xref: /linux/drivers/input/mousedev.c (revision 765532c8aaac624b5f8687af6d319c6a1138a257)
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/sched.h>
17 #include <linux/slab.h>
18 #include <linux/poll.h>
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/input.h>
22 #include <linux/random.h>
23 #include <linux/major.h>
24 #include <linux/device.h>
25 #include <linux/kernel.h>
26 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
27 #include <linux/miscdevice.h>
28 #endif
29 
30 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
31 MODULE_DESCRIPTION("Mouse (ExplorerPS/2) device interfaces");
32 MODULE_LICENSE("GPL");
33 
34 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_X
35 #define CONFIG_INPUT_MOUSEDEV_SCREEN_X	1024
36 #endif
37 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_Y
38 #define CONFIG_INPUT_MOUSEDEV_SCREEN_Y	768
39 #endif
40 
41 static int xres = CONFIG_INPUT_MOUSEDEV_SCREEN_X;
42 module_param(xres, uint, 0644);
43 MODULE_PARM_DESC(xres, "Horizontal screen resolution");
44 
45 static int yres = CONFIG_INPUT_MOUSEDEV_SCREEN_Y;
46 module_param(yres, uint, 0644);
47 MODULE_PARM_DESC(yres, "Vertical screen resolution");
48 
49 static unsigned tap_time = 200;
50 module_param(tap_time, uint, 0644);
51 MODULE_PARM_DESC(tap_time, "Tap time for touchpads in absolute mode (msecs)");
52 
53 struct mousedev_hw_data {
54 	int dx, dy, dz;
55 	int x, y;
56 	int abs_event;
57 	unsigned long buttons;
58 };
59 
60 struct mousedev {
61 	int open;
62 	int minor;
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 	bool exist;
70 
71 	struct list_head mixdev_node;
72 	int mixdev_open;
73 
74 	struct mousedev_hw_data packet;
75 	unsigned int pkt_count;
76 	int old_x[4], old_y[4];
77 	int frac_dx, frac_dy;
78 	unsigned long touch;
79 };
80 
81 enum mousedev_emul {
82 	MOUSEDEV_EMUL_PS2,
83 	MOUSEDEV_EMUL_IMPS,
84 	MOUSEDEV_EMUL_EXPS
85 };
86 
87 struct mousedev_motion {
88 	int dx, dy, dz;
89 	unsigned long buttons;
90 };
91 
92 #define PACKET_QUEUE_LEN	16
93 struct mousedev_client {
94 	struct fasync_struct *fasync;
95 	struct mousedev *mousedev;
96 	struct list_head node;
97 
98 	struct mousedev_motion packets[PACKET_QUEUE_LEN];
99 	unsigned int head, tail;
100 	spinlock_t packet_lock;
101 	int pos_x, pos_y;
102 
103 	signed char ps2[6];
104 	unsigned char ready, buffer, bufsiz;
105 	unsigned char imexseq, impsseq;
106 	enum mousedev_emul mode;
107 	unsigned long last_buttons;
108 };
109 
110 #define MOUSEDEV_SEQ_LEN	6
111 
112 static unsigned char mousedev_imps_seq[] = { 0xf3, 200, 0xf3, 100, 0xf3, 80 };
113 static unsigned char mousedev_imex_seq[] = { 0xf3, 200, 0xf3, 200, 0xf3, 80 };
114 
115 static struct input_handler mousedev_handler;
116 
117 static struct mousedev *mousedev_table[MOUSEDEV_MINORS];
118 static DEFINE_MUTEX(mousedev_table_mutex);
119 static struct mousedev *mousedev_mix;
120 static LIST_HEAD(mousedev_mix_list);
121 
122 static void mixdev_open_devices(void);
123 static void mixdev_close_devices(void);
124 
125 #define fx(i)  (mousedev->old_x[(mousedev->pkt_count - (i)) & 03])
126 #define fy(i)  (mousedev->old_y[(mousedev->pkt_count - (i)) & 03])
127 
128 static void mousedev_touchpad_event(struct input_dev *dev,
129 				    struct mousedev *mousedev,
130 				    unsigned int code, int value)
131 {
132 	int size, tmp;
133 	enum { FRACTION_DENOM = 128 };
134 
135 	switch (code) {
136 
137 	case ABS_X:
138 
139 		fx(0) = value;
140 		if (mousedev->touch && mousedev->pkt_count >= 2) {
141 			size = input_abs_get_max(dev, ABS_X) -
142 					input_abs_get_min(dev, ABS_X);
143 			if (size == 0)
144 				size = 256 * 2;
145 
146 			tmp = ((value - fx(2)) * 256 * FRACTION_DENOM) / size;
147 			tmp += mousedev->frac_dx;
148 			mousedev->packet.dx = tmp / FRACTION_DENOM;
149 			mousedev->frac_dx =
