Lowlevel i/o routines for ZIP+ support. Mostly written with microseq

mechanism

1 files changed, 771 insertions, 0 deletions

diff --git a/sys/dev/ppbus/immio.c b/sys/dev/ppbus/immio.c
new file mode 100644
index 0000000..47ac638
--- /dev/null
+++ b/sys/dev/ppbus/immio.c
@@ -0,0 +1,771 @@
+/*-
+ * Copyright (c) 1998 Nicolas Souchu
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	$Id$
+ *
+ */
+
+/*
+ * Iomega ZIP+ Matchmaker Parallel Port Interface driver
+ *
+ * Thanks to David Campbell work on the Linux driver and the Iomega specs
+ * Thanks to Thiebault Moeglin for the drive
+ */
+#ifdef KERNEL
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/malloc.h>
+#include <sys/buf.h>
+
+#include <machine/clock.h>
+
+#endif	/* KERNEL */
+
+#ifdef	KERNEL
+#include <sys/kernel.h>
+#endif /*KERNEL */
+
+#include <dev/ppbus/ppbconf.h>
+#include <dev/ppbus/ppb_msq.h>
+#include <dev/ppbus/vpoio.h>
+#include <dev/ppbus/ppb_1284.h>
+
+#define VP0_SELTMO		5000	/* select timeout */
+#define VP0_FAST_SPINTMO	500000	/* wait status timeout */
+#define VP0_LOW_SPINTMO		5000000	/* wait status timeout */
+
+#define VP0_SECTOR_SIZE	512
+
+/*
+ * Microcode to execute very fast I/O sequences at the lowest bus level.
+ */
+
+#define SELECT_TARGET		MS_PARAM(6, 1, MS_TYP_CHA)
+
+#define DECLARE_SELECT_MICROSEQUENCE					\
+struct ppb_microseq select_microseq[] = {				\
+	MS_CASS(0xc),							\
+	/* first, check there is nothing holding onto the bus */	\
+	MS_SET(VP0_SELTMO),						\
+/* _loop: */								\
+	MS_BRCLEAR(0x8, 3 /* _ready */),				\
+	MS_DBRA(-1 /* _loop */),					\
+	MS_RET(2),			/* bus busy */			\
+/* _ready: */								\
+	MS_CASS(0x4),							\
+	MS_DASS(MS_UNKNOWN /* 0x80 | 1 << target */),			\
+	MS_DELAY(1),							\
+	MS_CASS(0xc),							\
+	MS_CASS(0xd),							\
+	/* now, wait until the drive is ready */			\
+	MS_SET(VP0_SELTMO),						\
+/* loop: */								\
+	MS_BRSET(0x8, 4 /* ready */),					\
+	MS_DBRA(-1 /* loop */),						\
+/* error: */								\
+	MS_CASS(0xc),							\
+	MS_RET(VP0_ESELECT_TIMEOUT),					\
+/* ready: */								\
+	MS_CASS(0xc),							\
+	MS_RET(0)							\
+}
+
+static struct ppb_microseq transfer_epilog[] = {
+	MS_CASS(0x4),
+	MS_CASS(0xc),
+	MS_CASS(0xe),
+	MS_CASS(0x4),
+	MS_RET(0)
+};
+
+#define CPP_S1		MS_PARAM(10, 2, MS_TYP_PTR)
+#define CPP_S2		MS_PARAM(13, 2, MS_TYP_PTR)
+#define CPP_S3		MS_PARAM(16, 2, MS_TYP_PTR)
+#define CPP_PARAM	MS_PARAM(17, 1, MS_TYP_CHA)
+
+#define DECLARE_CPP_MICROSEQ \
