drivers/gpu/drm/drm_dp_mst_topology.c

   1 /*
   2  * Copyright © 2014 Red Hat
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and its
   5  * documentation for any purpose is hereby granted without fee, provided that
   6  * the above copyright notice appear in all copies and that both that copyright
   7  * notice and this permission notice appear in supporting documentation, and
   8  * that the name of the copyright holders not be used in advertising or
   9  * publicity pertaining to distribution of the software without specific,
  10  * written prior permission.  The copyright holders make no representations
  11  * about the suitability of this software for any purpose.  It is provided "as
  12  * is" without express or implied warranty.
  13  *
  14  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  15  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  16  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  17  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  18  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  19  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  20  * OF THIS SOFTWARE.
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/delay.h>
  25 #include <linux/init.h>
  26 #include <linux/errno.h>
  27 #include <linux/sched.h>
  28 #include <linux/seq_file.h>
  29 #include <linux/i2c.h>
  30 #include <drm/drm_dp_mst_helper.h>
  31 #include <drm/drmP.h>
  32
  33 #include <drm/drm_fixed.h>
  34
  35 /**
  36  * DOC: dp mst helper
  37  *
  38  * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
  39  * protocol. The helpers contain a topology manager and bandwidth manager.
  40  * The helpers encapsulate the sending and received of sideband msgs.
  41  */
  42 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
  43                                   char *buf);
  44 static int test_calc_pbn_mode(void);
  45
  46 static void drm_dp_put_port(struct drm_dp_mst_port *port);
  47
  48 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
  49                                      int id,
  50                                      struct drm_dp_payload *payload);
  51
  52 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
  53                                   struct drm_dp_mst_port *port,
  54                                   int offset, int size, u8 *bytes);
  55
  56 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
  57                                      struct drm_dp_mst_branch *mstb);
  58 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
  59                                            struct drm_dp_mst_branch *mstb,
  60                                            struct drm_dp_mst_port *port);
  61 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
  62                                  u8 *guid);
  63
  64 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
  65 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
  66 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
  67 /* sideband msg handling */
  68 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
  69 {
  70         u8 bitmask = 0x80;
  71         u8 bitshift = 7;
  72         u8 array_index = 0;
  73         int number_of_bits = num_nibbles * 4;
  74         u8 remainder = 0;
  75
  76         while (number_of_bits != 0) {
  77                 number_of_bits--;
  78                 remainder <<= 1;
  79                 remainder |= (data[array_index] & bitmask) >> bitshift;
  80                 bitmask >>= 1;
  81                 bitshift--;
  82                 if (bitmask == 0) {
  83                         bitmask = 0x80;
  84                         bitshift = 7;
  85                         array_index++;
  86                 }
  87                 if ((remainder & 0x10) == 0x10)
  88                         remainder ^= 0x13;
  89         }
  90
  91         number_of_bits = 4;
  92         while (number_of_bits != 0) {
  93                 number_of_bits--;
  94                 remainder <<= 1;
  95                 if ((remainder & 0x10) != 0)
  96                         remainder ^= 0x13;
  97         }
  98
  99         return remainder;
 100 }
 101
 102 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
 103 {
 104         u8 bitmask = 0x80;
 105         u8 bitshift = 7;
 106         u8 array_index = 0;
 107         int number_of_bits = number_of_bytes * 8;
 108         u16 remainder = 0;
 109
 110         while (number_of_bits != 0) {
 111                 number_of_bits--;
 112                 remainder <<= 1;
 113                 remainder |= (data[array_index] & bitmask) >> bitshift;
 114                 bitmask >>= 1;
 115                 bitshift--;
 116                 if (bitmask == 0) {
 117                         bitmask = 0x80;
 118                         bitshift = 7;
 119                         array_index++;
 120                 }
 121                 if ((remainder & 0x100) == 0x100)
 122                         remainder ^= 0xd5;
 123         }
 124
 125         number_of_bits = 8;
 126         while (number_of_bits != 0) {
 127                 number_of_bits--;
 128                 remainder <<= 1;
 129                 if ((remainder & 0x100) != 0)
 130                         remainder ^= 0xd5;
 131         }
 132
 133         return remainder & 0xff;
 134 }
 135 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
 136 {
 137         u8 size = 3;
 138         size += (hdr->lct / 2);
 139         return size;
 140 }
 141
 142 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
 143                                            u8 *buf, int *len)
 144 {
 145         int idx = 0;
 146         int i;
 147         u8 crc4;
 148         buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
 149         for (i = 0; i < (hdr->lct / 2); i++)
 150                 buf[idx++] = hdr->rad[i];
 151         buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
 152                 (hdr->msg_len & 0x3f);
 153         buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
 154
 155         crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
 156         buf[idx - 1] |= (crc4 & 0xf);
 157
 158         *len = idx;
 159 }
 160
 161 static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
 162                                            u8 *buf, int buflen, u8 *hdrlen)
 163 {
 164         u8 crc4;
 165         u8 len;
 166         int i;
 167         u8 idx;
 168         if (buf[0] == 0)
 169                 return false;
 170         len = 3;
 171         len += ((buf[0] & 0xf0) >> 4) / 2;
 172         if (len > buflen)
 173                 return false;
 174         crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
 175
 176         if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
 177                 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
 178                 return false;
 179         }
 180
 181         hdr->lct = (buf[0] & 0xf0) >> 4;
 182         hdr->lcr = (buf[0] & 0xf);
 183         idx = 1;
 184         for (i = 0; i < (hdr->lct / 2); i++)
 185                 hdr->rad[i] = buf[idx++];
 186         hdr->broadcast = (buf[idx] >> 7) & 0x1;
 187         hdr->path_msg = (buf[idx] >> 6) & 0x1;
 188         hdr->msg_len = buf[idx] & 0x3f;
 189         idx++;
 190         hdr->somt = (buf[idx] >> 7) & 0x1;
 191         hdr->eomt = (buf[idx] >> 6) & 0x1;
 192         hdr->seqno = (buf[idx] >> 4) & 0x1;
 193         idx++;
 194         *hdrlen = idx;
 195         return true;
 196 }
 197
 198 static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req,
 199                                        struct drm_dp_sideband_msg_tx *raw)
 200 {
 201         int idx = 0;
 202         int i;
 203         u8 *buf = raw->msg;
 204         buf[idx++] = req->req_type & 0x7f;
 205
 206         switch (req->req_type) {
 207         case DP_ENUM_PATH_RESOURCES:
 208                 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
 209                 idx++;
 210                 break;
 211         case DP_ALLOCATE_PAYLOAD:
 212                 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
 213                         (req->u.allocate_payload.number_sdp_streams & 0xf);
 214                 idx++;
 215                 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
 216                 idx++;
 217                 buf[idx] = (req->u.allocate_payload.pbn >> 8);
 218                 idx++;
 219                 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
 220                 idx++;
 221                 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
 222                         buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
 223                                 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
 224                         idx++;
 225                 }
 226                 if (req->u.allocate_payload.number_sdp_streams & 1) {
 227                         i = req->u.allocate_payload.number_sdp_streams - 1;
 228                         buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
 229                         idx++;
 230                 }
 231                 break;
 232         case DP_QUERY_PAYLOAD:
 233                 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
 234                 idx++;
 235                 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
 236                 idx++;
 237                 break;
 238         case DP_REMOTE_DPCD_READ:
 239                 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
 240                 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
 241                 idx++;
 242                 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
 243                 idx++;
 244                 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
 245                 idx++;
 246                 buf[idx] = (req->u.dpcd_read.num_bytes);
 247                 idx++;
 248                 break;
 249
 250         case DP_REMOTE_DPCD_WRITE:
 251                 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
 252                 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
 253                 idx++;
 254                 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
 255                 idx++;
 256                 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
 257                 idx++;
 258                 buf[idx] = (req->u.dpcd_write.num_bytes);
 259                 idx++;
 260                 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
 261                 idx += req->u.dpcd_write.num_bytes;
 262                 break;
 263         case DP_REMOTE_I2C_READ:
 264                 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
 265                 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
 266                 idx++;
 267                 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
 268                         buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
 269                         idx++;
 270                         buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
 271                         idx++;
 272                         memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
 273                         idx += req->u.i2c_read.transactions[i].num_bytes;
 274
 275                         buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
 276                         buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
 277                         idx++;
 278                 }
 279                 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
 280                 idx++;
 281                 buf[idx] = (req->u.i2c_read.num_bytes_read);
 282                 idx++;
 283                 break;
 284
 285         case DP_REMOTE_I2C_WRITE:
 286                 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
 287                 idx++;
 288                 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
 289                 idx++;
 290                 buf[idx] = (req->u.i2c_write.num_bytes);
 291                 idx++;
 292                 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
 293                 idx += req->u.i2c_write.num_bytes;
 294                 break;
 295         }
 296         raw->cur_len = idx;
 297 }
 298
 299 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
 300 {
 301         u8 crc4;
 302         crc4 = drm_dp_msg_data_crc4(msg, len);
 303         msg[len] = crc4;
 304 }
 305
 306 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
 307                                          struct drm_dp_sideband_msg_tx *raw)
 308 {
 309         int idx = 0;
 310         u8 *buf = raw->msg;
 311
 312         buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
 313
 314         raw->cur_len = idx;
 315 }
 316
 317 /* this adds a chunk of msg to the builder to get the final msg */
 318 static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
 319                                       u8 *replybuf, u8 replybuflen, bool hdr)
 320 {
 321         int ret;
 322         u8 crc4;
 323
 324         if (hdr) {
 325                 u8 hdrlen;
 326                 struct drm_dp_sideband_msg_hdr recv_hdr;
 327                 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
 328                 if (ret == false) {
 329                         print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
 330                         return false;
 331                 }
 332
 333                 /* get length contained in this portion */
 334                 msg->curchunk_len = recv_hdr.msg_len;
 335                 msg->curchunk_hdrlen = hdrlen;
 336
 337                 /* we have already gotten an somt - don't bother parsing */
 338                 if (recv_hdr.somt && msg->have_somt)
 339                         return false;
 340
 341                 if (recv_hdr.somt) {
 342                         memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
 343                         msg->have_somt = true;
 344                 }
 345                 if (recv_hdr.eomt)
 346                         msg->have_eomt = true;
 347
 348                 /* copy the bytes for the remainder of this header chunk */
 349                 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
 350                 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
 351         } else {
 352                 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
 353                 msg->curchunk_idx += replybuflen;
 354         }
 355
 356         if (msg->curchunk_idx >= msg->curchunk_len) {
 357                 /* do CRC */
 358                 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
 359                 /* copy chunk into bigger msg */
 360                 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
 361                 msg->curlen += msg->curchunk_len - 1;
 362         }
 363         return true;
 364 }
 365
 366 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
 367                                                struct drm_dp_sideband_msg_reply_body *repmsg)
 368 {
 369         int idx = 1;
 370         int i;
 371         memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
 372         idx += 16;
 373         repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
 374         idx++;
 375         if (idx > raw->curlen)
 376                 goto fail_len;
 377         for (i = 0; i < repmsg->u.link_addr.nports; i++) {
 378                 if (raw->msg[idx] & 0x80)
 379                         repmsg->u.link_addr.ports[i].input_port = 1;
 380
 381                 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
 382                 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
 383
 384                 idx++;
 385                 if (idx > raw->curlen)
 386                         goto fail_len;
 387                 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
 388                 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
 389                 if (repmsg->u.link_addr.ports[i].input_port == 0)
 390                         repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
