/* * 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 * * 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 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 , 03/01/2001. * Added GETFLAGS/SETFLAGS ioctls, Fred Barnes, 04/2001 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #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->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; 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, ®, sizeof (reg))) return -EFAULT; return 0; case PPRDATA: reg = parport_read_data (port); if (copy_to_user (argp, ®, sizeof (reg))) return -EFAULT; return 0; case PPRCONTROL: reg = parport_read_control (port); if (copy_to_user (argp, ®, 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 (®, argp, sizeof (reg))) return -EFAULT; parport_write_control (port, reg); return 0; case PPWDATA: if (copy_from_user (®, 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 (®, 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 (®, 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; } 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);