xref: /openbmc/linux/drivers/input/mousedev.c (revision 545e4006)
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/smp_lock.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 	char name[16];
64 	struct input_handle handle;
65 	wait_queue_head_t wait;
66 	struct list_head client_list;
67 	spinlock_t client_lock; /* protects client_list */
68 	struct mutex mutex;
69 	struct device dev;
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 		fx(0) = value;
139 		if (mousedev->touch && mousedev->pkt_count >= 2) {
140 			size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
141 			if (size == 0)
142 				size = 256 * 2;
143 			tmp = ((value - fx(2)) * 256 * FRACTION_DENOM) / size;
144 			tmp += mousedev->frac_dx;
145 			mousedev->packet.dx = tmp / FRACTION_DENOM;
146 			mousedev->frac_dx =
147 				tmp - mousedev->packet.dx * FRACTION_DENOM;
148 		}
149 		break;
150 
151 	case ABS_Y:
152 		fy(0) = value;
153 		if (mousedev->touch && mousedev->pkt_count >= 2) {
154 			/* use X size to keep the same scale */
155 			size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
156 			if (size == 0)
157 				size = 256 * 2;
158 			tmp = -((value - fy(2)) * 256 * FRACTION_DENOM) / size;
159 			tmp += mousedev->frac_dy;
160 			mousedev->packet.dy = tmp / FRACTION_DENOM;
161 			mousedev->frac_dy = tmp -
162 				mousedev->packet.dy * FRACTION_DENOM;
163 		}
164 		break;
165 	}
166 }
167 
168 static void mousedev_abs_event(struct input_dev *dev, struct mousedev *mousedev,
169 				unsigned int code, int value)
170 {
171 	int size;
172 
173 	switch (code) {
174 
175 	case ABS_X:
176 		size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
177 		if (size == 0)
178 			size = xres ? : 1;
179 		if (value > dev->absmax[ABS_X])
180 			value = dev->absmax[ABS_X];
181 		if (value < dev->absmin[ABS_X])
182 			value = dev->absmin[ABS_X];
183 		mousedev->packet.x =
184 			((value - dev->absmin[ABS_X]) * xres) / size;
185 		mousedev->packet.abs_event = 1;
186 		break;
187 
188 	case ABS_Y:
189 		size = dev->absmax[ABS_Y] - dev->absmin[ABS_Y];
190 		if (size == 0)
191 			size = yres ? : 1;
192 		if (value > dev->absmax[ABS_Y])
193 			value = dev->absmax[ABS_Y];
194 		if (value < dev->absmin[ABS_Y])
195 			value = dev->absmin[ABS_Y];
196 		mousedev->packet.y = yres -
197 			((value - dev->absmin[ABS_Y]) * yres) / size;
198 		mousedev->packet.abs_event = 1;
199 		break;
200 	}
201 }
202 
203 static void mousedev_rel_event(struct mousedev *mousedev,
204 				unsigned int code, int value)
205 {
206 	switch (code) {
207 	case REL_X:
208 		mousedev->packet.dx += value;
209 		break;
210 
211 	case REL_Y:
212 		mousedev->packet.dy -= value;
213 		break;
214 
215 	case REL_WHEEL:
216 		mousedev->packet.dz -= value;
217 		break;
218 	}
219 }
220 
221 static void mousedev_key_event(struct mousedev *mousedev,
222 				unsigned int code, int value)
223 {
224 	int index;
225 
226 	switch (code) {
