drm_dp_mst_topology.c revision 1.2
1 /* $NetBSD: drm_dp_mst_topology.c,v 1.2 2018/08/27 04:58:19 riastradh Exp $ */ 2 3 /* 4 * Copyright 2014 Red Hat 5 * 6 * Permission to use, copy, modify, distribute, and sell this software and its 7 * documentation for any purpose is hereby granted without fee, provided that 8 * the above copyright notice appear in all copies and that both that copyright 9 * notice and this permission notice appear in supporting documentation, and 10 * that the name of the copyright holders not be used in advertising or 11 * publicity pertaining to distribution of the software without specific, 12 * written prior permission. The copyright holders make no representations 13 * about the suitability of this software for any purpose. It is provided "as 14 * is" without express or implied warranty. 15 * 16 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 17 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO 18 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR 19 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, 20 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER 21 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 22 * OF THIS SOFTWARE. 23 */ 24 25 #include <sys/cdefs.h> 26 __KERNEL_RCSID(0, "$NetBSD: drm_dp_mst_topology.c,v 1.2 2018/08/27 04:58:19 riastradh Exp $"); 27 28 #include <linux/kernel.h> 29 #include <linux/delay.h> 30 #include <linux/init.h> 31 #include <linux/errno.h> 32 #include <linux/sched.h> 33 #include <linux/seq_file.h> 34 #include <linux/i2c.h> 35 #include <drm/drm_dp_mst_helper.h> 36 #include <drm/drmP.h> 37 38 #include <drm/drm_fixed.h> 39 40 /** 41 * DOC: dp mst helper 42 * 43 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport 44 * protocol. The helpers contain a topology manager and bandwidth manager. 45 * The helpers encapsulate the sending and received of sideband msgs. 46 */ 47 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, 48 char *buf); 49 static int test_calc_pbn_mode(void); 50 51 static void drm_dp_put_port(struct drm_dp_mst_port *port); 52 53 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, 54 int id, 55 struct drm_dp_payload *payload); 56 57 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, 58 struct drm_dp_mst_port *port, 59 int offset, int size, u8 *bytes); 60 61 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 62 struct drm_dp_mst_branch *mstb); 63 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, 64 struct drm_dp_mst_branch *mstb, 65 struct drm_dp_mst_port *port); 66 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, 67 u8 *guid); 68 69 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux); 70 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux); 71 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr); 72 /* sideband msg handling */ 73 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles) 74 { 75 u8 bitmask = 0x80; 76 u8 bitshift = 7; 77 u8 array_index = 0; 78 int number_of_bits = num_nibbles * 4; 79 u8 remainder = 0; 80 81 while (number_of_bits != 0) { 82 number_of_bits--; 83 remainder <<= 1; 84 remainder |= (data[array_index] & bitmask) >> bitshift; 85 bitmask >>= 1; 86 bitshift--; 87 if (bitmask == 0) { 88 bitmask = 0x80; 89 bitshift = 7; 90 array_index++; 91 } 92 if ((remainder & 0x10) == 0x10) 93 remainder ^= 0x13; 94 } 95 96 number_of_bits = 4; 97 while (number_of_bits != 0) { 98 number_of_bits--; 99 remainder <<= 1; 100 if ((remainder & 0x10) != 0) 101 remainder ^= 0x13; 102 } 103 104 return remainder; 105 } 106 107 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes) 108 { 109 u8 bitmask = 0x80; 110 u8 bitshift = 7; 111 u8 array_index = 0; 112 int number_of_bits = number_of_bytes * 8; 113 u16 remainder = 0; 114 115 while (number_of_bits != 0) { 116 number_of_bits--; 117 remainder <<= 1; 118 remainder |= (data[array_index] & bitmask) >> bitshift; 119 bitmask >>= 1; 120 bitshift--; 121 if (bitmask == 0) { 122 bitmask = 0x80; 