Rationalize fasync return values
[linux-2.6.git] / 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 MOUSEDEV_MINOR_BASE     32
13 #define MOUSEDEV_MINORS         32
14 #define MOUSEDEV_MIX            31
15
16 #include <linux/slab.h>
17 #include <linux/smp_lock.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 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
26 #include <linux/miscdevice.h>
27 #endif
28
29 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
30 MODULE_DESCRIPTION("Mouse (ExplorerPS/2) device interfaces");
31 MODULE_LICENSE("GPL");
32
33 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_X
34 #define CONFIG_INPUT_MOUSEDEV_SCREEN_X  1024
35 #endif
36 #ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_Y
37 #define CONFIG_INPUT_MOUSEDEV_SCREEN_Y  768
38 #endif
39
40 static int xres = CONFIG_INPUT_MOUSEDEV_SCREEN_X;
41 module_param(xres, uint, 0644);
42 MODULE_PARM_DESC(xres, "Horizontal screen resolution");
43
44 static int yres = CONFIG_INPUT_MOUSEDEV_SCREEN_Y;
45 module_param(yres, uint, 0644);
46 MODULE_PARM_DESC(yres, "Vertical screen resolution");
47
48 static unsigned tap_time = 200;
49 module_param(tap_time, uint, 0644);
50 MODULE_PARM_DESC(tap_time, "Tap time for touchpads in absolute mode (msecs)");
51
52 struct mousedev_hw_data {
53         int dx, dy, dz;
54         int x, y;
55         int abs_event;
56         unsigned long buttons;
57 };
58
59 struct mousedev {
60         int exist;
61         int open;
62         int minor;
63         char name[16];
64         struct input_handle handle;
65         wait_queue_head_t wait;
66         struct list_head client_list;
67         spinlock_t client_lock; /* protects client_list */
68         struct mutex mutex;
69         struct device dev;
70
71         struct list_head mixdev_node;
72         int mixdev_open;
73
74         struct mousedev_hw_data packet;
75         unsigned int pkt_count;
76         int old_x[4], old_y[4];
77         int frac_dx, frac_dy;
78         unsigned long touch;
79 };
80
81 enum mousedev_emul {
82         MOUSEDEV_EMUL_PS2,
83         MOUSEDEV_EMUL_IMPS,
84         MOUSEDEV_EMUL_EXPS
85 };
86
87 struct mousedev_motion {
88         int dx, dy, dz;
89         unsigned long buttons;
90 };
91
92 #define PACKET_QUEUE_LEN        16
93 struct mousedev_client {
94         struct fasync_struct *fasync;
95         struct mousedev *mousedev;
96         struct list_head node;
97
98         struct mousedev_motion packets[PACKET_QUEUE_LEN];
99         unsigned int head, tail;
100         spinlock_t packet_lock;
101         int pos_x, pos_y;
102
103         signed char ps2[6];
104         unsigned char ready, buffer, bufsiz;
105         unsigned char imexseq, impsseq;
106         enum mousedev_emul mode;
107         unsigned long last_buttons;
108 };
109
110 #define MOUSEDEV_SEQ_LEN        6
111
112 static unsigned char mousedev_imps_seq[] = { 0xf3, 200, 0xf3, 100, 0xf3, 80 };
113 static unsigned char mousedev_imex_seq[] = { 0xf3, 200, 0xf3, 200, 0xf3, 80 };
114
115 static struct input_handler mousedev_handler;
116
117 static struct mousedev *mousedev_table[MOUSEDEV_MINORS];
118 static DEFINE_MUTEX(mousedev_table_mutex);
119 static struct mousedev *mousedev_mix;
120 static LIST_HEAD(mousedev_mix_list);
121
122 static void mixdev_open_devices(void);
123 static void mixdev_close_devices(void);
124
125 #define fx(i)  (mousedev->old_x[(mousedev->pkt_count - (i)) & 03])
126 #define fy(i)  (mousedev->old_y[(mousedev->pkt_count - (i)) & 03])
127
128 static void mousedev_touchpad_event(struct input_dev *dev,
129                                     struct mousedev *mousedev,
130                                     unsigned int code, int value)
131 {
132         int size, tmp;
133         enum { FRACTION_DENOM = 128 };
134
135         switch (code) {
136
137         case ABS_X:
138                 fx(0) = value;
139                 if (mousedev->touch && mousedev->pkt_count >= 2) {
140                         size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
141                         if (size == 0)
142                                 size = 256 * 2;
143                         tmp = ((value - fx(2)) * 256 * FRACTION_DENOM) / size;
144                         tmp += mousedev->frac_dx;
145                         mousedev->packet.dx = tmp / FRACTION_DENOM;
146                         mousedev->frac_dx =
147                                 tmp - mousedev->packet.dx * FRACTION_DENOM;
148                 }
149                 break;
150
151         case ABS_Y:
152                 fy(0) = value;
153                 if (mousedev->touch && mousedev->pkt_count >= 2) {
154                         /* use X size to keep the same scale */
155                         size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
156                         if (size == 0)
157                                 size = 256 * 2;