227 
228 	case BTN_TOUCH:
229 	case BTN_0:
230 	case BTN_LEFT:		index = 0; break;
231 
232 	case BTN_STYLUS:
233 	case BTN_1:
234 	case BTN_RIGHT:		index = 1; break;
235 
236 	case BTN_2:
237 	case BTN_FORWARD:
238 	case BTN_STYLUS2:
239 	case BTN_MIDDLE:	index = 2; break;
240 
241 	case BTN_3:
242 	case BTN_BACK:
243 	case BTN_SIDE:		index = 3; break;
244 
245 	case BTN_4:
246 	case BTN_EXTRA:		index = 4; break;
247 
248 	default:		return;
249 	}
250 
251 	if (value) {
252 		set_bit(index, &mousedev->packet.buttons);
253 		set_bit(index, &mousedev_mix->packet.buttons);
254 	} else {
255 		clear_bit(index, &mousedev->packet.buttons);
256 		clear_bit(index, &mousedev_mix->packet.buttons);
257 	}
258 }
259 
260 static void mousedev_notify_readers(struct mousedev *mousedev,
261 				    struct mousedev_hw_data *packet)
262 {
263 	struct mousedev_client *client;
264 	struct mousedev_motion *p;
265 	unsigned int new_head;
266 	int wake_readers = 0;
267 
268 	rcu_read_lock();
269 	list_for_each_entry_rcu(client, &mousedev->client_list, node) {
270 
271 		/* Just acquire the lock, interrupts already disabled */
272 		spin_lock(&client->packet_lock);
273 
274 		p = &client->packets[client->head];
275 		if (client->ready && p->buttons != mousedev->packet.buttons) {
276 			new_head = (client->head + 1) % PACKET_QUEUE_LEN;
277 			if (new_head != client->tail) {
278 				p = &client->packets[client->head = new_head];
279 				memset(p, 0, sizeof(struct mousedev_motion));
280 			}
281 		}
282 
283 		if (packet->abs_event) {
284 			p->dx += packet->x - client->pos_x;
285 			p->dy += packet->y - client->pos_y;
286 			client->pos_x = packet->x;
287 			client->pos_y = packet->y;
288 		}
289 
290 		client->pos_x += packet->dx;
291 		client->pos_x = client->pos_x < 0 ?
292 			0 : (client->pos_x >= xres ? xres : client->pos_x);
293 		client->pos_y += packet->dy;
294 		client->pos_y = client->pos_y < 0 ?
295 			0 : (client->pos_y >= yres ? yres : client->pos_y);
296 
297 		p->dx += packet->dx;
298 		p->dy += packet->dy;
299 		p->dz += packet->dz;
300 		p->buttons = mousedev->packet.buttons;
301 
302 		if (p->dx || p->dy || p->dz ||
303 		    p->buttons != client->last_buttons)
304 			client->ready = 1;
305 
306 		spin_unlock(&client->packet_lock);
307 
308 		if (client->ready) {
309 			kill_fasync(&client->fasync, SIGIO, POLL_IN);
310 			wake_readers = 1;
311 		}
312 	}
313 	rcu_read_unlock();
314 
315 	if (wake_readers)
316 		wake_up_interruptible(&mousedev->wait);
317 }
318 
319 static void mousedev_touchpad_touch(struct mousedev *mousedev, int value)
320 {
321 	if (!value) {
322 		if (mousedev->touch &&
323 		    time_before(jiffies,
324 				mousedev->touch + msecs_to_jiffies(tap_time))) {
325 			/*
326 			 * Toggle left button to emulate tap.
327 			 * We rely on the fact that mousedev_mix always has 0
328 			 * motion packet so we won't mess current position.
