1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Input driver to ExplorerPS/2 device driver module.
4 *
5 * Copyright (c) 1999-2002 Vojtech Pavlik
6 * Copyright (c) 2004      Dmitry Torokhov
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#define MOUSEDEV_MINOR_BASE	32
12#define MOUSEDEV_MINORS		31
13#define MOUSEDEV_MIX		63
14
15#include <linux/bitops.h>
16#include <linux/sched.h>
17#include <linux/slab.h>
18#include <linux/poll.h>
19#include <linux/module.h>
20#include <linux/init.h>
21#include <linux/input.h>
22#include <linux/random.h>
23#include <linux/major.h>
24#include <linux/device.h>
25#include <linux/cdev.h>
26#include <linux/kernel.h>
27
28MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
29MODULE_DESCRIPTION("Mouse (ExplorerPS/2) device interfaces");
30MODULE_LICENSE("GPL");
31
32#ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_X
33#define CONFIG_INPUT_MOUSEDEV_SCREEN_X	1024
34#endif
35#ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_Y
36#define CONFIG_INPUT_MOUSEDEV_SCREEN_Y	768
37#endif
38
39static int xres = CONFIG_INPUT_MOUSEDEV_SCREEN_X;
40module_param(xres, uint, 0644);
41MODULE_PARM_DESC(xres, "Horizontal screen resolution");
42
43static int yres = CONFIG_INPUT_MOUSEDEV_SCREEN_Y;
44module_param(yres, uint, 0644);
45MODULE_PARM_DESC(yres, "Vertical screen resolution");
46
47static unsigned tap_time = 200;
48module_param(tap_time, uint, 0644);
49MODULE_PARM_DESC(tap_time, "Tap time for touchpads in absolute mode (msecs)");
50
51struct mousedev_hw_data {
52	int dx, dy, dz;
53	int x, y;
54	int abs_event;
55	unsigned long buttons;
56};
57
58struct mousedev {
59	int open;
60	struct input_handle handle;
61	wait_queue_head_t wait;
62	struct list_head client_list;
63	spinlock_t client_lock; /* protects client_list */
64	struct mutex mutex;
65	struct device dev;
66	struct cdev cdev;
67	bool exist;
68
69	struct list_head mixdev_node;
70	bool opened_by_mixdev;
71
72	struct mousedev_hw_data packet;
73	unsigned int pkt_count;
74	int old_x[4], old_y[4];
75	int frac_dx, frac_dy;
76	unsigned long touch;
77
78	int (*open_device)(struct mousedev *mousedev);
79	void (*close_device)(struct mousedev *mousedev);
80};
81
82enum mousedev_emul {
83	MOUSEDEV_EMUL_PS2,
84	MOUSEDEV_EMUL_IMPS,
85	MOUSEDEV_EMUL_EXPS
86};
87
88struct mousedev_motion {
89	int dx, dy, dz;
90	unsigned long buttons;
91};
92
93#define PACKET_QUEUE_LEN	16
94struct mousedev_client {
95	struct fasync_struct *fasync;
96	struct mousedev *mousedev;
97	struct list_head node;
98
99	struct mousedev_motion packets[PACKET_QUEUE_LEN];
100	unsigned int head, tail;
101	spinlock_t packet_lock;
102	int pos_x, pos_y;
103
104	u8 ps2[6];
105	unsigned char ready, buffer, bufsiz;
106	unsigned char imexseq, impsseq;
107	enum mousedev_emul mode;
108	unsigned long last_buttons;
109};
110
111#define MOUSEDEV_SEQ_LEN	6
112
113static unsigned char mousedev_imps_seq[] = { 0xf3, 200, 0xf3, 100, 0xf3, 80 };
114static unsigned char mousedev_imex_seq[] = { 0xf3, 200, 0xf3, 200, 0xf3, 80 };
115
116static struct mousedev *mousedev_mix;
117static LIST_HEAD(mousedev_mix_list);
118
