/*  $Id$
 *  1993/03/31
 *  linux/kernel/aha1740.c
 *
 *  Based loosely on aha1542.c which is
 *  Copyright (C) 1992  Tommy Thorn and
 *  Modified by Eric Youngdale
 *
 *  This file is aha1740.c, written and
 *  Copyright (C) 1992,1993  Brad McLean
 *  
 *  Modifications to makecode and queuecommand
 *  for proper handling of multiple devices courteously
 *  provided by Michael Weller, March, 1993
 *
 *  Multiple adapter support, extended translation detection,
 *  update to current scsi subsystem changes, proc fs support,
 *  working (!) module support based on patches from Andreas Arens,
 *  by Andreas Degert <ad@papyrus.hamburg.com>, 2/1997
 *
 * aha1740_makecode may still need even more work
 * if it doesn't work for your devices, take a look.
 */

#ifdef MODULE
#include <linux/module.h>
#endif

#include <linux/kernel.h>
#include <linux/head.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/proc_fs.h>
#include <linux/sched.h>
#include <asm/dma.h>

#include <asm/system.h>
#include <asm/io.h>
#include <linux/blk.h>
#include "scsi.h"
#include "hosts.h"
#include "sd.h"

#include "aha1740.h"
#include<linux/stat.h>

struct proc_dir_entry proc_scsi_aha1740 = {
    PROC_SCSI_AHA1740, 7, "aha1740",
    S_IFDIR | S_IRUGO | S_IXUGO, 2
};

/* IF YOU ARE HAVING PROBLEMS WITH THIS DRIVER, AND WANT TO WATCH
   IT WORK, THEN:
#define DEBUG
*/
#ifdef DEBUG
#define DEB(x) x
#else
#define DEB(x)
#endif

/*
static const char RCSid[] = "$Header: /usr/src/linux/kernel/blk_drv/scsi/RCS/aha1740.c,v 1.1 1992/07/24 06:27:38 root Exp root $";
*/

struct aha1740_hostdata {
    unsigned int slot;
    unsigned int translation;
    unsigned int last_ecb_used;
    struct ecb ecb[AHA1740_ECBS];
};

#define HOSTDATA(host) ((struct aha1740_hostdata *) &host->hostdata)

/* One for each IRQ level (9-15) */
static struct Scsi_Host * aha_host[8] = {NULL, };

int aha1740_proc_info(char *buffer, char **start, off_t offset,
		      int length, int hostno, int inout)
{
    int len;
    struct Scsi_Host * shpnt;
    struct aha1740_hostdata *host;

    if (inout)
	return(-ENOSYS);

    for (len = 0; len < 8; len++) {
	shpnt = aha_host[len];
	if (shpnt && shpnt->host_no == hostno)
	    break;
    }
    host = HOSTDATA(shpnt);

    len = sprintf(buffer, "aha174x at IO:%lx, IRQ %d, SLOT %d.\n"
		  "Extended translation %sabled.\n",
		  shpnt->io_port, shpnt->irq, host->slot,
		  host->translation ? "en" : "dis");

    if (offset > len) {
	*start = buffer;
	return 0;
    }

    *start = buffer + offset;
    len -= offset;
    if (len > length)
	len = length;
    return len;
}


int aha1740_makecode(unchar *sense, unchar *status)
{
    struct statusword
    {
	ushort	don:1,	/* Command Done - No Error */
		du:1,	/* Data underrun */
	:1,	qf:1,	/* Queue full */
		sc:1,	/* Specification Check */
		dor:1,	/* Data overrun */
		ch:1,	/* Chaining Halted */
		intr:1,	/* Interrupt issued */
		asa:1,	/* Additional Status Available */
		sns:1,	/* Sense information Stored */
	:1,	ini:1,	/* Initialization Required */
		me:1,	/* Major error or exception */
	:1,	eca:1,  /* Extended Contingent alliance */
	:1;
    } status_word;
    int retval = DID_OK;

