xref: /linux/drivers/input/mousedev.c (revision a33f32244d8550da8b4a26e277ce07d5c6d158b5)
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 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
26 #include <linux/miscdevice.h>
27 #endif
28 
29 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
30 MODULE_DESCRIPTION("Mouse (ExplorerPS/2) device interfaces");
31 MODULE_LICENSE("GPL");
32 
33 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_X
34 #define CONFIG_INPUT_MOUSEDEV_SCREEN_X	1024
35 #endif
36 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_Y
37 #define CONFIG_INPUT_MOUSEDEV_SCREEN_Y	768
38 #endif
39 
40 static int xres = CONFIG_INPUT_MOUSEDEV_SCREEN_X;
41 module_param(xres, uint, 0644);
42 MODULE_PARM_DESC(xres, "Horizontal screen resolution");
43 
44 static int yres = CONFIG_INPUT_MOUSEDEV_SCREEN_Y;
45 module_param(yres, uint, 0644);
46 MODULE_PARM_DESC(yres, "Vertical screen resolution");
47 
48 static unsigned tap_time = 200;
49 module_param(tap_time, uint, 0644);
50 MODULE_PARM_DESC(tap_time, "Tap time for touchpads in absolute mode (msecs)");
51 
52 struct mousedev_hw_data {
53 	int dx, dy, dz;
54 	int x, y;
55 	int abs_event;
56 	unsigned long buttons;
57 };
58 
59 struct mousedev {
60 	int exist;
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 
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 	struct mousedev_client *client = file->private_data;
406 
407 	return fasync_helper(fd, file, on, &client->fasync);
408 }
409 
410 static void mousedev_free(struct device *dev)
411 {
412 	struct mousedev *mousedev = container_of(dev, struct mousedev, dev);
413 
414 	input_put_device(mousedev->handle.dev);
415 	kfree(mousedev);
416 }
417 
418 static int mousedev_open_device(struct mousedev *mousedev)
419 {
420 	int retval;
421 
422 	retval = mutex_lock_interruptible(&mousedev->mutex);
423 	if (retval)
424 		return retval;
425 
426 	if (mousedev->minor == MOUSEDEV_MIX)
427 		mixdev_open_devices();
428 	else if (!mousedev->exist)
429 		retval = -ENODEV;
430 	else if (!mousedev->open++) {
431 		retval = input_open_device(&mousedev->handle);
432 		if (retval)
433 			mousedev->open--;
434 	}
435 
436 	mutex_unlock(&mousedev->mutex);
437 	return retval;
438 }
439 
440 static void mousedev_close_device(struct mousedev *mousedev)
441 {
442 	mutex_lock(&mousedev->mutex);
443 
444 	if (mousedev->minor == MOUSEDEV_MIX)
445 		mixdev_close_devices();
446 	else if (mousedev->exist && !--mousedev->open)
447 		input_close_device(&mousedev->handle);
448 
449 	mutex_unlock(&mousedev->mutex);
450 }
451 
452 /*
453  * Open all available devices so they can all be multiplexed in one.
454  * stream. Note that this function is called with mousedev_mix->mutex
455  * held.
456  */
457 static void mixdev_open_devices(void)
458 {
459 	struct mousedev *mousedev;
460 
461 	if (mousedev_mix->open++)
462 		return;
463 
464 	list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
465 		if (!mousedev->mixdev_open) {
466 			if (mousedev_open_device(mousedev))
467 				continue;
468 
469 			mousedev->mixdev_open = 1;
470 		}
471 	}
472 }
473 
474 /*
475  * Close all devices that were opened as part of multiplexed
476  * device. Note that this function is called with mousedev_mix->mutex
477  * held.
