xref: /linux/drivers/input/mousedev.c (revision 2e483528cebad089d0bb3f9aebb0ada22d968ffa)
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 pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 
14 #define MOUSEDEV_MINOR_BASE	32
15 #define MOUSEDEV_MINORS		32
16 #define MOUSEDEV_MIX		31
17 
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/poll.h>
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/input.h>
24 #include <linux/random.h>
25 #include <linux/major.h>
26 #include <linux/device.h>
27 #include <linux/kernel.h>
28 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
29 #include <linux/miscdevice.h>
30 #endif
31 
32 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
33 MODULE_DESCRIPTION("Mouse (ExplorerPS/2) device interfaces");
34 MODULE_LICENSE("GPL");
35 
36 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_X
37 #define CONFIG_INPUT_MOUSEDEV_SCREEN_X	1024
38 #endif
39 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_Y
40 #define CONFIG_INPUT_MOUSEDEV_SCREEN_Y	768
41 #endif
42 
43 static int xres = CONFIG_INPUT_MOUSEDEV_SCREEN_X;
44 module_param(xres, uint, 0644);
45 MODULE_PARM_DESC(xres, "Horizontal screen resolution");
46 
47 static int yres = CONFIG_INPUT_MOUSEDEV_SCREEN_Y;
48 module_param(yres, uint, 0644);
49 MODULE_PARM_DESC(yres, "Vertical screen resolution");
50 
51 static unsigned tap_time = 200;
52 module_param(tap_time, uint, 0644);
53 MODULE_PARM_DESC(tap_time, "Tap time for touchpads in absolute mode (msecs)");
54 
55 struct mousedev_hw_data {
56 	int dx, dy, dz;
57 	int x, y;
58 	int abs_event;
59 	unsigned long buttons;
60 };
61 
62 struct mousedev {
63 	int open;
64 	int minor;
65 	struct input_handle handle;
66 	wait_queue_head_t wait;
67 	struct list_head client_list;
68 	spinlock_t client_lock; /* protects client_list */
69 	struct mutex mutex;
70 	struct device dev;
71 	bool exist;
72 
73 	struct list_head mixdev_node;
74 	int mixdev_open;
75 
76 	struct mousedev_hw_data packet;
77 	unsigned int pkt_count;
78 	int old_x[4], old_y[4];
79 	int frac_dx, frac_dy;
80 	unsigned long touch;
81 };
82 
83 enum mousedev_emul {
84 	MOUSEDEV_EMUL_PS2,
85 	MOUSEDEV_EMUL_IMPS,
86 	MOUSEDEV_EMUL_EXPS
87 };
88 
89 struct mousedev_motion {
90 	int dx, dy, dz;
91 	unsigned long buttons;
92 };
93 
94 #define PACKET_QUEUE_LEN	16
95 struct mousedev_client {
96 	struct fasync_struct *fasync;
97 	struct mousedev *mousedev;
98 	struct list_head node;
99 
100 	struct mousedev_motion packets[PACKET_QUEUE_LEN];
101 	unsigned int head, tail;
102 	spinlock_t packet_lock;
103 	int pos_x, pos_y;
104 
105 	signed char ps2[6];
106 	unsigned char ready, buffer, bufsiz;
107 	unsigned char imexseq, impsseq;
108 	enum mousedev_emul mode;
109 	unsigned long last_buttons;
110 };
111 
112 #define MOUSEDEV_SEQ_LEN	6
113 
114 static unsigned char mousedev_imps_seq[] = { 0xf3, 200, 0xf3, 100, 0xf3, 80 };
115 static unsigned char mousedev_imex_seq[] = { 0xf3, 200, 0xf3, 200, 0xf3, 80 };
116 
117 static struct input_handler mousedev_handler;
118 
119 static struct mousedev *mousedev_table[MOUSEDEV_MINORS];
120 static DEFINE_MUTEX(mousedev_table_mutex);
121 static struct mousedev *mousedev_mix;
122 static LIST_HEAD(mousedev_mix_list);
123 
124 static void mixdev_open_devices(void);