150 				tmp - mousedev->packet.dx * FRACTION_DENOM;
151 		}
152 		break;
153 
154 	case ABS_Y:
155 		fy(0) = value;
156 		if (mousedev->touch && mousedev->pkt_count >= 2) {
157 			/* use X size for ABS_Y to keep the same scale */
158 			size = input_abs_get_max(dev, ABS_X) -
159 					input_abs_get_min(dev, ABS_X);
160 			if (size == 0)
161 				size = 256 * 2;
162 
163 			tmp = -((value - fy(2)) * 256 * FRACTION_DENOM) / size;
164 			tmp += mousedev->frac_dy;
165 			mousedev->packet.dy = tmp / FRACTION_DENOM;
166 			mousedev->frac_dy = tmp -
167 				mousedev->packet.dy * FRACTION_DENOM;
168 		}
169 		break;
170 	}
171 }
172 
173 static void mousedev_abs_event(struct input_dev *dev, struct mousedev *mousedev,
174 				unsigned int code, int value)
175 {
176 	int min, max, size;
177 
178 	switch (code) {
179 
180 	case ABS_X:
181 		min = input_abs_get_min(dev, ABS_X);
182 		max = input_abs_get_max(dev, ABS_X);
183 
184 		size = max - min;
185 		if (size == 0)
186 			size = xres ? : 1;
187 
188 		clamp(value, min, max);
189 
190 		mousedev->packet.x = ((value - min) * xres) / size;
191 		mousedev->packet.abs_event = 1;
192 		break;
193 
194 	case ABS_Y:
195 		min = input_abs_get_min(dev, ABS_Y);
196 		max = input_abs_get_max(dev, ABS_Y);
197 
198 		size = max - min;
199 		if (size == 0)
200 			size = yres ? : 1;
201 
202 		clamp(value, min, max);
203 
204 		mousedev->packet.y = yres - ((value - min) * yres) / size;
205 		mousedev->packet.abs_event = 1;
206 		break;
207 	}
208 }
209 
210 static void mousedev_rel_event(struct mousedev *mousedev,
211 				unsigned int code, int value)
212 {
213 	switch (code) {
214 	case REL_X:
215 		mousedev->packet.dx += value;
216 		break;
217 
218 	case REL_Y:
219 		mousedev->packet.dy -= value;
220 		break;
221 
222 	case REL_WHEEL:
223 		mousedev->packet.dz -= value;
224 		break;
225 	}
226 }
227 
228 static void mousedev_key_event(struct mousedev *mousedev,
229 				unsigned int code, int value)
230 {
231 	int index;
232 
233 	switch (code) {
234 
235 	case BTN_TOUCH:
236 	case BTN_0:
237 	case BTN_LEFT:		index = 0; break;
238 
239 	case BTN_STYLUS:
240 	case BTN_1:
241 	case BTN_RIGHT:		index = 1; break;
242 
243 	case BTN_2:
244 	case BTN_FORWARD:
245 	case BTN_STYLUS2:
246 	case BTN_MIDDLE:	index = 2; break;
247 
248 	case BTN_3:
249 	case BTN_BACK:
250 	case BTN_SIDE:		index = 3; break;
251 
252 	case BTN_4:
253 	case BTN_EXTRA:		index = 4; break;
254 
255 	default:		return;
256 	}
257 
258 	if (value) {
259 		set_bit(index, &mousedev->packet.buttons);
260 		set_bit(index, &mousedev_mix->packet.buttons);
261 	} else {
262 		clear_bit(index, &mousedev->packet.buttons);
263 		clear_bit(index, &mousedev_mix->packet.buttons);
264 	}
265 }
266 
267 static void mousedev_notify_readers(struct mousedev *mousedev,
268 				    struct mousedev_hw_data *packet)
269 {
270 	struct mousedev_client *client;
271 	struct mousedev_motion *p;
272 	unsigned int new_head;
273 	int wake_readers = 0;
274 
275 	rcu_read_lock();
276 	list_for_each_entry_rcu(client, &mousedev->client_list, node) {
277 
278 		/* Just acquire the lock, interrupts already disabled */
279 		spin_lock(&client->packet_lock);
280 
281 		p = &client->packets[client->head];
282 		if (client->ready && p->buttons != mousedev->packet.buttons) {
283 			new_head = (client->head + 1) % PACKET_QUEUE_LEN;
284 			if (new_head != client->tail) {
285 				p = &client->packets[client->head = new_head];
286 				memset(p, 0, sizeof(struct mousedev_motion));
287 			}
288 		}
289 
290 		if (packet->abs_event) {
291 			p->dx += packet->x - client->pos_x;
292 			p->dy += packet->y - client->pos_y;
293 			client->pos_x = packet->x;
294 			client->pos_y = packet->y;
295 		}
296 
297 		client->pos_x += packet->dx;
298 		client->pos_x = client->pos_x < 0 ?