329 			 */
330 			set_bit(0, &mousedev->packet.buttons);
331 			set_bit(0, &mousedev_mix->packet.buttons);
332 			mousedev_notify_readers(mousedev, &mousedev_mix->packet);
333 			mousedev_notify_readers(mousedev_mix,
334 						&mousedev_mix->packet);
335 			clear_bit(0, &mousedev->packet.buttons);
336 			clear_bit(0, &mousedev_mix->packet.buttons);
337 		}
338 		mousedev->touch = mousedev->pkt_count = 0;
339 		mousedev->frac_dx = 0;
340 		mousedev->frac_dy = 0;
341 
342 	} else if (!mousedev->touch)
343 		mousedev->touch = jiffies;
344 }
345 
346 static void mousedev_event(struct input_handle *handle,
347 			   unsigned int type, unsigned int code, int value)
348 {
349 	struct mousedev *mousedev = handle->private;
350 
351 	switch (type) {
352 
353 	case EV_ABS:
354 		/* Ignore joysticks */
355 		if (test_bit(BTN_TRIGGER, handle->dev->keybit))
356 			return;
357 
358 		if (test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
359 			mousedev_touchpad_event(handle->dev,
360 						mousedev, code, value);
361 		else
362 			mousedev_abs_event(handle->dev, mousedev, code, value);
363 
364 		break;
365 
366 	case EV_REL:
367 		mousedev_rel_event(mousedev, code, value);
368 		break;
369 
370 	case EV_KEY:
371 		if (value != 2) {
372 			if (code == BTN_TOUCH &&
373 			    test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
374 				mousedev_touchpad_touch(mousedev, value);
375 			else
376 				mousedev_key_event(mousedev, code, value);
377 		}
378 		break;
379 
380 	case EV_SYN:
381 		if (code == SYN_REPORT) {
382 			if (mousedev->touch) {
383 				mousedev->pkt_count++;
384 				/*
385 				 * Input system eats duplicate events,
386 				 * but we need all of them to do correct
387 				 * averaging so apply present one forward
388 				 */
389 				fx(0) = fx(1);
390 				fy(0) = fy(1);
391 			}
392 
393 			mousedev_notify_readers(mousedev, &mousedev->packet);
394 			mousedev_notify_readers(mousedev_mix, &mousedev->packet);
395 
396 			mousedev->packet.dx = mousedev->packet.dy =
397 				mousedev->packet.dz = 0;
398 			mousedev->packet.abs_event = 0;
399 		}
400 		break;
401 	}
402 }
403 
404 static int mousedev_fasync(int fd, struct file *file, int on)
405 {
406 	int retval;
407 	struct mousedev_client *client = file->private_data;
408 
409 	retval = fasync_helper(fd, file, on, &client->fasync);
410 
411 	return retval < 0 ? retval : 0;
412 }
413 
414 static void mousedev_free(struct device *dev)
415 {
416 	struct mousedev *mousedev = container_of(dev, struct mousedev, dev);
417 
418 	input_put_device(mousedev->handle.dev);
419 	kfree(mousedev);
420 }
421 
422 static int mousedev_open_device(struct mousedev *mousedev)
423 {
424 	int retval;
425 
426 	retval = mutex_lock_interruptible(&mousedev->mutex);
427 	if (retval)
428 		return retval;
429 
430 	if (mousedev->minor == MOUSEDEV_MIX)
431 		mixdev_open_devices();
432 	else if (!mousedev->exist)
433 		retval = -ENODEV;
434 	else if (!mousedev->open++) {
435 		retval = input_open_device(&mousedev->handle);
436 		if (retval)
437 			mousedev->open--;
438 	}
439 
440 	mutex_unlock(&mousedev->mutex);
441 	return retval;
442 }
443 
444 static void mousedev_close_device(struct mousedev *mousedev)
445 {
446 	mutex_lock(&mousedev->mutex);
447 
448 	if (mousedev->minor == MOUSEDEV_MIX)
449 		mixdev_close_devices();
450 	else if (mousedev->exist && !--mousedev->open)
451 		input_close_device(&mousedev->handle);
452 
453 	mutex_unlock(&mousedev->mutex);
454 }
455 
456 /*
457  * Open all available devices so they can all be multiplexed in one.
458  * stream. Note that this function is called with mousedev_mix->mutex
459  * held.
460  */
461 static void mixdev_open_devices(void)
462 {
463 	struct mousedev *mousedev;
464 
465 	if (mousedev_mix->open++)
466 		return;
467 
468 	list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
469 		if (!mousedev->mixdev_open) {
470 			if (mousedev_open_device(mousedev))
471 				continue;
472 
473 			mousedev->mixdev_open = 1;
474 		}
475 	}
476 }
477 
478 /*
479  * Close all devices that were opened as part of multiplexed
480  * device. Note that this function is called with mousedev_mix->mutex
481  * held.