125 static void mixdev_close_devices(void);
126 
127 #define fx(i)  (mousedev->old_x[(mousedev->pkt_count - (i)) & 03])
128 #define fy(i)  (mousedev->old_y[(mousedev->pkt_count - (i)) & 03])
129 
130 static void mousedev_touchpad_event(struct input_dev *dev,
131 				    struct mousedev *mousedev,
132 				    unsigned int code, int value)
133 {
134 	int size, tmp;
135 	enum { FRACTION_DENOM = 128 };
136 
137 	switch (code) {
138 
139 	case ABS_X:
140 
141 		fx(0) = value;
142 		if (mousedev->touch && mousedev->pkt_count >= 2) {
143 			size = input_abs_get_max(dev, ABS_X) -
144 					input_abs_get_min(dev, ABS_X);
145 			if (size == 0)
146 				size = 256 * 2;
147 
148 			tmp = ((value - fx(2)) * 256 * FRACTION_DENOM) / size;
149 			tmp += mousedev->frac_dx;
150 			mousedev->packet.dx = tmp / FRACTION_DENOM;
151 			mousedev->frac_dx =
152 				tmp - mousedev->packet.dx * FRACTION_DENOM;
153 		}
154 		break;
155 
156 	case ABS_Y:
157 		fy(0) = value;
158 		if (mousedev->touch && mousedev->pkt_count >= 2) {
159 			/* use X size for ABS_Y to keep the same scale */
160 			size = input_abs_get_max(dev, ABS_X) -
161 					input_abs_get_min(dev, ABS_X);
162 			if (size == 0)
163 				size = 256 * 2;
164 
165 			tmp = -((value - fy(2)) * 256 * FRACTION_DENOM) / size;
166 			tmp += mousedev->frac_dy;
167 			mousedev->packet.dy = tmp / FRACTION_DENOM;
168 			mousedev->frac_dy = tmp -
169 				mousedev->packet.dy * FRACTION_DENOM;
170 		}
171 		break;
172 	}
173 }
174 
175 static void mousedev_abs_event(struct input_dev *dev, struct mousedev *mousedev,
176 				unsigned int code, int value)
177 {
178 	int min, max, size;
179 
180 	switch (code) {
181 
182 	case ABS_X:
183 		min = input_abs_get_min(dev, ABS_X);
184 		max = input_abs_get_max(dev, ABS_X);
185 
186 		size = max - min;
187 		if (size == 0)
188 			size = xres ? : 1;
189 
190 		clamp(value, min, max);
191 
192 		mousedev->packet.x = ((value - min) * xres) / size;
193 		mousedev->packet.abs_event = 1;
194 		break;
195 
196 	case ABS_Y:
197 		min = input_abs_get_min(dev, ABS_Y);
198 		max = input_abs_get_max(dev, ABS_Y);
199 
200 		size = max - min;
201 		if (size == 0)
202 			size = yres ? : 1;
203 
204 		clamp(value, min, max);
205 
206 		mousedev->packet.y = yres - ((value - min) * yres) / size;
207 		mousedev->packet.abs_event = 1;
208 		break;
209 	}
210 }
211 
212 static void mousedev_rel_event(struct mousedev *mousedev,
213 				unsigned int code, int value)
214 {
215 	switch (code) {
216 	case REL_X:
217 		mousedev->packet.dx += value;
218 		break;
219 
220 	case REL_Y:
221 		mousedev->packet.dy -= value;
222 		break;
223 
224 	case REL_WHEEL:
225 		mousedev->packet.dz -= value;
226 		break;
227 	}
228 }
229 
230 static void mousedev_key_event(struct mousedev *mousedev,
231 				unsigned int code, int value)
232 {
233 	int index;
234 
235 	switch (code) {
236 
237 	case BTN_TOUCH:
238 	case BTN_0:
239 	case BTN_LEFT:		index = 0; break;
240 
241 	case BTN_STYLUS:
242 	case BTN_1:
243 	case BTN_RIGHT:		index = 1; break;
244 
245 	case BTN_2:
246 	case BTN_FORWARD:
247 	case BTN_STYLUS2:
248 	case BTN_MIDDLE:	index = 2; break;
249 
250 	case BTN_3:
251 	case BTN_BACK:
252 	case BTN_SIDE:		index = 3; break;
253 
254 	case BTN_4:
255 	case BTN_EXTRA:		index = 4; break;
256 
257 	default:		return;
