aboutsummaryrefslogtreecommitdiff
path: root/drivers/char/lp.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/char/lp.c')
-rw-r--r--drivers/char/lp.c995
1 files changed, 995 insertions, 0 deletions
diff --git a/drivers/char/lp.c b/drivers/char/lp.c
new file mode 100644
index 00000000000..4dee945031d
--- /dev/null
+++ b/drivers/char/lp.c
@@ -0,0 +1,995 @@
+/*
+ * Generic parallel printer driver
+ *
+ * Copyright (C) 1992 by Jim Weigand and Linus Torvalds
+ * Copyright (C) 1992,1993 by Michael K. Johnson
+ * - Thanks much to Gunter Windau for pointing out to me where the error
+ * checking ought to be.
+ * Copyright (C) 1993 by Nigel Gamble (added interrupt code)
+ * Copyright (C) 1994 by Alan Cox (Modularised it)
+ * LPCAREFUL, LPABORT, LPGETSTATUS added by Chris Metcalf, metcalf@lcs.mit.edu
+ * Statistics and support for slow printers by Rob Janssen, rob@knoware.nl
+ * "lp=" command line parameters added by Grant Guenther, grant@torque.net
+ * lp_read (Status readback) support added by Carsten Gross,
+ * carsten@sol.wohnheim.uni-ulm.de
+ * Support for parport by Philip Blundell <philb@gnu.org>
+ * Parport sharing hacking by Andrea Arcangeli
+ * Fixed kernel_(to/from)_user memory copy to check for errors
+ * by Riccardo Facchetti <fizban@tin.it>
+ * 22-JAN-1998 Added support for devfs Richard Gooch <rgooch@atnf.csiro.au>
+ * Redesigned interrupt handling for handle printers with buggy handshake
+ * by Andrea Arcangeli, 11 May 1998
+ * Full efficient handling of printer with buggy irq handshake (now I have
+ * understood the meaning of the strange handshake). This is done sending new
+ * characters if the interrupt is just happened, even if the printer say to
+ * be still BUSY. This is needed at least with Epson Stylus Color. To enable
+ * the new TRUST_IRQ mode read the `LP OPTIMIZATION' section below...
+ * Fixed the irq on the rising edge of the strobe case.
+ * Obsoleted the CAREFUL flag since a printer that doesn' t work with
+ * CAREFUL will block a bit after in lp_check_status().
+ * Andrea Arcangeli, 15 Oct 1998
+ * Obsoleted and removed all the lowlevel stuff implemented in the last
+ * month to use the IEEE1284 functions (that handle the _new_ compatibilty
+ * mode fine).
+ */
+
+/* This driver should, in theory, work with any parallel port that has an
+ * appropriate low-level driver; all I/O is done through the parport
+ * abstraction layer.
+ *
+ * If this driver is built into the kernel, you can configure it using the
+ * kernel command-line. For example:
+ *
+ * lp=parport1,none,parport2 (bind lp0 to parport1, disable lp1 and
+ * bind lp2 to parport2)
+ *
+ * lp=auto (assign lp devices to all ports that
+ * have printers attached, as determined
+ * by the IEEE-1284 autoprobe)
+ *
+ * lp=reset (reset the printer during
+ * initialisation)
+ *
+ * lp=off (disable the printer driver entirely)
+ *
+ * If the driver is loaded as a module, similar functionality is available
+ * using module parameters. The equivalent of the above commands would be:
+ *
+ * # insmod lp.o parport=1,none,2
+ *
+ * # insmod lp.o parport=auto
+ *
+ * # insmod lp.o reset=1
+ */
+
+/* COMPATIBILITY WITH OLD KERNELS
+ *
+ * Under Linux 2.0 and previous versions, lp devices were bound to ports at
+ * particular I/O addresses, as follows:
+ *
+ * lp0 0x3bc
+ * lp1 0x378
+ * lp2 0x278
+ *
+ * The new driver, by default, binds lp devices to parport devices as it
+ * finds them. This means that if you only have one port, it will be bound
+ * to lp0 regardless of its I/O address. If you need the old behaviour, you
+ * can force it using the parameters described above.