482  */
483 static void mixdev_close_devices(void)
484 {
485 	struct mousedev *mousedev;
486 
487 	if (--mousedev_mix->open)
488 		return;
489 
490 	list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
491 		if (mousedev->mixdev_open) {
492 			mousedev->mixdev_open = 0;
493 			mousedev_close_device(mousedev);
494 		}
495 	}
496 }
497 
498 
499 static void mousedev_attach_client(struct mousedev *mousedev,
500 				   struct mousedev_client *client)
501 {
502 	spin_lock(&mousedev->client_lock);
503 	list_add_tail_rcu(&client->node, &mousedev->client_list);
504 	spin_unlock(&mousedev->client_lock);
505 	synchronize_rcu();
506 }
507 
508 static void mousedev_detach_client(struct mousedev *mousedev,
509 				   struct mousedev_client *client)
510 {
511 	spin_lock(&mousedev->client_lock);
512 	list_del_rcu(&client->node);
513 	spin_unlock(&mousedev->client_lock);
514 	synchronize_rcu();
515 }
516 
517 static int mousedev_release(struct inode *inode, struct file *file)
518 {
519 	struct mousedev_client *client = file->private_data;
520 	struct mousedev *mousedev = client->mousedev;
521 
522 	mousedev_fasync(-1, file, 0);
523 	mousedev_detach_client(mousedev, client);
524 	kfree(client);
525 
526 	mousedev_close_device(mousedev);
527 	put_device(&mousedev->dev);
528 
529 	return 0;
530 }
531 
532 static int mousedev_open(struct inode *inode, struct file *file)
533 {
534 	struct mousedev_client *client;
535 	struct mousedev *mousedev;
536 	int error;
537 	int i;
538 
539 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
540 	if (imajor(inode) == MISC_MAJOR)
541 		i = MOUSEDEV_MIX;
542 	else
543 #endif
544 		i = iminor(inode) - MOUSEDEV_MINOR_BASE;
545 
546 	if (i >= MOUSEDEV_MINORS)
547 		return -ENODEV;
548 
549 	lock_kernel();
550 	error = mutex_lock_interruptible(&mousedev_table_mutex);
551 	if (error) {
552 		unlock_kernel();
553 		return error;
554 	}
555 	mousedev = mousedev_table[i];
556 	if (mousedev)
557 		get_device(&mousedev->dev);
558 	mutex_unlock(&mousedev_table_mutex);
559 
560 	if (!mousedev) {
561 		unlock_kernel();
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 	unlock_kernel();
583 	return 0;
584 
585  err_free_client:
586 	mousedev_detach_client(mousedev, client);
587 	kfree(client);
588  err_put_mousedev:
589 	put_device(&mousedev->dev);
590 	unlock_kernel();
591 	return error;
592 }
593 
594 static inline int mousedev_limit_delta(int delta, int limit)
595 {
596 	return delta > limit ? limit : (delta < -limit ? -limit : delta);
597 }
598 
599 static void mousedev_packet(struct mousedev_client *client,
600 			    signed char *ps2_data)
601 {
602 	struct mousedev_motion *p = &client->packets[client->tail];
603 
604 	ps2_data[0] = 0x08 |
605 		((p->dx < 0) << 4) | ((p->dy < 0) << 5) | (p->buttons & 0x07);
606 	ps2_data[1] = mousedev_limit_delta(p->dx, 127);
607 	ps2_data[2] = mousedev_limit_delta(p->dy, 127);
608 	p->dx -= ps2_data[1];
609 	p->dy -= ps2_data[2];
610 
611 	switch (client->mode) {
612 	case MOUSEDEV_EMUL_EXPS:
613 		ps2_data[3] = mousedev_limit_delta(p->dz, 7);
614 		p->dz -= ps2_data[3];
615 		ps2_data[3] = (ps2_data[3] & 0x0f) | ((p->buttons & 0x18) << 1);
616 		client->bufsiz = 4;
617 		break;
618 
619 	case MOUSEDEV_EMUL_IMPS:
620 		ps2_data[0] |=
621 			((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
622 		ps2_data[3] = mousedev_limit_delta(p->dz, 127);
623 		p->dz -= ps2_data[3];
624 		client->bufsiz = 4;
625 		break;
626 
627 	case MOUSEDEV_EMUL_PS2:
628 	default:
629 		ps2_data[0] |=
630 			((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
631 		p->dz = 0;
632 		client->bufsiz = 3;
633 		break;
634 	}
635 
636 	if (!p->dx && !p->dy && !p->dz) {
637 		if (client->tail == client->head) {
638 			client->ready = 0;
639 			client->last_buttons = p->buttons;
640 		} else
641 			client->tail = (client->tail + 1) % PACKET_QUEUE_LEN;
642 	}
643 }
644 
645 static void mousedev_generate_response(struct mousedev_client *client,
646 					int command)
647 {
648 	client->ps2[0] = 0xfa; /* ACK */
649 
650 	switch (command) {
651 
652 	case 0xeb: /* Poll */
653 		mousedev_packet(client, &client->ps2[1]);
654 		client->bufsiz++; /* account for leading ACK */
655 		break;
656 
657 	case 0xf2: /* Get ID */
658 		switch (client->mode) {
659 		case MOUSEDEV_EMUL_PS2:
660 			client->ps2[1] = 0;
661 			break;
662 		case MOUSEDEV_EMUL_IMPS:
663 			client->ps2[1] = 3;
664 			break;
665 		case MOUSEDEV_EMUL_EXPS:
666 			client->ps2[1] = 4;
667 			break;
668 		}
669 		client->bufsiz = 2;
670 		break;
671 
672 	case 0xe9: /* Get info */
673 		client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200;
674 		client->bufsiz = 4;
675 		break;
676 
677 	case 0xff: /* Reset */
678 		client->impsseq = client->imexseq = 0;
679 		client->mode = MOUSEDEV_EMUL_PS2;
680 		client->ps2[1] = 0xaa; client->ps2[2] = 0x00;
681 		client->bufsiz = 3;
682 		break;
683 
684 	default:
685 		client->bufsiz = 1;
686 		break;
687 	}
688 	client->buffer = client->bufsiz;
689 }
690 
691 static ssize_t mousedev_write(struct file *file, const char __user *buffer,
692 				size_t count, loff_t *ppos)
693 {
694 	struct mousedev_client *client = file->private_data;
695 	unsigned char c;
696 	unsigned int i;
697 
698 	for (i = 0; i < count; i++) {
699 
700 		if (get_user(c, buffer + i))
701 			return -EFAULT;
702 
703 		spin_lock_irq(&client->packet_lock);
704 
705 		if (c == mousedev_imex_seq[client->imexseq]) {
706 			if (++client->imexseq == MOUSEDEV_SEQ_LEN) {
707 				client->imexseq = 0;
708 				client->mode = MOUSEDEV_EMUL_EXPS;
709 			}
710 		} else
711 			client->imexseq = 0;
712 
713 		if (c == mousedev_imps_seq[client->impsseq]) {
714 			if (++client->impsseq == MOUSEDEV_SEQ_LEN) {
715 				client->impsseq = 0;
716 				client->mode = MOUSEDEV_EMUL_IMPS;
717 			}
718 		} else
719 			client->impsseq = 0;
720 
721 		mousedev_generate_response(client, c);
722 
723 		spin_unlock_irq(&client->packet_lock);
724 	}
725 
726 	kill_fasync(&client->fasync, SIGIO, POLL_IN);
727 	wake_up_interruptible(&client->mousedev->wait);
728 
729 	return count;
730 }
731 
732 static ssize_t mousedev_read(struct file *file, char __user *buffer,
733 			     size_t count, loff_t *ppos)
734 {
735 	struct mousedev_client *client = file->private_data;
736 	struct mousedev *mousedev = client->mousedev;
737 	signed char data[sizeof(client->ps2)];
738 	int retval = 0;
739 
740 	if (!client->ready && !client->buffer && mousedev->exist &&
741 	    (file->f_flags & O_NONBLOCK))
742 		return -EAGAIN;
743 
744 	retval = wait_event_interruptible(mousedev->wait,
745 			!mousedev->exist || client->ready || client->buffer);
746 	if (retval)
747 		return retval;
748 
749 	if (!mousedev->exist)
750 		return -ENODEV;
751 
752 	spin_lock_irq(&client->packet_lock);
753 
754 	if (!client->buffer && client->ready) {
755 		mousedev_packet(client, client->ps2);
756 		client->buffer = client->bufsiz;
757 	}
758 
759 	if (count > client->buffer)
