1998-11-30 OKUJI Yoshinori <okuji@kuicr.kyoto-u.ac.jp>

	Clean up linux emulation code to make it architecture-independent
	as much as possible.

	* linux: Renamed from linuxdev.
	* Makefile.in (objfiles): Add linux.o instead of linuxdev.o.
	(MAKE): New variable. Used for the linux.o target.
	* configure.in: Add AC_CHECK_TOOL(MAKE, make).
	* i386/i386/spl.h: Include <i386/ipl.h>, for compatibility with
	OSF Mach 3.0. Suggested by Elgin Lee <ehl@funghi.com>.
	* linux/src: Renamed from linux/linux.
	* linux/dev: Renamed from linux/mach.
	* linux/Drivers.in (AC_INIT): Use dev/include/linux/autoconf.h,
	instead of mach/include/linux/autoconf.h.
	* Makefile.in (all): Target ../linux.o instead of ../linuxdev.o.
	* linux/dev/drivers/block/genhd.c: Include <machine/spl.h> instead
	of <i386/ipl.h>.
	* linux/dev/drivers/net/auto_irq.c: Remove unneeded header files,
	<i386/ipl.h> and <i386/pic.h>.
	* linux/dev/init/main.c: Many i386-dependent codes moved to ...
	* linux/dev/arch/i386/irq.c: ... here.
	* linux/dev/arch/i386/setup.c: New file.
	* linux/dev/arch/i386/linux_emul.h: Likewise.
	* linux/dev/arch/i386/glue/timer.c: Merged into sched.c.
	* linux/dev/arch/i386/glue/sched.c: Include <machine/spl.h> instead
	of <i386/ipl.h>, and moved to ...
	* linux/dev/kernel/sched.c: ... here.
	* linux/dev/arch/i386/glue/block.c: Include <machine/spl.h> and
	<linux_emul.h>, instead of i386-dependent header files, and
	moved to ...
	* linux/dev/glue/blocl.c: ... here.
	* linux/dev/arch/i386/glue/net.c: Include <machine/spl.h> and
	<linux_emul.h>, instead of i386-dependent header files, and
	moved to ...
	* linux/dev/glue/net.c: ... here.
	* linux/dev/arch/i386/glue/misc.c: Remove `x86' and moved to ...
	* linux/dev/glue/misc.c: ... here.
	* linux/dev/arch/i386/glue/kmem.c: Moved to ...
	* linux/dev/glue/kmem.c: ... here.

1 files changed, 1550 insertions, 0 deletions

diff --git a/linux/src/drivers/scsi/ppa.c b/linux/src/drivers/scsi/ppa.c
new file mode 100644
index 0000000..98749dd
--- /dev/null
+++ b/linux/src/drivers/scsi/ppa.c
@@ -0,0 +1,1550 @@
+/* ppa.c   --  low level driver for the IOMEGA PPA3 
+ * parallel port SCSI host adapter.
+ * 
+ * (The PPA3 is the embedded controller in the ZIP drive.)
+ * 
+ * (c) 1995,1996 Grant R. Guenther, grant@torque.net,
+ * under the terms of the GNU Public License.
+ *
+ * Current Maintainer: David Campbell (Perth, Western Australia)
+ *                     campbell@gear.torque.net
+ *                     dcampbel@p01.as17.honeywell.com.au
+ *
+ * My unoffical company acronym list is 21 pages long:
+ *      FLA:    Four letter acronym with built in facility for
+ *              future expansion to five letters.
+ */
+
+#include <linux/config.h>
+
+/* The following #define is to avoid a clash with hosts.c */
+#define PPA_CODE 1
+#ifndef HAVE_PC87332
+#define HAVE_PC87332    0
+#endif
+#define PPA_PROBE_SPP   0x0001
+#define PPA_PROBE_PS2   0x0002
+#define PPA_PROBE_ECR   0x0010
+#define PPA_PROBE_EPP17 0x0100
+#define PPA_PROBE_EPP19 0x0200
+int port_probe(unsigned short);
+
+#include <linux/blk.h>
+#include "sd.h"
+#include "hosts.h"
+typedef struct {
+    int base;			/* Actual port address          */
+    int mode;			/* Transfer mode                */
+    int host;			/* Host number (for proc)       */
+    Scsi_Cmnd *cur_cmd;		/* Current queued command       */
+    struct tq_struct ppa_tq;	/* Polling interupt stuff       */
+    unsigned long jstart;	/* Jiffies at start             */
+    unsigned failed:1;		/* Failure flag                 */
+} ppa_struct;
+
+#define PPA_EMPTY \
+{-1,            /* base */      \
+PPA_AUTODETECT, /* mode */      \
+-1,             /* host */      \
+NULL,           /* cur_cmd */   \
+{0, 0, ppa_interrupt, NULL},    \
+0,              /* jstart */    \
+0               /* failed */    \
+}
+
+#include "ppa.h"
+#undef CONFIG_PARPORT
+#define NO_HOSTS 4
+static ppa_struct ppa_hosts[NO_HOSTS] =
+{PPA_EMPTY, PPA_EMPTY, PPA_EMPTY, PPA_EMPTY};
+
+#define PPA_BASE(x)	ppa_hosts[(x)].base
+
+int base[NO_HOSTS] =
+{0x03bc, 0x0378, 0x0278, 0x0000};
+#define parbus_base	base
+#define parbus_no	NO_HOSTS
+
+static inline int ppa_pb_claim(int host_no)
+{
+    if (ppa_hosts[host_no].cur_cmd)
+	ppa_hosts[host_no].cur_cmd->SCp.phase++;
+    return 0;
+}
+
+/***************************************************************************
+ *                   Parallel port probing routines                        *
+ ***************************************************************************/
+  
+#ifndef MODULE
+/*
+ * Command line parameters (for built-in driver):
+ *
+ * Syntax:  ppa=base[,mode[,use_sg]]
+ *
+ * For example:  ppa=0x378   or   ppa=0x378,0,3
+ *
+ */
+
+void ppa_setup(char *str, int *ints)
+{
+    static int x = 0;
+
+    if (x == 0) {		/* Disable ALL known ports */
+	int i;
+
+	for (i = 0; i < NO_HOSTS; i++)
+	    parbus_base[i] = 0x0000;
+    }
+    switch (ints[0]) {
+    case 3:
+	ppa_sg = ints[3];
+    case 2:
+	ppa_hosts[x].mode = ints[2];
+	parbus_base[x] = ints[1];
+	break;
+    default:
+	printk("PPA: I only use between 2 to 3 parameters.\n");
+	break;
+    }
+    x++;
+  }
+#else
+Scsi_Host_Template driver_template = PPA;
+#include  "scsi_module.c"
+#endif
+  
+/*
+ * Start of Chipset kludges
+ */
+
+#if HAVE_PC87332 > 0
+#warning PC87332 Kludge code included
+static inline int pc87332_port(int host_no)
+{
+    /* A routine to detect and kludge pc87332 chipsets into the
+     * "optimum" mode for parallel port data transfer.
+     * This assumes EPP is better than ECP...
