aboutsummaryrefslogblamecommitdiffstats
path: root/drivers/usb/class/usblp.c
blob: 357e75335f17d87396c88dfcb729899176ae2a49 (plain) (tree)
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219























































































































































































































































































































                                                                                                                                                                                                                            


                                                                       


































































                                                                                        

                                    






























































































































































































































                                                                                                   


                                                                                             



















































































































































                                                                                                    
                                                  






















































































                                                                                              
                               
                                    


















































































































































































































































































































































































                                                                                        
/*
 * usblp.c  Version 0.13
 *
 * Copyright (c) 1999 Michael Gee	<michael@linuxspecific.com>
 * Copyright (c) 1999 Pavel Machek	<pavel@suse.cz>
 * Copyright (c) 2000 Randy Dunlap	<rddunlap@osdl.org>
 * Copyright (c) 2000 Vojtech Pavlik	<vojtech@suse.cz>
 # Copyright (c) 2001 Pete Zaitcev	<zaitcev@redhat.com>
 # Copyright (c) 2001 David Paschal	<paschal@rcsis.com>
 *
 * 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_buffer_alloc() for read buf & write buf;
 */

/*
 * 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/smp_lock.h>
#include <linux/signal.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/lp.h>
#undef DEBUG
#include <linux/usb.h>

/*
 * Version Information
 */
#define DRIVER_VERSION "v0.13"
#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_DEVICE_ID_SIZE	1024

/* ioctls: */
#define LPGETSTATUS		0x060b		/* same as in drivers/char/lp.c */
#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_WRITE_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

struct usblp {
	struct usb_device 	*dev;			/* USB device */
	struct semaphore	sem;			/* locks this struct, especially "dev" */
	char			*writebuf;		/* write transfer_buffer */
	char			*readbuf;		/* read transfer_buffer */
	char			*statusbuf;		/* status transfer_buffer */
	struct urb		*readurb, *writeurb;	/* The urbs */
	wait_queue_head_t	wait;			/* Zzzzz ... */
	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;		/* writing is completed */
	int			rcomplete;		/* reading is completed */
	unsigned int		quirks;			/* quirks flags */
	unsigned char		used;			/* True if open */
	unsigned char		present;		/* True if not disconnected */
	unsigned char		bidir;			/* interface is bidirectional */
	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) {
	int p;

	dbg("usblp=0x%p", usblp);
	dbg("dev=0x%p", usblp->dev);
	dbg("present=%d", usblp->present);
	dbg("readbuf=0x%p", usblp->readbuf);
	dbg("writebuf=0x%p", usblp->writebuf);
	dbg("readurb=0x%p", usblp->readurb);
	dbg("writeurb=0x%p", usblp->writeurb);
	dbg("readcount=%d", usblp->readcount);
	dbg("ifnum=%d", usblp->ifnum);
    for (p = USBLP_FIRST_PROTOCOL; p <= USBLP_LAST_PROTOCOL; p++) {
	dbg("protocol[%d].alt_setting=%d", p, usblp->protocol[p].alt_setting);
	dbg("protocol[%d].epwrite=%p", p, usblp->protocol[p].epwrite);
	dbg("protocol[%d].epread=%p", p, usblp->protocol[p].epread);
    }
	dbg("current_protocol=%d", usblp->current_protocol);
	dbg("minor=%d", usblp->minor);
	dbg("wcomplete=%d", usblp->wcomplete);
	dbg("rcomplete=%d", usblp->rcomplete);
	dbg("quirks=%d", usblp->quirks);
	dbg("used=%d", usblp->used);
	dbg("bidir=%d", usblp->bidir);
	dbg("device_id_string=\"%s\"",
		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 */

static 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) */
	{ 0, 0 }
};