760 		count = client->buffer;
761 
762 	memcpy(data, client->ps2 + client->bufsiz - client->buffer, count);
763 	client->buffer -= count;
764 
765 	spin_unlock_irq(&client->packet_lock);
766 
767 	if (copy_to_user(buffer, data, count))
768 		return -EFAULT;
769 
770 	return count;
771 }
772 
773 /* No kernel lock - fine */
774 static unsigned int mousedev_poll(struct file *file, poll_table *wait)
775 {
776 	struct mousedev_client *client = file->private_data;
777 	struct mousedev *mousedev = client->mousedev;
778 
779 	poll_wait(file, &mousedev->wait, wait);
780 	return ((client->ready || client->buffer) ? (POLLIN | POLLRDNORM) : 0) |
781 		(mousedev->exist ? 0 : (POLLHUP | POLLERR));
782 }
783 
784 static const struct file_operations mousedev_fops = {
785 	.owner =	THIS_MODULE,
786 	.read =		mousedev_read,
787 	.write =	mousedev_write,
788 	.poll =		mousedev_poll,
789 	.open =		mousedev_open,
790 	.release =	mousedev_release,
791 	.fasync =	mousedev_fasync,
792 };
793 
794 static int mousedev_install_chrdev(struct mousedev *mousedev)
795 {
796 	mousedev_table[mousedev->minor] = mousedev;
797 	return 0;
798 }
799 
800 static void mousedev_remove_chrdev(struct mousedev *mousedev)
801 {
802 	mutex_lock(&mousedev_table_mutex);
803 	mousedev_table[mousedev->minor] = NULL;
804 	mutex_unlock(&mousedev_table_mutex);
805 }
806 
807 /*
808  * Mark device non-existent. This disables writes, ioctls and
809  * prevents new users from opening the device. Already posted
810  * blocking reads will stay, however new ones will fail.
811  */
812 static void mousedev_mark_dead(struct mousedev *mousedev)
813 {
814 	mutex_lock(&mousedev->mutex);
815 	mousedev->exist = 0;
816 	mutex_unlock(&mousedev->mutex);
817 }
818 
819 /*
820  * Wake up users waiting for IO so they can disconnect from
821  * dead device.
822  */
823 static void mousedev_hangup(struct mousedev *mousedev)
824 {
825 	struct mousedev_client *client;
826 
827 	spin_lock(&mousedev->client_lock);
828 	list_for_each_entry(client, &mousedev->client_list, node)
829 		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
830 	spin_unlock(&mousedev->client_lock);
831 
832 	wake_up_interruptible(&mousedev->wait);
833 }
834 
835 static void mousedev_cleanup(struct mousedev *mousedev)
836 {
837 	struct input_handle *handle = &mousedev->handle;
838 
839 	mousedev_mark_dead(mousedev);
840 	mousedev_hangup(mousedev);
841 	mousedev_remove_chrdev(mousedev);
842 
843 	/* mousedev is marked dead so no one else accesses mousedev->open */
844 	if (mousedev->open)
845 		input_close_device(handle);
846 }
847 
848 static struct mousedev *mousedev_create(struct input_dev *dev,
849 					struct input_handler *handler,
850 					int minor)
851 {
852 	struct mousedev *mousedev;
853 	int error;
854 
855 	mousedev = kzalloc(sizeof(struct mousedev), GFP_KERNEL);
856 	if (!mousedev) {
857 		error = -ENOMEM;
858 		goto err_out;
859 	}
860 
861 	INIT_LIST_HEAD(&mousedev->client_list);
862 	INIT_LIST_HEAD(&mousedev->mixdev_node);
863 	spin_lock_init(&mousedev->client_lock);
864 	mutex_init(&mousedev->mutex);
865 	lockdep_set_subclass(&mousedev->mutex,
866 			     minor == MOUSEDEV_MIX ? MOUSEDEV_MIX : 0);
867 	init_waitqueue_head(&mousedev->wait);
868 
869 	if (minor == MOUSEDEV_MIX)
870 		strlcpy(mousedev->name, "mice", sizeof(mousedev->name));
871 	else
872 		snprintf(mousedev->name, sizeof(mousedev->name),
873 			 "mouse%d", minor);
874 
875 	mousedev->minor = minor;
876 	mousedev->exist = 1;