+ */
+
+/*
+ * The new interrupt handling code take care of the buggy handshake
+ * of some HP and Epson printer:
+ * ___
+ * ACK _______________ ___________
+ * |__|
+ * ____
+ * BUSY _________ _______
+ * |____________|
+ *
+ * I discovered this using the printer scanner that you can find at:
+ *
+ * ftp://e-mind.com/pub/linux/pscan/
+ *
+ * 11 May 98, Andrea Arcangeli
+ *
+ * My printer scanner run on an Epson Stylus Color show that such printer
+ * generates the irq on the _rising_ edge of the STROBE. Now lp handle
+ * this case fine too.
+ *
+ * 15 Oct 1998, Andrea Arcangeli
+ *
+ * The so called `buggy' handshake is really the well documented
+ * compatibility mode IEEE1284 handshake. They changed the well known
+ * Centronics handshake acking in the middle of busy expecting to not
+ * break drivers or legacy application, while they broken linux lp
+ * until I fixed it reverse engineering the protocol by hand some
+ * month ago...
+ *
+ * 14 Dec 1998, Andrea Arcangeli
+ *
+ * Copyright (C) 2000 by Tim Waugh (added LPSETTIMEOUT ioctl)
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/sched.h>
+#include <linux/smp_lock.h>
+#include <linux/devfs_fs_kernel.h>
+#include <linux/slab.h>
+#include <linux/fcntl.h>
+#include <linux/delay.h>
+#include <linux/poll.h>
+#include <linux/console.h>
+#include <linux/device.h>
+#include <linux/wait.h>
+
+#include <linux/parport.h>
+#undef LP_STATS
+#include <linux/lp.h>
+
+#include <asm/irq.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+/* if you have more than 8 printers, remember to increase LP_NO */
+#define LP_NO 8
+
+/* ROUND_UP macro from fs/select.c */
+#define ROUND_UP(x,y) (((x)+(y)-1)/(y))
+
+static struct lp_struct lp_table[LP_NO];
+
+static unsigned int lp_count = 0;
+static struct class_simple *lp_class;
+
+#ifdef CONFIG_LP_CONSOLE
+static struct parport *console_registered; // initially NULL
+#endif /* CONFIG_LP_CONSOLE */
+
+#undef LP_DEBUG
+
+/* Bits used to manage claiming the parport device */
+#define LP_PREEMPT_REQUEST 1
+#define LP_PARPORT_CLAIMED 2
+
+/* --- low-level port access ----------------------------------- */
+
+#define r_dtr(x) (parport_read_data(lp_table[(x)].dev->port))
+#define r_str(x) (parport_read_status(lp_table[(x)].dev->port))
+#define w_ctr(x,y) do { parport_write_control(lp_table[(x)].dev->port, (y)); } while (0)
+#define w_dtr(x,y) do { parport_write_data(lp_table[(x)].dev->port, (y)); } while (0)
+
+/* Claim the parport or block trying unless we've already claimed it */
+static void lp_claim_parport_or_block(struct lp_struct *this_lp)
+{
+ if (!test_and_set_bit(LP_PARPORT_CLAIMED, &this_lp->bits)) {
+ parport_claim_or_block (this_lp->dev);
+ }
+}
+
+/* Claim the parport or block trying unless we've already claimed it */
+static void lp_release_parport(struct lp_struct *this_lp)
+{
+ if (test_and_clear_bit(LP_PARPORT_CLAIMED, &this_lp->bits)) {
+ parport_release (this_lp->dev);
+ }
+}
+
+
+
+static int lp_preempt(void *handle)
+{
+ struct lp_struct *this_lp = (struct lp_struct *)handle;
+ set_bit(LP_PREEMPT_REQUEST, &this_lp->bits);
+ return (1);
+}
+
+
+/*
+ * Try to negotiate to a new mode; if unsuccessful negotiate to
+ * compatibility mode. Return the mode we ended up in.
