[mirror_ubuntu-zesty-kernel.git] / drivers / input / serio / serport.c

/*
 * Input device TTY line discipline
 *
 * Copyright (c) 1999-2002 Vojtech Pavlik
 *
 * This is a module that converts a tty line into a much simpler
 * 'serial io port' abstraction that the input device drivers use.
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

#include <linux/uaccess.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/serio.h>
#include <linux/tty.h>
#include <linux/compat.h>

MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("Input device TTY line discipline");
MODULE_LICENSE("GPL");
MODULE_ALIAS_LDISC(N_MOUSE);

#define SERPORT_BUSY	1
#define SERPORT_ACTIVE	2
#define SERPORT_DEAD	3

struct serport {
	struct tty_struct *tty;
	wait_queue_head_t wait;
	struct serio *serio;
	struct serio_device_id id;
	spinlock_t lock;
	unsigned long flags;
};

/*
 * Callback functions from the serio code.
 */

static int serport_serio_write(struct serio *serio, unsigned char data)
{
	struct serport *serport = serio->port_data;
	return -(serport->tty->ops->write(serport->tty, &data, 1) != 1);
}

static int serport_serio_open(struct serio *serio)
{
	struct serport *serport = serio->port_data;
	unsigned long flags;

	spin_lock_irqsave(&serport->lock, flags);
	set_bit(SERPORT_ACTIVE, &serport->flags);
	spin_unlock_irqrestore(&serport->lock, flags);

	return 0;
}


static void serport_serio_close(struct serio *serio)
{
	struct serport *serport = serio->port_data;
	unsigned long flags;

	spin_lock_irqsave(&serport->lock, flags);
	clear_bit(SERPORT_ACTIVE, &serport->flags);
	spin_unlock_irqrestore(&serport->lock, flags);
}

/*
 * serport_ldisc_open() is the routine that is called upon setting our line
 * discipline on a tty. It prepares the serio struct.
 */

static int serport_ldisc_open(struct tty_struct *tty)
{
	struct serport *serport;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	serport = kzalloc(sizeof(struct serport), GFP_KERNEL);
	if (!serport)
		return -ENOMEM;

	serport->tty = tty;
	spin_lock_init(&serport->lock);
	init_waitqueue_head(&serport->wait);

	tty->disc_data = serport;
	tty->receive_room = 256;
	set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);

	return 0;
}

/*
 * serport_ldisc_close() is the opposite of serport_ldisc_open()
 */

static void serport_ldisc_close(struct tty_struct *tty)
{
	struct serport *serport = (struct serport *) tty->disc_data;

	kfree(serport);
}

/*
 * serport_ldisc_receive() is called by the low level tty driver when characters
 * are ready for us. We forward the characters and flags, one by one to the
 * 'interrupt' routine.
 */

static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *cp, char *fp, int count)
{
	struct serport *serport = (struct serport*) tty->disc_data;
	unsigned long flags;
	unsigned int ch_flags = 0;
	int i;

	spin_lock_irqsave(&serport->lock, flags);

	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
		goto out;

	for (i = 0; i < count; i++) {
		if (fp) {
			switch (fp[i]) {
			case TTY_FRAME:
				ch_flags = SERIO_FRAME;
				break;

			case TTY_PARITY:
				ch_flags = SERIO_PARITY;
				break;

			default:
				ch_flags = 0;
				break;
			}
		}

		serio_interrupt(serport->serio, cp[i], ch_flags);
	}

out:
	spin_unlock_irqrestore(&serport->lock, flags);
}

/*
 * serport_ldisc_read() just waits indefinitely if everything goes well.
 * However, when the serio driver closes the serio port, it finishes,
 * returning 0 characters.
 */

static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, unsigned char __user * buf, size_t nr)
{
	struct serport *serport = (struct serport*) tty->disc_data;
	struct serio *serio;

	if (test_and_set_bit(SERPORT_BUSY, &serport->flags))
		return -EBUSY;

	serport->serio = serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
	if (!serio)
		return -ENOMEM;