299 			0 : (client->pos_x >= xres ? xres : client->pos_x);
300 		client->pos_y += packet->dy;
301 		client->pos_y = client->pos_y < 0 ?
302 			0 : (client->pos_y >= yres ? yres : client->pos_y);
303 
304 		p->dx += packet->dx;
305 		p->dy += packet->dy;
306 		p->dz += packet->dz;
307 		p->buttons = mousedev->packet.buttons;
308 
309 		if (p->dx || p->dy || p->dz ||
310 		    p->buttons != client->last_buttons)
311 			client->ready = 1;
312 
313 		spin_unlock(&client->packet_lock);
314 
315 		if (client->ready) {
316 			kill_fasync(&client->fasync, SIGIO, POLL_IN);
317 			wake_readers = 1;
318 		}
319 	}
320 	rcu_read_unlock();
321 
322 	if (wake_readers)
323 		wake_up_interruptible(&mousedev->wait);
324 }
325 
326 static void mousedev_touchpad_touch(struct mousedev *mousedev, int value)
327 {
328 	if (!value) {
329 		if (mousedev->touch &&
330 		    time_before(jiffies,
331 				mousedev->touch + msecs_to_jiffies(tap_time))) {
332 			/*
333 			 * Toggle left button to emulate tap.
334 			 * We rely on the fact that mousedev_mix always has 0
335 			 * motion packet so we won't mess current position.
336 			 */
337 			set_bit(0, &mousedev->packet.buttons);
338 			set_bit(0, &mousedev_mix->packet.buttons);
339 			mousedev_notify_readers(mousedev, &mousedev_mix->packet);
340 			mousedev_notify_readers(mousedev_mix,
341 						&mousedev_mix->packet);
342 			clear_bit(0, &mousedev->packet.buttons);
343 			clear_bit(0, &mousedev_mix->packet.buttons);
344 		}
345 		mousedev->touch = mousedev->pkt_count = 0;
346 		mousedev->frac_dx = 0;
347 		mousedev->frac_dy = 0;
348 
349 	} else if (!mousedev->touch)
350 		mousedev->touch = jiffies;
351 }
352 
353 static void mousedev_event(struct input_handle *handle,
354 			   unsigned int type, unsigned int code, int value)
355 {
356 	struct mousedev *mousedev = handle->private;
357 
358 	switch (type) {
359 
360 	case EV_ABS:
361 		/* Ignore joysticks */
362 		if (test_bit(BTN_TRIGGER, handle->dev->keybit))
363 			return;
364 
365 		if (test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
366 			mousedev_touchpad_event(handle->dev,
367 						mousedev, code, value);
368 		else
369 			mousedev_abs_event(handle->dev, mousedev, code, value);
370 
371 		break;
372 
373 	case EV_REL:
374 		mousedev_rel_event(mousedev, code, value);
375 		break;
376 
377 	case EV_KEY:
378 		if (value != 2) {
379 			if (code == BTN_TOUCH &&
380 			    test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
381 				mousedev_touchpad_touch(mousedev, value);
382 			else
383 				mousedev_key_event(mousedev, code, value);
384 		}
385 		break;
386 
387 	case EV_SYN:
388 		if (code == SYN_REPORT) {
389 			if (mousedev->touch) {
390 				mousedev->pkt_count++;
391 				/*
392 				 * Input system eats duplicate events,
393 				 * but we need all of them to do correct
394 				 * averaging so apply present one forward
395 				 */
396 				fx(0) = fx(1);
397 				fy(0) = fy(1);
398 			}
399 
400 			mousedev_notify_readers(mousedev, &mousedev->packet);
401 			mousedev_notify_readers(mousedev_mix, &mousedev->packet);
402 
403 			mousedev->packet.dx = mousedev->packet.dy =
404 				mousedev->packet.dz = 0;
405 			mousedev->packet.abs_event = 0;
406 		}
407 		break;
408 	}
409 }
410 
411 static int mousedev_fasync(int fd, struct file *file, int on)
412 {
413 	struct mousedev_client *client = file->private_data;
414 
415 	return fasync_helper(fd, file, on, &client->fasync);
416 }
417 
418 static void mousedev_free(struct device *dev)
419 {
420 	struct mousedev *mousedev = container_of(dev, struct mousedev, dev);
421 
422 	input_put_device(mousedev->handle.dev);
423 	kfree(mousedev);
424 }
425 
426 static int mousedev_open_device(struct mousedev *mousedev)
427 {
428 	int retval;
429 
430 	retval = mutex_lock_interruptible(&mousedev->mutex);
431 	if (retval)
432 		return retval;
433 
434 	if (mousedev->minor == MOUSEDEV_MIX)
435 		mixdev_open_devices();
436 	else if (!mousedev->exist)
437 		retval = -ENODEV;
438 	else if (!mousedev->open++) {
439 		retval = input_open_device(&mousedev->handle);
440 		if (retval)
441 			mousedev->open--;
442 	}
443 
444 	mutex_unlock(&mousedev->mutex);
445 	return retval;
446 }
447 
448 static void mousedev_close_device(struct mousedev *mousedev)
449 {
450 	mutex_lock(&mousedev->mutex);
451 
452 	if (mousedev->minor == MOUSEDEV_MIX)
453 		mixdev_close_devices();
454 	else if (mousedev->exist && !--mousedev->open)
455 		input_close_device(&mousedev->handle);
456 
457 	mutex_unlock(&mousedev->mutex);
458 }
459 
460 /*
461  * Open all available devices so they can all be multiplexed in one.
