kernel/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                 .pm = &hdaps_pm,
 322         },
 323 };
 324
 325 /*
 326  * hdaps_calibrate - Set our "resting" values.  Callers must hold hdaps_mtx.
 327  */
 328 static void hdaps_calibrate(void)
 329 {
 330         __hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &rest_x, &rest_y);
 331 }
 332
 333 static void hdaps_mousedev_poll(struct input_polled_dev *dev)
 334 {
 335         struct input_dev *input_dev = dev->input;
 336         int x, y;
 337
 338         mutex_lock(&hdaps_mtx);
 339
 340         if (__hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y))
 341                 goto out;
 342
 343         input_report_abs(input_dev, ABS_X, x - rest_x);
 344         input_report_abs(input_dev, ABS_Y, y - rest_y);
 345         input_sync(input_dev);
 346
 347 out:
 348         mutex_unlock(&hdaps_mtx);
 349 }
 350
 351
 352 /* Sysfs Files */
 353
 354 static ssize_t hdaps_position_show(struct device *dev,
 355                                    struct device_attribute *attr, char *buf)
 356 {
 357         int ret, x, y;
 358
 359         ret = hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
 360         if (ret)
 361                 return ret;
 362
 363         return sprintf(buf, "(%d,%d)\n", x, y);
 364 }
 365
 366 static ssize_t hdaps_variance_show(struct device *dev,
 367                                    struct device_attribute *attr, char *buf)
 368 {
 369         int ret, x, y;
 370
 371         ret = hdaps_read_pair(HDAPS_PORT_XVAR, HDAPS_PORT_YVAR, &x, &y);
 372         if (ret)
 373                 return ret;
 374
 375         return sprintf(buf, "(%d,%d)\n", x, y);
 376 }
 377
 378 static ssize_t hdaps_temp1_show(struct device *dev,
 379                                 struct device_attribute *attr, char *buf)
 380 {
 381         u8 uninitialized_var(temp);
 382         int ret;
 383
 384         ret = hdaps_readb_one(HDAPS_PORT_TEMP1, &temp);
 385         if (ret)
 386                 return ret;
 387
 388         return sprintf(buf, "%u\n", temp);
 389 }
 390
 391 static ssize_t hdaps_temp2_show(struct device *dev,
 392                                 struct device_attribute *attr, char *buf)
 393 {
 394         u8 uninitialized_var(temp);
 395         int ret;
 396
 397         ret = hdaps_readb_one(HDAPS_PORT_TEMP2, &temp);
 398         if (ret)
 399                 return ret;
 400
 401         return sprintf(buf, "%u\n", temp);
 402 }
 403
 404 static ssize_t hdaps_keyboard_activity_show(struct device *dev,
 405                                             struct device_attribute *attr,
 406                                             char *buf)
 407 {
 408         return sprintf(buf, "%u\n", KEYBD_ISSET(km_activity));
 409 }
 410
 411 static ssize_t hdaps_mouse_activity_show(struct device *dev,
 412                                          struct device_attribute *attr,
 413                                          char *buf)
 414 {
 415         return sprintf(buf, "%u\n", MOUSE_ISSET(km_activity));
 416 }
 417
 418 static ssize_t hdaps_calibrate_show(struct device *dev,
 419                                     struct device_attribute *attr, char *buf)
 420 {
 421         return sprintf(buf, "(%d,%d)\n", rest_x, rest_y);
 422 }
 423
 424 static ssize_t hdaps_calibrate_store(struct device *dev,
 425                                      struct device_attribute *attr,
