drivers/platform/x86/samsung-laptop.c

   1 /*
   2  * Samsung Laptop driver
   3  *
   4  * Copyright (C) 2009,2011 Greg Kroah-Hartman (gregkh@suse.de)
   5  * Copyright (C) 2009,2011 Novell Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * 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 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/module.h>
  17 #include <linux/delay.h>
  18 #include <linux/pci.h>
  19 #include <linux/backlight.h>
  20 #include <linux/fb.h>
  21 #include <linux/dmi.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/rfkill.h>
  24
  25 /*
  26  * This driver is needed because a number of Samsung laptops do not hook
  27  * their control settings through ACPI.  So we have to poke around in the
  28  * BIOS to do things like brightness values, and "special" key controls.
  29  */
  30
  31 /*
  32  * We have 0 - 8 as valid brightness levels.  The specs say that level 0 should
  33  * be reserved by the BIOS (which really doesn't make much sense), we tell
  34  * userspace that the value is 0 - 7 and then just tell the hardware 1 - 8
  35  */
  36 #define MAX_BRIGHT      0x07
  37
  38
  39 #define SABI_IFACE_MAIN                 0x00
  40 #define SABI_IFACE_SUB                  0x02
  41 #define SABI_IFACE_COMPLETE             0x04
  42 #define SABI_IFACE_DATA                 0x05
  43
  44 /* Structure to get data back to the calling function */
  45 struct sabi_retval {
  46         u8 retval[20];
  47 };
  48
  49 struct sabi_header_offsets {
  50         u8 port;
  51         u8 re_mem;
  52         u8 iface_func;
  53         u8 en_mem;
  54         u8 data_offset;
  55         u8 data_segment;
  56 };
  57
  58 struct sabi_commands {
  59         /*
  60          * Brightness is 0 - 8, as described above.
  61          * Value 0 is for the BIOS to use
  62          */
  63         u8 get_brightness;
  64         u8 set_brightness;
  65
  66         /*
  67          * first byte:
  68          * 0x00 - wireless is off
  69          * 0x01 - wireless is on
  70          * second byte:
  71          * 0x02 - 3G is off
  72          * 0x03 - 3G is on
  73          * TODO, verify 3G is correct, that doesn't seem right...
  74          */
  75         u8 get_wireless_button;
  76         u8 set_wireless_button;
  77
  78         /* 0 is off, 1 is on */
  79         u8 get_backlight;
  80         u8 set_backlight;
  81
  82         /*
  83          * 0x80 or 0x00 - no action
  84          * 0x81 - recovery key pressed
  85          */
  86         u8 get_recovery_mode;
  87         u8 set_recovery_mode;
  88
  89         /*
  90          * on seclinux: 0 is low, 1 is high,
  91          * on swsmi: 0 is normal, 1 is silent, 2 is turbo
  92          */
  93         u8 get_performance_level;
  94         u8 set_performance_level;
  95
  96         /*
  97          * Tell the BIOS that Linux is running on this machine.
