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/errno.h> 26 #include <linux/sched.h> 27 #include <linux/seq_file.h> 28 #include <linux/i2c.h> 29 #include <drm/drm_dp_mst_helper.h> 30 #include <drm/drmP.h> 31 32 #include <drm/drm_fixed.h> 33 34 /** 35 * DOC: dp mst helper 36 * 37 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport 38 * protocol. The helpers contain a topology manager and bandwidth manager. 39 * The helpers encapsulate the sending and received of sideband msgs. 40 */ 41 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, 42 char *buf); 43 static int test_calc_pbn_mode(void); 44 45 static void drm_dp_put_port(struct drm_dp_mst_port *port); 46 47 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, 48 int id, 49 struct drm_dp_payload *payload); 50 51 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, 52 struct drm_dp_mst_port *port, 53 int offset, int size, u8 *bytes); 54 55 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 56 struct drm_dp_mst_branch *mstb); 57 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, 58 struct drm_dp_mst_branch *mstb, 59 struct drm_dp_mst_port *port); 60 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, 61 u8 *guid); 62 63 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux); 64 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux); 65 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr); 66 /* sideband msg handling */ 67 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles) 68 { 69 u8 bitmask = 0x80; 70 u8 bitshift = 7; 71 u8 array_index = 0; 72 int number_of_bits = num_nibbles * 4; 73 u8 remainder = 0; 74 75 while (number_of_bits != 0) { 76 number_of_bits--; 77 remainder <<= 1; 78 remainder |= (data[array_index] & bitmask) >> bitshift; 79 bitmask >>= 1; 80 bitshift--; 81 if (bitmask == 0) { 82 bitmask = 0x80; 83 bitshift = 7; 84 array_index++; 85 } 86 if ((remainder & 0x10) == 0x10) 87 remainder ^= 0x13; 88 } 89 90 number_of_bits = 4; 91 while (number_of_bits != 0) { 92 number_of_bits--; 93 remainder <<= 1; 94 if ((remainder & 0x10) != 0) 95 remainder ^= 0x13; 96 } 97 98 return remainder; 99 } 100 101 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes) 102 { 103 u8 bitmask = 0x80; 104 u8 bitshift = 7; 105 u8 array_index = 0; 106 int number_of_bits = number_of_bytes * 8; 107 u16 remainder = 0; 108 109 while (number_of_bits != 0) { 110 number_of_bits--; 111 remainder <<= 1; 112 remainder |= (data[array_index] & bitmask) >> bitshift; 113 bitmask >>= 1; 114 bitshift--; 115 if (bitmask == 0) { 116 bitmask = 0x80; 117 bitshift = 7; 118 array_index++; 119 } 120 if ((remainder & 0x100) == 0x100) 121 remainder ^= 0xd5; 122 } 123 124 number_of_bits = 8; 125 while (number_of_bits != 0) { 126 number_of_bits--; 127 remainder <<= 1; 128 if ((remainder & 0x100) != 0) 129 remainder ^= 0xd5; 130 } 131 132 return remainder & 0xff; 133 } 134 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr) 135 { 136 u8 size = 3; 137 size += (hdr->lct / 2); 138 return size; 139 } 140 141 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr, 142 u8 *buf, int *len) 143 { 144 int idx = 0; 145 int i; 146 u8 crc4; 147 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf); 148 for (i = 0; i < (hdr->lct / 2); i++) 149 buf[idx++] = hdr->rad[i]; 150 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) | 151 (hdr->msg_len & 0x3f); 152 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4); 153 154 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1); 155 buf[idx - 1] |= (crc4 & 0xf); 156 157 *len = idx; 158 } 159 160 static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr, 161 u8 *buf, int buflen, u8 *hdrlen) 162 { 163 u8 crc4; 164 u8 len; 165 int i; 166 u8 idx; 167 if (buf[0] == 0) 168 return false; 169 len = 3; 170 len += ((buf[0] & 0xf0) >> 4) / 2; 171 if (len > buflen) 172 return false; 173 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1); 174 175 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) { 176 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]); 177 return false; 178 } 179 180 hdr->lct = (buf[0] & 0xf0) >> 4; 181 hdr->lcr = (buf[0] & 0xf); 182 idx = 1; 183 for (i = 0; i < (hdr->lct / 2); i++) 184 hdr->rad[i] = buf[idx++]; 185 hdr->broadcast = (buf[idx] >> 7) & 0x1; 186 hdr->path_msg = (buf[idx] >> 6) & 0x1; 187 hdr->msg_len = buf[idx] & 0x3f; 188 idx++; 189 hdr->somt = (buf[idx] >> 7) & 0x1; 190 hdr->eomt = (buf[idx] >> 6) & 0x1; 191 hdr->seqno = (buf[idx] >> 4) & 0x1; 192 idx++; 193 *hdrlen = idx; 194 return true; 195 } 196 197 static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req, 198 struct drm_dp_sideband_msg_tx *raw) 199 { 200 int idx = 0; 201 int i; 202 u8 *buf = raw->msg; 203 buf[idx++] = req->req_type & 0x7f; 204 205 switch (req->req_type) { 206 case DP_ENUM_PATH_RESOURCES: 207 buf[idx] = (req->u.port_num.port_number & 0xf) << 4; 208 idx++; 209 break; 210 case DP_ALLOCATE_PAYLOAD: 211 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 | 212 (req->u.allocate_payload.number_sdp_streams & 0xf); 213 idx++; 214 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f); 215 idx++; 216 buf[idx] = (req->u.allocate_payload.pbn >> 8); 217 idx++; 218 buf[idx] = (req->u.allocate_payload.pbn & 0xff); 219 idx++; 220 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) { 221 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) | 222 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf); 223 idx++; 224 } 225 if (req->u.allocate_payload.number_sdp_streams & 1) { 226 i = req->u.allocate_payload.number_sdp_streams - 1; 227 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4; 228 idx++; 229 } 230 break; 231 case DP_QUERY_PAYLOAD: 232 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4; 233 idx++; 234 buf[idx] = (req->u.query_payload.vcpi & 0x7f); 235 idx++; 236 break; 237 case DP_REMOTE_DPCD_READ: 238 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4; 239 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf; 240 idx++; 241 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8; 242 idx++; 243 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff); 244 idx++; 245 buf[idx] = (req->u.dpcd_read.num_bytes); 246 idx++; 247 break; 248 249 case DP_REMOTE_DPCD_WRITE: 250 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4; 251 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf; 252 idx++; 253 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8; 254 idx++; 255 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff); 256 idx++; 257 buf[idx] = (req->u.dpcd_write.num_bytes); 258 idx++; 259 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes); 260 idx += req->u.dpcd_write.num_bytes; 261 break; 262 case DP_REMOTE_I2C_READ: 263 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4; 264 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3); 265 idx++; 266 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) { 267 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f; 268 idx++; 269 buf[idx] = req->u.i2c_read.transactions[i].num_bytes; 270 idx++; 271 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes); 272 idx += req->u.i2c_read.transactions[i].num_bytes; 273 274 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5; 275 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf); 276 idx++; 277 } 278 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f; 279 idx++; 280 buf[idx] = (req->u.i2c_read.num_bytes_read); 281 idx++; 282 break; 283 284 case DP_REMOTE_I2C_WRITE: 285 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4; 286 idx++; 287 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f; 288 idx++; 289 buf[idx] = (req->u.i2c_write.num_bytes); 290 idx++; 291 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes); 292 idx += req->u.i2c_write.num_bytes; 293 break; 294 } 295 raw->cur_len = idx; 296 } 297 298 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len) 299 { 300 u8 crc4; 301 crc4 = drm_dp_msg_data_crc4(msg, len); 302 msg[len] = crc4; 303 } 304 305 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep, 306 struct drm_dp_sideband_msg_tx *raw) 307 { 308 int idx = 0; 309 u8 *buf = raw->msg; 310 311 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f); 312 313 raw->cur_len = idx; 314 } 315 316 /* this adds a chunk of msg to the builder to get the final msg */ 317 static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg, 318 u8 *replybuf, u8 replybuflen, bool hdr) 319 { 320 int ret; 321 u8 crc4; 322 323 if (hdr) { 324 u8 hdrlen; 325 struct drm_dp_sideband_msg_hdr recv_hdr; 326 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen); 327 if (ret == false) { 328 #if 0 329 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false); 330 #endif 331 return false; 332 } 333 334 /* get length contained in this portion */ 335 msg->curchunk_len = recv_hdr.msg_len; 336 msg->curchunk_hdrlen = hdrlen; 337 338 /* we have already gotten an somt - don't bother parsing */ 339 if (recv_hdr.somt && msg->have_somt) 340 return false; 341 342 if (recv_hdr.somt) { 343 memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr)); 344 msg->have_somt = true; 345 } 346 if (recv_hdr.eomt) 347 msg->have_eomt = true; 348 349 /* copy the bytes for the remainder of this header chunk */ 350 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen)); 351 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx); 352 } else { 353 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen); 354 msg->curchunk_idx += replybuflen; 355 } 356 357 if (msg->curchunk_idx >= msg->curchunk_len) { 358 /* do CRC */ 359 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1); 360 /* copy chunk into bigger msg */ 361 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1); 362 msg->curlen += msg->curchunk_len - 1; 363 } 364 return true; 365 } 366 367 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw, 368 struct drm_dp_sideband_msg_reply_body *repmsg) 369 { 370 int idx = 1; 371 int i; 372 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16); 373 idx += 16; 374 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf; 375 idx++; 376 if (idx > raw->curlen) 377 goto fail_len; 378 for (i = 0; i < repmsg->u.link_addr.nports; i++) { 379 if (raw->msg[idx] & 0x80) 380 repmsg->u.link_addr.ports[i].input_port = 1; 381 382 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7; 383 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf); 384 385 idx++; 386 if (idx > raw->curlen) 387 goto fail_len; 388 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1; 389 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1; 390 if (repmsg->u.link_addr.ports[i].input_port == 0) 391 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1; 392 idx++; 393 if (idx > raw->curlen) 394 goto fail_len; 395 if (repmsg->u.link_addr.ports[i].input_port == 0) { 396 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]); 397 idx++; 398 if (idx > raw->curlen) 399 goto fail_len; 400 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16); 401 