lp.c

arm平台上的uclinux系统全部源代码

/*
 * 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, [e-mail]
 * Statistics and support for slow printers by Rob Janssen, [e-mail]
 * "lp=" command line parameters added by Grant Guenther, [e-mail]
 */

#include <linux/module.h>

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/sched.h>
#include <linux/lp.h>
#include <linux/malloc.h>
#include <linux/ioport.h>
#include <linux/fcntl.h>
#include <linux/delay.h>

#include <asm/io.h>
#include <asm/segment.h>
#include <asm/system.h>

#define NO_IRQ (-1)

/* the BIOS manuals say there can be up to 4 lpt devices
 * but I have not seen a board where the 4th address is listed
 * if you have different hardware change the table below
 * please let me know if you have different equipment
 * if you have more than 3 printers, remember to increase LP_NO
 */
struct lp_struct lp_table[] = {
	{ 0x3bc, NO_IRQ, 0, LP_INIT_CHAR, LP_INIT_TIME, LP_INIT_WAIT, NULL, NULL, 0, 0, 0, {0} },
	{ 0x378, NO_IRQ, 0, LP_INIT_CHAR, LP_INIT_TIME, LP_INIT_WAIT, NULL, NULL, 0, 0, 0, {0} },
	{ 0x278, NO_IRQ, 0, LP_INIT_CHAR, LP_INIT_TIME, LP_INIT_WAIT, NULL, NULL, 0, 0, 0, {0} },
};
#define LP_NO 3

/* Test if printer is ready (and optionally has no error conditions) */
#define LP_READY(minor, status) \
  ((LP_F(minor) & LP_CAREFUL) ? _LP_CAREFUL_READY(status) : (status & LP_PBUSY))
#define LP_CAREFUL_READY(minor, status) \
  ((LP_F(minor) & LP_CAREFUL) ? _LP_CAREFUL_READY(status) : 1)
#define _LP_CAREFUL_READY(status) \
   (status & (LP_PBUSY|LP_POUTPA|LP_PSELECD|LP_PERRORP)) == \
      (LP_PBUSY|LP_PSELECD|LP_PERRORP)

/*
 * All my debugging code assumes that you debug with only one printer at
 * a time. RWWH
 * Debug info moved into stats area, so this is no longer true (Rob Janssen)
 */

#undef LP_DEBUG

static int lp_reset(int minor)
{
	outb_p(LP_PSELECP, LP_C(minor));
	udelay(LP_DELAY);
	outb_p(LP_PSELECP | LP_PINITP, LP_C(minor));
	return LP_S(minor);
}

static inline int lp_char_polled(char lpchar, int minor)
{
	int status, wait = 0;
	unsigned long count  = 0;
	struct lp_stats *stats;

	do {
		status = LP_S(minor);
		count ++;
		if(need_resched)
			schedule();
	} while(!LP_READY(minor,status) && count < LP_CHAR(minor));

	if (count == LP_CHAR(minor)) {
		return 0;
		/* we timed out, and the character was /not/ printed */
	}
	outb_p(lpchar, LP_B(minor));
	stats = &LP_STAT(minor);
	stats->chars++;
	/* must wait before taking strobe high, and after taking strobe
	   low, according spec.  Some printers need it, others don't. */
	while(wait != LP_WAIT(minor)) wait++;
	/* control port takes strobe high */
	outb_p(( LP_PSELECP | LP_PINITP | LP_PSTROBE ), ( LP_C( minor )));
	/* Wait until NBUSY line goes high */
	count = 0;
	do {
		status = LP_S(minor);
		count++;
		if (need_resched)
			schedule();
	} while (LP_READY(minor, status) && (count<LP_CHAR(minor)));
	/* take strobe low */
	outb_p(( LP_PSELECP | LP_PINITP ), ( LP_C( minor )));
	/* update waittime statistics */
	if (count > stats->maxwait) {
#ifdef LP_DEBUG
	    printk(KERN_DEBUG "lp%d success after %d counts.\n",minor,count);
#endif
	    stats->maxwait = count;
	}
	count *= 256;
	wait = (count > stats->meanwait)? count - stats->meanwait :
					  stats->meanwait - count;
	stats->meanwait = (255*stats->meanwait + count + 128) / 256;
	stats->mdev = ((127 * stats->mdev) + wait + 64) / 128;