    status_word = * (struct statusword *) status;
#ifdef DEBUG
    printk("makecode from %x,%x,%x,%x %x,%x,%x,%x",
	   status[0], status[1], status[2], status[3],
	   sense[0], sense[1], sense[2], sense[3]);
#endif
    if (!status_word.don) /* Anything abnormal was detected */
    {
	if ( (status[1]&0x18) || status_word.sc ) /*Additional info available*/
	{
	    /* Use the supplied info for further diagnostics */
	    switch ( status[2] )
	    {
	    case 0x12:
		if ( status_word.dor )
		    retval=DID_ERROR;	/* It's an Overrun */
		/* If not overrun, assume underrun and ignore it! */
	    case 0x00: /* No info, assume no error, should not occur */
		break;
	    case 0x11:
	    case 0x21:
		retval=DID_TIME_OUT;
		break;
	    case 0x0a:
		retval=DID_BAD_TARGET;
		break;
	    case 0x04:
	    case 0x05:
		retval=DID_ABORT;
		/* Either by this driver or the AHA1740 itself */
		break;
	    default:
		retval=DID_ERROR; /* No further diagnostics possible */
	    } 
	}
	else
	{ /* Michael suggests, and Brad concurs: */
	    if ( status_word.qf )
	    {
		retval = DID_TIME_OUT; /* forces a redo */
		/* I think this specific one should not happen -Brad */
		printk("aha1740.c: WARNING: AHA1740 queue overflow!\n");
	    }
	    else if ( status[0]&0x60 )
	    {
		retval = DID_ERROR; /* Didn't find a better error */
	    }
	    /* In any other case return DID_OK so for example
	       CONDITION_CHECKS make it through to the appropriate
	       device driver */
	}
    }
    /* Under all circumstances supply the target status -Michael */
    return status[3] | retval << 16;
}

int aha1740_test_port(unsigned int base)
{
    char name[4], tmp;

    /* Okay, look for the EISA ID's */
    name[0]= 'A' -1 + ((tmp = inb(HID0(base))) >> 2); /* First character */
    name[1]= 'A' -1 + ((tmp & 3) << 3);
    name[1]+= ((tmp = inb(HID1(base))) >> 5)&0x7;	/* Second Character */
    name[2]= 'A' -1 + (tmp & 0x1f);		/* Third Character */
    name[3]=0;
    tmp = inb(HID2(base));
    if ( strcmp ( name, HID_MFG ) || inb(HID2(base)) != HID_PRD )
	return 0;   /* Not an Adaptec 174x */

/*  if ( inb(HID3(base)) != HID_REV )
	printk("aha174x: Warning; board revision of %d; expected %d\n",
	    inb(HID3(base)),HID_REV); */

    if ( inb(EBCNTRL(base)) != EBCNTRL_VALUE )
    {
	printk("aha174x: Board detected, but EBCNTRL = %x, so disabled it.\n",
	    inb(EBCNTRL(base)));
	return 0;
    }

    if ( inb(PORTADR(base)) & PORTADDR_ENH )
	return 1;   /* Okay, we're all set */
	
    printk("aha174x: Board detected, but not in enhanced mode, so disabled it.\n");
    return 0;
}

/* A "high" level interrupt handler */
void aha1740_intr_handle(int irq, void *dev_id, struct pt_regs * regs)
{
    void (*my_done)(Scsi_Cmnd *);
    int errstatus, adapstat;
    int number_serviced;
    struct ecb *ecbptr;
    Scsi_Cmnd *SCtmp;
    unsigned int base;
    unsigned long flags;

    spin_lock_irqsave(&io_request_lock, flags);

    if (!aha_host[irq - 9])
	panic("aha1740.c: Irq from unknown host!\n");
    base = aha_host[irq - 9]->io_port;
    number_serviced = 0;

    while(inb(G2STAT(base)) & G2STAT_INTPEND)
    {
	DEB(printk("aha1740_intr top of loop.\n"));
	adapstat = inb(G2INTST(base));
	ecbptr = (struct ecb *) bus_to_virt(inl(MBOXIN0(base)));
	outb(G2CNTRL_IRST,G2CNTRL(base)); /* interrupt reset */
      
