drivers/staging/samsung-laptop/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
 230 static int force;
 231 module_param(force, bool, 0);
 232 MODULE_PARM_DESC(force,
 233                 "Disable the DMI check and forces the driver to be loaded");
 234
 235 static int debug;
 236 module_param(debug, bool, S_IRUGO | S_IWUSR);
 237 MODULE_PARM_DESC(debug, "Debug enabled or not");
 238
 239 static int sabi_get_command(u8 command, struct sabi_retval *sretval)
 240 {
 241         int retval = 0;
 242         u16 port = readw(sabi + sabi_config->header_offsets.port);
 243         u8 complete, iface_data;
 244
 245         mutex_lock(&sabi_mutex);
 246
 247         /* enable memory to be able to write to it */
 248         outb(readb(sabi + sabi_config->header_offsets.en_mem), port);
 249
 250         /* write out the command */
 251         writew(sabi_config->main_function, sabi_iface + SABI_IFACE_MAIN);
 252         writew(command, sabi_iface + SABI_IFACE_SUB);
 253         writeb(0, sabi_iface + SABI_IFACE_COMPLETE);
 254         outb(readb(sabi + sabi_config->header_offsets.iface_func), port);
 255
 256         /* write protect memory to make it safe */
 257         outb(readb(sabi + sabi_config->header_offsets.re_mem), port);
 258
 259         /* see if the command actually succeeded */
 260         complete = readb(sabi_iface + SABI_IFACE_COMPLETE);
 261         iface_data = readb(sabi_iface + SABI_IFACE_DATA);
 262         if (complete != 0xaa || iface_data == 0xff) {
 263                 pr_warn("SABI get command 0x%02x failed with completion flag 0x%02x and data 0x%02x\n",
 264                         command, complete, iface_data);
 265                 retval = -EINVAL;
 266                 goto exit;
 267         }
 268         /*
 269          * Save off the data into a structure so the caller use it.
 270          * Right now we only want the first 4 bytes,
 271          * There are commands that need more, but not for the ones we
 272          * currently care about.
 273          */
 274         sretval->retval[0] = readb(sabi_iface + SABI_IFACE_DATA);
 275         sretval->retval[1] = readb(sabi_iface + SABI_IFACE_DATA + 1);
 276         sretval->retval[2] = readb(sabi_iface + SABI_IFACE_DATA + 2);
 277         sretval->retval[3] = readb(sabi_iface + SABI_IFACE_DATA + 3);
 278
 279 exit:
 280         mutex_unlock(&sabi_mutex);
 281         return retval;
 282
 283 }
 284
 285 static int sabi_set_command(u8 command, u8 data)
 286 {
 287         int retval = 0;
 288         u16 port = readw(sabi + sabi_config->header_offsets.port);
 289         u8 complete, iface_data;
 290
 291         mutex_lock(&sabi_mutex);
 292
 293         /* enable memory to be able to write to it */
 294         outb(readb(sabi + sabi_config->header_offsets.en_mem), port);
 295
 296         /* write out the command */
 297         writew(sabi_config->main_function, sabi_iface + SABI_IFACE_MAIN);
 298         writew(command, sabi_iface + SABI_IFACE_SUB);
 299         writeb(0, sabi_iface + SABI_IFACE_COMPLETE);
 300         writeb(data, sabi_iface + SABI_IFACE_DATA);
 301         outb(readb(sabi + sabi_config->header_offsets.iface_func), port);
 302
 303         /* write protect memory to make it safe */
 304         outb(readb(sabi + sabi_config->header_offsets.re_mem), port);
 305
 306         /* see if the command actually succeeded */
 307         complete = readb(sabi_iface + SABI_IFACE_COMPLETE);
 308         iface_data = readb(sabi_iface + SABI_IFACE_DATA);
 309         if (complete != 0xaa || iface_data == 0xff) {
 310                 pr_warn("SABI set command 0x%02x failed with completion flag 0x%02x and data 0x%02x\n",
 311                        command, complete, iface_data);
 312                 retval = -EINVAL;
 313         }
 314
 315         mutex_unlock(&sabi_mutex);
 316         return retval;
 317 }
 318
 319 static void test_backlight(void)
 320 {
 321         struct sabi_retval sretval;
 322
 323         sabi_get_command(sabi_config->commands.get_backlight, &sretval);
 324         printk(KERN_DEBUG "backlight = 0x%02x\n", sretval.retval[0]);
 325
 326         sabi_set_command(sabi_config->commands.set_backlight, 0);