478  */
479 static void mixdev_close_devices(void)
480 {
481 	struct mousedev *mousedev;
482 
483 	if (--mousedev_mix->open)
484 		return;
485 
486 	list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
487 		if (mousedev->mixdev_open) {
488 			mousedev->mixdev_open = 0;
489 			mousedev_close_device(mousedev);
490 		}
491 	}
492 }
493 
494 
495 static void mousedev_attach_client(struct mousedev *mousedev,
496 				   struct mousedev_client *client)
497 {
498 	spin_lock(&mousedev->client_lock);
499 	list_add_tail_rcu(&client->node, &mousedev->client_list);
500 	spin_unlock(&mousedev->client_lock);
501 	synchronize_rcu();
502 }
503 
504 static void mousedev_detach_client(struct mousedev *mousedev,
505 				   struct mousedev_client *client)
506 {
507 	spin_lock(&mousedev->client_lock);
508 	list_del_rcu(&client->node);
509 	spin_unlock(&mousedev->client_lock);
510 	synchronize_rcu();
511 }
512 
513 static int mousedev_release(struct inode *inode, struct file *file)
514 {
515 	struct mousedev_client *client = file->private_data;
516 	struct mousedev *mousedev = client->mousedev;
517 
518 	mousedev_detach_client(mousedev, client);
519 	kfree(client);
520 
521 	mousedev_close_device(mousedev);
522 	put_device(&mousedev->dev);
523 
524 	return 0;
525 }
526 
527 static int mousedev_open(struct inode *inode, struct file *file)
528 {
529 	struct mousedev_client *client;
530 	struct mousedev *mousedev;
531 	int error;
532 	int i;
533 
534 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
535 	if (imajor(inode) == MISC_MAJOR)
536 		i = MOUSEDEV_MIX;
537 	else
538 #endif
539 		i = iminor(inode) - MOUSEDEV_MINOR_BASE;
540 
541 	if (i >= MOUSEDEV_MINORS)
542 		return -ENODEV;
543 
544 	error = mutex_lock_interruptible(&mousedev_table_mutex);
545 	if (error) {
546 		return error;
547 	}
548 	mousedev = mousedev_table[i];
549 	if (mousedev)
550 		get_device(&mousedev->dev);
551 	mutex_unlock(&mousedev_table_mutex);
552 
553 	if (!mousedev) {
554 		return -ENODEV;
555 	}
556 
557 	client = kzalloc(sizeof(struct mousedev_client), GFP_KERNEL);
558 	if (!client) {
559 		error = -ENOMEM;
560 		goto err_put_mousedev;
561 	}
562 
563 	spin_lock_init(&client->packet_lock);
564 	client->pos_x = xres / 2;
565 	client->pos_y = yres / 2;
566 	client->mousedev = mousedev;
567 	mousedev_attach_client(mousedev, client);
568 
569 	error = mousedev_open_device(mousedev);
570 	if (error)
571 		goto err_free_client;
572 
573 	file->private_data = client;
574 	return 0;
575 
576  err_free_client:
577 	mousedev_detach_client(mousedev, client);
578 	kfree(client);
579  err_put_mousedev:
580 	put_device(&mousedev->dev);
581 	return error;
582 }
583 
584 static inline int mousedev_limit_delta(int delta, int limit)
585 {
586 	return delta > limit ? limit : (delta < -limit ? -limit : delta);
587 }
588 
589 static void mousedev_packet(struct mousedev_client *client,
590 			    signed char *ps2_data)
591 {
592 	struct mousedev_motion *p = &client->packets[client->tail];
593 
594 	ps2_data[0] = 0x08 |
595 		((p->dx < 0) << 4) | ((p->dy < 0) << 5) | (p->buttons & 0x07);
596 	ps2_data[1] = mousedev_limit_delta(p->dx, 127);
597 	ps2_data[2] = mousedev_limit_delta(p->dy, 127);
598 	p->dx -= ps2_data[1];
599 	p->dy -= ps2_data[2];
600 
601 	switch (client->mode) {
602 	case MOUSEDEV_EMUL_EXPS:
603 		ps2_data[3] = mousedev_limit_delta(p->dz, 7);
604 		p->dz -= ps2_data[3];
605 		ps2_data[3] = (ps2_data[3] & 0x0f) | ((p->buttons & 0x18) << 1);
606 		client->bufsiz = 4;
607 		break;
608 
609 	case MOUSEDEV_EMUL_IMPS:
610 		ps2_data[0] |=
611 			((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
612 		ps2_data[3] = mousedev_limit_delta(p->dz, 127);
613 		p->dz -= ps2_data[3];
614 		client->bufsiz = 4;
615 		break;
616 
617 	case MOUSEDEV_EMUL_PS2:
618 	default:
619 		ps2_data[0] |=
620 			((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
621 		p->dz = 0;
622 		client->bufsiz = 3;
623 		break;
624 	}
625 
626 	if (!p->dx && !p->dy && !p->dz) {
627 		if (client->tail == client->head) {
628 			client->ready = 0;
629 			client->last_buttons = p->buttons;
630 		} else
631 			client->tail = (client->tail + 1) % PACKET_QUEUE_LEN;
632 	}
633 }
634 
635 static void mousedev_generate_response(struct mousedev_client *client,
636 					int command)
637 {
638 	client->ps2[0] = 0xfa; /* ACK */
639 
640 	switch (command) {
641 
642 	case 0xeb: /* Poll */
643 		mousedev_packet(client, &client->ps2[1]);
644 		client->bufsiz++; /* account for leading ACK */
645 		break;
646 
647 	case 0xf2: /* Get ID */
648 		switch (client->mode) {
649 		case MOUSEDEV_EMUL_PS2:
650 			client->ps2[1] = 0;
651 			break;
652 		case MOUSEDEV_EMUL_IMPS:
653 			client->ps2[1] = 3;
654 			break;
655 		case MOUSEDEV_EMUL_EXPS:
656 			client->ps2[1] = 4;
657 			break;
658 		}
659 		client->bufsiz = 2;
660 		break;
661 
662 	case 0xe9: /* Get info */
663 		client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200;
664 		client->bufsiz = 4;
665 		break;
666 
667 	case 0xff: /* Reset */
668 		client->impsseq = client->imexseq = 0;
669 		client->mode = MOUSEDEV_EMUL_PS2;
670 		client->ps2[1] = 0xaa; client->ps2[2] = 0x00;
671 		client->bufsiz = 3;
672 		break;
673 
674 	default:
675 		client->bufsiz = 1;
676 		break;
677 	}
678 	client->buffer = client->bufsiz;
679 }
680 
681 static ssize_t mousedev_write(struct file *file, const char __user *buffer,
682 				size_t count, loff_t *ppos)
683 {
684 	struct mousedev_client *client = file->private_data;
685 	unsigned char c;
686 	unsigned int i;
687 
688 	for (i = 0; i < count; i++) {
689 
690 		if (get_user(c, buffer + i))
691 			return -EFAULT;
692 
693 		spin_lock_irq(&client->packet_lock);
694 
695 		if (c == mousedev_imex_seq[client->imexseq]) {
696 			if (++client->imexseq == MOUSEDEV_SEQ_LEN) {
697 				client->imexseq = 0;
698 				client->mode = MOUSEDEV_EMUL_EXPS;
699 			}
700 		} else
701 			client->imexseq = 0;
702 
703 		if (c == mousedev_imps_seq[client->impsseq]) {
704 			if (++client->impsseq == MOUSEDEV_SEQ_LEN) {
705 				client->impsseq = 0;
706 				client->mode = MOUSEDEV_EMUL_IMPS;
707 			}
708 		} else
709 			client->impsseq = 0;
710 
711 		mousedev_generate_response(client, c);
712 
713 		spin_unlock_irq(&client->packet_lock);
714 	}
715 
716 	kill_fasync(&client->fasync, SIGIO, POLL_IN);
717 	wake_up_interruptible(&client->mousedev->wait);
718 
719 	return count;
720 }
721 
722 static ssize_t mousedev_read(struct file *file, char __user *buffer,
723 			     size_t count, loff_t *ppos)
724 {
725 	struct mousedev_client *client = file->private_data;
726 	struct mousedev *mousedev = client->mousedev;
727 	signed char data[sizeof(client->ps2)];
728 	int retval = 0;
729 
730 	if (!client->ready && !client->buffer && mousedev->exist &&
731 	    (file->f_flags & O_NONBLOCK))
732 		return -EAGAIN;
733 
734 	retval = wait_event_interruptible(mousedev->wait,
735 			!mousedev->exist || client->ready || client->buffer);
736 	if (retval)
737 		return retval;
738 
739 	if (!mousedev->exist)
740 		return -ENODEV;
741 
742 	spin_lock_irq(&client->packet_lock);
743 
