Version:  2.0.40 2.2.26 2.4.37 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17

Linux/drivers/input/mousedev.c

  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         31
 16 #define MOUSEDEV_MIX            63
 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/cdev.h>
 28 #include <linux/kernel.h>
 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 open;
 62         struct input_handle handle;
 63         wait_queue_head_t wait;
 64         struct list_head client_list;
 65         spinlock_t client_lock; /* protects client_list */
 66         struct mutex mutex;
 67         struct device dev;
 68         struct cdev cdev;
 69         bool exist;
 70 
 71         struct list_head mixdev_node;
 72         bool opened_by_mixdev;
 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         int (*open_device)(struct mousedev *mousedev);
 81         void (*close_device)(struct mousedev *mousedev);
 82 };
 83 
 84 enum mousedev_emul {
 85         MOUSEDEV_EMUL_PS2,
 86         MOUSEDEV_EMUL_IMPS,
 87         MOUSEDEV_EMUL_EXPS
 88 };
 89 
 90 struct mousedev_motion {
 91         int dx, dy, dz;
 92         unsigned long buttons;
 93 };
 94 
 95 #define PACKET_QUEUE_LEN        16
 96 struct mousedev_client {
 97         struct fasync_struct *fasync;
 98         struct mousedev *mousedev;
 99         struct list_head node;
100 
101         struct mousedev_motion packets[PACKET_QUEUE_LEN];
102         unsigned int head, tail;
103         spinlock_t packet_lock;
104         int pos_x, pos_y;
105 
106         signed char ps2[6];
107         unsigned char ready, buffer, bufsiz;
108         unsigned char imexseq, impsseq;
109         enum mousedev_emul mode;
110         unsigned long last_buttons;
111 };
112 
113 #define MOUSEDEV_SEQ_LEN        6
114 
115 static unsigned char mousedev_imps_seq[] = { 0xf3, 200, 0xf3, 100, 0xf3, 80 };
116 static unsigned char mousedev_imex_seq[] = { 0xf3, 200, 0xf3, 200, 0xf3, 80 };
117 
118 static struct mousedev *mousedev_mix;
119 static LIST_HEAD(mousedev_mix_list);
120 
121 #define fx(i)  (mousedev->old_x[(mousedev->pkt_count - (i)) & 03])
122 #define fy(i)  (mousedev->old_y[(mousedev->pkt_count - (i)) & 03])
123 
124 static void mousedev_touchpad_event(struct input_dev *dev,
125                                     struct mousedev *mousedev,
126                                     unsigned int code, int value)
127 {
128         int size, tmp;
129         enum { FRACTION_DENOM = 128 };
130 
131         switch (code) {
132 
133         case ABS_X:
134 
135                 fx(0) = value;
136                 if (mousedev->touch && mousedev->pkt_count >= 2) {
137                         size = input_abs_get_max(dev, ABS_X) -
138                                         input_abs_get_min(dev, ABS_X);
139                         if (size == 0)
140                                 size = 256 * 2;
141 
142                         tmp = ((value - fx(2)) * 256 * FRACTION_DENOM) / size;
143                         tmp += mousedev->frac_dx;
144                         mousedev->packet.dx = tmp / FRACTION_DENOM;
145                         mousedev->frac_dx =
146                                 tmp - mousedev->packet.dx * FRACTION_DENOM;
147                 }
148                 break;
149 
150         case ABS_Y:
151                 fy(0) = value;
152                 if (mousedev->touch && mousedev->pkt_count >= 2) {
153                         /* use X size for ABS_Y to keep the same scale */
154                         size = input_abs_get_max(dev, ABS_X) -
155                                         input_abs_get_min(dev, ABS_X);
156                         if (size == 0)
157                                 size = 256 * 2;
158 
159                         tmp = -((value - fy(2)) * 256 * FRACTION_DENOM) / size;
160                         tmp += mousedev->frac_dy;
161                         mousedev->packet.dy = tmp / FRACTION_DENOM;
162                         mousedev->frac_dy = tmp -
163                                 mousedev->packet.dy * FRACTION_DENOM;
164                 }
165                 break;
166         }
167 }
168 
169 static void mousedev_abs_event(struct input_dev *dev, struct mousedev *mousedev,
170                                 unsigned int code, int value)
171 {
172         int min, max, size;
173 
174         switch (code) {
175 
176         case ABS_X:
177                 min = input_abs_get_min(dev, ABS_X);
178                 max = input_abs_get_max(dev, ABS_X);
179 
180                 size = max - min;
181                 if (size == 0)
182                         size = xres ? : 1;
183 
184                 value = clamp(value, min, max);
185 
186                 mousedev->packet.x = ((value - min) * xres) / size;
187                 mousedev->packet.abs_event = 1;
188                 break;
189 
190         case ABS_Y:
191                 min = input_abs_get_min(dev, ABS_Y);