158                         tmp = -((value - fy(2)) * 256 * FRACTION_DENOM) / size;
159                         tmp += mousedev->frac_dy;
160                         mousedev->packet.dy = tmp / FRACTION_DENOM;
161                         mousedev->frac_dy = tmp -
162                                 mousedev->packet.dy * FRACTION_DENOM;
163                 }
164                 break;
165         }
166 }
167
168 static void mousedev_abs_event(struct input_dev *dev, struct mousedev *mousedev,
169                                 unsigned int code, int value)
170 {
171         int size;
172
173         switch (code) {
174
175         case ABS_X:
176                 size = dev->absmax[ABS_X] - dev->absmin[ABS_X];
177                 if (size == 0)
178                         size = xres ? : 1;
179                 if (value > dev->absmax[ABS_X])
180                         value = dev->absmax[ABS_X];
181                 if (value < dev->absmin[ABS_X])
182                         value = dev->absmin[ABS_X];
183                 mousedev->packet.x =
184                         ((value - dev->absmin[ABS_X]) * xres) / size;
185                 mousedev->packet.abs_event = 1;
186                 break;
187
188         case ABS_Y:
189                 size = dev->absmax[ABS_Y] - dev->absmin[ABS_Y];
190                 if (size == 0)
191                         size = yres ? : 1;
192                 if (value > dev->absmax[ABS_Y])
193                         value = dev->absmax[ABS_Y];
194                 if (value < dev->absmin[ABS_Y])
195                         value = dev->absmin[ABS_Y];
196                 mousedev->packet.y = yres -
197                         ((value - dev->absmin[ABS_Y]) * yres) / size;
198                 mousedev->packet.abs_event = 1;
199                 break;
200         }
201 }
202
203 static void mousedev_rel_event(struct mousedev *mousedev,
204                                 unsigned int code, int value)
205 {
206         switch (code) {
207         case REL_X:
208                 mousedev->packet.dx += value;
209                 break;
210
211         case REL_Y:
212                 mousedev->packet.dy -= value;
213                 break;
214
215         case REL_WHEEL:
216                 mousedev->packet.dz -= value;
217                 break;
218         }
219 }
220
221 static void mousedev_key_event(struct mousedev *mousedev,
222                                 unsigned int code, int value)
223 {
224         int index;
225
226         switch (code) {
227
228         case BTN_TOUCH:
229         case BTN_0:
230         case BTN_LEFT:          index = 0; break;
231
232         case BTN_STYLUS:
233         case BTN_1:
234         case BTN_RIGHT:         index = 1; break;
235
236         case BTN_2:
237         case BTN_FORWARD:
238         case BTN_STYLUS2:
239         case BTN_MIDDLE:        index = 2; break;
240
241         case BTN_3:
242         case BTN_BACK:
243         case BTN_SIDE:          index = 3; break;
244
245         case BTN_4:
246         case BTN_EXTRA:         index = 4; break;
247
248         default:                return;
249         }
250
251         if (value) {
252                 set_bit(index, &mousedev->packet.buttons);
253                 set_bit(index, &mousedev_mix->packet.buttons);
254         } else {
255                 clear_bit(index, &mousedev->packet.buttons);
256                 clear_bit(index, &mousedev_mix->packet.buttons);
257         }
258 }
259
260 static void mousedev_notify_readers(struct mousedev *mousedev,
261                                     struct mousedev_hw_data *packet)
262 {
263         struct mousedev_client *client;
264         struct mousedev_motion *p;
265         unsigned int new_head;
266         int wake_readers = 0;
267
268         rcu_read_lock();
269         list_for_each_entry_rcu(client, &mousedev->client_list, node) {
270
271                 /* Just acquire the lock, interrupts already disabled */
272                 spin_lock(&client->packet_lock);
273
274                 p = &client->packets[client->head];
275                 if (client->ready && p->buttons != mousedev->packet.buttons) {
276                         new_head = (client->head + 1) % PACKET_QUEUE_LEN;
277                         if (new_head != client->tail) {
278                                 p = &client->packets[client->head = new_head];
279                                 memset(p, 0, sizeof(struct mousedev_motion));
280                         }
281                 }
282
283                 if (packet->abs_event) {
284                         p->dx += packet->x - client->pos_x;
285                         p->dy += packet->y - client->pos_y;
286                         client->pos_x = packet->x;
287                         client->pos_y = packet->y;
288                 }
289
290                 client->pos_x += packet->dx;
291                 client->pos_x = client->pos_x < 0 ?
