drivers/gpu/drm/i915/intel_lvds.c

   1 /*
   2  * Copyright © 2006-2007 Intel Corporation
   3  * Copyright (c) 2006 Dave Airlie <airlied@linux.ie>
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22  * DEALINGS IN THE SOFTWARE.
  23  *
  24  * Authors:
  25  *      Eric Anholt <eric@anholt.net>
  26  *      Dave Airlie <airlied@linux.ie>
  27  *      Jesse Barnes <jesse.barnes@intel.com>
  28  */
  29
  30 #include <linux/dmi.h>
  31 #include <linux/i2c.h>
  32 #include "drmP.h"
  33 #include "drm.h"
  34 #include "drm_crtc.h"
  35 #include "drm_edid.h"
  36 #include "intel_drv.h"
  37 #include "i915_drm.h"
  38 #include "i915_drv.h"
  39
  40 /**
  41  * Sets the backlight level.
  42  *
  43  * \param level backlight level, from 0 to intel_lvds_get_max_backlight().
  44  */
  45 static void intel_lvds_set_backlight(struct drm_device *dev, int level)
  46 {
  47         struct drm_i915_private *dev_priv = dev->dev_private;
  48         u32 blc_pwm_ctl, reg;
  49
  50         if (IS_IGDNG(dev))
  51                 reg = BLC_PWM_CPU_CTL;
  52         else
  53                 reg = BLC_PWM_CTL;
  54
  55         blc_pwm_ctl = I915_READ(reg) & ~BACKLIGHT_DUTY_CYCLE_MASK;
  56         I915_WRITE(reg, (blc_pwm_ctl |
  57                                  (level << BACKLIGHT_DUTY_CYCLE_SHIFT)));
  58 }
  59
  60 /**
  61  * Returns the maximum level of the backlight duty cycle field.
  62  */
  63 static u32 intel_lvds_get_max_backlight(struct drm_device *dev)
  64 {
  65         struct drm_i915_private *dev_priv = dev->dev_private;
  66         u32 reg;
  67
  68         if (IS_IGDNG(dev))
  69                 reg = BLC_PWM_PCH_CTL2;
  70         else
  71                 reg = BLC_PWM_CTL;
  72
  73         return ((I915_READ(reg) & BACKLIGHT_MODULATION_FREQ_MASK) >>
  74                 BACKLIGHT_MODULATION_FREQ_SHIFT) * 2;
  75 }
  76
  77 /**
  78  * Sets the power state for the panel.
  79  */
  80 static void intel_lvds_set_power(struct drm_device *dev, bool on)
  81 {
  82         struct drm_i915_private *dev_priv = dev->dev_private;
  83         u32 pp_status, ctl_reg, status_reg;
  84
  85         if (IS_IGDNG(dev)) {
  86                 ctl_reg = PCH_PP_CONTROL;
  87                 status_reg = PCH_PP_STATUS;
  88         } else {
  89                 ctl_reg = PP_CONTROL;
  90                 status_reg = PP_STATUS;
  91         }
  92
  93         if (on) {
  94                 I915_WRITE(ctl_reg, I915_READ(ctl_reg) |
  95                            POWER_TARGET_ON);
  96                 do {
  97                         pp_status = I915_READ(status_reg);
  98                 } while ((pp_status & PP_ON) == 0);
  99
 100                 intel_lvds_set_backlight(dev, dev_priv->backlight_duty_cycle);
 101         } else {
 102                 intel_lvds_set_backlight(dev, 0);
 103
 104                 I915_WRITE(ctl_reg, I915_READ(ctl_reg) &
 105                            ~POWER_TARGET_ON);
 106                 do {
 107                         pp_status = I915_READ(status_reg);
 108                 } while (pp_status & PP_ON);
 109         }
 110 }
 111
 112 static void intel_lvds_dpms(struct drm_encoder *encoder, int mode)
 113 {
 114         struct drm_device *dev = encoder->dev;
 115
 116         if (mode == DRM_MODE_DPMS_ON)
 117                 intel_lvds_set_power(dev, true);
 118         else
 119                 intel_lvds_set_power(dev, false);
 120
 121         /* XXX: We never power down the LVDS pairs. */
 122 }
 123
 124 static void intel_lvds_save(struct drm_connector *connector)
 125 {
 126         struct drm_device *dev = connector->dev;
 127         struct drm_i915_private *dev_priv = dev->dev_private;
 128         u32 pp_on_reg, pp_off_reg, pp_ctl_reg, pp_div_reg;
 129         u32 pwm_ctl_reg;
 130
 131         if (IS_IGDNG(dev)) {
 132                 pp_on_reg = PCH_PP_ON_DELAYS;
 133                 pp_off_reg = PCH_PP_OFF_DELAYS;
 134                 pp_ctl_reg = PCH_PP_CONTROL;
 135                 pp_div_reg = PCH_PP_DIVISOR;
 136                 pwm_ctl_reg = BLC_PWM_CPU_CTL;
 137         } else {
 138                 pp_on_reg = PP_ON_DELAYS;
 139                 pp_off_reg = PP_OFF_DELAYS;
 140                 pp_ctl_reg = PP_CONTROL;
 141                 pp_div_reg = PP_DIVISOR;