+     * (Which it is for disk drives but not printers and scanners)
+     */
+    int base = ppa_hosts[host_no].base;
+
+    /* This is where an pc87332 can hide */
+    unsigned short index_addr[4] =
+    {
+	0x0398, 0x026e, 0x015c, 0x002e
+    };
+
+    /* Bits 0&1 of FAR (Function Address Register) which specify where
+     * the LPT port will show up at.
+     */
+    unsigned short port_ref[4] =
+    {
+	0x378, 0x3bc, 0x278, 0xffff
+    };
+
+    unsigned char a;
+    int loop;
+
+    for (loop = 0; loop < 4; loop++) {
+	/* Clear the "wax" out of the pc87332, only needed after hard
+	 * reset.
+	 */
+	inb(index_addr[loop]);
+	inb(index_addr[loop]);
+	inb(index_addr[loop]);
+	inb(index_addr[loop]);
+
+	/* Anyone home ?? */
+	outb(0xff, index_addr[loop]);
+	a = inb(index_addr[loop]);
+	switch (a) {
+	case (0x0f):		/* PC87732 */
+	    break;
+	case (0x1f):		/* PC87306 */
+	    break;
+	case (0x7f):		/* PC87??? */
+	    break;
+	default:
+	    continue;
+	}			/* Is this pc87332 on the desired port */
+	outb(0x01, index_addr[loop]);
+	a = inb(index_addr[loop] + 1);
+	if (port_ref[a & 0x03] != base)
+	    continue;
+
+	/* Found a pc87332 */
+	printk("NatSemi PC87332 (or variant) at 0x%04x\n", base);
+
+	/* Try to enable EPP modes
+	 * with hardware data direction
+	 */
+	if (base != 0x3bc) {
+	    /* EPP 1.9 */
+	    outb(0x04, index_addr[loop]);
+	    a = inb(index_addr[loop] + 1);
+	    printk("Old reg1 = %02x\n", a);
+	    /* 0x01 for EPP 1.7, 0x03 for EPP 1.9, 0x0c for ECP */
+	    a = (a & 0xf0) | 0x03;
+	    outb(a, index_addr[loop] + 1);
+	    outb(a, index_addr[loop] + 1);
+
+	    /* Software data direction selection */
+	    outb(0x02, index_addr[loop]);
+	    a = inb(index_addr[loop] + 1);
+	    printk("Old reg2 = %02x\n", a);
+	    /* 0x80 for software, 0x00 for hardware */
+	    a = (a & 0x7f) | 0x80;
+	    outb(a, index_addr[loop] + 1);
+	    outb(a, index_addr[loop] + 1);
+	    ppa_hosts[host_no].mode = PPA_EPP_32;
+	} else {
+	    /* There is not enough address space for the 0x3bc port
+	     * to have EPP registers so we will kludge it into an
+	     * ECP
+	     * port to allow bi-directional byte mode...
+	     */
+	    /* ECP */
+	    outb(0x04, index_addr[loop]);
+	    a = inb(index_addr[loop] + 1);
+	    a = (a & 0xfb) | 0x06;
+	    outb(a, index_addr[loop] + 1);
+	    outb(a, index_addr[loop] + 1);
+	    ppa_hosts[host_no].mode = PPA_PS2;
+	}
+
+	outb(0x04, index_addr[loop]);
+	a = inb(index_addr[loop] + 1);
+	return ppa_hosts[host_no].mode;
+    }
+    return 0;
+  }
+#else
+#define pc87332_port(x)
+#endif				/* HAVE_PC87332 */
+  
+static inline int generic_port(int host_no)
+{
+    /* Generic parallel port detection
+     * This will try to discover if the port is
+     * EPP, ECP, PS/2 or NIBBLE (In that order, approx....)
+     */
+    unsigned int save_ctr, save_ecr, r;
+    int ppb = PPA_BASE(host_no);
+
+    save_ctr = r_ctr(ppb);
+    save_ecr = r_ecr(ppb);
+    r = port_probe(ppb);
+    w_ecr(ppb, save_ecr);
+    w_ctr(ppb, save_ctr);
+
+    if (r & PPA_PROBE_SPP)
+	ppa_hosts[host_no].mode = PPA_NIBBLE;
+
+    if (r & PPA_PROBE_PS2) {
+	ppa_hosts[host_no].mode = PPA_PS2;
+	if (r & PPA_PROBE_ECR)
+	    w_ecr(ppb, 0x20);
+    }
+    if ((r & PPA_PROBE_EPP17) || (r & PPA_PROBE_EPP19)) {
+	/* ppa_hosts[host_no].mode = PPA_EPP_32; */
+	if (r & PPA_PROBE_ECR)
+	    w_ecr(ppb, 0x80);
+    }
+    return ppa_hosts[host_no].mode;
+}
+
+int ppa_detect(Scsi_Host_Template * host)
+{
+    struct Scsi_Host *hreg;
+    int ports;
+    int i, nhosts;
+    unsigned short ppb;
+
+    printk("ppa: Version %s\n", PPA_VERSION);
+    nhosts = 0;
+
+    for (i = 0; i < parbus_no; i++) {
+	if (parbus_base[i] == 0x0000)
+	    continue;
+	ppb = ppa_hosts[i].base = parbus_base[i];
+
+	/* sanity checks */
+	if (check_region(parbus_base[i],
+			 (parbus_base[i] == 0x03bc) ? 3 : 8))
+	    continue;
+
+	pc87332_port(i);
+	if (!generic_port(i))
+	    continue;
+
+	if (ppa_init(i))
+	    continue;
+
+	/* now the glue ... */
+	switch (ppa_hosts[i].mode) {
+	case PPA_NIBBLE:
+	case PPA_PS2:
+	    ports = 3;
+	    break;
+	case PPA_EPP_8:
+	case PPA_EPP_16:
+	case PPA_EPP_32:
+	    ports = 8;
+	    break;
+	default:		/* Never gets here */
+	    continue;
+	}
+	request_region(ppa_hosts[i].base, ports, "ppa");
+	host->can_queue = PPA_CAN_QUEUE;
+	host->sg_tablesize = ppa_sg;
+	hreg = scsi_register(host, 0);
+	hreg->io_port = ppa_hosts[i].base;
+	hreg->n_io_port = ports;
+	hreg->dma_channel = -1;
+	hreg->unique_id = i;
+	ppa_hosts[i].host = hreg->host_no;
+	nhosts++;
+    }
+    if (nhosts == 0)
+	return 0;
+    else
+	return 1;		/* return number of hosts detected */
+}
+
+/* This is to give the ppa driver a way to modify the timings (and other
+ * parameters) by writing to the /proc/scsi/ppa/0 file.
+ * Very simple method really... (To simple, no error checking :( )
+ * Reason: Kernel hackers HATE having to unload and reload modules for
+ * testing...