258 	}
259 
260 	if (value) {
261 		set_bit(index, &mousedev->packet.buttons);
262 		set_bit(index, &mousedev_mix->packet.buttons);
263 	} else {
264 		clear_bit(index, &mousedev->packet.buttons);
265 		clear_bit(index, &mousedev_mix->packet.buttons);
266 	}
267 }
268 
269 static void mousedev_notify_readers(struct mousedev *mousedev,
270 				    struct mousedev_hw_data *packet)
271 {
272 	struct mousedev_client *client;
273 	struct mousedev_motion *p;
274 	unsigned int new_head;
275 	int wake_readers = 0;
276 
277 	rcu_read_lock();
278 	list_for_each_entry_rcu(client, &mousedev->client_list, node) {
279 
280 		/* Just acquire the lock, interrupts already disabled */
281 		spin_lock(&client->packet_lock);
282 
283 		p = &client->packets[client->head];
284 		if (client->ready && p->buttons != mousedev->packet.buttons) {
285 			new_head = (client->head + 1) % PACKET_QUEUE_LEN;
286 			if (new_head != client->tail) {
287 				p = &client->packets[client->head = new_head];
288 				memset(p, 0, sizeof(struct mousedev_motion));
289 			}
290 		}
291 
292 		if (packet->abs_event) {
293 			p->dx += packet->x - client->pos_x;
294 			p->dy += packet->y - client->pos_y;
295 			client->pos_x = packet->x;
296 			client->pos_y = packet->y;
297 		}
298 
299 		client->pos_x += packet->dx;
300 		client->pos_x = client->pos_x < 0 ?
301 			0 : (client->pos_x >= xres ? xres : client->pos_x);
302 		client->pos_y += packet->dy;
303 		client->pos_y = client->pos_y < 0 ?
304 			0 : (client->pos_y >= yres ? yres : client->pos_y);
305 
306 		p->dx += packet->dx;
307 		p->dy += packet->dy;
308 		p->dz += packet->dz;
309 		p->buttons = mousedev->packet.buttons;
310 
311 		if (p->dx || p->dy || p->dz ||
312 		    p->buttons != client->last_buttons)
313 			client->ready = 1;
314 
315 		spin_unlock(&client->packet_lock);
316 
317 		if (client->ready) {
318 			kill_fasync(&client->fasync, SIGIO, POLL_IN);
319 			wake_readers = 1;
320 		}
321 	}
322 	rcu_read_unlock();
323 
324 	if (wake_readers)
325 		wake_up_interruptible(&mousedev->wait);
326 }
327 
328 static void mousedev_touchpad_touch(struct mousedev *mousedev, int value)
329 {
330 	if (!value) {
331 		if (mousedev->touch &&
332 		    time_before(jiffies,
333 				mousedev->touch + msecs_to_jiffies(tap_time))) {
334 			/*
335 			 * Toggle left button to emulate tap.
336 			 * We rely on the fact that mousedev_mix always has 0
337 			 * motion packet so we won't mess current position.
338 			 */
339 			set_bit(0, &mousedev->packet.buttons);
340 			set_bit(0, &mousedev_mix->packet.buttons);
341 			mousedev_notify_readers(mousedev, &mousedev_mix->packet);
342 			mousedev_notify_readers(mousedev_mix,
343 						&mousedev_mix->packet);
344 			clear_bit(0, &mousedev->packet.buttons);
345 			clear_bit(0, &mousedev_mix->packet.buttons);
346 		}
347 		mousedev->touch = mousedev->pkt_count = 0;
348 		mousedev->frac_dx = 0;
349 		mousedev->frac_dy = 0;
350 
351 	} else if (!mousedev->touch)
352 		mousedev->touch = jiffies;
353 }
354 
355 static void mousedev_event(struct input_handle *handle,
356 			   unsigned int type, unsigned int code, int value)
357 {
358 	struct mousedev *mousedev = handle->private;
359 
360 	switch (type) {
361 
362 	case EV_ABS:
363 		/* Ignore joysticks */