192                 max = input_abs_get_max(dev, ABS_Y);
193 
194                 size = max - min;
195                 if (size == 0)
196                         size = yres ? : 1;
197 
198                 value = clamp(value, min, max);
199 
200                 mousedev->packet.y = yres - ((value - min) * yres) / size;
201                 mousedev->packet.abs_event = 1;
202                 break;
203         }
204 }
205 
206 static void mousedev_rel_event(struct mousedev *mousedev,
207                                 unsigned int code, int value)
208 {
209         switch (code) {
210         case REL_X:
211                 mousedev->packet.dx += value;
212                 break;
213 
214         case REL_Y:
215                 mousedev->packet.dy -= value;
216                 break;
217 
218         case REL_WHEEL:
219                 mousedev->packet.dz -= value;
220                 break;
221         }
222 }
223 
224 static void mousedev_key_event(struct mousedev *mousedev,
225                                 unsigned int code, int value)
226 {
227         int index;
228 
229         switch (code) {
230 
231         case BTN_TOUCH:
232         case BTN_0:
233         case BTN_LEFT:          index = 0; break;
234 
235         case BTN_STYLUS:
236         case BTN_1:
237         case BTN_RIGHT:         index = 1; break;
238 
239         case BTN_2:
240         case BTN_FORWARD:
241         case BTN_STYLUS2:
242         case BTN_MIDDLE:        index = 2; break;
243 
244         case BTN_3:
245         case BTN_BACK:
246         case BTN_SIDE:          index = 3; break;
247 
248         case BTN_4:
249         case BTN_EXTRA:         index = 4; break;
250 
251         default:                return;
252         }
253 
254         if (value) {
255                 set_bit(index, &mousedev->packet.buttons);
256                 set_bit(index, &mousedev_mix->packet.buttons);
257         } else {
258                 clear_bit(index, &mousedev->packet.buttons);
259                 clear_bit(index, &mousedev_mix->packet.buttons);
260         }
261 }
262 
263 static void mousedev_notify_readers(struct mousedev *mousedev,
264                                     struct mousedev_hw_data *packet)
265 {
266         struct mousedev_client *client;
267         struct mousedev_motion *p;
268         unsigned int new_head;
269         int wake_readers = 0;
270 
271         rcu_read_lock();
272         list_for_each_entry_rcu(client, &mousedev->client_list, node) {
273 
274                 /* Just acquire the lock, interrupts already disabled */
275                 spin_lock(&client->packet_lock);
276 
277                 p = &client->packets[client->head];
278                 if (client->ready && p->buttons != mousedev->packet.buttons) {
279                         new_head = (client->head + 1) % PACKET_QUEUE_LEN;
280                         if (new_head != client->tail) {
281                                 p = &client->packets[client->head = new_head];
282                                 memset(p, 0, sizeof(struct mousedev_motion));
283                         }
284                 }
285 
286                 if (packet->abs_event) {
287                         p->dx += packet->x - client->pos_x;
288                         p->dy += packet->y - client->pos_y;
289                         client->pos_x = packet->x;
290                         client->pos_y = packet->y;
291                 }
292 
293                 client->pos_x += packet->dx;
294                 client->pos_x = client->pos_x < 0 ?
295                         0 : (client->pos_x >= xres ? xres : client->pos_x);
296                 client->pos_y += packet->dy;
297                 client->pos_y = client->pos_y < 0 ?
298                         0 : (client->pos_y >= yres ? yres : client->pos_y);
299 
300                 p->dx += packet->dx;
301                 p->dy += packet->dy;
302                 p->dz += packet->dz;
303                 p->buttons = mousedev->packet.buttons;
304 
305                 if (p->dx || p->dy || p->dz ||
306                     p->buttons != client->last_buttons)
307                         client->ready = 1;
308 
309                 spin_unlock(&client->packet_lock);
310 
311                 if (client->ready) {
312                         kill_fasync(&client->fasync, SIGIO, POLL_IN);
313                         wake_readers = 1;
314                 }
315         }
316         rcu_read_unlock();
317 
318         if (wake_readers)
319                 wake_up_interruptible(&mousedev->wait);
320 }
321 
322 static void mousedev_touchpad_touch(struct mousedev *mousedev, int value)
323 {
324         if (!value) {
325                 if (mousedev->touch &&
326                     time_before(jiffies,
327                                 mousedev->touch + msecs_to_jiffies(tap_time))) {
328                         /*
329                          * Toggle left button to emulate tap.
