      parameter was not found or VPD encoding error
 */
static SK_VPD_PARA *vpd_find_para(
SK_AC           *pAC,   /* common data base */
const char      *key,   /* keyword to find (e.g. "MN") */
SK_VPD_PARA *p)         /* parameter description struct */
{
        char *v ;       /* points to VPD buffer */
        int max;        /* Maximum Number of Iterations */

        v = pAC->vpd.vpd_buf;
        max = 128;

        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_CTRL,
                ("VPD find para %s .. ",key));

        /* check mandatory resource type ID string (Product Name) */
        if (*v != (char)RES_ID) {
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR | SK_DBGCAT_FATAL,
                        ("Error: 0x%x missing\n", RES_ID));
                return NULL;
        }

        if (strcmp(key, VPD_NAME) == 0) {
                p->p_len = VPD_GET_RES_LEN(v);
                p->p_val = VPD_GET_VAL(v);
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_CTRL,
                        ("found, len = %d\n", p->p_len));
                return(p);
        }

        v += 3 + VPD_GET_RES_LEN(v) + 3;
        for (;; ) {
                if (SK_MEMCMP(key,v,2) == 0) {
                        p->p_len = VPD_GET_VPD_LEN(v);
                        p->p_val = VPD_GET_VAL(v);
                        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_CTRL,
                                ("found, len = %d\n",p->p_len));
                        return(p);
                }

                /* exit when reaching the "RW" Tag or the maximum of itera. */
                max--;
                if (SK_MEMCMP(VPD_RW,v,2) == 0 || max == 0) {
                        break;
                }

                if (SK_MEMCMP(VPD_RV,v,2) == 0) {
                        v += 3 + VPD_GET_VPD_LEN(v) + 3;        /* skip VPD-W */
                }
                else {
                        v += 3 + VPD_GET_VPD_LEN(v);
                }
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_CTRL,
                        ("scanning '%c%c' len = %d\n",v[0],v[1],v[2]));
        }

#ifdef DEBUG
        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_CTRL, ("not found\n"));
        if (max == 0) {
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR | SK_DBGCAT_FATAL,
                        ("Key/Len Encoding error\n"));
        }
#endif /* DEBUG */
        return NULL;
}

/*
 *      Move 'n' bytes. Begin with the last byte if 'n' is > 0,
 *      Start with the last byte if n is < 0.
 *
 * returns nothing
 */
static void vpd_move_para(
char    *start,         /* start of memory block */
char    *end,           /* end of memory block to move */
int             n)                      /* number of bytes the memory block has to be moved */
{
        char *p;
        int i;          /* number of byte copied */

        if (n == 0)
                return;

        i = (int) (end - start + 1);
        if (n < 0) {
                p = start + n;
                while (i != 0) {
                        *p++ = *start++;
                        i--;
                }
        }
        else {
                p = end + n;
                while (i != 0) {
                        *p-- = *end--;
                        i--;
                }
        }
}

/*
 *      setup the VPD keyword 'key' at 'ip'.
 *
 * returns nothing
 */
static void vpd_insert_key(
const char      *key,   /* keyword to insert */
const char      *buf,   /* buffer with the keyword value */
int             len,            /* length of the value string */
char    *ip)            /* inseration point */
{
        SK_VPD_KEY *p;

        p = (SK_VPD_KEY *) ip;
        p->p_key[0] = key[0];
        p->p_key[1] = key[1];
        p->p_len = (unsigned char) len;
        SK_MEMCPY(&p->p_val,buf,len);
}

/*
 *      Setup the VPD end tag "RV" / "RW".
 *      Also correct the remaining space variables vpd_free_ro / vpd_free_rw.
 *
 * returns      0:      success
 *              1:      encoding error
 */
static int vpd_mod_endtag(
SK_AC   *pAC,           /* common data base */
char    *etp)           /* end pointer input position */
{
        SK_VPD_KEY *p;
        unsigned char   x;
        int     i;
        int     vpd_size;

