xref: /openbmc/linux/drivers/input/mousedev.c (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
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_detach_client(mousedev, client);
523 	kfree(client);
524 
525 	mousedev_close_device(mousedev);
526 	put_device(&mousedev->dev);
527 
528 	return 0;
529 }
530 
531 static int mousedev_open(struct inode *inode, struct file *file)
532 {
533 	struct mousedev_client *client;
534 	struct mousedev *mousedev;
535 	int error;
536 	int i;
537 
538 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
539 	if (imajor(inode) == MISC_MAJOR)
540 		i = MOUSEDEV_MIX;
541 	else
542 #endif
543 		i = iminor(inode) - MOUSEDEV_MINOR_BASE;
544 
545 	if (i >= MOUSEDEV_MINORS)
546 		return -ENODEV;
547 
548 	lock_kernel();
549 	error = mutex_lock_interruptible(&mousedev_table_mutex);
550 	if (error) {
551 		unlock_kernel();
552 		return error;
553 	}
554 	mousedev = mousedev_table[i];
555 	if (mousedev)
556 		get_device(&mousedev->dev);
557 	mutex_unlock(&mousedev_table_mutex);
558 
559 	if (!mousedev) {
560 		unlock_kernel();
561 		return -ENODEV;
562 	}
563 
564 	client = kzalloc(sizeof(struct mousedev_client), GFP_KERNEL);
565 	if (!client) {
566 		error = -ENOMEM;
567 		goto err_put_mousedev;
568 	}
569 
570 	spin_lock_init(&client->packet_lock);
571 	client->pos_x = xres / 2;
572 	client->pos_y = yres / 2;
573 	client->mousedev = mousedev;
574 	mousedev_attach_client(mousedev, client);
575 
576 	error = mousedev_open_device(mousedev);
577 	if (error)
578 		goto err_free_client;
579 
580 	file->private_data = client;
581 	unlock_kernel();
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 	unlock_kernel();
590 	return error;
591 }
592 
593 static inline int mousedev_limit_delta(int delta, int limit)
594 {
595 	return delta > limit ? limit : (delta < -limit ? -limit : delta);
596 }
597 
598 static void mousedev_packet(struct mousedev_client *client,
599 			    signed char *ps2_data)
600 {
601 	struct mousedev_motion *p = &client->packets[client->tail];
602 
603 	ps2_data[0] = 0x08 |
604 		((p->dx < 0) << 4) | ((p->dy < 0) << 5) | (p->buttons & 0x07);
605 	ps2_data[1] = mousedev_limit_delta(p->dx, 127);
606 	ps2_data[2] = mousedev_limit_delta(p->dy, 127);
607 	p->dx -= ps2_data[1];
608 	p->dy -= ps2_data[2];
609 
610 	switch (client->mode) {
611 	case MOUSEDEV_EMUL_EXPS:
612 		ps2_data[3] = mousedev_limit_delta(p->dz, 7);
613 		p->dz -= ps2_data[3];
614 		ps2_data[3] = (ps2_data[3] & 0x0f) | ((p->buttons & 0x18) << 1);
615 		client->bufsiz = 4;
616 		break;
617 
618 	case MOUSEDEV_EMUL_IMPS:
619 		ps2_data[0] |=
620 			((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
621 		ps2_data[3] = mousedev_limit_delta(p->dz, 127);
622 		p->dz -= ps2_data[3];
623 		client->bufsiz = 4;
624 		break;
625 
626 	case MOUSEDEV_EMUL_PS2:
627 	default:
628 		ps2_data[0] |=
629 			((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
630 		p->dz = 0;
631 		client->bufsiz = 3;
632 		break;
633 	}
634 
635 	if (!p->dx && !p->dy && !p->dz) {
636 		if (client->tail == client->head) {
637 			client->ready = 0;
638 			client->last_buttons = p->buttons;
639 		} else
640 			client->tail = (client->tail + 1) % PACKET_QUEUE_LEN;
641 	}
642 }
643 
644 static void mousedev_generate_response(struct mousedev_client *client,
645 					int command)
646 {
647 	client->ps2[0] = 0xfa; /* ACK */
648 
649 	switch (command) {
