xref: /openbmc/linux/drivers/input/mousedev.c (revision b6dcefde)
1 /*
2  * Input driver to ExplorerPS/2 device driver module.
3  *
4  * Copyright (c) 1999-2002 Vojtech Pavlik
5  * Copyright (c) 2004      Dmitry Torokhov
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as published by
9  * the Free Software Foundation.
10  */
11 
12 #define MOUSEDEV_MINOR_BASE	32
13 #define MOUSEDEV_MINORS		32
14 #define MOUSEDEV_MIX		31
15 
16 #include <linux/sched.h>
17 #include <linux/slab.h>
18 #include <linux/smp_lock.h>
19 #include <linux/poll.h>
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/input.h>
23 #include <linux/random.h>
24 #include <linux/major.h>
25 #include <linux/device.h>
26 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
27 #include <linux/miscdevice.h>
28 #endif
29 
30 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
31 MODULE_DESCRIPTION("Mouse (ExplorerPS/2) device interfaces");
32 MODULE_LICENSE("GPL");
33 
34 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_X
35 #define CONFIG_INPUT_MOUSEDEV_SCREEN_X	1024
36 #endif
37 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_Y
38 #define CONFIG_INPUT_MOUSEDEV_SCREEN_Y	768
39 #endif
40 
41 static int xres = CONFIG_INPUT_MOUSEDEV_SCREEN_X;
42 module_param(xres, uint, 0644);
43 MODULE_PARM_DESC(xres, "Horizontal screen resolution");
44 
45 static int yres = CONFIG_INPUT_MOUSEDEV_SCREEN_Y;
46 module_param(yres, uint, 0644);
47 MODULE_PARM_DESC(yres, "Vertical screen resolution");
48 
49 static unsigned tap_time = 200;
50 module_param(tap_time, uint, 0644);
51 MODULE_PARM_DESC(tap_time, "Tap time for touchpads in absolute mode (msecs)");
52 
53 struct mousedev_hw_data {
54 	int dx, dy, dz;
55 	int x, y;
56 	int abs_event;
57 	unsigned long buttons;
58 };
59 
60 struct mousedev {
61 	int exist;
62 	int open;
63 	int minor;
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 	struct mousedev_client *client = file->private_data;
407 
408 	return fasync_helper(fd, file, on, &client->fasync);
409 }
410 
411 static void mousedev_free(struct device *dev)
412 {
413 	struct mousedev *mousedev = container_of(dev, struct mousedev, dev);
414 
415 	input_put_device(mousedev->handle.dev);
416 	kfree(mousedev);
417 }
418 
419 static int mousedev_open_device(struct mousedev *mousedev)
420 {
421 	int retval;
422 
423 	retval = mutex_lock_interruptible(&mousedev->mutex);
424 	if (retval)
425 		return retval;
426 
427 	if (mousedev->minor == MOUSEDEV_MIX)
428 		mixdev_open_devices();
429 	else if (!mousedev->exist)
430 		retval = -ENODEV;
431 	else if (!mousedev->open++) {
432 		retval = input_open_device(&mousedev->handle);
433 		if (retval)
434 			mousedev->open--;
435 	}
436 
437 	mutex_unlock(&mousedev->mutex);
438 	return retval;
439 }
440 
441 static void mousedev_close_device(struct mousedev *mousedev)
442 {
443 	mutex_lock(&mousedev->mutex);
444 
445 	if (mousedev->minor == MOUSEDEV_MIX)
446 		mixdev_close_devices();
447 	else if (mousedev->exist && !--mousedev->open)
448 		input_close_device(&mousedev->handle);
449 
450 	mutex_unlock(&mousedev->mutex);
451 }
452 
453 /*
454  * Open all available devices so they can all be multiplexed in one.
455  * stream. Note that this function is called with mousedev_mix->mutex
456  * held.
457  */
458 static void mixdev_open_devices(void)
459 {
460 	struct mousedev *mousedev;
461 
462 	if (mousedev_mix->open++)
463 		return;
464 
465 	list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
466 		if (!mousedev->mixdev_open) {
467 			if (mousedev_open_device(mousedev))
468 				continue;
469 
470 			mousedev->mixdev_open = 1;
471 		}
472 	}
473 }
474 
475 /*
476  * Close all devices that were opened as part of multiplexed
477  * device. Note that this function is called with mousedev_mix->mutex
478  * held.