  98          * 81 is on, 80 is off
  99          */
 100         u8 set_linux;
 101 };
 102
 103 struct sabi_performance_level {
 104         const char *name;
 105         u8 value;
 106 };
 107
 108 struct sabi_config {
 109         const char *test_string;
 110         u16 main_function;
 111         const struct sabi_header_offsets header_offsets;
 112         const struct sabi_commands commands;
 113         const struct sabi_performance_level performance_levels[4];
 114         u8 min_brightness;
 115         u8 max_brightness;
 116 };
 117
 118 static const struct sabi_config sabi_configs[] = {
 119         {
 120                 .test_string = "SECLINUX",
 121
 122                 .main_function = 0x4c49,
 123
 124                 .header_offsets = {
 125                         .port = 0x00,
 126                         .re_mem = 0x02,
 127                         .iface_func = 0x03,
 128                         .en_mem = 0x04,
 129                         .data_offset = 0x05,
 130                         .data_segment = 0x07,
 131                 },
 132
 133                 .commands = {
 134                         .get_brightness = 0x00,
 135                         .set_brightness = 0x01,
 136
 137                         .get_wireless_button = 0x02,
 138                         .set_wireless_button = 0x03,
 139
 140                         .get_backlight = 0x04,
 141                         .set_backlight = 0x05,
 142
 143                         .get_recovery_mode = 0x06,
 144                         .set_recovery_mode = 0x07,
 145
 146                         .get_performance_level = 0x08,
 147                         .set_performance_level = 0x09,
 148
 149                         .set_linux = 0x0a,
 150                 },
 151
 152                 .performance_levels = {
 153                         {
 154                                 .name = "silent",
 155                                 .value = 0,
 156                         },
 157                         {
 158                                 .name = "normal",
 159                                 .value = 1,
 160                         },
 161                         { },
 162                 },
 163                 .min_brightness = 1,
 164                 .max_brightness = 8,
 165         },
 166         {
 167                 .test_string = "SwSmi@",
 168
 169                 .main_function = 0x5843,
 170
 171                 .header_offsets = {
 172                         .port = 0x00,
 173                         .re_mem = 0x04,
 174                         .iface_func = 0x02,
 175                         .en_mem = 0x03,
 176                         .data_offset = 0x05,
 177                         .data_segment = 0x07,
 178                 },
 179
 180                 .commands = {
 181                         .get_brightness = 0x10,
 182                         .set_brightness = 0x11,
 183
 184                         .get_wireless_button = 0x12,
 185                         .set_wireless_button = 0x13,
 186
 187                         .get_backlight = 0x2d,
 188                         .set_backlight = 0x2e,
 189
 190                         .get_recovery_mode = 0xff,
 191                         .set_recovery_mode = 0xff,
 192
 193                         .get_performance_level = 0x31,
 194                         .set_performance_level = 0x32,
 195
 196                         .set_linux = 0xff,
 197                 },
 198
 199                 .performance_levels = {
 200                         {
 201                                 .name = "normal",
 202                                 .value = 0,
 203                         },
 204                         {
 205                                 .name = "silent",
 206                                 .value = 1,
 207                         },
 208                         {
 209                                 .name = "overclock",
 210                                 .value = 2,
 211                         },
 212                         { },
 213                 },
 214                 .min_brightness = 0,
 215                 .max_brightness = 8,
 216         },
 217         { },
 218 };
 219
 220 static const struct sabi_config *sabi_config;
 221
 222 static void __iomem *sabi;
 223 static void __iomem *sabi_iface;
 224 static void __iomem *f0000_segment;
 225 static struct backlight_device *backlight_device;
 226 static struct mutex sabi_mutex;
 227 static struct platform_device *sdev;
 228 static struct rfkill *rfk;
 229 static bool has_stepping_quirk;
 230
 231 static int force;
 232 module_param(force, bool, 0);
 233 MODULE_PARM_DESC(force,
 234                 "Disable the DMI check and forces the driver to be loaded");
 235
 236 static int debug;
 237 module_param(debug, bool, S_IRUGO | S_IWUSR);
 238 MODULE_PARM_DESC(debug, "Debug enabled or not");
 239
 240 static int sabi_get_command(u8 command, struct sabi_retval *sretval)
 241 {
 242         int retval = 0;
 243         u16 port = readw(sabi + sabi_config->header_offsets.port);
 244         u8 complete, iface_data;
 245
 246         mutex_lock(&sabi_mutex);
 247
 248         /* enable memory to be able to write to it */
 249         outb(readb(sabi + sabi_config->header_offsets.en_mem), port);
 250
 251         /* write out the command */
 252         writew(sabi_config->main_function, sabi_iface + SABI_IFACE_MAIN);
 253         writew(command, sabi_iface + SABI_IFACE_SUB);
 254         writeb(0, sabi_iface + SABI_IFACE_COMPLETE);
 255         outb(readb(sabi + sabi_config->header_offsets.iface_func), port);
 256
 257         /* write protect memory to make it safe */
 258         outb(readb(sabi + sabi_config->header_offsets.re_mem), port);
 259
 260         /* see if the command actually succeeded */
 261         complete = readb(sabi_iface + SABI_IFACE_COMPLETE);
 262         iface_data = readb(sabi_iface + SABI_IFACE_DATA);
 263         if (complete != 0xaa || iface_data == 0xff) {
 264                 pr_warn("SABI get command 0x%02x failed with completion flag 0x%02x and data 0x%02x\n",
 265                         command, complete, iface_data);
 266                 retval = -EINVAL;
 267                 goto exit;
 268         }
 269         /*
 270          * Save off the data into a structure so the caller use it.