 142                 pwm_ctl_reg = BLC_PWM_CTL;
 143         }
 144
 145         dev_priv->savePP_ON = I915_READ(pp_on_reg);
 146         dev_priv->savePP_OFF = I915_READ(pp_off_reg);
 147         dev_priv->savePP_CONTROL = I915_READ(pp_ctl_reg);
 148         dev_priv->savePP_DIVISOR = I915_READ(pp_div_reg);
 149         dev_priv->saveBLC_PWM_CTL = I915_READ(pwm_ctl_reg);
 150         dev_priv->backlight_duty_cycle = (dev_priv->saveBLC_PWM_CTL &
 151                                        BACKLIGHT_DUTY_CYCLE_MASK);
 152
 153         /*
 154          * If the light is off at server startup, just make it full brightness
 155          */
 156         if (dev_priv->backlight_duty_cycle == 0)
 157                 dev_priv->backlight_duty_cycle =
 158                         intel_lvds_get_max_backlight(dev);
 159 }
 160
 161 static void intel_lvds_restore(struct drm_connector *connector)
 162 {
 163         struct drm_device *dev = connector->dev;
 164         struct drm_i915_private *dev_priv = dev->dev_private;
 165         u32 pp_on_reg, pp_off_reg, pp_ctl_reg, pp_div_reg;
 166         u32 pwm_ctl_reg;
 167
 168         if (IS_IGDNG(dev)) {
 169                 pp_on_reg = PCH_PP_ON_DELAYS;
 170                 pp_off_reg = PCH_PP_OFF_DELAYS;
 171                 pp_ctl_reg = PCH_PP_CONTROL;
 172                 pp_div_reg = PCH_PP_DIVISOR;
 173                 pwm_ctl_reg = BLC_PWM_CPU_CTL;
 174         } else {
 175                 pp_on_reg = PP_ON_DELAYS;
 176                 pp_off_reg = PP_OFF_DELAYS;
 177                 pp_ctl_reg = PP_CONTROL;
 178                 pp_div_reg = PP_DIVISOR;
 179                 pwm_ctl_reg = BLC_PWM_CTL;
 180         }
 181
 182         I915_WRITE(pwm_ctl_reg, dev_priv->saveBLC_PWM_CTL);
 183         I915_WRITE(pp_on_reg, dev_priv->savePP_ON);
 184         I915_WRITE(pp_off_reg, dev_priv->savePP_OFF);
 185         I915_WRITE(pp_div_reg, dev_priv->savePP_DIVISOR);
 186         I915_WRITE(pp_ctl_reg, dev_priv->savePP_CONTROL);
 187         if (dev_priv->savePP_CONTROL & POWER_TARGET_ON)
 188                 intel_lvds_set_power(dev, true);
 189         else
 190                 intel_lvds_set_power(dev, false);
 191 }
 192
 193 static int intel_lvds_mode_valid(struct drm_connector *connector,
 194                                  struct drm_display_mode *mode)
 195 {
 196         struct drm_device *dev = connector->dev;
 197         struct drm_i915_private *dev_priv = dev->dev_private;
 198         struct drm_display_mode *fixed_mode = dev_priv->panel_fixed_mode;
 199
 200         if (fixed_mode) {
 201                 if (mode->hdisplay > fixed_mode->hdisplay)
 202                         return MODE_PANEL;
 203                 if (mode->vdisplay > fixed_mode->vdisplay)
 204                         return MODE_PANEL;
 205         }
 206
 207         return MODE_OK;
 208 }
 209
 210 static bool intel_lvds_mode_fixup(struct drm_encoder *encoder,
 211                                   struct drm_display_mode *mode,
 212                                   struct drm_display_mode *adjusted_mode)
 213 {
 214         struct drm_device *dev = encoder->dev;
 215         struct drm_i915_private *dev_priv = dev->dev_private;
 216         struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
 217         struct drm_encoder *tmp_encoder;
 218
 219         /* Should never happen!! */
 220         if (!IS_I965G(dev) && intel_crtc->pipe == 0) {
 221                 printk(KERN_ERR "Can't support LVDS on pipe A\n");
 222                 return false;
 223         }
 224
 225         /* Should never happen!! */
 226         list_for_each_entry(tmp_encoder, &dev->mode_config.encoder_list, head) {
 227                 if (tmp_encoder != encoder && tmp_encoder->crtc == encoder->crtc) {
 228                         printk(KERN_ERR "Can't enable LVDS and another "
 229                                "encoder on the same pipe\n");
 230                         return false;
 231                 }
 232         }
 233
 234         /*
 235          * If we have timings from the BIOS for the panel, put them in
 236          * to the adjusted mode.  The CRTC will be set up for this mode,
 237          * with the panel scaling set up to source from the H/VDisplay
 238          * of the original mode.
