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
 737         /*
 738          * All updates to txmsg->state are protected by mgr->qlock, and the two
 739          * cases we check here are terminal states. For those the barriers
 740          * provided by the wake_up/wait_event pair are enough.
 741          */
 742         ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
 743                txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
 744         return ret;
 745 }
 746
 747 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
 748                                     struct drm_dp_sideband_msg_tx *txmsg)
 749 {
 750         struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
 751         int ret;
 752
 753         ret = wait_event_timeout(mgr->tx_waitq,
 754                                  check_txmsg_state(mgr, txmsg),
 755                                  (4 * HZ));
 756         mutex_lock(&mstb->mgr->qlock);
 757         if (ret > 0) {
 758                 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
 759                         ret = -EIO;
 760                         goto out;
 761                 }
 762         } else {
 763                 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
 764
 765                 /* dump some state */
 766                 ret = -EIO;
 767
 768                 /* remove from q */
 769                 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
 770                     txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
 771                         list_del(&txmsg->next);
 772                 }
 773
 774                 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
 775                     txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
 776                         mstb->tx_slots[txmsg->seqno] = NULL;
 777                 }
 778         }
 779 out:
 780         mutex_unlock(&mgr->qlock);
 781
 782         return ret;
 783 }
 784
 785 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
 786 {
 787         struct drm_dp_mst_branch *mstb;
 788
 789         mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
 790         if (!mstb)
 791                 return NULL;
 792
 793         mstb->lct = lct;
 794         if (lct > 1)
 795                 memcpy(mstb->rad, rad, lct / 2);
 796         INIT_LIST_HEAD(&mstb->ports);
 797         kref_init(&mstb->kref);
 798         return mstb;
 799 }
 800
 801 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
 802 {
 803         struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
 804         struct drm_dp_mst_port *port, *tmp;
 805         bool wake_tx = false;
 806
 807         cancel_work_sync(&mstb->mgr->work);
 808
 809         /*
 810          * destroy all ports - don't need lock
 811          * as there are no more references to the mst branch
 812          * device at this point.
 813          */
 814         list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
 815                 list_del(&port->next);
 816                 drm_dp_put_port(port);
 817         }
 818
 819         /* drop any tx slots msg */
 820         mutex_lock(&mstb->mgr->qlock);
 821         if (mstb->tx_slots[0]) {
 822                 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 823                 mstb->tx_slots[0] = NULL;
 824                 wake_tx = true;
 825         }
 826         if (mstb->tx_slots[1]) {
 827                 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 828                 mstb->tx_slots[1] = NULL;
 829                 wake_tx = true;
 830         }
 831         mutex_unlock(&mstb->mgr->qlock);
 832
 833         if (wake_tx)
 834                 wake_up(&mstb->mgr->tx_waitq);
 835         kfree(mstb);
 836 }
 837
 838 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
 839 {
 840         kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
 841 }
 842
 843
 844 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
 845 {
 846         struct drm_dp_mst_branch *mstb;
 847
 848         switch (old_pdt) {
 849         case DP_PEER_DEVICE_DP_LEGACY_CONV:
 850         case DP_PEER_DEVICE_SST_SINK:
 851                 /* remove i2c over sideband */
 852                 drm_dp_mst_unregister_i2c_bus(&port->aux);
 853                 break;
 854         case DP_PEER_DEVICE_MST_BRANCHING:
 855                 mstb = port->mstb;
 856                 port->mstb = NULL;
 857                 drm_dp_put_mst_branch_device(mstb);
 858                 break;
 859         }
 860 }
 861
 862 static void drm_dp_destroy_port(struct kref *kref)
 863 {
 864         struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
 865         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
 866         if (!port->input) {
 867                 port->vcpi.num_slots = 0;
 868
 869                 kfree(port->cached_edid);
 870                 if (port->connector)
 871                         (*port->mgr->cbs->destroy_connector)(mgr, port->connector);
 872                 drm_dp_port_teardown_pdt(port, port->pdt);
 873
 874                 if (!port->input && port->vcpi.vcpi > 0)
 875                         drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
 876         }
 877         kfree(port);
 878
 879         (*mgr->cbs->hotplug)(mgr);
 880 }
 881
 882 static void drm_dp_put_port(struct drm_dp_mst_port *port)
 883 {
 884         kref_put(&port->kref, drm_dp_destroy_port);
 885 }
 886
 887 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)
 888 {
 889         struct drm_dp_mst_port *port;
 890         struct drm_dp_mst_branch *rmstb;
 891         if (to_find == mstb) {
 892                 kref_get(&mstb->kref);
 893                 return mstb;
 894         }
 895         list_for_each_entry(port, &mstb->ports, next) {
 896                 if (port->mstb) {
 897                         rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
 898                         if (rmstb)
 899                                 return rmstb;
 900                 }
 901         }
 902         return NULL;
 903 }
 904
 905 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)
 906 {
 907         struct drm_dp_mst_branch *rmstb = NULL;
 908         mutex_lock(&mgr->lock);
 909         if (mgr->mst_primary)
 910                 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
 911         mutex_unlock(&mgr->lock);
 912         return rmstb;
 913 }
 914
 915 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)
 916 {
 917         struct drm_dp_mst_port *port, *mport;
 918
 919         list_for_each_entry(port, &mstb->ports, next) {
 920                 if (port == to_find) {
 921                         kref_get(&port->kref);
 922                         return port;
 923                 }
 924                 if (port->mstb) {
 925                         mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
 926                         if (mport)
 927                                 return mport;
 928                 }
 929         }
 930         return NULL;
 931 }
 932
 933 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)
 934 {
 935         struct drm_dp_mst_port *rport = NULL;
 936         mutex_lock(&mgr->lock);
 937         if (mgr->mst_primary)
 938                 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
 939         mutex_unlock(&mgr->lock);
 940         return rport;
 941 }
 942
 943 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
 944 {
 945         struct drm_dp_mst_port *port;
 946
 947         list_for_each_entry(port, &mstb->ports, next) {
 948                 if (port->port_num == port_num) {
 949                         kref_get(&port->kref);
 950                         return port;
 951                 }
 952         }
 953
 954         return NULL;
 955 }
 956
 957 /*
 958  * calculate a new RAD for this MST branch device
 959  * if parent has an LCT of 2 then it has 1 nibble of RAD,
 960  * if parent has an LCT of 3 then it has 2 nibbles of RAD,
 961  */
 962 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
 963                                  u8 *rad)
 964 {
 965         int lct = port->parent->lct;
 966         int shift = 4;
 967         int idx = lct / 2;
 968         if (lct > 1) {
 969                 memcpy(rad, port->parent->rad, idx);
 970                 shift = (lct % 2) ? 4 : 0;
 971         } else
 972                 rad[0] = 0;
 973
 974         rad[idx] |= port->port_num << shift;
 975         return lct + 1;
 976 }
 977
 978 /*
 979  * return sends link address for new mstb
 980  */
 981 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
 982 {
 983         int ret;
 984         u8 rad[6], lct;
 985         bool send_link = false;
 986         switch (port->pdt) {
 987         case DP_PEER_DEVICE_DP_LEGACY_CONV:
 988         case DP_PEER_DEVICE_SST_SINK:
 989                 /* add i2c over sideband */
 990                 ret = drm_dp_mst_register_i2c_bus(&port->aux);
 991                 break;
 992         case DP_PEER_DEVICE_MST_BRANCHING:
 993                 lct = drm_dp_calculate_rad(port, rad);
 994
 995                 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
 996                 port->mstb->mgr = port->mgr;
 997                 port->mstb->port_parent = port;
 998
 999                 send_link = true;
1000                 break;