119#define fx(i)  (mousedev->old_x[(mousedev->pkt_count - (i)) & 03])
120#define fy(i)  (mousedev->old_y[(mousedev->pkt_count - (i)) & 03])
121
122static void mousedev_touchpad_event(struct input_dev *dev,
123				    struct mousedev *mousedev,
124				    unsigned int code, int value)
125{
126	int size, tmp;
127	enum { FRACTION_DENOM = 128 };
128
129	switch (code) {
130
131	case ABS_X:
132
133		fx(0) = value;
134		if (mousedev->touch && mousedev->pkt_count >= 2) {
135			size = input_abs_get_max(dev, ABS_X) -
136					input_abs_get_min(dev, ABS_X);
137			if (size == 0)
138				size = 256 * 2;
139
140			tmp = ((value - fx(2)) * 256 * FRACTION_DENOM) / size;
141			tmp += mousedev->frac_dx;
142			mousedev->packet.dx = tmp / FRACTION_DENOM;
143			mousedev->frac_dx =
144				tmp - mousedev->packet.dx * FRACTION_DENOM;
145		}
146		break;
147
148	case ABS_Y:
149		fy(0) = value;
150		if (mousedev->touch && mousedev->pkt_count >= 2) {
151			/* use X size for ABS_Y to keep the same scale */
152			size = input_abs_get_max(dev, ABS_X) -
153					input_abs_get_min(dev, ABS_X);
154			if (size == 0)
155				size = 256 * 2;
156
157			tmp = -((value - fy(2)) * 256 * FRACTION_DENOM) / size;
158			tmp += mousedev->frac_dy;
159			mousedev->packet.dy = tmp / FRACTION_DENOM;
160			mousedev->frac_dy = tmp -
161				mousedev->packet.dy * FRACTION_DENOM;
162		}
163		break;
164	}
165}
166
167static void mousedev_abs_event(struct input_dev *dev, struct mousedev *mousedev,
168				unsigned int code, int value)
169{
170	int min, max, size;
171
172	switch (code) {
173
174	case ABS_X:
175		min = input_abs_get_min(dev, ABS_X);
176		max = input_abs_get_max(dev, ABS_X);
177
178		size = max - min;
179		if (size == 0)
180			size = xres ? : 1;
181
182		value = clamp(value, min, max);
183
184		mousedev->packet.x = ((value - min) * xres) / size;
185		mousedev->packet.abs_event = 1;
186		break;
187
188	case ABS_Y:
189		min = input_abs_get_min(dev, ABS_Y);
190		max = input_abs_get_max(dev, ABS_Y);
191
192		size = max - min;
193		if (size == 0)
194			size = yres ? : 1;
195
196		value = clamp(value, min, max);
197
198		mousedev->packet.y = yres - ((value - min) * yres) / size;
199		mousedev->packet.abs_event = 1;
200		break;
201	}
202}
203
204static void mousedev_rel_event(struct mousedev *mousedev,
205				unsigned int code, int value)
206{
207	switch (code) {
208	case REL_X:
209		mousedev->packet.dx += value;
210		break;
211
212	case REL_Y:
213		mousedev->packet.dy -= value;
214		break;
215
216	case REL_WHEEL:
217		mousedev->packet.dz -= value;
218		break;
219	}
220}
221
222static void mousedev_key_event(struct mousedev *mousedev,
223				unsigned int code, int value)
224{
225	int index;
226
227	switch (code) {
228
229	case BTN_TOUCH:
230	case BTN_0:
231	case BTN_LEFT:		index = 0; break;
232
233	case BTN_STYLUS:
234	case BTN_1:
235	case BTN_RIGHT:		index = 1; break;
236
237	case BTN_2:
238	case BTN_FORWARD:
239	case BTN_STYLUS2:
240	case BTN_MIDDLE:	index = 2; break;
241
242	case BTN_3:
243	case BTN_BACK:
244	case BTN_SIDE:		index = 3; break;
245
246	case BTN_4:
247	case BTN_EXTRA:		index = 4; break;
248
249	default:		return;