idx += 16; 402 if (idx > raw->curlen) 403 goto fail_len; 404 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf; 405 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf); 406 idx++; 407 408 } 409 if (idx > raw->curlen) 410 goto fail_len; 411 } 412 413 return true; 414 fail_len: 415 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen); 416 return false; 417 } 418 419 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw, 420 struct drm_dp_sideband_msg_reply_body *repmsg) 421 { 422 int idx = 1; 423 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf; 424 idx++; 425 if (idx > raw->curlen) 426 goto fail_len; 427 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx]; 428 if (idx > raw->curlen) 429 goto fail_len; 430 431 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes); 432 return true; 433 fail_len: 434 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen); 435 return false; 436 } 437 438 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw, 439 struct drm_dp_sideband_msg_reply_body *repmsg) 440 { 441 int idx = 1; 442 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf; 443 idx++; 444 if (idx > raw->curlen) 445 goto fail_len; 446 return true; 447 fail_len: 448 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen); 449 return false; 450 } 451 452 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw, 453 struct drm_dp_sideband_msg_reply_body *repmsg) 454 { 455 int idx = 1; 456 457 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf); 458 idx++; 459 if (idx > raw->curlen) 460 goto fail_len; 461 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx]; 462 idx++; 463 /* TODO check */ 464 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes); 465 return true; 466 fail_len: 467 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen); 468 return false; 469 } 470 471 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw, 472 struct drm_dp_sideband_msg_reply_body *repmsg) 473 { 474 int idx = 1; 475 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf; 476 idx++; 477 if (idx > raw->curlen) 478 goto fail_len; 479 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 480 idx += 2; 481 if (idx > raw->curlen) 482 goto fail_len; 483 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 484 idx += 2; 485 if (idx > raw->curlen) 486 goto fail_len; 487 return true; 488 fail_len: 489 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen); 490 return false; 491 } 492 493 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw, 494 struct drm_dp_sideband_msg_reply_body *repmsg) 495 { 496 int idx = 1; 497 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf; 498 idx++; 499 if (idx > raw->curlen) 500 goto fail_len; 501 repmsg->u.allocate_payload.vcpi = raw->msg[idx]; 502 idx++; 503 if (idx > raw->curlen) 504 goto fail_len; 505 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 506 idx += 2; 507 if (idx > raw->curlen) 508 goto fail_len; 509 return true; 510 fail_len: 511 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen); 512 return false; 513 } 514 515 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw, 516 struct drm_dp_sideband_msg_reply_body *repmsg) 517 { 518 int idx = 1; 519 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf; 520 idx++; 521 if (idx > raw->curlen) 522 goto fail_len; 523 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]); 524 idx += 2; 525 if (idx > raw->curlen) 526 goto fail_len; 527 return true; 528 fail_len: 529 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen); 530 return false; 531 } 532 533 static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw, 534 struct drm_dp_sideband_msg_reply_body *msg) 535 { 536 memset(msg, 0, sizeof(*msg)); 537 msg->reply_type = (raw->msg[0] & 0x80) >> 7; 538 msg->req_type = (raw->msg[0] & 0x7f); 539 540 if (msg->reply_type) { 541 memcpy(msg->u.nak.guid, &raw->msg[1], 16); 542 msg->u.nak.reason = raw->msg[17]; 543 msg->u.nak.nak_data = raw->msg[18]; 544 return false; 545 } 546 547 switch (msg->req_type) { 548 case DP_LINK_ADDRESS: 549 return drm_dp_sideband_parse_link_address(raw, msg); 550 case DP_QUERY_PAYLOAD: 551 return drm_dp_sideband_parse_query_payload_ack(raw, msg); 552 case DP_REMOTE_DPCD_READ: 553 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg); 554 case DP_REMOTE_DPCD_WRITE: 555 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg); 556 case DP_REMOTE_I2C_READ: 557 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg); 558 case DP_ENUM_PATH_RESOURCES: 559 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg); 560 case DP_ALLOCATE_PAYLOAD: 561 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg); 562 default: 563 DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type); 564 return false; 565 } 566 } 567 568 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw, 569 struct drm_dp_sideband_msg_req_body *msg) 570 { 571 int idx = 1; 572 573 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4; 574 idx++; 575 if (idx > raw->curlen) 576 goto fail_len; 577 578 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16); 579 idx += 16; 580 if (idx > raw->curlen) 581 goto fail_len; 582 583 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1; 584 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1; 585 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1; 586 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1; 587 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7); 588 idx++; 589 return true; 590 fail_len: 591 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen); 592 return false; 593 } 594 595 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw, 596 struct drm_dp_sideband_msg_req_body *msg) 597 { 598 int idx = 1; 599 600 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4; 601 idx++; 602 if (idx > raw->curlen) 603 goto fail_len; 604 605 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16); 606 idx += 16; 607 if (idx > raw->curlen) 608 goto fail_len; 609 610 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]); 611 idx++; 612 return true; 613 fail_len: 614 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen); 615 return false; 616 } 617 618 static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw, 619 struct drm_dp_sideband_msg_req_body *msg) 620 { 621 memset(msg, 0, sizeof(*msg)); 622 msg->req_type = (raw->msg[0] & 0x7f); 623 624 switch (msg->req_type) { 625 case DP_CONNECTION_STATUS_NOTIFY: 626 return drm_dp_sideband_parse_connection_status_notify(raw, msg); 627 case DP_RESOURCE_STATUS_NOTIFY: 628 return drm_dp_sideband_parse_resource_status_notify(raw, msg); 629 default: 630 DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type); 631 return false; 632 } 633 } 634 635 static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes) 636 { 637 struct drm_dp_sideband_msg_req_body req; 638 639 req.req_type = DP_REMOTE_DPCD_WRITE; 640 req.u.dpcd_write.port_number = port_num; 641 req.u.dpcd_write.dpcd_address = offset; 642 req.u.dpcd_write.num_bytes = num_bytes; 643 req.u.dpcd_write.bytes = bytes; 644 drm_dp_encode_sideband_req(&req, msg); 645 646 return 0; 647 } 648 649 static int build_link_address(struct drm_dp_sideband_msg_tx *msg) 650 { 651 struct drm_dp_sideband_msg_req_body req; 652 653 req.req_type = DP_LINK_ADDRESS; 654 drm_dp_encode_sideband_req(&req, msg); 655 return 0; 656 } 657 658 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num) 659 { 660 struct drm_dp_sideband_msg_req_body req; 661 662 req.req_type = DP_ENUM_PATH_RESOURCES; 663 req.u.port_num.port_number = port_num; 664 drm_dp_encode_sideband_req(&req, msg); 665 msg->path_msg = true; 666 return 0; 667 } 668 669 static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num, 670 u8 vcpi, uint16_t pbn, 671 u8 number_sdp_streams, 672 u8 *sdp_stream_sink) 673 { 674 struct drm_dp_sideband_msg_req_body req; 675 memset(&req, 0, sizeof(req)); 676 req.req_type = DP_ALLOCATE_PAYLOAD; 677 req.u.allocate_payload.port_number = port_num; 678 req.u.allocate_payload.vcpi = vcpi; 679 req.u.allocate_payload.pbn = pbn; 680 req.u.allocate_payload.number_sdp_streams = number_sdp_streams; 681 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink, 682 number_sdp_streams); 683 drm_dp_encode_sideband_req(&req, msg); 684 msg->path_msg = true; 685 return 0; 686 } 687 688 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr, 689 struct drm_dp_vcpi *vcpi) 690 { 691 int ret, vcpi_ret; 692 693 mutex_lock(&mgr->payload_lock); 694 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1); 695 if (ret > mgr->max_payloads) { 696 ret = -EINVAL; 697 DRM_DEBUG_KMS("out of payload ids %d\n", ret); 698 goto out_unlock; 699 } 700 701 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1); 702 if (vcpi_ret > mgr->max_payloads) { 703 ret = -EINVAL; 704 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret); 705 goto out_unlock; 706 } 707 708 set_bit(ret, &mgr->payload_mask); 709 set_bit(vcpi_ret, &mgr->vcpi_mask); 710 vcpi->vcpi = vcpi_ret + 1; 711 mgr->proposed_vcpis[ret - 1] = vcpi; 712 out_unlock: 713 mutex_unlock(&mgr->payload_lock); 714 return ret; 715 } 716 717 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr, 718 int vcpi) 719 { 720 int i; 721 if (vcpi == 0) 722 return; 723 724 mutex_lock(&mgr->payload_lock); 725 DRM_DEBUG_KMS("putting payload %d\n", vcpi); 726 clear_bit(vcpi - 1, &mgr->vcpi_mask); 727 728 for (i = 0; i < mgr->max_payloads; i++) { 729 if (mgr->proposed_vcpis[i]) 730 if (mgr->proposed_vcpis[i]->vcpi == vcpi) { 731 mgr->proposed_vcpis[i] = NULL; 732 clear_bit(i + 1, &mgr->payload_mask); 733 } 734 } 735 mutex_unlock(&mgr->payload_lock); 736 } 737 738 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr, 739 struct drm_dp_sideband_msg_tx *txmsg) 740 { 741 bool ret; 742 743 /* 744 * All updates to txmsg->state are protected by mgr->qlock, and the two 745 * cases we check here are terminal states. For those the barriers 746 * provided by the wake_up/wait_event pair are enough. 