drivers/ide/ide-acpi.c

   1 /*
   2  * Provides ACPI support for IDE drives.
   3  *
   4  * Copyright (C) 2005 Intel Corp.
   5  * Copyright (C) 2005 Randy Dunlap
   6  * Copyright (C) 2006 SUSE Linux Products GmbH
   7  * Copyright (C) 2006 Hannes Reinecke
   8  */
   9
  10 #include <linux/ata.h>
  11 #include <linux/delay.h>
  12 #include <linux/device.h>
  13 #include <linux/errno.h>
  14 #include <linux/kernel.h>
  15 #include <acpi/acpi.h>
  16 #include <linux/ide.h>
  17 #include <linux/pci.h>
  18 #include <linux/dmi.h>
  19
  20 #include <acpi/acpi_bus.h>
  21 #include <acpi/acnames.h>
  22 #include <acpi/acnamesp.h>
  23 #include <acpi/acparser.h>
  24 #include <acpi/acexcep.h>
  25 #include <acpi/acmacros.h>
  26 #include <acpi/actypes.h>
  27
  28 #define REGS_PER_GTF            7
  29 struct taskfile_array {
  30         u8      tfa[REGS_PER_GTF];      /* regs. 0x1f1 - 0x1f7 */
  31 };
  32
  33 struct GTM_buffer {
  34         u32     PIO_speed0;
  35         u32     DMA_speed0;
  36         u32     PIO_speed1;
  37         u32     DMA_speed1;
  38         u32     GTM_flags;
  39 };
  40
  41 struct ide_acpi_drive_link {
  42         ide_drive_t     *drive;
  43         acpi_handle      obj_handle;
  44         u8               idbuff[512];
  45 };
  46
  47 struct ide_acpi_hwif_link {
  48         ide_hwif_t                      *hwif;
  49         acpi_handle                      obj_handle;
  50         struct GTM_buffer                gtm;
  51         struct ide_acpi_drive_link       master;
  52         struct ide_acpi_drive_link       slave;
  53 };
  54
  55 #undef DEBUGGING
  56 /* note: adds function name and KERN_DEBUG */
  57 #ifdef DEBUGGING
  58 #define DEBPRINT(fmt, args...)  \
  59                 printk(KERN_DEBUG "%s: " fmt, __FUNCTION__, ## args)
  60 #else
  61 #define DEBPRINT(fmt, args...)  do {} while (0)
  62 #endif  /* DEBUGGING */
  63
  64 extern int ide_noacpi;
  65 extern int ide_noacpitfs;
  66 extern int ide_noacpionboot;
  67
  68 static bool ide_noacpi_psx;
  69 static int no_acpi_psx(const struct dmi_system_id *id)
  70 {
  71         ide_noacpi_psx = true;
  72         printk(KERN_NOTICE"%s detected - disable ACPI _PSx.\n", id->ident);
  73         return 0;
  74 }
  75
  76 static const struct dmi_system_id ide_acpi_dmi_table[] = {
  77         /* Bug 9673. */
  78         /* We should check if this is because ACPI NVS isn't save/restored. */
  79         {
  80                 .callback = no_acpi_psx,
  81                 .ident    = "HP nx9005",
  82                 .matches  = {
  83                         DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies Ltd."),
  84                         DMI_MATCH(DMI_BIOS_VERSION, "KAM1.60")
  85                 },
  86         },
  87
  88         { }     /* terminate list */
  89 };
  90
  91 static int ide_acpi_blacklist(void)
  92 {
  93         static int done;
  94         if (done)
  95                 return 0;
  96         done = 1;
  97         dmi_check_system(ide_acpi_dmi_table);
  98         return 0;
  99 }
 100
 101 /**
 102  * ide_get_dev_handle - finds acpi_handle and PCI device.function
 103  * @dev: device to locate
 104  * @handle: returned acpi_handle for @dev
 105  * @pcidevfn: return PCI device.func for @dev
 106  *
 107  * Returns the ACPI object handle to the corresponding PCI device.
 108  *
 109  * Returns 0 on success, <0 on error.
