drivers/usb/typec/altmodes/displayport.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * USB Typec-C DisplayPort Alternate Mode driver
   4  *
   5  * Copyright (C) 2018 Intel Corporation
   6  * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
   7  *
   8  * DisplayPort is trademark of VESA (www.vesa.org)
   9  */
  10
  11 #include <linux/delay.h>
  12 #include <linux/mutex.h>
  13 #include <linux/module.h>
  14 #include <linux/property.h>
  15 #include <linux/usb/pd_vdo.h>
  16 #include <linux/usb/typec_dp.h>
  17 #include <drm/drm_connector.h>
  18 #include "displayport.h"
  19
  20 #define DP_HEADER(_dp, ver, cmd)        (VDO((_dp)->alt->svid, 1, ver, cmd)     \
  21                                          | VDO_OPOS(USB_TYPEC_DP_MODE))
  22
  23 enum {
  24         DP_CONF_USB,
  25         DP_CONF_DFP_D,
  26         DP_CONF_UFP_D,
  27         DP_CONF_DUAL_D,
  28 };
  29
  30 /* Pin assignments that use USB3.1 Gen2 signaling to carry DP protocol */
  31 #define DP_PIN_ASSIGN_GEN2_BR_MASK      (BIT(DP_PIN_ASSIGN_A) | \
  32                                          BIT(DP_PIN_ASSIGN_B))
  33
  34 /* Pin assignments that use DP v1.3 signaling to carry DP protocol */
  35 #define DP_PIN_ASSIGN_DP_BR_MASK        (BIT(DP_PIN_ASSIGN_C) | \
  36                                          BIT(DP_PIN_ASSIGN_D) | \
  37                                          BIT(DP_PIN_ASSIGN_E) | \
  38                                          BIT(DP_PIN_ASSIGN_F))
  39
  40 /* DP only pin assignments */
  41 #define DP_PIN_ASSIGN_DP_ONLY_MASK      (BIT(DP_PIN_ASSIGN_A) | \
  42                                          BIT(DP_PIN_ASSIGN_C) | \
  43                                          BIT(DP_PIN_ASSIGN_E))
  44
  45 /* Pin assignments where one channel is for USB */
  46 #define DP_PIN_ASSIGN_MULTI_FUNC_MASK   (BIT(DP_PIN_ASSIGN_B) | \
  47                                          BIT(DP_PIN_ASSIGN_D) | \
  48                                          BIT(DP_PIN_ASSIGN_F))
  49
  50 enum dp_state {
  51         DP_STATE_IDLE,
  52         DP_STATE_ENTER,
  53         DP_STATE_ENTER_PRIME,
  54         DP_STATE_UPDATE,
  55         DP_STATE_CONFIGURE,
  56         DP_STATE_CONFIGURE_PRIME,
  57         DP_STATE_EXIT,
  58         DP_STATE_EXIT_PRIME,
  59 };
  60
  61 struct dp_altmode {
  62         struct typec_displayport_data data;
  63         struct typec_displayport_data data_prime;
  64
  65         enum dp_state state;
  66         bool hpd;
  67         bool pending_hpd;
  68
  69         struct mutex lock; /* device lock */
  70         struct work_struct work;
  71         struct typec_altmode *alt;
  72         const struct typec_altmode *port;
  73         struct fwnode_handle *connector_fwnode;
  74         struct typec_altmode *plug_prime;
  75 };
  76
  77 static int dp_altmode_notify(struct dp_altmode *dp)
  78 {
  79         unsigned long conf;
  80         u8 state;
  81
  82         if (dp->data.conf) {
  83                 state = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
  84                 conf = TYPEC_MODAL_STATE(state);
  85         } else {
  86                 conf = TYPEC_STATE_USB;
  87         }
  88
  89         return typec_altmode_notify(dp->alt, conf, &dp->data);
  90 }
  91
  92 static int dp_altmode_configure(struct dp_altmode *dp, u8 con)
  93 {
  94         u8 pin_assign = 0;
  95         u32 conf;
  96
  97         /* DP Signalling */
  98         conf = (dp->data.conf & DP_CONF_SIGNALLING_MASK) >> DP_CONF_SIGNALLING_SHIFT;
  99
 100         switch (con) {
 101         case DP_STATUS_CON_DISABLED:
 102                 return 0;
 103         case DP_STATUS_CON_DFP_D:
 104                 conf |= DP_CONF_UFP_U_AS_DFP_D;
 105                 pin_assign = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo) &
 106                              DP_CAP_DFP_D_PIN_ASSIGN(dp->port->vdo);
 107                 /* Account for active cable capabilities */
 108                 if (dp->plug_prime)
