Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 824 insertions, 0 deletions

diff --git a/drivers/usb/misc/uss720.c b/drivers/usb/misc/uss720.c
new file mode 100644
index 0000000000..b00d92db5d
--- /dev/null
+++ b/drivers/usb/misc/uss720.c
@@ -0,0 +1,824 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*****************************************************************************/
+
+/*
+ *	uss720.c  --  USS720 USB Parport Cable.
+ *
+ *	Copyright (C) 1999, 2005, 2010
+ *	    Thomas Sailer (t.sailer@alumni.ethz.ch)
+ *
+ *  Based on parport_pc.c
+ *
+ *  History:
+ *   0.1  04.08.1999  Created
+ *   0.2  07.08.1999  Some fixes mainly suggested by Tim Waugh
+ *		      Interrupt handling currently disabled because
+ *		      usb_request_irq crashes somewhere within ohci.c
+ *		      for no apparent reason (that is for me, anyway)
+ *		      ECP currently untested
+ *   0.3  10.08.1999  fixing merge errors
+ *   0.4  13.08.1999  Added Vendor/Product ID of Brad Hard's cable
+ *   0.5  20.09.1999  usb_control_msg wrapper used
+ *        Nov01.2000  usb_device_table support by Adam J. Richter
+ *        08.04.2001  Identify version on module load.  gb
+ *   0.6  02.09.2005  Fix "scheduling in interrupt" problem by making save/restore
+ *                    context asynchronous
+ *
+ */
+
+/*****************************************************************************/
+
+#include <linux/module.h>
+#include <linux/socket.h>
+#include <linux/parport.h>
+#include <linux/init.h>
+#include <linux/usb.h>
+#include <linux/delay.h>
+#include <linux/completion.h>
+#include <linux/kref.h>
+#include <linux/slab.h>
+#include <linux/sched/signal.h>
+
+#define DRIVER_AUTHOR "Thomas M. Sailer, t.sailer@alumni.ethz.ch"
+#define DRIVER_DESC "USB Parport Cable driver for Cables using the Lucent Technologies USS720 Chip"
+
+/* --------------------------------------------------------------------- */
+
+struct parport_uss720_private {
+	struct usb_device *usbdev;
+	struct parport *pp;
+	struct kref ref_count;
+	__u8 reg[7];  /* USB registers */
+	struct list_head asynclist;
+	spinlock_t asynclock;
+};
+
+struct uss720_async_request {
+	struct parport_uss720_private *priv;
+	struct kref ref_count;
+	struct list_head asynclist;
+	struct completion compl;
+	struct urb *urb;
+	struct usb_ctrlrequest *dr;
+	__u8 reg[7];
+};
+
+/* --------------------------------------------------------------------- */
+
+static void destroy_priv(struct kref *kref)
+{
+	struct parport_uss720_private *priv = container_of(kref, struct parport_uss720_private, ref_count);
+
+	dev_dbg(&priv->usbdev->dev, "destroying priv datastructure\n");
+	usb_put_dev(priv->usbdev);
+	priv->usbdev = NULL;
+	kfree(priv);
+}
+
+static void destroy_async(struct kref *kref)
+{
+	struct uss720_async_request *rq = container_of(kref, struct uss720_async_request, ref_count);
+	struct parport_uss720_private *priv = rq->priv;
+	unsigned long flags;
+
+	if (likely(rq->urb))
+		usb_free_urb(rq->urb);
+	kfree(rq->dr);
+	spin_lock_irqsave(&priv->asynclock, flags);
+	list_del_init(&rq->asynclist);
+	spin_unlock_irqrestore(&priv->asynclock, flags);
+	kfree(rq);
+	kref_put(&priv->ref_count, destroy_priv);
