Adding upstream version 6.1.76.upstream/6.1.76

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

1 files changed, 1474 insertions, 0 deletions

diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
new file mode 100644
index 000000000..f27b4aecf
--- /dev/null
+++ b/drivers/usb/class/usblp.c
@@ -0,0 +1,1474 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * usblp.c
+ *
+ * Copyright (c) 1999 Michael Gee	<michael@linuxspecific.com>
+ * Copyright (c) 1999 Pavel Machek	<pavel@ucw.cz>
+ * Copyright (c) 2000 Randy Dunlap	<rdunlap@xenotime.net>
+ * Copyright (c) 2000 Vojtech Pavlik	<vojtech@suse.cz>
+ # Copyright (c) 2001 Pete Zaitcev	<zaitcev@redhat.com>
+ # Copyright (c) 2001 David Paschal	<paschal@rcsis.com>
+ * Copyright (c) 2006 Oliver Neukum	<oliver@neukum.name>
+ *
+ * USB Printer Device Class driver for USB printers and printer cables
+ *
+ * Sponsored by SuSE
+ *
+ * ChangeLog:
+ *	v0.1 - thorough cleaning, URBification, almost a rewrite
+ *	v0.2 - some more cleanups
+ *	v0.3 - cleaner again, waitqueue fixes
+ *	v0.4 - fixes in unidirectional mode
+ *	v0.5 - add DEVICE_ID string support
+ *	v0.6 - never time out
+ *	v0.7 - fixed bulk-IN read and poll (David Paschal)
+ *	v0.8 - add devfs support
+ *	v0.9 - fix unplug-while-open paths
+ *	v0.10- remove sleep_on, fix error on oom (oliver@neukum.org)
+ *	v0.11 - add proto_bias option (Pete Zaitcev)
+ *	v0.12 - add hpoj.sourceforge.net ioctls (David Paschal)
+ *	v0.13 - alloc space for statusbuf (<status> not on stack);
+ *		use usb_alloc_coherent() for read buf & write buf;
+ *      none  - Maintained in Linux kernel after v0.13
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched/signal.h>
+#include <linux/signal.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/lp.h>
+#include <linux/mutex.h>
+#undef DEBUG
+#include <linux/usb.h>
+#include <linux/usb/ch9.h>
+#include <linux/ratelimit.h>
+
+/*
+ * Version Information
+ */
+#define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap, Pete Zaitcev, David Paschal"
+#define DRIVER_DESC "USB Printer Device Class driver"
+
+#define USBLP_BUF_SIZE		8192
+#define USBLP_BUF_SIZE_IN	1024
+#define USBLP_DEVICE_ID_SIZE	1024
+
+/* ioctls: */
+#define IOCNR_GET_DEVICE_ID		1
+#define IOCNR_GET_PROTOCOLS		2
+#define IOCNR_SET_PROTOCOL		3
+#define IOCNR_HP_SET_CHANNEL		4
+#define IOCNR_GET_BUS_ADDRESS		5
+#define IOCNR_GET_VID_PID		6
+#define IOCNR_SOFT_RESET		7
+/* Get device_id string: */
+#define LPIOC_GET_DEVICE_ID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_DEVICE_ID, len)
+/* The following ioctls were added for http://hpoj.sourceforge.net:
+ * Get two-int array:
+ * [0]=current protocol
+ *     (1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
+ *         3=USB_CLASS_PRINTER/1/3),
+ * [1]=supported protocol mask (mask&(1<<n)!=0 means
+ *     USB_CLASS_PRINTER/1/n supported):
+ */
+#define LPIOC_GET_PROTOCOLS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_PROTOCOLS, len)
+/*
+ * Set protocol
+ *     (arg: 1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
+ *         3=USB_CLASS_PRINTER/1/3):
+ */
+#define LPIOC_SET_PROTOCOL _IOC(_IOC_WRITE, 'P', IOCNR_SET_PROTOCOL, 0)
+/* Set channel number (HP Vendor-specific command): */
+#define LPIOC_HP_SET_CHANNEL _IOC(_IOC_WRITE, 'P', IOCNR_HP_SET_CHANNEL, 0)
+/* Get two-int array: [0]=bus number, [1]=device address: */
+#define LPIOC_GET_BUS_ADDRESS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_BUS_ADDRESS, len)
+/* Get two-int array: [0]=vendor ID, [1]=product ID: */
+#define LPIOC_GET_VID_PID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_VID_PID, len)
+/* Perform class specific soft reset */
+#define LPIOC_SOFT_RESET _IOC(_IOC_NONE, 'P', IOCNR_SOFT_RESET, 0);
+
+/*
+ * A DEVICE_ID string may include the printer's serial number.
+ * It should end with a semi-colon (';').
+ * An example from an HP 970C DeskJet printer is (this is one long string,
+ * with the serial number changed):
+MFG:HEWLETT-PACKARD;MDL:DESKJET 970C;CMD:MLC,PCL,PML;CLASS:PRINTER;DESCRIPTION:Hewlett-Packard DeskJet 970C;SERN:US970CSEPROF;VSTATUS:$HB0$NC0,ff,DN,IDLE,CUT,K1,C0,DP,NR,KP000,CP027;VP:0800,FL,B0;VJ:                    ;
+ */
+
+/*
+ * USB Printer Requests
+ */
+
+#define USBLP_REQ_GET_ID			0x00
+#define USBLP_REQ_GET_STATUS			0x01
+#define USBLP_REQ_RESET				0x02
+#define USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST	0x00	/* HP Vendor-specific */
+
+#define USBLP_MINORS		16
+#define USBLP_MINOR_BASE	0
+
+#define USBLP_CTL_TIMEOUT	5000			/* 5 seconds */
+
+#define USBLP_FIRST_PROTOCOL	1
+#define USBLP_LAST_PROTOCOL	3
+#define USBLP_MAX_PROTOCOLS	(USBLP_LAST_PROTOCOL+1)
+
+/*
+ * some arbitrary status buffer size;
+ * need a status buffer that is allocated via kmalloc(), not on stack
+ */
+#define STATUS_BUF_SIZE		8
+
+/*
+ * Locks down the locking order:
+ * ->wmut locks wstatus.
+ * ->mut locks the whole usblp, except [rw]complete, and thus, by indirection,
+ * [rw]status. We only touch status when we know the side idle.
+ * ->lock locks what interrupt accesses.