 391                 idx++;
 392                 if (idx > raw->curlen)
 393                         goto fail_len;
 394                 if (repmsg->u.link_addr.ports[i].input_port == 0) {
 395                         repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
 396                         idx++;
 397                         if (idx > raw->curlen)
 398                                 goto fail_len;
 399                         memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
 400                         idx += 16;
 401                         if (idx > raw->curlen)
 402                                 goto fail_len;
 403                         repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
 404                         repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
 405                         idx++;
 406
 407                 }
 408                 if (idx > raw->curlen)
 409                         goto fail_len;
 410         }
 411
 412         return true;
 413 fail_len:
 414         DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
 415         return false;
 416 }
 417
 418 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
 419                                                    struct drm_dp_sideband_msg_reply_body *repmsg)
 420 {
 421         int idx = 1;
 422         repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
 423         idx++;
 424         if (idx > raw->curlen)
 425                 goto fail_len;
 426         repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
 427         if (idx > raw->curlen)
 428                 goto fail_len;
 429
 430         memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
 431         return true;
 432 fail_len:
 433         DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
 434         return false;
 435 }
 436
 437 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
 438                                                       struct drm_dp_sideband_msg_reply_body *repmsg)
 439 {
 440         int idx = 1;
 441         repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
 442         idx++;
 443         if (idx > raw->curlen)
 444                 goto fail_len;
 445         return true;
 446 fail_len:
 447         DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
 448         return false;
 449 }
 450
 451 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
 452                                                       struct drm_dp_sideband_msg_reply_body *repmsg)
 453 {
 454         int idx = 1;
 455
 456         repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
 457         idx++;
 458         if (idx > raw->curlen)
 459                 goto fail_len;
 460         repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
 461         idx++;
 462         /* TODO check */
 463         memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
 464         return true;
 465 fail_len:
 466         DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
 467         return false;
 468 }
 469
 470 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
 471                                                           struct drm_dp_sideband_msg_reply_body *repmsg)
 472 {
 473         int idx = 1;
 474         repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
 475         idx++;
 476         if (idx > raw->curlen)
 477                 goto fail_len;
 478         repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 479         idx += 2;
 480         if (idx > raw->curlen)
 481                 goto fail_len;
 482         repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 483         idx += 2;
 484         if (idx > raw->curlen)
 485                 goto fail_len;
 486         return true;
 487 fail_len:
 488         DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
 489         return false;
 490 }
 491
 492 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
 493                                                           struct drm_dp_sideband_msg_reply_body *repmsg)
 494 {
 495         int idx = 1;
 496         repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
 497         idx++;
 498         if (idx > raw->curlen)
 499                 goto fail_len;
 500         repmsg->u.allocate_payload.vcpi = raw->msg[idx];
 501         idx++;
 502         if (idx > raw->curlen)
 503                 goto fail_len;
 504         repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 505         idx += 2;
 506         if (idx > raw->curlen)
 507                 goto fail_len;
 508         return true;
 509 fail_len:
 510         DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
 511         return false;
 512 }
 513
 514 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
 515                                                     struct drm_dp_sideband_msg_reply_body *repmsg)
 516 {
 517         int idx = 1;
 518         repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
 519         idx++;
 520         if (idx > raw->curlen)
 521                 goto fail_len;
 522         repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
 523         idx += 2;
 524         if (idx > raw->curlen)
 525                 goto fail_len;
 526         return true;
 527 fail_len:
 528         DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
 529         return false;
 530 }
 531
 532 static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
 533                                         struct drm_dp_sideband_msg_reply_body *msg)
 534 {
 535         memset(msg, 0, sizeof(*msg));
 536         msg->reply_type = (raw->msg[0] & 0x80) >> 7;
 537         msg->req_type = (raw->msg[0] & 0x7f);
 538
 539         if (msg->reply_type) {
 540                 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
 541                 msg->u.nak.reason = raw->msg[17];
 542                 msg->u.nak.nak_data = raw->msg[18];
 543                 return false;
 544         }
 545
 546         switch (msg->req_type) {
 547         case DP_LINK_ADDRESS:
 548                 return drm_dp_sideband_parse_link_address(raw, msg);
 549         case DP_QUERY_PAYLOAD:
 550                 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
 551         case DP_REMOTE_DPCD_READ:
 552                 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
 553         case DP_REMOTE_DPCD_WRITE:
 554                 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
 555         case DP_REMOTE_I2C_READ:
 556                 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
 557         case DP_ENUM_PATH_RESOURCES:
 558                 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
 559         case DP_ALLOCATE_PAYLOAD:
 560                 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
 561         default:
 562                 DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
 563                 return false;
 564         }
 565 }
 566
 567 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
 568                                                            struct drm_dp_sideband_msg_req_body *msg)
 569 {
 570         int idx = 1;
 571
 572         msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
 573         idx++;
 574         if (idx > raw->curlen)
 575                 goto fail_len;
 576
 577         memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
 578         idx += 16;
 579         if (idx > raw->curlen)
 580                 goto fail_len;
 581
 582         msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
 583         msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
 584         msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
 585         msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
 586         msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
 587         idx++;
 588         return true;
 589 fail_len:
 590         DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
 591         return false;
 592 }
 593
 594 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
 595                                                            struct drm_dp_sideband_msg_req_body *msg)
 596 {
 597         int idx = 1;
 598
 599         msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
 600         idx++;
 601         if (idx > raw->curlen)
 602                 goto fail_len;
 603
 604         memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
 605         idx += 16;
 606         if (idx > raw->curlen)
 607                 goto fail_len;
 608
 609         msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
 610         idx++;
 611         return true;
 612 fail_len:
 613         DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
 614         return false;
 615 }
 616
 617 static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
 618                                       struct drm_dp_sideband_msg_req_body *msg)
 619 {
 620         memset(msg, 0, sizeof(*msg));
 621         msg->req_type = (raw->msg[0] & 0x7f);
 622
 623         switch (msg->req_type) {
 624         case DP_CONNECTION_STATUS_NOTIFY:
 625                 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
 626         case DP_RESOURCE_STATUS_NOTIFY:
 627                 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
 628         default:
 629                 DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
 630                 return false;
 631         }
 632 }
 633
 634 static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
 635 {
 636         struct drm_dp_sideband_msg_req_body req;
 637
 638         req.req_type = DP_REMOTE_DPCD_WRITE;
 639         req.u.dpcd_write.port_number = port_num;
 640         req.u.dpcd_write.dpcd_address = offset;
 641         req.u.dpcd_write.num_bytes = num_bytes;
 642         req.u.dpcd_write.bytes = bytes;
 643         drm_dp_encode_sideband_req(&req, msg);
 644
 645         return 0;
 646 }
 647
 648 static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
 649 {
 650         struct drm_dp_sideband_msg_req_body req;
 651
 652         req.req_type = DP_LINK_ADDRESS;
 653         drm_dp_encode_sideband_req(&req, msg);
 654         return 0;
 655 }
 656
 657 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
 658 {
 659         struct drm_dp_sideband_msg_req_body req;
 660
 661         req.req_type = DP_ENUM_PATH_RESOURCES;
 662         req.u.port_num.port_number = port_num;
 663         drm_dp_encode_sideband_req(&req, msg);
 664         msg->path_msg = true;
 665         return 0;
 666 }
 667
 668 static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
 669                                   u8 vcpi, uint16_t pbn,
 670                                   u8 number_sdp_streams,
 671                                   u8 *sdp_stream_sink)
 672 {
 673         struct drm_dp_sideband_msg_req_body req;
 674         memset(&req, 0, sizeof(req));
 675         req.req_type = DP_ALLOCATE_PAYLOAD;
 676         req.u.allocate_payload.port_number = port_num;
 677         req.u.allocate_payload.vcpi = vcpi;
 678         req.u.allocate_payload.pbn = pbn;
 679         req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
 680         memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
 681                    number_sdp_streams);
 682         drm_dp_encode_sideband_req(&req, msg);
 683         msg->path_msg = true;
 684         return 0;
 685 }
 686
 687 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
 688                                         struct drm_dp_vcpi *vcpi)
 689 {
 690         int ret, vcpi_ret;
 691
 692         mutex_lock(&mgr->payload_lock);
 693         ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
 694         if (ret > mgr->max_payloads) {
 695                 ret = -EINVAL;
 696                 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
 697                 goto out_unlock;
 698         }
 699
 700         vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
 701         if (vcpi_ret > mgr->max_payloads) {
 702                 ret = -EINVAL;
 703                 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
 704                 goto out_unlock;
 705         }
 706
 707         set_bit(ret, &mgr->payload_mask);
 708         set_bit(vcpi_ret, &mgr->vcpi_mask);
 709         vcpi->vcpi = vcpi_ret + 1;
 710         mgr->proposed_vcpis[ret - 1] = vcpi;
 711 out_unlock:
 712         mutex_unlock(&mgr->payload_lock);
 713         return ret;
 714 }
 715
 716 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
 717                                       int vcpi)
 718 {
 719         int i;
 720         if (vcpi == 0)
 721                 return;
 722
 723         mutex_lock(&mgr->payload_lock);
 724         DRM_DEBUG_KMS("putting payload %d\n", vcpi);
 725         clear_bit(vcpi - 1, &mgr->vcpi_mask);
 726
 727         for (i = 0; i < mgr->max_payloads; i++) {
 728                 if (mgr->proposed_vcpis[i])
 729                         if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
 730                                 mgr->proposed_vcpis[i] = NULL;
 731                                 clear_bit(i + 1, &mgr->payload_mask);
 732                         }
 733         }
 734         mutex_unlock(&mgr->payload_lock);
 735 }
 736
 737 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
 738                               struct drm_dp_sideband_msg_tx *txmsg)
 739 {
 740         bool ret;
 741
 742         /*
 743          * All updates to txmsg->state are protected by mgr->qlock, and the two
 744          * cases we check here are terminal states. For those the barriers
 745          * provided by the wake_up/wait_event pair are enough.
 746          */
 747         ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
 748                txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
 749         return ret;
 750 }
 751
 752 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
 753                                     struct drm_dp_sideband_msg_tx *txmsg)
 754 {
 755         struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
 756         int ret;
 757
 758         ret = wait_event_timeout(mgr->tx_waitq,
 759                                  check_txmsg_state(mgr, txmsg),
 760                                  (4 * HZ));
 761         mutex_lock(&mstb->mgr->qlock);
 762         if (ret > 0) {
 763                 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
 764                         ret = -EIO;
 765                         goto out;
 766                 }
 767         } else {
 768                 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
 769
 770                 /* dump some state */
 771                 ret = -EIO;
 772
 773                 /* remove from q */
 774                 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
 775                     txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
 776                         list_del(&txmsg->next);
 777                 }
 778
 779                 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
 780                     txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
 781                         mstb->tx_slots[txmsg->seqno] = NULL;
 782                 }
 783         }
 784 out:
 785         mutex_unlock(&mgr->qlock);
 786
 787         return ret;
 788 }
 789
 790 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
 791 {
 792         struct drm_dp_mst_branch *mstb;
 793
 794         mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
 795         if (!mstb)
 796                 return NULL;
 797
 798         mstb->lct = lct;
 799         if (lct > 1)
 800                 memcpy(mstb->rad, rad, lct / 2);
 801         INIT_LIST_HEAD(&mstb->ports);
 802         kref_init(&mstb->kref);
 803         return mstb;
 804 }
 805
 806 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
 807 {
 808         struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
 809         struct drm_dp_mst_port *port, *tmp;
 810         bool wake_tx = false;
 811
 812         /*
 813          * destroy all ports - don't need lock
 814          * as there are no more references to the mst branch
 815          * device at this point.