650 
651 	case 0xeb: /* Poll */
652 		mousedev_packet(client, &client->ps2[1]);
653 		client->bufsiz++; /* account for leading ACK */
654 		break;
655 
656 	case 0xf2: /* Get ID */
657 		switch (client->mode) {
658 		case MOUSEDEV_EMUL_PS2:
659 			client->ps2[1] = 0;
660 			break;
661 		case MOUSEDEV_EMUL_IMPS:
662 			client->ps2[1] = 3;
663 			break;
664 		case MOUSEDEV_EMUL_EXPS:
665 			client->ps2[1] = 4;
666 			break;
667 		}
668 		client->bufsiz = 2;
669 		break;
670 
671 	case 0xe9: /* Get info */
672 		client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200;
673 		client->bufsiz = 4;
674 		break;
675 
676 	case 0xff: /* Reset */
677 		client->impsseq = client->imexseq = 0;
678 		client->mode = MOUSEDEV_EMUL_PS2;
679 		client->ps2[1] = 0xaa; client->ps2[2] = 0x00;
680 		client->bufsiz = 3;
681 		break;
682 
683 	default:
684 		client->bufsiz = 1;
685 		break;
686 	}
687 	client->buffer = client->bufsiz;
688 }
689 
690 static ssize_t mousedev_write(struct file *file, const char __user *buffer,
691 				size_t count, loff_t *ppos)
692 {
693 	struct mousedev_client *client = file->private_data;
694 	unsigned char c;
695 	unsigned int i;
696 
697 	for (i = 0; i < count; i++) {
698 
699 		if (get_user(c, buffer + i))
700 			return -EFAULT;
701 
702 		spin_lock_irq(&client->packet_lock);
703 
704 		if (c == mousedev_imex_seq[client->imexseq]) {
705 			if (++client->imexseq == MOUSEDEV_SEQ_LEN) {
706 				client->imexseq = 0;
707 				client->mode = MOUSEDEV_EMUL_EXPS;
708 			}
709 		} else
710 			client->imexseq = 0;
711 
712 		if (c == mousedev_imps_seq[client->impsseq]) {
713 			if (++client->impsseq == MOUSEDEV_SEQ_LEN) {
714 				client->impsseq = 0;
715 				client->mode = MOUSEDEV_EMUL_IMPS;
716 			}
717 		} else
718 			client->impsseq = 0;
719 
720 		mousedev_generate_response(client, c);
721 
722 		spin_unlock_irq(&client->packet_lock);
723 	}
724 
725 	kill_fasync(&client->fasync, SIGIO, POLL_IN);
726 	wake_up_interruptible(&client->mousedev->wait);
727 
728 	return count;
729 }
730 
731 static ssize_t mousedev_read(struct file *file, char __user *buffer,
732 			     size_t count, loff_t *ppos)
733 {
734 	struct mousedev_client *client = file->private_data;
735 	struct mousedev *mousedev = client->mousedev;
736 	signed char data[sizeof(client->ps2)];
737 	int retval = 0;
738 
739 	if (!client->ready && !client->buffer && mousedev->exist &&
740 	    (file->f_flags & O_NONBLOCK))
741 		return -EAGAIN;
742 
743 	retval = wait_event_interruptible(mousedev->wait,
744 			!mousedev->exist || client->ready || client->buffer);
745 	if (retval)
746 		return retval;
747 
748 	if (!mousedev->exist)
749 		return -ENODEV;
750 
751 	spin_lock_irq(&client->packet_lock);
752 
753 	if (!client->buffer && client->ready) {
754 		mousedev_packet(client, client->ps2);
755 		client->buffer = client->bufsiz;
756 	}
757 
758 	if (count > client->buffer)
759 		count = client->buffer;
760 
761 	memcpy(data, client->ps2 + client->bufsiz - client->buffer, count);
762 	client->buffer -= count;
763 
764 	spin_unlock_irq(&client->packet_lock);
765 
766 	if (copy_to_user(buffer, data, count))
767 		return -EFAULT;
768 
769 	return count;
770 }
771 
772 /* No kernel lock - fine */
773 static unsigned int mousedev_poll(struct file *file, poll_table *wait)
774 {
775 	struct mousedev_client *client = file->private_data;