330                          * We rely on the fact that mousedev_mix always has 0
331                          * motion packet so we won't mess current position.
332                          */
333                         set_bit(0, &mousedev->packet.buttons);
334                         set_bit(0, &mousedev_mix->packet.buttons);
335                         mousedev_notify_readers(mousedev, &mousedev_mix->packet);
336                         mousedev_notify_readers(mousedev_mix,
337                                                 &mousedev_mix->packet);
338                         clear_bit(0, &mousedev->packet.buttons);
339                         clear_bit(0, &mousedev_mix->packet.buttons);
340                 }
341                 mousedev->touch = mousedev->pkt_count = 0;
342                 mousedev->frac_dx = 0;
343                 mousedev->frac_dy = 0;
344 
345         } else if (!mousedev->touch)
346                 mousedev->touch = jiffies;
347 }
348 
349 static void mousedev_event(struct input_handle *handle,
350                            unsigned int type, unsigned int code, int value)
351 {
352         struct mousedev *mousedev = handle->private;
353 
354         switch (type) {
355 
356         case EV_ABS:
357                 /* Ignore joysticks */
358                 if (test_bit(BTN_TRIGGER, handle->dev->keybit))
359                         return;
360 
361                 if (test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
362                         mousedev_touchpad_event(handle->dev,
363                                                 mousedev, code, value);
364                 else
365                         mousedev_abs_event(handle->dev, mousedev, code, value);
366 
367                 break;
368 
369         case EV_REL:
370                 mousedev_rel_event(mousedev, code, value);
371                 break;
372 
373         case EV_KEY:
374                 if (value != 2) {
375                         if (code == BTN_TOUCH &&
376                             test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
377                                 mousedev_touchpad_touch(mousedev, value);
378                         else
379                                 mousedev_key_event(mousedev, code, value);
380                 }
381                 break;
382 
383         case EV_SYN:
384                 if (code == SYN_REPORT) {
385                         if (mousedev->touch) {
386                                 mousedev->pkt_count++;
387                                 /*
388                                  * Input system eats duplicate events,
389                                  * but we need all of them to do correct
390                                  * averaging so apply present one forward
391                                  */
392                                 fx(0) = fx(1);
393                                 fy(0) = fy(1);
394                         }
395 
396                         mousedev_notify_readers(mousedev, &mousedev->packet);
397                         mousedev_notify_readers(mousedev_mix, &mousedev->packet);
398 
399                         mousedev->packet.dx = mousedev->packet.dy =
400                                 mousedev->packet.dz = 0;
401                         mousedev->packet.abs_event = 0;
402                 }
403                 break;
404         }
405 }
406 
407 static int mousedev_fasync(int fd, struct file *file, int on)
408 {
409         struct mousedev_client *client = file->private_data;
410 
411         return fasync_helper(fd, file, on, &client->fasync);
412 }
413 
414 static void mousedev_free(struct device *dev)
415 {
416         struct mousedev *mousedev = container_of(dev, struct mousedev, dev);
417 
418         input_put_device(mousedev->handle.dev);
419         kfree(mousedev);
420 }
421 
422 static int mousedev_open_device(struct mousedev *mousedev)
423 {
424         int retval;
425 
426         retval = mutex_lock_interruptible(&mousedev->mutex);
427         if (retval)
428                 return retval;
429 
430         if (!mousedev->exist)
431                 retval = -ENODEV;
432         else if (!mousedev->open++) {
433                 retval = input_open_device(&mousedev->handle);
434                 if (retval)
435                         mousedev->open--;
436         }
437 
438         mutex_unlock(&mousedev->mutex);
439         return retval;
440 }
441 
442 static void mousedev_close_device(struct mousedev *mousedev)
443 {
444         mutex_lock(&mousedev->mutex);
445 
446         if (mousedev->exist && !--mousedev->open)
447                 input_close_device(&mousedev->handle);
448 
449         mutex_unlock(&mousedev->mutex);
450 }
451 
452 /*
453  * Open all available devices so they can all be multiplexed in one.
