[deliverable/linux.git] / drivers / char / tipar.c

/* Hey EMACS -*- linux-c -*-
 *
 * tipar - low level driver for handling a parallel link cable designed
 * for Texas Instruments graphing calculators (http://lpg.ticalc.org).
 * A part of the TiLP project.
 *
 * Copyright (C) 2000-2002, Romain Lievin <roms@lpg.ticalc.org>
 * under the terms of the GNU General Public License.
 *
 * Various fixes & clean-up from the Linux Kernel Mailing List
 * (Alan Cox, Richard B. Johnson, Christoph Hellwig).
 */

/* 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:
 *
 *      tipar=timeout,delay       (set timeout and delay)
 *
 * If the driver is loaded as a module, similar functionality is available
 * using module parameters.  The equivalent of the above commands would be:
 *
 *      # insmod tipar timeout=15 delay=10
 */

/* COMPATIBILITY WITH OLD KERNELS
 *
 * Usually, parallel cables were bound to ports at
 * particular I/O addresses, as follows:
 *
 *      tipar0             0x378
 *      tipar1             0x278
 *      tipar2             0x3bc
 *
 *
 * This driver, by default, binds tipar devices according to parport and
 * the minor number.
 *
 */
#undef DEBUG				/* change to #define to get debugging
					 * output - for pr_debug() */
#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/fcntl.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <asm/uaccess.h>
#include <linux/ioport.h>
#include <asm/io.h>
#include <linux/bitops.h>
#include <linux/parport.h>		/* Our code depend on parport */
#include <linux/device.h>

/*
 * TI definitions
 */
#include <linux/ticable.h>

/*
 * Version Information
 */
#define DRIVER_VERSION "1.19"
#define DRIVER_AUTHOR  "Romain Lievin <roms@lpg.ticalc.org>"
#define DRIVER_DESC    "Device driver for TI/PC parallel link cables"
#define DRIVER_LICENSE "GPL"

#define VERSION(ver,rel,seq) (((ver)<<16) | ((rel)<<8) | (seq))

/* ----- global variables --------------------------------------------- */

struct tipar_struct {
	struct pardevice *dev;	/* Parport device entry */
};

#define PP_NO 3
static struct tipar_struct table[PP_NO];

static int delay = IO_DELAY;	/* inter-bit delay in microseconds */
static int timeout = TIMAXTIME;	/* timeout in tenth of seconds     */

static unsigned int tp_count;	/* tipar count */
static unsigned long opened;	/* opened devices */

static struct class *tipar_class;

/* --- macros for parport access -------------------------------------- */

#define r_dtr(x)        (parport_read_data(table[(x)].dev->port))
#define r_str(x)        (parport_read_status(table[(x)].dev->port))
#define w_ctr(x,y)      (parport_write_control(table[(x)].dev->port, (y)))
#define w_dtr(x,y)      (parport_write_data(table[(x)].dev->port, (y)))

/* --- setting states on the D-bus with the right timing: ------------- */

static inline void
outbyte(int value, int minor)
{
	w_dtr(minor, value);
}

static inline int
inbyte(int minor)
{
	return (r_str(minor));
}

static inline void
init_ti_parallel(int minor)
{
	outbyte(3, minor);
}

/* ----- global defines ----------------------------------------------- */

#define START(x) { x = jiffies + (HZ * timeout) / 10; }
#define WAIT(x)  { \
  if (time_before((x), jiffies)) return -1; \
  if (need_resched()) schedule(); }

/* ----- D-bus bit-banging functions ---------------------------------- */

/* D-bus protocol (45kbit/s max):
                    1                 0                      0
       _______        ______|______    __________|________    __________
Red  :        ________      |      ____          |        ____
       _        ____________|________      ______|__________       _____
White:  ________            |        ______      |          _______
*/