 271          * Right now we only want the first 4 bytes,
 272          * There are commands that need more, but not for the ones we
 273          * currently care about.
 274          */
 275         sretval->retval[0] = readb(sabi_iface + SABI_IFACE_DATA);
 276         sretval->retval[1] = readb(sabi_iface + SABI_IFACE_DATA + 1);
 277         sretval->retval[2] = readb(sabi_iface + SABI_IFACE_DATA + 2);
 278         sretval->retval[3] = readb(sabi_iface + SABI_IFACE_DATA + 3);
 279
 280 exit:
 281         mutex_unlock(&sabi_mutex);
 282         return retval;
 283
 284 }
 285
 286 static int sabi_set_command(u8 command, u8 data)
 287 {
 288         int retval = 0;
 289         u16 port = readw(sabi + sabi_config->header_offsets.port);
 290         u8 complete, iface_data;
 291
 292         mutex_lock(&sabi_mutex);
 293
 294         /* enable memory to be able to write to it */
 295         outb(readb(sabi + sabi_config->header_offsets.en_mem), port);
 296
 297         /* write out the command */
 298         writew(sabi_config->main_function, sabi_iface + SABI_IFACE_MAIN);
 299         writew(command, sabi_iface + SABI_IFACE_SUB);
 300         writeb(0, sabi_iface + SABI_IFACE_COMPLETE);
 301         writeb(data, sabi_iface + SABI_IFACE_DATA);
 302         outb(readb(sabi + sabi_config->header_offsets.iface_func), port);
 303
 304         /* write protect memory to make it safe */
 305         outb(readb(sabi + sabi_config->header_offsets.re_mem), port);
 306
 307         /* see if the command actually succeeded */
 308         complete = readb(sabi_iface + SABI_IFACE_COMPLETE);
 309         iface_data = readb(sabi_iface + SABI_IFACE_DATA);
 310         if (complete != 0xaa || iface_data == 0xff) {
 311                 pr_warn("SABI set command 0x%02x failed with completion flag 0x%02x and data 0x%02x\n",
 312                        command, complete, iface_data);
 313                 retval = -EINVAL;
 314         }
 315
 316         mutex_unlock(&sabi_mutex);
 317         return retval;
 318 }
 319
 320 static void test_backlight(void)
 321 {
 322         struct sabi_retval sretval;
 323
 324         sabi_get_command(sabi_config->commands.get_backlight, &sretval);
 325         printk(KERN_DEBUG "backlight = 0x%02x\n", sretval.retval[0]);
 326
 327         sabi_set_command(sabi_config->commands.set_backlight, 0);
 328         printk(KERN_DEBUG "backlight should be off\n");
 329
 330         sabi_get_command(sabi_config->commands.get_backlight, &sretval);
 331         printk(KERN_DEBUG "backlight = 0x%02x\n", sretval.retval[0]);
 332
 333         msleep(1000);
 334
 335         sabi_set_command(sabi_config->commands.set_backlight, 1);
 336         printk(KERN_DEBUG "backlight should be on\n");
 337
 338         sabi_get_command(sabi_config->commands.get_backlight, &sretval);
 339         printk(KERN_DEBUG "backlight = 0x%02x\n", sretval.retval[0]);