+ * Also gives a method to use a script to obtain optimum timings (TODO)
+ */
+
+static inline int ppa_strncmp(const char *a, const char *b, int len)
+{
+    int loop;
+    for (loop = 0; loop < len; loop++)
+	if (a[loop] != b[loop])
+	    return 1;
+
+    return 0;
+}
+static inline int ppa_proc_write(int hostno, char *buffer, int length)
+{
+    unsigned long x;
+
+    if ((length > 5) && (ppa_strncmp(buffer, "mode=", 5) == 0)) {
+	x = simple_strtoul(buffer + 5, NULL, 0);
+	ppa_hosts[hostno].mode = x;
+	return length;
+    }
+    printk("ppa /proc: invalid variable\n");
+    return (-EINVAL);
+}
+
+int ppa_proc_info(char *buffer, char **start, off_t offset,
+		  int length, int hostno, int inout)
+{
+    int i;
+    int len = 0;
+
+    for (i = 0; i < 4; i++)
+	if (ppa_hosts[i].host == hostno)
+	    break;
+
+    if (inout)
+	return ppa_proc_write(i, buffer, length);
+
+    len += sprintf(buffer + len, "Version : %s\n", PPA_VERSION);
+    len += sprintf(buffer + len, "Port    : 0x%04x\n", ppa_hosts[i].base);
+    len += sprintf(buffer + len, "Mode    : %s\n", PPA_MODE_STRING[ppa_hosts[i].mode]);
+
+    /* Request for beyond end of buffer */
+    if (offset > len)
+	return 0;
+
+    *start = buffer + offset;
+    len -= offset;
+    if (len > length)
+	len = length;
+    return len;
+}				/* end of ppa.c */
+static int device_check(int host_no);
+
+#if PPA_DEBUG > 0
+#define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
+	   y, __FUNCTION__, __LINE__); ppa_fail_func(x,y);
+static inline void ppa_fail_func(int host_no, int error_code)
+#else
+static inline void ppa_fail(int host_no, int error_code)
+  #endif
+{
+    /* If we fail a device then we trash status / message bytes */
+    if (ppa_hosts[host_no].cur_cmd) {
+	ppa_hosts[host_no].cur_cmd->result = error_code << 16;
+	ppa_hosts[host_no].failed = 1;
+    }
+}
+
+/*
+ * Wait for the high bit to be set.
+ * 
+ * In principle, this could be tied to an interrupt, but the adapter
+ * doesn't appear to be designed to support interrupts.  We spin on
+ * the 0x80 ready bit. 
+ */
+static unsigned char ppa_wait(int host_no)
+{
+    int k;
+    unsigned short ppb = PPA_BASE(host_no);
+    unsigned char r;
+
+    k = PPA_SPIN_TMO;
+    do {
+	r = r_str(ppb);
+	k--;
+	udelay(1);
+    }
+    while (!(r & 0x80) && (k));
+
+    /*
+     * return some status information.
+     * Semantics: 0xc0 = ZIP wants more data
+     *            0xd0 = ZIP wants to send more data
+     *            0xe0 = ZIP is expecting SCSI command data
+     *            0xf0 = end of transfer, ZIP is sending status
+     */
+    if (k)
+	return (r & 0xf0);
+
+    /* Counter expired - Time out occurred */
+    ppa_fail(host_no, DID_TIME_OUT);
+    printk("ppa timeout in ppa_wait\n");
+    return 0;			/* command timed out */
+}
+
+/*
+ * output a string, in whatever mode is available, according to the
+ * PPA protocol. 
+ */
+static inline void epp_reset(unsigned short ppb)
+{
+    int i;
+
+    i = r_str(ppb);
+    w_str(ppb, i);
+    w_str(ppb, i & 0xfe);
+}
+
+static inline void ecp_sync(unsigned short ppb)
+{
+    int i;
+
+    if ((r_ecr(ppb) & 0xe0) != 0x80)
+	return;
+
+    for (i = 0; i < 100; i++) {
+	if (r_ecr(ppb) & 0x01)
+	    return;
+	udelay(5);
+    }
+    printk("ppa: ECP sync failed as data still present in FIFO.\n");
+}
+
+/*
+ * Here is the asm code for the SPP/PS2 protocols for the i386.
+ * This has been optimised for speed on 386/486 machines. There will
+ * be very little improvement on the current 586+ machines as it is the
+ * IO statements which will limit throughput.
+ */
+#ifdef __i386__
+#define BYTE_OUT(reg) \
+	"	movb " #reg ",%%al\n" \
+	"	outb %%al,(%%dx)\n" \
+	"	addl $2,%%edx\n" \
+	"	movb $0x0e,%%al\n" \
+	"	outb %%al,(%%dx)\n" \
+	"	movb $0x0c,%%al\n" \
+	"	outb %%al,(%%dx)\n" \
+	"	subl $2,%%edx\n"
+
+static inline int ppa_byte_out(unsigned short base, char *buffer, unsigned int len)
+{
+    /*
+     * %eax scratch
+     * %ebx Data to transfer
+     * %ecx Counter (Don't touch!!)
+     * %edx Port
+     * %esi Source buffer (mem pointer)
+     *
+     * In case you are wondering what the last line of the asm does...
+     * <output allocation> : <input allocation> : <trashed registers>
+     */
+    asm("shr $2,%%ecx\n" \
+	"	jz .no_more_bulk_bo\n" \
+	"	.align 4\n" \
+	".loop_bulk_bo:\n" \
+	"	movl (%%esi),%%ebx\n" \
+	BYTE_OUT(%%bl) \
+	BYTE_OUT(%%bh) \
+	"	rorl $16,%%ebx\n" \
+	BYTE_OUT(%%bl) \
+	BYTE_OUT(%%bh) \
+	"	addl $4,%%esi\n" \
+	"	loop .loop_bulk_bo\n" \
+	"	.align 4\n" \
+	".no_more_bulk_bo:" \
+  : "=S"(buffer): "c"(len), "d"(base), "S"(buffer):"eax", "ebx", "ecx");
+
+    asm("andl $3,%%ecx\n" \
+	"	jz .no_more_loose_bo\n" \
+	"	.align 4\n" \
+	".loop_loose_bo:\n" \
+	BYTE_OUT((%%esi)) \
+	"	incl %%esi\n" \
+	"	loop .loop_loose_bo\n" \
+	".no_more_loose_bo:\n" \
+  : /* no output */ : "c"(len), "d"(base), "S"(buffer):"eax", "ebx", "ecx");
+    return 1;			/* All went well - we hope! */
+}
+
+#define BYTE_IN(reg) \
+	"	inb (%%dx),%%al\n" \
+	"	movb %%al," #reg "\n" \
+	"	addl $2,%%edx\n" \
+	"	movb $0x27,%%al\n" \
+	"	outb %%al,(%%dx)\n" \
+	"	movb $0x25,%%al\n" \
+	"	outb %%al,(%%dx)\n" \
+	"	subl $2,%%edx\n"
+
+static inline int ppa_byte_in(unsigned short base, char *buffer, int len)
+{
+    /*
+     * %eax scratch
+     * %ebx Data to transfer
+     * %ecx Counter (Don't touch!!)
+     * %edx Port
+     * %esi Source buffer (mem pointer)
+     *
+     * In case you are wondering what the last line of the asm does...
