drivers/char/ppdev.c - kernel/msm - Gitiles

 /*
  * linux/drivers/char/ppdev.c
  *
  * This is the code behind /dev/parport* -- it allows a user-space
  * application to use the parport subsystem.
  *
  * Copyright (C) 1998-2000, 2002 Tim Waugh <tim@cyberelk.net>
  *
  * 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.
  *
  * A /dev/parportx device node represents an arbitrary device
  * on port 'x'.  The following operations are possible:
  *
  * open		do nothing, set up default IEEE 1284 protocol to be COMPAT
  * close	release port and unregister device (if necessary)
  * ioctl
  *   EXCL	register device exclusively (may fail)
  *   CLAIM	(register device first time) parport_claim_or_block
  *   RELEASE	parport_release
  *   SETMODE	set the IEEE 1284 protocol to use for read/write
  *   SETPHASE	set the IEEE 1284 phase of a particular mode.  Not to be
  *              confused with ioctl(fd, SETPHASER, &stun). ;-)
  *   DATADIR	data_forward / data_reverse
  *   WDATA	write_data
  *   RDATA	read_data
  *   WCONTROL	write_control
  *   RCONTROL	read_control
  *   FCONTROL	frob_control
  *   RSTATUS	read_status
  *   NEGOT	parport_negotiate
  *   YIELD	parport_yield_blocking
  *   WCTLONIRQ	on interrupt, set control lines
  *   CLRIRQ	clear (and return) interrupt count
  *   SETTIME	sets device timeout (struct timeval)
  *   GETTIME	gets device timeout (struct timeval)
  *   GETMODES	gets hardware supported modes (unsigned int)
  *   GETMODE	gets the current IEEE1284 mode
  *   GETPHASE   gets the current IEEE1284 phase
  *   GETFLAGS   gets current (user-visible) flags
  *   SETFLAGS   sets current (user-visible) flags
  * read/write	read or write in current IEEE 1284 protocol
  * select	wait for interrupt (in readfds)
  *
  * Changes:
  * Added SETTIME/GETTIME ioctl, Fred Barnes, 1999.
  *
  * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 2000/08/25
  * - On error, copy_from_user and copy_to_user do not return -EFAULT,
  *   They return the positive number of bytes *not* copied due to address
  *   space errors.
  *
  * Added GETMODES/GETMODE/GETPHASE ioctls, Fred Barnes <frmb2@ukc.ac.uk>, 03/01/2001.
  * Added GETFLAGS/SETFLAGS ioctls, Fred Barnes, 04/2001
  */

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/sched.h>
 #include <linux/device.h>
 #include <linux/ioctl.h>
 #include <linux/parport.h>
 #include <linux/ctype.h>
 #include <linux/poll.h>
 #include <linux/slab.h>
 #include <linux/major.h>
 #include <linux/ppdev.h>
 #include <linux/smp_lock.h>
 #include <linux/uaccess.h>

 #define PP_VERSION "ppdev: user-space parallel port driver"
 #define CHRDEV "ppdev"

 struct pp_struct {
 	struct pardevice * pdev;
 	wait_queue_head_t irq_wait;
 	atomic_t irqc;
 	unsigned int flags;
 	int irqresponse;
 	unsigned char irqctl;
 	struct ieee1284_info state;
 	struct ieee1284_info saved_state;
 	long default_inactivity;
 };

 /* pp_struct.flags bitfields */
 #define PP_CLAIMED    (1<<0)
 #define PP_EXCL       (1<<1)

 /* Other constants */
 #define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
 #define PP_BUFFER_SIZE 1024
 #define PARDEVICE_MAX 8

 /* ROUND_UP macro from fs/select.c */
 #define ROUND_UP(x,y) (((x)+(y)-1)/(y))

 static inline void pp_enable_irq (struct pp_struct *pp)
 {
 	struct parport *port = pp->pdev->port;
 	port->ops->enable_irq (port);
 }

 static ssize_t pp_read (struct file * file, char __user * buf, size_t count,
 			loff_t * ppos)
 {
 	unsigned int minor = iminor(file->f_path.dentry->d_inode);
 	struct pp_struct *pp = file->private_data;
 	char * kbuffer;
 	ssize_t bytes_read = 0;
 	struct parport *pport;
 	int mode;

 	if (!(pp->flags & PP_CLAIMED)) {
 		/* Don't have the port claimed */
 		pr_debug(CHRDEV "%x: claim the port first\n", minor);
 		return -EINVAL;
 	}

 	/* Trivial case. */
 	if (count == 0)
 		return 0;

 	kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
 	if (!kbuffer) {
 		return -ENOMEM;
 	}
 	pport = pp->pdev->port;
 	mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);

 	parport_set_timeout (pp->pdev,
 			     (file->f_flags & O_NONBLOCK) ?
 			     PARPORT_INACTIVITY_O_NONBLOCK :
 			     pp->default_inactivity);

 	while (bytes_read == 0) {
 		ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);

 		if (mode == IEEE1284_MODE_EPP) {
 			/* various specials for EPP mode */
 			int flags = 0;
 			size_t (*fn)(struct parport *, void *, size_t, int);

 			if (pp->flags & PP_W91284PIC) {
 				flags |= PARPORT_W91284PIC;
 			}
 			if (pp->flags & PP_FASTREAD) {
 				flags |= PARPORT_EPP_FAST;
 			}
 			if (pport->ieee1284.mode & IEEE1284_ADDR) {
 				fn = pport->ops->epp_read_addr;
 			} else {
 				fn = pport->ops->epp_read_data;
 			}
 			bytes_read = (*fn)(pport, kbuffer, need, flags);
 		} else {
 			bytes_read = parport_read (pport, kbuffer, need);
 		}

 		if (bytes_read != 0)
 			break;