 109                         pin_assign &= DP_CAP_DFP_D_PIN_ASSIGN(dp->plug_prime->vdo);
 110                 break;
 111         case DP_STATUS_CON_UFP_D:
 112         case DP_STATUS_CON_BOTH: /* NOTE: First acting as DP source */
 113                 conf |= DP_CONF_UFP_U_AS_UFP_D;
 114                 pin_assign = DP_CAP_PIN_ASSIGN_UFP_D(dp->alt->vdo) &
 115                                  DP_CAP_PIN_ASSIGN_DFP_D(dp->port->vdo);
 116                 /* Account for active cable capabilities */
 117                 if (dp->plug_prime)
 118                         pin_assign &= DP_CAP_UFP_D_PIN_ASSIGN(dp->plug_prime->vdo);
 119                 break;
 120         default:
 121                 break;
 122         }
 123
 124         /* Determining the initial pin assignment. */
 125         if (!DP_CONF_GET_PIN_ASSIGN(dp->data.conf)) {
 126                 /* Is USB together with DP preferred */
 127                 if (dp->data.status & DP_STATUS_PREFER_MULTI_FUNC &&
 128                     pin_assign & DP_PIN_ASSIGN_MULTI_FUNC_MASK)
 129                         pin_assign &= DP_PIN_ASSIGN_MULTI_FUNC_MASK;
 130                 else if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK) {
 131                         pin_assign &= DP_PIN_ASSIGN_DP_ONLY_MASK;
 132                         /* Default to pin assign C if available */
 133                         if (pin_assign & BIT(DP_PIN_ASSIGN_C))
 134                                 pin_assign = BIT(DP_PIN_ASSIGN_C);
 135                 }
 136
 137                 if (!pin_assign)
 138                         return -EINVAL;
 139
 140                 conf |= DP_CONF_SET_PIN_ASSIGN(pin_assign);
 141         }
 142
 143         dp->data.conf = conf;
 144         if (dp->plug_prime)
 145                 dp->data_prime.conf = conf;
 146
 147         return 0;
 148 }
 149
 150 static int dp_altmode_status_update(struct dp_altmode *dp)
 151 {
 152         bool configured = !!DP_CONF_GET_PIN_ASSIGN(dp->data.conf);
 153         bool hpd = !!(dp->data.status & DP_STATUS_HPD_STATE);
 154         u8 con = DP_STATUS_CONNECTION(dp->data.status);
 155         int ret = 0;
 156
 157         if (configured && (dp->data.status & DP_STATUS_SWITCH_TO_USB)) {
 158                 dp->data.conf = 0;
 159                 dp->data_prime.conf = 0;
 160                 dp->state = dp->plug_prime ? DP_STATE_CONFIGURE_PRIME :
 161                                              DP_STATE_CONFIGURE;
 162         } else if (dp->data.status & DP_STATUS_EXIT_DP_MODE) {
 163                 dp->state = DP_STATE_EXIT;
 164         } else if (!(con & DP_CONF_CURRENTLY(dp->data.conf))) {
 165                 ret = dp_altmode_configure(dp, con);
 166                 if (!ret) {
 167                         dp->state = dp->plug_prime ? DP_STATE_CONFIGURE_PRIME :
 168                                                      DP_STATE_CONFIGURE;
 169                         if (dp->hpd != hpd) {
 170                                 dp->hpd = hpd;
 171                                 dp->pending_hpd = true;
 172                         }
 173                 }
 174         } else {
 175                 drm_connector_oob_hotplug_event(dp->connector_fwnode,
 176                                                 hpd ? connector_status_connected :
 177                                                       connector_status_disconnected);
 178                 dp->hpd = hpd;
 179                 sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
 180         }
 181
 182         return ret;
 183 }
 184
 185 static int dp_altmode_configured(struct dp_altmode *dp)
 186 {
 187         sysfs_notify(&dp->alt->dev.kobj, "displayport", "configuration");
 188         sysfs_notify(&dp->alt->dev.kobj, "displayport", "pin_assignment");
 189         /*
 190          * If the DFP_D/UFP_D sends a change in HPD when first notifying the
 191          * DisplayPort driver that it is connected, then we wait until
 192          * configuration is complete to signal HPD.