        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_CTRL,
                ("VPD modify endtag at 0x%x = '%c%c'\n",etp,etp[0],etp[1]));

        vpd_size = pAC->vpd.vpd_size;

        p = (SK_VPD_KEY *) etp;

        if (p->p_key[0] != 'R' || (p->p_key[1] != 'V' && p->p_key[1] != 'W')) {
                /* something wrong here, encoding error */
                SK_DBG_MSG(pAC,SK_DBGMOD_VPD,SK_DBGCAT_ERR | SK_DBGCAT_FATAL,
                        ("Encoding Error: invalid end tag\n"));
                return(1);
        }
        if (etp > pAC->vpd.vpd_buf + vpd_size/2) {
                /* create "RW" tag */
                p->p_len = (unsigned char)(pAC->vpd.vpd_buf+vpd_size-etp-3-1);
                pAC->vpd.v.vpd_free_rw = (int) p->p_len;
                i = pAC->vpd.v.vpd_free_rw;
                etp += 3;
        }
        else {
                /* create "RV" tag */
                p->p_len = (unsigned char)(pAC->vpd.vpd_buf+vpd_size/2-etp-3);
                pAC->vpd.v.vpd_free_ro = (int) p->p_len - 1;

                /* setup checksum */
                for (i = 0, x = 0; i < vpd_size/2 - p->p_len; i++) {
                        x += pAC->vpd.vpd_buf[i];
                }
                p->p_val = (char) 0 - x;
                i = pAC->vpd.v.vpd_free_ro;
                etp += 4;
        }
        while (i) {
                *etp++ = 0x00;
                i--;
        }

        return(0);
}

/*
 *      Insert a VPD keyword into the VPD buffer.
 *
 *      The keyword 'key' is inserted at the position 'ip' in the
 *      VPD buffer.
 *      The keywords behind the input position will
 *      be moved. The VPD end tag "RV" or "RW" is generated again.
 *
 * returns      0:      success
 *              2:      value string was cut
 *              4:      VPD full, keyword was not written
 *              6:      fatal VPD error
 *
 */
static int      VpdSetupPara(
SK_AC   *pAC,           /* common data base */
const char      *key,   /* keyword to insert */
const char      *buf,   /* buffer with the keyword value */
int             len,            /* length of the keyword value */
int             type,           /* VPD_RO_KEY or VPD_RW_KEY */
int             op)                     /* operation to do: ADD_KEY or OWR_KEY */
{
        SK_VPD_PARA vp;
        char    *etp;           /* end tag position */
        int     free;           /* remaining space in selected area */
        char    *ip;            /* input position inside the VPD buffer */
        int     rtv;            /* return code */
        int     head;           /* additional haeder bytes to move */
        int     found;          /* additinoal bytes if the keyword was found */
        int vpd_size;

        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_CTRL,
                ("VPD setup para key = %s, val = %s\n",key,buf));
        
        vpd_size = pAC->vpd.vpd_size;

        rtv = 0;
        ip = NULL;
        if (type == VPD_RW_KEY) {
                /* end tag is "RW" */
                free = pAC->vpd.v.vpd_free_rw;
                etp = pAC->vpd.vpd_buf + (vpd_size - free - 1 - 3);
        }
        else {
                /* end tag is "RV" */
                free = pAC->vpd.v.vpd_free_ro;
                etp = pAC->vpd.vpd_buf + (vpd_size/2 - free - 4);
        }
        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_CTRL,
                ("Free RO = %d, Free RW = %d\n",
                pAC->vpd.v.vpd_free_ro, pAC->vpd.v.vpd_free_rw));