747 */ 748 ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX || 749 txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT); 750 return ret; 751 } 752 753 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb, 754 struct drm_dp_sideband_msg_tx *txmsg) 755 { 756 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 757 int ret; 758 759 ret = wait_event_timeout(mgr->tx_waitq, 760 check_txmsg_state(mgr, txmsg), 761 (4 * HZ)); 762 mutex_lock(&mstb->mgr->qlock); 763 if (ret > 0) { 764 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) { 765 ret = -EIO; 766 goto out; 767 } 768 } else { 769 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno); 770 771 /* dump some state */ 772 ret = -EIO; 773 774 /* remove from q */ 775 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED || 776 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) { 777 list_del(&txmsg->next); 778 } 779 780 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND || 781 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) { 782 mstb->tx_slots[txmsg->seqno] = NULL; 783 } 784 } 785 out: 786 mutex_unlock(&mgr->qlock); 787 788 return ret; 789 } 790 791 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad) 792 { 793 struct drm_dp_mst_branch *mstb; 794 795 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL); 796 if (!mstb) 797 return NULL; 798 799 mstb->lct = lct; 800 if (lct > 1) 801 memcpy(mstb->rad, rad, lct / 2); 802 INIT_LIST_HEAD(&mstb->ports); 803 kref_init(&mstb->kref); 804 return mstb; 805 } 806 807 static void drm_dp_free_mst_port(struct kref *kref); 808 809 static void drm_dp_free_mst_branch_device(struct kref *kref) 810 { 811 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref); 812 if (mstb->port_parent) { 813 if (list_empty(&mstb->port_parent->next)) 814 kref_put(&mstb->port_parent->kref, drm_dp_free_mst_port); 815 } 816 kfree(mstb); 817 } 818 819 static void drm_dp_destroy_mst_branch_device(struct kref *kref) 820 { 821 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref); 822 struct drm_dp_mst_port *port, *tmp; 823 bool wake_tx = false; 824 825 /* 826 * init kref again to be used by ports to remove mst branch when it is 827 * not needed anymore 828 */ 829 kref_init(kref); 830 831 if (mstb->port_parent && list_empty(&mstb->port_parent->next)) 832 kref_get(&mstb->port_parent->kref); 833 834 /* 835 * destroy all ports - don't need lock 836 * as there are no more references to the mst branch 837 * device at this point. 838 */ 839 list_for_each_entry_safe(port, tmp, &mstb->ports, next) { 840 list_del(&port->next); 841 drm_dp_put_port(port); 842 } 843 844 /* drop any tx slots msg */ 845 mutex_lock(&mstb->mgr->qlock); 846 if (mstb->tx_slots[0]) { 847 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 848 mstb->tx_slots[0] = NULL; 849 wake_tx = true; 850 } 851 if (mstb->tx_slots[1]) { 852 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 853 mstb->tx_slots[1] = NULL; 854 wake_tx = true; 855 } 856 mutex_unlock(&mstb->mgr->qlock); 857 858 if (wake_tx) 859 wake_up(&mstb->mgr->tx_waitq); 860 861 kref_put(kref, drm_dp_free_mst_branch_device); 862 } 863 864 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb) 865 { 866 kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device); 867 } 868 869 870 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt) 871 { 872 struct drm_dp_mst_branch *mstb; 873 874 switch (old_pdt) { 875 case DP_PEER_DEVICE_DP_LEGACY_CONV: 876 case DP_PEER_DEVICE_SST_SINK: 877 /* remove i2c over sideband */ 878 drm_dp_mst_unregister_i2c_bus(&port->aux); 879 break; 880 case DP_PEER_DEVICE_MST_BRANCHING: 881 mstb = port->mstb; 882 port->mstb = NULL; 883 drm_dp_put_mst_branch_device(mstb); 884 break; 885 } 886 } 887 888 static void drm_dp_destroy_port(struct kref *kref) 889 { 890 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref); 891 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 892 893 if (!port->input) { 894 port->vcpi.num_slots = 0; 895 896 kfree(port->cached_edid); 897 898 /* 899 * The only time we don't have a connector 900 * on an output port is if the connector init 901 * fails. 902 */ 903 if (port->connector) { 904 /* we can't destroy the connector here, as 905 * we might be holding the mode_config.mutex 906 * from an EDID retrieval */ 907 908 mutex_lock(&mgr->destroy_connector_lock); 909 kref_get(&port->parent->kref); 910 list_add(&port->next, &mgr->destroy_connector_list); 911 mutex_unlock(&mgr->destroy_connector_lock); 912 schedule_work(&mgr->destroy_connector_work); 913 return; 914 } 915 /* no need to clean up vcpi 916 * as if we have no connector we never setup a vcpi */ 917 drm_dp_port_teardown_pdt(port, port->pdt); 918 } 919 kfree(port); 920 } 921 922 static void drm_dp_put_port(struct drm_dp_mst_port *port) 923 { 924 kref_put(&port->kref, drm_dp_destroy_port); 925 } 926 927 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) 928 { 929 struct drm_dp_mst_port *port; 930 struct drm_dp_mst_branch *rmstb; 931 if (to_find == mstb) { 932 kref_get(&mstb->kref); 933 return mstb; 934 } 935 list_for_each_entry(port, &mstb->ports, next) { 936 if (port->mstb) { 937 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find); 938 if (rmstb) 939 return rmstb; 940 } 941 } 942 return NULL; 943 } 944 945 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) 946 { 947 struct drm_dp_mst_branch *rmstb = NULL; 948 mutex_lock(&mgr->lock); 949 if (mgr->mst_primary) 950 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb); 951 mutex_unlock(&mgr->lock); 952 return rmstb; 953 } 954 955 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) 956 { 957 struct drm_dp_mst_port *port, *mport; 958 959 list_for_each_entry(port, &mstb->ports, next) { 960 if (port == to_find) { 961 kref_get(&port->kref); 962 return port; 963 } 964 if (port->mstb) { 965 mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find); 966 if (mport) 967 return mport; 968 } 969 } 970 return NULL; 971 } 972 973 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) 974 { 975 struct drm_dp_mst_port *rport = NULL; 976 mutex_lock(&mgr->lock); 977 if (mgr->mst_primary) 978 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port); 979 mutex_unlock(&mgr->lock); 980 return rport; 981 } 982 983 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num) 984 { 985 struct drm_dp_mst_port *port; 986 987 list_for_each_entry(port, &mstb->ports, next) { 988 if (port->port_num == port_num) { 989 kref_get(&port->kref); 990 return port; 991 } 992 } 993 994 return NULL; 995 } 996 997 /* 998 * calculate a new RAD for this MST branch device 999 * if parent has an LCT of 2 then it has 1 nibble of RAD, 1000 * if parent has an LCT of 3 then it has 2 nibbles of RAD, 1001 */ 1002 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port, 1003 u8 *rad) 1004 { 1005 int parent_lct = port->parent->lct; 1006 int shift = 4; 1007 int idx = (parent_lct - 1) / 2; 1008 if (parent_lct > 1) { 1009 memcpy(rad, port->parent->rad, idx + 1); 1010 shift = (parent_lct % 2) ? 4 : 0; 1011 } else 1012 rad[0] = 0; 1013 1014 rad[idx] |= port->port_num << shift; 1015 return parent_lct + 1; 1016 } 1017 1018 /* 1019 * return sends link address for new mstb 1020 */ 1021 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port) 1022 { 1023 int ret; 1024 u8 rad[6], lct; 1025 bool send_link = false; 1026 switch (port->pdt) { 1027 case DP_PEER_DEVICE_DP_LEGACY_CONV: 1028 case DP_PEER_DEVICE_SST_SINK: 1029 /* add i2c over sideband */ 1030 ret = drm_dp_mst_register_i2c_bus(&port->aux); 1031 break; 1032 case DP_PEER_DEVICE_MST_BRANCHING: 1033 lct = drm_dp_calculate_rad(port, rad); 1034 1035 port->mstb = drm_dp_add_mst_branch_device(lct, rad); 1036 port->mstb->mgr = port->mgr; 1037 port->mstb->port_parent = port; 1038 1039 send_link = true; 1040 break; 1041 } 1042 return send_link; 1043 } 1044 1045 static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid) 1046 { 1047 int ret; 1048 1049 memcpy(mstb->guid, guid, 16); 1050 1051 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) { 1052 if (mstb->port_parent) { 1053 ret = drm_dp_send_dpcd_write( 1054 mstb->mgr, 1055 mstb->port_parent, 1056 DP_GUID, 1057 16, 1058 mstb->guid); 1059 } else { 1060 1061 ret = drm_dp_dpcd_write( 1062 mstb->mgr->aux, 1063 DP_GUID, 1064 mstb->guid, 1065 16); 1066 } 1067 } 1068 } 1069 1070 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb, 1071 int pnum, 1072 char *proppath, 1073 size_t proppath_size) 1074 { 1075 int i; 1076 char temp[8]; 1077 ksnprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id); 1078 for (i = 0; i < (mstb->lct - 1); i++) { 1079 int shift = (i % 2) ? 0 : 4; 1080 int port_num = (mstb->rad[i / 2] >> shift) & 0xf; 1081 ksnprintf(temp, sizeof(temp), "-%d", port_num); 1082 strlcat(proppath, temp, proppath_size); 1083 } 1084 ksnprintf(temp, sizeof(temp), "-%d", pnum); 1085 strlcat(proppath, temp, proppath_size); 1086 } 1087 1088 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb, 1089 struct device *dev, 1090 struct drm_dp_link_addr_reply_port *port_msg) 1091 { 1092 struct drm_dp_mst_port *port; 1093 bool ret; 1094 bool created = false; 1095 int old_pdt = 0; 1096 int old_ddps = 0; 1097 port = drm_dp_get_port(mstb, port_msg->port_number); 1098 if (!port) { 1099 port = kzalloc(sizeof(*port), GFP_KERNEL); 1100 if (!port) 1101 return; 1102 kref_init(&port->kref); 1103 port->parent = mstb; 1104 port->port_num = port_msg->port_number; 1105 port->mgr = mstb->mgr; 1106 port->aux.name = "DPMST"; 1107 port->aux.dev = dev; 1108 created = true; 1109 } else { 1110 old_pdt = port->pdt; 1111 old_ddps = port->ddps; 1112 } 1113 1114 port->pdt = port_msg->peer_device_type; 1115 port->input = port_msg->input_port; 1116 port->mcs = port_msg->mcs; 1117 port->ddps = port_msg->ddps; 1118 port->ldps = port_msg->legacy_device_plug_status; 1119 port->dpcd_rev = port_msg->dpcd_revision; 1120 port->num_sdp_streams = port_msg->num_sdp_streams; 1121 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks; 1122 1123 /* manage mstb port lists with mgr lock - take a reference 1124 for this list */ 1125 if (created) { 1126 mutex_lock(&mstb->mgr->lock); 1127 kref_get(&port->kref); 1128 list_add(&port->next, &mstb->ports); 1129 mutex_unlock(&mstb->mgr->lock); 1130 } 1131 1132 if (old_ddps != port->ddps) { 1133 if (port->ddps) { 1134 if (!port->input) 1135 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port); 1136 } else { 1137 port->available_pbn = 0; 1138 } 1139 } 1140 1141 if (old_pdt != port->pdt && !port->input) { 1142 drm_dp_port_teardown_pdt(port, old_pdt); 1143 1144 ret = drm_dp_port_setup_pdt(port); 1145 if (ret == true) 1146 drm_dp_send_link_address(mstb->mgr, port->mstb); 1147 } 1148 1149 if (created && !port->input) { 1150 char proppath[255]; 1151 1152 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath)); 1153 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath); 1154 if (!port->connector) { 1155 /* remove it from the port list */ 1156 mutex_lock(&mstb->mgr->lock); 1157 list_del(&port->next); 1158 mutex_unlock(&mstb->mgr->lock); 1159 /* drop port list reference */ 1160 drm_dp_put_port(port); 1161 goto out; 1162 } 1163 if (port->port_num >= DP_MST_LOGICAL_PORT_0) { 1164 port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc); 1165 drm_mode_connector_set_tile_property(port->connector); 1166 } 1167 (*mstb->mgr->cbs->register_connector)(port->connector); 1168 } 1169 1170 out: 1171 /* put reference to this port */ 1172 drm_dp_put_port(port); 1173 } 1174 1175 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb, 1176 struct drm_dp_connection_status_notify *conn_stat) 1177 { 1178 struct drm_dp_mst_port *port; 1179 int old_pdt; 1180 int old_ddps; 1181 bool dowork = false; 1182 port = drm_dp_get_port(mstb, conn_stat->port_number); 1183 if (!port) 1184 return; 1185 1186 old_ddps = port->ddps; 1187 old_pdt = port->pdt; 1188 port->pdt = conn_stat->peer_device_type; 1189 port->mcs = conn_stat->message_capability_status; 1190 port->ldps = conn_stat->legacy_device_plug_status; 1191 port->ddps = conn_stat->displayport_device_plug_status; 1192 1193 if (old_ddps != port->ddps) { 1194 if (port->ddps) { 1195 dowork = true; 1196 } else { 1197 port->available_pbn = 0; 1198 } 1199 } 1200 if (old_pdt != port->pdt && !port->input) { 1201 drm_dp_port_teardown_pdt(port, old_pdt); 1202 1203 if (drm_dp_port_setup_pdt(port)) 1204 dowork = true; 1205 } 1206 1207 drm_dp_put_port(port); 1208 if (dowork) 1209 queue_work(system_long_wq, &mstb->mgr->work); 1210 1211 } 1212 1213 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr, 1214 u8 lct, u8 *rad) 1215 { 1216 struct drm_dp_mst_branch *mstb; 1217 struct drm_dp_mst_port *port; 1218 int i; 1219 /* find the port by iterating down */ 1220 1221 mutex_lock(&mgr->lock); 1222 mstb = mgr->mst_primary; 1223 1224 for (i = 0; i < lct - 1; i++) { 1225 int shift = (i % 2) ? 