drivers/gpu/drm/i915/intel_bios.c

   1 /*
   2  * Copyright © 2006 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  *
  23  * Authors:
  24  *    Eric Anholt <eric@anholt.net>
  25  *
  26  */
  27 #include <linux/dmi.h>
  28 #include <drm/drm_dp_helper.h>
  29 #include "drmP.h"
  30 #include "drm.h"
  31 #include "i915_drm.h"
  32 #include "i915_drv.h"
  33 #include "intel_bios.h"
  34
  35 #define SLAVE_ADDR1     0x70
  36 #define SLAVE_ADDR2     0x72
  37
  38 static int panel_type;
  39
  40 static void *
  41 find_section(struct bdb_header *bdb, int section_id)
  42 {
  43         u8 *base = (u8 *)bdb;
  44         int index = 0;
  45         u16 total, current_size;
  46         u8 current_id;
  47
  48         /* skip to first section */
  49         index += bdb->header_size;
  50         total = bdb->bdb_size;
  51
  52         /* walk the sections looking for section_id */
  53         while (index < total) {
  54                 current_id = *(base + index);
  55                 index++;
  56                 current_size = *((u16 *)(base + index));
  57                 index += 2;
  58                 if (current_id == section_id)
  59                         return base + index;
  60                 index += current_size;
  61         }
  62
  63         return NULL;
  64 }
  65
  66 static u16
  67 get_blocksize(void *p)
  68 {
  69         u16 *block_ptr, block_size;
  70
  71         block_ptr = (u16 *)((char *)p - 2);
  72         block_size = *block_ptr;
  73         return block_size;
  74 }
  75
  76 static void
  77 fill_detail_timing_data(struct drm_display_mode *panel_fixed_mode,
  78                         const struct lvds_dvo_timing *dvo_timing)
  79 {
  80         panel_fixed_mode->hdisplay = (dvo_timing->hactive_hi << 8) |
  81                 dvo_timing->hactive_lo;
  82         panel_fixed_mode->hsync_start = panel_fixed_mode->hdisplay +
  83                 ((dvo_timing->hsync_off_hi << 8) | dvo_timing->hsync_off_lo);
  84         panel_fixed_mode->hsync_end = panel_fixed_mode->hsync_start +
  85                 dvo_timing->hsync_pulse_width;
  86         panel_fixed_mode->htotal = panel_fixed_mode->hdisplay +
  87                 ((dvo_timing->hblank_hi << 8) | dvo_timing->hblank_lo);
  88
  89         panel_fixed_mode->vdisplay = (dvo_timing->vactive_hi << 8) |
  90                 dvo_timing->vactive_lo;
  91         panel_fixed_mode->vsync_start = panel_fixed_mode->vdisplay +
  92                 dvo_timing->vsync_off;
  93         panel_fixed_mode->vsync_end = panel_fixed_mode->vsync_start +
  94                 dvo_timing->vsync_pulse_width;
  95         panel_fixed_mode->vtotal = panel_fixed_mode->vdisplay +
  96                 ((dvo_timing->vblank_hi << 8) | dvo_timing->vblank_lo);
  97         panel_fixed_mode->clock = dvo_timing->clock * 10;
  98         panel_fixed_mode->type = DRM_MODE_TYPE_PREFERRED;
  99
 100         if (dvo_timing->hsync_positive)
 101                 panel_fixed_mode->flags |= DRM_MODE_FLAG_PHSYNC;
 102         else
 103                 panel_fixed_mode->flags |= DRM_MODE_FLAG_NHSYNC;
 104
 105         if (dvo_timing->vsync_positive)
 106                 panel_fixed_mode->flags |= DRM_MODE_FLAG_PVSYNC;
 107         else
 108                 panel_fixed_mode->flags |= DRM_MODE_FLAG_NVSYNC;
 109
 110         /* Some VBTs have bogus h/vtotal values */
 111         if (panel_fixed_mode->hsync_end > panel_fixed_mode->htotal)
 112                 panel_fixed_mode->htotal = panel_fixed_mode->hsync_end + 1;
 113         if (panel_fixed_mode->vsync_end > panel_fixed_mode->vtotal)
 114                 panel_fixed_mode->vtotal = panel_fixed_mode->vsync_end + 1;
 115
 116         drm_mode_set_name(panel_fixed_mode);
 117 }
 118
 119 static bool
 120 lvds_dvo_timing_equal_size(const struct lvds_dvo_timing *a,