250	}
251
252	if (value) {
253		set_bit(index, &mousedev->packet.buttons);
254		set_bit(index, &mousedev_mix->packet.buttons);
255	} else {
256		clear_bit(index, &mousedev->packet.buttons);
257		clear_bit(index, &mousedev_mix->packet.buttons);
258	}
259}
260
261static void mousedev_notify_readers(struct mousedev *mousedev,
262				    struct mousedev_hw_data *packet)
263{
264	struct mousedev_client *client;
265	struct mousedev_motion *p;
266	unsigned int new_head;
267	int wake_readers = 0;
268
269	rcu_read_lock();
270	list_for_each_entry_rcu(client, &mousedev->client_list, node) {
271
272		/* Just acquire the lock, interrupts already disabled */
273		spin_lock(&client->packet_lock);
274
275		p = &client->packets[client->head];
276		if (client->ready && p->buttons != mousedev->packet.buttons) {
277			new_head = (client->head + 1) % PACKET_QUEUE_LEN;
278			if (new_head != client->tail) {
279				p = &client->packets[client->head = new_head];
280				memset(p, 0, sizeof(struct mousedev_motion));
281			}
282		}
283
284		if (packet->abs_event) {
285			p->dx += packet->x - client->pos_x;
286			p->dy += packet->y - client->pos_y;
287			client->pos_x = packet->x;
288			client->pos_y = packet->y;
289		}
290
291		client->pos_x += packet->dx;
292		client->pos_x = clamp_val(client->pos_x, 0, xres);
293
294		client->pos_y += packet->dy;
295		client->pos_y = clamp_val(client->pos_y, 0, yres);
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
319static 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
346static 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
404static 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
411static 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
419static 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->exist)
428		retval = -ENODEV;
429	else if (!mousedev->open++) {
430		retval = input_open_device(&mousedev->handle);
431		if (retval)
432			mousedev->open--;
433	}
434
435	mutex_unlock(&mousedev->mutex);
436	return retval;
437}
438
439static void mousedev_close_device(struct mousedev *mousedev)
440{
441	mutex_lock(&mousedev->mutex);
442
443	if (mousedev->exist && !--mousedev->open)
444		input_close_device(&mousedev->handle);
445
446	mutex_unlock(&mousedev->mutex);
447}
448
449/*
450 * Open all available devices so they can all be multiplexed in one.
451 * stream. Note that this function is called with mousedev_mix->mutex
452 * held.
453 */
454static int mixdev_open_devices(struct mousedev *mixdev)
455{
456	int error;
457
458	error = mutex_lock_interruptible(&mixdev->mutex);
459	if (error)
460		return error;
461
462	if (!mixdev->open++) {
463		struct mousedev *mousedev;
464
465		list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
466			if (!mousedev->opened_by_mixdev) {
467				if (mousedev_open_device(mousedev))
468					continue;
469
470				mousedev->opened_by_mixdev = true;
471			}
472		}
473	}
474
475	mutex_unlock(&mixdev->mutex);
476	return 0;
477}
478
479/*
480 * Close all devices that were opened as part of multiplexed
481 * device. Note that this function is called with mousedev_mix->mutex
482 * held.
