[mirror_ubuntu-bionic-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 <asm/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>

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

	wake_up_interruptible(&serport->wait);
}

/*
 * 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;
	int i;

	spin_lock_irqsave(&serport->lock, flags);

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

	for (i = 0; i < count; i++) {
		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;
	char name[64];

	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, name));
	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, name));

	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;
}

/*
 * 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)
{
	struct serport *serport = (struct serport*) tty->disc_data;
	unsigned long type;

	if (cmd == SPIOCSTYPE) {
		if (get_user(type, (unsigned long __user *) arg))
			return -EFAULT;

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

		return 0;
	}

	return -EINVAL;
}

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,
	.receive_buf =	serport_ldisc_receive,
	.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
	16	#include <asm/uaccess.h>
	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>
	24
	25	MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
	26	MODULE_DESCRIPTION("Input device TTY line discipline");
	27	MODULE_LICENSE("GPL");
	28	MODULE_ALIAS_LDISC(N_MOUSE);
	29
	30	#define SERPORT_BUSY 1
1ff2c873 DT	31	#define SERPORT_ACTIVE 2
1ff2c873 DT	32	#define SERPORT_DEAD 3
1da177e4 LT	33
	34	struct serport {
	35	struct tty_struct *tty;
	36	wait_queue_head_t wait;
	37	struct serio *serio;
1ff2c873 DT	38	struct serio_device_id id;
1ff2c873 DT	39	spinlock_t lock;
1da177e4 LT	40	unsigned long flags;
	41	};
	42
	43	/*
	44	* Callback functions from the serio code.
	45	*/
	46
	47	static int serport_serio_write(struct serio *serio, unsigned char data)
	48	{
	49	struct serport *serport = serio->port_data;
f34d7a5b	50	return -(serport->tty->ops->write(serport->tty, &data, 1) != 1);
1da177e4 LT	51	}
1da177e4 LT	52
1ff2c873 DT	53	static int serport_serio_open(struct serio *serio)
	54	{
	55	struct serport *serport = serio->port_data;
	56	unsigned long flags;
	57
	58	spin_lock_irqsave(&serport->lock, flags);
	59	set_bit(SERPORT_ACTIVE, &serport->flags);
	60	spin_unlock_irqrestore(&serport->lock, flags);
	61
	62	return 0;
	63	}
	64
	65
1da177e4 LT	66	static void serport_serio_close(struct serio *serio)
	67	{
	68	struct serport *serport = serio->port_data;
1ff2c873 DT	69	unsigned long flags;
	70
	71	spin_lock_irqsave(&serport->lock, flags);
	72	clear_bit(SERPORT_ACTIVE, &serport->flags);
	73	set_bit(SERPORT_DEAD, &serport->flags);
	74	spin_unlock_irqrestore(&serport->lock, flags);
1da177e4	75
1da177e4 LT	76	wake_up_interruptible(&serport->wait);
	77	}
	78
	79	/*
	80	* serport_ldisc_open() is the routine that is called upon setting our line
	81	* discipline on a tty. It prepares the serio struct.
	82	*/
	83
	84	static int serport_ldisc_open(struct tty_struct *tty)
	85	{
	86	struct serport *serport;
1da177e4 LT	87
	88	if (!capable(CAP_SYS_ADMIN))
	89	return -EPERM;
	90
a97e148a	91	serport = kzalloc(sizeof(struct serport), GFP_KERNEL);
1ff2c873	92	if (!serport)
1da177e4	93	return -ENOMEM;
1da177e4	94
1da177e4	95	serport->tty = tty;
1ff2c873	96	spin_lock_init(&serport->lock);
1da177e4 LT	97	init_waitqueue_head(&serport->wait);
1da177e4 LT	98
1ff2c873	99	tty->disc_data = serport;
33f0f88f	100	tty->receive_room = 256;
1ff2c873 DT	101	set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
1ff2c873 DT	102
1da177e4 LT	103	return 0;
	104	}
	105
	106	/*
	107	* serport_ldisc_close() is the opposite of serport_ldisc_open()
	108	*/
	109
	110	static void serport_ldisc_close(struct tty_struct *tty)
	111	{
1ff2c873 DT	112	struct serport serport = (struct serport ) tty->disc_data;
1ff2c873 DT	113
1da177e4 LT	114	kfree(serport);
	115	}
	116
	117	/*
	118	* serport_ldisc_receive() is called by the low level tty driver when characters
