drivers/input/tsdev.c

   1 /*
   2  * $Id: tsdev.c,v 1.15 2002/04/10 16:50:19 jsimmons Exp $
   3  *
   4  *  Copyright (c) 2001 "Crazy" james Simmons
   5  *
   6  *  Compaq touchscreen protocol driver. The protocol emulated by this driver
   7  *  is obsolete; for new programs use the tslib library which can read directly
   8  *  from evdev and perform dejittering, variance filtering and calibration -
   9  *  all in user space, not at kernel level. The meaning of this driver is
  10  *  to allow usage of newer input drivers with old applications that use the
  11  *  old /dev/h3600_ts and /dev/h3600_tsraw devices.
  12  *
  13  *  09-Apr-2004: Andrew Zabolotny <zap@homelink.ru>
  14  *      Fixed to actually work, not just output random numbers.
  15  *      Added support for both h3600_ts and h3600_tsraw protocol
  16  *      emulation.
  17  */
  18
  19 /*
  20  * This program is free software; you can redistribute it and/or modify
  21  * it under the terms of the GNU General Public License as published by
  22  * the Free Software Foundation; either version 2 of the License, or
  23  * (at your option) any later version.
  24  *
  25  * This program is distributed in the hope that it will be useful,
  26  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  27  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28  * GNU General Public License for more details.
  29  *
  30  * You should have received a copy of the GNU General Public License
  31  * along with this program; if not, write to the Free Software
  32  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  33  *
  34  * Should you need to contact me, the author, you can do so either by
  35  * e-mail - mail your message to <jsimmons@infradead.org>.
  36  */
  37
  38 #define TSDEV_MINOR_BASE        128
  39 #define TSDEV_MINORS            32
  40 /* First 16 devices are h3600_ts compatible; second 16 are h3600_tsraw */
  41 #define TSDEV_MINOR_MASK        15
  42 #define TSDEV_BUFFER_SIZE       64
  43
  44 #include <linux/slab.h>
  45 #include <linux/poll.h>
  46 #include <linux/module.h>
  47 #include <linux/moduleparam.h>
  48 #include <linux/init.h>
  49 #include <linux/input.h>
  50 #include <linux/major.h>
  51 #include <linux/config.h>
  52 #include <linux/smp_lock.h>
  53 #include <linux/random.h>
  54 #include <linux/time.h>
  55 #include <linux/device.h>
  56
  57 #ifndef CONFIG_INPUT_TSDEV_SCREEN_X
  58 #define CONFIG_INPUT_TSDEV_SCREEN_X     240
  59 #endif
  60 #ifndef CONFIG_INPUT_TSDEV_SCREEN_Y
  61 #define CONFIG_INPUT_TSDEV_SCREEN_Y     320
  62 #endif
  63
  64 /* This driver emulates both protocols of the old h3600_ts and h3600_tsraw
  65  * devices. The first one must output X/Y data in 'cooked' format, e.g.
  66  * filtered, dejittered and calibrated. Second device just outputs raw
  67  * data received from the hardware.
  68  *
  69  * This driver doesn't support filtering and dejittering; it supports only
  70  * calibration. Filtering and dejittering must be done in the low-level
  71  * driver, if needed, because it may gain additional benefits from knowing
  72  * the low-level details, the nature of noise and so on.
  73  *
  74  * The driver precomputes a calibration matrix given the initial xres and
  75  * yres values (quite innacurate for most touchscreens) that will result
  76  * in a more or less expected range of output values. The driver supports
  77  * the TS_SET_CAL ioctl, which will replace the calibration matrix with a
  78  * new one, supposedly generated from the values taken from the raw device.
