11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * Input device TTY line discipline 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Copyright (c) 1999-2002 Vojtech Pavlik 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * This is a module that converts a tty line into a much simpler 71da177e4SLinus Torvalds * 'serial io port' abstraction that the input device drivers use. 81da177e4SLinus Torvalds */ 91da177e4SLinus Torvalds 101da177e4SLinus Torvalds /* 111da177e4SLinus Torvalds * This program is free software; you can redistribute it and/or modify it 121da177e4SLinus Torvalds * under the terms of the GNU General Public License version 2 as published by 131da177e4SLinus Torvalds * the Free Software Foundation. 141da177e4SLinus Torvalds */ 151da177e4SLinus Torvalds 161da177e4SLinus Torvalds #include <asm/uaccess.h> 171da177e4SLinus Torvalds #include <linux/kernel.h> 18d43c36dcSAlexey Dobriyan #include <linux/sched.h> 191da177e4SLinus Torvalds #include <linux/slab.h> 201da177e4SLinus Torvalds #include <linux/module.h> 211da177e4SLinus Torvalds #include <linux/init.h> 221da177e4SLinus Torvalds #include <linux/serio.h> 231da177e4SLinus Torvalds #include <linux/tty.h> 24a80d8b02SJohn Sung #include <linux/compat.h> 251da177e4SLinus Torvalds 261da177e4SLinus Torvalds MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>"); 271da177e4SLinus Torvalds MODULE_DESCRIPTION("Input device TTY line discipline"); 281da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 291da177e4SLinus Torvalds MODULE_ALIAS_LDISC(N_MOUSE); 301da177e4SLinus Torvalds 311da177e4SLinus Torvalds #define SERPORT_BUSY 1 321ff2c873SDmitry Torokhov #define SERPORT_ACTIVE 2 331ff2c873SDmitry Torokhov #define SERPORT_DEAD 3 341da177e4SLinus Torvalds 351da177e4SLinus Torvalds struct serport { 361da177e4SLinus Torvalds struct tty_struct *tty; 371da177e4SLinus Torvalds wait_queue_head_t wait; 381da177e4SLinus Torvalds struct serio *serio; 391ff2c873SDmitry Torokhov struct serio_device_id id; 401ff2c873SDmitry Torokhov spinlock_t lock; 411da177e4SLinus Torvalds unsigned long flags; 421da177e4SLinus Torvalds }; 431da177e4SLinus Torvalds 441da177e4SLinus Torvalds /* 451da177e4SLinus Torvalds * Callback functions from the serio code. 461da177e4SLinus Torvalds */ 471da177e4SLinus Torvalds 481da177e4SLinus Torvalds static int serport_serio_write(struct serio *serio, unsigned char data) 491da177e4SLinus Torvalds { 501da177e4SLinus Torvalds struct serport *serport = serio->port_data; 51f34d7a5bSAlan Cox return -(serport->tty->ops->write(serport->tty, &data, 1) != 1); 521da177e4SLinus Torvalds } 531da177e4SLinus Torvalds 541ff2c873SDmitry Torokhov static int serport_serio_open(struct serio *serio) 551ff2c873SDmitry Torokhov { 561ff2c873SDmitry Torokhov struct serport *serport = serio->port_data; 571ff2c873SDmitry Torokhov unsigned long flags; 581ff2c873SDmitry Torokhov 591ff2c873SDmitry Torokhov spin_lock_irqsave(&serport->lock, flags); 601ff2c873SDmitry Torokhov set_bit(SERPORT_ACTIVE, &serport->flags); 611ff2c873SDmitry Torokhov spin_unlock_irqrestore(&serport->lock, flags); 621ff2c873SDmitry Torokhov 631ff2c873SDmitry Torokhov return 0; 641ff2c873SDmitry Torokhov } 651ff2c873SDmitry Torokhov 661ff2c873SDmitry Torokhov 671da177e4SLinus Torvalds static void serport_serio_close(struct serio *serio) 681da177e4SLinus Torvalds { 691da177e4SLinus Torvalds struct serport *serport = serio->port_data; 701ff2c873SDmitry Torokhov unsigned long flags; 711da177e4SLinus Torvalds 721ff2c873SDmitry Torokhov spin_lock_irqsave(&serport->lock, flags); 731ff2c873SDmitry Torokhov clear_bit(SERPORT_ACTIVE, &serport->flags); 741ff2c873SDmitry Torokhov set_bit(SERPORT_DEAD, &serport->flags); 751ff2c873SDmitry Torokhov spin_unlock_irqrestore(&serport->lock, flags); 761ff2c873SDmitry Torokhov 771da177e4SLinus Torvalds wake_up_interruptible(&serport->wait); 781da177e4SLinus Torvalds } 791da177e4SLinus Torvalds 801da177e4SLinus Torvalds /* 811da177e4SLinus Torvalds * serport_ldisc_open() is the routine that is called upon setting our line 821da177e4SLinus Torvalds * discipline on a tty. It prepares the serio struct. 