drivers/gpu/drm/i915/intel_dp.c

   1 /*
   2  * Copyright © 2008 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
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Keith Packard <keithp@keithp.com>
  25  *
  26  */
  27
  28 #include <linux/i2c.h>
  29 #include <linux/slab.h>
  30 #include "drmP.h"
  31 #include "drm.h"
  32 #include "drm_crtc.h"
  33 #include "drm_crtc_helper.h"
  34 #include "intel_drv.h"
  35 #include "i915_drm.h"
  36 #include "i915_drv.h"
  37 #include "drm_dp_helper.h"
  38
  39
  40 #define DP_LINK_STATUS_SIZE     6
  41 #define DP_LINK_CHECK_TIMEOUT   (10 * 1000)
  42
  43 #define DP_LINK_CONFIGURATION_SIZE      9
  44
  45 #define IS_eDP(i) ((i)->base.type == INTEL_OUTPUT_EDP)
  46 #define IS_PCH_eDP(i) ((i)->is_pch_edp)
  47
  48 struct intel_dp {
  49         struct intel_encoder base;
  50         uint32_t output_reg;
  51         uint32_t DP;
  52         uint8_t  link_configuration[DP_LINK_CONFIGURATION_SIZE];
  53         bool has_audio;
  54         int dpms_mode;
  55         uint8_t link_bw;
  56         uint8_t lane_count;
  57         uint8_t dpcd[4];
  58         struct i2c_adapter adapter;
  59         struct i2c_algo_dp_aux_data algo;
  60         bool is_pch_edp;
  61         uint8_t train_set[4];
  62         uint8_t link_status[DP_LINK_STATUS_SIZE];
  63 };
  64
  65 static struct intel_dp *enc_to_intel_dp(struct drm_encoder *encoder)
  66 {
  67         return container_of(encoder, struct intel_dp, base.base);
  68 }
  69
  70 static struct intel_dp *intel_attached_dp(struct drm_connector *connector)
  71 {
  72         return container_of(intel_attached_encoder(connector),
  73                             struct intel_dp, base);
  74 }
  75
  76 static void intel_dp_start_link_train(struct intel_dp *intel_dp);
  77 static void intel_dp_complete_link_train(struct intel_dp *intel_dp);
  78 static void intel_dp_link_down(struct intel_dp *intel_dp);
  79
  80 void
  81 intel_edp_link_config (struct intel_encoder *intel_encoder,
  82                        int *lane_num, int *link_bw)
  83 {
  84         struct intel_dp *intel_dp = container_of(intel_encoder, struct intel_dp, base);
  85
  86         *lane_num = intel_dp->lane_count;
  87         if (intel_dp->link_bw == DP_LINK_BW_1_62)
  88                 *link_bw = 162000;
  89         else if (intel_dp->link_bw == DP_LINK_BW_2_7)
  90                 *link_bw = 270000;
  91 }
  92
  93 static int
  94 intel_dp_max_lane_count(struct intel_dp *intel_dp)
  95 {
  96         int max_lane_count = 4;
  97
  98         if (intel_dp->dpcd[0] >= 0x11) {
  99                 max_lane_count = intel_dp->dpcd[2] & 0x1f;
 100                 switch (max_lane_count) {
 101                 case 1: case 2: case 4:
 102                         break;
 103                 default:
 104                         max_lane_count = 4;
 105                 }
 106         }
 107         return max_lane_count;
 108 }
 109
 110 static int
 111 intel_dp_max_link_bw(struct intel_dp *intel_dp)
 112 {
 113         int max_link_bw = intel_dp->dpcd[1];
 114
 115         switch (max_link_bw) {
 116         case DP_LINK_BW_1_62:
 117         case DP_LINK_BW_2_7:
 118                 break;
 119         default:
 120                 max_link_bw = DP_LINK_BW_1_62;
 121                 break;
 122         }
 123         return max_link_bw;
 124 }
 125
 126 static int
 127 intel_dp_link_clock(uint8_t link_bw)
 128 {
 129         if (link_bw == DP_LINK_BW_2_7)
 130                 return 270000;
 131         else
 132                 return 162000;
 133 }
 134
 135 /* I think this is a fiction */
 136 static int
 137 intel_dp_link_required(struct drm_device *dev, struct intel_dp *intel_dp, int pixel_clock)
 138 {
 139         struct drm_i915_private *dev_priv = dev->dev_private;
 140
 141         if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp))
 142                 return (pixel_clock * dev_priv->edp.bpp + 7) / 8;
 143         else
 144                 return pixel_clock * 3;
 145 }
 146
 147 static int
 148 intel_dp_max_data_rate(int max_link_clock, int max_lanes)
 149 {
 150         return (max_link_clock * max_lanes * 8) / 10;
 151 }
 152
 153 static int
 154 intel_dp_mode_valid(struct drm_connector *connector,
 155                     struct drm_display_mode *mode)
 156 {
 157         struct intel_dp *intel_dp = intel_attached_dp(connector);
 158         struct drm_device *dev = connector->dev;
 159         struct drm_i915_private *dev_priv = dev->dev_private;
 160         int max_link_clock = intel_dp_link_clock(intel_dp_max_link_bw(intel_dp));
 161         int max_lanes = intel_dp_max_lane_count(intel_dp);
 162
 163         if ((IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp)) &&
 164             dev_priv->panel_fixed_mode) {
 165                 if (mode->hdisplay > dev_priv->panel_fixed_mode->hdisplay)
 166                         return MODE_PANEL;
 167
 168                 if (mode->vdisplay > dev_priv->panel_fixed_mode->vdisplay)
 169                         return MODE_PANEL;
 170         }
 171
 172         /* only refuse the mode on non eDP since we have seen some wierd eDP panels
 173            which are outside spec tolerances but somehow work by magic */
 174         if (!IS_eDP(intel_dp) &&
 175             (intel_dp_link_required(connector->dev, intel_dp, mode->clock)
 176              > intel_dp_max_data_rate(max_link_clock, max_lanes)))
 177                 return MODE_CLOCK_HIGH;
 178
 179         if (mode->clock < 10000)
 180                 return MODE_CLOCK_LOW;
 181
 182         return MODE_OK;
 183 }
 184
 185 static uint32_t
 186 pack_aux(uint8_t *src, int src_bytes)
 187 {
 188         int     i;
 189         uint32_t v = 0;
 190
 191         if (src_bytes > 4)
 192                 src_bytes = 4;
 193         for (i = 0; i < src_bytes; i++)
 194                 v |= ((uint32_t) src[i]) << ((3-i) * 8);
 195         return v;
 196 }
 197
 198 static void
 199 unpack_aux(uint32_t src, uint8_t *dst, int dst_bytes)
 200 {
 201         int i;
 202         if (dst_bytes > 4)
 203                 dst_bytes = 4;
 204         for (i = 0; i < dst_bytes; i++)
 205                 dst[i] = src >> ((3-i) * 8);
 206 }
 207
 208 /* hrawclock is 1/4 the FSB frequency */
 209 static int
 210 intel_hrawclk(struct drm_device *dev)
 211 {
 212         struct drm_i915_private *dev_priv = dev->dev_private;
 213         uint32_t clkcfg;
 214
 215         clkcfg = I915_READ(CLKCFG);
 216         switch (clkcfg & CLKCFG_FSB_MASK) {
 217         case CLKCFG_FSB_400:
 218                 return 100;
 219         case CLKCFG_FSB_533:
 220                 return 133;
 221         case CLKCFG_FSB_667:
 222                 return 166;
 223         case CLKCFG_FSB_800:
 224                 return 200;
 225         case CLKCFG_FSB_1067:
 226                 return 266;
 227         case CLKCFG_FSB_1333:
 228                 return 333;
 229         /* these two are just a guess; one of them might be right */
 230         case CLKCFG_FSB_1600:
 231         case CLKCFG_FSB_1600_ALT:
 232                 return 400;
 233         default:
 234                 return 133;
 235         }
 236 }
 237
 238 static int
 239 intel_dp_aux_ch(struct intel_dp *intel_dp,
 240                 uint8_t *send, int send_bytes,
 241                 uint8_t *recv, int recv_size)
 242 {
 243         uint32_t output_reg = intel_dp->output_reg;
 244         struct drm_device *dev = intel_dp->base.base.dev;
 245         struct drm_i915_private *dev_priv = dev->dev_private;
 246         uint32_t ch_ctl = output_reg + 0x10;
 247         uint32_t ch_data = ch_ctl + 4;
 248         int i;
 249         int recv_bytes;
 250         uint32_t status;
 251         uint32_t aux_clock_divider;
 252         int try, precharge;
 253
 254         /* The clock divider is based off the hrawclk,
 255          * and would like to run at 2MHz. So, take the
 256          * hrawclk value and divide by 2 and use that
 257          *
 258          * Note that PCH attached eDP panels should use a 125MHz input
 259          * clock divider.