 239          */
 240         if (dev_priv->panel_fixed_mode != NULL) {
 241                 adjusted_mode->hdisplay = dev_priv->panel_fixed_mode->hdisplay;
 242                 adjusted_mode->hsync_start =
 243                         dev_priv->panel_fixed_mode->hsync_start;
 244                 adjusted_mode->hsync_end =
 245                         dev_priv->panel_fixed_mode->hsync_end;
 246                 adjusted_mode->htotal = dev_priv->panel_fixed_mode->htotal;
 247                 adjusted_mode->vdisplay = dev_priv->panel_fixed_mode->vdisplay;
 248                 adjusted_mode->vsync_start =
 249                         dev_priv->panel_fixed_mode->vsync_start;
 250                 adjusted_mode->vsync_end =
 251                         dev_priv->panel_fixed_mode->vsync_end;
 252                 adjusted_mode->vtotal = dev_priv->panel_fixed_mode->vtotal;
 253                 adjusted_mode->clock = dev_priv->panel_fixed_mode->clock;
 254                 drm_mode_set_crtcinfo(adjusted_mode, CRTC_INTERLACE_HALVE_V);
 255         }
 256
 257         /*
 258          * XXX: It would be nice to support lower refresh rates on the
 259          * panels to reduce power consumption, and perhaps match the
 260          * user's requested refresh rate.
 261          */
 262
 263         return true;
 264 }
 265
 266 static void intel_lvds_prepare(struct drm_encoder *encoder)
 267 {
 268         struct drm_device *dev = encoder->dev;
 269         struct drm_i915_private *dev_priv = dev->dev_private;
 270         u32 reg;
 271
 272         if (IS_IGDNG(dev))
 273                 reg = BLC_PWM_CPU_CTL;
 274         else
 275                 reg = BLC_PWM_CTL;
 276
 277         dev_priv->saveBLC_PWM_CTL = I915_READ(reg);
 278         dev_priv->backlight_duty_cycle = (dev_priv->saveBLC_PWM_CTL &
 279                                        BACKLIGHT_DUTY_CYCLE_MASK);
 280
 281         intel_lvds_set_power(dev, false);
 282 }
 283
 284 static void intel_lvds_commit( struct drm_encoder *encoder)
 285 {
 286         struct drm_device *dev = encoder->dev;
 287         struct drm_i915_private *dev_priv = dev->dev_private;
 288
 289         if (dev_priv->backlight_duty_cycle == 0)
 290                 dev_priv->backlight_duty_cycle =
 291                         intel_lvds_get_max_backlight(dev);
 292
 293         intel_lvds_set_power(dev, true);
 294 }
 295
 296 static void intel_lvds_mode_set(struct drm_encoder *encoder,
 297                                 struct drm_display_mode *mode,
 298                                 struct drm_display_mode *adjusted_mode)
 299 {
 300         struct drm_device *dev = encoder->dev;
 301         struct drm_i915_private *dev_priv = dev->dev_private;
 302         struct intel_crtc *intel_crtc = to_intel_crtc(encoder->crtc);
 303         u32 pfit_control;
 304
 305         /*
 306          * The LVDS pin pair will already have been turned on in the
 307          * intel_crtc_mode_set since it has a large impact on the DPLL
 308          * settings.
