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 int 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         mutex_lock(&mgr->qlock);
 737         ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
 738                txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
 739         mutex_unlock(&mgr->qlock);
 740         return ret;
 741 }
 742
 743 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
 744                                     struct drm_dp_sideband_msg_tx *txmsg)
 745 {
 746         struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
 747         int ret;
 748
 749         ret = wait_event_timeout(mgr->tx_waitq,
 750                                  check_txmsg_state(mgr, txmsg),
 751                                  (4 * HZ));
 752         mutex_lock(&mstb->mgr->qlock);
 753         if (ret > 0) {
 754                 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
 755                         ret = -EIO;
 756                         goto out;
 757                 }
 758         } else {
 759                 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
 760
 761                 /* dump some state */
 762                 ret = -EIO;
 763
 764                 /* remove from q */
 765                 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
 766                     txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
 767                         list_del(&txmsg->next);
 768                 }
 769
 770                 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
 771                     txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
 772                         mstb->tx_slots[txmsg->seqno] = NULL;
 773                 }
 774         }
 775 out:
 776         mutex_unlock(&mgr->qlock);
 777
 778         return ret;
 779 }
 780
 781 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
 782 {
 783         struct drm_dp_mst_branch *mstb;
 784
 785         mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
 786         if (!mstb)
 787                 return NULL;
 788
 789         mstb->lct = lct;
 790         if (lct > 1)
 791                 memcpy(mstb->rad, rad, lct / 2);
 792         INIT_LIST_HEAD(&mstb->ports);
 793         kref_init(&mstb->kref);
 794         return mstb;
 795 }
 796
 797 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
 798 {
 799         struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
 800         struct drm_dp_mst_port *port, *tmp;
 801         bool wake_tx = false;
 802
 803         cancel_work_sync(&mstb->mgr->work);
 804
 805         /*
 806          * destroy all ports - don't need lock
 807          * as there are no more references to the mst branch
 808          * device at this point.
 809          */
 810         list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
 811                 list_del(&port->next);
 812                 drm_dp_put_port(port);
 813         }
 814
 815         /* drop any tx slots msg */
 816         mutex_lock(&mstb->mgr->qlock);
 817         if (mstb->tx_slots[0]) {
 818                 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 819                 mstb->tx_slots[0] = NULL;
 820                 wake_tx = true;
 821         }
 822         if (mstb->tx_slots[1]) {
 823                 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 824                 mstb->tx_slots[1] = NULL;
 825                 wake_tx = true;
 826         }
 827         mutex_unlock(&mstb->mgr->qlock);
 828
 829         if (wake_tx)
 830                 wake_up(&mstb->mgr->tx_waitq);
 831         kfree(mstb);
 832 }
 833
 834 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
 835 {
 836         kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
 837 }
 838
 839
 840 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
 841 {
 842         struct drm_dp_mst_branch *mstb;
 843
 844         switch (old_pdt) {
 845         case DP_PEER_DEVICE_DP_LEGACY_CONV:
 846         case DP_PEER_DEVICE_SST_SINK:
 847                 /* remove i2c over sideband */
 848                 drm_dp_mst_unregister_i2c_bus(&port->aux);
 849                 break;
 850         case DP_PEER_DEVICE_MST_BRANCHING:
 851                 mstb = port->mstb;
 852                 port->mstb = NULL;
 853                 drm_dp_put_mst_branch_device(mstb);
 854                 break;
 855         }
 856 }
 857
 858 static void drm_dp_destroy_port(struct kref *kref)
 859 {
 860         struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
 861         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
 862         if (!port->input) {
 863                 port->vcpi.num_slots = 0;
 864
 865                 kfree(port->cached_edid);
 866                 if (port->connector)
 867                         (*port->mgr->cbs->destroy_connector)(mgr, port->connector);
 868                 drm_dp_port_teardown_pdt(port, port->pdt);
 869
 870                 if (!port->input && port->vcpi.vcpi > 0)
 871                         drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
 872         }
 873         kfree(port);
 874
 875         (*mgr->cbs->hotplug)(mgr);
 876 }
 877
 878 static void drm_dp_put_port(struct drm_dp_mst_port *port)
 879 {
 880         kref_put(&port->kref, drm_dp_destroy_port);
 881 }
 882
 883 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)
 884 {
 885         struct drm_dp_mst_port *port;
 886         struct drm_dp_mst_branch *rmstb;
 887         if (to_find == mstb) {
 888                 kref_get(&mstb->kref);
 889                 return mstb;
 890         }
 891         list_for_each_entry(port, &mstb->ports, next) {
 892                 if (port->mstb) {
 893                         rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
 894                         if (rmstb)
 895                                 return rmstb;
 896                 }
 897         }
 898         return NULL;
 899 }
 900
 901 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)
 902 {
 903         struct drm_dp_mst_branch *rmstb = NULL;
 904         mutex_lock(&mgr->lock);
 905         if (mgr->mst_primary)
 906                 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
 907         mutex_unlock(&mgr->lock);
 908         return rmstb;
 909 }
 910
 911 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)
 912 {
 913         struct drm_dp_mst_port *port, *mport;
 914
 915         list_for_each_entry(port, &mstb->ports, next) {
 916                 if (port == to_find) {
 917                         kref_get(&port->kref);
 918                         return port;
 919                 }
 920                 if (port->mstb) {
 921                         mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
 922                         if (mport)
 923                                 return mport;
 924                 }
 925         }
 926         return NULL;
 927 }
 928
 929 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)
 930 {
 931         struct drm_dp_mst_port *rport = NULL;
 932         mutex_lock(&mgr->lock);
 933         if (mgr->mst_primary)
 934                 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
 935         mutex_unlock(&mgr->lock);
 936         return rport;
 937 }
 938
 939 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
 940 {
 941         struct drm_dp_mst_port *port;
 942
 943         list_for_each_entry(port, &mstb->ports, next) {
 944                 if (port->port_num == port_num) {
 945                         kref_get(&port->kref);
 946                         return port;
 947                 }
 948         }
 949
 950         return NULL;
 951 }
 952
 953 /*
 954  * calculate a new RAD for this MST branch device
 955  * if parent has an LCT of 2 then it has 1 nibble of RAD,
 956  * if parent has an LCT of 3 then it has 2 nibbles of RAD,
 957  */
 958 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
 959                                  u8 *rad)
 960 {
 961         int lct = port->parent->lct;
 962         int shift = 4;
 963         int idx = lct / 2;
 964         if (lct > 1) {
 965                 memcpy(rad, port->parent->rad, idx);
 966                 shift = (lct % 2) ? 4 : 0;
 967         } else
 968                 rad[0] = 0;
 969
 970         rad[idx] |= port->port_num << shift;
 971         return lct + 1;
 972 }
 973
 974 /*
 975  * return sends link address for new mstb
 976  */
 977 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
 978 {
 979         int ret;
 980         u8 rad[6], lct;
 981         bool send_link = false;
 982         switch (port->pdt) {
 983         case DP_PEER_DEVICE_DP_LEGACY_CONV:
 984         case DP_PEER_DEVICE_SST_SINK:
 985                 /* add i2c over sideband */
 986                 ret = drm_dp_mst_register_i2c_bus(&port->aux);
 987                 break;
 988         case DP_PEER_DEVICE_MST_BRANCHING:
 989                 lct = drm_dp_calculate_rad(port, rad);
 990
 991                 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
 992                 port->mstb->mgr = port->mgr;
 993                 port->mstb->port_parent = port;
 994
 995                 send_link = true;
 996                 break;
 997         }
 998         return send_link;
 999 }
1000