0 : 4; 1226 int port_num = (rad[i / 2] >> shift) & 0xf; 1227 1228 list_for_each_entry(port, &mstb->ports, next) { 1229 if (port->port_num == port_num) { 1230 mstb = port->mstb; 1231 if (!mstb) { 1232 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]); 1233 goto out; 1234 } 1235 1236 break; 1237 } 1238 } 1239 } 1240 kref_get(&mstb->kref); 1241 out: 1242 mutex_unlock(&mgr->lock); 1243 return mstb; 1244 } 1245 1246 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper( 1247 struct drm_dp_mst_branch *mstb, 1248 uint8_t *guid) 1249 { 1250 struct drm_dp_mst_branch *found_mstb; 1251 struct drm_dp_mst_port *port; 1252 1253 if (memcmp(mstb->guid, guid, 16) == 0) 1254 return mstb; 1255 1256 1257 list_for_each_entry(port, &mstb->ports, next) { 1258 if (!port->mstb) 1259 continue; 1260 1261 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid); 1262 1263 if (found_mstb) 1264 return found_mstb; 1265 } 1266 1267 return NULL; 1268 } 1269 1270 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid( 1271 struct drm_dp_mst_topology_mgr *mgr, 1272 uint8_t *guid) 1273 { 1274 struct drm_dp_mst_branch *mstb; 1275 1276 /* find the port by iterating down */ 1277 mutex_lock(&mgr->lock); 1278 1279 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid); 1280 1281 if (mstb) 1282 kref_get(&mstb->kref); 1283 1284 mutex_unlock(&mgr->lock); 1285 return mstb; 1286 } 1287 1288 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 1289 struct drm_dp_mst_branch *mstb) 1290 { 1291 struct drm_dp_mst_port *port; 1292 struct drm_dp_mst_branch *mstb_child; 1293 if (!mstb->link_address_sent) 1294 drm_dp_send_link_address(mgr, mstb); 1295 1296 list_for_each_entry(port, &mstb->ports, next) { 1297 if (port->input) 1298 continue; 1299 1300 if (!port->ddps) 1301 continue; 1302 1303 if (!port->available_pbn) 1304 drm_dp_send_enum_path_resources(mgr, mstb, port); 1305 1306 if (port->mstb) { 1307 mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb); 1308 if (mstb_child) { 1309 drm_dp_check_and_send_link_address(mgr, mstb_child); 1310 drm_dp_put_mst_branch_device(mstb_child); 1311 } 1312 } 1313 } 1314 } 1315 1316 static void drm_dp_mst_link_probe_work(struct work_struct *work) 1317 { 1318 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work); 1319 struct drm_dp_mst_branch *mstb; 1320 1321 mutex_lock(&mgr->lock); 1322 mstb = mgr->mst_primary; 1323 if (mstb) { 1324 kref_get(&mstb->kref); 1325 } 1326 mutex_unlock(&mgr->lock); 1327 if (mstb) { 1328 drm_dp_check_and_send_link_address(mgr, mstb); 1329 drm_dp_put_mst_branch_device(mstb); 1330 } 1331 } 1332 1333 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, 1334 u8 *guid) 1335 { 1336 static u8 zero_guid[16]; 1337 1338 if (!memcmp(guid, zero_guid, 16)) { 1339 u64 salt = get_jiffies_64(); 1340 memcpy(&guid[0], &salt, sizeof(u64)); 1341 memcpy(&guid[8], &salt, sizeof(u64)); 1342 return false; 1343 } 1344 return true; 1345 } 1346 1347 #if 0 1348 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes) 1349 { 1350 struct drm_dp_sideband_msg_req_body req; 1351 1352 req.req_type = DP_REMOTE_DPCD_READ; 1353 req.u.dpcd_read.port_number = port_num; 1354 req.u.dpcd_read.dpcd_address = offset; 1355 req.u.dpcd_read.num_bytes = num_bytes; 1356 drm_dp_encode_sideband_req(&req, msg); 1357 1358 return 0; 1359 } 1360 #endif 1361 1362 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr, 1363 bool up, u8 *msg, int len) 1364 { 1365 int ret; 1366 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE; 1367 int tosend, total, offset; 1368 int retries = 0; 1369 1370 retry: 1371 total = len; 1372 offset = 0; 1373 do { 1374 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total); 1375 1376 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset, 1377 &msg[offset], 1378 tosend); 1379 if (ret != tosend) { 1380 if (ret == -EIO && retries < 5) { 1381 retries++; 1382 goto retry; 1383 } 1384 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret); 1385 1386 return -EIO; 1387 } 1388 offset += tosend; 1389 total -= tosend; 1390 } while (total > 0); 1391 return 0; 1392 } 1393 1394 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr, 1395 struct drm_dp_sideband_msg_tx *txmsg) 1396 { 1397 struct drm_dp_mst_branch *mstb = txmsg->dst; 1398 u8 req_type; 1399 1400 /* both msg slots are full */ 1401 if (txmsg->seqno == -1) { 1402 if (mstb->tx_slots[0] && mstb->tx_slots[1]) { 1403 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__); 1404 return -EAGAIN; 1405 } 1406 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) { 1407 txmsg->seqno = mstb->last_seqno; 1408 mstb->last_seqno ^= 1; 1409 } else if (mstb->tx_slots[0] == NULL) 1410 txmsg->seqno = 0; 1411 else 1412 txmsg->seqno = 1; 1413 mstb->tx_slots[txmsg->seqno] = txmsg; 1414 } 1415 1416 req_type = txmsg->msg[0] & 0x7f; 1417 if (req_type == DP_CONNECTION_STATUS_NOTIFY || 1418 req_type == DP_RESOURCE_STATUS_NOTIFY) 1419 hdr->broadcast = 1; 1420 else 1421 hdr->broadcast = 0; 1422 hdr->path_msg = txmsg->path_msg; 1423 hdr->lct = mstb->lct; 1424 hdr->lcr = mstb->lct - 1; 1425 if (mstb->lct > 1) 1426 memcpy(hdr->rad, mstb->rad, mstb->lct / 2); 1427 hdr->seqno = txmsg->seqno; 1428 return 0; 1429 } 1430 /* 1431 * process a single block of the next message in the sideband queue 1432 */ 1433 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr, 1434 struct drm_dp_sideband_msg_tx *txmsg, 1435 bool up) 1436 { 1437 u8 chunk[48]; 1438 struct drm_dp_sideband_msg_hdr hdr; 1439 int len, space, idx, tosend; 1440 int ret; 1441 1442 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr)); 1443 1444 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) { 1445 txmsg->seqno = -1; 1446 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND; 1447 } 1448 1449 /* make hdr from dst mst - for replies use seqno 1450 otherwise assign one */ 1451 ret = set_hdr_from_dst_qlock(&hdr, txmsg); 1452 if (ret < 0) 1453 return ret; 1454 1455 /* amount left to send in this message */ 1456 len = txmsg->cur_len - txmsg->cur_offset; 1457 1458 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */ 1459 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr); 1460 1461 tosend = min(len, space); 1462 if (len == txmsg->cur_len) 1463 hdr.somt = 1; 1464 if (space >= len) 1465 hdr.eomt = 1; 1466 1467 1468 hdr.msg_len = tosend + 1; 1469 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx); 1470 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend); 1471 /* add crc at end */ 1472 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend); 1473 idx += tosend + 1; 1474 1475 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx); 1476 if (ret) { 1477 DRM_DEBUG_KMS("sideband msg failed to send\n"); 1478 return ret; 1479 } 1480 1481 txmsg->cur_offset += tosend; 1482 if (txmsg->cur_offset == txmsg->cur_len) { 1483 txmsg->state = DRM_DP_SIDEBAND_TX_SENT; 1484 return 1; 1485 } 1486 return 0; 1487 } 1488 1489 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr) 1490 { 1491 struct drm_dp_sideband_msg_tx *txmsg; 1492 int ret; 1493 1494 WARN_ON(!mutex_is_locked(&mgr->qlock)); 1495 1496 /* construct a chunk from the first msg in the tx_msg queue */ 1497 if (list_empty(&mgr->tx_msg_downq)) { 1498 mgr->tx_down_in_progress = false; 1499 return; 1500 } 1501 mgr->tx_down_in_progress = true; 1502 1503 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next); 1504 ret = process_single_tx_qlock(mgr, txmsg, false); 1505 if (ret == 1) { 1506 /* txmsg is sent it should be in the slots now */ 1507 list_del(&txmsg->next); 1508 } else if (ret) { 1509 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret); 1510 list_del(&txmsg->next); 1511 if (txmsg->seqno != -1) 1512 txmsg->dst->tx_slots[txmsg->seqno] = NULL; 1513 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 1514 wake_up(&mgr->tx_waitq); 1515 } 1516 if (list_empty(&mgr->tx_msg_downq)) { 1517 mgr->tx_down_in_progress = false; 1518 return; 1519 } 1520 } 1521 1522 /* called holding qlock */ 1523 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr, 1524 struct drm_dp_sideband_msg_tx *txmsg) 1525 { 1526 int ret; 1527 1528 /* construct a chunk from the first msg in the tx_msg queue */ 1529 ret = process_single_tx_qlock(mgr, txmsg, true); 1530 1531 if (ret != 1) 1532 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret); 1533 1534 txmsg->dst->tx_slots[txmsg->seqno] = NULL; 1535 } 1536 1537 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr, 1538 struct drm_dp_sideband_msg_tx *txmsg) 1539 { 1540 mutex_lock(&mgr->qlock); 1541 list_add_tail(&txmsg->next, &mgr->tx_msg_downq); 1542 if (!mgr->tx_down_in_progress) 1543 process_single_down_tx_qlock(mgr); 1544 mutex_unlock(&mgr->qlock); 1545 } 1546 1547 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 1548 struct drm_dp_mst_branch *mstb) 1549 { 1550 int len; 1551 struct drm_dp_sideband_msg_tx *txmsg; 1552 int ret; 1553 1554 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 1555 if (!txmsg) 1556 return; 1557 1558 txmsg->dst = mstb; 1559 len = build_link_address(txmsg); 1560 1561 mstb->link_address_sent = true; 1562 drm_dp_queue_down_tx(mgr, txmsg); 1563 1564 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 1565 if (ret > 0) { 1566 int i; 1567 1568 if (txmsg->reply.reply_type == 1) 1569 DRM_DEBUG_KMS("link address nak received\n"); 1570 else { 1571 DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports); 1572 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) { 1573 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, 1574 txmsg->reply.u.link_addr.ports[i].input_port, 1575 txmsg->reply.u.link_addr.ports[i].peer_device_type, 1576 txmsg->reply.u.link_addr.ports[i].port_number, 1577 txmsg->reply.u.link_addr.ports[i].dpcd_revision, 1578 txmsg->reply.u.link_addr.ports[i].mcs, 1579 txmsg->reply.u.link_addr.ports[i].ddps, 1580 txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status, 1581 txmsg->reply.u.link_addr.ports[i].num_sdp_streams, 1582 txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks); 1583 } 1584 1585 drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid); 1586 1587 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) { 1588 