 193          */
 194         if (dp->pending_hpd) {
 195                 drm_connector_oob_hotplug_event(dp->connector_fwnode,
 196                                                 connector_status_connected);
 197                 sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
 198                 dp->pending_hpd = false;
 199         }
 200
 201         return dp_altmode_notify(dp);
 202 }
 203
 204 static int dp_altmode_configure_vdm(struct dp_altmode *dp, u32 conf)
 205 {
 206         int svdm_version = typec_altmode_get_svdm_version(dp->alt);
 207         u32 header;
 208         int ret;
 209
 210         if (svdm_version < 0)
 211                 return svdm_version;
 212
 213         header = DP_HEADER(dp, svdm_version, DP_CMD_CONFIGURE);
 214         ret = typec_altmode_notify(dp->alt, TYPEC_STATE_SAFE, &dp->data);
 215         if (ret) {
 216                 dev_err(&dp->alt->dev,
 217                         "unable to put to connector to safe mode\n");
 218                 return ret;
 219         }
 220
 221         ret = typec_altmode_vdm(dp->alt, header, &conf, 2);
 222         if (ret)
 223                 dp_altmode_notify(dp);
 224
 225         return ret;
 226 }
 227
 228 static int dp_altmode_configure_vdm_cable(struct dp_altmode *dp, u32 conf)
 229 {
 230         int svdm_version = typec_altmode_get_cable_svdm_version(dp->plug_prime);
 231         u32 header;
 232
 233         if (svdm_version < 0)
 234                 return svdm_version;
 235
 236         header = DP_HEADER(dp, svdm_version, DP_CMD_CONFIGURE);
 237
 238         return typec_cable_altmode_vdm(dp->plug_prime, TYPEC_PLUG_SOP_P, header, &conf, 2);
 239 }
 240
 241 static void dp_altmode_work(struct work_struct *work)
 242 {
 243         struct dp_altmode *dp = container_of(work, struct dp_altmode, work);
 244         int svdm_version;
 245         u32 header;
 246         u32 vdo;
 247         int ret;
 248
 249         mutex_lock(&dp->lock);
 250
 251         switch (dp->state) {
 252         case DP_STATE_ENTER:
 253                 ret = typec_altmode_enter(dp->alt, NULL);
 254                 if (ret && ret != -EBUSY)
 255                         dev_err(&dp->alt->dev, "failed to enter mode\n");
 256                 break;
 257         case DP_STATE_ENTER_PRIME:
 258                 ret = typec_cable_altmode_enter(dp->alt, TYPEC_PLUG_SOP_P, NULL);
 259                 /*
 260                  * If we fail to enter Alt Mode on SOP', then we should drop the
 261                  * plug from the driver and attempt to run the driver without
 262                  * it.
