Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / char / ppdev.c
diff --git a/kernel/drivers/char/ppdev.c b/kernel/drivers/char/ppdev.c
new file mode 100644 (file)
index 0000000..ae0b42b
--- /dev/null
@@ -0,0 +1,811 @@
+/*
+ * 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/mutex.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 DEFINE_MUTEX(pp_do_mutex);
+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;
+       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_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) {
+                       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;
+               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;
+               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;
+               memset(&par_timeout, 0, sizeof(par_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;
+       mutex_lock(&pp_do_mutex);
+       ret = pp_do_ioctl(file, cmd, arg);
+       mutex_unlock(&pp_do_mutex);
+       return ret;
+}
+
+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);
+               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;
+       }
+       err = parport_register_driver(&pp_driver);
+       if (err < 0) {
+               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);