1001 static void drm_dp_check_port_guid(struct drm_dp_mst_branch *mstb,
1002                                    struct drm_dp_mst_port *port)
1003 {
1004         int ret;
1005         if (port->dpcd_rev >= 0x12) {
1006                 port->guid_valid = drm_dp_validate_guid(mstb->mgr, port->guid);
1007                 if (!port->guid_valid) {
1008                         ret = drm_dp_send_dpcd_write(mstb->mgr,
1009                                                      port,
1010                                                      DP_GUID,
1011                                                      16, port->guid);
1012                         port->guid_valid = true;
1013                 }
1014         }
1015 }
1016
1017 static void build_mst_prop_path(struct drm_dp_mst_port *port,
1018                                 struct drm_dp_mst_branch *mstb,
1019                                 char *proppath,
1020                                 size_t proppath_size)
1021 {
1022         int i;
1023         char temp[8];
1024         snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1025         for (i = 0; i < (mstb->lct - 1); i++) {
1026                 int shift = (i % 2) ? 0 : 4;
1027                 int port_num = mstb->rad[i / 2] >> shift;
1028                 snprintf(temp, sizeof(temp), "-%d", port_num);
1029                 strlcat(proppath, temp, proppath_size);
1030         }
1031         snprintf(temp, sizeof(temp), "-%d", port->port_num);
1032         strlcat(proppath, temp, proppath_size);
1033 }
1034
1035 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1036                             struct device *dev,
1037                             struct drm_dp_link_addr_reply_port *port_msg)
1038 {
1039         struct drm_dp_mst_port *port;
1040         bool ret;
1041         bool created = false;
1042         int old_pdt = 0;
1043         int old_ddps = 0;
1044         port = drm_dp_get_port(mstb, port_msg->port_number);
1045         if (!port) {
1046                 port = kzalloc(sizeof(*port), GFP_KERNEL);
1047                 if (!port)
1048                         return;
1049                 kref_init(&port->kref);
1050                 port->parent = mstb;
1051                 port->port_num = port_msg->port_number;
1052                 port->mgr = mstb->mgr;
1053                 port->aux.name = "DPMST";
1054                 port->aux.dev = dev;
1055                 created = true;
1056         } else {
1057                 old_pdt = port->pdt;
1058                 old_ddps = port->ddps;
1059         }
1060
1061         port->pdt = port_msg->peer_device_type;
1062         port->input = port_msg->input_port;
1063         port->mcs = port_msg->mcs;
1064         port->ddps = port_msg->ddps;
1065         port->ldps = port_msg->legacy_device_plug_status;
1066         port->dpcd_rev = port_msg->dpcd_revision;
1067         port->num_sdp_streams = port_msg->num_sdp_streams;
1068         port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1069         memcpy(port->guid, port_msg->peer_guid, 16);
1070
1071         /* manage mstb port lists with mgr lock - take a reference
1072            for this list */
1073         if (created) {
1074                 mutex_lock(&mstb->mgr->lock);
1075                 kref_get(&port->kref);
1076                 list_add(&port->next, &mstb->ports);
1077                 mutex_unlock(&mstb->mgr->lock);
1078         }
1079
1080         if (old_ddps != port->ddps) {
1081                 if (port->ddps) {
1082                         drm_dp_check_port_guid(mstb, port);
1083                         if (!port->input)
1084                                 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1085                 } else {
1086                         port->guid_valid = false;
1087                         port->available_pbn = 0;
1088                         }
1089         }
1090
1091         if (old_pdt != port->pdt && !port->input) {
1092                 drm_dp_port_teardown_pdt(port, old_pdt);
1093
1094                 ret = drm_dp_port_setup_pdt(port);
1095                 if (ret == true) {
1096                         drm_dp_send_link_address(mstb->mgr, port->mstb);
1097                         port->mstb->link_address_sent = true;
1098                 }
1099         }
1100
1101         if (created && !port->input) {
1102                 char proppath[255];
1103                 build_mst_prop_path(port, mstb, proppath, sizeof(proppath));
1104                 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1105
1106                 if (port->port_num >= 8) {
1107                         port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1108                 }
1109         }
1110
1111         /* put reference to this port */
1112         drm_dp_put_port(port);
1113 }
1114
1115 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1116                                struct drm_dp_connection_status_notify *conn_stat)
1117 {
1118         struct drm_dp_mst_port *port;
1119         int old_pdt;
1120         int old_ddps;
1121         bool dowork = false;
1122         port = drm_dp_get_port(mstb, conn_stat->port_number);
1123         if (!port)
1124                 return;
1125
1126         old_ddps = port->ddps;
1127         old_pdt = port->pdt;
1128         port->pdt = conn_stat->peer_device_type;
1129         port->mcs = conn_stat->message_capability_status;
1130         port->ldps = conn_stat->legacy_device_plug_status;
1131         port->ddps = conn_stat->displayport_device_plug_status;
1132
1133         if (old_ddps != port->ddps) {
1134                 if (port->ddps) {
1135                         drm_dp_check_port_guid(mstb, port);
1136                         dowork = true;
1137                 } else {
1138                         port->guid_valid = false;
1139                         port->available_pbn = 0;
1140                 }
1141         }
1142         if (old_pdt != port->pdt && !port->input) {
1143                 drm_dp_port_teardown_pdt(port, old_pdt);
1144
1145                 if (drm_dp_port_setup_pdt(port))
1146                         dowork = true;
1147         }
1148
1149         drm_dp_put_port(port);
1150         if (dowork)
1151                 queue_work(system_long_wq, &mstb->mgr->work);
1152
1153 }
1154
1155 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1156                                                                u8 lct, u8 *rad)
1157 {
1158         struct drm_dp_mst_branch *mstb;
1159         struct drm_dp_mst_port *port;
1160         int i;
1161         /* find the port by iterating down */
1162         mstb = mgr->mst_primary;
1163
1164         for (i = 0; i < lct - 1; i++) {
1165                 int shift = (i % 2) ? 0 : 4;
1166                 int port_num = rad[i / 2] >> shift;
1167
1168                 list_for_each_entry(port, &mstb->ports, next) {
1169                         if (port->port_num == port_num) {
1170                                 if (!port->mstb) {
1171                                         DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1172                                         return NULL;
1173                                 }
1174
1175                                 mstb = port->mstb;
1176                                 break;
1177                         }
1178                 }
1179         }
1180         kref_get(&mstb->kref);
1181         return mstb;
1182 }
1183
1184 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1185                                                struct drm_dp_mst_branch *mstb)
1186 {
1187         struct drm_dp_mst_port *port;
1188
1189         if (!mstb->link_address_sent) {
1190                 drm_dp_send_link_address(mgr, mstb);
1191                 mstb->link_address_sent = true;
1192         }
1193         list_for_each_entry(port, &mstb->ports, next) {
1194                 if (port->input)
1195                         continue;
1196
1197                 if (!port->ddps)
1198                         continue;
1199
1200                 if (!port->available_pbn)
1201                         drm_dp_send_enum_path_resources(mgr, mstb, port);
1202
1203                 if (port->mstb)
1204                         drm_dp_check_and_send_link_address(mgr, port->mstb);
1205         }
1206 }
1207
1208 static void drm_dp_mst_link_probe_work(struct work_struct *work)
1209 {
1210         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1211
1212         drm_dp_check_and_send_link_address(mgr, mgr->mst_primary);
1213
1214 }
1215
1216 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1217                                  u8 *guid)
1218 {
1219         static u8 zero_guid[16];
1220
1221         if (!memcmp(guid, zero_guid, 16)) {
1222                 u64 salt = get_jiffies_64();
1223                 memcpy(&guid[0], &salt, sizeof(u64));
1224                 memcpy(&guid[8], &salt, sizeof(u64));
1225                 return false;
1226         }
1227         return true;
1228 }
1229
1230 #if 0
1231 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1232 {
1233         struct drm_dp_sideband_msg_req_body req;
1234
1235         req.req_type = DP_REMOTE_DPCD_READ;
1236         req.u.dpcd_read.port_number = port_num;
1237         req.u.dpcd_read.dpcd_address = offset;
1238         req.u.dpcd_read.num_bytes = num_bytes;