 816          */
 817         list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
 818                 list_del(&port->next);
 819                 drm_dp_put_port(port);
 820         }
 821
 822         /* drop any tx slots msg */
 823         mutex_lock(&mstb->mgr->qlock);
 824         if (mstb->tx_slots[0]) {
 825                 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 826                 mstb->tx_slots[0] = NULL;
 827                 wake_tx = true;
 828         }
 829         if (mstb->tx_slots[1]) {
 830                 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 831                 mstb->tx_slots[1] = NULL;
 832                 wake_tx = true;
 833         }
 834         mutex_unlock(&mstb->mgr->qlock);
 835
 836         if (wake_tx)
 837                 wake_up(&mstb->mgr->tx_waitq);
 838         kfree(mstb);
 839 }
 840
 841 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
 842 {
 843         kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
 844 }
 845
 846
 847 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
 848 {
 849         struct drm_dp_mst_branch *mstb;
 850
 851         switch (old_pdt) {
 852         case DP_PEER_DEVICE_DP_LEGACY_CONV:
 853         case DP_PEER_DEVICE_SST_SINK:
 854                 /* remove i2c over sideband */
 855                 drm_dp_mst_unregister_i2c_bus(&port->aux);
 856                 break;
 857         case DP_PEER_DEVICE_MST_BRANCHING:
 858                 mstb = port->mstb;
 859                 port->mstb = NULL;
 860                 drm_dp_put_mst_branch_device(mstb);
 861                 break;
 862         }
 863 }
 864
 865 static void drm_dp_destroy_port(struct kref *kref)
 866 {
 867         struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
 868         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
 869
 870         if (!port->input) {
 871                 port->vcpi.num_slots = 0;
 872
 873                 kfree(port->cached_edid);
 874
 875                 /*
 876                  * The only time we don't have a connector
 877                  * on an output port is if the connector init
 878                  * fails.
 879                  */
 880                 if (port->connector) {
 881                         /* we can't destroy the connector here, as
 882                          * we might be holding the mode_config.mutex
 883                          * from an EDID retrieval */
 884
 885                         mutex_lock(&mgr->destroy_connector_lock);
 886                         list_add(&port->next, &mgr->destroy_connector_list);
 887                         mutex_unlock(&mgr->destroy_connector_lock);
 888                         schedule_work(&mgr->destroy_connector_work);
 889                         return;
 890                 }
 891                 /* no need to clean up vcpi
 892                  * as if we have no connector we never setup a vcpi */
 893                 drm_dp_port_teardown_pdt(port, port->pdt);
 894         }
 895         kfree(port);
 896 }
 897
 898 static void drm_dp_put_port(struct drm_dp_mst_port *port)
 899 {
 900         kref_put(&port->kref, drm_dp_destroy_port);
 901 }
 902
 903 static struct drm_dp_mst_branch *drm_dp_mst_get_validated_mstb_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_branch *to_find)
 904 {
 905         struct drm_dp_mst_port *port;
 906         struct drm_dp_mst_branch *rmstb;
 907         if (to_find == mstb) {
 908                 kref_get(&mstb->kref);
 909                 return mstb;
 910         }
 911         list_for_each_entry(port, &mstb->ports, next) {
 912                 if (port->mstb) {
 913                         rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
 914                         if (rmstb)
 915                                 return rmstb;
 916                 }
 917         }
 918         return NULL;
 919 }
 920
 921 static struct drm_dp_mst_branch *drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb)
 922 {
 923         struct drm_dp_mst_branch *rmstb = NULL;
 924         mutex_lock(&mgr->lock);
 925         if (mgr->mst_primary)
 926                 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
 927         mutex_unlock(&mgr->lock);
 928         return rmstb;
 929 }
 930
 931 static struct drm_dp_mst_port *drm_dp_mst_get_port_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_port *to_find)
 932 {
 933         struct drm_dp_mst_port *port, *mport;
 934
 935         list_for_each_entry(port, &mstb->ports, next) {
 936                 if (port == to_find) {
 937                         kref_get(&port->kref);
 938                         return port;
 939                 }
 940                 if (port->mstb) {
 941                         mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
 942                         if (mport)
 943                                 return mport;
 944                 }
 945         }
 946         return NULL;
 947 }
 948
 949 static struct drm_dp_mst_port *drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
 950 {
 951         struct drm_dp_mst_port *rport = NULL;
 952         mutex_lock(&mgr->lock);
 953         if (mgr->mst_primary)
 954                 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
 955         mutex_unlock(&mgr->lock);
 956         return rport;
 957 }
 958
 959 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
 960 {
 961         struct drm_dp_mst_port *port;
 962
 963         list_for_each_entry(port, &mstb->ports, next) {
 964                 if (port->port_num == port_num) {
 965                         kref_get(&port->kref);
 966                         return port;
 967                 }
 968         }
 969
 970         return NULL;
 971 }
 972
 973 /*
 974  * calculate a new RAD for this MST branch device
 975  * if parent has an LCT of 2 then it has 1 nibble of RAD,
 976  * if parent has an LCT of 3 then it has 2 nibbles of RAD,
 977  */
 978 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
 979                                  u8 *rad)
 980 {
 981         int lct = port->parent->lct;
 982         int shift = 4;
 983         int idx = lct / 2;
 984         if (lct > 1) {
 985                 memcpy(rad, port->parent->rad, idx);
 986                 shift = (lct % 2) ? 4 : 0;
 987         } else
 988                 rad[0] = 0;
 989
 990         rad[idx] |= port->port_num << shift;
 991         return lct + 1;
 992 }
 993
 994 /*
 995  * return sends link address for new mstb
 996  */
 997 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
 998 {
 999         int ret;
1000         u8 rad[6], lct;
1001         bool send_link = false;
1002         switch (port->pdt) {
1003         case DP_PEER_DEVICE_DP_LEGACY_CONV:
1004         case DP_PEER_DEVICE_SST_SINK:
1005                 /* add i2c over sideband */
1006                 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1007                 break;
1008         case DP_PEER_DEVICE_MST_BRANCHING:
1009                 lct = drm_dp_calculate_rad(port, rad);
1010
1011                 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
1012                 port->mstb->mgr = port->mgr;
1013                 port->mstb->port_parent = port;
1014
1015                 send_link = true;
1016                 break;
1017         }
1018         return send_link;
1019 }
1020
1021 static void drm_dp_check_port_guid(struct drm_dp_mst_branch *mstb,
1022                                    struct drm_dp_mst_port *port)
1023 {
1024         int ret;
1025         if (port->dpcd_rev >= 0x12) {
1026                 port->guid_valid = drm_dp_validate_guid(mstb->mgr, port->guid);
1027                 if (!port->guid_valid) {
1028                         ret = drm_dp_send_dpcd_write(mstb->mgr,
1029                                                      port,
1030                                                      DP_GUID,
1031                                                      16, port->guid);
1032                         port->guid_valid = true;
1033                 }
1034         }
1035 }
1036
1037 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1038                                 int pnum,
1039                                 char *proppath,
1040                                 size_t proppath_size)
1041 {
1042         int i;
1043         char temp[8];
1044         snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1045         for (i = 0; i < (mstb->lct - 1); i++) {
1046                 int shift = (i % 2) ? 0 : 4;
1047                 int port_num = mstb->rad[i / 2] >> shift;
1048                 snprintf(temp, sizeof(temp), "-%d", port_num);
1049                 strlcat(proppath, temp, proppath_size);
1050         }
1051         snprintf(temp, sizeof(temp), "-%d", pnum);
1052         strlcat(proppath, temp, proppath_size);
1053 }
1054
1055 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1056                             struct device *dev,
1057                             struct drm_dp_link_addr_reply_port *port_msg)
1058 {
1059         struct drm_dp_mst_port *port;
1060         bool ret;
1061         bool created = false;
1062         int old_pdt = 0;
1063         int old_ddps = 0;
1064         port = drm_dp_get_port(mstb, port_msg->port_number);
1065         if (!port) {
1066                 port = kzalloc(sizeof(*port), GFP_KERNEL);
1067                 if (!port)
1068                         return;
1069                 kref_init(&port->kref);
1070                 port->parent = mstb;
1071                 port->port_num = port_msg->port_number;
1072                 port->mgr = mstb->mgr;
1073                 port->aux.name = "DPMST";
1074                 port->aux.dev = dev;
1075                 created = true;
1076         } else {
1077                 old_pdt = port->pdt;
1078                 old_ddps = port->ddps;
1079         }
1080
1081         port->pdt = port_msg->peer_device_type;
1082         port->input = port_msg->input_port;
1083         port->mcs = port_msg->mcs;
1084         port->ddps = port_msg->ddps;
1085         port->ldps = port_msg->legacy_device_plug_status;
1086         port->dpcd_rev = port_msg->dpcd_revision;
1087         port->num_sdp_streams = port_msg->num_sdp_streams;
1088         port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1089         memcpy(port->guid, port_msg->peer_guid, 16);
1090
1091         /* manage mstb port lists with mgr lock - take a reference
1092            for this list */
1093         if (created) {
1094                 mutex_lock(&mstb->mgr->lock);
1095                 kref_get(&port->kref);
1096                 list_add(&port->next, &mstb->ports);
1097                 mutex_unlock(&mstb->mgr->lock);
1098         }
1099
1100         if (old_ddps != port->ddps) {
1101                 if (port->ddps) {
1102                         drm_dp_check_port_guid(mstb, port);
1103                         if (!port->input)
1104                                 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1105                 } else {
1106                         port->guid_valid = false;
1107                         port->available_pbn = 0;
1108                         }
1109         }
1110
1111         if (old_pdt != port->pdt && !port->input) {
1112                 drm_dp_port_teardown_pdt(port, old_pdt);
1113
1114                 ret = drm_dp_port_setup_pdt(port);
1115                 if (ret == true)
1116                         drm_dp_send_link_address(mstb->mgr, port->mstb);
1117         }
1118
1119         if (created && !port->input) {
1120                 char proppath[255];
1121
1122                 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
1123                 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1124                 if (!port->connector) {
1125                         /* remove it from the port list */
1126                         mutex_lock(&mstb->mgr->lock);
1127                         list_del(&port->next);
1128                         mutex_unlock(&mstb->mgr->lock);
1129                         /* drop port list reference */
1130                         drm_dp_put_port(port);
1131                         goto out;
1132                 }
1133                 if (port->port_num >= DP_MST_LOGICAL_PORT_0) {
1134                         port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1135                         drm_mode_connector_set_tile_property(port->connector);
1136                 }
1137                 (*mstb->mgr->cbs->register_connector)(port->connector);
1138         }
1139
1140 out:
1141         /* put reference to this port */
1142         drm_dp_put_port(port);
1143 }
1144
1145 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1146                                struct drm_dp_connection_status_notify *conn_stat)
1147 {
1148         struct drm_dp_mst_port *port;
1149         int old_pdt;