 340 }
 341
 342 static void test_wireless(void)
 343 {
 344         struct sabi_retval sretval;
 345
 346         sabi_get_command(sabi_config->commands.get_wireless_button, &sretval);
 347         printk(KERN_DEBUG "wireless led = 0x%02x\n", sretval.retval[0]);
 348
 349         sabi_set_command(sabi_config->commands.set_wireless_button, 0);
 350         printk(KERN_DEBUG "wireless led should be off\n");
 351
 352         sabi_get_command(sabi_config->commands.get_wireless_button, &sretval);
 353         printk(KERN_DEBUG "wireless led = 0x%02x\n", sretval.retval[0]);
 354
 355         msleep(1000);
 356
 357         sabi_set_command(sabi_config->commands.set_wireless_button, 1);
 358         printk(KERN_DEBUG "wireless led should be on\n");
 359
 360         sabi_get_command(sabi_config->commands.get_wireless_button, &sretval);
 361         printk(KERN_DEBUG "wireless led = 0x%02x\n", sretval.retval[0]);
 362 }
 363
 364 static u8 read_brightness(void)
 365 {
 366         struct sabi_retval sretval;
 367         int user_brightness = 0;
 368         int retval;
 369
 370         retval = sabi_get_command(sabi_config->commands.get_brightness,
 371                                   &sretval);
 372         if (!retval) {
 373                 user_brightness = sretval.retval[0];
 374                 if (user_brightness > sabi_config->min_brightness)
 375                         user_brightness -= sabi_config->min_brightness;
 376                 else
 377                         user_brightness = 0;
 378         }
 379         return user_brightness;
 380 }
 381
 382 static void set_brightness(u8 user_brightness)
 383 {
 384         u8 user_level = user_brightness + sabi_config->min_brightness;
 385
 386         if (has_stepping_quirk && user_level != 0) {
 387                 /*
 388                  * short circuit if the specified level is what's already set
 389                  * to prevent the screen from flickering needlessly
 390                  */
 391                 if (user_brightness == read_brightness())
 392                         return;
 393
 394                 sabi_set_command(sabi_config->commands.set_brightness, 0);
 395         }
 396
 397         sabi_set_command(sabi_config->commands.set_brightness, user_level);
 398 }
 399
 400 static int get_brightness(struct backlight_device *bd)
 401 {
 402         return (int)read_brightness();
 403 }
 404
 405 static void check_for_stepping_quirk(void)
 406 {
 407         u8 initial_level;
 408         u8 check_level;
 409         u8 orig_level = read_brightness();
 410
 411         /*
 412          * Some laptops exhibit the strange behaviour of stepping toward
 413          * (rather than setting) the brightness except when changing to/from
 414          * brightness level 0. This behaviour is checked for here and worked
 415          * around in set_brightness.
