kernel/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 {
 671         struct drm_dp_sideband_msg_req_body req;
 672         memset(&req, 0, sizeof(req));
 673         req.req_type = DP_ALLOCATE_PAYLOAD;
 674         req.u.allocate_payload.port_number = port_num;
 675         req.u.allocate_payload.vcpi = vcpi;
 676         req.u.allocate_payload.pbn = pbn;
 677         drm_dp_encode_sideband_req(&req, msg);
 678         msg->path_msg = true;
 679         return 0;
 680 }
 681
 682 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
 683                                         struct drm_dp_vcpi *vcpi)
 684 {
 685         int ret, vcpi_ret;
 686
 687         mutex_lock(&mgr->payload_lock);
 688         ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
 689         if (ret > mgr->max_payloads) {
 690                 ret = -EINVAL;
 691                 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
 692                 goto out_unlock;
 693         }
 694
 695         vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
 696         if (vcpi_ret > mgr->max_payloads) {
 697                 ret = -EINVAL;
 698                 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
 699                 goto out_unlock;
 700         }
 701
 702         set_bit(ret, &mgr->payload_mask);
 703         set_bit(vcpi_ret, &mgr->vcpi_mask);
 704         vcpi->vcpi = vcpi_ret + 1;
 705         mgr->proposed_vcpis[ret - 1] = vcpi;
 706 out_unlock:
 707         mutex_unlock(&mgr->payload_lock);
 708         return ret;
 709 }
 710
 711 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
 712                                       int vcpi)
 713 {
 714         int i;
 715         if (vcpi == 0)
 716                 return;
 717
 718         mutex_lock(&mgr->payload_lock);
 719         DRM_DEBUG_KMS("putting payload %d\n", vcpi);
 720         clear_bit(vcpi - 1, &mgr->vcpi_mask);
 721
 722         for (i = 0; i < mgr->max_payloads; i++) {
 723                 if (mgr->proposed_vcpis[i])
 724                         if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
 725                                 mgr->proposed_vcpis[i] = NULL;
 726                                 clear_bit(i + 1, &mgr->payload_mask);
 727                         }
 728         }
 729         mutex_unlock(&mgr->payload_lock);
 730 }
 731
 732 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
 733                               struct drm_dp_sideband_msg_tx *txmsg)
 734 {
 735         bool ret;
 736
 737         /*
 738          * All updates to txmsg->state are protected by mgr->qlock, and the two
 739          * cases we check here are terminal states. For those the barriers
 740          * provided by the wake_up/wait_event pair are enough.
 741          */
 742         ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
 743                txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
 744         return ret;
 745 }
 746
 747 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
 748                                     struct drm_dp_sideband_msg_tx *txmsg)
 749 {
 750         struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
 751         int ret;
 752
 753         ret = wait_event_timeout(mgr->tx_waitq,
 754                                  check_txmsg_state(mgr, txmsg),
 755                                  (4 * HZ));
 756         mutex_lock(&mstb->mgr->qlock);
 757         if (ret > 0) {
 758                 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
 759                         ret = -EIO;
 760                         goto out;
 761                 }
 762         } else {
 763                 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
 764
 765                 /* dump some state */
 766                 ret = -EIO;
 767
 768                 /* remove from q */
 769                 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
 770                     txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
 771                         list_del(&txmsg->next);
 772                 }
 773
 774                 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
 775                     txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
 776                         mstb->tx_slots[txmsg->seqno] = NULL;
 777                 }
 778         }
 779 out:
 780         mutex_unlock(&mgr->qlock);
 781
 782         return ret;
 783 }
 784
 785 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
 786 {
 787         struct drm_dp_mst_branch *mstb;
 788
 789         mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
 790         if (!mstb)
 791                 return NULL;
 792
 793         mstb->lct = lct;
 794         if (lct > 1)
 795                 memcpy(mstb->rad, rad, lct / 2);
 796         INIT_LIST_HEAD(&mstb->ports);
 797         kref_init(&mstb->kref);
 798         return mstb;
 799 }
 800
 801 static void drm_dp_free_mst_port(struct kref *kref);
 802
 803 static void drm_dp_free_mst_branch_device(struct kref *kref)
 804 {
 805         struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
 806         if (mstb->port_parent) {
 807                 if (list_empty(&mstb->port_parent->next))
 808                         kref_put(&mstb->port_parent->kref, drm_dp_free_mst_port);
 809         }
 810         kfree(mstb);
 811 }
 812
 813 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
 814 {
 815         struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
 816         struct drm_dp_mst_port *port, *tmp;
 817         bool wake_tx = false;
 818
 819         /*
 820          * init kref again to be used by ports to remove mst branch when it is
 821          * not needed anymore
 822          */
 823         kref_init(kref);
 824
 825         if (mstb->port_parent && list_empty(&mstb->port_parent->next))
 826                 kref_get(&mstb->port_parent->kref);
 827
 828         /*
 829          * destroy all ports - don't need lock
 830          * as there are no more references to the mst branch
 831          * device at this point.
 832          */
 833         list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
 834                 list_del(&port->next);
 835                 drm_dp_put_port(port);
 836         }
 837
 838         /* drop any tx slots msg */
 839         mutex_lock(&mstb->mgr->qlock);
 840         if (mstb->tx_slots[0]) {
 841                 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 842                 mstb->tx_slots[0] = NULL;
 843                 wake_tx = true;
 844         }
 845         if (mstb->tx_slots[1]) {
 846                 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 847                 mstb->tx_slots[1] = NULL;
 848                 wake_tx = true;
 849         }
 850         mutex_unlock(&mstb->mgr->qlock);
 851
 852         if (wake_tx)
 853                 wake_up(&mstb->mgr->tx_waitq);
 854
 855         kref_put(kref, drm_dp_free_mst_branch_device);
 856 }
 857
 858 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
 859 {
 860         kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
 861 }
 862
 863
 864 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
 865 {
 866         struct drm_dp_mst_branch *mstb;
 867
 868         switch (old_pdt) {
 869         case DP_PEER_DEVICE_DP_LEGACY_CONV:
 870         case DP_PEER_DEVICE_SST_SINK:
 871                 /* remove i2c over sideband */
 872                 drm_dp_mst_unregister_i2c_bus(&port->aux);
 873                 break;
 874         case DP_PEER_DEVICE_MST_BRANCHING:
 875                 mstb = port->mstb;
 876                 port->mstb = NULL;
 877                 drm_dp_put_mst_branch_device(mstb);
 878                 break;
 879         }
 880 }
 881
 882 static void drm_dp_destroy_port(struct kref *kref)
 883 {
 884         struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
 885         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
 886
 887         if (!port->input) {
 888                 port->vcpi.num_slots = 0;
 889
 890                 kfree(port->cached_edid);
 891
 892                 /*
 893                  * The only time we don't have a connector
 894                  * on an output port is if the connector init
 895                  * fails.