 		if (file->f_flags & O_NONBLOCK) {
 			bytes_read = -EAGAIN;
 			break;
 		}

 		if (signal_pending (current)) {
 			bytes_read = -ERESTARTSYS;
 			break;
 		}

 		cond_resched();
 	}

 	parport_set_timeout (pp->pdev, pp->default_inactivity);

 	if (bytes_read > 0 && copy_to_user (buf, kbuffer, bytes_read))
 		bytes_read = -EFAULT;

 	kfree (kbuffer);
 	pp_enable_irq (pp);
 	return bytes_read;
 }

 static ssize_t pp_write (struct file * file, const char __user * buf,
 			 size_t count, loff_t * ppos)
 {
 	unsigned int minor = iminor(file->f_path.dentry->d_inode);
 	struct pp_struct *pp = file->private_data;
 	char * kbuffer;
 	ssize_t bytes_written = 0;
 	ssize_t wrote;
 	int mode;
 	struct parport *pport;

 	if (!(pp->flags & PP_CLAIMED)) {
 		/* Don't have the port claimed */
 		pr_debug(CHRDEV "%x: claim the port first\n", minor);
 		return -EINVAL;
 	}

 	kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
 	if (!kbuffer) {
 		return -ENOMEM;
 	}
 	pport = pp->pdev->port;
 	mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);

 	parport_set_timeout (pp->pdev,
 			     (file->f_flags & O_NONBLOCK) ?
 			     PARPORT_INACTIVITY_O_NONBLOCK :
 			     pp->default_inactivity);

 	while (bytes_written < count) {
 		ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);

 		if (copy_from_user (kbuffer, buf + bytes_written, n)) {
 			bytes_written = -EFAULT;
 			break;
 		}

 		if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
 			/* do a fast EPP write */
 			if (pport->ieee1284.mode & IEEE1284_ADDR) {
 				wrote = pport->ops->epp_write_addr (pport,
 					kbuffer, n, PARPORT_EPP_FAST);
 			} else {
 				wrote = pport->ops->epp_write_data (pport,
 					kbuffer, n, PARPORT_EPP_FAST);
 			}
 		} else {
 			wrote = parport_write (pp->pdev->port, kbuffer, n);
 		}

 		if (wrote <= 0) {
 			if (!bytes_written) {
 				bytes_written = wrote;
 			}
 			break;
 		}

 		bytes_written += wrote;

 		if (file->f_flags & O_NONBLOCK) {
 			if (!bytes_written)
 				bytes_written = -EAGAIN;
 			break;
 		}

 		if (signal_pending (current)) {
 			if (!bytes_written) {
 				bytes_written = -EINTR;
 			}
 			break;
 		}

 		cond_resched();
 	}

 	parport_set_timeout (pp->pdev, pp->default_inactivity);

 	kfree (kbuffer);
 	pp_enable_irq (pp);
 	return bytes_written;
 }

 static void pp_irq (void *private)
 {
 	struct pp_struct *pp = private;

 	if (pp->irqresponse) {
 		parport_write_control (pp->pdev->port, pp->irqctl);
 		pp->irqresponse = 0;
 	}

 	atomic_inc (&pp->irqc);
 	wake_up_interruptible (&pp->irq_wait);
 }

 static int register_device (int minor, struct pp_struct *pp)
 {
 	struct parport *port;
 	struct pardevice * pdev = NULL;
 	char *name;
 	int fl;

 	name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
 	if (name == NULL)
 		return -ENOMEM;

 	port = parport_find_number (minor);
 	if (!port) {
 		printk (KERN_WARNING "%s: no associated port!\n", name);
 		kfree (name);
 		return -ENXIO;
 	}

 	fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
 	pdev = parport_register_device (port, name, NULL,
 					NULL, pp_irq, fl, pp);
 	parport_put_port (port);

 	if (!pdev) {
 		printk (KERN_WARNING "%s: failed to register device!\n", name);
 		kfree (name);
 		return -ENXIO;
 	}

 	pp->pdev = pdev;
 	pr_debug("%s: registered pardevice\n", name);
 	return 0;
 }

 static enum ieee1284_phase init_phase (int mode)
 {
 	switch (mode & ~(IEEE1284_DEVICEID
 			 | IEEE1284_ADDR)) {
 	case IEEE1284_MODE_NIBBLE:
 	case IEEE1284_MODE_BYTE:
 		return IEEE1284_PH_REV_IDLE;
 	}
 	return IEEE1284_PH_FWD_IDLE;
 }

 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	unsigned int minor = iminor(file->f_path.dentry->d_inode);
 	struct pp_struct *pp = file->private_data;
 	struct parport * port;
 	void __user *argp = (void __user *)arg;

 	/* First handle the cases that don't take arguments. */
 	switch (cmd) {
 	case PPCLAIM:
 	    {
 		struct ieee1284_info *info;
 		int ret;

 		if (pp->flags & PP_CLAIMED) {
 			pr_debug(CHRDEV "%x: you've already got it!\n", minor);
 			return -EINVAL;
 		}

 		/* Deferred device registration. */
 		if (!pp->pdev) {
 			int err = register_device (minor, pp);
 			if (err) {
 				return err;
 			}
 		}

 		ret = parport_claim_or_block (pp->pdev);
 		if (ret < 0)
 			return ret;

 		pp->flags |= PP_CLAIMED;

 		/* For interrupt-reporting to work, we need to be
 		 * informed of each interrupt. */
 		pp_enable_irq (pp);

 		/* We may need to fix up the state machine. */
 		info = &pp->pdev->port->ieee1284;
 		pp->saved_state.mode = info->mode;
 		pp->saved_state.phase = info->phase;
 		info->mode = pp->state.mode;
 		info->phase = pp->state.phase;
 		pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
 		parport_set_timeout (pp->pdev, pp->default_inactivity);

 		return 0;
 	    }
 	case PPEXCL:
 		if (pp->pdev) {
 			pr_debug(CHRDEV "%x: too late for PPEXCL; "
 				"already registered\n", minor);
 			if (pp->flags & PP_EXCL)
 				/* But it's not really an error. */
 				return 0;
 			/* There's no chance of making the driver happy. */
 			return -EINVAL;
 		}