 121                            const struct lvds_dvo_timing *b)
 122 {
 123         if (a->hactive_hi != b->hactive_hi ||
 124             a->hactive_lo != b->hactive_lo)
 125                 return false;
 126
 127         if (a->hsync_off_hi != b->hsync_off_hi ||
 128             a->hsync_off_lo != b->hsync_off_lo)
 129                 return false;
 130
 131         if (a->hsync_pulse_width != b->hsync_pulse_width)
 132                 return false;
 133
 134         if (a->hblank_hi != b->hblank_hi ||
 135             a->hblank_lo != b->hblank_lo)
 136                 return false;
 137
 138         if (a->vactive_hi != b->vactive_hi ||
 139             a->vactive_lo != b->vactive_lo)
 140                 return false;
 141
 142         if (a->vsync_off != b->vsync_off)
 143                 return false;
 144
 145         if (a->vsync_pulse_width != b->vsync_pulse_width)
 146                 return false;
 147
 148         if (a->vblank_hi != b->vblank_hi ||
 149             a->vblank_lo != b->vblank_lo)
 150                 return false;
 151
 152         return true;
 153 }
 154
 155 static const struct lvds_dvo_timing *
 156 get_lvds_dvo_timing(const struct bdb_lvds_lfp_data *lvds_lfp_data,
 157                     const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs,
 158                     int index)
 159 {
 160         /*
 161          * the size of fp_timing varies on the different platform.
 162          * So calculate the DVO timing relative offset in LVDS data
 163          * entry to get the DVO timing entry
 164          */
 165
 166         int lfp_data_size =
 167                 lvds_lfp_data_ptrs->ptr[1].dvo_timing_offset -
 168                 lvds_lfp_data_ptrs->ptr[0].dvo_timing_offset;
 169         int dvo_timing_offset =
 170                 lvds_lfp_data_ptrs->ptr[0].dvo_timing_offset -
 171                 lvds_lfp_data_ptrs->ptr[0].fp_timing_offset;
 172         char *entry = (char *)lvds_lfp_data->data + lfp_data_size * index;
 173
 174         return (struct lvds_dvo_timing *)(entry + dvo_timing_offset);
 175 }
 176
 177 /* get lvds_fp_timing entry
 178  * this function may return NULL if the corresponding entry is invalid
 179  */
 180 static const struct lvds_fp_timing *
 181 get_lvds_fp_timing(const struct bdb_header *bdb,
 182                    const struct bdb_lvds_lfp_data *data,
 183                    const struct bdb_lvds_lfp_data_ptrs *ptrs,
 184                    int index)
 185 {
 186         size_t data_ofs = (const u8 *)data - (const u8 *)bdb;
 187         u16 data_size = ((const u16 *)data)[-1]; /* stored in header */
 188         size_t ofs;
 189
 190         if (index >= ARRAY_SIZE(ptrs->ptr))
 191                 return NULL;
 192         ofs = ptrs->ptr[index].fp_timing_offset;
 193         if (ofs < data_ofs ||
 194             ofs + sizeof(struct lvds_fp_timing) > data_ofs + data_size)
 195                 return NULL;
 196         return (const struct lvds_fp_timing *)((const u8 *)bdb + ofs);
 197 }
 198
 199 /* Try to find integrated panel data */
 200 static void
 201 parse_lfp_panel_data(struct drm_i915_private *dev_priv,
 202                             struct bdb_header *bdb)
 203 {
 204         const struct bdb_lvds_options *lvds_options;
 205         const struct bdb_lvds_lfp_data *lvds_lfp_data;
 206         const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs;
 207         const struct lvds_dvo_timing *panel_dvo_timing;
 208         const struct lvds_fp_timing *fp_timing;
 209         struct drm_display_mode *panel_fixed_mode;
 210         int i, downclock;
 211
 212         lvds_options = find_section(bdb, BDB_LVDS_OPTIONS);
 213         if (!lvds_options)
 214                 return;
 215
 216         dev_priv->lvds_dither = lvds_options->pixel_dither;