744 	if (!client->buffer && client->ready) {
745 		mousedev_packet(client, client->ps2);
746 		client->buffer = client->bufsiz;
747 	}
748 
749 	if (count > client->buffer)
750 		count = client->buffer;
751 
752 	memcpy(data, client->ps2 + client->bufsiz - client->buffer, count);
753 	client->buffer -= count;
754 
755 	spin_unlock_irq(&client->packet_lock);
756 
757 	if (copy_to_user(buffer, data, count))
758 		return -EFAULT;
759 
760 	return count;
761 }
762 
763 /* No kernel lock - fine */
764 static unsigned int mousedev_poll(struct file *file, poll_table *wait)
765 {
766 	struct mousedev_client *client = file->private_data;
767 	struct mousedev *mousedev = client->mousedev;
768 
769 	poll_wait(file, &mousedev->wait, wait);
770 	return ((client->ready || client->buffer) ? (POLLIN | POLLRDNORM) : 0) |
771 		(mousedev->exist ? 0 : (POLLHUP | POLLERR));
772 }
773 
774 static const struct file_operations mousedev_fops = {
775 	.owner =	THIS_MODULE,
776 	.read =		mousedev_read,
777 	.write =	mousedev_write,
778 	.poll =		mousedev_poll,
779 	.open =		mousedev_open,
780 	.release =	mousedev_release,
781 	.fasync =	mousedev_fasync,
782 };
783 
784 static int mousedev_install_chrdev(struct mousedev *mousedev)
785 {
786 	mousedev_table[mousedev->minor] = mousedev;
787 	return 0;
788 }
789 
790 static void mousedev_remove_chrdev(struct mousedev *mousedev)
791 {
792 	mutex_lock(&mousedev_table_mutex);
793 	mousedev_table[mousedev->minor] = NULL;
794 	mutex_unlock(&mousedev_table_mutex);
795 }
796 
797 /*
798  * Mark device non-existent. This disables writes, ioctls and
799  * prevents new users from opening the device. Already posted
800  * blocking reads will stay, however new ones will fail.
801  */
802 static void mousedev_mark_dead(struct mousedev *mousedev)
803 {
804 	mutex_lock(&mousedev->mutex);
805 	mousedev->exist = 0;
806 	mutex_unlock(&mousedev->mutex);
807 }
808 
809 /*
810  * Wake up users waiting for IO so they can disconnect from
811  * dead device.
812  */
813 static void mousedev_hangup(struct mousedev *mousedev)
814 {
815 	struct mousedev_client *client;
816 
817 	spin_lock(&mousedev->client_lock);
818 	list_for_each_entry(client, &mousedev->client_list, node)
819 		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
820 	spin_unlock(&mousedev->client_lock);
821 
822 	wake_up_interruptible(&mousedev->wait);
823 }
824 
825 static void mousedev_cleanup(struct mousedev *mousedev)
826 {
827 	struct input_handle *handle = &mousedev->handle;
828 
829 	mousedev_mark_dead(mousedev);
830 	mousedev_hangup(mousedev);
831 	mousedev_remove_chrdev(mousedev);
832 
833 	/* mousedev is marked dead so no one else accesses mousedev->open */
834 	if (mousedev->open)
835 		input_close_device(handle);
836 }
837 
838 static struct mousedev *mousedev_create(struct input_dev *dev,
839 					struct input_handler *handler,
840 					int minor)
841 {
842 	struct mousedev *mousedev;
843 	int error;
844 
845 	mousedev = kzalloc(sizeof(struct mousedev), GFP_KERNEL);
846 	if (!mousedev) {
847 		error = -ENOMEM;
848 		goto err_out;
849 	}
850 
851 	INIT_LIST_HEAD(&mousedev->client_list);
852 	INIT_LIST_HEAD(&mousedev->mixdev_node);
853 	spin_lock_init(&mousedev->client_lock);
854 	mutex_init(&mousedev->mutex);
855 	lockdep_set_subclass(&mousedev->mutex,
856 			     minor == MOUSEDEV_MIX ? MOUSEDEV_MIX : 0);
857 	init_waitqueue_head(&mousedev->wait);
858 
859 	if (minor == MOUSEDEV_MIX)
860 		dev_set_name(&mousedev->dev, "mice");
861 	else
862 		dev_set_name(&mousedev->dev, "mouse%d", minor);
863 