1239         drm_dp_encode_sideband_req(&req, msg);
1240
1241         return 0;
1242 }
1243 #endif
1244
1245 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1246                                     bool up, u8 *msg, int len)
1247 {
1248         int ret;
1249         int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1250         int tosend, total, offset;
1251         int retries = 0;
1252
1253 retry:
1254         total = len;
1255         offset = 0;
1256         do {
1257                 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1258
1259                 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1260                                         &msg[offset],
1261                                         tosend);
1262                 if (ret != tosend) {
1263                         if (ret == -EIO && retries < 5) {
1264                                 retries++;
1265                                 goto retry;
1266                         }
1267                         DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1268                         WARN(1, "fail\n");
1269
1270                         return -EIO;
1271                 }
1272                 offset += tosend;
1273                 total -= tosend;
1274         } while (total > 0);
1275         return 0;
1276 }
1277
1278 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1279                                   struct drm_dp_sideband_msg_tx *txmsg)
1280 {
1281         struct drm_dp_mst_branch *mstb = txmsg->dst;
1282
1283         /* both msg slots are full */
1284         if (txmsg->seqno == -1) {
1285                 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1286                         DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1287                         return -EAGAIN;
1288                 }
1289                 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1290                         txmsg->seqno = mstb->last_seqno;
1291                         mstb->last_seqno ^= 1;
1292                 } else if (mstb->tx_slots[0] == NULL)
1293                         txmsg->seqno = 0;
1294                 else
1295                         txmsg->seqno = 1;
1296                 mstb->tx_slots[txmsg->seqno] = txmsg;
1297         }
1298         hdr->broadcast = 0;
1299         hdr->path_msg = txmsg->path_msg;
1300         hdr->lct = mstb->lct;
1301         hdr->lcr = mstb->lct - 1;
1302         if (mstb->lct > 1)
1303                 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1304         hdr->seqno = txmsg->seqno;
1305         return 0;
1306 }
1307 /*
1308  * process a single block of the next message in the sideband queue
1309  */
1310 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1311                                    struct drm_dp_sideband_msg_tx *txmsg,
1312                                    bool up)
1313 {
1314         u8 chunk[48];
1315         struct drm_dp_sideband_msg_hdr hdr;
1316         int len, space, idx, tosend;
1317         int ret;
1318
1319         memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1320
1321         if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1322                 txmsg->seqno = -1;
1323                 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1324         }
1325
1326         /* make hdr from dst mst - for replies use seqno
1327            otherwise assign one */
1328         ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1329         if (ret < 0)
1330                 return ret;
1331
1332         /* amount left to send in this message */
1333         len = txmsg->cur_len - txmsg->cur_offset;
1334
1335         /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1336         space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1337
1338         tosend = min(len, space);
1339         if (len == txmsg->cur_len)
1340                 hdr.somt = 1;
1341         if (space >= len)
1342                 hdr.eomt = 1;
1343
1344
1345         hdr.msg_len = tosend + 1;
1346         drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1347         memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1348         /* add crc at end */
1349         drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1350         idx += tosend + 1;
1351
1352         ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1353         if (ret) {
1354                 DRM_DEBUG_KMS("sideband msg failed to send\n");
1355                 return ret;
1356         }
1357
1358         txmsg->cur_offset += tosend;
1359         if (txmsg->cur_offset == txmsg->cur_len) {
1360                 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1361                 return 1;
1362         }
1363         return 0;
1364 }
1365
1366 /* must be called holding qlock */
1367 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1368 {
1369         struct drm_dp_sideband_msg_tx *txmsg;
1370         int ret;
1371
1372         /* construct a chunk from the first msg in the tx_msg queue */
1373         if (list_empty(&mgr->tx_msg_downq)) {
1374                 mgr->tx_down_in_progress = false;
1375                 return;
1376         }
1377         mgr->tx_down_in_progress = true;
1378
1379         txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1380         ret = process_single_tx_qlock(mgr, txmsg, false);
1381         if (ret == 1) {
1382                 /* txmsg is sent it should be in the slots now */
1383                 list_del(&txmsg->next);
1384         } else if (ret) {
1385                 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1386                 list_del(&txmsg->next);
1387                 if (txmsg->seqno != -1)
1388                         txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1389                 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1390                 wake_up(&mgr->tx_waitq);
1391         }
1392         if (list_empty(&mgr->tx_msg_downq)) {
1393                 mgr->tx_down_in_progress = false;
1394                 return;
1395         }
1396 }
1397
1398 /* called holding qlock */
1399 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1400 {
1401         struct drm_dp_sideband_msg_tx *txmsg;
1402         int ret;
1403
1404         /* construct a chunk from the first msg in the tx_msg queue */
1405         if (list_empty(&mgr->tx_msg_upq)) {
1406                 mgr->tx_up_in_progress = false;
1407                 return;
1408         }
1409
1410         txmsg = list_first_entry(&mgr->tx_msg_upq, struct drm_dp_sideband_msg_tx, next);
1411         ret = process_single_tx_qlock(mgr, txmsg, true);
1412         if (ret == 1) {
1413                 /* up txmsgs aren't put in slots - so free after we send it */
1414                 list_del(&txmsg->next);
1415                 kfree(txmsg);
1416         } else if (ret)
1417                 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1418         mgr->tx_up_in_progress = true;
1419 }
1420
1421 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1422                                  struct drm_dp_sideband_msg_tx *txmsg)
1423 {
1424         mutex_lock(&mgr->qlock);
1425         list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1426         if (!mgr->tx_down_in_progress)
1427                 process_single_down_tx_qlock(mgr);
1428         mutex_unlock(&mgr->qlock);
1429 }
1430
1431 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1432                                     struct drm_dp_mst_branch *mstb)
1433 {
1434         int len;
1435         struct drm_dp_sideband_msg_tx *txmsg;
1436         int ret;
1437
1438         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1439         if (!txmsg)
1440                 return -ENOMEM;
1441
1442         txmsg->dst = mstb;
1443         len = build_link_address(txmsg);
1444
1445         drm_dp_queue_down_tx(mgr, txmsg);
1446
1447         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1448         if (ret > 0) {
1449                 int i;
1450
1451                 if (txmsg->reply.reply_type == 1)
1452                         DRM_DEBUG_KMS("link address nak received\n");
1453                 else {
1454                         DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1455                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1456                                 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,
1457                                        txmsg->reply.u.link_addr.ports[i].input_port,
1458                                        txmsg->reply.u.link_addr.ports[i].peer_device_type,
1459                                        txmsg->reply.u.link_addr.ports[i].port_number,
1460                                        txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1461                                        txmsg->reply.u.link_addr.ports[i].mcs,
1462                                        txmsg->reply.u.link_addr.ports[i].ddps,
1463                                        txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1464                                        txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1465                                        txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1466                         }