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 DECLARE_MUTEX(usblp_sem);	/* 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_WRITE_TIMEOUT);
	dbg("usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d idx: %d len: %#x result: %d",
		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 pt_regs *regs)
{
	struct usblp *usblp = urb->context;

	if (!usblp || !usblp->dev || !usblp->used || !usblp->present)
		return;

	if (unlikely(urb->status))
		warn("usblp%d: nonzero read/write bulk status received: %d",
			usblp->minor, urb->status);
	usblp->rcomplete = 1;
	wake_up_interruptible(&usblp->wait);
}

static void usblp_bulk_write(struct urb *urb, struct pt_regs *regs)
{
	struct usblp *usblp = urb->context;

	if (!usblp || !usblp->dev || !usblp->used || !usblp->present)
		return;

	if (unlikely(urb->status))
		warn("usblp%d: nonzero read/write bulk status received: %d",
			usblp->minor, urb->status);
	usblp->wcomplete = 1;
	wake_up_interruptible(&usblp->wait);
}

/*
 * Get and print printer errors.
 */

static 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;

	error = usblp_read_status (usblp, usblp->statusbuf);
	if (error < 0) {
		if (printk_ratelimit())
			err("usblp%d: error %d reading printer status",
				usblp->minor, error);
		return 0;
	}

	status = *usblp->statusbuf;

	if (~status & LP_PERRORP)
		newerr = 3;
	if (status & LP_POUTPA)
		newerr = 1;
	if (~status & LP_PSELECD)
		newerr = 2;

	if (newerr != err)
		info("usblp%d: %s", usblp->minor, usblp_messages[newerr]);

	return newerr;
}

/*
 * 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;

	down (&usblp_sem);

	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;

	/*
	 * TODO: need to implement LP_ABORTOPEN + O_NONBLOCK as in drivers/char/lp.c ???
	 * This is #if 0-ed because we *don't* want to fail an open
	 * just because the printer is off-line.
	 */
#if 0
	if ((retval = usblp_check_status(usblp, 0))) {
		retval = retval > 1 ? -EIO : -ENOSPC;
		goto out;
	}
#else
	retval = 0;
#endif

	usblp->used = 1;
	file->private_data = usblp;

	usblp->writeurb->transfer_buffer_length = 0;
	usblp->wcomplete = 1; /* we begin writeable */
	usblp->rcomplete = 0;
	usblp->writeurb->status = 0;
	usblp->readurb->status = 0;

	if (usblp->bidir) {
		usblp->readcount = 0;
		usblp->readurb->dev = usblp->dev;
		if (usb_submit_urb(usblp->readurb, GFP_KERNEL) < 0) {
			retval = -EIO;
			usblp->used = 0;
			file->private_data = NULL;
		}
	}
out:
	up (&usblp_sem);
	return retval;
}

static void usblp_cleanup (struct usblp *usblp)
{
	info("usblp%d: removed", usblp->minor);

	kfree (usblp->device_id_string);
	kfree (usblp->statusbuf);
	usb_free_urb(usblp->writeurb);
	usb_free_urb(usblp->readurb);
	kfree (usblp);
}

static void usblp_unlink_urbs(struct usblp *usblp)
{
	usb_kill_urb(usblp->writeurb);
	if (usblp->bidir)
		usb_kill_urb(usblp->readurb);
}

static int usblp_release(struct inode *inode, struct file *file)
{
	struct usblp *usblp = file->private_data;

	down (&usblp_sem);
	usblp->used = 0;
	if (usblp->present) {
		usblp_unlink_urbs(usblp);
	} else 		/* finish cleanup from disconnect */
		usblp_cleanup (usblp);
	up (&usblp_sem);
	return 0;
}

/* No kernel lock - fine */
static unsigned int usblp_poll(struct file *file, struct poll_table_struct *wait)
{
	struct usblp *usblp = file->private_data;
	poll_wait(file, &usblp->wait, wait);
 	return ((!usblp->bidir || !usblp->rcomplete) ? 0 : POLLIN  | POLLRDNORM)
 			       | (!usblp->wcomplete ? 0 : POLLOUT | POLLWRNORM);
}

static int usblp_ioctl(struct inode *inode, 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;

	down (&usblp->sem);
	if (!usblp->present) {
		retval = -ENODEV;
		goto done;
	}

	dbg("usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)", 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) {
					err("usblp%d: error = %d setting "
						"HP channel",
						usblp->minor, err);
					retval = -EIO;
					goto done;
				}

				dbg("usblp%d requested/got HP channel %ld/%d",
					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;
				}