1150         int old_ddps;
1151         bool dowork = false;
1152         port = drm_dp_get_port(mstb, conn_stat->port_number);
1153         if (!port)
1154                 return;
1155
1156         old_ddps = port->ddps;
1157         old_pdt = port->pdt;
1158         port->pdt = conn_stat->peer_device_type;
1159         port->mcs = conn_stat->message_capability_status;
1160         port->ldps = conn_stat->legacy_device_plug_status;
1161         port->ddps = conn_stat->displayport_device_plug_status;
1162
1163         if (old_ddps != port->ddps) {
1164                 if (port->ddps) {
1165                         drm_dp_check_port_guid(mstb, port);
1166                         dowork = true;
1167                 } else {
1168                         port->guid_valid = false;
1169                         port->available_pbn = 0;
1170                 }
1171         }
1172         if (old_pdt != port->pdt && !port->input) {
1173                 drm_dp_port_teardown_pdt(port, old_pdt);
1174
1175                 if (drm_dp_port_setup_pdt(port))
1176                         dowork = true;
1177         }
1178
1179         drm_dp_put_port(port);
1180         if (dowork)
1181                 queue_work(system_long_wq, &mstb->mgr->work);
1182
1183 }
1184
1185 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1186                                                                u8 lct, u8 *rad)
1187 {
1188         struct drm_dp_mst_branch *mstb;
1189         struct drm_dp_mst_port *port;
1190         int i;
1191         /* find the port by iterating down */
1192
1193         mutex_lock(&mgr->lock);
1194         mstb = mgr->mst_primary;
1195
1196         for (i = 0; i < lct - 1; i++) {
1197                 int shift = (i % 2) ? 0 : 4;
1198                 int port_num = rad[i / 2] >> shift;
1199
1200                 list_for_each_entry(port, &mstb->ports, next) {
1201                         if (port->port_num == port_num) {
1202                                 mstb = port->mstb;
1203                                 if (!mstb) {
1204                                         DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1205                                         goto out;
1206                                 }
1207
1208                                 break;
1209                         }
1210                 }
1211         }
1212         kref_get(&mstb->kref);
1213 out:
1214         mutex_unlock(&mgr->lock);
1215         return mstb;
1216 }
1217
1218 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1219         struct drm_dp_mst_branch *mstb,
1220         uint8_t *guid)
1221 {
1222         struct drm_dp_mst_branch *found_mstb;
1223         struct drm_dp_mst_port *port;
1224
1225         list_for_each_entry(port, &mstb->ports, next) {
1226                 if (!port->mstb)
1227                         continue;
1228
1229                 if (port->guid_valid && memcmp(port->guid, guid, 16) == 0)
1230                         return port->mstb;
1231
1232                 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1233
1234                 if (found_mstb)
1235                         return found_mstb;
1236         }
1237
1238         return NULL;
1239 }
1240
1241 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
1242         struct drm_dp_mst_topology_mgr *mgr,
1243         uint8_t *guid)
1244 {
1245         struct drm_dp_mst_branch *mstb;
1246
1247         /* find the port by iterating down */
1248         mutex_lock(&mgr->lock);
1249
1250         if (mgr->guid_valid && memcmp(mgr->guid, guid, 16) == 0)
1251                 mstb = mgr->mst_primary;
1252         else
1253                 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
1254
1255         if (mstb)
1256                 kref_get(&mstb->kref);
1257
1258         mutex_unlock(&mgr->lock);
1259         return mstb;
1260 }
1261
1262 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1263                                                struct drm_dp_mst_branch *mstb)
1264 {
1265         struct drm_dp_mst_port *port;
1266         struct drm_dp_mst_branch *mstb_child;
1267         if (!mstb->link_address_sent)
1268                 drm_dp_send_link_address(mgr, mstb);
1269
1270         list_for_each_entry(port, &mstb->ports, next) {
1271                 if (port->input)
1272                         continue;
1273
1274                 if (!port->ddps)
1275                         continue;
1276
1277                 if (!port->available_pbn)
1278                         drm_dp_send_enum_path_resources(mgr, mstb, port);
1279
1280                 if (port->mstb) {
1281                         mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1282                         if (mstb_child) {
1283                                 drm_dp_check_and_send_link_address(mgr, mstb_child);
1284                                 drm_dp_put_mst_branch_device(mstb_child);
1285                         }
1286                 }
1287         }
1288 }
1289
1290 static void drm_dp_mst_link_probe_work(struct work_struct *work)
1291 {
1292         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1293         struct drm_dp_mst_branch *mstb;
1294
1295         mutex_lock(&mgr->lock);
1296         mstb = mgr->mst_primary;
1297         if (mstb) {
1298                 kref_get(&mstb->kref);
1299         }
1300         mutex_unlock(&mgr->lock);
1301         if (mstb) {
1302                 drm_dp_check_and_send_link_address(mgr, mstb);
1303                 drm_dp_put_mst_branch_device(mstb);
1304         }
1305 }
1306
1307 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1308                                  u8 *guid)
1309 {
1310         static u8 zero_guid[16];
1311
1312         if (!memcmp(guid, zero_guid, 16)) {
1313                 u64 salt = get_jiffies_64();
1314                 memcpy(&guid[0], &salt, sizeof(u64));
1315                 memcpy(&guid[8], &salt, sizeof(u64));
1316                 return false;
1317         }
1318         return true;
1319 }
1320
1321 #if 0
1322 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1323 {
1324         struct drm_dp_sideband_msg_req_body req;
1325
1326         req.req_type = DP_REMOTE_DPCD_READ;
1327         req.u.dpcd_read.port_number = port_num;
1328         req.u.dpcd_read.dpcd_address = offset;
1329         req.u.dpcd_read.num_bytes = num_bytes;
1330         drm_dp_encode_sideband_req(&req, msg);
1331
1332         return 0;
1333 }
1334 #endif
1335
1336 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1337                                     bool up, u8 *msg, int len)
1338 {
1339         int ret;
1340         int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1341         int tosend, total, offset;
1342         int retries = 0;
1343
1344 retry:
1345         total = len;
1346         offset = 0;
1347         do {
1348                 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1349
1350                 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1351                                         &msg[offset],
1352                                         tosend);
1353                 if (ret != tosend) {
1354                         if (ret == -EIO && retries < 5) {
1355                                 retries++;
1356                                 goto retry;
1357                         }
1358                         DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1359
1360                         return -EIO;
1361                 }
1362                 offset += tosend;
1363                 total -= tosend;
1364         } while (total > 0);
1365         return 0;
1366 }
1367
1368 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1369                                   struct drm_dp_sideband_msg_tx *txmsg)
1370 {
1371         struct drm_dp_mst_branch *mstb = txmsg->dst;
1372         u8 req_type;
1373
1374         /* both msg slots are full */
1375         if (txmsg->seqno == -1) {
1376                 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1377                         DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1378                         return -EAGAIN;
1379                 }
1380                 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1381                         txmsg->seqno = mstb->last_seqno;
1382                         mstb->last_seqno ^= 1;
1383                 } else if (mstb->tx_slots[0] == NULL)
1384                         txmsg->seqno = 0;
1385                 else
1386                         txmsg->seqno = 1;
1387                 mstb->tx_slots[txmsg->seqno] = txmsg;
1388         }
1389
1390         req_type = txmsg->msg[0] & 0x7f;
1391         if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1392                 req_type == DP_RESOURCE_STATUS_NOTIFY)
1393                 hdr->broadcast = 1;
1394         else
1395                 hdr->broadcast = 0;
1396         hdr->path_msg = txmsg->path_msg;
1397         hdr->lct = mstb->lct;
1398         hdr->lcr = mstb->lct - 1;
1399         if (mstb->lct > 1)
1400                 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1401         hdr->seqno = txmsg->seqno;
1402         return 0;
1403 }
1404 /*
1405  * process a single block of the next message in the sideband queue
1406  */
1407 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1408                                    struct drm_dp_sideband_msg_tx *txmsg,
1409                                    bool up)
1410 {
1411         u8 chunk[48];
1412         struct drm_dp_sideband_msg_hdr hdr;
1413         int len, space, idx, tosend;
1414         int ret;
1415
1416         memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1417
1418         if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1419                 txmsg->seqno = -1;
1420                 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1421         }
1422
1423         /* make hdr from dst mst - for replies use seqno
1424            otherwise assign one */
1425         ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1426         if (ret < 0)
1427                 return ret;
1428
1429         /* amount left to send in this message */
1430         len = txmsg->cur_len - txmsg->cur_offset;
1431
1432         /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1433         space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1434
1435         tosend = min(len, space);
1436         if (len == txmsg->cur_len)
1437                 hdr.somt = 1;
1438         if (space >= len)
1439                 hdr.eomt = 1;
1440
1441
1442         hdr.msg_len = tosend + 1;
1443         drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1444         memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1445         /* add crc at end */
1446         drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1447         idx += tosend + 1;
1448
1449         ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1450         if (ret) {
1451                 DRM_DEBUG_KMS("sideband msg failed to send\n");
1452                 return ret;
1453         }
1454
1455         txmsg->cur_offset += tosend;
1456         if (txmsg->cur_offset == txmsg->cur_len) {
1457                 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1458                 return 1;
1459         }
1460         return 0;
1461 }
1462
1463 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1464 {
1465         struct drm_dp_sideband_msg_tx *txmsg;
1466         int ret;
1467
1468         WARN_ON(!mutex_is_locked(&mgr->qlock));
1469
1470         /* construct a chunk from the first msg in the tx_msg queue */
1471         if (list_empty(&mgr->tx_msg_downq)) {
1472                 mgr->tx_down_in_progress = false;
1473                 return;
1474         }
1475         mgr->tx_down_in_progress = true;
1476
1477         txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1478         ret = process_single_tx_qlock(mgr, txmsg, false);
1479         if (ret == 1) {
1480                 /* txmsg is sent it should be in the slots now */
1481                 list_del(&txmsg->next);
1482         } else if (ret) {
1483                 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1484                 list_del(&txmsg->next);
1485                 if (txmsg->seqno != -1)
1486                         txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1487                 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1488                 wake_up(&mgr->tx_waitq);
1489         }
1490         if (list_empty(&mgr->tx_msg_downq)) {
1491                 mgr->tx_down_in_progress = false;
1492                 return;
1493         }
1494 }
1495
1496 /* called holding qlock */
1497 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1498 {
1499         struct drm_dp_sideband_msg_tx *txmsg;
1500         int ret;
1501
1502         /* construct a chunk from the first msg in the tx_msg queue */
