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 parent_lct = port->parent->lct;
 982         int shift = 4;
 983         int idx = (parent_lct - 1) / 2;
 984         if (parent_lct > 1) {
 985                 memcpy(rad, port->parent->rad, idx + 1);
 986                 shift = (parent_lct % 2) ? 4 : 0;
 987         } else
 988                 rad[0] = 0;
 989
 990         rad[idx] |= port->port_num << shift;
 991         return parent_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) & 0xf;
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) & 0xf;
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                                        struct drm_dp_sideband_msg_tx *txmsg)
1499 {
1500         int ret;
1501
1502         /* construct a chunk from the first msg in the tx_msg queue */
1503         ret = process_single_tx_qlock(mgr, txmsg, true);
1504
1505         if (ret != 1)
1506                 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1507
1508         txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1509 }
1510
1511 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1512                                  struct drm_dp_sideband_msg_tx *txmsg)
1513 {
1514         mutex_lock(&mgr->qlock);
1515         list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1516         if (!mgr->tx_down_in_progress)
1517                 process_single_down_tx_qlock(mgr);
1518         mutex_unlock(&mgr->qlock);
1519 }
1520
1521 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1522                                      struct drm_dp_mst_branch *mstb)
1523 {
1524         int len;
1525         struct drm_dp_sideband_msg_tx *txmsg;
1526         int ret;
1527
1528         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1529         if (!txmsg)
1530                 return;
1531
1532         txmsg->dst = mstb;
1533         len = build_link_address(txmsg);
1534
1535         mstb->link_address_sent = true;
1536         drm_dp_queue_down_tx(mgr, txmsg);
1537
1538         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1539         if (ret > 0) {
1540                 int i;
1541
1542                 if (txmsg->reply.reply_type == 1)
1543                         DRM_DEBUG_KMS("link address nak received\n");
1544                 else {
1545                         DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1546                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1547                                 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,
1548                                        txmsg->reply.u.link_addr.ports[i].input_port,
1549                                        txmsg->reply.u.link_addr.ports[i].peer_device_type,
1550                                        txmsg->reply.u.link_addr.ports[i].port_number,
1551                                        txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1552                                        txmsg->reply.u.link_addr.ports[i].mcs,
1553                                        txmsg->reply.u.link_addr.ports[i].ddps,
1554                                        txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1555                                        txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1556                                        txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1557                         }
1558                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1559                                 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1560                         }
1561                         (*mgr->cbs->hotplug)(mgr);
1562                 }
1563         } else {
1564                 mstb->link_address_sent = false;
1565                 DRM_DEBUG_KMS("link address failed %d\n", ret);
1566         }
1567
1568         kfree(txmsg);
1569 }
1570
1571 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1572                                            struct drm_dp_mst_branch *mstb,
1573                                            struct drm_dp_mst_port *port)
1574 {
1575         int len;
1576         struct drm_dp_sideband_msg_tx *txmsg;
1577         int ret;
1578
1579         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1580         if (!txmsg)
1581                 return -ENOMEM;
1582
1583         txmsg->dst = mstb;
1584         len = build_enum_path_resources(txmsg, port->port_num);
1585
1586         drm_dp_queue_down_tx(mgr, txmsg);
1587
1588         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1589         if (ret > 0) {
1590                 if (txmsg->reply.reply_type == 1)
1591                         DRM_DEBUG_KMS("enum path resources nak received\n");
1592                 else {
1593                         if (port->port_num != txmsg->reply.u.path_resources.port_number)
1594                                 DRM_ERROR("got incorrect port in response\n");
1595                         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,
1596                                txmsg->reply.u.path_resources.avail_payload_bw_number);
1597                         port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1598                 }
1599         }
1600
1601         kfree(txmsg);
1602         return 0;
1603 }
1604
1605 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1606                                    struct drm_dp_mst_port *port,
1607                                    int id,
1608                                    int pbn)
1609 {
1610         struct drm_dp_sideband_msg_tx *txmsg;
1611         struct drm_dp_mst_branch *mstb;
1612         int len, ret;
1613         u8 sinks[DRM_DP_MAX_SDP_STREAMS];
1614         int i;
1615
1616         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1617         if (!mstb)
1618                 return -EINVAL;
1619
1620         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1621         if (!txmsg) {
1622                 ret = -ENOMEM;
1623                 goto fail_put;
1624         }
1625
1626         for (i = 0; i < port->num_sdp_streams; i++)
1627                 sinks[i] = i;
1628
1629         txmsg->dst = mstb;
1630         len = build_allocate_payload(txmsg, port->port_num,
1631                                      id,
1632                                      pbn, port->num_sdp_streams, sinks);
1633
1634         drm_dp_queue_down_tx(mgr, txmsg);
1635
1636         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1637         if (ret > 0) {
1638                 if (txmsg->reply.reply_type == 1) {
1639                         ret = -EINVAL;
1640                 } else
1641                         ret = 0;
1642         }
1643         kfree(txmsg);
1644 fail_put:
1645         drm_dp_put_mst_branch_device(mstb);
1646         return ret;
1647 }
1648
1649 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1650                                        int id,
1651                                        struct drm_dp_payload *payload)
1652 {
1653         int ret;
1654
1655         ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1656         if (ret < 0) {
1657                 payload->payload_state = 0;
1658                 return ret;
1659         }
1660         payload->payload_state = DP_PAYLOAD_LOCAL;
1661         return 0;
1662 }
1663
1664 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1665                                        struct drm_dp_mst_port *port,
1666                                        int id,
1667                                        struct drm_dp_payload *payload)
1668 {
1669         int ret;
1670         ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1671         if (ret < 0)
1672                 return ret;
1673         payload->payload_state = DP_PAYLOAD_REMOTE;
1674         return ret;
1675 }
1676
1677 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1678                                         struct drm_dp_mst_port *port,
1679                                         int id,
1680                                         struct drm_dp_payload *payload)
1681 {
1682         DRM_DEBUG_KMS("\n");
1683         /* its okay for these to fail */
1684         if (port) {
1685                 drm_dp_payload_send_msg(mgr, port, id, 0);
1686         }
1687
1688         drm_dp_dpcd_write_payload(mgr, id, payload);
1689         payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1690         return 0;
1691 }
1692
1693 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1694                                         int id,
1695                                         struct drm_dp_payload *payload)
1696 {
1697         payload->payload_state = 0;
1698         return 0;
1699 }
1700
1701 /**
1702  * drm_dp_update_payload_part1() - Execute payload update part 1
1703  * @mgr: manager to use.