/* Try to transmit a byte on the specified port (-1 if error). */
static int
put_ti_parallel(int minor, unsigned char data)
{
	unsigned int bit;
	unsigned long max;

	for (bit = 0; bit < 8; bit++) {
		if (data & 1) {
			outbyte(2, minor);
			START(max);
			do {
				WAIT(max);
			} while (inbyte(minor) & 0x10);

			outbyte(3, minor);
			START(max);
			do {
				WAIT(max);
			} while (!(inbyte(minor) & 0x10));
		} else {
			outbyte(1, minor);
			START(max);
			do {
				WAIT(max);
			} while (inbyte(minor) & 0x20);

			outbyte(3, minor);
			START(max);
			do {
				WAIT(max);
			} while (!(inbyte(minor) & 0x20));
		}

		data >>= 1;
		udelay(delay);

		if (need_resched())
			schedule();
	}

	return 0;
}

/* Receive a byte on the specified port or -1 if error. */
static int
get_ti_parallel(int minor)
{
	unsigned int bit;
	unsigned char v, data = 0;
	unsigned long max;

	for (bit = 0; bit < 8; bit++) {
		START(max);
		do {
			WAIT(max);
		} while ((v = inbyte(minor) & 0x30) == 0x30);

		if (v == 0x10) {
			data = (data >> 1) | 0x80;
			outbyte(1, minor);
			START(max);
			do {
				WAIT(max);
			} while (!(inbyte(minor) & 0x20));
			outbyte(3, minor);
		} else {
			data = data >> 1;
			outbyte(2, minor);
			START(max);
			do {
				WAIT(max);
			} while (!(inbyte(minor) & 0x10));
			outbyte(3, minor);
		}

		udelay(delay);
		if (need_resched())
			schedule();
	}

	return (int) data;
}

/* Try to detect a parallel link cable on the specified port */
static int
probe_ti_parallel(int minor)
{
	int i;
	int seq[] = { 0x00, 0x20, 0x10, 0x30 };
	int data;

	for (i = 3; i >= 0; i--) {
		outbyte(3, minor);
		outbyte(i, minor);
		udelay(delay);
		data = inbyte(minor) & 0x30;
		pr_debug("tipar: Probing -> %i: 0x%02x 0x%02x\n", i,
			data, seq[i]);
		if (data != seq[i]) {
			outbyte(3, minor);
			return -1;
		}
	}

	outbyte(3, minor);
	return 0;
}

/* ----- kernel module functions--------------------------------------- */

static int
tipar_open(struct inode *inode, struct file *file)
{
	unsigned int minor = iminor(inode) - TIPAR_MINOR;

	if (tp_count == 0 || minor > tp_count - 1)
		return -ENXIO;

	if (test_and_set_bit(minor, &opened))
		return -EBUSY;

	if (!table[minor].dev) {
		printk(KERN_ERR "%s: NULL device for minor %u\n",
				__FUNCTION__, minor);
		return -ENXIO;
	}
	parport_claim_or_block(table[minor].dev);
	init_ti_parallel(minor);
	parport_release(table[minor].dev);

	return nonseekable_open(inode, file);
}

static int
tipar_close(struct inode *inode, struct file *file)
{
	unsigned int minor = iminor(inode) - TIPAR_MINOR;

	if (minor > tp_count - 1)
		return -ENXIO;

	clear_bit(minor, &opened);

	return 0;
}

static ssize_t
tipar_write (struct file *file, const char __user *buf, size_t count,
		loff_t * ppos)
{
	unsigned int minor = iminor(file->f_path.dentry->d_inode) - TIPAR_MINOR;
	ssize_t n;

	parport_claim_or_block(table[minor].dev);

	for (n = 0; n < count; n++) {
		unsigned char b;

		if (get_user(b, buf + n)) {
			n = -EFAULT;
			goto out;
		}

		if (put_ti_parallel(minor, b) == -1) {
			init_ti_parallel(minor);
			n = -ETIMEDOUT;
			goto out;
		}
	}
      out:
	parport_release(table[minor].dev);
	return n;
}

static ssize_t
tipar_read(struct file *file, char __user *buf, size_t count, loff_t * ppos)
{
	int b = 0;
	unsigned int minor = iminor(file->f_path.dentry->d_inode) - TIPAR_MINOR;
	ssize_t retval = 0;
	ssize_t n = 0;

	if (count == 0)
		return 0;

	parport_claim_or_block(table[minor].dev);

	while (n < count) {
		b = get_ti_parallel(minor);
		if (b == -1) {
			init_ti_parallel(minor);
			retval = -ETIMEDOUT;
			goto out;
		} else {
			if (put_user(b, buf + n)) {
				retval = -EFAULT;
				break;
			} else
				retval = ++n;
		}

