drivers/platform/x86/dell-laptop.c

   1 /*
   2  *  Driver for Dell laptop extras
   3  *
   4  *  Copyright (c) Red Hat <mjg@redhat.com>
   5  *
   6  *  Based on documentation in the libsmbios package, Copyright (C) 2005 Dell
   7  *  Inc.
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2 as
  11  *  published by the Free Software Foundation.
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/module.h>
  17 #include <linux/kernel.h>
  18 #include <linux/init.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/backlight.h>
  21 #include <linux/err.h>
  22 #include <linux/dmi.h>
  23 #include <linux/io.h>
  24 #include <linux/rfkill.h>
  25 #include <linux/power_supply.h>
  26 #include <linux/acpi.h>
  27 #include <linux/mm.h>
  28 #include <linux/i8042.h>
  29 #include <linux/slab.h>
  30 #include <linux/debugfs.h>
  31 #include <linux/seq_file.h>
  32 #include "../../firmware/dcdbas.h"
  33
  34 #define BRIGHTNESS_TOKEN 0x7d
  35
  36 /* This structure will be modified by the firmware when we enter
  37  * system management mode, hence the volatiles */
  38
  39 struct calling_interface_buffer {
  40         u16 class;
  41         u16 select;
  42         volatile u32 input[4];
  43         volatile u32 output[4];
  44 } __packed;
  45
  46 struct calling_interface_token {
  47         u16 tokenID;
  48         u16 location;
  49         union {
  50                 u16 value;
  51                 u16 stringlength;
  52         };
  53 };
  54
  55 struct calling_interface_structure {
  56         struct dmi_header header;
  57         u16 cmdIOAddress;
  58         u8 cmdIOCode;
  59         u32 supportedCmds;
  60         struct calling_interface_token tokens[];
  61 } __packed;
  62
  63 static int da_command_address;
  64 static int da_command_code;
  65 static int da_num_tokens;
  66 static struct calling_interface_token *da_tokens;
  67
  68 static struct platform_driver platform_driver = {
  69         .driver = {
  70                 .name = "dell-laptop",
  71                 .owner = THIS_MODULE,
  72         }
  73 };
  74
  75 static struct platform_device *platform_device;
  76 static struct backlight_device *dell_backlight_device;
  77 static struct rfkill *wifi_rfkill;
  78 static struct rfkill *bluetooth_rfkill;
  79 static struct rfkill *wwan_rfkill;
  80
  81 static const struct dmi_system_id __initdata dell_device_table[] = {
  82         {
  83                 .ident = "Dell laptop",
  84                 .matches = {
  85                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
  86                         DMI_MATCH(DMI_CHASSIS_TYPE, "8"),
  87                 },
  88         },
  89         {
  90                 .matches = {
  91                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
  92                         DMI_MATCH(DMI_CHASSIS_TYPE, "9"), /*Laptop*/
  93                 },
  94         },
  95         {
  96                 .ident = "Dell Computer Corporation",
  97                 .matches = {
  98                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
  99                         DMI_MATCH(DMI_CHASSIS_TYPE, "8"),
 100                 },
 101         },
 102         { }
 103 };
 104
 105 static struct dmi_system_id __devinitdata dell_blacklist[] = {
 106         /* Supported by compal-laptop */
 107         {
 108                 .ident = "Dell Mini 9",
 109                 .matches = {
 110                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 111                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 910"),
 112                 },
 113         },
 114         {
 115                 .ident = "Dell Mini 10",
 116                 .matches = {
 117                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 118                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 1010"),
 119                 },
 120         },
 121         {
 122                 .ident = "Dell Mini 10v",
 123                 .matches = {