  79  */
  80
  81 MODULE_AUTHOR("James Simmons <jsimmons@transvirtual.com>");
  82 MODULE_DESCRIPTION("Input driver to touchscreen converter");
  83 MODULE_LICENSE("GPL");
  84
  85 static int xres = CONFIG_INPUT_TSDEV_SCREEN_X;
  86 module_param(xres, uint, 0);
  87 MODULE_PARM_DESC(xres, "Horizontal screen resolution (can be negative for X-mirror)");
  88
  89 static int yres = CONFIG_INPUT_TSDEV_SCREEN_Y;
  90 module_param(yres, uint, 0);
  91 MODULE_PARM_DESC(yres, "Vertical screen resolution (can be negative for Y-mirror)");
  92
  93 /* From Compaq's Touch Screen Specification version 0.2 (draft) */
  94 struct ts_event {
  95         short pressure;
  96         short x;
  97         short y;
  98         short millisecs;
  99 };
 100
 101 struct ts_calibration {
 102         int xscale;
 103         int xtrans;
 104         int yscale;
 105         int ytrans;
 106         int xyswap;
 107 };
 108
 109 struct tsdev {
 110         int exist;
 111         int open;
 112         int minor;
 113         char name[8];
 114         wait_queue_head_t wait;
 115         struct list_head list;
 116         struct input_handle handle;
 117         int x, y, pressure;
 118         struct ts_calibration cal;
 119 };
 120
 121 struct tsdev_list {
 122         struct fasync_struct *fasync;
 123         struct list_head node;
 124         struct tsdev *tsdev;
 125         int head, tail;
 126         struct ts_event event[TSDEV_BUFFER_SIZE];
 127         int raw;
 128 };
 129
 130 /* The following ioctl codes are defined ONLY for backward compatibility.
 131  * Don't use tsdev for new developement; use the tslib library instead.
 132  * Touchscreen calibration is a fully userspace task.
 133  */
 134 /* Use 'f' as magic number */
 135 #define IOC_H3600_TS_MAGIC  'f'
 136 #define TS_GET_CAL      _IOR(IOC_H3600_TS_MAGIC, 10, struct ts_calibration)
 137 #define TS_SET_CAL      _IOW(IOC_H3600_TS_MAGIC, 11, struct ts_calibration)
 138
 139 static struct input_handler tsdev_handler;
 140
 141 static struct tsdev *tsdev_table[TSDEV_MINORS/2];
 142
 143 static int tsdev_fasync(int fd, struct file *file, int on)
 144 {
 145         struct tsdev_list *list = file->private_data;
 146         int retval;
 147
 148         retval = fasync_helper(fd, file, on, &list->fasync);
 149         return retval < 0 ? retval : 0;
 150 }
 151
 152 static int tsdev_open(struct inode *inode, struct file *file)
 153 {
 154         int i = iminor(inode) - TSDEV_MINOR_BASE;
 155         struct tsdev_list *list;
 156
 157         if (i >= TSDEV_MINORS || !tsdev_table[i & TSDEV_MINOR_MASK])
 158                 return -ENODEV;
 159
 160         if (!(list = kzalloc(sizeof(struct tsdev_list), GFP_KERNEL)))
 161                 return -ENOMEM;
 162
 163         list->raw = (i >= TSDEV_MINORS/2) ? 1 : 0;
 164
 165         i &= TSDEV_MINOR_MASK;
 166         list->tsdev = tsdev_table[i];
 167         list_add_tail(&list->node, &tsdev_table[i]->list);
 168         file->private_data = list;
 169
 170         if (!list->tsdev->open++)
 171                 if (list->tsdev->exist)
 172                         input_open_device(&list->tsdev->handle);
 173         return 0;
 174 }
 175
 176 static void tsdev_free(struct tsdev *tsdev)
 177 {
 178         tsdev_table[tsdev->minor] = NULL;
 179         kfree(tsdev);
 180 }
 181
 182 static int tsdev_release(struct inode *inode, struct file *file)
 183 {
 184         struct tsdev_list *list = file->private_data;
 185
 186         tsdev_fasync(-1, file, 0);
 187         list_del(&list->node);
 188
 189         if (!--list->tsdev->open) {
 190                 if (list->tsdev->exist)
 191                         input_close_device(&list->tsdev->handle);
 192                 else
 193                         tsdev_free(list->tsdev);
 194         }
 195         kfree(list);
 196         return 0;
 197 }
 198