		/* Non-blocking mode : try again ! */
		if (file->f_flags & O_NONBLOCK) {
			retval = -EAGAIN;
			goto out;
		}

		/* Signal pending, try again ! */
		if (signal_pending(current)) {
			retval = -ERESTARTSYS;
			goto out;
		}

		if (need_resched())
			schedule();
	}

      out:
	parport_release(table[minor].dev);
	return retval;
}

static int
tipar_ioctl(struct inode *inode, struct file *file,
	    unsigned int cmd, unsigned long arg)
{
	int retval = 0;

	switch (cmd) {
	case IOCTL_TIPAR_DELAY:
		delay = (int)arg;    //get_user(delay, &arg);
		break;
	case IOCTL_TIPAR_TIMEOUT:
		if (arg != 0)
                        timeout = (int)arg;
                else
                        retval = -EINVAL;
	  break;
	default:
		retval = -ENOTTY;
		break;
	}

	return retval;
}

/* ----- kernel module registering ------------------------------------ */

static const struct file_operations tipar_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.read = tipar_read,
	.write = tipar_write,
	.ioctl = tipar_ioctl,
	.open = tipar_open,
	.release = tipar_close,
};

/* --- initialisation code ------------------------------------- */

#ifndef MODULE
/*      You must set these - there is no sane way to probe for this cable.
 *      You can use 'tipar=timeout,delay' to set these now. */
static int __init
tipar_setup(char *str)
{
	int ints[3];

	str = get_options(str, ARRAY_SIZE(ints), ints);

	if (ints[0] > 0) {
		if (ints[1] != 0)
                        timeout = ints[1];
                else
                        printk(KERN_WARNING "tipar: bad timeout value (0), "
				"using default value instead");
		if (ints[0] > 1) {
			delay = ints[2];
		}
	}

	return 1;
}
#endif

/*
 * Register our module into parport.
 * Pass also 2 callbacks functions to parport: a pre-emptive function and an
 * interrupt handler function (unused).
 * Display a message such "tipar0: using parport0 (polling)".
 */
static int
tipar_register(int nr, struct parport *port)
{
	int err = 0;

	/* Register our module into parport */
	table[nr].dev = parport_register_device(port, "tipar",
						NULL, NULL, NULL, 0,
						(void *) &table[nr]);

	if (table[nr].dev == NULL) {
		err = 1;
		goto out;
	}

	device_create(tipar_class, port->dev, MKDEV(TIPAR_MAJOR,
			TIPAR_MINOR + nr), "par%d", nr);

	/* Display informations */
	pr_info("tipar%d: using %s (%s)\n", nr, port->name, (port->irq ==
		PARPORT_IRQ_NONE) ? "polling" : "interrupt-driven");

	if (probe_ti_parallel(nr) != -1)
		pr_info("tipar%d: link cable found\n", nr);
	else
		pr_info("tipar%d: link cable not found\n", nr);

	err = 0;

out:
	return err;
}

static void
tipar_attach(struct parport *port)
{
	if (tp_count == PP_NO) {
		pr_info("tipar: ignoring parallel port (max. %d)\n", PP_NO);
		return;
	}

	if (!tipar_register(tp_count, port))
		tp_count++;
}

static void
tipar_detach(struct parport *port)
{
	/* Nothing to do */
}

static struct parport_driver tipar_driver = {
	.name = "tipar",
	.attach = tipar_attach,
	.detach = tipar_detach,
};

static int __init
tipar_init_module(void)
{
	int err = 0;

	pr_info("tipar: parallel link cable driver, version %s\n",
		DRIVER_VERSION);