479  */
480 static void mixdev_close_devices(void)
481 {
482 	struct mousedev *mousedev;
483 
484 	if (--mousedev_mix->open)
485 		return;
486 
487 	list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
488 		if (mousedev->mixdev_open) {
489 			mousedev->mixdev_open = 0;
490 			mousedev_close_device(mousedev);
491 		}
492 	}
493 }
494 
495 
496 static void mousedev_attach_client(struct mousedev *mousedev,
497 				   struct mousedev_client *client)
498 {
499 	spin_lock(&mousedev->client_lock);
500 	list_add_tail_rcu(&client->node, &mousedev->client_list);
501 	spin_unlock(&mousedev->client_lock);
502 	synchronize_rcu();
503 }
504 
505 static void mousedev_detach_client(struct mousedev *mousedev,
506 				   struct mousedev_client *client)
507 {
508 	spin_lock(&mousedev->client_lock);
509 	list_del_rcu(&client->node);
510 	spin_unlock(&mousedev->client_lock);
511 	synchronize_rcu();
512 }
513 
514 static int mousedev_release(struct inode *inode, struct file *file)
515 {
516 	struct mousedev_client *client = file->private_data;
517 	struct mousedev *mousedev = client->mousedev;
518 
519 	mousedev_detach_client(mousedev, client);
520 	kfree(client);
521 
522 	mousedev_close_device(mousedev);
523 	put_device(&mousedev->dev);
524 
525 	return 0;
526 }
527 
528 static int mousedev_open(struct inode *inode, struct file *file)
529 {
530 	struct mousedev_client *client;
531 	struct mousedev *mousedev;
532 	int error;
533 	int i;
534 
535 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
536 	if (imajor(inode) == MISC_MAJOR)
537 		i = MOUSEDEV_MIX;
538 	else
539 #endif
540 		i = iminor(inode) - MOUSEDEV_MINOR_BASE;
541 
542 	if (i >= MOUSEDEV_MINORS)
543 		return -ENODEV;
544 
545 	lock_kernel();
546 	error = mutex_lock_interruptible(&mousedev_table_mutex);
547 	if (error) {
548 		unlock_kernel();
549 		return error;
550 	}
551 	mousedev = mousedev_table[i];
552 	if (mousedev)
553 		get_device(&mousedev->dev);
554 	mutex_unlock(&mousedev_table_mutex);
555 
556 	if (!mousedev) {
557 		unlock_kernel();
558 		return -ENODEV;
559 	}
560 
561 	client = kzalloc(sizeof(struct mousedev_client), GFP_KERNEL);
562 	if (!client) {
563 		error = -ENOMEM;
564 		goto err_put_mousedev;
565 	}
566 
567 	spin_lock_init(&client->packet_lock);
568 	client->pos_x = xres / 2;
569 	client->pos_y = yres / 2;
570 	client->mousedev = mousedev;
571 	mousedev_attach_client(mousedev, client);
572 
573 	error = mousedev_open_device(mousedev);
574 	if (error)
575 		goto err_free_client;
576 
577 	file->private_data = client;
578 	unlock_kernel();
579 	return 0;
580 
581  err_free_client:
582 	mousedev_detach_client(mousedev, client);
583 	kfree(client);
584  err_put_mousedev:
585 	put_device(&mousedev->dev);
586 	unlock_kernel();
587 	return error;
588 }
589 
590 static inline int mousedev_limit_delta(int delta, int limit)
591 {
592 	return delta > limit ? limit : (delta < -limit ? -limit : delta);
593 }
594 
595 static void mousedev_packet(struct mousedev_client *client,
596 			    signed char *ps2_data)
597 {