				dbg("usblp%d is bus=%d, device=%d",
					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;
				}

				dbg("usblp%d is VID=0x%4.4X, PID=0x%4.4X",
					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 (usblp_read_status(usblp, usblp->statusbuf)) {
					if (printk_ratelimit())
						err("usblp%d: failed reading printer status",
							usblp->minor);
					retval = -EIO;
					goto done;
				}
				status = *usblp->statusbuf;
				if (copy_to_user ((void __user *)arg, &status, sizeof(int)))
					retval = -EFAULT;
				break;

			default:
				retval = -ENOTTY;
		}

done:
	up (&usblp->sem);
	return retval;
}

static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
{
	DECLARE_WAITQUEUE(wait, current);
	struct usblp *usblp = file->private_data;
	int timeout, err = 0, transfer_length = 0;
	size_t writecount = 0;

	while (writecount < count) {
		if (!usblp->wcomplete) {
			barrier();
			if (file->f_flags & O_NONBLOCK) {
				writecount += transfer_length;
				return writecount ? writecount : -EAGAIN;
			}

			timeout = USBLP_WRITE_TIMEOUT;
			add_wait_queue(&usblp->wait, &wait);
			while ( 1==1 ) {

				if (signal_pending(current)) {
					remove_wait_queue(&usblp->wait, &wait);
					return writecount ? writecount : -EINTR;
				}
				set_current_state(TASK_INTERRUPTIBLE);
				if (timeout && !usblp->wcomplete) {
					timeout = schedule_timeout(timeout);
				} else {
					set_current_state(TASK_RUNNING);
					break;
				}
			}
			remove_wait_queue(&usblp->wait, &wait);
		}

		down (&usblp->sem);
		if (!usblp->present) {
			up (&usblp->sem);
			return -ENODEV;
		}

		if (usblp->writeurb->status != 0) {
			if (usblp->quirks & USBLP_QUIRK_BIDIR) {
				if (!usblp->wcomplete)
					err("usblp%d: error %d writing to printer",
						usblp->minor, usblp->writeurb->status);
				err = usblp->writeurb->status;
			} else
				err = usblp_check_status(usblp, err);
			up (&usblp->sem);

			/* if the fault was due to disconnect, let khubd's
			 * call to usblp_disconnect() grab usblp->sem ...
			 */
			schedule ();
			continue;
		}

		/* We must increment writecount here, and not at the
		 * end of the loop. Otherwise, the final loop iteration may
		 * be skipped, leading to incomplete printer output.
		 */
		writecount += transfer_length;
		if (writecount == count) {
			up(&usblp->sem);
			break;
		}

		transfer_length=(count - writecount);
		if (transfer_length > USBLP_BUF_SIZE)
			transfer_length = USBLP_BUF_SIZE;

		usblp->writeurb->transfer_buffer_length = transfer_length;

		if (copy_from_user(usblp->writeurb->transfer_buffer, 
				   buffer + writecount, transfer_length)) {
			up(&usblp->sem);
			return writecount ? writecount : -EFAULT;
		}

		usblp->writeurb->dev = usblp->dev;
		usblp->wcomplete = 0;
		err = usb_submit_urb(usblp->writeurb, GFP_KERNEL);
		if (err) {
			if (err != -ENOMEM)
				count = -EIO;
			else
				count = writecount ? writecount : -ENOMEM;
			up (&usblp->sem);
			break;
		}
		up (&usblp->sem);
	}

	return count;
}

static ssize_t usblp_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
{
	struct usblp *usblp = file->private_data;
	DECLARE_WAITQUEUE(wait, current);

	if (!usblp->bidir)
		return -EINVAL;

	down (&usblp->sem);
	if (!usblp->present) {
		count = -ENODEV;
		goto done;
	}

	if (!usblp->rcomplete) {
		barrier();

		if (file->f_flags & O_NONBLOCK) {
			count = -EAGAIN;
			goto done;
		}

		add_wait_queue(&usblp->wait, &wait);
		while (1==1) {
			if (signal_pending(current)) {
				count = -EINTR;
				remove_wait_queue(&usblp->wait, &wait);
				goto done;
			}
			up (&usblp->sem);
			set_current_state(TASK_INTERRUPTIBLE);
			if (!usblp->rcomplete) {
				schedule();
			} else {
				set_current_state(TASK_RUNNING);
				down(&usblp->sem);
				break;
			}
			down (&usblp->sem);
		}
		remove_wait_queue(&usblp->wait, &wait);
	}

