2 * Input device TTY line discipline
4 * Copyright (c) 1999-2002 Vojtech Pavlik
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.
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.
16 #include <asm/uaccess.h>
17 #include <linux/kernel.h>
18 #include <linux/sched.h>
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 #include <linux/compat.h>
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
);
31 #define SERPORT_BUSY 1
32 #define SERPORT_ACTIVE 2
33 #define SERPORT_DEAD 3
36 struct tty_struct
*tty
;
37 wait_queue_head_t wait
;
39 struct serio_device_id id
;
45 * Callback functions from the serio code.
48 static int serport_serio_write(struct serio
*serio
, unsigned char data
)
50 struct serport
*serport
= serio
->port_data
;
51 return -(serport
->tty
->ops
->write(serport
->tty
, &data
, 1) != 1);
54 static int serport_serio_open(struct serio
*serio
)
56 struct serport
*serport
= serio
->port_data
;
59 spin_lock_irqsave(&serport
->lock
, flags
);
60 set_bit(SERPORT_ACTIVE
, &serport
->flags
);
61 spin_unlock_irqrestore(&serport
->lock
, flags
);
67 static void serport_serio_close(struct serio
*serio
)
69 struct serport
*serport
= serio
->port_data
;
72 spin_lock_irqsave(&serport
->lock
, flags
);
73 clear_bit(SERPORT_ACTIVE
, &serport
->flags
);
74 set_bit(SERPORT_DEAD
, &serport
->flags
);
75 spin_unlock_irqrestore(&serport
->lock
, flags
);
77 wake_up_interruptible(&serport
->wait
);
81 * serport_ldisc_open() is the routine that is called upon setting our line
82 * discipline on a tty. It prepares the serio struct.
85 static int serport_ldisc_open(struct tty_struct
*tty
)
87 struct serport
*serport
;
89 if (!capable(CAP_SYS_ADMIN
))
92 serport
= kzalloc(sizeof(struct serport
), GFP_KERNEL
);
97 spin_lock_init(&serport
->lock
);
98 init_waitqueue_head(&serport
->wait
);
100 tty
->disc_data
= serport
;
101 tty
->receive_room
= 256;
102 set_bit(TTY_DO_WRITE_WAKEUP
, &tty
->flags
);
108 * serport_ldisc_close() is the opposite of serport_ldisc_open()
111 static void serport_ldisc_close(struct tty_struct
*tty
)
113 struct serport
*serport
= (struct serport
*) tty
->disc_data
;
119 * serport_ldisc_receive() is called by the low level tty driver when characters
120 * are ready for us. We forward the characters and flags, one by one to the
121 * 'interrupt' routine.
124 static void serport_ldisc_receive(struct tty_struct
*tty
, const unsigned char *cp
, char *fp
, int count
)
126 struct serport
*serport
= (struct serport
*) tty
->disc_data
;
128 unsigned int ch_flags
= 0;
131 spin_lock_irqsave(&serport
->lock
, flags
);
133 if (!test_bit(SERPORT_ACTIVE
, &serport
->flags
))
136 for (i
= 0; i
< count
; i
++) {
140 ch_flags
= SERIO_FRAME
;
144 ch_flags
= SERIO_PARITY
;
153 serio_interrupt(serport
->serio
, cp
[i
], ch_flags
);
157 spin_unlock_irqrestore(&serport
->lock
, flags
);
161 * serport_ldisc_read() just waits indefinitely if everything goes well.
162 * However, when the serio driver closes the serio port, it finishes,
163 * returning 0 characters.
