xref: /linux/drivers/input/mousedev.c (revision ed3174d93c342b8b2eeba6bbd124707d55304a7b)
1 /*
2  * Input driver to ExplorerPS/2 device driver module.
3  *
4  * Copyright (c) 1999-2002 Vojtech Pavlik
5  * Copyright (c) 2004      Dmitry Torokhov
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as published by
9  * the Free Software Foundation.
10  */
11 
12 #define MOUSEDEV_MINOR_BASE	32
13 #define MOUSEDEV_MINORS		32
14 #define MOUSEDEV_MIX		31
15 
16 #include <linux/slab.h>
17 #include <linux/poll.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/input.h>
21 #include <linux/random.h>
22 #include <linux/major.h>
23 #include <linux/device.h>
24 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
25 #include <linux/miscdevice.h>
26 #endif
27 
28 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
29 MODULE_DESCRIPTION("Mouse (ExplorerPS/2) device interfaces");
30 MODULE_LICENSE("GPL");
31 
32 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_X
33 #define CONFIG_INPUT_MOUSEDEV_SCREEN_X	1024
34 #endif
35 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_Y
36 #define CONFIG_INPUT_MOUSEDEV_SCREEN_Y	768
37 #endif
38 
39 static int xres = CONFIG_INPUT_MOUSEDEV_SCREEN_X;
40 module_param(xres, uint, 0644);
41 MODULE_PARM_DESC(xres, "Horizontal screen resolution");
42 
43 static int yres = CONFIG_INPUT_MOUSEDEV_SCREEN_Y;
44 module_param(yres, uint, 0644);
45 MODULE_PARM_DESC(yres, "Vertical screen resolution");
46 
47 static unsigned tap_time = 200;
48 module_param(tap_time, uint, 0644);
49 MODULE_PARM_DESC(tap_time, "Tap time for touchpads in absolute mode (msecs)");
50 
51 struct mousedev_hw_data {
52 	int dx, dy, dz;
53 	int x, y;
54 	int abs_event;
55 	unsigned long buttons;
56 };
57 
58 struct mousedev {
59 	int exist;
60 	int open;
61 	int minor;
62 	char name[16];
63 	struct input_handle handle;
64 	wait_queue_head_t wait;
65 	struct list_head client_list;
66 	spinlock_t client_lock; /* protects client_list */
67 	struct mutex mutex;
68 	struct device dev;
69 
70 	struct list_head mixdev_node;
71 	int mixdev_open;
72 
73 	struct mousedev_hw_data packet;
74 	unsigned int pkt_count;
75 	int old_x[4], old_y[4];
76 	int frac_dx, frac_dy;
77 	unsigned long touch;
78 };
79 
80 enum mousedev_emul {
81 	MOUSEDEV_EMUL_PS2,
82 	MOUSEDEV_EMUL_IMPS,
83 	MOUSEDEV_EMUL_EXPS
84 };
85 
86 struct mousedev_motion {
87 	int dx, dy, dz;
88 	unsigned long buttons;
89 };
90 
91 #define PACKET_QUEUE_LEN	16
92 struct mousedev_client {
93 	struct fasync_struct *fasync;
94 	struct mousedev *mousedev;
95 	struct list_head node;
96 
97 	struct mousedev_motion packets[PACKET_QUEUE_LEN];
98 	unsigned int head, tail;
99 	spinlock_t packet_lock;
100 	int pos_x, pos_y;
101 
102 	signed char ps2[6];
103 	unsigned char ready, buffer, bufsiz;
104 	unsigned char imexseq, impsseq;
105 	enum mousedev_emul mode;
106 	unsigned long last_buttons;
107 };
108 
109 #define MOUSEDEV_SEQ_LEN	6
110 
111 static unsigned char mousedev_imps_seq[] = { 0xf3, 200, 0xf3, 100, 0xf3, 80 };
112 static unsigned char mousedev_imex_seq[] = { 0xf3, 200, 0xf3, 200, 0xf3, 80 };
113 
114 static struct input_handler mousedev_handler;
115 
116 static struct mousedev *mousedev_table[MOUSEDEV_MINORS];
117 static DEFINE_MUTEX(mousedev_table_mutex);
118 static struct mousedev *mousedev_mix;
119 static LIST_HEAD(mousedev_mix_list);
120 
121 static void mixdev_open_devices(void);
122 static void mixdev_close_devices(void);
123 
124 #define fx(i)  (mousedev->old_x[(mousedev->pkt_count - (i)) & 03])
125 #define fy(i)  (mousedev->old_y[(mousedev->pkt_count - (i)) & 03])
126 
127 static void mousedev_touchpad_event(struct input_dev *dev,
128 				    struct mousedev *mousedev,
129 				    unsigned int code, int value)
130 {
131 	int size, tmp;
132 	enum { FRACTION_DENOM = 128 };
133 
134 	switch (code) {
135 
136 	case ABS_X:
137 		fx(0) = value;
138 		if (mousedev->touch && mousedev->pkt_count >= 2) {
139 			size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
140 			if (size == 0)
141 				size = 256 * 2;