877 	mousedev->handle.dev = input_get_device(dev);
878 	mousedev->handle.name = mousedev->name;
879 	mousedev->handle.handler = handler;
880 	mousedev->handle.private = mousedev;
881 
882 	strlcpy(mousedev->dev.bus_id, mousedev->name,
883 		sizeof(mousedev->dev.bus_id));
884 	mousedev->dev.class = &input_class;
885 	if (dev)
886 		mousedev->dev.parent = &dev->dev;
887 	mousedev->dev.devt = MKDEV(INPUT_MAJOR, MOUSEDEV_MINOR_BASE + minor);
888 	mousedev->dev.release = mousedev_free;
889 	device_initialize(&mousedev->dev);
890 
891 	if (minor != MOUSEDEV_MIX) {
892 		error = input_register_handle(&mousedev->handle);
893 		if (error)
894 			goto err_free_mousedev;
895 	}
896 
897 	error = mousedev_install_chrdev(mousedev);
898 	if (error)
899 		goto err_unregister_handle;
900 
901 	error = device_add(&mousedev->dev);
902 	if (error)
903 		goto err_cleanup_mousedev;
904 
905 	return mousedev;
906 
907  err_cleanup_mousedev:
908 	mousedev_cleanup(mousedev);
909  err_unregister_handle:
910 	if (minor != MOUSEDEV_MIX)
911 		input_unregister_handle(&mousedev->handle);
912  err_free_mousedev:
913 	put_device(&mousedev->dev);
914  err_out:
915 	return ERR_PTR(error);
916 }
917 
918 static void mousedev_destroy(struct mousedev *mousedev)
919 {
920 	device_del(&mousedev->dev);
921 	mousedev_cleanup(mousedev);
922 	if (mousedev->minor != MOUSEDEV_MIX)
923 		input_unregister_handle(&mousedev->handle);
924 	put_device(&mousedev->dev);
925 }
926 
927 static int mixdev_add_device(struct mousedev *mousedev)
928 {
929 	int retval;
930 
931 	retval = mutex_lock_interruptible(&mousedev_mix->mutex);
932 	if (retval)
933 		return retval;
934 
935 	if (mousedev_mix->open) {
936 		retval = mousedev_open_device(mousedev);
937 		if (retval)
938 			goto out;
939 
940 		mousedev->mixdev_open = 1;
941 	}
942 
943 	get_device(&mousedev->dev);
944 	list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list);
945 
946  out:
947 	mutex_unlock(&mousedev_mix->mutex);
948 	return retval;
949 }
950 
951 static void mixdev_remove_device(struct mousedev *mousedev)
952 {
953 	mutex_lock(&mousedev_mix->mutex);
954 
955 	if (mousedev->mixdev_open) {
956 		mousedev->mixdev_open = 0;
957 		mousedev_close_device(mousedev);
958 	}
959 
960 	list_del_init(&mousedev->mixdev_node);
961 	mutex_unlock(&mousedev_mix->mutex);
962 
963 	put_device(&mousedev->dev);
964 }
965 
966 static int mousedev_connect(struct input_handler *handler,
967 			    struct input_dev *dev,
968 			    const struct input_device_id *id)
969 {
970 	struct mousedev *mousedev;
971 	int minor;
972 	int error;
973 
974 	for (minor = 0; minor < MOUSEDEV_MINORS; minor++)
975 		if (!mousedev_table[minor])
976 			break;
977 
978 	if (minor == MOUSEDEV_MINORS) {
979 		printk(KERN_ERR "mousedev: no more free mousedev devices\n");
980 		return -ENFILE;
981 	}
982 
983 	mousedev = mousedev_create(dev, handler, minor);
984 	if (IS_ERR(mousedev))
985 		return PTR_ERR(mousedev);
986 
987 	error = mixdev_add_device(mousedev);
988 	if (error) {
989 		mousedev_destroy(mousedev);
990 		return error;
991 	}
992 
993 	return 0;
994 }
995 
996 static void mousedev_disconnect(struct input_handle *handle)
997 {
998 	struct mousedev *mousedev = handle->private;
999 
1000 	mixdev_remove_device(mousedev);
1001 	mousedev_destroy(mousedev);
1002 }
1003 
1004 static const struct input_device_id mousedev_ids[] = {
1005 	{
1006 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1007 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1008 				INPUT_DEVICE_ID_MATCH_RELBIT,