+     * <output allocation> : <input allocation> : <trashed registers>
+     */
+    asm("shr $2,%%ecx\n" \
+	"	jz .no_more_bulk_bi\n" \
+	"	.align 4\n" \
+	".loop_bulk_bi:\n" \
+	BYTE_IN(%%bl) \
+	BYTE_IN(%%bh) \
+	"	rorl $16,%%ebx\n" \
+	BYTE_IN(%%bl) \
+	BYTE_IN(%%bh) \
+	"	rorl $16,%%ebx\n" \
+	"	movl %%ebx,(%%esi)\n" \
+	"	addl $4,%%esi\n" \
+	"	loop .loop_bulk_bi\n" \
+	"	.align 4\n" \
+	".no_more_bulk_bi:" \
+  : "=S"(buffer): "c"(len), "d"(base), "S"(buffer):"eax", "ebx", "ecx");
+
+    asm("andl $3,%%ecx\n" \
+	"	jz .no_more_loose_bi\n" \
+	"	.align 4\n" \
+	".loop_loose_bi:\n" \
+	BYTE_IN((%%esi)) \
+	"	incl %%esi\n" \
+	"	loop .loop_loose_bi\n" \
+	".no_more_loose_bi:\n" \
+  : /* no output */ : "c"(len), "d"(base), "S"(buffer):"eax", "ebx", "ecx");
+    return 1;			/* All went well - we hope! */
+}
+
+#define NIBBLE_IN(reg) \
+	"	incl %%edx\n" \
+	"	movb $0x04,%%al\n" \
+	"	outb %%al,(%%dx)\n" \
+	"	decl %%edx\n" \
+	"	inb (%%dx),%%al\n" \
+	"	andb $0xf0,%%al\n" \
+	"	movb %%al," #reg "\n" \
+	"	incl %%edx\n" \
+	"	movb $0x06,%%al\n" \
+	"	outb %%al,(%%dx)\n" \
+	"	decl %%edx\n" \
+	"	inb (%%dx),%%al\n" \
+	"	shrb $4,%%al\n" \
+	"	orb %%al," #reg "\n"
+
+static inline int ppa_nibble_in(unsigned short str_p, char *buffer, int len)
+{
+    /*
+     * %eax scratch
+     * %ebx Data to transfer
+     * %ecx Counter (Don't touch!!)
+     * %edx Port
+     * %esi Source buffer (mem pointer)
+     *
+     * In case you are wondering what the last line of the asm does...
+     * <output allocation> : <input allocation> : <trashed registers>
+     */
+    asm("shr $2,%%ecx\n" \
+	"	jz .no_more_bulk_ni\n" \
+	"	.align 4\n" \
+	".loop_bulk_ni:\n" \
+	NIBBLE_IN(%%bl) \
+	NIBBLE_IN(%%bh) \
+	"	rorl $16,%%ebx\n" \
+	NIBBLE_IN(%%bl) \
+	NIBBLE_IN(%%bh) \
+	"	rorl $16,%%ebx\n" \
+	"	movl %%ebx,(%%esi)\n" \
+	"	addl $4,%%esi\n" \
+	"	loop .loop_bulk_ni\n" \
+	"	.align 4\n" \
+	".no_more_bulk_ni:" \
+  : "=S"(buffer): "c"(len), "d"(str_p), "S"(buffer):"eax", "ebx", "ecx");
+
+    asm("andl $3,%%ecx\n" \
+	"	jz .no_more_loose_ni\n" \
+	"	.align 4\n" \
+	".loop_loose_ni:\n" \
+	NIBBLE_IN((%%esi)) \
+	"	incl %%esi\n" \
+	"	loop .loop_loose_ni\n" \
+	".no_more_loose_ni:\n" \
+  : /* no output */ : "c"(len), "d"(str_p), "S"(buffer):"eax", "ebx", "ecx");
+    return 1;			/* All went well - we hope! */
+}
+#else				/* Old style C routines */
+
+static inline int ppa_byte_out(unsigned short base, const char *buffer, int len)
+{
+    unsigned short ctr_p = base + 2;
+    int i;
+
+    for (i = len; i; i--) {
+	outb(*buffer++, base);
+	outb(0xe, ctr_p);
+	outb(0xc, ctr_p);
+    }
+    return 1;			/* All went well - we hope! */
+}
+
+static inline int ppa_byte_in(unsigned short base, char *buffer, int len)
+{
+    unsigned short ctr_p = base + 2;
+    int i;
+
+    for (i = len; i; i--) {
+	*buffer++ = inb(base);
+	outb(0x27, ctr_p);
+	outb(0x25, ctr_p);
+    }
+    return 1;			/* All went well - we hope! */
+}
+
+static inline int ppa_nibble_in(unsigned short str_p, char *buffer, int len)
+{
+    unsigned short ctr_p = str_p + 1;
+    unsigned char h, l;
+    int i;
+
+    for (i = len; i; i--) {
+	outb(0x4, ctr_p);
+	h = inb(str_p);
+	outb(0x6, ctr_p);
+	l = inb(str_p);
+	*buffer++ = (h & 0xf0) | ((l & 0xf0) >> 4);
+    }
+    return 1;			/* All went well - we hope! */
+  }
+  #endif
+  
+static inline int ppa_epp_out(unsigned short epp_p, unsigned short str_p, const char *buffer, int len)
+{
+    int i;
+    for (i = len; i; i--) {
+	outb(*buffer++, epp_p);
+#ifdef CONFIG_SCSI_PPA_HAVE_PEDANTIC
+	if (inb(str_p) & 0x01)
+	    return 0;
+  #endif
+    }
+    return 1;
+  }
+  
+static int ppa_out(int host_no, char *buffer, int len)
+{
+    int r;
+    unsigned short ppb = PPA_BASE(host_no);
+
+    r = ppa_wait(host_no);
+
+    if ((r & 0x50) != 0x40) {
+	ppa_fail(host_no, DID_ERROR);
+	return 0;
+    }
+    switch (ppa_hosts[host_no].mode) {
+    case PPA_NIBBLE:
+    case PPA_PS2:
+	/* 8 bit output, with a loop */
+	r = ppa_byte_out(ppb, buffer, len);
+	break;
+
+    case PPA_EPP_32:
+    case PPA_EPP_16:
+    case PPA_EPP_8:
+	epp_reset(ppb);
+	w_ctr(ppb, 0x4);
+#ifdef CONFIG_SCSI_PPA_HAVE_PEDANTIC
+	r = ppa_epp_out(ppb + 4, ppb + 1, buffer, len);
+#else
+	if (!(((long) buffer | len) & 0x03))
+	    outsl(ppb + 4, buffer, len >> 2);
+	else
+	    outsb(ppb + 4, buffer, len);
+	w_ctr(ppb, 0xc);
+	r = !(r_str(ppb) & 0x01);
+#endif
+	w_ctr(ppb, 0xc);
+	ecp_sync(ppb);
+	break;
+
+    default:
+	printk("PPA: bug in ppa_out()\n");
+	r = 0;
+    }
+    return r;
+}
+
+static inline int ppa_epp_in(int epp_p, int str_p, char *buffer, int len)
+{
+    int i;
+    for (i = len; i; i--) {
+	*buffer++ = inb(epp_p);
+#ifdef CONFIG_SCSI_PPA_HAVE_PEDANTIC
+	if (inb(str_p) & 0x01)
+	    return 0;
+#endif
+    }
+    return 1;
+  }
+  
+static int ppa_in(int host_no, char *buffer, int len)