 896                  */
 897                 if (port->connector) {
 898                         /* we can't destroy the connector here, as
 899                          * we might be holding the mode_config.mutex
 900                          * from an EDID retrieval */
 901
 902                         mutex_lock(&mgr->destroy_connector_lock);
 903                         kref_get(&port->parent->kref);
 904                         list_add(&port->next, &mgr->destroy_connector_list);
 905                         mutex_unlock(&mgr->destroy_connector_lock);
 906                         schedule_work(&mgr->destroy_connector_work);
 907                         return;
 908                 }
 909                 /* no need to clean up vcpi
 910                  * as if we have no connector we never setup a vcpi */
 911                 drm_dp_port_teardown_pdt(port, port->pdt);
 912         }
 913         kfree(port);
 914 }
 915
 916 static void drm_dp_put_port(struct drm_dp_mst_port *port)
 917 {
 918         kref_put(&port->kref, drm_dp_destroy_port);
 919 }
 920
 921 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)
 922 {
 923         struct drm_dp_mst_port *port;
 924         struct drm_dp_mst_branch *rmstb;
 925         if (to_find == mstb) {
 926                 kref_get(&mstb->kref);
 927                 return mstb;
 928         }
 929         list_for_each_entry(port, &mstb->ports, next) {
 930                 if (port->mstb) {
 931                         rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
 932                         if (rmstb)
 933                                 return rmstb;
 934                 }
 935         }
 936         return NULL;
 937 }
 938
 939 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)
 940 {
 941         struct drm_dp_mst_branch *rmstb = NULL;
 942         mutex_lock(&mgr->lock);
 943         if (mgr->mst_primary)
 944                 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
 945         mutex_unlock(&mgr->lock);
 946         return rmstb;
 947 }
 948
 949 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)
 950 {
 951         struct drm_dp_mst_port *port, *mport;
 952
 953         list_for_each_entry(port, &mstb->ports, next) {
 954                 if (port == to_find) {
 955                         kref_get(&port->kref);
 956                         return port;
 957                 }
 958                 if (port->mstb) {
 959                         mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
 960                         if (mport)
 961                                 return mport;
 962                 }
 963         }
 964         return NULL;
 965 }
 966
 967 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)
 968 {
 969         struct drm_dp_mst_port *rport = NULL;
 970         mutex_lock(&mgr->lock);
 971         if (mgr->mst_primary)
 972                 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
 973         mutex_unlock(&mgr->lock);
 974         return rport;
 975 }
 976
 977 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
 978 {
 979         struct drm_dp_mst_port *port;
 980
 981         list_for_each_entry(port, &mstb->ports, next) {
 982                 if (port->port_num == port_num) {
 983                         kref_get(&port->kref);
 984                         return port;
 985                 }
 986         }
 987
 988         return NULL;
 989 }
 990
 991 /*
 992  * calculate a new RAD for this MST branch device
 993  * if parent has an LCT of 2 then it has 1 nibble of RAD,
 994  * if parent has an LCT of 3 then it has 2 nibbles of RAD,
 995  */
 996 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
 997                                  u8 *rad)
 998 {
 999         int parent_lct = port->parent->lct;
1000         int shift = 4;
1001         int idx = (parent_lct - 1) / 2;
1002         if (parent_lct > 1) {
1003                 memcpy(rad, port->parent->rad, idx + 1);
1004                 shift = (parent_lct % 2) ? 4 : 0;
1005         } else
1006                 rad[0] = 0;
1007
1008         rad[idx] |= port->port_num << shift;
1009         return parent_lct + 1;
1010 }
1011
1012 /*
1013  * return sends link address for new mstb
1014  */
1015 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
1016 {
1017         int ret;
1018         u8 rad[6], lct;
1019         bool send_link = false;
1020         switch (port->pdt) {
1021         case DP_PEER_DEVICE_DP_LEGACY_CONV:
1022         case DP_PEER_DEVICE_SST_SINK:
1023                 /* add i2c over sideband */
1024                 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1025                 break;
1026         case DP_PEER_DEVICE_MST_BRANCHING:
1027                 lct = drm_dp_calculate_rad(port, rad);
1028
1029                 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
1030                 port->mstb->mgr = port->mgr;
1031                 port->mstb->port_parent = port;
1032
1033                 send_link = true;
1034                 break;
1035         }
1036         return send_link;
1037 }
1038
1039 static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
1040 {
1041         int ret;
1042
1043         memcpy(mstb->guid, guid, 16);
1044
1045         if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
1046                 if (mstb->port_parent) {
1047                         ret = drm_dp_send_dpcd_write(
1048                                         mstb->mgr,
1049                                         mstb->port_parent,
1050                                         DP_GUID,
1051                                         16,
1052                                         mstb->guid);
1053                 } else {
1054
1055                         ret = drm_dp_dpcd_write(
1056                                         mstb->mgr->aux,
1057                                         DP_GUID,
1058                                         mstb->guid,
1059                                         16);
1060                 }
1061         }
1062 }
1063
1064 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1065                                 int pnum,
1066                                 char *proppath,
1067                                 size_t proppath_size)
1068 {
1069         int i;
1070         char temp[8];
1071         snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1072         for (i = 0; i < (mstb->lct - 1); i++) {
1073                 int shift = (i % 2) ? 0 : 4;
1074                 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
1075                 snprintf(temp, sizeof(temp), "-%d", port_num);
1076                 strlcat(proppath, temp, proppath_size);
1077         }
1078         snprintf(temp, sizeof(temp), "-%d", pnum);
1079         strlcat(proppath, temp, proppath_size);
1080 }
1081
1082 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1083                             struct device *dev,
1084                             struct drm_dp_link_addr_reply_port *port_msg)
1085 {
1086         struct drm_dp_mst_port *port;
1087         bool ret;
1088         bool created = false;
1089         int old_pdt = 0;
1090         int old_ddps = 0;
1091         port = drm_dp_get_port(mstb, port_msg->port_number);
1092         if (!port) {
1093                 port = kzalloc(sizeof(*port), GFP_KERNEL);
1094                 if (!port)
1095                         return;
1096                 kref_init(&port->kref);
1097                 port->parent = mstb;
1098                 port->port_num = port_msg->port_number;
1099                 port->mgr = mstb->mgr;
1100                 port->aux.name = "DPMST";
1101                 port->aux.dev = dev;
1102                 created = true;
1103         } else {
1104                 old_pdt = port->pdt;
1105                 old_ddps = port->ddps;
1106         }
1107
1108         port->pdt = port_msg->peer_device_type;
1109         port->input = port_msg->input_port;
1110         port->mcs = port_msg->mcs;
1111         port->ddps = port_msg->ddps;
1112         port->ldps = port_msg->legacy_device_plug_status;
1113         port->dpcd_rev = port_msg->dpcd_revision;
1114         port->num_sdp_streams = port_msg->num_sdp_streams;
1115         port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1116
1117         /* manage mstb port lists with mgr lock - take a reference
1118            for this list */
1119         if (created) {
1120                 mutex_lock(&mstb->mgr->lock);
1121                 kref_get(&port->kref);
1122                 list_add(&port->next, &mstb->ports);
1123                 mutex_unlock(&mstb->mgr->lock);
1124         }
1125
1126         if (old_ddps != port->ddps) {
1127                 if (port->ddps) {
1128                         if (!port->input)
1129                                 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1130                 } else {
1131                         port->available_pbn = 0;
1132                         }
1133         }
1134
1135         if (old_pdt != port->pdt && !port->input) {
1136                 drm_dp_port_teardown_pdt(port, old_pdt);
1137
1138                 ret = drm_dp_port_setup_pdt(port);
1139                 if (ret == true)
1140                         drm_dp_send_link_address(mstb->mgr, port->mstb);
1141         }
1142
1143         if (created && !port->input) {
1144                 char proppath[255];
1145
1146                 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
1147                 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1148                 if (!port->connector) {
1149                         /* remove it from the port list */
1150                         mutex_lock(&mstb->mgr->lock);
1151                         list_del(&port->next);
1152                         mutex_unlock(&mstb->mgr->lock);
1153                         /* drop port list reference */
1154                         drm_dp_put_port(port);
1155                         goto out;
1156                 }
1157                 if (port->port_num >= DP_MST_LOGICAL_PORT_0) {
1158                         port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1159                         drm_mode_connector_set_tile_property(port->connector);
1160                 }
1161                 (*mstb->mgr->cbs->register_connector)(port->connector);
1162         }
1163
1164 out:
1165         /* put reference to this port */
1166         drm_dp_put_port(port);
1167 }
1168
1169 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1170                                struct drm_dp_connection_status_notify *conn_stat)
1171 {
1172         struct drm_dp_mst_port *port;
1173         int old_pdt;
1174         int old_ddps;
1175         bool dowork = false;
1176         port = drm_dp_get_port(mstb, conn_stat->port_number);
1177         if (!port)
1178                 return;
1179
1180         old_ddps = port->ddps;
1181         old_pdt = port->pdt;
1182         port->pdt = conn_stat->peer_device_type;
1183         port->mcs = conn_stat->message_capability_status;
1184         port->ldps = conn_stat->legacy_device_plug_status;
1185         port->ddps = conn_stat->displayport_device_plug_status;
1186
1187         if (old_ddps != port->ddps) {
1188                 if (port->ddps) {
1189                         dowork = true;
1190                 } else {
1191                         port->available_pbn = 0;
1192                 }
1193         }
1194         if (old_pdt != port->pdt && !port->input) {
1195                 drm_dp_port_teardown_pdt(port, old_pdt);
1196
1197                 if (drm_dp_port_setup_pdt(port))
1198                         dowork = true;
1199         }
1200
1201         drm_dp_put_port(port);
1202         if (dowork)
1203                 queue_work(system_long_wq, &mstb->mgr->work);
1204
1205 }
1206
1207 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1208                                                                u8 lct, u8 *rad)
1209 {
1210         struct drm_dp_mst_branch *mstb;
1211         struct drm_dp_mst_port *port;
1212         int i;
1213         /* find the port by iterating down */
1214
1215         mutex_lock(&mgr->lock);