1704  *
1705  * This iterates over all proposed virtual channels, and tries to
1706  * allocate space in the link for them. For 0->slots transitions,
1707  * this step just writes the VCPI to the MST device. For slots->0
1708  * transitions, this writes the updated VCPIs and removes the
1709  * remote VC payloads.
1710  *
1711  * after calling this the driver should generate ACT and payload
1712  * packets.
1713  */
1714 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1715 {
1716         int i, j;
1717         int cur_slots = 1;
1718         struct drm_dp_payload req_payload;
1719         struct drm_dp_mst_port *port;
1720
1721         mutex_lock(&mgr->payload_lock);
1722         for (i = 0; i < mgr->max_payloads; i++) {
1723                 /* solve the current payloads - compare to the hw ones
1724                    - update the hw view */
1725                 req_payload.start_slot = cur_slots;
1726                 if (mgr->proposed_vcpis[i]) {
1727                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1728                         req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1729                         req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi;
1730                 } else {
1731                         port = NULL;
1732                         req_payload.num_slots = 0;
1733                 }
1734
1735                 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1736                         mgr->payloads[i].start_slot = req_payload.start_slot;
1737                 }
1738                 /* work out what is required to happen with this payload */
1739                 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1740
1741                         /* need to push an update for this payload */
1742                         if (req_payload.num_slots) {
1743                                 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1744                                 mgr->payloads[i].num_slots = req_payload.num_slots;
1745                                 mgr->payloads[i].vcpi = req_payload.vcpi;
1746                         } else if (mgr->payloads[i].num_slots) {
1747                                 mgr->payloads[i].num_slots = 0;
1748                                 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
1749                                 req_payload.payload_state = mgr->payloads[i].payload_state;
1750                                 mgr->payloads[i].start_slot = 0;
1751                         }
1752                         mgr->payloads[i].payload_state = req_payload.payload_state;
1753                 }
1754                 cur_slots += req_payload.num_slots;
1755         }
1756
1757         for (i = 0; i < mgr->max_payloads; i++) {
1758                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1759                         DRM_DEBUG_KMS("removing payload %d\n", i);
1760                         for (j = i; j < mgr->max_payloads - 1; j++) {
1761                                 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1762                                 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1763                                 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1764                                         set_bit(j + 1, &mgr->payload_mask);
1765                                 } else {
1766                                         clear_bit(j + 1, &mgr->payload_mask);
1767                                 }
1768                         }
1769                         memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1770                         mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1771                         clear_bit(mgr->max_payloads, &mgr->payload_mask);
1772
1773                 }
1774         }
1775         mutex_unlock(&mgr->payload_lock);
1776
1777         return 0;
1778 }
1779 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1780
1781 /**
1782  * drm_dp_update_payload_part2() - Execute payload update part 2
1783  * @mgr: manager to use.
1784  *
1785  * This iterates over all proposed virtual channels, and tries to
1786  * allocate space in the link for them. For 0->slots transitions,
1787  * this step writes the remote VC payload commands. For slots->0
1788  * this just resets some internal state.