462  * stream. Note that this function is called with mousedev_mix->mutex
463  * held.
464  */
465 static void mixdev_open_devices(void)
466 {
467 	struct mousedev *mousedev;
468 
469 	if (mousedev_mix->open++)
470 		return;
471 
472 	list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
473 		if (!mousedev->mixdev_open) {
474 			if (mousedev_open_device(mousedev))
475 				continue;
476 
477 			mousedev->mixdev_open = 1;
478 		}
479 	}
480 }
481 
482 /*
483  * Close all devices that were opened as part of multiplexed
484  * device. Note that this function is called with mousedev_mix->mutex
485  * held.
486  */
487 static void mixdev_close_devices(void)
488 {
489 	struct mousedev *mousedev;
490 
491 	if (--mousedev_mix->open)
492 		return;
493 
494 	list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
495 		if (mousedev->mixdev_open) {
496 			mousedev->mixdev_open = 0;
497 			mousedev_close_device(mousedev);
498 		}
499 	}
500 }
501 
502 
503 static void mousedev_attach_client(struct mousedev *mousedev,
504 				   struct mousedev_client *client)
505 {
506 	spin_lock(&mousedev->client_lock);
507 	list_add_tail_rcu(&client->node, &mousedev->client_list);
508 	spin_unlock(&mousedev->client_lock);
509 	synchronize_rcu();
510 }
511 
512 static void mousedev_detach_client(struct mousedev *mousedev,
513 				   struct mousedev_client *client)
514 {
515 	spin_lock(&mousedev->client_lock);
516 	list_del_rcu(&client->node);
517 	spin_unlock(&mousedev->client_lock);
518 	synchronize_rcu();
519 }
520 
521 static int mousedev_release(struct inode *inode, struct file *file)
522 {
523 	struct mousedev_client *client = file->private_data;
524 	struct mousedev *mousedev = client->mousedev;
525 
526 	mousedev_detach_client(mousedev, client);
527 	kfree(client);
528 
529 	mousedev_close_device(mousedev);
530 	put_device(&mousedev->dev);
531 
532 	return 0;
533 }
534 
535 static int mousedev_open(struct inode *inode, struct file *file)
536 {
537 	struct mousedev_client *client;
538 	struct mousedev *mousedev;
539 	int error;
540 	int i;
541 
542 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
543 	if (imajor(inode) == MISC_MAJOR)
544 		i = MOUSEDEV_MIX;
545 	else
546 #endif
547 		i = iminor(inode) - MOUSEDEV_MINOR_BASE;
548 
549 	if (i >= MOUSEDEV_MINORS)
550 		return -ENODEV;
551 
552 	error = mutex_lock_interruptible(&mousedev_table_mutex);
553 	if (error) {
554 		return error;
555 	}
556 	mousedev = mousedev_table[i];
557 	if (mousedev)
558 		get_device(&mousedev->dev);
559 	mutex_unlock(&mousedev_table_mutex);
560 
561 	if (!mousedev) {
562 		return -ENODEV;
563 	}
564 
565 	client = kzalloc(sizeof(struct mousedev_client), GFP_KERNEL);
566 	if (!client) {
567 		error = -ENOMEM;
568 		goto err_put_mousedev;
569 	}
570 
571 	spin_lock_init(&client->packet_lock);
572 	client->pos_x = xres / 2;
573 	client->pos_y = yres / 2;
574 	client->mousedev = mousedev;
575 	mousedev_attach_client(mousedev, client);
576 
577 	error = mousedev_open_device(mousedev);
578 	if (error)
579 		goto err_free_client;
580 
581 	file->private_data = client;
582 	return 0;
583 
584  err_free_client:
585 	mousedev_detach_client(mousedev, client);
586 	kfree(client);
587  err_put_mousedev:
588 	put_device(&mousedev->dev);
589 	return error;