166 static ssize_t
serport_ldisc_read(struct tty_struct
* tty
, struct file
* file
, unsigned char __user
* buf
, size_t nr
)
168 struct serport
*serport
= (struct serport
*) tty
->disc_data
;
172 if (test_and_set_bit(SERPORT_BUSY
, &serport
->flags
))
175 serport
->serio
= serio
= kzalloc(sizeof(struct serio
), GFP_KERNEL
);
179 strlcpy(serio
->name
, "Serial port", sizeof(serio
->name
));
180 snprintf(serio
->phys
, sizeof(serio
->phys
), "%s/serio0", tty_name(tty
, name
));
181 serio
->id
= serport
->id
;
182 serio
->id
.type
= SERIO_RS232
;
183 serio
->write
= serport_serio_write
;
184 serio
->open
= serport_serio_open
;
185 serio
->close
= serport_serio_close
;
186 serio
->port_data
= serport
;
187 serio
->dev
.parent
= tty
->dev
;
189 serio_register_port(serport
->serio
);
190 printk(KERN_INFO
"serio: Serial port %s\n", tty_name(tty
, name
));
192 wait_event_interruptible(serport
->wait
, test_bit(SERPORT_DEAD
, &serport
->flags
));
193 serio_unregister_port(serport
->serio
);
194 serport
->serio
= NULL
;
196 clear_bit(SERPORT_DEAD
, &serport
->flags
);
197 clear_bit(SERPORT_BUSY
, &serport
->flags
);
202 static void serport_set_type(struct tty_struct
*tty
, unsigned long type
)
204 struct serport
*serport
= tty
->disc_data
;
206 serport
->id
.proto
= type
& 0x000000ff;
207 serport
->id
.id
= (type
& 0x0000ff00) >> 8;
208 serport
->id
.extra
= (type
& 0x00ff0000) >> 16;
212 * serport_ldisc_ioctl() allows to set the port protocol, and device ID
215 static int serport_ldisc_ioctl(struct tty_struct
*tty
, struct file
*file
,
216 unsigned int cmd
, unsigned long arg
)
218 if (cmd
== SPIOCSTYPE
) {
221 if (get_user(type
, (unsigned long __user
*) arg
))
224 serport_set_type(tty
, type
);
232 #define COMPAT_SPIOCSTYPE _IOW('q', 0x01, compat_ulong_t)
233 static long serport_ldisc_compat_ioctl(struct tty_struct
*tty
,
235 unsigned int cmd
, unsigned long arg
)
237 if (cmd
== COMPAT_SPIOCSTYPE
) {
238 void __user
*uarg
= compat_ptr(arg
);
239 compat_ulong_t compat_type
;
241 if (get_user(compat_type
, (compat_ulong_t __user
*)uarg
))
244 serport_set_type(tty
, compat_type
);
252 static void serport_ldisc_write_wakeup(struct tty_struct
* tty
)
254 struct serport
*serport
= (struct serport
*) tty
->disc_data
;
257 spin_lock_irqsave(&serport
->lock
, flags
);
258 if (test_bit(SERPORT_ACTIVE
, &serport
->flags
))
259 serio_drv_write_wakeup(serport
->serio
);
260 spin_unlock_irqrestore(&serport
->lock
, flags
);
264 * The line discipline structure.
267 static struct tty_ldisc_ops serport_ldisc
= {
268 .owner
= THIS_MODULE
,
270 .open
= serport_ldisc_open
,
271 .close
= serport_ldisc_close
,
272 .read
= serport_ldisc_read
,
273 .ioctl
= serport_ldisc_ioctl
,
275 .compat_ioctl
= serport_ldisc_compat_ioctl
,
277 .receive_buf
= serport_ldisc_receive
,
278 .write_wakeup
= serport_ldisc_write_wakeup
282 * The functions for insering/removing us as a module.
285 static int __init
serport_init(void)
288 retval
= tty_register_ldisc(N_MOUSE
, &serport_ldisc
);
290 printk(KERN_ERR
"serport.c: Error registering line discipline.\n");
295 static void __exit
serport_exit(void)
297 tty_unregister_ldisc(N_MOUSE
);
300 module_init(serport_init
);
301 module_exit(serport_exit
);