 263                  */
 264                 if (ret && ret != -EBUSY) {
 265                         dev_err(&dp->alt->dev, "plug failed to enter mode\n");
 266                         dp->state = DP_STATE_ENTER;
 267                         goto disable_prime;
 268                 }
 269                 break;
 270         case DP_STATE_UPDATE:
 271                 svdm_version = typec_altmode_get_svdm_version(dp->alt);
 272                 if (svdm_version < 0)
 273                         break;
 274                 header = DP_HEADER(dp, svdm_version, DP_CMD_STATUS_UPDATE);
 275                 vdo = 1;
 276                 ret = typec_altmode_vdm(dp->alt, header, &vdo, 2);
 277                 if (ret)
 278                         dev_err(&dp->alt->dev,
 279                                 "unable to send Status Update command (%d)\n",
 280                                 ret);
 281                 break;
 282         case DP_STATE_CONFIGURE:
 283                 ret = dp_altmode_configure_vdm(dp, dp->data.conf);
 284                 if (ret)
 285                         dev_err(&dp->alt->dev,
 286                                 "unable to send Configure command (%d)\n", ret);
 287                 break;
 288         case DP_STATE_CONFIGURE_PRIME:
 289                 ret = dp_altmode_configure_vdm_cable(dp, dp->data_prime.conf);
 290                 if (ret) {
 291                         dev_err(&dp->plug_prime->dev,
 292                                 "unable to send Configure command (%d)\n",
 293                                 ret);
 294                         dp->state = DP_STATE_CONFIGURE;
 295                         goto disable_prime;
 296                 }
 297                 break;
 298         case DP_STATE_EXIT:
 299                 if (typec_altmode_exit(dp->alt))
 300                         dev_err(&dp->alt->dev, "Exit Mode Failed!\n");
 301                 break;
 302         case DP_STATE_EXIT_PRIME:
 303                 if (typec_cable_altmode_exit(dp->plug_prime, TYPEC_PLUG_SOP_P))
 304                         dev_err(&dp->plug_prime->dev, "Exit Mode Failed!\n");
 305                 break;
 306         default:
 307                 break;
 308         }
 309
 310         dp->state = DP_STATE_IDLE;
 311
 312         mutex_unlock(&dp->lock);
 313         return;
 314
 315 disable_prime:
 316         typec_altmode_put_plug(dp->plug_prime);
 317         dp->plug_prime = NULL;
 318         schedule_work(&dp->work);
 319         mutex_unlock(&dp->lock);
 320 }
 321
 322 static void dp_altmode_attention(struct typec_altmode *alt, const u32 vdo)
 323 {
 324         struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
 325         u8 old_state;
 326
 327         mutex_lock(&dp->lock);
 328
 329         old_state = dp->state;
 330         dp->data.status = vdo;
 331
 332         if (old_state != DP_STATE_IDLE)
 333                 dev_warn(&alt->dev, "ATTENTION while processing state %d\n",
 334                          old_state);
 335
 336         if (dp_altmode_status_update(dp))
 337                 dev_warn(&alt->dev, "%s: status update failed\n", __func__);
 338
 339         if (dp_altmode_notify(dp))
 340                 dev_err(&alt->dev, "%s: notification failed\n", __func__);
 341
 342         if (old_state == DP_STATE_IDLE && dp->state != DP_STATE_IDLE)
 343                 schedule_work(&dp->work);
 344
 345         mutex_unlock(&dp->lock);
 346 }
 347
 348 static int dp_altmode_vdm(struct typec_altmode *alt,
 349                           const u32 hdr, const u32 *vdo, int count)
 350 {
 351         struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
 352         int cmd_type = PD_VDO_CMDT(hdr);
 353         int cmd = PD_VDO_CMD(hdr);
 354         int ret = 0;
 355
 356         mutex_lock(&dp->lock);
 357
 358         if (dp->state != DP_STATE_IDLE) {
 359                 ret = -EBUSY;
 360                 goto err_unlock;
 361         }
 362
 363         switch (cmd_type) {
 364         case CMDT_RSP_ACK:
 365                 switch (cmd) {
 366                 case CMD_ENTER_MODE:
 367                         typec_altmode_update_active(alt, true);
