linux/drivers/input/mousedev.c
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   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         32
  16#define MOUSEDEV_MIX            31
  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/kernel.h>
  28#ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
  29#include <linux/miscdevice.h>
  30#endif
  31
  32MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  33MODULE_DESCRIPTION("Mouse (ExplorerPS/2) device interfaces");
  34MODULE_LICENSE("GPL");
  35
  36#ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_X
  37#define CONFIG_INPUT_MOUSEDEV_SCREEN_X  1024
  38#endif
  39#ifndef CONFIG_INPUT_MOUSEDEV_SCREEN_Y
  40#define CONFIG_INPUT_MOUSEDEV_SCREEN_Y  768
  41#endif
  42
  43static int xres = CONFIG_INPUT_MOUSEDEV_SCREEN_X;
  44module_param(xres, uint, 0644);
  45MODULE_PARM_DESC(xres, "Horizontal screen resolution");
  46
  47static int yres = CONFIG_INPUT_MOUSEDEV_SCREEN_Y;
  48module_param(yres, uint, 0644);
  49MODULE_PARM_DESC(yres, "Vertical screen resolution");
  50
  51static unsigned tap_time = 200;
  52module_param(tap_time, uint, 0644);
  53MODULE_PARM_DESC(tap_time, "Tap time for touchpads in absolute mode (msecs)");
  54
  55struct mousedev_hw_data {
  56        int dx, dy, dz;
  57        int x, y;
  58        int abs_event;
  59        unsigned long buttons;
  60};
  61
  62struct mousedev {
  63        int open;
  64        int minor;
  65        struct input_handle handle;
  66        wait_queue_head_t wait;
  67        struct list_head client_list;
  68        spinlock_t client_lock; /* protects client_list */
  69        struct mutex mutex;
  70        struct device dev;
  71        bool exist;
  72
  73        struct list_head mixdev_node;
  74        int mixdev_open;
  75
  76        struct mousedev_hw_data packet;
  77        unsigned int pkt_count;
  78        int old_x[4], old_y[4];
  79        int frac_dx, frac_dy;
  80        unsigned long touch;
  81};
  82
  83enum mousedev_emul {
  84        MOUSEDEV_EMUL_PS2,
  85        MOUSEDEV_EMUL_IMPS,
  86        MOUSEDEV_EMUL_EXPS
  87};
  88
  89struct mousedev_motion {
  90        int dx, dy, dz;
  91        unsigned long buttons;
  92};
  93
  94#define PACKET_QUEUE_LEN        16
  95struct mousedev_client {
  96        struct fasync_struct *fasync;
  97        struct mousedev *mousedev;
  98        struct list_head node;
  99
 100        struct mousedev_motion packets[PACKET_QUEUE_LEN];
 101        unsigned int head, tail;
 102        spinlock_t packet_lock;
 103        int pos_x, pos_y;
 104
 105        signed char ps2[6];
 106        unsigned char ready, buffer, bufsiz;
 107        unsigned char imexseq, impsseq;
 108        enum mousedev_emul mode;
 109        unsigned long last_buttons;
 110};
 111
 112#define MOUSEDEV_SEQ_LEN        6
 113
 114static unsigned char mousedev_imps_seq[] = { 0xf3, 200, 0xf3, 100, 0xf3, 80 };
 115static unsigned char mousedev_imex_seq[] = { 0xf3, 200, 0xf3, 200, 0xf3, 80 };
 116
 117static struct input_handler mousedev_handler;
 118
 119static struct mousedev *mousedev_table[MOUSEDEV_MINORS];
 120static DEFINE_MUTEX(mousedev_table_mutex);
 121static struct mousedev *mousedev_mix;
 122static LIST_HEAD(mousedev_mix_list);
 123
 124static void mixdev_open_devices(void);
 125static void mixdev_close_devices(void);
 126
 127#define fx(i)  (mousedev->old_x[(mousedev->pkt_count - (i)) & 03])
 128#define fy(i)  (mousedev->old_y[(mousedev->pkt_count - (i)) & 03])
 129
 130static void mousedev_touchpad_event(struct input_dev *dev,
 131                                    struct mousedev *mousedev,
 132                                    unsigned int code, int value)
 133{
 134        int size, tmp;
 135        enum { FRACTION_DENOM = 128 };
 136
 137        switch (code) {
 138
 139        case ABS_X:
 140
 141                fx(0) = value;
 142                if (mousedev->touch && mousedev->pkt_count >= 2) {
 143                        size = input_abs_get_max(dev, ABS_X) -
 144                                        input_abs_get_min(dev, ABS_X);
 145                        if (size == 0)
 146                                size = 256 * 2;
 147
 148                        tmp = ((value - fx(2)) * 256 * FRACTION_DENOM) / size;
 149                        tmp += mousedev->frac_dx;
 150                        mousedev->packet.dx = tmp / FRACTION_DENOM;
 151                        mousedev->frac_dx =
 152                                tmp - mousedev->packet.dx * FRACTION_DENOM;
 153                }
 154                break;
 155
 156        case ABS_Y:
 157                fy(0) = value;
 158                if (mousedev->touch && mousedev->pkt_count >= 2) {
 159                        /* use X size for ABS_Y to keep the same scale */
 160                        size = input_abs_get_max(dev, ABS_X) -