	strlcpy(serio->name, "Serial port", sizeof(serio->name));
	snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty));
	serio->id = serport->id;
	serio->id.type = SERIO_RS232;
	serio->write = serport_serio_write;
	serio->open = serport_serio_open;
	serio->close = serport_serio_close;
	serio->port_data = serport;
	serio->dev.parent = tty->dev;

	serio_register_port(serport->serio);
	printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty));

	wait_event_interruptible(serport->wait, test_bit(SERPORT_DEAD, &serport->flags));
	serio_unregister_port(serport->serio);
	serport->serio = NULL;

	clear_bit(SERPORT_DEAD, &serport->flags);
	clear_bit(SERPORT_BUSY, &serport->flags);

	return 0;
}

static void serport_set_type(struct tty_struct *tty, unsigned long type)
{
	struct serport *serport = tty->disc_data;

	serport->id.proto = type & 0x000000ff;
	serport->id.id    = (type & 0x0000ff00) >> 8;
	serport->id.extra = (type & 0x00ff0000) >> 16;
}

/*
 * serport_ldisc_ioctl() allows to set the port protocol, and device ID
 */

static int serport_ldisc_ioctl(struct tty_struct *tty, struct file *file,
			       unsigned int cmd, unsigned long arg)
{
	if (cmd == SPIOCSTYPE) {
		unsigned long type;

		if (get_user(type, (unsigned long __user *) arg))
			return -EFAULT;

		serport_set_type(tty, type);
		return 0;
	}

	return -EINVAL;
}

#ifdef CONFIG_COMPAT
#define COMPAT_SPIOCSTYPE	_IOW('q', 0x01, compat_ulong_t)
static long serport_ldisc_compat_ioctl(struct tty_struct *tty,
				       struct file *file,
				       unsigned int cmd, unsigned long arg)
{
	if (cmd == COMPAT_SPIOCSTYPE) {
		void __user *uarg = compat_ptr(arg);
		compat_ulong_t compat_type;

		if (get_user(compat_type, (compat_ulong_t __user *)uarg))
			return -EFAULT;

		serport_set_type(tty, compat_type);
		return 0;
	}

	return -EINVAL;
}
#endif

static int serport_ldisc_hangup(struct tty_struct *tty)
{
	struct serport *serport = (struct serport *) tty->disc_data;
	unsigned long flags;

	spin_lock_irqsave(&serport->lock, flags);
	set_bit(SERPORT_DEAD, &serport->flags);
	spin_unlock_irqrestore(&serport->lock, flags);

	wake_up_interruptible(&serport->wait);
	return 0;
}

static void serport_ldisc_write_wakeup(struct tty_struct * tty)
{
	struct serport *serport = (struct serport *) tty->disc_data;
	unsigned long flags;

	spin_lock_irqsave(&serport->lock, flags);
	if (test_bit(SERPORT_ACTIVE, &serport->flags))
		serio_drv_write_wakeup(serport->serio);
	spin_unlock_irqrestore(&serport->lock, flags);
}

/*
 * The line discipline structure.
 */

static struct tty_ldisc_ops serport_ldisc = {
	.owner =	THIS_MODULE,
	.name =		"input",
	.open =		serport_ldisc_open,
	.close =	serport_ldisc_close,
	.read =		serport_ldisc_read,
	.ioctl =	serport_ldisc_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl =	serport_ldisc_compat_ioctl,
#endif
	.receive_buf =	serport_ldisc_receive,
	.hangup =	serport_ldisc_hangup,
	.write_wakeup =	serport_ldisc_write_wakeup
};