598 	struct mousedev_motion *p = &client->packets[client->tail];
599 
600 	ps2_data[0] = 0x08 |
601 		((p->dx < 0) << 4) | ((p->dy < 0) << 5) | (p->buttons & 0x07);
602 	ps2_data[1] = mousedev_limit_delta(p->dx, 127);
603 	ps2_data[2] = mousedev_limit_delta(p->dy, 127);
604 	p->dx -= ps2_data[1];
605 	p->dy -= ps2_data[2];
606 
607 	switch (client->mode) {
608 	case MOUSEDEV_EMUL_EXPS:
609 		ps2_data[3] = mousedev_limit_delta(p->dz, 7);
610 		p->dz -= ps2_data[3];
611 		ps2_data[3] = (ps2_data[3] & 0x0f) | ((p->buttons & 0x18) << 1);
612 		client->bufsiz = 4;
613 		break;
614 
615 	case MOUSEDEV_EMUL_IMPS:
616 		ps2_data[0] |=
617 			((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
618 		ps2_data[3] = mousedev_limit_delta(p->dz, 127);
619 		p->dz -= ps2_data[3];
620 		client->bufsiz = 4;
621 		break;
622 
623 	case MOUSEDEV_EMUL_PS2:
624 	default:
625 		ps2_data[0] |=
626 			((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
627 		p->dz = 0;
628 		client->bufsiz = 3;
629 		break;
630 	}
631 
632 	if (!p->dx && !p->dy && !p->dz) {
633 		if (client->tail == client->head) {
634 			client->ready = 0;
635 			client->last_buttons = p->buttons;
636 		} else
637 			client->tail = (client->tail + 1) % PACKET_QUEUE_LEN;
638 	}
639 }
640 
641 static void mousedev_generate_response(struct mousedev_client *client,
642 					int command)
643 {
644 	client->ps2[0] = 0xfa; /* ACK */
645 
646 	switch (command) {
647 
648 	case 0xeb: /* Poll */
649 		mousedev_packet(client, &client->ps2[1]);
650 		client->bufsiz++; /* account for leading ACK */
651 		break;
652 
653 	case 0xf2: /* Get ID */
654 		switch (client->mode) {
655 		case MOUSEDEV_EMUL_PS2:
656 			client->ps2[1] = 0;
657 			break;
658 		case MOUSEDEV_EMUL_IMPS:
659 			client->ps2[1] = 3;
660 			break;
661 		case MOUSEDEV_EMUL_EXPS:
662 			client->ps2[1] = 4;
663 			break;
664 		}
665 		client->bufsiz = 2;
666 		break;
667 
668 	case 0xe9: /* Get info */
669 		client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200;
670 		client->bufsiz = 4;
671 		break;
672 
673 	case 0xff: /* Reset */
674 		client->impsseq = client->imexseq = 0;
675 		client->mode = MOUSEDEV_EMUL_PS2;
676 		client->ps2[1] = 0xaa; client->ps2[2] = 0x00;
677 		client->bufsiz = 3;
678 		break;
679 
680 	default:
681 		client->bufsiz = 1;
682 		break;
683 	}
684 	client->buffer = client->bufsiz;
685 }
686 
687 static ssize_t mousedev_write(struct file *file, const char __user *buffer,
688 				size_t count, loff_t *ppos)
689 {
690 	struct mousedev_client *client = file->private_data;
691 	unsigned char c;
692 	unsigned int i;
693 
694 	for (i = 0; i < count; i++) {
695 
696 		if (get_user(c, buffer + i))
697 			return -EFAULT;
698 
699 		spin_lock_irq(&client->packet_lock);
700 
701 		if (c == mousedev_imex_seq[client->imexseq]) {
702 			if (++client->imexseq == MOUSEDEV_SEQ_LEN) {
703 				client->imexseq = 0;
704 				client->mode = MOUSEDEV_EMUL_EXPS;
705 			}
706 		} else
707 			client->imexseq = 0;
708 
709 		if (c == mousedev_imps_seq[client->impsseq]) {
710 			if (++client->impsseq == MOUSEDEV_SEQ_LEN) {