292                         0 : (client->pos_x >= xres ? xres : client->pos_x);
293                 client->pos_y += packet->dy;
294                 client->pos_y = client->pos_y < 0 ?
295                         0 : (client->pos_y >= yres ? yres : client->pos_y);
296
297                 p->dx += packet->dx;
298                 p->dy += packet->dy;
299                 p->dz += packet->dz;
300                 p->buttons = mousedev->packet.buttons;
301
302                 if (p->dx || p->dy || p->dz ||
303                     p->buttons != client->last_buttons)
304                         client->ready = 1;
305
306                 spin_unlock(&client->packet_lock);
307
308                 if (client->ready) {
309                         kill_fasync(&client->fasync, SIGIO, POLL_IN);
310                         wake_readers = 1;
311                 }
312         }
313         rcu_read_unlock();
314
315         if (wake_readers)
316                 wake_up_interruptible(&mousedev->wait);
317 }
318
319 static void mousedev_touchpad_touch(struct mousedev *mousedev, int value)
320 {
321         if (!value) {
322                 if (mousedev->touch &&
323                     time_before(jiffies,
324                                 mousedev->touch + msecs_to_jiffies(tap_time))) {
325                         /*
326                          * Toggle left button to emulate tap.
327                          * We rely on the fact that mousedev_mix always has 0
328                          * motion packet so we won't mess current position.
329                          */
330                         set_bit(0, &mousedev->packet.buttons);
331                         set_bit(0, &mousedev_mix->packet.buttons);
332                         mousedev_notify_readers(mousedev, &mousedev_mix->packet);
333                         mousedev_notify_readers(mousedev_mix,
334                                                 &mousedev_mix->packet);
335                         clear_bit(0, &mousedev->packet.buttons);
336                         clear_bit(0, &mousedev_mix->packet.buttons);
337                 }
338                 mousedev->touch = mousedev->pkt_count = 0;
339                 mousedev->frac_dx = 0;
340                 mousedev->frac_dy = 0;
341
342         } else if (!mousedev->touch)
343                 mousedev->touch = jiffies;
344 }
345
346 static void mousedev_event(struct input_handle *handle,
347                            unsigned int type, unsigned int code, int value)
348 {
349         struct mousedev *mousedev = handle->private;
350
351         switch (type) {
352
353         case EV_ABS:
354                 /* Ignore joysticks */
355                 if (test_bit(BTN_TRIGGER, handle->dev->keybit))
356                         return;
357
358                 if (test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
359                         mousedev_touchpad_event(handle->dev,
360                                                 mousedev, code, value);
361                 else
362                         mousedev_abs_event(handle->dev, mousedev, code, value);
363
364                 break;
365
366         case EV_REL:
367                 mousedev_rel_event(mousedev, code, value);
368                 break;
369
370         case EV_KEY:
371                 if (value != 2) {
372                         if (code == BTN_TOUCH &&
373                             test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
374                                 mousedev_touchpad_touch(mousedev, value);
375                         else
376                                 mousedev_key_event(mousedev, code, value);
377                 }
378                 break;
379
380         case EV_SYN:
381                 if (code == SYN_REPORT) {
382                         if (mousedev->touch) {
383                                 mousedev->pkt_count++;
384                                 /*
385                                  * Input system eats duplicate events,
386                                  * but we need all of them to do correct
387                                  * averaging so apply present one forward
388                                  */
389                                 fx(0) = fx(1);
390                                 fy(0) = fy(1);
391                         }
392
393                         mousedev_notify_readers(mousedev, &mousedev->packet);
394                         mousedev_notify_readers(mousedev_mix, &mousedev->packet);
395
396                         mousedev->packet.dx = mousedev->packet.dy =
397                                 mousedev->packet.dz = 0;
398                         mousedev->packet.abs_event = 0;
399                 }
400                 break;
401         }
402 }
403
404 static int mousedev_fasync(int fd, struct file *file, int on)
405 {
406         struct mousedev_client *client = file->private_data;
407
408         return fasync_helper(fd, file, on, &client->fasync);
409 }
410
411 static void mousedev_free(struct device *dev)
412 {
413         struct mousedev *mousedev = container_of(dev, struct mousedev, dev);
414
415         input_put_device(mousedev->handle.dev);
416         kfree(mousedev);
417 }
418
419 static int mousedev_open_device(struct mousedev *mousedev)
420 {
421         int retval;
422
423         retval = mutex_lock_interruptible(&mousedev->mutex);
424         if (retval)
425                 return retval;
426
427         if (mousedev->minor == MOUSEDEV_MIX)
428                 mixdev_open_devices();
429         else if (!mousedev->exist)
430                 retval = -ENODEV;
431         else if (!mousedev->open++) {
432                 retval = input_open_device(&mousedev->handle);
433                 if (retval)
434                         mousedev->open--;
435         }
436
437         mutex_unlock(&mousedev->mutex);
438         return retval;
439 }
440
441 static void mousedev_close_device(struct mousedev *mousedev)
442 {
443         mutex_lock(&mousedev->mutex);
444
445         if (mousedev->minor == MOUSEDEV_MIX)
446                 mixdev_close_devices();
447         else if (mousedev->exist && !--mousedev->open)
448                 input_close_device(&mousedev->handle);
449
450         mutex_unlock(&mousedev->mutex);
451 }
452
453 /*
454  * Open all available devices so they can all be multiplexed in one.