/*
 * The functions for insering/removing us as a module.
 */

static int __init serport_init(void)
{
	int retval;
	retval = tty_register_ldisc(N_MOUSE, &serport_ldisc);
	if (retval)
		printk(KERN_ERR "serport.c: Error registering line discipline.\n");

	return  retval;
}

static void __exit serport_exit(void)
{
	tty_unregister_ldisc(N_MOUSE);
}

module_init(serport_init);
module_exit(serport_exit);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Input device TTY line discipline
	3	*
	4	* Copyright (c) 1999-2002 Vojtech Pavlik
	5	*
	6	* This is a module that converts a tty line into a much simpler
	7	* 'serial io port' abstraction that the input device drivers use.
	8	*/
	9
	10	/*
	11	* This program is free software; you can redistribute it and/or modify it
	12	* under the terms of the GNU General Public License version 2 as published by
	13	* the Free Software Foundation.
	14	*/
	15
7c0f6ba6	16	#include <linux/uaccess.h>
1da177e4	17	#include <linux/kernel.h>
d43c36dc	18	#include <linux/sched.h>
1da177e4 LT	19	#include <linux/slab.h>
	20	#include <linux/module.h>
	21	#include <linux/init.h>
	22	#include <linux/serio.h>
	23	#include <linux/tty.h>
a80d8b02	24	#include <linux/compat.h>
1da177e4 LT	25
	26	MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
	27	MODULE_DESCRIPTION("Input device TTY line discipline");
	28	MODULE_LICENSE("GPL");
	29	MODULE_ALIAS_LDISC(N_MOUSE);
	30
	31	#define SERPORT_BUSY 1
1ff2c873 DT	32	#define SERPORT_ACTIVE 2
1ff2c873 DT	33	#define SERPORT_DEAD 3
1da177e4 LT	34
	35	struct serport {
	36	struct tty_struct *tty;
	37	wait_queue_head_t wait;
	38	struct serio *serio;
1ff2c873 DT	39	struct serio_device_id id;
1ff2c873 DT	40	spinlock_t lock;
1da177e4 LT	41	unsigned long flags;
	42	};
	43
	44	/*
	45	* Callback functions from the serio code.
	46	*/
	47
	48	static int serport_serio_write(struct serio *serio, unsigned char data)
	49	{
	50	struct serport *serport = serio->port_data;
f34d7a5b	51	return -(serport->tty->ops->write(serport->tty, &data, 1) != 1);
1da177e4 LT	52	}
1da177e4 LT	53
1ff2c873 DT	54	static int serport_serio_open(struct serio *serio)
	55	{
	56	struct serport *serport = serio->port_data;
	57	unsigned long flags;
	58
	59	spin_lock_irqsave(&serport->lock, flags);
	60	set_bit(SERPORT_ACTIVE, &serport->flags);
	61	spin_unlock_irqrestore(&serport->lock, flags);
	62
	63	return 0;
	64	}
	65
	66
1da177e4 LT	67	static void serport_serio_close(struct serio *serio)
	68	{
	69	struct serport *serport = serio->port_data;
1ff2c873 DT	70	unsigned long flags;
	71
	72	spin_lock_irqsave(&serport->lock, flags);
	73	clear_bit(SERPORT_ACTIVE, &serport->flags);
1ff2c873	74	spin_unlock_irqrestore(&serport->lock, flags);
1da177e4 LT	75	}
	76
	77	/*
	78	* serport_ldisc_open() is the routine that is called upon setting our line
	79	* discipline on a tty. It prepares the serio struct.
	80	*/
	81
	82	static int serport_ldisc_open(struct tty_struct *tty)
	83	{
	84	struct serport *serport;
1da177e4 LT	85
	86	if (!capable(CAP_SYS_ADMIN))
	87	return -EPERM;
	88
a97e148a	89	serport = kzalloc(sizeof(struct serport), GFP_KERNEL);
1ff2c873	90	if (!serport)
1da177e4	91	return -ENOMEM;
1da177e4	92
1da177e4	93	serport->tty = tty;
1ff2c873	94	spin_lock_init(&serport->lock);
1da177e4 LT	95	init_waitqueue_head(&serport->wait);
1da177e4 LT	96