142 			tmp = ((value - fx(2)) * 256 * FRACTION_DENOM) / size;
143 			tmp += mousedev->frac_dx;
144 			mousedev->packet.dx = tmp / FRACTION_DENOM;
145 			mousedev->frac_dx =
146 				tmp - mousedev->packet.dx * FRACTION_DENOM;
147 		}
148 		break;
149 
150 	case ABS_Y:
151 		fy(0) = value;
152 		if (mousedev->touch && mousedev->pkt_count >= 2) {
153 			/* use X size to keep the same scale */
154 			size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
155 			if (size == 0)
156 				size = 256 * 2;
157 			tmp = -((value - fy(2)) * 256 * FRACTION_DENOM) / size;
158 			tmp += mousedev->frac_dy;
159 			mousedev->packet.dy = tmp / FRACTION_DENOM;
160 			mousedev->frac_dy = tmp -
161 				mousedev->packet.dy * FRACTION_DENOM;
162 		}
163 		break;
164 	}
165 }
166 
167 static void mousedev_abs_event(struct input_dev *dev, struct mousedev *mousedev,
168 				unsigned int code, int value)
169 {
170 	int size;
171 
172 	switch (code) {
173 
174 	case ABS_X:
175 		size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
176 		if (size == 0)
177 			size = xres ? : 1;
178 		if (value > dev->absmax[ABS_X])
179 			value = dev->absmax[ABS_X];
180 		if (value < dev->absmin[ABS_X])
181 			value = dev->absmin[ABS_X];
182 		mousedev->packet.x =
183 			((value - dev->absmin[ABS_X]) * xres) / size;
184 		mousedev->packet.abs_event = 1;
185 		break;
186 
187 	case ABS_Y:
188 		size = dev->absmax[ABS_Y] - dev->absmin[ABS_Y];
189 		if (size == 0)
190 			size = yres ? : 1;
191 		if (value > dev->absmax[ABS_Y])
192 			value = dev->absmax[ABS_Y];
193 		if (value < dev->absmin[ABS_Y])
194 			value = dev->absmin[ABS_Y];
195 		mousedev->packet.y = yres -
196 			((value - dev->absmin[ABS_Y]) * yres) / size;
197 		mousedev->packet.abs_event = 1;
198 		break;
199 	}
200 }
201 
202 static void mousedev_rel_event(struct mousedev *mousedev,
203 				unsigned int code, int value)
204 {
205 	switch (code) {
206 	case REL_X:
207 		mousedev->packet.dx += value;
208 		break;
209 
210 	case REL_Y:
211 		mousedev->packet.dy -= value;
212 		break;
213 
214 	case REL_WHEEL:
215 		mousedev->packet.dz -= value;
216 		break;
217 	}
218 }
219 
220 static void mousedev_key_event(struct mousedev *mousedev,
221 				unsigned int code, int value)
222 {
223 	int index;
224 
225 	switch (code) {
226 
227 	case BTN_TOUCH:
228 	case BTN_0:
229 	case BTN_LEFT:		index = 0; break;
230 
231 	case BTN_STYLUS:
232 	case BTN_1:
233 	case BTN_RIGHT:		index = 1; break;
234 
235 	case BTN_2:
236 	case BTN_FORWARD:
237 	case BTN_STYLUS2:
238 	case BTN_MIDDLE:	index = 2; break;
239 
240 	case BTN_3:
241 	case BTN_BACK:
242 	case BTN_SIDE:		index = 3; break;
243 
244 	case BTN_4:
245 	case BTN_EXTRA:		index = 4; break;
246 
247 	default:		return;
248 	}
249 
250 	if (value) {
251 		set_bit(index, &mousedev->packet.buttons);
252 		set_bit(index, &mousedev_mix->packet.buttons);
253 	} else {
254 		clear_bit(index, &mousedev->packet.buttons);
255 		clear_bit(index, &mousedev_mix->packet.buttons);
256 	}
257 }
258 
259 static void mousedev_notify_readers(struct mousedev *mousedev,
260 				    struct mousedev_hw_data *packet)
261 {
262 	struct mousedev_client *client;
263 	struct mousedev_motion *p;
264 	unsigned int new_head;
265 	int wake_readers = 0;
266 
267 	rcu_read_lock();
268 	list_for_each_entry_rcu(client, &mousedev->client_list, node) {
269 
270 		/* Just acquire the lock, interrupts already disabled */
271 		spin_lock(&client->packet_lock);
272 
273 		p = &client->packets[client->head];
274 		if (client->ready && p->buttons != mousedev->packet.buttons) {
275 			new_head = (client->head + 1) % PACKET_QUEUE_LEN;
276 			if (new_head != client->tail) {
277 				p = &client->packets[client->head = new_head];
278 				memset(p, 0, sizeof(struct mousedev_motion));
279 			}
280 		}
281 
282 		if (packet->abs_event) {
283 			p->dx += packet->x - client->pos_x;
284 			p->dy += packet->y - client->pos_y;
285 			client->pos_x = packet->x;
286 			client->pos_y = packet->y;
287 		}
288 
289 		client->pos_x += packet->dx;
290 		client->pos_x = client->pos_x < 0 ?