776 	struct mousedev *mousedev = client->mousedev;
777 
778 	poll_wait(file, &mousedev->wait, wait);
779 	return ((client->ready || client->buffer) ? (POLLIN | POLLRDNORM) : 0) |
780 		(mousedev->exist ? 0 : (POLLHUP | POLLERR));
781 }
782 
783 static const struct file_operations mousedev_fops = {
784 	.owner =	THIS_MODULE,
785 	.read =		mousedev_read,
786 	.write =	mousedev_write,
787 	.poll =		mousedev_poll,
788 	.open =		mousedev_open,
789 	.release =	mousedev_release,
790 	.fasync =	mousedev_fasync,
791 };
792 
793 static int mousedev_install_chrdev(struct mousedev *mousedev)
794 {
795 	mousedev_table[mousedev->minor] = mousedev;
796 	return 0;
797 }
798 
799 static void mousedev_remove_chrdev(struct mousedev *mousedev)
800 {
801 	mutex_lock(&mousedev_table_mutex);
802 	mousedev_table[mousedev->minor] = NULL;
803 	mutex_unlock(&mousedev_table_mutex);
804 }
805 
806 /*
807  * Mark device non-existent. This disables writes, ioctls and
808  * prevents new users from opening the device. Already posted
809  * blocking reads will stay, however new ones will fail.
810  */
811 static void mousedev_mark_dead(struct mousedev *mousedev)
812 {
813 	mutex_lock(&mousedev->mutex);
814 	mousedev->exist = 0;
815 	mutex_unlock(&mousedev->mutex);
816 }
817 
818 /*
819  * Wake up users waiting for IO so they can disconnect from
820  * dead device.
821  */
822 static void mousedev_hangup(struct mousedev *mousedev)
823 {
824 	struct mousedev_client *client;
825 
826 	spin_lock(&mousedev->client_lock);
827 	list_for_each_entry(client, &mousedev->client_list, node)
828 		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
829 	spin_unlock(&mousedev->client_lock);
830 
831 	wake_up_interruptible(&mousedev->wait);
832 }
833 
834 static void mousedev_cleanup(struct mousedev *mousedev)
835 {
836 	struct input_handle *handle = &mousedev->handle;
837 
838 	mousedev_mark_dead(mousedev);
839 	mousedev_hangup(mousedev);
840 	mousedev_remove_chrdev(mousedev);
841 
842 	/* mousedev is marked dead so no one else accesses mousedev->open */
843 	if (mousedev->open)
844 		input_close_device(handle);
845 }
846 
847 static struct mousedev *mousedev_create(struct input_dev *dev,
848 					struct input_handler *handler,
849 					int minor)
850 {
851 	struct mousedev *mousedev;
852 	int error;
853 
854 	mousedev = kzalloc(sizeof(struct mousedev), GFP_KERNEL);
855 	if (!mousedev) {
856 		error = -ENOMEM;
857 		goto err_out;
858 	}
859 
860 	INIT_LIST_HEAD(&mousedev->client_list);
861 	INIT_LIST_HEAD(&mousedev->mixdev_node);
862 	spin_lock_init(&mousedev->client_lock);
863 	mutex_init(&mousedev->mutex);
864 	lockdep_set_subclass(&mousedev->mutex,
865 			     minor == MOUSEDEV_MIX ? MOUSEDEV_MIX : 0);
866 	init_waitqueue_head(&mousedev->wait);
867 
868 	if (minor == MOUSEDEV_MIX)
869 		strlcpy(mousedev->name, "mice", sizeof(mousedev->name));
870 	else
871 		snprintf(mousedev->name, sizeof(mousedev->name),
872 			 "mouse%d", minor);
873 
874 	mousedev->minor = minor;
875 	mousedev->exist = 1;
876 	mousedev->handle.dev = input_get_device(dev);
877 	mousedev->handle.name = mousedev->name;
878 	mousedev->handle.handler = handler;
879 	mousedev->handle.private = mousedev;
880 
881 	strlcpy(mousedev->dev.bus_id, mousedev->name,
882 		sizeof(mousedev->dev.bus_id));
883 	mousedev->dev.class = &input_class;
884 	if (dev)
885 		mousedev->dev.parent = &dev->dev;