 217         if (lvds_options->panel_type == 0xff)
 218                 return;
 219
 220         panel_type = lvds_options->panel_type;
 221
 222         lvds_lfp_data = find_section(bdb, BDB_LVDS_LFP_DATA);
 223         if (!lvds_lfp_data)
 224                 return;
 225
 226         lvds_lfp_data_ptrs = find_section(bdb, BDB_LVDS_LFP_DATA_PTRS);
 227         if (!lvds_lfp_data_ptrs)
 228                 return;
 229
 230         dev_priv->lvds_vbt = 1;
 231
 232         panel_dvo_timing = get_lvds_dvo_timing(lvds_lfp_data,
 233                                                lvds_lfp_data_ptrs,
 234                                                lvds_options->panel_type);
 235
 236         panel_fixed_mode = kzalloc(sizeof(*panel_fixed_mode), GFP_KERNEL);
 237         if (!panel_fixed_mode)
 238                 return;
 239
 240         fill_detail_timing_data(panel_fixed_mode, panel_dvo_timing);
 241
 242         dev_priv->lfp_lvds_vbt_mode = panel_fixed_mode;
 243
 244         DRM_DEBUG_KMS("Found panel mode in BIOS VBT tables:\n");
 245         drm_mode_debug_printmodeline(panel_fixed_mode);
 246
 247         /*
 248          * Iterate over the LVDS panel timing info to find the lowest clock
 249          * for the native resolution.
 250          */
 251         downclock = panel_dvo_timing->clock;
 252         for (i = 0; i < 16; i++) {
 253                 const struct lvds_dvo_timing *dvo_timing;
 254
 255                 dvo_timing = get_lvds_dvo_timing(lvds_lfp_data,
 256                                                  lvds_lfp_data_ptrs,
 257                                                  i);
 258                 if (lvds_dvo_timing_equal_size(dvo_timing, panel_dvo_timing) &&
 259                     dvo_timing->clock < downclock)
 260                         downclock = dvo_timing->clock;
 261         }
 262
 263         if (downclock < panel_dvo_timing->clock && i915_lvds_downclock) {
 264                 dev_priv->lvds_downclock_avail = 1;
 265                 dev_priv->lvds_downclock = downclock * 10;
 266                 DRM_DEBUG_KMS("LVDS downclock is found in VBT. "
 267                               "Normal Clock %dKHz, downclock %dKHz\n",
 268                               panel_fixed_mode->clock, 10*downclock);
 269         }
 270
 271         fp_timing = get_lvds_fp_timing(bdb, lvds_lfp_data,
 272                                        lvds_lfp_data_ptrs,
 273                                        lvds_options->panel_type);
 274         if (fp_timing) {
 275                 /* check the resolution, just to be sure */
 276                 if (fp_timing->x_res == panel_fixed_mode->hdisplay &&
 277                     fp_timing->y_res == panel_fixed_mode->vdisplay) {
 278                         dev_priv->bios_lvds_val = fp_timing->lvds_reg_val;
 279                         DRM_DEBUG_KMS("VBT initial LVDS value %x\n",
 280                                       dev_priv->bios_lvds_val);
 281                 }
 282         }
 283 }
 284
 285 /* Try to find sdvo panel data */
 286 static void
 287 parse_sdvo_panel_data(struct drm_i915_private *dev_priv,
 288                       struct bdb_header *bdb)
 289 {
 290         struct lvds_dvo_timing *dvo_timing;
 291         struct drm_display_mode *panel_fixed_mode;
 292         int index;
 293
 294         index = i915_vbt_sdvo_panel_type;
 295         if (index == -1) {
 296                 struct bdb_sdvo_lvds_options *sdvo_lvds_options;
 297
 298                 sdvo_lvds_options = find_section(bdb, BDB_SDVO_LVDS_OPTIONS);
 299                 if (!sdvo_lvds_options)
 300                         return;
 301
 302                 index = sdvo_lvds_options->panel_type;
 303         }
 304
 305         dvo_timing = find_section(bdb, BDB_SDVO_PANEL_DTDS);