364 		if (test_bit(BTN_TRIGGER, handle->dev->keybit))
365 			return;
366 
367 		if (test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
368 			mousedev_touchpad_event(handle->dev,
369 						mousedev, code, value);
370 		else
371 			mousedev_abs_event(handle->dev, mousedev, code, value);
372 
373 		break;
374 
375 	case EV_REL:
376 		mousedev_rel_event(mousedev, code, value);
377 		break;
378 
379 	case EV_KEY:
380 		if (value != 2) {
381 			if (code == BTN_TOUCH &&
382 			    test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
383 				mousedev_touchpad_touch(mousedev, value);
384 			else
385 				mousedev_key_event(mousedev, code, value);
386 		}
387 		break;
388 
389 	case EV_SYN:
390 		if (code == SYN_REPORT) {
391 			if (mousedev->touch) {
392 				mousedev->pkt_count++;
393 				/*
394 				 * Input system eats duplicate events,
395 				 * but we need all of them to do correct
396 				 * averaging so apply present one forward
397 				 */
398 				fx(0) = fx(1);
399 				fy(0) = fy(1);
400 			}
401 
402 			mousedev_notify_readers(mousedev, &mousedev->packet);
403 			mousedev_notify_readers(mousedev_mix, &mousedev->packet);
404 
405 			mousedev->packet.dx = mousedev->packet.dy =
406 				mousedev->packet.dz = 0;
407 			mousedev->packet.abs_event = 0;
408 		}
409 		break;
410 	}
411 }
412 
413 static int mousedev_fasync(int fd, struct file *file, int on)
414 {
415 	struct mousedev_client *client = file->private_data;
416 
417 	return fasync_helper(fd, file, on, &client->fasync);
418 }
419 
420 static void mousedev_free(struct device *dev)
421 {
422 	struct mousedev *mousedev = container_of(dev, struct mousedev, dev);
423 
424 	input_put_device(mousedev->handle.dev);
425 	kfree(mousedev);
426 }
427 
428 static int mousedev_open_device(struct mousedev *mousedev)
429 {
430 	int retval;
431 
432 	retval = mutex_lock_interruptible(&mousedev->mutex);
433 	if (retval)
434 		return retval;
435 
436 	if (mousedev->minor == MOUSEDEV_MIX)
437 		mixdev_open_devices();
438 	else if (!mousedev->exist)
439 		retval = -ENODEV;
440 	else if (!mousedev->open++) {
441 		retval = input_open_device(&mousedev->handle);
442 		if (retval)
443 			mousedev->open--;
444 	}
445 
446 	mutex_unlock(&mousedev->mutex);
447 	return retval;
448 }
449 
450 static void mousedev_close_device(struct mousedev *mousedev)
451 {
452 	mutex_lock(&mousedev->mutex);
453 
454 	if (mousedev->minor == MOUSEDEV_MIX)
455 		mixdev_close_devices();
456 	else if (mousedev->exist && !--mousedev->open)
457 		input_close_device(&mousedev->handle);
458 
459 	mutex_unlock(&mousedev->mutex);
460 }
461 
462 /*
463  * Open all available devices so they can all be multiplexed in one.
464  * stream. Note that this function is called with mousedev_mix->mutex
465  * held.
466  */
467 static void mixdev_open_devices(void)
468 {
469 	struct mousedev *mousedev;
470 
471 	if (mousedev_mix->open++)
472 		return;
473 
474 	list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
475 		if (!mousedev->mixdev_open) {
476 			if (mousedev_open_device(mousedev))
477 				continue;
478 
479 			mousedev->mixdev_open = 1;
480 		}
481 	}
482 }
483 
484 /*
485  * Close all devices that were opened as part of multiplexed
486  * device. Note that this function is called with mousedev_mix->mutex
487  * held.