483 */
484static void mixdev_close_devices(struct mousedev *mixdev)
485{
486	mutex_lock(&mixdev->mutex);
487
488	if (!--mixdev->open) {
489		struct mousedev *mousedev;
490
491		list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
492			if (mousedev->opened_by_mixdev) {
493				mousedev->opened_by_mixdev = false;
494				mousedev_close_device(mousedev);
495			}
496		}
497	}
498
499	mutex_unlock(&mixdev->mutex);
500}
501
502
503static void mousedev_attach_client(struct mousedev *mousedev,
504				   struct mousedev_client *client)
505{
506	spin_lock(&mousedev->client_lock);
507	list_add_tail_rcu(&client->node, &mousedev->client_list);
508	spin_unlock(&mousedev->client_lock);
509}
510
511static void mousedev_detach_client(struct mousedev *mousedev,
512				   struct mousedev_client *client)
513{
514	spin_lock(&mousedev->client_lock);
515	list_del_rcu(&client->node);
516	spin_unlock(&mousedev->client_lock);
517	synchronize_rcu();
518}
519
520static int mousedev_release(struct inode *inode, struct file *file)
521{
522	struct mousedev_client *client = file->private_data;
523	struct mousedev *mousedev = client->mousedev;
524
525	mousedev_detach_client(mousedev, client);
526	kfree(client);
527
528	mousedev->close_device(mousedev);
529
530	return 0;
531}
532
533static int mousedev_open(struct inode *inode, struct file *file)
534{
535	struct mousedev_client *client;
536	struct mousedev *mousedev;
537	int error;
538
539#ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
540	if (imajor(inode) == MISC_MAJOR)
541		mousedev = mousedev_mix;
542	else
543#endif
544		mousedev = container_of(inode->i_cdev, struct mousedev, cdev);
545
546	client = kzalloc(sizeof(struct mousedev_client), GFP_KERNEL);
547	if (!client)
548		return -ENOMEM;
549
550	spin_lock_init(&client->packet_lock);
551	client->pos_x = xres / 2;
552	client->pos_y = yres / 2;
553	client->mousedev = mousedev;
554	mousedev_attach_client(mousedev, client);
555
556	error = mousedev->open_device(mousedev);
557	if (error)
558		goto err_free_client;
559
560	file->private_data = client;
561	stream_open(inode, file);
562
563	return 0;
564
565 err_free_client:
566	mousedev_detach_client(mousedev, client);
567	kfree(client);
568	return error;
569}
570
571static void mousedev_packet(struct mousedev_client *client, u8 *ps2_data)
572{
573	struct mousedev_motion *p = &client->packets[client->tail];
574	s8 dx, dy, dz;
575
576	dx = clamp_val(p->dx, -127, 127);
577	p->dx -= dx;
578
579	dy = clamp_val(p->dy, -127, 127);
580	p->dy -= dy;
581
582	ps2_data[0] = BIT(3);
583	ps2_data[0] |= ((dx & BIT(7)) >> 3) | ((dy & BIT(7)) >> 2);
584	ps2_data[0] |= p->buttons & 0x07;
585	ps2_data[1] = dx;
586	ps2_data[2] = dy;
587
588	switch (client->mode) {
589	case MOUSEDEV_EMUL_EXPS:
590		dz = clamp_val(p->dz, -7, 7);
591		p->dz -= dz;
592
593		ps2_data[3] = (dz & 0x0f) | ((p->buttons & 0x18) << 1);
594		client->bufsiz = 4;
595		break;
596
597	case MOUSEDEV_EMUL_IMPS:
598		dz = clamp_val(p->dz, -127, 127);
599		p->dz -= dz;
600
601		ps2_data[0] |= ((p->buttons & 0x10) >> 3) |
602			       ((p->buttons & 0x08) >> 1);
603		ps2_data[3] = dz;
604
605		client->bufsiz = 4;
606		break;
607
608	case MOUSEDEV_EMUL_PS2:
609	default:
610		p->dz = 0;
611
612		ps2_data[0] |= ((p->buttons & 0x10) >> 3) |
613			       ((p->buttons & 0x08) >> 1);
614
615		client->bufsiz = 3;
616		break;
617	}
618
619	if (!p->dx && !p->dy && !p->dz) {
620		if (client->tail == client->head) {
621			client->ready = 0;
622			client->last_buttons = p->buttons;
623		} else
624			client->tail = (client->tail + 1) % PACKET_QUEUE_LEN;
625	}
626}
627
628static void mousedev_generate_response(struct mousedev_client *client,
629					int command)
630{
631	client->ps2[0] = 0xfa; /* ACK */
632
633	switch (command) {
634
635	case 0xeb: /* Poll */
636		mousedev_packet(client, &client->ps2[1]);
637		client->bufsiz++; /* account for leading ACK */
638		break;