+struct ppb_microseq cpp_microseq[] = {					\
+	MS_CASS(0x0c), MS_DELAY(2),					\
+	MS_DASS(0xaa), MS_DELAY(10),					\
+	MS_DASS(0x55), MS_DELAY(10),					\
+	MS_DASS(0x00), MS_DELAY(10),					\
+	MS_DASS(0xff), MS_DELAY(10),					\
+	MS_RFETCH(MS_REG_STR, 0xb8, MS_UNKNOWN /* &s1 */),		\
+	MS_DASS(0x87), MS_DELAY(10),					\
+	MS_RFETCH(MS_REG_STR, 0xb8, MS_UNKNOWN /* &s2 */),		\
+	MS_DASS(0x78), MS_DELAY(10),					\
+	MS_RFETCH(MS_REG_STR, 0x38, MS_UNKNOWN /* &s3 */),		\
+	MS_DASS(MS_UNKNOWN /* param */),				\
+	MS_DELAY(2),							\
+	MS_CASS(0x0c), MS_DELAY(10),					\
+	MS_CASS(0x0d), MS_DELAY(2),					\
+	MS_CASS(0x0c), MS_DELAY(10),					\
+	MS_DASS(0xff), MS_DELAY(10),					\
+	MS_RET(0)							\
+}
+
+#define NEGOCIATED_MODE		MS_PARAM(2, 1, MS_TYP_CHA)
+
+#define DECLARE_NEGOCIATE_MICROSEQ \
+static struct ppb_microseq negociate_microseq[] = { 			\
+	MS_CASS(0x4),							\
+	MS_DELAY(5),							\
+	MS_DASS(MS_UNKNOWN /* mode */),					\
+	MS_DELAY(100),							\
+	MS_CASS(0x6),							\
+	MS_DELAY(5),							\
+	MS_BRSET(0x20, 6 /* continue */),				\
+	MS_DELAY(5),							\
+	MS_CASS(0x7),							\
+	MS_DELAY(5),							\
+	MS_CASS(0x6),							\
+	MS_RET(VP0_ENEGOCIATE),						\
+/* continue: */								\
+	MS_DELAY(5),							\
+	MS_CASS(0x7),							\
+	MS_DELAY(5),							\
+	MS_CASS(0x6),							\
+	MS_RET(0)							\
+}
+
+static struct ppb_microseq reset_microseq[] = {
+	MS_CASS(0x04),
+	MS_DASS(0x40),
+	MS_DELAY(1),
+	MS_CASS(0x0c),
+	MS_CASS(0x0d),
+	MS_DELAY(50),
+	MS_CASS(0x0c),
+	MS_CASS(0x04),
+	MS_RET(0)
+};
+
+/*
+ * nibble_inbyte_hook()
+ *
+ * Formats high and low nibble into a character
+ */
+static int
+nibble_inbyte_hook (void *p, char *ptr)
+{
+	struct vpo_nibble *s = (struct vpo_nibble *)p;
+
+	/* increment the buffer pointer */
+	*ptr = ((s->l >> 4) & 0x0f) + (s->h & 0xf0);
+
+	return (0);
+}
+
+/*
+ * Macro used to initialize each vpoio_data structure during
+ * low level attachment
+ *
+ * XXX should be converted to ppb_MS_init_msq()
+ */
+#define INIT_NIBBLE_INBYTE_SUBMICROSEQ(vpo) {		    	\
+	(vpo)->vpo_nibble_inbyte_msq[6].arg[2].p =		\
+			(void *)&(vpo)->vpo_nibble.h;		\
+	(vpo)->vpo_nibble_inbyte_msq[3].arg[2].p =		\
+			(void *)&(vpo)->vpo_nibble.l;		\
+	(vpo)->vpo_nibble_inbyte_msq[9].arg[0].f =		\
+			nibble_inbyte_hook;			\
+	(vpo)->vpo_nibble_inbyte_msq[9].arg[1].p =		\
+			(void *)&(vpo)->vpo_nibble;		\
+}
+
+/*
+ * This is the sub-microseqence for MS_GET in NIBBLE mode