 199 static ssize_t tsdev_read(struct file *file, char __user *buffer, size_t count,
 200                           loff_t * ppos)
 201 {
 202         struct tsdev_list *list = file->private_data;
 203         int retval = 0;
 204
 205         if (list->head == list->tail && list->tsdev->exist && (file->f_flags & O_NONBLOCK))
 206                 return -EAGAIN;
 207
 208         retval = wait_event_interruptible(list->tsdev->wait,
 209                         list->head != list->tail || !list->tsdev->exist);
 210
 211         if (retval)
 212                 return retval;
 213
 214         if (!list->tsdev->exist)
 215                 return -ENODEV;
 216
 217         while (list->head != list->tail &&
 218                retval + sizeof (struct ts_event) <= count) {
 219                 if (copy_to_user (buffer + retval, list->event + list->tail,
 220                                   sizeof (struct ts_event)))
 221                         return -EFAULT;
 222                 list->tail = (list->tail + 1) & (TSDEV_BUFFER_SIZE - 1);
 223                 retval += sizeof (struct ts_event);
 224         }
 225
 226         return retval;
 227 }
 228
 229 /* No kernel lock - fine */
 230 static unsigned int tsdev_poll(struct file *file, poll_table * wait)
 231 {
 232         struct tsdev_list *list = file->private_data;
 233         poll_wait(file, &list->tsdev->wait, wait);
 234         return ((list->head == list->tail) ? 0 : (POLLIN | POLLRDNORM)) |
 235                 (list->tsdev->exist ? 0 : (POLLHUP | POLLERR));
 236 }
 237
 238 static int tsdev_ioctl(struct inode *inode, struct file *file,
 239                        unsigned int cmd, unsigned long arg)
 240 {
 241         struct tsdev_list *list = file->private_data;
 242         struct tsdev *tsdev = list->tsdev;
 243         int retval = 0;
 244
 245         switch (cmd) {
 246         case TS_GET_CAL:
 247                 if (copy_to_user ((void __user *)arg, &tsdev->cal,
 248                                   sizeof (struct ts_calibration)))
 249                         retval = -EFAULT;
 250                 break;
 251         case TS_SET_CAL:
 252                 if (copy_from_user (&tsdev->cal, (void __user *)arg,
 253                                     sizeof (struct ts_calibration)))
 254                         retval = -EFAULT;
 255                 break;
 256         default:
 257                 retval = -EINVAL;
 258                 break;
 259         }
 260
 261         return retval;
 262 }
 263
 264 static struct file_operations tsdev_fops = {
 265         .owner =        THIS_MODULE,
 266         .open =         tsdev_open,
 267         .release =      tsdev_release,
 268         .read =         tsdev_read,
 269         .poll =         tsdev_poll,
 270         .fasync =       tsdev_fasync,
 271         .ioctl =        tsdev_ioctl,
 272 };
 273
 274 static void tsdev_event(struct input_handle *handle, unsigned int type,
 275                         unsigned int code, int value)
 276 {
 277         struct tsdev *tsdev = handle->private;
 278         struct tsdev_list *list;
 279         struct timeval time;
 280
 281         switch (type) {
 282         case EV_ABS:
 283                 switch (code) {
 284                 case ABS_X:
 285                         tsdev->x = value;
 286                         break;
 287                 case ABS_Y:
 288                         tsdev->y = value;
 289                         break;
 290                 case ABS_PRESSURE:
 291                         if (value > handle->dev->absmax[ABS_PRESSURE])
 292                                 value = handle->dev->absmax[ABS_PRESSURE];
 293                         value -= handle->dev->absmin[ABS_PRESSURE];
 294                         if (value < 0)
 295                                 value = 0;
 296                         tsdev->pressure = value;