639
640	case 0xf2: /* Get ID */
641		switch (client->mode) {
642		case MOUSEDEV_EMUL_PS2:
643			client->ps2[1] = 0;
644			break;
645		case MOUSEDEV_EMUL_IMPS:
646			client->ps2[1] = 3;
647			break;
648		case MOUSEDEV_EMUL_EXPS:
649			client->ps2[1] = 4;
650			break;
651		}
652		client->bufsiz = 2;
653		break;
654
655	case 0xe9: /* Get info */
656		client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200;
657		client->bufsiz = 4;
658		break;
659
660	case 0xff: /* Reset */
661		client->impsseq = client->imexseq = 0;
662		client->mode = MOUSEDEV_EMUL_PS2;
663		client->ps2[1] = 0xaa; client->ps2[2] = 0x00;
664		client->bufsiz = 3;
665		break;
666
667	default:
668		client->bufsiz = 1;
669		break;
670	}
671	client->buffer = client->bufsiz;
672}
673
674static ssize_t mousedev_write(struct file *file, const char __user *buffer,
675				size_t count, loff_t *ppos)
676{
677	struct mousedev_client *client = file->private_data;
678	unsigned char c;
679	unsigned int i;
680
681	for (i = 0; i < count; i++) {
682
683		if (get_user(c, buffer + i))
684			return -EFAULT;
685
686		spin_lock_irq(&client->packet_lock);
687
688		if (c == mousedev_imex_seq[client->imexseq]) {
689			if (++client->imexseq == MOUSEDEV_SEQ_LEN) {
690				client->imexseq = 0;
691				client->mode = MOUSEDEV_EMUL_EXPS;
692			}
693		} else
694			client->imexseq = 0;
695
696		if (c == mousedev_imps_seq[client->impsseq]) {
697			if (++client->impsseq == MOUSEDEV_SEQ_LEN) {
698				client->impsseq = 0;
699				client->mode = MOUSEDEV_EMUL_IMPS;
700			}
701		} else
702			client->impsseq = 0;
703
704		mousedev_generate_response(client, c);
705
706		spin_unlock_irq(&client->packet_lock);
707		cond_resched();
708	}
709
710	kill_fasync(&client->fasync, SIGIO, POLL_IN);
711	wake_up_interruptible(&client->mousedev->wait);
712
713	return count;
714}
715
716static ssize_t mousedev_read(struct file *file, char __user *buffer,
717			     size_t count, loff_t *ppos)
718{
719	struct mousedev_client *client = file->private_data;
720	struct mousedev *mousedev = client->mousedev;
721	u8 data[sizeof(client->ps2)];
722	int retval = 0;
723
724	if (!client->ready && !client->buffer && mousedev->exist &&
725	    (file->f_flags & O_NONBLOCK))
726		return -EAGAIN;
727
728	retval = wait_event_interruptible(mousedev->wait,
729			!mousedev->exist || client->ready || client->buffer);
730	if (retval)
731		return retval;
732
733	if (!mousedev->exist)
734		return -ENODEV;
735
736	spin_lock_irq(&client->packet_lock);
737
738	if (!client->buffer && client->ready) {
739		mousedev_packet(client, client->ps2);
740		client->buffer = client->bufsiz;
741	}
742
743	if (count > client->buffer)
744		count = client->buffer;
745
746	memcpy(data, client->ps2 + client->bufsiz - client->buffer, count);
747	client->buffer -= count;
748
749	spin_unlock_irq(&client->packet_lock);
750
751	if (copy_to_user(buffer, data, count))
752		return -EFAULT;
753
754	return count;
755}
756
757/* No kernel lock - fine */
758static __poll_t mousedev_poll(struct file *file, poll_table *wait)
759{
760	struct mousedev_client *client = file->private_data;
761	struct mousedev *mousedev = client->mousedev;
762	__poll_t mask;
763
764	poll_wait(file, &mousedev->wait, wait);
765
766	mask = mousedev->exist ? EPOLLOUT | EPOLLWRNORM : EPOLLHUP | EPOLLERR;
767	if (client->ready || client->buffer)
768		mask |= EPOLLIN | EPOLLRDNORM;
769
770	return mask;
771}
772
773static const struct file_operations mousedev_fops = {
774	.owner		= THIS_MODULE,
775	.read		= mousedev_read,
776	.write		= mousedev_write,
777	.poll		= mousedev_poll,
778	.open		= mousedev_open,
779	.release	= mousedev_release,
780	.fasync		= mousedev_fasync,
781	.llseek		= noop_llseek,
782};
783
784/*
785 * Mark device non-existent. This disables writes, ioctls and
786 * prevents new users from opening the device. Already posted
787 * blocking reads will stay, however new ones will fail.