590 }
591 
592 static inline int mousedev_limit_delta(int delta, int limit)
593 {
594 	return delta > limit ? limit : (delta < -limit ? -limit : delta);
595 }
596 
597 static void mousedev_packet(struct mousedev_client *client,
598 			    signed char *ps2_data)
599 {
600 	struct mousedev_motion *p = &client->packets[client->tail];
601 
602 	ps2_data[0] = 0x08 |
603 		((p->dx < 0) << 4) | ((p->dy < 0) << 5) | (p->buttons & 0x07);
604 	ps2_data[1] = mousedev_limit_delta(p->dx, 127);
605 	ps2_data[2] = mousedev_limit_delta(p->dy, 127);
606 	p->dx -= ps2_data[1];
607 	p->dy -= ps2_data[2];
608 
609 	switch (client->mode) {
610 	case MOUSEDEV_EMUL_EXPS:
611 		ps2_data[3] = mousedev_limit_delta(p->dz, 7);
612 		p->dz -= ps2_data[3];
613 		ps2_data[3] = (ps2_data[3] & 0x0f) | ((p->buttons & 0x18) << 1);
614 		client->bufsiz = 4;
615 		break;
616 
617 	case MOUSEDEV_EMUL_IMPS:
618 		ps2_data[0] |=
619 			((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
620 		ps2_data[3] = mousedev_limit_delta(p->dz, 127);
621 		p->dz -= ps2_data[3];
622 		client->bufsiz = 4;
623 		break;
624 
625 	case MOUSEDEV_EMUL_PS2:
626 	default:
627 		ps2_data[0] |=
628 			((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
629 		p->dz = 0;
630 		client->bufsiz = 3;
631 		break;
632 	}
633 
634 	if (!p->dx && !p->dy && !p->dz) {
635 		if (client->tail == client->head) {
636 			client->ready = 0;
637 			client->last_buttons = p->buttons;
638 		} else
639 			client->tail = (client->tail + 1) % PACKET_QUEUE_LEN;
640 	}
641 }
642 
643 static void mousedev_generate_response(struct mousedev_client *client,
644 					int command)
645 {
646 	client->ps2[0] = 0xfa; /* ACK */
647 
648 	switch (command) {
649 
650 	case 0xeb: /* Poll */
651 		mousedev_packet(client, &client->ps2[1]);
652 		client->bufsiz++; /* account for leading ACK */
653 		break;
654 
655 	case 0xf2: /* Get ID */
656 		switch (client->mode) {
657 		case MOUSEDEV_EMUL_PS2:
658 			client->ps2[1] = 0;
659 			break;
660 		case MOUSEDEV_EMUL_IMPS:
661 			client->ps2[1] = 3;
662 			break;
663 		case MOUSEDEV_EMUL_EXPS:
664 			client->ps2[1] = 4;
665 			break;
666 		}
667 		client->bufsiz = 2;
668 		break;
669 
670 	case 0xe9: /* Get info */
671 		client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200;
672 		client->bufsiz = 4;
673 		break;
674 
675 	case 0xff: /* Reset */
676 		client->impsseq = client->imexseq = 0;
677 		client->mode = MOUSEDEV_EMUL_PS2;
678 		client->ps2[1] = 0xaa; client->ps2[2] = 0x00;
679 		client->bufsiz = 3;
680 		break;
681 
682 	default:
683 		client->bufsiz = 1;
684 		break;
685 	}
686 	client->buffer = client->bufsiz;
687 }
688 
689 static ssize_t mousedev_write(struct file *file, const char __user *buffer,
690 				size_t count, loff_t *ppos)
691 {
692 	struct mousedev_client *client = file->private_data;
693 	unsigned char c;
694 	unsigned int i;
695 
696 	for (i = 0; i < count; i++) {
697 
698 		if (get_user(c, buffer + i))
699 			return -EFAULT;
700 
701 		spin_lock_irq(&client->packet_lock);
702 
703 		if (c == mousedev_imex_seq[client->imexseq]) {
704 			if (++client->imexseq == MOUSEDEV_SEQ_LEN) {
705 				client->imexseq = 0;
706 				client->mode = MOUSEDEV_EMUL_EXPS;
707 			}
708 		} else
709 			client->imexseq = 0;
710 