+ */
+struct usblp {
+	struct usb_device	*dev;			/* USB device */
+	struct mutex		wmut;
+	struct mutex		mut;
+	spinlock_t		lock;		/* locks rcomplete, wcomplete */
+	char			*readbuf;		/* read transfer_buffer */
+	char			*statusbuf;		/* status transfer_buffer */
+	struct usb_anchor	urbs;
+	wait_queue_head_t	rwait, wwait;
+	int			readcount;		/* Counter for reads */
+	int			ifnum;			/* Interface number */
+	struct usb_interface	*intf;			/* The interface */
+	/*
+	 * Alternate-setting numbers and endpoints for each protocol
+	 * (USB_CLASS_PRINTER/1/{index=1,2,3}) that the device supports:
+	 */
+	struct {
+		int				alt_setting;
+		struct usb_endpoint_descriptor	*epwrite;
+		struct usb_endpoint_descriptor	*epread;
+	}			protocol[USBLP_MAX_PROTOCOLS];
+	int			current_protocol;
+	int			minor;			/* minor number of device */
+	int			wcomplete, rcomplete;
+	int			wstatus;	/* bytes written or error */
+	int			rstatus;	/* bytes ready or error */
+	unsigned int		quirks;			/* quirks flags */
+	unsigned int		flags;			/* mode flags */
+	unsigned char		used;			/* True if open */
+	unsigned char		present;		/* True if not disconnected */
+	unsigned char		bidir;			/* interface is bidirectional */
+	unsigned char		no_paper;		/* Paper Out happened */
+	unsigned char		*device_id_string;	/* IEEE 1284 DEVICE ID string (ptr) */
+							/* first 2 bytes are (big-endian) length */
+};
+
+#ifdef DEBUG
+static void usblp_dump(struct usblp *usblp)
+{
+	struct device *dev = &usblp->intf->dev;
+	int p;
+
+	dev_dbg(dev, "usblp=0x%p\n", usblp);
+	dev_dbg(dev, "dev=0x%p\n", usblp->dev);
+	dev_dbg(dev, "present=%d\n", usblp->present);
+	dev_dbg(dev, "readbuf=0x%p\n", usblp->readbuf);
+	dev_dbg(dev, "readcount=%d\n", usblp->readcount);
+	dev_dbg(dev, "ifnum=%d\n", usblp->ifnum);
+	for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
+		dev_dbg(dev, "protocol[%d].alt_setting=%d\n", p,
+			usblp->protocol[p].alt_setting);
+		dev_dbg(dev, "protocol[%d].epwrite=%p\n", p,
+			usblp->protocol[p].epwrite);
+		dev_dbg(dev, "protocol[%d].epread=%p\n", p,
+			usblp->protocol[p].epread);
+	}
+	dev_dbg(dev, "current_protocol=%d\n", usblp->current_protocol);
+	dev_dbg(dev, "minor=%d\n", usblp->minor);
+	dev_dbg(dev, "wstatus=%d\n", usblp->wstatus);
+	dev_dbg(dev, "rstatus=%d\n", usblp->rstatus);
+	dev_dbg(dev, "quirks=%d\n", usblp->quirks);
+	dev_dbg(dev, "used=%d\n", usblp->used);
+	dev_dbg(dev, "bidir=%d\n", usblp->bidir);
+	dev_dbg(dev, "device_id_string=\"%s\"\n",
+		usblp->device_id_string ?
+			usblp->device_id_string + 2 :
+			(unsigned char *)"(null)");
+}
+#endif
+
+/* Quirks: various printer quirks are handled by this table & its flags. */
+
+struct quirk_printer_struct {
+	__u16 vendorId;
+	__u16 productId;
+	unsigned int quirks;
+};
+
+#define USBLP_QUIRK_BIDIR	0x1	/* reports bidir but requires unidirectional mode (no INs/reads) */
+#define USBLP_QUIRK_USB_INIT	0x2	/* needs vendor USB init string */
+#define USBLP_QUIRK_BAD_CLASS	0x4	/* descriptor uses vendor-specific Class or SubClass */
+
+static const struct quirk_printer_struct quirk_printers[] = {
+	{ 0x03f0, 0x0004, USBLP_QUIRK_BIDIR }, /* HP DeskJet 895C */
+	{ 0x03f0, 0x0104, USBLP_QUIRK_BIDIR }, /* HP DeskJet 880C */
+	{ 0x03f0, 0x0204, USBLP_QUIRK_BIDIR }, /* HP DeskJet 815C */
+	{ 0x03f0, 0x0304, USBLP_QUIRK_BIDIR }, /* HP DeskJet 810C/812C */
+	{ 0x03f0, 0x0404, USBLP_QUIRK_BIDIR }, /* HP DeskJet 830C */
+	{ 0x03f0, 0x0504, USBLP_QUIRK_BIDIR }, /* HP DeskJet 885C */
+	{ 0x03f0, 0x0604, USBLP_QUIRK_BIDIR }, /* HP DeskJet 840C */
+	{ 0x03f0, 0x0804, USBLP_QUIRK_BIDIR }, /* HP DeskJet 816C */
+	{ 0x03f0, 0x1104, USBLP_QUIRK_BIDIR }, /* HP Deskjet 959C */
+	{ 0x0409, 0xefbe, USBLP_QUIRK_BIDIR }, /* NEC Picty900 (HP OEM) */
+	{ 0x0409, 0xbef4, USBLP_QUIRK_BIDIR }, /* NEC Picty760 (HP OEM) */
+	{ 0x0409, 0xf0be, USBLP_QUIRK_BIDIR }, /* NEC Picty920 (HP OEM) */
+	{ 0x0409, 0xf1be, USBLP_QUIRK_BIDIR }, /* NEC Picty800 (HP OEM) */
+	{ 0x0482, 0x0010, USBLP_QUIRK_BIDIR }, /* Kyocera Mita FS 820, by zut <kernel@zut.de> */
+	{ 0x04f9, 0x000d, USBLP_QUIRK_BIDIR }, /* Brother Industries, Ltd HL-1440 Laser Printer */
+	{ 0x04b8, 0x0202, USBLP_QUIRK_BAD_CLASS }, /* Seiko Epson Receipt Printer M129C */
+	{ 0, 0 }
+};
+
+static int usblp_wwait(struct usblp *usblp, int nonblock);
+static int usblp_wtest(struct usblp *usblp, int nonblock);
+static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock);
+static int usblp_rtest(struct usblp *usblp, int nonblock);
+static int usblp_submit_read(struct usblp *usblp);
+static int usblp_select_alts(struct usblp *usblp);
+static int usblp_set_protocol(struct usblp *usblp, int protocol);
+static int usblp_cache_device_id_string(struct usblp *usblp);
+
+/* forward reference to make our lives easier */
+static struct usb_driver usblp_driver;
+static DEFINE_MUTEX(usblp_mutex);	/* locks the existence of usblp's */
+
+/*
+ * Functions for usblp control messages.
+ */
+
+static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, int recip, int value, void *buf, int len)
+{
+	int retval;
+	int index = usblp->ifnum;
+
+	/* High byte has the interface index.