454  * stream. Note that this function is called with mousedev_mix->mutex
455  * held.
456  */
457 static int mixdev_open_devices(struct mousedev *mixdev)
458 {
459         int error;
460 
461         error = mutex_lock_interruptible(&mixdev->mutex);
462         if (error)
463                 return error;
464 
465         if (!mixdev->open++) {
466                 struct mousedev *mousedev;
467 
468                 list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
469                         if (!mousedev->opened_by_mixdev) {
470                                 if (mousedev_open_device(mousedev))
471                                         continue;
472 
473                                 mousedev->opened_by_mixdev = true;
474                         }
475                 }
476         }
477 
478         mutex_unlock(&mixdev->mutex);
479         return 0;
480 }
481 
482 /*
483  * Close all devices that were opened as part of multiplexed
484  * device. Note that this function is called with mousedev_mix->mutex
485  * held.
486  */
487 static void mixdev_close_devices(struct mousedev *mixdev)
488 {
489         mutex_lock(&mixdev->mutex);
490 
491         if (!--mixdev->open) {
492                 struct mousedev *mousedev;
493 
494                 list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
495                         if (mousedev->opened_by_mixdev) {
496                                 mousedev->opened_by_mixdev = false;
497                                 mousedev_close_device(mousedev);
498                         }
499                 }
500         }
501 
502         mutex_unlock(&mixdev->mutex);
503 }
504 
505 
506 static void mousedev_attach_client(struct mousedev *mousedev,
507                                    struct mousedev_client *client)
508 {
509         spin_lock(&mousedev->client_lock);
510         list_add_tail_rcu(&client->node, &mousedev->client_list);
511         spin_unlock(&mousedev->client_lock);
512 }
513 
514 static void mousedev_detach_client(struct mousedev *mousedev,
515                                    struct mousedev_client *client)
516 {
517         spin_lock(&mousedev->client_lock);
518         list_del_rcu(&client->node);
519         spin_unlock(&mousedev->client_lock);
520         synchronize_rcu();
521 }
522 
523 static int mousedev_release(struct inode *inode, struct file *file)
524 {
525         struct mousedev_client *client = file->private_data;
526         struct mousedev *mousedev = client->mousedev;
527 
528         mousedev_detach_client(mousedev, client);
529         kfree(client);
530 
531         mousedev->close_device(mousedev);
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 
542 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
543         if (imajor(inode) == MISC_MAJOR)
544                 mousedev = mousedev_mix;
545         else
546 #endif
547                 mousedev = container_of(inode->i_cdev, struct mousedev, cdev);
548 
549         client = kzalloc(sizeof(struct mousedev_client), GFP_KERNEL);
550         if (!client)
551                 return -ENOMEM;
552 
553         spin_lock_init(&client->packet_lock);
554         client->pos_x = xres / 2;
555         client->pos_y = yres / 2;
556         client->mousedev = mousedev;
557         mousedev_attach_client(mousedev, client);
558 
559         error = mousedev->open_device(mousedev);
560         if (error)
561                 goto err_free_client;
562 
563         file->private_data = client;
564         nonseekable_open(inode, file);
565 
566         return 0;
567 
568  err_free_client:
569         mousedev_detach_client(mousedev, client);
570         kfree(client);
571         return error;
572 }
573 
574 static inline int mousedev_limit_delta(int delta, int limit)
575 {
576         return delta > limit ? limit : (delta < -limit ? -limit : delta);
577 }
578 
579 static void mousedev_packet(struct mousedev_client *client,
580                             signed char *ps2_data)
581 {
582         struct mousedev_motion *p = &client->packets[client->tail];
583 
584         ps2_data[0] = 0x08 |
585                 ((p->dx < 0) << 4) | ((p->dy < 0) << 5) | (p->buttons & 0x07);
586         ps2_data[1] = mousedev_limit_delta(p->dx, 127);
587         ps2_data[2] = mousedev_limit_delta(p->dy, 127);
588         p->dx -= ps2_data[1];
589         p->dy -= ps2_data[2];
590 
591         switch (client->mode) {
592         case MOUSEDEV_EMUL_EXPS:
593                 ps2_data[3] = mousedev_limit_delta(p->dz, 7);
594                 p->dz -= ps2_data[3];
595                 ps2_data[3] = (ps2_data[3] & 0x0f) | ((p->buttons & 0x18) << 1);
596                 client->bufsiz = 4;
597                 break;
598 
599         case MOUSEDEV_EMUL_IMPS:
600                 ps2_data[0] |=