1789  */
1790 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1791 {
1792         struct drm_dp_mst_port *port;
1793         int i;
1794         int ret = 0;
1795         mutex_lock(&mgr->payload_lock);
1796         for (i = 0; i < mgr->max_payloads; i++) {
1797
1798                 if (!mgr->proposed_vcpis[i])
1799                         continue;
1800
1801                 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1802
1803                 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1804                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1805                         ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1806                 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1807                         ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1808                 }
1809                 if (ret) {
1810                         mutex_unlock(&mgr->payload_lock);
1811                         return ret;
1812                 }
1813         }
1814         mutex_unlock(&mgr->payload_lock);
1815         return 0;
1816 }
1817 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1818
1819 #if 0 /* unused as of yet */
1820 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1821                                  struct drm_dp_mst_port *port,
1822                                  int offset, int size)
1823 {
1824         int len;
1825         struct drm_dp_sideband_msg_tx *txmsg;
1826
1827         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1828         if (!txmsg)
1829                 return -ENOMEM;
1830
1831         len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1832         txmsg->dst = port->parent;
1833
1834         drm_dp_queue_down_tx(mgr, txmsg);
1835
1836         return 0;
1837 }
1838 #endif
1839
1840 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1841                                   struct drm_dp_mst_port *port,
1842                                   int offset, int size, u8 *bytes)
1843 {
1844         int len;
1845         int ret;
1846         struct drm_dp_sideband_msg_tx *txmsg;
1847         struct drm_dp_mst_branch *mstb;
1848
1849         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1850         if (!mstb)
1851                 return -EINVAL;
1852
1853         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1854         if (!txmsg) {
1855                 ret = -ENOMEM;
1856                 goto fail_put;
1857         }
1858
1859         len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1860         txmsg->dst = mstb;
1861
1862         drm_dp_queue_down_tx(mgr, txmsg);
1863
1864         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1865         if (ret > 0) {
1866                 if (txmsg->reply.reply_type == 1) {
1867                         ret = -EINVAL;
1868                 } else
1869                         ret = 0;
1870         }
1871         kfree(txmsg);
1872 fail_put:
1873         drm_dp_put_mst_branch_device(mstb);
1874         return ret;
1875 }
1876
1877 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1878 {
1879         struct drm_dp_sideband_msg_reply_body reply;
1880
1881         reply.reply_type = 0;
1882         reply.req_type = req_type;
1883         drm_dp_encode_sideband_reply(&reply, msg);
1884         return 0;
1885 }
1886
1887 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1888                                     struct drm_dp_mst_branch *mstb,
1889                                     int req_type, int seqno, bool broadcast)
1890 {
1891         struct drm_dp_sideband_msg_tx *txmsg;
1892
1893         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1894         if (!txmsg)
1895                 return -ENOMEM;
1896
1897         txmsg->dst = mstb;
1898         txmsg->seqno = seqno;
1899         drm_dp_encode_up_ack_reply(txmsg, req_type);
1900
1901         mutex_lock(&mgr->qlock);
1902
1903         process_single_up_tx_qlock(mgr, txmsg);
1904
1905         mutex_unlock(&mgr->qlock);
1906
1907         kfree(txmsg);
1908         return 0;
1909 }
1910
1911 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1912                                      int dp_link_count,
1913                                      int *out)
1914 {
1915         switch (dp_link_bw) {
1916         default:
1917                 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1918                               dp_link_bw, dp_link_count);
1919                 return false;
1920
1921         case DP_LINK_BW_1_62:
1922                 *out = 3 * dp_link_count;
1923                 break;
1924         case DP_LINK_BW_2_7:
1925                 *out = 5 * dp_link_count;
1926                 break;
1927         case DP_LINK_BW_5_4:
1928                 *out = 10 * dp_link_count;
1929                 break;
1930         }
1931         return true;
1932 }
1933
1934 /**
1935  * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
1936  * @mgr: manager to set state for
1937  * @mst_state: true to enable MST on this connector - false to disable.
1938  *
1939  * This is called by the driver when it detects an MST capable device plugged
1940  * into a DP MST capable port, or when a DP MST capable device is unplugged.
1941  */
1942 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
1943 {
1944         int ret = 0;
1945         struct drm_dp_mst_branch *mstb = NULL;
1946
1947         mutex_lock(&mgr->lock);
1948         if (mst_state == mgr->mst_state)
1949                 goto out_unlock;
1950
1951         mgr->mst_state = mst_state;
1952         /* set the device into MST mode */
1953         if (mst_state) {
1954                 WARN_ON(mgr->mst_primary);
1955
1956                 /* get dpcd info */
1957                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
1958                 if (ret != DP_RECEIVER_CAP_SIZE) {
1959                         DRM_DEBUG_KMS("failed to read DPCD\n");
1960                         goto out_unlock;
1961                 }
1962
1963                 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
1964                                               mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
1965                                               &mgr->pbn_div)) {
1966                         ret = -EINVAL;
1967                         goto out_unlock;
1968                 }
1969
1970                 mgr->total_pbn = 2560;
1971                 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
1972                 mgr->avail_slots = mgr->total_slots;
1973
1974                 /* add initial branch device at LCT 1 */
1975                 mstb = drm_dp_add_mst_branch_device(1, NULL);
1976                 if (mstb == NULL) {
1977                         ret = -ENOMEM;
1978                         goto out_unlock;
1979                 }
1980                 mstb->mgr = mgr;
1981
1982                 /* give this the main reference */
1983                 mgr->mst_primary = mstb;
1984                 kref_get(&mgr->mst_primary->kref);
1985
1986                 {
1987                         struct drm_dp_payload reset_pay;
1988                         reset_pay.start_slot = 0;
1989                         reset_pay.num_slots = 0x3f;
1990                         drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
1991                 }
1992
1993                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1994                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
1995                 if (ret < 0) {
1996                         goto out_unlock;
1997                 }
1998
1999
2000                 /* sort out guid */
2001                 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
2002                 if (ret != 16) {
2003                         DRM_DEBUG_KMS("failed to read DP GUID %d\n", ret);
2004                         goto out_unlock;
2005                 }
2006
2007                 mgr->guid_valid = drm_dp_validate_guid(mgr, mgr->guid);
2008                 if (!mgr->guid_valid) {
2009                         ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, mgr->guid, 16);
2010                         mgr->guid_valid = true;
2011                 }
2012
2013                 queue_work(system_long_wq, &mgr->work);
2014
2015                 ret = 0;
2016         } else {
2017                 /* disable MST on the device */
2018                 mstb = mgr->mst_primary;
2019                 mgr->mst_primary = NULL;
2020                 /* this can fail if the device is gone */
2021                 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2022                 ret = 0;
2023                 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2024                 mgr->payload_mask = 0;
2025                 set_bit(0, &mgr->payload_mask);
2026                 mgr->vcpi_mask = 0;
2027         }
2028
2029 out_unlock:
2030         mutex_unlock(&mgr->lock);
2031         if (mstb)
2032                 drm_dp_put_mst_branch_device(mstb);
2033         return ret;
2034
2035 }
2036 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2037
2038 /**
2039  * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2040  * @mgr: manager to suspend
2041  *
2042  * This function tells the MST device that we can't handle UP messages
2043  * anymore. This should stop it from sending any since we are suspended.