 		/* Just remember to register the device exclusively
 		 * when we finally do the registration. */
 		pp->flags |= PP_EXCL;
 		return 0;
 	case PPSETMODE:
 	    {
 		int mode;
 		if (copy_from_user (&mode, argp, sizeof (mode)))
 			return -EFAULT;
 		/* FIXME: validate mode */
 		pp->state.mode = mode;
 		pp->state.phase = init_phase (mode);

 		if (pp->flags & PP_CLAIMED) {
 			pp->pdev->port->ieee1284.mode = mode;
 			pp->pdev->port->ieee1284.phase = pp->state.phase;
 		}

 		return 0;
 	    }
 	case PPGETMODE:
 	    {
 		int mode;

 		if (pp->flags & PP_CLAIMED) {
 			mode = pp->pdev->port->ieee1284.mode;
 		} else {
 			mode = pp->state.mode;
 		}
 		if (copy_to_user (argp, &mode, sizeof (mode))) {
 			return -EFAULT;
 		}
 		return 0;
 	    }
 	case PPSETPHASE:
 	    {
 		int phase;
 		if (copy_from_user (&phase, argp, sizeof (phase))) {
 			return -EFAULT;
 		}
 		/* FIXME: validate phase */
 		pp->state.phase = phase;

 		if (pp->flags & PP_CLAIMED) {
 			pp->pdev->port->ieee1284.phase = phase;
 		}

 		return 0;
 	    }
 	case PPGETPHASE:
 	    {
 		int phase;

 		if (pp->flags & PP_CLAIMED) {
 			phase = pp->pdev->port->ieee1284.phase;
 		} else {
 			phase = pp->state.phase;
 		}
 		if (copy_to_user (argp, &phase, sizeof (phase))) {
 			return -EFAULT;
 		}
 		return 0;
 	    }
 	case PPGETMODES:
 	    {
 		unsigned int modes;

 		port = parport_find_number (minor);
 		if (!port)
 			return -ENODEV;

 		modes = port->modes;
 		if (copy_to_user (argp, &modes, sizeof (modes))) {
 			return -EFAULT;
 		}
 		return 0;
 	    }
 	case PPSETFLAGS:
 	    {
 		int uflags;

 		if (copy_from_user (&uflags, argp, sizeof (uflags))) {
 			return -EFAULT;
 		}
 		pp->flags &= ~PP_FLAGMASK;
 		pp->flags |= (uflags & PP_FLAGMASK);
 		return 0;
 	    }
 	case PPGETFLAGS:
 	    {
 		int uflags;

 		uflags = pp->flags & PP_FLAGMASK;
 		if (copy_to_user (argp, &uflags, sizeof (uflags))) {
 			return -EFAULT;
 		}
 		return 0;
 	    }
 	}	/* end switch() */

 	/* Everything else requires the port to be claimed, so check
 	 * that now. */
 	if ((pp->flags & PP_CLAIMED) == 0) {
 		pr_debug(CHRDEV "%x: claim the port first\n", minor);
 		return -EINVAL;
 	}

 	port = pp->pdev->port;
 	switch (cmd) {
 		struct ieee1284_info *info;
 		unsigned char reg;
 		unsigned char mask;
 		int mode;
 		int ret;
 		struct timeval par_timeout;
 		long to_jiffies;

 	case PPRSTATUS:
 		reg = parport_read_status (port);
 		if (copy_to_user (argp, &reg, sizeof (reg)))
 			return -EFAULT;
 		return 0;
 	case PPRDATA:
 		reg = parport_read_data (port);
 		if (copy_to_user (argp, &reg, sizeof (reg)))
 			return -EFAULT;
 		return 0;
 	case PPRCONTROL:
 		reg = parport_read_control (port);
 		if (copy_to_user (argp, &reg, sizeof (reg)))
 			return -EFAULT;
 		return 0;
 	case PPYIELD:
 		parport_yield_blocking (pp->pdev);
 		return 0;

 	case PPRELEASE:
 		/* Save the state machine's state. */
 		info = &pp->pdev->port->ieee1284;
 		pp->state.mode = info->mode;
 		pp->state.phase = info->phase;
 		info->mode = pp->saved_state.mode;
 		info->phase = pp->saved_state.phase;
 		parport_release (pp->pdev);
 		pp->flags &= ~PP_CLAIMED;
 		return 0;

 	case PPWCONTROL:
 		if (copy_from_user (&reg, argp, sizeof (reg)))
 			return -EFAULT;
 		parport_write_control (port, reg);
 		return 0;

 	case PPWDATA:
 		if (copy_from_user (&reg, argp, sizeof (reg)))
 			return -EFAULT;
 		parport_write_data (port, reg);
 		return 0;

 	case PPFCONTROL:
 		if (copy_from_user (&mask, argp,
 				    sizeof (mask)))
 			return -EFAULT;
 		if (copy_from_user (&reg, 1 + (unsigned char __user *) arg,
 				    sizeof (reg)))
 			return -EFAULT;
 		parport_frob_control (port, mask, reg);
 		return 0;

 	case PPDATADIR:
 		if (copy_from_user (&mode, argp, sizeof (mode)))
 			return -EFAULT;
 		if (mode)
 			port->ops->data_reverse (port);
 		else
 			port->ops->data_forward (port);
 		return 0;

 	case PPNEGOT:
 		if (copy_from_user (&mode, argp, sizeof (mode)))
 			return -EFAULT;
 		switch ((ret = parport_negotiate (port, mode))) {
 		case 0: break;
 		case -1: /* handshake failed, peripheral not IEEE 1284 */
 			ret = -EIO;
 			break;
 		case 1:  /* handshake succeeded, peripheral rejected mode */
 			ret = -ENXIO;
 			break;
 		}
 		pp_enable_irq (pp);
 		return ret;

 	case PPWCTLONIRQ:
 		if (copy_from_user (&reg, argp, sizeof (reg)))
 			return -EFAULT;