601                         ((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
602                 ps2_data[3] = mousedev_limit_delta(p->dz, 127);
603                 p->dz -= ps2_data[3];
604                 client->bufsiz = 4;
605                 break;
606 
607         case MOUSEDEV_EMUL_PS2:
608         default:
609                 ps2_data[0] |=
610                         ((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
611                 p->dz = 0;
612                 client->bufsiz = 3;
613                 break;
614         }
615 
616         if (!p->dx && !p->dy && !p->dz) {
617                 if (client->tail == client->head) {
618                         client->ready = 0;
619                         client->last_buttons = p->buttons;
620                 } else
621                         client->tail = (client->tail + 1) % PACKET_QUEUE_LEN;
622         }
623 }
624 
625 static void mousedev_generate_response(struct mousedev_client *client,
626                                         int command)
627 {
628         client->ps2[0] = 0xfa; /* ACK */
629 
630         switch (command) {
631 
632         case 0xeb: /* Poll */
633                 mousedev_packet(client, &client->ps2[1]);
634                 client->bufsiz++; /* account for leading ACK */
635                 break;
636 
637         case 0xf2: /* Get ID */
638                 switch (client->mode) {
639                 case MOUSEDEV_EMUL_PS2:
640                         client->ps2[1] = 0;
641                         break;
642                 case MOUSEDEV_EMUL_IMPS:
643                         client->ps2[1] = 3;
644                         break;
645                 case MOUSEDEV_EMUL_EXPS:
646                         client->ps2[1] = 4;
647                         break;
648                 }
649                 client->bufsiz = 2;
650                 break;
651 
652         case 0xe9: /* Get info */
653                 client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200;
654                 client->bufsiz = 4;
655                 break;
656 
657         case 0xff: /* Reset */
658                 client->impsseq = client->imexseq = 0;
659                 client->mode = MOUSEDEV_EMUL_PS2;
660                 client->ps2[1] = 0xaa; client->ps2[2] = 0x00;
661                 client->bufsiz = 3;
662                 break;
663 
664         default:
665                 client->bufsiz = 1;
666                 break;
667         }
668         client->buffer = client->bufsiz;
669 }
670 
671 static ssize_t mousedev_write(struct file *file, const char __user *buffer,
672                                 size_t count, loff_t *ppos)
673 {
674         struct mousedev_client *client = file->private_data;
675         unsigned char c;
676         unsigned int i;
677 
678         for (i = 0; i < count; i++) {
679 
680                 if (get_user(c, buffer + i))
681                         return -EFAULT;
682 
683                 spin_lock_irq(&client->packet_lock);
684 
685                 if (c == mousedev_imex_seq[client->imexseq]) {
686                         if (++client->imexseq == MOUSEDEV_SEQ_LEN) {
687                                 client->imexseq = 0;
688                                 client->mode = MOUSEDEV_EMUL_EXPS;
689                         }
690                 } else
691                         client->imexseq = 0;
692 
693                 if (c == mousedev_imps_seq[client->impsseq]) {
694                         if (++client->impsseq == MOUSEDEV_SEQ_LEN) {
695                                 client->impsseq = 0;
696                                 client->mode = MOUSEDEV_EMUL_IMPS;
697                         }
698                 } else
699                         client->impsseq = 0;
700 
701                 mousedev_generate_response(client, c);
702 
703                 spin_unlock_irq(&client->packet_lock);
704         }
705 
706         kill_fasync(&client->fasync, SIGIO, POLL_IN);
707         wake_up_interruptible(&client->mousedev->wait);
708 
709         return count;
710 }
711 
712 static ssize_t mousedev_read(struct file *file, char __user *buffer,
713                              size_t count, loff_t *ppos)
714 {
715         struct mousedev_client *client = file->private_data;
716         struct mousedev *mousedev = client->mousedev;
717         signed char data[sizeof(client->ps2)];
718         int retval = 0;
719 
720         if (!client->ready && !client->buffer && mousedev->exist &&
721             (file->f_flags & O_NONBLOCK))
722                 return -EAGAIN;
723 
724         retval = wait_event_interruptible(mousedev->wait,
725                         !mousedev->exist || client->ready || client->buffer);
726         if (retval)
727                 return retval;
728 
729         if (!mousedev->exist)
730                 return -ENODEV;