 161                                        input_abs_get_min(dev, ABS_X);
 162                        if (size == 0)
 163                                size = 256 * 2;
 164
 165                        tmp = -((value - fy(2)) * 256 * FRACTION_DENOM) / size;
 166                        tmp += mousedev->frac_dy;
 167                        mousedev->packet.dy = tmp / FRACTION_DENOM;
 168                        mousedev->frac_dy = tmp -
 169                                mousedev->packet.dy * FRACTION_DENOM;
 170                }
 171                break;
 172        }
 173}
 174
 175static void mousedev_abs_event(struct input_dev *dev, struct mousedev *mousedev,
 176                                unsigned int code, int value)
 177{
 178        int min, max, size;
 179
 180        switch (code) {
 181
 182        case ABS_X:
 183                min = input_abs_get_min(dev, ABS_X);
 184                max = input_abs_get_max(dev, ABS_X);
 185
 186                size = max - min;
 187                if (size == 0)
 188                        size = xres ? : 1;
 189
 190                value = clamp(value, min, max);
 191
 192                mousedev->packet.x = ((value - min) * xres) / size;
 193                mousedev->packet.abs_event = 1;
 194                break;
 195
 196        case ABS_Y:
 197                min = input_abs_get_min(dev, ABS_Y);
 198                max = input_abs_get_max(dev, ABS_Y);
 199
 200                size = max - min;
 201                if (size == 0)
 202                        size = yres ? : 1;
 203
 204                value = clamp(value, min, max);
 205
 206                mousedev->packet.y = yres - ((value - min) * yres) / size;
 207                mousedev->packet.abs_event = 1;
 208                break;
 209        }
 210}
 211
 212static void mousedev_rel_event(struct mousedev *mousedev,
 213                                unsigned int code, int value)
 214{
 215        switch (code) {
 216        case REL_X:
 217                mousedev->packet.dx += value;
 218                break;
 219
 220        case REL_Y:
 221                mousedev->packet.dy -= value;
 222                break;
 223
 224        case REL_WHEEL:
 225                mousedev->packet.dz -= value;
 226                break;
 227        }
 228}
 229
 230static void mousedev_key_event(struct mousedev *mousedev,
 231                                unsigned int code, int value)
 232{
 233        int index;
 234
 235        switch (code) {
 236
 237        case BTN_TOUCH:
 238        case BTN_0:
 239        case BTN_LEFT:          index = 0; break;
 240
 241        case BTN_STYLUS:
 242        case BTN_1:
 243        case BTN_RIGHT:         index = 1; break;
 244
 245        case BTN_2:
 246        case BTN_FORWARD:
 247        case BTN_STYLUS2:
 248        case BTN_MIDDLE:        index = 2; break;
 249
 250        case BTN_3:
 251        case BTN_BACK:
 252        case BTN_SIDE:          index = 3; break;
 253
 254        case BTN_4:
 255        case BTN_EXTRA:         index = 4; break;
 256
 257        default:                return;
 258        }
 259
 260        if (value) {
 261                set_bit(index, &mousedev->packet.buttons);
 262                set_bit(index, &mousedev_mix->packet.buttons);
 263        } else {
 264                clear_bit(index, &mousedev->packet.buttons);
 265                clear_bit(index, &mousedev_mix->packet.buttons);
 266        }
 267}
 268
 269static void mousedev_notify_readers(struct mousedev *mousedev,
 270                                    struct mousedev_hw_data *packet)
 271{
 272        struct mousedev_client *client;
 273        struct mousedev_motion *p;
 274        unsigned int new_head;
 275        int wake_readers = 0;
 276
 277        rcu_read_lock();
 278        list_for_each_entry_rcu(client, &mousedev->client_list, node) {
 279
 280                /* Just acquire the lock, interrupts already disabled */
 281                spin_lock(&client->packet_lock);
 282
 283                p = &client->packets[client->head];
 284                if (client->ready && p->buttons != mousedev->packet.buttons) {
 285                        new_head = (client->head + 1) % PACKET_QUEUE_LEN;
 286                        if (new_head != client->tail) {
 287                                p = &client->packets[client->head = new_head];
 288                                memset(p, 0, sizeof(struct mousedev_motion));
 289                        }
 290                }
 291
 292                if (packet->abs_event) {
 293                        p->dx += packet->x - client->pos_x;
 294                        p->dy += packet->y - client->pos_y;
 295                        client->pos_x = packet->x;
 296                        client->pos_y = packet->y;
 297                }
 298
 299                client->pos_x += packet->dx;
 300                client->pos_x = client->pos_x < 0 ?