788 */
789static void mousedev_mark_dead(struct mousedev *mousedev)
790{
791	mutex_lock(&mousedev->mutex);
792	mousedev->exist = false;
793	mutex_unlock(&mousedev->mutex);
794}
795
796/*
797 * Wake up users waiting for IO so they can disconnect from
798 * dead device.
799 */
800static void mousedev_hangup(struct mousedev *mousedev)
801{
802	struct mousedev_client *client;
803
804	spin_lock(&mousedev->client_lock);
805	list_for_each_entry(client, &mousedev->client_list, node)
806		kill_fasync(&client->fasync, SIGIO, POLL_HUP);
807	spin_unlock(&mousedev->client_lock);
808
809	wake_up_interruptible(&mousedev->wait);
810}
811
812static void mousedev_cleanup(struct mousedev *mousedev)
813{
814	struct input_handle *handle = &mousedev->handle;
815
816	mousedev_mark_dead(mousedev);
817	mousedev_hangup(mousedev);
818
819	/* mousedev is marked dead so no one else accesses mousedev->open */
820	if (mousedev->open)
821		input_close_device(handle);
822}
823
824static int mousedev_reserve_minor(bool mixdev)
825{
826	int minor;
827
828	if (mixdev) {
829		minor = input_get_new_minor(MOUSEDEV_MIX, 1, false);
830		if (minor < 0)
831			pr_err("failed to reserve mixdev minor: %d\n", minor);
832	} else {
833		minor = input_get_new_minor(MOUSEDEV_MINOR_BASE,
834					    MOUSEDEV_MINORS, true);
835		if (minor < 0)
836			pr_err("failed to reserve new minor: %d\n", minor);
837	}
838
839	return minor;
840}
841
842static struct mousedev *mousedev_create(struct input_dev *dev,
843					struct input_handler *handler,
844					bool mixdev)
845{
846	struct mousedev *mousedev;
847	int minor;
848	int error;
849
850	minor = mousedev_reserve_minor(mixdev);
851	if (minor < 0) {
852		error = minor;
853		goto err_out;
854	}
855
856	mousedev = kzalloc(sizeof(struct mousedev), GFP_KERNEL);
857	if (!mousedev) {
858		error = -ENOMEM;
859		goto err_free_minor;
860	}
861
862	INIT_LIST_HEAD(&mousedev->client_list);
863	INIT_LIST_HEAD(&mousedev->mixdev_node);
864	spin_lock_init(&mousedev->client_lock);
865	mutex_init(&mousedev->mutex);
866	lockdep_set_subclass(&mousedev->mutex,
867			     mixdev ? SINGLE_DEPTH_NESTING : 0);
868	init_waitqueue_head(&mousedev->wait);
869
870	if (mixdev) {
871		dev_set_name(&mousedev->dev, "mice");
872
873		mousedev->open_device = mixdev_open_devices;
874		mousedev->close_device = mixdev_close_devices;
875	} else {
876		int dev_no = minor;
877		/* Normalize device number if it falls into legacy range */
878		if (dev_no < MOUSEDEV_MINOR_BASE + MOUSEDEV_MINORS)
879			dev_no -= MOUSEDEV_MINOR_BASE;
880		dev_set_name(&mousedev->dev, "mouse%d", dev_no);
881
882		mousedev->open_device = mousedev_open_device;
883		mousedev->close_device = mousedev_close_device;
884	}
885
886	mousedev->exist = true;
887	mousedev->handle.dev = input_get_device(dev);
888	mousedev->handle.name = dev_name(&mousedev->dev);
889	mousedev->handle.handler = handler;
890	mousedev->handle.private = mousedev;
891
892	mousedev->dev.class = &input_class;
893	if (dev)
894		mousedev->dev.parent = &dev->dev;
895	mousedev->dev.devt = MKDEV(INPUT_MAJOR, minor);
896	mousedev->dev.release = mousedev_free;
897	device_initialize(&mousedev->dev);
898
899	if (!mixdev) {