+}
+
+/* --------------------------------------------------------------------- */
+
+static void async_complete(struct urb *urb)
+{
+	struct uss720_async_request *rq;
+	struct parport *pp;
+	struct parport_uss720_private *priv;
+	int status = urb->status;
+
+	rq = urb->context;
+	priv = rq->priv;
+	pp = priv->pp;
+	if (status) {
+		dev_err(&urb->dev->dev, "async_complete: urb error %d\n",
+			status);
+	} else if (rq->dr->bRequest == 3) {
+		memcpy(priv->reg, rq->reg, sizeof(priv->reg));
+#if 0
+		dev_dbg(&priv->usbdev->dev, "async_complete regs %7ph\n",
+			priv->reg);
+#endif
+		/* if nAck interrupts are enabled and we have an interrupt, call the interrupt procedure */
+		if (rq->reg[2] & rq->reg[1] & 0x10 && pp)
+			parport_generic_irq(pp);
+	}
+	complete(&rq->compl);
+	kref_put(&rq->ref_count, destroy_async);
+}
+
+static struct uss720_async_request *submit_async_request(struct parport_uss720_private *priv,
+							 __u8 request, __u8 requesttype, __u16 value, __u16 index,
+							 gfp_t mem_flags)
+{
+	struct usb_device *usbdev;
+	struct uss720_async_request *rq;
+	unsigned long flags;
+	int ret;
+
+	if (!priv)
+		return NULL;
+	usbdev = priv->usbdev;
+	if (!usbdev)
+		return NULL;
+	rq = kzalloc(sizeof(struct uss720_async_request), mem_flags);
+	if (!rq)
+		return NULL;
+	kref_init(&rq->ref_count);
+	INIT_LIST_HEAD(&rq->asynclist);
+	init_completion(&rq->compl);
+	kref_get(&priv->ref_count);
+	rq->priv = priv;
+	rq->urb = usb_alloc_urb(0, mem_flags);
+	if (!rq->urb) {
+		kref_put(&rq->ref_count, destroy_async);
+		return NULL;
+	}
+	rq->dr = kmalloc(sizeof(*rq->dr), mem_flags);
+	if (!rq->dr) {
+		kref_put(&rq->ref_count, destroy_async);
+		return NULL;
+	}
+	rq->dr->bRequestType = requesttype;
+	rq->dr->bRequest = request;
+	rq->dr->wValue = cpu_to_le16(value);
+	rq->dr->wIndex = cpu_to_le16(index);
+	rq->dr->wLength = cpu_to_le16((request == 3) ? sizeof(rq->reg) : 0);
+	usb_fill_control_urb(rq->urb, usbdev, (requesttype & 0x80) ? usb_rcvctrlpipe(usbdev, 0) : usb_sndctrlpipe(usbdev, 0),
+			     (unsigned char *)rq->dr,
+			     (request == 3) ? rq->reg : NULL, (request == 3) ? sizeof(rq->reg) : 0, async_complete, rq);
+	/* rq->urb->transfer_flags |= URB_ASYNC_UNLINK; */
+	spin_lock_irqsave(&priv->asynclock, flags);
+	list_add_tail(&rq->asynclist, &priv->asynclist);
+	spin_unlock_irqrestore(&priv->asynclock, flags);
+	kref_get(&rq->ref_count);
+	ret = usb_submit_urb(rq->urb, mem_flags);
+	if (!ret)
+		return rq;
+	destroy_async(&rq->ref_count);
+	dev_err(&usbdev->dev, "submit_async_request submit_urb failed with %d\n", ret);
+	return NULL;
+}
+
+static unsigned int kill_all_async_requests_priv(struct parport_uss720_private *priv)
+{
+	struct uss720_async_request *rq;
+	unsigned long flags;
+	unsigned int ret = 0;
+
+	spin_lock_irqsave(&priv->asynclock, flags);
+	list_for_each_entry(rq, &priv->asynclist, asynclist) {
+		usb_unlink_urb(rq->urb);
+		ret++;
+	}
+	spin_unlock_irqrestore(&priv->asynclock, flags);
+	return ret;
+}
+
+/* --------------------------------------------------------------------- */
+
+static int get_1284_register(struct parport *pp, unsigned char reg, unsigned char *val, gfp_t mem_flags)
+{