 301                        0 : (client->pos_x >= xres ? xres : client->pos_x);
 302                client->pos_y += packet->dy;
 303                client->pos_y = client->pos_y < 0 ?
 304                        0 : (client->pos_y >= yres ? yres : client->pos_y);
 305
 306                p->dx += packet->dx;
 307                p->dy += packet->dy;
 308                p->dz += packet->dz;
 309                p->buttons = mousedev->packet.buttons;
 310
 311                if (p->dx || p->dy || p->dz ||
 312                    p->buttons != client->last_buttons)
 313                        client->ready = 1;
 314
 315                spin_unlock(&client->packet_lock);
 316
 317                if (client->ready) {
 318                        kill_fasync(&client->fasync, SIGIO, POLL_IN);
 319                        wake_readers = 1;
 320                }
 321        }
 322        rcu_read_unlock();
 323
 324        if (wake_readers)
 325                wake_up_interruptible(&mousedev->wait);
 326}
 327
 328static void mousedev_touchpad_touch(struct mousedev *mousedev, int value)
 329{
 330        if (!value) {
 331                if (mousedev->touch &&
 332                    time_before(jiffies,
 333                                mousedev->touch + msecs_to_jiffies(tap_time))) {
 334                        /*
 335                         * Toggle left button to emulate tap.
 336                         * We rely on the fact that mousedev_mix always has 0
 337                         * motion packet so we won't mess current position.
 338                         */
 339                        set_bit(0, &mousedev->packet.buttons);
 340                        set_bit(0, &mousedev_mix->packet.buttons);
 341                        mousedev_notify_readers(mousedev, &mousedev_mix->packet);
 342                        mousedev_notify_readers(mousedev_mix,
 343                                                &mousedev_mix->packet);
 344                        clear_bit(0, &mousedev->packet.buttons);
 345                        clear_bit(0, &mousedev_mix->packet.buttons);
 346                }
 347                mousedev->touch = mousedev->pkt_count = 0;
 348                mousedev->frac_dx = 0;
 349                mousedev->frac_dy = 0;
 350
 351        } else if (!mousedev->touch)
 352                mousedev->touch = jiffies;
 353}
 354
 355static void mousedev_event(struct input_handle *handle,
 356                           unsigned int type, unsigned int code, int value)
 357{
 358        struct mousedev *mousedev = handle->private;
 359
 360        switch (type) {
 361
 362        case EV_ABS:
 363                /* Ignore joysticks */
 364                if (test_bit(BTN_TRIGGER, handle->dev->keybit))
 365                        return;
 366
 367                if (test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
 368                        mousedev_touchpad_event(handle->dev,
 369                                                mousedev, code, value);
 370                else
 371                        mousedev_abs_event(handle->dev, mousedev, code, value);
 372
 373                break;
 374
 375        case EV_REL:
 376                mousedev_rel_event(mousedev, code, value);
 377                break;
 378
 379        case EV_KEY:
 380                if (value != 2) {
 381                        if (code == BTN_TOUCH &&
 382                            test_bit(BTN_TOOL_FINGER, handle->dev->keybit))
 383                                mousedev_touchpad_touch(mousedev, value);
 384                        else
 385                                mousedev_key_event(mousedev, code, value);
 386                }
 387                break;
 388
 389        case EV_SYN:
 390                if (code == SYN_REPORT) {
 391                        if (mousedev->touch) {
 392                                mousedev->pkt_count++;
 393                                /*
 394                                 * Input system eats duplicate events,
 395                                 * but we need all of them to do correct
 396                                 * averaging so apply present one forward
 397                                 */
 398                                fx(0) = fx(1);
 399                                fy(0) = fy(1);
 400                        }
 401
 402                        mousedev_notify_readers(mousedev, &mousedev->packet);
 403                        mousedev_notify_readers(mousedev_mix, &mousedev->packet);
 404
 405                        mousedev->packet.dx = mousedev->packet.dy =
 406                                mousedev->packet.dz = 0;
 407                        mousedev->packet.abs_event = 0;
 408                }
 409                break;
 410        }
 411}
 412
 413static int mousedev_fasync(int fd, struct file *file, int on)
 414{
 415        struct mousedev_client *client = file->private_data;
 416
 417        return fasync_helper(fd, file, on, &client->fasync);
 418}
 419
 420static void mousedev_free(struct device *dev)
 421{
 422        struct mousedev *mousedev = container_of(dev, struct mousedev, dev);
 423
 424        input_put_device(mousedev->handle.dev);
 425        kfree(mousedev);
 426}
 427
 428static int mousedev_open_device(struct mousedev *mousedev)
 429{
 430        int retval;
 431
 432        retval = mutex_lock_interruptible(&mousedev->mutex);
 433        if (retval)
 434                return retval;
 435
 436        if (mousedev->minor == MOUSEDEV_MIX)
 437                mixdev_open_devices();
 438        else if (!mousedev->exist)
 439                retval = -ENODEV;
 440        else if (!mousedev->open++) {
 441                retval = input_open_device(&mousedev->handle);
 442                if (retval)
 443                        mousedev->open--;
 444        }
 445
 446        mutex_unlock(&mousedev->mutex);
 447        return retval;
 448}
 449
 450static void mousedev_close_device(struct mousedev *mousedev)
 451{
 452        mutex_lock(&mousedev->mutex);
 453
 454        if (mousedev->minor == MOUSEDEV_MIX)
 455                mixdev_close_devices();
 456        else if (mousedev->exist && !--mousedev->open)
 457                input_close_device(&mousedev->handle);
 458
 459        mutex_unlock(&mousedev->mutex);
 460}
 461
 462/*
 463 * Open all available devices so they can all be multiplexed in one.