 110  */
 111 static int ide_get_dev_handle(struct device *dev, acpi_handle *handle,
 112                                acpi_integer *pcidevfn)
 113 {
 114         struct pci_dev *pdev = to_pci_dev(dev);
 115         unsigned int bus, devnum, func;
 116         acpi_integer addr;
 117         acpi_handle dev_handle;
 118         struct acpi_buffer buffer = {.length = ACPI_ALLOCATE_BUFFER,
 119                                         .pointer = NULL};
 120         acpi_status status;
 121         struct acpi_device_info *dinfo = NULL;
 122         int ret = -ENODEV;
 123
 124         bus = pdev->bus->number;
 125         devnum = PCI_SLOT(pdev->devfn);
 126         func = PCI_FUNC(pdev->devfn);
 127         /* ACPI _ADR encoding for PCI bus: */
 128         addr = (acpi_integer)(devnum << 16 | func);
 129
 130         DEBPRINT("ENTER: pci %02x:%02x.%01x\n", bus, devnum, func);
 131
 132         dev_handle = DEVICE_ACPI_HANDLE(dev);
 133         if (!dev_handle) {
 134                 DEBPRINT("no acpi handle for device\n");
 135                 goto err;
 136         }
 137
 138         status = acpi_get_object_info(dev_handle, &buffer);
 139         if (ACPI_FAILURE(status)) {
 140                 DEBPRINT("get_object_info for device failed\n");
 141                 goto err;
 142         }
 143         dinfo = buffer.pointer;
 144         if (dinfo && (dinfo->valid & ACPI_VALID_ADR) &&
 145             dinfo->address == addr) {
 146                 *pcidevfn = addr;
 147                 *handle = dev_handle;
 148         } else {
 149                 DEBPRINT("get_object_info for device has wrong "
 150                         " address: %llu, should be %u\n",
 151                         dinfo ? (unsigned long long)dinfo->address : -1ULL,
 152                         (unsigned int)addr);
 153                 goto err;
 154         }
 155
 156         DEBPRINT("for dev=0x%x.%x, addr=0x%llx, *handle=0x%p\n",
 157                  devnum, func, (unsigned long long)addr, *handle);
 158         ret = 0;
 159 err:
 160         kfree(dinfo);
 161         return ret;
 162 }
 163
 164 /**
 165  * ide_acpi_hwif_get_handle - Get ACPI object handle for a given hwif
 166  * @hwif: device to locate
 167  *
 168  * Retrieves the object handle for a given hwif.
 169  *
 170  * Returns handle on success, 0 on error.
 171  */
 172 static acpi_handle ide_acpi_hwif_get_handle(ide_hwif_t *hwif)
 173 {
 174         struct device           *dev = hwif->gendev.parent;
 175         acpi_handle             dev_handle;
 176         acpi_integer            pcidevfn;
 177         acpi_handle             chan_handle;
 178         int                     err;
 179
 180         DEBPRINT("ENTER: device %s\n", hwif->name);
 181
 182         if (!dev) {
 183                 DEBPRINT("no PCI device for %s\n", hwif->name);
 184                 return NULL;
 185         }
 186
 187         err = ide_get_dev_handle(dev, &dev_handle, &pcidevfn);
 188         if (err < 0) {
 189                 DEBPRINT("ide_get_dev_handle failed (%d)\n", err);
 190                 return NULL;
 191         }
 192
 193         /* get child objects of dev_handle == channel objects,
 194          * + _their_ children == drive objects */
 195         /* channel is hwif->channel */
 196         chan_handle = acpi_get_child(dev_handle, hwif->channel);
 197         DEBPRINT("chan adr=%d: handle=0x%p\n",
 198                  hwif->channel, chan_handle);
 199
 200         return chan_handle;
 201 }
 202
 203 /**
 204  * ide_acpi_drive_get_handle - Get ACPI object handle for a given drive
 205  * @drive: device to locate
 206  *
 207  * Retrieves the object handle of a given drive. According to the ACPI
 208  * spec the drive is a child of the hwif.
 209  *
 210  * Returns handle on success, 0 on error.