 327         printk(KERN_DEBUG "backlight should be off\n");
 328
 329         sabi_get_command(sabi_config->commands.get_backlight, &sretval);
 330         printk(KERN_DEBUG "backlight = 0x%02x\n", sretval.retval[0]);
 331
 332         msleep(1000);
 333
 334         sabi_set_command(sabi_config->commands.set_backlight, 1);
 335         printk(KERN_DEBUG "backlight should be on\n");
 336
 337         sabi_get_command(sabi_config->commands.get_backlight, &sretval);
 338         printk(KERN_DEBUG "backlight = 0x%02x\n", sretval.retval[0]);
 339 }
 340
 341 static void test_wireless(void)
 342 {
 343         struct sabi_retval sretval;
 344
 345         sabi_get_command(sabi_config->commands.get_wireless_button, &sretval);
 346         printk(KERN_DEBUG "wireless led = 0x%02x\n", sretval.retval[0]);
 347
 348         sabi_set_command(sabi_config->commands.set_wireless_button, 0);
 349         printk(KERN_DEBUG "wireless led should be off\n");
 350
 351         sabi_get_command(sabi_config->commands.get_wireless_button, &sretval);
 352         printk(KERN_DEBUG "wireless led = 0x%02x\n", sretval.retval[0]);
 353
 354         msleep(1000);
 355
 356         sabi_set_command(sabi_config->commands.set_wireless_button, 1);
 357         printk(KERN_DEBUG "wireless led should be on\n");
 358
 359         sabi_get_command(sabi_config->commands.get_wireless_button, &sretval);
 360         printk(KERN_DEBUG "wireless led = 0x%02x\n", sretval.retval[0]);
 361 }
 362
 363 static u8 read_brightness(void)
 364 {
 365         struct sabi_retval sretval;
 366         int user_brightness = 0;
 367         int retval;
 368
 369         retval = sabi_get_command(sabi_config->commands.get_brightness,
 370                                   &sretval);
 371         if (!retval) {
 372                 user_brightness = sretval.retval[0];
 373                 if (user_brightness != 0)
 374                         user_brightness -= sabi_config->min_brightness;
 375         }
 376         return user_brightness;
 377 }
 378
 379 static void set_brightness(u8 user_brightness)
 380 {
 381         u8 user_level = user_brightness - sabi_config->min_brightness;
 382
 383         sabi_set_command(sabi_config->commands.set_brightness, user_level);
 384 }
 385
 386 static int get_brightness(struct backlight_device *bd)
 387 {
 388         return (int)read_brightness();
 389 }
 390
 391 static int update_status(struct backlight_device *bd)
 392 {
 393         set_brightness(bd->props.brightness);
 394
 395         if (bd->props.power == FB_BLANK_UNBLANK)
 396                 sabi_set_command(sabi_config->commands.set_backlight, 1);
 397         else
 398                 sabi_set_command(sabi_config->commands.set_backlight, 0);
 399         return 0;
 400 }
 401
 402 static const struct backlight_ops backlight_ops = {
 403         .get_brightness = get_brightness,
 404         .update_status  = update_status,
 405 };
 406
 407 static int rfkill_set(void *data, bool blocked)
 408 {
 409         /* Do something with blocked...*/
 410         /*
 411          * blocked == false is on
 412          * blocked == true is off
 413          */
 414         if (blocked)
 415                 sabi_set_command(sabi_config->commands.set_wireless_button, 0);
 416         else
 417                 sabi_set_command(sabi_config->commands.set_wireless_button, 1);
 418
 419         return 0;
 420 }
 421
 422 static struct rfkill_ops rfkill_ops = {
 423         .set_block = rfkill_set,
 424 };
 425
 426 static int init_wireless(struct platform_device *sdev)
 427 {
 428         int retval;
 429
 430         rfk = rfkill_alloc("samsung-wifi", &sdev->dev, RFKILL_TYPE_WLAN,
 431                            &rfkill_ops, NULL);
 432         if (!rfk)
 433                 return -ENOMEM;
 434
 435         retval = rfkill_register(rfk);
 436         if (retval) {
 437                 rfkill_destroy(rfk);
 438                 return -ENODEV;
 439         }
 440
 441         return 0;
 442 }
 443
 444 static void destroy_wireless(void)
 445 {
 446         rfkill_unregister(rfk);
 447         rfkill_destroy(rfk);
 448 }
 449