731 
732         spin_lock_irq(&client->packet_lock);
733 
734         if (!client->buffer && client->ready) {
735                 mousedev_packet(client, client->ps2);
736                 client->buffer = client->bufsiz;
737         }
738 
739         if (count > client->buffer)
740                 count = client->buffer;
741 
742         memcpy(data, client->ps2 + client->bufsiz - client->buffer, count);
743         client->buffer -= count;
744 
745         spin_unlock_irq(&client->packet_lock);
746 
747         if (copy_to_user(buffer, data, count))
748                 return -EFAULT;
749 
750         return count;
751 }
752 
753 /* No kernel lock - fine */
754 static unsigned int mousedev_poll(struct file *file, poll_table *wait)
755 {
756         struct mousedev_client *client = file->private_data;
757         struct mousedev *mousedev = client->mousedev;
758         unsigned int mask;
759 
760         poll_wait(file, &mousedev->wait, wait);
761 
762         mask = mousedev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR;
763         if (client->ready || client->buffer)
764                 mask |= POLLIN | POLLRDNORM;
765 
766         return mask;
767 }
768 
769 static const struct file_operations mousedev_fops = {
770         .owner          = THIS_MODULE,
771         .read           = mousedev_read,
772         .write          = mousedev_write,
773         .poll           = mousedev_poll,
774         .open           = mousedev_open,
775         .release        = mousedev_release,
776         .fasync         = mousedev_fasync,
777         .llseek         = noop_llseek,
778 };
779 
780 /*
781  * Mark device non-existent. This disables writes, ioctls and
782  * prevents new users from opening the device. Already posted
783  * blocking reads will stay, however new ones will fail.
784  */
785 static void mousedev_mark_dead(struct mousedev *mousedev)
786 {
787         mutex_lock(&mousedev->mutex);
788         mousedev->exist = false;
789         mutex_unlock(&mousedev->mutex);
790 }
791 
792 /*
793  * Wake up users waiting for IO so they can disconnect from
794  * dead device.
795  */
796 static void mousedev_hangup(struct mousedev *mousedev)
797 {
798         struct mousedev_client *client;
799 
800         spin_lock(&mousedev->client_lock);
801         list_for_each_entry(client, &mousedev->client_list, node)
802                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
803         spin_unlock(&mousedev->client_lock);
804 
805         wake_up_interruptible(&mousedev->wait);
806 }
807 
808 static void mousedev_cleanup(struct mousedev *mousedev)
809 {
810         struct input_handle *handle = &mousedev->handle;
811 
812         mousedev_mark_dead(mousedev);
813         mousedev_hangup(mousedev);
814 
815         cdev_del(&mousedev->cdev);
816 
817         /* mousedev is marked dead so no one else accesses mousedev->open */
818         if (mousedev->open)
819                 input_close_device(handle);
820 }
821 
822 static int mousedev_reserve_minor(bool mixdev)
823 {
824         int minor;
825 
826         if (mixdev) {
827                 minor = input_get_new_minor(MOUSEDEV_MIX, 1, false);
828                 if (minor < 0)
829                         pr_err("failed to reserve mixdev minor: %d\n", minor);
830         } else {
831                 minor = input_get_new_minor(MOUSEDEV_MINOR_BASE,
832                                             MOUSEDEV_MINORS, true);
833                 if (minor < 0)
834                         pr_err("failed to reserve new minor: %d\n", minor);
835         }
836 
837         return minor;
838 }
839 
840 static struct mousedev *mousedev_create(struct input_dev *dev,
841                                         struct input_handler *handler,
842                                         bool mixdev)
843 {
844         struct mousedev *mousedev;
845         int minor;
846         int error;
847 
848         minor = mousedev_reserve_minor(mixdev);
849         if (minor < 0) {
850                 error = minor;
851                 goto err_out;
852         }
853 
854         mousedev = kzalloc(sizeof(struct mousedev), GFP_KERNEL);
855         if (!mousedev) {
856                 error = -ENOMEM;
857                 goto err_free_minor;
858         }
859 
860         INIT_LIST_HEAD(&mousedev->client_list);
861         INIT_LIST_HEAD(&mousedev->mixdev_node);
862         spin_lock_init(&mousedev->client_lock);
863         mutex_init(&mousedev->mutex);
864         lockdep_set_subclass(&mousedev->mutex,
865                              mixdev ? SINGLE_DEPTH_NESTING : 0);
866         init_waitqueue_head(&mousedev->wait);
867 
868         if (mixdev) {
869                 dev_set_name(&mousedev->dev, "mice");
870 
871                 mousedev->open_device = mixdev_open_devices;