+	struct parport_uss720_private *priv;
+	struct uss720_async_request *rq;
+	static const unsigned char regindex[9] = {
+		4, 0, 1, 5, 5, 0, 2, 3, 6
+	};
+	int ret;
+
+	if (!pp)
+		return -EIO;
+	priv = pp->private_data;
+	rq = submit_async_request(priv, 3, 0xc0, ((unsigned int)reg) << 8, 0, mem_flags);
+	if (!rq) {
+		dev_err(&priv->usbdev->dev, "get_1284_register(%u) failed",
+			(unsigned int)reg);
+		return -EIO;
+	}
+	if (!val) {
+		kref_put(&rq->ref_count, destroy_async);
+		return 0;
+	}
+	if (wait_for_completion_timeout(&rq->compl, HZ)) {
+		ret = rq->urb->status;
+		*val = priv->reg[(reg >= 9) ? 0 : regindex[reg]];
+		if (ret)
+			printk(KERN_WARNING "get_1284_register: "
+			       "usb error %d\n", ret);
+		kref_put(&rq->ref_count, destroy_async);
+		return ret;
+	}
+	printk(KERN_WARNING "get_1284_register timeout\n");
+	kill_all_async_requests_priv(priv);
+	return -EIO;
+}
+
+static int set_1284_register(struct parport *pp, unsigned char reg, unsigned char val, gfp_t mem_flags)
+{
+	struct parport_uss720_private *priv;
+	struct uss720_async_request *rq;
+
+	if (!pp)
+		return -EIO;
+	priv = pp->private_data;
+	rq = submit_async_request(priv, 4, 0x40, (((unsigned int)reg) << 8) | val, 0, mem_flags);
+	if (!rq) {
+		dev_err(&priv->usbdev->dev, "set_1284_register(%u,%u) failed",
+			(unsigned int)reg, (unsigned int)val);
+		return -EIO;
+	}
+	kref_put(&rq->ref_count, destroy_async);
+	return 0;
+}
+
+/* --------------------------------------------------------------------- */
+
+/* ECR modes */
+#define ECR_SPP 00
+#define ECR_PS2 01
+#define ECR_PPF 02
+#define ECR_ECP 03
+#define ECR_EPP 04
+
+/* Safely change the mode bits in the ECR */
+static int change_mode(struct parport *pp, int m)
+{
+	struct parport_uss720_private *priv = pp->private_data;
+	int mode;
+	__u8 reg;
+
+	if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
+		return -EIO;
+	/* Bits <7:5> contain the mode. */
+	mode = (priv->reg[2] >> 5) & 0x7;
+	if (mode == m)
+		return 0;
+	/* We have to go through mode 000 or 001 */
+	if (mode > ECR_PS2 && m > ECR_PS2)
+		if (change_mode(pp, ECR_PS2))
+			return -EIO;
+
+	if (m <= ECR_PS2 && !(priv->reg[1] & 0x20)) {
+		/* This mode resets the FIFO, so we may
+		 * have to wait for it to drain first. */
+		unsigned long expire = jiffies + pp->physport->cad->timeout;
+		switch (mode) {
+		case ECR_PPF: /* Parallel Port FIFO mode */
+		case ECR_ECP: /* ECP Parallel Port mode */
+			/* Poll slowly. */
+			for (;;) {
+				if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
+					return -EIO;
+				if (priv->reg[2] & 0x01)
+					break;
+				if (time_after_eq (jiffies, expire))
+					/* The FIFO is stuck. */
+					return -EBUSY;
+				msleep_interruptible(10);
+				if (signal_pending (current))
+					break;
+			}
+		}
+	}
+	/* Set the mode. */
+	if (set_1284_register(pp, 6, m << 5, GFP_KERNEL))
+		return -EIO;
+	if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
+		return -EIO;
+	return 0;
+}
+
+/*
+ * Clear TIMEOUT BIT in EPP MODE
+ */
+static int clear_epp_timeout(struct parport *pp)
+{
+	unsigned char stat;
+
+	if (get_1284_register(pp, 1, &stat, GFP_KERNEL))
+		return 1;
+	return stat & 1;
+}
+
+/*
+ * Access functions.