+	   Low byte has the alternate setting.
+	 */
+	if ((request == USBLP_REQ_GET_ID) && (type == USB_TYPE_CLASS))
+		index = (usblp->ifnum<<8)|usblp->protocol[usblp->current_protocol].alt_setting;
+
+	retval = usb_control_msg(usblp->dev,
+		dir ? usb_rcvctrlpipe(usblp->dev, 0) : usb_sndctrlpipe(usblp->dev, 0),
+		request, type | dir | recip, value, index, buf, len, USBLP_CTL_TIMEOUT);
+	dev_dbg(&usblp->intf->dev,
+		"usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d\n",
+		request, !!dir, recip, value, index, len, retval);
+	return retval < 0 ? retval : 0;
+}
+
+#define usblp_read_status(usblp, status)\
+	usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, 0, status, 1)
+#define usblp_get_id(usblp, config, id, maxlen)\
+	usblp_ctrl_msg(usblp, USBLP_REQ_GET_ID, USB_TYPE_CLASS, USB_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
+#define usblp_reset(usblp)\
+	usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
+
+static int usblp_hp_channel_change_request(struct usblp *usblp, int channel, u8 *new_channel)
+{
+	u8 *buf;
+	int ret;
+
+	buf = kzalloc(1, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST,
+			USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE,
+			channel, buf, 1);
+	if (ret == 0)
+		*new_channel = buf[0];
+
+	kfree(buf);
+
+	return ret;
+}
+
+/*
+ * See the description for usblp_select_alts() below for the usage
+ * explanation.  Look into your /sys/kernel/debug/usb/devices and dmesg in
+ * case of any trouble.
+ */
+static int proto_bias = -1;
+
+/*
+ * URB callback.
+ */
+
+static void usblp_bulk_read(struct urb *urb)
+{
+	struct usblp *usblp = urb->context;
+	int status = urb->status;
+	unsigned long flags;
+
+	if (usblp->present && usblp->used) {
+		if (status)
+			printk(KERN_WARNING "usblp%d: "
+			    "nonzero read bulk status received: %d\n",
+			    usblp->minor, status);
+	}
+	spin_lock_irqsave(&usblp->lock, flags);
+	if (status < 0)
+		usblp->rstatus = status;
+	else
+		usblp->rstatus = urb->actual_length;
+	usblp->rcomplete = 1;
+	wake_up(&usblp->rwait);
+	spin_unlock_irqrestore(&usblp->lock, flags);
+
+	usb_free_urb(urb);
+}
+
+static void usblp_bulk_write(struct urb *urb)
+{
+	struct usblp *usblp = urb->context;
+	int status = urb->status;
+	unsigned long flags;
+
+	if (usblp->present && usblp->used) {
+		if (status)
+			printk(KERN_WARNING "usblp%d: "
+			    "nonzero write bulk status received: %d\n",
+			    usblp->minor, status);
+	}
+	spin_lock_irqsave(&usblp->lock, flags);
+	if (status < 0)
+		usblp->wstatus = status;
+	else
+		usblp->wstatus = urb->actual_length;
+	usblp->no_paper = 0;
+	usblp->wcomplete = 1;
+	wake_up(&usblp->wwait);
+	spin_unlock_irqrestore(&usblp->lock, flags);
+
+	usb_free_urb(urb);
+}
+
+/*
+ * Get and print printer errors.
+ */
+
+static const char *usblp_messages[] = { "ok", "out of paper", "off-line", "on fire" };
+
+static int usblp_check_status(struct usblp *usblp, int err)
+{
+	unsigned char status, newerr = 0;
+	int error;
+
+	mutex_lock(&usblp->mut);
+	if ((error = usblp_read_status(usblp, usblp->statusbuf)) < 0) {
+		mutex_unlock(&usblp->mut);
+		printk_ratelimited(KERN_ERR
+				"usblp%d: error %d reading printer status\n",
+				usblp->minor, error);
+		return 0;
+	}
+	status = *usblp->statusbuf;
+	mutex_unlock(&usblp->mut);
+
+	if (~status & LP_PERRORP)
+		newerr = 3;
+	if (status & LP_POUTPA)
+		newerr = 1;
+	if (~status & LP_PSELECD)
+		newerr = 2;
+
+	if (newerr != err) {
+		printk(KERN_INFO "usblp%d: %s\n",
+		   usblp->minor, usblp_messages[newerr]);
+	}
+
+	return newerr;
+}
+
+static int handle_bidir(struct usblp *usblp)
+{
+	if (usblp->bidir && usblp->used) {
+		if (usblp_submit_read(usblp) < 0)
+			return -EIO;
+	}
+	return 0;
+}
+
+/*
+ * File op functions.
+ */
+
+static int usblp_open(struct inode *inode, struct file *file)
+{
+	int minor = iminor(inode);
+	struct usblp *usblp;
+	struct usb_interface *intf;
+	int retval;
+
+	if (minor < 0)
+		return -ENODEV;
+
+	mutex_lock(&usblp_mutex);
+
+	retval = -ENODEV;
+	intf = usb_find_interface(&usblp_driver, minor);
+	if (!intf)
+		goto out;
+	usblp = usb_get_intfdata(intf);
+	if (!usblp || !usblp->dev || !usblp->present)
+		goto out;
+
+	retval = -EBUSY;
+	if (usblp->used)
+		goto out;
+
+	/*
+	 * We do not implement LP_ABORTOPEN/LPABORTOPEN for two reasons:
+	 *  - We do not want persistent state which close(2) does not clear
+	 *  - It is not used anyway, according to CUPS people
+	 */
+
+	retval = usb_autopm_get_interface(intf);
+	if (retval < 0)
+		goto out;
+	usblp->used = 1;
+	file->private_data = usblp;
+
+	usblp->wcomplete = 1; /* we begin writeable */
+	usblp->wstatus = 0;
+	usblp->rcomplete = 0;
+
+	if (handle_bidir(usblp) < 0) {
+		usb_autopm_put_interface(intf);
+		usblp->used = 0;
+		file->private_data = NULL;
+		retval = -EIO;
+	}
+out:
+	mutex_unlock(&usblp_mutex);
+	return retval;
+}
+
+static void usblp_cleanup(struct usblp *usblp)
+{
+	printk(KERN_INFO "usblp%d: removed\n", usblp->minor);
+
+	kfree(usblp->readbuf);
+	kfree(usblp->device_id_string);
+	kfree(usblp->statusbuf);
+	usb_put_intf(usblp->intf);
+	kfree(usblp);
+}
+
+static void usblp_unlink_urbs(struct usblp *usblp)
+{
+	usb_kill_anchored_urbs(&usblp->urbs);
+}
+
+static int usblp_release(struct inode *inode, struct file *file)
+{
+	struct usblp *usblp = file->private_data;
+
+	usblp->flags &= ~LP_ABORT;
+
+	mutex_lock(&usblp_mutex);
+	usblp->used = 0;
+	if (usblp->present)
+		usblp_unlink_urbs(usblp);
+
+	usb_autopm_put_interface(usblp->intf);
+
+	if (!usblp->present)		/* finish cleanup from disconnect */
+		usblp_cleanup(usblp);	/* any URBs must be dead */
+
+	mutex_unlock(&usblp_mutex);
+	return 0;
+}
+
+/* No kernel lock - fine */
+static __poll_t usblp_poll(struct file *file, struct poll_table_struct *wait)
+{
+	struct usblp *usblp = file->private_data;
+	__poll_t ret = 0;
+	unsigned long flags;
+
+	/* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
+	poll_wait(file, &usblp->rwait, wait);