886 	mousedev->dev.devt = MKDEV(INPUT_MAJOR, MOUSEDEV_MINOR_BASE + minor);
887 	mousedev->dev.release = mousedev_free;
888 	device_initialize(&mousedev->dev);
889 
890 	if (minor != MOUSEDEV_MIX) {
891 		error = input_register_handle(&mousedev->handle);
892 		if (error)
893 			goto err_free_mousedev;
894 	}
895 
896 	error = mousedev_install_chrdev(mousedev);
897 	if (error)
898 		goto err_unregister_handle;
899 
900 	error = device_add(&mousedev->dev);
901 	if (error)
902 		goto err_cleanup_mousedev;
903 
904 	return mousedev;
905 
906  err_cleanup_mousedev:
907 	mousedev_cleanup(mousedev);
908  err_unregister_handle:
909 	if (minor != MOUSEDEV_MIX)
910 		input_unregister_handle(&mousedev->handle);
911  err_free_mousedev:
912 	put_device(&mousedev->dev);
913  err_out:
914 	return ERR_PTR(error);
915 }
916 
917 static void mousedev_destroy(struct mousedev *mousedev)
918 {
919 	device_del(&mousedev->dev);
920 	mousedev_cleanup(mousedev);
921 	if (mousedev->minor != MOUSEDEV_MIX)
922 		input_unregister_handle(&mousedev->handle);
923 	put_device(&mousedev->dev);
924 }
925 
926 static int mixdev_add_device(struct mousedev *mousedev)
927 {
928 	int retval;
929 
930 	retval = mutex_lock_interruptible(&mousedev_mix->mutex);
931 	if (retval)
932 		return retval;
933 
934 	if (mousedev_mix->open) {
935 		retval = mousedev_open_device(mousedev);
936 		if (retval)
937 			goto out;
938 
939 		mousedev->mixdev_open = 1;
940 	}
941 
942 	get_device(&mousedev->dev);
943 	list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list);
944 
945  out:
946 	mutex_unlock(&mousedev_mix->mutex);
947 	return retval;
948 }
949 
950 static void mixdev_remove_device(struct mousedev *mousedev)
951 {
952 	mutex_lock(&mousedev_mix->mutex);
953 
954 	if (mousedev->mixdev_open) {
955 		mousedev->mixdev_open = 0;
956 		mousedev_close_device(mousedev);
957 	}
958 
959 	list_del_init(&mousedev->mixdev_node);
960 	mutex_unlock(&mousedev_mix->mutex);
961 
962 	put_device(&mousedev->dev);
963 }
964 
965 static int mousedev_connect(struct input_handler *handler,
966 			    struct input_dev *dev,
967 			    const struct input_device_id *id)
968 {
969 	struct mousedev *mousedev;
970 	int minor;
971 	int error;
972 
973 	for (minor = 0; minor < MOUSEDEV_MINORS; minor++)
974 		if (!mousedev_table[minor])
975 			break;
976 
977 	if (minor == MOUSEDEV_MINORS) {
978 		printk(KERN_ERR "mousedev: no more free mousedev devices\n");
979 		return -ENFILE;
980 	}
981 
982 	mousedev = mousedev_create(dev, handler, minor);
983 	if (IS_ERR(mousedev))
984 		return PTR_ERR(mousedev);
985 
986 	error = mixdev_add_device(mousedev);
987 	if (error) {
988 		mousedev_destroy(mousedev);
989 		return error;
990 	}
991 
992 	return 0;
993 }
994 
995 static void mousedev_disconnect(struct input_handle *handle)
996 {
997 	struct mousedev *mousedev = handle->private;
998 
999 	mixdev_remove_device(mousedev);
1000 	mousedev_destroy(mousedev);
1001 }
1002 
1003 static const struct input_device_id mousedev_ids[] = {
1004 	{
1005 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1006 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1007 				INPUT_DEVICE_ID_MATCH_RELBIT,
1008 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1009 		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1010 		.relbit = { BIT_MASK(REL_X) | BIT_MASK(REL_Y) },
1011 	},	/* A mouse like device, at least one button,