+ */
+#if 0
+static int uss720_irq(int usbstatus, void *buffer, int len, void *dev_id)
+{
+	struct parport *pp = (struct parport *)dev_id;
+	struct parport_uss720_private *priv = pp->private_data;	
+
+	if (usbstatus != 0 || len < 4 || !buffer)
+		return 1;
+	memcpy(priv->reg, buffer, 4);
+	/* if nAck interrupts are enabled and we have an interrupt, call the interrupt procedure */
+	if (priv->reg[2] & priv->reg[1] & 0x10)
+		parport_generic_irq(pp);
+	return 1;
+}
+#endif
+
+static void parport_uss720_write_data(struct parport *pp, unsigned char d)
+{
+	set_1284_register(pp, 0, d, GFP_KERNEL);
+}
+
+static unsigned char parport_uss720_read_data(struct parport *pp)
+{
+	unsigned char ret;
+
+	if (get_1284_register(pp, 0, &ret, GFP_KERNEL))
+		return 0;
+	return ret;
+}
+
+static void parport_uss720_write_control(struct parport *pp, unsigned char d)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+
+	d = (d & 0xf) | (priv->reg[1] & 0xf0);
+	if (set_1284_register(pp, 2, d, GFP_KERNEL))
+		return;
+	priv->reg[1] = d;
+}
+
+static unsigned char parport_uss720_read_control(struct parport *pp)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	return priv->reg[1] & 0xf; /* Use soft copy */
+}
+
+static unsigned char parport_uss720_frob_control(struct parport *pp, unsigned char mask, unsigned char val)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	unsigned char d;
+
+	mask &= 0x0f;
+	val &= 0x0f;
+	d = (priv->reg[1] & (~mask)) ^ val;
+	if (set_1284_register(pp, 2, d, GFP_ATOMIC))
+		return 0;
+	priv->reg[1] = d;
+	return d & 0xf;
+}
+
+static unsigned char parport_uss720_read_status(struct parport *pp)
+{
+	unsigned char ret;
+
+	if (get_1284_register(pp, 1, &ret, GFP_ATOMIC))
+		return 0;
+	return ret & 0xf8;
+}
+
+static void parport_uss720_disable_irq(struct parport *pp)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	unsigned char d;
+
+	d = priv->reg[1] & ~0x10;
+	if (set_1284_register(pp, 2, d, GFP_KERNEL))
+		return;
+	priv->reg[1] = d;
+}
+
+static void parport_uss720_enable_irq(struct parport *pp)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	unsigned char d;
+
+	d = priv->reg[1] | 0x10;
+	if (set_1284_register(pp, 2, d, GFP_KERNEL))
+		return;
+	priv->reg[1] = d;
+}
+
+static void parport_uss720_data_forward (struct parport *pp)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	unsigned char d;
+
+	d = priv->reg[1] & ~0x20;
+	if (set_1284_register(pp, 2, d, GFP_KERNEL))
+		return;
+	priv->reg[1] = d;
+}
+
+static void parport_uss720_data_reverse (struct parport *pp)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	unsigned char d;
+
+	d = priv->reg[1] | 0x20;
+	if (set_1284_register(pp, 2, d, GFP_KERNEL))
+		return;
+	priv->reg[1] = d;
+}
+
+static void parport_uss720_init_state(struct pardevice *dev, struct parport_state *s)
+{
+	s->u.pc.ctr = 0xc | (dev->irq_func ? 0x10 : 0x0);
+	s->u.pc.ecr = 0x24;
+}
+
+static void parport_uss720_save_state(struct parport *pp, struct parport_state *s)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+
+#if 0
+	if (get_1284_register(pp, 2, NULL, GFP_ATOMIC))
+		return;
+#endif
+	s->u.pc.ctr = priv->reg[1];
+	s->u.pc.ecr = priv->reg[2];
+}
+
+static void parport_uss720_restore_state(struct parport *pp, struct parport_state *s)
+{
+	struct parport_uss720_private *priv = pp->private_data;
+
+	set_1284_register(pp, 2, s->u.pc.ctr, GFP_ATOMIC);
+	set_1284_register(pp, 6, s->u.pc.ecr, GFP_ATOMIC);
+	get_1284_register(pp, 2, NULL, GFP_ATOMIC);