+	poll_wait(file, &usblp->wwait, wait);
+
+	mutex_lock(&usblp->mut);
+	if (!usblp->present)
+		ret |= EPOLLHUP;
+	mutex_unlock(&usblp->mut);
+
+	spin_lock_irqsave(&usblp->lock, flags);
+	if (usblp->bidir && usblp->rcomplete)
+		ret |= EPOLLIN  | EPOLLRDNORM;
+	if (usblp->no_paper || usblp->wcomplete)
+		ret |= EPOLLOUT | EPOLLWRNORM;
+	spin_unlock_irqrestore(&usblp->lock, flags);
+	return ret;
+}
+
+static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct usblp *usblp = file->private_data;
+	int length, err, i;
+	unsigned char newChannel;
+	int status;
+	int twoints[2];
+	int retval = 0;
+
+	mutex_lock(&usblp->mut);
+	if (!usblp->present) {
+		retval = -ENODEV;
+		goto done;
+	}
+
+	dev_dbg(&usblp->intf->dev,
+		"usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)\n", cmd,
+		_IOC_TYPE(cmd), _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd));
+
+	if (_IOC_TYPE(cmd) == 'P')	/* new-style ioctl number */
+
+		switch (_IOC_NR(cmd)) {
+
+		case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
+			if (_IOC_DIR(cmd) != _IOC_READ) {
+				retval = -EINVAL;
+				goto done;
+			}
+
+			length = usblp_cache_device_id_string(usblp);
+			if (length < 0) {
+				retval = length;
+				goto done;
+			}
+			if (length > _IOC_SIZE(cmd))
+				length = _IOC_SIZE(cmd); /* truncate */
+
+			if (copy_to_user((void __user *) arg,
+					usblp->device_id_string,
+					(unsigned long) length)) {
+				retval = -EFAULT;
+				goto done;
+			}
+
+			break;
+
+		case IOCNR_GET_PROTOCOLS:
+			if (_IOC_DIR(cmd) != _IOC_READ ||
+			    _IOC_SIZE(cmd) < sizeof(twoints)) {
+				retval = -EINVAL;
+				goto done;
+			}
+
+			twoints[0] = usblp->current_protocol;
+			twoints[1] = 0;
+			for (i = USBLP_FIRST_PROTOCOL;
+			     i <= USBLP_LAST_PROTOCOL; i++) {
+				if (usblp->protocol[i].alt_setting >= 0)
+					twoints[1] |= (1<<i);
+			}
+
+			if (copy_to_user((void __user *)arg,
+					(unsigned char *)twoints,
+					sizeof(twoints))) {
+				retval = -EFAULT;
+				goto done;
+			}
+
+			break;
+
+		case IOCNR_SET_PROTOCOL:
+			if (_IOC_DIR(cmd) != _IOC_WRITE) {
+				retval = -EINVAL;
+				goto done;
+			}
+
+#ifdef DEBUG
+			if (arg == -10) {
+				usblp_dump(usblp);
+				break;
+			}
+#endif
+
+			usblp_unlink_urbs(usblp);
+			retval = usblp_set_protocol(usblp, arg);
+			if (retval < 0) {
+				usblp_set_protocol(usblp,
+					usblp->current_protocol);
+			}
+			break;
+
+		case IOCNR_HP_SET_CHANNEL:
+			if (_IOC_DIR(cmd) != _IOC_WRITE ||
+			    le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
+			    usblp->quirks & USBLP_QUIRK_BIDIR) {
+				retval = -EINVAL;
+				goto done;
+			}
+
+			err = usblp_hp_channel_change_request(usblp,
+				arg, &newChannel);
+			if (err < 0) {
+				dev_err(&usblp->dev->dev,
+					"usblp%d: error = %d setting "
+					"HP channel\n",
+					usblp->minor, err);
+				retval = -EIO;
+				goto done;
+			}
+
+			dev_dbg(&usblp->intf->dev,
+				"usblp%d requested/got HP channel %ld/%d\n",
+				usblp->minor, arg, newChannel);
+			break;
+
+		case IOCNR_GET_BUS_ADDRESS:
+			if (_IOC_DIR(cmd) != _IOC_READ ||
+			    _IOC_SIZE(cmd) < sizeof(twoints)) {
+				retval = -EINVAL;
+				goto done;
+			}
+
+			twoints[0] = usblp->dev->bus->busnum;
+			twoints[1] = usblp->dev->devnum;
+			if (copy_to_user((void __user *)arg,
+					(unsigned char *)twoints,
+					sizeof(twoints))) {
+				retval = -EFAULT;
+				goto done;
+			}
+
+			dev_dbg(&usblp->intf->dev,
+				"usblp%d is bus=%d, device=%d\n",
+				usblp->minor, twoints[0], twoints[1]);
+			break;
+
+		case IOCNR_GET_VID_PID:
+			if (_IOC_DIR(cmd) != _IOC_READ ||
+			    _IOC_SIZE(cmd) < sizeof(twoints)) {
+				retval = -EINVAL;
+				goto done;
+			}
+
+			twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
+			twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
+			if (copy_to_user((void __user *)arg,
+					(unsigned char *)twoints,
+					sizeof(twoints))) {
+				retval = -EFAULT;
+				goto done;
+			}
+
+			dev_dbg(&usblp->intf->dev,
+				"usblp%d is VID=0x%4.4X, PID=0x%4.4X\n",
+				usblp->minor, twoints[0], twoints[1]);
+			break;
+
+		case IOCNR_SOFT_RESET:
+			if (_IOC_DIR(cmd) != _IOC_NONE) {
+				retval = -EINVAL;
+				goto done;
+			}
+			retval = usblp_reset(usblp);
+			break;
+		default:
+			retval = -ENOTTY;
+		}
+	else	/* old-style ioctl value */
+		switch (cmd) {
+
+		case LPGETSTATUS:
+			retval = usblp_read_status(usblp, usblp->statusbuf);
+			if (retval) {
+				printk_ratelimited(KERN_ERR "usblp%d:"
+					    "failed reading printer status (%d)\n",
+					    usblp->minor, retval);
+				retval = -EIO;
+				goto done;
+			}
+			status = *usblp->statusbuf;
+			if (copy_to_user((void __user *)arg, &status, sizeof(int)))
+				retval = -EFAULT;
+			break;
+
+		case LPABORT:
+			if (arg)
+				usblp->flags |= LP_ABORT;
+			else
+				usblp->flags &= ~LP_ABORT;
+			break;
+
+		default:
+			retval = -ENOTTY;
+		}
+
+done:
+	mutex_unlock(&usblp->mut);
+	return retval;
+}
+
+static struct urb *usblp_new_writeurb(struct usblp *usblp, int transfer_length)
+{
+	struct urb *urb;
+	char *writebuf;
+
+	writebuf = kmalloc(transfer_length, GFP_KERNEL);
+	if (writebuf == NULL)
+		return NULL;
+	urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (urb == NULL) {
+		kfree(writebuf);
+		return NULL;
+	}
+
+	usb_fill_bulk_urb(urb, usblp->dev,
+		usb_sndbulkpipe(usblp->dev,
+		 usblp->protocol[usblp->current_protocol].epwrite->bEndpointAddress),
+		writebuf, transfer_length, usblp_bulk_write, usblp);
+	urb->transfer_flags |= URB_FREE_BUFFER;
+
+	return urb;
+}
+
+static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
+{
+	struct usblp *usblp = file->private_data;
+	struct urb *writeurb;
+	int rv;
+	int transfer_length;
+	ssize_t writecount = 0;
+
+	if (mutex_lock_interruptible(&usblp->wmut)) {
+		rv = -EINTR;
+		goto raise_biglock;
+	}
+	if ((rv = usblp_wwait(usblp, !!(file->f_flags & O_NONBLOCK))) < 0)
+		goto raise_wait;
+
+	while (writecount < count) {
+		/*
+		 * Step 1: Submit next block.