 306         if (!dvo_timing)
 307                 return;
 308
 309         panel_fixed_mode = kzalloc(sizeof(*panel_fixed_mode), GFP_KERNEL);
 310         if (!panel_fixed_mode)
 311                 return;
 312
 313         fill_detail_timing_data(panel_fixed_mode, dvo_timing + index);
 314
 315         dev_priv->sdvo_lvds_vbt_mode = panel_fixed_mode;
 316
 317         DRM_DEBUG_KMS("Found SDVO panel mode in BIOS VBT tables:\n");
 318         drm_mode_debug_printmodeline(panel_fixed_mode);
 319 }
 320
 321 static int intel_bios_ssc_frequency(struct drm_device *dev,
 322                                     bool alternate)
 323 {
 324         switch (INTEL_INFO(dev)->gen) {
 325         case 2:
 326                 return alternate ? 66 : 48;
 327         case 3:
 328         case 4:
 329                 return alternate ? 100 : 96;
 330         default:
 331                 return alternate ? 100 : 120;
 332         }
 333 }
 334
 335 static void
 336 parse_general_features(struct drm_i915_private *dev_priv,
 337                        struct bdb_header *bdb)
 338 {
 339         struct drm_device *dev = dev_priv->dev;
 340         struct bdb_general_features *general;
 341
 342         general = find_section(bdb, BDB_GENERAL_FEATURES);
 343         if (general) {
 344                 dev_priv->int_tv_support = general->int_tv_support;
 345                 dev_priv->int_crt_support = general->int_crt_support;
 346                 dev_priv->lvds_use_ssc = general->enable_ssc;
 347                 dev_priv->lvds_ssc_freq =
 348                         intel_bios_ssc_frequency(dev, general->ssc_freq);
 349                 dev_priv->display_clock_mode = general->display_clock_mode;
 350                 DRM_DEBUG_KMS("BDB_GENERAL_FEATURES int_tv_support %d int_crt_support %d lvds_use_ssc %d lvds_ssc_freq %d display_clock_mode %d\n",
 351                               dev_priv->int_tv_support,
 352                               dev_priv->int_crt_support,
 353                               dev_priv->lvds_use_ssc,
 354                               dev_priv->lvds_ssc_freq,
 355                               dev_priv->display_clock_mode);
 356         }
 357 }
 358
 359 static void
 360 parse_general_definitions(struct drm_i915_private *dev_priv,
 361                           struct bdb_header *bdb)
 362 {
 363         struct bdb_general_definitions *general;
 364
 365         general = find_section(bdb, BDB_GENERAL_DEFINITIONS);
 366         if (general) {
 367                 u16 block_size = get_blocksize(general);
 368                 if (block_size >= sizeof(*general)) {
 369                         int bus_pin = general->crt_ddc_gmbus_pin;
 370                         DRM_DEBUG_KMS("crt_ddc_bus_pin: %d\n", bus_pin);
 371                         if (bus_pin >= 1 && bus_pin <= 6)
 372                                 dev_priv->crt_ddc_pin = bus_pin;
 373                 } else {
 374                         DRM_DEBUG_KMS("BDB_GD too small (%d). Invalid.\n",
 375                                   block_size);
 376                 }
 377         }
 378 }
 379
 380 static void
 381 parse_sdvo_device_mapping(struct drm_i915_private *dev_priv,
 382                           struct bdb_header *bdb)
 383 {
 384         struct sdvo_device_mapping *p_mapping;
 385         struct bdb_general_definitions *p_defs;
 386         struct child_device_config *p_child;
 387         int i, child_device_num, count;
 388         u16     block_size;
 389
 390         p_defs = find_section(bdb, BDB_GENERAL_DEFINITIONS);
 391         if (!p_defs) {
 392                 DRM_DEBUG_KMS("No general definition block is found, unable to construct sdvo mapping.\n");
 393                 return;
 394         }
 395         /* judge whether the size of child device meets the requirements.