2044  */
2045 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2046 {
2047         mutex_lock(&mgr->lock);
2048         drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2049                            DP_MST_EN | DP_UPSTREAM_IS_SRC);
2050         mutex_unlock(&mgr->lock);
2051         flush_work(&mgr->work);
2052         flush_work(&mgr->destroy_connector_work);
2053 }
2054 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2055
2056 /**
2057  * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2058  * @mgr: manager to resume
2059  *
2060  * This will fetch DPCD and see if the device is still there,
2061  * if it is, it will rewrite the MSTM control bits, and return.
2062  *
2063  * if the device fails this returns -1, and the driver should do
2064  * a full MST reprobe, in case we were undocked.
2065  */
2066 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2067 {
2068         int ret = 0;
2069
2070         mutex_lock(&mgr->lock);
2071
2072         if (mgr->mst_primary) {
2073                 int sret;
2074                 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2075                 if (sret != DP_RECEIVER_CAP_SIZE) {
2076                         DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2077                         ret = -1;
2078                         goto out_unlock;
2079                 }
2080
2081                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2082                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2083                 if (ret < 0) {
2084                         DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2085                         ret = -1;
2086                         goto out_unlock;
2087                 }
2088                 ret = 0;
2089         } else
2090                 ret = -1;
2091
2092 out_unlock:
2093         mutex_unlock(&mgr->lock);
2094         return ret;
2095 }
2096 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2097
2098 static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2099 {
2100         int len;
2101         u8 replyblock[32];
2102         int replylen, origlen, curreply;
2103         int ret;
2104         struct drm_dp_sideband_msg_rx *msg;
2105         int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2106         msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2107
2108         len = min(mgr->max_dpcd_transaction_bytes, 16);
2109         ret = drm_dp_dpcd_read(mgr->aux, basereg,
2110                                replyblock, len);
2111         if (ret != len) {
2112                 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2113                 return;
2114         }
2115         ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2116         if (!ret) {
2117                 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2118                 return;
2119         }
2120         replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2121
2122         origlen = replylen;
2123         replylen -= len;
2124         curreply = len;
2125         while (replylen > 0) {
2126                 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2127                 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2128                                     replyblock, len);
2129                 if (ret != len) {
2130                         DRM_DEBUG_KMS("failed to read a chunk\n");
2131                 }
2132                 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2133                 if (ret == false)
2134                         DRM_DEBUG_KMS("failed to build sideband msg\n");
2135                 curreply += len;
2136                 replylen -= len;
2137         }
2138 }
2139
2140 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2141 {
2142         int ret = 0;
2143
2144         drm_dp_get_one_sb_msg(mgr, false);
2145
2146         if (mgr->down_rep_recv.have_eomt) {
2147                 struct drm_dp_sideband_msg_tx *txmsg;
2148                 struct drm_dp_mst_branch *mstb;
2149                 int slot = -1;
2150                 mstb = drm_dp_get_mst_branch_device(mgr,
2151                                                     mgr->down_rep_recv.initial_hdr.lct,
2152                                                     mgr->down_rep_recv.initial_hdr.rad);
2153
2154                 if (!mstb) {
2155                         DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2156                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2157                         return 0;
2158                 }
2159
2160                 /* find the message */
2161                 slot = mgr->down_rep_recv.initial_hdr.seqno;
2162                 mutex_lock(&mgr->qlock);
2163                 txmsg = mstb->tx_slots[slot];
2164                 /* remove from slots */
2165                 mutex_unlock(&mgr->qlock);
2166
2167                 if (!txmsg) {
2168                         DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2169                                mstb,
2170                                mgr->down_rep_recv.initial_hdr.seqno,
2171                                mgr->down_rep_recv.initial_hdr.lct,
2172                                       mgr->down_rep_recv.initial_hdr.rad[0],
2173                                       mgr->down_rep_recv.msg[0]);
2174                         drm_dp_put_mst_branch_device(mstb);
2175                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2176                         return 0;
2177                 }
2178
2179                 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2180                 if (txmsg->reply.reply_type == 1) {
2181                         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);
2182                 }
2183
2184                 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2185                 drm_dp_put_mst_branch_device(mstb);
2186
2187                 mutex_lock(&mgr->qlock);
2188                 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2189                 mstb->tx_slots[slot] = NULL;
2190                 mutex_unlock(&mgr->qlock);
2191
2192                 wake_up(&mgr->tx_waitq);
2193         }
2194         return ret;
2195 }
2196
2197 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2198 {
2199         int ret = 0;
2200         drm_dp_get_one_sb_msg(mgr, true);
2201
2202         if (mgr->up_req_recv.have_eomt) {
2203                 struct drm_dp_sideband_msg_req_body msg;
2204                 struct drm_dp_mst_branch *mstb = NULL;
2205                 bool seqno;
2206
2207                 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2208                         mstb = drm_dp_get_mst_branch_device(mgr,
2209                                                             mgr->up_req_recv.initial_hdr.lct,
2210                                                             mgr->up_req_recv.initial_hdr.rad);
2211                         if (!mstb) {
2212                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2213                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2214                                 return 0;
2215                         }
2216                 }
2217
2218                 seqno = mgr->up_req_recv.initial_hdr.seqno;
2219                 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2220
2221                 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2222                         drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2223
2224                         if (!mstb)
2225                                 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2226
2227                         if (!mstb) {
2228                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2229                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2230                                 return 0;
2231                         }
2232
2233                         drm_dp_update_port(mstb, &msg.u.conn_stat);
2234                         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);
2235                         (*mgr->cbs->hotplug)(mgr);
2236
2237                 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2238                         drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2239                         if (!mstb)
2240                                 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2241
2242                         if (!mstb) {
2243                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2244                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2245                                 return 0;
2246                         }
2247
2248                         DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2249                 }
2250
2251                 drm_dp_put_mst_branch_device(mstb);
2252                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2253         }
2254         return ret;
2255 }
2256
2257 /**
2258  * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2259  * @mgr: manager to notify irq for.