1001         }
1002         return send_link;
1003 }
1004
1005 static void drm_dp_check_port_guid(struct drm_dp_mst_branch *mstb,
1006                                    struct drm_dp_mst_port *port)
1007 {
1008         int ret;
1009         if (port->dpcd_rev >= 0x12) {
1010                 port->guid_valid = drm_dp_validate_guid(mstb->mgr, port->guid);
1011                 if (!port->guid_valid) {
1012                         ret = drm_dp_send_dpcd_write(mstb->mgr,
1013                                                      port,
1014                                                      DP_GUID,
1015                                                      16, port->guid);
1016                         port->guid_valid = true;
1017                 }
1018         }
1019 }
1020
1021 static void build_mst_prop_path(struct drm_dp_mst_port *port,
1022                                 struct drm_dp_mst_branch *mstb,
1023                                 char *proppath,
1024                                 size_t proppath_size)
1025 {
1026         int i;
1027         char temp[8];
1028         snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1029         for (i = 0; i < (mstb->lct - 1); i++) {
1030                 int shift = (i % 2) ? 0 : 4;
1031                 int port_num = mstb->rad[i / 2] >> shift;
1032                 snprintf(temp, sizeof(temp), "-%d", port_num);
1033                 strlcat(proppath, temp, proppath_size);
1034         }
1035         snprintf(temp, sizeof(temp), "-%d", port->port_num);
1036         strlcat(proppath, temp, proppath_size);
1037 }
1038
1039 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1040                             struct device *dev,
1041                             struct drm_dp_link_addr_reply_port *port_msg)
1042 {
1043         struct drm_dp_mst_port *port;
1044         bool ret;
1045         bool created = false;
1046         int old_pdt = 0;
1047         int old_ddps = 0;
1048         port = drm_dp_get_port(mstb, port_msg->port_number);
1049         if (!port) {
1050                 port = kzalloc(sizeof(*port), GFP_KERNEL);
1051                 if (!port)
1052                         return;
1053                 kref_init(&port->kref);
1054                 port->parent = mstb;
1055                 port->port_num = port_msg->port_number;
1056                 port->mgr = mstb->mgr;
1057                 port->aux.name = "DPMST";
1058                 port->aux.dev = dev;
1059                 created = true;
1060         } else {
1061                 old_pdt = port->pdt;
1062                 old_ddps = port->ddps;
1063         }
1064
1065         port->pdt = port_msg->peer_device_type;
1066         port->input = port_msg->input_port;
1067         port->mcs = port_msg->mcs;
1068         port->ddps = port_msg->ddps;
1069         port->ldps = port_msg->legacy_device_plug_status;
1070         port->dpcd_rev = port_msg->dpcd_revision;
1071         port->num_sdp_streams = port_msg->num_sdp_streams;
1072         port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1073         memcpy(port->guid, port_msg->peer_guid, 16);
1074
1075         /* manage mstb port lists with mgr lock - take a reference
1076            for this list */
1077         if (created) {
1078                 mutex_lock(&mstb->mgr->lock);
1079                 kref_get(&port->kref);
1080                 list_add(&port->next, &mstb->ports);
1081                 mutex_unlock(&mstb->mgr->lock);
1082         }
1083
1084         if (old_ddps != port->ddps) {
1085                 if (port->ddps) {
1086                         drm_dp_check_port_guid(mstb, port);
1087                         if (!port->input)
1088                                 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1089                 } else {
1090                         port->guid_valid = false;
1091                         port->available_pbn = 0;
1092                         }
1093         }
1094
1095         if (old_pdt != port->pdt && !port->input) {
1096                 drm_dp_port_teardown_pdt(port, old_pdt);
1097
1098                 ret = drm_dp_port_setup_pdt(port);
1099                 if (ret == true) {
1100                         drm_dp_send_link_address(mstb->mgr, port->mstb);
1101                         port->mstb->link_address_sent = true;
1102                 }
1103         }
1104
1105         if (created && !port->input) {
1106                 char proppath[255];
1107                 build_mst_prop_path(port, mstb, proppath, sizeof(proppath));
1108                 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1109
1110                 if (port->port_num >= 8) {
1111                         port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1112                 }
1113         }
1114
1115         /* put reference to this port */
1116         drm_dp_put_port(port);
1117 }
1118
1119 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1120                                struct drm_dp_connection_status_notify *conn_stat)
1121 {
1122         struct drm_dp_mst_port *port;
1123         int old_pdt;
1124         int old_ddps;
1125         bool dowork = false;
1126         port = drm_dp_get_port(mstb, conn_stat->port_number);
1127         if (!port)
1128                 return;
1129
1130         old_ddps = port->ddps;
1131         old_pdt = port->pdt;
1132         port->pdt = conn_stat->peer_device_type;
1133         port->mcs = conn_stat->message_capability_status;
1134         port->ldps = conn_stat->legacy_device_plug_status;
1135         port->ddps = conn_stat->displayport_device_plug_status;
1136
1137         if (old_ddps != port->ddps) {
1138                 if (port->ddps) {
1139                         drm_dp_check_port_guid(mstb, port);
1140                         dowork = true;
1141                 } else {
1142                         port->guid_valid = false;
1143                         port->available_pbn = 0;
1144                 }
1145         }
1146         if (old_pdt != port->pdt && !port->input) {
1147                 drm_dp_port_teardown_pdt(port, old_pdt);
1148
1149                 if (drm_dp_port_setup_pdt(port))
1150                         dowork = true;
1151         }
1152
1153         drm_dp_put_port(port);
1154         if (dowork)
1155                 queue_work(system_long_wq, &mstb->mgr->work);
1156
1157 }
1158
1159 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1160                                                                u8 lct, u8 *rad)
1161 {
1162         struct drm_dp_mst_branch *mstb;
1163         struct drm_dp_mst_port *port;
1164         int i;
1165         /* find the port by iterating down */
1166         mstb = mgr->mst_primary;
1167
1168         for (i = 0; i < lct - 1; i++) {
1169                 int shift = (i % 2) ? 0 : 4;
1170                 int port_num = rad[i / 2] >> shift;
1171
1172                 list_for_each_entry(port, &mstb->ports, next) {
1173                         if (port->port_num == port_num) {
1174                                 if (!port->mstb) {
1175                                         DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1176                                         return NULL;
1177                                 }
1178
1179                                 mstb = port->mstb;
1180                                 break;
1181                         }
1182                 }
1183         }
1184         kref_get(&mstb->kref);
1185         return mstb;
1186 }
1187
1188 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1189                                                struct drm_dp_mst_branch *mstb)
1190 {
1191         struct drm_dp_mst_port *port;
1192
1193         if (!mstb->link_address_sent) {
1194                 drm_dp_send_link_address(mgr, mstb);
1195                 mstb->link_address_sent = true;
1196         }
1197         list_for_each_entry(port, &mstb->ports, next) {
1198                 if (port->input)
1199                         continue;
1200
1201                 if (!port->ddps)
1202                         continue;
1203
1204                 if (!port->available_pbn)
1205                         drm_dp_send_enum_path_resources(mgr, mstb, port);
1206
1207                 if (port->mstb)
1208                         drm_dp_check_and_send_link_address(mgr, port->mstb);
1209         }
1210 }
1211
1212 static void drm_dp_mst_link_probe_work(struct work_struct *work)
1213 {
1214         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1215
1216         drm_dp_check_and_send_link_address(mgr, mgr->mst_primary);
1217
1218 }
1219
1220 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1221                                  u8 *guid)
1222 {
1223         static u8 zero_guid[16];
1224
1225         if (!memcmp(guid, zero_guid, 16)) {
1226                 u64 salt = get_jiffies_64();
1227                 memcpy(&guid[0], &salt, sizeof(u64));
1228                 memcpy(&guid[8], &salt, sizeof(u64));
1229                 return false;
1230         }
1231         return true;
1232 }
1233
1234 #if 0
1235 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1236 {
1237         struct drm_dp_sideband_msg_req_body req;
1238
1239         req.req_type = DP_REMOTE_DPCD_READ;
1240         req.u.dpcd_read.port_number = port_num;
1241         req.u.dpcd_read.dpcd_address = offset;