 260          */
 261         if (IS_eDP(intel_dp) && !IS_PCH_eDP(intel_dp)) {
 262                 if (IS_GEN6(dev))
 263                         aux_clock_divider = 200; /* SNB eDP input clock at 400Mhz */
 264                 else
 265                         aux_clock_divider = 225; /* eDP input clock at 450Mhz */
 266         } else if (HAS_PCH_SPLIT(dev))
 267                 aux_clock_divider = 62; /* IRL input clock fixed at 125Mhz */
 268         else
 269                 aux_clock_divider = intel_hrawclk(dev) / 2;
 270
 271         if (IS_GEN6(dev))
 272                 precharge = 3;
 273         else
 274                 precharge = 5;
 275
 276         if (I915_READ(ch_ctl) & DP_AUX_CH_CTL_SEND_BUSY) {
 277                 DRM_ERROR("dp_aux_ch not started status 0x%08x\n",
 278                           I915_READ(ch_ctl));
 279                 return -EBUSY;
 280         }
 281
 282         /* Must try at least 3 times according to DP spec */
 283         for (try = 0; try < 5; try++) {
 284                 /* Load the send data into the aux channel data registers */
 285                 for (i = 0; i < send_bytes; i += 4)
 286                         I915_WRITE(ch_data + i,
 287                                    pack_aux(send + i, send_bytes - i));
 288
 289                 /* Send the command and wait for it to complete */
 290                 I915_WRITE(ch_ctl,
 291                            DP_AUX_CH_CTL_SEND_BUSY |
 292                            DP_AUX_CH_CTL_TIME_OUT_400us |
 293                            (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) |
 294                            (precharge << DP_AUX_CH_CTL_PRECHARGE_2US_SHIFT) |
 295                            (aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT) |
 296                            DP_AUX_CH_CTL_DONE |
 297                            DP_AUX_CH_CTL_TIME_OUT_ERROR |
 298                            DP_AUX_CH_CTL_RECEIVE_ERROR);
 299                 for (;;) {
 300                         status = I915_READ(ch_ctl);
 301                         if ((status & DP_AUX_CH_CTL_SEND_BUSY) == 0)
 302                                 break;
 303                         udelay(100);
 304                 }
 305
 306                 /* Clear done status and any errors */
 307                 I915_WRITE(ch_ctl,
 308                            status |
 309                            DP_AUX_CH_CTL_DONE |
 310                            DP_AUX_CH_CTL_TIME_OUT_ERROR |
 311                            DP_AUX_CH_CTL_RECEIVE_ERROR);
 312                 if (status & DP_AUX_CH_CTL_DONE)
 313                         break;
 314         }
 315
 316         if ((status & DP_AUX_CH_CTL_DONE) == 0) {
 317                 DRM_ERROR("dp_aux_ch not done status 0x%08x\n", status);
 318                 return -EBUSY;
 319         }
 320
 321         /* Check for timeout or receive error.
 322          * Timeouts occur when the sink is not connected
 323          */
 324         if (status & DP_AUX_CH_CTL_RECEIVE_ERROR) {
 325                 DRM_ERROR("dp_aux_ch receive error status 0x%08x\n", status);
 326                 return -EIO;
 327         }
 328
 329         /* Timeouts occur when the device isn't connected, so they're
 330          * "normal" -- don't fill the kernel log with these */
 331         if (status & DP_AUX_CH_CTL_TIME_OUT_ERROR) {
 332                 DRM_DEBUG_KMS("dp_aux_ch timeout status 0x%08x\n", status);
 333                 return -ETIMEDOUT;
 334         }
 335
 336         /* Unload any bytes sent back from the other side */
 337         recv_bytes = ((status & DP_AUX_CH_CTL_MESSAGE_SIZE_MASK) >>
 338                       DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT);
 339         if (recv_bytes > recv_size)
 340                 recv_bytes = recv_size;
 341
 342         for (i = 0; i < recv_bytes; i += 4)
 343                 unpack_aux(I915_READ(ch_data + i),
 344                            recv + i, recv_bytes - i);
 345
 346         return recv_bytes;
 347 }
 348
 349 /* Write data to the aux channel in native mode */
 350 static int
 351 intel_dp_aux_native_write(struct intel_dp *intel_dp,
 352                           uint16_t address, uint8_t *send, int send_bytes)
 353 {
 354         int ret;
 355         uint8_t msg[20];
 356         int msg_bytes;
 357         uint8_t ack;
 358
 359         if (send_bytes > 16)
 360                 return -1;
 361         msg[0] = AUX_NATIVE_WRITE << 4;
 362         msg[1] = address >> 8;
 363         msg[2] = address & 0xff;
 364         msg[3] = send_bytes - 1;
 365         memcpy(&msg[4], send, send_bytes);
 366         msg_bytes = send_bytes + 4;
 367         for (;;) {
 368                 ret = intel_dp_aux_ch(intel_dp, msg, msg_bytes, &ack, 1);
 369                 if (ret < 0)
 370                         return ret;
 371                 if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_ACK)
 372                         break;
 373                 else if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_DEFER)
 374                         udelay(100);
 375                 else
 376                         return -EIO;
 377         }
 378         return send_bytes;
 379 }
 380
 381 /* Write a single byte to the aux channel in native mode */
 382 static int
 383 intel_dp_aux_native_write_1(struct intel_dp *intel_dp,
 384                             uint16_t address, uint8_t byte)
 385 {
 386         return intel_dp_aux_native_write(intel_dp, address, &byte, 1);
 387 }
 388
 389 /* read bytes from a native aux channel */
 390 static int
 391 intel_dp_aux_native_read(struct intel_dp *intel_dp,
 392                          uint16_t address, uint8_t *recv, int recv_bytes)
 393 {
 394         uint8_t msg[4];
 395         int msg_bytes;
 396         uint8_t reply[20];
 397         int reply_bytes;
 398         uint8_t ack;
 399         int ret;
 400
 401         msg[0] = AUX_NATIVE_READ << 4;
 402         msg[1] = address >> 8;
 403         msg[2] = address & 0xff;
 404         msg[3] = recv_bytes - 1;
 405
 406         msg_bytes = 4;
 407         reply_bytes = recv_bytes + 1;
 408
 409         for (;;) {
 410                 ret = intel_dp_aux_ch(intel_dp, msg, msg_bytes,
 411                                       reply, reply_bytes);
 412                 if (ret == 0)
 413                         return -EPROTO;
 414                 if (ret < 0)
 415                         return ret;
 416                 ack = reply[0];
 417                 if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_ACK) {
 418                         memcpy(recv, reply + 1, ret - 1);
 419                         return ret - 1;
 420                 }
 421                 else if ((ack & AUX_NATIVE_REPLY_MASK) == AUX_NATIVE_REPLY_DEFER)
 422                         udelay(100);
 423                 else
 424                         return -EIO;
 425         }
 426 }
 427
 428 static int
 429 intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
 430                     uint8_t write_byte, uint8_t *read_byte)
 431 {
 432         struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
 433         struct intel_dp *intel_dp = container_of(adapter,
 434                                                 struct intel_dp,
 435                                                 adapter);
 436         uint16_t address = algo_data->address;
 437         uint8_t msg[5];
 438         uint8_t reply[2];
 439         int msg_bytes;
 440         int reply_bytes;
 441         int ret;
 442
 443         /* Set up the command byte */
 444         if (mode & MODE_I2C_READ)
 445                 msg[0] = AUX_I2C_READ << 4;
 446         else
 447                 msg[0] = AUX_I2C_WRITE << 4;
 448
 449         if (!(mode & MODE_I2C_STOP))
 450                 msg[0] |= AUX_I2C_MOT << 4;
 451
 452         msg[1] = address >> 8;
 453         msg[2] = address;
 454
 455         switch (mode) {
 456         case MODE_I2C_WRITE:
 457                 msg[3] = 0;
 458                 msg[4] = write_byte;
 459                 msg_bytes = 5;
 460                 reply_bytes = 1;
 461                 break;
 462         case MODE_I2C_READ:
 463                 msg[3] = 0;
 464                 msg_bytes = 4;
 465                 reply_bytes = 2;
 466                 break;
 467         default:
 468                 msg_bytes = 3;
 469                 reply_bytes = 1;
 470                 break;
 471         }
 472
 473         for (;;) {
 474           ret = intel_dp_aux_ch(intel_dp,
 475                                 msg, msg_bytes,
 476                                 reply, reply_bytes);
 477                 if (ret < 0) {
 478                         DRM_DEBUG_KMS("aux_ch failed %d\n", ret);
 479                         return ret;
 480                 }
 481                 switch (reply[0] & AUX_I2C_REPLY_MASK) {
 482                 case AUX_I2C_REPLY_ACK:
 483                         if (mode == MODE_I2C_READ) {
 484                                 *read_byte = reply[1];
 485                         }
 486                         return reply_bytes - 1;
 487                 case AUX_I2C_REPLY_NACK:
 488                         DRM_DEBUG_KMS("aux_ch nack\n");
 489                         return -EREMOTEIO;
 490                 case AUX_I2C_REPLY_DEFER:
 491                         DRM_DEBUG_KMS("aux_ch defer\n");
 492                         udelay(100);
 493                         break;
 494                 default:
 495                         DRM_ERROR("aux_ch invalid reply 0x%02x\n", reply[0]);
 496                         return -EREMOTEIO;
 497                 }
 498         }
 499 }
 500
 501 static int
 502 intel_dp_i2c_init(struct intel_dp *intel_dp,
 503                   struct intel_connector *intel_connector, const char *name)
 504 {
 505         DRM_DEBUG_KMS("i2c_init %s\n", name);
 506         intel_dp->algo.running = false;
 507         intel_dp->algo.address = 0;
 508         intel_dp->algo.aux_ch = intel_dp_i2c_aux_ch;
 509
 510         memset(&intel_dp->adapter, '\0', sizeof (intel_dp->adapter));
 511         intel_dp->adapter.owner = THIS_MODULE;
 512         intel_dp->adapter.class = I2C_CLASS_DDC;
 513         strncpy (intel_dp->adapter.name, name, sizeof(intel_dp->adapter.name) - 1);
 514         intel_dp->adapter.name[sizeof(intel_dp->adapter.name) - 1] = '\0';
 515         intel_dp->adapter.algo_data = &intel_dp->algo;
 516         intel_dp->adapter.dev.parent = &intel_connector->base.kdev;
 517
 518         return i2c_dp_aux_add_bus(&intel_dp->adapter);
 519 }
 520
 521 static bool
 522 intel_dp_mode_fixup(struct drm_encoder *encoder, struct drm_display_mode *mode,
 523                     struct drm_display_mode *adjusted_mode)
 524 {
 525         struct drm_device *dev = encoder->dev;
 526         struct drm_i915_private *dev_priv = dev->dev_private;
 527         struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 528         int lane_count, clock;
 529         int max_lane_count = intel_dp_max_lane_count(intel_dp);
 530         int max_clock = intel_dp_max_link_bw(intel_dp) == DP_LINK_BW_2_7 ? 1 : 0;
 531         static int bws[2] = { DP_LINK_BW_1_62, DP_LINK_BW_2_7 };
 532
 533         if ((IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp)) &&
 534             dev_priv->panel_fixed_mode) {
 535                 intel_fixed_panel_mode(dev_priv->panel_fixed_mode, adjusted_mode);
 536                 intel_pch_panel_fitting(dev, DRM_MODE_SCALE_FULLSCREEN,
 537                                         mode, adjusted_mode);
 538                 /*
 539                  * the mode->clock is used to calculate the Data&Link M/N
 540                  * of the pipe. For the eDP the fixed clock should be used.