 464 * stream. Note that this function is called with mousedev_mix->mutex
 465 * held.
 466 */
 467static void mixdev_open_devices(void)
 468{
 469        struct mousedev *mousedev;
 470
 471        if (mousedev_mix->open++)
 472                return;
 473
 474        list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
 475                if (!mousedev->mixdev_open) {
 476                        if (mousedev_open_device(mousedev))
 477                                continue;
 478
 479                        mousedev->mixdev_open = 1;
 480                }
 481        }
 482}
 483
 484/*
 485 * Close all devices that were opened as part of multiplexed
 486 * device. Note that this function is called with mousedev_mix->mutex
 487 * held.
 488 */
 489static void mixdev_close_devices(void)
 490{
 491        struct mousedev *mousedev;
 492
 493        if (--mousedev_mix->open)
 494                return;
 495
 496        list_for_each_entry(mousedev, &mousedev_mix_list, mixdev_node) {
 497                if (mousedev->mixdev_open) {
 498                        mousedev->mixdev_open = 0;
 499                        mousedev_close_device(mousedev);
 500                }
 501        }
 502}
 503
 504
 505static void mousedev_attach_client(struct mousedev *mousedev,
 506                                   struct mousedev_client *client)
 507{
 508        spin_lock(&mousedev->client_lock);
 509        list_add_tail_rcu(&client->node, &mousedev->client_list);
 510        spin_unlock(&mousedev->client_lock);
 511}
 512
 513static void mousedev_detach_client(struct mousedev *mousedev,
 514                                   struct mousedev_client *client)
 515{
 516        spin_lock(&mousedev->client_lock);
 517        list_del_rcu(&client->node);
 518        spin_unlock(&mousedev->client_lock);
 519        synchronize_rcu();
 520}
 521
 522static int mousedev_release(struct inode *inode, struct file *file)
 523{
 524        struct mousedev_client *client = file->private_data;
 525        struct mousedev *mousedev = client->mousedev;
 526
 527        mousedev_detach_client(mousedev, client);
 528        kfree(client);
 529
 530        mousedev_close_device(mousedev);
 531        put_device(&mousedev->dev);
 532
 533        return 0;
 534}
 535
 536static int mousedev_open(struct inode *inode, struct file *file)
 537{
 538        struct mousedev_client *client;
 539        struct mousedev *mousedev;
 540        int error;
 541        int i;
 542
 543#ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
 544        if (imajor(inode) == MISC_MAJOR)
 545                i = MOUSEDEV_MIX;
 546        else
 547#endif
 548                i = iminor(inode) - MOUSEDEV_MINOR_BASE;
 549
 550        if (i >= MOUSEDEV_MINORS)
 551                return -ENODEV;
 552
 553        error = mutex_lock_interruptible(&mousedev_table_mutex);
 554        if (error) {
 555                return error;
 556        }
 557        mousedev = mousedev_table[i];
 558        if (mousedev)
 559                get_device(&mousedev->dev);
 560        mutex_unlock(&mousedev_table_mutex);
 561
 562        if (!mousedev) {
 563                return -ENODEV;
 564        }
 565
 566        client = kzalloc(sizeof(struct mousedev_client), GFP_KERNEL);
 567        if (!client) {
 568                error = -ENOMEM;
 569                goto err_put_mousedev;
 570        }
 571
 572        spin_lock_init(&client->packet_lock);
 573        client->pos_x = xres / 2;
 574        client->pos_y = yres / 2;
 575        client->mousedev = mousedev;
 576        mousedev_attach_client(mousedev, client);
 577
 578        error = mousedev_open_device(mousedev);
 579        if (error)
 580                goto err_free_client;
 581
 582        file->private_data = client;
 583        return 0;
 584
 585 err_free_client:
 586        mousedev_detach_client(mousedev, client);
 587        kfree(client);
 588 err_put_mousedev:
 589        put_device(&mousedev->dev);
 590        return error;
 591}
 592
 593static inline int mousedev_limit_delta(int delta, int limit)
 594{
 595        return delta > limit ? limit : (delta < -limit ? -limit : delta);