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]); 1589 } 1590 (*mgr->cbs->hotplug)(mgr); 1591 } 1592 } else { 1593 mstb->link_address_sent = false; 1594 DRM_DEBUG_KMS("link address failed %d\n", ret); 1595 } 1596 1597 kfree(txmsg); 1598 } 1599 1600 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, 1601 struct drm_dp_mst_branch *mstb, 1602 struct drm_dp_mst_port *port) 1603 { 1604 int len; 1605 struct drm_dp_sideband_msg_tx *txmsg; 1606 int ret; 1607 1608 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 1609 if (!txmsg) 1610 return -ENOMEM; 1611 1612 txmsg->dst = mstb; 1613 len = build_enum_path_resources(txmsg, port->port_num); 1614 1615 drm_dp_queue_down_tx(mgr, txmsg); 1616 1617 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 1618 if (ret > 0) { 1619 if (txmsg->reply.reply_type == 1) 1620 DRM_DEBUG_KMS("enum path resources nak received\n"); 1621 else { 1622 if (port->port_num != txmsg->reply.u.path_resources.port_number) 1623 DRM_ERROR("got incorrect port in response\n"); 1624 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, 1625 txmsg->reply.u.path_resources.avail_payload_bw_number); 1626 port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number; 1627 } 1628 } 1629 1630 kfree(txmsg); 1631 return 0; 1632 } 1633 1634 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb) 1635 { 1636 if (!mstb->port_parent) 1637 return NULL; 1638 1639 if (mstb->port_parent->mstb != mstb) 1640 return mstb->port_parent; 1641 1642 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent); 1643 } 1644 1645 static struct drm_dp_mst_branch *drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr, 1646 struct drm_dp_mst_branch *mstb, 1647 int *port_num) 1648 { 1649 struct drm_dp_mst_branch *rmstb = NULL; 1650 struct drm_dp_mst_port *found_port; 1651 mutex_lock(&mgr->lock); 1652 if (mgr->mst_primary) { 1653 found_port = drm_dp_get_last_connected_port_to_mstb(mstb); 1654 1655 if (found_port) { 1656 rmstb = found_port->parent; 1657 kref_get(&rmstb->kref); 1658 *port_num = found_port->port_num; 1659 } 1660 } 1661 mutex_unlock(&mgr->lock); 1662 return rmstb; 1663 } 1664 1665 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr, 1666 struct drm_dp_mst_port *port, 1667 int id, 1668 int pbn) 1669 { 1670 struct drm_dp_sideband_msg_tx *txmsg; 1671 struct drm_dp_mst_branch *mstb; 1672 int len, ret, port_num; 1673 u8 sinks[DRM_DP_MAX_SDP_STREAMS]; 1674 int i; 1675 1676 port_num = port->port_num; 1677 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent); 1678 if (!mstb) { 1679 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, port->parent, &port_num); 1680 1681 if (!mstb) 1682 return -EINVAL; 1683 } 1684 1685 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 1686 if (!txmsg) { 1687 ret = -ENOMEM; 1688 goto fail_put; 1689 } 1690 1691 for (i = 0; i < port->num_sdp_streams; i++) 1692 sinks[i] = i; 1693 1694 txmsg->dst = mstb; 1695 len = build_allocate_payload(txmsg, port_num, 1696 id, 1697 pbn, port->num_sdp_streams, sinks); 1698 1699 drm_dp_queue_down_tx(mgr, txmsg); 1700 1701 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 1702 if (ret > 0) { 1703 if (txmsg->reply.reply_type == 1) { 1704 ret = -EINVAL; 1705 } else 1706 ret = 0; 1707 } 1708 kfree(txmsg); 1709 fail_put: 1710 drm_dp_put_mst_branch_device(mstb); 1711 return ret; 1712 } 1713 1714 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr, 1715 int id, 1716 struct drm_dp_payload *payload) 1717 { 1718 int ret; 1719 1720 ret = drm_dp_dpcd_write_payload(mgr, id, payload); 1721 if (ret < 0) { 1722 payload->payload_state = 0; 1723 return ret; 1724 } 1725 payload->payload_state = DP_PAYLOAD_LOCAL; 1726 return 0; 1727 } 1728 1729 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr, 1730 struct drm_dp_mst_port *port, 1731 int id, 1732 struct drm_dp_payload *payload) 1733 { 1734 int ret; 1735 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn); 1736 if (ret < 0) 1737 return ret; 1738 payload->payload_state = DP_PAYLOAD_REMOTE; 1739 return ret; 1740 } 1741 1742 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr, 1743 struct drm_dp_mst_port *port, 1744 int id, 1745 struct drm_dp_payload *payload) 1746 { 1747 DRM_DEBUG_KMS("\n"); 1748 /* its okay for these to fail */ 1749 if (port) { 1750 drm_dp_payload_send_msg(mgr, port, id, 0); 1751 } 1752 1753 drm_dp_dpcd_write_payload(mgr, id, payload); 1754 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL; 1755 return 0; 1756 } 1757 1758 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr, 1759 int id, 1760 struct drm_dp_payload *payload) 1761 { 1762 payload->payload_state = 0; 1763 return 0; 1764 } 1765 1766 /** 1767 * drm_dp_update_payload_part1() - Execute payload update part 1 1768 * @mgr: manager to use. 1769 * 1770 * This iterates over all proposed virtual channels, and tries to 1771 * allocate space in the link for them. For 0->slots transitions, 1772 * this step just writes the VCPI to the MST device. For slots->0 1773 * transitions, this writes the updated VCPIs and removes the 1774 * remote VC payloads. 1775 * 1776 * after calling this the driver should generate ACT and payload 1777 * packets. 1778 */ 1779 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr) 1780 { 1781 int i, j; 1782 int cur_slots = 1; 1783 struct drm_dp_payload req_payload; 1784 struct drm_dp_mst_port *port; 1785 1786 mutex_lock(&mgr->payload_lock); 1787 for (i = 0; i < mgr->max_payloads; i++) { 1788 /* solve the current payloads - compare to the hw ones 1789 - update the hw view */ 1790 req_payload.start_slot = cur_slots; 1791 if (mgr->proposed_vcpis[i]) { 1792 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi); 1793 req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots; 1794 req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi; 1795 } else { 1796 port = NULL; 1797 req_payload.num_slots = 0; 1798 } 1799 1800 if (mgr->payloads[i].start_slot != req_payload.start_slot) { 1801 mgr->payloads[i].start_slot = req_payload.start_slot; 1802 } 1803 /* work out what is required to happen with this payload */ 1804 if (mgr->payloads[i].num_slots != req_payload.num_slots) { 1805 1806 /* need to push an update for this payload */ 1807 if (req_payload.num_slots) { 1808 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload); 1809 mgr->payloads[i].num_slots = req_payload.num_slots; 1810 mgr->payloads[i].vcpi = req_payload.vcpi; 1811 } else if (mgr->payloads[i].num_slots) { 1812 mgr->payloads[i].num_slots = 0; 1813 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]); 1814 req_payload.payload_state = mgr->payloads[i].payload_state; 1815 mgr->payloads[i].start_slot = 0; 1816 } 1817 mgr->payloads[i].payload_state = req_payload.payload_state; 1818 } 1819 cur_slots += req_payload.num_slots; 1820 } 1821 1822 for (i = 0; i < mgr->max_payloads; i++) { 1823 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) { 1824 DRM_DEBUG_KMS("removing payload %d\n", i); 1825 for (j = i; j < mgr->max_payloads - 1; j++) { 1826 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload)); 1827 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1]; 1828 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) { 1829 set_bit(j + 1, &mgr->payload_mask); 1830 } else { 1831 clear_bit(j + 1, &mgr->payload_mask); 1832 } 1833 } 1834 memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload)); 1835 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL; 1836 clear_bit(mgr->max_payloads, &mgr->payload_mask); 1837 1838 } 1839 } 1840 mutex_unlock(&mgr->payload_lock); 1841 1842 return 0; 1843 } 1844 EXPORT_SYMBOL(drm_dp_update_payload_part1); 1845 1846 /** 1847 * drm_dp_update_payload_part2() - Execute payload update part 2 1848 * @mgr: manager to use. 1849 * 1850 * This iterates over all proposed virtual channels, and tries to 1851 * allocate space in the link for them. For 0->slots transitions, 1852 * this step writes the remote VC payload commands. For slots->0 1853 * this just resets some internal state. 1854 */ 1855 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr) 1856 { 1857 struct drm_dp_mst_port *port; 1858 int i; 1859 int ret = 0; 1860 mutex_lock(&mgr->payload_lock); 1861 for (i = 0; i < mgr->max_payloads; i++) { 1862 1863 if (!mgr->proposed_vcpis[i]) 1864 continue; 1865 1866 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi); 1867 1868 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state); 1869 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) { 1870 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]); 1871 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) { 1872 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]); 1873 } 1874 if (ret) { 1875 mutex_unlock(&mgr->payload_lock); 1876 return ret; 1877 } 1878 } 1879 mutex_unlock(&mgr->payload_lock); 1880 return 0; 1881 } 1882 EXPORT_SYMBOL(drm_dp_update_payload_part2); 1883 1884 #if 0 /* unused as of yet */ 1885 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr, 1886 struct drm_dp_mst_port *port, 1887 int offset, int size) 1888 { 1889 int len; 1890 struct drm_dp_sideband_msg_tx *txmsg; 1891 1892 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 1893 if (!txmsg) 1894 return -ENOMEM; 1895 1896 len = build_dpcd_read(txmsg, port->port_num, 0, 8); 1897 txmsg->dst = port->parent; 1898 1899 drm_dp_queue_down_tx(mgr, txmsg); 1900 1901 return 0; 1902 } 1903 #endif 1904 1905 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, 1906 struct drm_dp_mst_port *port, 1907 int offset, int size, u8 *bytes) 1908 { 1909 int len; 1910 int ret; 1911 struct drm_dp_sideband_msg_tx *txmsg; 1912 struct drm_dp_mst_branch *mstb; 1913 1914 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent); 1915 if (!mstb) 1916 return -EINVAL; 1917 1918 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 1919 if (!txmsg) { 1920 ret = -ENOMEM; 1921 goto fail_put; 1922 } 1923 1924 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes); 1925 txmsg->dst = mstb; 1926 1927 drm_dp_queue_down_tx(mgr, txmsg); 1928 1929 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 1930 if (ret > 0) { 1931 if (txmsg->reply.reply_type == 1) { 1932 ret = -EINVAL; 1933 } else 1934 ret = 0; 1935 } 1936 kfree(txmsg); 1937 fail_put: 1938 drm_dp_put_mst_branch_device(mstb); 1939 return ret; 1940 } 1941 1942 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type) 1943 { 1944 struct drm_dp_sideband_msg_reply_body reply; 1945 1946 reply.reply_type = 0; 1947 reply.req_type = req_type; 1948 drm_dp_encode_sideband_reply(&reply, msg); 1949 return 0; 1950 } 1951 1952 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr, 1953 struct drm_dp_mst_branch *mstb, 1954 int req_type, int seqno, bool broadcast) 1955 { 1956 struct drm_dp_sideband_msg_tx *txmsg; 1957 1958 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 1959 if (!txmsg) 1960 return -ENOMEM; 1961 1962 txmsg->dst = mstb; 1963 txmsg->seqno = seqno; 1964 drm_dp_encode_up_ack_reply(txmsg, req_type); 1965 1966 mutex_lock(&mgr->qlock); 1967 1968 process_single_up_tx_qlock(mgr, txmsg); 1969 1970 mutex_unlock(&mgr->qlock); 1971 1972 kfree(txmsg); 1973 return 0; 1974 } 1975 1976 static bool drm_dp_get_vc_payload_bw(int dp_link_bw, 1977 int dp_link_count, 1978 int *out) 1979 { 1980 switch (dp_link_bw) { 1981 default: 1982 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n", 1983 dp_link_bw, dp_link_count); 1984 return false; 1985 1986 case DP_LINK_BW_1_62: 1987 *out = 3 * dp_link_count; 1988 break; 1989 case DP_LINK_BW_2_7: 1990 *out = 5 * dp_link_count; 1991 break; 1992 case DP_LINK_BW_5_4: 1993 *out = 10 * dp_link_count; 1994 break; 1995 } 1996 return true; 1997 } 1998 1999 /** 2000 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager 2001 * @mgr: manager to set state for 2002 * @mst_state: true to enable MST on this connector - false to disable. 