+ * Retrieve the two nibbles and call the C function to generate the character
+ * and store it in the buffer (see nibble_inbyte_hook())
+ */
+static struct ppb_microseq nibble_inbyte_submicroseq[] = {
+	  MS_CASS(0x4),
+
+/* loop: */
+	  MS_CASS(0x6),
+	  MS_DELAY(1),
+	  MS_RFETCH(MS_REG_STR, MS_FETCH_ALL, MS_UNKNOWN /* low nibble */),
+	  MS_CASS(0x5),
+	  MS_DELAY(1),
+	  MS_RFETCH(MS_REG_STR, MS_FETCH_ALL, MS_UNKNOWN /* high nibble */),
+	  MS_CASS(0x4),
+	  MS_DELAY(1),
+
+	  /* do a C call to format the received nibbles */
+	  MS_C_CALL(MS_UNKNOWN /* C hook */, MS_UNKNOWN /* param */),
+	  MS_DBRA(-6 /* loop */),
+	  MS_RET(0)
+};
+
+/*
+ * This is the sub-microseqence for MS_GET in PS2 mode
+ */
+static struct ppb_microseq ps2_inbyte_submicroseq[] = {
+	  MS_CASS(0x4),
+
+/* loop: */
+	  MS_CASS(PCD | 0x6),
+	  MS_RFETCH_P(1, MS_REG_DTR, MS_FETCH_ALL),
+	  MS_CASS(PCD | 0x5),
+	  MS_DBRA(-3 /* loop */),
+
+	  MS_RET(0)
+};
+
+/*
+ * This is the sub-microsequence for MS_PUT in both NIBBLE and PS2 modes
+ */
+static struct ppb_microseq spp_outbyte_submicroseq[] = {
+	  MS_CASS(0x4),
+
+/* loop: */
+	  MS_RASSERT_P(1, MS_REG_DTR), 
+	  MS_CASS(0x5),
+	  MS_DBRA(1),				/* decrement counter */
+	  MS_RASSERT_P(1, MS_REG_DTR), 
+	  MS_CASS(0x0),
+	  MS_DBRA(-5 /* loop */),
+
+	  /* return from the put call */
+	  MS_CASS(0x4),
+	  MS_RET(0)
+};
+
+/* EPP 1.7 microsequences, ptr and len set at runtime */
+static struct ppb_microseq epp17_outstr[] = {
+	  MS_CASS(0x4),
+	  MS_RASSERT_P(MS_ACCUM, MS_REG_EPP), 
+	  MS_CASS(0xc),
+	  MS_RET(0),
+};
+
+static struct ppb_microseq epp17_instr[] = {
+	  MS_CASS(PCD | 0x4),
+	  MS_RFETCH_P(MS_ACCUM, MS_REG_EPP, MS_FETCH_ALL), 
+	  MS_CASS(PCD | 0xc),
+	  MS_RET(0),
+};
+
+static int
+imm_disconnect(struct vpoio_data *vpo, int *disconnected)
+{
+	DECLARE_CPP_MICROSEQ;
+
+	char s1, s2, s3;
+	int ret;
+
+	/* all should be ok */
+	if (disconnected)
+		*disconnected = 0;
+
+	ppb_MS_init_msq(cpp_microseq, 4, CPP_S1, (void *)&s1,
+			CPP_S2, (void *)&s2, CPP_S3, (void *)&s3,
+			CPP_PARAM, 0x30);
+
+	ppb_MS_microseq(&vpo->vpo_dev, cpp_microseq, &ret);
+
+	if ((s1 != (char)0xb8 || s2 != (char)0x18 || s3 != (char)0x38) &&
+								disconnected)
+		*disconnected = VP0_ECONNECT;
+
+	return (ppb_release_bus(&vpo->vpo_dev));
+}
+
+/*
+ * how	: PPB_WAIT or PPB_DONTWAIT
+ */
+static int
+imm_connect(struct vpoio_data *vpo, int how, int *not_connected)
+{
+	DECLARE_CPP_MICROSEQ;
+
+	char s1, s2, s3;
+	int error;
