[linux-2.6-block.git] / drivers / input / serio / serport.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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.
 */


#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 int 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
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	/*
	3	* Input device TTY line discipline
	4	*
	5	* Copyright (c) 1999-2002 Vojtech Pavlik
	6	*
	7	* This is a module that converts a tty line into a much simpler
	8	* 'serial io port' abstraction that the input device drivers use.
	9	*/
	10
1da177e4	11
7c0f6ba6	12	#include <linux/uaccess.h>
1da177e4	13	#include <linux/kernel.h>
d43c36dc	14	#include <linux/sched.h>
1da177e4 LT	15	#include <linux/slab.h>
	16	#include <linux/module.h>
	17	#include <linux/init.h>
	18	#include <linux/serio.h>
	19	#include <linux/tty.h>
a80d8b02	20	#include <linux/compat.h>
1da177e4 LT	21
	22	MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
	23	MODULE_DESCRIPTION("Input device TTY line discipline");
	24	MODULE_LICENSE("GPL");
	25	MODULE_ALIAS_LDISC(N_MOUSE);
	26
	27	#define SERPORT_BUSY 1
1ff2c873 DT	28	#define SERPORT_ACTIVE 2
1ff2c873 DT	29	#define SERPORT_DEAD 3
1da177e4 LT	30
	31	struct serport {
	32	struct tty_struct *tty;
	33	wait_queue_head_t wait;
	34	struct serio *serio;
1ff2c873 DT	35	struct serio_device_id id;
1ff2c873 DT	36	spinlock_t lock;
1da177e4 LT	37	unsigned long flags;
	38	};
	39
	40	/*
	41	* Callback functions from the serio code.
	42	*/
	43
	44	static int serport_serio_write(struct serio *serio, unsigned char data)
	45	{
	46	struct serport *serport = serio->port_data;
f34d7a5b	47	return -(serport->tty->ops->write(serport->tty, &data, 1) != 1);
1da177e4 LT	48	}
1da177e4 LT	49
1ff2c873 DT	50	static int serport_serio_open(struct serio *serio)
	51	{
	52	struct serport *serport = serio->port_data;
	53	unsigned long flags;
	54
	55	spin_lock_irqsave(&serport->lock, flags);
	56	set_bit(SERPORT_ACTIVE, &serport->flags);
	57	spin_unlock_irqrestore(&serport->lock, flags);
	58
	59	return 0;
	60	}
	61
	62
1da177e4 LT	63	static void serport_serio_close(struct serio *serio)
	64	{
	65	struct serport *serport = serio->port_data;
1ff2c873 DT	66	unsigned long flags;
	67
	68	spin_lock_irqsave(&serport->lock, flags);
	69	clear_bit(SERPORT_ACTIVE, &serport->flags);
1ff2c873	70	spin_unlock_irqrestore(&serport->lock, flags);
1da177e4 LT	71	}
	72
	73	/*
	74	* serport_ldisc_open() is the routine that is called upon setting our line
	75	* discipline on a tty. It prepares the serio struct.
	76	*/
	77
	78	static int serport_ldisc_open(struct tty_struct *tty)
	79	{
	80	struct serport *serport;
1da177e4 LT	81
	82	if (!capable(CAP_SYS_ADMIN))
	83	return -EPERM;
	84
a97e148a	85	serport = kzalloc(sizeof(struct serport), GFP_KERNEL);
1ff2c873	86	if (!serport)
1da177e4	87	return -ENOMEM;
1da177e4	88
1da177e4	89	serport->tty = tty;
1ff2c873	90	spin_lock_init(&serport->lock);
1da177e4 LT	91	init_waitqueue_head(&serport->wait);
1da177e4 LT	92
1ff2c873	93	tty->disc_data = serport;
33f0f88f	94	tty->receive_room = 256;
1ff2c873 DT	95	set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
1ff2c873 DT	96
1da177e4 LT	97	return 0;
	98	}
	99
	100	/*
	101	* serport_ldisc_close() is the opposite of serport_ldisc_open()
	102	*/
	103
	104	static void serport_ldisc_close(struct tty_struct *tty)
	105	{
1ff2c873 DT	106	struct serport serport = (struct serport ) tty->disc_data;
1ff2c873 DT	107
1da177e4 LT	108	kfree(serport);
	109	}
	110
	111	/*
	112	* serport_ldisc_receive() is called by the low level tty driver when characters
48c27016 DE	113	* are ready for us. We forward the characters and flags, one by one to the
48c27016 DE	114	* 'interrupt' routine.
