Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 896 insertions, 0 deletions

diff --git a/drivers/char/ppdev.c b/drivers/char/ppdev.c
new file mode 100644
index 000000000..51faafd31
--- /dev/null
+++ b/drivers/char/ppdev.c
@@ -0,0 +1,896 @@
+/*
+ * 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/signal.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/mutex.h>
+#include <linux/uaccess.h>
+#include <linux/compat.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;
+	int index;
+};
+
+/* should we use PARDEVICE_MAX here? */
+static struct device *devices[PARPORT_MAX];
+
+static DEFINE_IDA(ida_index);
+
+/* 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
+
+static DEFINE_MUTEX(pp_do_mutex);
+
+/* define fixed sized ioctl cmd for y2038 migration */
+#define PPGETTIME32	_IOR(PP_IOCTL, 0x95, s32[2])
+#define PPSETTIME32	_IOW(PP_IOCTL, 0x96, s32[2])
+#define PPGETTIME64	_IOR(PP_IOCTL, 0x95, s64[2])
+#define PPSETTIME64	_IOW(PP_IOCTL, 0x96, s64[2])
+
+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_inode(file));
+	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_inode(file));
+	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))
+			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;
+	struct pardev_cb ppdev_cb;
+	int rc = 0, index;
+
+	name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
+	if (name == NULL)
+		return -ENOMEM;
+
+	port = parport_find_number(minor);
+	if (!port) {
+		pr_warn("%s: no associated port!\n", name);
+		rc = -ENXIO;
+		goto err;
+	}
+
+	index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL);
+	memset(&ppdev_cb, 0, sizeof(ppdev_cb));
+	ppdev_cb.irq_func = pp_irq;
+	ppdev_cb.flags = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
+	ppdev_cb.private = pp;
+	pdev = parport_register_dev_model(port, name, &ppdev_cb, index);
+	parport_put_port(port);
+
+	if (!pdev) {
+		pr_warn("%s: failed to register device!\n", name);
+		rc = -ENXIO;
+		ida_simple_remove(&ida_index, index);
+		goto err;
+	}
+
+	pp->pdev = pdev;
+	pp->index = index;
+	dev_dbg(&pdev->dev, "registered pardevice\n");
+err:
+	kfree(name);
+	return rc;
+}
+
+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_set_timeout(struct pardevice *pdev, long tv_sec, int tv_usec)
+{
+	long to_jiffies;
+
+	if ((tv_sec < 0) || (tv_usec < 0))
+		return -EINVAL;
+
+	to_jiffies = usecs_to_jiffies(tv_usec);
+	to_jiffies += tv_sec * HZ;
+	if (to_jiffies <= 0)
+		return -EINVAL;
+
+	pdev->timeout = to_jiffies;
+	return 0;
+}
+
+static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	unsigned int minor = iminor(file_inode(file));
+	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) {
+			dev_dbg(&pp->pdev->dev, "you've already got it!\n");
+			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) {
+			dev_dbg(&pp->pdev->dev,
+				"too late for PPEXCL; already registered\n");
+			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;
+		parport_put_port(port);
+		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;
+		s32 time32[2];
+		s64 time64[2];
+		struct timespec64 ts;
+		int ret;
+
+	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 PPSETTIME32:
+		if (copy_from_user(time32, argp, sizeof(time32)))
+			return -EFAULT;
+
+		if ((time32[0] < 0) || (time32[1] < 0))
+			return -EINVAL;
+
+		return pp_set_timeout(pp->pdev, time32[0], time32[1]);
+
+	case PPSETTIME64:
+		if (copy_from_user(time64, argp, sizeof(time64)))
+			return -EFAULT;
+
+		if ((time64[0] < 0) || (time64[1] < 0))
+			return -EINVAL;
+