+{
+    int r;
+    unsigned short ppb = PPA_BASE(host_no);
+
+    r = ppa_wait(host_no);
+
+    if ((r & 0x50) != 0x50) {
+	ppa_fail(host_no, DID_ERROR);
+	return 0;
+    }
+    switch (ppa_hosts[host_no].mode) {
+    case PPA_NIBBLE:
+	/* 4 bit input, with a loop */
+	r = ppa_nibble_in(ppb + 1, buffer, len);
+	w_ctr(ppb, 0xc);
+	break;
+
+    case PPA_PS2:
+	/* 8 bit input, with a loop */
+	w_ctr(ppb, 0x25);
+	r = ppa_byte_in(ppb, buffer, len);
+	w_ctr(ppb, 0x4);
+	w_ctr(ppb, 0xc);
+	break;
+
+    case PPA_EPP_32:
+    case PPA_EPP_16:
+    case PPA_EPP_8:
+	epp_reset(ppb);
+	w_ctr(ppb, 0x24);
+#ifdef CONFIG_SCSI_PPA_HAVE_PEDANTIC
+	r = ppa_epp_in(ppb + 4, ppb + 1, buffer, len);
+  #else
+	if (!(((long) buffer | len) & 0x03))
+	    insl(ppb + 4, buffer, len >> 2);
+	else
+	    insb(ppb + 4, buffer, len);
+	w_ctr(ppb, 0x2c);
+	r = !(r_str(ppb) & 0x01);
+#endif
+	w_ctr(ppb, 0x2c);
+	ecp_sync(ppb);
+	break;
+
+    default:
+	printk("PPA: bug in ppa_ins()\n");
+	r = 0;
+	break;
+    }
+    return r;
+}
+
+/* end of ppa_io.h */
+static inline void ppa_d_pulse(unsigned short ppb, unsigned char b)
+{
+    w_dtr(ppb, b);
+    w_ctr(ppb, 0xc);
+    w_ctr(ppb, 0xe);
+    w_ctr(ppb, 0xc);
+    w_ctr(ppb, 0x4);
+    w_ctr(ppb, 0xc);
+}
+
+static void ppa_disconnect(int host_no)
+{
+    unsigned short ppb = PPA_BASE(host_no);
+
+    ppa_d_pulse(ppb, 0);
+    ppa_d_pulse(ppb, 0x3c);
+    ppa_d_pulse(ppb, 0x20);
+    ppa_d_pulse(ppb, 0xf);
+}
+
+static inline void ppa_c_pulse(unsigned short ppb, unsigned char b)
+{
+    w_dtr(ppb, b);
+    w_ctr(ppb, 0x4);
+    w_ctr(ppb, 0x6);
+    w_ctr(ppb, 0x4);
+    w_ctr(ppb, 0xc);
+}
+
+static inline void ppa_connect(int host_no, int flag)
+{
+    unsigned short ppb = PPA_BASE(host_no);
+
+    ppa_c_pulse(ppb, 0);
+    ppa_c_pulse(ppb, 0x3c);
+    ppa_c_pulse(ppb, 0x20);
+    if ((flag == CONNECT_EPP_MAYBE) &&
+	IN_EPP_MODE(ppa_hosts[host_no].mode))
+	ppa_c_pulse(ppb, 0xcf);
+    else
+	ppa_c_pulse(ppb, 0x8f);
+}
+
+static int ppa_select(int host_no, int target)
+{
+    int k;
+    unsigned short ppb = PPA_BASE(host_no);
+
+    /*
+     * Bit 6 (0x40) is the device selected bit.
+     * First we must wait till the current device goes off line...
+     */
+    k = PPA_SELECT_TMO;
+    do {
+	k--;
+    } while ((r_str(ppb) & 0x40) && (k));
+    if (!k)
+	return 0;
+
+    w_dtr(ppb, (1 << target));
+    w_ctr(ppb, 0xe);
+    w_ctr(ppb, 0xc);
+    w_dtr(ppb, 0x80);		/* This is NOT the initator */
+    w_ctr(ppb, 0x8);
+
+    k = PPA_SELECT_TMO;
+    do {
+	k--;
+    }
+    while (!(r_str(ppb) & 0x40) && (k));
+    if (!k)
+	return 0;
+
+    return 1;
+}
+
+/* 
+ * This is based on a trace of what the Iomega DOS 'guest' driver does.
+ * I've tried several different kinds of parallel ports with guest and
+ * coded this to react in the same ways that it does.
+ * 
+ * The return value from this function is just a hint about where the
+ * handshaking failed.
+ * 
+ */
+static int ppa_init(int host_no)
+{
+    int retv;
+    unsigned short ppb = PPA_BASE(host_no);
+
+    ppa_disconnect(host_no);
+    ppa_connect(host_no, CONNECT_NORMAL);
+
+    retv = 2;			/* Failed */
+
+    w_ctr(ppb, 0xe);
+    if ((r_str(ppb) & 0x08) == 0x08)
+	retv--;
+
+    w_ctr(ppb, 0xc);
+    if ((r_str(ppb) & 0x08) == 0x00)
+	retv--;
+
+    /* This is a SCSI BUS reset signal */
+    if (!retv) {
+	w_dtr(ppb, 0x40);
+	w_ctr(ppb, 0x08);
+	udelay(30);
+	w_ctr(ppb, 0x0c);
+	udelay(1000);		/* Allow devices to settle down */
+    }
+    ppa_disconnect(host_no);
+    udelay(1000);		/* Another delay to allow devices to settle */
+
+    if (!retv)
+	retv = device_check(host_no);
+
+    return retv;
+}
+
+static inline int ppa_send_command(Scsi_Cmnd * cmd)
+{
+    int host_no = cmd->host->unique_id;
+    int k;
+
+    w_ctr(PPA_BASE(host_no), 0x0c);
+
+    for (k = 0; k < cmd->cmd_len; k++)
+	if (!ppa_out(host_no, &cmd->cmnd[k], 1))
+	    return 0;
+    return 1;
+}
+
+/*
+ * The bulk flag enables some optimisations in the data transfer loops,
+ * it should be true for any command that transfers data in integral
+ * numbers of sectors.
+ * 
+ * The driver appears to remain stable if we speed up the parallel port
+ * i/o in this function, but not elsewhere.
+ */
+static int ppa_completion(Scsi_Cmnd * cmd)
+{
+    /* Return codes:
+     * -1     Error
+     *  0     Told to schedule
+     *  1     Finished data transfer
+     */
+    int host_no = cmd->host->unique_id;
+    unsigned short ppb = PPA_BASE(host_no);
+    unsigned long start_jiffies = jiffies;
+
+    unsigned char r, v;
+    int fast, bulk, status;
+
+    v = cmd->cmnd[0];
+    bulk = ((v == READ_6) ||
+	    (v == READ_10) ||
+	    (v == WRITE_6) ||
+	    (v == WRITE_10));
+
+    /*
+     * We only get here if the drive is ready to comunicate,
+     * hence no need for a full ppa_wait.
