drivers/platform/x86/hdaps.c

   1 /*
   2  * hdaps.c - driver for IBM's Hard Drive Active Protection System
   3  *
   4  * Copyright (C) 2005 Robert Love <rml@novell.com>
   5  * Copyright (C) 2005 Jesper Juhl <jj@chaosbits.net>
   6  *
   7  * The HardDisk Active Protection System (hdaps) is present in IBM ThinkPads
   8  * starting with the R40, T41, and X40.  It provides a basic two-axis
   9  * accelerometer and other data, such as the device's temperature.
  10  *
  11  * This driver is based on the document by Mark A. Smith available at
  12  * http://www.almaden.ibm.com/cs/people/marksmith/tpaps.html and a lot of trial
  13  * and error.
  14  *
  15  * This program is free software; you can redistribute it and/or modify it
  16  * under the terms of the GNU General Public License v2 as published by the
  17  * Free Software Foundation.
  18  *
  19  * This program is distributed in the hope that it will be useful, but WITHOUT
  20  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  21  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  22  * more details.
  23  *
  24  * You should have received a copy of the GNU General Public License along with
  25  * this program; if not, write to the Free Software Foundation, Inc.,
  26  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  27  */
  28
  29 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  30
  31 #include <linux/delay.h>
  32 #include <linux/platform_device.h>
  33 #include <linux/input-polldev.h>
  34 #include <linux/kernel.h>
  35 #include <linux/mutex.h>
  36 #include <linux/module.h>
  37 #include <linux/timer.h>
  38 #include <linux/dmi.h>
  39 #include <linux/jiffies.h>
  40 #include <linux/io.h>
  41
  42 #define HDAPS_LOW_PORT          0x1600  /* first port used by hdaps */
  43 #define HDAPS_NR_PORTS          0x30    /* number of ports: 0x1600 - 0x162f */
  44
  45 #define HDAPS_PORT_STATE        0x1611  /* device state */
  46 #define HDAPS_PORT_YPOS         0x1612  /* y-axis position */
  47 #define HDAPS_PORT_XPOS         0x1614  /* x-axis position */
  48 #define HDAPS_PORT_TEMP1        0x1616  /* device temperature, in Celsius */
  49 #define HDAPS_PORT_YVAR         0x1617  /* y-axis variance (what is this?) */
  50 #define HDAPS_PORT_XVAR         0x1619  /* x-axis variance (what is this?) */
  51 #define HDAPS_PORT_TEMP2        0x161b  /* device temperature (again?) */
  52 #define HDAPS_PORT_UNKNOWN      0x161c  /* what is this? */
  53 #define HDAPS_PORT_KMACT        0x161d  /* keyboard or mouse activity */
  54
  55 #define STATE_FRESH             0x50    /* accelerometer data is fresh */
  56
  57 #define KEYBD_MASK              0x20    /* set if keyboard activity */
  58 #define MOUSE_MASK              0x40    /* set if mouse activity */
  59 #define KEYBD_ISSET(n)          (!! (n & KEYBD_MASK))   /* keyboard used? */
  60 #define MOUSE_ISSET(n)          (!! (n & MOUSE_MASK))   /* mouse used? */
  61
  62 #define INIT_TIMEOUT_MSECS      4000    /* wait up to 4s for device init ... */
  63 #define INIT_WAIT_MSECS         200     /* ... in 200ms increments */
  64
  65 #define HDAPS_POLL_INTERVAL     50      /* poll for input every 1/20s (50 ms)*/
  66 #define HDAPS_INPUT_FUZZ        4       /* input event threshold */
  67 #define HDAPS_INPUT_FLAT        4
  68
  69 #define HDAPS_X_AXIS            (1 << 0)
  70 #define HDAPS_Y_AXIS            (1 << 1)
  71 #define HDAPS_BOTH_AXES         (HDAPS_X_AXIS | HDAPS_Y_AXIS)
  72
  73 static struct platform_device *pdev;
  74 static struct input_polled_dev *hdaps_idev;
  75 static unsigned int hdaps_invert;
  76 static u8 km_activity;
  77 static int rest_x;
  78 static int rest_y;
  79
  80 static DEFINE_MUTEX(hdaps_mtx);
  81
  82 /*
  83  * __get_latch - Get the value from a given port.  Callers must hold hdaps_mtx.