831da177e4SLinus Torvalds */ 841da177e4SLinus Torvalds 851da177e4SLinus Torvalds static int serport_ldisc_open(struct tty_struct *tty) 861da177e4SLinus Torvalds { 871da177e4SLinus Torvalds struct serport *serport; 881da177e4SLinus Torvalds 891da177e4SLinus Torvalds if (!capable(CAP_SYS_ADMIN)) 901da177e4SLinus Torvalds return -EPERM; 911da177e4SLinus Torvalds 92a97e148aSPekka Enberg serport = kzalloc(sizeof(struct serport), GFP_KERNEL); 931ff2c873SDmitry Torokhov if (!serport) 941da177e4SLinus Torvalds return -ENOMEM; 951da177e4SLinus Torvalds 961da177e4SLinus Torvalds serport->tty = tty; 971ff2c873SDmitry Torokhov spin_lock_init(&serport->lock); 981da177e4SLinus Torvalds init_waitqueue_head(&serport->wait); 991da177e4SLinus Torvalds 1001ff2c873SDmitry Torokhov tty->disc_data = serport; 10133f0f88fSAlan Cox tty->receive_room = 256; 1021ff2c873SDmitry Torokhov set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); 1031ff2c873SDmitry Torokhov 1041da177e4SLinus Torvalds return 0; 1051da177e4SLinus Torvalds } 1061da177e4SLinus Torvalds 1071da177e4SLinus Torvalds /* 1081da177e4SLinus Torvalds * serport_ldisc_close() is the opposite of serport_ldisc_open() 1091da177e4SLinus Torvalds */ 1101da177e4SLinus Torvalds 1111da177e4SLinus Torvalds static void serport_ldisc_close(struct tty_struct *tty) 1121da177e4SLinus Torvalds { 1131da177e4SLinus Torvalds struct serport *serport = (struct serport *) tty->disc_data; 1141ff2c873SDmitry Torokhov 1151da177e4SLinus Torvalds kfree(serport); 1161da177e4SLinus Torvalds } 1171da177e4SLinus Torvalds 1181da177e4SLinus Torvalds /* 1191da177e4SLinus Torvalds * serport_ldisc_receive() is called by the low level tty driver when characters 12048c27016SDavid Engraf * are ready for us. We forward the characters and flags, one by one to the 12148c27016SDavid Engraf * 'interrupt' routine. 1221da177e4SLinus Torvalds */ 1231da177e4SLinus Torvalds 12455db4c64SLinus Torvalds static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) 1251da177e4SLinus Torvalds { 1261da177e4SLinus Torvalds struct serport *serport = (struct serport*) tty->disc_data; 1271ff2c873SDmitry Torokhov unsigned long flags; 12882f91fe0SPeter Hurley unsigned int ch_flags = 0; 1291da177e4SLinus Torvalds int i; 1301ff2c873SDmitry Torokhov 1311ff2c873SDmitry Torokhov spin_lock_irqsave(&serport->lock, flags); 1321ff2c873SDmitry Torokhov 13355db4c64SLinus Torvalds if (!test_bit(SERPORT_ACTIVE, &serport->flags)) 1341ff2c873SDmitry Torokhov goto out; 1351ff2c873SDmitry Torokhov 13648c27016SDavid Engraf for (i = 0; i < count; i++) { 13782f91fe0SPeter Hurley if (fp) { 13848c27016SDavid Engraf switch (fp[i]) { 13948c27016SDavid Engraf case TTY_FRAME: 14048c27016SDavid Engraf ch_flags = SERIO_FRAME; 14148c27016SDavid Engraf break; 14248c27016SDavid Engraf 14348c27016SDavid Engraf case TTY_PARITY: 14448c27016SDavid Engraf ch_flags = SERIO_PARITY; 14548c27016SDavid Engraf break; 14648c27016SDavid Engraf 14748c27016SDavid Engraf default: 14848c27016SDavid Engraf ch_flags = 0; 14948c27016SDavid Engraf break; 15048c27016SDavid Engraf } 15182f91fe0SPeter Hurley } 15248c27016SDavid Engraf 15348c27016SDavid Engraf