ppdev.c
上传用户:jlfgdled
上传日期:2013-04-10
资源大小:33168k
文件大小:19k
- /*
- * 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/devfs_fs_kernel.h>
- #include <linux/ioctl.h>
- #include <linux/parport.h>
- #include <linux/ctype.h>
- #include <linux/poll.h>
- #include <asm/uaccess.h>
- #include <linux/ppdev.h>
- #include <linux/smp_lock.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 * buf, size_t count,
- loff_t * ppos)
- {
- unsigned int minor = MINOR (file->f_dentry->d_inode->i_rdev);
- 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 */
- printk (KERN_DEBUG CHRDEV "%x: claim the port firstn",
- 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;
- }
- if (current->need_resched)
- schedule ();
- }
- 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 * buf, size_t count,
- loff_t * ppos)
- {
- unsigned int minor = MINOR (file->f_dentry->d_inode->i_rdev);
- 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 */
- printk (KERN_DEBUG CHRDEV "%x: claim the port firstn",
- 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;
- }
- if (current->need_resched) {
- schedule ();
- }
- }
- parport_set_timeout (pp->pdev, pp->default_inactivity);
- kfree (kbuffer);
- pp_enable_irq (pp);
- return bytes_written;
- }
- static void pp_irq (int irq, void * private, struct pt_regs * unused)
- {
- struct pp_struct * pp = (struct pp_struct *) 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 = kmalloc (strlen (CHRDEV) + 3, GFP_KERNEL);
- if (name == NULL)
- return -ENOMEM;
- sprintf (name, CHRDEV "%x", minor);
- 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;
- printk (KERN_DEBUG "%s: registered pardevicen", 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_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg)
- {
- unsigned int minor = MINOR(inode->i_rdev);
- struct pp_struct *pp = file->private_data;
- struct parport * port;
- /* First handle the cases that don't take arguments. */
- switch (cmd) {
- case PPCLAIM:
- {
- struct ieee1284_info *info;
- int ret;
- if (pp->flags & PP_CLAIMED) {
- printk (KERN_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) {
- printk (KERN_DEBUG CHRDEV "%x: too late for PPEXCL; "
- "already registeredn", 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, (int *) arg, 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 ((int *)arg, &mode, sizeof (mode))) {
- return -EFAULT;
- }
- return 0;
- }
- case PPSETPHASE:
- {
- int phase;
- if (copy_from_user (&phase, (int *) arg, 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 ((int *)arg, &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 ((unsigned int *)arg, &modes, sizeof (modes))) {
- return -EFAULT;
- }
- return 0;
- }
- case PPSETFLAGS:
- {
- int uflags;
- if (copy_from_user (&uflags, (int *)arg, 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 ((int *)arg, &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) {
- printk (KERN_DEBUG CHRDEV "%x: claim the port firstn",
- 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 ((unsigned char *) arg, ®, sizeof (reg)))
- return -EFAULT;
- return 0;
- case PPRDATA:
- reg = parport_read_data (port);
- if (copy_to_user ((unsigned char *) arg, ®, sizeof (reg)))
- return -EFAULT;
- return 0;
- case PPRCONTROL:
- reg = parport_read_control (port);
- if (copy_to_user ((unsigned char *) arg, ®, 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 (®, (unsigned char *) arg, sizeof (reg)))
- return -EFAULT;
- parport_write_control (port, reg);
- return 0;
- case PPWDATA:
- if (copy_from_user (®, (unsigned char *) arg, sizeof (reg)))
- return -EFAULT;
- parport_write_data (port, reg);
- return 0;
- case PPFCONTROL:
- if (copy_from_user (&mask, (unsigned char *) arg,
- sizeof (mask)))
- return -EFAULT;
- if (copy_from_user (®, 1 + (unsigned char *) arg,
- sizeof (reg)))
- return -EFAULT;
- parport_frob_control (port, mask, reg);
- return 0;
- case PPDATADIR:
- if (copy_from_user (&mode, (int *) arg, 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, (int *) arg, 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 (®, (unsigned char *) arg,
- 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 ((int *) arg, &ret, sizeof (ret)))
- return -EFAULT;
- atomic_sub (ret, &pp->irqc);
- return 0;
- case PPSETTIME:
- if (copy_from_user (&par_timeout, (struct timeval *)arg,
- 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 ((struct timeval *)arg, &par_timeout,
- sizeof(struct timeval))) {
- return -EFAULT;
- }
- return 0;
- default:
- printk (KERN_DEBUG CHRDEV "%x: What? (cmd=0x%x)n", minor,
- cmd);
- return -EINVAL;
- }
- /* Keep the compiler happy */
- return 0;
- }
- static int pp_open (struct inode * inode, struct file * file)
- {
- unsigned int minor = MINOR (inode->i_rdev);
- 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 = MINOR (inode->i_rdev);
- struct pp_struct *pp = file->private_data;
- int compat_negot;
- lock_kernel();
- 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 compatability 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);
- printk (KERN_DEBUG CHRDEV
- "%x: negotiated back to compatibility mode because "
- "user-space forgotn", 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) {
- printk (KERN_DEBUG CHRDEV "%x: released pardevice "
- "because user-space forgotn", minor);
- }
- }
- if (pp->pdev) {
- const char *name = pp->pdev->name;
- parport_unregister_device (pp->pdev);
- kfree (name);
- pp->pdev = NULL;
- printk (KERN_DEBUG CHRDEV "%x: unregistered pardevicen",
- minor);
- }
- unlock_kernel();
- 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 file_operations pp_fops = {
- owner: THIS_MODULE,
- llseek: no_llseek,
- read: pp_read,
- write: pp_write,
- poll: pp_poll,
- ioctl: pp_ioctl,
- open: pp_open,
- release: pp_release,
- };
- static devfs_handle_t devfs_handle;
- static int __init ppdev_init (void)
- {
- if (devfs_register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
- printk (KERN_WARNING CHRDEV ": unable to get major %dn",
- PP_MAJOR);
- return -EIO;
- }
- devfs_handle = devfs_mk_dir (NULL, "parports", NULL);
- devfs_register_series (devfs_handle, "%u", PARPORT_MAX,
- DEVFS_FL_DEFAULT, PP_MAJOR, 0,
- S_IFCHR | S_IRUGO | S_IWUGO,
- &pp_fops, NULL);
- printk (KERN_INFO PP_VERSION "n");
- return 0;
- }
- static void __exit ppdev_cleanup (void)
- {
- /* Clean up all parport stuff */
- devfs_unregister (devfs_handle);
- devfs_unregister_chrdev (PP_MAJOR, CHRDEV);
- }
- module_init(ppdev_init);
- module_exit(ppdev_cleanup);
- MODULE_LICENSE("GPL");
- EXPORT_NO_SYMBOLS;