455  * stream. Note that this function is called with mousedev_mix->mutex
456  * held.
457  */
458 static void mixdev_open_devices(void)
459 {
460         struct mousedev *mousedev;
461
462         if (mousedev_mix->open++)
463                 return;
464
465         list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
466                 if (!mousedev->mixdev_open) {
467                         if (mousedev_open_device(mousedev))
468                                 continue;
469
470                         mousedev->mixdev_open = 1;
471                 }
472         }
473 }
474
475 /*
476  * Close all devices that were opened as part of multiplexed
477  * device. Note that this function is called with mousedev_mix->mutex
478  * held.
479  */
480 static void mixdev_close_devices(void)
481 {
482         struct mousedev *mousedev;
483
484         if (--mousedev_mix->open)
485                 return;
486
487         list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
488                 if (mousedev->mixdev_open) {
489                         mousedev->mixdev_open = 0;
490                         mousedev_close_device(mousedev);
491                 }
492         }
493 }
494
495
496 static void mousedev_attach_client(struct mousedev *mousedev,
497                                    struct mousedev_client *client)
498 {
499         spin_lock(&mousedev->client_lock);
500         list_add_tail_rcu(&client->node, &mousedev->client_list);
501         spin_unlock(&mousedev->client_lock);
502         synchronize_rcu();
503 }
504
505 static void mousedev_detach_client(struct mousedev *mousedev,
506                                    struct mousedev_client *client)
507 {
508         spin_lock(&mousedev->client_lock);
509         list_del_rcu(&client->node);
510         spin_unlock(&mousedev->client_lock);
511         synchronize_rcu();
512 }
513
514 static int mousedev_release(struct inode *inode, struct file *file)
515 {
516         struct mousedev_client *client = file->private_data;
517         struct mousedev *mousedev = client->mousedev;
518
519         mousedev_detach_client(mousedev, client);
520         kfree(client);
521
522         mousedev_close_device(mousedev);
523         put_device(&mousedev->dev);
524
525         return 0;
526 }
527
528 static int mousedev_open(struct inode *inode, struct file *file)
529 {
530         struct mousedev_client *client;
531         struct mousedev *mousedev;
532         int error;
533         int i;
534
535 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
536         if (imajor(inode) == MISC_MAJOR)
537                 i = MOUSEDEV_MIX;
538         else
539 #endif
540                 i = iminor(inode) - MOUSEDEV_MINOR_BASE;
541
542         if (i >= MOUSEDEV_MINORS)
543                 return -ENODEV;
544
545         lock_kernel();
546         error = mutex_lock_interruptible(&mousedev_table_mutex);
547         if (error) {
548                 unlock_kernel();
549                 return error;
550         }
551         mousedev = mousedev_table[i];
552         if (mousedev)
553                 get_device(&mousedev->dev);
554         mutex_unlock(&mousedev_table_mutex);
555
556         if (!mousedev) {
557                 unlock_kernel();
558                 return -ENODEV;
559         }
560
561         client = kzalloc(sizeof(struct mousedev_client), GFP_KERNEL);
562         if (!client) {
563                 error = -ENOMEM;
564                 goto err_put_mousedev;
565         }
566
567         spin_lock_init(&client->packet_lock);
568         client->pos_x = xres / 2;
569         client->pos_y = yres / 2;
570         client->mousedev = mousedev;
571         mousedev_attach_client(mousedev, client);
572
573         error = mousedev_open_device(mousedev);
574         if (error)
575                 goto err_free_client;
576
577         file->private_data = client;
578         unlock_kernel();
579         return 0;
580
581  err_free_client:
582         mousedev_detach_client(mousedev, client);
583         kfree(client);
584  err_put_mousedev:
585         put_device(&mousedev->dev);
586         unlock_kernel();