 		/* Remember what to set the control lines to, for next
 		 * time we get an interrupt. */
 		pp->irqctl = reg;
 		pp->irqresponse = 1;
 		return 0;

 	case PPCLRIRQ:
 		ret = atomic_read (&pp->irqc);
 		if (copy_to_user (argp, &ret, sizeof (ret)))
 			return -EFAULT;
 		atomic_sub (ret, &pp->irqc);
 		return 0;

 	case PPSETTIME:
 		if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
 			return -EFAULT;
 		}
 		/* Convert to jiffies, place in pp->pdev->timeout */
 		if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
 			return -EINVAL;
 		}
 		to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
 		to_jiffies += par_timeout.tv_sec * (long)HZ;
 		if (to_jiffies <= 0) {
 			return -EINVAL;
 		}
 		pp->pdev->timeout = to_jiffies;
 		return 0;

 	case PPGETTIME:
 		to_jiffies = pp->pdev->timeout;
 		par_timeout.tv_sec = to_jiffies / HZ;
 		par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
 		if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
 			return -EFAULT;
 		return 0;

 	default:
 		pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
 		return -EINVAL;
 	}

 	/* Keep the compiler happy */
 	return 0;
 }

 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	long ret;
 	lock_kernel();
 	ret = pp_do_ioctl(file, cmd, arg);
 	unlock_kernel();
 	return ret;
 }

 static int pp_open (struct inode * inode, struct file * file)
 {
 	unsigned int minor = iminor(inode);
 	struct pp_struct *pp;

 	cycle_kernel_lock();
 	if (minor >= PARPORT_MAX)
 		return -ENXIO;

 	pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
 	if (!pp)
 		return -ENOMEM;

 	pp->state.mode = IEEE1284_MODE_COMPAT;
 	pp->state.phase = init_phase (pp->state.mode);
 	pp->flags = 0;
 	pp->irqresponse = 0;
 	atomic_set (&pp->irqc, 0);
 	init_waitqueue_head (&pp->irq_wait);

 	/* Defer the actual device registration until the first claim.
 	 * That way, we know whether or not the driver wants to have
 	 * exclusive access to the port (PPEXCL).
 	 */
 	pp->pdev = NULL;
 	file->private_data = pp;

 	return 0;
 }

 static int pp_release (struct inode * inode, struct file * file)
 {
 	unsigned int minor = iminor(inode);
 	struct pp_struct *pp = file->private_data;
 	int compat_negot;

 	compat_negot = 0;
 	if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
 	    (pp->state.mode != IEEE1284_MODE_COMPAT)) {
 	    	struct ieee1284_info *info;

 		/* parport released, but not in compatibility mode */
 		parport_claim_or_block (pp->pdev);
 		pp->flags |= PP_CLAIMED;
 		info = &pp->pdev->port->ieee1284;
 		pp->saved_state.mode = info->mode;
 		pp->saved_state.phase = info->phase;
 		info->mode = pp->state.mode;
 		info->phase = pp->state.phase;
 		compat_negot = 1;
 	} else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
 	    (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
 		compat_negot = 2;
 	}
 	if (compat_negot) {
 		parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
 		pr_debug(CHRDEV "%x: negotiated back to compatibility "
 			"mode because user-space forgot\n", minor);
 	}

 	if (pp->flags & PP_CLAIMED) {
 		struct ieee1284_info *info;

 		info = &pp->pdev->port->ieee1284;
 		pp->state.mode = info->mode;
 		pp->state.phase = info->phase;
 		info->mode = pp->saved_state.mode;
 		info->phase = pp->saved_state.phase;
 		parport_release (pp->pdev);
 		if (compat_negot != 1) {
 			pr_debug(CHRDEV "%x: released pardevice "
 				"because user-space forgot\n", minor);
 		}
 	}

 	if (pp->pdev) {
 		const char *name = pp->pdev->name;
 		parport_unregister_device (pp->pdev);
 		kfree (name);
 		pp->pdev = NULL;
 		pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
 	}

 	kfree (pp);

 	return 0;
 }

 /* No kernel lock held - fine */
 static unsigned int pp_poll (struct file * file, poll_table * wait)
 {
 	struct pp_struct *pp = file->private_data;
 	unsigned int mask = 0;

 	poll_wait (file, &pp->irq_wait, wait);
 	if (atomic_read (&pp->irqc))
 		mask |= POLLIN | POLLRDNORM;

 	return mask;
 }

 static struct class *ppdev_class;

 static const struct file_operations pp_fops = {
 	.owner		= THIS_MODULE,
 	.llseek		= no_llseek,
 	.read		= pp_read,
 	.write		= pp_write,
 	.poll		= pp_poll,
 	.unlocked_ioctl	= pp_ioctl,
 	.open		= pp_open,
 	.release	= pp_release,
 };

 static void pp_attach(struct parport *port)
 {
 	device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
 		      NULL, "parport%d", port->number);
 }

 static void pp_detach(struct parport *port)
 {
 	device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
 }

 static struct parport_driver pp_driver = {
 	.name		= CHRDEV,
 	.attach		= pp_attach,
 	.detach		= pp_detach,
 };

 static int __init ppdev_init (void)
 {
 	int err = 0;

 	if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
 		printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
 			PP_MAJOR);
 		return -EIO;
 	}
 	ppdev_class = class_create(THIS_MODULE, CHRDEV);
 	if (IS_ERR(ppdev_class)) {
 		err = PTR_ERR(ppdev_class);
 		goto out_chrdev;
 	}
 	if (parport_register_driver(&pp_driver)) {
 		printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
 		goto out_class;
 	}

 	printk (KERN_INFO PP_VERSION "\n");
 	goto out;

 out_class:
 	class_destroy(ppdev_class);
 out_chrdev:
 	unregister_chrdev(PP_MAJOR, CHRDEV);
 out:
 	return err;
 }

 static void __exit ppdev_cleanup (void)
 {
 	/* Clean up all parport stuff */
 	parport_unregister_driver(&pp_driver);
 	class_destroy(ppdev_class);
 	unregister_chrdev (PP_MAJOR, CHRDEV);
 }

 module_init(ppdev_init);
 module_exit(ppdev_cleanup);