        head = 0;
        found = 0;
        if (op == OWR_KEY) {
                if (vpd_find_para(pAC, key, &vp)) {
                        found = 3;
                        ip = vp.p_val - 3;
                        free += vp.p_len + 3;
                        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_CTRL,
                                ("Overwrite Key\n"));
                }
                else {
                        op = ADD_KEY;
                        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_CTRL,
                                ("Add Key\n"));
                }
        }
        if (op == ADD_KEY) {
                ip = etp;
                vp.p_len = 0;
                head = 3;
        }

        if (len + 3 > free) {
                if (free < 7) {
                        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                                ("VPD Buffer Overflow, keyword not written\n"));
                        return(4);
                }
                /* cut it again */
                len = free - 3;
                rtv = 2;
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                        ("VPD Buffer Full, Keyword was cut\n"));
        }

        vpd_move_para(ip + vp.p_len + found, etp+2, len-vp.p_len+head);
        vpd_insert_key(key, buf, len, ip);
        if (vpd_mod_endtag(pAC, etp + len - vp.p_len + head)) {
                pAC->vpd.v.vpd_status &= ~VPD_VALID;
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                        ("VPD Encoding Error\n"));
                return(6);
        }

        return(rtv);
}


/*
 *      Read the contents of the VPD EEPROM and copy it to the
 *      VPD buffer if not already done.
 *
 * return:      A pointer to the vpd_status structure. The structure contains
 *              this fields.
 */
SK_VPD_STATUS *VpdStat(
SK_AC   *pAC,   /* Adapters context */
SK_IOC  IoC)    /* IO Context */
{
        if ((pAC->vpd.v.vpd_status & VPD_VALID) == 0) {
                (void)VpdInit(pAC, IoC);
        }
        return(&pAC->vpd.v);
}


/*
 *      Read the contents of the VPD EEPROM and copy it to the VPD
 *      buffer if not already done.
 *      Scan the VPD buffer for VPD keywords and create the VPD
 *      keyword list by copying the keywords to 'buf', all after
 *      each other and terminated with a '\0'.
 *
 * Exceptions:  o The Resource Type ID String (product name) is called "Name"
 *              o The VPD end tags 'RV' and 'RW' are not listed
 *
 *      The number of copied keywords is counted in 'elements'.
 *
 * returns      0:      success
 *              2:      buffer overfull, one or more keywords are missing
 *              6:      fatal VPD error
 *
 *      example values after returning:
 *
 *              buf =   "Name\0PN\0EC\0MN\0SN\0CP\0VF\0VL\0YA\0"
 *              *len =          30
 *              *elements =      9
 */
int VpdKeys(
SK_AC   *pAC,           /* common data base */
SK_IOC  IoC,            /* IO Context */
char    *buf,           /* buffer where to copy the keywords */
int             *len,           /* buffer length */
int             *elements)      /* number of keywords returned */
{
        char *v;
        int n;

        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_RX, ("list VPD keys .. "));
        *elements = 0;
        if ((pAC->vpd.v.vpd_status & VPD_VALID) == 0) {
                if (VpdInit(pAC, IoC) != 0) {
                        *len = 0;
                        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                                ("VPD Init Error, terminated\n"));
                        return(6);
                }
        }

        if ((signed)strlen(VPD_NAME) + 1 <= *len) {
                v = pAC->vpd.vpd_buf;
                strcpy(buf,VPD_NAME);
                n = strlen(VPD_NAME) + 1;
                buf += n;
                *elements = 1;
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_RX,
                        ("'%c%c' ",v[0],v[1]));
        }
        else {
                *len = 0;
                SK_DBG_MSG(pAC,SK_DBGMOD_VPD,SK_DBGCAT_ERR,
                        ("buffer overflow\n"));
                return(2);
        }

        v += 3 + VPD_GET_RES_LEN(v) + 3;
        for (;; ) {
                /* exit when reaching the "RW" Tag */
                if (SK_MEMCMP(VPD_RW,v,2) == 0) {
                        break;
                }

                if (SK_MEMCMP(VPD_RV,v,2) == 0) {
                        v += 3 + VPD_GET_VPD_LEN(v) + 3;        /* skip VPD-W */
                        continue;
                }

                if (n+3 <= *len) {
                        SK_MEMCPY(buf,v,2);
                        buf += 2;
                        *buf++ = '\0';
                        n += 3;
                        v += 3 + VPD_GET_VPD_LEN(v);
                        *elements += 1;
                        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_RX,
                                ("'%c%c' ",v[0],v[1]));
                }
                else {
                        *len = n;
                        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                                ("buffer overflow\n"));
                        return(2);
                }
        }