1467                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1468                                 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1469                         }
1470                         (*mgr->cbs->hotplug)(mgr);
1471                 }
1472         } else
1473                 DRM_DEBUG_KMS("link address failed %d\n", ret);
1474
1475         kfree(txmsg);
1476         return 0;
1477 }
1478
1479 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1480                                            struct drm_dp_mst_branch *mstb,
1481                                            struct drm_dp_mst_port *port)
1482 {
1483         int len;
1484         struct drm_dp_sideband_msg_tx *txmsg;
1485         int ret;
1486
1487         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1488         if (!txmsg)
1489                 return -ENOMEM;
1490
1491         txmsg->dst = mstb;
1492         len = build_enum_path_resources(txmsg, port->port_num);
1493
1494         drm_dp_queue_down_tx(mgr, txmsg);
1495
1496         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1497         if (ret > 0) {
1498                 if (txmsg->reply.reply_type == 1)
1499                         DRM_DEBUG_KMS("enum path resources nak received\n");
1500                 else {
1501                         if (port->port_num != txmsg->reply.u.path_resources.port_number)
1502                                 DRM_ERROR("got incorrect port in response\n");
1503                         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,
1504                                txmsg->reply.u.path_resources.avail_payload_bw_number);
1505                         port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1506                 }
1507         }
1508
1509         kfree(txmsg);
1510         return 0;
1511 }
1512
1513 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1514                                    struct drm_dp_mst_port *port,
1515                                    int id,
1516                                    int pbn)
1517 {
1518         struct drm_dp_sideband_msg_tx *txmsg;
1519         struct drm_dp_mst_branch *mstb;
1520         int len, ret;
1521
1522         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1523         if (!mstb)
1524                 return -EINVAL;
1525
1526         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1527         if (!txmsg) {
1528                 ret = -ENOMEM;
1529                 goto fail_put;
1530         }
1531
1532         txmsg->dst = mstb;
1533         len = build_allocate_payload(txmsg, port->port_num,
1534                                      id,
1535                                      pbn);
1536
1537         drm_dp_queue_down_tx(mgr, txmsg);
1538
1539         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1540         if (ret > 0) {
1541                 if (txmsg->reply.reply_type == 1) {
1542                         ret = -EINVAL;
1543                 } else
1544                         ret = 0;
1545         }
1546         kfree(txmsg);
1547 fail_put:
1548         drm_dp_put_mst_branch_device(mstb);
1549         return ret;
1550 }
1551
1552 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1553                                        int id,
1554                                        struct drm_dp_payload *payload)
1555 {
1556         int ret;
1557
1558         ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1559         if (ret < 0) {
1560                 payload->payload_state = 0;
1561                 return ret;
1562         }
1563         payload->payload_state = DP_PAYLOAD_LOCAL;
1564         return 0;
1565 }
1566
1567 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1568                                        struct drm_dp_mst_port *port,
1569                                        int id,
1570                                        struct drm_dp_payload *payload)
1571 {
1572         int ret;
1573         ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1574         if (ret < 0)
1575                 return ret;
1576         payload->payload_state = DP_PAYLOAD_REMOTE;
1577         return ret;
1578 }
1579
1580 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1581                                         struct drm_dp_mst_port *port,
1582                                         int id,
1583                                         struct drm_dp_payload *payload)
1584 {
1585         DRM_DEBUG_KMS("\n");
1586         /* its okay for these to fail */
1587         if (port) {
1588                 drm_dp_payload_send_msg(mgr, port, id, 0);
1589         }
1590
1591         drm_dp_dpcd_write_payload(mgr, id, payload);
1592         payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1593         return 0;
1594 }
1595
1596 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1597                                         int id,
1598                                         struct drm_dp_payload *payload)
1599 {
1600         payload->payload_state = 0;
1601         return 0;
1602 }
1603
1604 /**
1605  * drm_dp_update_payload_part1() - Execute payload update part 1
1606  * @mgr: manager to use.
1607  *
1608  * This iterates over all proposed virtual channels, and tries to
1609  * allocate space in the link for them. For 0->slots transitions,
1610  * this step just writes the VCPI to the MST device. For slots->0
1611  * transitions, this writes the updated VCPIs and removes the
1612  * remote VC payloads.
1613  *
1614  * after calling this the driver should generate ACT and payload
1615  * packets.
1616  */
1617 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1618 {
1619         int i, j;
1620         int cur_slots = 1;
1621         struct drm_dp_payload req_payload;
1622         struct drm_dp_mst_port *port;
1623
1624         mutex_lock(&mgr->payload_lock);
1625         for (i = 0; i < mgr->max_payloads; i++) {
1626                 /* solve the current payloads - compare to the hw ones
1627                    - update the hw view */
1628                 req_payload.start_slot = cur_slots;
1629                 if (mgr->proposed_vcpis[i]) {
1630                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1631                         req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1632                 } else {
1633                         port = NULL;
1634                         req_payload.num_slots = 0;
1635                 }
1636
1637                 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1638                         mgr->payloads[i].start_slot = req_payload.start_slot;
1639                 }
1640                 /* work out what is required to happen with this payload */
1641                 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1642
1643                         /* need to push an update for this payload */
1644                         if (req_payload.num_slots) {
1645                                 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1646                                 mgr->payloads[i].num_slots = req_payload.num_slots;
1647                         } else if (mgr->payloads[i].num_slots) {
1648                                 mgr->payloads[i].num_slots = 0;
1649                                 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
1650                                 req_payload.payload_state = mgr->payloads[i].payload_state;
1651                                 mgr->payloads[i].start_slot = 0;
1652                         }
1653                         mgr->payloads[i].payload_state = req_payload.payload_state;
1654                 }
1655                 cur_slots += req_payload.num_slots;
1656         }
1657
1658         for (i = 0; i < mgr->max_payloads; i++) {
1659                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1660                         DRM_DEBUG_KMS("removing payload %d\n", i);
1661                         for (j = i; j < mgr->max_payloads - 1; j++) {
1662                                 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1663                                 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1664                                 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1665                                         set_bit(j + 1, &mgr->payload_mask);
1666                                 } else {
1667                                         clear_bit(j + 1, &mgr->payload_mask);
1668                                 }
1669                         }
1670                         memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1671                         mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1672                         clear_bit(mgr->max_payloads, &mgr->payload_mask);
1673
1674                 }
1675         }
1676         mutex_unlock(&mgr->payload_lock);
1677
1678         return 0;
1679 }
1680 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1681
1682 /**
1683  * drm_dp_update_payload_part2() - Execute payload update part 2
1684  * @mgr: manager to use.
1685  *
1686  * This iterates over all proposed virtual channels, and tries to
1687  * allocate space in the link for them. For 0->slots transitions,
1688  * this step writes the remote VC payload commands. For slots->0
1689  * this just resets some internal state.