 426                                      const char *buf, size_t count)
 427 {
 428         mutex_lock(&hdaps_mtx);
 429         hdaps_calibrate();
 430         mutex_unlock(&hdaps_mtx);
 431
 432         return count;
 433 }
 434
 435 static ssize_t hdaps_invert_show(struct device *dev,
 436                                  struct device_attribute *attr, char *buf)
 437 {
 438         return sprintf(buf, "%u\n", hdaps_invert);
 439 }
 440
 441 static ssize_t hdaps_invert_store(struct device *dev,
 442                                   struct device_attribute *attr,
 443                                   const char *buf, size_t count)
 444 {
 445         int invert;
 446
 447         if (sscanf(buf, "%d", &invert) != 1 ||
 448             invert < 0 || invert > HDAPS_BOTH_AXES)
 449                 return -EINVAL;
 450
 451         hdaps_invert = invert;
 452         hdaps_calibrate();
 453
 454         return count;
 455 }
 456
 457 static DEVICE_ATTR(position, 0444, hdaps_position_show, NULL);
 458 static DEVICE_ATTR(variance, 0444, hdaps_variance_show, NULL);
 459 static DEVICE_ATTR(temp1, 0444, hdaps_temp1_show, NULL);
 460 static DEVICE_ATTR(temp2, 0444, hdaps_temp2_show, NULL);
 461 static DEVICE_ATTR(keyboard_activity, 0444, hdaps_keyboard_activity_show, NULL);
 462 static DEVICE_ATTR(mouse_activity, 0444, hdaps_mouse_activity_show, NULL);
 463 static DEVICE_ATTR(calibrate, 0644, hdaps_calibrate_show,hdaps_calibrate_store);
 464 static DEVICE_ATTR(invert, 0644, hdaps_invert_show, hdaps_invert_store);
 465
 466 static struct attribute *hdaps_attributes[] = {
 467         &dev_attr_position.attr,
 468         &dev_attr_variance.attr,
 469         &dev_attr_temp1.attr,
 470         &dev_attr_temp2.attr,
 471         &dev_attr_keyboard_activity.attr,
 472         &dev_attr_mouse_activity.attr,
 473         &dev_attr_calibrate.attr,
 474         &dev_attr_invert.attr,
 475         NULL,
 476 };
 477
 478 static struct attribute_group hdaps_attribute_group = {
 479         .attrs = hdaps_attributes,
 480 };
 481
 482
 483 /* Module stuff */
 484
 485 /* hdaps_dmi_match - found a match.  return one, short-circuiting the hunt. */
 486 static int __init hdaps_dmi_match(const struct dmi_system_id *id)
 487 {
 488         pr_info("%s detected\n", id->ident);
 489         return 1;
 490 }
 491
 492 /* hdaps_dmi_match_invert - found an inverted match. */
 493 static int __init hdaps_dmi_match_invert(const struct dmi_system_id *id)
 494 {
 495         hdaps_invert = (unsigned long)id->driver_data;
 496         pr_info("inverting axis (%u) readings\n", hdaps_invert);
 497         return hdaps_dmi_match(id);
 498 }
 499
 500 #define HDAPS_DMI_MATCH_INVERT(vendor, model, axes) {   \
 501         .ident = vendor " " model,                      \
 502         .callback = hdaps_dmi_match_invert,             \
 503         .driver_data = (void *)axes,                    \
 504         .matches = {                                    \
 505                 DMI_MATCH(DMI_BOARD_VENDOR, vendor),    \
 506                 DMI_MATCH(DMI_PRODUCT_VERSION, model)   \
 507         }                                               \
 508 }
 509
 510 #define HDAPS_DMI_MATCH_NORMAL(vendor, model)           \
 511         HDAPS_DMI_MATCH_INVERT(vendor, model, 0)
 512
 513 /* Note that HDAPS_DMI_MATCH_NORMAL("ThinkPad T42") would match
 514    "ThinkPad T42p", so the order of the entries matters.