 124                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 125                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 1011"),
 126                 },
 127         },
 128         {
 129                 .ident = "Dell Mini 1012",
 130                 .matches = {
 131                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 132                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 1012"),
 133                 },
 134         },
 135         {
 136                 .ident = "Dell Inspiron 11z",
 137                 .matches = {
 138                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 139                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 1110"),
 140                 },
 141         },
 142         {
 143                 .ident = "Dell Mini 12",
 144                 .matches = {
 145                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 146                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 1210"),
 147                 },
 148         },
 149         {}
 150 };
 151
 152 static struct calling_interface_buffer *buffer;
 153 static struct page *bufferpage;
 154 static DEFINE_MUTEX(buffer_mutex);
 155
 156 static int hwswitch_state;
 157
 158 static void get_buffer(void)
 159 {
 160         mutex_lock(&buffer_mutex);
 161         memset(buffer, 0, sizeof(struct calling_interface_buffer));
 162 }
 163
 164 static void release_buffer(void)
 165 {
 166         mutex_unlock(&buffer_mutex);
 167 }
 168
 169 static void __init parse_da_table(const struct dmi_header *dm)
 170 {
 171         /* Final token is a terminator, so we don't want to copy it */
 172         int tokens = (dm->length-11)/sizeof(struct calling_interface_token)-1;
 173         struct calling_interface_structure *table =
 174                 container_of(dm, struct calling_interface_structure, header);
 175
 176         /* 4 bytes of table header, plus 7 bytes of Dell header, plus at least
 177            6 bytes of entry */
 178
 179         if (dm->length < 17)
 180                 return;
 181
 182         da_command_address = table->cmdIOAddress;
 183         da_command_code = table->cmdIOCode;
 184
 185         da_tokens = krealloc(da_tokens, (da_num_tokens + tokens) *
 186                              sizeof(struct calling_interface_token),
 187                              GFP_KERNEL);
 188
 189         if (!da_tokens)
 190                 return;
 191
 192         memcpy(da_tokens+da_num_tokens, table->tokens,
 193                sizeof(struct calling_interface_token) * tokens);
 194
 195         da_num_tokens += tokens;
 196 }
 197
 198 static void __init find_tokens(const struct dmi_header *dm, void *dummy)
 199 {
 200         switch (dm->type) {
 201         case 0xd4: /* Indexed IO */
 202                 break;
 203         case 0xd5: /* Protected Area Type 1 */
 204                 break;
 205         case 0xd6: /* Protected Area Type 2 */
 206                 break;
 207         case 0xda: /* Calling interface */
 208                 parse_da_table(dm);
 209                 break;
 210         }
 211 }
 212
 213 static int find_token_location(int tokenid)
 214 {
 215         int i;
 216         for (i = 0; i < da_num_tokens; i++) {
 217                 if (da_tokens[i].tokenID == tokenid)
 218                         return da_tokens[i].location;
 219         }
 220
 221         return -1;
 222 }
 223
 224 static struct calling_interface_buffer *
 225 dell_send_request(struct calling_interface_buffer *buffer, int class,
 226                   int select)
 227 {
 228         struct smi_cmd command;
 229
 230         command.magic = SMI_CMD_MAGIC;
 231         command.command_address = da_command_address;
 232         command.command_code = da_command_code;
 233         command.ebx = virt_to_phys(buffer);
 234         command.ecx = 0x42534931;
 235
 236         buffer->class = class;
 237         buffer->select = select;
 238
 239         dcdbas_smi_request(&command);
 240
 241         return buffer;
 242 }
 243
 244 /* Derived from information in DellWirelessCtl.cpp:
 245    Class 17, select 11 is radio control. It returns an array of 32-bit values.
 246
 247    Input byte 0 = 0: Wireless information
 248
 249    result[0]: return code
 250    result[1]:
 251      Bit 0:      Hardware switch supported
 252      Bit 1:      Wifi locator supported
 253      Bit 2:      Wifi is supported
 254      Bit 3:      Bluetooth is supported
 255      Bit 4:      WWAN is supported
 256      Bit 5:      Wireless keyboard supported
 257      Bits 6-7:   Reserved
 258      Bit 8:      Wifi is installed
 259      Bit 9:      Bluetooth is installed
 260      Bit 10:     WWAN is installed
 261      Bits 11-15: Reserved
 262      Bit 16:     Hardware switch is on
 263      Bit 17:     Wifi is blocked
 264      Bit 18:     Bluetooth is blocked
 265      Bit 19:     WWAN is blocked
 266      Bits 20-31: Reserved
 267    result[2]: NVRAM size in bytes
 268    result[3]: NVRAM format version number
 269
 270    Input byte 0 = 2: Wireless switch configuration
 271    result[0]: return code
 272    result[1]:
 273      Bit 0:      Wifi controlled by switch
 274      Bit 1:      Bluetooth controlled by switch
 275      Bit 2:      WWAN controlled by switch
 276      Bits 3-6:   Reserved
 277      Bit 7:      Wireless switch config locked
 278      Bit 8:      Wifi locator enabled
 279      Bits 9-14:  Reserved
 280      Bit 15:     Wifi locator setting locked
 281      Bits 16-31: Reserved
 282 */
 283
 284 static int dell_rfkill_set(void *data, bool blocked)
 285 {
 286         int disable = blocked ? 1 : 0;
 287         unsigned long radio = (unsigned long)data;
 288         int hwswitch_bit = (unsigned long)data - 1;
 289         int ret = 0;
 290
 291         get_buffer();
 292         dell_send_request(buffer, 17, 11);
 293
 294         /* If the hardware switch controls this radio, and the hardware
 295            switch is disabled, don't allow changing the software state */
 296         if ((hwswitch_state & BIT(hwswitch_bit)) &&
 297             !(buffer->output[1] & BIT(16))) {
 298                 ret = -EINVAL;
 299                 goto out;
 300         }
 301
 302         buffer->input[0] = (1 | (radio<<8) | (disable << 16));
 303         dell_send_request(buffer, 17, 11);
 304
 305 out:
 306         release_buffer();
 307         return ret;
 308 }
 309
 310 static void dell_rfkill_query(struct rfkill *rfkill, void *data)
 311 {
 312         int status;
 313         int bit = (unsigned long)data + 16;
 314         int hwswitch_bit = (unsigned long)data - 1;
 315
 316         get_buffer();
 317         dell_send_request(buffer, 17, 11);
 318         status = buffer->output[1];
 319         release_buffer();
 320
 321         rfkill_set_sw_state(rfkill, !!(status & BIT(bit)));
 322
 323         if (hwswitch_state & (BIT(hwswitch_bit)))
 324                 rfkill_set_hw_state(rfkill, !(status & BIT(16)));
 325 }
 326
 327 static const struct rfkill_ops dell_rfkill_ops = {
 328         .set_block = dell_rfkill_set,
 329         .query = dell_rfkill_query,
 330 };
 331
 332 static struct dentry *dell_laptop_dir;
 333
 334 static int dell_debugfs_show(struct seq_file *s, void *data)
 335 {
 336         int status;
 337
 338         get_buffer();
 339         dell_send_request(buffer, 17, 11);
 340         status = buffer->output[1];
 341         release_buffer();
 342
 343         seq_printf(s, "status:\t0x%X\n", status);
 344         seq_printf(s, "Bit 0 : Hardware switch supported:   %lu\n",
 345                    status & BIT(0));
 346         seq_printf(s, "Bit 1 : Wifi locator supported:      %lu\n",
 347                   (status & BIT(1)) >> 1);
 348         seq_printf(s, "Bit 2 : Wifi is supported:           %lu\n",
 349                   (status & BIT(2)) >> 2);
 350         seq_printf(s, "Bit 3 : Bluetooth is supported:      %lu\n",
 351                   (status & BIT(3)) >> 3);
 352         seq_printf(s, "Bit 4 : WWAN is supported:           %lu\n",
 353                   (status & BIT(4)) >> 4);
 354         seq_printf(s, "Bit 5 : Wireless keyboard supported: %lu\n",
 355                   (status & BIT(5)) >> 5);
 356         seq_printf(s, "Bit 8 : Wifi is installed:           %lu\n",
 357                   (status & BIT(8)) >> 8);
 358         seq_printf(s, "Bit 9 : Bluetooth is installed:      %lu\n",
 359                   (status & BIT(9)) >> 9);
 360         seq_printf(s, "Bit 10: WWAN is installed:           %lu\n",
 361                   (status & BIT(10)) >> 10);