1216         mstb = mgr->mst_primary;
1217
1218         for (i = 0; i < lct - 1; i++) {
1219                 int shift = (i % 2) ? 0 : 4;
1220                 int port_num = (rad[i / 2] >> shift) & 0xf;
1221
1222                 list_for_each_entry(port, &mstb->ports, next) {
1223                         if (port->port_num == port_num) {
1224                                 mstb = port->mstb;
1225                                 if (!mstb) {
1226                                         DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1227                                         goto out;
1228                                 }
1229
1230                                 break;
1231                         }
1232                 }
1233         }
1234         kref_get(&mstb->kref);
1235 out:
1236         mutex_unlock(&mgr->lock);
1237         return mstb;
1238 }
1239
1240 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1241         struct drm_dp_mst_branch *mstb,
1242         uint8_t *guid)
1243 {
1244         struct drm_dp_mst_branch *found_mstb;
1245         struct drm_dp_mst_port *port;
1246
1247         if (memcmp(mstb->guid, guid, 16) == 0)
1248                 return mstb;
1249
1250
1251         list_for_each_entry(port, &mstb->ports, next) {
1252                 if (!port->mstb)
1253                         continue;
1254
1255                 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1256
1257                 if (found_mstb)
1258                         return found_mstb;
1259         }
1260
1261         return NULL;
1262 }
1263
1264 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
1265         struct drm_dp_mst_topology_mgr *mgr,
1266         uint8_t *guid)
1267 {
1268         struct drm_dp_mst_branch *mstb;
1269
1270         /* find the port by iterating down */
1271         mutex_lock(&mgr->lock);
1272
1273         mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
1274
1275         if (mstb)
1276                 kref_get(&mstb->kref);
1277
1278         mutex_unlock(&mgr->lock);
1279         return mstb;
1280 }
1281
1282 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1283                                                struct drm_dp_mst_branch *mstb)
1284 {
1285         struct drm_dp_mst_port *port;
1286         struct drm_dp_mst_branch *mstb_child;
1287         if (!mstb->link_address_sent)
1288                 drm_dp_send_link_address(mgr, mstb);
1289
1290         list_for_each_entry(port, &mstb->ports, next) {
1291                 if (port->input)
1292                         continue;
1293
1294                 if (!port->ddps)
1295                         continue;
1296
1297                 if (!port->available_pbn)
1298                         drm_dp_send_enum_path_resources(mgr, mstb, port);
1299
1300                 if (port->mstb) {
1301                         mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1302                         if (mstb_child) {
1303                                 drm_dp_check_and_send_link_address(mgr, mstb_child);
1304                                 drm_dp_put_mst_branch_device(mstb_child);
1305                         }
1306                 }
1307         }
1308 }
1309
1310 static void drm_dp_mst_link_probe_work(struct work_struct *work)
1311 {
1312         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1313         struct drm_dp_mst_branch *mstb;
1314
1315         mutex_lock(&mgr->lock);
1316         mstb = mgr->mst_primary;
1317         if (mstb) {
1318                 kref_get(&mstb->kref);
1319         }
1320         mutex_unlock(&mgr->lock);
1321         if (mstb) {
1322                 drm_dp_check_and_send_link_address(mgr, mstb);
1323                 drm_dp_put_mst_branch_device(mstb);
1324         }
1325 }
1326
1327 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1328                                  u8 *guid)
1329 {
1330         static u8 zero_guid[16];
1331
1332         if (!memcmp(guid, zero_guid, 16)) {
1333                 u64 salt = get_jiffies_64();
1334                 memcpy(&guid[0], &salt, sizeof(u64));
1335                 memcpy(&guid[8], &salt, sizeof(u64));
1336                 return false;
1337         }
1338         return true;
1339 }
1340
1341 #if 0
1342 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1343 {
1344         struct drm_dp_sideband_msg_req_body req;
1345
1346         req.req_type = DP_REMOTE_DPCD_READ;
1347         req.u.dpcd_read.port_number = port_num;
1348         req.u.dpcd_read.dpcd_address = offset;
1349         req.u.dpcd_read.num_bytes = num_bytes;
1350         drm_dp_encode_sideband_req(&req, msg);
1351
1352         return 0;
1353 }
1354 #endif
1355
1356 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1357                                     bool up, u8 *msg, int len)
1358 {
1359         int ret;
1360         int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1361         int tosend, total, offset;
1362         int retries = 0;
1363
1364 retry:
1365         total = len;
1366         offset = 0;
1367         do {
1368                 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1369
1370                 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1371                                         &msg[offset],
1372                                         tosend);
1373                 if (ret != tosend) {
1374                         if (ret == -EIO && retries < 5) {
1375                                 retries++;
1376                                 goto retry;
1377                         }
1378                         DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1379
1380                         return -EIO;
1381                 }
1382                 offset += tosend;
1383                 total -= tosend;
1384         } while (total > 0);
1385         return 0;
1386 }
1387
1388 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1389                                   struct drm_dp_sideband_msg_tx *txmsg)
1390 {
1391         struct drm_dp_mst_branch *mstb = txmsg->dst;
1392         u8 req_type;
1393
1394         /* both msg slots are full */
1395         if (txmsg->seqno == -1) {
1396                 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1397                         DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1398                         return -EAGAIN;
1399                 }
1400                 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1401                         txmsg->seqno = mstb->last_seqno;
1402                         mstb->last_seqno ^= 1;
1403                 } else if (mstb->tx_slots[0] == NULL)
1404                         txmsg->seqno = 0;
1405                 else
1406                         txmsg->seqno = 1;
1407                 mstb->tx_slots[txmsg->seqno] = txmsg;
1408         }
1409
1410         req_type = txmsg->msg[0] & 0x7f;
1411         if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1412                 req_type == DP_RESOURCE_STATUS_NOTIFY)
1413                 hdr->broadcast = 1;
1414         else
1415                 hdr->broadcast = 0;
1416         hdr->path_msg = txmsg->path_msg;
1417         hdr->lct = mstb->lct;
1418         hdr->lcr = mstb->lct - 1;
1419         if (mstb->lct > 1)
1420                 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1421         hdr->seqno = txmsg->seqno;
1422         return 0;
1423 }
1424 /*
1425  * process a single block of the next message in the sideband queue
1426  */
1427 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1428                                    struct drm_dp_sideband_msg_tx *txmsg,
1429                                    bool up)
1430 {
1431         u8 chunk[48];
1432         struct drm_dp_sideband_msg_hdr hdr;
1433         int len, space, idx, tosend;
1434         int ret;
1435
1436         memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1437
1438         if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1439                 txmsg->seqno = -1;
1440                 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1441         }
1442
1443         /* make hdr from dst mst - for replies use seqno
1444            otherwise assign one */
1445         ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1446         if (ret < 0)
1447                 return ret;
1448
1449         /* amount left to send in this message */
1450         len = txmsg->cur_len - txmsg->cur_offset;
1451
1452         /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1453         space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1454
1455         tosend = min(len, space);
1456         if (len == txmsg->cur_len)
1457                 hdr.somt = 1;
1458         if (space >= len)
1459                 hdr.eomt = 1;
1460
1461
1462         hdr.msg_len = tosend + 1;
1463         drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1464         memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1465         /* add crc at end */
1466         drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1467         idx += tosend + 1;
1468
1469         ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1470         if (ret) {
1471                 DRM_DEBUG_KMS("sideband msg failed to send\n");
1472                 return ret;
1473         }
1474
1475         txmsg->cur_offset += tosend;
1476         if (txmsg->cur_offset == txmsg->cur_len) {
1477                 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1478                 return 1;
1479         }
1480         return 0;
1481 }
1482
1483 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1484 {
1485         struct drm_dp_sideband_msg_tx *txmsg;
1486         int ret;
1487
1488         WARN_ON(!mutex_is_locked(&mgr->qlock));
1489
1490         /* construct a chunk from the first msg in the tx_msg queue */
1491         if (list_empty(&mgr->tx_msg_downq)) {
1492                 mgr->tx_down_in_progress = false;
1493                 return;
1494         }
1495         mgr->tx_down_in_progress = true;
1496
1497         txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1498         ret = process_single_tx_qlock(mgr, txmsg, false);
1499         if (ret == 1) {
1500                 /* txmsg is sent it should be in the slots now */
1501                 list_del(&txmsg->next);
1502         } else if (ret) {
1503                 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1504                 list_del(&txmsg->next);
1505                 if (txmsg->seqno != -1)
1506                         txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1507                 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1508                 wake_up(&mgr->tx_waitq);
1509         }
1510         if (list_empty(&mgr->tx_msg_downq)) {
1511                 mgr->tx_down_in_progress = false;
1512                 return;
1513         }
1514 }
1515
1516 /* called holding qlock */
1517 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1518                                        struct drm_dp_sideband_msg_tx *txmsg)
1519 {
1520         int ret;
1521
1522         /* construct a chunk from the first msg in the tx_msg queue */
1523         ret = process_single_tx_qlock(mgr, txmsg, true);
1524
1525         if (ret != 1)
1526                 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1527
1528         txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1529 }
1530
1531 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1532                                  struct drm_dp_sideband_msg_tx *txmsg)
1533 {
1534         mutex_lock(&mgr->qlock);
1535         list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1536         if (!mgr->tx_down_in_progress)
1537                 process_single_down_tx_qlock(mgr);
1538         mutex_unlock(&mgr->qlock);
1539 }
1540
1541 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1542                                      struct drm_dp_mst_branch *mstb)
1543 {
1544         int len;
1545         struct drm_dp_sideband_msg_tx *txmsg;
1546         int ret;
1547
1548         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1549         if (!txmsg)
1550                 return;
1551
1552         txmsg->dst = mstb;