2003 * 2004 * This is called by the driver when it detects an MST capable device plugged 2005 * into a DP MST capable port, or when a DP MST capable device is unplugged. 2006 */ 2007 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state) 2008 { 2009 int ret = 0; 2010 struct drm_dp_mst_branch *mstb = NULL; 2011 2012 mutex_lock(&mgr->lock); 2013 if (mst_state == mgr->mst_state) 2014 goto out_unlock; 2015 2016 mgr->mst_state = mst_state; 2017 /* set the device into MST mode */ 2018 if (mst_state) { 2019 WARN_ON(mgr->mst_primary); 2020 2021 /* get dpcd info */ 2022 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE); 2023 if (ret != DP_RECEIVER_CAP_SIZE) { 2024 DRM_DEBUG_KMS("failed to read DPCD\n"); 2025 goto out_unlock; 2026 } 2027 2028 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1], 2029 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK, 2030 &mgr->pbn_div)) { 2031 ret = -EINVAL; 2032 goto out_unlock; 2033 } 2034 2035 mgr->total_pbn = 2560; 2036 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div); 2037 mgr->avail_slots = mgr->total_slots; 2038 2039 /* add initial branch device at LCT 1 */ 2040 mstb = drm_dp_add_mst_branch_device(1, NULL); 2041 if (mstb == NULL) { 2042 ret = -ENOMEM; 2043 goto out_unlock; 2044 } 2045 mstb->mgr = mgr; 2046 2047 /* give this the main reference */ 2048 mgr->mst_primary = mstb; 2049 kref_get(&mgr->mst_primary->kref); 2050 2051 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 2052 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC); 2053 if (ret < 0) { 2054 goto out_unlock; 2055 } 2056 2057 { 2058 struct drm_dp_payload reset_pay; 2059 reset_pay.start_slot = 0; 2060 reset_pay.num_slots = 0x3f; 2061 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay); 2062 } 2063 2064 queue_work(system_long_wq, &mgr->work); 2065 2066 ret = 0; 2067 } else { 2068 /* disable MST on the device */ 2069 mstb = mgr->mst_primary; 2070 mgr->mst_primary = NULL; 2071 /* this can fail if the device is gone */ 2072 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0); 2073 ret = 0; 2074 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload)); 2075 mgr->payload_mask = 0; 2076 set_bit(0, &mgr->payload_mask); 2077 mgr->vcpi_mask = 0; 2078 } 2079 2080 out_unlock: 2081 mutex_unlock(&mgr->lock); 2082 if (mstb) 2083 drm_dp_put_mst_branch_device(mstb); 2084 return ret; 2085 2086 } 2087 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst); 2088 2089 /** 2090 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager 2091 * @mgr: manager to suspend 2092 * 2093 * This function tells the MST device that we can't handle UP messages 2094 * anymore. This should stop it from sending any since we are suspended. 2095 */ 2096 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr) 2097 { 2098 mutex_lock(&mgr->lock); 2099 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 2100 DP_MST_EN | DP_UPSTREAM_IS_SRC); 2101 mutex_unlock(&mgr->lock); 2102 flush_work(&mgr->work); 2103 flush_work(&mgr->destroy_connector_work); 2104 } 2105 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend); 2106 2107 /** 2108 * drm_dp_mst_topology_mgr_resume() - resume the MST manager 2109 * @mgr: manager to resume 2110 * 2111 * This will fetch DPCD and see if the device is still there, 2112 * if it is, it will rewrite the MSTM control bits, and return. 2113 * 2114 * if the device fails this returns -1, and the driver should do 2115 * a full MST reprobe, in case we were undocked. 2116 */ 2117 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr) 2118 { 2119 int ret = 0; 2120 2121 mutex_lock(&mgr->lock); 2122 2123 if (mgr->mst_primary) { 2124 int sret; 2125 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE); 2126 if (sret != DP_RECEIVER_CAP_SIZE) { 2127 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n"); 2128 ret = -1; 2129 goto out_unlock; 2130 } 2131 2132 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 2133 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC); 2134 if (ret < 0) { 2135 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n"); 2136 ret = -1; 2137 goto out_unlock; 2138 } 2139 ret = 0; 2140 } else 2141 ret = -1; 2142 2143 out_unlock: 2144 mutex_unlock(&mgr->lock); 2145 return ret; 2146 } 2147 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume); 2148 2149 static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up) 2150 { 2151 int len; 2152 u8 replyblock[32]; 2153 int replylen, origlen, curreply; 2154 int ret; 2155 struct drm_dp_sideband_msg_rx *msg; 2156 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE; 2157 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv; 2158 2159 len = min(mgr->max_dpcd_transaction_bytes, 16); 2160 ret = drm_dp_dpcd_read(mgr->aux, basereg, 2161 replyblock, len); 2162 if (ret != len) { 2163 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret); 2164 return; 2165 } 2166 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true); 2167 if (!ret) { 2168 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]); 2169 return; 2170 } 2171 replylen = msg->curchunk_len + msg->curchunk_hdrlen; 2172 2173 origlen = replylen; 2174 replylen -= len; 2175 curreply = len; 2176 while (replylen > 0) { 2177 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16); 2178 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply, 2179 replyblock, len); 2180 if (ret != len) { 2181 DRM_DEBUG_KMS("failed to read a chunk\n"); 2182 } 2183 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false); 2184 if (ret == false) 2185 DRM_DEBUG_KMS("failed to build sideband msg\n"); 2186 curreply += len; 2187 replylen -= len; 2188 } 2189 } 2190 2191 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr) 2192 { 2193 int ret = 0; 2194 2195 drm_dp_get_one_sb_msg(mgr, false); 2196 2197 if (mgr->down_rep_recv.have_eomt) { 2198 struct drm_dp_sideband_msg_tx *txmsg; 2199 struct drm_dp_mst_branch *mstb; 2200 int slot = -1; 2201 mstb = drm_dp_get_mst_branch_device(mgr, 2202 mgr->down_rep_recv.initial_hdr.lct, 2203 mgr->down_rep_recv.initial_hdr.rad); 2204 2205 if (!mstb) { 2206 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct); 2207 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 2208 return 0; 2209 } 2210 2211 /* find the message */ 2212 slot = mgr->down_rep_recv.initial_hdr.seqno; 2213 mutex_lock(&mgr->qlock); 2214 txmsg = mstb->tx_slots[slot]; 2215 /* remove from slots */ 2216 mutex_unlock(&mgr->qlock); 2217 2218 if (!txmsg) { 2219 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n", 2220 mstb, 2221 mgr->down_rep_recv.initial_hdr.seqno, 2222 mgr->down_rep_recv.initial_hdr.lct, 2223 mgr->down_rep_recv.initial_hdr.rad[0], 2224 mgr->down_rep_recv.msg[0]); 2225 drm_dp_put_mst_branch_device(mstb); 2226 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 2227 return 0; 2228 } 2229 2230 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply); 2231 if (txmsg->reply.reply_type == 1) { 2232 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); 2233 } 2234 2235 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 2236 drm_dp_put_mst_branch_device(mstb); 2237 2238 mutex_lock(&mgr->qlock); 2239 txmsg->state = DRM_DP_SIDEBAND_TX_RX; 2240 mstb->tx_slots[slot] = NULL; 2241 mutex_unlock(&mgr->qlock); 2242 2243 wake_up(&mgr->tx_waitq); 2244 } 2245 return ret; 2246 } 2247 2248 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr) 2249 { 2250 int ret = 0; 2251 drm_dp_get_one_sb_msg(mgr, true); 2252 2253 if (mgr->up_req_recv.have_eomt) { 2254 struct drm_dp_sideband_msg_req_body msg; 2255 struct drm_dp_mst_branch *mstb = NULL; 2256 bool seqno; 2257 2258 if (!mgr->up_req_recv.initial_hdr.broadcast) { 2259 mstb = drm_dp_get_mst_branch_device(mgr, 2260 mgr->up_req_recv.initial_hdr.lct, 2261 mgr->up_req_recv.initial_hdr.rad); 2262 if (!mstb) { 2263 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct); 2264 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 2265 return 0; 2266 } 2267 } 2268 2269 seqno = mgr->up_req_recv.initial_hdr.seqno; 2270 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg); 2271 2272 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) { 2273 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false); 2274 2275 if (!mstb) 2276 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid); 2277 2278 if (!mstb) { 2279 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct); 2280 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 2281 return 0; 2282 } 2283 2284 drm_dp_update_port(mstb, &msg.u.conn_stat); 2285 2286 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); 2287 (*mgr->cbs->hotplug)(mgr); 2288 2289 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) { 2290 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false); 2291 if (!mstb) 2292 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid); 2293 2294 if (!mstb) { 2295 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct); 2296 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 2297 return 0; 2298 } 2299 2300 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn); 2301 } 2302 2303 drm_dp_put_mst_branch_device(mstb); 2304 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 2305 } 2306 return ret; 2307 } 2308 2309 /** 2310 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify 2311 * @mgr: manager to notify irq for. 2312 * @esi: 4 bytes from SINK_COUNT_ESI 2313 * @handled: whether the hpd interrupt was consumed or not 2314 * 2315 * This should be called from the driver when it detects a short IRQ, 2316 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The 2317 * topology manager will process the sideband messages received as a result 2318 * of this. 2319 */ 2320 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled) 2321 { 2322 int ret = 0; 2323 int sc; 2324 *handled = false; 2325 sc = esi[0] & 0x3f; 2326 2327 if (sc != mgr->sink_count) { 2328 mgr->sink_count = sc; 2329 *handled = true; 2330 } 2331 2332 if (esi[1] & DP_DOWN_REP_MSG_RDY) { 2333 ret = drm_dp_mst_handle_down_rep(mgr); 2334 *handled = true; 2335 } 2336 2337 if (esi[1] & DP_UP_REQ_MSG_RDY) { 2338 ret |= drm_dp_mst_handle_up_req(mgr); 2339 *handled = true; 2340 } 2341 2342 drm_dp_mst_kick_tx(mgr); 