 596}
 597
 598static void mousedev_packet(struct mousedev_client *client,
 599                            signed char *ps2_data)
 600{
 601        struct mousedev_motion *p = &client->packets[client->tail];
 602
 603        ps2_data[0] = 0x08 |
 604                ((p->dx < 0) << 4) | ((p->dy < 0) << 5) | (p->buttons & 0x07);
 605        ps2_data[1] = mousedev_limit_delta(p->dx, 127);
 606        ps2_data[2] = mousedev_limit_delta(p->dy, 127);
 607        p->dx -= ps2_data[1];
 608        p->dy -= ps2_data[2];
 609
 610        switch (client->mode) {
 611        case MOUSEDEV_EMUL_EXPS:
 612                ps2_data[3] = mousedev_limit_delta(p->dz, 7);
 613                p->dz -= ps2_data[3];
 614                ps2_data[3] = (ps2_data[3] & 0x0f) | ((p->buttons & 0x18) << 1);
 615                client->bufsiz = 4;
 616                break;
 617
 618        case MOUSEDEV_EMUL_IMPS:
 619                ps2_data[0] |=
 620                        ((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
 621                ps2_data[3] = mousedev_limit_delta(p->dz, 127);
 622                p->dz -= ps2_data[3];
 623                client->bufsiz = 4;
 624                break;
 625
 626        case MOUSEDEV_EMUL_PS2:
 627        default:
 628                ps2_data[0] |=
 629                        ((p->buttons & 0x10) >> 3) | ((p->buttons & 0x08) >> 1);
 630                p->dz = 0;
 631                client->bufsiz = 3;
 632                break;
 633        }
 634
 635        if (!p->dx && !p->dy && !p->dz) {
 636                if (client->tail == client->head) {
 637                        client->ready = 0;
 638                        client->last_buttons = p->buttons;
 639                } else
 640                        client->tail = (client->tail + 1) % PACKET_QUEUE_LEN;
 641        }
 642}
 643
 644static void mousedev_generate_response(struct mousedev_client *client,
 645                                        int command)
 646{
 647        client->ps2[0] = 0xfa; /* ACK */
 648
 649        switch (command) {
 650
 651        case 0xeb: /* Poll */
 652                mousedev_packet(client, &client->ps2[1]);
 653                client->bufsiz++; /* account for leading ACK */
 654                break;
 655
 656        case 0xf2: /* Get ID */
 657                switch (client->mode) {
 658                case MOUSEDEV_EMUL_PS2:
 659                        client->ps2[1] = 0;
 660                        break;
 661                case MOUSEDEV_EMUL_IMPS:
 662                        client->ps2[1] = 3;
 663                        break;
 664                case MOUSEDEV_EMUL_EXPS:
 665                        client->ps2[1] = 4;
 666                        break;
 667                }
 668                client->bufsiz = 2;
 669                break;
 670
 671        case 0xe9: /* Get info */
 672                client->ps2[1] = 0x60; client->ps2[2] = 3; client->ps2[3] = 200;
 673                client->bufsiz = 4;
 674                break;
 675
 676        case 0xff: /* Reset */
 677                client->impsseq = client->imexseq = 0;
 678                client->mode = MOUSEDEV_EMUL_PS2;
 679                client->ps2[1] = 0xaa; client->ps2[2] = 0x00;
 680                client->bufsiz = 3;
 681                break;
 682
 683        default:
 684                client->bufsiz = 1;
 685                break;
 686        }
 687        client->buffer = client->bufsiz;
 688}
 689
 690static ssize_t mousedev_write(struct file *file, const char __user *buffer,
 691                                size_t count, loff_t *ppos)
 692{
 693        struct mousedev_client *client = file->private_data;
 694        unsigned char c;
 695        unsigned int i;
 696
 697        for (i = 0; i < count; i++) {
 698
 699                if (get_user(c, buffer + i))
 700                        return -EFAULT;
 701
 702                spin_lock_irq(&client->packet_lock);
 703
 704                if (c == mousedev_imex_seq[client->imexseq]) {
 705                        if (++client->imexseq == MOUSEDEV_SEQ_LEN) {
 706                                client->imexseq = 0;