1553         len = build_link_address(txmsg);
1554
1555         mstb->link_address_sent = true;
1556         drm_dp_queue_down_tx(mgr, txmsg);
1557
1558         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1559         if (ret > 0) {
1560                 int i;
1561
1562                 if (txmsg->reply.reply_type == 1)
1563                         DRM_DEBUG_KMS("link address nak received\n");
1564                 else {
1565                         DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1566                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1567                                 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,
1568                                        txmsg->reply.u.link_addr.ports[i].input_port,
1569                                        txmsg->reply.u.link_addr.ports[i].peer_device_type,
1570                                        txmsg->reply.u.link_addr.ports[i].port_number,
1571                                        txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1572                                        txmsg->reply.u.link_addr.ports[i].mcs,
1573                                        txmsg->reply.u.link_addr.ports[i].ddps,
1574                                        txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1575                                        txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1576                                        txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1577                         }
1578
1579                         drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);
1580
1581                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1582                                 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1583                         }
1584                         (*mgr->cbs->hotplug)(mgr);
1585                 }
1586         } else {
1587                 mstb->link_address_sent = false;
1588                 DRM_DEBUG_KMS("link address failed %d\n", ret);
1589         }
1590
1591         kfree(txmsg);
1592 }
1593
1594 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1595                                            struct drm_dp_mst_branch *mstb,
1596                                            struct drm_dp_mst_port *port)
1597 {
1598         int len;
1599         struct drm_dp_sideband_msg_tx *txmsg;
1600         int ret;
1601
1602         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1603         if (!txmsg)
1604                 return -ENOMEM;
1605
1606         txmsg->dst = mstb;
1607         len = build_enum_path_resources(txmsg, port->port_num);
1608
1609         drm_dp_queue_down_tx(mgr, txmsg);
1610
1611         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1612         if (ret > 0) {
1613                 if (txmsg->reply.reply_type == 1)
1614                         DRM_DEBUG_KMS("enum path resources nak received\n");
1615                 else {
1616                         if (port->port_num != txmsg->reply.u.path_resources.port_number)
1617                                 DRM_ERROR("got incorrect port in response\n");
1618                         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,
1619                                txmsg->reply.u.path_resources.avail_payload_bw_number);
1620                         port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1621                 }
1622         }
1623
1624         kfree(txmsg);
1625         return 0;
1626 }
1627
1628 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
1629 {
1630         if (!mstb->port_parent)
1631                 return NULL;
1632
1633         if (mstb->port_parent->mstb != mstb)
1634                 return mstb->port_parent;
1635
1636         return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
1637 }
1638
1639 static struct drm_dp_mst_branch *drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
1640                                                                          struct drm_dp_mst_branch *mstb,
1641                                                                          int *port_num)
1642 {
1643         struct drm_dp_mst_branch *rmstb = NULL;
1644         struct drm_dp_mst_port *found_port;
1645         mutex_lock(&mgr->lock);
1646         if (mgr->mst_primary) {
1647                 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
1648
1649                 if (found_port) {
1650                         rmstb = found_port->parent;
1651                         kref_get(&rmstb->kref);
1652                         *port_num = found_port->port_num;
1653                 }
1654         }
1655         mutex_unlock(&mgr->lock);
1656         return rmstb;
1657 }
1658
1659 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1660                                    struct drm_dp_mst_port *port,
1661                                    int id,
1662                                    int pbn)
1663 {
1664         struct drm_dp_sideband_msg_tx *txmsg;
1665         struct drm_dp_mst_branch *mstb;
1666         int len, ret, port_num;
1667
1668         port_num = port->port_num;
1669         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1670         if (!mstb) {
1671                 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, port->parent, &port_num);
1672
1673                 if (!mstb)
1674                         return -EINVAL;
1675         }
1676
1677         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1678         if (!txmsg) {
1679                 ret = -ENOMEM;
1680                 goto fail_put;
1681         }
1682
1683         txmsg->dst = mstb;
1684         len = build_allocate_payload(txmsg, port_num,
1685                                      id,
1686                                      pbn);
1687
1688         drm_dp_queue_down_tx(mgr, txmsg);
1689
1690         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1691         if (ret > 0) {
1692                 if (txmsg->reply.reply_type == 1) {
1693                         ret = -EINVAL;
1694                 } else
1695                         ret = 0;
1696         }
1697         kfree(txmsg);
1698 fail_put:
1699         drm_dp_put_mst_branch_device(mstb);
1700         return ret;
1701 }
1702
1703 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1704                                        int id,
1705                                        struct drm_dp_payload *payload)
1706 {
1707         int ret;
1708
1709         ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1710         if (ret < 0) {
1711                 payload->payload_state = 0;
1712                 return ret;
1713         }
1714         payload->payload_state = DP_PAYLOAD_LOCAL;
1715         return 0;
1716 }
1717
1718 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1719                                        struct drm_dp_mst_port *port,
1720                                        int id,
1721                                        struct drm_dp_payload *payload)
1722 {
1723         int ret;
1724         ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1725         if (ret < 0)
1726                 return ret;
1727         payload->payload_state = DP_PAYLOAD_REMOTE;
1728         return ret;
1729 }
1730
1731 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1732                                         struct drm_dp_mst_port *port,
1733                                         int id,
1734                                         struct drm_dp_payload *payload)
1735 {
1736         DRM_DEBUG_KMS("\n");
1737         /* its okay for these to fail */
1738         if (port) {
1739                 drm_dp_payload_send_msg(mgr, port, id, 0);
1740         }
1741
1742         drm_dp_dpcd_write_payload(mgr, id, payload);
1743         payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1744         return 0;
1745 }
1746
1747 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1748                                         int id,
1749                                         struct drm_dp_payload *payload)
1750 {
1751         payload->payload_state = 0;
1752         return 0;
1753 }
1754
1755 /**
1756  * drm_dp_update_payload_part1() - Execute payload update part 1
1757  * @mgr: manager to use.
1758  *
1759  * This iterates over all proposed virtual channels, and tries to
1760  * allocate space in the link for them. For 0->slots transitions,
1761  * this step just writes the VCPI to the MST device. For slots->0
1762  * transitions, this writes the updated VCPIs and removes the
1763  * remote VC payloads.
1764  *
1765  * after calling this the driver should generate ACT and payload
1766  * packets.
1767  */
1768 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1769 {
1770         int i, j;
1771         int cur_slots = 1;
1772         struct drm_dp_payload req_payload;
1773         struct drm_dp_mst_port *port;
1774
1775         mutex_lock(&mgr->payload_lock);
1776         for (i = 0; i < mgr->max_payloads; i++) {
1777                 /* solve the current payloads - compare to the hw ones
1778                    - update the hw view */
1779                 req_payload.start_slot = cur_slots;
1780                 if (mgr->proposed_vcpis[i]) {
1781                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1782                         req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1783                 } else {
1784                         port = NULL;
1785                         req_payload.num_slots = 0;
1786                 }
1787
1788                 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1789                         mgr->payloads[i].start_slot = req_payload.start_slot;
1790                 }
1791                 /* work out what is required to happen with this payload */
1792                 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1793
1794                         /* need to push an update for this payload */
1795                         if (req_payload.num_slots) {
1796                                 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1797                                 mgr->payloads[i].num_slots = req_payload.num_slots;
1798                         } else if (mgr->payloads[i].num_slots) {
1799                                 mgr->payloads[i].num_slots = 0;
1800                                 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
1801                                 req_payload.payload_state = mgr->payloads[i].payload_state;
1802                                 mgr->payloads[i].start_slot = 0;
1803                         }
1804                         mgr->payloads[i].payload_state = req_payload.payload_state;
1805                 }
1806                 cur_slots += req_payload.num_slots;
1807         }
1808
1809         for (i = 0; i < mgr->max_payloads; i++) {
1810                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1811                         DRM_DEBUG_KMS("removing payload %d\n", i);
1812                         for (j = i; j < mgr->max_payloads - 1; j++) {
1813                                 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1814                                 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1815                                 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1816                                         set_bit(j + 1, &mgr->payload_mask);
1817                                 } else {
1818                                         clear_bit(j + 1, &mgr->payload_mask);
1819                                 }
1820                         }
1821                         memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1822                         mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1823                         clear_bit(mgr->max_payloads, &mgr->payload_mask);
1824
1825                 }
1826         }
1827         mutex_unlock(&mgr->payload_lock);
1828
1829         return 0;
1830 }
1831 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1832
1833 /**
1834  * drm_dp_update_payload_part2() - Execute payload update part 2
1835  * @mgr: manager to use.