 416          */
 417
 418         if (orig_level == 0)
 419                 set_brightness(1);
 420
 421         initial_level = read_brightness();
 422
 423         if (initial_level <= 2)
 424                 check_level = initial_level + 2;
 425         else
 426                 check_level = initial_level - 2;
 427
 428         has_stepping_quirk = false;
 429         set_brightness(check_level);
 430
 431         if (read_brightness() != check_level) {
 432                 has_stepping_quirk = true;
 433                 pr_info("enabled workaround for brightness stepping quirk\n");
 434         }
 435
 436         set_brightness(orig_level);
 437 }
 438
 439 static int update_status(struct backlight_device *bd)
 440 {
 441         set_brightness(bd->props.brightness);
 442
 443         if (bd->props.power == FB_BLANK_UNBLANK)
 444                 sabi_set_command(sabi_config->commands.set_backlight, 1);
 445         else
 446                 sabi_set_command(sabi_config->commands.set_backlight, 0);
 447         return 0;
 448 }
 449
 450 static const struct backlight_ops backlight_ops = {
 451         .get_brightness = get_brightness,
 452         .update_status  = update_status,
 453 };
 454
 455 static int rfkill_set(void *data, bool blocked)
 456 {
 457         /* Do something with blocked...*/
 458         /*
 459          * blocked == false is on
 460          * blocked == true is off
 461          */
 462         if (blocked)
 463                 sabi_set_command(sabi_config->commands.set_wireless_button, 0);
 464         else
 465                 sabi_set_command(sabi_config->commands.set_wireless_button, 1);
 466
 467         return 0;
 468 }
 469
 470 static struct rfkill_ops rfkill_ops = {
 471         .set_block = rfkill_set,
 472 };
 473
 474 static int init_wireless(struct platform_device *sdev)
 475 {
 476         int retval;
 477
 478         rfk = rfkill_alloc("samsung-wifi", &sdev->dev, RFKILL_TYPE_WLAN,
 479                            &rfkill_ops, NULL);
 480         if (!rfk)
 481                 return -ENOMEM;
 482
 483         retval = rfkill_register(rfk);
 484         if (retval) {
 485                 rfkill_destroy(rfk);
 486                 return -ENODEV;
 487         }
 488
 489         return 0;
 490 }
 491
 492 static void destroy_wireless(void)
 493 {
 494         rfkill_unregister(rfk);
 495         rfkill_destroy(rfk);
 496 }
 497
 498 static ssize_t get_performance_level(struct device *dev,
 499                                      struct device_attribute *attr, char *buf)
 500 {
 501         struct sabi_retval sretval;
 502         int retval;
 503         int i;
 504
 505         /* Read the state */
 506         retval = sabi_get_command(sabi_config->commands.get_performance_level,
 507                                   &sretval);
 508         if (retval)
 509                 return retval;
 510
 511         /* The logic is backwards, yeah, lots of fun... */
 512         for (i = 0; sabi_config->performance_levels[i].name; ++i) {
 513                 if (sretval.retval[0] == sabi_config->performance_levels[i].value)
 514                         return sprintf(buf, "%s\n", sabi_config->performance_levels[i].name);
 515         }
 516         return sprintf(buf, "%s\n", "unknown");
 517 }
 518
 519 static ssize_t set_performance_level(struct device *dev,
 520                                 struct device_attribute *attr, const char *buf,
 521                                 size_t count)
 522 {
 523         if (count >= 1) {
 524                 int i;
 525                 for (i = 0; sabi_config->performance_levels[i].name; ++i) {
 526                         const struct sabi_performance_level *level =
 527                                 &sabi_config->performance_levels[i];
 528                         if (!strncasecmp(level->name, buf, strlen(level->name))) {
 529                                 sabi_set_command(sabi_config->commands.set_performance_level,
 530                                                  level->value);
 531                                 break;
 532                         }
 533                 }
 534                 if (!sabi_config->performance_levels[i].name)
 535                         return -EINVAL;
 536         }
 537         return count;
 538 }