1242         req.u.dpcd_read.num_bytes = num_bytes;
1243         drm_dp_encode_sideband_req(&req, msg);
1244
1245         return 0;
1246 }
1247 #endif
1248
1249 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1250                                     bool up, u8 *msg, int len)
1251 {
1252         int ret;
1253         int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1254         int tosend, total, offset;
1255         int retries = 0;
1256
1257 retry:
1258         total = len;
1259         offset = 0;
1260         do {
1261                 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1262
1263                 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1264                                         &msg[offset],
1265                                         tosend);
1266                 if (ret != tosend) {
1267                         if (ret == -EIO && retries < 5) {
1268                                 retries++;
1269                                 goto retry;
1270                         }
1271                         DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1272                         WARN(1, "fail\n");
1273
1274                         return -EIO;
1275                 }
1276                 offset += tosend;
1277                 total -= tosend;
1278         } while (total > 0);
1279         return 0;
1280 }
1281
1282 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1283                                   struct drm_dp_sideband_msg_tx *txmsg)
1284 {
1285         struct drm_dp_mst_branch *mstb = txmsg->dst;
1286
1287         /* both msg slots are full */
1288         if (txmsg->seqno == -1) {
1289                 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1290                         DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1291                         return -EAGAIN;
1292                 }
1293                 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1294                         txmsg->seqno = mstb->last_seqno;
1295                         mstb->last_seqno ^= 1;
1296                 } else if (mstb->tx_slots[0] == NULL)
1297                         txmsg->seqno = 0;
1298                 else
1299                         txmsg->seqno = 1;
1300                 mstb->tx_slots[txmsg->seqno] = txmsg;
1301         }
1302         hdr->broadcast = 0;
1303         hdr->path_msg = txmsg->path_msg;
1304         hdr->lct = mstb->lct;
1305         hdr->lcr = mstb->lct - 1;
1306         if (mstb->lct > 1)
1307                 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1308         hdr->seqno = txmsg->seqno;
1309         return 0;
1310 }
1311 /*
1312  * process a single block of the next message in the sideband queue
1313  */
1314 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1315                                    struct drm_dp_sideband_msg_tx *txmsg,
1316                                    bool up)
1317 {
1318         u8 chunk[48];
1319         struct drm_dp_sideband_msg_hdr hdr;
1320         int len, space, idx, tosend;
1321         int ret;
1322
1323         memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1324
1325         if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1326                 txmsg->seqno = -1;
1327                 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1328         }
1329
1330         /* make hdr from dst mst - for replies use seqno
1331            otherwise assign one */
1332         ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1333         if (ret < 0)
1334                 return ret;
1335
1336         /* amount left to send in this message */
1337         len = txmsg->cur_len - txmsg->cur_offset;
1338
1339         /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1340         space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1341
1342         tosend = min(len, space);
1343         if (len == txmsg->cur_len)
1344                 hdr.somt = 1;
1345         if (space >= len)
1346                 hdr.eomt = 1;
1347
1348
1349         hdr.msg_len = tosend + 1;
1350         drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1351         memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1352         /* add crc at end */
1353         drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1354         idx += tosend + 1;
1355
1356         ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1357         if (ret) {
1358                 DRM_DEBUG_KMS("sideband msg failed to send\n");
1359                 return ret;
1360         }
1361
1362         txmsg->cur_offset += tosend;
1363         if (txmsg->cur_offset == txmsg->cur_len) {
1364                 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1365                 return 1;
1366         }
1367         return 0;
1368 }
1369
1370 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1371 {
1372         struct drm_dp_sideband_msg_tx *txmsg;
1373         int ret;
1374
1375         WARN_ON(!mutex_is_locked(&mgr->qlock));
1376
1377         /* construct a chunk from the first msg in the tx_msg queue */
1378         if (list_empty(&mgr->tx_msg_downq)) {
1379                 mgr->tx_down_in_progress = false;
1380                 return;
1381         }
1382         mgr->tx_down_in_progress = true;
1383
1384         txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1385         ret = process_single_tx_qlock(mgr, txmsg, false);
1386         if (ret == 1) {
1387                 /* txmsg is sent it should be in the slots now */
1388                 list_del(&txmsg->next);
1389         } else if (ret) {
1390                 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1391                 list_del(&txmsg->next);
1392                 if (txmsg->seqno != -1)
1393                         txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1394                 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1395                 wake_up(&mgr->tx_waitq);
1396         }
1397         if (list_empty(&mgr->tx_msg_downq)) {
1398                 mgr->tx_down_in_progress = false;
1399                 return;
1400         }
1401 }
1402
1403 /* called holding qlock */
1404 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1405 {
1406         struct drm_dp_sideband_msg_tx *txmsg;
1407         int ret;
1408
1409         /* construct a chunk from the first msg in the tx_msg queue */
1410         if (list_empty(&mgr->tx_msg_upq)) {
1411                 mgr->tx_up_in_progress = false;
1412                 return;
1413         }
1414
1415         txmsg = list_first_entry(&mgr->tx_msg_upq, struct drm_dp_sideband_msg_tx, next);
1416         ret = process_single_tx_qlock(mgr, txmsg, true);
1417         if (ret == 1) {
1418                 /* up txmsgs aren't put in slots - so free after we send it */
1419                 list_del(&txmsg->next);
1420                 kfree(txmsg);
1421         } else if (ret)
1422                 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1423         mgr->tx_up_in_progress = true;
1424 }
1425
1426 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1427                                  struct drm_dp_sideband_msg_tx *txmsg)
1428 {
1429         mutex_lock(&mgr->qlock);
1430         list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1431         if (!mgr->tx_down_in_progress)
1432                 process_single_down_tx_qlock(mgr);
1433         mutex_unlock(&mgr->qlock);
1434 }
1435
1436 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1437                                     struct drm_dp_mst_branch *mstb)
1438 {
1439         int len;
1440         struct drm_dp_sideband_msg_tx *txmsg;
1441         int ret;
1442
1443         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1444         if (!txmsg)
1445                 return -ENOMEM;
1446
1447         txmsg->dst = mstb;
1448         len = build_link_address(txmsg);
1449
1450         drm_dp_queue_down_tx(mgr, txmsg);
1451
1452         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1453         if (ret > 0) {
1454                 int i;
1455
1456                 if (txmsg->reply.reply_type == 1)
1457                         DRM_DEBUG_KMS("link address nak received\n");
1458                 else {
1459                         DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1460                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1461                                 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,
1462                                        txmsg->reply.u.link_addr.ports[i].input_port,
1463                                        txmsg->reply.u.link_addr.ports[i].peer_device_type,
1464                                        txmsg->reply.u.link_addr.ports[i].port_number,
1465                                        txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1466                                        txmsg->reply.u.link_addr.ports[i].mcs,
1467                                        txmsg->reply.u.link_addr.ports[i].ddps,
1468                                        txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1469                                        txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1470                                        txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1471                         }