+		 */
+		if ((transfer_length = count - writecount) > USBLP_BUF_SIZE)
+			transfer_length = USBLP_BUF_SIZE;
+
+		rv = -ENOMEM;
+		writeurb = usblp_new_writeurb(usblp, transfer_length);
+		if (writeurb == NULL)
+			goto raise_urb;
+		usb_anchor_urb(writeurb, &usblp->urbs);
+
+		if (copy_from_user(writeurb->transfer_buffer,
+				   buffer + writecount, transfer_length)) {
+			rv = -EFAULT;
+			goto raise_badaddr;
+		}
+
+		spin_lock_irq(&usblp->lock);
+		usblp->wcomplete = 0;
+		spin_unlock_irq(&usblp->lock);
+		if ((rv = usb_submit_urb(writeurb, GFP_KERNEL)) < 0) {
+			usblp->wstatus = 0;
+			spin_lock_irq(&usblp->lock);
+			usblp->no_paper = 0;
+			usblp->wcomplete = 1;
+			wake_up(&usblp->wwait);
+			spin_unlock_irq(&usblp->lock);
+			if (rv != -ENOMEM)
+				rv = -EIO;
+			goto raise_submit;
+		}
+
+		/*
+		 * Step 2: Wait for transfer to end, collect results.
+		 */
+		rv = usblp_wwait(usblp, !!(file->f_flags&O_NONBLOCK));
+		if (rv < 0) {
+			if (rv == -EAGAIN) {
+				/* Presume that it's going to complete well. */
+				writecount += transfer_length;
+			}
+			if (rv == -ENOSPC) {
+				spin_lock_irq(&usblp->lock);
+				usblp->no_paper = 1;	/* Mark for poll(2) */
+				spin_unlock_irq(&usblp->lock);
+				writecount += transfer_length;
+			}
+			/* Leave URB dangling, to be cleaned on close. */
+			goto collect_error;
+		}
+
+		if (usblp->wstatus < 0) {
+			rv = -EIO;
+			goto collect_error;
+		}
+		/*
+		 * This is critical: it must be our URB, not other writer's.
+		 * The wmut exists mainly to cover us here.
+		 */
+		writecount += usblp->wstatus;
+	}
+
+	mutex_unlock(&usblp->wmut);
+	return writecount;
+
+raise_submit:
+raise_badaddr:
+	usb_unanchor_urb(writeurb);
+	usb_free_urb(writeurb);
+raise_urb:
+raise_wait:
+collect_error:		/* Out of raise sequence */
+	mutex_unlock(&usblp->wmut);
+raise_biglock:
+	return writecount ? writecount : rv;
+}
+
+/*
+ * Notice that we fail to restart in a few cases: on EFAULT, on restart
+ * error, etc. This is the historical behaviour. In all such cases we return
+ * EIO, and applications loop in order to get the new read going.
+ */
+static ssize_t usblp_read(struct file *file, char __user *buffer, size_t len, loff_t *ppos)
+{
+	struct usblp *usblp = file->private_data;
+	ssize_t count;
+	ssize_t avail;
+	int rv;
+
+	if (!usblp->bidir)
+		return -EINVAL;
+
+	rv = usblp_rwait_and_lock(usblp, !!(file->f_flags & O_NONBLOCK));
+	if (rv < 0)
+		return rv;
+
+	if (!usblp->present) {
+		count = -ENODEV;
+		goto done;
+	}
+
+	if ((avail = usblp->rstatus) < 0) {
+		printk(KERN_ERR "usblp%d: error %d reading from printer\n",
+		    usblp->minor, (int)avail);
+		usblp_submit_read(usblp);
+		count = -EIO;
+		goto done;
+	}
+
+	count = len < avail - usblp->readcount ? len : avail - usblp->readcount;
+	if (count != 0 &&
+	    copy_to_user(buffer, usblp->readbuf + usblp->readcount, count)) {
+		count = -EFAULT;
+		goto done;
+	}
+
+	if ((usblp->readcount += count) == avail) {
+		if (usblp_submit_read(usblp) < 0) {
+			/* We don't want to leak USB return codes into errno. */
+			if (count == 0)
+				count = -EIO;
+			goto done;
+		}
+	}
+
+done:
+	mutex_unlock(&usblp->mut);
+	return count;
+}
+
+/*
+ * Wait for the write path to come idle.
+ * This is called under the ->wmut, so the idle path stays idle.
+ *
+ * Our write path has a peculiar property: it does not buffer like a tty,
+ * but waits for the write to succeed. This allows our ->release to bug out
+ * without waiting for writes to drain. But it obviously does not work
+ * when O_NONBLOCK is set. So, applications setting O_NONBLOCK must use
+ * select(2) or poll(2) to wait for the buffer to drain before closing.