864 	mousedev->minor = minor;
865 	mousedev->exist = 1;
866 	mousedev->handle.dev = input_get_device(dev);
867 	mousedev->handle.name = dev_name(&mousedev->dev);
868 	mousedev->handle.handler = handler;
869 	mousedev->handle.private = mousedev;
870 
871 	mousedev->dev.class = &input_class;
872 	if (dev)
873 		mousedev->dev.parent = &dev->dev;
874 	mousedev->dev.devt = MKDEV(INPUT_MAJOR, MOUSEDEV_MINOR_BASE + minor);
875 	mousedev->dev.release = mousedev_free;
876 	device_initialize(&mousedev->dev);
877 
878 	if (minor != MOUSEDEV_MIX) {
879 		error = input_register_handle(&mousedev->handle);
880 		if (error)
881 			goto err_free_mousedev;
882 	}
883 
884 	error = mousedev_install_chrdev(mousedev);
885 	if (error)
886 		goto err_unregister_handle;
887 
888 	error = device_add(&mousedev->dev);
889 	if (error)
890 		goto err_cleanup_mousedev;
891 
892 	return mousedev;
893 
894  err_cleanup_mousedev:
895 	mousedev_cleanup(mousedev);
896  err_unregister_handle:
897 	if (minor != MOUSEDEV_MIX)
898 		input_unregister_handle(&mousedev->handle);
899  err_free_mousedev:
900 	put_device(&mousedev->dev);
901  err_out:
902 	return ERR_PTR(error);
903 }
904 
905 static void mousedev_destroy(struct mousedev *mousedev)
906 {
907 	device_del(&mousedev->dev);
908 	mousedev_cleanup(mousedev);
909 	if (mousedev->minor != MOUSEDEV_MIX)
910 		input_unregister_handle(&mousedev->handle);
911 	put_device(&mousedev->dev);
912 }
913 
914 static int mixdev_add_device(struct mousedev *mousedev)
915 {
916 	int retval;
917 
918 	retval = mutex_lock_interruptible(&mousedev_mix->mutex);
919 	if (retval)
920 		return retval;
921 
922 	if (mousedev_mix->open) {
923 		retval = mousedev_open_device(mousedev);
924 		if (retval)
925 			goto out;
926 
927 		mousedev->mixdev_open = 1;
928 	}
929 
930 	get_device(&mousedev->dev);
931 	list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list);
932 
933  out:
934 	mutex_unlock(&mousedev_mix->mutex);
935 	return retval;
936 }
937 
938 static void mixdev_remove_device(struct mousedev *mousedev)
939 {
940 	mutex_lock(&mousedev_mix->mutex);
941 
942 	if (mousedev->mixdev_open) {
943 		mousedev->mixdev_open = 0;
944 		mousedev_close_device(mousedev);
945 	}
946 
947 	list_del_init(&mousedev->mixdev_node);
948 	mutex_unlock(&mousedev_mix->mutex);
949 
950 	put_device(&mousedev->dev);
951 }
952 
953 static int mousedev_connect(struct input_handler *handler,
954 			    struct input_dev *dev,
955 			    const struct input_device_id *id)
956 {
957 	struct mousedev *mousedev;
958 	int minor;
959 	int error;
960 
961 	for (minor = 0; minor < MOUSEDEV_MINORS; minor++)
962 		if (!mousedev_table[minor])
963 			break;
964 
965 	if (minor == MOUSEDEV_MINORS) {
966 		printk(KERN_ERR "mousedev: no more free mousedev devices\n");
967 		return -ENFILE;
968 	}
969 
970 	mousedev = mousedev_create(dev, handler, minor);
971 	if (IS_ERR(mousedev))
972 		return PTR_ERR(mousedev);
973 
974 	error = mixdev_add_device(mousedev);
975 	if (error) {
976 		mousedev_destroy(mousedev);
977 		return error;
978 	}
979 
980 	return 0;
981 }
982 
983 static void mousedev_disconnect(struct input_handle *handle)
984 {
985 	struct mousedev *mousedev = handle->private;
986 
987 	mixdev_remove_device(mousedev);
988 	mousedev_destroy(mousedev);
989 }
990 
991 static const struct input_device_id mousedev_ids[] = {
992 	{
993 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
994 				INPUT_DEVICE_ID_MATCH_KEYBIT |
995 				INPUT_DEVICE_ID_MATCH_RELBIT,
996 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