1836  *
1837  * This iterates over all proposed virtual channels, and tries to
1838  * allocate space in the link for them. For 0->slots transitions,
1839  * this step writes the remote VC payload commands. For slots->0
1840  * this just resets some internal state.
1841  */
1842 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1843 {
1844         struct drm_dp_mst_port *port;
1845         int i;
1846         int ret = 0;
1847         mutex_lock(&mgr->payload_lock);
1848         for (i = 0; i < mgr->max_payloads; i++) {
1849
1850                 if (!mgr->proposed_vcpis[i])
1851                         continue;
1852
1853                 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1854
1855                 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1856                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1857                         ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1858                 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1859                         ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1860                 }
1861                 if (ret) {
1862                         mutex_unlock(&mgr->payload_lock);
1863                         return ret;
1864                 }
1865         }
1866         mutex_unlock(&mgr->payload_lock);
1867         return 0;
1868 }
1869 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1870
1871 #if 0 /* unused as of yet */
1872 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1873                                  struct drm_dp_mst_port *port,
1874                                  int offset, int size)
1875 {
1876         int len;
1877         struct drm_dp_sideband_msg_tx *txmsg;
1878
1879         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1880         if (!txmsg)
1881                 return -ENOMEM;
1882
1883         len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1884         txmsg->dst = port->parent;
1885
1886         drm_dp_queue_down_tx(mgr, txmsg);
1887
1888         return 0;
1889 }
1890 #endif
1891
1892 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1893                                   struct drm_dp_mst_port *port,
1894                                   int offset, int size, u8 *bytes)
1895 {
1896         int len;
1897         int ret;
1898         struct drm_dp_sideband_msg_tx *txmsg;
1899         struct drm_dp_mst_branch *mstb;
1900
1901         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1902         if (!mstb)
1903                 return -EINVAL;
1904
1905         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1906         if (!txmsg) {
1907                 ret = -ENOMEM;
1908                 goto fail_put;
1909         }
1910
1911         len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1912         txmsg->dst = mstb;
1913
1914         drm_dp_queue_down_tx(mgr, txmsg);
1915
1916         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1917         if (ret > 0) {
1918                 if (txmsg->reply.reply_type == 1) {
1919                         ret = -EINVAL;
1920                 } else
1921                         ret = 0;
1922         }
1923         kfree(txmsg);
1924 fail_put:
1925         drm_dp_put_mst_branch_device(mstb);
1926         return ret;
1927 }
1928
1929 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1930 {
1931         struct drm_dp_sideband_msg_reply_body reply;
1932
1933         reply.reply_type = 1;
1934         reply.req_type = req_type;
1935         drm_dp_encode_sideband_reply(&reply, msg);
1936         return 0;
1937 }
1938
1939 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1940                                     struct drm_dp_mst_branch *mstb,
1941                                     int req_type, int seqno, bool broadcast)
1942 {
1943         struct drm_dp_sideband_msg_tx *txmsg;
1944
1945         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1946         if (!txmsg)
1947                 return -ENOMEM;
1948
1949         txmsg->dst = mstb;
1950         txmsg->seqno = seqno;
1951         drm_dp_encode_up_ack_reply(txmsg, req_type);
1952
1953         mutex_lock(&mgr->qlock);
1954
1955         process_single_up_tx_qlock(mgr, txmsg);
1956
1957         mutex_unlock(&mgr->qlock);
1958
1959         kfree(txmsg);
1960         return 0;
1961 }
1962
1963 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1964                                      int dp_link_count,
1965                                      int *out)
1966 {
1967         switch (dp_link_bw) {
1968         default:
1969                 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1970                               dp_link_bw, dp_link_count);
1971                 return false;
1972
1973         case DP_LINK_BW_1_62:
1974                 *out = 3 * dp_link_count;
1975                 break;
1976         case DP_LINK_BW_2_7:
1977                 *out = 5 * dp_link_count;
1978                 break;
1979         case DP_LINK_BW_5_4:
1980                 *out = 10 * dp_link_count;
1981                 break;
1982         }
1983         return true;
1984 }
1985
1986 /**
1987  * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
1988  * @mgr: manager to set state for
1989  * @mst_state: true to enable MST on this connector - false to disable.
1990  *
1991  * This is called by the driver when it detects an MST capable device plugged
1992  * into a DP MST capable port, or when a DP MST capable device is unplugged.
1993  */
1994 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
1995 {
1996         int ret = 0;
1997         struct drm_dp_mst_branch *mstb = NULL;
1998
1999         mutex_lock(&mgr->lock);
2000         if (mst_state == mgr->mst_state)
2001                 goto out_unlock;
2002
2003         mgr->mst_state = mst_state;
2004         /* set the device into MST mode */
2005         if (mst_state) {
2006                 WARN_ON(mgr->mst_primary);
2007
2008                 /* get dpcd info */
2009                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2010                 if (ret != DP_RECEIVER_CAP_SIZE) {
2011                         DRM_DEBUG_KMS("failed to read DPCD\n");
2012                         goto out_unlock;
2013                 }
2014
2015                 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
2016                                               mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
2017                                               &mgr->pbn_div)) {
2018                         ret = -EINVAL;
2019                         goto out_unlock;
2020                 }
2021
2022                 mgr->total_pbn = 2560;
2023                 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
2024                 mgr->avail_slots = mgr->total_slots;
2025
2026                 /* add initial branch device at LCT 1 */
2027                 mstb = drm_dp_add_mst_branch_device(1, NULL);
2028                 if (mstb == NULL) {
2029                         ret = -ENOMEM;
2030                         goto out_unlock;
2031                 }
2032                 mstb->mgr = mgr;
2033
2034                 /* give this the main reference */
2035                 mgr->mst_primary = mstb;
2036                 kref_get(&mgr->mst_primary->kref);
2037
2038                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2039                                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2040                 if (ret < 0) {
2041                         goto out_unlock;
2042                 }
2043
2044                 {
2045                         struct drm_dp_payload reset_pay;
2046                         reset_pay.start_slot = 0;
2047                         reset_pay.num_slots = 0x3f;
2048                         drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
2049                 }
2050
2051                 queue_work(system_long_wq, &mgr->work);
2052
2053                 ret = 0;
2054         } else {
2055                 /* disable MST on the device */
2056                 mstb = mgr->mst_primary;
2057                 mgr->mst_primary = NULL;
2058                 /* this can fail if the device is gone */
2059                 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2060                 ret = 0;
2061                 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2062                 mgr->payload_mask = 0;
2063                 set_bit(0, &mgr->payload_mask);
2064                 mgr->vcpi_mask = 0;
2065         }
2066
2067 out_unlock:
2068         mutex_unlock(&mgr->lock);
2069         if (mstb)
2070                 drm_dp_put_mst_branch_device(mstb);
2071         return ret;
2072
2073 }
2074 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2075
2076 /**
2077  * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2078  * @mgr: manager to suspend
2079  *
2080  * This function tells the MST device that we can't handle UP messages
2081  * anymore. This should stop it from sending any since we are suspended.
2082  */
2083 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2084 {
2085         mutex_lock(&mgr->lock);
2086         drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2087                            DP_MST_EN | DP_UPSTREAM_IS_SRC);
2088         mutex_unlock(&mgr->lock);
2089         flush_work(&mgr->work);
2090         flush_work(&mgr->destroy_connector_work);
2091 }
2092 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2093
2094 /**
2095  * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2096  * @mgr: manager to resume
2097  *
2098  * This will fetch DPCD and see if the device is still there,
2099  * if it is, it will rewrite the MSTM control bits, and return.
2100  *
2101  * if the device fails this returns -1, and the driver should do
2102  * a full MST reprobe, in case we were undocked.