 211  */
 212 static acpi_handle ide_acpi_drive_get_handle(ide_drive_t *drive)
 213 {
 214         ide_hwif_t      *hwif = HWIF(drive);
 215         int              port;
 216         acpi_handle      drive_handle;
 217
 218         if (!hwif->acpidata)
 219                 return NULL;
 220
 221         if (!hwif->acpidata->obj_handle)
 222                 return NULL;
 223
 224         port = hwif->channel ? drive->dn - 2: drive->dn;
 225
 226         DEBPRINT("ENTER: %s at channel#: %d port#: %d\n",
 227                  drive->name, hwif->channel, port);
 228
 229
 230         /* TBD: could also check ACPI object VALID bits */
 231         drive_handle = acpi_get_child(hwif->acpidata->obj_handle, port);
 232         DEBPRINT("drive %s handle 0x%p\n", drive->name, drive_handle);
 233
 234         return drive_handle;
 235 }
 236
 237 /**
 238  * do_drive_get_GTF - get the drive bootup default taskfile settings
 239  * @drive: the drive for which the taskfile settings should be retrieved
 240  * @gtf_length: number of bytes of _GTF data returned at @gtf_address
 241  * @gtf_address: buffer containing _GTF taskfile arrays
 242  *
 243  * The _GTF method has no input parameters.
 244  * It returns a variable number of register set values (registers
 245  * hex 1F1..1F7, taskfiles).
 246  * The <variable number> is not known in advance, so have ACPI-CA
 247  * allocate the buffer as needed and return it, then free it later.
 248  *
 249  * The returned @gtf_length and @gtf_address are only valid if the
 250  * function return value is 0.
 251  */
 252 static int do_drive_get_GTF(ide_drive_t *drive,
 253                      unsigned int *gtf_length, unsigned long *gtf_address,
 254                      unsigned long *obj_loc)
 255 {
 256         acpi_status                     status;
 257         struct acpi_buffer              output;
 258         union acpi_object               *out_obj;
 259         ide_hwif_t                      *hwif = HWIF(drive);
 260         struct device                   *dev = hwif->gendev.parent;
 261         int                             err = -ENODEV;
 262         int                             port;
 263
 264         *gtf_length = 0;
 265         *gtf_address = 0UL;
 266         *obj_loc = 0UL;
 267
 268         if (ide_noacpi)
 269                 return 0;
 270
 271         if (!dev) {
 272                 DEBPRINT("no PCI device for %s\n", hwif->name);
 273                 goto out;
 274         }
 275
 276         if (!hwif->acpidata) {
 277                 DEBPRINT("no ACPI data for %s\n", hwif->name);
 278                 goto out;
 279         }
 280
 281         port = hwif->channel ? drive->dn - 2: drive->dn;
 282
 283         if (!drive->acpidata) {
 284                 if (port == 0) {
 285                         drive->acpidata = &hwif->acpidata->master;
 286                         hwif->acpidata->master.drive = drive;
 287                 } else {
 288                         drive->acpidata = &hwif->acpidata->slave;
 289                         hwif->acpidata->slave.drive = drive;
 290                 }
 291         }
 292
 293         DEBPRINT("ENTER: %s at %s, port#: %d, hard_port#: %d\n",
 294                  hwif->name, dev->bus_id, port, hwif->channel);
 295
 296         if (!drive->present) {
 297                 DEBPRINT("%s drive %d:%d not present\n",
 298                          hwif->name, hwif->channel, port);
 299                 goto out;
 300         }
 301
 302         /* Get this drive's _ADR info. if not already known. */
 303         if (!drive->acpidata->obj_handle) {
 304                 drive->acpidata->obj_handle = ide_acpi_drive_get_handle(drive);
 305                 if (!drive->acpidata->obj_handle) {
 306                         DEBPRINT("No ACPI object found for %s\n",
 307                                  drive->name);
 308                         goto out;
 309                 }
 310         }
 311
 312         /* Setting up output buffer */
 313         output.length = ACPI_ALLOCATE_BUFFER;
 314         output.pointer = NULL;  /* ACPI-CA sets this; save/free it later */
 315
 316         /* _GTF has no input parameters */
 317         err = -EIO;
 318         status = acpi_evaluate_object(drive->acpidata->obj_handle, "_GTF",
 319                                       NULL, &output);
 320         if (ACPI_FAILURE(status)) {
 321                 printk(KERN_DEBUG
 322                        "%s: Run _GTF error: status = 0x%x\n",
 323                        __FUNCTION__, status);
 324                 goto out;
 325         }
 326
 327         if (!output.length || !output.pointer) {
 328                 DEBPRINT("Run _GTF: "
 329                        "length or ptr is NULL (0x%llx, 0x%p)\n",
 330                        (unsigned long long)output.length,