+ * Alternatively, set blocking mode with fcntl and issue a zero-size write.
+ */
+static int usblp_wwait(struct usblp *usblp, int nonblock)
+{
+	DECLARE_WAITQUEUE(waita, current);
+	int rc;
+	int err = 0;
+
+	add_wait_queue(&usblp->wwait, &waita);
+	for (;;) {
+		if (mutex_lock_interruptible(&usblp->mut)) {
+			rc = -EINTR;
+			break;
+		}
+		set_current_state(TASK_INTERRUPTIBLE);
+		rc = usblp_wtest(usblp, nonblock);
+		mutex_unlock(&usblp->mut);
+		if (rc <= 0)
+			break;
+
+		if (schedule_timeout(msecs_to_jiffies(1500)) == 0) {
+			if (usblp->flags & LP_ABORT) {
+				err = usblp_check_status(usblp, err);
+				if (err == 1) {	/* Paper out */
+					rc = -ENOSPC;
+					break;
+				}
+			} else {
+				/* Prod the printer, Gentoo#251237. */
+				mutex_lock(&usblp->mut);
+				usblp_read_status(usblp, usblp->statusbuf);
+				mutex_unlock(&usblp->mut);
+			}
+		}
+	}
+	set_current_state(TASK_RUNNING);
+	remove_wait_queue(&usblp->wwait, &waita);
+	return rc;
+}
+
+static int usblp_wtest(struct usblp *usblp, int nonblock)
+{
+	unsigned long flags;
+
+	if (!usblp->present)
+		return -ENODEV;
+	if (signal_pending(current))
+		return -EINTR;
+	spin_lock_irqsave(&usblp->lock, flags);
+	if (usblp->wcomplete) {
+		spin_unlock_irqrestore(&usblp->lock, flags);
+		return 0;
+	}
+	spin_unlock_irqrestore(&usblp->lock, flags);
+	if (nonblock)
+		return -EAGAIN;
+	return 1;
+}
+
+/*
+ * Wait for read bytes to become available. This probably should have been
+ * called usblp_r_lock_and_wait(), because we lock first. But it's a traditional
+ * name for functions which lock and return.
+ *
+ * We do not use wait_event_interruptible because it makes locking iffy.
+ */
+static int usblp_rwait_and_lock(struct usblp *usblp, int nonblock)
+{
+	DECLARE_WAITQUEUE(waita, current);
+	int rc;
+
+	add_wait_queue(&usblp->rwait, &waita);
+	for (;;) {
+		if (mutex_lock_interruptible(&usblp->mut)) {
+			rc = -EINTR;
+			break;
+		}
+		set_current_state(TASK_INTERRUPTIBLE);
+		if ((rc = usblp_rtest(usblp, nonblock)) < 0) {
+			mutex_unlock(&usblp->mut);
+			break;
+		}
+		if (rc == 0)	/* Keep it locked */
+			break;
+		mutex_unlock(&usblp->mut);
+		schedule();
+	}
+	set_current_state(TASK_RUNNING);
+	remove_wait_queue(&usblp->rwait, &waita);
+	return rc;
+}
+
+static int usblp_rtest(struct usblp *usblp, int nonblock)
+{
+	unsigned long flags;
+
+	if (!usblp->present)
+		return -ENODEV;
+	if (signal_pending(current))
+		return -EINTR;
+	spin_lock_irqsave(&usblp->lock, flags);
+	if (usblp->rcomplete) {
+		spin_unlock_irqrestore(&usblp->lock, flags);
+		return 0;
+	}
+	spin_unlock_irqrestore(&usblp->lock, flags);
+	if (nonblock)
+		return -EAGAIN;
+	return 1;
+}
+
+/*
+ * Please check ->bidir and other such things outside for now.
+ */
+static int usblp_submit_read(struct usblp *usblp)
+{
+	struct urb *urb;
+	unsigned long flags;
+	int rc;
+
+	rc = -ENOMEM;
+	urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (urb == NULL)
+		goto raise_urb;
+
+	usb_fill_bulk_urb(urb, usblp->dev,
+		usb_rcvbulkpipe(usblp->dev,
+		  usblp->protocol[usblp->current_protocol].epread->bEndpointAddress),
+		usblp->readbuf, USBLP_BUF_SIZE_IN,
+		usblp_bulk_read, usblp);
+	usb_anchor_urb(urb, &usblp->urbs);
+
+	spin_lock_irqsave(&usblp->lock, flags);
+	usblp->readcount = 0; /* XXX Why here? */
+	usblp->rcomplete = 0;
+	spin_unlock_irqrestore(&usblp->lock, flags);
+	if ((rc = usb_submit_urb(urb, GFP_KERNEL)) < 0) {
+		dev_dbg(&usblp->intf->dev, "error submitting urb (%d)\n", rc);
+		spin_lock_irqsave(&usblp->lock, flags);
+		usblp->rstatus = rc;
+		usblp->rcomplete = 1;
+		spin_unlock_irqrestore(&usblp->lock, flags);
+		goto raise_submit;
+	}
+
+	return 0;
+
+raise_submit:
+	usb_unanchor_urb(urb);
+	usb_free_urb(urb);
+raise_urb:
+	return rc;
+}
+
+/*
+ * Checks for printers that have quirks, such as requiring unidirectional
+ * communication but reporting bidirectional; currently some HP printers
+ * have this flaw (HP 810, 880, 895, etc.), or needing an init string
+ * sent at each open (like some Epsons).
+ * Returns 1 if found, 0 if not found.
+ *
+ * HP recommended that we use the bidirectional interface but
+ * don't attempt any bulk IN transfers from the IN endpoint.
+ * Here's some more detail on the problem:
+ * The problem is not that it isn't bidirectional though. The problem
+ * is that if you request a device ID, or status information, while
+ * the buffers are full, the return data will end up in the print data
+ * buffer. For example if you make sure you never request the device ID
+ * while you are sending print data, and you don't try to query the
+ * printer status every couple of milliseconds, you will probably be OK.