 541                  */
 542                 mode->clock = dev_priv->panel_fixed_mode->clock;
 543         }
 544
 545         for (lane_count = 1; lane_count <= max_lane_count; lane_count <<= 1) {
 546                 for (clock = 0; clock <= max_clock; clock++) {
 547                         int link_avail = intel_dp_max_data_rate(intel_dp_link_clock(bws[clock]), lane_count);
 548
 549                         if (intel_dp_link_required(encoder->dev, intel_dp, mode->clock)
 550                                         <= link_avail) {
 551                                 intel_dp->link_bw = bws[clock];
 552                                 intel_dp->lane_count = lane_count;
 553                                 adjusted_mode->clock = intel_dp_link_clock(intel_dp->link_bw);
 554                                 DRM_DEBUG_KMS("Display port link bw %02x lane "
 555                                                 "count %d clock %d\n",
 556                                        intel_dp->link_bw, intel_dp->lane_count,
 557                                        adjusted_mode->clock);
 558                                 return true;
 559                         }
 560                 }
 561         }
 562
 563         if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp)) {
 564                 /* okay we failed just pick the highest */
 565                 intel_dp->lane_count = max_lane_count;
 566                 intel_dp->link_bw = bws[max_clock];
 567                 adjusted_mode->clock = intel_dp_link_clock(intel_dp->link_bw);
 568                 DRM_DEBUG_KMS("Force picking display port link bw %02x lane "
 569                               "count %d clock %d\n",
 570                               intel_dp->link_bw, intel_dp->lane_count,
 571                               adjusted_mode->clock);
 572
 573                 return true;
 574         }
 575
 576         return false;
 577 }
 578
 579 struct intel_dp_m_n {
 580         uint32_t        tu;
 581         uint32_t        gmch_m;
 582         uint32_t        gmch_n;
 583         uint32_t        link_m;
 584         uint32_t        link_n;
 585 };
 586
 587 static void
 588 intel_reduce_ratio(uint32_t *num, uint32_t *den)
 589 {
 590         while (*num > 0xffffff || *den > 0xffffff) {
 591                 *num >>= 1;
 592                 *den >>= 1;
 593         }
 594 }
 595
 596 static void
 597 intel_dp_compute_m_n(int bpp,
 598                      int nlanes,
 599                      int pixel_clock,
 600                      int link_clock,
 601                      struct intel_dp_m_n *m_n)
 602 {
 603         m_n->tu = 64;
 604         m_n->gmch_m = (pixel_clock * bpp) >> 3;
 605         m_n->gmch_n = link_clock * nlanes;
 606         intel_reduce_ratio(&m_n->gmch_m, &m_n->gmch_n);
 607         m_n->link_m = pixel_clock;
 608         m_n->link_n = link_clock;
 609         intel_reduce_ratio(&m_n->link_m, &m_n->link_n);
 610 }
 611
 612 bool intel_pch_has_edp(struct drm_crtc *crtc)
 613 {
 614         struct drm_device *dev = crtc->dev;
 615         struct drm_mode_config *mode_config = &dev->mode_config;
 616         struct drm_encoder *encoder;
 617
 618         list_for_each_entry(encoder, &mode_config->encoder_list, head) {
 619                 struct intel_dp *intel_dp;
 620
 621                 if (encoder->crtc != crtc)
 622                         continue;
 623
 624                 intel_dp = enc_to_intel_dp(encoder);
 625                 if (intel_dp->base.type == INTEL_OUTPUT_DISPLAYPORT)
 626                         return intel_dp->is_pch_edp;
 627         }
 628         return false;
 629 }
 630
 631 void
 632 intel_dp_set_m_n(struct drm_crtc *crtc, struct drm_display_mode *mode,
 633                  struct drm_display_mode *adjusted_mode)
 634 {
 635         struct drm_device *dev = crtc->dev;
 636         struct drm_mode_config *mode_config = &dev->mode_config;
 637         struct drm_encoder *encoder;
 638         struct drm_i915_private *dev_priv = dev->dev_private;
 639         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 640         int lane_count = 4, bpp = 24;
 641         struct intel_dp_m_n m_n;
 642
 643         /*
 644          * Find the lane count in the intel_encoder private
 645          */
 646         list_for_each_entry(encoder, &mode_config->encoder_list, head) {
 647                 struct intel_dp *intel_dp;
 648
 649                 if (encoder->crtc != crtc)
 650                         continue;
 651
 652                 intel_dp = enc_to_intel_dp(encoder);
 653                 if (intel_dp->base.type == INTEL_OUTPUT_DISPLAYPORT) {
 654                         lane_count = intel_dp->lane_count;
 655                         if (IS_PCH_eDP(intel_dp))
 656                                 bpp = dev_priv->edp.bpp;
 657                         break;
 658                 }
 659         }
 660
 661         /*
 662          * Compute the GMCH and Link ratios. The '3' here is
 663          * the number of bytes_per_pixel post-LUT, which we always
 664          * set up for 8-bits of R/G/B, or 3 bytes total.