1ff2c873	97	tty->disc_data = serport;
33f0f88f	98	tty->receive_room = 256;
1ff2c873 DT	99	set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
1ff2c873 DT	100
1da177e4 LT	101	return 0;
	102	}
	103
	104	/*
	105	* serport_ldisc_close() is the opposite of serport_ldisc_open()
	106	*/
	107
	108	static void serport_ldisc_close(struct tty_struct *tty)
	109	{
1ff2c873 DT	110	struct serport serport = (struct serport ) tty->disc_data;
1ff2c873 DT	111
1da177e4 LT	112	kfree(serport);
	113	}
	114
	115	/*
	116	* serport_ldisc_receive() is called by the low level tty driver when characters
48c27016 DE	117	* are ready for us. We forward the characters and flags, one by one to the
48c27016 DE	118	* 'interrupt' routine.
1da177e4 LT	119	*/
1da177e4 LT	120
55db4c64	121	static void serport_ldisc_receive(struct tty_struct tty, const unsigned char cp, char *fp, int count)
1da177e4 LT	122	{
1da177e4 LT	123	struct serport serport = (struct serport) tty->disc_data;
1ff2c873	124	unsigned long flags;
82f91fe0	125	unsigned int ch_flags = 0;
1da177e4	126	int i;
1ff2c873 DT	127
	128	spin_lock_irqsave(&serport->lock, flags);
	129
55db4c64	130	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
1ff2c873 DT	131	goto out;
1ff2c873 DT	132
48c27016	133	for (i = 0; i < count; i++) {
82f91fe0 PH	134	if (fp) {
	135	switch (fp[i]) {
	136	case TTY_FRAME:
	137	ch_flags = SERIO_FRAME;
	138	break;
	139
	140	case TTY_PARITY:
	141	ch_flags = SERIO_PARITY;
	142	break;
	143
	144	default:
	145	ch_flags = 0;
	146	break;
	147	}
48c27016 DE	148	}
	149
	150	serio_interrupt(serport->serio, cp[i], ch_flags);
	151	}
1ff2c873 DT	152
	153	out:
	154	spin_unlock_irqrestore(&serport->lock, flags);
1da177e4 LT	155	}
1da177e4 LT	156
1da177e4 LT	157	/*
	158	* serport_ldisc_read() just waits indefinitely if everything goes well.
	159	* However, when the serio driver closes the serio port, it finishes,
	160	* returning 0 characters.
	161	*/
	162
	163	static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, unsigned char __user * buf, size_t nr)
	164	{
	165	struct serport serport = (struct serport) tty->disc_data;
1ff2c873	166	struct serio *serio;
1da177e4 LT	167
	168	if (test_and_set_bit(SERPORT_BUSY, &serport->flags))
	169	return -EBUSY;
	170
a97e148a	171	serport->serio = serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
1ff2c873 DT	172	if (!serio)
	173	return -ENOMEM;
	174
	175	strlcpy(serio->name, "Serial port", sizeof(serio->name));
429b4749	176	snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty));
1ff2c873 DT	177	serio->id = serport->id;
	178	serio->id.type = SERIO_RS232;
	179	serio->write = serport_serio_write;
	180	serio->open = serport_serio_open;
	181	serio->close = serport_serio_close;
	182	serio->port_data = serport;
de838a93	183	serio->dev.parent = tty->dev;
1ff2c873	184
1da177e4	185	serio_register_port(serport->serio);
429b4749	186	printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty));
1ff2c873 DT	187
1ff2c873 DT	188	wait_event_interruptible(serport->wait, test_bit(SERPORT_DEAD, &serport->flags));
1da177e4	189	serio_unregister_port(serport->serio);
1ff2c873	190	serport->serio = NULL;
1da177e4	191
1ff2c873	192	clear_bit(SERPORT_DEAD, &serport->flags);
1da177e4 LT	193	clear_bit(SERPORT_BUSY, &serport->flags);
	194
	195	return 0;
	196	}
	197
a80d8b02 JS	198	static void serport_set_type(struct tty_struct *tty, unsigned long type)