291 			0 : (client->pos_x >= xres ? xres : client->pos_x);
292 		client->pos_y += packet->dy;
293 		client->pos_y = client->pos_y < 0 ?
294 			0 : (client->pos_y >= yres ? yres : client->pos_y);
295 
296 		p->dx += packet->dx;
297 		p->dy += packet->dy;
298 		p->dz += packet->dz;
299 		p->buttons = mousedev->packet.buttons;
300 
301 		if (p->dx || p->dy || p->dz ||
302 		    p->buttons != client->last_buttons)
303 			client->ready = 1;
304 
305 		spin_unlock(&client->packet_lock);
306 
307 		if (client->ready) {
308 			kill_fasync(&client->fasync, SIGIO, POLL_IN);
309 			wake_readers = 1;
310 		}
311 	}
312 	rcu_read_unlock();
313 
314 	if (wake_readers)
315 		wake_up_interruptible(&mousedev->wait);
316 }
317 
318 static void mousedev_touchpad_touch(struct mousedev *mousedev, int value)
319 {
320 	if (!value) {
321 		if (mousedev->touch &&
322 		    time_before(jiffies,
323 				mousedev->touch + msecs_to_jiffies(tap_time))) {
324 			/*
325 			 * Toggle left button to emulate tap.
326 			 * We rely on the fact that mousedev_mix always has 0
327 			 * motion packet so we won't mess current position.
328 			 */
329 			set_bit(0, &mousedev->packet.buttons);
330 			set_bit(0, &mousedev_mix->packet.buttons);
331 			mousedev_notify_readers(mousedev, &mousedev_mix->packet);
332 			mousedev_notify_readers(mousedev_mix,
333 						&mousedev_mix->packet);
334 			clear_bit(0, &mousedev->packet.buttons);
335 			clear_bit(0, &mousedev_mix->packet.buttons);
336 		}
337 		mousedev->touch = mousedev->pkt_count = 0;
338 		mousedev->frac_dx = 0;
339 		mousedev->frac_dy = 0;
340 
341 	} else if (!mousedev->touch)
342 		mousedev->touch = jiffies;
343 }
344 
345 static void mousedev_event(struct input_handle *handle,
346 			   unsigned int type, unsigned int code, int value)
347 {
348 	struct mousedev *mousedev = handle->private;
349 
350 	switch (type) {
351 
352 	case EV_ABS:
353 		/* Ignore joysticks */
354 		if (test_bit(BTN_TRIGGER, handle->dev->keybit))
355 			return;
356 
357 		if (test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
358 			mousedev_touchpad_event(handle->dev,
359 						mousedev, code, value);
360 		else
361 			mousedev_abs_event(handle->dev, mousedev, code, value);
362 
363 		break;
364 
365 	case EV_REL:
366 		mousedev_rel_event(mousedev, code, value);
367 		break;
368 
369 	case EV_KEY:
370 		if (value != 2) {
371 			if (code == BTN_TOUCH &&
372 			    test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
373 				mousedev_touchpad_touch(mousedev, value);
374 			else
375 				mousedev_key_event(mousedev, code, value);
376 		}
377 		break;
378 
379 	case EV_SYN:
380 		if (code == SYN_REPORT) {
381 			if (mousedev->touch) {
382 				mousedev->pkt_count++;
383 				/*
384 				 * Input system eats duplicate events,
385 				 * but we need all of them to do correct
386 				 * averaging so apply present one forward
387 				 */
388 				fx(0) = fx(1);
389 				fy(0) = fy(1);
390 			}
391 
392 			mousedev_notify_readers(mousedev, &mousedev->packet);
393 			mousedev_notify_readers(mousedev_mix, &mousedev->packet);
394 
395 			mousedev->packet.dx = mousedev->packet.dy =
396 				mousedev->packet.dz = 0;
397 			mousedev->packet.abs_event = 0;
398 		}
399 		break;
400 	}
401 }
402 
403 static int mousedev_fasync(int fd, struct file *file, int on)
404 {
405 	int retval;
406 	struct mousedev_client *client = file->private_data;
407 
408 	retval = fasync_helper(fd, file, on, &client->fasync);
409 
410 	return retval < 0 ? retval : 0;
411 }
412 
413 static void mousedev_free(struct device *dev)
414 {