 MODULE_LICENSE("GPL");
 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);
	/*
	* linux/drivers/char/ppdev.c
	*
	* This is the code behind /dev/parport* -- it allows a user-space
	* application to use the parport subsystem.
	*
	* Copyright (C) 1998-2000, 2002 Tim Waugh <tim@cyberelk.net>
	*
	* 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.
	*
	* A /dev/parportx device node represents an arbitrary device
	* on port 'x'. The following operations are possible:
	*
	* open do nothing, set up default IEEE 1284 protocol to be COMPAT
	* close release port and unregister device (if necessary)
	* ioctl
	* EXCL register device exclusively (may fail)
	* CLAIM (register device first time) parport_claim_or_block
	* RELEASE parport_release
	* SETMODE set the IEEE 1284 protocol to use for read/write
	* SETPHASE set the IEEE 1284 phase of a particular mode. Not to be
	* confused with ioctl(fd, SETPHASER, &stun). ;-)
	* DATADIR data_forward / data_reverse
	* WDATA write_data
	* RDATA read_data
	* WCONTROL write_control
	* RCONTROL read_control
	* FCONTROL frob_control
	* RSTATUS read_status
	* NEGOT parport_negotiate
	* YIELD parport_yield_blocking
	* WCTLONIRQ on interrupt, set control lines
	* CLRIRQ clear (and return) interrupt count
	* SETTIME sets device timeout (struct timeval)
	* GETTIME gets device timeout (struct timeval)
	* GETMODES gets hardware supported modes (unsigned int)
	* GETMODE gets the current IEEE1284 mode
	* GETPHASE gets the current IEEE1284 phase
	* GETFLAGS gets current (user-visible) flags
	* SETFLAGS sets current (user-visible) flags
	* read/write read or write in current IEEE 1284 protocol
	* select wait for interrupt (in readfds)
	*
	* Changes:
	* Added SETTIME/GETTIME ioctl, Fred Barnes, 1999.
	*
	* Arnaldo Carvalho de Melo <acme@conectiva.com.br> 2000/08/25
	* - On error, copy_from_user and copy_to_user do not return -EFAULT,
	* They return the positive number of bytes not copied due to address
	* space errors.
	*
	* Added GETMODES/GETMODE/GETPHASE ioctls, Fred Barnes <frmb2@ukc.ac.uk>, 03/01/2001.
	* Added GETFLAGS/SETFLAGS ioctls, Fred Barnes, 04/2001
	*/

	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/sched.h>
	#include <linux/device.h>
	#include <linux/ioctl.h>
	#include <linux/parport.h>
	#include <linux/ctype.h>
	#include <linux/poll.h>
	#include <linux/slab.h>
	#include <linux/major.h>
	#include <linux/ppdev.h>
	#include <linux/smp_lock.h>
	#include <linux/uaccess.h>

	#define PP_VERSION "ppdev: user-space parallel port driver"
	#define CHRDEV "ppdev"

	struct pp_struct {
	struct pardevice * pdev;
	wait_queue_head_t irq_wait;
	atomic_t irqc;
	unsigned int flags;
	int irqresponse;
	unsigned char irqctl;
	struct ieee1284_info state;
	struct ieee1284_info saved_state;
	long default_inactivity;
	};

	/* pp_struct.flags bitfields */
	#define PP_CLAIMED (1<<0)
	#define PP_EXCL (1<<1)

	/* Other constants */
	#define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
	#define PP_BUFFER_SIZE 1024
	#define PARDEVICE_MAX 8

	/* ROUND_UP macro from fs/select.c */
	#define ROUND_UP(x,y) (((x)+(y)-1)/(y))

	static inline void pp_enable_irq (struct pp_struct *pp)
	{
	struct parport *port = pp->pdev->port;
	port->ops->enable_irq (port);
	}

	static ssize_t pp_read (struct file * file, char __user * buf, size_t count,
	loff_t * ppos)
	{
	unsigned int minor = iminor(file->f_path.dentry->d_inode);
	struct pp_struct *pp = file->private_data;
	char * kbuffer;
	ssize_t bytes_read = 0;
	struct parport *pport;
	int mode;

	if (!(pp->flags & PP_CLAIMED)) {
	/* Don't have the port claimed */
	pr_debug(CHRDEV "%x: claim the port first\n", minor);
	return -EINVAL;
	}