+	int ret;
+
+	/* all should be ok */
+	if (not_connected)
+		*not_connected = 0;
+
+	if ((error = ppb_request_bus(&vpo->vpo_dev, how)))
+		return (error);
+
+	ppb_MS_init_msq(cpp_microseq, 3, CPP_S1, (void *)&s1,
+			CPP_S2, (void *)&s2, CPP_S3, (void *)&s3);
+
+	/* select device 0 in compatible mode */
+	ppb_MS_init_msq(cpp_microseq, 1, CPP_PARAM, 0xe0);
+	ppb_MS_microseq(&vpo->vpo_dev, cpp_microseq, &ret);
+
+	/* disconnect all devices */
+	ppb_MS_init_msq(cpp_microseq, 1, CPP_PARAM, 0x30);
+	ppb_MS_microseq(&vpo->vpo_dev, cpp_microseq, &ret);
+
+	if (PPB_IN_EPP_MODE(&vpo->vpo_dev))
+		ppb_MS_init_msq(cpp_microseq, 1, CPP_PARAM, 0x28);
+	else
+		ppb_MS_init_msq(cpp_microseq, 1, CPP_PARAM, 0xe0);
+
+	ppb_MS_microseq(&vpo->vpo_dev, cpp_microseq, &ret);
+
+	if ((s1 != (char)0xb8 || s2 != (char)0x18 || s3 != (char)0x30)
+							&& not_connected)
+		*not_connected = VP0_ECONNECT;
+
+	return (0);
+}
+
+/*
+ * imm_detect()
+ *
+ * Detect and initialise the VP0 adapter.
+ */
+static int
+imm_detect(struct vpoio_data *vpo)
+{
+	int error;
+
+	imm_disconnect(vpo, NULL);
+	imm_connect(vpo, PPB_DONTWAIT, &error);
+
+	if (error)
+		return (VP0_EINITFAILED);
+
+	/* send SCSI reset signal */
+	ppb_MS_microseq(&vpo->vpo_dev, reset_microseq, NULL);
+
+	imm_disconnect(vpo, &error);
+
+	/* ensure we are disconnected or daisy chained peripheral 
+	 * may cause serious problem to the disk */
+
+	if (error)
+		return (VP0_EINITFAILED);
+
+	return (0);
+}
+
+/*
+ * imm_outstr()
+ */
+static int
+imm_outstr(struct vpoio_data *vpo, char *buffer, int size)
+{
+	int error = 0;
+
+	if (PPB_IN_EPP_MODE(&vpo->vpo_dev))
+		ppb_reset_epp_timeout(&vpo->vpo_dev);
+
+	ppb_MS_exec(&vpo->vpo_dev, MS_OP_PUT, buffer, size, MS_UNKNOWN, &error);
+
+	return (error);
+}
+
+/*
+ * imm_instr()
+ */
+static int
+imm_instr(struct vpoio_data *vpo, char *buffer, int size)
+{
+	int error = 0;
+
+	if (PPB_IN_EPP_MODE(&vpo->vpo_dev))
+		ppb_reset_epp_timeout(&vpo->vpo_dev);
+
+	ppb_MS_exec(&vpo->vpo_dev, MS_OP_GET, buffer, size, MS_UNKNOWN, &error);
+
+	return (error);
+}
+
+static char
+imm_select(struct vpoio_data *vpo, int initiator, int target)
+{
+	DECLARE_SELECT_MICROSEQUENCE;
+	int ret;
+
+	/* initialize the select microsequence */
+	ppb_MS_init_msq(select_microseq, 1,
+			SELECT_TARGET, 1 << initiator | 1 << target);
+				
+	ppb_MS_microseq(&vpo->vpo_dev, select_microseq, &ret);
+
+	return (ret);
+}
+
+/*
+ * imm_wait()
+ *
+ * H_SELIN must be low.