	if (register_chrdev(TIPAR_MAJOR, "tipar", &tipar_fops)) {
		printk(KERN_ERR "tipar: unable to get major %d\n", TIPAR_MAJOR);
		err = -EIO;
		goto out;
	}

	tipar_class = class_create(THIS_MODULE, "ticables");
	if (IS_ERR(tipar_class)) {
		err = PTR_ERR(tipar_class);
		goto out_chrdev;
	}
	if (parport_register_driver(&tipar_driver)) {
		printk(KERN_ERR "tipar: unable to register with parport\n");
		err = -EIO;
		goto out_class;
	}

	err = 0;
	goto out;

out_class:
	class_destroy(tipar_class);

out_chrdev:
	unregister_chrdev(TIPAR_MAJOR, "tipar");
out:
	return err;	
}

static void __exit
tipar_cleanup_module(void)
{
	unsigned int i;

	/* Unregistering module */
	parport_unregister_driver(&tipar_driver);

	unregister_chrdev(TIPAR_MAJOR, "tipar");

	for (i = 0; i < PP_NO; i++) {
		if (table[i].dev == NULL)
			continue;
		parport_unregister_device(table[i].dev);
		device_destroy(tipar_class, MKDEV(TIPAR_MAJOR, i));
	}
	class_destroy(tipar_class);

	pr_info("tipar: module unloaded\n");
}

/* --------------------------------------------------------------------- */

__setup("tipar=", tipar_setup);
module_init(tipar_init_module);
module_exit(tipar_cleanup_module);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE(DRIVER_LICENSE);