	/* Trivial case. */
	if (count == 0)
	return 0;

	kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
	if (!kbuffer) {
	return -ENOMEM;
	}
	pport = pp->pdev->port;
	mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID \| IEEE1284_ADDR);

	parport_set_timeout (pp->pdev,
	(file->f_flags & O_NONBLOCK) ?
	PARPORT_INACTIVITY_O_NONBLOCK :
	pp->default_inactivity);

	while (bytes_read == 0) {
	ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);

	if (mode == IEEE1284_MODE_EPP) {
	/* various specials for EPP mode */
	int flags = 0;
	size_t (fn)(struct parport , void *, size_t, int);

	if (pp->flags & PP_W91284PIC) {
	flags \|= PARPORT_W91284PIC;
	}
	if (pp->flags & PP_FASTREAD) {
	flags \|= PARPORT_EPP_FAST;
	}
	if (pport->ieee1284.mode & IEEE1284_ADDR) {
	fn = pport->ops->epp_read_addr;
	} else {
	fn = pport->ops->epp_read_data;
	}
	bytes_read = (*fn)(pport, kbuffer, need, flags);
	} else {
	bytes_read = parport_read (pport, kbuffer, need);
	}

	if (bytes_read != 0)
	break;

	if (file->f_flags & O_NONBLOCK) {
	bytes_read = -EAGAIN;
	break;
	}

	if (signal_pending (current)) {
	bytes_read = -ERESTARTSYS;
	break;
	}

	cond_resched();
	}

	parport_set_timeout (pp->pdev, pp->default_inactivity);

	if (bytes_read > 0 && copy_to_user (buf, kbuffer, bytes_read))
	bytes_read = -EFAULT;

	kfree (kbuffer);
	pp_enable_irq (pp);
	return bytes_read;
	}

	static ssize_t pp_write (struct file * file, const char __user * buf,
	size_t count, loff_t * ppos)
	{
	unsigned int minor = iminor(file->f_path.dentry->d_inode);
	struct pp_struct *pp = file->private_data;
	char * kbuffer;
	ssize_t bytes_written = 0;
	ssize_t wrote;
	int mode;
	struct parport *pport;

	if (!(pp->flags & PP_CLAIMED)) {
	/* Don't have the port claimed */
	pr_debug(CHRDEV "%x: claim the port first\n", minor);
	return -EINVAL;
	}

	kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
	if (!kbuffer) {
	return -ENOMEM;
	}
	pport = pp->pdev->port;
	mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID \| IEEE1284_ADDR);

	parport_set_timeout (pp->pdev,
	(file->f_flags & O_NONBLOCK) ?
	PARPORT_INACTIVITY_O_NONBLOCK :
	pp->default_inactivity);

	while (bytes_written < count) {
	ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);

	if (copy_from_user (kbuffer, buf + bytes_written, n)) {
	bytes_written = -EFAULT;
	break;
	}

	if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
	/* do a fast EPP write */
	if (pport->ieee1284.mode & IEEE1284_ADDR) {
	wrote = pport->ops->epp_write_addr (pport,
	kbuffer, n, PARPORT_EPP_FAST);
	} else {
	wrote = pport->ops->epp_write_data (pport,
	kbuffer, n, PARPORT_EPP_FAST);
	}
	} else {
	wrote = parport_write (pp->pdev->port, kbuffer, n);
	}

	if (wrote <= 0) {
	if (!bytes_written) {
	bytes_written = wrote;
	}
	break;
	}

	bytes_written += wrote;

	if (file->f_flags & O_NONBLOCK) {
	if (!bytes_written)
	bytes_written = -EAGAIN;
	break;
	}

	if (signal_pending (current)) {
	if (!bytes_written) {
	bytes_written = -EINTR;
	}
	break;
	}

	cond_resched();
	}

	parport_set_timeout (pp->pdev, pp->default_inactivity);

	kfree (kbuffer);
	pp_enable_irq (pp);
	return bytes_written;
	}

	static void pp_irq (void *private)
	{
	struct pp_struct *pp = private;

	if (pp->irqresponse) {
	parport_write_control (pp->pdev->port, pp->irqctl);
	pp->irqresponse = 0;
	}

	atomic_inc (&pp->irqc);
	wake_up_interruptible (&pp->irq_wait);
	}

	static int register_device (int minor, struct pp_struct *pp)
	{
	struct parport *port;
	struct pardevice * pdev = NULL;
	char *name;
	int fl;

	name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
	if (name == NULL)
	return -ENOMEM;

	port = parport_find_number (minor);
	if (!port) {
	printk (KERN_WARNING "%s: no associated port!\n", name);
	kfree (name);
	return -ENXIO;
	}

	fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
	pdev = parport_register_device (port, name, NULL,
	NULL, pp_irq, fl, pp);
	parport_put_port (port);

	if (!pdev) {
	printk (KERN_WARNING "%s: failed to register device!\n", name);
	kfree (name);
	return -ENXIO;
	}

	pp->pdev = pdev;
	pr_debug("%s: registered pardevice\n", name);
	return 0;
	}

	static enum ieee1284_phase init_phase (int mode)
	{
	switch (mode & ~(IEEE1284_DEVICEID
	\| IEEE1284_ADDR)) {
	case IEEE1284_MODE_NIBBLE:
	case IEEE1284_MODE_BYTE:
	return IEEE1284_PH_REV_IDLE;
	}
	return IEEE1284_PH_FWD_IDLE;
	}

	static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	{
	unsigned int minor = iminor(file->f_path.dentry->d_inode);
	struct pp_struct *pp = file->private_data;
	struct parport * port;
	void __user argp = (void __user )arg;

	/* First handle the cases that don't take arguments. */
	switch (cmd) {
	case PPCLAIM:
	{
	struct ieee1284_info *info;
	int ret;

	if (pp->flags & PP_CLAIMED) {
	pr_debug(CHRDEV "%x: you've already got it!\n", minor);
	return -EINVAL;
	}

	/* Deferred device registration. */
	if (!pp->pdev) {
	int err = register_device (minor, pp);
	if (err) {
	return err;
	}
	}

	ret = parport_claim_or_block (pp->pdev);
	if (ret < 0)
	return ret;

	pp->flags \|= PP_CLAIMED;

	/* For interrupt-reporting to work, we need to be
	* informed of each interrupt. */
	pp_enable_irq (pp);