+ *
+ * XXX should be ported to microseq
+ */
+static char
+imm_wait(struct vpoio_data *vpo, int tmo)
+{
+
+	register int	k;
+	register char	r;
+
+	ppb_wctr(&vpo->vpo_dev, 0xc);
+
+	/* XXX should be ported to microseq */
+	k = 0;
+	while (!((r = ppb_rstr(&vpo->vpo_dev)) & 0x80) && (k++ < tmo))
+		DELAY(1);
+
+	/*
+	 * Return some status information.
+	 * Semantics :	0x88 = ZIP+ wants more data
+	 *		0x98 = ZIP+ wants to send more data
+	 *		0xa8 = ZIP+ wants command
+	 *		0xb8 = end of transfer, ZIP+ is sending status
+	 */
+	ppb_wctr(&vpo->vpo_dev, 0x4);
+	if (k < tmo)
+	  return (r & 0xb8);
+
+	return (0);			   /* command timed out */	
+}
+
+static int
+imm_negociate(struct vpoio_data *vpo)
+{
+	DECLARE_NEGOCIATE_MICROSEQ;
+	int negociate_mode;
+	int ret;
+
+	if (PPB_IN_NIBBLE_MODE(&vpo->vpo_dev))
+		negociate_mode = 0;
+	else if (PPB_IN_PS2_MODE(&vpo->vpo_dev))
+		negociate_mode = 1;
+	else
+		return (0);
+
+#if 0 /* XXX use standalone code not to depend on ppb_1284 code yet */
+	ret = ppb_1284_negociate(&vpo->vpo_dev, negociate_mode);
+
+	if (ret)
+		return (VP0_ENEGOCIATE);
+#endif
+	
+	ppb_MS_init_msq(negociate_microseq, 1, NEGOCIATED_MODE, negociate_mode);
+
+	ppb_MS_microseq(&vpo->vpo_dev, negociate_microseq, &ret);
+
+	return (ret);
+}
+
+/*
+ * imm_probe()
+ *
+ * Low level probe of vpo device
+ *
+ */
+struct ppb_device *
+imm_probe(struct ppb_data *ppb, struct vpoio_data *vpo)
+{
+
+	/* ppbus dependent initialisation */
+	vpo->vpo_dev.id_unit = vpo->vpo_unit;
+	vpo->vpo_dev.name = "vpo";
+	vpo->vpo_dev.ppb = ppb;
+
+	/* now, try to initialise the drive */
+	if (imm_detect(vpo)) {
+		return (NULL);
+	}
+
+	return (&vpo->vpo_dev);
+}
+
+/*
+ * imm_attach()
+ *
+ * Low level attachment of vpo device
+ *
+ */
+int
+imm_attach(struct vpoio_data *vpo)
+{
+	int epp;
+
+	/*
+	 * Report ourselves
+	 */
+	printf("imm%d: <Iomega Matchmaker Parallel to SCSI interface> on ppbus %d\n",
+		vpo->vpo_dev.id_unit, vpo->vpo_dev.ppb->ppb_link->adapter_unit);
+
+	/*
+	 * Initialize microsequence code
+	 */
+	vpo->vpo_nibble_inbyte_msq = (struct ppb_microseq *)malloc(
+		sizeof(nibble_inbyte_submicroseq), M_DEVBUF, M_NOWAIT);
+
+	if (!vpo->vpo_nibble_inbyte_msq)
+		return (0);
+
+	bcopy((void *)nibble_inbyte_submicroseq,
+		(void *)vpo->vpo_nibble_inbyte_msq,
+		sizeof(nibble_inbyte_submicroseq));
+
+	INIT_NIBBLE_INBYTE_SUBMICROSEQ(vpo);
+
+	/*
+	 * Initialize mode dependent in/out microsequences
+	 */
+	ppb_request_bus(&vpo->vpo_dev, PPB_WAIT);
+
+	/* enter NIBBLE mode to configure submsq */