 309          */
 310
 311         /* No panel fitting yet, fixme */
 312         if (IS_IGDNG(dev))
 313                 return;
 314
 315         /*
 316          * Enable automatic panel scaling so that non-native modes fill the
 317          * screen.  Should be enabled before the pipe is enabled, according to
 318          * register description and PRM.
 319          */
 320         if (mode->hdisplay != adjusted_mode->hdisplay ||
 321             mode->vdisplay != adjusted_mode->vdisplay)
 322                 pfit_control = (PFIT_ENABLE | VERT_AUTO_SCALE |
 323                                 HORIZ_AUTO_SCALE | VERT_INTERP_BILINEAR |
 324                                 HORIZ_INTERP_BILINEAR);
 325         else
 326                 pfit_control = 0;
 327
 328         if (!IS_I965G(dev)) {
 329                 if (dev_priv->panel_wants_dither || dev_priv->lvds_dither)
 330                         pfit_control |= PANEL_8TO6_DITHER_ENABLE;
 331         }
 332         else
 333                 pfit_control |= intel_crtc->pipe << PFIT_PIPE_SHIFT;
 334
 335         I915_WRITE(PFIT_CONTROL, pfit_control);
 336 }
 337
 338 /**
 339  * Detect the LVDS connection.
 340  *
 341  * This always returns CONNECTOR_STATUS_CONNECTED.  This connector should only have
 342  * been set up if the LVDS was actually connected anyway.
 343  */
 344 static enum drm_connector_status intel_lvds_detect(struct drm_connector *connector)
 345 {
 346         return connector_status_connected;
 347 }
 348
 349 /**
 350  * Return the list of DDC modes if available, or the BIOS fixed mode otherwise.
 351  */
 352 static int intel_lvds_get_modes(struct drm_connector *connector)
 353 {
 354         struct drm_device *dev = connector->dev;
 355         struct intel_output *intel_output = to_intel_output(connector);
 356         struct drm_i915_private *dev_priv = dev->dev_private;
 357         int ret = 0;
 358
 359         ret = intel_ddc_get_modes(intel_output);
 360
 361         if (ret)
 362                 return ret;
 363
 364         /* Didn't get an EDID, so
 365          * Set wide sync ranges so we get all modes
 366          * handed to valid_mode for checking
 367          */
 368         connector->display_info.min_vfreq = 0;
 369         connector->display_info.max_vfreq = 200;
 370         connector->display_info.min_hfreq = 0;
 371         connector->display_info.max_hfreq = 200;
 372
 373         if (dev_priv->panel_fixed_mode != NULL) {
 374                 struct drm_display_mode *mode;
 375
 376                 mode = drm_mode_duplicate(dev, dev_priv->panel_fixed_mode);
 377                 drm_mode_probed_add(connector, mode);
 378
 379                 return 1;
 380         }
 381
 382         return 0;
 383 }
 384
 385 /**
 386  * intel_lvds_destroy - unregister and free LVDS structures
 387  * @connector: connector to free
 388  *
 389  * Unregister the DDC bus for this connector then free the driver private
 390  * structure.
 391  */
 392 static void intel_lvds_destroy(struct drm_connector *connector)
 393 {
 394         struct intel_output *intel_output = to_intel_output(connector);
 395
 396         if (intel_output->ddc_bus)
 397                 intel_i2c_destroy(intel_output->ddc_bus);
 398         drm_sysfs_connector_remove(connector);
 399         drm_connector_cleanup(connector);
 400         kfree(connector);
 401 }
 402
 403 static int intel_lvds_set_property(struct drm_connector *connector,
 404                                    struct drm_property *property,
 405                                    uint64_t value)
 406 {
 407         struct drm_device *dev = connector->dev;
 408
 409         if (property == dev->mode_config.dpms_property && connector->encoder)
 410                 intel_lvds_dpms(connector->encoder, (uint32_t)(value & 0xf));
 411
 412         return 0;
 413 }
 414
 415 static const struct drm_encoder_helper_funcs intel_lvds_helper_funcs = {
 416         .dpms = intel_lvds_dpms,
 417         .mode_fixup = intel_lvds_mode_fixup,
 418         .prepare = intel_lvds_prepare,
 419         .mode_set = intel_lvds_mode_set,
 420         .commit = intel_lvds_commit,
 421 };
 422
 423 static const struct drm_connector_helper_funcs intel_lvds_connector_helper_funcs = {
 424         .get_modes = intel_lvds_get_modes,
 425         .mode_valid = intel_lvds_mode_valid,
 426         .best_encoder = intel_best_encoder,
 427 };
 428
 429 static const struct drm_connector_funcs intel_lvds_connector_funcs = {
 430         .save = intel_lvds_save,
 431         .restore = intel_lvds_restore,
 432         .detect = intel_lvds_detect,
 433         .fill_modes = drm_helper_probe_single_connector_modes,
 434         .set_property = intel_lvds_set_property,
 435         .destroy = intel_lvds_destroy,
 436 };
 437
 438
 439 static void intel_lvds_enc_destroy(struct drm_encoder *encoder)
 440 {
 441         drm_encoder_cleanup(encoder);