 362         seq_printf(s, "Bit 16: Hardware switch is on:       %lu\n",
 363                   (status & BIT(16)) >> 16);
 364         seq_printf(s, "Bit 17: Wifi is blocked:             %lu\n",
 365                   (status & BIT(17)) >> 17);
 366         seq_printf(s, "Bit 18: Bluetooth is blocked:        %lu\n",
 367                   (status & BIT(18)) >> 18);
 368         seq_printf(s, "Bit 19: WWAN is blocked:             %lu\n",
 369                   (status & BIT(19)) >> 19);
 370
 371         seq_printf(s, "\nhwswitch_state:\t0x%X\n", hwswitch_state);
 372         seq_printf(s, "Bit 0 : Wifi controlled by switch:      %lu\n",
 373                    hwswitch_state & BIT(0));
 374         seq_printf(s, "Bit 1 : Bluetooth controlled by switch: %lu\n",
 375                    (hwswitch_state & BIT(1)) >> 1);
 376         seq_printf(s, "Bit 2 : WWAN controlled by switch:      %lu\n",
 377                    (hwswitch_state & BIT(2)) >> 2);
 378         seq_printf(s, "Bit 7 : Wireless switch config locked:  %lu\n",
 379                    (hwswitch_state & BIT(7)) >> 7);
 380         seq_printf(s, "Bit 8 : Wifi locator enabled:           %lu\n",
 381                    (hwswitch_state & BIT(8)) >> 8);
 382         seq_printf(s, "Bit 15: Wifi locator setting locked:    %lu\n",
 383                    (hwswitch_state & BIT(15)) >> 15);
 384
 385         return 0;
 386 }
 387
 388 static int dell_debugfs_open(struct inode *inode, struct file *file)
 389 {
 390         return single_open(file, dell_debugfs_show, inode->i_private);
 391 }
 392
 393 static const struct file_operations dell_debugfs_fops = {
 394         .owner = THIS_MODULE,
 395         .open = dell_debugfs_open,
 396         .read = seq_read,
 397         .llseek = seq_lseek,
 398         .release = single_release,
 399 };
 400
 401 static void dell_update_rfkill(struct work_struct *ignored)
 402 {
 403         if (wifi_rfkill)
 404                 dell_rfkill_query(wifi_rfkill, (void *)1);
 405         if (bluetooth_rfkill)
 406                 dell_rfkill_query(bluetooth_rfkill, (void *)2);
 407         if (wwan_rfkill)
 408                 dell_rfkill_query(wwan_rfkill, (void *)3);
 409 }
 410 static DECLARE_DELAYED_WORK(dell_rfkill_work, dell_update_rfkill);
 411
 412
 413 static int __init dell_setup_rfkill(void)
 414 {
 415         int status;
 416         int ret;
 417
 418         if (dmi_check_system(dell_blacklist)) {
 419                 pr_info("Blacklisted hardware detected - not enabling rfkill\n");
 420                 return 0;
 421         }
 422
 423         get_buffer();
 424         dell_send_request(buffer, 17, 11);
 425         status = buffer->output[1];
 426         buffer->input[0] = 0x2;
 427         dell_send_request(buffer, 17, 11);
 428         hwswitch_state = buffer->output[1];
 429         release_buffer();
 430
 431         if ((status & (1<<2|1<<8)) == (1<<2|1<<8)) {
 432                 wifi_rfkill = rfkill_alloc("dell-wifi", &platform_device->dev,
 433                                            RFKILL_TYPE_WLAN,
 434                                            &dell_rfkill_ops, (void *) 1);
 435                 if (!wifi_rfkill) {
 436                         ret = -ENOMEM;
 437                         goto err_wifi;
 438                 }
 439                 ret = rfkill_register(wifi_rfkill);
 440                 if (ret)
 441                         goto err_wifi;
 442         }
 443
 444         if ((status & (1<<3|1<<9)) == (1<<3|1<<9)) {
 445                 bluetooth_rfkill = rfkill_alloc("dell-bluetooth",
 446                                                 &platform_device->dev,
 447                                                 RFKILL_TYPE_BLUETOOTH,
 448                                                 &dell_rfkill_ops, (void *) 2);
 449                 if (!bluetooth_rfkill) {
 450                         ret = -ENOMEM;
 451                         goto err_bluetooth;
 452                 }
 453                 ret = rfkill_register(bluetooth_rfkill);
 454                 if (ret)
 455                         goto err_bluetooth;
 456         }
 457
 458         if ((status & (1<<4|1<<10)) == (1<<4|1<<10)) {
 459                 wwan_rfkill = rfkill_alloc("dell-wwan",
 460                                            &platform_device->dev,
 461                                            RFKILL_TYPE_WWAN,
 462                                            &dell_rfkill_ops, (void *) 3);
 463                 if (!wwan_rfkill) {
