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

    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;
}