 331                        output.pointer);
 332                 goto out;
 333         }
 334
 335         out_obj = output.pointer;
 336         if (out_obj->type != ACPI_TYPE_BUFFER) {
 337                 DEBPRINT("Run _GTF: error: "
 338                        "expected object type of ACPI_TYPE_BUFFER, "
 339                        "got 0x%x\n", out_obj->type);
 340                 err = -ENOENT;
 341                 kfree(output.pointer);
 342                 goto out;
 343         }
 344
 345         if (!out_obj->buffer.length || !out_obj->buffer.pointer ||
 346             out_obj->buffer.length % REGS_PER_GTF) {
 347                 printk(KERN_ERR
 348                        "%s: unexpected GTF length (%d) or addr (0x%p)\n",
 349                        __FUNCTION__, out_obj->buffer.length,
 350                        out_obj->buffer.pointer);
 351                 err = -ENOENT;
 352                 kfree(output.pointer);
 353                 goto out;
 354         }
 355
 356         *gtf_length = out_obj->buffer.length;
 357         *gtf_address = (unsigned long)out_obj->buffer.pointer;
 358         *obj_loc = (unsigned long)out_obj;
 359         DEBPRINT("returning gtf_length=%d, gtf_address=0x%lx, obj_loc=0x%lx\n",
 360                  *gtf_length, *gtf_address, *obj_loc);
 361         err = 0;
 362 out:
 363         return err;
 364 }
 365
 366 /**
 367  * taskfile_load_raw - send taskfile registers to drive
 368  * @drive: drive to which output is sent
 369  * @gtf: raw ATA taskfile register set (0x1f1 - 0x1f7)
 370  *
 371  * Outputs IDE taskfile to the drive.
 372  */
 373 static int taskfile_load_raw(ide_drive_t *drive,
 374                               const struct taskfile_array *gtf)
 375 {
 376         ide_task_t args;
 377         int err = 0;
 378
 379         DEBPRINT("(0x1f1-1f7): hex: "
 380                "%02x %02x %02x %02x %02x %02x %02x\n",
 381                gtf->tfa[0], gtf->tfa[1], gtf->tfa[2],
 382                gtf->tfa[3], gtf->tfa[4], gtf->tfa[5], gtf->tfa[6]);
 383
 384         memset(&args, 0, sizeof(ide_task_t));
 385
 386         /* convert gtf to IDE Taskfile */
 387         memcpy(&args.tf_array[7], &gtf->tfa, 7);
 388         args.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE;
 389
 390         if (ide_noacpitfs) {
 391                 DEBPRINT("_GTF execution disabled\n");
 392                 return err;
 393         }
 394
 395         err = ide_no_data_taskfile(drive, &args);
 396         if (err)
 397                 printk(KERN_ERR "%s: ide_no_data_taskfile failed: %u\n",
 398                        __FUNCTION__, err);
 399
 400         return err;
 401 }
 402
 403 /**
 404  * do_drive_set_taskfiles - write the drive taskfile settings from _GTF
 405  * @drive: the drive to which the taskfile command should be sent
 406  * @gtf_length: total number of bytes of _GTF taskfiles
 407  * @gtf_address: location of _GTF taskfile arrays
 408  *
 409  * Write {gtf_address, length gtf_length} in groups of
 410  * REGS_PER_GTF bytes.
 411  */
 412 static int do_drive_set_taskfiles(ide_drive_t *drive,
 413                                   unsigned int gtf_length,
 414                                   unsigned long gtf_address)
 415 {
 416         int                     rc = -ENODEV, err;
 417         int                     gtf_count = gtf_length / REGS_PER_GTF;
 418         int                     ix;
 419         struct taskfile_array   *gtf;
 420
 421         if (ide_noacpi)
 422                 return 0;
 423
 424         DEBPRINT("ENTER: %s, hard_port#: %d\n", drive->name, drive->dn);
 425
 426         if (!drive->present)
 427                 goto out;
 428         if (!gtf_count)         /* shouldn't be here */
 429                 goto out;
 430
 431         DEBPRINT("total GTF bytes=%u (0x%x), gtf_count=%d, addr=0x%lx\n",
 432                  gtf_length, gtf_length, gtf_count, gtf_address);
 433
 434         if (gtf_length % REGS_PER_GTF) {
 435                 printk(KERN_ERR "%s: unexpected GTF length (%d)\n",
 436                        __FUNCTION__, gtf_length);
 437                 goto out;
 438         }
 439
 440         rc = 0;
 441         for (ix = 0; ix < gtf_count; ix++) {
 442                 gtf = (struct taskfile_array *)
 443                         (gtf_address + ix * REGS_PER_GTF);
 444
 445                 /* send all TaskFile registers (0x1f1-0x1f7) *in*that*order* */
 446                 err = taskfile_load_raw(drive, gtf);
 447                 if (err)
 448                         rc = err;
 449         }
 450
 451 out:
 452         return rc;
 453 }
 454
 455 /**
 456  * ide_acpi_exec_tfs - get then write drive taskfile settings
 457  * @drive: the drive for which the taskfile settings should be
 458  *         written.