	return 1;
}

static inline int lp_char_interrupt(char lpchar, int minor)
{
	int wait;
	unsigned long count = 0;
	unsigned char status;
	struct lp_stats *stats;

	do {
	    if(need_resched)
		schedule();
	    if ((status = LP_S(minor)) & LP_PBUSY) {
		if (!LP_CAREFUL_READY(minor, status))
			return 0;
		outb_p(lpchar, LP_B(minor));
		stats = &LP_STAT(minor);
		stats->chars++;
		/* must wait before taking strobe high, and after taking strobe
		   low, according spec.  Some printers need it, others don't. */
		wait = 0;
		while(wait != LP_WAIT(minor)) wait++;
		/* control port takes strobe high */
		outb_p(( LP_PSELECP | LP_PINITP | LP_PSTROBE ), ( LP_C( minor )));
		while(wait) wait--;
		/* take strobe low */
		outb_p(( LP_PSELECP | LP_PINITP ), ( LP_C( minor )));
		/* update waittime statistics */
		if (count) {
		    if (count > stats->maxwait)
			stats->maxwait = count;
		    count *= 256;
		    wait = (count > stats->meanwait)? count - stats->meanwait :
						      stats->meanwait - count;
		    stats->meanwait = (255*stats->meanwait + count + 128) / 256;
		    stats->mdev = ((127 * stats->mdev) + wait + 64) / 128;
		}
		return 1;
	    }
	} while (count++ < LP_CHAR(minor));

	return 0;
}

static void lp_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct lp_struct *lp = &lp_table[0];

	while (irq != lp->irq) {
		if (++lp >= &lp_table[LP_NO])
			return;
	}

	wake_up(&lp->lp_wait_q);
}

static inline int lp_write_interrupt(unsigned int minor, const char * buf, int count)
{
	unsigned long copy_size;
	unsigned long total_bytes_written = 0;
	unsigned long bytes_written;
	struct lp_struct *lp = &lp_table[minor];
	unsigned char status;

	do {
		bytes_written = 0;
		copy_size = (count <= LP_BUFFER_SIZE ? count : LP_BUFFER_SIZE);
		memcpy_fromfs(lp->lp_buffer, buf, copy_size);

		while (copy_size) {
			if (lp_char_interrupt(lp->lp_buffer[bytes_written], minor)) {
				--copy_size;
				++bytes_written;
				lp_table[minor].runchars++;
			} else {
				int rc = total_bytes_written + bytes_written;
				if (lp_table[minor].runchars > LP_STAT(minor).maxrun)
					 LP_STAT(minor).maxrun = lp_table[minor].runchars;
				status = LP_S(minor);
				if ((status & LP_POUTPA)) {
					printk(KERN_INFO "lp%d out of paper\n", minor);
					if (LP_F(minor) & LP_ABORT)
						return rc?rc:-ENOSPC;
				} else if (!(status & LP_PSELECD)) {
					printk(KERN_INFO "lp%d off-line\n", minor);
					if (LP_F(minor) & LP_ABORT)
						return rc?rc:-EIO;
				} else if (!(status & LP_PERRORP)) {
					printk(KERN_ERR "lp%d printer error\n", minor);
					if (LP_F(minor) & LP_ABORT)
						return rc?rc:-EIO;
				}
				LP_STAT(minor).sleeps++;
				cli();
				outb_p((LP_PSELECP|LP_PINITP|LP_PINTEN), (LP_C(minor)));
				status = LP_S(minor);
				if ((!(status & LP_PACK) || (status & LP_PBUSY))
				  && LP_CAREFUL_READY(minor, status)) {
					outb_p((LP_PSELECP|LP_PINITP), (LP_C(minor)));
					sti();
					continue;
				}
				lp_table[minor].runchars=0;
				current->timeout = jiffies + LP_TIMEOUT_INTERRUPT;
				interruptible_sleep_on(&lp->lp_wait_q);
				outb_p((LP_PSELECP|LP_PINITP), (LP_C(minor)));
				sti();
				if (current->signal & ~current->blocked) {
					if (total_bytes_written + bytes_written)
						return total_bytes_written + bytes_written;
					else
						return -EINTR;
				}
			}
		}

		total_bytes_written += bytes_written;
		buf += bytes_written;
		count -= bytes_written;