+     */
+    r = (r_str(ppb) & 0xf0);
+
+    while (r != (unsigned char) 0xf0) {
+	/*
+	 * If we have been running for more than a full timer tick
+	 * then take a rest.
+	 */
+	if (jiffies > start_jiffies + 1)
+	    return 0;
+
+	if (((r & 0xc0) != 0xc0) || (cmd->SCp.this_residual <= 0)) {
+	    ppa_fail(host_no, DID_ERROR);
+	    return -1;		/* ERROR_RETURN */
+	}
+	/* determine if we should use burst I/O */ fast = (bulk && (cmd->SCp.this_residual >= PPA_BURST_SIZE))
+	    ? PPA_BURST_SIZE : 1;
+
+	if (r == (unsigned char) 0xc0)
+	    status = ppa_out(host_no, cmd->SCp.ptr, fast);
+	else
+	    status = ppa_in(host_no, cmd->SCp.ptr, fast);
+
+	cmd->SCp.ptr += fast;
+	cmd->SCp.this_residual -= fast;
+
+	if (!status) {
+	    ppa_fail(host_no, DID_BUS_BUSY);
+	    return -1;		/* ERROR_RETURN */
+	}
+	if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
+	    /* if scatter/gather, advance to the next segment */
+	    if (cmd->SCp.buffers_residual--) {
+		cmd->SCp.buffer++;
+		cmd->SCp.this_residual = cmd->SCp.buffer->length;
+		cmd->SCp.ptr = cmd->SCp.buffer->address;
+	    }
+	}
+	/* Now check to see if the drive is ready to comunicate */
+	r = (r_str(ppb) & 0xf0);
+	/* If not, drop back down to the scheduler and wait a timer tick */
+	if (!(r & 0x80))
+	    return 0;
+    }
+    return 1;			/* FINISH_RETURN */
+}
+
+/*
+ * Since the PPA itself doesn't generate interrupts, we use
+ * the scheduler's task queue to generate a stream of call-backs and
+ * complete the request when the drive is ready.
+ */
+static void ppa_interrupt(void *data)
+{
+    ppa_struct *tmp = (ppa_struct *) data;
+    Scsi_Cmnd *cmd = tmp->cur_cmd;
+
+    if (!cmd) {
+	printk("PPA: bug in ppa_interrupt\n");
+	return;
+    }
+    if (ppa_engine(tmp, cmd)) {
+	tmp->ppa_tq.data = (void *) tmp;
+	tmp->ppa_tq.sync = 0;
+	queue_task(&tmp->ppa_tq, &tq_timer);
+	return;
+    }
+    /* Command must of completed hence it is safe to let go... */
+#if PPA_DEBUG > 0
+    switch ((cmd->result >> 16) & 0xff) {
+    case DID_OK:
+	break;
+    case DID_NO_CONNECT:
+	printk("ppa: no device at SCSI ID %i\n", cmd->target);
+	break;
+    case DID_BUS_BUSY:
+	printk("ppa: BUS BUSY - EPP timeout detected\n");
+	break;
+    case DID_TIME_OUT:
+	printk("ppa: unknown timeout\n");
+	break;
+    case DID_ABORT:
+	printk("ppa: told to abort\n");
+	break;
+    case DID_PARITY:
+	printk("ppa: parity error (???)\n");
+	break;
+    case DID_ERROR:
+	printk("ppa: internal driver error\n");
+	break;
+    case DID_RESET:
+	printk("ppa: told to reset device\n");
+	break;
+    case DID_BAD_INTR:
+	printk("ppa: bad interrupt (???)\n");
+	break;
+    default:
+	printk("ppa: bad return code (%02x)\n", (cmd->result >> 16) & 0xff);
+    }
+  #endif
+  
+    if (cmd->SCp.phase > 1)
+	ppa_disconnect(cmd->host->unique_id);
+
+    tmp->cur_cmd = 0;
+    cmd->scsi_done(cmd);
+    return;
+}
+
+static int ppa_engine(ppa_struct * tmp, Scsi_Cmnd * cmd)
+{
+    int host_no = cmd->host->unique_id;
+    unsigned short ppb = PPA_BASE(host_no);
+    unsigned char l = 0, h = 0;
+    int retv;
+
+    /* First check for any errors that may have occurred
+     * Here we check for internal errors
+     */
+    if (tmp->failed)
+	return 0;
+
+    switch (cmd->SCp.phase) {
+    case 0:			/* Phase 0 - Waiting for parport */
+	if ((jiffies - tmp->jstart) > HZ) {
+	    /*
+	     * We waited more than a second
+	     * for parport to call us
+	     */
+	    ppa_fail(host_no, DID_BUS_BUSY);
+	    return 0;
+	}
+	return 1;		/* wait until ppa_wakeup claims parport */
+    case 1:			/* Phase 1 - Connected */
+	{			/* Perform a sanity check for cable unplugged */
+	    int retv = 2;	/* Failed */
+
+	    ppa_connect(host_no, CONNECT_EPP_MAYBE);
+
+	    w_ctr(ppb, 0xe);
+	    if ((r_str(ppb) & 0x08) == 0x08)
+		retv--;
+
+	    w_ctr(ppb, 0xc);
+	    if ((r_str(ppb) & 0x08) == 0x00)
+		retv--;
+
+	    if (retv)
+		if ((jiffies - tmp->jstart) > (1 * HZ)) {
+		    printk("ppa: Parallel port cable is unplugged!!\n");
+		    ppa_fail(host_no, DID_BUS_BUSY);
+		    return 0;
+		} else {
+		    ppa_disconnect(host_no);
+		    return 1;	/* Try again in a jiffy */
+		}
+	    cmd->SCp.phase++;
+	}
+
+    case 2:			/* Phase 2 - We are now talking to the scsi bus */
+	if (!ppa_select(host_no, cmd->target)) {
+	    ppa_fail(host_no, DID_NO_CONNECT);
+	    return 0;
+	}
+	cmd->SCp.phase++;
+
+    case 3:			/* Phase 3 - Ready to accept a command */
+	w_ctr(ppb, 0x0c);
+	if (!(r_str(ppb) & 0x80))