 707                                client->mode = MOUSEDEV_EMUL_EXPS;
 708                        }
 709                } else
 710                        client->imexseq = 0;
 711
 712                if (c == mousedev_imps_seq[client->impsseq]) {
 713                        if (++client->impsseq == MOUSEDEV_SEQ_LEN) {
 714                                client->impsseq = 0;
 715                                client->mode = MOUSEDEV_EMUL_IMPS;
 716                        }
 717                } else
 718                        client->impsseq = 0;
 719
 720                mousedev_generate_response(client, c);
 721
 722                spin_unlock_irq(&client->packet_lock);
 723        }
 724
 725        kill_fasync(&client->fasync, SIGIO, POLL_IN);
 726        wake_up_interruptible(&client->mousedev->wait);
 727
 728        return count;
 729}
 730
 731static ssize_t mousedev_read(struct file *file, char __user *buffer,
 732                             size_t count, loff_t *ppos)
 733{
 734        struct mousedev_client *client = file->private_data;
 735        struct mousedev *mousedev = client->mousedev;
 736        signed char data[sizeof(client->ps2)];
 737        int retval = 0;
 738
 739        if (!client->ready && !client->buffer && mousedev->exist &&
 740            (file->f_flags & O_NONBLOCK))
 741                return -EAGAIN;
 742
 743        retval = wait_event_interruptible(mousedev->wait,
 744                        !mousedev->exist || client->ready || client->buffer);
 745        if (retval)
 746                return retval;
 747
 748        if (!mousedev->exist)
 749                return -ENODEV;
 750
 751        spin_lock_irq(&client->packet_lock);
 752
 753        if (!client->buffer && client->ready) {
 754                mousedev_packet(client, client->ps2);
 755                client->buffer = client->bufsiz;
 756        }
 757
 758        if (count > client->buffer)
 759                count = client->buffer;
 760
 761        memcpy(data, client->ps2 + client->bufsiz - client->buffer, count);
 762        client->buffer -= count;
 763
 764        spin_unlock_irq(&client->packet_lock);
 765
 766        if (copy_to_user(buffer, data, count))
 767                return -EFAULT;
 768
 769        return count;
 770}
 771
 772/* No kernel lock - fine */
 773static unsigned int mousedev_poll(struct file *file, poll_table *wait)
 774{
 775        struct mousedev_client *client = file->private_data;
 776        struct mousedev *mousedev = client->mousedev;
 777        unsigned int mask;
 778
 779        poll_wait(file, &mousedev->wait, wait);
 780
 781        mask = mousedev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR;
 782        if (client->ready || client->buffer)
 783                mask |= POLLIN | POLLRDNORM;
 784
 785        return mask;
 786}
 787
 788static const struct file_operations mousedev_fops = {
 789        .owner =        THIS_MODULE,
 790        .read =         mousedev_read,
 791        .write =        mousedev_write,
 792        .poll =         mousedev_poll,
 793        .open =         mousedev_open,
 794        .release =      mousedev_release,
 795        .fasync =       mousedev_fasync,
 796        .llseek = noop_llseek,
 797};
 798
 799static int mousedev_install_chrdev(struct mousedev *mousedev)
 800{
 801        mousedev_table[mousedev->minor] = mousedev;
 802        return 0;
 803}
 804
 805static void mousedev_remove_chrdev(struct mousedev *mousedev)
 806{
 807        mutex_lock(&mousedev_table_mutex);
 808        mousedev_table[mousedev->minor] = NULL;
 809        mutex_unlock(&mousedev_table_mutex);
 810}
 811
 812/*
 813 * Mark device non-existent. This disables writes, ioctls and
 814 * prevents new users from opening the device. Already posted
 815 * blocking reads will stay, however new ones will fail.
 816 */
 817static void mousedev_mark_dead(struct mousedev *mousedev)
 818{
 819        mutex_lock(&mousedev->mutex);
 820        mousedev->exist = false;
 821        mutex_unlock(&mousedev->mutex);
 822}
 823
 824/*
 825 * Wake up users waiting for IO so they can disconnect from
 826 * dead device.
