[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 = 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 u8 *cp,
				  const u8 *fp, size_t count)
{
	struct serport *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,
				  u8 *kbuf, size_t nr, void **cookie,
				  unsigned long offset)
{
	struct serport *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;

	strscpy(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, 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,
				       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 void serport_ldisc_hangup(struct tty_struct *tty)
{
	struct serport *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);
}

static void serport_ldisc_write_wakeup(struct tty_struct * tty)
{
	struct serport *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,
	.num =		N_MOUSE,
	.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(&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(&serport_ldisc);
}

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	{
ca1a8d2f	106	struct serport *serport = tty->disc_data;
1ff2c873	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
a8d9cd23	117	static void serport_ldisc_receive(struct tty_struct tty, const u8 cp,
892bc209	118	const u8 *fp, size_t count)
1da177e4	119	{
ca1a8d2f	120	struct serport *serport = tty->disc_data;
1ff2c873	121	unsigned long flags;
82f91fe0	122	unsigned int ch_flags = 0;
1da177e4	123	int i;
1ff2c873 DT	124
	125	spin_lock_irqsave(&serport->lock, flags);
	126
55db4c64	127	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
1ff2c873 DT	128	goto out;
1ff2c873 DT	129
48c27016	130	for (i = 0; i < count; i++) {
82f91fe0 PH	131	if (fp) {
	132	switch (fp[i]) {
	133	case TTY_FRAME:
	134	ch_flags = SERIO_FRAME;
	135	break;
	136
	137	case TTY_PARITY:
	138	ch_flags = SERIO_PARITY;
	139	break;
	140
	141	default:
	142	ch_flags = 0;
	143	break;
	144	}
48c27016 DE	145	}
	146
	147	serio_interrupt(serport->serio, cp[i], ch_flags);
	148	}
1ff2c873 DT	149
	150	out:
	151	spin_unlock_irqrestore(&serport->lock, flags);
1da177e4 LT	152	}
1da177e4 LT	153
1da177e4 LT	154	/*
	155	* serport_ldisc_read() just waits indefinitely if everything goes well.
	156	* However, when the serio driver closes the serio port, it finishes,
	157	* returning 0 characters.
	158	*/
	159
3b830a9c	160	static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file,
49b8220c JSS	161	u8 kbuf, size_t nr, void *cookie,
49b8220c JSS	162	unsigned long offset)
1da177e4	163	{
ca1a8d2f	164	struct serport *serport = tty->disc_data;
1ff2c873	165	struct serio *serio;
1da177e4 LT	166
	167	if (test_and_set_bit(SERPORT_BUSY, &serport->flags))
	168	return -EBUSY;
	169
a97e148a	170	serport->serio = serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
1ff2c873 DT	171	if (!serio)
	172	return -ENOMEM;
	173
a9f08ad7	174	strscpy(serio->name, "Serial port", sizeof(serio->name));
429b4749	175	snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty));
1ff2c873 DT	176	serio->id = serport->id;
	177	serio->id.type = SERIO_RS232;
	178	serio->write = serport_serio_write;
	179	serio->open = serport_serio_open;
	180	serio->close = serport_serio_close;
	181	serio->port_data = serport;
de838a93	182	serio->dev.parent = tty->dev;
1ff2c873	183
1da177e4	184	serio_register_port(serport->serio);
429b4749	185	printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty));
1ff2c873 DT	186
1ff2c873 DT	187	wait_event_interruptible(serport->wait, test_bit(SERPORT_DEAD, &serport->flags));
1da177e4	188	serio_unregister_port(serport->serio);
1ff2c873	189	serport->serio = NULL;