module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Timeout (default=1.5 seconds)");
module_param(delay, int, 0);
MODULE_PARM_DESC(delay, "Inter-bit delay (default=10 microseconds)");
Commit	Line	Data
1da177e4 LT	1	/* Hey EMACS -- linux-c --
	2	*
	3	* tipar - low level driver for handling a parallel link cable designed
	4	* for Texas Instruments graphing calculators (http://lpg.ticalc.org).
	5	* A part of the TiLP project.
	6	*
	7	* Copyright (C) 2000-2002, Romain Lievin <roms@lpg.ticalc.org>
	8	* under the terms of the GNU General Public License.
	9	*
	10	* Various fixes & clean-up from the Linux Kernel Mailing List
	11	* (Alan Cox, Richard B. Johnson, Christoph Hellwig).
	12	*/
	13
	14	/* This driver should, in theory, work with any parallel port that has an
	15	* appropriate low-level driver; all I/O is done through the parport
	16	* abstraction layer.
	17	*
	18	* If this driver is built into the kernel, you can configure it using the
	19	* kernel command-line. For example:
	20	*
	21	* tipar=timeout,delay (set timeout and delay)
	22	*
	23	* If the driver is loaded as a module, similar functionality is available
	24	* using module parameters. The equivalent of the above commands would be:
	25	*
	26	* # insmod tipar timeout=15 delay=10
	27	*/
	28
	29	/* COMPATIBILITY WITH OLD KERNELS
	30	*
	31	* Usually, parallel cables were bound to ports at
	32	* particular I/O addresses, as follows:
	33	*
	34	* tipar0 0x378
	35	* tipar1 0x278
	36	* tipar2 0x3bc
	37	*
	38	*
	39	* This driver, by default, binds tipar devices according to parport and
	40	* the minor number.
	41	*
	42	*/
	43	#undef DEBUG /* change to #define to get debugging
	44	* output - for pr_debug() */
1da177e4 LT	45	#include <linux/module.h>
	46	#include <linux/types.h>
	47	#include <linux/errno.h>
	48	#include <linux/kernel.h>
	49	#include <linux/sched.h>
	50	#include <linux/delay.h>
	51	#include <linux/fcntl.h>
	52	#include <linux/fs.h>
	53	#include <linux/init.h>
	54	#include <asm/uaccess.h>
	55	#include <linux/ioport.h>
	56	#include <asm/io.h>
	57	#include <linux/bitops.h>
1da177e4 LT	58	#include <linux/parport.h> /* Our code depend on parport */
	59	#include <linux/device.h>
	60
	61	/*
	62	* TI definitions
	63	*/
	64	#include <linux/ticable.h>
	65
	66	/*
	67	* Version Information
	68	*/
	69	#define DRIVER_VERSION "1.19"
	70	#define DRIVER_AUTHOR "Romain Lievin <roms@lpg.ticalc.org>"
	71	#define DRIVER_DESC "Device driver for TI/PC parallel link cables"
	72	#define DRIVER_LICENSE "GPL"
	73
	74	#define VERSION(ver,rel,seq) (((ver)<<16) \| ((rel)<<8) \| (seq))
	75
	76	/* ----- global variables --------------------------------------------- */
	77
	78	struct tipar_struct {
	79	struct pardevice dev; / Parport device entry */
	80	};
	81
	82	#define PP_NO 3
	83	static struct tipar_struct table[PP_NO];
	84
	85	static int delay = IO_DELAY; /* inter-bit delay in microseconds */
	86	static int timeout = TIMAXTIME; /* timeout in tenth of seconds */
	87
	88	static unsigned int tp_count; /* tipar count */
	89	static unsigned long opened; /* opened devices */
	90
ca8eca68	91	static struct class *tipar_class;
1da177e4 LT	92
	93	/* --- macros for parport access -------------------------------------- */
	94
	95	#define r_dtr(x) (parport_read_data(table[(x)].dev->port))
	96	#define r_str(x) (parport_read_status(table[(x)].dev->port))
	97	#define w_ctr(x,y) (parport_write_control(table[(x)].dev->port, (y)))
	98	#define w_dtr(x,y) (parport_write_data(table[(x)].dev->port, (y)))
	99
	100	/* --- setting states on the D-bus with the right timing: ------------- */
	101
	102	static inline void