+	priv->reg[1] = s->u.pc.ctr;
+	priv->reg[2] = s->u.pc.ecr;
+}
+
+static size_t parport_uss720_epp_read_data(struct parport *pp, void *buf, size_t length, int flags)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	size_t got = 0;
+
+	if (change_mode(pp, ECR_EPP))
+		return 0;
+	for (; got < length; got++) {
+		if (get_1284_register(pp, 4, (char *)buf, GFP_KERNEL))
+			break;
+		buf++;
+		if (priv->reg[0] & 0x01) {
+			clear_epp_timeout(pp);
+			break;
+		}
+	}
+	change_mode(pp, ECR_PS2);
+	return got;
+}
+
+static size_t parport_uss720_epp_write_data(struct parport *pp, const void *buf, size_t length, int flags)
+{
+#if 0
+	struct parport_uss720_private *priv = pp->private_data;	
+	size_t written = 0;
+
+	if (change_mode(pp, ECR_EPP))
+		return 0;
+	for (; written < length; written++) {
+		if (set_1284_register(pp, 4, (char *)buf, GFP_KERNEL))
+			break;
+		((char*)buf)++;
+		if (get_1284_register(pp, 1, NULL, GFP_KERNEL))
+			break;
+		if (priv->reg[0] & 0x01) {
+			clear_epp_timeout(pp);
+			break;
+		}
+	}
+	change_mode(pp, ECR_PS2);
+	return written;
+#else
+	struct parport_uss720_private *priv = pp->private_data;
+	struct usb_device *usbdev = priv->usbdev;
+	int rlen = 0;
+	int i;
+
+	if (!usbdev)
+		return 0;
+	if (change_mode(pp, ECR_EPP))
+		return 0;
+	i = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 1), (void *)buf, length, &rlen, 20000);
+	if (i)
+		printk(KERN_ERR "uss720: sendbulk ep 1 buf %p len %zu rlen %u\n", buf, length, rlen);
+	change_mode(pp, ECR_PS2);
+	return rlen;
+#endif
+}
+
+static size_t parport_uss720_epp_read_addr(struct parport *pp, void *buf, size_t length, int flags)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	size_t got = 0;
+
+	if (change_mode(pp, ECR_EPP))
+		return 0;
+	for (; got < length; got++) {
+		if (get_1284_register(pp, 3, (char *)buf, GFP_KERNEL))
+			break;
+		buf++;
+		if (priv->reg[0] & 0x01) {
+			clear_epp_timeout(pp);
+			break;
+		}
+	}
+	change_mode(pp, ECR_PS2);
+	return got;
+}
+
+static size_t parport_uss720_epp_write_addr(struct parport *pp, const void *buf, size_t length, int flags)
+{
+	struct parport_uss720_private *priv = pp->private_data;	
+	size_t written = 0;
+
+	if (change_mode(pp, ECR_EPP))
+		return 0;
+	for (; written < length; written++) {
+		if (set_1284_register(pp, 3, *(char *)buf, GFP_KERNEL))
+			break;
+		buf++;
+		if (get_1284_register(pp, 1, NULL, GFP_KERNEL))
+			break;
+		if (priv->reg[0] & 0x01) {
+			clear_epp_timeout(pp);
+			break;
+		}
+	}
+	change_mode(pp, ECR_PS2);
+	return written;
+}
+
+static size_t parport_uss720_ecp_write_data(struct parport *pp, const void *buffer, size_t len, int flags)
+{
+	struct parport_uss720_private *priv = pp->private_data;
+	struct usb_device *usbdev = priv->usbdev;
+	int rlen = 0;
+	int i;
+
+	if (!usbdev)
+		return 0;
+	if (change_mode(pp, ECR_ECP))
+		return 0;
+	i = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 1), (void *)buffer, len, &rlen, 20000);
+	if (i)
+		printk(KERN_ERR "uss720: sendbulk ep 1 buf %p len %zu rlen %u\n", buffer, len, rlen);
+	change_mode(pp, ECR_PS2);
+	return rlen;
+}
+
+static size_t parport_uss720_ecp_read_data(struct parport *pp, void *buffer, size_t len, int flags)
+{
+	struct parport_uss720_private *priv = pp->private_data;
+	struct usb_device *usbdev = priv->usbdev;
+	int rlen = 0;
+	int i;
+
+	if (!usbdev)
+		return 0;
+	if (change_mode(pp, ECR_ECP))
+		return 0;