  84  */
  85 static inline u8 __get_latch(u16 port)
  86 {
  87         return inb(port) & 0xff;
  88 }
  89
  90 /*
  91  * __check_latch - Check a port latch for a given value.  Returns zero if the
  92  * port contains the given value.  Callers must hold hdaps_mtx.
  93  */
  94 static inline int __check_latch(u16 port, u8 val)
  95 {
  96         if (__get_latch(port) == val)
  97                 return 0;
  98         return -EINVAL;
  99 }
 100
 101 /*
 102  * __wait_latch - Wait up to 100us for a port latch to get a certain value,
 103  * returning zero if the value is obtained.  Callers must hold hdaps_mtx.
 104  */
 105 static int __wait_latch(u16 port, u8 val)
 106 {
 107         unsigned int i;
 108
 109         for (i = 0; i < 20; i++) {
 110                 if (!__check_latch(port, val))
 111                         return 0;
 112                 udelay(5);
 113         }
 114
 115         return -EIO;
 116 }
 117
 118 /*
 119  * __device_refresh - request a refresh from the accelerometer.  Does not wait
 120  * for refresh to complete.  Callers must hold hdaps_mtx.
 121  */
 122 static void __device_refresh(void)
 123 {
 124         udelay(200);
 125         if (inb(0x1604) != STATE_FRESH) {
 126                 outb(0x11, 0x1610);
 127                 outb(0x01, 0x161f);
 128         }
 129 }
 130
 131 /*
 132  * __device_refresh_sync - request a synchronous refresh from the
 133  * accelerometer.  We wait for the refresh to complete.  Returns zero if
 134  * successful and nonzero on error.  Callers must hold hdaps_mtx.
 135  */
 136 static int __device_refresh_sync(void)
 137 {
 138         __device_refresh();
 139         return __wait_latch(0x1604, STATE_FRESH);
 140 }
 141
 142 /*
 143  * __device_complete - indicate to the accelerometer that we are done reading
 144  * data, and then initiate an async refresh.  Callers must hold hdaps_mtx.
 145  */
 146 static inline void __device_complete(void)
 147 {
 148         inb(0x161f);
 149         inb(0x1604);
 150         __device_refresh();
 151 }
 152
 153 /*
 154  * hdaps_readb_one - reads a byte from a single I/O port, placing the value in
 155  * the given pointer.  Returns zero on success or a negative error on failure.
 156  * Can sleep.
 157  */
 158 static int hdaps_readb_one(unsigned int port, u8 *val)
 159 {
 160         int ret;
 161
 162         mutex_lock(&hdaps_mtx);
 163
 164         /* do a sync refresh -- we need to be sure that we read fresh data */
 165         ret = __device_refresh_sync();
 166         if (ret)
 167                 goto out;
 168
 169         *val = inb(port);
 170         __device_complete();
 171
 172 out:
 173         mutex_unlock(&hdaps_mtx);
 174         return ret;
 175 }
 176
 177 /* __hdaps_read_pair - internal lockless helper for hdaps_read_pair(). */
 178 static int __hdaps_read_pair(unsigned int port1, unsigned int port2,
 179                              int *x, int *y)
 180 {
 181         /* do a sync refresh -- we need to be sure that we read fresh data */
 182         if (__device_refresh_sync())
 183                 return -EIO;
 184
 185         *y = inw(port2);
 186         *x = inw(port1);
 187         km_activity = inb(HDAPS_PORT_KMACT);
 188         __device_complete();
 189
 190         /* hdaps_invert is a bitvector to negate the axes */
 191         if (hdaps_invert & HDAPS_X_AXIS)
 192                 *x = -*x;
 193         if (hdaps_invert & HDAPS_Y_AXIS)
 194                 *y = -*y;
 195
 196         return 0;
 197 }
 198
 199 /*
 200  * hdaps_read_pair - reads the values from a pair of ports, placing the values
 201  * in the given pointers.  Returns zero on success.  Can sleep.