	103	outbyte(int value, int minor)
	104	{
	105	w_dtr(minor, value);
	106	}
	107
	108	static inline int
	109	inbyte(int minor)
	110	{
	111	return (r_str(minor));
	112	}
	113
	114	static inline void
	115	init_ti_parallel(int minor)
	116	{
	117	outbyte(3, minor);
	118	}
	119
	120	/* ----- global defines ----------------------------------------------- */
	121
	122	#define START(x) { x = jiffies + (HZ * timeout) / 10; }
	123	#define WAIT(x) { \
	124	if (time_before((x), jiffies)) return -1; \
	125	if (need_resched()) schedule(); }
	126
	127	/* ----- D-bus bit-banging functions ---------------------------------- */
	128
	129	/* D-bus protocol (45kbit/s max):
	130	1 0 0
	131	_______ ______\|______ __________\|________ __________
	132	Red : ________ \| ____ \| ____
	133	_ ____________\|________ ______\|__________ _____
	134	White: ________ \| ______ \| _______
	135	*/
	136
	137	/* Try to transmit a byte on the specified port (-1 if error). */
	138	static int
	139	put_ti_parallel(int minor, unsigned char data)
	140	{
	141	unsigned int bit;
	142	unsigned long max;
	143
	144	for (bit = 0; bit < 8; bit++) {
	145	if (data & 1) {
	146	outbyte(2, minor);
	147	START(max);
	148	do {
	149	WAIT(max);
	150	} while (inbyte(minor) & 0x10);
	151
	152	outbyte(3, minor);
	153	START(max);
	154	do {
	155	WAIT(max);
156	} while (!(inbyte(minor) & 0x10));
157	} else {
158	outbyte(1, minor);
159	START(max);
160	do {
161	WAIT(max);
162	} while (inbyte(minor) & 0x20);
163
164	outbyte(3, minor);
165	START(max);
166	do {
167	WAIT(max);
168	} while (!(inbyte(minor) & 0x20));
169	}
170
171	data >>= 1;
172	udelay(delay);
173
174	if (need_resched())
175	schedule();
176	}
177
178	return 0;
179	}
180
181	/* Receive a byte on the specified port or -1 if error. */
182	static int
183	get_ti_parallel(int minor)
184	{
185	unsigned int bit;
186	unsigned char v, data = 0;
187	unsigned long max;
188
189	for (bit = 0; bit < 8; bit++) {
190	START(max);
191	do {
192	WAIT(max);
193	} while ((v = inbyte(minor) & 0x30) == 0x30);
194
195	if (v == 0x10) {
196	data = (data >> 1) \| 0x80;
197	outbyte(1, minor);
198	START(max);
199	do {
200	WAIT(max);
201	} while (!(inbyte(minor) & 0x20));
202	outbyte(3, minor);
203	} else {
204	data = data >> 1;
205	outbyte(2, minor);
206	START(max);
207	do {
208	WAIT(max);
209	} while (!(inbyte(minor) & 0x10));
210	outbyte(3, minor);
211	}
212
213	udelay(delay);
214	if (need_resched())
215	schedule();
216	}
217
218	return (int) data;
219	}
220
221	/* Try to detect a parallel link cable on the specified port */
222	static int
223	probe_ti_parallel(int minor)
224	{
225	int i;
226	int seq[] = { 0x00, 0x20, 0x10, 0x30 };
5df0a29d	227	int data;
1da177e4 LT	228
	229	for (i = 3; i >= 0; i--) {
	230	outbyte(3, minor);
	231	outbyte(i, minor);
	232	udelay(delay);
5df0a29d	233	data = inbyte(minor) & 0x30;
1da177e4	234	pr_debug("tipar: Probing -> %i: 0x%02x 0x%02x\n", i,
5df0a29d ZB	235	data, seq[i]);
5df0a29d ZB	236	if (data != seq[i]) {
1da177e4 LT	237	outbyte(3, minor);
	238	return -1;
	239	}
	240	}
	241
	242	outbyte(3, minor);
	243	return 0;
	244	}
	245
	246	/* ----- kernel module functions--------------------------------------- */
	247
	248	static int
	249	tipar_open(struct inode inode, struct file file)
	250	{
	251	unsigned int minor = iminor(inode) - TIPAR_MINOR;
	252
1d308839	253	if (tp_count == 0 \|\| minor > tp_count - 1)
1da177e4 LT	254	return -ENXIO;
	255
	256	if (test_and_set_bit(minor, &opened))
	257	return -EBUSY;
	258
1d308839 AM	259	if (!table[minor].dev) {
	260	printk(KERN_ERR "%s: NULL device for minor %u\n",
	261	__FUNCTION__, minor);
	262	return -ENXIO;
	263	}