	/* We may need to fix up the state machine. */
	info = &pp->pdev->port->ieee1284;
	pp->saved_state.mode = info->mode;
	pp->saved_state.phase = info->phase;
	info->mode = pp->state.mode;
	info->phase = pp->state.phase;
	pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
	parport_set_timeout (pp->pdev, pp->default_inactivity);

	return 0;
	}
	case PPEXCL:
	if (pp->pdev) {
	pr_debug(CHRDEV "%x: too late for PPEXCL; "
	"already registered\n", minor);
	if (pp->flags & PP_EXCL)
	/* But it's not really an error. */
	return 0;
	/* There's no chance of making the driver happy. */
	return -EINVAL;
	}

	/* Just remember to register the device exclusively
	* when we finally do the registration. */
	pp->flags \|= PP_EXCL;
	return 0;
	case PPSETMODE:
	{
	int mode;
	if (copy_from_user (&mode, argp, sizeof (mode)))
	return -EFAULT;
	/* FIXME: validate mode */
	pp->state.mode = mode;
	pp->state.phase = init_phase (mode);

	if (pp->flags & PP_CLAIMED) {
	pp->pdev->port->ieee1284.mode = mode;
	pp->pdev->port->ieee1284.phase = pp->state.phase;
	}

	return 0;
	}
	case PPGETMODE:
	{
	int mode;

	if (pp->flags & PP_CLAIMED) {
	mode = pp->pdev->port->ieee1284.mode;
	} else {
	mode = pp->state.mode;
	}
	if (copy_to_user (argp, &mode, sizeof (mode))) {
	return -EFAULT;
	}
	return 0;
	}
	case PPSETPHASE:
	{
	int phase;
	if (copy_from_user (&phase, argp, sizeof (phase))) {
	return -EFAULT;
	}
	/* FIXME: validate phase */
	pp->state.phase = phase;

	if (pp->flags & PP_CLAIMED) {
	pp->pdev->port->ieee1284.phase = phase;
	}

	return 0;
	}
	case PPGETPHASE:
	{
	int phase;

	if (pp->flags & PP_CLAIMED) {
	phase = pp->pdev->port->ieee1284.phase;
	} else {
	phase = pp->state.phase;
	}
	if (copy_to_user (argp, &phase, sizeof (phase))) {
	return -EFAULT;
	}
	return 0;
	}
	case PPGETMODES:
	{
	unsigned int modes;

	port = parport_find_number (minor);
	if (!port)
	return -ENODEV;

	modes = port->modes;
	if (copy_to_user (argp, &modes, sizeof (modes))) {
	return -EFAULT;
	}
	return 0;
	}
	case PPSETFLAGS:
	{
	int uflags;

	if (copy_from_user (&uflags, argp, sizeof (uflags))) {
	return -EFAULT;
	}
	pp->flags &= ~PP_FLAGMASK;
	pp->flags \|= (uflags & PP_FLAGMASK);
	return 0;
	}
	case PPGETFLAGS:
	{
	int uflags;

	uflags = pp->flags & PP_FLAGMASK;
	if (copy_to_user (argp, &uflags, sizeof (uflags))) {
	return -EFAULT;
	}
	return 0;
	}
	} /* end switch() */

	/* Everything else requires the port to be claimed, so check
	* that now. */
	if ((pp->flags & PP_CLAIMED) == 0) {
	pr_debug(CHRDEV "%x: claim the port first\n", minor);
	return -EINVAL;
	}

	port = pp->pdev->port;
	switch (cmd) {
	struct ieee1284_info *info;
	unsigned char reg;
	unsigned char mask;
	int mode;
	int ret;
	struct timeval par_timeout;
	long to_jiffies;

	case PPRSTATUS:
	reg = parport_read_status (port);
	if (copy_to_user (argp, &reg, sizeof (reg)))
	return -EFAULT;
	return 0;
	case PPRDATA:
	reg = parport_read_data (port);
	if (copy_to_user (argp, &reg, sizeof (reg)))
	return -EFAULT;
	return 0;
	case PPRCONTROL:
	reg = parport_read_control (port);
	if (copy_to_user (argp, &reg, sizeof (reg)))
	return -EFAULT;
	return 0;
	case PPYIELD:
	parport_yield_blocking (pp->pdev);
	return 0;

	case PPRELEASE:
	/* Save the state machine's state. */
	info = &pp->pdev->port->ieee1284;
	pp->state.mode = info->mode;
	pp->state.phase = info->phase;
	info->mode = pp->saved_state.mode;
	info->phase = pp->saved_state.phase;
	parport_release (pp->pdev);
	pp->flags &= ~PP_CLAIMED;
	return 0;

	case PPWCONTROL:
	if (copy_from_user (&reg, argp, sizeof (reg)))
	return -EFAULT;
	parport_write_control (port, reg);
	return 0;

	case PPWDATA:
	if (copy_from_user (&reg, argp, sizeof (reg)))
	return -EFAULT;
	parport_write_data (port, reg);
	return 0;

	case PPFCONTROL:
	if (copy_from_user (&mask, argp,
	sizeof (mask)))
	return -EFAULT;
	if (copy_from_user (&reg, 1 + (unsigned char __user *) arg,
	sizeof (reg)))
	return -EFAULT;
	parport_frob_control (port, mask, reg);
	return 0;

	case PPDATADIR:
	if (copy_from_user (&mode, argp, sizeof (mode)))
	return -EFAULT;
	if (mode)
	port->ops->data_reverse (port);
	else
	port->ops->data_forward (port);
	return 0;

	case PPNEGOT:
	if (copy_from_user (&mode, argp, sizeof (mode)))
	return -EFAULT;
	switch ((ret = parport_negotiate (port, mode))) {
	case 0: break;
	case -1: /* handshake failed, peripheral not IEEE 1284 */
	ret = -EIO;
	break;
	case 1: /* handshake succeeded, peripheral rejected mode */
	ret = -ENXIO;
	break;
	}
	pp_enable_irq (pp);
	return ret;

	case PPWCTLONIRQ:
	if (copy_from_user (&reg, argp, sizeof (reg)))
	return -EFAULT;