 450 static ssize_t get_performance_level(struct device *dev,
 451                                      struct device_attribute *attr, char *buf)
 452 {
 453         struct sabi_retval sretval;
 454         int retval;
 455         int i;
 456
 457         /* Read the state */
 458         retval = sabi_get_command(sabi_config->commands.get_performance_level,
 459                                   &sretval);
 460         if (retval)
 461                 return retval;
 462
 463         /* The logic is backwards, yeah, lots of fun... */
 464         for (i = 0; sabi_config->performance_levels[i].name; ++i) {
 465                 if (sretval.retval[0] == sabi_config->performance_levels[i].value)
 466                         return sprintf(buf, "%s\n", sabi_config->performance_levels[i].name);
 467         }
 468         return sprintf(buf, "%s\n", "unknown");
 469 }
 470
 471 static ssize_t set_performance_level(struct device *dev,
 472                                 struct device_attribute *attr, const char *buf,
 473                                 size_t count)
 474 {
 475         if (count >= 1) {
 476                 int i;
 477                 for (i = 0; sabi_config->performance_levels[i].name; ++i) {
 478                         const struct sabi_performance_level *level =
 479                                 &sabi_config->performance_levels[i];
 480                         if (!strncasecmp(level->name, buf, strlen(level->name))) {
 481                                 sabi_set_command(sabi_config->commands.set_performance_level,
 482                                                  level->value);
 483                                 break;
 484                         }
 485                 }
 486                 if (!sabi_config->performance_levels[i].name)
 487                         return -EINVAL;
 488         }
 489         return count;
 490 }
 491 static DEVICE_ATTR(performance_level, S_IWUSR | S_IRUGO,
 492                    get_performance_level, set_performance_level);
 493
 494
 495 static int __init dmi_check_cb(const struct dmi_system_id *id)
 496 {
 497         pr_info("found laptop model '%s'\n",
 498                 id->ident);
 499         return 0;
 500 }
 501
 502 static struct dmi_system_id __initdata samsung_dmi_table[] = {
 503         {
 504                 .ident = "N128",
 505                 .matches = {
 506                         DMI_MATCH(DMI_SYS_VENDOR,
 507                                         "SAMSUNG ELECTRONICS CO., LTD."),
 508                         DMI_MATCH(DMI_PRODUCT_NAME, "N128"),
 509                         DMI_MATCH(DMI_BOARD_NAME, "N128"),
 510                 },
 511                 .callback = dmi_check_cb,
 512         },
 513         {
 514                 .ident = "N130",
 515                 .matches = {
 516                         DMI_MATCH(DMI_SYS_VENDOR,
 517                                         "SAMSUNG ELECTRONICS CO., LTD."),
 518                         DMI_MATCH(DMI_PRODUCT_NAME, "N130"),
 519                         DMI_MATCH(DMI_BOARD_NAME, "N130"),
 520                 },
 521                 .callback = dmi_check_cb,
 522         },
 523         {
 524                 .ident = "X125",
 525                 .matches = {
 526                         DMI_MATCH(DMI_SYS_VENDOR,
 527                                         "SAMSUNG ELECTRONICS CO., LTD."),
 528                         DMI_MATCH(DMI_PRODUCT_NAME, "X125"),
 529                         DMI_MATCH(DMI_BOARD_NAME, "X125"),
 530                 },
 531                 .callback = dmi_check_cb,
 532         },
 533         {
 534                 .ident = "X120/X170",
 535                 .matches = {
 536                         DMI_MATCH(DMI_SYS_VENDOR,
 537                                         "SAMSUNG ELECTRONICS CO., LTD."),
 538                         DMI_MATCH(DMI_PRODUCT_NAME, "X120/X170"),
 539                         DMI_MATCH(DMI_BOARD_NAME, "X120/X170"),
 540                 },
 541                 .callback = dmi_check_cb,
 542         },
 543         {
 544                 .ident = "NC10",
 545                 .matches = {
 546                         DMI_MATCH(DMI_SYS_VENDOR,