2260  * @esi: 4 bytes from SINK_COUNT_ESI
2261  * @handled: whether the hpd interrupt was consumed or not
2262  *
2263  * This should be called from the driver when it detects a short IRQ,
2264  * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2265  * topology manager will process the sideband messages received as a result
2266  * of this.
2267  */
2268 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2269 {
2270         int ret = 0;
2271         int sc;
2272         *handled = false;
2273         sc = esi[0] & 0x3f;
2274
2275         if (sc != mgr->sink_count) {
2276                 mgr->sink_count = sc;
2277                 *handled = true;
2278         }
2279
2280         if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2281                 ret = drm_dp_mst_handle_down_rep(mgr);
2282                 *handled = true;
2283         }
2284
2285         if (esi[1] & DP_UP_REQ_MSG_RDY) {
2286                 ret |= drm_dp_mst_handle_up_req(mgr);
2287                 *handled = true;
2288         }
2289
2290         drm_dp_mst_kick_tx(mgr);
2291         return ret;
2292 }
2293 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2294
2295 /**
2296  * drm_dp_mst_detect_port() - get connection status for an MST port
2297  * @mgr: manager for this port
2298  * @port: unverified pointer to a port
2299  *
2300  * This returns the current connection state for a port. It validates the
2301  * port pointer still exists so the caller doesn't require a reference
2302  */
2303 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2304                                                  struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2305 {
2306         enum drm_connector_status status = connector_status_disconnected;
2307
2308         /* we need to search for the port in the mgr in case its gone */
2309         port = drm_dp_get_validated_port_ref(mgr, port);
2310         if (!port)
2311                 return connector_status_disconnected;
2312
2313         if (!port->ddps)
2314                 goto out;
2315
2316         switch (port->pdt) {
2317         case DP_PEER_DEVICE_NONE:
2318         case DP_PEER_DEVICE_MST_BRANCHING:
2319                 break;
2320
2321         case DP_PEER_DEVICE_SST_SINK:
2322                 status = connector_status_connected;
2323                 /* for logical ports - cache the EDID */
2324                 if (port->port_num >= 8 && !port->cached_edid) {
2325                         port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2326                 }
2327                 break;
2328         case DP_PEER_DEVICE_DP_LEGACY_CONV:
2329                 if (port->ldps)
2330                         status = connector_status_connected;
2331                 break;
2332         }
2333 out:
2334         drm_dp_put_port(port);
2335         return status;
2336 }
2337 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2338
2339 /**
2340  * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
2341  * @mgr: manager for this port
2342  * @port: unverified pointer to a port.
2343  *
2344  * This returns whether the port supports audio or not.
2345  */
2346 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
2347                                         struct drm_dp_mst_port *port)
2348 {
2349         bool ret = false;
2350
2351         port = drm_dp_get_validated_port_ref(mgr, port);
2352         if (!port)
2353                 return ret;
2354         ret = port->has_audio;
2355         drm_dp_put_port(port);
2356         return ret;
2357 }
2358 EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
2359
2360 /**
2361  * drm_dp_mst_get_edid() - get EDID for an MST port
2362  * @connector: toplevel connector to get EDID for
2363  * @mgr: manager for this port
2364  * @port: unverified pointer to a port.
2365  *
2366  * This returns an EDID for the port connected to a connector,
2367  * It validates the pointer still exists so the caller doesn't require a
2368  * reference.
2369  */
2370 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2371 {
2372         struct edid *edid = NULL;
2373
2374         /* we need to search for the port in the mgr in case its gone */
2375         port = drm_dp_get_validated_port_ref(mgr, port);
2376         if (!port)
2377                 return NULL;
2378
2379         if (port->cached_edid)
2380                 edid = drm_edid_duplicate(port->cached_edid);
2381         else {
2382                 edid = drm_get_edid(connector, &port->aux.ddc);
2383                 drm_mode_connector_set_tile_property(connector);
2384         }
2385         port->has_audio = drm_detect_monitor_audio(edid);
2386         drm_dp_put_port(port);
2387         return edid;
2388 }
2389 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2390
2391 /**
2392  * drm_dp_find_vcpi_slots() - find slots for this PBN value
2393  * @mgr: manager to use
2394  * @pbn: payload bandwidth to convert into slots.
2395  */
2396 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2397                            int pbn)
2398 {
2399         int num_slots;
2400
2401         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2402
2403         if (num_slots > mgr->avail_slots)
2404                 return -ENOSPC;
2405         return num_slots;
2406 }
2407 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2408
2409 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2410                             struct drm_dp_vcpi *vcpi, int pbn)
2411 {
2412         int num_slots;
2413         int ret;
2414
2415         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2416
2417         if (num_slots > mgr->avail_slots)
2418                 return -ENOSPC;
2419
2420         vcpi->pbn = pbn;
2421         vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2422         vcpi->num_slots = num_slots;
2423
2424         ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2425         if (ret < 0)
2426                 return ret;
2427         return 0;
2428 }
2429
2430 /**
2431  * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2432  * @mgr: manager for this port
2433  * @port: port to allocate a virtual channel for.
2434  * @pbn: payload bandwidth number to request
2435  * @slots: returned number of slots for this PBN.