 827 */
 828static void mousedev_hangup(struct mousedev *mousedev)
 829{
 830        struct mousedev_client *client;
 831
 832        spin_lock(&mousedev->client_lock);
 833        list_for_each_entry(client, &mousedev->client_list, node)
 834                kill_fasync(&client->fasync, SIGIO, POLL_HUP);
 835        spin_unlock(&mousedev->client_lock);
 836
 837        wake_up_interruptible(&mousedev->wait);
 838}
 839
 840static void mousedev_cleanup(struct mousedev *mousedev)
 841{
 842        struct input_handle *handle = &mousedev->handle;
 843
 844        mousedev_mark_dead(mousedev);
 845        mousedev_hangup(mousedev);
 846        mousedev_remove_chrdev(mousedev);
 847
 848        /* mousedev is marked dead so no one else accesses mousedev->open */
 849        if (mousedev->open)
 850                input_close_device(handle);
 851}
 852
 853static struct mousedev *mousedev_create(struct input_dev *dev,
 854                                        struct input_handler *handler,
 855                                        int minor)
 856{
 857        struct mousedev *mousedev;
 858        int error;
 859
 860        mousedev = kzalloc(sizeof(struct mousedev), GFP_KERNEL);
 861        if (!mousedev) {
 862                error = -ENOMEM;
 863                goto err_out;
 864        }
 865
 866        INIT_LIST_HEAD(&mousedev->client_list);
 867        INIT_LIST_HEAD(&mousedev->mixdev_node);
 868        spin_lock_init(&mousedev->client_lock);
 869        mutex_init(&mousedev->mutex);
 870        lockdep_set_subclass(&mousedev->mutex,
 871                             minor == MOUSEDEV_MIX ? SINGLE_DEPTH_NESTING : 0);
 872        init_waitqueue_head(&mousedev->wait);
 873
 874        if (minor == MOUSEDEV_MIX)
 875                dev_set_name(&mousedev->dev, "mice");
 876        else
 877                dev_set_name(&mousedev->dev, "mouse%d", minor);
 878
 879        mousedev->minor = minor;
 880        mousedev->exist = true;
 881        mousedev->handle.dev = input_get_device(dev);
 882        mousedev->handle.name = dev_name(&mousedev->dev);
 883        mousedev->handle.handler = handler;
 884        mousedev->handle.private = mousedev;
 885
 886        mousedev->dev.class = &input_class;
 887        if (dev)
 888                mousedev->dev.parent = &dev->dev;
 889        mousedev->dev.devt = MKDEV(INPUT_MAJOR, MOUSEDEV_MINOR_BASE + minor);
 890        mousedev->dev.release = mousedev_free;
 891        device_initialize(&mousedev->dev);
 892
 893        if (minor != MOUSEDEV_MIX) {
 894                error = input_register_handle(&mousedev->handle);
 895                if (error)
 896                        goto err_free_mousedev;
 897        }
 898
 899        error = mousedev_install_chrdev(mousedev);
 900        if (error)
 901                goto err_unregister_handle;
 902
 903        error = device_add(&mousedev->dev);
 904        if (error)
 905                goto err_cleanup_mousedev;
 906
 907        return mousedev;
 908
 909 err_cleanup_mousedev:
 910        mousedev_cleanup(mousedev);
 911 err_unregister_handle:
 912        if (minor != MOUSEDEV_MIX)
 913                input_unregister_handle(&mousedev->handle);
 914 err_free_mousedev:
 915        put_device(&mousedev->dev);
 916 err_out:
 917        return ERR_PTR(error);
 918}
 919
 920static void mousedev_destroy(struct mousedev *mousedev)
 921{
 922        device_del(&mousedev->dev);
 923        mousedev_cleanup(mousedev);
 924        if (mousedev->minor != MOUSEDEV_MIX)
 925                input_unregister_handle(&mousedev->handle);
 926        put_device(&mousedev->dev);
 927}
 928
 929static int mixdev_add_device(struct mousedev *mousedev)
 930{
 931        int retval;
 932
 933        retval = mutex_lock_interruptible(&mousedev_mix->mutex);
 934        if (retval)
 935                return retval;
 936
 937        if (mousedev_mix->open) {
 938                retval = mousedev_open_device(mousedev);
 939                if (retval)
 940                        goto out;
 941
 942                mousedev->mixdev_open = 1;
 943        }
 944
 945        get_device(&mousedev->dev);
 946        list_add_tail(&mousedev->mixdev_node, &mousedev_mix_list);
 947
 948 out:
 949        mutex_unlock(&mousedev_mix->mutex);
 950        return retval;
 951}
 952
 953static void mixdev_remove_device(struct mousedev *mousedev)
 954{
 955        mutex_lock(&mousedev_mix->mutex);
 956
 957        if (mousedev->mixdev_open) {
 958                mousedev->mixdev_open = 0;
 959                mousedev_close_device(mousedev);
 960        }
 961
 962        list_del_init(&mousedev->mixdev_node);
 963        mutex_unlock(&mousedev_mix->mutex);
 964
 965        put_device(&mousedev->dev);
 966}
 967
 968static int mousedev_connect(struct input_handler *handler,
 969                            struct input_dev *dev,
 970                            const struct input_device_id *id)
 971{
 972        struct mousedev *mousedev;
 973        int minor;
 974        int error;
 975
 976        for (minor = 0; minor < MOUSEDEV_MINORS; minor++)
 977                if (!mousedev_table[minor])
 978                        break;
 979
 980        if (minor == MOUSEDEV_MINORS) {
 981                pr_err("no more free mousedev devices\n");
 982                return -ENFILE;
 983        }