587         return error;
588 }
589
590 static inline int mousedev_limit_delta(int delta, int limit)
591 {
592         return delta > limit ? limit : (delta < -limit ? -limit : delta);
593 }
594
595 static void mousedev_packet(struct mousedev_client *client,
596                             signed char *ps2_data)
597 {
598         struct mousedev_motion *p = &client->packets[client->tail];
599
600         ps2_data[0] = 0x08 |
601                 ((p->dx < 0) << 4) | ((p->dy < 0) << 5) | (p->buttons & 0x07);
602         ps2_data[1] = mousedev_limit_delta(p->dx, 127);
603         ps2_data[2] = mousedev_limit_delta(p->dy, 127);
604         p->dx -= ps2_data[1];
605         p->dy -= ps2_data[2];
606
607         switch (client->mode) {
608         case MOUSEDEV_EMUL_EXPS:
609                 ps2_data[3] = mousedev_limit_delta(p->dz, 7);
610                 p->dz -= ps2_data[3];
611                 ps2_data[3] = (ps2_data[3] & 0x0f) | ((p->buttons & 0x18) << 1);
612                 client->bufsiz = 4;
613                 break;
614
615         case MOUSEDEV_EMUL_IMPS:
616                 ps2_data[0] |=
617                         ((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
618                 ps2_data[3] = mousedev_limit_delta(p->dz, 127);
619                 p->dz -= ps2_data[3];
620                 client->bufsiz = 4;
621                 break;
622
623         case MOUSEDEV_EMUL_PS2:
624         default:
625                 ps2_data[0] |=
626                         ((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
627                 p->dz = 0;
628                 client->bufsiz = 3;
629                 break;
630         }
631
632         if (!p->dx && !p->dy && !p->dz) {
633                 if (client->tail == client->head) {
634                         client->ready = 0;
635                         client->last_buttons = p->buttons;
636                 } else
637                         client->tail = (client->tail + 1) % PACKET_QUEUE_LEN;
638         }
639 }
640
641 static void mousedev_generate_response(struct mousedev_client *client,
642                                         int command)
643 {
644         client->ps2[0] = 0xfa; /* ACK */
645
646         switch (command) {
647
648         case 0xeb: /* Poll */
649                 mousedev_packet(client, &client->ps2[1]);
650                 client->bufsiz++; /* account for leading ACK */
651                 break;
652
653         case 0xf2: /* Get ID */
654                 switch (client->mode) {
655                 case MOUSEDEV_EMUL_PS2:
656                         client->ps2[1] = 0;
657                         break;
658                 case MOUSEDEV_EMUL_IMPS:
659                         client->ps2[1] = 3;
660                         break;
661                 case MOUSEDEV_EMUL_EXPS:
662                         client->ps2[1] = 4;
663                         break;
664                 }
665                 client->bufsiz = 2;
666                 break;
667
668         case 0xe9: /* Get info */
669                 client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200;
670                 client->bufsiz = 4;
671                 break;
672
673         case 0xff: /* Reset */
674                 client->impsseq = client->imexseq = 0;
675                 client->mode = MOUSEDEV_EMUL_PS2;
676                 client->ps2[1] = 0xaa; client->ps2[2] = 0x00;
677                 client->bufsiz = 3;
678                 break;
679
680         default:
681                 client->bufsiz = 1;
682                 break;
683         }
684         client->buffer = client->bufsiz;
685 }
686
687 static ssize_t mousedev_write(struct file *file, const char __user *buffer,
688                                 size_t count, loff_t *ppos)
689 {
690         struct mousedev_client *client = file->private_data;
691         unsigned char c;
692         unsigned int i;
693
694         for (i = 0; i < count; i++) {
695
696                 if (get_user(c, buffer + i))
697                         return -EFAULT;
698
699                 spin_lock_irq(&client->packet_lock);
700
701                 if (c == mousedev_imex_seq[client->imexseq]) {