 459  *
 460  * According to the ACPI spec this should be called after _STM
 461  * has been evaluated for the interface. Some ACPI vendors interpret
 462  * that as a hard requirement and modify the taskfile according
 463  * to the Identify Drive information passed down with _STM.
 464  * So one should really make sure to call this only after _STM has
 465  * been executed.
 466  */
 467 int ide_acpi_exec_tfs(ide_drive_t *drive)
 468 {
 469         int             ret;
 470         unsigned int    gtf_length;
 471         unsigned long   gtf_address;
 472         unsigned long   obj_loc;
 473
 474         if (ide_noacpi)
 475                 return 0;
 476
 477         DEBPRINT("call get_GTF, drive=%s port=%d\n", drive->name, drive->dn);
 478
 479         ret = do_drive_get_GTF(drive, &gtf_length, &gtf_address, &obj_loc);
 480         if (ret < 0) {
 481                 DEBPRINT("get_GTF error (%d)\n", ret);
 482                 return ret;
 483         }
 484
 485         DEBPRINT("call set_taskfiles, drive=%s\n", drive->name);
 486
 487         ret = do_drive_set_taskfiles(drive, gtf_length, gtf_address);
 488         kfree((void *)obj_loc);
 489         if (ret < 0) {
 490                 DEBPRINT("set_taskfiles error (%d)\n", ret);
 491         }
 492
 493         DEBPRINT("ret=%d\n", ret);
 494
 495         return ret;
 496 }
 497
 498 /**
 499  * ide_acpi_get_timing - get the channel (controller) timings
 500  * @hwif: target IDE interface (channel)
 501  *
 502  * This function executes the _GTM ACPI method for the target channel.
 503  *
 504  */
 505 void ide_acpi_get_timing(ide_hwif_t *hwif)
 506 {
 507         acpi_status             status;
 508         struct acpi_buffer      output;
 509         union acpi_object       *out_obj;
 510
 511         if (ide_noacpi)
 512                 return;
 513
 514         DEBPRINT("ENTER:\n");
 515
 516         if (!hwif->acpidata) {
 517                 DEBPRINT("no ACPI data for %s\n", hwif->name);
 518                 return;
 519         }
 520
 521         /* Setting up output buffer for _GTM */
 522         output.length = ACPI_ALLOCATE_BUFFER;
 523         output.pointer = NULL;  /* ACPI-CA sets this; save/free it later */
 524
 525         /* _GTM has no input parameters */
 526         status = acpi_evaluate_object(hwif->acpidata->obj_handle, "_GTM",
 527                                       NULL, &output);
 528
 529         DEBPRINT("_GTM status: %d, outptr: 0x%p, outlen: 0x%llx\n",
 530                  status, output.pointer,
 531                  (unsigned long long)output.length);
 532
 533         if (ACPI_FAILURE(status)) {
 534                 DEBPRINT("Run _GTM error: status = 0x%x\n", status);
 535                 return;
 536         }
 537
 538         if (!output.length || !output.pointer) {
 539                 DEBPRINT("Run _GTM: length or ptr is NULL (0x%llx, 0x%p)\n",
 540                        (unsigned long long)output.length,
 541                        output.pointer);
 542                 kfree(output.pointer);
 543                 return;
 544         }
 545
 546         out_obj = output.pointer;
 547         if (out_obj->type != ACPI_TYPE_BUFFER) {
 548                 kfree(output.pointer);
 549                 DEBPRINT("Run _GTM: error: "
 550                        "expected object type of ACPI_TYPE_BUFFER, "
 551                        "got 0x%x\n", out_obj->type);
 552                 return;
 553         }
 554
 555         if (!out_obj->buffer.length || !out_obj->buffer.pointer ||
 556             out_obj->buffer.length != sizeof(struct GTM_buffer)) {