711 		if (c == mousedev_imps_seq[client->impsseq]) {
712 			if (++client->impsseq == MOUSEDEV_SEQ_LEN) {
713 				client->impsseq = 0;
714 				client->mode = MOUSEDEV_EMUL_IMPS;
715 			}
716 		} else
717 			client->impsseq = 0;
718 
719 		mousedev_generate_response(client, c);
720 
721 		spin_unlock_irq(&client->packet_lock);
722 	}
723 
724 	kill_fasync(&client->fasync, SIGIO, POLL_IN);
725 	wake_up_interruptible(&client->mousedev->wait);
726 
727 	return count;
728 }
729 
730 static ssize_t mousedev_read(struct file *file, char __user *buffer,
731 			     size_t count, loff_t *ppos)
732 {
733 	struct mousedev_client *client = file->private_data;
734 	struct mousedev *mousedev = client->mousedev;
735 	signed char data[sizeof(client->ps2)];
736 	int retval = 0;
737 
738 	if (!client->ready && !client->buffer && mousedev->exist &&
739 	    (file->f_flags & O_NONBLOCK))
740 		return -EAGAIN;
741 
742 	retval = wait_event_interruptible(mousedev->wait,
743 			!mousedev->exist || client->ready || client->buffer);
744 	if (retval)
745 		return retval;
746 
747 	if (!mousedev->exist)
748 		return -ENODEV;
749 
750 	spin_lock_irq(&client->packet_lock);
751 
752 	if (!client->buffer && client->ready) {
753 		mousedev_packet(client, client->ps2);
754 		client->buffer = client->bufsiz;
755 	}
756 
757 	if (count > client->buffer)
758 		count = client->buffer;
759 
760 	memcpy(data, client->ps2 + client->bufsiz - client->buffer, count);
761 	client->buffer -= count;
762 
763 	spin_unlock_irq(&client->packet_lock);
764 
765 	if (copy_to_user(buffer, data, count))
766 		return -EFAULT;
767 
768 	return count;
769 }
770 
771 /* No kernel lock - fine */
772 static unsigned int mousedev_poll(struct file *file, poll_table *wait)
773 {
774 	struct mousedev_client *client = file->private_data;
775 	struct mousedev *mousedev = client->mousedev;
776 	unsigned int mask;
777 
778 	poll_wait(file, &mousedev->wait, wait);
779 
780 	mask = mousedev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR;
781 	if (client->ready || client->buffer)
782 		mask |= POLLIN | POLLRDNORM;
783 
784 	return mask;
785 }
786 
787 static const struct file_operations mousedev_fops = {
788 	.owner =	THIS_MODULE,
789 	.read =		mousedev_read,
790 	.write =	mousedev_write,
791 	.poll =		mousedev_poll,
792 	.open =		mousedev_open,
793 	.release =	mousedev_release,
794 	.fasync =	mousedev_fasync,
795 	.llseek = noop_llseek,
796 };
797 
798 static int mousedev_install_chrdev(struct mousedev *mousedev)
799 {
800 	mousedev_table[mousedev->minor] = mousedev;
801 	return 0;
802 }
803 
804 static void mousedev_remove_chrdev(struct mousedev *mousedev)
805 {
806 	mutex_lock(&mousedev_table_mutex);
807 	mousedev_table[mousedev->minor] = NULL;
808 	mutex_unlock(&mousedev_table_mutex);
809 }
810 
811 /*
812  * Mark device non-existent. This disables writes, ioctls and
813  * prevents new users from opening the device. Already posted
814  * blocking reads will stay, however new ones will fail.
815  */
816 static void mousedev_mark_dead(struct mousedev *mousedev)
817 {
818 	mutex_lock(&mousedev->mutex);
819 	mousedev->exist = false;
820 	mutex_unlock(&mousedev->mutex);
821 }
822 
823 /*
824  * Wake up users waiting for IO so they can disconnect from
825  * dead device.