1472                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1473                                 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1474                         }
1475                         (*mgr->cbs->hotplug)(mgr);
1476                 }
1477         } else
1478                 DRM_DEBUG_KMS("link address failed %d\n", ret);
1479
1480         kfree(txmsg);
1481         return 0;
1482 }
1483
1484 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1485                                            struct drm_dp_mst_branch *mstb,
1486                                            struct drm_dp_mst_port *port)
1487 {
1488         int len;
1489         struct drm_dp_sideband_msg_tx *txmsg;
1490         int ret;
1491
1492         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1493         if (!txmsg)
1494                 return -ENOMEM;
1495
1496         txmsg->dst = mstb;
1497         len = build_enum_path_resources(txmsg, port->port_num);
1498
1499         drm_dp_queue_down_tx(mgr, txmsg);
1500
1501         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1502         if (ret > 0) {
1503                 if (txmsg->reply.reply_type == 1)
1504                         DRM_DEBUG_KMS("enum path resources nak received\n");
1505                 else {
1506                         if (port->port_num != txmsg->reply.u.path_resources.port_number)
1507                                 DRM_ERROR("got incorrect port in response\n");
1508                         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,
1509                                txmsg->reply.u.path_resources.avail_payload_bw_number);
1510                         port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1511                 }
1512         }
1513
1514         kfree(txmsg);
1515         return 0;
1516 }
1517
1518 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1519                                    struct drm_dp_mst_port *port,
1520                                    int id,
1521                                    int pbn)
1522 {
1523         struct drm_dp_sideband_msg_tx *txmsg;
1524         struct drm_dp_mst_branch *mstb;
1525         int len, ret;
1526
1527         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1528         if (!mstb)
1529                 return -EINVAL;
1530
1531         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1532         if (!txmsg) {
1533                 ret = -ENOMEM;
1534                 goto fail_put;
1535         }
1536
1537         txmsg->dst = mstb;
1538         len = build_allocate_payload(txmsg, port->port_num,
1539                                      id,
1540                                      pbn);
1541
1542         drm_dp_queue_down_tx(mgr, txmsg);
1543
1544         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1545         if (ret > 0) {
1546                 if (txmsg->reply.reply_type == 1) {
1547                         ret = -EINVAL;
1548                 } else
1549                         ret = 0;
1550         }
1551         kfree(txmsg);
1552 fail_put:
1553         drm_dp_put_mst_branch_device(mstb);
1554         return ret;
1555 }
1556
1557 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1558                                        int id,
1559                                        struct drm_dp_payload *payload)
1560 {
1561         int ret;
1562
1563         ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1564         if (ret < 0) {
1565                 payload->payload_state = 0;
1566                 return ret;
1567         }
1568         payload->payload_state = DP_PAYLOAD_LOCAL;
1569         return 0;
1570 }
1571
1572 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1573                                        struct drm_dp_mst_port *port,
1574                                        int id,
1575                                        struct drm_dp_payload *payload)
1576 {
1577         int ret;
1578         ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1579         if (ret < 0)
1580                 return ret;
1581         payload->payload_state = DP_PAYLOAD_REMOTE;
1582         return ret;
1583 }
1584
1585 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1586                                         struct drm_dp_mst_port *port,
1587                                         int id,
1588                                         struct drm_dp_payload *payload)
1589 {
1590         DRM_DEBUG_KMS("\n");
1591         /* its okay for these to fail */
1592         if (port) {
1593                 drm_dp_payload_send_msg(mgr, port, id, 0);
1594         }
1595
1596         drm_dp_dpcd_write_payload(mgr, id, payload);
1597         payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1598         return 0;
1599 }
1600
1601 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1602                                         int id,
1603                                         struct drm_dp_payload *payload)
1604 {
1605         payload->payload_state = 0;
1606         return 0;
1607 }
1608
1609 /**
1610  * drm_dp_update_payload_part1() - Execute payload update part 1
1611  * @mgr: manager to use.
1612  *
1613  * This iterates over all proposed virtual channels, and tries to
1614  * allocate space in the link for them. For 0->slots transitions,
1615  * this step just writes the VCPI to the MST device. For slots->0
1616  * transitions, this writes the updated VCPIs and removes the
1617  * remote VC payloads.
1618  *
1619  * after calling this the driver should generate ACT and payload
1620  * packets.
1621  */
1622 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1623 {
1624         int i, j;
1625         int cur_slots = 1;
1626         struct drm_dp_payload req_payload;
1627         struct drm_dp_mst_port *port;
1628
1629         mutex_lock(&mgr->payload_lock);
1630         for (i = 0; i < mgr->max_payloads; i++) {
1631                 /* solve the current payloads - compare to the hw ones
1632                    - update the hw view */
1633                 req_payload.start_slot = cur_slots;
1634                 if (mgr->proposed_vcpis[i]) {
1635                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1636                         req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1637                 } else {
1638                         port = NULL;
1639                         req_payload.num_slots = 0;
1640                 }
1641
1642                 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1643                         mgr->payloads[i].start_slot = req_payload.start_slot;
1644                 }
1645                 /* work out what is required to happen with this payload */
1646                 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1647
1648                         /* need to push an update for this payload */
1649                         if (req_payload.num_slots) {
1650                                 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1651                                 mgr->payloads[i].num_slots = req_payload.num_slots;
1652                         } else if (mgr->payloads[i].num_slots) {
1653                                 mgr->payloads[i].num_slots = 0;
1654                                 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
1655                                 req_payload.payload_state = mgr->payloads[i].payload_state;
1656                                 mgr->payloads[i].start_slot = 0;
1657                         }
1658                         mgr->payloads[i].payload_state = req_payload.payload_state;
1659                 }
1660                 cur_slots += req_payload.num_slots;
1661         }
1662
1663         for (i = 0; i < mgr->max_payloads; i++) {
1664                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1665                         DRM_DEBUG_KMS("removing payload %d\n", i);
1666                         for (j = i; j < mgr->max_payloads - 1; j++) {
1667                                 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1668                                 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1669                                 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1670                                         set_bit(j + 1, &mgr->payload_mask);
1671                                 } else {
1672                                         clear_bit(j + 1, &mgr->payload_mask);
1673                                 }
1674                         }
1675                         memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1676                         mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1677                         clear_bit(mgr->max_payloads, &mgr->payload_mask);
1678
1679                 }
1680         }
1681         mutex_unlock(&mgr->payload_lock);
1682
1683         return 0;
1684 }
1685 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1686
1687 /**
1688  * drm_dp_update_payload_part2() - Execute payload update part 2
1689  * @mgr: manager to use.
1690  *
1691  * This iterates over all proposed virtual channels, and tries to
1692  * allocate space in the link for them. For 0->slots transitions,
1693  * this step writes the remote VC payload commands. For slots->0
1694  * this just resets some internal state.