 547                                         "SAMSUNG ELECTRONICS CO., LTD."),
 548                         DMI_MATCH(DMI_PRODUCT_NAME, "NC10"),
 549                         DMI_MATCH(DMI_BOARD_NAME, "NC10"),
 550                 },
 551                 .callback = dmi_check_cb,
 552         },
 553                 {
 554                 .ident = "NP-Q45",
 555                 .matches = {
 556                         DMI_MATCH(DMI_SYS_VENDOR,
 557                                         "SAMSUNG ELECTRONICS CO., LTD."),
 558                         DMI_MATCH(DMI_PRODUCT_NAME, "SQ45S70S"),
 559                         DMI_MATCH(DMI_BOARD_NAME, "SQ45S70S"),
 560                 },
 561                 .callback = dmi_check_cb,
 562                 },
 563         {
 564                 .ident = "X360",
 565                 .matches = {
 566                         DMI_MATCH(DMI_SYS_VENDOR,
 567                                         "SAMSUNG ELECTRONICS CO., LTD."),
 568                         DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
 569                         DMI_MATCH(DMI_BOARD_NAME, "X360"),
 570                 },
 571                 .callback = dmi_check_cb,
 572         },
 573         {
 574                 .ident = "R410 Plus",
 575                 .matches = {
 576                         DMI_MATCH(DMI_SYS_VENDOR,
 577                                         "SAMSUNG ELECTRONICS CO., LTD."),
 578                         DMI_MATCH(DMI_PRODUCT_NAME, "R410P"),
 579                         DMI_MATCH(DMI_BOARD_NAME, "R460"),
 580                 },
 581                 .callback = dmi_check_cb,
 582         },
 583         {
 584                 .ident = "R518",
 585                 .matches = {
 586                         DMI_MATCH(DMI_SYS_VENDOR,
 587                                         "SAMSUNG ELECTRONICS CO., LTD."),
 588                         DMI_MATCH(DMI_PRODUCT_NAME, "R518"),
 589                         DMI_MATCH(DMI_BOARD_NAME, "R518"),
 590                 },
 591                 .callback = dmi_check_cb,
 592         },
 593         {
 594                 .ident = "R519/R719",
 595                 .matches = {
 596                         DMI_MATCH(DMI_SYS_VENDOR,
 597                                         "SAMSUNG ELECTRONICS CO., LTD."),
 598                         DMI_MATCH(DMI_PRODUCT_NAME, "R519/R719"),
 599                         DMI_MATCH(DMI_BOARD_NAME, "R519/R719"),
 600                 },
 601                 .callback = dmi_check_cb,
 602         },
 603         {
 604                 .ident = "N150/N210/N220/N230",
 605                 .matches = {
 606                         DMI_MATCH(DMI_SYS_VENDOR,
 607                                         "SAMSUNG ELECTRONICS CO., LTD."),
 608                         DMI_MATCH(DMI_PRODUCT_NAME, "N150/N210/N220/N230"),
 609                         DMI_MATCH(DMI_BOARD_NAME, "N150/N210/N220/N230"),
 610                 },
 611                 .callback = dmi_check_cb,
 612         },
 613         {
 614                 .ident = "N150P/N210P/N220P",
 615                 .matches = {
 616                         DMI_MATCH(DMI_SYS_VENDOR,
 617                                         "SAMSUNG ELECTRONICS CO., LTD."),
 618                         DMI_MATCH(DMI_PRODUCT_NAME, "N150P/N210P/N220P"),
 619                         DMI_MATCH(DMI_BOARD_NAME, "N150P/N210P/N220P"),
 620                 },
 621                 .callback = dmi_check_cb,
 622         },
 623         {
 624                 .ident = "R530/R730",
 625                 .matches = {
 626                       DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 627                       DMI_MATCH(DMI_PRODUCT_NAME, "R530/R730"),
 628                       DMI_MATCH(DMI_BOARD_NAME, "R530/R730"),
 629                 },
 630                 .callback = dmi_check_cb,
 631         },
 632         {
 633                 .ident = "NF110/NF210/NF310",
 634                 .matches = {
 635                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 636                         DMI_MATCH(DMI_PRODUCT_NAME, "NF110/NF210/NF310"),