 442 }
 443
 444 static const struct drm_encoder_funcs intel_lvds_enc_funcs = {
 445         .destroy = intel_lvds_enc_destroy,
 446 };
 447
 448 static int __init intel_no_lvds_dmi_callback(const struct dmi_system_id *id)
 449 {
 450         DRM_DEBUG("Skipping LVDS initialization for %s\n", id->ident);
 451         return 1;
 452 }
 453
 454 /* These systems claim to have LVDS, but really don't */
 455 static const struct dmi_system_id __initdata intel_no_lvds[] = {
 456         {
 457                 .callback = intel_no_lvds_dmi_callback,
 458                 .ident = "Apple Mac Mini (Core series)",
 459                 .matches = {
 460                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 461                         DMI_MATCH(DMI_PRODUCT_NAME, "Macmini1,1"),
 462                 },
 463         },
 464         {
 465                 .callback = intel_no_lvds_dmi_callback,
 466                 .ident = "Apple Mac Mini (Core 2 series)",
 467                 .matches = {
 468                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 469                         DMI_MATCH(DMI_PRODUCT_NAME, "Macmini2,1"),
 470                 },
 471         },
 472         {
 473                 .callback = intel_no_lvds_dmi_callback,
 474                 .ident = "MSI IM-945GSE-A",
 475                 .matches = {
 476                         DMI_MATCH(DMI_SYS_VENDOR, "MSI"),
 477                         DMI_MATCH(DMI_PRODUCT_NAME, "A9830IMS"),
 478                 },
 479         },
 480         {
 481                 .callback = intel_no_lvds_dmi_callback,
 482                 .ident = "Dell Studio Hybrid",
 483                 .matches = {
 484                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 485                         DMI_MATCH(DMI_PRODUCT_NAME, "Studio Hybrid 140g"),
 486                 },
 487         },
 488
 489         /* FIXME: add a check for the Aopen Mini PC */
 490
 491         { }     /* terminating entry */
 492 };
 493
 494 /**
 495  * intel_lvds_init - setup LVDS connectors on this device
 496  * @dev: drm device
 497  *
 498  * Create the connector, register the LVDS DDC bus, and try to figure out what
 499  * modes we can display on the LVDS panel (if present).
 500  */
 501 void intel_lvds_init(struct drm_device *dev)
 502 {
 503         struct drm_i915_private *dev_priv = dev->dev_private;
 504         struct intel_output *intel_output;
 505         struct drm_connector *connector;
 506         struct drm_encoder *encoder;
 507         struct drm_display_mode *scan; /* *modes, *bios_mode; */
 508         struct drm_crtc *crtc;
 509         u32 lvds;
 510         int pipe, gpio = GPIOC;
 511
 512         /* Skip init on machines we know falsely report LVDS */
 513         if (dmi_check_system(intel_no_lvds))
 514                 return;
 515
 516         if (IS_IGDNG(dev)) {
 517                 if ((I915_READ(PCH_LVDS) & LVDS_DETECTED) == 0)
 518                         return;
 519                 gpio = PCH_GPIOC;
 520         }
 521
 522         intel_output = kzalloc(sizeof(struct intel_output), GFP_KERNEL);
 523         if (!intel_output) {
 524                 return;
 525         }
 526
 527         connector = &intel_output->base;
 528         encoder = &intel_output->enc;
 529         drm_connector_init(dev, &intel_output->base, &intel_lvds_connector_funcs,
 530                            DRM_MODE_CONNECTOR_LVDS);
 531
 532         drm_encoder_init(dev, &intel_output->enc, &intel_lvds_enc_funcs,
 533                          DRM_MODE_ENCODER_LVDS);
 534
 535         drm_mode_connector_attach_encoder(&intel_output->base, &intel_output->enc);
 536         intel_output->type = INTEL_OUTPUT_LVDS;
 537
 538         drm_encoder_helper_add(encoder, &intel_lvds_helper_funcs);
 539         drm_connector_helper_add(connector, &intel_lvds_connector_helper_funcs);
 540         connector->display_info.subpixel_order = SubPixelHorizontalRGB;
 541         connector->interlace_allowed = false;
 542         connector->doublescan_allowed = false;
 543
 544
 545         /*
 546          * LVDS discovery:
 547          * 1) check for EDID on DDC
 548          * 2) check for VBT data
 549          * 3) check to see if LVDS is already on
 550          *    if none of the above, no panel
 551          * 4) make sure lid is open
 552          *    if closed, act like it's not there for now
 553          */
 554
 555         /* Set up the DDC bus. */
 556         intel_output->ddc_bus = intel_i2c_create(dev, gpio, "LVDSDDC_C");
 557         if (!intel_output->ddc_bus) {
 558                 dev_printk(KERN_ERR, &dev->pdev->dev, "DDC bus registration "
 559                            "failed.\n");
 560                 goto failed;
 561         }
 562
 563         /*
 564          * Attempt to get the fixed panel mode from DDC.  Assume that the
 565          * preferred mode is the right one.