+ */
+static int lp_negotiate(struct parport * port, int mode)
+{
+ if (parport_negotiate (port, mode) != 0) {
+ mode = IEEE1284_MODE_COMPAT;
+ parport_negotiate (port, mode);
+ }
+
+ return (mode);
+}
+
+static int lp_reset(int minor)
+{
+ int retval;
+ lp_claim_parport_or_block (&lp_table[minor]);
+ w_ctr(minor, LP_PSELECP);
+ udelay (LP_DELAY);
+ w_ctr(minor, LP_PSELECP | LP_PINITP);
+ retval = r_str(minor);
+ lp_release_parport (&lp_table[minor]);
+ return retval;
+}
+
+static void lp_error (int minor)
+{
+ DEFINE_WAIT(wait);
+ int polling;
+
+ if (LP_F(minor) & LP_ABORT)
+ return;
+
+ polling = lp_table[minor].dev->port->irq == PARPORT_IRQ_NONE;
+ if (polling) lp_release_parport (&lp_table[minor]);
+ prepare_to_wait(&lp_table[minor].waitq, &wait, TASK_INTERRUPTIBLE);
+ schedule_timeout(LP_TIMEOUT_POLLED);
+ finish_wait(&lp_table[minor].waitq, &wait);
+ if (polling) lp_claim_parport_or_block (&lp_table[minor]);
+ else parport_yield_blocking (lp_table[minor].dev);
+}
+
+static int lp_check_status(int minor)
+{
+ int error = 0;
+ unsigned int last = lp_table[minor].last_error;
+ unsigned char status = r_str(minor);
+ if ((status & LP_PERRORP) && !(LP_F(minor) & LP_CAREFUL))
+ /* No error. */
+ last = 0;
+ else if ((status & LP_POUTPA)) {
+ if (last != LP_POUTPA) {
+ last = LP_POUTPA;
+ printk(KERN_INFO "lp%d out of paper\n", minor);
+ }
+ error = -ENOSPC;
+ } else if (!(status & LP_PSELECD)) {
+ if (last != LP_PSELECD) {
+ last = LP_PSELECD;
+ printk(KERN_INFO "lp%d off-line\n", minor);
+ }
+ error = -EIO;
+ } else if (!(status & LP_PERRORP)) {
+ if (last != LP_PERRORP) {
+ last = LP_PERRORP;
+ printk(KERN_INFO "lp%d on fire\n", minor);
+ }
+ error = -EIO;
+ } else {
+ last = 0; /* Come here if LP_CAREFUL is set and no
+ errors are reported. */
+ }
+
+ lp_table[minor].last_error = last;
+
+ if (last != 0)
+ lp_error(minor);
+
+ return error;
+}
+
+static int lp_wait_ready(int minor, int nonblock)
+{
+ int error = 0;
+
+ /* If we're not in compatibility mode, we're ready now! */
+ if (lp_table[minor].current_mode != IEEE1284_MODE_COMPAT) {
+ return (0);
+ }
+
+ do {
+ error = lp_check_status (minor);
+ if (error && (nonblock || (LP_F(minor) & LP_ABORT)))
+ break;
+ if (signal_pending (current)) {
+ error = -EINTR;
+ break;
+ }
+ } while (error);
+ return error;
+}
+
+static ssize_t lp_write(struct file * file, const char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned int minor = iminor(file->f_dentry->d_inode);
+ struct parport *port = lp_table[minor].dev->port;
+ char *kbuf = lp_table[minor].lp_buffer;
+ ssize_t retv = 0;
+ ssize_t written;
+ size_t copy_size = count;
+ int nonblock = ((file->f_flags & O_NONBLOCK) ||
+ (LP_F(minor) & LP_ABORT));
+
+#ifdef LP_STATS
+ if (jiffies-lp_table[minor].lastcall > LP_TIME(minor))
+ lp_table[minor].runchars = 0;
+
+ lp_table[minor].lastcall = jiffies;
+#endif
+
+ /* Need to copy the data from user-space. */
+ if (copy_size > LP_BUFFER_SIZE)
+ copy_size = LP_BUFFER_SIZE;
+
+ if (down_interruptible (&lp_table[minor].port_mutex))
+ return -EINTR;
+
+ if (copy_from_user (kbuf, buf, copy_size)) {
+ retv = -EFAULT;
+ goto out_unlock;
+ }
+