        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_RX, ("\n"));
        *len = n;
        return(0);
}


/*
 *      Read the contents of the VPD EEPROM and copy it to the
 *      VPD buffer if not already done. Search for the VPD keyword
 *      'key' and copy its value to 'buf'. Add a terminating '\0'.
 *      If the value does not fit into the buffer cut it after
 *      'len' - 1 bytes.
 *
 * returns      0:      success
 *              1:      keyword not found
 *              2:      value string was cut
 *              3:      VPD transfer timeout
 *              6:      fatal VPD error
 */
int VpdRead(
SK_AC           *pAC,   /* common data base */
SK_IOC          IoC,    /* IO Context */
const char      *key,   /* keyword to read (e.g. "MN") */
char            *buf,   /* buffer where to copy the keyword value */
int                     *len)   /* buffer length */
{
        SK_VPD_PARA *p, vp;

        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_RX, ("VPD read %s .. ", key));
        if ((pAC->vpd.v.vpd_status & VPD_VALID) == 0) {
                if (VpdInit(pAC, IoC) != 0) {
                        *len = 0;
                        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                                ("VPD init error\n"));
                        return(6);
                }
        }

        if ((p = vpd_find_para(pAC, key, &vp)) != NULL) {
                if (p->p_len > (*(unsigned *)len)-1) {
                        p->p_len = *len - 1;
                }
                SK_MEMCPY(buf, p->p_val, p->p_len);
                buf[p->p_len] = '\0';
                *len = p->p_len;
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_RX,
                        ("%c%c%c%c.., len = %d\n",
                        buf[0],buf[1],buf[2],buf[3],*len));
        }
        else {
                *len = 0;
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR, ("not found\n"));
                return(1);
        }
        return(0);
}


/*
 *      Check whether a given key may be written
 *
 * returns
 *      SK_TRUE         Yes it may be written
 *      SK_FALSE        No it may be written
 */
SK_BOOL VpdMayWrite(
char    *key)   /* keyword to write (allowed values "Yx", "Vx") */
{
        if ((*key != 'Y' && *key != 'V') ||
                key[1] < '0' || key[1] > 'Z' ||
                (key[1] > '9' && key[1] < 'A') || strlen(key) != 2) {

                return(SK_FALSE);
        }
        return(SK_TRUE);
}

/*
 *      Read the contents of the VPD EEPROM and copy it to the VPD
 *      buffer if not already done. Insert/overwrite the keyword 'key'
 *      in the VPD buffer. Cut the keyword value if it does not fit
 *      into the VPD read / write area.
 *
 * returns      0:      success
 *              2:      value string was cut
 *              3:      VPD transfer timeout
 *              4:      VPD full, keyword was not written
 *              5:      keyword cannot be written
 *              6:      fatal VPD error
 */
int VpdWrite(
SK_AC           *pAC,   /* common data base */
SK_IOC          IoC,    /* IO Context */
const char      *key,   /* keyword to write (allowed values "Yx", "Vx") */
const char      *buf)   /* buffer where the keyword value can be read from */
{
        int len;                /* length of the keyword to write */
        int rtv;                /* return code */
        int rtv2;

        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_TX,
                ("VPD write %s = %s\n",key,buf));

        if ((*key != 'Y' && *key != 'V') ||
                key[1] < '0' || key[1] > 'Z' ||
                (key[1] > '9' && key[1] < 'A') || strlen(key) != 2) {