711 				client->impsseq = 0;
712 				client->mode = MOUSEDEV_EMUL_IMPS;
713 			}
714 		} else
715 			client->impsseq = 0;
716 
717 		mousedev_generate_response(client, c);
718 
719 		spin_unlock_irq(&client->packet_lock);
720 	}
721 
722 	kill_fasync(&client->fasync, SIGIO, POLL_IN);
723 	wake_up_interruptible(&client->mousedev->wait);
724 
725 	return count;
726 }
727 
728 static ssize_t mousedev_read(struct file *file, char __user *buffer,
729 			     size_t count, loff_t *ppos)
730 {
731 	struct mousedev_client *client = file->private_data;
732 	struct mousedev *mousedev = client->mousedev;
733 	signed char data[sizeof(client->ps2)];
734 	int retval = 0;
735 
736 	if (!client->ready && !client->buffer && mousedev->exist &&
737 	    (file->f_flags & O_NONBLOCK))
738 		return -EAGAIN;
739 
740 	retval = wait_event_interruptible(mousedev->wait,
741 			!mousedev->exist || client->ready || client->buffer);
742 	if (retval)
743 		return retval;
744 
745 	if (!mousedev->exist)
746 		return -ENODEV;
747 
748 	spin_lock_irq(&client->packet_lock);
749 
750 	if (!client->buffer && client->ready) {
751 		mousedev_packet(client, client->ps2);
752 		client->buffer = client->bufsiz;
753 	}
754 
755 	if (count > client->buffer)
756 		count = client->buffer;
757 
758 	memcpy(data, client->ps2 + client->bufsiz - client->buffer, count);
759 	client->buffer -= count;
760 
761 	spin_unlock_irq(&client->packet_lock);
762 
763 	if (copy_to_user(buffer, data, count))
764 		return -EFAULT;
765 
766 	return count;
767 }
768 
769 /* No kernel lock - fine */
770 static unsigned int mousedev_poll(struct file *file, poll_table *wait)
771 {
772 	struct mousedev_client *client = file->private_data;
773 	struct mousedev *mousedev = client->mousedev;
774 
775 	poll_wait(file, &mousedev->wait, wait);
776 	return ((client->ready || client->buffer) ? (POLLIN | POLLRDNORM) : 0) |
777 		(mousedev->exist ? 0 : (POLLHUP | POLLERR));
778 }
779 
780 static const struct file_operations mousedev_fops = {
781 	.owner =	THIS_MODULE,
782 	.read =		mousedev_read,
783 	.write =	mousedev_write,
784 	.poll =		mousedev_poll,
785 	.open =		mousedev_open,
786 	.release =	mousedev_release,
787 	.fasync =	mousedev_fasync,
788 };
789 
790 static int mousedev_install_chrdev(struct mousedev *mousedev)
791 {
792 	mousedev_table[mousedev->minor] = mousedev;
793 	return 0;
794 }
795 
796 static void mousedev_remove_chrdev(struct mousedev *mousedev)
797 {
798 	mutex_lock(&mousedev_table_mutex);
799 	mousedev_table[mousedev->minor] = NULL;
800 	mutex_unlock(&mousedev_table_mutex);
801 }
802 
803 /*
804  * Mark device non-existent. This disables writes, ioctls and
805  * prevents new users from opening the device. Already posted
806  * blocking reads will stay, however new ones will fail.
807  */
808 static void mousedev_mark_dead(struct mousedev *mousedev)
809 {
810 	mutex_lock(&mousedev->mutex);
811 	mousedev->exist = 0;
812 	mutex_unlock(&mousedev->mutex);
813 }
814 
815 /*
816  * Wake up users waiting for IO so they can disconnect from
817  * dead device.