+	if (ppb_set_mode(&vpo->vpo_dev, PPB_NIBBLE) != -1) {
+
+		ppb_MS_GET_init(&vpo->vpo_dev, vpo->vpo_nibble_inbyte_msq);
+		ppb_MS_PUT_init(&vpo->vpo_dev, spp_outbyte_submicroseq);
+	}
+
+	/* enter PS2 mode to configure submsq */
+	if (ppb_set_mode(&vpo->vpo_dev, PPB_PS2) != -1) {
+
+		ppb_MS_GET_init(&vpo->vpo_dev, ps2_inbyte_submicroseq);
+		ppb_MS_PUT_init(&vpo->vpo_dev, spp_outbyte_submicroseq);
+	}
+
+	epp = ppb_get_epp_protocol(&vpo->vpo_dev);
+
+	/* enter EPP mode to configure submsq */
+	if (ppb_set_mode(&vpo->vpo_dev, PPB_EPP) != -1) {
+
+		switch (epp) {
+		case EPP_1_9:
+		case EPP_1_7:
+			ppb_MS_GET_init(&vpo->vpo_dev, epp17_instr);
+			ppb_MS_PUT_init(&vpo->vpo_dev, epp17_outstr);
+			break;
+		default:
+			panic("%s: unknown EPP protocol (0x%x)", __FUNCTION__,
+				epp);
+		}
+	}
+
+	/* try to enter EPP or PS/2 mode, NIBBLE otherwise */
+	if (ppb_set_mode(&vpo->vpo_dev, PPB_EPP) != -1) {
+		switch (epp) {
+		case EPP_1_9:
+			printf("imm%d: EPP 1.9 mode\n", vpo->vpo_unit);
+			break;
+		case EPP_1_7:
+			printf("imm%d: EPP 1.7 mode\n", vpo->vpo_unit);
+			break;
+		default:
+			panic("%s: unknown EPP protocol (0x%x)", __FUNCTION__,
+				epp);
+		}
+	} else if (ppb_set_mode(&vpo->vpo_dev, PPB_PS2) != -1)
+		printf("imm%d: PS2 mode\n", vpo->vpo_unit);
+
+	else if (ppb_set_mode(&vpo->vpo_dev, PPB_NIBBLE) != -1)
+		printf("imm%d: NIBBLE mode\n", vpo->vpo_unit);
+
+	else {
+		printf("imm%d: can't enter NIBBLE, PS2 or EPP mode\n",
+			vpo->vpo_unit);
+
+		ppb_release_bus(&vpo->vpo_dev);
+
+		free(vpo->vpo_nibble_inbyte_msq, M_DEVBUF);
+		return (0);
+	}
+
+	ppb_release_bus(&vpo->vpo_dev);
+
+	return (1);
+}
+
+/*
+ * imm_reset_bus()
+ *
+ */
+int
+imm_reset_bus(struct vpoio_data *vpo)
+{
+	int not_connected;
+
+	/* first, connect to the drive */
+	imm_connect(vpo, PPB_WAIT|PPB_INTR, &not_connected);
+
+	if (!not_connected) {
+
+		/* reset the SCSI bus */
+		ppb_MS_microseq(&vpo->vpo_dev, reset_microseq, NULL);
+
+		/* then disconnect */
+		imm_disconnect(vpo, NULL);
+	}
+
+	return (0);
+}
+
+/*
+ * imm_do_scsi()
+ *
+ * Send an SCSI command
+ *
+ */
+int 
+imm_do_scsi(struct vpoio_data *vpo, int host, int target, char *command,
+		int clen, char *buffer, int blen, int *result, int *count,
+		int *ret)
+{
+
+	register char r;
+	char l, h = 0;
+	int len, error = 0, not_connected = 0;
+	register int k;
+	int negociated = 0;
+
+	/*
+	 * enter disk state, allocate the ppbus
+	 *
+	 * XXX
+	 * Should we allow this call to be interruptible?