2103  */
2104 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2105 {
2106         int ret = 0;
2107
2108         mutex_lock(&mgr->lock);
2109
2110         if (mgr->mst_primary) {
2111                 int sret;
2112                 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2113                 if (sret != DP_RECEIVER_CAP_SIZE) {
2114                         DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2115                         ret = -1;
2116                         goto out_unlock;
2117                 }
2118
2119                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2120                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2121                 if (ret < 0) {
2122                         DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2123                         ret = -1;
2124                         goto out_unlock;
2125                 }
2126                 ret = 0;
2127         } else
2128                 ret = -1;
2129
2130 out_unlock:
2131         mutex_unlock(&mgr->lock);
2132         return ret;
2133 }
2134 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2135
2136 static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2137 {
2138         int len;
2139         u8 replyblock[32];
2140         int replylen, origlen, curreply;
2141         int ret;
2142         struct drm_dp_sideband_msg_rx *msg;
2143         int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2144         msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2145
2146         len = min(mgr->max_dpcd_transaction_bytes, 16);
2147         ret = drm_dp_dpcd_read(mgr->aux, basereg,
2148                                replyblock, len);
2149         if (ret != len) {
2150                 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2151                 return;
2152         }
2153         ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2154         if (!ret) {
2155                 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2156                 return;
2157         }
2158         replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2159
2160         origlen = replylen;
2161         replylen -= len;
2162         curreply = len;
2163         while (replylen > 0) {
2164                 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2165                 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2166                                     replyblock, len);
2167                 if (ret != len) {
2168                         DRM_DEBUG_KMS("failed to read a chunk\n");
2169                 }
2170                 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2171                 if (ret == false)
2172                         DRM_DEBUG_KMS("failed to build sideband msg\n");
2173                 curreply += len;
2174                 replylen -= len;
2175         }
2176 }
2177
2178 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2179 {
2180         int ret = 0;
2181
2182         drm_dp_get_one_sb_msg(mgr, false);
2183
2184         if (mgr->down_rep_recv.have_eomt) {
2185                 struct drm_dp_sideband_msg_tx *txmsg;
2186                 struct drm_dp_mst_branch *mstb;
2187                 int slot = -1;
2188                 mstb = drm_dp_get_mst_branch_device(mgr,
2189                                                     mgr->down_rep_recv.initial_hdr.lct,
2190                                                     mgr->down_rep_recv.initial_hdr.rad);
2191
2192                 if (!mstb) {
2193                         DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2194                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2195                         return 0;
2196                 }
2197
2198                 /* find the message */
2199                 slot = mgr->down_rep_recv.initial_hdr.seqno;
2200                 mutex_lock(&mgr->qlock);
2201                 txmsg = mstb->tx_slots[slot];
2202                 /* remove from slots */
2203                 mutex_unlock(&mgr->qlock);
2204
2205                 if (!txmsg) {
2206                         DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2207                                mstb,
2208                                mgr->down_rep_recv.initial_hdr.seqno,
2209                                mgr->down_rep_recv.initial_hdr.lct,
2210                                       mgr->down_rep_recv.initial_hdr.rad[0],
2211                                       mgr->down_rep_recv.msg[0]);
2212                         drm_dp_put_mst_branch_device(mstb);
2213                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2214                         return 0;
2215                 }
2216
2217                 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2218                 if (txmsg->reply.reply_type == 1) {
2219                         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);
2220                 }
2221
2222                 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2223                 drm_dp_put_mst_branch_device(mstb);
2224
2225                 mutex_lock(&mgr->qlock);
2226                 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2227                 mstb->tx_slots[slot] = NULL;
2228                 mutex_unlock(&mgr->qlock);
2229
2230                 wake_up(&mgr->tx_waitq);
2231         }
2232         return ret;
2233 }
2234
2235 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2236 {
2237         int ret = 0;
2238         drm_dp_get_one_sb_msg(mgr, true);
2239
2240         if (mgr->up_req_recv.have_eomt) {
2241                 struct drm_dp_sideband_msg_req_body msg;
2242                 struct drm_dp_mst_branch *mstb = NULL;
2243                 bool seqno;
2244
2245                 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2246                         mstb = drm_dp_get_mst_branch_device(mgr,
2247                                                             mgr->up_req_recv.initial_hdr.lct,
2248                                                             mgr->up_req_recv.initial_hdr.rad);
2249                         if (!mstb) {
2250                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2251                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2252                                 return 0;
2253                         }
2254                 }
2255
2256                 seqno = mgr->up_req_recv.initial_hdr.seqno;
2257                 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2258
2259                 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2260                         drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2261
2262                         if (!mstb)
2263                                 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2264
2265                         if (!mstb) {
2266                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2267                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2268                                 return 0;
2269                         }
2270
2271                         drm_dp_update_port(mstb, &msg.u.conn_stat);
2272
2273                         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);
2274                         (*mgr->cbs->hotplug)(mgr);
2275
2276                 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2277                         drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2278                         if (!mstb)
2279                                 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2280
2281                         if (!mstb) {
2282                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2283                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2284                                 return 0;
2285                         }
2286
2287                         DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2288                 }
2289
2290                 drm_dp_put_mst_branch_device(mstb);
2291                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2292         }
2293         return ret;
2294 }
2295
2296 /**
2297  * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2298  * @mgr: manager to notify irq for.
2299  * @esi: 4 bytes from SINK_COUNT_ESI
2300  * @handled: whether the hpd interrupt was consumed or not
2301  *
2302  * This should be called from the driver when it detects a short IRQ,
2303  * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2304  * topology manager will process the sideband messages received as a result
2305  * of this.
2306  */
2307 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2308 {
2309         int ret = 0;
2310         int sc;
2311         *handled = false;
2312         sc = esi[0] & 0x3f;
2313
2314         if (sc != mgr->sink_count) {
2315                 mgr->sink_count = sc;
2316                 *handled = true;
2317         }
2318
2319         if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2320                 ret = drm_dp_mst_handle_down_rep(mgr);
2321                 *handled = true;
2322         }
2323
2324         if (esi[1] & DP_UP_REQ_MSG_RDY) {
2325                 ret |= drm_dp_mst_handle_up_req(mgr);
2326                 *handled = true;
2327         }
2328
2329         drm_dp_mst_kick_tx(mgr);
2330         return ret;
2331 }
2332 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2333
2334 /**
2335  * drm_dp_mst_detect_port() - get connection status for an MST port
2336  * @mgr: manager for this port
2337  * @port: unverified pointer to a port
2338  *
2339  * This returns the current connection state for a port. It validates the
2340  * port pointer still exists so the caller doesn't require a reference
2341  */
2342 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2343                                                  struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2344 {
2345         enum drm_connector_status status = connector_status_disconnected;
2346
2347         /* we need to search for the port in the mgr in case its gone */
2348         port = drm_dp_get_validated_port_ref(mgr, port);
2349         if (!port)
2350                 return connector_status_disconnected;
2351
2352         if (!port->ddps)
2353                 goto out;
2354
2355         switch (port->pdt) {
2356         case DP_PEER_DEVICE_NONE:
2357         case DP_PEER_DEVICE_MST_BRANCHING:
2358                 break;
2359
2360         case DP_PEER_DEVICE_SST_SINK:
2361                 status = connector_status_connected;
2362                 /* for logical ports - cache the EDID */
2363                 if (port->port_num >= 8 && !port->cached_edid) {
2364                         port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2365                 }
2366                 break;
2367         case DP_PEER_DEVICE_DP_LEGACY_CONV:
2368                 if (port->ldps)
2369                         status = connector_status_connected;
2370                 break;
2371         }
2372 out:
2373         drm_dp_put_port(port);
2374         return status;
2375 }
2376 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2377
2378 /**
2379  * drm_dp_mst_get_edid() - get EDID for an MST port
2380  * @connector: toplevel connector to get EDID for
2381  * @mgr: manager for this port
2382  * @port: unverified pointer to a port.
2383  *
2384  * This returns an EDID for the port connected to a connector,
2385  * It validates the pointer still exists so the caller doesn't require a
2386  * reference.
2387  */
2388 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2389 {
2390         struct edid *edid = NULL;
2391
2392         /* we need to search for the port in the mgr in case its gone */
2393         port = drm_dp_get_validated_port_ref(mgr, port);
2394         if (!port)
2395                 return NULL;
2396
2397         if (port->cached_edid)
2398                 edid = drm_edid_duplicate(port->cached_edid);
2399         else {
2400                 edid = drm_get_edid(connector, &port->aux.ddc);
2401                 drm_mode_connector_set_tile_property(connector);
2402         }
2403         drm_dp_put_port(port);
2404         return edid;
2405 }
2406 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2407
2408 /**
2409  * drm_dp_find_vcpi_slots() - find slots for this PBN value
2410  * @mgr: manager to use
2411  * @pbn: payload bandwidth to convert into slots.
2412  */
2413 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2414                            int pbn)
2415 {
2416         int num_slots;
2417
2418         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2419
2420         if (num_slots > mgr->avail_slots)
2421                 return -ENOSPC;
2422         return num_slots;
2423 }
2424 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2425
2426 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2427                             struct drm_dp_vcpi *vcpi, int pbn)
2428 {
2429         int num_slots;
2430         int ret;
2431
2432         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2433
2434         if (num_slots > mgr->avail_slots)
2435                 return -ENOSPC;
2436
2437         vcpi->pbn = pbn;
2438         vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2439         vcpi->num_slots = num_slots;
2440
2441         ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2442         if (ret < 0)
2443                 return ret;
2444         return 0;
2445 }
2446
2447 /**
2448  * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2449  * @mgr: manager for this port
2450  * @port: port to allocate a virtual channel for.