 396          * If the child device size obtained from general definition block
 397          * is different with sizeof(struct child_device_config), skip the
 398          * parsing of sdvo device info
 399          */
 400         if (p_defs->child_dev_size != sizeof(*p_child)) {
 401                 /* different child dev size . Ignore it */
 402                 DRM_DEBUG_KMS("different child size is found. Invalid.\n");
 403                 return;
 404         }
 405         /* get the block size of general definitions */
 406         block_size = get_blocksize(p_defs);
 407         /* get the number of child device */
 408         child_device_num = (block_size - sizeof(*p_defs)) /
 409                                 sizeof(*p_child);
 410         count = 0;
 411         for (i = 0; i < child_device_num; i++) {
 412                 p_child = &(p_defs->devices[i]);
 413                 if (!p_child->device_type) {
 414                         /* skip the device block if device type is invalid */
 415                         continue;
 416                 }
 417                 if (p_child->slave_addr != SLAVE_ADDR1 &&
 418                         p_child->slave_addr != SLAVE_ADDR2) {
 419                         /*
 420                          * If the slave address is neither 0x70 nor 0x72,
 421                          * it is not a SDVO device. Skip it.
 422                          */
 423                         continue;
 424                 }
 425                 if (p_child->dvo_port != DEVICE_PORT_DVOB &&
 426                         p_child->dvo_port != DEVICE_PORT_DVOC) {
 427                         /* skip the incorrect SDVO port */
 428                         DRM_DEBUG_KMS("Incorrect SDVO port. Skip it\n");
 429                         continue;
 430                 }
 431                 DRM_DEBUG_KMS("the SDVO device with slave addr %2x is found on"
 432                                 " %s port\n",
 433                                 p_child->slave_addr,
 434                                 (p_child->dvo_port == DEVICE_PORT_DVOB) ?
 435                                         "SDVOB" : "SDVOC");
 436                 p_mapping = &(dev_priv->sdvo_mappings[p_child->dvo_port - 1]);
 437                 if (!p_mapping->initialized) {
 438                         p_mapping->dvo_port = p_child->dvo_port;
 439                         p_mapping->slave_addr = p_child->slave_addr;
 440                         p_mapping->dvo_wiring = p_child->dvo_wiring;
 441                         p_mapping->ddc_pin = p_child->ddc_pin;
 442                         p_mapping->i2c_pin = p_child->i2c_pin;
 443                         p_mapping->initialized = 1;
 444                         DRM_DEBUG_KMS("SDVO device: dvo=%x, addr=%x, wiring=%d, ddc_pin=%d, i2c_pin=%d\n",
 445                                       p_mapping->dvo_port,
 446                                       p_mapping->slave_addr,
 447                                       p_mapping->dvo_wiring,
 448                                       p_mapping->ddc_pin,
 449                                       p_mapping->i2c_pin);
 450                 } else {
 451                         DRM_DEBUG_KMS("Maybe one SDVO port is shared by "
 452                                          "two SDVO device.\n");
 453                 }
 454                 if (p_child->slave2_addr) {
 455                         /* Maybe this is a SDVO device with multiple inputs */
 456                         /* And the mapping info is not added */
 457                         DRM_DEBUG_KMS("there exists the slave2_addr. Maybe this"
 458                                 " is a SDVO device with multiple inputs.\n");
 459                 }
 460                 count++;
 461         }
 462
 463         if (!count) {
 464                 /* No SDVO device info is found */
 465                 DRM_DEBUG_KMS("No SDVO device info is found in VBT\n");
 466         }
 467         return;
 468 }
 469
 470 static void
 471 parse_driver_features(struct drm_i915_private *dev_priv,
 472                        struct bdb_header *bdb)