	switch ( adapstat & G2INTST_MASK )
	{
	case	G2INTST_CCBRETRY:
	case	G2INTST_CCBERROR:
	case	G2INTST_CCBGOOD:
	    /* Host Ready -> Mailbox in complete */
	    outb(G2CNTRL_HRDY,G2CNTRL(base));
	    if (!ecbptr)
	    {
		printk("Aha1740 null ecbptr in interrupt (%x,%x,%x,%d)\n",
		       inb(G2STAT(base)),adapstat,
		       inb(G2INTST(base)), number_serviced++);
		continue;
	    }
	    SCtmp = ecbptr->SCpnt;
	    if (!SCtmp)
	    {
		printk("Aha1740 null SCtmp in interrupt (%x,%x,%x,%d)\n",
		       inb(G2STAT(base)),adapstat,
		       inb(G2INTST(base)), number_serviced++);
		continue;
	    }
	    if (SCtmp->host_scribble)
		scsi_free(SCtmp->host_scribble, 512);
	    /* Fetch the sense data, and tuck it away, in the required slot.
	       The Adaptec automatically fetches it, and there is no
	       guarantee that we will still have it in the cdb when we come
	       back */
	    if ( (adapstat & G2INTST_MASK) == G2INTST_CCBERROR )
	    {
		memcpy(SCtmp->sense_buffer, ecbptr->sense, 
		       sizeof(SCtmp->sense_buffer));
		errstatus = aha1740_makecode(ecbptr->sense,ecbptr->status);
	    }
	    else
		errstatus = 0;
	    DEB(if (errstatus) printk("aha1740_intr_handle: returning %6x\n",
				      errstatus));
	    SCtmp->result = errstatus;
	    my_done = ecbptr->done;
	    memset(ecbptr,0,sizeof(struct ecb)); 
	    if ( my_done )
		my_done(SCtmp);
	    break;
	case	G2INTST_HARDFAIL:
	    printk(KERN_ALERT "aha1740 hardware failure!\n");
	    panic("aha1740.c");	/* Goodbye */
	case	G2INTST_ASNEVENT:
	    printk("aha1740 asynchronous event: %02x %02x %02x %02x %02x\n",
		   adapstat, inb(MBOXIN0(base)), inb(MBOXIN1(base)),
		   inb(MBOXIN2(base)), inb(MBOXIN3(base))); /* Say What? */
	    /* Host Ready -> Mailbox in complete */
	    outb(G2CNTRL_HRDY,G2CNTRL(base));
	    break;
	case	G2INTST_CMDGOOD:
	    /* set immediate command success flag here: */
	    break;
	case	G2INTST_CMDERROR:
	    /* Set immediate command failure flag here: */
	    break;
	}
	number_serviced++;
    }

    spin_unlock_irqrestore(&io_request_lock, flags);
}

int aha1740_queuecommand(Scsi_Cmnd * SCpnt, void (*done)(Scsi_Cmnd *))
{
    unchar direction;
    unchar *cmd = (unchar *) SCpnt->cmnd;
    unchar target = SCpnt->target;
    struct aha1740_hostdata *host = HOSTDATA(SCpnt->host);
    unsigned long flags;
    void *buff = SCpnt->request_buffer;
    int bufflen = SCpnt->request_bufflen;
    int ecbno;
    DEB(int i);

    if(*cmd == REQUEST_SENSE)
    {
	if (bufflen != sizeof(SCpnt->sense_buffer))
	{
	    printk("Wrong buffer length supplied for request sense (%d)\n",
		   bufflen);
	}
	SCpnt->result = 0;
	done(SCpnt); 
	return 0;
    }

#ifdef DEBUG
    if (*cmd == READ_10 || *cmd == WRITE_10)
	i = xscsi2int(cmd+2);
    else if (*cmd == READ_6 || *cmd == WRITE_6)
	i = scsi2int(cmd+2);
    else
	i = -1;
    printk("aha1740_queuecommand: dev %d cmd %02x pos %d len %d ",
	   target, *cmd, i, bufflen);
    printk("scsi cmd:");
    for (i = 0; i < SCpnt->cmd_len; i++) printk("%02x ", cmd[i]);
    printk("\n");
#endif

    /* locate an available ecb */
    save_flags(flags);
    cli();
    ecbno = host->last_ecb_used + 1;		/* An optimization */
    if (ecbno >= AHA1740_ECBS)
	ecbno = 0;
    do {
	if (!host->ecb[ecbno].cmdw)
	    break;
	ecbno++;
	if (ecbno >= AHA1740_ECBS)
	    ecbno = 0;
    } while (ecbno != host->last_ecb_used);

    if (host->ecb[ecbno].cmdw)
	panic("Unable to find empty ecb for aha1740.\n");

    host->ecb[ecbno].cmdw = AHA1740CMD_INIT;	/* SCSI Initiator Command
						   doubles as reserved flag */

    host->last_ecb_used = ecbno;    
    restore_flags(flags);

#ifdef DEBUG
    printk("Sending command (%d %x)...", ecbno, done);
#endif

    host->ecb[ecbno].cdblen = SCpnt->cmd_len;	/* SCSI Command Descriptor Block Length */

    direction = 0;
    if (*cmd == READ_10 || *cmd == READ_6)
	direction = 1;
    else if (*cmd == WRITE_10 || *cmd == WRITE_6)
	direction = 0;

    memcpy(host->ecb[ecbno].cdb, cmd, SCpnt->cmd_len);

    if (SCpnt->use_sg)
    {
	struct scatterlist * sgpnt;
	struct aha1740_chain * cptr;
	int i;
	DEB(unsigned char * ptr);