123 bitshift = 7; 124 array_index++; 125 } 126 if ((remainder & 0x100) == 0x100) 127 remainder ^= 0xd5; 128 } 129 130 number_of_bits = 8; 131 while (number_of_bits != 0) { 132 number_of_bits--; 133 remainder <<= 1; 134 if ((remainder & 0x100) != 0) 135 remainder ^= 0xd5; 136 } 137 138 return remainder & 0xff; 139 } 140 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr) 141 { 142 u8 size = 3; 143 size += (hdr->lct / 2); 144 return size; 145 } 146 147 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr, 148 u8 *buf, int *len) 149 { 150 int idx = 0; 151 int i; 152 u8 crc4; 153 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf); 154 for (i = 0; i < (hdr->lct / 2); i++) 155 buf[idx++] = hdr->rad[i]; 156 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) | 157 (hdr->msg_len & 0x3f); 158 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4); 159 160 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1); 161 buf[idx - 1] |= (crc4 & 0xf); 162 163 *len = idx; 164 } 165 166 static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr, 167 u8 *buf, int buflen, u8 *hdrlen) 168 { 169 u8 crc4; 170 u8 len; 171 int i; 172 u8 idx; 173 if (buf[0] == 0) 174 return false; 175 len = 3; 176 len += ((buf[0] & 0xf0) >> 4) / 2; 177 if (len > buflen) 178 return false; 179 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1); 180 181 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) { 182 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]); 183 return false; 184 } 185 186 hdr->lct = (buf[0] & 0xf0) >> 4; 187 hdr->lcr = (buf[0] & 0xf); 188 idx = 1; 189 for (i = 0; i < (hdr->lct / 2); i++) 190 hdr->rad[i] = buf[idx++]; 191 hdr->broadcast = (buf[idx] >> 7) & 0x1; 192 hdr->path_msg = (buf[idx] >> 6) & 0x1; 193 hdr->msg_len = buf[idx] & 0x3f; 194 idx++; 195 hdr->somt = (buf[idx] >> 7) & 0x1; 196 hdr->eomt = (buf[idx] >> 6) & 0x1; 197 hdr->seqno = (buf[idx] >> 4) & 0x1; 198 idx++; 199 *hdrlen = idx; 200 return true; 201 } 202 203 static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req, 204 struct drm_dp_sideband_msg_tx *raw) 205 { 206 int idx = 0; 207 int i; 208 u8 *buf = raw->msg; 209 buf[idx++] = req->req_type & 0x7f; 210 211 switch (req->req_type) { 212 case DP_ENUM_PATH_RESOURCES: 213 buf[idx] = (req->u.port_num.port_number & 0xf) << 4; 214 idx++; 215 break; 216 case DP_ALLOCATE_PAYLOAD: 217 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 | 218 (req->u.allocate_payload.number_sdp_streams & 0xf); 219 idx++; 220 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f); 221 idx++; 222 buf[idx] = (req->u.allocate_payload.pbn >> 8); 223 idx++; 224 buf[idx] = (req->u.allocate_payload.pbn & 0xff); 225 idx++; 226 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) { 227 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) | 228 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf); 229 idx++; 230 } 231 if (req->u.allocate_payload.number_sdp_streams & 1) { 232 i = req->u.allocate_payload.number_sdp_streams - 1; 233 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4; 234 idx++; 235 } 236 break; 237 case DP_QUERY_PAYLOAD: 238 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4; 239 idx++; 240 buf[idx] = (req->u.query_payload.vcpi & 0x7f); 241 idx++; 242 break; 243 case DP_REMOTE_DPCD_READ: 244 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4; 245 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf; 246 idx++; 247 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8; 248 idx++; 249 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff); 250 idx++; 251 buf[idx] = (req->u.dpcd_read.num_bytes); 252 idx++; 253 break; 254 255 case DP_REMOTE_DPCD_WRITE: 256 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4; 257 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf; 258 idx++; 259 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8; 260 idx++; 261 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff); 262 idx++; 263 