818  */
819 static void mousedev_hangup(struct mousedev *mousedev)
820 {
821 	struct mousedev_client *client;
822 
823 	spin_lock(&mousedev->client_lock);
824 	list_for_each_entry(client, &mousedev->client_list, node)
825 		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
826 	spin_unlock(&mousedev->client_lock);
827 
828 	wake_up_interruptible(&mousedev->wait);
829 }
830 
831 static void mousedev_cleanup(struct mousedev *mousedev)
832 {
833 	struct input_handle *handle = &mousedev->handle;
834 
835 	mousedev_mark_dead(mousedev);
836 	mousedev_hangup(mousedev);
837 	mousedev_remove_chrdev(mousedev);
838 
839 	/* mousedev is marked dead so no one else accesses mousedev->open */
840 	if (mousedev->open)
841 		input_close_device(handle);
842 }
843 
844 static struct mousedev *mousedev_create(struct input_dev *dev,
845 					struct input_handler *handler,
846 					int minor)
847 {
848 	struct mousedev *mousedev;
849 	int error;
850 
851 	mousedev = kzalloc(sizeof(struct mousedev), GFP_KERNEL);
852 	if (!mousedev) {
853 		error = -ENOMEM;
854 		goto err_out;
855 	}
856 
857 	INIT_LIST_HEAD(&mousedev->client_list);
858 	INIT_LIST_HEAD(&mousedev->mixdev_node);
859 	spin_lock_init(&mousedev->client_lock);
860 	mutex_init(&mousedev->mutex);
861 	lockdep_set_subclass(&mousedev->mutex,
862 			     minor == MOUSEDEV_MIX ? MOUSEDEV_MIX : 0);
863 	init_waitqueue_head(&mousedev->wait);
864 
865 	if (minor == MOUSEDEV_MIX)
866 		dev_set_name(&mousedev->dev, "mice");
867 	else
868 		dev_set_name(&mousedev->dev, "mouse%d", minor);
869 
870 	mousedev->minor = minor;
871 	mousedev->exist = 1;
872 	mousedev->handle.dev = input_get_device(dev);
873 	mousedev->handle.name = dev_name(&mousedev->dev);
874 	mousedev->handle.handler = handler;
875 	mousedev->handle.private = mousedev;
876 
877 	mousedev->dev.class = &input_class;
878 	if (dev)
879 		mousedev->dev.parent = &dev->dev;
880 	mousedev->dev.devt = MKDEV(INPUT_MAJOR, MOUSEDEV_MINOR_BASE + minor);
881 	mousedev->dev.release = mousedev_free;
882 	device_initialize(&mousedev->dev);
883 
884 	if (minor != MOUSEDEV_MIX) {
885 		error = input_register_handle(&mousedev->handle);
886 		if (error)
887 			goto err_free_mousedev;
888 	}
889 
890 	error = mousedev_install_chrdev(mousedev);
891 	if (error)
892 		goto err_unregister_handle;
893 
894 	error = device_add(&mousedev->dev);
895 	if (error)
896 		goto err_cleanup_mousedev;
897 
898 	return mousedev;
899 
900  err_cleanup_mousedev:
901 	mousedev_cleanup(mousedev);
902  err_unregister_handle:
903 	if (minor != MOUSEDEV_MIX)
904 		input_unregister_handle(&mousedev->handle);
905  err_free_mousedev:
906 	put_device(&mousedev->dev);
907  err_out:
908 	return ERR_PTR(error);
909 }
910 
911 static void mousedev_destroy(struct mousedev *mousedev)
912 {
913 	device_del(&mousedev->dev);
914 	mousedev_cleanup(mousedev);
915 	if (mousedev->minor != MOUSEDEV_MIX)
916 		input_unregister_handle(&mousedev->handle);
917 	put_device(&mousedev->dev);
918 }
919 
920 static int mixdev_add_device(struct mousedev *mousedev)
921 {
922 	int retval;
923 
924 	retval = mutex_lock_interruptible(&mousedev_mix->mutex);
925 	if (retval)
926 		return retval;
927 
928 	if (mousedev_mix->open) {
929 		retval = mousedev_open_device(mousedev);
930 		if (retval)
931 			goto out;
932 
933 		mousedev->mixdev_open = 1;
934 	}
935 
936 	get_device(&mousedev->dev);
937 	list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list);
938 
939  out:
940 	mutex_unlock(&mousedev_mix->mutex);
941 	return retval;
942 }
943 
944 static void mixdev_remove_device(struct mousedev *mousedev)
945 {
946 	mutex_lock(&mousedev_mix->mutex);
947 
948 	if (mousedev->mixdev_open) {
949 		mousedev->mixdev_open = 0;
950 		mousedev_close_device(mousedev);
951 	}
952 
953 	list_del_init(&mousedev->mixdev_node);
954 	mutex_unlock(&mousedev_mix->mutex);
955 
956 	put_device(&mousedev->dev);
957 }
958 
959 static int mousedev_connect(struct input_handler *handler,
960 			    struct input_dev *dev,
961 			    const struct input_device_id *id)
962 {
963 	struct mousedev *mousedev;
964 	int minor;
965 	int error;
966 
967 	for (minor = 0; minor < MOUSEDEV_MINORS; minor++)
968 		if (!mousedev_table[minor])
969 			break;