 637                         DMI_MATCH(DMI_BOARD_NAME, "NF110/NF210/NF310"),
 638                 },
 639                 .callback = dmi_check_cb,
 640         },
 641         {
 642                 .ident = "N145P/N250P/N260P",
 643                 .matches = {
 644                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 645                         DMI_MATCH(DMI_PRODUCT_NAME, "N145P/N250P/N260P"),
 646                         DMI_MATCH(DMI_BOARD_NAME, "N145P/N250P/N260P"),
 647                 },
 648                 .callback = dmi_check_cb,
 649         },
 650         {
 651                 .ident = "R70/R71",
 652                 .matches = {
 653                         DMI_MATCH(DMI_SYS_VENDOR,
 654                                         "SAMSUNG ELECTRONICS CO., LTD."),
 655                         DMI_MATCH(DMI_PRODUCT_NAME, "R70/R71"),
 656                         DMI_MATCH(DMI_BOARD_NAME, "R70/R71"),
 657                 },
 658                 .callback = dmi_check_cb,
 659         },
 660         {
 661                 .ident = "P460",
 662                 .matches = {
 663                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 664                         DMI_MATCH(DMI_PRODUCT_NAME, "P460"),
 665                         DMI_MATCH(DMI_BOARD_NAME, "P460"),
 666                 },
 667                 .callback = dmi_check_cb,
 668         },
 669         { },
 670 };
 671 MODULE_DEVICE_TABLE(dmi, samsung_dmi_table);
 672
 673 static int find_signature(void __iomem *memcheck, const char *testStr)
 674 {
 675         int i = 0;
 676         int loca;
 677
 678         for (loca = 0; loca < 0xffff; loca++) {
 679                 char temp = readb(memcheck + loca);
 680
 681                 if (temp == testStr[i]) {
 682                         if (i == strlen(testStr)-1)
 683                                 break;
 684                         ++i;
 685                 } else {
 686                         i = 0;
 687                 }
 688         }
 689         return loca;
 690 }
 691
 692 static int __init samsung_init(void)
 693 {
 694         struct backlight_properties props;
 695         struct sabi_retval sretval;
 696         unsigned int ifaceP;
 697         int i;
 698         int loca;
 699         int retval;
 700
 701         mutex_init(&sabi_mutex);
 702
 703         if (!force && !dmi_check_system(samsung_dmi_table))
 704                 return -ENODEV;
 705
 706         f0000_segment = ioremap_nocache(0xf0000, 0xffff);
 707         if (!f0000_segment) {
 708                 pr_err("Can't map the segment at 0xf0000\n");
 709                 return -EINVAL;
 710         }
 711
 712         /* Try to find one of the signatures in memory to find the header */
 713         for (i = 0; sabi_configs[i].test_string != 0; ++i) {
 714                 sabi_config = &sabi_configs[i];
 715                 loca = find_signature(f0000_segment, sabi_config->test_string);
 716                 if (loca != 0xffff)
 717                         break;
 718         }
 719
 720         if (loca == 0xffff) {
 721                 pr_err("This computer does not support SABI\n");
 722                 goto error_no_signature;
 723         }
 724
 725         /* point to the SMI port Number */
 726         loca += 1;
 727         sabi = (f0000_segment + loca);
 728
 729         if (debug) {
 730                 printk(KERN_DEBUG "This computer supports SABI==%x\n",
 731                         loca + 0xf0000 - 6);
 732                 printk(KERN_DEBUG "SABI header:\n");
 733                 printk(KERN_DEBUG " SMI Port Number = 0x%04x\n",
 734                         readw(sabi + sabi_config->header_offsets.port));
 735                 printk(KERN_DEBUG " SMI Interface Function = 0x%02x\n",
 736                         readb(sabi + sabi_config->header_offsets.iface_func));
 737                 printk(KERN_DEBUG " SMI enable memory buffer = 0x%02x\n",
 738                         readb(sabi + sabi_config->header_offsets.en_mem));
 739                 printk(KERN_DEBUG " SMI restore memory buffer = 0x%02x\n",
 740                         readb(sabi + sabi_config->header_offsets.re_mem));