+	    return 1;
+
+	if (!ppa_send_command(cmd))
+	    return 0;
+	cmd->SCp.phase++;
+
+    case 4:			/* Phase 4 - Setup scatter/gather buffers */
+	if (cmd->use_sg) {
+	    /* if many buffers are available, start filling the first */
+	    cmd->SCp.buffer = (struct scatterlist *) cmd->request_buffer;
+	    cmd->SCp.this_residual = cmd->SCp.buffer->length;
+	    cmd->SCp.ptr = cmd->SCp.buffer->address;
+	} else {
+	    /* else fill the only available buffer */
+	    cmd->SCp.buffer = NULL;
+	    cmd->SCp.this_residual = cmd->request_bufflen;
+	    cmd->SCp.ptr = cmd->request_buffer;
+	}
+	cmd->SCp.buffers_residual = cmd->use_sg;
+	cmd->SCp.phase++;
+
+    case 5:			/* Phase 5 - Data transfer stage */
+	w_ctr(ppb, 0x0c);
+	if (!(r_str(ppb) & 0x80))
+	    return 1;
+
+	retv = ppa_completion(cmd);
+	if (retv == -1)
+	    return 0;
+	if (retv == 0)
+	    return 1;
+	cmd->SCp.phase++;
+
+    case 6:			/* Phase 6 - Read status/message */
+	cmd->result = DID_OK << 16;
+	/* Check for data overrun */
+	if (ppa_wait(host_no) != (unsigned char) 0xf0) {
+	    ppa_fail(host_no, DID_ERROR);
+	    return 0;
+	}
+	if (ppa_in(host_no, &l, 1)) {	/* read status byte */
+	    /* Check for optional message byte */
+	    if (ppa_wait(host_no) == (unsigned char) 0xf0)
+		ppa_in(host_no, &h, 1);
+	    cmd->result = (DID_OK << 16) + (h << 8) + (l & STATUS_MASK);
+	}
+	return 0;		/* Finished */
+	break;
+
+    default:
+	printk("ppa: Invalid scsi phase\n");
+    }
+    return 0;
+}
+
+int ppa_queuecommand(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *))
+{
+    int host_no = cmd->host->unique_id;
+
+    if (ppa_hosts[host_no].cur_cmd) {
+	printk("PPA: bug in ppa_queuecommand\n");
+	return 0;
+    }
+    ppa_hosts[host_no].failed = 0;
+    ppa_hosts[host_no].jstart = jiffies;
+    ppa_hosts[host_no].cur_cmd = cmd;
+    cmd->scsi_done = done;
+    cmd->result = DID_ERROR << 16;	/* default return code */
+    cmd->SCp.phase = 0;		/* bus free */
+
+    ppa_pb_claim(host_no);
+
+    ppa_hosts[host_no].ppa_tq.data = ppa_hosts + host_no;
+    ppa_hosts[host_no].ppa_tq.sync = 0;
+    queue_task(&ppa_hosts[host_no].ppa_tq, &tq_immediate);
+    mark_bh(IMMEDIATE_BH);
+
+    return 0;
+}
+
+/*
+ * Apparently the disk->capacity attribute is off by 1 sector 
+ * for all disk drives.  We add the one here, but it should really
+ * be done in sd.c.  Even if it gets fixed there, this will still
+ * work.
+ */
+int ppa_biosparam(Disk * disk, kdev_t dev, int ip[])
+{
+    ip[0] = 0x40;
+    ip[1] = 0x20;
+    ip[2] = (disk->capacity + 1) / (ip[0] * ip[1]);
+    if (ip[2] > 1024) {
+	ip[0] = 0xff;
+	ip[1] = 0x3f;
+	ip[2] = (disk->capacity + 1) / (ip[0] * ip[1]);
+	if (ip[2] > 1023)
+	    ip[2] = 1023;
+    }
+    return 0;
+}
+
+int ppa_abort(Scsi_Cmnd * cmd)
+{
+    /*
+     * There is no method for aborting commands since Iomega
+     * have tied the SCSI_MESSAGE line high in the interface
+     */
+
+    switch (cmd->SCp.phase) {
+    case 0:			/* Do not have access to parport */
+    case 1:			/* Have not connected to interface */
+	cmd->result = DID_ABORT;
+	cmd->done(cmd);
+	return SCSI_ABORT_SUCCESS;
+	break;
+    default:			/* SCSI command sent, can not abort */
+	return SCSI_ABORT_BUSY;
+	break;
+    }
+}
+
+int ppa_reset(Scsi_Cmnd * cmd, unsigned int x)
+{
+    int host_no = cmd->host->unique_id;
+    int ppb = PPA_BASE(host_no);
+
+    /*
+     * PHASE1:
+     * Bring the interface crashing down on whatever is running
+     * hopefully this will kill the request.
+     * Bring back up the interface, reset the drive (and anything
+     * attached for that manner)
+     */
+    if (cmd)
+	if (cmd->SCp.phase)
+	    ppa_disconnect(cmd->host->unique_id);
+
+    ppa_connect(host_no, CONNECT_NORMAL);
+    w_dtr(ppb, 0x40);
+    w_ctr(ppb, 0x8);
+    udelay(30);
+    w_ctr(ppb, 0xc);
+    udelay(1000);		/* delay for devices to settle down */
+    ppa_disconnect(host_no);
+    udelay(1000);		/* Additional delay to allow devices to settle down */
+
+    /*
+     * PHASE2:
+     * Sanity check for the sake of mid-level driver
+     */
+    if (!cmd) {
+	printk("ppa bus reset called for invalid command.\n");
+	return SCSI_RESET_NOT_RUNNING;
+    }
+    /*
+     * PHASE3:
+     * Flag the current command as having died due to reset
+     */
+    ppa_connect(host_no, CONNECT_NORMAL);
+    ppa_fail(host_no, DID_RESET);
+
+    /* Since the command was already on the timer queue ppa_interrupt
+     * will be called shortly.