1695  */
1696 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1697 {
1698         struct drm_dp_mst_port *port;
1699         int i;
1700         int ret = 0;
1701         mutex_lock(&mgr->payload_lock);
1702         for (i = 0; i < mgr->max_payloads; i++) {
1703
1704                 if (!mgr->proposed_vcpis[i])
1705                         continue;
1706
1707                 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1708
1709                 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1710                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1711                         ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1712                 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1713                         ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1714                 }
1715                 if (ret) {
1716                         mutex_unlock(&mgr->payload_lock);
1717                         return ret;
1718                 }
1719         }
1720         mutex_unlock(&mgr->payload_lock);
1721         return 0;
1722 }
1723 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1724
1725 #if 0 /* unused as of yet */
1726 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1727                                  struct drm_dp_mst_port *port,
1728                                  int offset, int size)
1729 {
1730         int len;
1731         struct drm_dp_sideband_msg_tx *txmsg;
1732
1733         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1734         if (!txmsg)
1735                 return -ENOMEM;
1736
1737         len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1738         txmsg->dst = port->parent;
1739
1740         drm_dp_queue_down_tx(mgr, txmsg);
1741
1742         return 0;
1743 }
1744 #endif
1745
1746 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1747                                   struct drm_dp_mst_port *port,
1748                                   int offset, int size, u8 *bytes)
1749 {
1750         int len;
1751         int ret;
1752         struct drm_dp_sideband_msg_tx *txmsg;
1753         struct drm_dp_mst_branch *mstb;
1754
1755         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1756         if (!mstb)
1757                 return -EINVAL;
1758
1759         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1760         if (!txmsg) {
1761                 ret = -ENOMEM;
1762                 goto fail_put;
1763         }
1764
1765         len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1766         txmsg->dst = mstb;
1767
1768         drm_dp_queue_down_tx(mgr, txmsg);
1769
1770         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1771         if (ret > 0) {
1772                 if (txmsg->reply.reply_type == 1) {
1773                         ret = -EINVAL;
1774                 } else
1775                         ret = 0;
1776         }
1777         kfree(txmsg);
1778 fail_put:
1779         drm_dp_put_mst_branch_device(mstb);
1780         return ret;
1781 }
1782
1783 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1784 {
1785         struct drm_dp_sideband_msg_reply_body reply;
1786
1787         reply.reply_type = 1;
1788         reply.req_type = req_type;
1789         drm_dp_encode_sideband_reply(&reply, msg);
1790         return 0;
1791 }
1792
1793 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1794                                     struct drm_dp_mst_branch *mstb,
1795                                     int req_type, int seqno, bool broadcast)
1796 {
1797         struct drm_dp_sideband_msg_tx *txmsg;
1798
1799         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1800         if (!txmsg)
1801                 return -ENOMEM;
1802
1803         txmsg->dst = mstb;
1804         txmsg->seqno = seqno;
1805         drm_dp_encode_up_ack_reply(txmsg, req_type);
1806
1807         mutex_lock(&mgr->qlock);
1808         list_add_tail(&txmsg->next, &mgr->tx_msg_upq);
1809         if (!mgr->tx_up_in_progress) {
1810                 process_single_up_tx_qlock(mgr);
1811         }
1812         mutex_unlock(&mgr->qlock);
1813         return 0;
1814 }
1815
1816 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1817                                      int dp_link_count,
1818                                      int *out)
1819 {
1820         switch (dp_link_bw) {
1821         default:
1822                 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1823                               dp_link_bw, dp_link_count);
1824                 return false;
1825
1826         case DP_LINK_BW_1_62:
1827                 *out = 3 * dp_link_count;
1828                 break;
1829         case DP_LINK_BW_2_7:
1830                 *out = 5 * dp_link_count;
1831                 break;
1832         case DP_LINK_BW_5_4:
1833                 *out = 10 * dp_link_count;
1834                 break;
1835         }
1836         return true;
1837 }
1838
1839 /**
1840  * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
1841  * @mgr: manager to set state for
1842  * @mst_state: true to enable MST on this connector - false to disable.
1843  *
1844  * This is called by the driver when it detects an MST capable device plugged
1845  * into a DP MST capable port, or when a DP MST capable device is unplugged.
1846  */
1847 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
1848 {
1849         int ret = 0;
1850         struct drm_dp_mst_branch *mstb = NULL;
1851
1852         mutex_lock(&mgr->lock);
1853         if (mst_state == mgr->mst_state)
1854                 goto out_unlock;
1855
1856         mgr->mst_state = mst_state;
1857         /* set the device into MST mode */
1858         if (mst_state) {
1859                 WARN_ON(mgr->mst_primary);
1860
1861                 /* get dpcd info */
1862                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
1863                 if (ret != DP_RECEIVER_CAP_SIZE) {
1864                         DRM_DEBUG_KMS("failed to read DPCD\n");
1865                         goto out_unlock;
1866                 }
1867
1868                 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
1869                                               mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
1870                                               &mgr->pbn_div)) {
1871                         ret = -EINVAL;
1872                         goto out_unlock;
1873                 }
1874
1875                 mgr->total_pbn = 2560;
1876                 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
1877                 mgr->avail_slots = mgr->total_slots;
1878
1879                 /* add initial branch device at LCT 1 */
1880                 mstb = drm_dp_add_mst_branch_device(1, NULL);
1881                 if (mstb == NULL) {
1882                         ret = -ENOMEM;
1883                         goto out_unlock;
1884                 }
1885                 mstb->mgr = mgr;
1886
1887                 /* give this the main reference */
1888                 mgr->mst_primary = mstb;
1889                 kref_get(&mgr->mst_primary->kref);
1890
1891                 {
1892                         struct drm_dp_payload reset_pay;
1893                         reset_pay.start_slot = 0;
1894                         reset_pay.num_slots = 0x3f;
1895                         drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
1896                 }
1897
1898                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1899                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
1900                 if (ret < 0) {
1901                         goto out_unlock;
1902                 }
1903
1904
1905                 /* sort out guid */
1906                 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
1907                 if (ret != 16) {
1908                         DRM_DEBUG_KMS("failed to read DP GUID %d\n", ret);
1909                         goto out_unlock;
1910                 }
1911
1912                 mgr->guid_valid = drm_dp_validate_guid(mgr, mgr->guid);
1913                 if (!mgr->guid_valid) {
1914                         ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, mgr->guid, 16);
1915                         mgr->guid_valid = true;
1916                 }
1917
1918                 queue_work(system_long_wq, &mgr->work);
1919
1920                 ret = 0;
1921         } else {
1922                 /* disable MST on the device */
1923                 mstb = mgr->mst_primary;
1924                 mgr->mst_primary = NULL;
1925                 /* this can fail if the device is gone */
1926                 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
1927                 ret = 0;
1928                 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
1929                 mgr->payload_mask = 0;
1930                 set_bit(0, &mgr->payload_mask);
1931                 mgr->vcpi_mask = 0;
1932         }
1933
1934 out_unlock:
1935         mutex_unlock(&mgr->lock);
1936         if (mstb)
1937                 drm_dp_put_mst_branch_device(mstb);
1938         return ret;
1939
1940 }
1941 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
1942
1943 /**
1944  * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
1945  * @mgr: manager to suspend
1946  *
1947  * This function tells the MST device that we can't handle UP messages
1948  * anymore. This should stop it from sending any since we are suspended.
1949  */
1950 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
1951 {
1952         mutex_lock(&mgr->lock);
1953         drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1954                            DP_MST_EN | DP_UPSTREAM_IS_SRC);
1955         mutex_unlock(&mgr->lock);
1956 }
1957 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
1958
1959 /**
1960  * drm_dp_mst_topology_mgr_resume() - resume the MST manager
1961  * @mgr: manager to resume
1962  *
1963  * This will fetch DPCD and see if the device is still there,
1964  * if it is, it will rewrite the MSTM control bits, and return.
1965  *
1966  * if the device fails this returns -1, and the driver should do
1967  * a full MST reprobe, in case we were undocked.