 202  */
 203 static int hdaps_read_pair(unsigned int port1, unsigned int port2,
 204                            int *val1, int *val2)
 205 {
 206         int ret;
 207
 208         mutex_lock(&hdaps_mtx);
 209         ret = __hdaps_read_pair(port1, port2, val1, val2);
 210         mutex_unlock(&hdaps_mtx);
 211
 212         return ret;
 213 }
 214
 215 /*
 216  * hdaps_device_init - initialize the accelerometer.  Returns zero on success
 217  * and negative error code on failure.  Can sleep.
 218  */
 219 static int hdaps_device_init(void)
 220 {
 221         int total, ret = -ENXIO;
 222
 223         mutex_lock(&hdaps_mtx);
 224
 225         outb(0x13, 0x1610);
 226         outb(0x01, 0x161f);
 227         if (__wait_latch(0x161f, 0x00))
 228                 goto out;
 229
 230         /*
 231          * Most ThinkPads return 0x01.
 232          *
 233          * Others--namely the R50p, T41p, and T42p--return 0x03.  These laptops
 234          * have "inverted" axises.
 235          *
 236          * The 0x02 value occurs when the chip has been previously initialized.
 237          */
 238         if (__check_latch(0x1611, 0x03) &&
 239                      __check_latch(0x1611, 0x02) &&
 240                      __check_latch(0x1611, 0x01))
 241                 goto out;
 242
 243         printk(KERN_DEBUG "hdaps: initial latch check good (0x%02x)\n",
 244                __get_latch(0x1611));
 245
 246         outb(0x17, 0x1610);
 247         outb(0x81, 0x1611);
 248         outb(0x01, 0x161f);
 249         if (__wait_latch(0x161f, 0x00))
 250                 goto out;
 251         if (__wait_latch(0x1611, 0x00))
 252                 goto out;
 253         if (__wait_latch(0x1612, 0x60))
 254                 goto out;
 255         if (__wait_latch(0x1613, 0x00))
 256                 goto out;
 257         outb(0x14, 0x1610);
 258         outb(0x01, 0x1611);
 259         outb(0x01, 0x161f);
 260         if (__wait_latch(0x161f, 0x00))
 261                 goto out;
 262         outb(0x10, 0x1610);
 263         outb(0xc8, 0x1611);
 264         outb(0x00, 0x1612);
 265         outb(0x02, 0x1613);
 266         outb(0x01, 0x161f);
 267         if (__wait_latch(0x161f, 0x00))
 268                 goto out;
 269         if (__device_refresh_sync())
 270                 goto out;
 271         if (__wait_latch(0x1611, 0x00))
 272                 goto out;
 273
 274         /* we have done our dance, now let's wait for the applause */
 275         for (total = INIT_TIMEOUT_MSECS; total > 0; total -= INIT_WAIT_MSECS) {
 276                 int x, y;
 277
 278                 /* a read of the device helps push it into action */
 279                 __hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
 280                 if (!__wait_latch(0x1611, 0x02)) {
 281                         ret = 0;
 282                         break;
 283                 }
 284
 285                 msleep(INIT_WAIT_MSECS);
 286         }
 287
 288 out:
 289         mutex_unlock(&hdaps_mtx);
 290         return ret;
 291 }
 292
 293
 294 /* Device model stuff */
 295
 296 static int hdaps_probe(struct platform_device *dev)
 297 {
 298         int ret;
 299
 300         ret = hdaps_device_init();
 301         if (ret)
 302                 return ret;
 303
 304         pr_info("device successfully initialized\n");
 305         return 0;
 306 }
 307
 308 #ifdef CONFIG_PM_SLEEP
 309 static int hdaps_resume(struct device *dev)
 310 {
 311         return hdaps_device_init();
 312 }
 313 #endif
 314
 315 static SIMPLE_DEV_PM_OPS(hdaps_pm, NULL, hdaps_resume);
 316
 317 static struct platform_driver hdaps_driver = {
 318         .probe = hdaps_probe,
 319         .driver = {
 320                 .name = "hdaps",
 321                 .owner = THIS_MODULE,
 322                 .pm = &hdaps_pm,
 323         },
 324 };
 325
 326 /*
 327  * hdaps_calibrate - Set our "resting" values.  Callers must hold hdaps_mtx.