 297                         break;
 298                 }
 299                 break;
 300
 301         case EV_REL:
 302                 switch (code) {
 303                 case REL_X:
 304                         tsdev->x += value;
 305                         if (tsdev->x < 0)
 306                                 tsdev->x = 0;
 307                         else if (tsdev->x > xres)
 308                                 tsdev->x = xres;
 309                         break;
 310                 case REL_Y:
 311                         tsdev->y += value;
 312                         if (tsdev->y < 0)
 313                                 tsdev->y = 0;
 314                         else if (tsdev->y > yres)
 315                                 tsdev->y = yres;
 316                         break;
 317                 }
 318                 break;
 319
 320         case EV_KEY:
 321                 if (code == BTN_TOUCH || code == BTN_MOUSE) {
 322                         switch (value) {
 323                         case 0:
 324                                 tsdev->pressure = 0;
 325                                 break;
 326                         case 1:
 327                                 if (!tsdev->pressure)
 328                                         tsdev->pressure = 1;
 329                                 break;
 330                         }
 331                 }
 332                 break;
 333         }
 334
 335         if (type != EV_SYN || code != SYN_REPORT)
 336                 return;
 337
 338         list_for_each_entry(list, &tsdev->list, node) {
 339                 int x, y, tmp;
 340
 341                 do_gettimeofday(&time);
 342                 list->event[list->head].millisecs = time.tv_usec / 100;
 343                 list->event[list->head].pressure = tsdev->pressure;
 344
 345                 x = tsdev->x;
 346                 y = tsdev->y;
 347
 348                 /* Calibration */
 349                 if (!list->raw) {
 350                         x = ((x * tsdev->cal.xscale) >> 8) + tsdev->cal.xtrans;
 351                         y = ((y * tsdev->cal.yscale) >> 8) + tsdev->cal.ytrans;
 352                         if (tsdev->cal.xyswap) {
 353                                 tmp = x; x = y; y = tmp;
 354                         }
 355                 }
 356
 357                 list->event[list->head].x = x;
 358                 list->event[list->head].y = y;
 359                 list->head = (list->head + 1) & (TSDEV_BUFFER_SIZE - 1);
 360                 kill_fasync(&list->fasync, SIGIO, POLL_IN);
 361         }
 362         wake_up_interruptible(&tsdev->wait);
 363 }
 364
 365 static struct input_handle *tsdev_connect(struct input_handler *handler,
 366                                           struct input_dev *dev,
 367                                           struct input_device_id *id)
 368 {
 369         struct tsdev *tsdev;
 370         struct class_device *cdev;
 371         int minor, delta;
 372
 373         for (minor = 0; minor < TSDEV_MINORS/2 && tsdev_table[minor];
 374              minor++);
 375         if (minor >= TSDEV_MINORS/2) {
 376                 printk(KERN_ERR
 377                        "tsdev: You have way too many touchscreens\n");
 378                 return NULL;
 379         }
 380
 381         if (!(tsdev = kzalloc(sizeof(struct tsdev), GFP_KERNEL)))
 382                 return NULL;
 383
 384         INIT_LIST_HEAD(&tsdev->list);
 385         init_waitqueue_head(&tsdev->wait);
 386
 387         sprintf(tsdev->name, "ts%d", minor);
 388
 389         tsdev->exist = 1;
 390         tsdev->minor = minor;
 391         tsdev->handle.dev = dev;
 392         tsdev->handle.name = tsdev->name;
 393         tsdev->handle.handler = handler;
 394         tsdev->handle.private = tsdev;
 395
 396         /* Precompute the rough calibration matrix */