 473 {
 474         struct drm_device *dev = dev_priv->dev;
 475         struct bdb_driver_features *driver;
 476
 477         driver = find_section(bdb, BDB_DRIVER_FEATURES);
 478         if (!driver)
 479                 return;
 480
 481         if (SUPPORTS_EDP(dev) &&
 482             driver->lvds_config == BDB_DRIVER_FEATURE_EDP)
 483                 dev_priv->edp.support = 1;
 484
 485         if (driver->dual_frequency)
 486                 dev_priv->render_reclock_avail = true;
 487 }
 488
 489 static void
 490 parse_edp(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
 491 {
 492         struct bdb_edp *edp;
 493         struct edp_power_seq *edp_pps;
 494         struct edp_link_params *edp_link_params;
 495
 496         edp = find_section(bdb, BDB_EDP);
 497         if (!edp) {
 498                 if (SUPPORTS_EDP(dev_priv->dev) && dev_priv->edp.support) {
 499                         DRM_DEBUG_KMS("No eDP BDB found but eDP panel "
 500                                       "supported, assume %dbpp panel color "
 501                                       "depth.\n",
 502                                       dev_priv->edp.bpp);
 503                 }
 504                 return;
 505         }
 506
 507         switch ((edp->color_depth >> (panel_type * 2)) & 3) {
 508         case EDP_18BPP:
 509                 dev_priv->edp.bpp = 18;
 510                 break;
 511         case EDP_24BPP:
 512                 dev_priv->edp.bpp = 24;
 513                 break;
 514         case EDP_30BPP:
 515                 dev_priv->edp.bpp = 30;
 516                 break;
 517         }
 518
 519         /* Get the eDP sequencing and link info */
 520         edp_pps = &edp->power_seqs[panel_type];
 521         edp_link_params = &edp->link_params[panel_type];
 522
 523         dev_priv->edp.pps = *edp_pps;
 524
 525         dev_priv->edp.rate = edp_link_params->rate ? DP_LINK_BW_2_7 :
 526                 DP_LINK_BW_1_62;
 527         switch (edp_link_params->lanes) {
 528         case 0:
 529                 dev_priv->edp.lanes = 1;
 530                 break;
 531         case 1:
 532                 dev_priv->edp.lanes = 2;
 533                 break;
 534         case 3:
 535         default:
 536                 dev_priv->edp.lanes = 4;
 537                 break;
 538         }
 539         switch (edp_link_params->preemphasis) {
 540         case 0:
 541                 dev_priv->edp.preemphasis = DP_TRAIN_PRE_EMPHASIS_0;
 542                 break;
 543         case 1:
 544                 dev_priv->edp.preemphasis = DP_TRAIN_PRE_EMPHASIS_3_5;
 545                 break;
 546         case 2:
 547                 dev_priv->edp.preemphasis = DP_TRAIN_PRE_EMPHASIS_6;
 548                 break;
 549         case 3:
 550                 dev_priv->edp.preemphasis = DP_TRAIN_PRE_EMPHASIS_9_5;
 551                 break;
 552         }
 553         switch (edp_link_params->vswing) {
 554         case 0:
 555                 dev_priv->edp.vswing = DP_TRAIN_VOLTAGE_SWING_400;
 556                 break;
 557         case 1:
 558                 dev_priv->edp.vswing = DP_TRAIN_VOLTAGE_SWING_600;
 559                 break;
 560         case 2:
 561                 dev_priv->edp.vswing = DP_TRAIN_VOLTAGE_SWING_800;
 562                 break;
 563         case 3:
 564                 dev_priv->edp.vswing = DP_TRAIN_VOLTAGE_SWING_1200;
 565                 break;
 566         }
 567 }
 568
 569 static void
 570 parse_device_mapping(struct drm_i915_private *dev_priv,
 571                        struct bdb_header *bdb)
 572 {
 573         struct bdb_general_definitions *p_defs;
 574         struct child_device_config *p_child, *child_dev_ptr;
 575         int i, child_device_num, count;
 576         u16     block_size;
 577
 578         p_defs = find_section(bdb, BDB_GENERAL_DEFINITIONS);
 579         if (!p_defs) {
 580                 DRM_DEBUG_KMS("No general definition block is found, no devices defined.\n");
 581                 return;
 582         }
 583         /* judge whether the size of child device meets the requirements.