488  */
489 static void mixdev_close_devices(void)
490 {
491 	struct mousedev *mousedev;
492 
493 	if (--mousedev_mix->open)
494 		return;
495 
496 	list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
497 		if (mousedev->mixdev_open) {
498 			mousedev->mixdev_open = 0;
499 			mousedev_close_device(mousedev);
500 		}
501 	}
502 }
503 
504 
505 static void mousedev_attach_client(struct mousedev *mousedev,
506 				   struct mousedev_client *client)
507 {
508 	spin_lock(&mousedev->client_lock);
509 	list_add_tail_rcu(&client->node, &mousedev->client_list);
510 	spin_unlock(&mousedev->client_lock);
511 }
512 
513 static void mousedev_detach_client(struct mousedev *mousedev,
514 				   struct mousedev_client *client)
515 {
516 	spin_lock(&mousedev->client_lock);
517 	list_del_rcu(&client->node);
518 	spin_unlock(&mousedev->client_lock);
519 	synchronize_rcu();
520 }
521 
522 static int mousedev_release(struct inode *inode, struct file *file)
523 {
524 	struct mousedev_client *client = file->private_data;
525 	struct mousedev *mousedev = client->mousedev;
526 
527 	mousedev_detach_client(mousedev, client);
528 	kfree(client);
529 
530 	mousedev_close_device(mousedev);
531 	put_device(&mousedev->dev);
532 
533 	return 0;
534 }
535 
536 static int mousedev_open(struct inode *inode, struct file *file)
537 {
538 	struct mousedev_client *client;
539 	struct mousedev *mousedev;
540 	int error;
541 	int i;
542 
543 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
544 	if (imajor(inode) == MISC_MAJOR)
545 		i = MOUSEDEV_MIX;
546 	else
547 #endif
548 		i = iminor(inode) - MOUSEDEV_MINOR_BASE;
549 
550 	if (i >= MOUSEDEV_MINORS)
551 		return -ENODEV;
552 
553 	error = mutex_lock_interruptible(&mousedev_table_mutex);
554 	if (error) {
555 		return error;
556 	}
557 	mousedev = mousedev_table[i];
558 	if (mousedev)
559 		get_device(&mousedev->dev);
560 	mutex_unlock(&mousedev_table_mutex);
561 
562 	if (!mousedev) {
563 		return -ENODEV;
564 	}
565 
566 	client = kzalloc(sizeof(struct mousedev_client), GFP_KERNEL);
567 	if (!client) {
568 		error = -ENOMEM;
569 		goto err_put_mousedev;
570 	}
571 
572 	spin_lock_init(&client->packet_lock);
573 	client->pos_x = xres / 2;
574 	client->pos_y = yres / 2;
575 	client->mousedev = mousedev;
576 	mousedev_attach_client(mousedev, client);
577 
578 	error = mousedev_open_device(mousedev);
579 	if (error)
580 		goto err_free_client;
581 
582 	file->private_data = client;
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 	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 	unsigned int mask;
778 
779 	poll_wait(file, &mousedev->wait, wait);
780 
781 	mask = mousedev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR;
782 	if (client->ready || client->buffer)
783 		mask |= POLLIN | POLLRDNORM;
784 
785 	return mask;
786 }
787 
788 static const struct file_operations mousedev_fops = {
789 	.owner =	THIS_MODULE,
790 	.read =		mousedev_read,
791 	.write =	mousedev_write,
792 	.poll =		mousedev_poll,
793 	.open =		mousedev_open,
794 	.release =	mousedev_release,
795 	.fasync =	mousedev_fasync,
796 	.llseek = noop_llseek,
797 };
798 
799 static int mousedev_install_chrdev(struct mousedev *mousedev)
800 {
801 	mousedev_table[mousedev->minor] = mousedev;
802 	return 0;
803 }
804 
805 static void mousedev_remove_chrdev(struct mousedev *mousedev)
806 {
807 	mutex_lock(&mousedev_table_mutex);
808 	mousedev_table[mousedev->minor] = NULL;
809 	mutex_unlock(&mousedev_table_mutex);
810 }
811 
812 /*
813  * Mark device non-existent. This disables writes, ioctls and
814  * prevents new users from opening the device. Already posted
815  * blocking reads will stay, however new ones will fail.
816  */
817 static void mousedev_mark_dead(struct mousedev *mousedev)
818 {
819 	mutex_lock(&mousedev->mutex);
820 	mousedev->exist = false;
821 	mutex_unlock(&mousedev->mutex);
822 }
823 
824 /*
825  * Wake up users waiting for IO so they can disconnect from
826  * dead device.