970 
971 	if (minor == MOUSEDEV_MINORS) {
972 		printk(KERN_ERR "mousedev: no more free mousedev devices\n");
973 		return -ENFILE;
974 	}
975 
976 	mousedev = mousedev_create(dev, handler, minor);
977 	if (IS_ERR(mousedev))
978 		return PTR_ERR(mousedev);
979 
980 	error = mixdev_add_device(mousedev);
981 	if (error) {
982 		mousedev_destroy(mousedev);
983 		return error;
984 	}
985 
986 	return 0;
987 }
988 
989 static void mousedev_disconnect(struct input_handle *handle)
990 {
991 	struct mousedev *mousedev = handle->private;
992 
993 	mixdev_remove_device(mousedev);
994 	mousedev_destroy(mousedev);
995 }
996 
997 static const struct input_device_id mousedev_ids[] = {
998 	{
999 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1000 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1001 				INPUT_DEVICE_ID_MATCH_RELBIT,
1002 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1003 		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1004 		.relbit = { BIT_MASK(REL_X) | BIT_MASK(REL_Y) },
1005 	},	/* A mouse like device, at least one button,
1006 		   two relative axes */
1007 	{
1008 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1009 				INPUT_DEVICE_ID_MATCH_RELBIT,
1010 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1011 		.relbit = { BIT_MASK(REL_WHEEL) },
1012 	},	/* A separate scrollwheel */
1013 	{
1014 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1015 				INPUT_DEVICE_ID_MATCH_KEYBIT |
1016 				INPUT_DEVICE_ID_MATCH_ABSBIT,
1017 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1018 		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
1019 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1020 	},	/* A tablet like device, at least touch detection,
1021 		   two absolute axes */
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_TOOL_FINGER)] =
1028 				BIT_MASK(BTN_TOOL_FINGER) },
1029 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
1030 				BIT_MASK(ABS_PRESSURE) |
1031 				BIT_MASK(ABS_TOOL_WIDTH) },
1032 	},	/* A touchpad */
1033 	{
1034 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1035 			INPUT_DEVICE_ID_MATCH_KEYBIT |
1036 			INPUT_DEVICE_ID_MATCH_ABSBIT,
1037 		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1038 		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1039 		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1040 	},	/* Mouse-like device with absolute X and Y but ordinary
1041 		   clicks, like hp ILO2 High Performance mouse */
1042 
1043 	{ },	/* Terminating entry */
1044 };
1045 
1046 MODULE_DEVICE_TABLE(input, mousedev_ids);
1047 
1048 static struct input_handler mousedev_handler = {
1049 	.event =	mousedev_event,
1050 	.connect =	mousedev_connect,
1051 	.disconnect =	mousedev_disconnect,
1052 	.fops =		&mousedev_fops,
1053 	.minor =	MOUSEDEV_MINOR_BASE,
1054 	.name =		"mousedev",
1055 	.id_table =	mousedev_ids,
1056 };
1057 
1058 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1059 static struct miscdevice psaux_mouse = {
1060 	PSMOUSE_MINOR, "psaux", &mousedev_fops
1061 };
1062 static int psaux_registered;
1063 #endif
1064 
1065 static int __init mousedev_init(void)
1066 {
1067 	int error;
1068 
1069 	mousedev_mix = mousedev_create(NULL, &mousedev_handler, MOUSEDEV_MIX);
1070 	if (IS_ERR(mousedev_mix))
1071 		return PTR_ERR(mousedev_mix);
1072 
1073 	error = input_register_handler(&mousedev_handler);
1074 	if (error) {
1075 		mousedev_destroy(mousedev_mix);
1076 		return error;
1077 	}
1078 
1079 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1080 	error = misc_register(&psaux_mouse);
1081 	if (error)
1082 		printk(KERN_WARNING "mice: could not register psaux device, "
1083 			"error: %d\n", error);
1084 	else
1085 		psaux_registered = 1;
1086 #endif
1087 
1088 	printk(KERN_INFO "mice: PS/2 mouse device common for all mice\n");
1089 
1090 	return 0;
1091 }
1092 
1093 static void __exit mousedev_exit(void)
1094 {
1095 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1096 	if (psaux_registered)
1097 		misc_deregister(&psaux_mouse);
1098 #endif
1099 	input_unregister_handler(&mousedev_handler);
1100 	mousedev_destroy(mousedev_mix);
1101 }
1102 
1103 module_init(mousedev_init);
1104 module_exit(mousedev_exit);
1105