buf[idx] = (req->u.dpcd_write.num_bytes); 264 idx++; 265 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes); 266 idx += req->u.dpcd_write.num_bytes; 267 break; 268 case DP_REMOTE_I2C_READ: 269 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4; 270 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3); 271 idx++; 272 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) { 273 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f; 274 idx++; 275 buf[idx] = req->u.i2c_read.transactions[i].num_bytes; 276 idx++; 277 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes); 278 idx += req->u.i2c_read.transactions[i].num_bytes; 279 280 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5; 281 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf); 282 idx++; 283 } 284 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f; 285 idx++; 286 buf[idx] = (req->u.i2c_read.num_bytes_read); 287 idx++; 288 break; 289 290 case DP_REMOTE_I2C_WRITE: 291 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4; 292 idx++; 293 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f; 294 idx++; 295 buf[idx] = (req->u.i2c_write.num_bytes); 296 idx++; 297 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes); 298 idx += req->u.i2c_write.num_bytes; 299 break; 300 } 301 raw->cur_len = idx; 302 } 303 304 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len) 305 { 306 u8 crc4; 307 crc4 = drm_dp_msg_data_crc4(msg, len); 308 msg[len] = crc4; 309 } 310 311 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep, 312 struct drm_dp_sideband_msg_tx *raw) 313 { 314 int idx = 0; 315 u8 *buf = raw->msg; 316 317 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f); 318 319 raw->cur_len = idx; 320 } 321 322 /* this adds a chunk of msg to the builder to get the final msg */ 323 static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg, 324 u8 *replybuf, u8 replybuflen, bool hdr) 325 { 326 int ret; 327 u8 crc4; 328 329 if (hdr) { 330 u8 hdrlen; 331 struct drm_dp_sideband_msg_hdr recv_hdr; 332 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen); 333 if (ret == false) { 334 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false); 335 return false; 336 } 337 338 /* 339 * ignore out-of-order messages or messages that are part of a 340 * failed transaction 341 */ 342 if (!recv_hdr.somt && !msg->have_somt) 343 return false; 344 345 /* get length contained in this portion */ 346 msg->curchunk_len = recv_hdr.msg_len; 347 msg->curchunk_hdrlen = hdrlen; 348 349 /* we have already gotten an somt - don't bother parsing */ 350 if (recv_hdr.somt && msg->have_somt) 351 return false; 352 353 if (recv_hdr.somt) { 354 memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr)); 355 msg->have_somt = true; 356 } 357 if (recv_hdr.eomt) 358 msg->have_eomt = true; 359 360 /* copy the bytes for the remainder of this header chunk */ 361 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen)); 362 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx); 363 } else { 364 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen); 365 msg->curchunk_idx += replybuflen; 366 } 367 368 if (msg->curchunk_idx >= msg->curchunk_len) { 369 /* do CRC */ 370 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1); 371 /* copy chunk into bigger msg */ 372 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1); 373 msg->curlen += msg->curchunk_len - 1; 374 } 375 return true; 376 } 377 378 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw, 379 struct drm_dp_sideband_msg_reply_body *repmsg) 380 { 381 int idx = 1; 382 int i; 383 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16); 384 idx += 16; 385 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf; 386 idx++; 387 if (idx > raw->curlen) 388 goto fail_len; 389 for (i = 0; i < repmsg->u.link_addr.nports; i++) { 390 if (raw->msg[idx] & 0x80) 391 repmsg->u.link_addr.ports[i].input_port = 1; 392 393 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7; 394 