827  */
828 static void mousedev_hangup(struct mousedev *mousedev)
829 {
830 	struct mousedev_client *client;
831 
832 	spin_lock(&mousedev->client_lock);
833 	list_for_each_entry(client, &mousedev->client_list, node)
834 		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
835 	spin_unlock(&mousedev->client_lock);
836 
837 	wake_up_interruptible(&mousedev->wait);
838 }
839 
840 static void mousedev_cleanup(struct mousedev *mousedev)
841 {
842 	struct input_handle *handle = &mousedev->handle;
843 
844 	mousedev_mark_dead(mousedev);
845 	mousedev_hangup(mousedev);
846 	mousedev_remove_chrdev(mousedev);
847 
848 	/* mousedev is marked dead so no one else accesses mousedev->open */
849 	if (mousedev->open)
850 		input_close_device(handle);
851 }
852 
853 static struct mousedev *mousedev_create(struct input_dev *dev,
854 					struct input_handler *handler,
855 					int minor)
856 {
857 	struct mousedev *mousedev;
858 	int error;
859 
860 	mousedev = kzalloc(sizeof(struct mousedev), GFP_KERNEL);
861 	if (!mousedev) {
862 		error = -ENOMEM;
863 		goto err_out;
864 	}
865 
866 	INIT_LIST_HEAD(&mousedev->client_list);
867 	INIT_LIST_HEAD(&mousedev->mixdev_node);
868 	spin_lock_init(&mousedev->client_lock);
869 	mutex_init(&mousedev->mutex);
870 	lockdep_set_subclass(&mousedev->mutex,
871 			     minor == MOUSEDEV_MIX ? SINGLE_DEPTH_NESTING : 0);
872 	init_waitqueue_head(&mousedev->wait);
873 
874 	if (minor == MOUSEDEV_MIX)
875 		dev_set_name(&mousedev->dev, "mice");
876 	else
877 		dev_set_name(&mousedev->dev, "mouse%d", minor);
878 
879 	mousedev->minor = minor;
880 	mousedev->exist = true;
881 	mousedev->handle.dev = input_get_device(dev);
882 	mousedev->handle.name = dev_name(&mousedev->dev);
883 	mousedev->handle.handler = handler;
884 	mousedev->handle.private = mousedev;
885 
886 	mousedev->dev.class = &input_class;
887 	if (dev)
888 		mousedev->dev.parent = &dev->dev;
889 	mousedev->dev.devt = MKDEV(INPUT_MAJOR, MOUSEDEV_MINOR_BASE + minor);
890 	mousedev->dev.release = mousedev_free;
891 	device_initialize(&mousedev->dev);
892 
893 	if (minor != MOUSEDEV_MIX) {
894 		error = input_register_handle(&mousedev->handle);
895 		if (error)
896 			goto err_free_mousedev;
897 	}
898 
899 	error = mousedev_install_chrdev(mousedev);
900 	if (error)
901 		goto err_unregister_handle;
902 
903 	error = device_add(&mousedev->dev);
904 	if (error)
905 		goto err_cleanup_mousedev;
906 
907 	return mousedev;
908 
909  err_cleanup_mousedev:
910 	mousedev_cleanup(mousedev);
911  err_unregister_handle:
912 	if (minor != MOUSEDEV_MIX)
913 		input_unregister_handle(&mousedev->handle);
914  err_free_mousedev:
915 	put_device(&mousedev->dev);
916  err_out:
917 	return ERR_PTR(error);
918 }
919 
920 static void mousedev_destroy(struct mousedev *mousedev)
921 {
922 	device_del(&mousedev->dev);
923 	mousedev_cleanup(mousedev);
924 	if (mousedev->minor != MOUSEDEV_MIX)
925 		input_unregister_handle(&mousedev->handle);
926 	put_device(&mousedev->dev);
927 }
928 
929 static int mixdev_add_device(struct mousedev *mousedev)
930 {
931 	int retval;
932 
933 	retval = mutex_lock_interruptible(&mousedev_mix->mutex);
934 	if (retval)
935 		return retval;
936 
937 	if (mousedev_mix->open) {
938 		retval = mousedev_open_device(mousedev);
939 		if (retval)
940 			goto out;
941 
942 		mousedev->mixdev_open = 1;
943 	}
944 
945 	get_device(&mousedev->dev);
946 	list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list);
947 
948  out:
949 	mutex_unlock(&mousedev_mix->mutex);
950 	return retval;
951 }
952 
953 static void mixdev_remove_device(struct mousedev *mousedev)
954 {
955 	mutex_lock(&mousedev_mix->mutex);
956 
957 	if (mousedev->mixdev_open) {
958 		mousedev->mixdev_open = 0;
959 		mousedev_close_device(mousedev);
960 	}
961 
962 	list_del_init(&mousedev->mixdev_node);
963 	mutex_unlock(&mousedev_mix->mutex);
964 
965 	put_device(&mousedev->dev);
966 }
967 
968 static int mousedev_connect(struct input_handler *handler,
969 			    struct input_dev *dev,
970 			    const struct input_device_id *id)
971 {
972 	struct mousedev *mousedev;
973 	int minor;
974 	int error;
975 
976 	for (minor = 0; minor < MOUSEDEV_MINORS; minor++)
977 		if (!mousedev_table[minor])
978 			break;
979 
980 	if (minor == MOUSEDEV_MINORS) {
981 		pr_err("no more free mousedev devices\n");