1503         if (list_empty(&mgr->tx_msg_upq)) {
1504                 mgr->tx_up_in_progress = false;
1505                 return;
1506         }
1507
1508         txmsg = list_first_entry(&mgr->tx_msg_upq, struct drm_dp_sideband_msg_tx, next);
1509         ret = process_single_tx_qlock(mgr, txmsg, true);
1510         if (ret == 1) {
1511                 /* up txmsgs aren't put in slots - so free after we send it */
1512                 list_del(&txmsg->next);
1513                 kfree(txmsg);
1514         } else if (ret)
1515                 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1516         mgr->tx_up_in_progress = true;
1517 }
1518
1519 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1520                                  struct drm_dp_sideband_msg_tx *txmsg)
1521 {
1522         mutex_lock(&mgr->qlock);
1523         list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1524         if (!mgr->tx_down_in_progress)
1525                 process_single_down_tx_qlock(mgr);
1526         mutex_unlock(&mgr->qlock);
1527 }
1528
1529 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1530                                      struct drm_dp_mst_branch *mstb)
1531 {
1532         int len;
1533         struct drm_dp_sideband_msg_tx *txmsg;
1534         int ret;
1535
1536         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1537         if (!txmsg)
1538                 return;
1539
1540         txmsg->dst = mstb;
1541         len = build_link_address(txmsg);
1542
1543         mstb->link_address_sent = true;
1544         drm_dp_queue_down_tx(mgr, txmsg);
1545
1546         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1547         if (ret > 0) {
1548                 int i;
1549
1550                 if (txmsg->reply.reply_type == 1)
1551                         DRM_DEBUG_KMS("link address nak received\n");
1552                 else {
1553                         DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1554                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1555                                 DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n", i,
1556                                        txmsg->reply.u.link_addr.ports[i].input_port,
1557                                        txmsg->reply.u.link_addr.ports[i].peer_device_type,
1558                                        txmsg->reply.u.link_addr.ports[i].port_number,
1559                                        txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1560                                        txmsg->reply.u.link_addr.ports[i].mcs,
1561                                        txmsg->reply.u.link_addr.ports[i].ddps,
1562                                        txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1563                                        txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1564                                        txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1565                         }
1566                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1567                                 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1568                         }
1569                         (*mgr->cbs->hotplug)(mgr);
1570                 }
1571         } else {
1572                 mstb->link_address_sent = false;
1573                 DRM_DEBUG_KMS("link address failed %d\n", ret);
1574         }
1575
1576         kfree(txmsg);
1577 }
1578
1579 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1580                                            struct drm_dp_mst_branch *mstb,
1581                                            struct drm_dp_mst_port *port)
1582 {
1583         int len;
1584         struct drm_dp_sideband_msg_tx *txmsg;
1585         int ret;
1586
1587         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1588         if (!txmsg)
1589                 return -ENOMEM;
1590
1591         txmsg->dst = mstb;
1592         len = build_enum_path_resources(txmsg, port->port_num);
1593
1594         drm_dp_queue_down_tx(mgr, txmsg);
1595
1596         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1597         if (ret > 0) {
1598                 if (txmsg->reply.reply_type == 1)
1599                         DRM_DEBUG_KMS("enum path resources nak received\n");
1600                 else {
1601                         if (port->port_num != txmsg->reply.u.path_resources.port_number)
1602                                 DRM_ERROR("got incorrect port in response\n");
1603                         DRM_DEBUG_KMS("enum path resources %d: %d %d\n", txmsg->reply.u.path_resources.port_number, txmsg->reply.u.path_resources.full_payload_bw_number,
1604                                txmsg->reply.u.path_resources.avail_payload_bw_number);
1605                         port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1606                 }
1607         }
1608
1609         kfree(txmsg);
1610         return 0;
1611 }
1612
1613 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1614                                    struct drm_dp_mst_port *port,
1615                                    int id,
1616                                    int pbn)
1617 {
1618         struct drm_dp_sideband_msg_tx *txmsg;
1619         struct drm_dp_mst_branch *mstb;
1620         int len, ret;
1621         u8 sinks[DRM_DP_MAX_SDP_STREAMS];
1622         int i;
1623
1624         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1625         if (!mstb)
1626                 return -EINVAL;
1627
1628         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1629         if (!txmsg) {
1630                 ret = -ENOMEM;
1631                 goto fail_put;
1632         }
1633
1634         for (i = 0; i < port->num_sdp_streams; i++)
1635                 sinks[i] = i;
1636
1637         txmsg->dst = mstb;
1638         len = build_allocate_payload(txmsg, port->port_num,
1639                                      id,
1640                                      pbn, port->num_sdp_streams, sinks);
1641
1642         drm_dp_queue_down_tx(mgr, txmsg);
1643
1644         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1645         if (ret > 0) {
1646                 if (txmsg->reply.reply_type == 1) {
1647                         ret = -EINVAL;
1648                 } else
1649                         ret = 0;
1650         }
1651         kfree(txmsg);
1652 fail_put:
1653         drm_dp_put_mst_branch_device(mstb);
1654         return ret;
1655 }
1656
1657 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1658                                        int id,
1659                                        struct drm_dp_payload *payload)
1660 {
1661         int ret;
1662
1663         ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1664         if (ret < 0) {
1665                 payload->payload_state = 0;
1666                 return ret;
1667         }
1668         payload->payload_state = DP_PAYLOAD_LOCAL;
1669         return 0;
1670 }
1671
1672 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1673                                        struct drm_dp_mst_port *port,
1674                                        int id,
1675                                        struct drm_dp_payload *payload)
1676 {
1677         int ret;
1678         ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1679         if (ret < 0)
1680                 return ret;
1681         payload->payload_state = DP_PAYLOAD_REMOTE;
1682         return ret;
1683 }
1684
1685 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1686                                         struct drm_dp_mst_port *port,
1687                                         int id,
1688                                         struct drm_dp_payload *payload)
1689 {
1690         DRM_DEBUG_KMS("\n");
1691         /* its okay for these to fail */
1692         if (port) {
1693                 drm_dp_payload_send_msg(mgr, port, id, 0);
1694         }
1695
1696         drm_dp_dpcd_write_payload(mgr, id, payload);
1697         payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1698         return 0;
1699 }
1700
1701 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1702                                         int id,
1703                                         struct drm_dp_payload *payload)
1704 {
1705         payload->payload_state = 0;
1706         return 0;
1707 }
1708
1709 /**
1710  * drm_dp_update_payload_part1() - Execute payload update part 1
1711  * @mgr: manager to use.
1712  *
1713  * This iterates over all proposed virtual channels, and tries to
1714  * allocate space in the link for them. For 0->slots transitions,
1715  * this step just writes the VCPI to the MST device. For slots->0
1716  * transitions, this writes the updated VCPIs and removes the
1717  * remote VC payloads.
1718  *
1719  * after calling this the driver should generate ACT and payload
1720  * packets.
1721  */
1722 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1723 {
1724         int i, j;
1725         int cur_slots = 1;
1726         struct drm_dp_payload req_payload;
1727         struct drm_dp_mst_port *port;
1728
1729         mutex_lock(&mgr->payload_lock);
1730         for (i = 0; i < mgr->max_payloads; i++) {
1731                 /* solve the current payloads - compare to the hw ones
1732                    - update the hw view */
1733                 req_payload.start_slot = cur_slots;
1734                 if (mgr->proposed_vcpis[i]) {
1735                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1736                         req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1737                         req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi;
1738                 } else {
1739                         port = NULL;
1740                         req_payload.num_slots = 0;
1741                 }
1742
1743                 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1744                         mgr->payloads[i].start_slot = req_payload.start_slot;
1745                 }
1746                 /* work out what is required to happen with this payload */
1747                 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1748
1749                         /* need to push an update for this payload */
1750                         if (req_payload.num_slots) {
1751                                 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1752                                 mgr->payloads[i].num_slots = req_payload.num_slots;
1753                                 mgr->payloads[i].vcpi = req_payload.vcpi;
1754                         } else if (mgr->payloads[i].num_slots) {
1755                                 mgr->payloads[i].num_slots = 0;
1756                                 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
1757                                 req_payload.payload_state = mgr->payloads[i].payload_state;
1758                                 mgr->payloads[i].start_slot = 0;
1759                         }
1760                         mgr->payloads[i].payload_state = req_payload.payload_state;
1761                 }
1762                 cur_slots += req_payload.num_slots;
1763         }
1764
1765         for (i = 0; i < mgr->max_payloads; i++) {
1766                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1767                         DRM_DEBUG_KMS("removing payload %d\n", i);
1768                         for (j = i; j < mgr->max_payloads - 1; j++) {
1769                                 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1770                                 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1771                                 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1772                                         set_bit(j + 1, &mgr->payload_mask);
1773                                 } else {
1774                                         clear_bit(j + 1, &mgr->payload_mask);
1775                                 }
1776                         }
1777                         memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1778                         mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1779                         clear_bit(mgr->max_payloads, &mgr->payload_mask);
1780
1781                 }
1782         }
1783         mutex_unlock(&mgr->payload_lock);
1784
1785         return 0;
1786 }
1787 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1788
1789 /**
1790  * drm_dp_update_payload_part2() - Execute payload update part 2
1791  * @mgr: manager to use.
1792  *
1793  * This iterates over all proposed virtual channels, and tries to
1794  * allocate space in the link for them. For 0->slots transitions,
1795  * this step writes the remote VC payload commands. For slots->0
1796  * this just resets some internal state.