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf); 395 396 idx++; 397 if (idx > raw->curlen) 398 goto fail_len; 399 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1; 400 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1; 401 if (repmsg->u.link_addr.ports[i].input_port == 0) 402 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1; 403 idx++; 404 if (idx > raw->curlen) 405 goto fail_len; 406 if (repmsg->u.link_addr.ports[i].input_port == 0) { 407 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]); 408 idx++; 409 if (idx > raw->curlen) 410 goto fail_len; 411 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16); 412 idx += 16; 413 if (idx > raw->curlen) 414 goto fail_len; 415 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf; 416 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf); 417 idx++; 418 419 } 420 if (idx > raw->curlen) 421 goto fail_len; 422 } 423 424 return true; 425 fail_len: 426 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen); 427 return false; 428 } 429 430 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw, 431 struct drm_dp_sideband_msg_reply_body *repmsg) 432 { 433 int idx = 1; 434 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf; 435 idx++; 436 if (idx > raw->curlen) 437 goto fail_len; 438 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx]; 439 if (idx > raw->curlen) 440 goto fail_len; 441 442 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes); 443 return true; 444 fail_len: 445 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen); 446 return false; 447 } 448 449 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw, 450 struct drm_dp_sideband_msg_reply_body *repmsg) 451 { 452 int idx = 1; 453 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf; 454 idx++; 455 if (idx > raw->curlen) 456 goto fail_len; 457 return true; 458 fail_len: 459 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen); 460 return false; 461 } 462 463 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw, 464 struct drm_dp_sideband_msg_reply_body *repmsg) 465 { 466 int idx = 1; 467 468 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf); 469 idx++; 470 if (idx > raw->curlen) 471 goto fail_len; 472 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx]; 473 idx++; 474 /* TODO check */ 475 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes); 476 return true; 477 fail_len: 478 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen); 479 return false; 480 } 481 482 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw, 483 struct drm_dp_sideband_msg_reply_body *repmsg) 484 { 485 int idx = 1; 486 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf; 487 idx++; 488 if (idx > raw->curlen) 489 goto fail_len; 490 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 491 idx += 2; 492 if (idx > raw->curlen) 493 goto fail_len; 494 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 495 idx += 2; 496 if (idx > raw->curlen) 497 goto fail_len; 498 return true; 499 fail_len: 500 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen); 501 return false; 502 } 503 504 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw, 505 struct drm_dp_sideband_msg_reply_body *repmsg) 506 { 507 int idx = 1; 508 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf; 509 idx++; 510 if (idx > raw->curlen) 511 goto fail_len; 512 repmsg->u.allocate_payload.vcpi = raw->msg[idx]; 513 idx++; 514 if (idx > raw->curlen) 515 goto fail_len; 516 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 517 idx += 2; 518 if (idx > raw->curlen) 519 goto fail_len; 520 return true; 521 fail_len: 522 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen); 523 return false; 524 } 525 526 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw, 527 struct drm_dp_sideband_msg_reply_body *repmsg) 528 { 529 int idx = 1; 530 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf; 531 idx++; 532 if (idx > raw->curlen) 533 goto fail_len; 534 