	/* Remember what to set the control lines to, for next
	* time we get an interrupt. */
	pp->irqctl = reg;
	pp->irqresponse = 1;
	return 0;

	case PPCLRIRQ:
	ret = atomic_read (&pp->irqc);
	if (copy_to_user (argp, &ret, sizeof (ret)))
	return -EFAULT;
	atomic_sub (ret, &pp->irqc);
	return 0;

	case PPSETTIME:
	if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
	return -EFAULT;
	}
	/* Convert to jiffies, place in pp->pdev->timeout */
	if ((par_timeout.tv_sec < 0) \|\| (par_timeout.tv_usec < 0)) {
	return -EINVAL;
	}
	to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
	to_jiffies += par_timeout.tv_sec * (long)HZ;
	if (to_jiffies <= 0) {
	return -EINVAL;
	}
	pp->pdev->timeout = to_jiffies;
	return 0;

	case PPGETTIME:
	to_jiffies = pp->pdev->timeout;
	par_timeout.tv_sec = to_jiffies / HZ;
	par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
	if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
	return -EFAULT;
	return 0;

	default:
	pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
	return -EINVAL;
	}

	/* Keep the compiler happy */
	return 0;
	}

	static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	{
	long ret;
	lock_kernel();
	ret = pp_do_ioctl(file, cmd, arg);
	unlock_kernel();
	return ret;
	}

	static int pp_open (struct inode * inode, struct file * file)
	{
	unsigned int minor = iminor(inode);
	struct pp_struct *pp;

	cycle_kernel_lock();
	if (minor >= PARPORT_MAX)
	return -ENXIO;

	pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
	if (!pp)
	return -ENOMEM;

	pp->state.mode = IEEE1284_MODE_COMPAT;
	pp->state.phase = init_phase (pp->state.mode);
	pp->flags = 0;
	pp->irqresponse = 0;
	atomic_set (&pp->irqc, 0);
	init_waitqueue_head (&pp->irq_wait);

	/* Defer the actual device registration until the first claim.
	* That way, we know whether or not the driver wants to have
	* exclusive access to the port (PPEXCL).
	*/
	pp->pdev = NULL;
	file->private_data = pp;

	return 0;
	}

	static int pp_release (struct inode * inode, struct file * file)
	{
	unsigned int minor = iminor(inode);
	struct pp_struct *pp = file->private_data;
	int compat_negot;

	compat_negot = 0;
	if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
	(pp->state.mode != IEEE1284_MODE_COMPAT)) {
	struct ieee1284_info *info;

	/* parport released, but not in compatibility mode */
	parport_claim_or_block (pp->pdev);
	pp->flags \|= PP_CLAIMED;
	info = &pp->pdev->port->ieee1284;
	pp->saved_state.mode = info->mode;
	pp->saved_state.phase = info->phase;
	info->mode = pp->state.mode;
	info->phase = pp->state.phase;
	compat_negot = 1;
	} else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
	(pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
	compat_negot = 2;
	}
	if (compat_negot) {
	parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
	pr_debug(CHRDEV "%x: negotiated back to compatibility "
	"mode because user-space forgot\n", minor);
	}

	if (pp->flags & PP_CLAIMED) {
	struct ieee1284_info *info;

	info = &pp->pdev->port->ieee1284;
	pp->state.mode = info->mode;
	pp->state.phase = info->phase;
	info->mode = pp->saved_state.mode;
	info->phase = pp->saved_state.phase;
	parport_release (pp->pdev);
	if (compat_negot != 1) {
	pr_debug(CHRDEV "%x: released pardevice "
	"because user-space forgot\n", minor);
	}
	}

	if (pp->pdev) {
	const char *name = pp->pdev->name;
	parport_unregister_device (pp->pdev);
	kfree (name);
	pp->pdev = NULL;
	pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
	}

	kfree (pp);

	return 0;
	}

	/* No kernel lock held - fine */
	static unsigned int pp_poll (struct file * file, poll_table * wait)
	{
	struct pp_struct *pp = file->private_data;
	unsigned int mask = 0;

	poll_wait (file, &pp->irq_wait, wait);
	if (atomic_read (&pp->irqc))
	mask \|= POLLIN \| POLLRDNORM;

	return mask;
	}

	static struct class *ppdev_class;

	static const struct file_operations pp_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.read = pp_read,
	.write = pp_write,
	.poll = pp_poll,
	.unlocked_ioctl = pp_ioctl,
	.open = pp_open,
	.release = pp_release,
	};

	static void pp_attach(struct parport *port)
	{
	device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
	NULL, "parport%d", port->number);
	}

	static void pp_detach(struct parport *port)
	{
	device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
	}

	static struct parport_driver pp_driver = {
	.name = CHRDEV,
	.attach = pp_attach,
	.detach = pp_detach,
	};

	static int __init ppdev_init (void)
	{
	int err = 0;

	if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
	printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
	PP_MAJOR);
	return -EIO;
	}
	ppdev_class = class_create(THIS_MODULE, CHRDEV);
	if (IS_ERR(ppdev_class)) {
	err = PTR_ERR(ppdev_class);
	goto out_chrdev;
	}
	if (parport_register_driver(&pp_driver)) {
	printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
	goto out_class;
	}

	printk (KERN_INFO PP_VERSION "\n");
	goto out;

	out_class:
	class_destroy(ppdev_class);
	out_chrdev:
	unregister_chrdev(PP_MAJOR, CHRDEV);
	out:
	return err;
	}

	static void __exit ppdev_cleanup (void)
	{
	/* Clean up all parport stuff */
	parport_unregister_driver(&pp_driver);
	class_destroy(ppdev_class);
	unregister_chrdev (PP_MAJOR, CHRDEV);
	}

	module_init(ppdev_init);
	module_exit(ppdev_cleanup);

	MODULE_LICENSE("GPL");
	MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);