+		if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
+			time64[1] >>= 32;
+
+		return pp_set_timeout(pp->pdev, time64[0], time64[1]);
+
+	case PPGETTIME32:
+		jiffies_to_timespec64(pp->pdev->timeout, &ts);
+		time32[0] = ts.tv_sec;
+		time32[1] = ts.tv_nsec / NSEC_PER_USEC;
+
+		if (copy_to_user(argp, time32, sizeof(time32)))
+			return -EFAULT;
+
+		return 0;
+
+	case PPGETTIME64:
+		jiffies_to_timespec64(pp->pdev->timeout, &ts);
+		time64[0] = ts.tv_sec;
+		time64[1] = ts.tv_nsec / NSEC_PER_USEC;
+
+		if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
+			time64[1] <<= 32;
+
+		if (copy_to_user(argp, time64, sizeof(time64)))
+			return -EFAULT;
+
+		return 0;
+
+	default:
+		dev_dbg(&pp->pdev->dev, "What? (cmd=0x%x)\n", cmd);
+		return -EINVAL;
+	}
+
+	/* Keep the compiler happy */
+	return 0;
+}
+
+static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	long ret;
+
+	mutex_lock(&pp_do_mutex);
+	ret = pp_do_ioctl(file, cmd, arg);
+	mutex_unlock(&pp_do_mutex);
+	return ret;
+}
+
+#ifdef CONFIG_COMPAT
+static long pp_compat_ioctl(struct file *file, unsigned int cmd,
+			    unsigned long arg)
+{
+	return pp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+static int pp_open(struct inode *inode, struct file *file)
+{
+	unsigned int minor = iminor(inode);
+	struct pp_struct *pp;
+
+	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);
+		dev_dbg(&pp->pdev->dev,
+			"negotiated back to compatibility mode because user-space forgot\n");
+	}
+
+	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) {
+		parport_unregister_device(pp->pdev);
+		ida_simple_remove(&ida_index, pp->index);
+		pp->pdev = NULL;
+		pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
+	}
+
+	kfree(pp);
+
+	return 0;
+}
+
+/* No kernel lock held - fine */
+static __poll_t pp_poll(struct file *file, poll_table *wait)
+{
+	struct pp_struct *pp = file->private_data;
+	__poll_t mask = 0;
+
+	poll_wait(file, &pp->irq_wait, wait);
+	if (atomic_read(&pp->irqc))
+		mask |= EPOLLIN | EPOLLRDNORM;
+
+	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,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl   = pp_compat_ioctl,
+#endif
+	.open		= pp_open,
+	.release	= pp_release,
+};
+
+static void pp_attach(struct parport *port)
+{
+	struct device *ret;
+
+	if (devices[port->number])
+		return;
+
+	ret = device_create(ppdev_class, port->dev,
+			    MKDEV(PP_MAJOR, port->number), NULL,
+			    "parport%d", port->number);
+	if (IS_ERR(ret)) {
+		pr_err("Failed to create device parport%d\n",
+		       port->number);
+		return;
+	}
+	devices[port->number] = ret;
+}
+
+static void pp_detach(struct parport *port)
+{
+	if (!devices[port->number])
+		return;
+
+	device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
+	devices[port->number] = NULL;
+}
+
+static int pp_probe(struct pardevice *par_dev)
+{
+	struct device_driver *drv = par_dev->dev.driver;
+	int len = strlen(drv->name);
+
+	if (strncmp(par_dev->name, drv->name, len))
+		return -ENODEV;
+
+	return 0;
+}
+
+static struct parport_driver pp_driver = {
+	.name		= CHRDEV,
+	.probe		= pp_probe,
+	.match_port	= pp_attach,
+	.detach		= pp_detach,
+	.devmodel	= true,
+};
+
+static int __init ppdev_init(void)
+{
+	int err = 0;
+
+	if (register_chrdev(PP_MAJOR, CHRDEV, &pp_fops)) {
+		pr_warn(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;
+	}
+	err = parport_register_driver(&pp_driver);
+	if (err < 0) {
+		pr_warn(CHRDEV ": unable to register with parport\n");
+		goto out_class;
+	}
+
+	pr_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);