48c27016 DE	119	* are ready for us. We forward the characters and flags, one by one to the
48c27016 DE	120	* 'interrupt' routine.
1da177e4 LT	121	*/
	122
	123	static void serport_ldisc_receive(struct tty_struct tty, const unsigned char cp, char *fp, int count)
	124	{
	125	struct serport serport = (struct serport) tty->disc_data;
1ff2c873	126	unsigned long flags;
48c27016	127	unsigned int ch_flags;
1da177e4	128	int i;
1ff2c873 DT	129
	130	spin_lock_irqsave(&serport->lock, flags);
	131
	132	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
	133	goto out;
	134
48c27016 DE	135	for (i = 0; i < count; i++) {
	136	switch (fp[i]) {
	137	case TTY_FRAME:
	138	ch_flags = SERIO_FRAME;
	139	break;
	140
	141	case TTY_PARITY:
	142	ch_flags = SERIO_PARITY;
	143	break;
	144
	145	default:
	146	ch_flags = 0;
	147	break;
	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	char name[64];
	168
	169	if (test_and_set_bit(SERPORT_BUSY, &serport->flags))
	170	return -EBUSY;
	171
a97e148a	172	serport->serio = serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
1ff2c873 DT	173	if (!serio)
	174	return -ENOMEM;
	175
	176	strlcpy(serio->name, "Serial port", sizeof(serio->name));
	177	snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty, name));
	178	serio->id = serport->id;
	179	serio->id.type = SERIO_RS232;
	180	serio->write = serport_serio_write;
	181	serio->open = serport_serio_open;
	182	serio->close = serport_serio_close;
	183	serio->port_data = serport;
de838a93	184	serio->dev.parent = tty->dev;
1ff2c873	185
1da177e4 LT	186	serio_register_port(serport->serio);
1da177e4 LT	187	printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty, name));
1ff2c873 DT	188
1ff2c873 DT	189	wait_event_interruptible(serport->wait, test_bit(SERPORT_DEAD, &serport->flags));
1da177e4	190	serio_unregister_port(serport->serio);
1ff2c873	191	serport->serio = NULL;
1da177e4	192
1ff2c873	193	clear_bit(SERPORT_DEAD, &serport->flags);
1da177e4 LT	194	clear_bit(SERPORT_BUSY, &serport->flags);
	195
	196	return 0;
	197	}
	198
	199	/*
	200	* serport_ldisc_ioctl() allows to set the port protocol, and device ID
	201	*/
	202
	203	static int serport_ldisc_ioctl(struct tty_struct * tty, struct file * file, unsigned int cmd, unsigned long arg)
	204	{
	205	struct serport serport = (struct serport) tty->disc_data;
1da177e4 LT	206	unsigned long type;
	207
	208	if (cmd == SPIOCSTYPE) {
	209	if (get_user(type, (unsigned long __user *) arg))
	210	return -EFAULT;
	211
1ff2c873 DT	212	serport->id.proto = type & 0x000000ff;
	213	serport->id.id = (type & 0x0000ff00) >> 8;
	214	serport->id.extra = (type & 0x00ff0000) >> 16;
1da177e4 LT	215
	216	return 0;
	217	}
	218
	219	return -EINVAL;
	220	}
	221
	222	static void serport_ldisc_write_wakeup(struct tty_struct * tty)
	223	{
1ff2c873 DT	224	struct serport serport = (struct serport ) tty->disc_data;
1ff2c873 DT	225	unsigned long flags;
1da177e4	226
1ff2c873 DT	227	spin_lock_irqsave(&serport->lock, flags);
	228	if (test_bit(SERPORT_ACTIVE, &serport->flags))
	229	serio_drv_write_wakeup(serport->serio);
	230	spin_unlock_irqrestore(&serport->lock, flags);
1da177e4 LT	231	}
	232
	233	/*
	234	* The line discipline structure.
	235	*/
	236
a352def2	237	static struct tty_ldisc_ops serport_ldisc = {
1da177e4 LT	238	.owner = THIS_MODULE,
	239	.name = "input",
	240	.open = serport_ldisc_open,
	241	.close = serport_ldisc_close,
	242	.read = serport_ldisc_read,
	243	.ioctl = serport_ldisc_ioctl,
	244	.receive_buf = serport_ldisc_receive,
1da177e4 LT	245	.write_wakeup = serport_ldisc_write_wakeup
	246	};
	247
	248	/*
	249	* The functions for insering/removing us as a module.
	250	*/
	251
	252	static int __init serport_init(void)
	253	{
	254	int retval;
	255	retval = tty_register_ldisc(N_MOUSE, &serport_ldisc);
	256	if (retval)
	257	printk(KERN_ERR "serport.c: Error registering line discipline.\n");
	258
	259	return retval;
	260	}
	261
	262	static void __exit serport_exit(void)
	263	{
64ccd715	264	tty_unregister_ldisc(N_MOUSE);
1da177e4 LT	265	}
	266
	267	module_init(serport_init);
	268	module_exit(serport_exit);