	host->ecb[ecbno].sg = 1;  /* SCSI Initiator Command  w/scatter-gather*/
	SCpnt->host_scribble = (unsigned char *) scsi_malloc(512);
	sgpnt = (struct scatterlist *) SCpnt->request_buffer;
	cptr = (struct aha1740_chain *) SCpnt->host_scribble; 
	if (cptr == NULL) panic("aha1740.c: unable to allocate DMA memory\n");
	for(i=0; i<SCpnt->use_sg; i++)
	{
	    cptr[i].datalen = sgpnt[i].length;
	    cptr[i].dataptr = virt_to_bus(sgpnt[i].address);
	}
	host->ecb[ecbno].datalen = SCpnt->use_sg * sizeof(struct aha1740_chain);
	host->ecb[ecbno].dataptr = virt_to_bus(cptr);
#ifdef DEBUG
	printk("cptr %x: ",cptr);
	ptr = (unsigned char *) cptr;
	for(i=0;i<24;i++) printk("%02x ", ptr[i]);
#endif
    }
    else
    {
	SCpnt->host_scribble = NULL;
	host->ecb[ecbno].datalen = bufflen;
	host->ecb[ecbno].dataptr = virt_to_bus(buff);
    }
    host->ecb[ecbno].lun = SCpnt->lun;
    host->ecb[ecbno].ses = 1;	/* Suppress underrun errors */
    host->ecb[ecbno].dir = direction;
    host->ecb[ecbno].ars = 1;  /* Yes, get the sense on an error */
    host->ecb[ecbno].senselen = 12;
    host->ecb[ecbno].senseptr = virt_to_bus(host->ecb[ecbno].sense);
    host->ecb[ecbno].statusptr = virt_to_bus(host->ecb[ecbno].status);
    host->ecb[ecbno].done = done;
    host->ecb[ecbno].SCpnt = SCpnt;
#ifdef DEBUG
    {
	int i;
	printk("aha1740_command: sending.. ");
	for (i = 0; i < sizeof(host->ecb[ecbno]) - 10; i++)
	    printk("%02x ", ((unchar *)&host->ecb[ecbno])[i]);
    }
    printk("\n");
#endif
    if (done)
    { /*  The Adaptec Spec says the card is so fast that the loops will
	  only be executed once in the code below. Even if this was true
	  with the fastest processors when the spec was written, it doesn't
	  seem to be true with todays fast processors. We print a warning
	  if the code is executed more often than LOOPCNT_WARN. If this
	  happens, it should be investigated. If the count reaches
	  LOOPCNT_MAX, we assume something is broken; since there is no
	  way to return an error (the return value is ignored by the
	  mid-level scsi layer) we have to panic (and maybe that's the
	  best thing we can do then anyhow). */

#define LOOPCNT_WARN 10		/* excessive mbxout wait -> syslog-msg */
#define LOOPCNT_MAX 1000000	/* mbxout deadlock -> panic() after ~ 2 sec. */
	int loopcnt;
	unsigned int base = SCpnt->host->io_port;
	DEB(printk("aha1740[%d] critical section\n",ecbno));
	save_flags(flags);
	cli();
	for (loopcnt = 0; ; loopcnt++) {
	    if (inb(G2STAT(base)) & G2STAT_MBXOUT) break;
	    if (loopcnt == LOOPCNT_WARN) {
		printk("aha1740[%d]_mbxout wait!\n",ecbno);
		cli(); /* printk may have done a sti()! */
	    }
	    if (loopcnt == LOOPCNT_MAX)
		panic("aha1740.c: mbxout busy!\n");
	}
	outl(virt_to_bus(host->ecb + ecbno), MBOXOUT0(base));
	for (loopcnt = 0; ; loopcnt++) {
	    if (! (inb(G2STAT(base)) & G2STAT_BUSY)) break;
	    if (loopcnt == LOOPCNT_WARN) {
		printk("aha1740[%d]_attn wait!\n",ecbno);
		cli();
	    }
	    if (loopcnt == LOOPCNT_MAX)
		panic("aha1740.c: attn wait failed!\n");
	}
	outb(ATTN_START | (target & 7), ATTN(base)); /* Start it up */
	restore_flags(flags);
	DEB(printk("aha1740[%d] request queued.\n",ecbno));
    }
    else
	printk(KERN_ALERT "aha1740_queuecommand: done can't be NULL\n");
    return 0;
}

static void internal_done(Scsi_Cmnd * SCpnt)
{
    SCpnt->SCp.Status++;
}

int aha1740_command(Scsi_Cmnd * SCpnt)
{
    aha1740_queuecommand(SCpnt, internal_done);
    SCpnt->SCp.Status = 0;
    while (!SCpnt->SCp.Status)
	barrier();
    return SCpnt->result;
}