 665          */
 666         intel_dp_compute_m_n(bpp, lane_count,
 667                              mode->clock, adjusted_mode->clock, &m_n);
 668
 669         if (HAS_PCH_SPLIT(dev)) {
 670                 if (intel_crtc->pipe == 0) {
 671                         I915_WRITE(TRANSA_DATA_M1,
 672                                    ((m_n.tu - 1) << PIPE_GMCH_DATA_M_TU_SIZE_SHIFT) |
 673                                    m_n.gmch_m);
 674                         I915_WRITE(TRANSA_DATA_N1, m_n.gmch_n);
 675                         I915_WRITE(TRANSA_DP_LINK_M1, m_n.link_m);
 676                         I915_WRITE(TRANSA_DP_LINK_N1, m_n.link_n);
 677                 } else {
 678                         I915_WRITE(TRANSB_DATA_M1,
 679                                    ((m_n.tu - 1) << PIPE_GMCH_DATA_M_TU_SIZE_SHIFT) |
 680                                    m_n.gmch_m);
 681                         I915_WRITE(TRANSB_DATA_N1, m_n.gmch_n);
 682                         I915_WRITE(TRANSB_DP_LINK_M1, m_n.link_m);
 683                         I915_WRITE(TRANSB_DP_LINK_N1, m_n.link_n);
 684                 }
 685         } else {
 686                 if (intel_crtc->pipe == 0) {
 687                         I915_WRITE(PIPEA_GMCH_DATA_M,
 688                                    ((m_n.tu - 1) << PIPE_GMCH_DATA_M_TU_SIZE_SHIFT) |
 689                                    m_n.gmch_m);
 690                         I915_WRITE(PIPEA_GMCH_DATA_N,
 691                                    m_n.gmch_n);
 692                         I915_WRITE(PIPEA_DP_LINK_M, m_n.link_m);
 693                         I915_WRITE(PIPEA_DP_LINK_N, m_n.link_n);
 694                 } else {
 695                         I915_WRITE(PIPEB_GMCH_DATA_M,
 696                                    ((m_n.tu - 1) << PIPE_GMCH_DATA_M_TU_SIZE_SHIFT) |
 697                                    m_n.gmch_m);
 698                         I915_WRITE(PIPEB_GMCH_DATA_N,
 699                                         m_n.gmch_n);
 700                         I915_WRITE(PIPEB_DP_LINK_M, m_n.link_m);
 701                         I915_WRITE(PIPEB_DP_LINK_N, m_n.link_n);
 702                 }
 703         }
 704 }
 705
 706 static void
 707 intel_dp_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode,
 708                   struct drm_display_mode *adjusted_mode)
 709 {
 710         struct drm_device *dev = encoder->dev;
 711         struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 712         struct drm_crtc *crtc = intel_dp->base.base.crtc;
 713         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 714
 715         intel_dp->DP = (DP_VOLTAGE_0_4 |
 716                        DP_PRE_EMPHASIS_0);
 717
 718         if (adjusted_mode->flags & DRM_MODE_FLAG_PHSYNC)
 719                 intel_dp->DP |= DP_SYNC_HS_HIGH;
 720         if (adjusted_mode->flags & DRM_MODE_FLAG_PVSYNC)
 721                 intel_dp->DP |= DP_SYNC_VS_HIGH;
 722
 723         if (HAS_PCH_CPT(dev) && !IS_eDP(intel_dp))
 724                 intel_dp->DP |= DP_LINK_TRAIN_OFF_CPT;
 725         else
 726                 intel_dp->DP |= DP_LINK_TRAIN_OFF;
 727
 728         switch (intel_dp->lane_count) {
 729         case 1:
 730                 intel_dp->DP |= DP_PORT_WIDTH_1;
 731                 break;
 732         case 2:
 733                 intel_dp->DP |= DP_PORT_WIDTH_2;
 734                 break;
 735         case 4:
 736                 intel_dp->DP |= DP_PORT_WIDTH_4;
 737                 break;
 738         }
 739         if (intel_dp->has_audio)
 740                 intel_dp->DP |= DP_AUDIO_OUTPUT_ENABLE;
 741
 742         memset(intel_dp->link_configuration, 0, DP_LINK_CONFIGURATION_SIZE);
 743         intel_dp->link_configuration[0] = intel_dp->link_bw;
 744         intel_dp->link_configuration[1] = intel_dp->lane_count;
 745
 746         /*
 747          * Check for DPCD version > 1.1 and enhanced framing support
 748          */
 749         if (intel_dp->dpcd[0] >= 0x11 && (intel_dp->dpcd[2] & DP_ENHANCED_FRAME_CAP)) {
 750                 intel_dp->link_configuration[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
 751                 intel_dp->DP |= DP_ENHANCED_FRAMING;
 752         }
 753
 754         /* CPT DP's pipe select is decided in TRANS_DP_CTL */
 755         if (intel_crtc->pipe == 1 && !HAS_PCH_CPT(dev))
 756                 intel_dp->DP |= DP_PIPEB_SELECT;
 757
 758         if (IS_eDP(intel_dp)) {
 759                 /* don't miss out required setting for eDP */
 760                 intel_dp->DP |= DP_PLL_ENABLE;
 761                 if (adjusted_mode->clock < 200000)
 762                         intel_dp->DP |= DP_PLL_FREQ_160MHZ;
 763                 else
 764                         intel_dp->DP |= DP_PLL_FREQ_270MHZ;
 765         }
 766 }
 767
 768 /* Returns true if the panel was already on when called */
 769 static bool ironlake_edp_panel_on (struct drm_device *dev)
 770 {
 771         struct drm_i915_private *dev_priv = dev->dev_private;
 772         u32 pp;
 773
 774         if (I915_READ(PCH_PP_STATUS) & PP_ON)
 775                 return true;
 776
 777         pp = I915_READ(PCH_PP_CONTROL);
 778
 779         /* ILK workaround: disable reset around power sequence */
 780         pp &= ~PANEL_POWER_RESET;
 781         I915_WRITE(PCH_PP_CONTROL, pp);
 782         POSTING_READ(PCH_PP_CONTROL);
 783
 784         pp |= POWER_TARGET_ON;
 785         I915_WRITE(PCH_PP_CONTROL, pp);
 786
 787         /* Ouch. We need to wait here for some panels, like Dell e6510
 788          * https://bugs.freedesktop.org/show_bug.cgi?id=29278i
 789          */
 790         msleep(300);
 791
 792         if (wait_for(I915_READ(PCH_PP_STATUS) & PP_ON, 5000))
 793                 DRM_ERROR("panel on wait timed out: 0x%08x\n",
 794                           I915_READ(PCH_PP_STATUS));
 795
 796         pp &= ~(PANEL_UNLOCK_REGS);
 797         pp |= PANEL_POWER_RESET; /* restore panel reset bit */
 798         I915_WRITE(PCH_PP_CONTROL, pp);
 799         POSTING_READ(PCH_PP_CONTROL);
 800
 801         return false;
 802 }
 803
 804 static void ironlake_edp_panel_off (struct drm_device *dev)
 805 {
 806         struct drm_i915_private *dev_priv = dev->dev_private;
 807         u32 pp;
 808
 809         pp = I915_READ(PCH_PP_CONTROL);
 810
 811         /* ILK workaround: disable reset around power sequence */
 812         pp &= ~PANEL_POWER_RESET;
 813         I915_WRITE(PCH_PP_CONTROL, pp);
 814         POSTING_READ(PCH_PP_CONTROL);
 815
 816         pp &= ~POWER_TARGET_ON;
 817         I915_WRITE(PCH_PP_CONTROL, pp);
 818
 819         if (wait_for((I915_READ(PCH_PP_STATUS) & PP_ON) == 0, 5000))
 820                 DRM_ERROR("panel off wait timed out: 0x%08x\n",
 821                           I915_READ(PCH_PP_STATUS));
 822
 823         /* Make sure VDD is enabled so DP AUX will work */
 824         pp |= PANEL_POWER_RESET; /* restore panel reset bit */
 825         I915_WRITE(PCH_PP_CONTROL, pp);
 826         POSTING_READ(PCH_PP_CONTROL);
 827
 828         /* Ouch. We need to wait here for some panels, like Dell e6510
 829          * https://bugs.freedesktop.org/show_bug.cgi?id=29278i
 830          */
 831         msleep(300);
 832 }
 833
 834 static void ironlake_edp_panel_vdd_on(struct drm_device *dev)
 835 {
 836         struct drm_i915_private *dev_priv = dev->dev_private;
 837         u32 pp;
 838
 839         pp = I915_READ(PCH_PP_CONTROL);
 840         pp |= EDP_FORCE_VDD;
 841         I915_WRITE(PCH_PP_CONTROL, pp);
 842         POSTING_READ(PCH_PP_CONTROL);
 843         msleep(300);
 844 }
 845
 846 static void ironlake_edp_panel_vdd_off(struct drm_device *dev)
 847 {
 848         struct drm_i915_private *dev_priv = dev->dev_private;
 849         u32 pp;
 850
 851         pp = I915_READ(PCH_PP_CONTROL);
 852         pp &= ~EDP_FORCE_VDD;
 853         I915_WRITE(PCH_PP_CONTROL, pp);
 854         POSTING_READ(PCH_PP_CONTROL);
 855         msleep(300);
 856 }
 857
 858 static void ironlake_edp_backlight_on (struct drm_device *dev)
 859 {
 860         struct drm_i915_private *dev_priv = dev->dev_private;
 861         u32 pp;
 862
 863         DRM_DEBUG_KMS("\n");
 864         pp = I915_READ(PCH_PP_CONTROL);
 865         pp |= EDP_BLC_ENABLE;
 866         I915_WRITE(PCH_PP_CONTROL, pp);
 867 }
 868
 869 static void ironlake_edp_backlight_off (struct drm_device *dev)
 870 {
 871         struct drm_i915_private *dev_priv = dev->dev_private;
 872         u32 pp;
 873
 874         DRM_DEBUG_KMS("\n");
 875         pp = I915_READ(PCH_PP_CONTROL);
 876         pp &= ~EDP_BLC_ENABLE;
 877         I915_WRITE(PCH_PP_CONTROL, pp);