 539 static DEVICE_ATTR(performance_level, S_IWUSR | S_IRUGO,
 540                    get_performance_level, set_performance_level);
 541
 542
 543 static struct dmi_system_id __initdata samsung_dmi_table[] = {
 544         {
 545                 .matches = {
 546                         DMI_MATCH(DMI_SYS_VENDOR,
 547                                         "SAMSUNG ELECTRONICS CO., LTD."),
 548                         DMI_MATCH(DMI_CHASSIS_TYPE, "8"), /* Portable */
 549                 },
 550         },
 551         {
 552                 .matches = {
 553                         DMI_MATCH(DMI_SYS_VENDOR,
 554                                         "SAMSUNG ELECTRONICS CO., LTD."),
 555                         DMI_MATCH(DMI_CHASSIS_TYPE, "9"), /* Laptop */
 556                 },
 557         },
 558         {
 559                 .matches = {
 560                         DMI_MATCH(DMI_SYS_VENDOR,
 561                                         "SAMSUNG ELECTRONICS CO., LTD."),
 562                         DMI_MATCH(DMI_CHASSIS_TYPE, "10"), /* Notebook */
 563                 },
 564         },
 565         {
 566                 .matches = {
 567                         DMI_MATCH(DMI_SYS_VENDOR,
 568                                         "SAMSUNG ELECTRONICS CO., LTD."),
 569                         DMI_MATCH(DMI_CHASSIS_TYPE, "14"), /* Sub-Notebook */
 570                 },
 571         },
 572         { },
 573 };
 574 MODULE_DEVICE_TABLE(dmi, samsung_dmi_table);
 575
 576 static int find_signature(void __iomem *memcheck, const char *testStr)
 577 {
 578         int i = 0;
 579         int loca;
 580
 581         for (loca = 0; loca < 0xffff; loca++) {
 582                 char temp = readb(memcheck + loca);
 583
 584                 if (temp == testStr[i]) {
 585                         if (i == strlen(testStr)-1)
 586                                 break;
 587                         ++i;
 588                 } else {
 589                         i = 0;
 590                 }
 591         }
 592         return loca;
 593 }
 594
 595 static int __init samsung_init(void)
 596 {
 597         struct backlight_properties props;
 598         struct sabi_retval sretval;
 599         unsigned int ifaceP;
 600         int i;
 601         int loca;
 602         int retval;
 603
 604         mutex_init(&sabi_mutex);
 605
 606         if (!force && !dmi_check_system(samsung_dmi_table))
 607                 return -ENODEV;
 608
 609         f0000_segment = ioremap_nocache(0xf0000, 0xffff);
 610         if (!f0000_segment) {
 611                 if (debug || force)
 612                         pr_err("Can't map the segment at 0xf0000\n");
 613                 return -EINVAL;
 614         }
 615
 616         /* Try to find one of the signatures in memory to find the header */
 617         for (i = 0; sabi_configs[i].test_string != 0; ++i) {
 618                 sabi_config = &sabi_configs[i];
 619                 loca = find_signature(f0000_segment, sabi_config->test_string);
 620                 if (loca != 0xffff)
 621                         break;
 622         }
 623
 624         if (loca == 0xffff) {
 625                 if (debug || force)
 626                         pr_err("This computer does not support SABI\n");
 627                 goto error_no_signature;
 628         }
 629
 630         /* point to the SMI port Number */
 631         loca += 1;
 632         sabi = (f0000_segment + loca);
 633
 634         if (debug) {
 635                 printk(KERN_DEBUG "This computer supports SABI==%x\n",
 636                         loca + 0xf0000 - 6);
 637                 printk(KERN_DEBUG "SABI header:\n");
 638                 printk(KERN_DEBUG " SMI Port Number = 0x%04x\n",
 639                         readw(sabi + sabi_config->header_offsets.port));
 640                 printk(KERN_DEBUG " SMI Interface Function = 0x%02x\n",
 641                         readb(sabi + sabi_config->header_offsets.iface_func));
 642                 printk(KERN_DEBUG " SMI enable memory buffer = 0x%02x\n",
 643                         readb(sabi + sabi_config->header_offsets.en_mem));
 644                 printk(KERN_DEBUG " SMI restore memory buffer = 0x%02x\n",
 645                         readb(sabi + sabi_config->header_offsets.re_mem));