	} while (count > 0);

	return total_bytes_written;
}

static inline int lp_write_polled(unsigned int minor, const char * buf, int count)
{
	int  retval,status;
	char c;
	const char *temp;

	temp = buf;
	while (count > 0) {
		c = get_user(temp);
		retval = lp_char_polled(c, minor);
		/* only update counting vars if character was printed */
		if (retval) {
			count--; temp++;
			lp_table[minor].runchars++;
		} else { /* if printer timed out */
			if (lp_table[minor].runchars > LP_STAT(minor).maxrun)
				 LP_STAT(minor).maxrun = lp_table[minor].runchars;
			status = LP_S(minor);

			if (status & LP_POUTPA) {
				printk(KERN_INFO "lp%d out of paper\n", minor);
				if(LP_F(minor) & LP_ABORT)
					return temp-buf?temp-buf:-ENOSPC;
				current->state = TASK_INTERRUPTIBLE;
				current->timeout = jiffies + LP_TIMEOUT_POLLED;
				schedule();
			} else
			if (!(status & LP_PSELECD)) {
				printk(KERN_INFO "lp%d off-line\n", minor);
				if(LP_F(minor) & LP_ABORT)
					return temp-buf?temp-buf:-EIO;
				current->state = TASK_INTERRUPTIBLE;
				current->timeout = jiffies + LP_TIMEOUT_POLLED;
				schedule();
			} else
			/* not offline or out of paper. on fire? */
			if (!(status & LP_PERRORP)) {
				printk(KERN_ERR "lp%d reported invalid error status (on fire, eh?)\n", minor);
				if(LP_F(minor) & LP_ABORT)
					return temp-buf?temp-buf:-EIO;
				current->state = TASK_INTERRUPTIBLE;
				current->timeout = jiffies + LP_TIMEOUT_POLLED;
				schedule();
			}

			/* check for signals before going to sleep */
			if (current->signal & ~current->blocked) {
				if (temp != buf)
					return temp-buf;
				else
					return -EINTR;
			}
			LP_STAT(minor).sleeps++;
#ifdef LP_DEBUG
			printk(KERN_DEBUG "lp%d sleeping at %d characters for %d jiffies\n",
				minor,lp_table[minor].runchars, LP_TIME(minor));
#endif
			lp_table[minor].runchars=0;
			current->state = TASK_INTERRUPTIBLE;
			current->timeout = jiffies + LP_TIME(minor);
			schedule();
		}
	}
	return temp-buf;
}

static int lp_write(struct inode * inode, struct file * file, const char * buf, int count)
{
	unsigned int minor = MINOR(inode->i_rdev);

	if (jiffies-lp_table[minor].lastcall > LP_TIME(minor))
		lp_table[minor].runchars = 0;
	lp_table[minor].lastcall = jiffies;

	if (LP_IRQ(minor) != NO_IRQ)
		return lp_write_interrupt(minor, buf, count);
	else
		return lp_write_polled(minor, buf, count);
}

static int lp_lseek(struct inode * inode, struct file * file,
		    off_t offset, int origin)
{
	return -ESPIPE;
}

static int lp_open(struct inode * inode, struct file * file)
{
	unsigned int minor = MINOR(inode->i_rdev);
	int ret;
	unsigned int irq;

	if (minor >= LP_NO)
		return -ENXIO;
	if ((LP_F(minor) & LP_EXIST) == 0)
		return -ENXIO;
	if (LP_F(minor) & LP_BUSY)
		return -EBUSY;

	MOD_INC_USE_COUNT;

	/* If ABORTOPEN is set and the printer is offline or out of paper,