 557                 kfree(output.pointer);
 558                 printk(KERN_ERR
 559                         "%s: unexpected _GTM length (0x%x)[should be 0x%zx] or "
 560                         "addr (0x%p)\n",
 561                         __FUNCTION__, out_obj->buffer.length,
 562                         sizeof(struct GTM_buffer), out_obj->buffer.pointer);
 563                 return;
 564         }
 565
 566         memcpy(&hwif->acpidata->gtm, out_obj->buffer.pointer,
 567                sizeof(struct GTM_buffer));
 568
 569         DEBPRINT("_GTM info: ptr: 0x%p, len: 0x%x, exp.len: 0x%Zx\n",
 570                  out_obj->buffer.pointer, out_obj->buffer.length,
 571                  sizeof(struct GTM_buffer));
 572
 573         DEBPRINT("_GTM fields: 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n",
 574                  hwif->acpidata->gtm.PIO_speed0,
 575                  hwif->acpidata->gtm.DMA_speed0,
 576                  hwif->acpidata->gtm.PIO_speed1,
 577                  hwif->acpidata->gtm.DMA_speed1,
 578                  hwif->acpidata->gtm.GTM_flags);
 579
 580         kfree(output.pointer);
 581 }
 582
 583 /**
 584  * ide_acpi_push_timing - set the channel (controller) timings
 585  * @hwif: target IDE interface (channel)
 586  *
 587  * This function executes the _STM ACPI method for the target channel.
 588  *
 589  * _STM requires Identify Drive data, which has to passed as an argument.
 590  * Unfortunately hd_driveid is a mangled version which we can't readily
 591  * use; hence we'll get the information afresh.
 592  */
 593 void ide_acpi_push_timing(ide_hwif_t *hwif)
 594 {
 595         acpi_status             status;
 596         struct acpi_object_list input;
 597         union acpi_object       in_params[3];
 598         struct ide_acpi_drive_link      *master = &hwif->acpidata->master;
 599         struct ide_acpi_drive_link      *slave = &hwif->acpidata->slave;
 600
 601         if (ide_noacpi)
 602                 return;
 603
 604         DEBPRINT("ENTER:\n");
 605
 606         if (!hwif->acpidata) {
 607                 DEBPRINT("no ACPI data for %s\n", hwif->name);
 608                 return;
 609         }
 610
 611         /* Give the GTM buffer + drive Identify data to the channel via the
 612          * _STM method: */
 613         /* setup input parameters buffer for _STM */
 614         input.count = 3;
 615         input.pointer = in_params;
 616         in_params[0].type = ACPI_TYPE_BUFFER;
 617         in_params[0].buffer.length = sizeof(struct GTM_buffer);
 618         in_params[0].buffer.pointer = (u8 *)&hwif->acpidata->gtm;
 619         in_params[1].type = ACPI_TYPE_BUFFER;
 620         in_params[1].buffer.length = sizeof(struct hd_driveid);
 621         in_params[1].buffer.pointer = (u8 *)&master->idbuff;
 622         in_params[2].type = ACPI_TYPE_BUFFER;
 623         in_params[2].buffer.length = sizeof(struct hd_driveid);
 624         in_params[2].buffer.pointer = (u8 *)&slave->idbuff;
 625         /* Output buffer: _STM has no output */
 626
 627         status = acpi_evaluate_object(hwif->acpidata->obj_handle, "_STM",
 628                                       &input, NULL);
 629
 630         if (ACPI_FAILURE(status)) {
 631                 DEBPRINT("Run _STM error: status = 0x%x\n", status);
 632         }
 633         DEBPRINT("_STM status: %d\n", status);
 634 }
 635
 636 /**
 637  * ide_acpi_set_state - set the channel power state
 638  * @hwif: target IDE interface
 639  * @on: state, on/off
 640  *
 641  * This function executes the _PS0/_PS3 ACPI method to set the power state.