 584          * If the child device size obtained from general definition block
 585          * is different with sizeof(struct child_device_config), skip the
 586          * parsing of sdvo device info
 587          */
 588         if (p_defs->child_dev_size != sizeof(*p_child)) {
 589                 /* different child dev size . Ignore it */
 590                 DRM_DEBUG_KMS("different child size is found. Invalid.\n");
 591                 return;
 592         }
 593         /* get the block size of general definitions */
 594         block_size = get_blocksize(p_defs);
 595         /* get the number of child device */
 596         child_device_num = (block_size - sizeof(*p_defs)) /
 597                                 sizeof(*p_child);
 598         count = 0;
 599         /* get the number of child device that is present */
 600         for (i = 0; i < child_device_num; i++) {
 601                 p_child = &(p_defs->devices[i]);
 602                 if (!p_child->device_type) {
 603                         /* skip the device block if device type is invalid */
 604                         continue;
 605                 }
 606                 count++;
 607         }
 608         if (!count) {
 609                 DRM_DEBUG_KMS("no child dev is parsed from VBT\n");
 610                 return;
 611         }
 612         dev_priv->child_dev = kzalloc(sizeof(*p_child) * count, GFP_KERNEL);
 613         if (!dev_priv->child_dev) {
 614                 DRM_DEBUG_KMS("No memory space for child device\n");
 615                 return;
 616         }
 617
 618         dev_priv->child_dev_num = count;
 619         count = 0;
 620         for (i = 0; i < child_device_num; i++) {
 621                 p_child = &(p_defs->devices[i]);
 622                 if (!p_child->device_type) {
 623                         /* skip the device block if device type is invalid */
 624                         continue;
 625                 }
 626                 child_dev_ptr = dev_priv->child_dev + count;
 627                 count++;
 628                 memcpy((void *)child_dev_ptr, (void *)p_child,
 629                                         sizeof(*p_child));
 630         }
 631         return;
 632 }
 633
 634 static void
 635 init_vbt_defaults(struct drm_i915_private *dev_priv)
 636 {
 637         struct drm_device *dev = dev_priv->dev;
 638
 639         dev_priv->crt_ddc_pin = GMBUS_PORT_VGADDC;
 640
 641         /* LFP panel data */
 642         dev_priv->lvds_dither = 1;
 643         dev_priv->lvds_vbt = 0;
 644
 645         /* SDVO panel data */
 646         dev_priv->sdvo_lvds_vbt_mode = NULL;
 647
 648         /* general features */
 649         dev_priv->int_tv_support = 1;
 650         dev_priv->int_crt_support = 1;
 651
 652         /* Default to using SSC */
 653         dev_priv->lvds_use_ssc = 1;
 654         dev_priv->lvds_ssc_freq = intel_bios_ssc_frequency(dev, 1);
 655         DRM_DEBUG_KMS("Set default to SSC at %dMHz\n", dev_priv->lvds_ssc_freq);
 656
 657         /* eDP data */
 658         dev_priv->edp.bpp = 18;
 659 }
 660
 661 static int __init intel_no_opregion_vbt_callback(const struct dmi_system_id *id)
 662 {
 663         DRM_DEBUG_KMS("Falling back to manually reading VBT from "
 664                       "VBIOS ROM for %s\n",
 665                       id->ident);
 666         return 1;
 667 }
 668
 669 static const struct dmi_system_id intel_no_opregion_vbt[] = {
 670         {
 671                 .callback = intel_no_opregion_vbt_callback,
 672                 .ident = "ThinkCentre A57",
 673                 .matches = {
 674                         DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 675                         DMI_MATCH(DMI_PRODUCT_NAME, "97027RG"),
 676                 },
 677         },
 678         { }
 679 };
 680
 681 /**
 682  * intel_parse_bios - find VBT and initialize settings from the BIOS
 683  * @dev: DRM device
 684  *
 685  * Loads the Video BIOS and checks that the VBT exists.  Sets scratch registers
 686  * to appropriate values.