702                         if (++client->imexseq == MOUSEDEV_SEQ_LEN) {
703                                 client->imexseq = 0;
704                                 client->mode = MOUSEDEV_EMUL_EXPS;
705                         }
706                 } else
707                         client->imexseq = 0;
708
709                 if (c == mousedev_imps_seq[client->impsseq]) {
710                         if (++client->impsseq == MOUSEDEV_SEQ_LEN) {
711                                 client->impsseq = 0;
712                                 client->mode = MOUSEDEV_EMUL_IMPS;
713                         }
714                 } else
715                         client->impsseq = 0;
716
717                 mousedev_generate_response(client, c);
718
719                 spin_unlock_irq(&client->packet_lock);
720         }
721
722         kill_fasync(&client->fasync, SIGIO, POLL_IN);
723         wake_up_interruptible(&client->mousedev->wait);
724
725         return count;
726 }
727
728 static ssize_t mousedev_read(struct file *file, char __user *buffer,
729                              size_t count, loff_t *ppos)
730 {
731         struct mousedev_client *client = file->private_data;
732         struct mousedev *mousedev = client->mousedev;
733         signed char data[sizeof(client->ps2)];
734         int retval = 0;
735
736         if (!client->ready && !client->buffer && mousedev->exist &&
737             (file->f_flags & O_NONBLOCK))
738                 return -EAGAIN;
739
740         retval = wait_event_interruptible(mousedev->wait,
741                         !mousedev->exist || client->ready || client->buffer);
742         if (retval)
743                 return retval;
744
745         if (!mousedev->exist)
746                 return -ENODEV;
747
748         spin_lock_irq(&client->packet_lock);
749
750         if (!client->buffer && client->ready) {
751                 mousedev_packet(client, client->ps2);
752                 client->buffer = client->bufsiz;
753         }
754
755         if (count > client->buffer)
756                 count = client->buffer;
757
758         memcpy(data, client->ps2 + client->bufsiz - client->buffer, count);
759         client->buffer -= count;
760
761         spin_unlock_irq(&client->packet_lock);
762
763         if (copy_to_user(buffer, data, count))
764                 return -EFAULT;
765
766         return count;
767 }
768
769 /* No kernel lock - fine */
770 static unsigned int mousedev_poll(struct file *file, poll_table *wait)
771 {
772         struct mousedev_client *client = file->private_data;
773         struct mousedev *mousedev = client->mousedev;
774
775         poll_wait(file, &mousedev->wait, wait);
776         return ((client->ready || client->buffer) ? (POLLIN | POLLRDNORM) : 0) |
777                 (mousedev->exist ? 0 : (POLLHUP | POLLERR));
778 }
779
780 static const struct file_operations mousedev_fops = {
781         .owner =        THIS_MODULE,
782         .read =         mousedev_read,
783         .write =        mousedev_write,
784         .poll =         mousedev_poll,
785         .open =         mousedev_open,
786         .release =      mousedev_release,
787         .fasync =       mousedev_fasync,
788 };
789
790 static int mousedev_install_chrdev(struct mousedev *mousedev)
791 {
792         mousedev_table[mousedev->minor] = mousedev;
793         return 0;
794 }
795
796 static void mousedev_remove_chrdev(struct mousedev *mousedev)
797 {
798         mutex_lock(&mousedev_table_mutex);
799         mousedev_table[mousedev->minor] = NULL;
800         mutex_unlock(&mousedev_table_mutex);
801 }
802
803 /*
804  * Mark device non-existent. This disables writes, ioctls and
805  * prevents new users from opening the device. Already posted
806  * blocking reads will stay, however new ones will fail.
807  */
808 static void mousedev_mark_dead(struct mousedev *mousedev)
809 {
810         mutex_lock(&mousedev->mutex);
811         mousedev->exist = 0;
812         mutex_unlock(&mousedev->mutex);
813 }
814
815 /*
816  * Wake up users waiting for IO so they can disconnect from
817  * dead device.