415 	struct mousedev *mousedev = container_of(dev, struct mousedev, dev);
416 
417 	kfree(mousedev);
418 }
419 
420 static int mousedev_open_device(struct mousedev *mousedev)
421 {
422 	int retval;
423 
424 	retval = mutex_lock_interruptible(&mousedev->mutex);
425 	if (retval)
426 		return retval;
427 
428 	if (mousedev->minor == MOUSEDEV_MIX)
429 		mixdev_open_devices();
430 	else if (!mousedev->exist)
431 		retval = -ENODEV;
432 	else if (!mousedev->open++) {
433 		retval = input_open_device(&mousedev->handle);
434 		if (retval)
435 			mousedev->open--;
436 	}
437 
438 	mutex_unlock(&mousedev->mutex);
439 	return retval;
440 }
441 
442 static void mousedev_close_device(struct mousedev *mousedev)
443 {
444 	mutex_lock(&mousedev->mutex);
445 
446 	if (mousedev->minor == MOUSEDEV_MIX)
447 		mixdev_close_devices();
448 	else if (mousedev->exist && !--mousedev->open)
449 		input_close_device(&mousedev->handle);
450 
451 	mutex_unlock(&mousedev->mutex);
452 }
453 
454 /*
455  * Open all available devices so they can all be multiplexed in one.
456  * stream. Note that this function is called with mousedev_mix->mutex
457  * held.
458  */
459 static void mixdev_open_devices(void)
460 {
461 	struct mousedev *mousedev;
462 
463 	if (mousedev_mix->open++)
464 		return;
465 
466 	list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
467 		if (!mousedev->mixdev_open) {
468 			if (mousedev_open_device(mousedev))
469 				continue;
470 
471 			mousedev->mixdev_open = 1;
472 		}
473 	}
474 }
475 
476 /*
477  * Close all devices that were opened as part of multiplexed
478  * device. Note that this function is called with mousedev_mix->mutex
479  * held.
480  */
481 static void mixdev_close_devices(void)
482 {
483 	struct mousedev *mousedev;
484 
485 	if (--mousedev_mix->open)
486 		return;
487 
488 	list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
489 		if (mousedev->mixdev_open) {
490 			mousedev->mixdev_open = 0;
491 			mousedev_close_device(mousedev);
492 		}
493 	}
494 }
495 
496 
497 static void mousedev_attach_client(struct mousedev *mousedev,
498 				   struct mousedev_client *client)
499 {
500 	spin_lock(&mousedev->client_lock);
501 	list_add_tail_rcu(&client->node, &mousedev->client_list);
502 	spin_unlock(&mousedev->client_lock);
503 	synchronize_rcu();
504 }
505 
506 static void mousedev_detach_client(struct mousedev *mousedev,
507 				   struct mousedev_client *client)
508 {
509 	spin_lock(&mousedev->client_lock);
510 	list_del_rcu(&client->node);
511 	spin_unlock(&mousedev->client_lock);
512 	synchronize_rcu();
513 }
514 
515 static int mousedev_release(struct inode *inode, struct file *file)
516 {
517 	struct mousedev_client *client = file->private_data;
518 	struct mousedev *mousedev = client->mousedev;
519 
520 	mousedev_fasync(-1, file, 0);
521 	mousedev_detach_client(mousedev, client);
522 	kfree(client);
523 
524 	mousedev_close_device(mousedev);
525 	put_device(&mousedev->dev);
526 
527 	return 0;
528 }
529 
530 static int mousedev_open(struct inode *inode, struct file *file)
531 {
532 	struct mousedev_client *client;
533 	struct mousedev *mousedev;
534 	int error;
535 	int i;
536 
537 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
538 	if (imajor(inode) == MISC_MAJOR)
539 		i = MOUSEDEV_MIX;
540 	else
541 #endif
542 		i = iminor(inode) - MOUSEDEV_MINOR_BASE;
543 
544 	if (i >= MOUSEDEV_MINORS)
545 		return -ENODEV;
546 
547 	error = mutex_lock_interruptible(&mousedev_table_mutex);
548 	if (error)
549 		return error;
550 	mousedev = mousedev_table[i];
551 	if (mousedev)
552 		get_device(&mousedev->dev);