+ /* Claim Parport or sleep until it becomes available
+ */
+ lp_claim_parport_or_block (&lp_table[minor]);
+ /* Go to the proper mode. */
+ lp_table[minor].current_mode = lp_negotiate (port,
+ lp_table[minor].best_mode);
+
+ parport_set_timeout (lp_table[minor].dev,
+ (nonblock ? PARPORT_INACTIVITY_O_NONBLOCK
+ : lp_table[minor].timeout));
+
+ if ((retv = lp_wait_ready (minor, nonblock)) == 0)
+ do {
+ /* Write the data. */
+ written = parport_write (port, kbuf, copy_size);
+ if (written > 0) {
+ copy_size -= written;
+ count -= written;
+ buf += written;
+ retv += written;
+ }
+
+ if (signal_pending (current)) {
+ if (retv == 0)
+ retv = -EINTR;
+
+ break;
+ }
+
+ if (copy_size > 0) {
+ /* incomplete write -> check error ! */
+ int error;
+
+ parport_negotiate (lp_table[minor].dev->port,
+ IEEE1284_MODE_COMPAT);
+ lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
+
+ error = lp_wait_ready (minor, nonblock);
+
+ if (error) {
+ if (retv == 0)
+ retv = error;
+ break;
+ } else if (nonblock) {
+ if (retv == 0)
+ retv = -EAGAIN;
+ break;
+ }
+
+ parport_yield_blocking (lp_table[minor].dev);
+ lp_table[minor].current_mode
+ = lp_negotiate (port,
+ lp_table[minor].best_mode);
+
+ } else if (need_resched())
+ schedule ();
+
+ if (count) {
+ copy_size = count;
+ if (copy_size > LP_BUFFER_SIZE)
+ copy_size = LP_BUFFER_SIZE;
+
+ if (copy_from_user(kbuf, buf, copy_size)) {
+ if (retv == 0)
+ retv = -EFAULT;
+ break;
+ }
+ }
+ } while (count > 0);
+
+ if (test_and_clear_bit(LP_PREEMPT_REQUEST,
+ &lp_table[minor].bits)) {
+ printk(KERN_INFO "lp%d releasing parport\n", minor);
+ parport_negotiate (lp_table[minor].dev->port,
+ IEEE1284_MODE_COMPAT);
+ lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
+ lp_release_parport (&lp_table[minor]);
+ }
+out_unlock:
+ up (&lp_table[minor].port_mutex);
+
+ return retv;
+}
+
+#ifdef CONFIG_PARPORT_1284
+
+/* Status readback conforming to ieee1284 */
+static ssize_t lp_read(struct file * file, char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ DEFINE_WAIT(wait);
+ unsigned int minor=iminor(file->f_dentry->d_inode);
+ struct parport *port = lp_table[minor].dev->port;
+ ssize_t retval = 0;
+ char *kbuf = lp_table[minor].lp_buffer;
+ int nonblock = ((file->f_flags & O_NONBLOCK) ||
+ (LP_F(minor) & LP_ABORT));
+
+ if (count > LP_BUFFER_SIZE)
+ count = LP_BUFFER_SIZE;
+
+ if (down_interruptible (&lp_table[minor].port_mutex))
+ return -EINTR;
+
+ lp_claim_parport_or_block (&lp_table[minor]);
+
+ parport_set_timeout (lp_table[minor].dev,
+ (nonblock ? PARPORT_INACTIVITY_O_NONBLOCK
+ : lp_table[minor].timeout));
+
+ parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
+ if (parport_negotiate (lp_table[minor].dev->port,
+ IEEE1284_MODE_NIBBLE)) {
+ retval = -EIO;
+ goto out;
+ }
+
+ while (retval == 0) {
+ retval = parport_read (port, kbuf, count);
+
+ if (retval > 0)
+ break;
+
+ if (nonblock) {
+ retval = -EAGAIN;
+ break;
+ }
+
+ /* Wait for data. */
+
+ if (lp_table[minor].dev->port->irq == PARPORT_IRQ_NONE) {
+ parport_negotiate (lp_table[minor].dev->port,
+ IEEE1284_MODE_COMPAT);
+ lp_error (minor);
+ if (parport_negotiate (lp_table[minor].dev->port,