818  */
819 static void mousedev_hangup(struct mousedev *mousedev)
820 {
821         struct mousedev_client *client;
822
823         spin_lock(&mousedev->client_lock);
824         list_for_each_entry(client, &mousedev->client_list, node)
825                 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
826         spin_unlock(&mousedev->client_lock);
827
828         wake_up_interruptible(&mousedev->wait);
829 }
830
831 static void mousedev_cleanup(struct mousedev *mousedev)
832 {
833         struct input_handle *handle = &mousedev->handle;
834
835         mousedev_mark_dead(mousedev);
836         mousedev_hangup(mousedev);
837         mousedev_remove_chrdev(mousedev);
838
839         /* mousedev is marked dead so no one else accesses mousedev->open */
840         if (mousedev->open)
841                 input_close_device(handle);
842 }
843
844 static struct mousedev *mousedev_create(struct input_dev *dev,
845                                         struct input_handler *handler,
846                                         int minor)
847 {
848         struct mousedev *mousedev;
849         int error;
850
851         mousedev = kzalloc(sizeof(struct mousedev), GFP_KERNEL);
852         if (!mousedev) {
853                 error = -ENOMEM;
854                 goto err_out;
855         }
856
857         INIT_LIST_HEAD(&mousedev->client_list);
858         INIT_LIST_HEAD(&mousedev->mixdev_node);
859         spin_lock_init(&mousedev->client_lock);
860         mutex_init(&mousedev->mutex);
861         lockdep_set_subclass(&mousedev->mutex,
862                              minor == MOUSEDEV_MIX ? MOUSEDEV_MIX : 0);
863         init_waitqueue_head(&mousedev->wait);
864
865         if (minor == MOUSEDEV_MIX)
866                 strlcpy(mousedev->name, "mice", sizeof(mousedev->name));
867         else
868                 snprintf(mousedev->name, sizeof(mousedev->name),
869                          "mouse%d", minor);
870
871         mousedev->minor = minor;
872         mousedev->exist = 1;
873         mousedev->handle.dev = input_get_device(dev);
874         mousedev->handle.name = mousedev->name;
875         mousedev->handle.handler = handler;
876         mousedev->handle.private = mousedev;
877
878         dev_set_name(&mousedev->dev, mousedev->name);
879         mousedev->dev.class = &input_class;
880         if (dev)
881                 mousedev->dev.parent = &dev->dev;
882         mousedev->dev.devt = MKDEV(INPUT_MAJOR, MOUSEDEV_MINOR_BASE + minor);
883         mousedev->dev.release = mousedev_free;
884         device_initialize(&mousedev->dev);
885
886         if (minor != MOUSEDEV_MIX) {
887                 error = input_register_handle(&mousedev->handle);
888                 if (error)
889                         goto err_free_mousedev;
890         }
891
892         error = mousedev_install_chrdev(mousedev);
893         if (error)
894                 goto err_unregister_handle;
895
896         error = device_add(&mousedev->dev);
897         if (error)
898                 goto err_cleanup_mousedev;
899
900         return mousedev;
901
902  err_cleanup_mousedev:
903         mousedev_cleanup(mousedev);
904  err_unregister_handle:
905         if (minor != MOUSEDEV_MIX)
906                 input_unregister_handle(&mousedev->handle);
907  err_free_mousedev:
908         put_device(&mousedev->dev);
909  err_out:
910         return ERR_PTR(error);
911 }
912
913 static void mousedev_destroy(struct mousedev *mousedev)
914 {
915         device_del(&mousedev->dev);
916         mousedev_cleanup(mousedev);
917         if (mousedev->minor != MOUSEDEV_MIX)
918                 input_unregister_handle(&mousedev->handle);
919         put_device(&mousedev->dev);
920 }
921
922 static int mixdev_add_device(struct mousedev *mousedev)
923 {
924         int retval;
925
926         retval = mutex_lock_interruptible(&mousedev_mix->mutex);
927         if (retval)
928                 return retval;
929
930         if (mousedev_mix->open) {
931                 retval = mousedev_open_device(mousedev);
932                 if (retval)
933                         goto out;
934
935                 mousedev->mixdev_open = 1;
936         }
937
938         get_device(&mousedev->dev);
939         list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list);
940
941  out:
942         mutex_unlock(&mousedev_mix->mutex);
943         return retval;
944 }
945
946 static void mixdev_remove_device(struct mousedev *mousedev)
947 {
948         mutex_lock(&mousedev_mix->mutex);
949
950         if (mousedev->mixdev_open) {
951                 mousedev->mixdev_open = 0;
952                 mousedev_close_device(mousedev);
953         }
954
955         list_del_init(&mousedev->mixdev_node);
956         mutex_unlock(&mousedev_mix->mutex);
957
958         put_device(&mousedev->dev);
959 }
960
961 static int mousedev_connect(struct input_handler *handler,
962                             struct input_dev *dev,
963                             const struct input_device_id *id)
964 {
965         struct mousedev *mousedev;
966         int minor;
967         int error;
968
969         for (minor = 0; minor < MOUSEDEV_MINORS; minor++)
970                 if (!mousedev_table[minor])
971                         break;
972
973         if (minor == MOUSEDEV_MINORS) {
974                 printk(KERN_ERR "mousedev: no more free mousedev devices\n");
975                 return -ENFILE;