 464                         ret = -ENOMEM;
 465                         goto err_wwan;
 466                 }
 467                 ret = rfkill_register(wwan_rfkill);
 468                 if (ret)
 469                         goto err_wwan;
 470         }
 471
 472         return 0;
 473 err_wwan:
 474         rfkill_destroy(wwan_rfkill);
 475         if (bluetooth_rfkill)
 476                 rfkill_unregister(bluetooth_rfkill);
 477 err_bluetooth:
 478         rfkill_destroy(bluetooth_rfkill);
 479         if (wifi_rfkill)
 480                 rfkill_unregister(wifi_rfkill);
 481 err_wifi:
 482         rfkill_destroy(wifi_rfkill);
 483
 484         return ret;
 485 }
 486
 487 static void dell_cleanup_rfkill(void)
 488 {
 489         if (wifi_rfkill) {
 490                 rfkill_unregister(wifi_rfkill);
 491                 rfkill_destroy(wifi_rfkill);
 492         }
 493         if (bluetooth_rfkill) {
 494                 rfkill_unregister(bluetooth_rfkill);
 495                 rfkill_destroy(bluetooth_rfkill);
 496         }
 497         if (wwan_rfkill) {
 498                 rfkill_unregister(wwan_rfkill);
 499                 rfkill_destroy(wwan_rfkill);
 500         }
 501 }
 502
 503 static int dell_send_intensity(struct backlight_device *bd)
 504 {
 505         int ret = 0;
 506
 507         get_buffer();
 508         buffer->input[0] = find_token_location(BRIGHTNESS_TOKEN);
 509         buffer->input[1] = bd->props.brightness;
 510
 511         if (buffer->input[0] == -1) {
 512                 ret = -ENODEV;
 513                 goto out;
 514         }
 515
 516         if (power_supply_is_system_supplied() > 0)
 517                 dell_send_request(buffer, 1, 2);
 518         else
 519                 dell_send_request(buffer, 1, 1);
 520
 521 out:
 522         release_buffer();
 523         return 0;
 524 }
 525
 526 static int dell_get_intensity(struct backlight_device *bd)
 527 {
 528         int ret = 0;
 529
 530         get_buffer();
 531         buffer->input[0] = find_token_location(BRIGHTNESS_TOKEN);
 532
 533         if (buffer->input[0] == -1) {
 534                 ret = -ENODEV;
 535                 goto out;
 536         }
 537
 538         if (power_supply_is_system_supplied() > 0)
 539                 dell_send_request(buffer, 0, 2);
 540         else
 541                 dell_send_request(buffer, 0, 1);
 542
 543         ret = buffer->output[1];
 544
 545 out:
 546         release_buffer();
 547         return ret;
 548 }
 549
 550 static const struct backlight_ops dell_ops = {
 551         .get_brightness = dell_get_intensity,
 552         .update_status  = dell_send_intensity,
 553 };
 554
 555 static bool dell_laptop_i8042_filter(unsigned char data, unsigned char str,
 556                               struct serio *port)
 557 {
 558         static bool extended;
 559
 560         if (str & 0x20)
 561                 return false;
 562
 563         if (unlikely(data == 0xe0)) {
 564                 extended = true;
 565                 return false;
 566         } else if (unlikely(extended)) {
 567                 switch (data) {
 568                 case 0x8:
 569                         schedule_delayed_work(&dell_rfkill_work,
 570                                               round_jiffies_relative(HZ));
 571                         break;
 572                 }
 573                 extended = false;
 574         }
 575
 576         return false;
 577 }
 578
 579 static int __init dell_init(void)
 580 {
 581         int max_intensity = 0;
 582         int ret;
 583
 584         if (!dmi_check_system(dell_device_table))
 585                 return -ENODEV;
 586
 587         dmi_walk(find_tokens, NULL);
 588
 589         if (!da_tokens)  {
 590                 pr_info("Unable to find dmi tokens\n");
 591                 return -ENODEV;
 592         }
 593
 594         ret = platform_driver_register(&platform_driver);
 595         if (ret)
 596                 goto fail_platform_driver;
 597         platform_device = platform_device_alloc("dell-laptop", -1);
 598         if (!platform_device) {
 599                 ret = -ENOMEM;
 600                 goto fail_platform_device1;
 601         }
 602         ret = platform_device_add(platform_device);
 603         if (ret)
 604                 goto fail_platform_device2;
 605
 606         /*
 607          * Allocate buffer below 4GB for SMI data--only 32-bit physical addr
 608          * is passed to SMI handler.