 397         delta = dev->absmax [ABS_X] - dev->absmin [ABS_X] + 1;
 398         if (delta == 0)
 399                 delta = 1;
 400         tsdev->cal.xscale = (xres << 8) / delta;
 401         tsdev->cal.xtrans = - ((dev->absmin [ABS_X] * tsdev->cal.xscale) >> 8);
 402
 403         delta = dev->absmax [ABS_Y] - dev->absmin [ABS_Y] + 1;
 404         if (delta == 0)
 405                 delta = 1;
 406         tsdev->cal.yscale = (yres << 8) / delta;
 407         tsdev->cal.ytrans = - ((dev->absmin [ABS_Y] * tsdev->cal.yscale) >> 8);
 408
 409         tsdev_table[minor] = tsdev;
 410
 411         cdev = class_device_create(&input_class, &dev->cdev,
 412                         MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + minor),
 413                         dev->cdev.dev, tsdev->name);
 414
 415         /* temporary symlink to keep userspace happy */
 416         sysfs_create_link(&input_class.subsys.kset.kobj, &cdev->kobj,
 417                           tsdev->name);
 418
 419         return &tsdev->handle;
 420 }
 421
 422 static void tsdev_disconnect(struct input_handle *handle)
 423 {
 424         struct tsdev *tsdev = handle->private;
 425         struct tsdev_list *list;
 426
 427         sysfs_remove_link(&input_class.subsys.kset.kobj, tsdev->name);
 428         class_device_destroy(&input_class,
 429                         MKDEV(INPUT_MAJOR, TSDEV_MINOR_BASE + tsdev->minor));
 430         tsdev->exist = 0;
 431
 432         if (tsdev->open) {
 433                 input_close_device(handle);
 434                 wake_up_interruptible(&tsdev->wait);
 435                 list_for_each_entry(list, &tsdev->list, node)
 436                         kill_fasync(&list->fasync, SIGIO, POLL_HUP);
 437         } else
 438                 tsdev_free(tsdev);
 439 }
 440
 441 static struct input_device_id tsdev_ids[] = {
 442         {
 443               .flags    = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_RELBIT,
 444               .evbit    = { BIT(EV_KEY) | BIT(EV_REL) },
 445               .keybit   = { [LONG(BTN_LEFT)] = BIT(BTN_LEFT) },
 446               .relbit   = { BIT(REL_X) | BIT(REL_Y) },
 447          },/* A mouse like device, at least one button, two relative axes */
 448
 449         {
 450               .flags    = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_KEYBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
 451               .evbit    = { BIT(EV_KEY) | BIT(EV_ABS) },
 452               .keybit   = { [LONG(BTN_TOUCH)] = BIT(BTN_TOUCH) },
 453               .absbit   = { BIT(ABS_X) | BIT(ABS_Y) },
 454          },/* A tablet like device, at least touch detection, two absolute axes */
 455
 456         {
 457               .flags    = INPUT_DEVICE_ID_MATCH_EVBIT | INPUT_DEVICE_ID_MATCH_ABSBIT,
 458               .evbit    = { BIT(EV_ABS) },
 459               .absbit   = { BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_PRESSURE) },
 460          },/* A tablet like device with several gradations of pressure */
 461
 462         {},/* Terminating entry */
 463 };
 464
 465 MODULE_DEVICE_TABLE(input, tsdev_ids);
 466
 467 static struct input_handler tsdev_handler = {
 468         .event =        tsdev_event,
 469         .connect =      tsdev_connect,
 470         .disconnect =   tsdev_disconnect,
 471         .fops =         &tsdev_fops,
 472         .minor =        TSDEV_MINOR_BASE,
 473         .name =         "tsdev",
 474         .id_table =     tsdev_ids,
 475 };
 476
 477 static int __init tsdev_init(void)
 478 {
 479         input_register_handler(&tsdev_handler);
 480         printk(KERN_INFO "ts: Compaq touchscreen protocol output\n");
 481         return 0;
 482 }
 483
 484 static void __exit tsdev_exit(void)
 485 {
 486         input_unregister_handler(&tsdev_handler);
 487 }
 488
 489 module_init(tsdev_init);
 490 module_exit(tsdev_exit);