1968  */
1969 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
1970 {
1971         int ret = 0;
1972
1973         mutex_lock(&mgr->lock);
1974
1975         if (mgr->mst_primary) {
1976                 int sret;
1977                 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
1978                 if (sret != DP_RECEIVER_CAP_SIZE) {
1979                         DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
1980                         ret = -1;
1981                         goto out_unlock;
1982                 }
1983
1984                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1985                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
1986                 if (ret < 0) {
1987                         DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
1988                         ret = -1;
1989                         goto out_unlock;
1990                 }
1991                 ret = 0;
1992         } else
1993                 ret = -1;
1994
1995 out_unlock:
1996         mutex_unlock(&mgr->lock);
1997         return ret;
1998 }
1999 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2000
2001 static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2002 {
2003         int len;
2004         u8 replyblock[32];
2005         int replylen, origlen, curreply;
2006         int ret;
2007         struct drm_dp_sideband_msg_rx *msg;
2008         int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2009         msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2010
2011         len = min(mgr->max_dpcd_transaction_bytes, 16);
2012         ret = drm_dp_dpcd_read(mgr->aux, basereg,
2013                                replyblock, len);
2014         if (ret != len) {
2015                 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2016                 return;
2017         }
2018         ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2019         if (!ret) {
2020                 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2021                 return;
2022         }
2023         replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2024
2025         origlen = replylen;
2026         replylen -= len;
2027         curreply = len;
2028         while (replylen > 0) {
2029                 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2030                 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2031                                     replyblock, len);
2032                 if (ret != len) {
2033                         DRM_DEBUG_KMS("failed to read a chunk\n");
2034                 }
2035                 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2036                 if (ret == false)
2037                         DRM_DEBUG_KMS("failed to build sideband msg\n");
2038                 curreply += len;
2039                 replylen -= len;
2040         }
2041 }
2042
2043 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2044 {
2045         int ret = 0;
2046
2047         drm_dp_get_one_sb_msg(mgr, false);
2048
2049         if (mgr->down_rep_recv.have_eomt) {
2050                 struct drm_dp_sideband_msg_tx *txmsg;
2051                 struct drm_dp_mst_branch *mstb;
2052                 int slot = -1;
2053                 mstb = drm_dp_get_mst_branch_device(mgr,
2054                                                     mgr->down_rep_recv.initial_hdr.lct,
2055                                                     mgr->down_rep_recv.initial_hdr.rad);
2056
2057                 if (!mstb) {
2058                         DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2059                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2060                         return 0;
2061                 }
2062
2063                 /* find the message */
2064                 slot = mgr->down_rep_recv.initial_hdr.seqno;
2065                 mutex_lock(&mgr->qlock);
2066                 txmsg = mstb->tx_slots[slot];
2067                 /* remove from slots */
2068                 mutex_unlock(&mgr->qlock);
2069
2070                 if (!txmsg) {
2071                         DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2072                                mstb,
2073                                mgr->down_rep_recv.initial_hdr.seqno,
2074                                mgr->down_rep_recv.initial_hdr.lct,
2075                                       mgr->down_rep_recv.initial_hdr.rad[0],
2076                                       mgr->down_rep_recv.msg[0]);
2077                         drm_dp_put_mst_branch_device(mstb);
2078                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2079                         return 0;
2080                 }
2081
2082                 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2083                 if (txmsg->reply.reply_type == 1) {
2084                         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);
2085                 }
2086
2087                 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2088                 drm_dp_put_mst_branch_device(mstb);
2089
2090                 mutex_lock(&mgr->qlock);
2091                 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2092                 mstb->tx_slots[slot] = NULL;
2093                 mutex_unlock(&mgr->qlock);
2094
2095                 wake_up(&mgr->tx_waitq);
2096         }
2097         return ret;
2098 }
2099
2100 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2101 {
2102         int ret = 0;
2103         drm_dp_get_one_sb_msg(mgr, true);
2104
2105         if (mgr->up_req_recv.have_eomt) {
2106                 struct drm_dp_sideband_msg_req_body msg;
2107                 struct drm_dp_mst_branch *mstb;
2108                 bool seqno;
2109                 mstb = drm_dp_get_mst_branch_device(mgr,
2110                                                     mgr->up_req_recv.initial_hdr.lct,
2111                                                     mgr->up_req_recv.initial_hdr.rad);
2112                 if (!mstb) {
2113                         DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2114                         memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2115                         return 0;
2116                 }
2117
2118                 seqno = mgr->up_req_recv.initial_hdr.seqno;
2119                 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2120
2121                 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2122                         drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
2123                         drm_dp_update_port(mstb, &msg.u.conn_stat);
2124                         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);
2125                         (*mgr->cbs->hotplug)(mgr);
2126
2127                 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2128                         drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
2129                         DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2130                 }
2131
2132                 drm_dp_put_mst_branch_device(mstb);
2133                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2134         }
2135         return ret;
2136 }
2137
2138 /**
2139  * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2140  * @mgr: manager to notify irq for.
2141  * @esi: 4 bytes from SINK_COUNT_ESI
2142  * @handled: whether the hpd interrupt was consumed or not
2143  *
2144  * This should be called from the driver when it detects a short IRQ,
2145  * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2146  * topology manager will process the sideband messages received as a result
2147  * of this.
2148  */
2149 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2150 {
2151         int ret = 0;
2152         int sc;
2153         *handled = false;
2154         sc = esi[0] & 0x3f;
2155
2156         if (sc != mgr->sink_count) {
2157                 mgr->sink_count = sc;
2158                 *handled = true;
2159         }
2160
2161         if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2162                 ret = drm_dp_mst_handle_down_rep(mgr);
2163                 *handled = true;
2164         }
2165
2166         if (esi[1] & DP_UP_REQ_MSG_RDY) {
2167                 ret |= drm_dp_mst_handle_up_req(mgr);
2168                 *handled = true;
2169         }
2170
2171         drm_dp_mst_kick_tx(mgr);
2172         return ret;
2173 }
2174 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2175
2176 /**
2177  * drm_dp_mst_detect_port() - get connection status for an MST port
2178  * @mgr: manager for this port
2179  * @port: unverified pointer to a port
2180  *
2181  * This returns the current connection state for a port. It validates the
2182  * port pointer still exists so the caller doesn't require a reference
2183  */
2184 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2185                                                  struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2186 {
2187         enum drm_connector_status status = connector_status_disconnected;
2188
2189         /* we need to search for the port in the mgr in case its gone */
2190         port = drm_dp_get_validated_port_ref(mgr, port);
2191         if (!port)
2192                 return connector_status_disconnected;
2193
2194         if (!port->ddps)
2195                 goto out;
2196
2197         switch (port->pdt) {
2198         case DP_PEER_DEVICE_NONE:
2199         case DP_PEER_DEVICE_MST_BRANCHING:
2200                 break;
2201
2202         case DP_PEER_DEVICE_SST_SINK:
2203                 status = connector_status_connected;
2204                 /* for logical ports - cache the EDID */
2205                 if (port->port_num >= 8 && !port->cached_edid) {
2206                         port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2207                 }
2208                 break;
2209         case DP_PEER_DEVICE_DP_LEGACY_CONV:
2210                 if (port->ldps)
2211                         status = connector_status_connected;
2212                 break;
2213         }
2214 out:
2215         drm_dp_put_port(port);
2216         return status;
2217 }
2218 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2219
2220 /**
2221  * drm_dp_mst_get_edid() - get EDID for an MST port
2222  * @connector: toplevel connector to get EDID for
2223  * @mgr: manager for this port
2224  * @port: unverified pointer to a port.
2225  *
2226  * This returns an EDID for the port connected to a connector,
2227  * It validates the pointer still exists so the caller doesn't require a
2228  * reference.
2229  */
2230 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2231 {
2232         struct edid *edid = NULL;
2233
2234         /* we need to search for the port in the mgr in case its gone */
2235         port = drm_dp_get_validated_port_ref(mgr, port);
2236         if (!port)
2237                 return NULL;
2238
2239         if (port->cached_edid)
2240                 edid = drm_edid_duplicate(port->cached_edid);
2241         else
2242                 edid = drm_get_edid(connector, &port->aux.ddc);
2243
2244         drm_mode_connector_set_tile_property(connector);
2245         drm_dp_put_port(port);
2246         return edid;
2247 }
2248 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2249
2250 /**
2251  * drm_dp_find_vcpi_slots() - find slots for this PBN value
2252  * @mgr: manager to use
2253  * @pbn: payload bandwidth to convert into slots.