1690  */
1691 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1692 {
1693         struct drm_dp_mst_port *port;
1694         int i;
1695         int ret = 0;
1696         mutex_lock(&mgr->payload_lock);
1697         for (i = 0; i < mgr->max_payloads; i++) {
1698
1699                 if (!mgr->proposed_vcpis[i])
1700                         continue;
1701
1702                 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1703
1704                 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1705                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1706                         ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1707                 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1708                         ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1709                 }
1710                 if (ret) {
1711                         mutex_unlock(&mgr->payload_lock);
1712                         return ret;
1713                 }
1714         }
1715         mutex_unlock(&mgr->payload_lock);
1716         return 0;
1717 }
1718 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1719
1720 #if 0 /* unused as of yet */
1721 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1722                                  struct drm_dp_mst_port *port,
1723                                  int offset, int size)
1724 {
1725         int len;
1726         struct drm_dp_sideband_msg_tx *txmsg;
1727
1728         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1729         if (!txmsg)
1730                 return -ENOMEM;
1731
1732         len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1733         txmsg->dst = port->parent;
1734
1735         drm_dp_queue_down_tx(mgr, txmsg);
1736
1737         return 0;
1738 }
1739 #endif
1740
1741 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1742                                   struct drm_dp_mst_port *port,
1743                                   int offset, int size, u8 *bytes)
1744 {
1745         int len;
1746         int ret;
1747         struct drm_dp_sideband_msg_tx *txmsg;
1748         struct drm_dp_mst_branch *mstb;
1749
1750         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1751         if (!mstb)
1752                 return -EINVAL;
1753
1754         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1755         if (!txmsg) {
1756                 ret = -ENOMEM;
1757                 goto fail_put;
1758         }
1759
1760         len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1761         txmsg->dst = mstb;
1762
1763         drm_dp_queue_down_tx(mgr, txmsg);
1764
1765         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1766         if (ret > 0) {
1767                 if (txmsg->reply.reply_type == 1) {
1768                         ret = -EINVAL;
1769                 } else
1770                         ret = 0;
1771         }
1772         kfree(txmsg);
1773 fail_put:
1774         drm_dp_put_mst_branch_device(mstb);
1775         return ret;
1776 }
1777
1778 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1779 {
1780         struct drm_dp_sideband_msg_reply_body reply;
1781
1782         reply.reply_type = 1;
1783         reply.req_type = req_type;
1784         drm_dp_encode_sideband_reply(&reply, msg);
1785         return 0;
1786 }
1787
1788 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1789                                     struct drm_dp_mst_branch *mstb,
1790                                     int req_type, int seqno, bool broadcast)
1791 {
1792         struct drm_dp_sideband_msg_tx *txmsg;
1793
1794         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1795         if (!txmsg)
1796                 return -ENOMEM;
1797
1798         txmsg->dst = mstb;
1799         txmsg->seqno = seqno;
1800         drm_dp_encode_up_ack_reply(txmsg, req_type);
1801
1802         mutex_lock(&mgr->qlock);
1803         list_add_tail(&txmsg->next, &mgr->tx_msg_upq);
1804         if (!mgr->tx_up_in_progress) {
1805                 process_single_up_tx_qlock(mgr);
1806         }
1807         mutex_unlock(&mgr->qlock);
1808         return 0;
1809 }
1810
1811 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1812                                      int dp_link_count,
1813                                      int *out)
1814 {
1815         switch (dp_link_bw) {
1816         default:
1817                 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1818                               dp_link_bw, dp_link_count);
1819                 return false;
1820
1821         case DP_LINK_BW_1_62:
1822                 *out = 3 * dp_link_count;
1823                 break;
1824         case DP_LINK_BW_2_7:
1825                 *out = 5 * dp_link_count;
1826                 break;
1827         case DP_LINK_BW_5_4:
1828                 *out = 10 * dp_link_count;
1829                 break;
1830         }
1831         return true;
1832 }
1833
1834 /**
1835  * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
1836  * @mgr: manager to set state for
1837  * @mst_state: true to enable MST on this connector - false to disable.
1838  *
1839  * This is called by the driver when it detects an MST capable device plugged
1840  * into a DP MST capable port, or when a DP MST capable device is unplugged.
1841  */
1842 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
1843 {
1844         int ret = 0;
1845         struct drm_dp_mst_branch *mstb = NULL;
1846
1847         mutex_lock(&mgr->lock);
1848         if (mst_state == mgr->mst_state)
1849                 goto out_unlock;
1850
1851         mgr->mst_state = mst_state;
1852         /* set the device into MST mode */
1853         if (mst_state) {
1854                 WARN_ON(mgr->mst_primary);
1855
1856                 /* get dpcd info */
1857                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
1858                 if (ret != DP_RECEIVER_CAP_SIZE) {
1859                         DRM_DEBUG_KMS("failed to read DPCD\n");
1860                         goto out_unlock;
1861                 }
1862
1863                 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
1864                                               mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
1865                                               &mgr->pbn_div)) {
1866                         ret = -EINVAL;
1867                         goto out_unlock;
1868                 }
1869
1870                 mgr->total_pbn = 2560;
1871                 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
1872                 mgr->avail_slots = mgr->total_slots;
1873
1874                 /* add initial branch device at LCT 1 */
1875                 mstb = drm_dp_add_mst_branch_device(1, NULL);
1876                 if (mstb == NULL) {
1877                         ret = -ENOMEM;
1878                         goto out_unlock;
1879                 }
1880                 mstb->mgr = mgr;
1881
1882                 /* give this the main reference */
1883                 mgr->mst_primary = mstb;
1884                 kref_get(&mgr->mst_primary->kref);
1885
1886                 {
1887                         struct drm_dp_payload reset_pay;
1888                         reset_pay.start_slot = 0;
1889                         reset_pay.num_slots = 0x3f;
1890                         drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
1891                 }
1892
1893                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1894                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
1895                 if (ret < 0) {
1896                         goto out_unlock;
1897                 }
1898
1899
1900                 /* sort out guid */
1901                 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
1902                 if (ret != 16) {
1903                         DRM_DEBUG_KMS("failed to read DP GUID %d\n", ret);
1904                         goto out_unlock;
1905                 }
1906
1907                 mgr->guid_valid = drm_dp_validate_guid(mgr, mgr->guid);
1908                 if (!mgr->guid_valid) {
1909                         ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, mgr->guid, 16);
1910                         mgr->guid_valid = true;
1911                 }
1912
1913                 queue_work(system_long_wq, &mgr->work);
1914
1915                 ret = 0;
1916         } else {
1917                 /* disable MST on the device */
1918                 mstb = mgr->mst_primary;
1919                 mgr->mst_primary = NULL;
1920                 /* this can fail if the device is gone */
1921                 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
1922                 ret = 0;
1923                 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
1924                 mgr->payload_mask = 0;
1925                 set_bit(0, &mgr->payload_mask);
1926                 mgr->vcpi_mask = 0;
1927         }
1928
1929 out_unlock:
1930         mutex_unlock(&mgr->lock);
1931         if (mstb)
1932                 drm_dp_put_mst_branch_device(mstb);
1933         return ret;
1934
1935 }
1936 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
1937
1938 /**
1939  * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
1940  * @mgr: manager to suspend
1941  *
1942  * This function tells the MST device that we can't handle UP messages
1943  * anymore. This should stop it from sending any since we are suspended.
1944  */
1945 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
1946 {
1947         mutex_lock(&mgr->lock);
1948         drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1949                            DP_MST_EN | DP_UPSTREAM_IS_SRC);
1950         mutex_unlock(&mgr->lock);
1951 }
1952 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
1953
1954 /**
1955  * drm_dp_mst_topology_mgr_resume() - resume the MST manager
1956  * @mgr: manager to resume
1957  *
1958  * This will fetch DPCD and see if the device is still there,
1959  * if it is, it will rewrite the MSTM control bits, and return.
1960  *
1961  * if the device fails this returns -1, and the driver should do
1962  * a full MST reprobe, in case we were undocked.