 566          */
 567         intel_ddc_get_modes(intel_output);
 568
 569         list_for_each_entry(scan, &connector->probed_modes, head) {
 570                 mutex_lock(&dev->mode_config.mutex);
 571                 if (scan->type & DRM_MODE_TYPE_PREFERRED) {
 572                         dev_priv->panel_fixed_mode =
 573                                 drm_mode_duplicate(dev, scan);
 574                         mutex_unlock(&dev->mode_config.mutex);
 575                         goto out;
 576                 }
 577                 mutex_unlock(&dev->mode_config.mutex);
 578         }
 579
 580         /* Failed to get EDID, what about VBT? */
 581         if (dev_priv->lfp_lvds_vbt_mode) {
 582                 mutex_lock(&dev->mode_config.mutex);
 583                 dev_priv->panel_fixed_mode =
 584                         drm_mode_duplicate(dev, dev_priv->lfp_lvds_vbt_mode);
 585                 mutex_unlock(&dev->mode_config.mutex);
 586                 if (dev_priv->panel_fixed_mode) {
 587                         dev_priv->panel_fixed_mode->type |=
 588                                 DRM_MODE_TYPE_PREFERRED;
 589                         goto out;
 590                 }
 591         }
 592
 593         /*
 594          * If we didn't get EDID, try checking if the panel is already turned
 595          * on.  If so, assume that whatever is currently programmed is the
 596          * correct mode.
 597          */
 598
 599         /* IGDNG: FIXME if still fail, not try pipe mode now */
 600         if (IS_IGDNG(dev))
 601                 goto failed;
 602
 603         lvds = I915_READ(LVDS);
 604         pipe = (lvds & LVDS_PIPEB_SELECT) ? 1 : 0;
 605         crtc = intel_get_crtc_from_pipe(dev, pipe);
 606
 607         if (crtc && (lvds & LVDS_PORT_EN)) {
 608                 dev_priv->panel_fixed_mode = intel_crtc_mode_get(dev, crtc);
 609                 if (dev_priv->panel_fixed_mode) {
 610                         dev_priv->panel_fixed_mode->type |=
 611                                 DRM_MODE_TYPE_PREFERRED;
 612                         goto out;
 613                 }
 614         }
 615
 616         /* If we still don't have a mode after all that, give up. */
 617         if (!dev_priv->panel_fixed_mode)
 618                 goto failed;
 619
 620 out:
 621         if (IS_IGDNG(dev)) {
 622                 u32 pwm;
 623                 /* make sure PWM is enabled */
 624                 pwm = I915_READ(BLC_PWM_CPU_CTL2);
 625                 pwm |= (PWM_ENABLE | PWM_PIPE_B);
 626                 I915_WRITE(BLC_PWM_CPU_CTL2, pwm);
 627
 628                 pwm = I915_READ(BLC_PWM_PCH_CTL1);
 629                 pwm |= PWM_PCH_ENABLE;
 630                 I915_WRITE(BLC_PWM_PCH_CTL1, pwm);
 631         }
 632         drm_sysfs_connector_add(connector);
 633         return;
 634
 635 failed:
 636         DRM_DEBUG("No LVDS modes found, disabling.\n");
 637         if (intel_output->ddc_bus)
 638                 intel_i2c_destroy(intel_output->ddc_bus);
 639         drm_connector_cleanup(connector);
 640         kfree(connector);
 641 }