1012 		   two relative axes */
1013 	{
1014 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1015 				INPUT_DEVICE_ID_MATCH_RELBIT,
1016 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1017 		.relbit = { BIT_MASK(REL_WHEEL) },
1018 	},	/* A separate scrollwheel */
1019 	{
1020 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1021 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1022 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1023 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1024 		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
1025 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1026 	},	/* A tablet like device, at least touch detection,
1027 		   two absolute axes */
1028 	{
1029 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1030 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1031 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1032 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1033 		.keybit = { [BIT_WORD(BTN_TOOL_FINGER)] =
1034 				BIT_MASK(BTN_TOOL_FINGER) },
1035 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
1036 				BIT_MASK(ABS_PRESSURE) |
1037 				BIT_MASK(ABS_TOOL_WIDTH) },
1038 	},	/* A touchpad */
1039 	{
1040 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1041 			INPUT_DEVICE_ID_MATCH_KEYBIT |
1042 			INPUT_DEVICE_ID_MATCH_ABSBIT,
1043 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1044 		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1045 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1046 	},	/* Mouse-like device with absolute X and Y but ordinary
1047 		   clicks, like hp ILO2 High Performance mouse */
1048 
1049 	{ },	/* Terminating entry */
1050 };
1051 
1052 MODULE_DEVICE_TABLE(input, mousedev_ids);
1053 
1054 static struct input_handler mousedev_handler = {
1055 	.event =	mousedev_event,
1056 	.connect =	mousedev_connect,
1057 	.disconnect =	mousedev_disconnect,
1058 	.fops =		&mousedev_fops,
1059 	.minor =	MOUSEDEV_MINOR_BASE,
1060 	.name =		"mousedev",
1061 	.id_table =	mousedev_ids,
1062 };
1063 
1064 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1065 static struct miscdevice psaux_mouse = {
1066 	PSMOUSE_MINOR, "psaux", &mousedev_fops
1067 };
1068 static int psaux_registered;
1069 #endif
1070 
1071 static int __init mousedev_init(void)
1072 {
1073 	int error;
1074 
1075 	mousedev_mix = mousedev_create(NULL, &mousedev_handler, MOUSEDEV_MIX);
1076 	if (IS_ERR(mousedev_mix))
1077 		return PTR_ERR(mousedev_mix);
1078 
1079 	error = input_register_handler(&mousedev_handler);
1080 	if (error) {
1081 		mousedev_destroy(mousedev_mix);
1082 		return error;
1083 	}
1084 
1085 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1086 	error = misc_register(&psaux_mouse);
1087 	if (error)
1088 		printk(KERN_WARNING "mice: could not register psaux device, "
1089 			"error: %d\n", error);
1090 	else
1091 		psaux_registered = 1;
1092 #endif
1093 
1094 	printk(KERN_INFO "mice: PS/2 mouse device common for all mice\n");
1095 
1096 	return 0;
1097 }
1098 
1099 static void __exit mousedev_exit(void)
1100 {
1101 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1102 	if (psaux_registered)
1103 		misc_deregister(&psaux_mouse);
1104 #endif
1105 	input_unregister_handler(&mousedev_handler);
1106 	mousedev_destroy(mousedev_mix);
1107 }
1108 
1109 module_init(mousedev_init);
1110 module_exit(mousedev_exit);
1111