553 	mutex_unlock(&mousedev_table_mutex);
554 
555 	if (!mousedev)
556 		return -ENODEV;
557 
558 	client = kzalloc(sizeof(struct mousedev_client), GFP_KERNEL);
559 	if (!client) {
560 		error = -ENOMEM;
561 		goto err_put_mousedev;
562 	}
563 
564 	spin_lock_init(&client->packet_lock);
565 	client->pos_x = xres / 2;
566 	client->pos_y = yres / 2;
567 	client->mousedev = mousedev;
568 	mousedev_attach_client(mousedev, client);
569 
570 	error = mousedev_open_device(mousedev);
571 	if (error)
572 		goto err_free_client;
573 
574 	file->private_data = client;
575 	return 0;
576 
577  err_free_client:
578 	mousedev_detach_client(mousedev, client);
579 	kfree(client);
580  err_put_mousedev:
581 	put_device(&mousedev->dev);
582 	return error;
583 }
584 
585 static inline int mousedev_limit_delta(int delta, int limit)
586 {
587 	return delta > limit ? limit : (delta < -limit ? -limit : delta);
588 }
589 
590 static void mousedev_packet(struct mousedev_client *client,
591 			    signed char *ps2_data)
592 {
593 	struct mousedev_motion *p = &client->packets[client->tail];
594 
595 	ps2_data[0] = 0x08 |
596 		((p->dx < 0) << 4) | ((p->dy < 0) << 5) | (p->buttons & 0x07);
597 	ps2_data[1] = mousedev_limit_delta(p->dx, 127);
598 	ps2_data[2] = mousedev_limit_delta(p->dy, 127);
599 	p->dx -= ps2_data[1];
600 	p->dy -= ps2_data[2];
601 
602 	switch (client->mode) {
603 	case MOUSEDEV_EMUL_EXPS:
604 		ps2_data[3] = mousedev_limit_delta(p->dz, 7);
605 		p->dz -= ps2_data[3];
606 		ps2_data[3] = (ps2_data[3] & 0x0f) | ((p->buttons & 0x18) << 1);
607 		client->bufsiz = 4;
608 		break;
609 
610 	case MOUSEDEV_EMUL_IMPS:
611 		ps2_data[0] |=
612 			((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
613 		ps2_data[3] = mousedev_limit_delta(p->dz, 127);
614 		p->dz -= ps2_data[3];
615 		client->bufsiz = 4;
616 		break;
617 
618 	case MOUSEDEV_EMUL_PS2:
619 	default:
620 		ps2_data[0] |=
621 			((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
622 		p->dz = 0;
623 		client->bufsiz = 3;
624 		break;
625 	}
626 
627 	if (!p->dx && !p->dy && !p->dz) {
628 		if (client->tail == client->head) {
629 			client->ready = 0;
630 			client->last_buttons = p->buttons;
631 		} else
632 			client->tail = (client->tail + 1) % PACKET_QUEUE_LEN;
633 	}
634 }
635 
636 static void mousedev_generate_response(struct mousedev_client *client,
637 					int command)
638 {
639 	client->ps2[0] = 0xfa; /* ACK */
640 
641 	switch (command) {
642 
643 	case 0xeb: /* Poll */
644 		mousedev_packet(client, &client->ps2[1]);
645 		client->bufsiz++; /* account for leading ACK */
646 		break;
647 
648 	case 0xf2: /* Get ID */
649 		switch (client->mode) {
650 		case MOUSEDEV_EMUL_PS2:
651 			client->ps2[1] = 0;
652 			break;
653 		case MOUSEDEV_EMUL_IMPS:
654 			client->ps2[1] = 3;
655 			break;
656 		case MOUSEDEV_EMUL_EXPS:
657 			client->ps2[1] = 4;
658 			break;
659 		}
660 		client->bufsiz = 2;
661 		break;
662 
663 	case 0xe9: /* Get info */
664 		client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200;
665 		client->bufsiz = 4;
666 		break;
667 
668 	case 0xff: /* Reset */
669 		client->impsseq = client->imexseq = 0;
670 		client->mode = MOUSEDEV_EMUL_PS2;
671 		client->ps2[1] = 0xaa; client->ps2[2] = 0x00;
672 		client->bufsiz = 3;
673 		break;
674 
675 	default:
676 		client->bufsiz = 1;
677 		break;
678 	}
679 	client->buffer = client->bufsiz;
680 }
681 
682 static ssize_t mousedev_write(struct file *file, const char __user *buffer,
683 				size_t count, loff_t *ppos)
684 {
685 	struct mousedev_client *client = file->private_data;
686 	unsigned char c;