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]); 535 idx += 2; 536 if (idx > raw->curlen) 537 goto fail_len; 538 return true; 539 fail_len: 540 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen); 541 return false; 542 } 543 544 static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw, 545 struct drm_dp_sideband_msg_reply_body *msg) 546 { 547 memset(msg, 0, sizeof(*msg)); 548 msg->reply_type = (raw->msg[0] & 0x80) >> 7; 549 msg->req_type = (raw->msg[0] & 0x7f); 550 551 if (msg->reply_type) { 552 memcpy(msg->u.nak.guid, &raw->msg[1], 16); 553 msg->u.nak.reason = raw->msg[17]; 554 msg->u.nak.nak_data = raw->msg[18]; 555 return false; 556 } 557 558 switch (msg->req_type) { 559 case DP_LINK_ADDRESS: 560 return drm_dp_sideband_parse_link_address(raw, msg); 561 case DP_QUERY_PAYLOAD: 562 return drm_dp_sideband_parse_query_payload_ack(raw, msg); 563 case DP_REMOTE_DPCD_READ: 564 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg); 565 case DP_REMOTE_DPCD_WRITE: 566 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg); 567 case DP_REMOTE_I2C_READ: 568 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg); 569 case DP_ENUM_PATH_RESOURCES: 570 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg); 571 case DP_ALLOCATE_PAYLOAD: 572 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg); 573 default: 574 DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type); 575 return false; 576 } 577 } 578 579 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw, 580 struct drm_dp_sideband_msg_req_body *msg) 581 { 582 int idx = 1; 583 584 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4; 585 idx++; 586 if (idx > raw->curlen) 587 goto fail_len; 588 589 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16); 590 idx += 16; 591 if (idx > raw->curlen) 592 goto fail_len; 593 594 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1; 595 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1; 596 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1; 597 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1; 598 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7); 599 idx++; 600 return true; 601 fail_len: 602 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen); 603 return false; 604 } 605 606 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw, 607 struct drm_dp_sideband_msg_req_body *msg) 608 { 609 int idx = 1; 610 611 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4; 612 idx++; 613 if (idx > raw->curlen) 614 goto fail_len; 615 616 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16); 617 idx += 16; 618 if (idx > raw->curlen) 619 goto fail_len; 620 621 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]); 622 idx++; 623 return true; 624 fail_len: 625 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen); 626 return false; 627 } 628 629 static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw, 630 struct drm_dp_sideband_msg_req_body *msg) 631 { 632 memset(msg, 0, sizeof(*msg)); 633 msg->req_type = (raw->msg[0] & 0x7f); 634 635 switch (msg->req_type) { 636 case DP_CONNECTION_STATUS_NOTIFY: 637 return drm_dp_sideband_parse_connection_status_notify(raw, msg); 638 case DP_RESOURCE_STATUS_NOTIFY: 639 return drm_dp_sideband_parse_resource_status_notify(raw, msg); 640 default: 641 DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type); 642 return false; 643 } 644 } 645 646 static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes) 647 { 648 struct drm_dp_sideband_msg_req_body req; 649 650 req.req_type = DP_REMOTE_DPCD_WRITE; 651 req.u.dpcd_write.port_number = port_num; 652 req.u.dpcd_write.dpcd_address = offset; 653 req.u.dpcd_write.num_bytes = num_bytes; 654 req.u.dpcd_write.bytes = bytes; 655 drm_dp_encode_sideband_req(&req, msg); 656 657 return 0; 658 } 659 660 static int build_link_address(struct drm_dp_sideband_msg_tx *msg) 661 { 662 struct drm_dp_sideband_msg_req_body req; 663 664 req.req_type = DP_LINK_ADDRESS; 665 