+	i = usb_bulk_msg(usbdev, usb_rcvbulkpipe(usbdev, 2), buffer, len, &rlen, 20000);
+	if (i)
+		printk(KERN_ERR "uss720: recvbulk ep 2 buf %p len %zu rlen %u\n", buffer, len, rlen);
+	change_mode(pp, ECR_PS2);
+	return rlen;
+}
+
+static size_t parport_uss720_ecp_write_addr(struct parport *pp, const void *buffer, size_t len, int flags)
+{
+	size_t written = 0;
+
+	if (change_mode(pp, ECR_ECP))
+		return 0;
+	for (; written < len; written++) {
+		if (set_1284_register(pp, 5, *(char *)buffer, GFP_KERNEL))
+			break;
+		buffer++;
+	}
+	change_mode(pp, ECR_PS2);
+	return written;
+}
+
+static size_t parport_uss720_write_compat(struct parport *pp, const void *buffer, size_t len, int flags)
+{
+	struct parport_uss720_private *priv = pp->private_data;
+	struct usb_device *usbdev = priv->usbdev;
+	int rlen = 0;
+	int i;
+
+	if (!usbdev)
+		return 0;
+	if (change_mode(pp, ECR_PPF))
+		return 0;
+	i = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 1), (void *)buffer, len, &rlen, 20000);
+	if (i)
+		printk(KERN_ERR "uss720: sendbulk ep 1 buf %p len %zu rlen %u\n", buffer, len, rlen);
+	change_mode(pp, ECR_PS2);
+	return rlen;
+}
+
+/* --------------------------------------------------------------------- */
+
+static struct parport_operations parport_uss720_ops = 
+{
+	.owner =		THIS_MODULE,
+	.write_data =		parport_uss720_write_data,
+	.read_data =		parport_uss720_read_data,
+
+	.write_control =	parport_uss720_write_control,
+	.read_control =		parport_uss720_read_control,
+	.frob_control =		parport_uss720_frob_control,
+
+	.read_status =		parport_uss720_read_status,
+
+	.enable_irq =		parport_uss720_enable_irq,
+	.disable_irq =		parport_uss720_disable_irq,
+
+	.data_forward =		parport_uss720_data_forward,
+	.data_reverse =		parport_uss720_data_reverse,
+
+	.init_state =		parport_uss720_init_state,
+	.save_state =		parport_uss720_save_state,
+	.restore_state =	parport_uss720_restore_state,
+
+	.epp_write_data =	parport_uss720_epp_write_data,
+	.epp_read_data =	parport_uss720_epp_read_data,
+	.epp_write_addr =	parport_uss720_epp_write_addr,
+	.epp_read_addr =	parport_uss720_epp_read_addr,
+
+	.ecp_write_data =	parport_uss720_ecp_write_data,
+	.ecp_read_data =	parport_uss720_ecp_read_data,
+	.ecp_write_addr =	parport_uss720_ecp_write_addr,
+
+	.compat_write_data =	parport_uss720_write_compat,
+	.nibble_read_data =	parport_ieee1284_read_nibble,
+	.byte_read_data =	parport_ieee1284_read_byte,
+};
+
+/* --------------------------------------------------------------------- */
+
+static int uss720_probe(struct usb_interface *intf,
+			const struct usb_device_id *id)
+{
+	struct usb_device *usbdev = usb_get_dev(interface_to_usbdev(intf));
+	struct usb_host_interface *interface;
+	struct usb_endpoint_descriptor *epd;
+	struct parport_uss720_private *priv;
+	struct parport *pp;
+	unsigned char reg;
+	int i;
+
+	dev_dbg(&intf->dev, "probe: vendor id 0x%x, device id 0x%x\n",
+		le16_to_cpu(usbdev->descriptor.idVendor),
+		le16_to_cpu(usbdev->descriptor.idProduct));
+
+	/* our known interfaces have 3 alternate settings */
+	if (intf->num_altsetting != 3) {
+		usb_put_dev(usbdev);
+		return -ENODEV;
+	}
+	i = usb_set_interface(usbdev, intf->altsetting->desc.bInterfaceNumber, 2);
+	dev_dbg(&intf->dev, "set interface result %d\n", i);
+
+	interface = intf->cur_altsetting;
+
+	if (interface->desc.bNumEndpoints < 3) {
+		usb_put_dev(usbdev);
+		return -ENODEV;
+	}
+
+	/*
+	 * Allocate parport interface 
+	 */
+	priv = kzalloc(sizeof(struct parport_uss720_private), GFP_KERNEL);