976         }
977
978         mousedev = mousedev_create(dev, handler, minor);
979         if (IS_ERR(mousedev))
980                 return PTR_ERR(mousedev);
981
982         error = mixdev_add_device(mousedev);
983         if (error) {
984                 mousedev_destroy(mousedev);
985                 return error;
986         }
987
988         return 0;
989 }
990
991 static void mousedev_disconnect(struct input_handle *handle)
992 {
993         struct mousedev *mousedev = handle->private;
994
995         mixdev_remove_device(mousedev);
996         mousedev_destroy(mousedev);
997 }
998
999 static const struct input_device_id mousedev_ids[] = {
1000         {
1001                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1002                                 INPUT_DEVICE_ID_MATCH_KEYBIT |
1003                                 INPUT_DEVICE_ID_MATCH_RELBIT,
1004                 .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1005                 .keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1006                 .relbit = { BIT_MASK(REL_X) | BIT_MASK(REL_Y) },
1007         },      /* A mouse like device, at least one button,
1008                    two relative axes */
1009         {
1010                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1011                                 INPUT_DEVICE_ID_MATCH_RELBIT,
1012                 .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1013                 .relbit = { BIT_MASK(REL_WHEEL) },
1014         },      /* A separate scrollwheel */
1015         {
1016                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1017                                 INPUT_DEVICE_ID_MATCH_KEYBIT |
1018                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
1019                 .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1020                 .keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
1021                 .absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1022         },      /* A tablet like device, at least touch detection,
1023                    two absolute axes */
1024         {
1025                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1026                                 INPUT_DEVICE_ID_MATCH_KEYBIT |
1027                                 INPUT_DEVICE_ID_MATCH_ABSBIT,
1028                 .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1029                 .keybit = { [BIT_WORD(BTN_TOOL_FINGER)] =
1030                                 BIT_MASK(BTN_TOOL_FINGER) },
1031                 .absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
1032                                 BIT_MASK(ABS_PRESSURE) |
1033                                 BIT_MASK(ABS_TOOL_WIDTH) },
1034         },      /* A touchpad */
1035         {
1036                 .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1037                         INPUT_DEVICE_ID_MATCH_KEYBIT |
1038                         INPUT_DEVICE_ID_MATCH_ABSBIT,
1039                 .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1040                 .keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1041                 .absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1042         },      /* Mouse-like device with absolute X and Y but ordinary
1043                    clicks, like hp ILO2 High Performance mouse */
1044
1045         { },    /* Terminating entry */
1046 };
1047
1048 MODULE_DEVICE_TABLE(input, mousedev_ids);
1049
1050 static struct input_handler mousedev_handler = {
1051         .event =        mousedev_event,
1052         .connect =      mousedev_connect,
1053         .disconnect =   mousedev_disconnect,
1054         .fops =         &mousedev_fops,
1055         .minor =        MOUSEDEV_MINOR_BASE,
1056         .name =         "mousedev",
1057         .id_table =     mousedev_ids,
1058 };
1059
1060 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1061 static struct miscdevice psaux_mouse = {
1062         PSMOUSE_MINOR, "psaux", &mousedev_fops
1063 };
1064 static int psaux_registered;
1065 #endif
1066
1067 static int __init mousedev_init(void)
1068 {
1069         int error;
1070
1071         mousedev_mix = mousedev_create(NULL, &mousedev_handler, MOUSEDEV_MIX);
1072         if (IS_ERR(mousedev_mix))
1073                 return PTR_ERR(mousedev_mix);
1074
1075         error = input_register_handler(&mousedev_handler);
1076         if (error) {
1077                 mousedev_destroy(mousedev_mix);
1078                 return error;
1079         }
1080
1081 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1082         error = misc_register(&psaux_mouse);
1083         if (error)
1084                 printk(KERN_WARNING "mice: could not register psaux device, "
1085                         "error: %d\n", error);
1086         else
1087                 psaux_registered = 1;
1088 #endif
1089
1090         printk(KERN_INFO "mice: PS/2 mouse device common for all mice\n");
1091
1092         return 0;
1093 }
1094
1095 static void __exit mousedev_exit(void)
1096 {
1097 #ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1098         if (psaux_registered)
1099                 misc_deregister(&psaux_mouse);
1100 #endif
1101         input_unregister_handler(&mousedev_handler);
1102         mousedev_destroy(mousedev_mix);
1103 }
1104
1105 module_init(mousedev_init);
1106 module_exit(mousedev_exit);