+	 * The only way to report the interruption is to return
+	 * EIO do upper SCSI code :^(
+	 */
+	if ((error = imm_connect(vpo, PPB_WAIT|PPB_INTR, &not_connected)))
+		return (error);
+
+	if (not_connected) {
+		*ret = VP0_ECONNECT; goto error;
+	}
+
+	/*
+	 * Select the drive ...
+	 */
+	if ((*ret = imm_select(vpo,host,target)))
+		goto error;
+
+	/*
+	 * Send the command ...
+	 */
+	for (k = 0; k < clen; k+=2) {
+		if (imm_wait(vpo, VP0_FAST_SPINTMO) != (char)0xa8) {
+			*ret = VP0_ECMD_TIMEOUT;
+			goto error;
+		}
+		if (imm_outstr(vpo, &command[k], 2)) {
+			*ret = VP0_EPPDATA_TIMEOUT;
+			goto error;
+		}
+	}
+
+	if (!(r = imm_wait(vpo, VP0_LOW_SPINTMO))) {
+		*ret = VP0_ESTATUS_TIMEOUT; goto error;
+	}
+
+	if ((r & 0x30) == 0x10) {
+		if (imm_negociate(vpo)) {
+			*ret = VP0_ENEGOCIATE;
+			goto error;
+		} else
+			negociated = 1;
+	}
+
+	/* 
+	 * Complete transfer ... 
+	 */
+	*count = 0;
+	for (;;) {
+
+		if (!(r = imm_wait(vpo, VP0_LOW_SPINTMO))) {
+			*ret = VP0_ESTATUS_TIMEOUT; goto error;
+		}
+
+		/* stop when the ZIP+ wants to send status */
+		if (r == (char)0xb8)
+			break;
+
+		if (*count >= blen) {
+			*ret = VP0_EDATA_OVERFLOW;
+			goto error;
+		}
+
+		/* ZIP+ wants to send data? */
+		if (r == (char)0x88) {
+			len = (((blen - *count) >= VP0_SECTOR_SIZE)) ?
+				VP0_SECTOR_SIZE : 2;
+
+			error = imm_outstr(vpo, &buffer[*count], len);
+		} else {
+			if (!PPB_IN_EPP_MODE(&vpo->vpo_dev))
+				len = 1;
+			else
+				len = (((blen - *count) >= VP0_SECTOR_SIZE)) ?
+					VP0_SECTOR_SIZE : 1;
+
+			error = imm_instr(vpo, &buffer[*count], len);
+		}
+
+		if (error) {
+			*ret = error;
+			goto error;
+		}
+
+		*count += len;
+	}
+
+	if ((PPB_IN_NIBBLE_MODE(&vpo->vpo_dev) ||
+			PPB_IN_PS2_MODE(&vpo->vpo_dev)) && negociated)
+		ppb_MS_microseq(&vpo->vpo_dev, transfer_epilog, NULL);
+
+	/*
+	 * Retrieve status ...
+	 */
+	if (imm_negociate(vpo)) {
+		*ret = VP0_ENEGOCIATE;
+		goto error;
+	} else
+		negociated = 1;
+
+	if (imm_instr(vpo, &l, 1)) {
+		*ret = VP0_EOTHER; goto error;
+	}
+
+	/* check if the ZIP+ wants to send more status */
+	if (imm_wait(vpo, VP0_FAST_SPINTMO) == (char)0xb8)
+		if (imm_instr(vpo, &h, 1)) {
+			*ret = VP0_EOTHER+2; goto error;
+		}
+
+	*result = ((int) h << 8) | ((int) l & 0xff);
+
+error:
+	if ((PPB_IN_NIBBLE_MODE(&vpo->vpo_dev) ||
+			PPB_IN_PS2_MODE(&vpo->vpo_dev)) && negociated)
+		ppb_MS_microseq(&vpo->vpo_dev, transfer_epilog, NULL);
+
+	/* return to printer state, release the ppbus */
+	imm_disconnect(vpo, NULL);
+
+	return (0);
+}