Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / usb / class / usblp.c
diff --git a/kernel/drivers/usb/class/usblp.c b/kernel/drivers/usb/class/usblp.c
new file mode 100644 (file)
index 0000000..0924ee4
--- /dev/null
@@ -0,0 +1,1432 @@
+/*
+ * 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
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.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/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=7/1/1, 2=7/1/2, 3=7/1/3),
+ * [1]=supported protocol mask (mask&(1<<n)!=0 means 7/1/n supported): */
+#define LPIOC_GET_PROTOCOLS(len) _IOC(_IOC_READ, 'P', IOCNR_GET_PROTOCOLS, len)
+/* Set protocol (arg: 1=7/1/1, 2=7/1/2, 3=7/1/3): */
+#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
+        * (7/1/{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)
+
+#define usblp_hp_channel_change_request(usblp, channel, buffer) \
+       usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
+
+/*
+ * See the description for usblp_select_alts() below for the usage
+ * explanation.  Look into your /proc/bus/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;
+
+       if (usblp->present && usblp->used) {
+               if (status)
+                       printk(KERN_WARNING "usblp%d: "
+                           "nonzero read bulk status received: %d\n",
+                           usblp->minor, status);
+       }
+       spin_lock(&usblp->lock);
+       if (status < 0)
+               usblp->rstatus = status;
+       else
+               usblp->rstatus = urb->actual_length;
+       usblp->rcomplete = 1;
+       wake_up(&usblp->rwait);
+       spin_unlock(&usblp->lock);
+
+       usb_free_urb(urb);
+}
+
+static void usblp_bulk_write(struct urb *urb)
+{
+       struct usblp *usblp = urb->context;
+       int status = urb->status;
+
+       if (usblp->present && usblp->used) {
+               if (status)
+                       printk(KERN_WARNING "usblp%d: "
+                           "nonzero write bulk status received: %d\n",
+                           usblp->minor, status);
+       }
+       spin_lock(&usblp->lock);
+       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(&usblp->lock);
+
+       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);
+       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);
+       } else          /* finish cleanup from disconnect */
+               usblp_cleanup(usblp);
+       mutex_unlock(&usblp_mutex);
+       return 0;
+}
+
+/* No kernel lock - fine */
+static unsigned int usblp_poll(struct file *file, struct poll_table_struct *wait)
+{
+       int ret;
+       unsigned long flags;
+
+       struct usblp *usblp = file->private_data;
+       /* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
+       poll_wait(file, &usblp->rwait, wait);
+       poll_wait(file, &usblp->wwait, wait);
+       spin_lock_irqsave(&usblp->lock, flags);
+       ret = ((usblp->bidir && usblp->rcomplete) ? POLLIN  | POLLRDNORM : 0) |
+          ((usblp->no_paper || usblp->wcomplete) ? POLLOUT | POLLWRNORM : 0);
+       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:
+                       if ((retval = usblp_read_status(usblp, usblp->statusbuf))) {
+                               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;
+
+       if ((writebuf = kmalloc(transfer_length, GFP_KERNEL)) == NULL)
+               return NULL;
+       if ((urb = usb_alloc_urb(0, GFP_KERNEL)) == 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;
+               if ((writeurb = usblp_new_writeurb(usblp, transfer_length)) == 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 ((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 (;;) {
+               set_current_state(TASK_INTERRUPTIBLE);
+               if (mutex_lock_interruptible(&usblp->mut)) {
+                       rc = -EINTR;
+                       break;
+               }
+               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;
+       if ((urb = usb_alloc_urb(0, GFP_KERNEL)) == 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 usblp_show_ieee1284_id(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(ieee1284_id, S_IRUGO, usblp_show_ieee1284_id, NULL);
+
+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 = 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);
+       retval = device_create_file(&intf->dev, &dev_attr_ieee1284_id);
+       if (retval)
+               goto abort_intfdata;
+
+#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);
+       device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
+abort:
+       kfree(usblp->readbuf);
+       kfree(usblp->statusbuf);
+       kfree(usblp->device_id_string);
+       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=7/1/1, 2=7/1/2, 3=7/1/3).  If the device
+ * supports the preferred protocol, then we bind to it.
+ *
+ * The best interface for us is 7/1/2, 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 7/1/3 (MLC/1284.4), so we provide them ioctls for this purpose.
+ *
+ * Failing 7/1/2, we look for 7/1/3, even though it's probably not
+ * stream-compatible, because this matches the behaviour of the old code.
+ *
+ * If nothing else, we bind to 7/1/1 - 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 *epd, *epwrite, *epread;
+       int p, i, e;
+
+       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 != 7 || 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 bulk OUT and IN endpoints. */
+               epwrite = epread = NULL;
+               for (e = 0; e < ifd->desc.bNumEndpoints; e++) {
+                       epd = &ifd->endpoint[e].desc;
+
+                       if (usb_endpoint_is_bulk_out(epd))
+                               if (!epwrite)
+                                       epwrite = epd;
+
+                       if (usb_endpoint_is_bulk_in(epd))
+                               if (!epread)
+                                       epread = epd;
+               }
+
+               /* Ignore buggy hardware without the right endpoints. */
+               if (!epwrite || (ifd->desc.bInterfaceProtocol > 1 && !epread))
+                       continue;
+
+               /* Turn off reads for 7/1/1 (unidirectional) interfaces
+                * and buggy bidirectional printers. */
+               if (ifd->desc.bInterfaceProtocol == 1) {
+                       epread = NULL;
+               } else 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;
+
+       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();
+       }
+
+       device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
+
+       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);
+
+       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(7, 1, 1) },
+       { USB_DEVICE_INFO(7, 1, 2) },
+       { USB_DEVICE_INFO(7, 1, 3) },
+       { USB_INTERFACE_INFO(7, 1, 1) },
+       { USB_INTERFACE_INFO(7, 1, 2) },
+       { USB_INTERFACE_INFO(7, 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,
+       .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");