1da177e4 LT	115	*/
1da177e4 LT	116
55db4c64	117	static void serport_ldisc_receive(struct tty_struct tty, const unsigned char cp, char *fp, int count)
1da177e4 LT	118	{
1da177e4 LT	119	struct serport serport = (struct serport) tty->disc_data;
1ff2c873	120	unsigned long flags;
82f91fe0	121	unsigned int ch_flags = 0;
1da177e4	122	int i;
1ff2c873 DT	123
	124	spin_lock_irqsave(&serport->lock, flags);
	125
55db4c64	126	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
1ff2c873 DT	127	goto out;
1ff2c873 DT	128
48c27016	129	for (i = 0; i < count; i++) {
82f91fe0 PH	130	if (fp) {
	131	switch (fp[i]) {
	132	case TTY_FRAME:
	133	ch_flags = SERIO_FRAME;
	134	break;
	135
	136	case TTY_PARITY:
	137	ch_flags = SERIO_PARITY;
	138	break;
	139
	140	default:
	141	ch_flags = 0;
	142	break;
	143	}
48c27016 DE	144	}
	145
	146	serio_interrupt(serport->serio, cp[i], ch_flags);
	147	}
1ff2c873 DT	148
	149	out:
	150	spin_unlock_irqrestore(&serport->lock, flags);
1da177e4 LT	151	}
1da177e4 LT	152
1da177e4 LT	153	/*
	154	* serport_ldisc_read() just waits indefinitely if everything goes well.
	155	* However, when the serio driver closes the serio port, it finishes,
	156	* returning 0 characters.
	157	*/
	158
	159	static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, unsigned char __user * buf, size_t nr)
	160	{
	161	struct serport serport = (struct serport) tty->disc_data;
1ff2c873	162	struct serio *serio;
1da177e4 LT	163
	164	if (test_and_set_bit(SERPORT_BUSY, &serport->flags))
	165	return -EBUSY;
	166
a97e148a	167	serport->serio = serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
1ff2c873 DT	168	if (!serio)
	169	return -ENOMEM;
	170
	171	strlcpy(serio->name, "Serial port", sizeof(serio->name));
429b4749	172	snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty));
1ff2c873 DT	173	serio->id = serport->id;
	174	serio->id.type = SERIO_RS232;
	175	serio->write = serport_serio_write;
	176	serio->open = serport_serio_open;
	177	serio->close = serport_serio_close;
	178	serio->port_data = serport;
de838a93	179	serio->dev.parent = tty->dev;
1ff2c873	180
1da177e4	181	serio_register_port(serport->serio);
429b4749	182	printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty));
1ff2c873 DT	183
1ff2c873 DT	184	wait_event_interruptible(serport->wait, test_bit(SERPORT_DEAD, &serport->flags));
1da177e4	185	serio_unregister_port(serport->serio);
1ff2c873	186	serport->serio = NULL;
1da177e4	187
1ff2c873	188	clear_bit(SERPORT_DEAD, &serport->flags);
1da177e4 LT	189	clear_bit(SERPORT_BUSY, &serport->flags);
	190
	191	return 0;
	192	}
	193
a80d8b02 JS	194	static void serport_set_type(struct tty_struct *tty, unsigned long type)
	195	{
	196	struct serport *serport = tty->disc_data;
	197
	198	serport->id.proto = type & 0x000000ff;
	199	serport->id.id = (type & 0x0000ff00) >> 8;
	200	serport->id.extra = (type & 0x00ff0000) >> 16;
	201	}
	202
1da177e4 LT	203	/*
	204	* serport_ldisc_ioctl() allows to set the port protocol, and device ID
	205	*/
	206