1da177e4 LT	264	parport_claim_or_block(table[minor].dev);
	265	init_ti_parallel(minor);
	266	parport_release(table[minor].dev);
	267
	268	return nonseekable_open(inode, file);
	269	}
	270
	271	static int
	272	tipar_close(struct inode inode, struct file file)
	273	{
	274	unsigned int minor = iminor(inode) - TIPAR_MINOR;
	275
	276	if (minor > tp_count - 1)
	277	return -ENXIO;
	278
	279	clear_bit(minor, &opened);
	280
	281	return 0;
	282	}
	283
	284	static ssize_t
	285	tipar_write (struct file file, const char __user buf, size_t count,
	286	loff_t * ppos)
	287	{
a7113a96	288	unsigned int minor = iminor(file->f_path.dentry->d_inode) - TIPAR_MINOR;
1da177e4 LT	289	ssize_t n;
	290
	291	parport_claim_or_block(table[minor].dev);
	292
	293	for (n = 0; n < count; n++) {
	294	unsigned char b;
	295
	296	if (get_user(b, buf + n)) {
	297	n = -EFAULT;
	298	goto out;
	299	}
	300
	301	if (put_ti_parallel(minor, b) == -1) {
	302	init_ti_parallel(minor);
	303	n = -ETIMEDOUT;
	304	goto out;
	305	}
	306	}
	307	out:
	308	parport_release(table[minor].dev);
	309	return n;
	310	}
	311
	312	static ssize_t
	313	tipar_read(struct file file, char __user buf, size_t count, loff_t * ppos)
	314	{
	315	int b = 0;
a7113a96	316	unsigned int minor = iminor(file->f_path.dentry->d_inode) - TIPAR_MINOR;
1da177e4 LT	317	ssize_t retval = 0;
	318	ssize_t n = 0;
	319
	320	if (count == 0)
	321	return 0;
	322
	323	parport_claim_or_block(table[minor].dev);
	324
	325	while (n < count) {
	326	b = get_ti_parallel(minor);
	327	if (b == -1) {
	328	init_ti_parallel(minor);
	329	retval = -ETIMEDOUT;
	330	goto out;
	331	} else {
	332	if (put_user(b, buf + n)) {
	333	retval = -EFAULT;
	334	break;
	335	} else
	336	retval = ++n;
	337	}
	338
	339	/* Non-blocking mode : try again ! */
	340	if (file->f_flags & O_NONBLOCK) {
	341	retval = -EAGAIN;
	342	goto out;
	343	}
	344
	345	/* Signal pending, try again ! */
	346	if (signal_pending(current)) {
	347	retval = -ERESTARTSYS;
	348	goto out;
	349	}
	350
	351	if (need_resched())
	352	schedule();
	353	}
	354
	355	out:
	356	parport_release(table[minor].dev);
	357	return retval;
	358	}
	359
	360	static int
	361	tipar_ioctl(struct inode inode, struct file file,
	362	unsigned int cmd, unsigned long arg)
	363	{
	364	int retval = 0;
	365
	366	switch (cmd) {
	367	case IOCTL_TIPAR_DELAY:
	368	delay = (int)arg; //get_user(delay, &arg);
	369	break;
	370	case IOCTL_TIPAR_TIMEOUT:
	371	if (arg != 0)
	372	timeout = (int)arg;
	373	else
	374	retval = -EINVAL;
	375	break;
	376	default:
	377	retval = -ENOTTY;
	378	break;
	379	}
	380
381	return retval;
382	}
383
384	/* ----- kernel module registering ------------------------------------ */
385
62322d25	386	static const struct file_operations tipar_fops = {
1da177e4 LT	387	.owner = THIS_MODULE,
	388	.llseek = no_llseek,
	389	.read = tipar_read,
	390	.write = tipar_write,
	391	.ioctl = tipar_ioctl,
	392	.open = tipar_open,
	393	.release = tipar_close,
	394	};
	395
	396	/* --- initialisation code ------------------------------------- */
	397
	398	#ifndef MODULE
	399	/* You must set these - there is no sane way to probe for this cable.
	400	* You can use 'tipar=timeout,delay' to set these now. */
	401	static int __init
	402	tipar_setup(char *str)
	403	{
45ae36cb	404	int ints[3];
1da177e4 LT	405
	406	str = get_options(str, ARRAY_SIZE(ints), ints);
	407
	408	if (ints[0] > 0) {
	409	if (ints[1] != 0)
	410	timeout = ints[1];
	411	else
	412	printk(KERN_WARNING "tipar: bad timeout value (0), "
	413	"using default value instead");
	414	if (ints[0] > 1) {
	415	delay = ints[2];
	416	}
	417	}
	418
	419	return 1;
	420	}
	421	#endif
	422
	423	/*