872                 mousedev->close_device = mixdev_close_devices;
873         } else {
874                 int dev_no = minor;
875                 /* Normalize device number if it falls into legacy range */
876                 if (dev_no < MOUSEDEV_MINOR_BASE + MOUSEDEV_MINORS)
877                         dev_no -= MOUSEDEV_MINOR_BASE;
878                 dev_set_name(&mousedev->dev, "mouse%d", dev_no);
879 
880                 mousedev->open_device = mousedev_open_device;
881                 mousedev->close_device = mousedev_close_device;
882         }
883 
884         mousedev->exist = true;
885         mousedev->handle.dev = input_get_device(dev);
886         mousedev->handle.name = dev_name(&mousedev->dev);
887         mousedev->handle.handler = handler;
888         mousedev->handle.private = mousedev;
889 
890         mousedev->dev.class = &input_class;
891         if (dev)
892                 mousedev->dev.parent = &dev->dev;
893         mousedev->dev.devt = MKDEV(INPUT_MAJOR, minor);
894         mousedev->dev.release = mousedev_free;
895         device_initialize(&mousedev->dev);
896 
897         if (!mixdev) {
898                 error = input_register_handle(&mousedev->handle);
899                 if (error)
900                         goto err_free_mousedev;
901         }
902 
903         cdev_init(&mousedev->cdev, &mousedev_fops);
904         mousedev->cdev.kobj.parent = &mousedev->dev.kobj;
905         error = cdev_add(&mousedev->cdev, mousedev->dev.devt, 1);
906         if (error)
907                 goto err_unregister_handle;
908 
909         error = device_add(&mousedev->dev);
910         if (error)
911                 goto err_cleanup_mousedev;
912 
913         return mousedev;
914 
915  err_cleanup_mousedev:
916         mousedev_cleanup(mousedev);
917  err_unregister_handle:
918         if (!mixdev)
919                 input_unregister_handle(&mousedev->handle);
920  err_free_mousedev:
921         put_device(&mousedev->dev);
922  err_free_minor:
923         input_free_minor(minor);
924  err_out:
925         return ERR_PTR(error);
926 }
927 
928 static void mousedev_destroy(struct mousedev *mousedev)
929 {
930         device_del(&mousedev->dev);
931         mousedev_cleanup(mousedev);
932         input_free_minor(MINOR(mousedev->dev.devt));
933         if (mousedev != mousedev_mix)
934                 input_unregister_handle(&mousedev->handle);
935         put_device(&mousedev->dev);
936 }
937 
938 static int mixdev_add_device(struct mousedev *mousedev)
939 {
940         int retval;
941 
942         retval = mutex_lock_interruptible(&mousedev_mix->mutex);
943         if (retval)
944                 return retval;
945 
946         if (mousedev_mix->open) {
947                 retval = mousedev_open_device(mousedev);
948                 if (retval)
949                         goto out;
950 
951                 mousedev->opened_by_mixdev = true;
952         }
953 
954         get_device(&mousedev->dev);
955         list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list);
956 
957  out:
958         mutex_unlock(&mousedev_mix->mutex);
959         return retval;
960 }
961 
962 static void mixdev_remove_device(struct mousedev *mousedev)
963 {
964         mutex_lock(&mousedev_mix->mutex);
965 
966         if (mousedev->opened_by_mixdev) {
967                 mousedev->opened_by_mixdev = false;
968                 mousedev_close_device(mousedev);
969         }
970 
971         list_del_init(&mousedev->mixdev_node);
972         mutex_unlock(&mousedev_mix->mutex);
973 
974         put_device(&mousedev->dev);
975 }
976 
977 static int mousedev_connect(struct input_handler *handler,
978                             struct input_dev *dev,
979                             const struct input_device_id *id)
980 {
981         struct mousedev *mousedev;
982         int error;
983 
984         mousedev = mousedev_create(dev, handler, false);
985         if (IS_ERR(mousedev))
986                 return PTR_ERR(mousedev);
987 
988         error = mixdev_add_device(mousedev);
989         if (error) {
990                 mousedev_destroy(mousedev);
991                 return error;
992         }
993 
994         return 0;
995 }
996 
997 static void mousedev_disconnect(struct input_handle *handle)
998 {
999         struct mousedev *mousedev = handle->private;
1000 
1001         mixdev_remove_device(mousedev);
1002         mousedev_destroy(mousedev);
1003 }
1004 
1005 static const struct input_device_id mousedev_ids[] = {
1006         {
1007                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1008                                 INPUT_DEVICE_ID_MATCH_KEYBIT |
1009                                 INPUT_DEVICE_ID_MATCH_RELBIT,
1010                 .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1011                 .keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1012                 .relbit = { BIT_MASK(REL_X) | BIT_MASK(REL_Y) },