982 		return -ENFILE;
983 	}
984 
985 	mousedev = mousedev_create(dev, handler, minor);
986 	if (IS_ERR(mousedev))
987 		return PTR_ERR(mousedev);
988 
989 	error = mixdev_add_device(mousedev);
990 	if (error) {
991 		mousedev_destroy(mousedev);
992 		return error;
993 	}
994 
995 	return 0;
996 }
997 
998 static void mousedev_disconnect(struct input_handle *handle)
999 {
1000 	struct mousedev *mousedev = handle->private;
1001 
1002 	mixdev_remove_device(mousedev);
1003 	mousedev_destroy(mousedev);
1004 }
1005 
1006 static const struct input_device_id mousedev_ids[] = {
1007 	{
1008 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1009 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1010 				INPUT_DEVICE_ID_MATCH_RELBIT,
1011 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1012 		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1013 		.relbit = { BIT_MASK(REL_X) | BIT_MASK(REL_Y) },
1014 	},	/* A mouse like device, at least one button,
1015 		   two relative axes */
1016 	{
1017 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1018 				INPUT_DEVICE_ID_MATCH_RELBIT,
1019 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1020 		.relbit = { BIT_MASK(REL_WHEEL) },
1021 	},	/* A separate scrollwheel */
1022 	{
1023 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1024 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1025 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1026 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1027 		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
1028 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1029 	},	/* A tablet like device, at least touch detection,
1030 		   two absolute axes */
1031 	{
1032 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1033 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1034 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1035 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1036 		.keybit = { [BIT_WORD(BTN_TOOL_FINGER)] =
1037 				BIT_MASK(BTN_TOOL_FINGER) },
1038 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
1039 				BIT_MASK(ABS_PRESSURE) |
1040 				BIT_MASK(ABS_TOOL_WIDTH) },
1041 	},	/* A touchpad */
1042 	{
1043 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1044 			INPUT_DEVICE_ID_MATCH_KEYBIT |
1045 			INPUT_DEVICE_ID_MATCH_ABSBIT,
1046 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1047 		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1048 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1049 	},	/* Mouse-like device with absolute X and Y but ordinary
1050 		   clicks, like hp ILO2 High Performance mouse */
1051 
1052 	{ },	/* Terminating entry */
1053 };
1054 
1055 MODULE_DEVICE_TABLE(input, mousedev_ids);
1056 
1057 static struct input_handler mousedev_handler = {
1058 	.event =	mousedev_event,
1059 	.connect =	mousedev_connect,
1060 	.disconnect =	mousedev_disconnect,
1061 	.fops =		&mousedev_fops,
1062 	.minor =	MOUSEDEV_MINOR_BASE,
1063 	.name =		"mousedev",
1064 	.id_table =	mousedev_ids,
1065 };
1066 
1067 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1068 static struct miscdevice psaux_mouse = {
1069 	PSMOUSE_MINOR, "psaux", &mousedev_fops
1070 };
1071 static int psaux_registered;
1072 #endif
1073 
1074 static int __init mousedev_init(void)
1075 {
1076 	int error;
1077 
1078 	mousedev_mix = mousedev_create(NULL, &mousedev_handler, MOUSEDEV_MIX);
1079 	if (IS_ERR(mousedev_mix))
1080 		return PTR_ERR(mousedev_mix);
1081 
1082 	error = input_register_handler(&mousedev_handler);
1083 	if (error) {
1084 		mousedev_destroy(mousedev_mix);
1085 		return error;
1086 	}
1087 
1088 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1089 	error = misc_register(&psaux_mouse);
1090 	if (error)
1091 		pr_warning("could not register psaux device, error: %d\n",
1092 			   error);
1093 	else
1094 		psaux_registered = 1;
1095 #endif
1096 
1097 	pr_info("PS/2 mouse device common for all mice\n");
1098 
1099 	return 0;
1100 }
1101 
1102 static void __exit mousedev_exit(void)
1103 {
1104 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1105 	if (psaux_registered)
1106 		misc_deregister(&psaux_mouse);
1107 #endif
1108 	input_unregister_handler(&mousedev_handler);
1109 	mousedev_destroy(mousedev_mix);
1110 }
1111 
1112 module_init(mousedev_init);
1113 module_exit(mousedev_exit);
1114