ppa.c

GNU Mach 微内核源代码, 基于美国卡内基美隆大学的 Mach 研究项目

/* 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, [e-mail],
 * under the terms of the GNU Public License.
 *
 * Current Maintainer: David Campbell (Perth, Western Australia)
 *                     [e-mail]
 *                     [e-mail]
 *
 * 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)
{
    int i;

    for (i = len; i; i--) {
        w_dtr(base, *buffer++);
        w_ctr(base, 0xe);
        w_ctr(base, 0xc);
    }
    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" \