 328  */
 329 static void hdaps_calibrate(void)
 330 {
 331         __hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &rest_x, &rest_y);
 332 }
 333
 334 static void hdaps_mousedev_poll(struct input_polled_dev *dev)
 335 {
 336         struct input_dev *input_dev = dev->input;
 337         int x, y;
 338
 339         mutex_lock(&hdaps_mtx);
 340
 341         if (__hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y))
 342                 goto out;
 343
 344         input_report_abs(input_dev, ABS_X, x - rest_x);
 345         input_report_abs(input_dev, ABS_Y, y - rest_y);
 346         input_sync(input_dev);
 347
 348 out:
 349         mutex_unlock(&hdaps_mtx);
 350 }
 351
 352
 353 /* Sysfs Files */
 354
 355 static ssize_t hdaps_position_show(struct device *dev,
 356                                    struct device_attribute *attr, char *buf)
 357 {
 358         int ret, x, y;
 359
 360         ret = hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
 361         if (ret)
 362                 return ret;
 363
 364         return sprintf(buf, "(%d,%d)\n", x, y);
 365 }
 366
 367 static ssize_t hdaps_variance_show(struct device *dev,
 368                                    struct device_attribute *attr, char *buf)
 369 {
 370         int ret, x, y;
 371
 372         ret = hdaps_read_pair(HDAPS_PORT_XVAR, HDAPS_PORT_YVAR, &x, &y);
 373         if (ret)
 374                 return ret;
 375
 376         return sprintf(buf, "(%d,%d)\n", x, y);
 377 }
 378
 379 static ssize_t hdaps_temp1_show(struct device *dev,
 380                                 struct device_attribute *attr, char *buf)
 381 {
 382         u8 uninitialized_var(temp);
 383         int ret;
 384
 385         ret = hdaps_readb_one(HDAPS_PORT_TEMP1, &temp);
 386         if (ret)
 387                 return ret;
 388
 389         return sprintf(buf, "%u\n", temp);
 390 }
 391
 392 static ssize_t hdaps_temp2_show(struct device *dev,
 393                                 struct device_attribute *attr, char *buf)
 394 {
 395         u8 uninitialized_var(temp);
 396         int ret;
 397
 398         ret = hdaps_readb_one(HDAPS_PORT_TEMP2, &temp);
 399         if (ret)
 400                 return ret;
 401
 402         return sprintf(buf, "%u\n", temp);
 403 }
 404
 405 static ssize_t hdaps_keyboard_activity_show(struct device *dev,
 406                                             struct device_attribute *attr,
 407                                             char *buf)
 408 {
 409         return sprintf(buf, "%u\n", KEYBD_ISSET(km_activity));
 410 }
 411
 412 static ssize_t hdaps_mouse_activity_show(struct device *dev,
 413                                          struct device_attribute *attr,
 414                                          char *buf)
 415 {
 416         return sprintf(buf, "%u\n", MOUSE_ISSET(km_activity));
 417 }
 418
 419 static ssize_t hdaps_calibrate_show(struct device *dev,
 420                                     struct device_attribute *attr, char *buf)
 421 {
 422         return sprintf(buf, "(%d,%d)\n", rest_x, rest_y);
 423 }
 424
 425 static ssize_t hdaps_calibrate_store(struct device *dev,
 426                                      struct device_attribute *attr,
 427                                      const char *buf, size_t count)
 428 {
 429         mutex_lock(&hdaps_mtx);