 878 }
 879
 880 static void ironlake_edp_pll_on(struct drm_encoder *encoder)
 881 {
 882         struct drm_device *dev = encoder->dev;
 883         struct drm_i915_private *dev_priv = dev->dev_private;
 884         u32 dpa_ctl;
 885
 886         DRM_DEBUG_KMS("\n");
 887         dpa_ctl = I915_READ(DP_A);
 888         dpa_ctl &= ~DP_PLL_ENABLE;
 889         I915_WRITE(DP_A, dpa_ctl);
 890 }
 891
 892 static void ironlake_edp_pll_off(struct drm_encoder *encoder)
 893 {
 894         struct drm_device *dev = encoder->dev;
 895         struct drm_i915_private *dev_priv = dev->dev_private;
 896         u32 dpa_ctl;
 897
 898         dpa_ctl = I915_READ(DP_A);
 899         dpa_ctl |= DP_PLL_ENABLE;
 900         I915_WRITE(DP_A, dpa_ctl);
 901         POSTING_READ(DP_A);
 902         udelay(200);
 903 }
 904
 905 static void intel_dp_prepare(struct drm_encoder *encoder)
 906 {
 907         struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 908         struct drm_device *dev = encoder->dev;
 909         struct drm_i915_private *dev_priv = dev->dev_private;
 910         uint32_t dp_reg = I915_READ(intel_dp->output_reg);
 911
 912         if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp)) {
 913                 ironlake_edp_panel_off(dev);
 914                 ironlake_edp_backlight_off(dev);
 915                 ironlake_edp_panel_vdd_on(dev);
 916                 ironlake_edp_pll_on(encoder);
 917         }
 918         if (dp_reg & DP_PORT_EN)
 919                 intel_dp_link_down(intel_dp);
 920 }
 921
 922 static void intel_dp_commit(struct drm_encoder *encoder)
 923 {
 924         struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 925         struct drm_device *dev = encoder->dev;
 926
 927         intel_dp_start_link_train(intel_dp);
 928
 929         if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp))
 930                 ironlake_edp_panel_on(dev);
 931
 932         intel_dp_complete_link_train(intel_dp);
 933
 934         if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp))
 935                 ironlake_edp_backlight_on(dev);
 936 }
 937
 938 static void
 939 intel_dp_dpms(struct drm_encoder *encoder, int mode)
 940 {
 941         struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 942         struct drm_device *dev = encoder->dev;
 943         struct drm_i915_private *dev_priv = dev->dev_private;
 944         uint32_t dp_reg = I915_READ(intel_dp->output_reg);
 945
 946         if (mode != DRM_MODE_DPMS_ON) {
 947                 if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp)) {
 948                         ironlake_edp_backlight_off(dev);
 949                         ironlake_edp_panel_off(dev);
 950                 }
 951                 if (dp_reg & DP_PORT_EN)
 952                         intel_dp_link_down(intel_dp);
 953                 if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp))
 954                         ironlake_edp_pll_off(encoder);
 955         } else {
 956                 if (!(dp_reg & DP_PORT_EN)) {
 957                         intel_dp_start_link_train(intel_dp);
 958                         if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp))
 959                                 ironlake_edp_panel_on(dev);
 960                         intel_dp_complete_link_train(intel_dp);
 961                         if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp))
 962                                 ironlake_edp_backlight_on(dev);
 963                 }
 964         }
 965         intel_dp->dpms_mode = mode;
 966 }
 967
 968 /*
 969  * Fetch AUX CH registers 0x202 - 0x207 which contain
 970  * link status information
 971  */
 972 static bool
 973 intel_dp_get_link_status(struct intel_dp *intel_dp)
 974 {
 975         int ret;
 976
 977         ret = intel_dp_aux_native_read(intel_dp,
 978                                        DP_LANE0_1_STATUS,
 979                                        intel_dp->link_status, DP_LINK_STATUS_SIZE);
 980         if (ret != DP_LINK_STATUS_SIZE)
 981                 return false;
 982         return true;
 983 }
 984
 985 static uint8_t
 986 intel_dp_link_status(uint8_t link_status[DP_LINK_STATUS_SIZE],
 987                      int r)
 988 {
 989         return link_status[r - DP_LANE0_1_STATUS];
 990 }
 991
 992 static uint8_t
 993 intel_get_adjust_request_voltage(uint8_t link_status[DP_LINK_STATUS_SIZE],
 994                                  int lane)
 995 {
 996         int         i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1);
 997         int         s = ((lane & 1) ?
 998                          DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT :
 999                          DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT);
1000         uint8_t l = intel_dp_link_status(link_status, i);
1001
1002         return ((l >> s) & 3) << DP_TRAIN_VOLTAGE_SWING_SHIFT;
1003 }
1004
1005 static uint8_t
1006 intel_get_adjust_request_pre_emphasis(uint8_t link_status[DP_LINK_STATUS_SIZE],
1007                                       int lane)
1008 {
1009         int         i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1);
1010         int         s = ((lane & 1) ?
1011                          DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT :
1012                          DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT);
1013         uint8_t l = intel_dp_link_status(link_status, i);
1014
1015         return ((l >> s) & 3) << DP_TRAIN_PRE_EMPHASIS_SHIFT;
1016 }
1017
1018
1019 #if 0
1020 static char     *voltage_names[] = {
1021         "0.4V", "0.6V", "0.8V", "1.2V"
1022 };
1023 static char     *pre_emph_names[] = {
1024         "0dB", "3.5dB", "6dB", "9.5dB"
1025 };
1026 static char     *link_train_names[] = {
1027         "pattern 1", "pattern 2", "idle", "off"
1028 };
1029 #endif
1030
1031 /*
1032  * These are source-specific values; current Intel hardware supports
1033  * a maximum voltage of 800mV and a maximum pre-emphasis of 6dB
1034  */
1035 #define I830_DP_VOLTAGE_MAX         DP_TRAIN_VOLTAGE_SWING_800
1036
1037 static uint8_t
1038 intel_dp_pre_emphasis_max(uint8_t voltage_swing)
1039 {
1040         switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
1041         case DP_TRAIN_VOLTAGE_SWING_400:
1042                 return DP_TRAIN_PRE_EMPHASIS_6;
1043         case DP_TRAIN_VOLTAGE_SWING_600:
1044                 return DP_TRAIN_PRE_EMPHASIS_6;
1045         case DP_TRAIN_VOLTAGE_SWING_800:
1046                 return DP_TRAIN_PRE_EMPHASIS_3_5;
1047         case DP_TRAIN_VOLTAGE_SWING_1200:
1048         default:
1049                 return DP_TRAIN_PRE_EMPHASIS_0;
1050         }
1051 }
1052
1053 static void
1054 intel_get_adjust_train(struct intel_dp *intel_dp)
1055 {
1056         uint8_t v = 0;
1057         uint8_t p = 0;
1058         int lane;
1059
1060         for (lane = 0; lane < intel_dp->lane_count; lane++) {
1061                 uint8_t this_v = intel_get_adjust_request_voltage(intel_dp->link_status, lane);
1062                 uint8_t this_p = intel_get_adjust_request_pre_emphasis(intel_dp->link_status, lane);
1063
1064                 if (this_v > v)
1065                         v = this_v;
1066                 if (this_p > p)
1067                         p = this_p;
1068         }
1069
1070         if (v >= I830_DP_VOLTAGE_MAX)
1071                 v = I830_DP_VOLTAGE_MAX | DP_TRAIN_MAX_SWING_REACHED;
1072
1073         if (p >= intel_dp_pre_emphasis_max(v))
1074                 p = intel_dp_pre_emphasis_max(v) | DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
1075
1076         for (lane = 0; lane < 4; lane++)
1077                 intel_dp->train_set[lane] = v | p;
1078 }
1079
1080 static uint32_t
1081 intel_dp_signal_levels(uint8_t train_set, int lane_count)
1082 {
1083         uint32_t        signal_levels = 0;
1084
1085         switch (train_set & DP_TRAIN_VOLTAGE_SWING_MASK) {
1086         case DP_TRAIN_VOLTAGE_SWING_400:
1087         default:
1088                 signal_levels |= DP_VOLTAGE_0_4;
1089                 break;
1090         case DP_TRAIN_VOLTAGE_SWING_600:
1091                 signal_levels |= DP_VOLTAGE_0_6;
1092                 break;
1093         case DP_TRAIN_VOLTAGE_SWING_800:
1094                 signal_levels |= DP_VOLTAGE_0_8;
1095                 break;
1096         case DP_TRAIN_VOLTAGE_SWING_1200:
1097                 signal_levels |= DP_VOLTAGE_1_2;
1098                 break;
1099         }
1100         switch (train_set & DP_TRAIN_PRE_EMPHASIS_MASK) {
1101         case DP_TRAIN_PRE_EMPHASIS_0:
1102         default:
1103                 signal_levels |= DP_PRE_EMPHASIS_0;
1104                 break;
1105         case DP_TRAIN_PRE_EMPHASIS_3_5:
1106                 signal_levels |= DP_PRE_EMPHASIS_3_5;
1107                 break;
1108         case DP_TRAIN_PRE_EMPHASIS_6:
1109                 signal_levels |= DP_PRE_EMPHASIS_6;
1110                 break;
1111         case DP_TRAIN_PRE_EMPHASIS_9_5:
1112                 signal_levels |= DP_PRE_EMPHASIS_9_5;
1113                 break;
1114         }
1115         return signal_levels;
1116 }
1117
1118 /* Gen6's DP voltage swing and pre-emphasis control */
1119 static uint32_t
1120 intel_gen6_edp_signal_levels(uint8_t train_set)
1121 {
1122         switch (train_set & (DP_TRAIN_VOLTAGE_SWING_MASK|DP_TRAIN_PRE_EMPHASIS_MASK)) {
1123         case DP_TRAIN_VOLTAGE_SWING_400 | DP_TRAIN_PRE_EMPHASIS_0:
1124                 return EDP_LINK_TRAIN_400MV_0DB_SNB_B;
1125         case DP_TRAIN_VOLTAGE_SWING_400 | DP_TRAIN_PRE_EMPHASIS_6:
1126                 return EDP_LINK_TRAIN_400MV_6DB_SNB_B;
1127         case DP_TRAIN_VOLTAGE_SWING_600 | DP_TRAIN_PRE_EMPHASIS_3_5:
1128                 return EDP_LINK_TRAIN_600MV_3_5DB_SNB_B;
1129         case DP_TRAIN_VOLTAGE_SWING_800 | DP_TRAIN_PRE_EMPHASIS_0:
1130                 return EDP_LINK_TRAIN_800MV_0DB_SNB_B;
1131         default:
1132                 DRM_DEBUG_KMS("Unsupported voltage swing/pre-emphasis level\n");
1133                 return EDP_LINK_TRAIN_400MV_0DB_SNB_B;
1134         }
1135 }
1136
1137 static uint8_t
1138 intel_get_lane_status(uint8_t link_status[DP_LINK_STATUS_SIZE],
1139                       int lane)
1140 {
1141         int i = DP_LANE0_1_STATUS + (lane >> 1);
1142         int s = (lane & 1) * 4;
1143         uint8_t l = intel_dp_link_status(link_status, i);
1144
1145         return (l >> s) & 0xf;
1146 }
1147
1148 /* Check for clock recovery is done on all channels */
1149 static bool
1150 intel_clock_recovery_ok(uint8_t link_status[DP_LINK_STATUS_SIZE], int lane_count)
1151 {
1152         int lane;
1153         uint8_t lane_status;
1154
1155         for (lane = 0; lane < lane_count; lane++) {
1156                 lane_status = intel_get_lane_status(link_status, lane);
1157                 if ((lane_status & DP_LANE_CR_DONE) == 0)
1158                         return false;
1159         }
1160         return true;
1161 }
1162
1163 /* Check to see if channel eq is done on all channels */
1164 #define CHANNEL_EQ_BITS (DP_LANE_CR_DONE|\
1165                          DP_LANE_CHANNEL_EQ_DONE|\
1166                          DP_LANE_SYMBOL_LOCKED)
1167 static bool
1168 intel_channel_eq_ok(struct intel_dp *intel_dp)
1169 {
1170         uint8_t lane_align;
1171         uint8_t lane_status;
1172         int lane;
1173
1174         lane_align = intel_dp_link_status(intel_dp->link_status,
1175                                           DP_LANE_ALIGN_STATUS_UPDATED);
1176         if ((lane_align & DP_INTERLANE_ALIGN_DONE) == 0)
1177                 return false;
1178         for (lane = 0; lane < intel_dp->lane_count; lane++) {
1179                 lane_status = intel_get_lane_status(intel_dp->link_status, lane);
1180                 if ((lane_status & CHANNEL_EQ_BITS) != CHANNEL_EQ_BITS)
1181                         return false;
1182         }
1183         return true;
1184 }
1185
1186 static bool
1187 intel_dp_set_link_train(struct intel_dp *intel_dp,
1188                         uint32_t dp_reg_value,
1189                         uint8_t dp_train_pat)
1190 {
1191         struct drm_device *dev = intel_dp->base.base.dev;
1192         struct drm_i915_private *dev_priv = dev->dev_private;
1193         int ret;
1194
1195         I915_WRITE(intel_dp->output_reg, dp_reg_value);
1196         POSTING_READ(intel_dp->output_reg);
1197
1198         intel_dp_aux_native_write_1(intel_dp,
1199                                     DP_TRAINING_PATTERN_SET,
1200                                     dp_train_pat);
1201
1202         ret = intel_dp_aux_native_write(intel_dp,
1203                                         DP_TRAINING_LANE0_SET,
1204                                         intel_dp->train_set, 4);
1205         if (ret != 4)
1206                 return false;
1207
1208         return true;
1209 }
1210
1211 /* Enable corresponding port and start training pattern 1 */
1212 static void
1213 intel_dp_start_link_train(struct intel_dp *intel_dp)
1214 {
1215         struct drm_device *dev = intel_dp->base.base.dev;
1216         struct drm_i915_private *dev_priv = dev->dev_private;
1217         struct intel_crtc *intel_crtc = to_intel_crtc(intel_dp->base.base.crtc);
1218         int i;
1219         uint8_t voltage;
1220         bool clock_recovery = false;
1221         int tries;
1222         u32 reg;
1223         uint32_t DP = intel_dp->DP;
1224
1225         /* Enable output, wait for it to become active */
1226         I915_WRITE(intel_dp->output_reg, intel_dp->DP);
1227         POSTING_READ(intel_dp->output_reg);
1228         intel_wait_for_vblank(dev, intel_crtc->pipe);
1229
1230         /* Write the link configuration data */
1231         intel_dp_aux_native_write(intel_dp, DP_LINK_BW_SET,
1232                                   intel_dp->link_configuration,
1233                                   DP_LINK_CONFIGURATION_SIZE);
1234
1235         DP |= DP_PORT_EN;
1236         if (HAS_PCH_CPT(dev) && !IS_eDP(intel_dp))
1237                 DP &= ~DP_LINK_TRAIN_MASK_CPT;
1238         else
1239                 DP &= ~DP_LINK_TRAIN_MASK;
1240         memset(intel_dp->train_set, 0, 4);
1241         voltage = 0xff;
1242         tries = 0;
1243         clock_recovery = false;
1244         for (;;) {
1245                 /* Use intel_dp->train_set[0] to set the voltage and pre emphasis values */
1246                 uint32_t    signal_levels;
1247                 if (IS_GEN6(dev) && IS_eDP(intel_dp)) {
1248                         signal_levels = intel_gen6_edp_signal_levels(intel_dp->train_set[0]);
1249                         DP = (DP & ~EDP_LINK_TRAIN_VOL_EMP_MASK_SNB) | signal_levels;
1250                 } else {
1251                         signal_levels = intel_dp_signal_levels(intel_dp->train_set[0], intel_dp->lane_count);
1252                         DP = (DP & ~(DP_VOLTAGE_MASK|DP_PRE_EMPHASIS_MASK)) | signal_levels;
1253                 }
1254
1255                 if (HAS_PCH_CPT(dev) && !IS_eDP(intel_dp))
1256                         reg = DP | DP_LINK_TRAIN_PAT_1_CPT;
1257                 else
1258                         reg = DP | DP_LINK_TRAIN_PAT_1;
1259
1260                 if (!intel_dp_set_link_train(intel_dp, reg,
1261                                              DP_TRAINING_PATTERN_1))
1262                         break;
1263                 /* Set training pattern 1 */
1264
1265                 udelay(100);
1266                 if (!intel_dp_get_link_status(intel_dp))
1267                         break;
1268
1269                 if (intel_clock_recovery_ok(intel_dp->link_status, intel_dp->lane_count)) {
1270                         clock_recovery = true;
1271                         break;
1272                 }
1273
1274                 /* Check to see if we've tried the max voltage */
1275                 for (i = 0; i < intel_dp->lane_count; i++)
1276                         if ((intel_dp->train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0)
1277                                 break;
1278                 if (i == intel_dp->lane_count)
1279                         break;
1280
1281                 /* Check to see if we've tried the same voltage 5 times */
1282                 if ((intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK) == voltage) {
1283                         ++tries;
1284                         if (tries == 5)
1285                                 break;
1286                 } else
1287                         tries = 0;
1288                 voltage = intel_dp->train_set[0] & DP_TRAIN_VOLTAGE_SWING_MASK;
1289
1290                 /* Compute new intel_dp->train_set as requested by target */
1291                 intel_get_adjust_train(intel_dp);
1292         }
1293
1294         intel_dp->DP = DP;
1295 }
1296
1297 static void
1298 intel_dp_complete_link_train(struct intel_dp *intel_dp)
1299 {
1300         struct drm_device *dev = intel_dp->base.base.dev;
1301         struct drm_i915_private *dev_priv = dev->dev_private;
1302         bool channel_eq = false;
1303         int tries;
1304         u32 reg;
1305         uint32_t DP = intel_dp->DP;
1306
1307         /* channel equalization */
1308         tries = 0;
1309         channel_eq = false;
1310         for (;;) {