 642  * ACPI spec requires _PS0 when IDE power on and _PS3 when power off
 643  */
 644 void ide_acpi_set_state(ide_hwif_t *hwif, int on)
 645 {
 646         int unit;
 647
 648         if (ide_noacpi || ide_noacpi_psx)
 649                 return;
 650
 651         DEBPRINT("ENTER:\n");
 652
 653         if (!hwif->acpidata) {
 654                 DEBPRINT("no ACPI data for %s\n", hwif->name);
 655                 return;
 656         }
 657         /* channel first and then drives for power on and verse versa for power off */
 658         if (on)
 659                 acpi_bus_set_power(hwif->acpidata->obj_handle, ACPI_STATE_D0);
 660         for (unit = 0; unit < MAX_DRIVES; ++unit) {
 661                 ide_drive_t *drive = &hwif->drives[unit];
 662
 663                 if (!drive->acpidata->obj_handle)
 664                         drive->acpidata->obj_handle = ide_acpi_drive_get_handle(drive);
 665
 666                 if (drive->acpidata->obj_handle && drive->present) {
 667                         acpi_bus_set_power(drive->acpidata->obj_handle,
 668                                 on? ACPI_STATE_D0: ACPI_STATE_D3);
 669                 }
 670         }
 671         if (!on)
 672                 acpi_bus_set_power(hwif->acpidata->obj_handle, ACPI_STATE_D3);
 673 }
 674
 675 /**
 676  * ide_acpi_init - initialize the ACPI link for an IDE interface
 677  * @hwif: target IDE interface (channel)
 678  *
 679  * The ACPI spec is not quite clear when the drive identify buffer
 680  * should be obtained. Calling IDENTIFY DEVICE during shutdown
 681  * is not the best of ideas as the drive might already being put to
 682  * sleep. And obviously we can't call it during resume.
 683  * So we get the information during startup; but this means that
 684  * any changes during run-time will be lost after resume.
 685  */
 686 void ide_acpi_init(ide_hwif_t *hwif)
 687 {
 688         int unit;
 689         int                     err;
 690         struct ide_acpi_drive_link      *master;
 691         struct ide_acpi_drive_link      *slave;
 692
 693         ide_acpi_blacklist();
 694
 695         hwif->acpidata = kzalloc(sizeof(struct ide_acpi_hwif_link), GFP_KERNEL);
 696         if (!hwif->acpidata)
 697                 return;
 698
 699         hwif->acpidata->obj_handle = ide_acpi_hwif_get_handle(hwif);
 700         if (!hwif->acpidata->obj_handle) {
 701                 DEBPRINT("no ACPI object for %s found\n", hwif->name);
 702                 kfree(hwif->acpidata);
 703                 hwif->acpidata = NULL;
 704                 return;
 705         }
 706
 707         /*
 708          * The ACPI spec mandates that we send information
 709          * for both drives, regardless whether they are connected
 710          * or not.
 711          */
 712         hwif->acpidata->master.drive = &hwif->drives[0];
 713         hwif->drives[0].acpidata = &hwif->acpidata->master;
 714         master = &hwif->acpidata->master;
 715
 716         hwif->acpidata->slave.drive = &hwif->drives[1];
 717         hwif->drives[1].acpidata = &hwif->acpidata->slave;
 718         slave = &hwif->acpidata->slave;
 719
 720
 721         /*
 722          * Send IDENTIFY for each drive
 723          */
 724         if (master->drive->present) {
 725                 err = taskfile_lib_get_identify(master->drive, master->idbuff);
 726                 if (err) {
 727                         DEBPRINT("identify device %s failed (%d)\n",
 728                                  master->drive->name, err);
 729                 }
 730         }
 731
 732         if (slave->drive->present) {
 733                 err = taskfile_lib_get_identify(slave->drive, slave->idbuff);
 734                 if (err) {
 735                         DEBPRINT("identify device %s failed (%d)\n",
 736                                  slave->drive->name, err);
 737                 }
 738         }
 739
 740         if (ide_noacpionboot) {
 741                 DEBPRINT("ACPI methods disabled on boot\n");
 742                 return;
 743         }
 744
 745         /* ACPI _PS0 before _STM */
 746         ide_acpi_set_state(hwif, 1);
 747         /*
 748          * ACPI requires us to call _STM on startup
 749          */
 750         ide_acpi_get_timing(hwif);
 751         ide_acpi_push_timing(hwif);
 752
 753         for (unit = 0; unit < MAX_DRIVES; ++unit) {
 754                 ide_drive_t *drive = &hwif->drives[unit];
 755
 756                 if (drive->present) {
 757                         /* Execute ACPI startup code */
 758                         ide_acpi_exec_tfs(drive);
 759                 }
 760         }
 761 }