826  */
827 static void mousedev_hangup(struct mousedev *mousedev)
828 {
829 	struct mousedev_client *client;
830 
831 	spin_lock(&mousedev->client_lock);
832 	list_for_each_entry(client, &mousedev->client_list, node)
833 		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
834 	spin_unlock(&mousedev->client_lock);
835 
836 	wake_up_interruptible(&mousedev->wait);
837 }
838 
839 static void mousedev_cleanup(struct mousedev *mousedev)
840 {
841 	struct input_handle *handle = &mousedev->handle;
842 
843 	mousedev_mark_dead(mousedev);
844 	mousedev_hangup(mousedev);
845 	mousedev_remove_chrdev(mousedev);
846 
847 	/* mousedev is marked dead so no one else accesses mousedev->open */
848 	if (mousedev->open)
849 		input_close_device(handle);
850 }
851 
852 static struct mousedev *mousedev_create(struct input_dev *dev,
853 					struct input_handler *handler,
854 					int minor)
855 {
856 	struct mousedev *mousedev;
857 	int error;
858 
859 	mousedev = kzalloc(sizeof(struct mousedev), GFP_KERNEL);
860 	if (!mousedev) {
861 		error = -ENOMEM;
862 		goto err_out;
863 	}
864 
865 	INIT_LIST_HEAD(&mousedev->client_list);
866 	INIT_LIST_HEAD(&mousedev->mixdev_node);
867 	spin_lock_init(&mousedev->client_lock);
868 	mutex_init(&mousedev->mutex);
869 	lockdep_set_subclass(&mousedev->mutex,
870 			     minor == MOUSEDEV_MIX ? SINGLE_DEPTH_NESTING : 0);
871 	init_waitqueue_head(&mousedev->wait);
872 
873 	if (minor == MOUSEDEV_MIX)
874 		dev_set_name(&mousedev->dev, "mice");
875 	else
876 		dev_set_name(&mousedev->dev, "mouse%d", minor);
877 
878 	mousedev->minor = minor;
879 	mousedev->exist = true;
880 	mousedev->handle.dev = input_get_device(dev);
881 	mousedev->handle.name = dev_name(&mousedev->dev);
882 	mousedev->handle.handler = handler;
883 	mousedev->handle.private = mousedev;
884 
885 	mousedev->dev.class = &input_class;
886 	if (dev)
887 		mousedev->dev.parent = &dev->dev;
888 	mousedev->dev.devt = MKDEV(INPUT_MAJOR, MOUSEDEV_MINOR_BASE + minor);
889 	mousedev->dev.release = mousedev_free;
890 	device_initialize(&mousedev->dev);
891 
892 	if (minor != MOUSEDEV_MIX) {
893 		error = input_register_handle(&mousedev->handle);
894 		if (error)
895 			goto err_free_mousedev;
896 	}
897 
898 	error = mousedev_install_chrdev(mousedev);
899 	if (error)
900 		goto err_unregister_handle;
901 
902 	error = device_add(&mousedev->dev);
903 	if (error)
904 		goto err_cleanup_mousedev;
905 
906 	return mousedev;
907 
908  err_cleanup_mousedev:
909 	mousedev_cleanup(mousedev);
910  err_unregister_handle:
911 	if (minor != MOUSEDEV_MIX)
912 		input_unregister_handle(&mousedev->handle);
913  err_free_mousedev:
914 	put_device(&mousedev->dev);
915  err_out:
916 	return ERR_PTR(error);
917 }
918 
919 static void mousedev_destroy(struct mousedev *mousedev)
920 {
921 	device_del(&mousedev->dev);
922 	mousedev_cleanup(mousedev);
923 	if (mousedev->minor != MOUSEDEV_MIX)
924 		input_unregister_handle(&mousedev->handle);
925 	put_device(&mousedev->dev);
926 }
927 
928 static int mixdev_add_device(struct mousedev *mousedev)
929 {
930 	int retval;
931 
932 	retval = mutex_lock_interruptible(&mousedev_mix->mutex);
933 	if (retval)
934 		return retval;
935 
936 	if (mousedev_mix->open) {
937 		retval = mousedev_open_device(mousedev);
938 		if (retval)
939 			goto out;
940 
941 		mousedev->mixdev_open = 1;
942 	}
943 
944 	get_device(&mousedev->dev);
945 	list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list);
946 
947  out:
948 	mutex_unlock(&mousedev_mix->mutex);
949 	return retval;
950 }
951 
952 static void mixdev_remove_device(struct mousedev *mousedev)
953 {
954 	mutex_lock(&mousedev_mix->mutex);
955 
956 	if (mousedev->mixdev_open) {
957 		mousedev->mixdev_open = 0;
958 		mousedev_close_device(mousedev);
959 	}
960 
961 	list_del_init(&mousedev->mixdev_node);
962 	mutex_unlock(&mousedev_mix->mutex);
963 
964 	put_device(&mousedev->dev);
965 }
966 
967 static int mousedev_connect(struct input_handler *handler,
968 			    struct input_dev *dev,
969 			    const struct input_device_id *id)
970 {
971 	struct mousedev *mousedev;
972 	int minor;
973 	int error;
974 
975 	for (minor = 0; minor < MOUSEDEV_MINORS; minor++)
976 		if (!mousedev_table[minor])
977 			break;
978 
979 	if (minor == MOUSEDEV_MINORS) {
980 		printk(KERN_ERR "mousedev: no more free mousedev devices\n");