	199	{
	200	struct serport *serport = tty->disc_data;
	201
	202	serport->id.proto = type & 0x000000ff;
	203	serport->id.id = (type & 0x0000ff00) >> 8;
	204	serport->id.extra = (type & 0x00ff0000) >> 16;
	205	}
	206
1da177e4 LT	207	/*
	208	* serport_ldisc_ioctl() allows to set the port protocol, and device ID
	209	*/
	210
a80d8b02 JS	211	static int serport_ldisc_ioctl(struct tty_struct tty, struct file file,
a80d8b02 JS	212	unsigned int cmd, unsigned long arg)
1da177e4	213	{
1da177e4	214	if (cmd == SPIOCSTYPE) {
a80d8b02 JS	215	unsigned long type;
a80d8b02 JS	216
1da177e4 LT	217	if (get_user(type, (unsigned long __user *) arg))
	218	return -EFAULT;
	219
a80d8b02 JS	220	serport_set_type(tty, type);
	221	return 0;
	222	}
	223
	224	return -EINVAL;
	225	}
	226
	227	#ifdef CONFIG_COMPAT
	228	#define COMPAT_SPIOCSTYPE _IOW('q', 0x01, compat_ulong_t)
	229	static long serport_ldisc_compat_ioctl(struct tty_struct *tty,
	230	struct file *file,
	231	unsigned int cmd, unsigned long arg)
	232	{
	233	if (cmd == COMPAT_SPIOCSTYPE) {
	234	void __user *uarg = compat_ptr(arg);
	235	compat_ulong_t compat_type;
	236
	237	if (get_user(compat_type, (compat_ulong_t __user *)uarg))
	238	return -EFAULT;
1da177e4	239
a80d8b02	240	serport_set_type(tty, compat_type);
1da177e4 LT	241	return 0;
	242	}
	243
	244	return -EINVAL;
	245	}
a80d8b02	246	#endif
1da177e4	247
51db0137 HV	248	static int serport_ldisc_hangup(struct tty_struct *tty)
	249	{
	250	struct serport serport = (struct serport ) tty->disc_data;
	251	unsigned long flags;
	252
	253	spin_lock_irqsave(&serport->lock, flags);
	254	set_bit(SERPORT_DEAD, &serport->flags);
	255	spin_unlock_irqrestore(&serport->lock, flags);
	256
	257	wake_up_interruptible(&serport->wait);
	258	return 0;
	259	}
	260
1da177e4 LT	261	static void serport_ldisc_write_wakeup(struct tty_struct * tty)
1da177e4 LT	262	{
1ff2c873 DT	263	struct serport serport = (struct serport ) tty->disc_data;
1ff2c873 DT	264	unsigned long flags;
1da177e4	265
1ff2c873 DT	266	spin_lock_irqsave(&serport->lock, flags);
	267	if (test_bit(SERPORT_ACTIVE, &serport->flags))
	268	serio_drv_write_wakeup(serport->serio);
	269	spin_unlock_irqrestore(&serport->lock, flags);
1da177e4 LT	270	}
	271
	272	/*
	273	* The line discipline structure.
	274	*/
	275
a352def2	276	static struct tty_ldisc_ops serport_ldisc = {
1da177e4 LT	277	.owner = THIS_MODULE,
	278	.name = "input",
	279	.open = serport_ldisc_open,
	280	.close = serport_ldisc_close,
	281	.read = serport_ldisc_read,
	282	.ioctl = serport_ldisc_ioctl,
a80d8b02 JS	283	#ifdef CONFIG_COMPAT
	284	.compat_ioctl = serport_ldisc_compat_ioctl,
	285	#endif
1da177e4	286	.receive_buf = serport_ldisc_receive,
51db0137	287	.hangup = serport_ldisc_hangup,
1da177e4 LT	288	.write_wakeup = serport_ldisc_write_wakeup
	289	};
	290
	291	/*
	292	* The functions for insering/removing us as a module.
	293	*/
	294
	295	static int __init serport_init(void)
	296	{
	297	int retval;
	298	retval = tty_register_ldisc(N_MOUSE, &serport_ldisc);
	299	if (retval)
	300	printk(KERN_ERR "serport.c: Error registering line discipline.\n");
	301
	302	return retval;
	303	}
	304
	305	static void __exit serport_exit(void)
	306	{
64ccd715	307	tty_unregister_ldisc(N_MOUSE);
1da177e4 LT	308	}
	309
	310	module_init(serport_init);
	311	module_exit(serport_exit);