 368                         dp->state = DP_STATE_UPDATE;
 369                         break;
 370                 case CMD_EXIT_MODE:
 371                         typec_altmode_update_active(alt, false);
 372                         dp->data.status = 0;
 373                         dp->data.conf = 0;
 374                         if (dp->hpd) {
 375                                 drm_connector_oob_hotplug_event(dp->connector_fwnode,
 376                                                                 connector_status_disconnected);
 377                                 dp->hpd = false;
 378                                 sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
 379                         }
 380                         if (dp->plug_prime)
 381                                 dp->state = DP_STATE_EXIT_PRIME;
 382                         break;
 383                 case DP_CMD_STATUS_UPDATE:
 384                         dp->data.status = *vdo;
 385                         ret = dp_altmode_status_update(dp);
 386                         break;
 387                 case DP_CMD_CONFIGURE:
 388                         ret = dp_altmode_configured(dp);
 389                         break;
 390                 default:
 391                         break;
 392                 }
 393                 break;
 394         case CMDT_RSP_NAK:
 395                 switch (cmd) {
 396                 case DP_CMD_CONFIGURE:
 397                         dp->data.conf = 0;
 398                         ret = dp_altmode_configured(dp);
 399                         break;
 400                 default:
 401                         break;
 402                 }
 403                 break;
 404         default:
 405                 break;
 406         }
 407
 408         if (dp->state != DP_STATE_IDLE)
 409                 schedule_work(&dp->work);
 410
 411 err_unlock:
 412         mutex_unlock(&dp->lock);
 413         return ret;
 414 }
 415
 416 static int dp_cable_altmode_vdm(struct typec_altmode *alt, enum typec_plug_index sop,
 417                                 const u32 hdr, const u32 *vdo, int count)
 418 {
 419         struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
 420         int cmd_type = PD_VDO_CMDT(hdr);
 421         int cmd = PD_VDO_CMD(hdr);
 422         int ret = 0;
 423
 424         mutex_lock(&dp->lock);
 425
 426         if (dp->state != DP_STATE_IDLE) {
 427                 ret = -EBUSY;
 428                 goto err_unlock;
 429         }
 430
 431         switch (cmd_type) {
 432         case CMDT_RSP_ACK:
 433                 switch (cmd) {
 434                 case CMD_ENTER_MODE:
 435                         typec_altmode_update_active(dp->plug_prime, true);
 436                         dp->state = DP_STATE_ENTER;
 437                         break;
 438                 case CMD_EXIT_MODE:
 439                         dp->data_prime.status = 0;
 440                         dp->data_prime.conf = 0;
 441                         typec_altmode_update_active(dp->plug_prime, false);
 442                         break;
 443                 case DP_CMD_CONFIGURE:
 444                         dp->state = DP_STATE_CONFIGURE;
 445                         break;
 446                 default:
 447                         break;
 448                 }
 449                 break;
 450         case CMDT_RSP_NAK:
 451                 switch (cmd) {
 452                 case DP_CMD_CONFIGURE:
 453                         dp->data_prime.conf = 0;
 454                         /* Attempt to configure on SOP, drop plug */
 455                         typec_altmode_put_plug(dp->plug_prime);
 456                         dp->plug_prime = NULL;
 457                         dp->state = DP_STATE_CONFIGURE;
 458                         break;
 459                 default:
 460                         break;
 461                 }
 462                 break;
 463         default:
 464                 break;
 465         }
 466
 467         if (dp->state != DP_STATE_IDLE)
 468                 schedule_work(&dp->work);
 469
 470 err_unlock:
 471         mutex_unlock(&dp->lock);
 472         return ret;
 473 }
 474