drm_dp_encode_sideband_req(&req, msg); 666 return 0; 667 } 668 669 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num) 670 { 671 struct drm_dp_sideband_msg_req_body req; 672 673 req.req_type = DP_ENUM_PATH_RESOURCES; 674 req.u.port_num.port_number = port_num; 675 drm_dp_encode_sideband_req(&req, msg); 676 msg->path_msg = true; 677 return 0; 678 } 679 680 static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num, 681 u8 vcpi, uint16_t pbn) 682 { 683 struct drm_dp_sideband_msg_req_body req; 684 memset(&req, 0, sizeof(req)); 685 req.req_type = DP_ALLOCATE_PAYLOAD; 686 req.u.allocate_payload.port_number = port_num; 687 req.u.allocate_payload.vcpi = vcpi; 688 req.u.allocate_payload.pbn = pbn; 689 drm_dp_encode_sideband_req(&req, msg); 690 msg->path_msg = true; 691 return 0; 692 } 693 694 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr, 695 struct drm_dp_vcpi *vcpi) 696 { 697 int ret, vcpi_ret; 698 699 mutex_lock(&mgr->payload_lock); 700 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1); 701 if (ret > mgr->max_payloads) { 702 ret = -EINVAL; 703 DRM_DEBUG_KMS("out of payload ids %d\n", ret); 704 goto out_unlock; 705 } 706 707 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1); 708 if (vcpi_ret > mgr->max_payloads) { 709 ret = -EINVAL; 710 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret); 711 goto out_unlock; 712 } 713 714 set_bit(ret, &mgr->payload_mask); 715 set_bit(vcpi_ret, &mgr->vcpi_mask); 716 vcpi->vcpi = vcpi_ret + 1; 717 mgr->proposed_vcpis[ret - 1] = vcpi; 718 out_unlock: 719 mutex_unlock(&mgr->payload_lock); 720 return ret; 721 } 722 723 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr, 724 int vcpi) 725 { 726 int i; 727 if (vcpi == 0) 728 return; 729 730 mutex_lock(&mgr->payload_lock); 731 DRM_DEBUG_KMS("putting payload %d\n", vcpi); 732 clear_bit(vcpi - 1, &mgr->vcpi_mask); 733 734 for (i = 0; i < mgr->max_payloads; i++) { 735 if (mgr->proposed_vcpis[i]) 736 if (mgr->proposed_vcpis[i]->vcpi == vcpi) { 737 mgr->proposed_vcpis[i] = NULL; 738 clear_bit(i + 1, &mgr->payload_mask); 739 } 740 } 741 mutex_unlock(&mgr->payload_lock); 742 } 743 744 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr, 745 struct drm_dp_sideband_msg_tx *txmsg) 746 { 747 bool ret; 748 749 /* 750 * All updates to txmsg->state are protected by mgr->qlock, and the two 751 * cases we check here are terminal states. For those the barriers 752 * provided by the wake_up/wait_event pair are enough. 753 */ 754 ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX || 755 txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT); 756 return ret; 757 } 758 759 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb, 760 struct drm_dp_sideband_msg_tx *txmsg) 761 { 762 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 763 int ret; 764 765 ret = wait_event_timeout(mgr->tx_waitq, 766 check_txmsg_state(mgr, txmsg), 767 (4 * HZ)); 768 mutex_lock(&mstb->mgr->qlock); 769 if (ret > 0) { 770 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) { 771 ret = -EIO; 772 goto out; 773 } 774 } else { 775 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno); 776 777 /* dump some state */ 778 ret = -EIO; 779 780 /* remove from q */ 781 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED || 782 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) { 783 list_del(&txmsg->next); 784 } 785 786 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND || 787 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) { 788 mstb->tx_slots[txmsg->seqno] = NULL; 789 } 790 } 791 out: 792 mutex_unlock(&mgr->qlock); 793 794 return ret; 795 } 796 797 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad) 798 { 799 struct drm_dp_mst_branch *mstb; 800 801 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL); 802 if (!mstb) 803 return NULL; 804 805 mstb->lct = lct; 806 if (lct > 1) 807 memcpy(mstb->rad, rad, lct / 2); 808 INIT_LIST_HEAD(&mstb->ports); 809 kref_init(&mstb->kref); 810 return