2451  * @pbn: payload bandwidth number to request
2452  * @slots: returned number of slots for this PBN.
2453  */
2454 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2455 {
2456         int ret;
2457
2458         port = drm_dp_get_validated_port_ref(mgr, port);
2459         if (!port)
2460                 return false;
2461
2462         if (port->vcpi.vcpi > 0) {
2463                 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2464                 if (pbn == port->vcpi.pbn) {
2465                         *slots = port->vcpi.num_slots;
2466                         drm_dp_put_port(port);
2467                         return true;
2468                 }
2469         }
2470
2471         ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2472         if (ret) {
2473                 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2474                 goto out;
2475         }
2476         DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2477         *slots = port->vcpi.num_slots;
2478
2479         drm_dp_put_port(port);
2480         return true;
2481 out:
2482         return false;
2483 }
2484 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2485
2486 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2487 {
2488         int slots = 0;
2489         port = drm_dp_get_validated_port_ref(mgr, port);
2490         if (!port)
2491                 return slots;
2492
2493         slots = port->vcpi.num_slots;
2494         drm_dp_put_port(port);
2495         return slots;
2496 }
2497 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2498
2499 /**
2500  * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2501  * @mgr: manager for this port
2502  * @port: unverified pointer to a port.
2503  *
2504  * This just resets the number of slots for the ports VCPI for later programming.
2505  */
2506 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2507 {
2508         port = drm_dp_get_validated_port_ref(mgr, port);
2509         if (!port)
2510                 return;
2511         port->vcpi.num_slots = 0;
2512         drm_dp_put_port(port);
2513 }
2514 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2515
2516 /**
2517  * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2518  * @mgr: manager for this port
2519  * @port: unverified port to deallocate vcpi for
2520  */
2521 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2522 {
2523         port = drm_dp_get_validated_port_ref(mgr, port);
2524         if (!port)
2525                 return;
2526
2527         drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2528         port->vcpi.num_slots = 0;
2529         port->vcpi.pbn = 0;
2530         port->vcpi.aligned_pbn = 0;
2531         port->vcpi.vcpi = 0;
2532         drm_dp_put_port(port);
2533 }
2534 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2535
2536 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2537                                      int id, struct drm_dp_payload *payload)
2538 {
2539         u8 payload_alloc[3], status;
2540         int ret;
2541         int retries = 0;
2542
2543         drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2544                            DP_PAYLOAD_TABLE_UPDATED);
2545
2546         payload_alloc[0] = id;
2547         payload_alloc[1] = payload->start_slot;
2548         payload_alloc[2] = payload->num_slots;
2549
2550         ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2551         if (ret != 3) {
2552                 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2553                 goto fail;
2554         }
2555
2556 retry:
2557         ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2558         if (ret < 0) {
2559                 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2560                 goto fail;
2561         }
2562
2563         if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2564                 retries++;
2565                 if (retries < 20) {
2566                         usleep_range(10000, 20000);
2567                         goto retry;
2568                 }
2569                 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2570                 ret = -EINVAL;
2571                 goto fail;
2572         }
2573         ret = 0;
2574 fail:
2575         return ret;
2576 }
2577
2578
2579 /**
2580  * drm_dp_check_act_status() - Check ACT handled status.
2581  * @mgr: manager to use
2582  *
2583  * Check the payload status bits in the DPCD for ACT handled completion.
2584  */
2585 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2586 {
2587         u8 status;
2588         int ret;
2589         int count = 0;
2590
2591         do {
2592                 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2593
2594                 if (ret < 0) {
2595                         DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2596                         goto fail;
2597                 }
2598
2599                 if (status & DP_PAYLOAD_ACT_HANDLED)
2600                         break;
2601                 count++;
2602                 udelay(100);
2603
2604         } while (count < 30);
2605
2606         if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2607                 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2608                 ret = -EINVAL;
2609                 goto fail;
2610         }
2611         return 0;
2612 fail:
2613         return ret;
2614 }
2615 EXPORT_SYMBOL(drm_dp_check_act_status);
2616
2617 /**
2618  * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2619  * @clock: dot clock for the mode
2620  * @bpp: bpp for the mode.
2621  *
2622  * This uses the formula in the spec to calculate the PBN value for a mode.
2623  */
2624 int drm_dp_calc_pbn_mode(int clock, int bpp)
2625 {
2626         u64 kbps;
2627         s64 peak_kbps;
2628         u32 numerator;
2629         u32 denominator;
2630
2631         kbps = clock * bpp;
2632
2633         /*
2634          * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
2635          * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
2636          * common multiplier to render an integer PBN for all link rate/lane
2637          * counts combinations
2638          * calculate
2639          * peak_kbps *= (1006/1000)
2640          * peak_kbps *= (64/54)
2641          * peak_kbps *= 8    convert to bytes
2642          */
2643
2644         numerator = 64 * 1006;
2645         denominator = 54 * 8 * 1000 * 1000;
2646
2647         kbps *= numerator;
2648         peak_kbps = drm_fixp_from_fraction(kbps, denominator);
2649
2650         return drm_fixp2int_ceil(peak_kbps);
2651 }
2652 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2653
2654 static int test_calc_pbn_mode(void)
2655 {
2656         int ret;
2657         ret = drm_dp_calc_pbn_mode(154000, 30);
2658         if (ret != 689) {
2659                 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2660                                 154000, 30, 689, ret);
2661                 return -EINVAL;
2662         }
2663         ret = drm_dp_calc_pbn_mode(234000, 30);
2664         if (ret != 1047) {
2665                 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2666                                 234000, 30, 1047, ret);
2667                 return -EINVAL;
2668         }
2669         ret = drm_dp_calc_pbn_mode(297000, 24);
2670         if (ret != 1063) {
2671                 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2672                                 297000, 24, 1063, ret);
2673                 return -EINVAL;
2674         }
2675         return 0;
2676 }
2677
2678 /* we want to kick the TX after we've ack the up/down IRQs. */
2679 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2680 {
2681         queue_work(system_long_wq, &mgr->tx_work);
2682 }
2683
2684 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2685                                  struct drm_dp_mst_branch *mstb)
2686 {
2687         struct drm_dp_mst_port *port;
2688         int tabs = mstb->lct;
2689         char prefix[10];
2690         int i;
2691
2692         for (i = 0; i < tabs; i++)
2693                 prefix[i] = '\t';
2694         prefix[i] = '\0';
2695
2696         seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2697         list_for_each_entry(port, &mstb->ports, next) {
2698                 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port, port->connector);
2699                 if (port->mstb)
2700                         drm_dp_mst_dump_mstb(m, port->mstb);
2701         }
2702 }
2703
2704 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2705                                   char *buf)
2706 {
2707         int ret;
2708         int i;
2709         for (i = 0; i < 4; i++) {
2710                 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2711                 if (ret != 16)
2712                         break;
2713         }
2714         if (i == 4)
2715                 return true;
2716         return false;
2717 }
2718
2719 /**
2720  * drm_dp_mst_dump_topology(): dump topology to seq file.
2721  * @m: seq_file to dump output to
2722  * @mgr: manager to dump current topology for.
2723  *
2724  * helper to dump MST topology to a seq file for debugfs.