+	if (!priv) {
+		usb_put_dev(usbdev);
+		return -ENOMEM;
+	}
+	priv->pp = NULL;
+	priv->usbdev = usbdev;
+	kref_init(&priv->ref_count);
+	spin_lock_init(&priv->asynclock);
+	INIT_LIST_HEAD(&priv->asynclist);
+	pp = parport_register_port(0, PARPORT_IRQ_NONE, PARPORT_DMA_NONE, &parport_uss720_ops);
+	if (!pp) {
+		printk(KERN_WARNING "uss720: could not register parport\n");
+		goto probe_abort;
+	}
+
+	priv->pp = pp;
+	pp->private_data = priv;
+	pp->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_TRISTATE | PARPORT_MODE_EPP | PARPORT_MODE_ECP | PARPORT_MODE_COMPAT;
+
+	/* set the USS720 control register to manual mode, no ECP compression, enable all ints */
+	set_1284_register(pp, 7, 0x00, GFP_KERNEL);
+	set_1284_register(pp, 6, 0x30, GFP_KERNEL);  /* PS/2 mode */
+	set_1284_register(pp, 2, 0x0c, GFP_KERNEL);
+	/* debugging */
+	get_1284_register(pp, 0, &reg, GFP_KERNEL);
+	dev_dbg(&intf->dev, "reg: %7ph\n", priv->reg);
+
+	i = usb_find_last_int_in_endpoint(interface, &epd);
+	if (!i) {
+		dev_dbg(&intf->dev, "epaddr %d interval %d\n",
+				epd->bEndpointAddress, epd->bInterval);
+	}
+	parport_announce_port(pp);
+
+	usb_set_intfdata(intf, pp);
+	return 0;
+
+probe_abort:
+	kill_all_async_requests_priv(priv);
+	kref_put(&priv->ref_count, destroy_priv);
+	return -ENODEV;
+}
+
+static void uss720_disconnect(struct usb_interface *intf)
+{
+	struct parport *pp = usb_get_intfdata(intf);
+	struct parport_uss720_private *priv;
+
+	dev_dbg(&intf->dev, "disconnect\n");
+	usb_set_intfdata(intf, NULL);
+	if (pp) {
+		priv = pp->private_data;
+		priv->pp = NULL;
+		dev_dbg(&intf->dev, "parport_remove_port\n");
+		parport_remove_port(pp);
+		parport_put_port(pp);
+		kill_all_async_requests_priv(priv);
+		kref_put(&priv->ref_count, destroy_priv);
+	}
+	dev_dbg(&intf->dev, "disconnect done\n");
+}
+
+/* table of cables that work through this driver */
+static const struct usb_device_id uss720_table[] = {
+	{ USB_DEVICE(0x047e, 0x1001) },
+	{ USB_DEVICE(0x04b8, 0x0002) },
+	{ USB_DEVICE(0x04b8, 0x0003) },
+	{ USB_DEVICE(0x050d, 0x0002) },
+	{ USB_DEVICE(0x050d, 0x1202) },
+	{ USB_DEVICE(0x0557, 0x2001) },
+	{ USB_DEVICE(0x05ab, 0x0002) },
+	{ USB_DEVICE(0x06c6, 0x0100) },
+	{ USB_DEVICE(0x0729, 0x1284) },
+	{ USB_DEVICE(0x1293, 0x0002) },
+	{ }						/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE (usb, uss720_table);
+
+
+static struct usb_driver uss720_driver = {
+	.name =		"uss720",
+	.probe =	uss720_probe,
+	.disconnect =	uss720_disconnect,
+	.id_table =	uss720_table,
+};
+
+/* --------------------------------------------------------------------- */
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+
+static int __init uss720_init(void)
+{
+	int retval;
+	retval = usb_register(&uss720_driver);
+	if (retval)
+		goto out;
+
+	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_DESC "\n");
+	printk(KERN_INFO KBUILD_MODNAME ": NOTE: this is a special purpose "
+	       "driver to allow nonstandard\n");
+	printk(KERN_INFO KBUILD_MODNAME ": protocols (eg. bitbang) over "
+	       "USS720 usb to parallel cables\n");
+	printk(KERN_INFO KBUILD_MODNAME ": If you just want to connect to a "
+	       "printer, use usblp instead\n");
+out:
+	return retval;
+}
+
+static void __exit uss720_cleanup(void)
+{
+	usb_deregister(&uss720_driver);
+}
+
+module_init(uss720_init);
+module_exit(uss720_cleanup);
+
+/* --------------------------------------------------------------------- */