 984
 985        mousedev = mousedev_create(dev, handler, minor);
 986        if (IS_ERR(mousedev))
 987                return PTR_ERR(mousedev);
 988
 989        error = mixdev_add_device(mousedev);
 990        if (error) {
 991                mousedev_destroy(mousedev);
 992                return error;
 993        }
 994
 995        return 0;
 996}
 997
 998static void mousedev_disconnect(struct input_handle *handle)
 999{
1000        struct mousedev *mousedev = handle->private;
1001
1002        mixdev_remove_device(mousedev);
1003        mousedev_destroy(mousedev);
1004}
1005
1006static const struct input_device_id mousedev_ids[] = {
1007        {
1008                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1009                                INPUT_DEVICE_ID_MATCH_KEYBIT |
1010                                INPUT_DEVICE_ID_MATCH_RELBIT,
1011                .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1012                .keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1013                .relbit = { BIT_MASK(REL_X) | BIT_MASK(REL_Y) },
1014        },      /* A mouse like device, at least one button,
1015                   two relative axes */
1016        {
1017                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1018                                INPUT_DEVICE_ID_MATCH_RELBIT,
1019                .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_REL) },
1020                .relbit = { BIT_MASK(REL_WHEEL) },
1021        },      /* A separate scrollwheel */
1022        {
1023                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1024                                INPUT_DEVICE_ID_MATCH_KEYBIT |
1025                                INPUT_DEVICE_ID_MATCH_ABSBIT,
1026                .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1027                .keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
1028                .absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1029        },      /* A tablet like device, at least touch detection,
1030                   two absolute axes */
1031        {
1032                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1033                                INPUT_DEVICE_ID_MATCH_KEYBIT |
1034                                INPUT_DEVICE_ID_MATCH_ABSBIT,
1035                .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1036                .keybit = { [BIT_WORD(BTN_TOOL_FINGER)] =
1037                                BIT_MASK(BTN_TOOL_FINGER) },
1038                .absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) |
1039                                BIT_MASK(ABS_PRESSURE) |
1040                                BIT_MASK(ABS_TOOL_WIDTH) },
1041        },      /* A touchpad */
1042        {
1043                .flags = INPUT_DEVICE_ID_MATCH_EVBIT |
1044                        INPUT_DEVICE_ID_MATCH_KEYBIT |
1045                        INPUT_DEVICE_ID_MATCH_ABSBIT,
1046                .evbit = { BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS) },
1047                .keybit = { [BIT_WORD(BTN_LEFT)] = BIT_MASK(BTN_LEFT) },
1048                .absbit = { BIT_MASK(ABS_X) | BIT_MASK(ABS_Y) },
1049        },      /* Mouse-like device with absolute X and Y but ordinary
1050                   clicks, like hp ILO2 High Performance mouse */
1051
1052        { },    /* Terminating entry */
1053};
1054
1055MODULE_DEVICE_TABLE(input, mousedev_ids);
1056
1057static struct input_handler mousedev_handler = {
1058        .event =        mousedev_event,
1059        .connect =      mousedev_connect,
1060        .disconnect =   mousedev_disconnect,
1061        .fops =         &mousedev_fops,
1062        .minor =        MOUSEDEV_MINOR_BASE,
1063        .name =         "mousedev",
1064        .id_table =     mousedev_ids,
1065};
1066
1067#ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1068static struct miscdevice psaux_mouse = {
1069        PSMOUSE_MINOR, "psaux", &mousedev_fops
1070};
1071static int psaux_registered;
1072#endif
1073
1074static int __init mousedev_init(void)
1075{
1076        int error;
1077
1078        mousedev_mix = mousedev_create(NULL, &mousedev_handler, MOUSEDEV_MIX);
1079        if (IS_ERR(mousedev_mix))
1080                return PTR_ERR(mousedev_mix);
1081
1082        error = input_register_handler(&mousedev_handler);
1083        if (error) {
1084                mousedev_destroy(mousedev_mix);
1085                return error;
1086        }
1087
1088#ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1089        error = misc_register(&psaux_mouse);
1090        if (error)
1091                pr_warning("could not register psaux device, error: %d\n",
1092                           error);
1093        else
1094                psaux_registered = 1;
1095#endif
1096
1097        pr_info("PS/2 mouse device common for all mice\n");
1098
1099        return 0;
1100}
1101
1102static void __exit mousedev_exit(void)
1103{
1104#ifdef CONFIG_INPUT_MOUSEDEV_PSAUX
1105        if (psaux_registered)
1106                misc_deregister(&psaux_mouse);
1107#endif
1108        input_unregister_handler(&mousedev_handler);
1109        mousedev_destroy(mousedev_mix);
1110}
1111
1112module_init(mousedev_init);
1113module_exit(mousedev_exit);
1114
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