 475 static int dp_altmode_activate(struct typec_altmode *alt, int activate)
 476 {
 477         struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
 478         int ret;
 479
 480         if (activate) {
 481                 if (dp->plug_prime) {
 482                         ret = typec_cable_altmode_enter(alt, TYPEC_PLUG_SOP_P, NULL);
 483                         if (ret < 0) {
 484                                 typec_altmode_put_plug(dp->plug_prime);
 485                                 dp->plug_prime = NULL;
 486                         } else {
 487                                 return ret;
 488                         }
 489                 }
 490                 return typec_altmode_enter(alt, NULL);
 491         } else {
 492                 return typec_altmode_exit(alt);
 493         }
 494 }
 495
 496 static const struct typec_altmode_ops dp_altmode_ops = {
 497         .attention = dp_altmode_attention,
 498         .vdm = dp_altmode_vdm,
 499         .activate = dp_altmode_activate,
 500 };
 501
 502 static const struct typec_cable_ops dp_cable_ops = {
 503         .vdm = dp_cable_altmode_vdm,
 504 };
 505
 506 static const char * const configurations[] = {
 507         [DP_CONF_USB]   = "USB",
 508         [DP_CONF_DFP_D] = "source",
 509         [DP_CONF_UFP_D] = "sink",
 510 };
 511
 512 static ssize_t
 513 configuration_store(struct device *dev, struct device_attribute *attr,
 514                     const char *buf, size_t size)
 515 {
 516         struct dp_altmode *dp = dev_get_drvdata(dev);
 517         u32 conf;
 518         u32 cap;
 519         int con;
 520         int ret = 0;
 521
 522         con = sysfs_match_string(configurations, buf);
 523         if (con < 0)
 524                 return con;
 525
 526         mutex_lock(&dp->lock);
 527
 528         if (dp->state != DP_STATE_IDLE) {
 529                 ret = -EBUSY;
 530                 goto err_unlock;
 531         }
 532
 533         cap = DP_CAP_CAPABILITY(dp->alt->vdo);
 534
 535         if ((con == DP_CONF_DFP_D && !(cap & DP_CAP_DFP_D)) ||
 536             (con == DP_CONF_UFP_D && !(cap & DP_CAP_UFP_D))) {
 537                 ret = -EINVAL;
 538                 goto err_unlock;
 539         }
 540
 541         conf = dp->data.conf & ~DP_CONF_DUAL_D;
 542         conf |= con;
 543
 544         if (dp->alt->active) {
 545                 ret = dp_altmode_configure_vdm(dp, conf);
 546                 if (ret)
 547                         goto err_unlock;
 548         }
 549
 550         dp->data.conf = conf;
 551
 552 err_unlock:
 553         mutex_unlock(&dp->lock);
 554
 555         return ret ? ret : size;
 556 }
 557
 558 static ssize_t configuration_show(struct device *dev,
 559                                   struct device_attribute *attr, char *buf)
 560 {
 561         struct dp_altmode *dp = dev_get_drvdata(dev);
 562         int len;
 563         u8 cap;
 564         u8 cur;
 565         int i;
 566
 567         mutex_lock(&dp->lock);
 568
 569         cap = DP_CAP_CAPABILITY(dp->alt->vdo);
 570         cur = DP_CONF_CURRENTLY(dp->data.conf);
 571
 572         len = sprintf(buf, "%s ", cur ? "USB" : "[USB]");
 573
 574         for (i = 1; i < ARRAY_SIZE(configurations); i++) {
 575                 if (i == cur)
 576                         len += sprintf(buf + len, "[%s] ", configurations[i]);
 577                 else if ((i == DP_CONF_DFP_D && cap & DP_CAP_DFP_D) ||
 578                          (i == DP_CONF_UFP_D && cap & DP_CAP_UFP_D))
 579                         len += sprintf(buf + len, "%s ", configurations[i]);
 580         }
 581
 582         mutex_unlock(&dp->lock);
 583
 584         buf[len - 1] = '\n';
 585         return len;
 586 }
 587 static DEVICE_ATTR_RW(configuration);
 588
 589 static const char * const pin_assignments[] = {
 590         [DP_PIN_ASSIGN_A] = "A",
 591         [DP_PIN_ASSIGN_B] = "B",
 592         [DP_PIN_ASSIGN_C] = "C",
 593         [DP_PIN_ASSIGN_D] = "D",
 594         [DP_PIN_ASSIGN_E] = "E",
 595         [DP_PIN_ASSIGN_F] = "F",
 596 };
 597
 598 /*
 599  * Helper function to extract a peripheral's currently supported
 600  * Pin Assignments from its DisplayPort alternate mode state.