+ IEEE1284_MODE_NIBBLE)) {
+ retval = -EIO;
+ goto out;
+ }
+ } else {
+ prepare_to_wait(&lp_table[minor].waitq, &wait, TASK_INTERRUPTIBLE);
+ schedule_timeout(LP_TIMEOUT_POLLED);
+ finish_wait(&lp_table[minor].waitq, &wait);
+ }
+
+ if (signal_pending (current)) {
+ retval = -ERESTARTSYS;
+ break;
+ }
+
+ cond_resched ();
+ }
+ parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
+ out:
+ lp_release_parport (&lp_table[minor]);
+
+ if (retval > 0 && copy_to_user (buf, kbuf, retval))
+ retval = -EFAULT;
+
+ up (&lp_table[minor].port_mutex);
+
+ return retval;
+}
+
+#endif /* IEEE 1284 support */
+
+static int lp_open(struct inode * inode, struct file * file)
+{
+ unsigned int minor = iminor(inode);
+
+ if (minor >= LP_NO)
+ return -ENXIO;
+ if ((LP_F(minor) & LP_EXIST) == 0)
+ return -ENXIO;
+ if (test_and_set_bit(LP_BUSY_BIT_POS, &LP_F(minor)))
+ return -EBUSY;
+
+ /* If ABORTOPEN is set and the printer is offline or out of paper,
+ we may still want to open it to perform ioctl()s. Therefore we
+ have commandeered O_NONBLOCK, even though it is being used in
+ a non-standard manner. This is strictly a Linux hack, and
+ should most likely only ever be used by the tunelp application. */
+ if ((LP_F(minor) & LP_ABORTOPEN) && !(file->f_flags & O_NONBLOCK)) {
+ int status;
+ lp_claim_parport_or_block (&lp_table[minor]);
+ status = r_str(minor);
+ lp_release_parport (&lp_table[minor]);
+ if (status & LP_POUTPA) {
+ printk(KERN_INFO "lp%d out of paper\n", minor);
+ LP_F(minor) &= ~LP_BUSY;
+ return -ENOSPC;
+ } else if (!(status & LP_PSELECD)) {
+ printk(KERN_INFO "lp%d off-line\n", minor);
+ LP_F(minor) &= ~LP_BUSY;
+ return -EIO;
+ } else if (!(status & LP_PERRORP)) {
+ printk(KERN_ERR "lp%d printer error\n", minor);
+ LP_F(minor) &= ~LP_BUSY;
+ return -EIO;
+ }
+ }
+ lp_table[minor].lp_buffer = (char *) kmalloc(LP_BUFFER_SIZE, GFP_KERNEL);
+ if (!lp_table[minor].lp_buffer) {
+ LP_F(minor) &= ~LP_BUSY;
+ return -ENOMEM;
+ }
+ /* Determine if the peripheral supports ECP mode */
+ lp_claim_parport_or_block (&lp_table[minor]);
+ if ( (lp_table[minor].dev->port->modes & PARPORT_MODE_ECP) &&
+ !parport_negotiate (lp_table[minor].dev->port,
+ IEEE1284_MODE_ECP)) {
+ printk (KERN_INFO "lp%d: ECP mode\n", minor);
+ lp_table[minor].best_mode = IEEE1284_MODE_ECP;
+ } else {
+ lp_table[minor].best_mode = IEEE1284_MODE_COMPAT;
+ }
+ /* Leave peripheral in compatibility mode */
+ parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
+ lp_release_parport (&lp_table[minor]);
+ lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
+ return 0;
+}
+
+static int lp_release(struct inode * inode, struct file * file)
+{
+ unsigned int minor = iminor(inode);
+
+ lp_claim_parport_or_block (&lp_table[minor]);
+ parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
+ lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
+ lp_release_parport (&lp_table[minor]);
+ kfree(lp_table[minor].lp_buffer);
+ lp_table[minor].lp_buffer = NULL;
+ LP_F(minor) &= ~LP_BUSY;
+ return 0;
+}
+
+static int lp_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ unsigned int minor = iminor(inode);
+ int status;
+ int retval = 0;