 687  *
 688  * Returns 0 on success, nonzero on failure.
 689  */
 690 bool
 691 intel_parse_bios(struct drm_device *dev)
 692 {
 693         struct drm_i915_private *dev_priv = dev->dev_private;
 694         struct pci_dev *pdev = dev->pdev;
 695         struct bdb_header *bdb = NULL;
 696         u8 __iomem *bios = NULL;
 697
 698         init_vbt_defaults(dev_priv);
 699
 700         /* XXX Should this validation be moved to intel_opregion.c? */
 701         if (!dmi_check_system(intel_no_opregion_vbt) && dev_priv->opregion.vbt) {
 702                 struct vbt_header *vbt = dev_priv->opregion.vbt;
 703                 if (memcmp(vbt->signature, "$VBT", 4) == 0) {
 704                         DRM_DEBUG_KMS("Using VBT from OpRegion: %20s\n",
 705                                          vbt->signature);
 706                         bdb = (struct bdb_header *)((char *)vbt + vbt->bdb_offset);
 707                 } else
 708                         dev_priv->opregion.vbt = NULL;
 709         }
 710
 711         if (bdb == NULL) {
 712                 struct vbt_header *vbt = NULL;
 713                 size_t size;
 714                 int i;
 715
 716                 bios = pci_map_rom(pdev, &size);
 717                 if (!bios)
 718                         return -1;
 719
 720                 /* Scour memory looking for the VBT signature */
 721                 for (i = 0; i + 4 < size; i++) {
 722                         if (!memcmp(bios + i, "$VBT", 4)) {
 723                                 vbt = (struct vbt_header *)(bios + i);
 724                                 break;
 725                         }
 726                 }
 727
 728                 if (!vbt) {
 729                         DRM_ERROR("VBT signature missing\n");
 730                         pci_unmap_rom(pdev, bios);
 731                         return -1;
 732                 }
 733
 734                 bdb = (struct bdb_header *)(bios + i + vbt->bdb_offset);
 735         }
 736
 737         /* Grab useful general definitions */
 738         parse_general_features(dev_priv, bdb);
 739         parse_general_definitions(dev_priv, bdb);
 740         parse_lfp_panel_data(dev_priv, bdb);
 741         parse_sdvo_panel_data(dev_priv, bdb);
 742         parse_sdvo_device_mapping(dev_priv, bdb);
 743         parse_device_mapping(dev_priv, bdb);
 744         parse_driver_features(dev_priv, bdb);
 745         parse_edp(dev_priv, bdb);
 746
 747         if (bios)
 748                 pci_unmap_rom(pdev, bios);
 749
 750         return 0;
 751 }
 752
 753 /* Ensure that vital registers have been initialised, even if the BIOS
 754  * is absent or just failing to do its job.
 755  */
 756 void intel_setup_bios(struct drm_device *dev)
 757 {
 758         struct drm_i915_private *dev_priv = dev->dev_private;
 759
 760          /* Set the Panel Power On/Off timings if uninitialized. */
 761         if ((I915_READ(PP_ON_DELAYS) == 0) && (I915_READ(PP_OFF_DELAYS) == 0)) {
 762                 /* Set T2 to 40ms and T5 to 200ms */
 763                 I915_WRITE(PP_ON_DELAYS, 0x019007d0);
 764
 765                 /* Set T3 to 35ms and Tx to 200ms */
 766                 I915_WRITE(PP_OFF_DELAYS, 0x015e07d0);
 767         }
 768 }