 601  */
 602 static u8 get_current_pin_assignments(struct dp_altmode *dp)
 603 {
 604         if (DP_CONF_CURRENTLY(dp->data.conf) == DP_CONF_UFP_U_AS_DFP_D)
 605                 return DP_CAP_PIN_ASSIGN_DFP_D(dp->alt->vdo);
 606         else
 607                 return DP_CAP_PIN_ASSIGN_UFP_D(dp->alt->vdo);
 608 }
 609
 610 static ssize_t
 611 pin_assignment_store(struct device *dev, struct device_attribute *attr,
 612                      const char *buf, size_t size)
 613 {
 614         struct dp_altmode *dp = dev_get_drvdata(dev);
 615         u8 assignments;
 616         u32 conf;
 617         int ret;
 618
 619         ret = sysfs_match_string(pin_assignments, buf);
 620         if (ret < 0)
 621                 return ret;
 622
 623         conf = DP_CONF_SET_PIN_ASSIGN(BIT(ret));
 624         ret = 0;
 625
 626         mutex_lock(&dp->lock);
 627
 628         if (conf & dp->data.conf)
 629                 goto out_unlock;
 630
 631         if (dp->state != DP_STATE_IDLE) {
 632                 ret = -EBUSY;
 633                 goto out_unlock;
 634         }
 635
 636         assignments = get_current_pin_assignments(dp);
 637
 638         if (!(DP_CONF_GET_PIN_ASSIGN(conf) & assignments)) {
 639                 ret = -EINVAL;
 640                 goto out_unlock;
 641         }
 642
 643         conf |= dp->data.conf & ~DP_CONF_PIN_ASSIGNEMENT_MASK;
 644
 645         /* Only send Configure command if a configuration has been set */
 646         if (dp->alt->active && DP_CONF_CURRENTLY(dp->data.conf)) {
 647                 /* todo: send manual configure over SOP'*/
 648                 ret = dp_altmode_configure_vdm(dp, conf);
 649                 if (ret)
 650                         goto out_unlock;
 651         }
 652
 653         dp->data.conf = conf;
 654
 655 out_unlock:
 656         mutex_unlock(&dp->lock);
 657
 658         return ret ? ret : size;
 659 }
 660
 661 static ssize_t pin_assignment_show(struct device *dev,
 662                                    struct device_attribute *attr, char *buf)
 663 {
 664         struct dp_altmode *dp = dev_get_drvdata(dev);
 665         u8 assignments;
 666         int len = 0;
 667         u8 cur;
 668         int i;
 669
 670         mutex_lock(&dp->lock);
 671
 672         cur = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
 673
 674         assignments = get_current_pin_assignments(dp);
 675
 676         for (i = 0; assignments; assignments >>= 1, i++) {
 677                 if (assignments & 1) {
 678                         if (i == cur)
 679                                 len += sprintf(buf + len, "[%s] ",
 680                                                pin_assignments[i]);
 681                         else
 682                                 len += sprintf(buf + len, "%s ",
 683                                                pin_assignments[i]);
 684                 }
 685         }
 686
 687         mutex_unlock(&dp->lock);
 688
 689         /* get_current_pin_assignments can return 0 when no matching pin assignments are found */
 690         if (len == 0)
 691                 len++;
 692
 693         buf[len - 1] = '\n';
 694         return len;
 695 }
 696 static DEVICE_ATTR_RW(pin_assignment);
 697
 698 static ssize_t hpd_show(struct device *dev, struct device_attribute *attr, char *buf)
 699 {
 700         struct dp_altmode *dp = dev_get_drvdata(dev);
 701
 702         return sysfs_emit(buf, "%d\n", dp->hpd);
 703 }
 704 static DEVICE_ATTR_RO(hpd);
 705
 706 static struct attribute *displayport_attrs[] = {
 707         &dev_attr_configuration.attr,
 708         &dev_attr_pin_assignment.attr,
 709         &dev_attr_hpd.attr,
 710         NULL