mstb; 811 } 812 813 static void drm_dp_free_mst_port(struct kref *kref); 814 815 static void drm_dp_free_mst_branch_device(struct kref *kref) 816 { 817 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref); 818 if (mstb->port_parent) { 819 if (list_empty(&mstb->port_parent->next)) 820 kref_put(&mstb->port_parent->kref, drm_dp_free_mst_port); 821 } 822 kfree(mstb); 823 } 824 825 static void drm_dp_destroy_mst_branch_device(struct kref *kref) 826 { 827 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref); 828 struct drm_dp_mst_port *port, *tmp; 829 bool wake_tx = false; 830 831 /* 832 * init kref again to be used by ports to remove mst branch when it is 833 * not needed anymore 834 */ 835 kref_init(kref); 836 837 if (mstb->port_parent && list_empty(&mstb->port_parent->next)) 838 kref_get(&mstb->port_parent->kref); 839 840 /* 841 * destroy all ports - don't need lock 842 * as there are no more references to the mst branch 843 * device at this point. 844 */ 845 list_for_each_entry_safe(port, tmp, &mstb->ports, next) { 846 list_del(&port->next); 847 drm_dp_put_port(port); 848 } 849 850 /* drop any tx slots msg */ 851 mutex_lock(&mstb->mgr->qlock); 852 if (mstb->tx_slots[0]) { 853 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 854 mstb->tx_slots[0] = NULL; 855 wake_tx = true; 856 } 857 if (mstb->tx_slots[1]) { 858 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 859 mstb->tx_slots[1] = NULL; 860 wake_tx = true; 861 } 862 mutex_unlock(&mstb->mgr->qlock); 863 864 if (wake_tx) 865 wake_up(&mstb->mgr->tx_waitq); 866 867 kref_put(kref, drm_dp_free_mst_branch_device); 868 } 869 870 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb) 871 { 872 kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device); 873 } 874 875 876 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt) 877 { 878 struct drm_dp_mst_branch *mstb; 879 880 switch (old_pdt) { 881 case DP_PEER_DEVICE_DP_LEGACY_CONV: 882 case DP_PEER_DEVICE_SST_SINK: 883 /* remove i2c over sideband */ 884 drm_dp_mst_unregister_i2c_bus(&port->aux); 885 break; 886 case DP_PEER_DEVICE_MST_BRANCHING: 887 mstb = port->mstb; 888 port->mstb = NULL; 889 drm_dp_put_mst_branch_device(mstb); 890 break; 891 } 892 } 893 894 static void drm_dp_destroy_port(struct kref *kref) 895 { 896 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref); 897 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 898 899 if (!port->input) { 900 port->vcpi.num_slots = 0; 901 902 kfree(port->cached_edid); 903 904 /* 905 * The only time we don't have a connector 906 * on an output port is if the connector init 907 * fails. 908 */ 909 if (port->connector) { 910 /* we can't destroy the connector here, as 911 * we might be holding the mode_config.mutex 912 * from an EDID retrieval */ 913 914 mutex_lock(&mgr->destroy_connector_lock); 915 kref_get(&port->parent->kref); 916 list_add(&port->next, &mgr->destroy_connector_list); 917 mutex_unlock(&mgr->destroy_connector_lock); 918 schedule_work(&mgr->destroy_connector_work); 919 return; 920 } 921 /* no need to clean up vcpi 922 * as if we have no connector we never setup a vcpi */ 923 drm_dp_port_teardown_pdt(port, port->pdt); 924 port->pdt = DP_PEER_DEVICE_NONE; 925 } 926 kfree(port); 927 } 928 929 static void drm_dp_put_port(struct drm_dp_mst_port *port) 930 { 931 kref_put(&port->kref, drm_dp_destroy_port); 932 } 933 934 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) 935 { 936 struct drm_dp_mst_port *port; 937 struct drm_dp_mst_branch *rmstb; 938 if (to_find == mstb) { 939 kref_get(&mstb->kref); 940 return mstb; 941 } 942 list_for_each_entry(port, &mstb->ports, next) { 943 if (port->mstb) { 944 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find); 945 if (rmstb) 946 return rmstb; 947 } 948 } 949 return NULL; 950 } 951 952 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) 953 { 954 struct drm_dp_mst_branch *rmstb = NULL; 955 mutex_lock(&mgr->lock); 956 if (mgr->mst_primary) 