 609          */
 610         bufferpage = alloc_page(GFP_KERNEL | GFP_DMA32);
 611
 612         if (!bufferpage)
 613                 goto fail_buffer;
 614         buffer = page_address(bufferpage);
 615
 616         ret = dell_setup_rfkill();
 617
 618         if (ret) {
 619                 pr_warn("Unable to setup rfkill\n");
 620                 goto fail_rfkill;
 621         }
 622
 623         ret = i8042_install_filter(dell_laptop_i8042_filter);
 624         if (ret) {
 625                 pr_warn("Unable to install key filter\n");
 626                 goto fail_filter;
 627         }
 628
 629         dell_laptop_dir = debugfs_create_dir("dell_laptop", NULL);
 630         if (dell_laptop_dir != NULL)
 631                 debugfs_create_file("rfkill", 0444, dell_laptop_dir, NULL,
 632                                     &dell_debugfs_fops);
 633
 634 #ifdef CONFIG_ACPI
 635         /* In the event of an ACPI backlight being available, don't
 636          * register the platform controller.
 637          */
 638         if (acpi_video_backlight_support())
 639                 return 0;
 640 #endif
 641
 642         get_buffer();
 643         buffer->input[0] = find_token_location(BRIGHTNESS_TOKEN);
 644         if (buffer->input[0] != -1) {
 645                 dell_send_request(buffer, 0, 2);
 646                 max_intensity = buffer->output[3];
 647         }
 648         release_buffer();
 649
 650         if (max_intensity) {
 651                 struct backlight_properties props;
 652                 memset(&props, 0, sizeof(struct backlight_properties));
 653                 props.type = BACKLIGHT_PLATFORM;
 654                 props.max_brightness = max_intensity;
 655                 dell_backlight_device = backlight_device_register("dell_backlight",
 656                                                                   &platform_device->dev,
 657                                                                   NULL,
 658                                                                   &dell_ops,
 659                                                                   &props);
 660
 661                 if (IS_ERR(dell_backlight_device)) {
 662                         ret = PTR_ERR(dell_backlight_device);
 663                         dell_backlight_device = NULL;
 664                         goto fail_backlight;
 665                 }
 666
 667                 dell_backlight_device->props.brightness =
 668                         dell_get_intensity(dell_backlight_device);
 669                 backlight_update_status(dell_backlight_device);
 670         }
 671
 672         return 0;
 673
 674 fail_backlight:
 675         i8042_remove_filter(dell_laptop_i8042_filter);
 676         cancel_delayed_work_sync(&dell_rfkill_work);
 677 fail_filter:
 678         dell_cleanup_rfkill();
 679 fail_rfkill:
 680         free_page((unsigned long)bufferpage);
 681 fail_buffer:
 682         platform_device_del(platform_device);
 683 fail_platform_device2:
 684         platform_device_put(platform_device);
 685 fail_platform_device1:
 686         platform_driver_unregister(&platform_driver);
 687 fail_platform_driver:
 688         kfree(da_tokens);
 689         return ret;
 690 }
 691
 692 static void __exit dell_exit(void)
 693 {
 694         debugfs_remove_recursive(dell_laptop_dir);
 695         i8042_remove_filter(dell_laptop_i8042_filter);
 696         cancel_delayed_work_sync(&dell_rfkill_work);
 697         backlight_device_unregister(dell_backlight_device);
 698         dell_cleanup_rfkill();
 699         if (platform_device) {
 700                 platform_device_unregister(platform_device);
 701                 platform_driver_unregister(&platform_driver);
 702         }
 703         kfree(da_tokens);
 704         free_page((unsigned long)buffer);
 705 }
 706
 707 module_init(dell_init);
 708 module_exit(dell_exit);
 709
 710 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
 711 MODULE_DESCRIPTION("Dell laptop driver");
 712 MODULE_LICENSE("GPL");
 713 MODULE_ALIAS("dmi:*svnDellInc.:*:ct8:*");
 714 MODULE_ALIAS("dmi:*svnDellInc.:*:ct9:*");
 715 MODULE_ALIAS("dmi:*svnDellComputerCorporation.:*:ct8:*");