1797  */
1798 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1799 {
1800         struct drm_dp_mst_port *port;
1801         int i;
1802         int ret = 0;
1803         mutex_lock(&mgr->payload_lock);
1804         for (i = 0; i < mgr->max_payloads; i++) {
1805
1806                 if (!mgr->proposed_vcpis[i])
1807                         continue;
1808
1809                 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1810
1811                 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1812                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1813                         ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1814                 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1815                         ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1816                 }
1817                 if (ret) {
1818                         mutex_unlock(&mgr->payload_lock);
1819                         return ret;
1820                 }
1821         }
1822         mutex_unlock(&mgr->payload_lock);
1823         return 0;
1824 }
1825 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1826
1827 #if 0 /* unused as of yet */
1828 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1829                                  struct drm_dp_mst_port *port,
1830                                  int offset, int size)
1831 {
1832         int len;
1833         struct drm_dp_sideband_msg_tx *txmsg;
1834
1835         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1836         if (!txmsg)
1837                 return -ENOMEM;
1838
1839         len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1840         txmsg->dst = port->parent;
1841
1842         drm_dp_queue_down_tx(mgr, txmsg);
1843
1844         return 0;
1845 }
1846 #endif
1847
1848 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1849                                   struct drm_dp_mst_port *port,
1850                                   int offset, int size, u8 *bytes)
1851 {
1852         int len;
1853         int ret;
1854         struct drm_dp_sideband_msg_tx *txmsg;
1855         struct drm_dp_mst_branch *mstb;
1856
1857         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1858         if (!mstb)
1859                 return -EINVAL;
1860
1861         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1862         if (!txmsg) {
1863                 ret = -ENOMEM;
1864                 goto fail_put;
1865         }
1866
1867         len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1868         txmsg->dst = mstb;
1869
1870         drm_dp_queue_down_tx(mgr, txmsg);
1871
1872         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1873         if (ret > 0) {
1874                 if (txmsg->reply.reply_type == 1) {
1875                         ret = -EINVAL;
1876                 } else
1877                         ret = 0;
1878         }
1879         kfree(txmsg);
1880 fail_put:
1881         drm_dp_put_mst_branch_device(mstb);
1882         return ret;
1883 }
1884
1885 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1886 {
1887         struct drm_dp_sideband_msg_reply_body reply;
1888
1889         reply.reply_type = 0;
1890         reply.req_type = req_type;
1891         drm_dp_encode_sideband_reply(&reply, msg);
1892         return 0;
1893 }
1894
1895 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1896                                     struct drm_dp_mst_branch *mstb,
1897                                     int req_type, int seqno, bool broadcast)
1898 {
1899         struct drm_dp_sideband_msg_tx *txmsg;
1900
1901         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1902         if (!txmsg)
1903                 return -ENOMEM;
1904
1905         txmsg->dst = mstb;
1906         txmsg->seqno = seqno;
1907         drm_dp_encode_up_ack_reply(txmsg, req_type);
1908
1909         mutex_lock(&mgr->qlock);
1910         list_add_tail(&txmsg->next, &mgr->tx_msg_upq);
1911         if (!mgr->tx_up_in_progress) {
1912                 process_single_up_tx_qlock(mgr);
1913         }
1914         mutex_unlock(&mgr->qlock);
1915         return 0;
1916 }
1917
1918 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1919                                      int dp_link_count,
1920                                      int *out)
1921 {
1922         switch (dp_link_bw) {
1923         default:
1924                 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1925                               dp_link_bw, dp_link_count);
1926                 return false;
1927
1928         case DP_LINK_BW_1_62:
1929                 *out = 3 * dp_link_count;
1930                 break;
1931         case DP_LINK_BW_2_7:
1932                 *out = 5 * dp_link_count;
1933                 break;
1934         case DP_LINK_BW_5_4:
1935                 *out = 10 * dp_link_count;
1936                 break;
1937         }
1938         return true;
1939 }
1940
1941 /**
1942  * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
1943  * @mgr: manager to set state for
1944  * @mst_state: true to enable MST on this connector - false to disable.
1945  *
1946  * This is called by the driver when it detects an MST capable device plugged
1947  * into a DP MST capable port, or when a DP MST capable device is unplugged.
1948  */
1949 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
1950 {
1951         int ret = 0;
1952         struct drm_dp_mst_branch *mstb = NULL;
1953
1954         mutex_lock(&mgr->lock);
1955         if (mst_state == mgr->mst_state)
1956                 goto out_unlock;
1957
1958         mgr->mst_state = mst_state;
1959         /* set the device into MST mode */
1960         if (mst_state) {
1961                 WARN_ON(mgr->mst_primary);
1962
1963                 /* get dpcd info */
1964                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
1965                 if (ret != DP_RECEIVER_CAP_SIZE) {
1966                         DRM_DEBUG_KMS("failed to read DPCD\n");
1967                         goto out_unlock;
1968                 }
1969
1970                 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
1971                                               mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
1972                                               &mgr->pbn_div)) {
1973                         ret = -EINVAL;
1974                         goto out_unlock;
1975                 }
1976
1977                 mgr->total_pbn = 2560;
1978                 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
1979                 mgr->avail_slots = mgr->total_slots;
1980
1981                 /* add initial branch device at LCT 1 */
1982                 mstb = drm_dp_add_mst_branch_device(1, NULL);
1983                 if (mstb == NULL) {
1984                         ret = -ENOMEM;
1985                         goto out_unlock;
1986                 }
1987                 mstb->mgr = mgr;
1988
1989                 /* give this the main reference */
1990                 mgr->mst_primary = mstb;
1991                 kref_get(&mgr->mst_primary->kref);
1992
1993                 {
1994                         struct drm_dp_payload reset_pay;
1995                         reset_pay.start_slot = 0;
1996                         reset_pay.num_slots = 0x3f;
1997                         drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
1998                 }
1999
2000                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2001                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2002                 if (ret < 0) {
2003                         goto out_unlock;
2004                 }
2005
2006
2007                 /* sort out guid */
2008                 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
2009                 if (ret != 16) {
2010                         DRM_DEBUG_KMS("failed to read DP GUID %d\n", ret);
2011                         goto out_unlock;
2012                 }
2013
2014                 mgr->guid_valid = drm_dp_validate_guid(mgr, mgr->guid);
2015                 if (!mgr->guid_valid) {
2016                         ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, mgr->guid, 16);
2017                         mgr->guid_valid = true;
2018                 }
2019
2020                 queue_work(system_long_wq, &mgr->work);
2021
2022                 ret = 0;
2023         } else {
2024                 /* disable MST on the device */
2025                 mstb = mgr->mst_primary;
2026                 mgr->mst_primary = NULL;
2027                 /* this can fail if the device is gone */
2028                 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2029                 ret = 0;
2030                 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2031                 mgr->payload_mask = 0;
2032                 set_bit(0, &mgr->payload_mask);
2033                 mgr->vcpi_mask = 0;
2034         }
2035
2036 out_unlock:
2037         mutex_unlock(&mgr->lock);
2038         if (mstb)
2039                 drm_dp_put_mst_branch_device(mstb);
2040         return ret;
2041
2042 }
2043 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2044
2045 /**
2046  * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2047  * @mgr: manager to suspend
2048  *
2049  * This function tells the MST device that we can't handle UP messages
2050  * anymore. This should stop it from sending any since we are suspended.
2051  */
2052 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2053 {
2054         mutex_lock(&mgr->lock);
2055         drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2056                            DP_MST_EN | DP_UPSTREAM_IS_SRC);
2057         mutex_unlock(&mgr->lock);
2058         flush_work(&mgr->work);
2059         flush_work(&mgr->destroy_connector_work);
2060 }
2061 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2062
2063 /**
2064  * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2065  * @mgr: manager to resume
2066  *
2067  * This will fetch DPCD and see if the device is still there,
2068  * if it is, it will rewrite the MSTM control bits, and return.
2069  *
2070  * if the device fails this returns -1, and the driver should do
2071  * a full MST reprobe, in case we were undocked.
2072  */
2073 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2074 {
2075         int ret = 0;
2076
2077         mutex_lock(&mgr->lock);
2078
2079         if (mgr->mst_primary) {
2080                 int sret;
2081                 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2082                 if (sret != DP_RECEIVER_CAP_SIZE) {
2083                         DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2084                         ret = -1;
2085                         goto out_unlock;
2086                 }
2087
2088                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2089                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2090                 if (ret < 0) {
2091                         DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2092                         ret = -1;
2093                         goto out_unlock;
2094                 }
2095                 ret = 0;
2096         } else
2097                 ret = -1;
2098
2099 out_unlock:
2100         mutex_unlock(&mgr->lock);
2101         return ret;
2102 }
2103 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2104
2105 static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2106 {
2107         int len;
2108         u8 replyblock[32];
2109         int replylen, origlen, curreply;
2110         int ret;
2111         struct drm_dp_sideband_msg_rx *msg;
2112         int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2113         msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2114
2115         len = min(mgr->max_dpcd_transaction_bytes, 16);
2116         ret = drm_dp_dpcd_read(mgr->aux, basereg,
2117                                replyblock, len);
2118         if (ret != len) {
2119                 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2120                 return;
2121         }
2122         ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2123         if (!ret) {
2124                 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2125                 return;
2126         }
2127         replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2128
2129         origlen = replylen;
2130         replylen -= len;
2131         curreply = len;
2132         while (replylen > 0) {
2133                 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2134                 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2135                                     replyblock, len);
2136                 if (ret != len) {
2137                         DRM_DEBUG_KMS("failed to read a chunk\n");
2138                 }
2139                 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2140                 if (ret == false)
2141                         DRM_DEBUG_KMS("failed to build sideband msg\n");
2142                 curreply += len;
2143                 replylen -= len;
2144         }
2145 }
2146
2147 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2148 {
2149         int ret = 0;
2150
2151         drm_dp_get_one_sb_msg(mgr, false);
2152
2153         if (mgr->down_rep_recv.have_eomt) {
2154                 struct drm_dp_sideband_msg_tx *txmsg;
2155                 struct drm_dp_mst_branch *mstb;
2156                 int slot = -1;
2157                 mstb = drm_dp_get_mst_branch_device(mgr,
2158                                                     mgr->down_rep_recv.initial_hdr.lct,
2159                                                     mgr->down_rep_recv.initial_hdr.rad);
2160
2161                 if (!mstb) {
2162                         DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2163                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2164                         return 0;
2165                 }
2166
2167                 /* find the message */
2168                 slot = mgr->down_rep_recv.initial_hdr.seqno;
2169                 mutex_lock(&mgr->qlock);
2170                 txmsg = mstb->tx_slots[slot];
2171                 /* remove from slots */
2172                 mutex_unlock(&mgr->qlock);
2173
2174                 if (!txmsg) {
2175                         DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2176                                mstb,
2177                                mgr->down_rep_recv.initial_hdr.seqno,
2178                                mgr->down_rep_recv.initial_hdr.lct,
2179                                       mgr->down_rep_recv.initial_hdr.rad[0],
2180                                       mgr->down_rep_recv.msg[0]);
2181                         drm_dp_put_mst_branch_device(mstb);
2182                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2183                         return 0;
2184                 }
2185
2186                 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2187                 if (txmsg->reply.reply_type == 1) {
2188                         DRM_DEBUG_KMS("Got NAK reply: req 0x%02x, reason 0x%02x, nak data 0x%02x\n", txmsg->reply.req_type, txmsg->reply.u.nak.reason, txmsg->reply.u.nak.nak_data);
2189                 }
2190
2191                 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2192                 drm_dp_put_mst_branch_device(mstb);
2193
2194                 mutex_lock(&mgr->qlock);
2195                 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2196                 mstb->tx_slots[slot] = NULL;
2197                 mutex_unlock(&mgr->qlock);
2198
2199                 wake_up(&mgr->tx_waitq);
2200         }
2201         return ret;
2202 }
2203
2204 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2205 {
2206         int ret = 0;
2207         drm_dp_get_one_sb_msg(mgr, true);
2208
2209         if (mgr->up_req_recv.have_eomt) {
2210                 struct drm_dp_sideband_msg_req_body msg;
2211                 struct drm_dp_mst_branch *mstb = NULL;
2212                 bool seqno;
2213
2214                 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2215                         mstb = drm_dp_get_mst_branch_device(mgr,
2216                                                             mgr->up_req_recv.initial_hdr.lct,
2217                                                             mgr->up_req_recv.initial_hdr.rad);
2218                         if (!mstb) {
2219                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2220                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2221                                 return 0;
2222                         }
2223                 }
2224
2225                 seqno = mgr->up_req_recv.initial_hdr.seqno;
2226                 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2227
2228                 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2229                         drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2230
2231                         if (!mstb)
2232                                 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2233
2234                         if (!mstb) {
2235                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2236                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2237                                 return 0;
2238                         }
2239
2240                         drm_dp_update_port(mstb, &msg.u.conn_stat);
2241                         DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", msg.u.conn_stat.port_number, msg.u.conn_stat.legacy_device_plug_status, msg.u.conn_stat.displayport_device_plug_status, msg.u.conn_stat.message_capability_status, msg.u.conn_stat.input_port, msg.u.conn_stat.peer_device_type);
2242                         (*mgr->cbs->hotplug)(mgr);
2243
2244                 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2245                         drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2246                         if (!mstb)
2247                                 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2248
2249                         if (!mstb) {
2250                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2251                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2252                                 return 0;
2253                         }
2254
2255                         DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2256                 }
2257
2258                 drm_dp_put_mst_branch_device(mstb);
2259                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2260         }
2261         return ret;
2262 }
2263
2264 /**
2265  * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2266  * @mgr: manager to notify irq for.