	if (!usblp->present) {
		count = -ENODEV;
		goto done;
	}

	if (usblp->readurb->status) {
		err("usblp%d: error %d reading from printer",
			usblp->minor, usblp->readurb->status);
		usblp->readurb->dev = usblp->dev;
 		usblp->readcount = 0;
		usblp->rcomplete = 0;
		if (usb_submit_urb(usblp->readurb, GFP_KERNEL) < 0)
			dbg("error submitting urb");
		count = -EIO;
		goto done;
	}

	count = count < usblp->readurb->actual_length - usblp->readcount ?
		count :	usblp->readurb->actual_length - usblp->readcount;

	if (copy_to_user(buffer, usblp->readurb->transfer_buffer + usblp->readcount, count)) {
		count = -EFAULT;
		goto done;
	}

	if ((usblp->readcount += count) == usblp->readurb->actual_length) {
		usblp->readcount = 0;
		usblp->readurb->dev = usblp->dev;
		usblp->rcomplete = 0;
		if (usb_submit_urb(usblp->readurb, GFP_KERNEL)) {
			count = -EIO;
			goto done;
		}
	}

done:
	up (&usblp->sem);
	return count;
}

/*
 * 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 struct file_operations usblp_fops = {
	.owner =	THIS_MODULE,
	.read =		usblp_read,
	.write =	usblp_write,
	.poll =		usblp_poll,
	.ioctl =	usblp_ioctl,
	.open =		usblp_open,
	.release =	usblp_release,
};

static struct usb_class_driver usblp_class = {
	.name =		"lp%d",
	.fops =		&usblp_fops,
	.minor_base =	USBLP_MINOR_BASE,
};

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 = NULL;
	int protocol;
	int retval;

	/* Malloc and start initializing usblp structure so we can use it
	 * directly. */
	if (!(usblp = kmalloc(sizeof(struct usblp), GFP_KERNEL))) {
		err("out of memory for usblp");
		goto abort;
	}
	memset(usblp, 0, sizeof(struct usblp));
	usblp->dev = dev;
	init_MUTEX (&usblp->sem);
	init_waitqueue_head(&usblp->wait);
	usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
	usblp->intf = intf;

	usblp->writeurb = usb_alloc_urb(0, GFP_KERNEL);
	if (!usblp->writeurb) {
		err("out of memory");
		goto abort;
	}
	usblp->readurb = usb_alloc_urb(0, GFP_KERNEL);
	if (!usblp->readurb) {
		err("out of memory");
		goto abort;
	}

	/* 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))) {
		err("out of memory for device_id_string");
		goto abort;
	}

	usblp->writebuf = usblp->readbuf = NULL;
	usblp->writeurb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
	usblp->readurb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
	/* Malloc write & read buffers.  We somewhat wastefully
	 * malloc both regardless of bidirectionality, because the
	 * alternate setting can be changed later via an ioctl. */
	if (!(usblp->writebuf = usb_buffer_alloc(dev, USBLP_BUF_SIZE,
				GFP_KERNEL, &usblp->writeurb->transfer_dma))) {
		err("out of memory for write buf");
		goto abort;
	}
	if (!(usblp->readbuf = usb_buffer_alloc(dev, USBLP_BUF_SIZE,
				GFP_KERNEL, &usblp->readurb->transfer_dma))) {
		err("out of memory for read buf");
		goto abort;
	}

	/* Allocate buffer for printer status */
	usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
	if (!usblp->statusbuf) {
		err("out of memory for statusbuf");
		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) {
		dbg("incompatible printer-class device 0x%4.4X/0x%4.4X",
			le16_to_cpu(dev->descriptor.idVendor),
			le16_to_cpu(dev->descriptor.idProduct));
		goto abort;
	}

	/* Setup the selected alternate setting and endpoints. */
	if (usblp_set_protocol(usblp, protocol) < 0)
		goto abort;