2436  */
2437 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2438 {
2439         int ret;
2440
2441         port = drm_dp_get_validated_port_ref(mgr, port);
2442         if (!port)
2443                 return false;
2444
2445         if (port->vcpi.vcpi > 0) {
2446                 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2447                 if (pbn == port->vcpi.pbn) {
2448                         *slots = port->vcpi.num_slots;
2449                         return true;
2450                 }
2451         }
2452
2453         ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2454         if (ret) {
2455                 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2456                 goto out;
2457         }
2458         DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2459         *slots = port->vcpi.num_slots;
2460
2461         drm_dp_put_port(port);
2462         return true;
2463 out:
2464         return false;
2465 }
2466 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2467
2468 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2469 {
2470         int slots = 0;
2471         port = drm_dp_get_validated_port_ref(mgr, port);
2472         if (!port)
2473                 return slots;
2474
2475         slots = port->vcpi.num_slots;
2476         drm_dp_put_port(port);
2477         return slots;
2478 }
2479 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2480
2481 /**
2482  * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2483  * @mgr: manager for this port
2484  * @port: unverified pointer to a port.
2485  *
2486  * This just resets the number of slots for the ports VCPI for later programming.
2487  */
2488 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2489 {
2490         port = drm_dp_get_validated_port_ref(mgr, port);
2491         if (!port)
2492                 return;
2493         port->vcpi.num_slots = 0;
2494         drm_dp_put_port(port);
2495 }
2496 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2497
2498 /**
2499  * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2500  * @mgr: manager for this port
2501  * @port: unverified port to deallocate vcpi for
2502  */
2503 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2504 {
2505         port = drm_dp_get_validated_port_ref(mgr, port);
2506         if (!port)
2507                 return;
2508
2509         drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2510         port->vcpi.num_slots = 0;
2511         port->vcpi.pbn = 0;
2512         port->vcpi.aligned_pbn = 0;
2513         port->vcpi.vcpi = 0;
2514         drm_dp_put_port(port);
2515 }
2516 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2517
2518 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2519                                      int id, struct drm_dp_payload *payload)
2520 {
2521         u8 payload_alloc[3], status;
2522         int ret;
2523         int retries = 0;
2524
2525         drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2526                            DP_PAYLOAD_TABLE_UPDATED);
2527
2528         payload_alloc[0] = id;
2529         payload_alloc[1] = payload->start_slot;
2530         payload_alloc[2] = payload->num_slots;
2531
2532         ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2533         if (ret != 3) {
2534                 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2535                 goto fail;
2536         }
2537
2538 retry:
2539         ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2540         if (ret < 0) {
2541                 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2542                 goto fail;
2543         }
2544
2545         if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2546                 retries++;
2547                 if (retries < 20) {
2548                         usleep_range(10000, 20000);
2549                         goto retry;
2550                 }
2551                 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2552                 ret = -EINVAL;
2553                 goto fail;
2554         }
2555         ret = 0;
2556 fail:
2557         return ret;
2558 }
2559
2560
2561 /**
2562  * drm_dp_check_act_status() - Check ACT handled status.
2563  * @mgr: manager to use
2564  *
2565  * Check the payload status bits in the DPCD for ACT handled completion.
2566  */
2567 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2568 {
2569         u8 status;
2570         int ret;
2571         int count = 0;
2572
2573         do {
2574                 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2575
2576                 if (ret < 0) {
2577                         DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2578                         goto fail;
2579                 }
2580
2581                 if (status & DP_PAYLOAD_ACT_HANDLED)
2582                         break;
2583                 count++;
2584                 udelay(100);
2585
2586         } while (count < 30);
2587
2588         if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2589                 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2590                 ret = -EINVAL;
2591                 goto fail;
2592         }
2593         return 0;
2594 fail:
2595         return ret;
2596 }
2597 EXPORT_SYMBOL(drm_dp_check_act_status);
2598
2599 /**
2600  * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2601  * @clock: dot clock for the mode
2602  * @bpp: bpp for the mode.
2603  *
2604  * This uses the formula in the spec to calculate the PBN value for a mode.
2605  */
2606 int drm_dp_calc_pbn_mode(int clock, int bpp)
2607 {
2608         fixed20_12 pix_bw;
2609         fixed20_12 fbpp;
2610         fixed20_12 result;
2611         fixed20_12 margin, tmp;
2612         u32 res;
2613
2614         pix_bw.full = dfixed_const(clock);
2615         fbpp.full = dfixed_const(bpp);
2616         tmp.full = dfixed_const(8);
2617         fbpp.full = dfixed_div(fbpp, tmp);
2618
2619         result.full = dfixed_mul(pix_bw, fbpp);
2620         margin.full = dfixed_const(54);
2621         tmp.full = dfixed_const(64);
2622         margin.full = dfixed_div(margin, tmp);
2623         result.full = dfixed_div(result, margin);
2624
2625         margin.full = dfixed_const(1006);
2626         tmp.full = dfixed_const(1000);
2627         margin.full = dfixed_div(margin, tmp);
2628         result.full = dfixed_mul(result, margin);
2629
2630         result.full = dfixed_div(result, tmp);
2631         result.full = dfixed_ceil(result);
2632         res = dfixed_trunc(result);
2633         return res;
2634 }
2635 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2636
2637 static int test_calc_pbn_mode(void)
2638 {
2639         int ret;
2640         ret = drm_dp_calc_pbn_mode(154000, 30);
2641         if (ret != 689)
2642                 return -EINVAL;
2643         ret = drm_dp_calc_pbn_mode(234000, 30);
2644         if (ret != 1047)
2645                 return -EINVAL;
2646         return 0;
2647 }
2648
2649 /* we want to kick the TX after we've ack the up/down IRQs. */
2650 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2651 {
2652         queue_work(system_long_wq, &mgr->tx_work);
2653 }
2654
2655 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2656                                  struct drm_dp_mst_branch *mstb)
2657 {
2658         struct drm_dp_mst_port *port;
2659         int tabs = mstb->lct;
2660         char prefix[10];
2661         int i;
2662
2663         for (i = 0; i < tabs; i++)
2664                 prefix[i] = '\t';
2665         prefix[i] = '\0';
2666
2667         seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2668         list_for_each_entry(port, &mstb->ports, next) {
2669                 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);
2670                 if (port->mstb)
2671                         drm_dp_mst_dump_mstb(m, port->mstb);
2672         }
2673 }
2674
2675 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2676                                   char *buf)
2677 {
2678         int ret;
2679         int i;
2680         for (i = 0; i < 4; i++) {
2681                 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2682                 if (ret != 16)
2683                         break;
2684         }
2685         if (i == 4)
2686                 return true;
2687         return false;
2688 }
2689
2690 /**
2691  * drm_dp_mst_dump_topology(): dump topology to seq file.