981 		return -ENFILE;
982 	}
983 
984 	mousedev = mousedev_create(dev, handler, minor);
985 	if (IS_ERR(mousedev))
986 		return PTR_ERR(mousedev);
987 
988 	error = mixdev_add_device(mousedev);
989 	if (error) {
990 		mousedev_destroy(mousedev);
991 		return error;
992 	}
993 
994 	return 0;
995 }
996 
997 static void mousedev_disconnect(struct input_handle *handle)
998 {
999 	struct mousedev *mousedev = handle->private;
1000 
1001 	mixdev_remove_device(mousedev);
1002 	mousedev_destroy(mousedev);
1003 }
1004 
1005 static const struct input_device_id mousedev_ids[] = {
1006 	{
1007 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1008 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1009 				INPUT_DEVICE_ID_MATCH_RELBIT,
1010 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1011 		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1012 		.relbit = { BIT_MASK(REL_X) | BIT_MASK(REL_Y) },
1013 	},	/* A mouse like device, at least one button,
1014 		   two relative axes */
1015 	{
1016 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1017 				INPUT_DEVICE_ID_MATCH_RELBIT,
1018 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1019 		.relbit = { BIT_MASK(REL_WHEEL) },
1020 	},	/* A separate scrollwheel */
1021 	{
1022 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1023 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1024 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1025 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1026 		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
1027 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1028 	},	/* A tablet like device, at least touch detection,
1029 		   two absolute axes */
1030 	{
1031 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1032 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1033 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1034 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1035 		.keybit = { [BIT_WORD(BTN_TOOL_FINGER)] =
1036 				BIT_MASK(BTN_TOOL_FINGER) },
1037 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
1038 				BIT_MASK(ABS_PRESSURE) |
1039 				BIT_MASK(ABS_TOOL_WIDTH) },
1040 	},	/* A touchpad */
1041 	{
1042 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1043 			INPUT_DEVICE_ID_MATCH_KEYBIT |
1044 			INPUT_DEVICE_ID_MATCH_ABSBIT,
1045 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1046 		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1047 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1048 	},	/* Mouse-like device with absolute X and Y but ordinary
1049 		   clicks, like hp ILO2 High Performance mouse */
1050 
1051 	{ },	/* Terminating entry */
1052 };
1053 
1054 MODULE_DEVICE_TABLE(input, mousedev_ids);
1055 
1056 static struct input_handler mousedev_handler = {
1057 	.event =	mousedev_event,
1058 	.connect =	mousedev_connect,
1059 	.disconnect =	mousedev_disconnect,
1060 	.fops =		&mousedev_fops,
1061 	.minor =	MOUSEDEV_MINOR_BASE,
1062 	.name =		"mousedev",
1063 	.id_table =	mousedev_ids,
1064 };
1065 
1066 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1067 static struct miscdevice psaux_mouse = {
1068 	PSMOUSE_MINOR, "psaux", &mousedev_fops
1069 };
1070 static int psaux_registered;
1071 #endif
1072 
1073 static int __init mousedev_init(void)
1074 {
1075 	int error;
1076 
1077 	mousedev_mix = mousedev_create(NULL, &mousedev_handler, MOUSEDEV_MIX);
1078 	if (IS_ERR(mousedev_mix))
1079 		return PTR_ERR(mousedev_mix);
1080 
1081 	error = input_register_handler(&mousedev_handler);
1082 	if (error) {
1083 		mousedev_destroy(mousedev_mix);
1084 		return error;
1085 	}
1086 
1087 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1088 	error = misc_register(&psaux_mouse);
1089 	if (error)
1090 		printk(KERN_WARNING "mice: could not register psaux device, "
1091 			"error: %d\n", error);
1092 	else
1093 		psaux_registered = 1;
1094 #endif
1095 
1096 	printk(KERN_INFO "mice: PS/2 mouse device common for all mice\n");
1097 
1098 	return 0;
1099 }
1100 
1101 static void __exit mousedev_exit(void)
1102 {
1103 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1104 	if (psaux_registered)
1105 		misc_deregister(&psaux_mouse);
1106 #endif
1107 	input_unregister_handler(&mousedev_handler);
1108 	mousedev_destroy(mousedev_mix);
1109 }
1110 
1111 module_init(mousedev_init);
1112 module_exit(mousedev_exit);
1113