2343 return ret; 2344 } 2345 EXPORT_SYMBOL(drm_dp_mst_hpd_irq); 2346 2347 /** 2348 * drm_dp_mst_detect_port() - get connection status for an MST port 2349 * @mgr: manager for this port 2350 * @port: unverified pointer to a port 2351 * 2352 * This returns the current connection state for a port. It validates the 2353 * port pointer still exists so the caller doesn't require a reference 2354 */ 2355 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector, 2356 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) 2357 { 2358 enum drm_connector_status status = connector_status_disconnected; 2359 2360 /* we need to search for the port in the mgr in case its gone */ 2361 port = drm_dp_get_validated_port_ref(mgr, port); 2362 if (!port) 2363 return connector_status_disconnected; 2364 2365 if (!port->ddps) 2366 goto out; 2367 2368 switch (port->pdt) { 2369 case DP_PEER_DEVICE_NONE: 2370 case DP_PEER_DEVICE_MST_BRANCHING: 2371 break; 2372 2373 case DP_PEER_DEVICE_SST_SINK: 2374 status = connector_status_connected; 2375 /* for logical ports - cache the EDID */ 2376 if (port->port_num >= 8 && !port->cached_edid) { 2377 port->cached_edid = drm_get_edid(connector, &port->aux.ddc); 2378 } 2379 break; 2380 case DP_PEER_DEVICE_DP_LEGACY_CONV: 2381 if (port->ldps) 2382 status = connector_status_connected; 2383 break; 2384 } 2385 out: 2386 drm_dp_put_port(port); 2387 return status; 2388 } 2389 EXPORT_SYMBOL(drm_dp_mst_detect_port); 2390 2391 /** 2392 * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not 2393 * @mgr: manager for this port 2394 * @port: unverified pointer to a port. 2395 * 2396 * This returns whether the port supports audio or not. 2397 */ 2398 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr, 2399 struct drm_dp_mst_port *port) 2400 { 2401 bool ret = false; 2402 2403 port = drm_dp_get_validated_port_ref(mgr, port); 2404 if (!port) 2405 return ret; 2406 ret = port->has_audio; 2407 drm_dp_put_port(port); 2408 return ret; 2409 } 2410 EXPORT_SYMBOL(drm_dp_mst_port_has_audio); 2411 2412 /** 2413 * drm_dp_mst_get_edid() - get EDID for an MST port 2414 * @connector: toplevel connector to get EDID for 2415 * @mgr: manager for this port 2416 * @port: unverified pointer to a port. 2417 * 2418 * This returns an EDID for the port connected to a connector, 2419 * It validates the pointer still exists so the caller doesn't require a 2420 * reference. 2421 */ 2422 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) 2423 { 2424 struct edid *edid = NULL; 2425 2426 /* we need to search for the port in the mgr in case its gone */ 2427 port = drm_dp_get_validated_port_ref(mgr, port); 2428 if (!port) 2429 return NULL; 2430 2431 if (port->cached_edid) 2432 edid = drm_edid_duplicate(port->cached_edid); 2433 else { 2434 edid = drm_get_edid(connector, &port->aux.ddc); 2435 drm_mode_connector_set_tile_property(connector); 2436 } 2437 port->has_audio = drm_detect_monitor_audio(edid); 2438 drm_dp_put_port(port); 2439 return edid; 2440 } 2441 EXPORT_SYMBOL(drm_dp_mst_get_edid); 2442 2443 /** 2444 * drm_dp_find_vcpi_slots() - find slots for this PBN value 2445 * @mgr: manager to use 2446 * @pbn: payload bandwidth to convert into slots. 2447 */ 2448 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, 2449 int pbn) 2450 { 2451 int num_slots; 2452 2453 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div); 2454 2455 if (num_slots > mgr->avail_slots) 2456 return -ENOSPC; 2457 return num_slots; 2458 } 2459 EXPORT_SYMBOL(drm_dp_find_vcpi_slots); 2460 2461 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr, 2462 struct drm_dp_vcpi *vcpi, int pbn) 2463 { 2464 int num_slots; 2465 int ret; 2466 2467 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div); 2468 2469 if (num_slots > mgr->avail_slots) 2470 return -ENOSPC; 2471 2472 vcpi->pbn = pbn; 2473 vcpi->aligned_pbn = num_slots * mgr->pbn_div; 2474 vcpi->num_slots = num_slots; 2475 2476 ret = drm_dp_mst_assign_payload_id(mgr, vcpi); 2477 if (ret < 0) 2478 return ret; 2479 return 0; 2480 } 2481 2482 /** 2483 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel 2484 * @mgr: manager for this port 2485 * @port: port to allocate a virtual channel for. 2486 * @pbn: payload bandwidth number to request 2487 * @slots: returned number of slots for this PBN. 2488 */ 2489 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots) 2490 { 2491 int ret; 2492 2493 port = drm_dp_get_validated_port_ref(mgr, port); 2494 if (!port) 2495 return false; 2496 2497 if (port->vcpi.vcpi > 0) { 2498 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn); 2499 if (pbn == port->vcpi.pbn) { 2500 *slots = port->vcpi.num_slots; 2501 drm_dp_put_port(port); 2502 return true; 2503 } 2504 } 2505 2506 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn); 2507 if (ret) { 2508 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret); 2509 goto out; 2510 } 2511 DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots); 2512 *slots = port->vcpi.num_slots; 2513 2514 drm_dp_put_port(port); 2515 return true; 2516 out: 2517 return false; 2518 } 2519 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi); 2520 2521 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) 2522 { 2523 int slots = 0; 2524 port = drm_dp_get_validated_port_ref(mgr, port); 2525 if (!port) 2526 return slots; 2527 2528 slots = port->vcpi.num_slots; 2529 drm_dp_put_port(port); 2530 return slots; 2531 } 2532 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots); 2533 2534 /** 2535 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI 2536 * @mgr: manager for this port 2537 * @port: unverified pointer to a port. 2538 * 2539 * This just resets the number of slots for the ports VCPI for later programming. 2540 */ 2541 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) 2542 { 2543 port = drm_dp_get_validated_port_ref(mgr, port); 2544 if (!port) 2545 return; 2546 port->vcpi.num_slots = 0; 2547 drm_dp_put_port(port); 2548 } 2549 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots); 2550 2551 /** 2552 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI 2553 * @mgr: manager for this port 2554 * @port: unverified port to deallocate vcpi for 2555 */ 2556 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) 2557 { 2558 port = drm_dp_get_validated_port_ref(mgr, port); 2559 if (!port) 2560 return; 2561 2562 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi); 2563 port->vcpi.num_slots = 0; 2564 port->vcpi.pbn = 0; 2565 port->vcpi.aligned_pbn = 0; 2566 port->vcpi.vcpi = 0; 2567 drm_dp_put_port(port); 2568 } 2569 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi); 2570 2571 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, 2572 int id, struct drm_dp_payload *payload) 2573 { 2574 u8 payload_alloc[3], status; 2575 int ret; 2576 int retries = 0; 2577 2578 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, 2579 DP_PAYLOAD_TABLE_UPDATED); 2580 2581 payload_alloc[0] = id; 2582 payload_alloc[1] = payload->start_slot; 2583 payload_alloc[2] = payload->num_slots; 2584 2585 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3); 2586 if (ret != 3) { 2587 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret); 2588 goto fail; 2589 } 2590 2591 retry: 2592 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); 2593 if (ret < 0) { 2594 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret); 2595 goto fail; 2596 } 2597 2598 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) { 2599 retries++; 2600 if (retries < 20) { 2601 usleep_range(10000, 20000); 2602 goto retry; 2603 } 2604 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status); 2605 ret = -EINVAL; 2606 goto fail; 2607 } 2608 ret = 0; 2609 fail: 2610 return ret; 2611 } 2612 2613 2614 /** 2615 * drm_dp_check_act_status() - Check ACT handled status. 2616 * @mgr: manager to use 2617 * 2618 * Check the payload status bits in the DPCD for ACT handled completion. 2619 */ 2620 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr) 2621 { 2622 u8 status; 2623 int ret; 2624 int count = 0; 2625 2626 do { 2627 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); 2628 2629 if (ret < 0) { 2630 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret); 2631 goto fail; 2632 } 2633 2634 if (status & DP_PAYLOAD_ACT_HANDLED) 2635 break; 2636 count++; 2637 udelay(100); 2638 2639 } while (count < 30); 2640 2641 if (!(status & DP_PAYLOAD_ACT_HANDLED)) { 2642 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count); 2643 ret = -EINVAL; 2644 goto fail; 2645 } 2646 return 0; 2647 fail: 2648 return ret; 2649 } 2650 EXPORT_SYMBOL(drm_dp_check_act_status); 2651 2652 /** 2653 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode. 2654 * @clock: dot clock for the mode 2655 * @bpp: bpp for the mode. 2656 * 2657 * This uses the formula in the spec to calculate the PBN value for a mode. 2658 */ 2659 int drm_dp_calc_pbn_mode(int clock, int bpp) 2660 { 2661 u64 kbps; 2662 s64 peak_kbps; 2663 u32 numerator; 2664 u32 denominator; 2665 2666 kbps = clock * bpp; 2667 2668 /* 2669 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006 2670 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on 2671 * common multiplier to render an integer PBN for all link rate/lane 2672 * counts combinations 2673 * calculate 2674 * peak_kbps *= (1006/1000) 2675 * peak_kbps *= (64/54) 2676 * peak_kbps *= 8 convert to bytes 2677 */ 2678 2679 numerator = 64 * 1006; 2680 denominator = 54 * 8 * 1000 * 1000; 2681 2682 kbps *= numerator; 2683 peak_kbps = drm_fixp_from_fraction(kbps, denominator); 2684 2685 return drm_fixp2int_ceil(peak_kbps); 2686 } 2687 EXPORT_SYMBOL(drm_dp_calc_pbn_mode); 2688 2689 static int test_calc_pbn_mode(void) 2690 { 2691 int ret; 2692 ret = drm_dp_calc_pbn_mode(154000, 30); 2693 if (ret != 689) { 2694 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n", 2695 154000, 30, 689, ret); 2696 return -EINVAL; 2697 } 2698 ret = drm_dp_calc_pbn_mode(234000, 30); 2699 if (ret != 1047) { 2700 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n", 2701 234000, 30, 1047, ret); 2702 return -EINVAL; 2703 } 2704 ret = drm_dp_calc_pbn_mode(297000, 24); 2705 if (ret != 1063) { 2706 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n", 2707 297000, 24, 1063, ret); 2708 return -EINVAL; 2709 } 2710 return 0; 2711 } 2712 2713 /* we want to kick the TX after we've ack the up/down IRQs. */ 2714 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr) 2715 { 2716 queue_work(system_long_wq, &mgr->tx_work); 2717 } 2718 2719 static void drm_dp_mst_dump_mstb(struct seq_file *m, 2720 struct drm_dp_mst_branch *mstb) 2721 { 2722 struct drm_dp_mst_port *port; 2723 int tabs = mstb->lct; 2724 char prefix[10]; 2725 int i; 2726 2727 for (i = 0; i < tabs; i++) 2728 prefix[i] = '\t'; 2729 prefix[i] = '\0'; 2730 2731 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports); 2732 list_for_each_entry(port, &mstb->ports, next) { 2733 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector); 2734 if (port->mstb) 2735 drm_dp_mst_dump_mstb(m, port->mstb); 2736 } 2737 } 2738 2739 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, 2740 char *buf) 2741 { 2742 int ret; 2743 int i; 2744 for (i = 0; i < 4; i++) { 2745 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16); 2746 if (ret != 16) 2747 break; 2748 } 2749 if (i == 4) 2750 return true; 2751 return false; 2752 } 2753 2754 /** 2755 * drm_dp_mst_dump_topology(): dump topology to seq file. 2756 * @m: seq_file to dump output to 2757 * @mgr: manager to dump current topology for. 2758 * 2759 * helper to dump MST topology to a seq file for debugfs. 