687 	unsigned int i;
688 
689 	for (i = 0; i < count; i++) {
690 
691 		if (get_user(c, buffer + i))
692 			return -EFAULT;
693 
694 		spin_lock_irq(&client->packet_lock);
695 
696 		if (c == mousedev_imex_seq[client->imexseq]) {
697 			if (++client->imexseq == MOUSEDEV_SEQ_LEN) {
698 				client->imexseq = 0;
699 				client->mode = MOUSEDEV_EMUL_EXPS;
700 			}
701 		} else
702 			client->imexseq = 0;
703 
704 		if (c == mousedev_imps_seq[client->impsseq]) {
705 			if (++client->impsseq == MOUSEDEV_SEQ_LEN) {
706 				client->impsseq = 0;
707 				client->mode = MOUSEDEV_EMUL_IMPS;
708 			}
709 		} else
710 			client->impsseq = 0;
711 
712 		mousedev_generate_response(client, c);
713 
714 		spin_unlock_irq(&client->packet_lock);
715 	}
716 
717 	kill_fasync(&client->fasync, SIGIO, POLL_IN);
718 	wake_up_interruptible(&client->mousedev->wait);
719 
720 	return count;
721 }
722 
723 static ssize_t mousedev_read(struct file *file, char __user *buffer,
724 			     size_t count, loff_t *ppos)
725 {
726 	struct mousedev_client *client = file->private_data;
727 	struct mousedev *mousedev = client->mousedev;
728 	signed char data[sizeof(client->ps2)];
729 	int retval = 0;
730 
731 	if (!client->ready && !client->buffer && mousedev->exist &&
732 	    (file->f_flags & O_NONBLOCK))
733 		return -EAGAIN;
734 
735 	retval = wait_event_interruptible(mousedev->wait,
736 			!mousedev->exist || client->ready || client->buffer);
737 	if (retval)
738 		return retval;
739 
740 	if (!mousedev->exist)
741 		return -ENODEV;
742 
743 	spin_lock_irq(&client->packet_lock);
744 
745 	if (!client->buffer && client->ready) {
746 		mousedev_packet(client, client->ps2);
747 		client->buffer = client->bufsiz;
748 	}
749 
750 	if (count > client->buffer)
751 		count = client->buffer;
752 
753 	memcpy(data, client->ps2 + client->bufsiz - client->buffer, count);
754 	client->buffer -= count;
755 
756 	spin_unlock_irq(&client->packet_lock);
757 
758 	if (copy_to_user(buffer, data, count))
759 		return -EFAULT;
760 
761 	return count;
762 }
763 
764 /* No kernel lock - fine */
765 static unsigned int mousedev_poll(struct file *file, poll_table *wait)
766 {
767 	struct mousedev_client *client = file->private_data;
768 	struct mousedev *mousedev = client->mousedev;
769 
770 	poll_wait(file, &mousedev->wait, wait);
771 	return ((client->ready || client->buffer) ? (POLLIN | POLLRDNORM) : 0) |
772 		(mousedev->exist ? 0 : (POLLHUP | POLLERR));
773 }
774 
775 static const struct file_operations mousedev_fops = {
776 	.owner =	THIS_MODULE,
777 	.read =		mousedev_read,
778 	.write =	mousedev_write,
779 	.poll =		mousedev_poll,
780 	.open =		mousedev_open,
781 	.release =	mousedev_release,
782 	.fasync =	mousedev_fasync,
783 };
784 
785 static int mousedev_install_chrdev(struct mousedev *mousedev)
786 {
787 	mousedev_table[mousedev->minor] = mousedev;
788 	return 0;
789 }
790 
791 static void mousedev_remove_chrdev(struct mousedev *mousedev)
792 {
793 	mutex_lock(&mousedev_table_mutex);
794 	mousedev_table[mousedev->minor] = NULL;
795 	mutex_unlock(&mousedev_table_mutex);
796 }
797 
798 /*
799  * Mark device non-existent. This disables writes, ioctls and
800  * prevents new users from opening the device. Already posted
801  * blocking reads will stay, however new ones will fail.
802  */
803 static void mousedev_mark_dead(struct mousedev *mousedev)
804 {
805 	mutex_lock(&mousedev->mutex);
806 	mousedev->exist = 0;
807 	mutex_unlock(&mousedev->mutex);
808 }
809 
810 /*
811  * Wake up users waiting for IO so they can disconnect from
812  * dead device.