 711 };
 712
 713 static const struct attribute_group displayport_group = {
 714         .name = "displayport",
 715         .attrs = displayport_attrs,
 716 };
 717
 718 static const struct attribute_group *displayport_groups[] = {
 719         &displayport_group,
 720         NULL,
 721 };
 722
 723 int dp_altmode_probe(struct typec_altmode *alt)
 724 {
 725         const struct typec_altmode *port = typec_altmode_get_partner(alt);
 726         struct typec_altmode *plug = typec_altmode_get_plug(alt, TYPEC_PLUG_SOP_P);
 727         struct fwnode_handle *fwnode;
 728         struct dp_altmode *dp;
 729
 730         /* FIXME: Port can only be DFP_U. */
 731
 732         /* Make sure we have compatiple pin configurations */
 733         if (!(DP_CAP_PIN_ASSIGN_DFP_D(port->vdo) &
 734               DP_CAP_PIN_ASSIGN_UFP_D(alt->vdo)) &&
 735             !(DP_CAP_PIN_ASSIGN_UFP_D(port->vdo) &
 736               DP_CAP_PIN_ASSIGN_DFP_D(alt->vdo)))
 737                 return -ENODEV;
 738
 739         dp = devm_kzalloc(&alt->dev, sizeof(*dp), GFP_KERNEL);
 740         if (!dp)
 741                 return -ENOMEM;
 742
 743         INIT_WORK(&dp->work, dp_altmode_work);
 744         mutex_init(&dp->lock);
 745         dp->port = port;
 746         dp->alt = alt;
 747
 748         alt->desc = "DisplayPort";
 749         alt->ops = &dp_altmode_ops;
 750
 751         if (plug) {
 752                 plug->desc = "Displayport";
 753                 plug->cable_ops = &dp_cable_ops;
 754         }
 755
 756         dp->plug_prime = plug;
 757
 758         fwnode = dev_fwnode(alt->dev.parent->parent); /* typec_port fwnode */
 759         if (fwnode_property_present(fwnode, "displayport"))
 760                 dp->connector_fwnode = fwnode_find_reference(fwnode, "displayport", 0);
 761         else
 762                 dp->connector_fwnode = fwnode_handle_get(fwnode); /* embedded DP */
 763         if (IS_ERR(dp->connector_fwnode))
 764                 dp->connector_fwnode = NULL;
 765
 766         typec_altmode_set_drvdata(alt, dp);
 767         if (plug)
 768                 typec_altmode_set_drvdata(plug, dp);
 769
 770         dp->state = plug ? DP_STATE_ENTER_PRIME : DP_STATE_ENTER;
 771         schedule_work(&dp->work);
 772
 773         return 0;
 774 }
 775 EXPORT_SYMBOL_GPL(dp_altmode_probe);
 776
 777 void dp_altmode_remove(struct typec_altmode *alt)
 778 {
 779         struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
 780
 781         cancel_work_sync(&dp->work);
 782         typec_altmode_put_plug(dp->plug_prime);
 783
 784         if (dp->connector_fwnode) {
 785                 drm_connector_oob_hotplug_event(dp->connector_fwnode,
 786                                                 connector_status_disconnected);
 787
 788                 fwnode_handle_put(dp->connector_fwnode);
 789         }
 790 }
 791 EXPORT_SYMBOL_GPL(dp_altmode_remove);
 792
 793 static const struct typec_device_id dp_typec_id[] = {
 794         { USB_TYPEC_DP_SID, USB_TYPEC_DP_MODE },
 795         { },
 796 };
 797 MODULE_DEVICE_TABLE(typec, dp_typec_id);
 798
 799 static struct typec_altmode_driver dp_altmode_driver = {
 800         .id_table = dp_typec_id,
 801         .probe = dp_altmode_probe,
 802         .remove = dp_altmode_remove,
 803         .driver = {
 804                 .name = "typec_displayport",
 805                 .owner = THIS_MODULE,
 806                 .dev_groups = displayport_groups,
 807         },
 808 };
 809 module_typec_altmode_driver(dp_altmode_driver);
 810
 811 MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
 812 MODULE_LICENSE("GPL v2");
 813 MODULE_DESCRIPTION("DisplayPort Alternate Mode");