+ void __user *argp = (void __user *)arg;
+
+#ifdef LP_DEBUG
+ printk(KERN_DEBUG "lp%d ioctl, cmd: 0x%x, arg: 0x%lx\n", minor, cmd, arg);
+#endif
+ if (minor >= LP_NO)
+ return -ENODEV;
+ if ((LP_F(minor) & LP_EXIST) == 0)
+ return -ENODEV;
+ switch ( cmd ) {
+ struct timeval par_timeout;
+ long to_jiffies;
+
+ case LPTIME:
+ LP_TIME(minor) = arg * HZ/100;
+ break;
+ case LPCHAR:
+ LP_CHAR(minor) = arg;
+ break;
+ case LPABORT:
+ if (arg)
+ LP_F(minor) |= LP_ABORT;
+ else
+ LP_F(minor) &= ~LP_ABORT;
+ break;
+ case LPABORTOPEN:
+ if (arg)
+ LP_F(minor) |= LP_ABORTOPEN;
+ else
+ LP_F(minor) &= ~LP_ABORTOPEN;
+ break;
+ case LPCAREFUL:
+ if (arg)
+ LP_F(minor) |= LP_CAREFUL;
+ else
+ LP_F(minor) &= ~LP_CAREFUL;
+ break;
+ case LPWAIT:
+ LP_WAIT(minor) = arg;
+ break;
+ case LPSETIRQ:
+ return -EINVAL;
+ break;
+ case LPGETIRQ:
+ if (copy_to_user(argp, &LP_IRQ(minor),
+ sizeof(int)))
+ return -EFAULT;
+ break;
+ case LPGETSTATUS:
+ lp_claim_parport_or_block (&lp_table[minor]);
+ status = r_str(minor);
+ lp_release_parport (&lp_table[minor]);
+
+ if (copy_to_user(argp, &status, sizeof(int)))
+ return -EFAULT;
+ break;
+ case LPRESET:
+ lp_reset(minor);
+ break;
+#ifdef LP_STATS
+ case LPGETSTATS:
+ if (copy_to_user(argp, &LP_STAT(minor),
+ sizeof(struct lp_stats)))
+ return -EFAULT;
+ if (capable(CAP_SYS_ADMIN))
+ memset(&LP_STAT(minor), 0,
+ sizeof(struct lp_stats));
+ break;
+#endif
+ case LPGETFLAGS:
+ status = LP_F(minor);
+ if (copy_to_user(argp, &status, sizeof(int)))
+ return -EFAULT;
+ break;
+
+ case LPSETTIMEOUT:
+ if (copy_from_user (&par_timeout, argp,
+ sizeof (struct timeval))) {
+ return -EFAULT;
+ }
+ /* Convert to jiffies, place in lp_table */
+ 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;
+ }
+ lp_table[minor].timeout = to_jiffies;
+ break;
+
+ default:
+ retval = -EINVAL;
+ }
+ return retval;
+}
+
+static struct file_operations lp_fops = {
+ .owner = THIS_MODULE,
+ .write = lp_write,
+ .ioctl = lp_ioctl,
+ .open = lp_open,
+ .release = lp_release,
+#ifdef CONFIG_PARPORT_1284
+ .read = lp_read,
+#endif
+};
+
+/* --- support for console on the line printer ----------------- */
+
+#ifdef CONFIG_LP_CONSOLE
+
+#define CONSOLE_LP 0
+
+/* If the printer is out of paper, we can either lose the messages or
+ * stall until the printer is happy again. Define CONSOLE_LP_STRICT
+ * non-zero to get the latter behaviour. */
+#define CONSOLE_LP_STRICT 1
+
+/* The console must be locked when we get here. */
+
+static void lp_console_write (struct console *co, const char *s,
+ unsigned count)
+{
+ struct pardevice *dev = lp_table[CONSOLE_LP].dev;
+ struct parport *port = dev->port;
+ ssize_t written;
+
+ if (parport_claim (dev))
+ /* Nothing we can do. */
+ return;
+
+ parport_set_timeout (dev, 0);
+
+ /* Go to compatibility mode. */
+ parport_negotiate (port, IEEE1284_MODE_COMPAT);
+
+ do {
+ /* Write the data, converting LF->CRLF as we go. */
+ ssize_t canwrite = count;
+ char *lf = memchr (s, '\n', count);
+ if (lf)
+ canwrite = lf - s;
+
+ if (canwrite > 0) {
+ written = parport_write (port, s, canwrite);
+
+ if (written <= 0)
+ continue;
+
+ s += written;
+ count -= written;