2692  * @m: seq_file to dump output to
2693  * @mgr: manager to dump current topology for.
2694  *
2695  * helper to dump MST topology to a seq file for debugfs.
2696  */
2697 void drm_dp_mst_dump_topology(struct seq_file *m,
2698                               struct drm_dp_mst_topology_mgr *mgr)
2699 {
2700         int i;
2701         struct drm_dp_mst_port *port;
2702         mutex_lock(&mgr->lock);
2703         if (mgr->mst_primary)
2704                 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2705
2706         /* dump VCPIs */
2707         mutex_unlock(&mgr->lock);
2708
2709         mutex_lock(&mgr->payload_lock);
2710         seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
2711
2712         for (i = 0; i < mgr->max_payloads; i++) {
2713                 if (mgr->proposed_vcpis[i]) {
2714                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2715                         seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2716                 } else
2717                         seq_printf(m, "vcpi %d:unsed\n", i);
2718         }
2719         for (i = 0; i < mgr->max_payloads; i++) {
2720                 seq_printf(m, "payload %d: %d, %d, %d\n",
2721                            i,
2722                            mgr->payloads[i].payload_state,
2723                            mgr->payloads[i].start_slot,
2724                            mgr->payloads[i].num_slots);
2725
2726
2727         }
2728         mutex_unlock(&mgr->payload_lock);
2729
2730         mutex_lock(&mgr->lock);
2731         if (mgr->mst_primary) {
2732                 u8 buf[64];
2733                 bool bret;
2734                 int ret;
2735                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2736                 seq_printf(m, "dpcd: ");
2737                 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2738                         seq_printf(m, "%02x ", buf[i]);
2739                 seq_printf(m, "\n");
2740                 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2741                 seq_printf(m, "faux/mst: ");
2742                 for (i = 0; i < 2; i++)
2743                         seq_printf(m, "%02x ", buf[i]);
2744                 seq_printf(m, "\n");
2745                 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2746                 seq_printf(m, "mst ctrl: ");
2747                 for (i = 0; i < 1; i++)
2748                         seq_printf(m, "%02x ", buf[i]);
2749                 seq_printf(m, "\n");
2750
2751                 /* dump the standard OUI branch header */
2752                 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
2753                 seq_printf(m, "branch oui: ");
2754                 for (i = 0; i < 0x3; i++)
2755                         seq_printf(m, "%02x", buf[i]);
2756                 seq_printf(m, " devid: ");
2757                 for (i = 0x3; i < 0x8; i++)
2758                         seq_printf(m, "%c", buf[i]);
2759                 seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
2760                 seq_printf(m, "\n");
2761                 bret = dump_dp_payload_table(mgr, buf);
2762                 if (bret == true) {
2763                         seq_printf(m, "payload table: ");
2764                         for (i = 0; i < 63; i++)
2765                                 seq_printf(m, "%02x ", buf[i]);
2766                         seq_printf(m, "\n");
2767                 }
2768
2769         }
2770
2771         mutex_unlock(&mgr->lock);
2772
2773 }
2774 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2775
2776 static void drm_dp_tx_work(struct work_struct *work)
2777 {
2778         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2779
2780         mutex_lock(&mgr->qlock);
2781         if (mgr->tx_down_in_progress)
2782                 process_single_down_tx_qlock(mgr);
2783         mutex_unlock(&mgr->qlock);
2784 }
2785
2786 static void drm_dp_destroy_connector_work(struct work_struct *work)
2787 {
2788         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
2789         struct drm_dp_mst_port *port;
2790         bool send_hotplug = false;
2791         /*
2792          * Not a regular list traverse as we have to drop the destroy
2793          * connector lock before destroying the connector, to avoid AB->BA
2794          * ordering between this lock and the config mutex.
2795          */
2796         for (;;) {
2797                 mutex_lock(&mgr->destroy_connector_lock);
2798                 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
2799                 if (!port) {
2800                         mutex_unlock(&mgr->destroy_connector_lock);
2801                         break;
2802                 }
2803                 list_del(&port->next);
2804                 mutex_unlock(&mgr->destroy_connector_lock);
2805
2806                 mgr->cbs->destroy_connector(mgr, port->connector);
2807
2808                 drm_dp_port_teardown_pdt(port, port->pdt);
2809
2810                 if (!port->input && port->vcpi.vcpi > 0)
2811                         drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2812                 kfree(port);
2813                 send_hotplug = true;
2814         }
2815         if (send_hotplug)
2816                 (*mgr->cbs->hotplug)(mgr);
2817 }
2818
2819 /**
2820  * drm_dp_mst_topology_mgr_init - initialise a topology manager
2821  * @mgr: manager struct to initialise
2822  * @dev: device providing this structure - for i2c addition.