813  */
814 static void mousedev_hangup(struct mousedev *mousedev)
815 {
816 	struct mousedev_client *client;
817 
818 	spin_lock(&mousedev->client_lock);
819 	list_for_each_entry(client, &mousedev->client_list, node)
820 		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
821 	spin_unlock(&mousedev->client_lock);
822 
823 	wake_up_interruptible(&mousedev->wait);
824 }
825 
826 static void mousedev_cleanup(struct mousedev *mousedev)
827 {
828 	struct input_handle *handle = &mousedev->handle;
829 
830 	mousedev_mark_dead(mousedev);
831 	mousedev_hangup(mousedev);
832 	mousedev_remove_chrdev(mousedev);
833 
834 	/* mousedev is marked dead so no one else accesses mousedev->open */
835 	if (mousedev->open)
836 		input_close_device(handle);
837 }
838 
839 static struct mousedev *mousedev_create(struct input_dev *dev,
840 					struct input_handler *handler,
841 					int minor)
842 {
843 	struct mousedev *mousedev;
844 	int error;
845 
846 	mousedev = kzalloc(sizeof(struct mousedev), GFP_KERNEL);
847 	if (!mousedev) {
848 		error = -ENOMEM;
849 		goto err_out;
850 	}
851 
852 	INIT_LIST_HEAD(&mousedev->client_list);
853 	INIT_LIST_HEAD(&mousedev->mixdev_node);
854 	spin_lock_init(&mousedev->client_lock);
855 	mutex_init(&mousedev->mutex);
856 	lockdep_set_subclass(&mousedev->mutex,
857 			     minor == MOUSEDEV_MIX ? MOUSEDEV_MIX : 0);
858 	init_waitqueue_head(&mousedev->wait);
859 
860 	if (minor == MOUSEDEV_MIX)
861 		strlcpy(mousedev->name, "mice", sizeof(mousedev->name));
862 	else
863 		snprintf(mousedev->name, sizeof(mousedev->name),
864 			 "mouse%d", minor);
865 
866 	mousedev->minor = minor;
867 	mousedev->exist = 1;
868 	mousedev->handle.dev = dev;
869 	mousedev->handle.name = mousedev->name;
870 	mousedev->handle.handler = handler;
871 	mousedev->handle.private = mousedev;
872 
873 	strlcpy(mousedev->dev.bus_id, mousedev->name,
874 		sizeof(mousedev->dev.bus_id));
875 	mousedev->dev.class = &input_class;
876 	if (dev)
877 		mousedev->dev.parent = &dev->dev;
878 	mousedev->dev.devt = MKDEV(INPUT_MAJOR, MOUSEDEV_MINOR_BASE + minor);
879 	mousedev->dev.release = mousedev_free;
880 	device_initialize(&mousedev->dev);
881 
882 	if (minor != MOUSEDEV_MIX) {
883 		error = input_register_handle(&mousedev->handle);
884 		if (error)
885 			goto err_free_mousedev;
886 	}
887 
888 	error = mousedev_install_chrdev(mousedev);
889 	if (error)
890 		goto err_unregister_handle;
891 
892 	error = device_add(&mousedev->dev);
893 	if (error)
894 		goto err_cleanup_mousedev;
895 
896 	return mousedev;
897 
898  err_cleanup_mousedev:
899 	mousedev_cleanup(mousedev);
900  err_unregister_handle:
901 	if (minor != MOUSEDEV_MIX)
902 		input_unregister_handle(&mousedev->handle);
903  err_free_mousedev:
904 	put_device(&mousedev->dev);
905  err_out:
906 	return ERR_PTR(error);
907 }
908 
909 static void mousedev_destroy(struct mousedev *mousedev)
910 {
911 	device_del(&mousedev->dev);
912 	mousedev_cleanup(mousedev);
913 	if (mousedev->minor != MOUSEDEV_MIX)
914 		input_unregister_handle(&mousedev->handle);
915 	put_device(&mousedev->dev);
916 }
917 
918 static int mixdev_add_device(struct mousedev *mousedev)
919 {
920 	int retval;
921 
922 	retval = mutex_lock_interruptible(&mousedev_mix->mutex);
923 	if (retval)
924 		return retval;
925 
926 	if (mousedev_mix->open) {
927 		retval = mousedev_open_device(mousedev);
928 		if (retval)
929 			goto out;
930 
931 		mousedev->mixdev_open = 1;
932 	}
933 
934 	get_device(&mousedev->dev);
935 	list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list);
936 
937  out:
938 	mutex_unlock(&mousedev_mix->mutex);
939 	return retval;
940 }
941 
942 static void mixdev_remove_device(struct mousedev *mousedev)
943 {
944 	mutex_lock(&mousedev_mix->mutex);
945 
946 	if (mousedev->mixdev_open) {
947 		mousedev->mixdev_open = 0;
948 		mousedev_close_device(mousedev);
949 	}
950 
951 	list_del_init(&mousedev->mixdev_node);
952 	mutex_unlock(&mousedev_mix->mutex);
953 
954 	put_device(&mousedev->dev);
955 }
956 
957 static int mousedev_connect(struct input_handler *handler,
958 			    struct input_dev *dev,
959 			    const struct input_device_id *id)
960 {
961 	struct mousedev *mousedev;
962 	int minor;
963 	int error;
964 
965 	for (minor = 0; minor < MOUSEDEV_MINORS; minor++)
966 		if (!mousedev_table[minor])
967 			break;
968 
969 	if (minor == MOUSEDEV_MINORS) {