+ canwrite -= written;
+ }
+
+ if (lf && canwrite <= 0) {
+ const char *crlf = "\r\n";
+ int i = 2;
+
+ /* Dodge the original '\n', and put '\r\n' instead. */
+ s++;
+ count--;
+ do {
+ written = parport_write (port, crlf, i);
+ if (written > 0)
+ i -= written, crlf += written;
+ } while (i > 0 && (CONSOLE_LP_STRICT || written > 0));
+ }
+ } while (count > 0 && (CONSOLE_LP_STRICT || written > 0));
+
+ parport_release (dev);
+}
+
+static struct console lpcons = {
+ .name = "lp",
+ .write = lp_console_write,
+ .flags = CON_PRINTBUFFER,
+};
+
+#endif /* console on line printer */
+
+/* --- initialisation code ------------------------------------- */
+
+static int parport_nr[LP_NO] = { [0 ... LP_NO-1] = LP_PARPORT_UNSPEC };
+static char *parport[LP_NO] = { NULL, };
+static int reset = 0;
+
+module_param_array(parport, charp, NULL, 0);
+module_param(reset, bool, 0);
+
+#ifndef MODULE
+static int __init lp_setup (char *str)
+{
+ static int parport_ptr; // initially zero
+ int x;
+
+ if (get_option (&str, &x)) {
+ if (x == 0) {
+ /* disable driver on "lp=" or "lp=0" */
+ parport_nr[0] = LP_PARPORT_OFF;
+ } else {
+ printk(KERN_WARNING "warning: 'lp=0x%x' is deprecated, ignored\n", x);
+ return 0;
+ }
+ } else if (!strncmp(str, "parport", 7)) {
+ int n = simple_strtoul(str+7, NULL, 10);
+ if (parport_ptr < LP_NO)
+ parport_nr[parport_ptr++] = n;
+ else
+ printk(KERN_INFO "lp: too many ports, %s ignored.\n",
+ str);
+ } else if (!strcmp(str, "auto")) {
+ parport_nr[0] = LP_PARPORT_AUTO;
+ } else if (!strcmp(str, "none")) {
+ parport_nr[parport_ptr++] = LP_PARPORT_NONE;
+ } else if (!strcmp(str, "reset")) {
+ reset = 1;
+ }
+ return 1;
+}
+#endif
+
+static int lp_register(int nr, struct parport *port)
+{
+ lp_table[nr].dev = parport_register_device(port, "lp",
+ lp_preempt, NULL, NULL, 0,
+ (void *) &lp_table[nr]);
+ if (lp_table[nr].dev == NULL)
+ return 1;
+ lp_table[nr].flags |= LP_EXIST;
+
+ if (reset)
+ lp_reset(nr);
+
+ class_simple_device_add(lp_class, MKDEV(LP_MAJOR, nr), NULL,
+ "lp%d", nr);
+ devfs_mk_cdev(MKDEV(LP_MAJOR, nr), S_IFCHR | S_IRUGO | S_IWUGO,
+ "printers/%d", nr);
+
+ printk(KERN_INFO "lp%d: using %s (%s).\n", nr, port->name,
+ (port->irq == PARPORT_IRQ_NONE)?"polling":"interrupt-driven");
+
+#ifdef CONFIG_LP_CONSOLE
+ if (!nr) {
+ if (port->modes & PARPORT_MODE_SAFEININT) {
+ register_console (&lpcons);
+ console_registered = port;
+ printk (KERN_INFO "lp%d: console ready\n", CONSOLE_LP);
+ } else
+ printk (KERN_ERR "lp%d: cannot run console on %s\n",
+ CONSOLE_LP, port->name);
+ }
+#endif
+
+ return 0;
+}
+
+static void lp_attach (struct parport *port)
+{
+ unsigned int i;
+
+ switch (parport_nr[0])
+ {
+ case LP_PARPORT_UNSPEC:
+ case LP_PARPORT_AUTO:
+ if (parport_nr[0] == LP_PARPORT_AUTO &&
+ port->probe_info[0].class != PARPORT_CLASS_PRINTER)
+ return;
+ if (lp_count == LP_NO) {
+ printk(KERN_INFO "lp: ignoring parallel port (max. %d)\n",LP_NO);
+ return;
+ }
+ if (!lp_register(lp_count, port))
+ lp_count++;
+ break;
+
+ default:
+ for (i = 0; i < LP_NO; i++) {
+ if (port->number == parport_nr[i]) {
+ if (!lp_register(i, port))
+ lp_count++;
+ break;
+ }
+ }
+ break;