 430         hdaps_calibrate();
 431         mutex_unlock(&hdaps_mtx);
 432
 433         return count;
 434 }
 435
 436 static ssize_t hdaps_invert_show(struct device *dev,
 437                                  struct device_attribute *attr, char *buf)
 438 {
 439         return sprintf(buf, "%u\n", hdaps_invert);
 440 }
 441
 442 static ssize_t hdaps_invert_store(struct device *dev,
 443                                   struct device_attribute *attr,
 444                                   const char *buf, size_t count)
 445 {
 446         int invert;
 447
 448         if (sscanf(buf, "%d", &invert) != 1 ||
 449             invert < 0 || invert > HDAPS_BOTH_AXES)
 450                 return -EINVAL;
 451
 452         hdaps_invert = invert;
 453         hdaps_calibrate();
 454
 455         return count;
 456 }
 457
 458 static DEVICE_ATTR(position, 0444, hdaps_position_show, NULL);
 459 static DEVICE_ATTR(variance, 0444, hdaps_variance_show, NULL);
 460 static DEVICE_ATTR(temp1, 0444, hdaps_temp1_show, NULL);
 461 static DEVICE_ATTR(temp2, 0444, hdaps_temp2_show, NULL);
 462 static DEVICE_ATTR(keyboard_activity, 0444, hdaps_keyboard_activity_show, NULL);
 463 static DEVICE_ATTR(mouse_activity, 0444, hdaps_mouse_activity_show, NULL);
 464 static DEVICE_ATTR(calibrate, 0644, hdaps_calibrate_show,hdaps_calibrate_store);
 465 static DEVICE_ATTR(invert, 0644, hdaps_invert_show, hdaps_invert_store);
 466
 467 static struct attribute *hdaps_attributes[] = {
 468         &dev_attr_position.attr,
 469         &dev_attr_variance.attr,
 470         &dev_attr_temp1.attr,
 471         &dev_attr_temp2.attr,
 472         &dev_attr_keyboard_activity.attr,
 473         &dev_attr_mouse_activity.attr,
 474         &dev_attr_calibrate.attr,
 475         &dev_attr_invert.attr,
 476         NULL,
 477 };
 478
 479 static struct attribute_group hdaps_attribute_group = {
 480         .attrs = hdaps_attributes,
 481 };
 482
 483
 484 /* Module stuff */
 485
 486 /* hdaps_dmi_match - found a match.  return one, short-circuiting the hunt. */
 487 static int __init hdaps_dmi_match(const struct dmi_system_id *id)
 488 {
 489         pr_info("%s detected\n", id->ident);
 490         return 1;
 491 }
 492
 493 /* hdaps_dmi_match_invert - found an inverted match. */
 494 static int __init hdaps_dmi_match_invert(const struct dmi_system_id *id)
 495 {
 496         hdaps_invert = (unsigned long)id->driver_data;
 497         pr_info("inverting axis (%u) readings\n", hdaps_invert);
 498         return hdaps_dmi_match(id);
 499 }
 500
 501 #define HDAPS_DMI_MATCH_INVERT(vendor, model, axes) {   \
 502         .ident = vendor " " model,                      \
 503         .callback = hdaps_dmi_match_invert,             \
 504         .driver_data = (void *)axes,                    \
 505         .matches = {                                    \
 506                 DMI_MATCH(DMI_BOARD_VENDOR, vendor),    \
 507                 DMI_MATCH(DMI_PRODUCT_VERSION, model)   \
 508         }                                               \
 509 }
 510
 511 #define HDAPS_DMI_MATCH_NORMAL(vendor, model)           \
 512         HDAPS_DMI_MATCH_INVERT(vendor, model, 0)
 513
 514 /* Note that HDAPS_DMI_MATCH_NORMAL("ThinkPad T42") would match
 515    "ThinkPad T42p", so the order of the entries matters.