1da177e4	190
1ff2c873	191	clear_bit(SERPORT_DEAD, &serport->flags);
1da177e4 LT	192	clear_bit(SERPORT_BUSY, &serport->flags);
	193
	194	return 0;
	195	}
	196
a80d8b02 JS	197	static void serport_set_type(struct tty_struct *tty, unsigned long type)
	198	{
	199	struct serport *serport = tty->disc_data;
	200
	201	serport->id.proto = type & 0x000000ff;
	202	serport->id.id = (type & 0x0000ff00) >> 8;
	203	serport->id.extra = (type & 0x00ff0000) >> 16;
	204	}
	205
1da177e4 LT	206	/*
	207	* serport_ldisc_ioctl() allows to set the port protocol, and device ID
	208	*/
	209
d78328bc JS	210	static int serport_ldisc_ioctl(struct tty_struct *tty, unsigned int cmd,
d78328bc JS	211	unsigned long arg)
1da177e4	212	{
1da177e4	213	if (cmd == SPIOCSTYPE) {
a80d8b02 JS	214	unsigned long type;
a80d8b02 JS	215
1da177e4 LT	216	if (get_user(type, (unsigned long __user *) arg))
	217	return -EFAULT;
	218
a80d8b02 JS	219	serport_set_type(tty, type);
	220	return 0;
	221	}
	222
	223	return -EINVAL;
	224	}
	225
	226	#ifdef CONFIG_COMPAT
	227	#define COMPAT_SPIOCSTYPE _IOW('q', 0x01, compat_ulong_t)
f0193d3e	228	static int serport_ldisc_compat_ioctl(struct tty_struct *tty,
a80d8b02 JS	229	unsigned int cmd, unsigned long arg)
	230	{
	231	if (cmd == COMPAT_SPIOCSTYPE) {
	232	void __user *uarg = compat_ptr(arg);
	233	compat_ulong_t compat_type;
	234
	235	if (get_user(compat_type, (compat_ulong_t __user *)uarg))
	236	return -EFAULT;
1da177e4	237
a80d8b02	238	serport_set_type(tty, compat_type);
1da177e4 LT	239	return 0;
	240	}
	241
	242	return -EINVAL;
	243	}
a80d8b02	244	#endif
1da177e4	245
28f194da	246	static void serport_ldisc_hangup(struct tty_struct *tty)
51db0137	247	{
ca1a8d2f	248	struct serport *serport = tty->disc_data;
51db0137 HV	249	unsigned long flags;
	250
	251	spin_lock_irqsave(&serport->lock, flags);
	252	set_bit(SERPORT_DEAD, &serport->flags);
	253	spin_unlock_irqrestore(&serport->lock, flags);
	254
	255	wake_up_interruptible(&serport->wait);
51db0137 HV	256	}
51db0137 HV	257
1da177e4 LT	258	static void serport_ldisc_write_wakeup(struct tty_struct * tty)
1da177e4 LT	259	{
ca1a8d2f	260	struct serport *serport = tty->disc_data;
1ff2c873	261	unsigned long flags;
1da177e4	262
1ff2c873 DT	263	spin_lock_irqsave(&serport->lock, flags);
	264	if (test_bit(SERPORT_ACTIVE, &serport->flags))
	265	serio_drv_write_wakeup(serport->serio);
	266	spin_unlock_irqrestore(&serport->lock, flags);
1da177e4 LT	267	}
	268
	269	/*
	270	* The line discipline structure.
	271	*/
	272
a352def2	273	static struct tty_ldisc_ops serport_ldisc = {
1da177e4	274	.owner = THIS_MODULE,
fbadf70a	275	.num = N_MOUSE,
1da177e4 LT	276	.name = "input",
	277	.open = serport_ldisc_open,
	278	.close = serport_ldisc_close,
	279	.read = serport_ldisc_read,
	280	.ioctl = serport_ldisc_ioctl,
a80d8b02 JS	281	#ifdef CONFIG_COMPAT
	282	.compat_ioctl = serport_ldisc_compat_ioctl,
	283	#endif
1da177e4	284	.receive_buf = serport_ldisc_receive,
51db0137	285	.hangup = serport_ldisc_hangup,
1da177e4 LT	286	.write_wakeup = serport_ldisc_write_wakeup
	287	};
	288
	289	/*
	290	* The functions for insering/removing us as a module.
	291	*/
	292
	293	static int __init serport_init(void)
	294	{
	295	int retval;
fbadf70a	296	retval = tty_register_ldisc(&serport_ldisc);
1da177e4 LT	297	if (retval)
	298	printk(KERN_ERR "serport.c: Error registering line discipline.\n");
	299
	300	return retval;
	301	}
	302
	303	static void __exit serport_exit(void)
	304	{
f81ee8b8	305	tty_unregister_ldisc(&serport_ldisc);
1da177e4 LT	306	}
	307
	308	module_init(serport_init);
	309	module_exit(serport_exit);