2823  * @aux: DP helper aux channel to talk to this device
2824  * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2825  * @max_payloads: maximum number of payloads this GPU can source
2826  * @conn_base_id: the connector object ID the MST device is connected to.
2827  *
2828  * Return 0 for success, or negative error code on failure
2829  */
2830 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2831                                  struct device *dev, struct drm_dp_aux *aux,
2832                                  int max_dpcd_transaction_bytes,
2833                                  int max_payloads, int conn_base_id)
2834 {
2835         mutex_init(&mgr->lock);
2836         mutex_init(&mgr->qlock);
2837         mutex_init(&mgr->payload_lock);
2838         mutex_init(&mgr->destroy_connector_lock);
2839         INIT_LIST_HEAD(&mgr->tx_msg_downq);
2840         INIT_LIST_HEAD(&mgr->destroy_connector_list);
2841         INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2842         INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2843         INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
2844         init_waitqueue_head(&mgr->tx_waitq);
2845         mgr->dev = dev;
2846         mgr->aux = aux;
2847         mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2848         mgr->max_payloads = max_payloads;
2849         mgr->conn_base_id = conn_base_id;
2850         mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2851         if (!mgr->payloads)
2852                 return -ENOMEM;
2853         mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2854         if (!mgr->proposed_vcpis)
2855                 return -ENOMEM;
2856         set_bit(0, &mgr->payload_mask);
2857         test_calc_pbn_mode();
2858         return 0;
2859 }
2860 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2861
2862 /**
2863  * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2864  * @mgr: manager to destroy
2865  */
2866 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2867 {
2868         flush_work(&mgr->work);
2869         flush_work(&mgr->destroy_connector_work);
2870         mutex_lock(&mgr->payload_lock);
2871         kfree(mgr->payloads);
2872         mgr->payloads = NULL;
2873         kfree(mgr->proposed_vcpis);
2874         mgr->proposed_vcpis = NULL;
2875         mutex_unlock(&mgr->payload_lock);
2876         mgr->dev = NULL;
2877         mgr->aux = NULL;
2878 }
2879 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
2880
2881 /* I2C device */
2882 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
2883                                int num)
2884 {
2885         struct drm_dp_aux *aux = adapter->algo_data;
2886         struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
2887         struct drm_dp_mst_branch *mstb;
2888         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2889         unsigned int i;
2890         bool reading = false;
2891         struct drm_dp_sideband_msg_req_body msg;
2892         struct drm_dp_sideband_msg_tx *txmsg = NULL;
2893         int ret;
2894
2895         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2896         if (!mstb)
2897                 return -EREMOTEIO;
2898
2899         /* construct i2c msg */
2900         /* see if last msg is a read */
2901         if (msgs[num - 1].flags & I2C_M_RD)
2902                 reading = true;
2903
2904         if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
2905                 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
2906                 ret = -EIO;
2907                 goto out;
2908         }
2909
2910         memset(&msg, 0, sizeof(msg));
2911         msg.req_type = DP_REMOTE_I2C_READ;
2912         msg.u.i2c_read.num_transactions = num - 1;
2913         msg.u.i2c_read.port_number = port->port_num;
2914         for (i = 0; i < num - 1; i++) {
2915                 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
2916                 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
2917                 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
2918         }
2919         msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
2920         msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
2921
2922         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2923         if (!txmsg) {
2924                 ret = -ENOMEM;
2925                 goto out;
2926         }
2927
2928         txmsg->dst = mstb;
2929         drm_dp_encode_sideband_req(&msg, txmsg);
2930
2931         drm_dp_queue_down_tx(mgr, txmsg);
2932
2933         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2934         if (ret > 0) {
2935
2936                 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
2937                         ret = -EREMOTEIO;
2938                         goto out;
2939                 }
2940                 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
2941                         ret = -EIO;
2942                         goto out;
2943                 }
2944                 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
2945                 ret = num;
2946         }
2947 out:
2948         kfree(txmsg);
2949         drm_dp_put_mst_branch_device(mstb);
2950         return ret;
2951 }
2952
2953 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
2954 {
2955         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
2956                I2C_FUNC_SMBUS_READ_BLOCK_DATA |
2957                I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
2958                I2C_FUNC_10BIT_ADDR;
2959 }
2960
2961 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
2962         .functionality = drm_dp_mst_i2c_functionality,
2963         .master_xfer = drm_dp_mst_i2c_xfer,
2964 };
2965
2966 /**
2967  * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
2968  * @aux: DisplayPort AUX channel
2969  *
2970  * Returns 0 on success or a negative error code on failure.
2971  */
2972 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
2973 {
2974         aux->ddc.algo = &drm_dp_mst_i2c_algo;
2975         aux->ddc.algo_data = aux;
2976         aux->ddc.retries = 3;
2977
2978         aux->ddc.class = I2C_CLASS_DDC;
2979         aux->ddc.owner = THIS_MODULE;
2980         aux->ddc.dev.parent = aux->dev;
2981         aux->ddc.dev.of_node = aux->dev->of_node;
2982
2983         strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
2984                 sizeof(aux->ddc.name));
2985
2986         return i2c_add_adapter(&aux->ddc);
2987 }
2988
2989 /**
2990  * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
2991  * @aux: DisplayPort AUX channel
2992  */
2993 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
2994 {
2995         i2c_del_adapter(&aux->ddc);
2996 }