1009 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1010 		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1011 		.relbit = { BIT_MASK(REL_X) | BIT_MASK(REL_Y) },
1012 	},	/* A mouse like device, at least one button,
1013 		   two relative axes */
1014 	{
1015 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1016 				INPUT_DEVICE_ID_MATCH_RELBIT,
1017 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1018 		.relbit = { BIT_MASK(REL_WHEEL) },
1019 	},	/* A separate scrollwheel */
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_TOUCH)] = BIT_MASK(BTN_TOUCH) },
1026 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1027 	},	/* A tablet like device, at least touch detection,
1028 		   two absolute axes */
1029 	{
1030 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1031 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1032 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1033 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1034 		.keybit = { [BIT_WORD(BTN_TOOL_FINGER)] =
1035 				BIT_MASK(BTN_TOOL_FINGER) },
1036 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
1037 				BIT_MASK(ABS_PRESSURE) |
1038 				BIT_MASK(ABS_TOOL_WIDTH) },
1039 	},	/* A touchpad */
1040 	{
1041 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1042 			INPUT_DEVICE_ID_MATCH_KEYBIT |
1043 			INPUT_DEVICE_ID_MATCH_ABSBIT,
1044 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1045 		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1046 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1047 	},	/* Mouse-like device with absolute X and Y but ordinary
1048 		   clicks, like hp ILO2 High Performance mouse */
1049 
1050 	{ },	/* Terminating entry */
1051 };
1052 
1053 MODULE_DEVICE_TABLE(input, mousedev_ids);
1054 
1055 static struct input_handler mousedev_handler = {
1056 	.event =	mousedev_event,
1057 	.connect =	mousedev_connect,
1058 	.disconnect =	mousedev_disconnect,
1059 	.fops =		&mousedev_fops,
1060 	.minor =	MOUSEDEV_MINOR_BASE,
1061 	.name =		"mousedev",
1062 	.id_table =	mousedev_ids,
1063 };
1064 
1065 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1066 static struct miscdevice psaux_mouse = {
1067 	PSMOUSE_MINOR, "psaux", &mousedev_fops
1068 };
1069 static int psaux_registered;
1070 #endif
1071 
1072 static int __init mousedev_init(void)
1073 {
1074 	int error;
1075 
1076 	mousedev_mix = mousedev_create(NULL, &mousedev_handler, MOUSEDEV_MIX);
1077 	if (IS_ERR(mousedev_mix))
1078 		return PTR_ERR(mousedev_mix);
1079 
1080 	error = input_register_handler(&mousedev_handler);
1081 	if (error) {
1082 		mousedev_destroy(mousedev_mix);
1083 		return error;
1084 	}
1085 
1086 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1087 	error = misc_register(&psaux_mouse);
1088 	if (error)
1089 		printk(KERN_WARNING "mice: could not register psaux device, "
1090 			"error: %d\n", error);
1091 	else
1092 		psaux_registered = 1;
1093 #endif
1094 
1095 	printk(KERN_INFO "mice: PS/2 mouse device common for all mice\n");
1096 
1097 	return 0;
1098 }
1099 
1100 static void __exit mousedev_exit(void)
1101 {
1102 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1103 	if (psaux_registered)
1104 		misc_deregister(&psaux_mouse);
1105 #endif
1106 	input_unregister_handler(&mousedev_handler);
1107 	mousedev_destroy(mousedev_mix);
1108 }
1109 
1110 module_init(mousedev_init);
1111 module_exit(mousedev_exit);
1112