2254  */
2255 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2256                            int pbn)
2257 {
2258         int num_slots;
2259
2260         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2261
2262         if (num_slots > mgr->avail_slots)
2263                 return -ENOSPC;
2264         return num_slots;
2265 }
2266 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2267
2268 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2269                             struct drm_dp_vcpi *vcpi, int pbn)
2270 {
2271         int num_slots;
2272         int ret;
2273
2274         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2275
2276         if (num_slots > mgr->avail_slots)
2277                 return -ENOSPC;
2278
2279         vcpi->pbn = pbn;
2280         vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2281         vcpi->num_slots = num_slots;
2282
2283         ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2284         if (ret < 0)
2285                 return ret;
2286         return 0;
2287 }
2288
2289 /**
2290  * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2291  * @mgr: manager for this port
2292  * @port: port to allocate a virtual channel for.
2293  * @pbn: payload bandwidth number to request
2294  * @slots: returned number of slots for this PBN.
2295  */
2296 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2297 {
2298         int ret;
2299
2300         port = drm_dp_get_validated_port_ref(mgr, port);
2301         if (!port)
2302                 return false;
2303
2304         if (port->vcpi.vcpi > 0) {
2305                 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2306                 if (pbn == port->vcpi.pbn) {
2307                         *slots = port->vcpi.num_slots;
2308                         return true;
2309                 }
2310         }
2311
2312         ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2313         if (ret) {
2314                 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2315                 goto out;
2316         }
2317         DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2318         *slots = port->vcpi.num_slots;
2319
2320         drm_dp_put_port(port);
2321         return true;
2322 out:
2323         return false;
2324 }
2325 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2326
2327 /**
2328  * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2329  * @mgr: manager for this port
2330  * @port: unverified pointer to a port.
2331  *
2332  * This just resets the number of slots for the ports VCPI for later programming.
2333  */
2334 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2335 {
2336         port = drm_dp_get_validated_port_ref(mgr, port);
2337         if (!port)
2338                 return;
2339         port->vcpi.num_slots = 0;
2340         drm_dp_put_port(port);
2341 }
2342 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2343
2344 /**
2345  * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2346  * @mgr: manager for this port
2347  * @port: unverified port to deallocate vcpi for
2348  */
2349 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2350 {
2351         port = drm_dp_get_validated_port_ref(mgr, port);
2352         if (!port)
2353                 return;
2354
2355         drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2356         port->vcpi.num_slots = 0;
2357         port->vcpi.pbn = 0;
2358         port->vcpi.aligned_pbn = 0;
2359         port->vcpi.vcpi = 0;
2360         drm_dp_put_port(port);
2361 }
2362 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2363
2364 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2365                                      int id, struct drm_dp_payload *payload)
2366 {
2367         u8 payload_alloc[3], status;
2368         int ret;
2369         int retries = 0;
2370
2371         drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2372                            DP_PAYLOAD_TABLE_UPDATED);
2373
2374         payload_alloc[0] = id;
2375         payload_alloc[1] = payload->start_slot;
2376         payload_alloc[2] = payload->num_slots;
2377
2378         ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2379         if (ret != 3) {
2380                 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2381                 goto fail;
2382         }
2383
2384 retry:
2385         ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2386         if (ret < 0) {
2387                 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2388                 goto fail;
2389         }
2390
2391         if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2392                 retries++;
2393                 if (retries < 20) {
2394                         usleep_range(10000, 20000);
2395                         goto retry;
2396                 }
2397                 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2398                 ret = -EINVAL;
2399                 goto fail;
2400         }
2401         ret = 0;
2402 fail:
2403         return ret;
2404 }
2405
2406
2407 /**
2408  * drm_dp_check_act_status() - Check ACT handled status.
2409  * @mgr: manager to use
2410  *
2411  * Check the payload status bits in the DPCD for ACT handled completion.
2412  */
2413 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2414 {
2415         u8 status;
2416         int ret;
2417         int count = 0;
2418
2419         do {
2420                 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2421
2422                 if (ret < 0) {
2423                         DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2424                         goto fail;
2425                 }
2426
2427                 if (status & DP_PAYLOAD_ACT_HANDLED)
2428                         break;
2429                 count++;
2430                 udelay(100);
2431
2432         } while (count < 30);
2433
2434         if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2435                 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2436                 ret = -EINVAL;
2437                 goto fail;
2438         }
2439         return 0;
2440 fail:
2441         return ret;
2442 }
2443 EXPORT_SYMBOL(drm_dp_check_act_status);
2444
2445 /**
2446  * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2447  * @clock: dot clock for the mode
2448  * @bpp: bpp for the mode.
2449  *
2450  * This uses the formula in the spec to calculate the PBN value for a mode.
2451  */
2452 int drm_dp_calc_pbn_mode(int clock, int bpp)
2453 {
2454         fixed20_12 pix_bw;
2455         fixed20_12 fbpp;
2456         fixed20_12 result;
2457         fixed20_12 margin, tmp;
2458         u32 res;
2459
2460         pix_bw.full = dfixed_const(clock);
2461         fbpp.full = dfixed_const(bpp);
2462         tmp.full = dfixed_const(8);
2463         fbpp.full = dfixed_div(fbpp, tmp);
2464
2465         result.full = dfixed_mul(pix_bw, fbpp);
2466         margin.full = dfixed_const(54);
2467         tmp.full = dfixed_const(64);
2468         margin.full = dfixed_div(margin, tmp);
2469         result.full = dfixed_div(result, margin);
2470
2471         margin.full = dfixed_const(1006);
2472         tmp.full = dfixed_const(1000);
2473         margin.full = dfixed_div(margin, tmp);
2474         result.full = dfixed_mul(result, margin);
2475
2476         result.full = dfixed_div(result, tmp);
2477         result.full = dfixed_ceil(result);
2478         res = dfixed_trunc(result);
2479         return res;
2480 }
2481 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2482
2483 static int test_calc_pbn_mode(void)
2484 {
2485         int ret;
2486         ret = drm_dp_calc_pbn_mode(154000, 30);
2487         if (ret != 689)
2488                 return -EINVAL;
2489         ret = drm_dp_calc_pbn_mode(234000, 30);
2490         if (ret != 1047)
2491                 return -EINVAL;
2492         return 0;
2493 }
2494
2495 /* we want to kick the TX after we've ack the up/down IRQs. */
2496 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2497 {
2498         queue_work(system_long_wq, &mgr->tx_work);
2499 }
2500
2501 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2502                                  struct drm_dp_mst_branch *mstb)
2503 {
2504         struct drm_dp_mst_port *port;
2505         int tabs = mstb->lct;
2506         char prefix[10];
2507         int i;
2508
2509         for (i = 0; i < tabs; i++)
2510                 prefix[i] = '\t';
2511         prefix[i] = '\0';
2512
2513         seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2514         list_for_each_entry(port, &mstb->ports, next) {
2515                 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port, port->connector);
2516                 if (port->mstb)
2517                         drm_dp_mst_dump_mstb(m, port->mstb);
2518         }
2519 }
2520
2521 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2522                                   char *buf)
2523 {
2524         int ret;
2525         int i;
2526         for (i = 0; i < 4; i++) {
2527                 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2528                 if (ret != 16)
2529                         break;
2530         }
2531         if (i == 4)
2532                 return true;
2533         return false;
2534 }
2535
2536 /**
2537  * drm_dp_mst_dump_topology(): dump topology to seq file.
2538  * @m: seq_file to dump output to
2539  * @mgr: manager to dump current topology for.
2540  *
2541  * helper to dump MST topology to a seq file for debugfs.
