sk98lin: resurrect driver

This reverts commit e1abecc48938fbe1966ea6e78267fc673fa59295.

The driver works on some hardware that skge doesn't handle yet.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/sk98lin/skvpd.c b/drivers/net/sk98lin/skvpd.c
new file mode 100644
index 0000000..1e662aa
--- /dev/null
+++ b/drivers/net/sk98lin/skvpd.c
@@ -0,0 +1,1091 @@
+/******************************************************************************
+ *
+ * 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);
+}
+