+ }
+}
+
+static void lp_detach (struct parport *port)
+{
+ /* Write this some day. */
+#ifdef CONFIG_LP_CONSOLE
+ if (console_registered == port) {
+ unregister_console (&lpcons);
+ console_registered = NULL;
+ }
+#endif /* CONFIG_LP_CONSOLE */
+}
+
+static struct parport_driver lp_driver = {
+ .name = "lp",
+ .attach = lp_attach,
+ .detach = lp_detach,
+};
+
+static int __init lp_init (void)
+{
+ int i, err = 0;
+
+ if (parport_nr[0] == LP_PARPORT_OFF)
+ return 0;
+
+ for (i = 0; i < LP_NO; i++) {
+ lp_table[i].dev = NULL;
+ lp_table[i].flags = 0;
+ lp_table[i].chars = LP_INIT_CHAR;
+ lp_table[i].time = LP_INIT_TIME;
+ lp_table[i].wait = LP_INIT_WAIT;
+ lp_table[i].lp_buffer = NULL;
+#ifdef LP_STATS
+ lp_table[i].lastcall = 0;
+ lp_table[i].runchars = 0;
+ memset (&lp_table[i].stats, 0, sizeof (struct lp_stats));
+#endif
+ lp_table[i].last_error = 0;
+ init_waitqueue_head (&lp_table[i].waitq);
+ init_waitqueue_head (&lp_table[i].dataq);
+ init_MUTEX (&lp_table[i].port_mutex);
+ lp_table[i].timeout = 10 * HZ;
+ }
+
+ if (register_chrdev (LP_MAJOR, "lp", &lp_fops)) {
+ printk (KERN_ERR "lp: unable to get major %d\n", LP_MAJOR);
+ return -EIO;
+ }
+
+ devfs_mk_dir("printers");
+ lp_class = class_simple_create(THIS_MODULE, "printer");
+ if (IS_ERR(lp_class)) {
+ err = PTR_ERR(lp_class);
+ goto out_devfs;
+ }
+
+ if (parport_register_driver (&lp_driver)) {
+ printk (KERN_ERR "lp: unable to register with parport\n");
+ err = -EIO;
+ goto out_class;
+ }
+
+ if (!lp_count) {
+ printk (KERN_INFO "lp: driver loaded but no devices found\n");
+#ifndef CONFIG_PARPORT_1284
+ if (parport_nr[0] == LP_PARPORT_AUTO)
+ printk (KERN_INFO "lp: (is IEEE 1284 support enabled?)\n");
+#endif
+ }
+
+ return 0;
+
+out_class:
+ class_simple_destroy(lp_class);
+out_devfs:
+ devfs_remove("printers");
+ unregister_chrdev(LP_MAJOR, "lp");
+ return err;
+}
+
+static int __init lp_init_module (void)
+{
+ if (parport[0]) {
+ /* The user gave some parameters. Let's see what they were. */
+ if (!strncmp(parport[0], "auto", 4))
+ parport_nr[0] = LP_PARPORT_AUTO;
+ else {
+ int n;
+ for (n = 0; n < LP_NO && parport[n]; n++) {
+ if (!strncmp(parport[n], "none", 4))
+ parport_nr[n] = LP_PARPORT_NONE;
+ else {
+ char *ep;
+ unsigned long r = simple_strtoul(parport[n], &ep, 0);
+ if (ep != parport[n])
+ parport_nr[n] = r;
+ else {
+ printk(KERN_ERR "lp: bad port specifier `%s'\n", parport[n]);
+ return -ENODEV;
+ }
+ }
+ }
+ }
+ }
+
+ return lp_init();
+}
+
+static void lp_cleanup_module (void)
+{
+ unsigned int offset;
+
+ parport_unregister_driver (&lp_driver);
+
+#ifdef CONFIG_LP_CONSOLE
+ unregister_console (&lpcons);
+#endif
+
+ unregister_chrdev(LP_MAJOR, "lp");
+ for (offset = 0; offset < LP_NO; offset++) {
+ if (lp_table[offset].dev == NULL)
+ continue;
+ parport_unregister_device(lp_table[offset].dev);
+ devfs_remove("printers/%d", offset);
+ class_simple_device_remove(MKDEV(LP_MAJOR, offset));
+ }
+ devfs_remove("printers");
+ class_simple_destroy(lp_class);
+}
+
+__setup("lp=", lp_setup);
+module_init(lp_init_module);
+module_exit(lp_cleanup_module);
+
+MODULE_ALIAS_CHARDEV_MAJOR(LP_MAJOR);
+MODULE_LICENSE("GPL");