1013         },      /* A mouse like device, at least one button,
1014                    two relative axes */
1015         {
1016                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1017                                 INPUT_DEVICE_ID_MATCH_RELBIT,
1018                 .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1019                 .relbit = { BIT_MASK(REL_WHEEL) },
1020         },      /* A separate scrollwheel */
1021         {
1022                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1023                                 INPUT_DEVICE_ID_MATCH_KEYBIT |
1024                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
1025                 .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1026                 .keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
1027                 .absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1028         },      /* A tablet like device, at least touch detection,
1029                    two absolute axes */
1030         {
1031                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1032                                 INPUT_DEVICE_ID_MATCH_KEYBIT |
1033                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
1034                 .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1035                 .keybit = { [BIT_WORD(BTN_TOOL_FINGER)] =
1036                                 BIT_MASK(BTN_TOOL_FINGER) },
1037                 .absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
1038                                 BIT_MASK(ABS_PRESSURE) |
1039                                 BIT_MASK(ABS_TOOL_WIDTH) },
1040         },      /* A touchpad */
1041         {
1042                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1043                         INPUT_DEVICE_ID_MATCH_KEYBIT |
1044                         INPUT_DEVICE_ID_MATCH_ABSBIT,
1045                 .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1046                 .keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1047                 .absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1048         },      /* Mouse-like device with absolute X and Y but ordinary
1049                    clicks, like hp ILO2 High Performance mouse */
1050 
1051         { },    /* Terminating entry */
1052 };
1053 
1054 MODULE_DEVICE_TABLE(input, mousedev_ids);
1055 
1056 static struct input_handler mousedev_handler = {
1057         .event          = mousedev_event,
1058         .connect        = mousedev_connect,
1059         .disconnect     = mousedev_disconnect,
1060         .legacy_minors  = true,
1061         .minor          = MOUSEDEV_MINOR_BASE,
1062         .name           = "mousedev",
1063         .id_table       = mousedev_ids,
1064 };
1065 
1066 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1067 #include <linux/miscdevice.h>
1068 
1069 static struct miscdevice psaux_mouse = {
1070         .minor  = PSMOUSE_MINOR,
1071         .name   = "psaux",
1072         .fops   = &mousedev_fops,
1073 };
1074 
1075 static bool psaux_registered;
1076 
1077 static void __init mousedev_psaux_register(void)
1078 {
1079         int error;
1080 
1081         error = misc_register(&psaux_mouse);
1082         if (error)
1083                 pr_warn("could not register psaux device, error: %d\n",
1084                            error);
1085         else
1086                 psaux_registered = true;
1087 }
1088 
1089 static void __exit mousedev_psaux_unregister(void)
1090 {
1091         if (psaux_registered)
1092                 misc_deregister(&psaux_mouse);
1093 }
1094 #else
1095 static inline void mousedev_psaux_register(void) { }
1096 static inline void mousedev_psaux_unregister(void) { }
1097 #endif
1098 
1099 static int __init mousedev_init(void)
1100 {
1101         int error;
1102 
1103         mousedev_mix = mousedev_create(NULL, &mousedev_handler, true);
1104         if (IS_ERR(mousedev_mix))
1105                 return PTR_ERR(mousedev_mix);
1106 
1107         error = input_register_handler(&mousedev_handler);
1108         if (error) {
1109                 mousedev_destroy(mousedev_mix);
1110                 return error;
1111         }
1112 
1113         mousedev_psaux_register();
1114 
1115         pr_info("PS/2 mouse device common for all mice\n");
1116 
1117         return 0;
1118 }
1119 
1120 static void __exit mousedev_exit(void)
1121 {
1122         mousedev_psaux_unregister();
1123         input_unregister_handler(&mousedev_handler);
1124         mousedev_destroy(mousedev_mix);
1125 }
1126 
1127 module_init(mousedev_init);
1128 module_exit(mousedev_exit);
1129 

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