900		error = input_register_handle(&mousedev->handle);
901		if (error)
902			goto err_free_mousedev;
903	}
904
905	cdev_init(&mousedev->cdev, &mousedev_fops);
906
907	error = cdev_device_add(&mousedev->cdev, &mousedev->dev);
908	if (error)
909		goto err_cleanup_mousedev;
910
911	return mousedev;
912
913 err_cleanup_mousedev:
914	mousedev_cleanup(mousedev);
915	if (!mixdev)
916		input_unregister_handle(&mousedev->handle);
917 err_free_mousedev:
918	put_device(&mousedev->dev);
919 err_free_minor:
920	input_free_minor(minor);
921 err_out:
922	return ERR_PTR(error);
923}
924
925static void mousedev_destroy(struct mousedev *mousedev)
926{
927	cdev_device_del(&mousedev->cdev, &mousedev->dev);
928	mousedev_cleanup(mousedev);
929	input_free_minor(MINOR(mousedev->dev.devt));
930	if (mousedev != mousedev_mix)
931		input_unregister_handle(&mousedev->handle);
932	put_device(&mousedev->dev);
933}
934
935static int mixdev_add_device(struct mousedev *mousedev)
936{
937	int retval;
938
939	retval = mutex_lock_interruptible(&mousedev_mix->mutex);
940	if (retval)
941		return retval;
942
943	if (mousedev_mix->open) {
944		retval = mousedev_open_device(mousedev);
945		if (retval)
946			goto out;
947
948		mousedev->opened_by_mixdev = true;
949	}
950
951	get_device(&mousedev->dev);
952	list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list);
953
954 out:
955	mutex_unlock(&mousedev_mix->mutex);
956	return retval;
957}
958
959static void mixdev_remove_device(struct mousedev *mousedev)
960{
961	mutex_lock(&mousedev_mix->mutex);
962
963	if (mousedev->opened_by_mixdev) {
964		mousedev->opened_by_mixdev = false;
965		mousedev_close_device(mousedev);
966	}
967
968	list_del_init(&mousedev->mixdev_node);
969	mutex_unlock(&mousedev_mix->mutex);
970
971	put_device(&mousedev->dev);
972}
973
974static int mousedev_connect(struct input_handler *handler,
975			    struct input_dev *dev,
976			    const struct input_device_id *id)
977{
978	struct mousedev *mousedev;
979	int error;
980
981	mousedev = mousedev_create(dev, handler, false);
982	if (IS_ERR(mousedev))
983		return PTR_ERR(mousedev);
984
985	error = mixdev_add_device(mousedev);
986	if (error) {
987		mousedev_destroy(mousedev);
988		return error;
989	}
990
991	return 0;
992}
993
994static void mousedev_disconnect(struct input_handle *handle)
995{
996	struct mousedev *mousedev = handle->private;
997
998	mixdev_remove_device(mousedev);
999	mousedev_destroy(mousedev);
1000}
1001
1002static const struct input_device_id mousedev_ids[] = {
1003	{
1004		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1005				INPUT_DEVICE_ID_MATCH_KEYBIT |
1006				INPUT_DEVICE_ID_MATCH_RELBIT,
1007		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1008		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1009		.relbit = { BIT_MASK(REL_X) | BIT_MASK(REL_Y) },
1010	},	/* A mouse like device, at least one button,
1011		   two relative axes */
1012	{
1013		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1014				INPUT_DEVICE_ID_MATCH_RELBIT,
1015		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1016		.relbit = { BIT_MASK(REL_WHEEL) },
1017	},	/* A separate scrollwheel */
1018	{
