xt.c

操作系统SunOS 4.1.3版本的源码

/*
 * Standalone driver for Xylogics 472 Tape Controller
 *
 * @(#)xt.c 1.1 92/07/30 Copyright (c) 1985 by Sun Microsystems, Inc.
 */
#ifndef XTBOOT
#ifndef lint
static	char sccsid[] = "@(#)xt.c 1.1 92/07/30 Copyr 1985 Sun Micro";
#endif	lint
#endif	XTBOOT

#include <mon/cpu.addrs.h>
#include <stand/saio.h>
#include <sundev/xycreg.h>
#include <sundev/xtreg.h>

#define NXTADDR	2
unsigned long xtaddrs[] = { 0xEE60, 0xEE68 };

#define MAXXTREC	(20*1024)	/* max size tape rec allowed */

struct xtdma {
	struct xtiopb	xtiopb;
	char 		xtblock[MAXXTREC];
};

/* Define resources needed by this driver */
struct devinfo xtinfo = {
	sizeof(struct xydevice), sizeof (struct xtdma), 0,
	NXTADDR, xtaddrs, MAP_MBIO,
	MAXXTREC,
};

int	xtstrategy(), xtopen(), xtclose();
extern int	nullsys(), ttboot();

struct boottab xtdriver = {
	"xt",	nullsys, ttboot, xtopen, xtclose, xtstrategy,
	"xt: Xylogics 472 tape",	&xtinfo,
};

xtopen(sip)
	register struct saioreq *sip;
{
	register skip;
	register struct xydevice *xyaddr;

	xyaddr = (struct xydevice *) sip->si_devaddr;

	/* Verify that xt is really present */
	if (peekc((char *)&xyaddr->xy_csr) == -1)
		return (-1);

	skip = xyaddr->xy_resupd;	/* controller reset */
	xtcmd(sip, XT_SEEK, XT_REW);
	skip = sip->si_boff;
	while (skip--) {
		sip->si_cc = 0;
		xtcmd(sip, XT_SEEK, XT_FILE);
	}
	return (0);
}

/*ARGSUSED*/
xtclose(sip)
	struct saioreq *sip;
{
	/*xtcmd(sip, XT_SEEK, XT_REW);*/
}

xtstrategy(sip, rw)
	struct saioreq *sip;
	int rw;
{
	int func = (rw == WRITE) ? XT_WRITE : XT_READ;

	return xtcmd(sip, func, 0);
}

xtcmd(sip, func, subfunc)
	register struct saioreq *sip;
{
	register struct xtiopb *xt = &((struct xtdma *)sip->si_dmaaddr)->xtiopb;
	register struct xydevice *xyaddr = (struct xydevice *)sip->si_devaddr;
	char *xtbuf = ((struct xtdma *)sip->si_dmaaddr)->xtblock;
	int err, t;

	/* If user buffer in DVMA space, use it instead of ours */
	if (sip->si_ma >= DVMA_BASE) 
		xtbuf = sip->si_ma;

	bzero((char *)xt, sizeof (struct xtiopb));
	xt->xt_reloc = 1;
	xt->xt_autoup = 1;
	xt->xt_cmd = func;
	xt->xt_subfunc = subfunc;
	xt->xt_unit = sip->si_unit & 3;
	xt->xt_throttle = 5;


	/* If destination buffer is in DVMA space, use it directly */

	switch (func) {
	case XT_READ:
		xt->xt_cnt = sip->si_cc;
		xt->xt_swab = 1;
		xt->xt_retry = 1;
		break;

	case XT_WRITE:
		if (sip->si_ma < DVMA_BASE)
			bcopy((char *)sip->si_ma, xtbuf, xt->xt_cnt);
		xt->xt_cnt = sip->si_cc;
		xt->xt_swab = 1;
		xt->xt_retry = 1;
		break;

	default:
		xt->xt_cnt = 1;
		break;
	}
	xt->xt_bufoff = XYOFF(xtbuf);
	xt->xt_bufrel = XYREL(xyaddr, xtbuf);

	t = XYREL(xyaddr, (char *)xt);
	xyaddr->xy_iopbrel[0] = t >> 8;
	xyaddr->xy_iopbrel[1] = t;
	xyaddr->xy_iopboff[0] = ((int)xt) >> 8;
	xyaddr->xy_iopboff[1] = (int)xt;
	xyaddr->xy_csr = XY_GO;

	do {
   		DELAY(30);
    } while (xyaddr->xy_csr & XY_BUSY);
	err = xt->xt_errno;

	if ( err != XTE_DLATE && err != XTE_NOERROR && err != XTE_SHORTREC && 
		err != XTE_LONGREC) {
		if (err == XTE_EOF || err == XTE_EOT)
			return (0);
		/* Note: controller does retries for us */
		printf("xt: hard err %x\n", err);
		return (-1);
	}

	/* If user buffer not in DVMA space, copy data to it */
	if (func == XT_READ  &&  sip->si_ma < DVMA_BASE)
		bcopy(xtbuf, (char *)sip->si_ma, xt->xt_acnt);
	return (xt->xt_acnt);
}