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
28 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
29 MODULE_DESCRIPTION("Mouse (ExplorerPS/2) device interfaces");
30 MODULE_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
39 static int xres = CONFIG_INPUT_MOUSEDEV_SCREEN_X;
40 module_param(xres, uint, 0644);
41 MODULE_PARM_DESC(xres, "Horizontal screen resolution");
42
43 static int yres = CONFIG_INPUT_MOUSEDEV_SCREEN_Y;
44 module_param(yres, uint, 0644);
45 MODULE_PARM_DESC(yres, "Vertical screen resolution");
46
47 static unsigned tap_time = 200;
48 module_param(tap_time, uint, 0644);
49 MODULE_PARM_DESC(tap_time, "Tap time for touchpads in absolute mode (msecs)");
50
51 struct mousedev_hw_data {
52 int dx, dy, dz;
53 int x, y;
54 int abs_event;
55 unsigned long buttons;
56 };
57
58 struct 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
82 enum mousedev_emul {
83 MOUSEDEV_EMUL_PS2,
84 MOUSEDEV_EMUL_IMPS,
85 MOUSEDEV_EMUL_EXPS
86 };
87
88 struct mousedev_motion {
89 int dx, dy, dz;
90 unsigned long buttons;
91 };
92
93 #define PACKET_QUEUE_LEN 16
94 struct 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
113 static unsigned char mousedev_imps_seq[] = { 0xf3, 200, 0xf3, 100, 0xf3, 80 };
114 static unsigned char mousedev_imex_seq[] = { 0xf3, 200, 0xf3, 200, 0xf3, 80 };
115
116 static struct mousedev *mousedev_mix;
117 static 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
mousedev_touchpad_event(struct input_dev * dev,struct mousedev * mousedev,unsigned int code,int value)122 static 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
mousedev_abs_event(struct input_dev * dev,struct mousedev * mousedev,unsigned int code,int value)167 static 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
mousedev_rel_event(struct mousedev * mousedev,unsigned int code,int value)204 static 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
mousedev_key_event(struct mousedev * mousedev,unsigned int code,int value)222 static 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
mousedev_notify_readers(struct mousedev * mousedev,struct mousedev_hw_data * packet)261 static 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
mousedev_touchpad_touch(struct mousedev * mousedev,int value)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
mousedev_event(struct input_handle * handle,unsigned int type,unsigned int code,int value)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
mousedev_fasync(int fd,struct file * file,int on)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
mousedev_free(struct device * dev)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
mousedev_open_device(struct mousedev * mousedev)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->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
mousedev_close_device(struct mousedev * mousedev)439 static 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 */
mixdev_open_devices(struct mousedev * mixdev)454 static 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 */
mixdev_close_devices(struct mousedev * mixdev)484 static 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
mousedev_attach_client(struct mousedev * mousedev,struct mousedev_client * client)503 static 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
mousedev_detach_client(struct mousedev * mousedev,struct mousedev_client * client)511 static 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
mousedev_release(struct inode * inode,struct file * file)520 static 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
mousedev_open(struct inode * inode,struct file * file)533 static 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
mousedev_packet(struct mousedev_client * client,u8 * ps2_data)571 static 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
mousedev_generate_response(struct mousedev_client * client,int command)628 static 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
mousedev_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)674 static 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
mousedev_read(struct file * file,char __user * buffer,size_t count,loff_t * ppos)716 static 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 */
mousedev_poll(struct file * file,poll_table * wait)758 static __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
773 static 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 */
mousedev_mark_dead(struct mousedev * mousedev)789 static 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 */
mousedev_hangup(struct mousedev * mousedev)800 static 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
mousedev_cleanup(struct mousedev * mousedev)812 static 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
mousedev_reserve_minor(bool mixdev)824 static 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
mousedev_create(struct input_dev * dev,struct input_handler * handler,bool mixdev)842 static 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
mousedev_destroy(struct mousedev * mousedev)925 static 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
mixdev_add_device(struct mousedev * mousedev)935 static 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
mixdev_remove_device(struct mousedev * mousedev)959 static 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
mousedev_connect(struct input_handler * handler,struct input_dev * dev,const struct input_device_id * id)974 static 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
mousedev_disconnect(struct input_handle * handle)994 static 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
1002 static 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
1051 MODULE_DEVICE_TABLE(input, mousedev_ids);
1052
1053 static 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
1066 static struct miscdevice psaux_mouse = {
1067 .minor = PSMOUSE_MINOR,
1068 .name = "psaux",
1069 .fops = &mousedev_fops,
1070 };
1071
1072 static bool psaux_registered;
1073
mousedev_psaux_register(void)1074 static 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
mousedev_psaux_unregister(void)1086 static void __exit mousedev_psaux_unregister(void)
1087 {
1088 if (psaux_registered)
1089 misc_deregister(&psaux_mouse);
1090 }
1091 #else
mousedev_psaux_register(void)1092 static inline void mousedev_psaux_register(void) { }
mousedev_psaux_unregister(void)1093 static inline void mousedev_psaux_unregister(void) { }
1094 #endif
1095
mousedev_init(void)1096 static 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
mousedev_exit(void)1117 static void __exit mousedev_exit(void)
1118 {
1119 mousedev_psaux_unregister();
1120 input_unregister_handler(&mousedev_handler);
1121 mousedev_destroy(mousedev_mix);
1122 }
1123
1124 module_init(mousedev_init);
1125 module_exit(mousedev_exit);
1126