1963  */
1964 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
1965 {
1966         int ret = 0;
1967
1968         mutex_lock(&mgr->lock);
1969
1970         if (mgr->mst_primary) {
1971                 int sret;
1972                 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
1973                 if (sret != DP_RECEIVER_CAP_SIZE) {
1974                         DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
1975                         ret = -1;
1976                         goto out_unlock;
1977                 }
1978
1979                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1980                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
1981                 if (ret < 0) {
1982                         DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
1983                         ret = -1;
1984                         goto out_unlock;
1985                 }
1986                 ret = 0;
1987         } else
1988                 ret = -1;
1989
1990 out_unlock:
1991         mutex_unlock(&mgr->lock);
1992         return ret;
1993 }
1994 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
1995
1996 static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
1997 {
1998         int len;
1999         u8 replyblock[32];
2000         int replylen, origlen, curreply;
2001         int ret;
2002         struct drm_dp_sideband_msg_rx *msg;
2003         int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2004         msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2005
2006         len = min(mgr->max_dpcd_transaction_bytes, 16);
2007         ret = drm_dp_dpcd_read(mgr->aux, basereg,
2008                                replyblock, len);
2009         if (ret != len) {
2010                 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2011                 return;
2012         }
2013         ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2014         if (!ret) {
2015                 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2016                 return;
2017         }
2018         replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2019
2020         origlen = replylen;
2021         replylen -= len;
2022         curreply = len;
2023         while (replylen > 0) {
2024                 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2025                 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2026                                     replyblock, len);
2027                 if (ret != len) {
2028                         DRM_DEBUG_KMS("failed to read a chunk\n");
2029                 }
2030                 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2031                 if (ret == false)
2032                         DRM_DEBUG_KMS("failed to build sideband msg\n");
2033                 curreply += len;
2034                 replylen -= len;
2035         }
2036 }
2037
2038 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2039 {
2040         int ret = 0;
2041
2042         drm_dp_get_one_sb_msg(mgr, false);
2043
2044         if (mgr->down_rep_recv.have_eomt) {
2045                 struct drm_dp_sideband_msg_tx *txmsg;
2046                 struct drm_dp_mst_branch *mstb;
2047                 int slot = -1;
2048                 mstb = drm_dp_get_mst_branch_device(mgr,
2049                                                     mgr->down_rep_recv.initial_hdr.lct,
2050                                                     mgr->down_rep_recv.initial_hdr.rad);
2051
2052                 if (!mstb) {
2053                         DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2054                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2055                         return 0;
2056                 }
2057
2058                 /* find the message */
2059                 slot = mgr->down_rep_recv.initial_hdr.seqno;
2060                 mutex_lock(&mgr->qlock);
2061                 txmsg = mstb->tx_slots[slot];
2062                 /* remove from slots */
2063                 mutex_unlock(&mgr->qlock);
2064
2065                 if (!txmsg) {
2066                         DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2067                                mstb,
2068                                mgr->down_rep_recv.initial_hdr.seqno,
2069                                mgr->down_rep_recv.initial_hdr.lct,
2070                                       mgr->down_rep_recv.initial_hdr.rad[0],
2071                                       mgr->down_rep_recv.msg[0]);
2072                         drm_dp_put_mst_branch_device(mstb);
2073                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2074                         return 0;
2075                 }
2076
2077                 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2078                 if (txmsg->reply.reply_type == 1) {
2079                         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);
2080                 }
2081
2082                 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2083                 drm_dp_put_mst_branch_device(mstb);
2084
2085                 mutex_lock(&mgr->qlock);
2086                 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2087                 mstb->tx_slots[slot] = NULL;
2088                 mutex_unlock(&mgr->qlock);
2089
2090                 wake_up(&mgr->tx_waitq);
2091         }
2092         return ret;
2093 }
2094
2095 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2096 {
2097         int ret = 0;
2098         drm_dp_get_one_sb_msg(mgr, true);
2099
2100         if (mgr->up_req_recv.have_eomt) {
2101                 struct drm_dp_sideband_msg_req_body msg;
2102                 struct drm_dp_mst_branch *mstb;
2103                 bool seqno;
2104                 mstb = drm_dp_get_mst_branch_device(mgr,
2105                                                     mgr->up_req_recv.initial_hdr.lct,
2106                                                     mgr->up_req_recv.initial_hdr.rad);
2107                 if (!mstb) {
2108                         DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2109                         memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2110                         return 0;
2111                 }
2112
2113                 seqno = mgr->up_req_recv.initial_hdr.seqno;
2114                 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2115
2116                 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2117                         drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
2118                         drm_dp_update_port(mstb, &msg.u.conn_stat);
2119                         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);
2120                         (*mgr->cbs->hotplug)(mgr);
2121
2122                 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2123                         drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
2124                         DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2125                 }
2126
2127                 drm_dp_put_mst_branch_device(mstb);
2128                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2129         }
2130         return ret;
2131 }
2132
2133 /**
2134  * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2135  * @mgr: manager to notify irq for.
2136  * @esi: 4 bytes from SINK_COUNT_ESI
2137  * @handled: whether the hpd interrupt was consumed or not
2138  *
2139  * This should be called from the driver when it detects a short IRQ,
2140  * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2141  * topology manager will process the sideband messages received as a result
2142  * of this.
2143  */
2144 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2145 {
2146         int ret = 0;
2147         int sc;
2148         *handled = false;
2149         sc = esi[0] & 0x3f;
2150
2151         if (sc != mgr->sink_count) {
2152                 mgr->sink_count = sc;
2153                 *handled = true;
2154         }
2155
2156         if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2157                 ret = drm_dp_mst_handle_down_rep(mgr);
2158                 *handled = true;
2159         }
2160
2161         if (esi[1] & DP_UP_REQ_MSG_RDY) {
2162                 ret |= drm_dp_mst_handle_up_req(mgr);
2163                 *handled = true;
2164         }
2165
2166         drm_dp_mst_kick_tx(mgr);
2167         return ret;
2168 }
2169 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2170
2171 /**
2172  * drm_dp_mst_detect_port() - get connection status for an MST port
2173  * @mgr: manager for this port
2174  * @port: unverified pointer to a port
2175  *
2176  * This returns the current connection state for a port. It validates the
2177  * port pointer still exists so the caller doesn't require a reference
2178  */
2179 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2180                                                  struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2181 {
2182         enum drm_connector_status status = connector_status_disconnected;
2183
2184         /* we need to search for the port in the mgr in case its gone */
2185         port = drm_dp_get_validated_port_ref(mgr, port);
2186         if (!port)
2187                 return connector_status_disconnected;
2188
2189         if (!port->ddps)
2190                 goto out;
2191
2192         switch (port->pdt) {
2193         case DP_PEER_DEVICE_NONE:
2194         case DP_PEER_DEVICE_MST_BRANCHING:
2195                 break;
2196
2197         case DP_PEER_DEVICE_SST_SINK:
2198                 status = connector_status_connected;
2199                 /* for logical ports - cache the EDID */
2200                 if (port->port_num >= 8 && !port->cached_edid) {
2201                         port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2202                 }
2203                 break;
2204         case DP_PEER_DEVICE_DP_LEGACY_CONV:
2205                 if (port->ldps)
2206                         status = connector_status_connected;
2207                 break;
2208         }
2209 out:
2210         drm_dp_put_port(port);
2211         return status;
2212 }
2213 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2214
2215 /**
2216  * drm_dp_mst_get_edid() - get EDID for an MST port
2217  * @connector: toplevel connector to get EDID for
2218  * @mgr: manager for this port
2219  * @port: unverified pointer to a port.
2220  *
2221  * This returns an EDID for the port connected to a connector,
2222  * It validates the pointer still exists so the caller doesn't require a
2223  * reference.
2224  */
2225 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2226 {
2227         struct edid *edid = NULL;
2228
2229         /* we need to search for the port in the mgr in case its gone */
2230         port = drm_dp_get_validated_port_ref(mgr, port);
2231         if (!port)
2232                 return NULL;
2233
2234         if (port->cached_edid)
2235                 edid = drm_edid_duplicate(port->cached_edid);
2236         else
2237                 edid = drm_get_edid(connector, &port->aux.ddc);
2238
2239         drm_mode_connector_set_tile_property(connector);
2240         drm_dp_put_port(port);
2241         return edid;
2242 }
2243 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2244
2245 /**
2246  * drm_dp_find_vcpi_slots() - find slots for this PBN value
2247  * @mgr: manager to use
2248  * @pbn: payload bandwidth to convert into slots.