serio_interrupt(serport->serio, cp[i], ch_flags); 15448c27016SDavid Engraf } 1551ff2c873SDmitry Torokhov 1561ff2c873SDmitry Torokhov out: 1571ff2c873SDmitry Torokhov spin_unlock_irqrestore(&serport->lock, flags); 1581da177e4SLinus Torvalds } 1591da177e4SLinus Torvalds 1601da177e4SLinus Torvalds /* 1611da177e4SLinus Torvalds * serport_ldisc_read() just waits indefinitely if everything goes well. 1621da177e4SLinus Torvalds * However, when the serio driver closes the serio port, it finishes, 1631da177e4SLinus Torvalds * returning 0 characters. 1641da177e4SLinus Torvalds */ 1651da177e4SLinus Torvalds 1661da177e4SLinus Torvalds static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, unsigned char __user * buf, size_t nr) 1671da177e4SLinus Torvalds { 1681da177e4SLinus Torvalds struct serport *serport = (struct serport*) tty->disc_data; 1691ff2c873SDmitry Torokhov struct serio *serio; 1701da177e4SLinus Torvalds 1711da177e4SLinus Torvalds if (test_and_set_bit(SERPORT_BUSY, &serport->flags)) 1721da177e4SLinus Torvalds return -EBUSY; 1731da177e4SLinus Torvalds 174a97e148aSPekka Enberg serport->serio = serio = kzalloc(sizeof(struct serio), GFP_KERNEL); 1751ff2c873SDmitry Torokhov if (!serio) 1761ff2c873SDmitry Torokhov return -ENOMEM; 1771ff2c873SDmitry Torokhov 1781ff2c873SDmitry Torokhov strlcpy(serio->name, "Serial port", sizeof(serio->name)); 179*429b4749SRasmus Villemoes snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty)); 1801ff2c873SDmitry Torokhov serio->id = serport->id; 1811ff2c873SDmitry Torokhov serio->id.type = SERIO_RS232; 1821ff2c873SDmitry Torokhov serio->write = serport_serio_write; 1831ff2c873SDmitry Torokhov serio->open = serport_serio_open; 1841ff2c873SDmitry Torokhov serio->close = serport_serio_close; 1851ff2c873SDmitry Torokhov serio->port_data = serport; 186de838a93SDmitry Eremin-Solenikov serio->dev.parent = tty->dev; 1871ff2c873SDmitry Torokhov 1881da177e4SLinus Torvalds serio_register_port(serport->serio); 189*429b4749SRasmus Villemoes printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty)); 1901da177e4SLinus Torvalds 1911ff2c873SDmitry Torokhov wait_event_interruptible(serport->wait, test_bit(SERPORT_DEAD, &serport->flags)); 1921ff2c873SDmitry Torokhov serio_unregister_port(serport->serio); 1931ff2c873SDmitry Torokhov serport->serio = NULL; 1941ff2c873SDmitry Torokhov 1951ff2c873SDmitry Torokhov clear_bit(SERPORT_DEAD, &serport->flags); 1961da177e4SLinus Torvalds clear_bit(SERPORT_BUSY, &serport->flags); 1971da177e4SLinus Torvalds 1981da177e4SLinus Torvalds return 0; 1991da177e4SLinus Torvalds } 2001da177e4SLinus Torvalds 201a80d8b02SJohn Sung static void serport_set_type(struct tty_struct *tty, unsigned long type) 2021da177e4SLinus Torvalds { 203a80d8b02SJohn Sung struct serport *serport = tty->disc_data; 2041da177e4SLinus Torvalds 2051ff2c873SDmitry Torokhov serport->id.proto = type & 0x000000ff; 2061ff2c873SDmitry Torokhov serport->id.id = (type & 0x0000ff00) >> 8; 2071ff2c873SDmitry Torokhov serport->id.extra = (type & 0x00ff0000) >> 16; 208a80d8b02SJohn Sung } 2091da177e4SLinus Torvalds 210a80d8b02SJohn Sung /* 211a80d8b02SJohn Sung * serport_ldisc_ioctl() allows to set the port protocol, and device ID 212a80d8b02SJohn Sung */ 213a80d8b02SJohn Sung 214a80d8b02SJohn Sung static int serport_ldisc_ioctl(struct tty_struct *tty, struct file *file, 215a80d8b02SJohn Sung unsigned int cmd, unsigned long arg) 216a80d8b02SJohn Sung { 217a80d8b02SJohn Sung if (cmd == SPIOCSTYPE) { 218a80d8b02SJohn Sung unsigned long type; 219a80d8b02SJohn Sung 220a80d8b02SJohn Sung if (get_user(type, (unsigned long __user *) arg)) 221a80d8b02SJohn Sung