970 		printk(KERN_ERR "mousedev: no more free mousedev devices\n");
971 		return -ENFILE;
972 	}
973 
974 	mousedev = mousedev_create(dev, handler, minor);
975 	if (IS_ERR(mousedev))
976 		return PTR_ERR(mousedev);
977 
978 	error = mixdev_add_device(mousedev);
979 	if (error) {
980 		mousedev_destroy(mousedev);
981 		return error;
982 	}
983 
984 	return 0;
985 }
986 
987 static void mousedev_disconnect(struct input_handle *handle)
988 {
989 	struct mousedev *mousedev = handle->private;
990 
991 	mixdev_remove_device(mousedev);
992 	mousedev_destroy(mousedev);
993 }
994 
995 static const struct input_device_id mousedev_ids[] = {
996 	{
997 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
998 				INPUT_DEVICE_ID_MATCH_KEYBIT |
999 				INPUT_DEVICE_ID_MATCH_RELBIT,
1000 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1001 		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1002 		.relbit = { BIT_MASK(REL_X) | BIT_MASK(REL_Y) },
1003 	},	/* A mouse like device, at least one button,
1004 		   two relative axes */
1005 	{
1006 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1007 				INPUT_DEVICE_ID_MATCH_RELBIT,
1008 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1009 		.relbit = { BIT_MASK(REL_WHEEL) },
1010 	},	/* A separate scrollwheel */
1011 	{
1012 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1013 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1014 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1015 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1016 		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
1017 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1018 	},	/* A tablet like device, at least touch detection,
1019 		   two absolute axes */
1020 	{
1021 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1022 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1023 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1024 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1025 		.keybit = { [BIT_WORD(BTN_TOOL_FINGER)] =
1026 				BIT_MASK(BTN_TOOL_FINGER) },
1027 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
1028 				BIT_MASK(ABS_PRESSURE) |
1029 				BIT_MASK(ABS_TOOL_WIDTH) },
1030 	},	/* A touchpad */
1031 	{
1032 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1033 			INPUT_DEVICE_ID_MATCH_KEYBIT |
1034 			INPUT_DEVICE_ID_MATCH_ABSBIT,
1035 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1036 		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1037 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1038 	},	/* Mouse-like device with absolute X and Y but ordinary
1039 		   clicks, like hp ILO2 High Performance mouse */
1040 
1041 	{ },	/* Terminating entry */
1042 };
1043 
1044 MODULE_DEVICE_TABLE(input, mousedev_ids);
1045 
1046 static struct input_handler mousedev_handler = {
1047 	.event =	mousedev_event,
1048 	.connect =	mousedev_connect,
1049 	.disconnect =	mousedev_disconnect,
1050 	.fops =		&mousedev_fops,
1051 	.minor =	MOUSEDEV_MINOR_BASE,
1052 	.name =		"mousedev",
1053 	.id_table =	mousedev_ids,
1054 };
1055 
1056 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1057 static struct miscdevice psaux_mouse = {
1058 	PSMOUSE_MINOR, "psaux", &mousedev_fops
1059 };
1060 static int psaux_registered;
1061 #endif
1062 
1063 static int __init mousedev_init(void)
1064 {
1065 	int error;
1066 
1067 	mousedev_mix = mousedev_create(NULL, &mousedev_handler, MOUSEDEV_MIX);
1068 	if (IS_ERR(mousedev_mix))
1069 		return PTR_ERR(mousedev_mix);
1070 
1071 	error = input_register_handler(&mousedev_handler);
1072 	if (error) {
1073 		mousedev_destroy(mousedev_mix);
1074 		return error;
1075 	}
1076 
1077 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1078 	error = misc_register(&psaux_mouse);
1079 	if (error)
1080 		printk(KERN_WARNING "mice: could not register psaux device, "
1081 			"error: %d\n", error);
1082 	else
1083 		psaux_registered = 1;
1084 #endif
1085 
1086 	printk(KERN_INFO "mice: PS/2 mouse device common for all mice\n");
1087 
1088 	return 0;
1089 }
1090 
1091 static void __exit mousedev_exit(void)
1092 {
1093 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1094 	if (psaux_registered)
1095 		misc_deregister(&psaux_mouse);
1096 #endif
1097 	input_unregister_handler(&mousedev_handler);
1098 	mousedev_destroy(mousedev_mix);
1099 }
1100 
1101 module_init(mousedev_init);
1102 module_exit(mousedev_exit);
1103