2249  */
2250 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2251                            int pbn)
2252 {
2253         int num_slots;
2254
2255         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2256
2257         if (num_slots > mgr->avail_slots)
2258                 return -ENOSPC;
2259         return num_slots;
2260 }
2261 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2262
2263 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2264                             struct drm_dp_vcpi *vcpi, int pbn)
2265 {
2266         int num_slots;
2267         int ret;
2268
2269         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2270
2271         if (num_slots > mgr->avail_slots)
2272                 return -ENOSPC;
2273
2274         vcpi->pbn = pbn;
2275         vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2276         vcpi->num_slots = num_slots;
2277
2278         ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2279         if (ret < 0)
2280                 return ret;
2281         return 0;
2282 }
2283
2284 /**
2285  * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2286  * @mgr: manager for this port
2287  * @port: port to allocate a virtual channel for.
2288  * @pbn: payload bandwidth number to request
2289  * @slots: returned number of slots for this PBN.
2290  */
2291 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2292 {
2293         int ret;
2294
2295         port = drm_dp_get_validated_port_ref(mgr, port);
2296         if (!port)
2297                 return false;
2298
2299         if (port->vcpi.vcpi > 0) {
2300                 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2301                 if (pbn == port->vcpi.pbn) {
2302                         *slots = port->vcpi.num_slots;
2303                         return true;
2304                 }
2305         }
2306
2307         ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2308         if (ret) {
2309                 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2310                 goto out;
2311         }
2312         DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2313         *slots = port->vcpi.num_slots;
2314
2315         drm_dp_put_port(port);
2316         return true;
2317 out:
2318         return false;
2319 }
2320 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2321
2322 /**
2323  * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2324  * @mgr: manager for this port
2325  * @port: unverified pointer to a port.
2326  *
2327  * This just resets the number of slots for the ports VCPI for later programming.
2328  */
2329 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2330 {
2331         port = drm_dp_get_validated_port_ref(mgr, port);
2332         if (!port)
2333                 return;
2334         port->vcpi.num_slots = 0;
2335         drm_dp_put_port(port);
2336 }
2337 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2338
2339 /**
2340  * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2341  * @mgr: manager for this port
2342  * @port: unverified port to deallocate vcpi for
2343  */
2344 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2345 {
2346         port = drm_dp_get_validated_port_ref(mgr, port);
2347         if (!port)
2348                 return;
2349
2350         drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2351         port->vcpi.num_slots = 0;
2352         port->vcpi.pbn = 0;
2353         port->vcpi.aligned_pbn = 0;
2354         port->vcpi.vcpi = 0;
2355         drm_dp_put_port(port);
2356 }
2357 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2358
2359 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2360                                      int id, struct drm_dp_payload *payload)
2361 {
2362         u8 payload_alloc[3], status;
2363         int ret;
2364         int retries = 0;
2365
2366         drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2367                            DP_PAYLOAD_TABLE_UPDATED);
2368
2369         payload_alloc[0] = id;
2370         payload_alloc[1] = payload->start_slot;
2371         payload_alloc[2] = payload->num_slots;
2372
2373         ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2374         if (ret != 3) {
2375                 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2376                 goto fail;
2377         }
2378
2379 retry:
2380         ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2381         if (ret < 0) {
2382                 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2383                 goto fail;
2384         }
2385
2386         if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2387                 retries++;
2388                 if (retries < 20) {
2389                         usleep_range(10000, 20000);
2390                         goto retry;
2391                 }
2392                 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2393                 ret = -EINVAL;
2394                 goto fail;
2395         }
2396         ret = 0;
2397 fail:
2398         return ret;
2399 }
2400
2401
2402 /**
2403  * drm_dp_check_act_status() - Check ACT handled status.
2404  * @mgr: manager to use
2405  *
2406  * Check the payload status bits in the DPCD for ACT handled completion.
2407  */
2408 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2409 {
2410         u8 status;
2411         int ret;
2412         int count = 0;
2413
2414         do {
2415                 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2416
2417                 if (ret < 0) {
2418                         DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2419                         goto fail;
2420                 }
2421
2422                 if (status & DP_PAYLOAD_ACT_HANDLED)
2423                         break;
2424                 count++;
2425                 udelay(100);
2426
2427         } while (count < 30);
2428
2429         if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2430                 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2431                 ret = -EINVAL;
2432                 goto fail;
2433         }
2434         return 0;
2435 fail:
2436         return ret;
2437 }
2438 EXPORT_SYMBOL(drm_dp_check_act_status);
2439
2440 /**
2441  * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2442  * @clock: dot clock for the mode
2443  * @bpp: bpp for the mode.
2444  *
2445  * This uses the formula in the spec to calculate the PBN value for a mode.
2446  */
2447 int drm_dp_calc_pbn_mode(int clock, int bpp)
2448 {
2449         fixed20_12 pix_bw;
2450         fixed20_12 fbpp;
2451         fixed20_12 result;
2452         fixed20_12 margin, tmp;
2453         u32 res;
2454
2455         pix_bw.full = dfixed_const(clock);
2456         fbpp.full = dfixed_const(bpp);
2457         tmp.full = dfixed_const(8);
2458         fbpp.full = dfixed_div(fbpp, tmp);
2459
2460         result.full = dfixed_mul(pix_bw, fbpp);
2461         margin.full = dfixed_const(54);
2462         tmp.full = dfixed_const(64);
2463         margin.full = dfixed_div(margin, tmp);
2464         result.full = dfixed_div(result, margin);
2465
2466         margin.full = dfixed_const(1006);
2467         tmp.full = dfixed_const(1000);
2468         margin.full = dfixed_div(margin, tmp);
2469         result.full = dfixed_mul(result, margin);
2470
2471         result.full = dfixed_div(result, tmp);
2472         result.full = dfixed_ceil(result);
2473         res = dfixed_trunc(result);
2474         return res;
2475 }
2476 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2477
2478 static int test_calc_pbn_mode(void)
2479 {
2480         int ret;
2481         ret = drm_dp_calc_pbn_mode(154000, 30);
2482         if (ret != 689)
2483                 return -EINVAL;
2484         ret = drm_dp_calc_pbn_mode(234000, 30);
2485         if (ret != 1047)
2486                 return -EINVAL;
2487         return 0;
2488 }
2489
2490 /* we want to kick the TX after we've ack the up/down IRQs. */
2491 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2492 {
2493         queue_work(system_long_wq, &mgr->tx_work);
2494 }
2495
2496 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2497                                  struct drm_dp_mst_branch *mstb)
2498 {
2499         struct drm_dp_mst_port *port;
2500         int tabs = mstb->lct;
2501         char prefix[10];
2502         int i;
2503
2504         for (i = 0; i < tabs; i++)
2505                 prefix[i] = '\t';
2506         prefix[i] = '\0';
2507
2508         seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2509         list_for_each_entry(port, &mstb->ports, next) {
2510                 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port, port->connector);
2511                 if (port->mstb)
2512                         drm_dp_mst_dump_mstb(m, port->mstb);
2513         }
2514 }
2515
2516 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2517                                   char *buf)
2518 {
2519         int ret;
2520         int i;
2521         for (i = 0; i < 4; i++) {
2522                 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2523                 if (ret != 16)
2524                         break;
2525         }
2526         if (i == 4)
2527                 return true;
2528         return false;
2529 }
2530
2531 /**
2532  * drm_dp_mst_dump_topology(): dump topology to seq file.
2533  * @m: seq_file to dump output to
2534  * @mgr: manager to dump current topology for.
2535  *
2536  * helper to dump MST topology to a seq file for debugfs.