 646                 printk(KERN_DEBUG " SABI data offset = 0x%04x\n",
 647                         readw(sabi + sabi_config->header_offsets.data_offset));
 648                 printk(KERN_DEBUG " SABI data segment = 0x%04x\n",
 649                         readw(sabi + sabi_config->header_offsets.data_segment));
 650         }
 651
 652         /* Get a pointer to the SABI Interface */
 653         ifaceP = (readw(sabi + sabi_config->header_offsets.data_segment) & 0x0ffff) << 4;
 654         ifaceP += readw(sabi + sabi_config->header_offsets.data_offset) & 0x0ffff;
 655         sabi_iface = ioremap_nocache(ifaceP, 16);
 656         if (!sabi_iface) {
 657                 pr_err("Can't remap %x\n", ifaceP);
 658                 goto error_no_signature;
 659         }
 660         if (debug) {
 661                 printk(KERN_DEBUG "ifaceP = 0x%08x\n", ifaceP);
 662                 printk(KERN_DEBUG "sabi_iface = %p\n", sabi_iface);
 663
 664                 test_backlight();
 665                 test_wireless();
 666
 667                 retval = sabi_get_command(sabi_config->commands.get_brightness,
 668                                           &sretval);
 669                 printk(KERN_DEBUG "brightness = 0x%02x\n", sretval.retval[0]);
 670         }
 671
 672         /* Turn on "Linux" mode in the BIOS */
 673         if (sabi_config->commands.set_linux != 0xff) {
 674                 retval = sabi_set_command(sabi_config->commands.set_linux,
 675                                           0x81);
 676                 if (retval) {
 677                         pr_warn("Linux mode was not set!\n");
 678                         goto error_no_platform;
 679                 }
 680         }
 681
 682         /* Check for stepping quirk */
 683         check_for_stepping_quirk();
 684
 685         /* knock up a platform device to hang stuff off of */
 686         sdev = platform_device_register_simple("samsung", -1, NULL, 0);
 687         if (IS_ERR(sdev))
 688                 goto error_no_platform;
 689
 690         /* create a backlight device to talk to this one */
 691         memset(&props, 0, sizeof(struct backlight_properties));
 692         props.type = BACKLIGHT_PLATFORM;
 693         props.max_brightness = sabi_config->max_brightness -
 694                                 sabi_config->min_brightness;
 695         backlight_device = backlight_device_register("samsung", &sdev->dev,
 696                                                      NULL, &backlight_ops,
 697                                                      &props);
 698         if (IS_ERR(backlight_device))
 699                 goto error_no_backlight;
 700
 701         backlight_device->props.brightness = read_brightness();
 702         backlight_device->props.power = FB_BLANK_UNBLANK;
 703         backlight_update_status(backlight_device);
 704
 705         retval = init_wireless(sdev);
 706         if (retval)
 707                 goto error_no_rfk;
 708
 709         retval = device_create_file(&sdev->dev, &dev_attr_performance_level);
 710         if (retval)
 711                 goto error_file_create;
 712
 713         return 0;
 714
 715 error_file_create:
 716         destroy_wireless();
 717
 718 error_no_rfk:
 719         backlight_device_unregister(backlight_device);
 720
 721 error_no_backlight:
 722         platform_device_unregister(sdev);
 723
 724 error_no_platform:
 725         iounmap(sabi_iface);
 726
 727 error_no_signature:
 728         iounmap(f0000_segment);
 729         return -EINVAL;
 730 }
 731
 732 static void __exit samsung_exit(void)
 733 {
 734         /* Turn off "Linux" mode in the BIOS */
 735         if (sabi_config->commands.set_linux != 0xff)
 736                 sabi_set_command(sabi_config->commands.set_linux, 0x80);
 737
 738         device_remove_file(&sdev->dev, &dev_attr_performance_level);
 739         backlight_device_unregister(backlight_device);
 740         destroy_wireless();
 741         iounmap(sabi_iface);
 742         iounmap(f0000_segment);
 743         platform_device_unregister(sdev);
 744 }
 745
 746 module_init(samsung_init);
 747 module_exit(samsung_exit);
 748
 749 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@suse.de>");
 750 MODULE_DESCRIPTION("Samsung Backlight driver");
 751 MODULE_LICENSE("GPL");