2542  */
2543 void drm_dp_mst_dump_topology(struct seq_file *m,
2544                               struct drm_dp_mst_topology_mgr *mgr)
2545 {
2546         int i;
2547         struct drm_dp_mst_port *port;
2548         mutex_lock(&mgr->lock);
2549         if (mgr->mst_primary)
2550                 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2551
2552         /* dump VCPIs */
2553         mutex_unlock(&mgr->lock);
2554
2555         mutex_lock(&mgr->payload_lock);
2556         seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
2557
2558         for (i = 0; i < mgr->max_payloads; i++) {
2559                 if (mgr->proposed_vcpis[i]) {
2560                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2561                         seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2562                 } else
2563                         seq_printf(m, "vcpi %d:unsed\n", i);
2564         }
2565         for (i = 0; i < mgr->max_payloads; i++) {
2566                 seq_printf(m, "payload %d: %d, %d, %d\n",
2567                            i,
2568                            mgr->payloads[i].payload_state,
2569                            mgr->payloads[i].start_slot,
2570                            mgr->payloads[i].num_slots);
2571
2572
2573         }
2574         mutex_unlock(&mgr->payload_lock);
2575
2576         mutex_lock(&mgr->lock);
2577         if (mgr->mst_primary) {
2578                 u8 buf[64];
2579                 bool bret;
2580                 int ret;
2581                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2582                 seq_printf(m, "dpcd: ");
2583                 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2584                         seq_printf(m, "%02x ", buf[i]);
2585                 seq_printf(m, "\n");
2586                 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2587                 seq_printf(m, "faux/mst: ");
2588                 for (i = 0; i < 2; i++)
2589                         seq_printf(m, "%02x ", buf[i]);
2590                 seq_printf(m, "\n");
2591                 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2592                 seq_printf(m, "mst ctrl: ");
2593                 for (i = 0; i < 1; i++)
2594                         seq_printf(m, "%02x ", buf[i]);
2595                 seq_printf(m, "\n");
2596
2597                 bret = dump_dp_payload_table(mgr, buf);
2598                 if (bret == true) {
2599                         seq_printf(m, "payload table: ");
2600                         for (i = 0; i < 63; i++)
2601                                 seq_printf(m, "%02x ", buf[i]);
2602                         seq_printf(m, "\n");
2603                 }
2604
2605         }
2606
2607         mutex_unlock(&mgr->lock);
2608
2609 }
2610 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2611
2612 static void drm_dp_tx_work(struct work_struct *work)
2613 {
2614         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2615
2616         mutex_lock(&mgr->qlock);
2617         if (mgr->tx_down_in_progress)
2618                 process_single_down_tx_qlock(mgr);
2619         mutex_unlock(&mgr->qlock);
2620 }
2621
2622 /**
2623  * drm_dp_mst_topology_mgr_init - initialise a topology manager
2624  * @mgr: manager struct to initialise
2625  * @dev: device providing this structure - for i2c addition.
2626  * @aux: DP helper aux channel to talk to this device
2627  * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2628  * @max_payloads: maximum number of payloads this GPU can source
2629  * @conn_base_id: the connector object ID the MST device is connected to.
2630  *
2631  * Return 0 for success, or negative error code on failure
2632  */
2633 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2634                                  struct device *dev, struct drm_dp_aux *aux,
2635                                  int max_dpcd_transaction_bytes,
2636                                  int max_payloads, int conn_base_id)
2637 {
2638         mutex_init(&mgr->lock);
2639         mutex_init(&mgr->qlock);
2640         mutex_init(&mgr->payload_lock);
2641         INIT_LIST_HEAD(&mgr->tx_msg_upq);
2642         INIT_LIST_HEAD(&mgr->tx_msg_downq);
2643         INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2644         INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2645         init_waitqueue_head(&mgr->tx_waitq);
2646         mgr->dev = dev;
2647         mgr->aux = aux;
2648         mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2649         mgr->max_payloads = max_payloads;
2650         mgr->conn_base_id = conn_base_id;
2651         mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2652         if (!mgr->payloads)
2653                 return -ENOMEM;
2654         mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2655         if (!mgr->proposed_vcpis)
2656                 return -ENOMEM;
2657         set_bit(0, &mgr->payload_mask);
2658         test_calc_pbn_mode();
2659         return 0;
2660 }
2661 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2662
2663 /**
2664  * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2665  * @mgr: manager to destroy
2666  */
2667 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2668 {
2669         mutex_lock(&mgr->payload_lock);
2670         kfree(mgr->payloads);
2671         mgr->payloads = NULL;
2672         kfree(mgr->proposed_vcpis);
2673         mgr->proposed_vcpis = NULL;
2674         mutex_unlock(&mgr->payload_lock);
2675         mgr->dev = NULL;
2676         mgr->aux = NULL;
2677 }
2678 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
2679
2680 /* I2C device */
2681 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
2682                                int num)
2683 {
2684         struct drm_dp_aux *aux = adapter->algo_data;
2685         struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
2686         struct drm_dp_mst_branch *mstb;
2687         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2688         unsigned int i;
2689         bool reading = false;
2690         struct drm_dp_sideband_msg_req_body msg;
2691         struct drm_dp_sideband_msg_tx *txmsg = NULL;
2692         int ret;
2693
2694         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2695         if (!mstb)
2696                 return -EREMOTEIO;
2697
2698         /* construct i2c msg */
2699         /* see if last msg is a read */
2700         if (msgs[num - 1].flags & I2C_M_RD)
2701                 reading = true;
2702
2703         if (!reading) {
2704                 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
2705                 ret = -EIO;
2706                 goto out;
2707         }
2708
2709         msg.req_type = DP_REMOTE_I2C_READ;
2710         msg.u.i2c_read.num_transactions = num - 1;
2711         msg.u.i2c_read.port_number = port->port_num;
2712         for (i = 0; i < num - 1; i++) {
2713                 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
2714                 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
2715                 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
2716         }
2717         msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
2718         msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
2719
2720         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2721         if (!txmsg) {
2722                 ret = -ENOMEM;
2723                 goto out;
2724         }
2725
2726         txmsg->dst = mstb;
2727         drm_dp_encode_sideband_req(&msg, txmsg);
2728
2729         drm_dp_queue_down_tx(mgr, txmsg);
2730
2731         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2732         if (ret > 0) {
2733
2734                 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
2735                         ret = -EREMOTEIO;
2736                         goto out;
2737                 }
2738                 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
2739                         ret = -EIO;
2740                         goto out;
2741                 }
2742                 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
2743                 ret = num;
2744         }
2745 out:
2746         kfree(txmsg);
2747         drm_dp_put_mst_branch_device(mstb);
2748         return ret;
2749 }
2750
2751 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
2752 {
2753         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
2754                I2C_FUNC_SMBUS_READ_BLOCK_DATA |
2755                I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
2756                I2C_FUNC_10BIT_ADDR;
2757 }
2758
2759 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
2760         .functionality = drm_dp_mst_i2c_functionality,
2761         .master_xfer = drm_dp_mst_i2c_xfer,
2762 };
2763
2764 /**
2765  * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
2766  * @aux: DisplayPort AUX channel
2767  *
2768  * Returns 0 on success or a negative error code on failure.
2769  */
2770 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
2771 {
2772         aux->ddc.algo = &drm_dp_mst_i2c_algo;
2773         aux->ddc.algo_data = aux;
2774         aux->ddc.retries = 3;
2775
2776         aux->ddc.class = I2C_CLASS_DDC;
2777         aux->ddc.owner = THIS_MODULE;
2778         aux->ddc.dev.parent = aux->dev;
2779         aux->ddc.dev.of_node = aux->dev->of_node;
2780
2781         strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
2782                 sizeof(aux->ddc.name));
2783
2784         return i2c_add_adapter(&aux->ddc);
2785 }
2786
2787 /**
2788  * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
2789  * @aux: DisplayPort AUX channel
2790  */
2791 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
2792 {
2793         i2c_del_adapter(&aux->ddc);
2794 }