a80d8b02 JS	207	static int serport_ldisc_ioctl(struct tty_struct tty, struct file file,
a80d8b02 JS	208	unsigned int cmd, unsigned long arg)
1da177e4	209	{
1da177e4	210	if (cmd == SPIOCSTYPE) {
a80d8b02 JS	211	unsigned long type;
a80d8b02 JS	212
1da177e4 LT	213	if (get_user(type, (unsigned long __user *) arg))
	214	return -EFAULT;
	215
a80d8b02 JS	216	serport_set_type(tty, type);
	217	return 0;
	218	}
	219
	220	return -EINVAL;
	221	}
	222
	223	#ifdef CONFIG_COMPAT
	224	#define COMPAT_SPIOCSTYPE _IOW('q', 0x01, compat_ulong_t)
f0193d3e	225	static int serport_ldisc_compat_ioctl(struct tty_struct *tty,
a80d8b02 JS	226	struct file *file,
	227	unsigned int cmd, unsigned long arg)
	228	{
	229	if (cmd == COMPAT_SPIOCSTYPE) {
	230	void __user *uarg = compat_ptr(arg);
	231	compat_ulong_t compat_type;
	232
	233	if (get_user(compat_type, (compat_ulong_t __user *)uarg))
	234	return -EFAULT;
1da177e4	235
a80d8b02	236	serport_set_type(tty, compat_type);
1da177e4 LT	237	return 0;
	238	}
	239
	240	return -EINVAL;
	241	}
a80d8b02	242	#endif
1da177e4	243
51db0137 HV	244	static int serport_ldisc_hangup(struct tty_struct *tty)
	245	{
	246	struct serport serport = (struct serport ) tty->disc_data;
	247	unsigned long flags;
	248
	249	spin_lock_irqsave(&serport->lock, flags);
	250	set_bit(SERPORT_DEAD, &serport->flags);
	251	spin_unlock_irqrestore(&serport->lock, flags);
	252
	253	wake_up_interruptible(&serport->wait);
	254	return 0;
	255	}
	256
1da177e4 LT	257	static void serport_ldisc_write_wakeup(struct tty_struct * tty)
1da177e4 LT	258	{
1ff2c873 DT	259	struct serport serport = (struct serport ) tty->disc_data;
1ff2c873 DT	260	unsigned long flags;
1da177e4	261
1ff2c873 DT	262	spin_lock_irqsave(&serport->lock, flags);
	263	if (test_bit(SERPORT_ACTIVE, &serport->flags))
	264	serio_drv_write_wakeup(serport->serio);
	265	spin_unlock_irqrestore(&serport->lock, flags);
1da177e4 LT	266	}
	267
	268	/*
	269	* The line discipline structure.
	270	*/
	271
a352def2	272	static struct tty_ldisc_ops serport_ldisc = {
1da177e4 LT	273	.owner = THIS_MODULE,
	274	.name = "input",
	275	.open = serport_ldisc_open,
	276	.close = serport_ldisc_close,
	277	.read = serport_ldisc_read,
	278	.ioctl = serport_ldisc_ioctl,
a80d8b02 JS	279	#ifdef CONFIG_COMPAT
	280	.compat_ioctl = serport_ldisc_compat_ioctl,
	281	#endif
1da177e4	282	.receive_buf = serport_ldisc_receive,
51db0137	283	.hangup = serport_ldisc_hangup,
1da177e4 LT	284	.write_wakeup = serport_ldisc_write_wakeup
	285	};
	286
	287	/*
	288	* The functions for insering/removing us as a module.
	289	*/
	290
	291	static int __init serport_init(void)
	292	{
	293	int retval;
	294	retval = tty_register_ldisc(N_MOUSE, &serport_ldisc);
	295	if (retval)
	296	printk(KERN_ERR "serport.c: Error registering line discipline.\n");
	297
	298	return retval;
	299	}
	300
	301	static void __exit serport_exit(void)
	302	{
64ccd715	303	tty_unregister_ldisc(N_MOUSE);
1da177e4 LT	304	}
	305
	306	module_init(serport_init);
	307	module_exit(serport_exit);