2760 */ 2761 void drm_dp_mst_dump_topology(struct seq_file *m, 2762 struct drm_dp_mst_topology_mgr *mgr) 2763 { 2764 int i; 2765 struct drm_dp_mst_port *port; 2766 mutex_lock(&mgr->lock); 2767 if (mgr->mst_primary) 2768 drm_dp_mst_dump_mstb(m, mgr->mst_primary); 2769 2770 /* dump VCPIs */ 2771 mutex_unlock(&mgr->lock); 2772 2773 mutex_lock(&mgr->payload_lock); 2774 seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask); 2775 2776 for (i = 0; i < mgr->max_payloads; i++) { 2777 if (mgr->proposed_vcpis[i]) { 2778 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi); 2779 seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots); 2780 } else 2781 seq_printf(m, "vcpi %d:unsed\n", i); 2782 } 2783 for (i = 0; i < mgr->max_payloads; i++) { 2784 seq_printf(m, "payload %d: %d, %d, %d\n", 2785 i, 2786 mgr->payloads[i].payload_state, 2787 mgr->payloads[i].start_slot, 2788 mgr->payloads[i].num_slots); 2789 2790 2791 } 2792 mutex_unlock(&mgr->payload_lock); 2793 2794 mutex_lock(&mgr->lock); 2795 if (mgr->mst_primary) { 2796 u8 buf[64]; 2797 bool bret; 2798 int ret; 2799 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE); 2800 seq_printf(m, "dpcd: "); 2801 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++) 2802 seq_printf(m, "%02x ", buf[i]); 2803 seq_printf(m, "\n"); 2804 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2); 2805 seq_printf(m, "faux/mst: "); 2806 for (i = 0; i < 2; i++) 2807 seq_printf(m, "%02x ", buf[i]); 2808 seq_printf(m, "\n"); 2809 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1); 2810 seq_printf(m, "mst ctrl: "); 2811 for (i = 0; i < 1; i++) 2812 seq_printf(m, "%02x ", buf[i]); 2813 seq_printf(m, "\n"); 2814 2815 /* dump the standard OUI branch header */ 2816 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE); 2817 seq_printf(m, "branch oui: "); 2818 for (i = 0; i < 0x3; i++) 2819 seq_printf(m, "%02x", buf[i]); 2820 seq_printf(m, " devid: "); 2821 for (i = 0x3; i < 0x8; i++) 2822 seq_printf(m, "%c", buf[i]); 2823 seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]); 2824 seq_printf(m, "\n"); 2825 bret = dump_dp_payload_table(mgr, buf); 2826 if (bret == true) { 2827 seq_printf(m, "payload table: "); 2828 for (i = 0; i < 63; i++) 2829 seq_printf(m, "%02x ", buf[i]); 2830 seq_printf(m, "\n"); 2831 } 2832 2833 } 2834 2835 mutex_unlock(&mgr->lock); 2836 2837 } 2838 EXPORT_SYMBOL(drm_dp_mst_dump_topology); 2839 2840 static void drm_dp_tx_work(struct work_struct *work) 2841 { 2842 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work); 2843 2844 mutex_lock(&mgr->qlock); 2845 if (mgr->tx_down_in_progress) 2846 process_single_down_tx_qlock(mgr); 2847 mutex_unlock(&mgr->qlock); 2848 } 2849 2850 static void drm_dp_free_mst_port(struct kref *kref) 2851 { 2852 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref); 2853 kref_put(&port->parent->kref, drm_dp_free_mst_branch_device); 2854 kfree(port); 2855 } 2856 2857 static void drm_dp_destroy_connector_work(struct work_struct *work) 2858 { 2859 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work); 2860 struct drm_dp_mst_port *port; 2861 bool send_hotplug = false; 2862 /* 2863 * Not a regular list traverse as we have to drop the destroy 2864 * connector lock before destroying the connector, to avoid AB->BA 2865 * ordering between this lock and the config mutex. 2866 */ 2867 for (;;) { 2868 mutex_lock(&mgr->destroy_connector_lock); 2869 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next); 2870 if (!port) { 2871 mutex_unlock(&mgr->destroy_connector_lock); 2872 break; 2873 } 2874 list_del(&port->next); 2875 mutex_unlock(&mgr->destroy_connector_lock); 2876 2877 kref_init(&port->kref); 2878 INIT_LIST_HEAD(&port->next); 2879 2880 mgr->cbs->destroy_connector(mgr, port->connector); 2881 2882 drm_dp_port_teardown_pdt(port, port->pdt); 2883 2884 if (!port->input && port->vcpi.vcpi > 0) { 2885 if (mgr->mst_state) { 2886 drm_dp_mst_reset_vcpi_slots(mgr, port); 2887 drm_dp_update_payload_part1(mgr); 2888 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi); 2889 } 2890 } 2891 2892 kref_put(&port->kref, drm_dp_free_mst_port); 2893 send_hotplug = true; 2894 } 2895 if (send_hotplug) 2896 (*mgr->cbs->hotplug)(mgr); 2897 } 2898 2899 /** 2900 * drm_dp_mst_topology_mgr_init - initialise a topology manager 2901 * @mgr: manager struct to initialise 2902 * @dev: device providing this structure - for i2c addition. 2903 * @aux: DP helper aux channel to talk to this device 2904 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit 2905 * @max_payloads: maximum number of payloads this GPU can source 2906 * @conn_base_id: the connector object ID the MST device is connected to. 2907 * 2908 * Return 0 for success, or negative error code on failure 2909 */ 2910 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr, 2911 struct device *dev, struct drm_dp_aux *aux, 2912 int max_dpcd_transaction_bytes, 2913 int max_payloads, int conn_base_id) 2914 { 2915 lockinit(&mgr->lock, "drmml", 0, LK_CANRECURSE); 2916 lockinit(&mgr->qlock, "drmmql", 0, LK_CANRECURSE); 2917 lockinit(&mgr->payload_lock, "drmmpl", 0, LK_CANRECURSE); 2918 lockinit(&mgr->destroy_connector_lock, "drmmdcl", 0, LK_CANRECURSE); 2919 INIT_LIST_HEAD(&mgr->tx_msg_downq); 2920 INIT_LIST_HEAD(&mgr->destroy_connector_list); 2921 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work); 2922 INIT_WORK(&mgr->tx_work, drm_dp_tx_work); 2923 INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work); 2924 init_waitqueue_head(&mgr->tx_waitq); 2925 mgr->dev = dev; 2926 mgr->aux = aux; 2927 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes; 2928 mgr->max_payloads = max_payloads; 2929 mgr->conn_base_id = conn_base_id; 2930 if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 || 2931 max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8) 2932 return -EINVAL; 2933 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL); 2934 if (!mgr->payloads) 2935 return -ENOMEM; 2936 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL); 2937 if (!mgr->proposed_vcpis) 2938 return -ENOMEM; 2939 set_bit(0, &mgr->payload_mask); 2940 if (test_calc_pbn_mode() < 0) 2941 DRM_ERROR("MST PBN self-test failed\n"); 2942 2943 return 0; 2944 } 2945 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init); 2946 2947 /** 2948 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager. 2949 * @mgr: manager to destroy 2950 */ 2951 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr) 2952 { 2953 flush_work(&mgr->work); 2954 flush_work(&mgr->destroy_connector_work); 2955 mutex_lock(&mgr->payload_lock); 2956 kfree(mgr->payloads); 2957 mgr->payloads = NULL; 2958 kfree(mgr->proposed_vcpis); 2959 mgr->proposed_vcpis = NULL; 2960 mutex_unlock(&mgr->payload_lock); 2961 mgr->dev = NULL; 2962 mgr->aux = NULL; 2963 } 2964 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy); 2965 2966 /* I2C device */ 2967 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, 2968 int num) 2969 { 2970 struct drm_dp_aux *aux = adapter->algo_data; 2971 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux); 2972 struct drm_dp_mst_branch *mstb; 2973 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 2974 unsigned int i; 2975 bool reading = false; 2976 struct drm_dp_sideband_msg_req_body msg; 2977 struct drm_dp_sideband_msg_tx *txmsg = NULL; 2978 int ret; 2979 2980 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent); 2981 if (!mstb) 2982 return -EREMOTEIO; 2983 2984 /* construct i2c msg */ 2985 /* see if last msg is a read */ 2986 if (msgs[num - 1].flags & I2C_M_RD) 2987 reading = true; 2988 2989 if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) { 2990 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n"); 2991 ret = -EIO; 2992 goto out; 2993 } 2994 2995 memset(&msg, 0, sizeof(msg)); 2996 msg.req_type = DP_REMOTE_I2C_READ; 2997 msg.u.i2c_read.num_transactions = num - 1; 2998 msg.u.i2c_read.port_number = port->port_num; 2999 for (i = 0; i < num - 1; i++) { 3000 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr; 3001 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len; 3002 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf; 3003 } 3004 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr; 3005 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len; 3006 3007 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3008 if (!txmsg) { 3009 ret = -ENOMEM; 3010 goto out; 3011 } 3012 3013 txmsg->dst = mstb; 3014 drm_dp_encode_sideband_req(&msg, txmsg); 3015 3016 drm_dp_queue_down_tx(mgr, txmsg); 3017 3018 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3019 if (ret > 0) { 3020 3021 if (txmsg->reply.reply_type == 1) { /* got a NAK back */ 3022 ret = -EREMOTEIO; 3023 goto out; 3024 } 3025 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) { 3026 ret = -EIO; 3027 goto out; 3028 } 3029 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len); 3030 ret = num; 3031 } 3032 out: 3033 kfree(txmsg); 3034 drm_dp_put_mst_branch_device(mstb); 3035 return ret; 3036 } 3037 3038 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter) 3039 { 3040 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | 3041 I2C_FUNC_SMBUS_READ_BLOCK_DATA | 3042 I2C_FUNC_SMBUS_BLOCK_PROC_CALL | 3043 I2C_FUNC_10BIT_ADDR; 3044 } 3045 3046 static const struct i2c_algorithm drm_dp_mst_i2c_algo = { 3047 .functionality = drm_dp_mst_i2c_functionality, 3048 .master_xfer = drm_dp_mst_i2c_xfer, 3049 }; 3050 3051 /** 3052 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX 3053 * @aux: DisplayPort AUX channel 3054 * 3055 * Returns 0 on success or a negative error code on failure. 3056 */ 3057 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux) 3058 { 3059 aux->ddc.algo = &drm_dp_mst_i2c_algo; 3060 aux->ddc.algo_data = aux; 3061 aux->ddc.retries = 3; 3062 3063 #if 0 3064 aux->ddc.class = I2C_CLASS_DDC; 3065 aux->ddc.owner = THIS_MODULE; 3066 #endif 3067 aux->ddc.dev.parent = aux->dev; 3068 #if 0 3069 aux->ddc.dev.of_node = aux->dev->of_node; 3070 #endif 3071 3072 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev), 3073 sizeof(aux->ddc.name)); 3074 3075 return i2c_add_adapter(&aux->ddc); 3076 } 3077 3078 /** 3079 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter 3080 * @aux: DisplayPort AUX channel 3081 */ 3082 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux) 3083 { 3084 i2c_del_adapter(&aux->ddc); 3085 } 3086