	424	* Register our module into parport.
	425	* Pass also 2 callbacks functions to parport: a pre-emptive function and an
	426	* interrupt handler function (unused).
	427	* Display a message such "tipar0: using parport0 (polling)".
	428	*/
	429	static int
	430	tipar_register(int nr, struct parport *port)
	431	{
	432	int err = 0;
	433
	434	/* Register our module into parport */
	435	table[nr].dev = parport_register_device(port, "tipar",
	436	NULL, NULL, NULL, 0,
	437	(void *) &table[nr]);
	438
	439	if (table[nr].dev == NULL) {
	440	err = 1;
	441	goto out;
	442	}
	443
07c015e7	444	device_create(tipar_class, port->dev, MKDEV(TIPAR_MAJOR,
07c015e7	445	TIPAR_MINOR + nr), "par%d", nr);
1da177e4 LT	446
	447	/* Display informations */
	448	pr_info("tipar%d: using %s (%s)\n", nr, port->name, (port->irq ==
	449	PARPORT_IRQ_NONE) ? "polling" : "interrupt-driven");
	450
	451	if (probe_ti_parallel(nr) != -1)
	452	pr_info("tipar%d: link cable found\n", nr);
	453	else
	454	pr_info("tipar%d: link cable not found\n", nr);
	455
	456	err = 0;
1da177e4	457
1da177e4 LT	458	out:
	459	return err;
	460	}
	461
	462	static void
	463	tipar_attach(struct parport *port)
	464	{
	465	if (tp_count == PP_NO) {
	466	pr_info("tipar: ignoring parallel port (max. %d)\n", PP_NO);
	467	return;
	468	}
	469
	470	if (!tipar_register(tp_count, port))
	471	tp_count++;
	472	}
	473
	474	static void
	475	tipar_detach(struct parport *port)
	476	{
	477	/* Nothing to do */
	478	}
	479
	480	static struct parport_driver tipar_driver = {
	481	.name = "tipar",
	482	.attach = tipar_attach,
	483	.detach = tipar_detach,
	484	};
	485
	486	static int __init
	487	tipar_init_module(void)
	488	{
	489	int err = 0;
	490
	491	pr_info("tipar: parallel link cable driver, version %s\n",
	492	DRIVER_VERSION);
	493
	494	if (register_chrdev(TIPAR_MAJOR, "tipar", &tipar_fops)) {
	495	printk(KERN_ERR "tipar: unable to get major %d\n", TIPAR_MAJOR);
	496	err = -EIO;
	497	goto out;
	498	}
	499
ca8eca68	500	tipar_class = class_create(THIS_MODULE, "ticables");
1da177e4 LT	501	if (IS_ERR(tipar_class)) {
	502	err = PTR_ERR(tipar_class);
	503	goto out_chrdev;
	504	}
1ac3836c	505	if (parport_register_driver(&tipar_driver)) {
1da177e4 LT	506	printk(KERN_ERR "tipar: unable to register with parport\n");
1da177e4 LT	507	err = -EIO;
1d308839	508	goto out_class;
1da177e4 LT	509	}
	510
	511	err = 0;
	512	goto out;
	513
1d308839 AM	514	out_class:
	515	class_destroy(tipar_class);
	516
1da177e4 LT	517	out_chrdev:
	518	unregister_chrdev(TIPAR_MAJOR, "tipar");
	519	out:
	520	return err;
	521	}
	522
	523	static void __exit
	524	tipar_cleanup_module(void)
	525	{
	526	unsigned int i;
	527
	528	/* Unregistering module */
	529	parport_unregister_driver(&tipar_driver);
	530
	531	unregister_chrdev(TIPAR_MAJOR, "tipar");
	532
	533	for (i = 0; i < PP_NO; i++) {
	534	if (table[i].dev == NULL)
	535	continue;
	536	parport_unregister_device(table[i].dev);
07c015e7	537	device_destroy(tipar_class, MKDEV(TIPAR_MAJOR, i));
1da177e4	538	}
ca8eca68	539	class_destroy(tipar_class);
1da177e4 LT	540
	541	pr_info("tipar: module unloaded\n");
	542	}
	543
	544	/* --------------------------------------------------------------------- */
	545
	546	__setup("tipar=", tipar_setup);
	547	module_init(tipar_init_module);
	548	module_exit(tipar_cleanup_module);
	549
	550	MODULE_AUTHOR(DRIVER_AUTHOR);
	551	MODULE_DESCRIPTION(DRIVER_DESC);
	552	MODULE_LICENSE(DRIVER_LICENSE);
	553
	554	module_param(timeout, int, 0);
	555	MODULE_PARM_DESC(timeout, "Timeout (default=1.5 seconds)");
	556	module_param(delay, int, 0);
	557	MODULE_PARM_DESC(delay, "Inter-bit delay (default=10 microseconds)");