997 		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
998 		.relbit = { BIT_MASK(REL_X) | BIT_MASK(REL_Y) },
999 	},	/* A mouse like device, at least one button,
1000 		   two relative axes */
1001 	{
1002 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1003 				INPUT_DEVICE_ID_MATCH_RELBIT,
1004 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1005 		.relbit = { BIT_MASK(REL_WHEEL) },
1006 	},	/* A separate scrollwheel */
1007 	{
1008 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1009 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1010 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1011 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1012 		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
1013 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1014 	},	/* A tablet like device, at least touch detection,
1015 		   two absolute axes */
1016 	{
1017 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1018 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1019 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1020 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1021 		.keybit = { [BIT_WORD(BTN_TOOL_FINGER)] =
1022 				BIT_MASK(BTN_TOOL_FINGER) },
1023 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
1024 				BIT_MASK(ABS_PRESSURE) |
1025 				BIT_MASK(ABS_TOOL_WIDTH) },
1026 	},	/* A touchpad */
1027 	{
1028 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1029 			INPUT_DEVICE_ID_MATCH_KEYBIT |
1030 			INPUT_DEVICE_ID_MATCH_ABSBIT,
1031 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1032 		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1033 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1034 	},	/* Mouse-like device with absolute X and Y but ordinary
1035 		   clicks, like hp ILO2 High Performance mouse */
1036 
1037 	{ },	/* Terminating entry */
1038 };
1039 
1040 MODULE_DEVICE_TABLE(input, mousedev_ids);
1041 
1042 static struct input_handler mousedev_handler = {
1043 	.event =	mousedev_event,
1044 	.connect =	mousedev_connect,
1045 	.disconnect =	mousedev_disconnect,
1046 	.fops =		&mousedev_fops,
1047 	.minor =	MOUSEDEV_MINOR_BASE,
1048 	.name =		"mousedev",
1049 	.id_table =	mousedev_ids,
1050 };
1051 
1052 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1053 static struct miscdevice psaux_mouse = {
1054 	PSMOUSE_MINOR, "psaux", &mousedev_fops
1055 };
1056 static int psaux_registered;
1057 #endif
1058 
1059 static int __init mousedev_init(void)
1060 {
1061 	int error;
1062 
1063 	mousedev_mix = mousedev_create(NULL, &mousedev_handler, MOUSEDEV_MIX);
1064 	if (IS_ERR(mousedev_mix))
1065 		return PTR_ERR(mousedev_mix);
1066 
1067 	error = input_register_handler(&mousedev_handler);
1068 	if (error) {
1069 		mousedev_destroy(mousedev_mix);
1070 		return error;
1071 	}
1072 
1073 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1074 	error = misc_register(&psaux_mouse);
1075 	if (error)
1076 		printk(KERN_WARNING "mice: could not register psaux device, "
1077 			"error: %d\n", error);
1078 	else
1079 		psaux_registered = 1;
1080 #endif
1081 
1082 	printk(KERN_INFO "mice: PS/2 mouse device common for all mice\n");
1083 
1084 	return 0;
1085 }
1086 
1087 static void __exit mousedev_exit(void)
1088 {
1089 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1090 	if (psaux_registered)
1091 		misc_deregister(&psaux_mouse);
1092 #endif
1093 	input_unregister_handler(&mousedev_handler);
1094 	mousedev_destroy(mousedev_mix);
1095 }
1096 
1097 module_init(mousedev_init);
1098 module_exit(mousedev_exit);
1099