 515    If your ThinkPad is not recognized, please update to latest
 516    BIOS. This is especially the case for some R52 ThinkPads. */
 517 static struct dmi_system_id __initdata hdaps_whitelist[] = {
 518         HDAPS_DMI_MATCH_INVERT("IBM", "ThinkPad R50p", HDAPS_BOTH_AXES),
 519         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad R50"),
 520         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad R51"),
 521         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad R52"),
 522         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad R61i", HDAPS_BOTH_AXES),
 523         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad R61", HDAPS_BOTH_AXES),
 524         HDAPS_DMI_MATCH_INVERT("IBM", "ThinkPad T41p", HDAPS_BOTH_AXES),
 525         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad T41"),
 526         HDAPS_DMI_MATCH_INVERT("IBM", "ThinkPad T42p", HDAPS_BOTH_AXES),
 527         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad T42"),
 528         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad T43"),
 529         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad T400", HDAPS_BOTH_AXES),
 530         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad T60", HDAPS_BOTH_AXES),
 531         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad T61p", HDAPS_BOTH_AXES),
 532         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad T61", HDAPS_BOTH_AXES),
 533         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad X40"),
 534         HDAPS_DMI_MATCH_INVERT("IBM", "ThinkPad X41", HDAPS_Y_AXIS),
 535         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad X60", HDAPS_BOTH_AXES),
 536         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad X61s", HDAPS_BOTH_AXES),
 537         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad X61", HDAPS_BOTH_AXES),
 538         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad Z60m"),
 539         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad Z61m", HDAPS_BOTH_AXES),
 540         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad Z61p", HDAPS_BOTH_AXES),
 541         { .ident = NULL }
 542 };
 543
 544 static int __init hdaps_init(void)
 545 {
 546         struct input_dev *idev;
 547         int ret;
 548
 549         if (!dmi_check_system(hdaps_whitelist)) {
 550                 pr_warn("supported laptop not found!\n");
 551                 ret = -ENODEV;
 552                 goto out;
 553         }
 554
 555         if (!request_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS, "hdaps")) {
 556                 ret = -ENXIO;
 557                 goto out;
 558         }
 559
 560         ret = platform_driver_register(&hdaps_driver);
 561         if (ret)
 562                 goto out_region;
 563
 564         pdev = platform_device_register_simple("hdaps", -1, NULL, 0);
 565         if (IS_ERR(pdev)) {
 566                 ret = PTR_ERR(pdev);
 567                 goto out_driver;
 568         }
 569
 570         ret = sysfs_create_group(&pdev->dev.kobj, &hdaps_attribute_group);
 571         if (ret)
 572                 goto out_device;
 573
 574         hdaps_idev = input_allocate_polled_device();
 575         if (!hdaps_idev) {
 576                 ret = -ENOMEM;
 577                 goto out_group;
 578         }
 579
 580         hdaps_idev->poll = hdaps_mousedev_poll;
 581         hdaps_idev->poll_interval = HDAPS_POLL_INTERVAL;
 582
 583         /* initial calibrate for the input device */
 584         hdaps_calibrate();
 585
 586         /* initialize the input class */
 587         idev = hdaps_idev->input;
 588         idev->name = "hdaps";
 589         idev->phys = "isa1600/input0";
 590         idev->id.bustype = BUS_ISA;
 591         idev->dev.parent = &pdev->dev;
 592         idev->evbit[0] = BIT_MASK(EV_ABS);
 593         input_set_abs_params(idev, ABS_X,
 594                         -256, 256, HDAPS_INPUT_FUZZ, HDAPS_INPUT_FLAT);
 595         input_set_abs_params(idev, ABS_Y,
 596                         -256, 256, HDAPS_INPUT_FUZZ, HDAPS_INPUT_FLAT);
 597
 598         ret = input_register_polled_device(hdaps_idev);
 599         if (ret)
 600                 goto out_idev;
 601
 602         pr_info("driver successfully loaded\n");
 603         return 0;
 604
 605 out_idev:
 606         input_free_polled_device(hdaps_idev);
 607 out_group:
 608         sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);
 609 out_device:
 610         platform_device_unregister(pdev);
 611 out_driver:
 612         platform_driver_unregister(&hdaps_driver);
 613 out_region:
 614         release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);
 615 out:
 616         pr_warn("driver init failed (ret=%d)!\n", ret);
 617         return ret;
 618 }
 619
 620 static void __exit hdaps_exit(void)
 621 {
 622         input_unregister_polled_device(hdaps_idev);
 623         input_free_polled_device(hdaps_idev);
 624         sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);
 625         platform_device_unregister(pdev);
 626         platform_driver_unregister(&hdaps_driver);
 627         release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);
 628
 629         pr_info("driver unloaded\n");
 630 }
 631
 632 module_init(hdaps_init);
 633 module_exit(hdaps_exit);
 634
 635 module_param_named(invert, hdaps_invert, int, 0);
 636 MODULE_PARM_DESC(invert, "invert data along each axis. 1 invert x-axis, "
 637                  "2 invert y-axis, 3 invert both axes.");
 638
 639 MODULE_AUTHOR("Robert Love");
 640 MODULE_DESCRIPTION("IBM Hard Drive Active Protection System (HDAPS) driver");
 641 MODULE_LICENSE("GPL v2");