1019		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1020				INPUT_DEVICE_ID_MATCH_KEYBIT |
1021				INPUT_DEVICE_ID_MATCH_ABSBIT,
1022		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1023		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
1024		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1025	},	/* A tablet like device, at least touch detection,
1026		   two absolute axes */
1027	{
1028		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1029				INPUT_DEVICE_ID_MATCH_KEYBIT |
1030				INPUT_DEVICE_ID_MATCH_ABSBIT,
1031		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1032		.keybit = { [BIT_WORD(BTN_TOOL_FINGER)] =
1033				BIT_MASK(BTN_TOOL_FINGER) },
1034		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
1035				BIT_MASK(ABS_PRESSURE) |
1036				BIT_MASK(ABS_TOOL_WIDTH) },
1037	},	/* A touchpad */
1038	{
1039		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1040			INPUT_DEVICE_ID_MATCH_KEYBIT |
1041			INPUT_DEVICE_ID_MATCH_ABSBIT,
1042		.evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1043		.keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1044		.absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1045	},	/* Mouse-like device with absolute X and Y but ordinary
1046		   clicks, like hp ILO2 High Performance mouse */
1047
1048	{ },	/* Terminating entry */
1049};
1050
1051MODULE_DEVICE_TABLE(input, mousedev_ids);
1052
1053static struct input_handler mousedev_handler = {
1054	.event		= mousedev_event,
1055	.connect	= mousedev_connect,
1056	.disconnect	= mousedev_disconnect,
1057	.legacy_minors	= true,
1058	.minor		= MOUSEDEV_MINOR_BASE,
1059	.name		= "mousedev",
1060	.id_table	= mousedev_ids,
1061};
1062
1063#ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1064#include <linux/miscdevice.h>
1065
1066static struct miscdevice psaux_mouse = {
1067	.minor	= PSMOUSE_MINOR,
1068	.name	= "psaux",
1069	.fops	= &mousedev_fops,
1070};
1071
1072static bool psaux_registered;
1073
1074static void __init mousedev_psaux_register(void)
1075{
1076	int error;
1077
1078	error = misc_register(&psaux_mouse);
1079	if (error)
1080		pr_warn("could not register psaux device, error: %d\n",
1081			   error);
1082	else
1083		psaux_registered = true;
1084}
1085
1086static void __exit mousedev_psaux_unregister(void)
1087{
1088	if (psaux_registered)
1089		misc_deregister(&psaux_mouse);
1090}
1091#else
1092static inline void mousedev_psaux_register(void) { }
1093static inline void mousedev_psaux_unregister(void) { }
1094#endif
1095
1096static int __init mousedev_init(void)
1097{
1098	int error;
1099
1100	mousedev_mix = mousedev_create(NULL, &mousedev_handler, true);
1101	if (IS_ERR(mousedev_mix))
1102		return PTR_ERR(mousedev_mix);
1103
1104	error = input_register_handler(&mousedev_handler);
1105	if (error) {
1106		mousedev_destroy(mousedev_mix);
1107		return error;
1108	}
1109
1110	mousedev_psaux_register();
1111
1112	pr_info("PS/2 mouse device common for all mice\n");
1113
1114	return 0;
1115}
1116
1117static void __exit mousedev_exit(void)
1118{
1119	mousedev_psaux_unregister();
1120	input_unregister_handler(&mousedev_handler);
1121	mousedev_destroy(mousedev_mix);
1122}
1123
1124module_init(mousedev_init);
1125module_exit(mousedev_exit);
1126