+ */
+static unsigned int usblp_quirks(__u16 vendor, __u16 product)
+{
+	int i;
+
+	for (i = 0; quirk_printers[i].vendorId; i++) {
+		if (vendor == quirk_printers[i].vendorId &&
+		    product == quirk_printers[i].productId)
+			return quirk_printers[i].quirks;
+	}
+	return 0;
+}
+
+static const struct file_operations usblp_fops = {
+	.owner =	THIS_MODULE,
+	.read =		usblp_read,
+	.write =	usblp_write,
+	.poll =		usblp_poll,
+	.unlocked_ioctl =	usblp_ioctl,
+	.compat_ioctl =		usblp_ioctl,
+	.open =		usblp_open,
+	.release =	usblp_release,
+	.llseek =	noop_llseek,
+};
+
+static char *usblp_devnode(struct device *dev, umode_t *mode)
+{
+	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
+}
+
+static struct usb_class_driver usblp_class = {
+	.name =		"lp%d",
+	.devnode =	usblp_devnode,
+	.fops =		&usblp_fops,
+	.minor_base =	USBLP_MINOR_BASE,
+};
+
+static ssize_t ieee1284_id_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct usblp *usblp = usb_get_intfdata(intf);
+
+	if (usblp->device_id_string[0] == 0 &&
+	    usblp->device_id_string[1] == 0)
+		return 0;
+
+	return sprintf(buf, "%s", usblp->device_id_string+2);
+}
+
+static DEVICE_ATTR_RO(ieee1284_id);
+
+static struct attribute *usblp_attrs[] = {
+	&dev_attr_ieee1284_id.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(usblp);
+
+static int usblp_probe(struct usb_interface *intf,
+		       const struct usb_device_id *id)
+{
+	struct usb_device *dev = interface_to_usbdev(intf);
+	struct usblp *usblp;
+	int protocol;
+	int retval;
+
+	/* Malloc and start initializing usblp structure so we can use it
+	 * directly. */
+	usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL);
+	if (!usblp) {
+		retval = -ENOMEM;
+		goto abort_ret;
+	}
+	usblp->dev = dev;
+	mutex_init(&usblp->wmut);
+	mutex_init(&usblp->mut);
+	spin_lock_init(&usblp->lock);
+	init_waitqueue_head(&usblp->rwait);
+	init_waitqueue_head(&usblp->wwait);
+	init_usb_anchor(&usblp->urbs);
+	usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
+	usblp->intf = usb_get_intf(intf);
+
+	/* Malloc device ID string buffer to the largest expected length,
+	 * since we can re-query it on an ioctl and a dynamic string
+	 * could change in length. */
+	if (!(usblp->device_id_string = kmalloc(USBLP_DEVICE_ID_SIZE, GFP_KERNEL))) {
+		retval = -ENOMEM;
+		goto abort;
+	}
+
+	/*
+	 * Allocate read buffer. We somewhat wastefully
+	 * malloc both regardless of bidirectionality, because the
+	 * alternate setting can be changed later via an ioctl.
+	 */
+	if (!(usblp->readbuf = kmalloc(USBLP_BUF_SIZE_IN, GFP_KERNEL))) {
+		retval = -ENOMEM;
+		goto abort;
+	}
+
+	/* Allocate buffer for printer status */
+	usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
+	if (!usblp->statusbuf) {
+		retval = -ENOMEM;
+		goto abort;
+	}
+
+	/* Lookup quirks for this printer. */
+	usblp->quirks = usblp_quirks(
+		le16_to_cpu(dev->descriptor.idVendor),
+		le16_to_cpu(dev->descriptor.idProduct));
+
+	/* Analyze and pick initial alternate settings and endpoints. */
+	protocol = usblp_select_alts(usblp);
+	if (protocol < 0) {
+		dev_dbg(&intf->dev,
+			"incompatible printer-class device 0x%4.4X/0x%4.4X\n",
+			le16_to_cpu(dev->descriptor.idVendor),
+			le16_to_cpu(dev->descriptor.idProduct));
+		retval = -ENODEV;
+		goto abort;
+	}
+
+	/* Setup the selected alternate setting and endpoints. */
+	if (usblp_set_protocol(usblp, protocol) < 0) {
+		retval = -ENODEV;	/* ->probe isn't ->ioctl */
+		goto abort;
+	}
+
+	/* Retrieve and store the device ID string. */
+	usblp_cache_device_id_string(usblp);
+
+#ifdef DEBUG
+	usblp_check_status(usblp, 0);
+#endif
+
+	usb_set_intfdata(intf, usblp);
+
+	usblp->present = 1;
+
+	retval = usb_register_dev(intf, &usblp_class);
+	if (retval) {
+		dev_err(&intf->dev,
+			"usblp: Not able to get a minor (base %u, slice default): %d\n",
+			USBLP_MINOR_BASE, retval);
+		goto abort_intfdata;
+	}
+	usblp->minor = intf->minor;
+	dev_info(&intf->dev,
+		"usblp%d: USB %sdirectional printer dev %d if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X\n",
+		usblp->minor, usblp->bidir ? "Bi" : "Uni", dev->devnum,
+		usblp->ifnum,
+		usblp->protocol[usblp->current_protocol].alt_setting,
+		usblp->current_protocol,
+		le16_to_cpu(usblp->dev->descriptor.idVendor),
+		le16_to_cpu(usblp->dev->descriptor.idProduct));
+
+	return 0;
+
+abort_intfdata:
+	usb_set_intfdata(intf, NULL);
+abort:
+	kfree(usblp->readbuf);
+	kfree(usblp->statusbuf);
+	kfree(usblp->device_id_string);
+	usb_put_intf(usblp->intf);
+	kfree(usblp);
+abort_ret:
+	return retval;
+}
+
+/*
+ * We are a "new" style driver with usb_device_id table,
+ * but our requirements are too intricate for simple match to handle.
+ *
+ * The "proto_bias" option may be used to specify the preferred protocol
+ * for all USB printers (1=USB_CLASS_PRINTER/1/1, 2=USB_CLASS_PRINTER/1/2,
+ * 3=USB_CLASS_PRINTER/1/3).  If the device supports the preferred protocol,
+ * then we bind to it.
+ *
+ * The best interface for us is USB_CLASS_PRINTER/1/2, because it
+ * is compatible with a stream of characters. If we find it, we bind to it.
+ *
+ * Note that the people from hpoj.sourceforge.net need to be able to
+ * bind to USB_CLASS_PRINTER/1/3 (MLC/1284.4), so we provide them ioctls
+ * for this purpose.
+ *
+ * Failing USB_CLASS_PRINTER/1/2, we look for USB_CLASS_PRINTER/1/3,
+ * even though it's probably not stream-compatible, because this matches
+ * the behaviour of the old code.
+ *
+ * If nothing else, we bind to USB_CLASS_PRINTER/1/1
+ * - the unidirectional interface.