	/* Retrieve and store the device ID string. */
	usblp_cache_device_id_string(usblp);

#ifdef DEBUG
	usblp_check_status(usblp, 0);
#endif

	info("usblp%d: USB %sdirectional printer dev %d "
		"if %d alt %d proto %d vid 0x%4.4X pid 0x%4.4X",
		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));

	usb_set_intfdata (intf, usblp);

	usblp->present = 1;

	retval = usb_register_dev(intf, &usblp_class);
	if (retval) {
		err("Not able to get a minor for this device.");
		goto abort_intfdata;
	}
	usblp->minor = intf->minor;

	return 0;

abort_intfdata:
	usb_set_intfdata (intf, NULL);
abort:
	if (usblp) {
		if (usblp->writebuf)
			usb_buffer_free (usblp->dev, USBLP_BUF_SIZE,
				usblp->writebuf, usblp->writeurb->transfer_dma);
		if (usblp->readbuf)
			usb_buffer_free (usblp->dev, USBLP_BUF_SIZE,
				usblp->readbuf, usblp->writeurb->transfer_dma);
		kfree(usblp->statusbuf);
		kfree(usblp->device_id_string);
		usb_free_urb(usblp->writeurb);
		usb_free_urb(usblp->readurb);
		kfree(usblp);
	}
	return -EIO;
}

/*
 * 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)
			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 ((epd->bmAttributes&USB_ENDPOINT_XFERTYPE_MASK)!=
			    USB_ENDPOINT_XFER_BULK)
				continue;

			if (!(epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK)) {
				if (!epwrite)
					epwrite = epd;

			} else {
				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) {
			info("Disabling reads from problem bidirectional "
				"printer on usblp%d", 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) {
		err("can't set desired altsetting %d on interface %d",
			alts, usblp->ifnum);
		return r;
	}

	usb_fill_bulk_urb(usblp->writeurb, usblp->dev,
		usb_sndbulkpipe(usblp->dev,
		  usblp->protocol[protocol].epwrite->bEndpointAddress),
		usblp->writebuf, 0,
		usblp_bulk_write, usblp);

	usblp->bidir = (usblp->protocol[protocol].epread != NULL);
	if (usblp->bidir)
		usb_fill_bulk_urb(usblp->readurb, usblp->dev,
			usb_rcvbulkpipe(usblp->dev,
			  usblp->protocol[protocol].epread->bEndpointAddress),
			usblp->readbuf, USBLP_BUF_SIZE,
			usblp_bulk_read, usblp);

	usblp->current_protocol = protocol;
	dbg("usblp%d set protocol %d", 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) {
		dbg("usblp%d: error = %d reading IEEE-1284 Device ID string",
			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';

	dbg("usblp%d Device ID string [len=%d]=\"%s\"",
		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) {
		err("bogus disconnect");
		BUG ();
	}

	down (&usblp_sem);
	down (&usblp->sem);
	usblp->present = 0;
	usb_set_intfdata (intf, NULL);

	usblp_unlink_urbs(usblp);
	usb_buffer_free (usblp->dev, USBLP_BUF_SIZE,
			usblp->writebuf, usblp->writeurb->transfer_dma);
	usb_buffer_free (usblp->dev, USBLP_BUF_SIZE,
			usblp->readbuf, usblp->readurb->transfer_dma);
	up (&usblp->sem);

	if (!usblp->used)
		usblp_cleanup (usblp);
	up (&usblp_sem);
}

static 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) },
	{ }						/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, usblp_ids);

static struct usb_driver usblp_driver = {
	.owner =	THIS_MODULE,
	.name =		"usblp",
	.probe =	usblp_probe,
	.disconnect =	usblp_disconnect,
	.id_table =	usblp_ids,
};

static int __init usblp_init(void)
{
	int retval;
	retval = usb_register(&usblp_driver);
	if (retval)
		goto out;
	info(DRIVER_VERSION ": " DRIVER_DESC);
out:
	return retval;
}

static void __exit usblp_exit(void)
{
	usb_deregister(&usblp_driver);
}

module_init(usblp_init);
module_exit(usblp_exit);

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");