 741                 printk(KERN_DEBUG " SABI data offset = 0x%04x\n",
 742                         readw(sabi + sabi_config->header_offsets.data_offset));
 743                 printk(KERN_DEBUG " SABI data segment = 0x%04x\n",
 744                         readw(sabi + sabi_config->header_offsets.data_segment));
 745         }
 746
 747         /* Get a pointer to the SABI Interface */
 748         ifaceP = (readw(sabi + sabi_config->header_offsets.data_segment) & 0x0ffff) << 4;
 749         ifaceP += readw(sabi + sabi_config->header_offsets.data_offset) & 0x0ffff;
 750         sabi_iface = ioremap_nocache(ifaceP, 16);
 751         if (!sabi_iface) {
 752                 pr_err("Can't remap %x\n", ifaceP);
 753                 goto exit;
 754         }
 755         if (debug) {
 756                 printk(KERN_DEBUG "ifaceP = 0x%08x\n", ifaceP);
 757                 printk(KERN_DEBUG "sabi_iface = %p\n", sabi_iface);
 758
 759                 test_backlight();
 760                 test_wireless();
 761
 762                 retval = sabi_get_command(sabi_config->commands.get_brightness,
 763                                           &sretval);
 764                 printk(KERN_DEBUG "brightness = 0x%02x\n", sretval.retval[0]);
 765         }
 766
 767         /* Turn on "Linux" mode in the BIOS */
 768         if (sabi_config->commands.set_linux != 0xff) {
 769                 retval = sabi_set_command(sabi_config->commands.set_linux,
 770                                           0x81);
 771                 if (retval) {
 772                         pr_warn("Linux mode was not set!\n");
 773                         goto error_no_platform;
 774                 }
 775         }
 776
 777         /* knock up a platform device to hang stuff off of */
 778         sdev = platform_device_register_simple("samsung", -1, NULL, 0);
 779         if (IS_ERR(sdev))
 780                 goto error_no_platform;
 781
 782         /* create a backlight device to talk to this one */
 783         memset(&props, 0, sizeof(struct backlight_properties));
 784         props.type = BACKLIGHT_PLATFORM;
 785         props.max_brightness = sabi_config->max_brightness;
 786         backlight_device = backlight_device_register("samsung", &sdev->dev,
 787                                                      NULL, &backlight_ops,
 788                                                      &props);
 789         if (IS_ERR(backlight_device))
 790                 goto error_no_backlight;
 791
 792         backlight_device->props.brightness = read_brightness();
 793         backlight_device->props.power = FB_BLANK_UNBLANK;
 794         backlight_update_status(backlight_device);
 795
 796         retval = init_wireless(sdev);
 797         if (retval)
 798                 goto error_no_rfk;
 799
 800         retval = device_create_file(&sdev->dev, &dev_attr_performance_level);
 801         if (retval)
 802                 goto error_file_create;
 803
 804 exit:
 805         return 0;
 806
 807 error_file_create:
 808         destroy_wireless();
 809
 810 error_no_rfk:
 811         backlight_device_unregister(backlight_device);
 812
 813 error_no_backlight:
 814         platform_device_unregister(sdev);
 815
 816 error_no_platform:
 817         iounmap(sabi_iface);
 818
 819 error_no_signature:
 820         iounmap(f0000_segment);
 821         return -EINVAL;
 822 }
 823
 824 static void __exit samsung_exit(void)
 825 {
 826         /* Turn off "Linux" mode in the BIOS */
 827         if (sabi_config->commands.set_linux != 0xff)
 828                 sabi_set_command(sabi_config->commands.set_linux, 0x80);
 829
 830         device_remove_file(&sdev->dev, &dev_attr_performance_level);
 831         backlight_device_unregister(backlight_device);
 832         destroy_wireless();
 833         iounmap(sabi_iface);
 834         iounmap(f0000_segment);
 835         platform_device_unregister(sdev);
 836 }
 837
 838 module_init(samsung_init);
 839 module_exit(samsung_exit);
 840
 841 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@suse.de>");
 842 MODULE_DESCRIPTION("Samsung Backlight driver");
 843 MODULE_LICENSE("GPL");