+ */
+static int usblp_select_alts(struct usblp *usblp)
+{
+	struct usb_interface *if_alt;
+	struct usb_host_interface *ifd;
+	struct usb_endpoint_descriptor *epwrite, *epread;
+	int p, i;
+	int res;
+
+	if_alt = usblp->intf;
+
+	for (p = 0; p < USBLP_MAX_PROTOCOLS; p++)
+		usblp->protocol[p].alt_setting = -1;
+
+	/* Find out what we have. */
+	for (i = 0; i < if_alt->num_altsetting; i++) {
+		ifd = &if_alt->altsetting[i];
+
+		if (ifd->desc.bInterfaceClass != USB_CLASS_PRINTER ||
+		    ifd->desc.bInterfaceSubClass != 1)
+			if (!(usblp->quirks & USBLP_QUIRK_BAD_CLASS))
+				continue;
+
+		if (ifd->desc.bInterfaceProtocol < USBLP_FIRST_PROTOCOL ||
+		    ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
+			continue;
+
+		/* Look for the expected bulk endpoints. */
+		if (ifd->desc.bInterfaceProtocol > 1) {
+			res = usb_find_common_endpoints(ifd,
+					&epread, &epwrite, NULL, NULL);
+		} else {
+			epread = NULL;
+			res = usb_find_bulk_out_endpoint(ifd, &epwrite);
+		}
+
+		/* Ignore buggy hardware without the right endpoints. */
+		if (res)
+			continue;
+
+		/* Turn off reads for buggy bidirectional printers. */
+		if (usblp->quirks & USBLP_QUIRK_BIDIR) {
+			printk(KERN_INFO "usblp%d: Disabling reads from "
+			    "problematic bidirectional printer\n",
+			    usblp->minor);
+			epread = NULL;
+		}
+
+		usblp->protocol[ifd->desc.bInterfaceProtocol].alt_setting =
+				ifd->desc.bAlternateSetting;
+		usblp->protocol[ifd->desc.bInterfaceProtocol].epwrite = epwrite;
+		usblp->protocol[ifd->desc.bInterfaceProtocol].epread = epread;
+	}
+
+	/* If our requested protocol is supported, then use it. */
+	if (proto_bias >= USBLP_FIRST_PROTOCOL &&
+	    proto_bias <= USBLP_LAST_PROTOCOL &&
+	    usblp->protocol[proto_bias].alt_setting != -1)
+		return proto_bias;
+
+	/* Ordering is important here. */
+	if (usblp->protocol[2].alt_setting != -1)
+		return 2;
+	if (usblp->protocol[1].alt_setting != -1)
+		return 1;
+	if (usblp->protocol[3].alt_setting != -1)
+		return 3;
+
+	/* If nothing is available, then don't bind to this device. */
+	return -1;
+}
+
+static int usblp_set_protocol(struct usblp *usblp, int protocol)
+{
+	int r, alts;
+
+	if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
+		return -EINVAL;
+
+	/* Don't unnecessarily set the interface if there's a single alt. */
+	if (usblp->intf->num_altsetting > 1) {
+		alts = usblp->protocol[protocol].alt_setting;
+		if (alts < 0)
+			return -EINVAL;
+		r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
+		if (r < 0) {
+			printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
+				alts, usblp->ifnum);
+			return r;
+		}
+	}
+
+	usblp->bidir = (usblp->protocol[protocol].epread != NULL);
+	usblp->current_protocol = protocol;
+	dev_dbg(&usblp->intf->dev, "usblp%d set protocol %d\n",
+		usblp->minor, protocol);
+	return 0;
+}
+
+/* Retrieves and caches device ID string.
+ * Returns length, including length bytes but not null terminator.
+ * On error, returns a negative errno value. */
+static int usblp_cache_device_id_string(struct usblp *usblp)
+{
+	int err, length;
+
+	err = usblp_get_id(usblp, 0, usblp->device_id_string, USBLP_DEVICE_ID_SIZE - 1);
+	if (err < 0) {
+		dev_dbg(&usblp->intf->dev,
+			"usblp%d: error = %d reading IEEE-1284 Device ID string\n",
+			usblp->minor, err);
+		usblp->device_id_string[0] = usblp->device_id_string[1] = '\0';
+		return -EIO;
+	}
+
+	/* First two bytes are length in big-endian.
+	 * They count themselves, and we copy them into
+	 * the user's buffer. */
+	length = be16_to_cpu(*((__be16 *)usblp->device_id_string));
+	if (length < 2)
+		length = 2;
+	else if (length >= USBLP_DEVICE_ID_SIZE)
+		length = USBLP_DEVICE_ID_SIZE - 1;
+	usblp->device_id_string[length] = '\0';
+
+	dev_dbg(&usblp->intf->dev, "usblp%d Device ID string [len=%d]=\"%s\"\n",
+		usblp->minor, length, &usblp->device_id_string[2]);
+
+	return length;
+}
+
+static void usblp_disconnect(struct usb_interface *intf)
+{
+	struct usblp *usblp = usb_get_intfdata(intf);
+
+	usb_deregister_dev(intf, &usblp_class);
+
+	if (!usblp || !usblp->dev) {
+		dev_err(&intf->dev, "bogus disconnect\n");
+		BUG();
+	}
+
+	mutex_lock(&usblp_mutex);
+	mutex_lock(&usblp->mut);
+	usblp->present = 0;
+	wake_up(&usblp->wwait);
+	wake_up(&usblp->rwait);
+	usb_set_intfdata(intf, NULL);
+
+	usblp_unlink_urbs(usblp);
+	mutex_unlock(&usblp->mut);
+	usb_poison_anchored_urbs(&usblp->urbs);
+
+	if (!usblp->used)
+		usblp_cleanup(usblp);
+
+	mutex_unlock(&usblp_mutex);
+}
+
+static int usblp_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct usblp *usblp = usb_get_intfdata(intf);
+
+	usblp_unlink_urbs(usblp);
+#if 0 /* XXX Do we want this? What if someone is reading, should we fail? */
+	/* not strictly necessary, but just in case */
+	wake_up(&usblp->wwait);
+	wake_up(&usblp->rwait);
+#endif
+
+	return 0;
+}
+
+static int usblp_resume(struct usb_interface *intf)
+{
+	struct usblp *usblp = usb_get_intfdata(intf);
+	int r;
+
+	r = handle_bidir(usblp);
+
+	return r;
+}
+
+static const struct usb_device_id usblp_ids[] = {
+	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 1) },
+	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 2) },
+	{ USB_DEVICE_INFO(USB_CLASS_PRINTER, 1, 3) },
+	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 1) },
+	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 2) },
+	{ USB_INTERFACE_INFO(USB_CLASS_PRINTER, 1, 3) },
+	{ USB_DEVICE(0x04b8, 0x0202) },	/* Seiko Epson Receipt Printer M129C */
+	{ }						/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, usblp_ids);
+
+static struct usb_driver usblp_driver = {
+	.name =		"usblp",
+	.probe =	usblp_probe,
+	.disconnect =	usblp_disconnect,
+	.suspend =	usblp_suspend,
+	.resume =	usblp_resume,
+	.id_table =	usblp_ids,
+	.dev_groups =	usblp_groups,
+	.supports_autosuspend =	1,
+};
+
+module_usb_driver(usblp_driver);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+module_param(proto_bias, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(proto_bias, "Favourite protocol number");
+MODULE_LICENSE("GPL");