return -EFAULT; 222a80d8b02SJohn Sung 223a80d8b02SJohn Sung serport_set_type(tty, type); 2241da177e4SLinus Torvalds return 0; 2251da177e4SLinus Torvalds } 2261da177e4SLinus Torvalds 2271da177e4SLinus Torvalds return -EINVAL; 2281da177e4SLinus Torvalds } 2291da177e4SLinus Torvalds 230a80d8b02SJohn Sung #ifdef CONFIG_COMPAT 231a80d8b02SJohn Sung #define COMPAT_SPIOCSTYPE _IOW('q', 0x01, compat_ulong_t) 232a80d8b02SJohn Sung static long serport_ldisc_compat_ioctl(struct tty_struct *tty, 233a80d8b02SJohn Sung struct file *file, 234a80d8b02SJohn Sung unsigned int cmd, unsigned long arg) 235a80d8b02SJohn Sung { 236a80d8b02SJohn Sung if (cmd == COMPAT_SPIOCSTYPE) { 237a80d8b02SJohn Sung void __user *uarg = compat_ptr(arg); 238a80d8b02SJohn Sung compat_ulong_t compat_type; 239a80d8b02SJohn Sung 240a80d8b02SJohn Sung if (get_user(compat_type, (compat_ulong_t __user *)uarg)) 241a80d8b02SJohn Sung return -EFAULT; 242a80d8b02SJohn Sung 243a80d8b02SJohn Sung serport_set_type(tty, compat_type); 244a80d8b02SJohn Sung return 0; 245a80d8b02SJohn Sung } 246a80d8b02SJohn Sung 247a80d8b02SJohn Sung return -EINVAL; 248a80d8b02SJohn Sung } 249a80d8b02SJohn Sung #endif 250a80d8b02SJohn Sung 2511da177e4SLinus Torvalds static void serport_ldisc_write_wakeup(struct tty_struct * tty) 2521da177e4SLinus Torvalds { 2531ff2c873SDmitry Torokhov struct serport *serport = (struct serport *) tty->disc_data; 2541ff2c873SDmitry Torokhov unsigned long flags; 2551da177e4SLinus Torvalds 2561ff2c873SDmitry Torokhov spin_lock_irqsave(&serport->lock, flags); 2571ff2c873SDmitry Torokhov if (test_bit(SERPORT_ACTIVE, &serport->flags)) 2581ff2c873SDmitry Torokhov serio_drv_write_wakeup(serport->serio); 2591ff2c873SDmitry Torokhov spin_unlock_irqrestore(&serport->lock, flags); 2601da177e4SLinus Torvalds } 2611da177e4SLinus Torvalds 2621da177e4SLinus Torvalds /* 2631da177e4SLinus Torvalds * The line discipline structure. 2641da177e4SLinus Torvalds */ 2651da177e4SLinus Torvalds 266a352def2SAlan Cox static struct tty_ldisc_ops serport_ldisc = { 2671da177e4SLinus Torvalds .owner = THIS_MODULE, 2681da177e4SLinus Torvalds .name = "input", 2691da177e4SLinus Torvalds .open = serport_ldisc_open, 2701da177e4SLinus Torvalds .close = serport_ldisc_close, 2711da177e4SLinus Torvalds .read = serport_ldisc_read, 2721da177e4SLinus Torvalds .ioctl = serport_ldisc_ioctl, 273a80d8b02SJohn Sung #ifdef CONFIG_COMPAT 274a80d8b02SJohn Sung .compat_ioctl = serport_ldisc_compat_ioctl, 275a80d8b02SJohn Sung #endif 2761da177e4SLinus Torvalds .receive_buf = serport_ldisc_receive, 2771da177e4SLinus Torvalds .write_wakeup = serport_ldisc_write_wakeup 2781da177e4SLinus Torvalds }; 2791da177e4SLinus Torvalds 2801da177e4SLinus Torvalds /* 2811da177e4SLinus Torvalds * The functions for insering/removing us as a module. 2821da177e4SLinus Torvalds */ 2831da177e4SLinus Torvalds 2841da177e4SLinus Torvalds static int __init serport_init(void) 2851da177e4SLinus Torvalds { 2861da177e4SLinus Torvalds int retval; 2871da177e4SLinus Torvalds retval = tty_register_ldisc(N_MOUSE, &serport_ldisc); 2881da177e4SLinus Torvalds if (retval) 2891da177e4SLinus Torvalds printk(KERN_ERR "serport.c: Error registering line discipline.\n"); 2901da177e4SLinus Torvalds 2911da177e4SLinus Torvalds return retval; 2921da177e4SLinus Torvalds } 2931da177e4SLinus Torvalds 2941da177e4SLinus Torvalds static void __exit serport_exit(void) 2951da177e4SLinus Torvalds { 29664ccd715SAlexey Dobriyan tty_unregister_ldisc(N_MOUSE); 2971da177e4SLinus Torvalds } 2981da177e4SLinus Torvalds 2991da177e4SLinus Torvalds module_init(serport_init); 3001da177e4SLinus Torvalds module_exit(serport_exit); 301