/* Query the board for its irq_level.  Nothing else matters
   in enhanced mode on an EISA bus. */

void aha1740_getconfig(unsigned int base, unsigned int *irq_level,
		       unsigned int *translation)
{
    static int intab[] = { 9, 10, 11, 12, 0, 14, 15, 0 };

    *irq_level = intab[inb(INTDEF(base)) & 0x7];
    *translation = inb(RESV1(base)) & 0x1;
    outb(inb(INTDEF(base)) | 0x10, INTDEF(base));
}

int aha1740_detect(Scsi_Host_Template * tpnt)
{
    int count = 0, slot;

    DEB(printk("aha1740_detect: \n"));

    for ( slot=MINEISA; slot <= MAXEISA; slot++ )
    {
	int slotbase;
	unsigned int irq_level, translation;
	struct Scsi_Host *shpnt;
	struct aha1740_hostdata *host;
	slotbase = SLOTBASE(slot);
	/*
	 * The ioports for eisa boards are generally beyond that used in the
	 * check/allocate region code, but this may change at some point,
	 * so we go through the motions.
	 */
	if (check_region(slotbase, SLOTSIZE))  /* See if in use */
	    continue;
	if (!aha1740_test_port(slotbase))
	    continue;
	aha1740_getconfig(slotbase,&irq_level,&translation);
	if ((inb(G2STAT(slotbase)) &
	     (G2STAT_MBXOUT|G2STAT_BUSY)) != G2STAT_MBXOUT)
	{	/* If the card isn't ready, hard reset it */
	    outb(G2CNTRL_HRST, G2CNTRL(slotbase));
	    outb(0, G2CNTRL(slotbase));
	}
	printk("Configuring aha174x at IO:%x, IRQ %d\n", slotbase, irq_level);
	printk("aha174x: Extended translation %sabled.\n",
	       translation ? "en" : "dis");
	DEB(printk("aha1740_detect: enable interrupt channel %d\n",irq_level));
	if (request_irq(irq_level,aha1740_intr_handle,0,"aha1740",NULL)) {
	    printk("Unable to allocate IRQ for adaptec controller.\n");
	    continue;
	}
	shpnt = scsi_register(tpnt, sizeof(struct aha1740_hostdata));
	request_region(slotbase, SLOTSIZE, "aha1740");
	shpnt->base = 0;
	shpnt->io_port = slotbase;
	shpnt->n_io_port = SLOTSIZE;
	shpnt->irq = irq_level;
	shpnt->dma_channel = 0xff;
	host = HOSTDATA(shpnt);
	host->slot = slot;
	host->translation = translation;
	aha_host[irq_level - 9] = shpnt;
	count++;
    }
    return count;
}

/* Note:  They following two functions do not apply very well to the Adaptec,
   which basically manages its own affairs quite well without our interference,
   so I haven't put anything into them.  I can faintly imagine someone with a
   *very* badly behaved SCSI target (perhaps an old tape?) wanting the abort(),
   but it hasn't happened yet, and doing aborts brings the Adaptec to its
   knees.  I cannot (at this moment in time) think of any reason to reset the
   card once it's running.  So there. */

int aha1740_abort(Scsi_Cmnd * SCpnt)
{
    DEB(printk("aha1740_abort called\n"));
    return SCSI_ABORT_SNOOZE;
}

/* We do not implement a reset function here, but the upper level code assumes
   that it will get some kind of response for the command in SCpnt.  We must
   oblige, or the command will hang the scsi system */

int aha1740_reset(Scsi_Cmnd * SCpnt, unsigned int ignored)
{
    DEB(printk("aha1740_reset called\n"));
    return SCSI_RESET_PUNT;
}

int aha1740_biosparam(Disk * disk, kdev_t dev, int* ip)
{
    int size = disk->capacity;
    int extended = HOSTDATA(disk->device->host)->translation;

    DEB(printk("aha1740_biosparam\n"));
    if (extended && (ip[2] > 1024))
    {
	ip[0] = 255;
	ip[1] = 63;
	ip[2] = size / (255 * 63);
    }
    else
    {
	ip[0] = 64;
	ip[1] = 32;
	ip[2] = size >> 11;
    }
    return 0;
}

#ifdef MODULE
/* Eventually this will go into an include file, but this will be later */
Scsi_Host_Template driver_template = AHA1740;

#include "scsi_module.c"
#endif

/* Okay, you made it all the way through.  As of this writing, 3/31/93, I'm
brad@saturn.gaylord.com or brad@bradpc.gaylord.com.  I'll try to help as time
permits if you have any trouble with this driver.  Happy Linuxing! */