 516    If your ThinkPad is not recognized, please update to latest
 517    BIOS. This is especially the case for some R52 ThinkPads. */
 518 static struct dmi_system_id __initdata hdaps_whitelist[] = {
 519         HDAPS_DMI_MATCH_INVERT("IBM", "ThinkPad R50p", HDAPS_BOTH_AXES),
 520         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad R50"),
 521         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad R51"),
 522         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad R52"),
 523         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad R61i", HDAPS_BOTH_AXES),
 524         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad R61", HDAPS_BOTH_AXES),
 525         HDAPS_DMI_MATCH_INVERT("IBM", "ThinkPad T41p", HDAPS_BOTH_AXES),
 526         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad T41"),
 527         HDAPS_DMI_MATCH_INVERT("IBM", "ThinkPad T42p", HDAPS_BOTH_AXES),
 528         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad T42"),
 529         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad T43"),
 530         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad T400", HDAPS_BOTH_AXES),
 531         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad T60", HDAPS_BOTH_AXES),
 532         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad T61p", HDAPS_BOTH_AXES),
 533         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad T61", HDAPS_BOTH_AXES),
 534         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad X40"),
 535         HDAPS_DMI_MATCH_INVERT("IBM", "ThinkPad X41", HDAPS_Y_AXIS),
 536         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad X60", HDAPS_BOTH_AXES),
 537         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad X61s", HDAPS_BOTH_AXES),
 538         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad X61", HDAPS_BOTH_AXES),
 539         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad Z60m"),
 540         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad Z61m", HDAPS_BOTH_AXES),
 541         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad Z61p", HDAPS_BOTH_AXES),
 542         { .ident = NULL }
 543 };
 544
 545 static int __init hdaps_init(void)
 546 {
 547         struct input_dev *idev;
 548         int ret;
 549
 550         if (!dmi_check_system(hdaps_whitelist)) {
 551                 pr_warn("supported laptop not found!\n");
 552                 ret = -ENODEV;
 553                 goto out;
 554         }
 555
 556         if (!request_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS, "hdaps")) {
 557                 ret = -ENXIO;
 558                 goto out;
 559         }
 560
 561         ret = platform_driver_register(&hdaps_driver);
 562         if (ret)
 563                 goto out_region;
 564
 565         pdev = platform_device_register_simple("hdaps", -1, NULL, 0);
 566         if (IS_ERR(pdev)) {
 567                 ret = PTR_ERR(pdev);
 568                 goto out_driver;
 569         }
 570
 571         ret = sysfs_create_group(&pdev->dev.kobj, &hdaps_attribute_group);
 572         if (ret)
 573                 goto out_device;
 574
 575         hdaps_idev = input_allocate_polled_device();
 576         if (!hdaps_idev) {
 577                 ret = -ENOMEM;
 578                 goto out_group;
 579         }
 580
 581         hdaps_idev->poll = hdaps_mousedev_poll;
 582         hdaps_idev->poll_interval = HDAPS_POLL_INTERVAL;
 583
 584         /* initial calibrate for the input device */
 585         hdaps_calibrate();
 586
 587         /* initialize the input class */
 588         idev = hdaps_idev->input;
 589         idev->name = "hdaps";
 590         idev->phys = "isa1600/input0";
 591         idev->id.bustype = BUS_ISA;
 592         idev->dev.parent = &pdev->dev;
 593         idev->evbit[0] = BIT_MASK(EV_ABS);
 594         input_set_abs_params(idev, ABS_X,
 595                         -256, 256, HDAPS_INPUT_FUZZ, HDAPS_INPUT_FLAT);
 596         input_set_abs_params(idev, ABS_Y,
 597                         -256, 256, HDAPS_INPUT_FUZZ, HDAPS_INPUT_FLAT);
 598
 599         ret = input_register_polled_device(hdaps_idev);
 600         if (ret)
 601                 goto out_idev;
 602
 603         pr_info("driver successfully loaded\n");
 604         return 0;
 605
 606 out_idev:
 607         input_free_polled_device(hdaps_idev);
 608 out_group:
 609         sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);
 610 out_device:
 611         platform_device_unregister(pdev);
 612 out_driver:
 613         platform_driver_unregister(&hdaps_driver);
 614 out_region:
 615         release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);
 616 out:
 617         pr_warn("driver init failed (ret=%d)!\n", ret);
 618         return ret;
 619 }
 620
 621 static void __exit hdaps_exit(void)
 622 {
 623         input_unregister_polled_device(hdaps_idev);
 624         input_free_polled_device(hdaps_idev);
 625         sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);
 626         platform_device_unregister(pdev);
 627         platform_driver_unregister(&hdaps_driver);
 628         release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);
 629
 630         pr_info("driver unloaded\n");
 631 }
 632
 633 module_init(hdaps_init);
 634 module_exit(hdaps_exit);
 635
 636 module_param_named(invert, hdaps_invert, int, 0);
 637 MODULE_PARM_DESC(invert, "invert data along each axis. 1 invert x-axis, "
 638                  "2 invert y-axis, 3 invert both axes.");
 639
 640 MODULE_AUTHOR("Robert Love");
 641 MODULE_DESCRIPTION("IBM Hard Drive Active Protection System (HDAPS) driver");
 642 MODULE_LICENSE("GPL v2");