1311                 /* Use intel_dp->train_set[0] to set the voltage and pre emphasis values */
1312                 uint32_t    signal_levels;
1313
1314                 if (IS_GEN6(dev) && IS_eDP(intel_dp)) {
1315                         signal_levels = intel_gen6_edp_signal_levels(intel_dp->train_set[0]);
1316                         DP = (DP & ~EDP_LINK_TRAIN_VOL_EMP_MASK_SNB) | signal_levels;
1317                 } else {
1318                         signal_levels = intel_dp_signal_levels(intel_dp->train_set[0], intel_dp->lane_count);
1319                         DP = (DP & ~(DP_VOLTAGE_MASK|DP_PRE_EMPHASIS_MASK)) | signal_levels;
1320                 }
1321
1322                 if (HAS_PCH_CPT(dev) && !IS_eDP(intel_dp))
1323                         reg = DP | DP_LINK_TRAIN_PAT_2_CPT;
1324                 else
1325                         reg = DP | DP_LINK_TRAIN_PAT_2;
1326
1327                 /* channel eq pattern */
1328                 if (!intel_dp_set_link_train(intel_dp, reg,
1329                                              DP_TRAINING_PATTERN_2))
1330                         break;
1331
1332                 udelay(400);
1333                 if (!intel_dp_get_link_status(intel_dp))
1334                         break;
1335
1336                 if (intel_channel_eq_ok(intel_dp)) {
1337                         channel_eq = true;
1338                         break;
1339                 }
1340
1341                 /* Try 5 times */
1342                 if (tries > 5)
1343                         break;
1344
1345                 /* Compute new intel_dp->train_set as requested by target */
1346                 intel_get_adjust_train(intel_dp);
1347                 ++tries;
1348         }
1349
1350         if (HAS_PCH_CPT(dev) && !IS_eDP(intel_dp))
1351                 reg = DP | DP_LINK_TRAIN_OFF_CPT;
1352         else
1353                 reg = DP | DP_LINK_TRAIN_OFF;
1354
1355         I915_WRITE(intel_dp->output_reg, reg);
1356         POSTING_READ(intel_dp->output_reg);
1357         intel_dp_aux_native_write_1(intel_dp,
1358                                     DP_TRAINING_PATTERN_SET, DP_TRAINING_PATTERN_DISABLE);
1359 }
1360
1361 static void
1362 intel_dp_link_down(struct intel_dp *intel_dp)
1363 {
1364         struct drm_device *dev = intel_dp->base.base.dev;
1365         struct drm_i915_private *dev_priv = dev->dev_private;
1366         uint32_t DP = intel_dp->DP;
1367
1368         DRM_DEBUG_KMS("\n");
1369
1370         if (IS_eDP(intel_dp)) {
1371                 DP &= ~DP_PLL_ENABLE;
1372                 I915_WRITE(intel_dp->output_reg, DP);
1373                 POSTING_READ(intel_dp->output_reg);
1374                 udelay(100);
1375         }
1376
1377         if (HAS_PCH_CPT(dev) && !IS_eDP(intel_dp)) {
1378                 DP &= ~DP_LINK_TRAIN_MASK_CPT;
1379                 I915_WRITE(intel_dp->output_reg, DP | DP_LINK_TRAIN_PAT_IDLE_CPT);
1380         } else {
1381                 DP &= ~DP_LINK_TRAIN_MASK;
1382                 I915_WRITE(intel_dp->output_reg, DP | DP_LINK_TRAIN_PAT_IDLE);
1383         }
1384         POSTING_READ(intel_dp->output_reg);
1385
1386         msleep(17);
1387
1388         if (IS_eDP(intel_dp))
1389                 DP |= DP_LINK_TRAIN_OFF;
1390         I915_WRITE(intel_dp->output_reg, DP & ~DP_PORT_EN);
1391         POSTING_READ(intel_dp->output_reg);
1392 }
1393
1394 /*
1395  * According to DP spec
1396  * 5.1.2:
1397  *  1. Read DPCD
1398  *  2. Configure link according to Receiver Capabilities
1399  *  3. Use Link Training from 2.5.3.3 and 3.5.1.3
1400  *  4. Check link status on receipt of hot-plug interrupt
1401  */
1402
1403 static void
1404 intel_dp_check_link_status(struct intel_dp *intel_dp)
1405 {
1406         if (!intel_dp->base.base.crtc)
1407                 return;
1408
1409         if (!intel_dp_get_link_status(intel_dp)) {
1410                 intel_dp_link_down(intel_dp);
1411                 return;
1412         }
1413
1414         if (!intel_channel_eq_ok(intel_dp)) {
1415                 intel_dp_start_link_train(intel_dp);
1416                 intel_dp_complete_link_train(intel_dp);
1417         }
1418 }
1419
1420 static enum drm_connector_status
1421 ironlake_dp_detect(struct drm_connector *connector)
1422 {
1423         struct intel_dp *intel_dp = intel_attached_dp(connector);
1424         enum drm_connector_status status;
1425
1426         /* Panel needs power for AUX to work */
1427         if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp))
1428                 ironlake_edp_panel_vdd_on(connector->dev);
1429         status = connector_status_disconnected;
1430         if (intel_dp_aux_native_read(intel_dp,
1431                                      0x000, intel_dp->dpcd,
1432                                      sizeof (intel_dp->dpcd)) == sizeof (intel_dp->dpcd))
1433         {
1434                 if (intel_dp->dpcd[0] != 0)
1435                         status = connector_status_connected;
1436         }
1437         DRM_DEBUG_KMS("DPCD: %hx%hx%hx%hx\n", intel_dp->dpcd[0],
1438                       intel_dp->dpcd[1], intel_dp->dpcd[2], intel_dp->dpcd[3]);
1439         if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp))
1440                 ironlake_edp_panel_vdd_off(connector->dev);
1441         return status;
1442 }
1443
1444 /**
1445  * Uses CRT_HOTPLUG_EN and CRT_HOTPLUG_STAT to detect DP connection.
1446  *
1447  * \return true if DP port is connected.
1448  * \return false if DP port is disconnected.
1449  */
1450 static enum drm_connector_status
1451 intel_dp_detect(struct drm_connector *connector, bool force)
1452 {
1453         struct intel_dp *intel_dp = intel_attached_dp(connector);
1454         struct drm_device *dev = intel_dp->base.base.dev;
1455         struct drm_i915_private *dev_priv = dev->dev_private;
1456         uint32_t temp, bit;
1457         enum drm_connector_status status;
1458
1459         intel_dp->has_audio = false;
1460
1461         if (HAS_PCH_SPLIT(dev))
1462                 return ironlake_dp_detect(connector);
1463
1464         switch (intel_dp->output_reg) {
1465         case DP_B:
1466                 bit = DPB_HOTPLUG_INT_STATUS;
1467                 break;
1468         case DP_C:
1469                 bit = DPC_HOTPLUG_INT_STATUS;
1470                 break;
1471         case DP_D:
1472                 bit = DPD_HOTPLUG_INT_STATUS;
1473                 break;
1474         default:
1475                 return connector_status_unknown;
1476         }
1477
1478         temp = I915_READ(PORT_HOTPLUG_STAT);
1479
1480         if ((temp & bit) == 0)
1481                 return connector_status_disconnected;
1482
1483         status = connector_status_disconnected;
1484         if (intel_dp_aux_native_read(intel_dp,
1485                                      0x000, intel_dp->dpcd,
1486                                      sizeof (intel_dp->dpcd)) == sizeof (intel_dp->dpcd))
1487         {
1488                 if (intel_dp->dpcd[0] != 0)
1489                         status = connector_status_connected;
1490         }
1491         return status;
1492 }
1493
1494 static int intel_dp_get_modes(struct drm_connector *connector)
1495 {
1496         struct intel_dp *intel_dp = intel_attached_dp(connector);
1497         struct drm_device *dev = intel_dp->base.base.dev;
1498         struct drm_i915_private *dev_priv = dev->dev_private;
1499         int ret;
1500
1501         /* We should parse the EDID data and find out if it has an audio sink
1502          */
1503
1504         ret = intel_ddc_get_modes(connector, &intel_dp->adapter);
1505         if (ret) {
1506                 if ((IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp)) &&
1507                     !dev_priv->panel_fixed_mode) {
1508                         struct drm_display_mode *newmode;
1509                         list_for_each_entry(newmode, &connector->probed_modes,
1510                                             head) {
1511                                 if (newmode->type & DRM_MODE_TYPE_PREFERRED) {
1512                                         dev_priv->panel_fixed_mode =
1513                                                 drm_mode_duplicate(dev, newmode);
1514                                         break;
1515                                 }
1516                         }
1517                 }
1518
1519                 return ret;
1520         }
1521
1522         /* if eDP has no EDID, try to use fixed panel mode from VBT */
1523         if (IS_eDP(intel_dp) || IS_PCH_eDP(intel_dp)) {
1524                 if (dev_priv->panel_fixed_mode != NULL) {