2537  */
2538 void drm_dp_mst_dump_topology(struct seq_file *m,
2539                               struct drm_dp_mst_topology_mgr *mgr)
2540 {
2541         int i;
2542         struct drm_dp_mst_port *port;
2543         mutex_lock(&mgr->lock);
2544         if (mgr->mst_primary)
2545                 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2546
2547         /* dump VCPIs */
2548         mutex_unlock(&mgr->lock);
2549
2550         mutex_lock(&mgr->payload_lock);
2551         seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
2552
2553         for (i = 0; i < mgr->max_payloads; i++) {
2554                 if (mgr->proposed_vcpis[i]) {
2555                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2556                         seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2557                 } else
2558                         seq_printf(m, "vcpi %d:unsed\n", i);
2559         }
2560         for (i = 0; i < mgr->max_payloads; i++) {
2561                 seq_printf(m, "payload %d: %d, %d, %d\n",
2562                            i,
2563                            mgr->payloads[i].payload_state,
2564                            mgr->payloads[i].start_slot,
2565                            mgr->payloads[i].num_slots);
2566
2567
2568         }
2569         mutex_unlock(&mgr->payload_lock);
2570
2571         mutex_lock(&mgr->lock);
2572         if (mgr->mst_primary) {
2573                 u8 buf[64];
2574                 bool bret;
2575                 int ret;
2576                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2577                 seq_printf(m, "dpcd: ");
2578                 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2579                         seq_printf(m, "%02x ", buf[i]);
2580                 seq_printf(m, "\n");
2581                 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2582                 seq_printf(m, "faux/mst: ");
2583                 for (i = 0; i < 2; i++)
2584                         seq_printf(m, "%02x ", buf[i]);
2585                 seq_printf(m, "\n");
2586                 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2587                 seq_printf(m, "mst ctrl: ");
2588                 for (i = 0; i < 1; i++)
2589                         seq_printf(m, "%02x ", buf[i]);
2590                 seq_printf(m, "\n");
2591
2592                 bret = dump_dp_payload_table(mgr, buf);
2593                 if (bret == true) {
2594                         seq_printf(m, "payload table: ");
2595                         for (i = 0; i < 63; i++)
2596                                 seq_printf(m, "%02x ", buf[i]);
2597                         seq_printf(m, "\n");
2598                 }
2599
2600         }
2601
2602         mutex_unlock(&mgr->lock);
2603
2604 }
2605 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2606
2607 static void drm_dp_tx_work(struct work_struct *work)
2608 {
2609         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2610
2611         mutex_lock(&mgr->qlock);
2612         if (mgr->tx_down_in_progress)
2613                 process_single_down_tx_qlock(mgr);
2614         mutex_unlock(&mgr->qlock);
2615 }
2616
2617 /**
2618  * drm_dp_mst_topology_mgr_init - initialise a topology manager
2619  * @mgr: manager struct to initialise
2620  * @dev: device providing this structure - for i2c addition.
2621  * @aux: DP helper aux channel to talk to this device
2622  * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2623  * @max_payloads: maximum number of payloads this GPU can source
2624  * @conn_base_id: the connector object ID the MST device is connected to.
2625  *
2626  * Return 0 for success, or negative error code on failure
2627  */
2628 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2629                                  struct device *dev, struct drm_dp_aux *aux,
2630                                  int max_dpcd_transaction_bytes,
2631                                  int max_payloads, int conn_base_id)
2632 {
2633         mutex_init(&mgr->lock);
2634         mutex_init(&mgr->qlock);
2635         mutex_init(&mgr->payload_lock);
2636         INIT_LIST_HEAD(&mgr->tx_msg_upq);
2637         INIT_LIST_HEAD(&mgr->tx_msg_downq);
2638         INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2639         INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2640         init_waitqueue_head(&mgr->tx_waitq);
2641         mgr->dev = dev;
2642         mgr->aux = aux;
2643         mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2644         mgr->max_payloads = max_payloads;
2645         mgr->conn_base_id = conn_base_id;
2646         mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2647         if (!mgr->payloads)
2648                 return -ENOMEM;
2649         mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2650         if (!mgr->proposed_vcpis)
2651                 return -ENOMEM;
2652         set_bit(0, &mgr->payload_mask);
2653         test_calc_pbn_mode();
2654         return 0;
2655 }
2656 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2657
2658 /**
2659  * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2660  * @mgr: manager to destroy
2661  */
2662 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2663 {
2664         mutex_lock(&mgr->payload_lock);
2665         kfree(mgr->payloads);
2666         mgr->payloads = NULL;
2667         kfree(mgr->proposed_vcpis);
2668         mgr->proposed_vcpis = NULL;
2669         mutex_unlock(&mgr->payload_lock);
2670         mgr->dev = NULL;
2671         mgr->aux = NULL;
2672 }
2673 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
2674
2675 /* I2C device */
2676 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
2677                                int num)
2678 {
2679         struct drm_dp_aux *aux = adapter->algo_data;
2680         struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
2681         struct drm_dp_mst_branch *mstb;
2682         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2683         unsigned int i;
2684         bool reading = false;
2685         struct drm_dp_sideband_msg_req_body msg;
2686         struct drm_dp_sideband_msg_tx *txmsg = NULL;
2687         int ret;
2688
2689         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2690         if (!mstb)
2691                 return -EREMOTEIO;
2692
2693         /* construct i2c msg */
2694         /* see if last msg is a read */
2695         if (msgs[num - 1].flags & I2C_M_RD)
2696                 reading = true;
2697
2698         if (!reading) {
2699                 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
2700                 ret = -EIO;
2701                 goto out;
2702         }
2703
2704         msg.req_type = DP_REMOTE_I2C_READ;
2705         msg.u.i2c_read.num_transactions = num - 1;
2706         msg.u.i2c_read.port_number = port->port_num;
2707         for (i = 0; i < num - 1; i++) {
2708                 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
2709                 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
2710                 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
2711         }
2712         msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
2713         msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
2714
2715         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2716         if (!txmsg) {
2717                 ret = -ENOMEM;
2718                 goto out;
2719         }
2720
2721         txmsg->dst = mstb;
2722         drm_dp_encode_sideband_req(&msg, txmsg);
2723
2724         drm_dp_queue_down_tx(mgr, txmsg);
2725
2726         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2727         if (ret > 0) {
2728
2729                 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
2730                         ret = -EREMOTEIO;
2731                         goto out;
2732                 }
2733                 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
2734                         ret = -EIO;
2735                         goto out;
2736                 }
2737                 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
2738                 ret = num;
2739         }
2740 out:
2741         kfree(txmsg);
2742         drm_dp_put_mst_branch_device(mstb);
2743         return ret;
2744 }
2745
2746 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
2747 {
2748         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
2749                I2C_FUNC_SMBUS_READ_BLOCK_DATA |
2750                I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
2751                I2C_FUNC_10BIT_ADDR;
2752 }
2753
2754 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
2755         .functionality = drm_dp_mst_i2c_functionality,
2756         .master_xfer = drm_dp_mst_i2c_xfer,
2757 };
2758
2759 /**
2760  * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
2761  * @aux: DisplayPort AUX channel
2762  *
2763  * Returns 0 on success or a negative error code on failure.
2764  */
2765 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
2766 {
2767         aux->ddc.algo = &drm_dp_mst_i2c_algo;
2768         aux->ddc.algo_data = aux;
2769         aux->ddc.retries = 3;
2770
2771         aux->ddc.class = I2C_CLASS_DDC;
2772         aux->ddc.owner = THIS_MODULE;
2773         aux->ddc.dev.parent = aux->dev;
2774         aux->ddc.dev.of_node = aux->dev->of_node;
2775
2776         strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
2777                 sizeof(aux->ddc.name));
2778
2779         return i2c_add_adapter(&aux->ddc);
2780 }
2781
2782 /**
2783  * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
2784  * @aux: DisplayPort AUX channel
2785  */
2786 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
2787 {
2788         i2c_del_adapter(&aux->ddc);
2789 }