2725  */
2726 void drm_dp_mst_dump_topology(struct seq_file *m,
2727                               struct drm_dp_mst_topology_mgr *mgr)
2728 {
2729         int i;
2730         struct drm_dp_mst_port *port;
2731         mutex_lock(&mgr->lock);
2732         if (mgr->mst_primary)
2733                 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2734
2735         /* dump VCPIs */
2736         mutex_unlock(&mgr->lock);
2737
2738         mutex_lock(&mgr->payload_lock);
2739         seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
2740
2741         for (i = 0; i < mgr->max_payloads; i++) {
2742                 if (mgr->proposed_vcpis[i]) {
2743                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2744                         seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2745                 } else
2746                         seq_printf(m, "vcpi %d:unsed\n", i);
2747         }
2748         for (i = 0; i < mgr->max_payloads; i++) {
2749                 seq_printf(m, "payload %d: %d, %d, %d\n",
2750                            i,
2751                            mgr->payloads[i].payload_state,
2752                            mgr->payloads[i].start_slot,
2753                            mgr->payloads[i].num_slots);
2754
2755
2756         }
2757         mutex_unlock(&mgr->payload_lock);
2758
2759         mutex_lock(&mgr->lock);
2760         if (mgr->mst_primary) {
2761                 u8 buf[64];
2762                 bool bret;
2763                 int ret;
2764                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2765                 seq_printf(m, "dpcd: ");
2766                 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2767                         seq_printf(m, "%02x ", buf[i]);
2768                 seq_printf(m, "\n");
2769                 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2770                 seq_printf(m, "faux/mst: ");
2771                 for (i = 0; i < 2; i++)
2772                         seq_printf(m, "%02x ", buf[i]);
2773                 seq_printf(m, "\n");
2774                 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2775                 seq_printf(m, "mst ctrl: ");
2776                 for (i = 0; i < 1; i++)
2777                         seq_printf(m, "%02x ", buf[i]);
2778                 seq_printf(m, "\n");
2779
2780                 /* dump the standard OUI branch header */
2781                 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
2782                 seq_printf(m, "branch oui: ");
2783                 for (i = 0; i < 0x3; i++)
2784                         seq_printf(m, "%02x", buf[i]);
2785                 seq_printf(m, " devid: ");
2786                 for (i = 0x3; i < 0x8; i++)
2787                         seq_printf(m, "%c", buf[i]);
2788                 seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
2789                 seq_printf(m, "\n");
2790                 bret = dump_dp_payload_table(mgr, buf);
2791                 if (bret == true) {
2792                         seq_printf(m, "payload table: ");
2793                         for (i = 0; i < 63; i++)
2794                                 seq_printf(m, "%02x ", buf[i]);
2795                         seq_printf(m, "\n");
2796                 }
2797
2798         }
2799
2800         mutex_unlock(&mgr->lock);
2801
2802 }
2803 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2804
2805 static void drm_dp_tx_work(struct work_struct *work)
2806 {
2807         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2808
2809         mutex_lock(&mgr->qlock);
2810         if (mgr->tx_down_in_progress)
2811                 process_single_down_tx_qlock(mgr);
2812         mutex_unlock(&mgr->qlock);
2813 }
2814
2815 static void drm_dp_free_mst_port(struct kref *kref)
2816 {
2817         struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
2818         kref_put(&port->parent->kref, drm_dp_free_mst_branch_device);
2819         kfree(port);
2820 }
2821
2822 static void drm_dp_destroy_connector_work(struct work_struct *work)
2823 {
2824         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
2825         struct drm_dp_mst_port *port;
2826         bool send_hotplug = false;
2827         /*
2828          * Not a regular list traverse as we have to drop the destroy
2829          * connector lock before destroying the connector, to avoid AB->BA
2830          * ordering between this lock and the config mutex.
2831          */
2832         for (;;) {
2833                 mutex_lock(&mgr->destroy_connector_lock);
2834                 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
2835                 if (!port) {
2836                         mutex_unlock(&mgr->destroy_connector_lock);
2837                         break;
2838                 }
2839                 list_del(&port->next);
2840                 mutex_unlock(&mgr->destroy_connector_lock);
2841
2842                 kref_init(&port->kref);
2843                 INIT_LIST_HEAD(&port->next);
2844
2845                 mgr->cbs->destroy_connector(mgr, port->connector);
2846
2847                 drm_dp_port_teardown_pdt(port, port->pdt);
2848
2849                 if (!port->input && port->vcpi.vcpi > 0) {
2850                         if (mgr->mst_state) {
2851                                 drm_dp_mst_reset_vcpi_slots(mgr, port);
2852                                 drm_dp_update_payload_part1(mgr);
2853                                 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2854                         }
2855                 }
2856
2857                 kref_put(&port->kref, drm_dp_free_mst_port);
2858                 send_hotplug = true;
2859         }
2860         if (send_hotplug)
2861                 (*mgr->cbs->hotplug)(mgr);
2862 }
2863
2864 /**
2865  * drm_dp_mst_topology_mgr_init - initialise a topology manager
2866  * @mgr: manager struct to initialise
2867  * @dev: device providing this structure - for i2c addition.
2868  * @aux: DP helper aux channel to talk to this device
2869  * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2870  * @max_payloads: maximum number of payloads this GPU can source
2871  * @conn_base_id: the connector object ID the MST device is connected to.
2872  *
2873  * Return 0 for success, or negative error code on failure
2874  */
2875 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2876                                  struct device *dev, struct drm_dp_aux *aux,
2877                                  int max_dpcd_transaction_bytes,
2878                                  int max_payloads, int conn_base_id)
2879 {
2880         mutex_init(&mgr->lock);
2881         mutex_init(&mgr->qlock);
2882         mutex_init(&mgr->payload_lock);
2883         mutex_init(&mgr->destroy_connector_lock);
2884         INIT_LIST_HEAD(&mgr->tx_msg_downq);
2885         INIT_LIST_HEAD(&mgr->destroy_connector_list);
2886         INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2887         INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2888         INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
2889         init_waitqueue_head(&mgr->tx_waitq);
2890         mgr->dev = dev;
2891         mgr->aux = aux;
2892         mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2893         mgr->max_payloads = max_payloads;
2894         mgr->conn_base_id = conn_base_id;
2895         mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2896         if (!mgr->payloads)
2897                 return -ENOMEM;
2898         mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2899         if (!mgr->proposed_vcpis)
2900                 return -ENOMEM;
2901         set_bit(0, &mgr->payload_mask);
2902         test_calc_pbn_mode();
2903         return 0;
2904 }
2905 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2906
2907 /**
2908  * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2909  * @mgr: manager to destroy
2910  */
2911 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2912 {
2913         flush_work(&mgr->work);
2914         flush_work(&mgr->destroy_connector_work);
2915         mutex_lock(&mgr->payload_lock);
2916         kfree(mgr->payloads);
2917         mgr->payloads = NULL;
2918         kfree(mgr->proposed_vcpis);
2919         mgr->proposed_vcpis = NULL;
2920         mutex_unlock(&mgr->payload_lock);
2921         mgr->dev = NULL;
2922         mgr->aux = NULL;
2923 }
2924 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
2925
2926 /* I2C device */
2927 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
2928                                int num)
2929 {
2930         struct drm_dp_aux *aux = adapter->algo_data;
2931         struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
2932         struct drm_dp_mst_branch *mstb;
2933         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2934         unsigned int i;
2935         bool reading = false;
2936         struct drm_dp_sideband_msg_req_body msg;
2937         struct drm_dp_sideband_msg_tx *txmsg = NULL;
2938         int ret;
2939
2940         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2941         if (!mstb)
2942                 return -EREMOTEIO;
2943
2944         /* construct i2c msg */
2945         /* see if last msg is a read */
2946         if (msgs[num - 1].flags & I2C_M_RD)
2947                 reading = true;
2948
2949         if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
2950                 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
2951                 ret = -EIO;
2952                 goto out;
2953         }
2954
2955         memset(&msg, 0, sizeof(msg));
2956         msg.req_type = DP_REMOTE_I2C_READ;
2957         msg.u.i2c_read.num_transactions = num - 1;
2958         msg.u.i2c_read.port_number = port->port_num;
2959         for (i = 0; i < num - 1; i++) {
2960                 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
2961                 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
2962                 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
2963         }
2964         msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
2965         msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
2966
2967         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2968         if (!txmsg) {
2969                 ret = -ENOMEM;
2970                 goto out;
2971         }
2972
2973         txmsg->dst = mstb;
2974         drm_dp_encode_sideband_req(&msg, txmsg);
2975
2976         drm_dp_queue_down_tx(mgr, txmsg);
2977
2978         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2979         if (ret > 0) {
2980
2981                 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
2982                         ret = -EREMOTEIO;
2983                         goto out;
2984                 }
2985                 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
2986                         ret = -EIO;
2987                         goto out;
2988                 }
2989                 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
2990                 ret = num;
2991         }
2992 out:
2993         kfree(txmsg);
2994         drm_dp_put_mst_branch_device(mstb);
2995         return ret;
2996 }
2997
2998 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
2999 {
3000         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
3001                I2C_FUNC_SMBUS_READ_BLOCK_DATA |
3002                I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
3003                I2C_FUNC_10BIT_ADDR;
3004 }
3005
3006 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
3007         .functionality = drm_dp_mst_i2c_functionality,
3008         .master_xfer = drm_dp_mst_i2c_xfer,
3009 };
3010
3011 /**
3012  * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
3013  * @aux: DisplayPort AUX channel
3014  *
3015  * Returns 0 on success or a negative error code on failure.
3016  */
3017 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
3018 {
3019         aux->ddc.algo = &drm_dp_mst_i2c_algo;
3020         aux->ddc.algo_data = aux;
3021         aux->ddc.retries = 3;
3022
3023         aux->ddc.class = I2C_CLASS_DDC;
3024         aux->ddc.owner = THIS_MODULE;
3025         aux->ddc.dev.parent = aux->dev;
3026         aux->ddc.dev.of_node = aux->dev->of_node;
3027
3028         strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
3029                 sizeof(aux->ddc.name));
3030
3031         return i2c_add_adapter(&aux->ddc);
3032 }
3033
3034 /**
3035  * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
3036  * @aux: DisplayPort AUX channel
3037  */
3038 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
3039 {
3040         i2c_del_adapter(&aux->ddc);
3041 }