                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                        ("illegal key tag, keyword not written\n"));
                return(5);
        }

        if ((pAC->vpd.v.vpd_status & VPD_VALID) == 0) {
                if (VpdInit(pAC, IoC) != 0) {
                        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                                ("VPD init error\n"));
                        return(6);
                }
        }

        rtv = 0;
        len = strlen(buf);
        if (len > VPD_MAX_LEN) {
                /* cut it */
                len = VPD_MAX_LEN;
                rtv = 2;
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                        ("keyword too long, cut after %d bytes\n",VPD_MAX_LEN));
        }
        if ((rtv2 = VpdSetupPara(pAC, key, buf, len, VPD_RW_KEY, OWR_KEY)) != 0) {
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                        ("VPD write error\n"));
                return(rtv2);
        }

        return(rtv);
}

/*
 *      Read the contents of the VPD EEPROM and copy it to the
 *      VPD buffer if not already done. Remove the VPD keyword
 *      'key' from the VPD buffer.
 *      Only the keywords in the read/write area can be deleted.
 *      Keywords in the read only area cannot be deleted.
 *
 * returns      0:      success, keyword was removed
 *              1:      keyword not found
 *              5:      keyword cannot be deleted
 *              6:      fatal VPD error
 */
int VpdDelete(
SK_AC   *pAC,   /* common data base */
SK_IOC  IoC,    /* IO Context */
char    *key)   /* keyword to read (e.g. "MN") */
{
        SK_VPD_PARA *p, vp;
        char *etp;
        int     vpd_size;

        vpd_size = pAC->vpd.vpd_size;

        SK_DBG_MSG(pAC,SK_DBGMOD_VPD,SK_DBGCAT_TX,("VPD delete key %s\n",key));
        if ((pAC->vpd.v.vpd_status & VPD_VALID) == 0) {
                if (VpdInit(pAC, IoC) != 0) {
                        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                                ("VPD init error\n"));
                        return(6);
                }
        }

        if ((p = vpd_find_para(pAC, key, &vp)) != NULL) {
                if (p->p_val < pAC->vpd.vpd_buf + vpd_size/2) {
                        /* try to delete read only keyword */
                        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                                ("cannot delete RO keyword\n"));
                        return(5);
                }

                etp = pAC->vpd.vpd_buf + (vpd_size-pAC->vpd.v.vpd_free_rw-1-3);

                vpd_move_para(vp.p_val+vp.p_len, etp+2,
                        - ((int)(vp.p_len + 3)));
                if (vpd_mod_endtag(pAC, etp - vp.p_len - 3)) {
                        pAC->vpd.v.vpd_status &= ~VPD_VALID;
                        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                                ("VPD encoding error\n"));
                        return(6);
                }
        }
        else {
                SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                        ("keyword not found\n"));
                return(1);
        }

        return(0);
}

/*
 *      If the VPD buffer contains valid data write the VPD
 *      read/write area back to the VPD EEPROM.
 *
 * returns      0:      success
 *              3:      VPD transfer timeout
 */
int VpdUpdate(
SK_AC   *pAC,   /* Adapters context */
SK_IOC  IoC)    /* IO Context */
{
        int vpd_size;

        vpd_size = pAC->vpd.vpd_size;

        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_TX, ("VPD update .. "));
        if ((pAC->vpd.v.vpd_status & VPD_VALID) != 0) {
                if (VpdTransferBlock(pAC, IoC, pAC->vpd.vpd_buf + vpd_size/2,
                        vpd_size/2, vpd_size/2, VPD_WRITE) != vpd_size/2) {

                        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_ERR,
                                ("transfer timed out\n"));
                        return(3);
                }
        }
        SK_DBG_MSG(pAC, SK_DBGMOD_VPD, SK_DBGCAT_TX, ("done\n"));
        return(0);
}