1525                         struct drm_display_mode *mode;
1526                         mode = drm_mode_duplicate(dev, dev_priv->panel_fixed_mode);
1527                         drm_mode_probed_add(connector, mode);
1528                         return 1;
1529                 }
1530         }
1531         return 0;
1532 }
1533
1534 static void
1535 intel_dp_destroy (struct drm_connector *connector)
1536 {
1537         drm_sysfs_connector_remove(connector);
1538         drm_connector_cleanup(connector);
1539         kfree(connector);
1540 }
1541
1542 static void intel_dp_encoder_destroy(struct drm_encoder *encoder)
1543 {
1544         struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
1545
1546         i2c_del_adapter(&intel_dp->adapter);
1547         drm_encoder_cleanup(encoder);
1548         kfree(intel_dp);
1549 }
1550
1551 static const struct drm_encoder_helper_funcs intel_dp_helper_funcs = {
1552         .dpms = intel_dp_dpms,
1553         .mode_fixup = intel_dp_mode_fixup,
1554         .prepare = intel_dp_prepare,
1555         .mode_set = intel_dp_mode_set,
1556         .commit = intel_dp_commit,
1557 };
1558
1559 static const struct drm_connector_funcs intel_dp_connector_funcs = {
1560         .dpms = drm_helper_connector_dpms,
1561         .detect = intel_dp_detect,
1562         .fill_modes = drm_helper_probe_single_connector_modes,
1563         .destroy = intel_dp_destroy,
1564 };
1565
1566 static const struct drm_connector_helper_funcs intel_dp_connector_helper_funcs = {
1567         .get_modes = intel_dp_get_modes,
1568         .mode_valid = intel_dp_mode_valid,
1569         .best_encoder = intel_best_encoder,
1570 };
1571
1572 static const struct drm_encoder_funcs intel_dp_enc_funcs = {
1573         .destroy = intel_dp_encoder_destroy,
1574 };
1575
1576 static void
1577 intel_dp_hot_plug(struct intel_encoder *intel_encoder)
1578 {
1579         struct intel_dp *intel_dp = container_of(intel_encoder, struct intel_dp, base);
1580
1581         if (intel_dp->dpms_mode == DRM_MODE_DPMS_ON)
1582                 intel_dp_check_link_status(intel_dp);
1583 }
1584
1585 /* Return which DP Port should be selected for Transcoder DP control */
1586 int
1587 intel_trans_dp_port_sel (struct drm_crtc *crtc)
1588 {
1589         struct drm_device *dev = crtc->dev;
1590         struct drm_mode_config *mode_config = &dev->mode_config;
1591         struct drm_encoder *encoder;
1592
1593         list_for_each_entry(encoder, &mode_config->encoder_list, head) {
1594                 struct intel_dp *intel_dp;
1595
1596                 if (encoder->crtc != crtc)
1597                         continue;
1598
1599                 intel_dp = enc_to_intel_dp(encoder);
1600                 if (intel_dp->base.type == INTEL_OUTPUT_DISPLAYPORT)
1601                         return intel_dp->output_reg;
1602         }
1603
1604         return -1;
1605 }
1606
1607 /* check the VBT to see whether the eDP is on DP-D port */
1608 bool intel_dpd_is_edp(struct drm_device *dev)
1609 {
1610         struct drm_i915_private *dev_priv = dev->dev_private;
1611         struct child_device_config *p_child;
1612         int i;
1613
1614         if (!dev_priv->child_dev_num)
1615                 return false;
1616
1617         for (i = 0; i < dev_priv->child_dev_num; i++) {
1618                 p_child = dev_priv->child_dev + i;
1619
1620                 if (p_child->dvo_port == PORT_IDPD &&
1621                     p_child->device_type == DEVICE_TYPE_eDP)
1622                         return true;
1623         }
1624         return false;
1625 }
1626
1627 void
1628 intel_dp_init(struct drm_device *dev, int output_reg)
1629 {
1630         struct drm_i915_private *dev_priv = dev->dev_private;
1631         struct drm_connector *connector;
1632         struct intel_dp *intel_dp;
1633         struct intel_encoder *intel_encoder;
1634         struct intel_connector *intel_connector;
1635         const char *name = NULL;
1636         int type;
1637
1638         intel_dp = kzalloc(sizeof(struct intel_dp), GFP_KERNEL);
1639         if (!intel_dp)
1640                 return;
1641
1642         intel_connector = kzalloc(sizeof(struct intel_connector), GFP_KERNEL);
1643         if (!intel_connector) {
1644                 kfree(intel_dp);
1645                 return;
1646         }
1647         intel_encoder = &intel_dp->base;
1648
1649         if (HAS_PCH_SPLIT(dev) && output_reg == PCH_DP_D)
1650                 if (intel_dpd_is_edp(dev))
1651                         intel_dp->is_pch_edp = true;
1652
1653         if (output_reg == DP_A || IS_PCH_eDP(intel_dp)) {
1654                 type = DRM_MODE_CONNECTOR_eDP;
1655                 intel_encoder->type = INTEL_OUTPUT_EDP;
1656         } else {
1657                 type = DRM_MODE_CONNECTOR_DisplayPort;
1658                 intel_encoder->type = INTEL_OUTPUT_DISPLAYPORT;
1659         }
1660
1661         connector = &intel_connector->base;
1662         drm_connector_init(dev, connector, &intel_dp_connector_funcs, type);
1663         drm_connector_helper_add(connector, &intel_dp_connector_helper_funcs);
1664
1665         connector->polled = DRM_CONNECTOR_POLL_HPD;
1666
1667         if (output_reg == DP_B || output_reg == PCH_DP_B)
1668                 intel_encoder->clone_mask = (1 << INTEL_DP_B_CLONE_BIT);
1669         else if (output_reg == DP_C || output_reg == PCH_DP_C)
1670                 intel_encoder->clone_mask = (1 << INTEL_DP_C_CLONE_BIT);
1671         else if (output_reg == DP_D || output_reg == PCH_DP_D)
1672                 intel_encoder->clone_mask = (1 << INTEL_DP_D_CLONE_BIT);
1673
1674         if (IS_eDP(intel_dp))
1675                 intel_encoder->clone_mask = (1 << INTEL_EDP_CLONE_BIT);
1676
1677         intel_encoder->crtc_mask = (1 << 0) | (1 << 1);
1678         connector->interlace_allowed = true;
1679         connector->doublescan_allowed = 0;
1680
1681         intel_dp->output_reg = output_reg;
1682         intel_dp->has_audio = false;
1683         intel_dp->dpms_mode = DRM_MODE_DPMS_ON;
1684
1685         drm_encoder_init(dev, &intel_encoder->base, &intel_dp_enc_funcs,
1686                          DRM_MODE_ENCODER_TMDS);
1687         drm_encoder_helper_add(&intel_encoder->base, &intel_dp_helper_funcs);
1688
1689         intel_connector_attach_encoder(intel_connector, intel_encoder);
1690         drm_sysfs_connector_add(connector);
1691
1692         /* Set up the DDC bus. */
1693         switch (output_reg) {
1694                 case DP_A:
1695                         name = "DPDDC-A";
1696                         break;
1697                 case DP_B:
1698                 case PCH_DP_B:
1699                         dev_priv->hotplug_supported_mask |=
1700                                 HDMIB_HOTPLUG_INT_STATUS;
1701                         name = "DPDDC-B";
1702                         break;
1703                 case DP_C:
1704                 case PCH_DP_C:
1705                         dev_priv->hotplug_supported_mask |=
1706                                 HDMIC_HOTPLUG_INT_STATUS;
1707                         name = "DPDDC-C";
1708                         break;
1709                 case DP_D:
1710                 case PCH_DP_D:
1711                         dev_priv->hotplug_supported_mask |=
1712                                 HDMID_HOTPLUG_INT_STATUS;
1713                         name = "DPDDC-D";
1714                         break;
1715         }
1716
1717         intel_dp_i2c_init(intel_dp, intel_connector, name);
1718
1719         intel_encoder->hot_plug = intel_dp_hot_plug;
1720
1721         if (output_reg == DP_A || IS_PCH_eDP(intel_dp)) {
1722                 /* initialize panel mode from VBT if available for eDP */
1723                 if (dev_priv->lfp_lvds_vbt_mode) {
1724                         dev_priv->panel_fixed_mode =
1725                                 drm_mode_duplicate(dev, dev_priv->lfp_lvds_vbt_mode);
1726                         if (dev_priv->panel_fixed_mode) {
1727                                 dev_priv->panel_fixed_mode->type |=
1728                                         DRM_MODE_TYPE_PREFERRED;
1729                         }
1730                 }
1731         }
1732
1733         /* For G4X desktop chip, PEG_BAND_GAP_DATA 3:0 must first be written
1734          * 0xd.  Failure to do so will result in spurious interrupts being
1735          * generated on the port when a cable is not attached.
1736          */
1737         if (IS_G4X(dev) && !IS_GM45(dev)) {
1738                 u32 temp = I915_READ(PEG_BAND_GAP_DATA);
1739                 I915_WRITE(PEG_BAND_GAP_DATA, (temp & ~0xf) | 0xd);
1740         }
1741 }