2267  * @esi: 4 bytes from SINK_COUNT_ESI
2268  * @handled: whether the hpd interrupt was consumed or not
2269  *
2270  * This should be called from the driver when it detects a short IRQ,
2271  * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2272  * topology manager will process the sideband messages received as a result
2273  * of this.
2274  */
2275 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2276 {
2277         int ret = 0;
2278         int sc;
2279         *handled = false;
2280         sc = esi[0] & 0x3f;
2281
2282         if (sc != mgr->sink_count) {
2283                 mgr->sink_count = sc;
2284                 *handled = true;
2285         }
2286
2287         if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2288                 ret = drm_dp_mst_handle_down_rep(mgr);
2289                 *handled = true;
2290         }
2291
2292         if (esi[1] & DP_UP_REQ_MSG_RDY) {
2293                 ret |= drm_dp_mst_handle_up_req(mgr);
2294                 *handled = true;
2295         }
2296
2297         drm_dp_mst_kick_tx(mgr);
2298         return ret;
2299 }
2300 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2301
2302 /**
2303  * drm_dp_mst_detect_port() - get connection status for an MST port
2304  * @mgr: manager for this port
2305  * @port: unverified pointer to a port
2306  *
2307  * This returns the current connection state for a port. It validates the
2308  * port pointer still exists so the caller doesn't require a reference
2309  */
2310 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2311                                                  struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2312 {
2313         enum drm_connector_status status = connector_status_disconnected;
2314
2315         /* we need to search for the port in the mgr in case its gone */
2316         port = drm_dp_get_validated_port_ref(mgr, port);
2317         if (!port)
2318                 return connector_status_disconnected;
2319
2320         if (!port->ddps)
2321                 goto out;
2322
2323         switch (port->pdt) {
2324         case DP_PEER_DEVICE_NONE:
2325         case DP_PEER_DEVICE_MST_BRANCHING:
2326                 break;
2327
2328         case DP_PEER_DEVICE_SST_SINK:
2329                 status = connector_status_connected;
2330                 /* for logical ports - cache the EDID */
2331                 if (port->port_num >= 8 && !port->cached_edid) {
2332                         port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2333                 }
2334                 break;
2335         case DP_PEER_DEVICE_DP_LEGACY_CONV:
2336                 if (port->ldps)
2337                         status = connector_status_connected;
2338                 break;
2339         }
2340 out:
2341         drm_dp_put_port(port);
2342         return status;
2343 }
2344 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2345
2346 /**
2347  * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
2348  * @mgr: manager for this port
2349  * @port: unverified pointer to a port.
2350  *
2351  * This returns whether the port supports audio or not.
2352  */
2353 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
2354                                         struct drm_dp_mst_port *port)
2355 {
2356         bool ret = false;
2357
2358         port = drm_dp_get_validated_port_ref(mgr, port);
2359         if (!port)
2360                 return ret;
2361         ret = port->has_audio;
2362         drm_dp_put_port(port);
2363         return ret;
2364 }
2365 EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
2366
2367 /**
2368  * drm_dp_mst_get_edid() - get EDID for an MST port
2369  * @connector: toplevel connector to get EDID for
2370  * @mgr: manager for this port
2371  * @port: unverified pointer to a port.
2372  *
2373  * This returns an EDID for the port connected to a connector,
2374  * It validates the pointer still exists so the caller doesn't require a
2375  * reference.
2376  */
2377 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2378 {
2379         struct edid *edid = NULL;
2380
2381         /* we need to search for the port in the mgr in case its gone */
2382         port = drm_dp_get_validated_port_ref(mgr, port);
2383         if (!port)
2384                 return NULL;
2385
2386         if (port->cached_edid)
2387                 edid = drm_edid_duplicate(port->cached_edid);
2388         else {
2389                 edid = drm_get_edid(connector, &port->aux.ddc);
2390                 drm_mode_connector_set_tile_property(connector);
2391         }
2392         port->has_audio = drm_detect_monitor_audio(edid);
2393         drm_dp_put_port(port);
2394         return edid;
2395 }
2396 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2397
2398 /**
2399  * drm_dp_find_vcpi_slots() - find slots for this PBN value
2400  * @mgr: manager to use
2401  * @pbn: payload bandwidth to convert into slots.
2402  */
2403 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2404                            int pbn)
2405 {
2406         int num_slots;
2407
2408         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2409
2410         if (num_slots > mgr->avail_slots)
2411                 return -ENOSPC;
2412         return num_slots;
2413 }
2414 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2415
2416 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2417                             struct drm_dp_vcpi *vcpi, int pbn)
2418 {
2419         int num_slots;
2420         int ret;
2421
2422         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2423
2424         if (num_slots > mgr->avail_slots)
2425                 return -ENOSPC;
2426
2427         vcpi->pbn = pbn;
2428         vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2429         vcpi->num_slots = num_slots;
2430
2431         ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2432         if (ret < 0)
2433                 return ret;
2434         return 0;
2435 }
2436
2437 /**
2438  * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2439  * @mgr: manager for this port
2440  * @port: port to allocate a virtual channel for.
2441  * @pbn: payload bandwidth number to request
2442  * @slots: returned number of slots for this PBN.
2443  */
2444 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2445 {
2446         int ret;
2447
2448         port = drm_dp_get_validated_port_ref(mgr, port);
2449         if (!port)
2450                 return false;
2451
2452         if (port->vcpi.vcpi > 0) {
2453                 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2454                 if (pbn == port->vcpi.pbn) {
2455                         *slots = port->vcpi.num_slots;
2456                         return true;
2457                 }
2458         }
2459
2460         ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2461         if (ret) {
2462                 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2463                 goto out;
2464         }
2465         DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2466         *slots = port->vcpi.num_slots;
2467
2468         drm_dp_put_port(port);
2469         return true;
2470 out:
2471         return false;
2472 }
2473 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2474
2475 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2476 {
2477         int slots = 0;
2478         port = drm_dp_get_validated_port_ref(mgr, port);
2479         if (!port)
2480                 return slots;
2481
2482         slots = port->vcpi.num_slots;
2483         drm_dp_put_port(port);
2484         return slots;
2485 }
2486 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2487
2488 /**
2489  * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2490  * @mgr: manager for this port
2491  * @port: unverified pointer to a port.
2492  *
2493  * This just resets the number of slots for the ports VCPI for later programming.
2494  */
2495 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2496 {
2497         port = drm_dp_get_validated_port_ref(mgr, port);
2498         if (!port)
2499                 return;
2500         port->vcpi.num_slots = 0;
2501         drm_dp_put_port(port);
2502 }
2503 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2504
2505 /**
2506  * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2507  * @mgr: manager for this port
2508  * @port: unverified port to deallocate vcpi for
2509  */
2510 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2511 {
2512         port = drm_dp_get_validated_port_ref(mgr, port);
2513         if (!port)
2514                 return;
2515
2516         drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2517         port->vcpi.num_slots = 0;
2518         port->vcpi.pbn = 0;
2519         port->vcpi.aligned_pbn = 0;
2520         port->vcpi.vcpi = 0;
2521         drm_dp_put_port(port);
2522 }
2523 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2524
2525 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2526                                      int id, struct drm_dp_payload *payload)
2527 {
2528         u8 payload_alloc[3], status;
2529         int ret;
2530         int retries = 0;
2531
2532         drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2533                            DP_PAYLOAD_TABLE_UPDATED);
2534
2535         payload_alloc[0] = id;
2536         payload_alloc[1] = payload->start_slot;
2537         payload_alloc[2] = payload->num_slots;
2538
2539         ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2540         if (ret != 3) {
2541                 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2542                 goto fail;
2543         }
2544
2545 retry:
2546         ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2547         if (ret < 0) {
2548                 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2549                 goto fail;
2550         }
2551
2552         if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2553                 retries++;
2554                 if (retries < 20) {
2555                         usleep_range(10000, 20000);
2556                         goto retry;
2557                 }
2558                 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2559                 ret = -EINVAL;
2560                 goto fail;
2561         }
2562         ret = 0;
2563 fail:
2564         return ret;
2565 }
2566
2567
2568 /**
2569  * drm_dp_check_act_status() - Check ACT handled status.
2570  * @mgr: manager to use
2571  *
2572  * Check the payload status bits in the DPCD for ACT handled completion.
2573  */
2574 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2575 {
2576         u8 status;
2577         int ret;
2578         int count = 0;
2579
2580         do {
2581                 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2582
2583                 if (ret < 0) {
2584                         DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2585                         goto fail;
2586                 }
2587
2588                 if (status & DP_PAYLOAD_ACT_HANDLED)
2589                         break;
2590                 count++;
2591                 udelay(100);
2592
2593         } while (count < 30);
2594
2595         if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2596                 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2597                 ret = -EINVAL;
2598                 goto fail;
2599         }
2600         return 0;
2601 fail:
2602         return ret;
2603 }
2604 EXPORT_SYMBOL(drm_dp_check_act_status);
2605
2606 /**
2607  * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2608  * @clock: dot clock for the mode
2609  * @bpp: bpp for the mode.
2610  *
2611  * This uses the formula in the spec to calculate the PBN value for a mode.
2612  */
2613 int drm_dp_calc_pbn_mode(int clock, int bpp)
2614 {
2615         fixed20_12 pix_bw;
2616         fixed20_12 fbpp;
2617         fixed20_12 result;
2618         fixed20_12 margin, tmp;
2619         u32 res;
2620
2621         pix_bw.full = dfixed_const(clock);
2622         fbpp.full = dfixed_const(bpp);
2623         tmp.full = dfixed_const(8);
2624         fbpp.full = dfixed_div(fbpp, tmp);
2625
2626         result.full = dfixed_mul(pix_bw, fbpp);
2627         margin.full = dfixed_const(54);
2628         tmp.full = dfixed_const(64);
2629         margin.full = dfixed_div(margin, tmp);
2630         result.full = dfixed_div(result, margin);
2631
2632         margin.full = dfixed_const(1006);
2633         tmp.full = dfixed_const(1000);
2634         margin.full = dfixed_div(margin, tmp);
2635         result.full = dfixed_mul(result, margin);
2636
2637         result.full = dfixed_div(result, tmp);
2638         result.full = dfixed_ceil(result);
2639         res = dfixed_trunc(result);
2640         return res;
2641 }
2642 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2643
2644 static int test_calc_pbn_mode(void)
2645 {
2646         int ret;
2647         ret = drm_dp_calc_pbn_mode(154000, 30);
2648         if (ret != 689)
2649                 return -EINVAL;
2650         ret = drm_dp_calc_pbn_mode(234000, 30);
2651         if (ret != 1047)
2652                 return -EINVAL;
2653         return 0;
2654 }
2655
2656 /* we want to kick the TX after we've ack the up/down IRQs. */
2657 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2658 {
2659         queue_work(system_long_wq, &mgr->tx_work);
2660 }
2661
2662 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2663                                  struct drm_dp_mst_branch *mstb)
2664 {
2665         struct drm_dp_mst_port *port;
2666         int tabs = mstb->lct;
2667         char prefix[10];
2668         int i;
2669
2670         for (i = 0; i < tabs; i++)
2671                 prefix[i] = '\t';
2672         prefix[i] = '\0';
2673
2674         seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2675         list_for_each_entry(port, &mstb->ports, next) {
2676                 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
2677                 if (port->mstb)
2678                         drm_dp_mst_dump_mstb(m, port->mstb);
2679         }
2680 }
2681
2682 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2683                                   char *buf)
2684 {
2685         int ret;
2686         int i;
2687         for (i = 0; i < 4; i++) {
2688                 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2689                 if (ret != 16)
2690                         break;
2691         }
2692         if (i == 4)
2693                 return true;
2694         return false;
2695 }
2696
2697 /**
2698  * drm_dp_mst_dump_topology(): dump topology to seq file.
