printer.c

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/*
 * printer.c  Version 0.6
 *
 * Copyright (c) 1999 Michael Gee	<[e-mail]>
 * Copyright (c) 1999 Pavel Machek	<[e-mail]>
 * Copyright (c) 2000 Randy Dunlap	<[e-mail]>
 * Copyright (c) 2000 Vojtech Pavlik	<[e-mail]>
 *
 * 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
 */

/*
 * 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/malloc.h>
#include <linux/lp.h>
#undef DEBUG
#include <linux/usb.h>

#define USBLP_BUF_SIZE		8192
#define DEVICE_ID_SIZE		1024

#define IOCNR_GET_DEVICE_ID	1
#define LPIOC_GET_DEVICE_ID(len) _IOC(_IOC_READ, 'P', IOCNR_GET_DEVICE_ID, len)	/* get device_id string */
#define LPGETSTATUS		0x060b		/* same as in drivers/char/lp.c */

/*
 * 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_MINORS		16
#define USBLP_MINOR_BASE	0

#define USBLP_WRITE_TIMEOUT	(5*HZ)			/* 5 seconds */

struct usblp {
	struct usb_device 	*dev;			/* USB device */
	struct urb		readurb, writeurb;	/* The urbs */
	wait_queue_head_t	wait;			/* Zzzzz ... */
	int			readcount;		/* Counter for reads */
	int			ifnum;			/* Interface number */
	int			minor;			/* minor number of device */
	unsigned int		quirks;			/* quirks flags */
	unsigned char		used;			/* True if open */
	unsigned char		bidir;			/* interface is bidirectional */
	unsigned char		*device_id_string;	/* IEEE 1284 DEVICE ID string (ptr) */
							/* first 2 bytes are (big-endian) length */
};

static struct usblp *usblp_table[USBLP_MINORS];

/* 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 */
	{ 0, 0 }
};

/*
 * Functions for usblp control messages.
 */

static int usblp_ctrl_msg(struct usblp *usblp, int request, int dir, int recip, int value, void *buf, int len)
{
	int retval = usb_control_msg(usblp->dev,
		dir ? usb_rcvctrlpipe(usblp->dev, 0) : usb_sndctrlpipe(usblp->dev, 0),
		request, USB_TYPE_CLASS | dir | recip, value, usblp->ifnum, buf, len, HZ * 5);
	dbg("usblp_control_msg: rq: 0x%02x dir: %d recip: %d value: %d len: %#x result: %d",
		request, !!dir, recip, value, len, retval);
	return retval < 0 ? retval : 0;
}

#define usblp_read_status(usblp, status)\
	usblp_ctrl_msg(usblp, USBLP_REQ_GET_STATUS, 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_DIR_IN, USB_RECIP_INTERFACE, config, id, maxlen)
#define usblp_reset(usblp)\
	usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)

/*
 * URB callback.
 */

static void usblp_bulk(struct urb *urb)
{
	struct usblp *usblp = urb->context;

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

	if (urb->status)
		warn("usblp%d: nonzero read/write bulk status received: %d",
			usblp->minor, urb->status);

	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;

	if (usblp_read_status(usblp, &status)) {
		err("usblp%d: failed reading printer status", usblp->minor);
		return 0;
	}

	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 = MINOR(inode->i_rdev) - USBLP_MINOR_BASE;
	struct usblp *usblp;
	int retval;

	if (minor < 0 || minor >= USBLP_MINORS)
		return -ENODEV;

	lock_kernel();
	usblp  = usblp_table[minor];

	retval = -ENODEV;
	if (!usblp || !usblp->dev)
		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->writeurb.status = 0;

	if (usblp->bidir) {
		usblp->readcount = 0;
		usblp->readurb.dev = usblp->dev;
		usb_submit_urb(&usblp->readurb);
	}
out:
	unlock_kernel();
	return retval;
}

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

	usblp->used = 0;

	if (usblp->dev) {
		if (usblp->bidir)
			usb_unlink_urb(&usblp->readurb);
		usb_unlink_urb(&usblp->writeurb);
		return 0;
	}

	usblp_table[usblp->minor] = NULL;
	kfree(usblp->device_id_string);
	kfree(usblp);

	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->readurb.status  == -EINPROGRESS) ? 0 : POLLIN  | POLLRDNORM)
	     		      | (usblp->writeurb.status == -EINPROGRESS  ? 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;
	unsigned char status;

	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)
					return -EINVAL;

				err = usblp_get_id(usblp, 0, usblp->device_id_string, 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;
				}

				length = (usblp->device_id_string[0] << 8) + usblp->device_id_string[1]; /* big-endian */
				if (length < DEVICE_ID_SIZE)
					usblp->device_id_string[length] = '\0';
				else
					usblp->device_id_string[DEVICE_ID_SIZE - 1] = '\0';

				dbg ("usblp%d Device ID string [%d/max %d]='%s'",
					usblp->minor, length, _IOC_SIZE(cmd), &usblp->device_id_string[2]);

				if (length > _IOC_SIZE(cmd)) length = _IOC_SIZE(cmd); /* truncate */

				if (copy_to_user((unsigned char *) arg, usblp->device_id_string, (unsigned long) length))
					return -EFAULT;

				break;

			default:
				return -EINVAL;
		}
	else	/* old-style ioctl value */
		switch (cmd) {

			case LPGETSTATUS:
				if (usblp_read_status(usblp, &status)) {
					err("usblp%d: failed reading printer status", usblp->minor);
					return -EIO;
				}
				if (copy_to_user ((unsigned char *)arg, &status, 1))
					return -EFAULT;
				break;

			default:
				return -EINVAL;
		}

	return 0;
}

static ssize_t usblp_write(struct file *file, const char *buffer, size_t count, loff_t *ppos)
{
	struct usblp *usblp = file->private_data;