+     */
+    return SCSI_RESET_PENDING;
+}
+
+static int device_check(int host_no)
+{
+    /* This routine looks for a device and then attempts to use EPP
+       to send a command. If all goes as planned then EPP is available. */
+
+    static char cmd[6] =
+    {0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+    int loop, old_mode, status, k, ppb = PPA_BASE(host_no);
+    unsigned char l;
+
+    old_mode = ppa_hosts[host_no].mode;
+    for (loop = 0; loop < 8; loop++) {
+	/* Attempt to use EPP for Test Unit Ready */
+	if ((ppb & 0x0007) == 0x0000)
+	    ppa_hosts[host_no].mode = PPA_EPP_32;
+
+      second_pass:
+	ppa_connect(host_no, CONNECT_EPP_MAYBE);
+	/* Select SCSI device */
+	if (!ppa_select(host_no, loop)) {
+	    ppa_disconnect(host_no);
+	    continue;
+	}
+	printk("ppa: Found device at ID %i, Attempting to use %s\n", loop,
+	       PPA_MODE_STRING[ppa_hosts[host_no].mode]);
+
+	/* Send SCSI command */
+	status = 1;
+	w_ctr(ppb, 0x0c);
+	for (l = 0; (l < 6) && (status); l++)
+	    status = ppa_out(host_no, cmd, 1);
+
+	if (!status) {
+	    ppa_disconnect(host_no);
+	    ppa_connect(host_no, CONNECT_EPP_MAYBE);
+	    w_dtr(ppb, 0x40);
+	    w_ctr(ppb, 0x08);
+	    udelay(30);
+	    w_ctr(ppb, 0x0c);
+	    udelay(1000);
+	    ppa_disconnect(host_no);
+	    udelay(1000);
+	    if (ppa_hosts[host_no].mode == PPA_EPP_32) {
+		ppa_hosts[host_no].mode = old_mode;
+		goto second_pass;
+	    }
+	    printk("ppa: Unable to establish communication, aborting driver load.\n");
+	    return 1;
+	}
+	w_ctr(ppb, 0x0c);
+	k = 1000000;		/* 1 Second */
+	do {
+	    l = r_str(ppb);
+	    k--;
+	    udelay(1);
+	} while (!(l & 0x80) && (k));
+
+	l &= 0xf0;
+
+	if (l != 0xf0) {
+	    ppa_disconnect(host_no);
+	    ppa_connect(host_no, CONNECT_EPP_MAYBE);
+	    w_dtr(ppb, 0x40);
+	    w_ctr(ppb, 0x08);
+	    udelay(30);
+	    w_ctr(ppb, 0x0c);
+	    udelay(1000);
+	    ppa_disconnect(host_no);
+	    udelay(1000);
+	    if (ppa_hosts[host_no].mode == PPA_EPP_32) {
+		ppa_hosts[host_no].mode = old_mode;
+		goto second_pass;
+	    }
+	    printk("ppa: Unable to establish communication, aborting driver load.\n");
+	    return 1;
+	}
+	ppa_disconnect(host_no);
+	printk("ppa: Communication established with ID %i using %s\n", loop,
+	       PPA_MODE_STRING[ppa_hosts[host_no].mode]);
+	return 0;
+    }
+    printk("ppa: No devices found, aborting driver load.\n");
+    return 1;
+}
+
+#define PPA_ID "ppa: "
+
+int port_probe(unsigned short port)
+{
+    int retv = 0;
+    unsigned char a, b, c;
+    unsigned int i, j;
+
+
+    printk(PPA_ID "Probing port %04x\n", port);
+
+/*                 #####  ######  ######
+ *                #     # #     # #     #
+ *                #       #     # #     #
+ *                 #####  ######  ######
+ *                      # #       #
+ *                #     # #       #
+ *                 #####  #       #
+ */
+
+    outb(0x0c, port + 0x402);
+    outb(0x0c, port + 0x002);
+    outb(0x55, port);
+    a = inb(port);
+    if (a != 0x55)
+	return retv;
+    printk(PPA_ID "    SPP port present\n");
+
+    retv += PPA_PROBE_SPP;
+
+/*                #######  #####  ######
+ *                #       #     # #     #
+ *                #       #       #     #
+ *                #####   #       ######
+ *                #       #       #
+ *                #       #     # #
+ *                #######  #####  #
+ */
+
+    for (i = 1024; i > 0; i--) {	/* clear at most 1k of data from FIFO */
+	a = inb(port + 0x402);
+	if ((a & 0x03) == 0x03)
+	    goto no_ecp;
+	if (a & 0x01)
+	    break;
+	inb(port + 0x400);	/* Remove byte from FIFO */
+    }
+
+    if (i <= 0)
+	goto no_ecp;
+
+    b = a ^ 3;
+    outb(b, port + 0x402);
+    c = inb(port + 0x402);
+
+    if (a == c) {
+	outb(0xc0, port + 0x402);	/* FIFO test */
+	j = 0;
+	while (!(inb(port + 0x402) & 0x01) && (j < 1024)) {
+	    inb(port + 0x400);
+	    j++;
+	}
+	if (j >= 1024)
+	    goto no_ecp;
+	i = 0;
+	j = 0;
+	while (!(inb(port + 0x402) & 0x02) && (j < 1024)) {
+	    outb(0x00, port + 0x400);
+	    i++;
+	    j++;
+	}
+	if (j >= 1024)
+	    goto no_ecp;
+	j = 0;
+	while (!(inb(port + 0x402) & 0x01) && (j < 1024)) {
+	    inb(port + 0x400);
+	    j++;
+	}
+	if (j >= 1024)
+	    goto no_ecp;
+	printk(PPA_ID "    ECP with a %i byte FIFO present\n", i);
+
+	retv += PPA_PROBE_ECR;
+    }
+/*                ######   #####   #####
+ *                #     # #     # #     #
+ *                #     # #             #
+ *                ######   #####   #####
+ *                #             # #
+ *                #       #     # #
+ *                #        #####  #######
+ */
+
+  no_ecp:
+    if (retv & PPA_PROBE_ECR)
+	outb(0x20, port + 0x402);
+
+    outb(0x55, port);
+    outb(0x0c, port + 2);
+    a = inb(port);
+    outb(0x55, port);
+    outb(0x2c, port + 2);
+    b = inb(port);
+    if (a != b) {
+	printk(PPA_ID "    PS/2 bidirectional port present\n");
+	retv += PPA_PROBE_PS2;
+    }
+/*                ####### ######  ######
+ *                #       #     # #     #
+ *                #       #     # #     #
+ *                #####   ######  ######
+ *                #       #       #
+ *                #       #       #
+ *                ####### #       #
+ */
+
+    if (port & 0x007) {
+	printk(PPA_ID "    EPP not supported at this address\n");
+	return retv;
+    }
+    if (retv & PPA_PROBE_ECR) {
+	for (i = 0x00; i < 0x80; i += 0x20) {
+	    outb(i, port + 0x402);
+
+	    a = inb(port + 1);
+	    outb(a, port + 1);
+	    outb(a & 0xfe, port + 1);
+	    a = inb(port + 1);
+	    if (!(a & 0x01)) {
+		printk(PPA_ID "    Failed Intel bug check. (Phony EPP in ECP)\n");
+		return retv;
+	    }
+	}
+	printk(PPA_ID "    Passed Intel bug check.\n");
+	outb(0x80, port + 0x402);
+    }
+    a = inb(port + 1);
+    outb(a, port + 1);
+    outb(a & 0xfe, port + 1);
+    a = inb(port + 1);
+
+    if (a & 0x01) {
+	outb(0x0c, port + 0x402);
+	outb(0x0c, port + 0x002);
+	return retv;
+    }
+
+    outb(0x04, port + 2);
+    inb(port + 4);
+    a = inb(port + 1);
+    outb(a, port + 1);
+    outb(a & 0xfe, port + 1);
+
+    if (a & 0x01) {
+	printk(PPA_ID "    EPP 1.9 with hardware direction protocol\n");
+	retv += PPA_PROBE_EPP19;
+    } else {
+	/* The EPP timeout bit was not set, this could either be:
+	 * EPP 1.7
+	 * EPP 1.9 with software direction
+	 */
+	outb(0x24, port + 2);
+	inb(port + 4);
+	a = inb(port + 1);
+	outb(a, port + 1);
+	outb(a & 0xfe, port + 1);
+	if (a & 0x01) {
+	    printk(PPA_ID "    EPP 1.9 with software direction protocol\n");
+	    retv += PPA_PROBE_EPP19;
+	} else {
+	    printk(PPA_ID "    EPP 1.7\n");
+	    retv += PPA_PROBE_EPP17;
+	}
+    }
+
+    outb(0x0c, port + 0x402);
+    outb(0x0c, port + 0x002);
+    return retv;
+}