2699  * @m: seq_file to dump output to
2700  * @mgr: manager to dump current topology for.
2701  *
2702  * helper to dump MST topology to a seq file for debugfs.
2703  */
2704 void drm_dp_mst_dump_topology(struct seq_file *m,
2705                               struct drm_dp_mst_topology_mgr *mgr)
2706 {
2707         int i;
2708         struct drm_dp_mst_port *port;
2709         mutex_lock(&mgr->lock);
2710         if (mgr->mst_primary)
2711                 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2712
2713         /* dump VCPIs */
2714         mutex_unlock(&mgr->lock);
2715
2716         mutex_lock(&mgr->payload_lock);
2717         seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
2718
2719         for (i = 0; i < mgr->max_payloads; i++) {
2720                 if (mgr->proposed_vcpis[i]) {
2721                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2722                         seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2723                 } else
2724                         seq_printf(m, "vcpi %d:unsed\n", i);
2725         }
2726         for (i = 0; i < mgr->max_payloads; i++) {
2727                 seq_printf(m, "payload %d: %d, %d, %d\n",
2728                            i,
2729                            mgr->payloads[i].payload_state,
2730                            mgr->payloads[i].start_slot,
2731                            mgr->payloads[i].num_slots);
2732
2733
2734         }
2735         mutex_unlock(&mgr->payload_lock);
2736
2737         mutex_lock(&mgr->lock);
2738         if (mgr->mst_primary) {
2739                 u8 buf[64];
2740                 bool bret;
2741                 int ret;
2742                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2743                 seq_printf(m, "dpcd: ");
2744                 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2745                         seq_printf(m, "%02x ", buf[i]);
2746                 seq_printf(m, "\n");
2747                 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2748                 seq_printf(m, "faux/mst: ");
2749                 for (i = 0; i < 2; i++)
2750                         seq_printf(m, "%02x ", buf[i]);
2751                 seq_printf(m, "\n");
2752                 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2753                 seq_printf(m, "mst ctrl: ");
2754                 for (i = 0; i < 1; i++)
2755                         seq_printf(m, "%02x ", buf[i]);
2756                 seq_printf(m, "\n");
2757
2758                 /* dump the standard OUI branch header */
2759                 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
2760                 seq_printf(m, "branch oui: ");
2761                 for (i = 0; i < 0x3; i++)
2762                         seq_printf(m, "%02x", buf[i]);
2763                 seq_printf(m, " devid: ");
2764                 for (i = 0x3; i < 0x8; i++)
2765                         seq_printf(m, "%c", buf[i]);
2766                 seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
2767                 seq_printf(m, "\n");
2768                 bret = dump_dp_payload_table(mgr, buf);
2769                 if (bret == true) {
2770                         seq_printf(m, "payload table: ");
2771                         for (i = 0; i < 63; i++)
2772                                 seq_printf(m, "%02x ", buf[i]);
2773                         seq_printf(m, "\n");
2774                 }
2775
2776         }
2777
2778         mutex_unlock(&mgr->lock);
2779
2780 }
2781 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2782
2783 static void drm_dp_tx_work(struct work_struct *work)
2784 {
2785         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2786
2787         mutex_lock(&mgr->qlock);
2788         if (mgr->tx_down_in_progress)
2789                 process_single_down_tx_qlock(mgr);
2790         mutex_unlock(&mgr->qlock);
2791 }
2792
2793 static void drm_dp_destroy_connector_work(struct work_struct *work)
2794 {
2795         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
2796         struct drm_dp_mst_port *port;
2797         bool send_hotplug = false;
2798         /*
2799          * Not a regular list traverse as we have to drop the destroy
2800          * connector lock before destroying the connector, to avoid AB->BA
2801          * ordering between this lock and the config mutex.
2802          */
2803         for (;;) {
2804                 mutex_lock(&mgr->destroy_connector_lock);
2805                 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
2806                 if (!port) {
2807                         mutex_unlock(&mgr->destroy_connector_lock);
2808                         break;
2809                 }
2810                 list_del(&port->next);
2811                 mutex_unlock(&mgr->destroy_connector_lock);
2812
2813                 mgr->cbs->destroy_connector(mgr, port->connector);
2814
2815                 drm_dp_port_teardown_pdt(port, port->pdt);
2816
2817                 if (!port->input && port->vcpi.vcpi > 0)
2818                         drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2819                 kfree(port);
2820                 send_hotplug = true;
2821         }
2822         if (send_hotplug)
2823                 (*mgr->cbs->hotplug)(mgr);
2824 }
2825
2826 /**
2827  * drm_dp_mst_topology_mgr_init - initialise a topology manager
2828  * @mgr: manager struct to initialise
2829  * @dev: device providing this structure - for i2c addition.
2830  * @aux: DP helper aux channel to talk to this device
2831  * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2832  * @max_payloads: maximum number of payloads this GPU can source
2833  * @conn_base_id: the connector object ID the MST device is connected to.
2834  *
2835  * Return 0 for success, or negative error code on failure
2836  */
2837 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2838                                  struct device *dev, struct drm_dp_aux *aux,
2839                                  int max_dpcd_transaction_bytes,
2840                                  int max_payloads, int conn_base_id)
2841 {
2842         mutex_init(&mgr->lock);
2843         mutex_init(&mgr->qlock);
2844         mutex_init(&mgr->payload_lock);
2845         mutex_init(&mgr->destroy_connector_lock);
2846         INIT_LIST_HEAD(&mgr->tx_msg_upq);
2847         INIT_LIST_HEAD(&mgr->tx_msg_downq);
2848         INIT_LIST_HEAD(&mgr->destroy_connector_list);
2849         INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2850         INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2851         INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
2852         init_waitqueue_head(&mgr->tx_waitq);
2853         mgr->dev = dev;
2854         mgr->aux = aux;
2855         mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2856         mgr->max_payloads = max_payloads;
2857         mgr->conn_base_id = conn_base_id;
2858         mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2859         if (!mgr->payloads)
2860                 return -ENOMEM;
2861         mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2862         if (!mgr->proposed_vcpis)
2863                 return -ENOMEM;
2864         set_bit(0, &mgr->payload_mask);
2865         test_calc_pbn_mode();
2866         return 0;
2867 }
2868 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2869
2870 /**
2871  * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2872  * @mgr: manager to destroy
2873  */
2874 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2875 {
2876         flush_work(&mgr->work);
2877         flush_work(&mgr->destroy_connector_work);
2878         mutex_lock(&mgr->payload_lock);
2879         kfree(mgr->payloads);
2880         mgr->payloads = NULL;
2881         kfree(mgr->proposed_vcpis);
2882         mgr->proposed_vcpis = NULL;
2883         mutex_unlock(&mgr->payload_lock);
2884         mgr->dev = NULL;
2885         mgr->aux = NULL;
2886 }
2887 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
2888
2889 /* I2C device */
2890 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
2891                                int num)
2892 {
2893         struct drm_dp_aux *aux = adapter->algo_data;
2894         struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
2895         struct drm_dp_mst_branch *mstb;
2896         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2897         unsigned int i;
2898         bool reading = false;
2899         struct drm_dp_sideband_msg_req_body msg;
2900         struct drm_dp_sideband_msg_tx *txmsg = NULL;
2901         int ret;
2902
2903         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2904         if (!mstb)
2905                 return -EREMOTEIO;
2906
2907         /* construct i2c msg */
2908         /* see if last msg is a read */
2909         if (msgs[num - 1].flags & I2C_M_RD)
2910                 reading = true;
2911
2912         if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
2913                 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
2914                 ret = -EIO;
2915                 goto out;
2916         }
2917
2918         memset(&msg, 0, sizeof(msg));
2919         msg.req_type = DP_REMOTE_I2C_READ;
2920         msg.u.i2c_read.num_transactions = num - 1;
2921         msg.u.i2c_read.port_number = port->port_num;
2922         for (i = 0; i < num - 1; i++) {
2923                 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
2924                 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
2925                 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
2926         }
2927         msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
2928         msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
2929
2930         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2931         if (!txmsg) {
2932                 ret = -ENOMEM;
2933                 goto out;
2934         }
2935
2936         txmsg->dst = mstb;
2937         drm_dp_encode_sideband_req(&msg, txmsg);
2938
2939         drm_dp_queue_down_tx(mgr, txmsg);
2940
2941         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2942         if (ret > 0) {
2943
2944                 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
2945                         ret = -EREMOTEIO;
2946                         goto out;
2947                 }
2948                 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
2949                         ret = -EIO;
2950                         goto out;
2951                 }
2952                 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
2953                 ret = num;
2954         }
2955 out:
2956         kfree(txmsg);
2957         drm_dp_put_mst_branch_device(mstb);
2958         return ret;
2959 }
2960
2961 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
2962 {
2963         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
2964                I2C_FUNC_SMBUS_READ_BLOCK_DATA |
2965                I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
2966                I2C_FUNC_10BIT_ADDR;
2967 }
2968
2969 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
2970         .functionality = drm_dp_mst_i2c_functionality,
2971         .master_xfer = drm_dp_mst_i2c_xfer,
2972 };
2973
2974 /**
2975  * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
2976  * @aux: DisplayPort AUX channel
2977  *
2978  * Returns 0 on success or a negative error code on failure.
2979  */
2980 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
2981 {
2982         aux->ddc.algo = &drm_dp_mst_i2c_algo;
2983         aux->ddc.algo_data = aux;
2984         aux->ddc.retries = 3;
2985
2986         aux->ddc.class = I2C_CLASS_DDC;
2987         aux->ddc.owner = THIS_MODULE;
2988         aux->ddc.dev.parent = aux->dev;
2989         aux->ddc.dev.of_node = aux->dev->of_node;
2990
2991         strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
2992                 sizeof(aux->ddc.name));
2993
2994         return i2c_add_adapter(&aux->ddc);
2995 }
2996
2997 /**
2998  * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
2999  * @aux: DisplayPort AUX channel
3000  */
3001 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
3002 {
3003         i2c_del_adapter(&aux->ddc);
3004 }