957 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb); 958 mutex_unlock(&mgr->lock); 959 return rmstb; 960 } 961 962 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) 963 { 964 struct drm_dp_mst_port *port, *mport; 965 966 list_for_each_entry(port, &mstb->ports, next) { 967 if (port == to_find) { 968 kref_get(&port->kref); 969 return port; 970 } 971 if (port->mstb) { 972 mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find); 973 if (mport) 974 return mport; 975 } 976 } 977 return NULL; 978 } 979 980 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) 981 { 982 struct drm_dp_mst_port *rport = NULL; 983 mutex_lock(&mgr->lock); 984 if (mgr->mst_primary) 985 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port); 986 mutex_unlock(&mgr->lock); 987 return rport; 988 } 989 990 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num) 991 { 992 struct drm_dp_mst_port *port; 993 994 list_for_each_entry(port, &mstb->ports, next) { 995 if (port->port_num == port_num) { 996 kref_get(&port->kref); 997 return port; 998 } 999 } 1000 1001 return NULL; 1002 } 1003 1004 /* 1005 * calculate a new RAD for this MST branch device 1006 * if parent has an LCT of 2 then it has 1 nibble of RAD, 1007 * if parent has an LCT of 3 then it has 2 nibbles of RAD, 1008 */ 1009 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port, 1010 u8 *rad) 1011 { 1012 int parent_lct = port->parent->lct; 1013 int shift = 4; 1014 int idx = (parent_lct - 1) / 2; 1015 if (parent_lct > 1) { 1016 memcpy(rad, port->parent->rad, idx + 1); 1017 shift = (parent_lct % 2) ? 4 : 0; 1018 } else 1019 rad[0] = 0; 1020 1021 rad[idx] |= port->port_num << shift; 1022 return parent_lct + 1; 1023 } 1024 1025 /* 1026 * return sends link address for new mstb 1027 */ 1028 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port) 1029 { 1030 int ret; 1031 u8 rad[6], lct; 1032 bool send_link = false; 1033 switch (port->pdt) { 1034 case DP_PEER_DEVICE_DP_LEGACY_CONV: 1035 case DP_PEER_DEVICE_SST_SINK: 1036 /* add i2c over sideband */ 1037 ret = drm_dp_mst_register_i2c_bus(&port->aux); 1038 break; 1039 case DP_PEER_DEVICE_MST_BRANCHING: 1040 lct = drm_dp_calculate_rad(port, rad); 1041 1042 port->mstb = drm_dp_add_mst_branch_device(lct, rad); 1043 port->mstb->mgr = port->mgr; 1044 port->mstb->port_parent = port; 1045 1046 send_link = true; 1047 break; 1048 } 1049 return send_link; 1050 } 1051 1052 static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid) 1053 { 1054 int ret; 1055 1056 memcpy(mstb->guid, guid, 16); 1057 1058 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) { 1059 if (mstb->port_parent) { 1060 ret = drm_dp_send_dpcd_write( 1061 mstb->mgr, 1062 mstb->port_parent, 1063 DP_GUID, 1064 16, 1065 mstb->guid); 1066 } else { 1067 1068 ret = drm_dp_dpcd_write( 1069 mstb->mgr->aux, 1070 DP_GUID, 1071 mstb->guid, 1072 16); 1073 } 1074 } 1075 } 1076 1077 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb, 1078 int pnum, 1079 char *proppath, 1080 size_t proppath_size) 1081 { 1082 int i; 1083 char temp[8]; 1084 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id); 1085 for (i = 0; i < (mstb->lct - 1); i++) { 1086 int shift = (i % 2) ? 0 : 4; 1087 int port_num = (mstb->rad[i / 2] >> shift) & 0xf; 1088 snprintf(temp, sizeof(temp), "-%d", port_num); 1089 strlcat(proppath, temp, proppath_size); 1090 } 1091 snprintf(temp, sizeof(temp), "-%d", pnum); 1092 strlcat(proppath, temp, proppath_size); 1093 } 1094 1095 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb, 1096 struct device *dev, 1097 struct drm_dp_link_addr_reply_port *port_msg) 1098 { 1099 struct drm_dp_mst_port *port; 1100 bool ret; 1101 bool created = false; 1102 int old_pdt = 0; 1103 int old_ddps = 0; 1104 port = drm_dp_get_port(mstb, port_msg->port_number); 1105 if (!port) { 1106 port = kzalloc(sizeof(*port), GFP_KERNEL); 1107 if (!port) 1108 return; 1109 kref_init(&port->kref); 1110 port->parent = mstb; 1111 port->port_num = port_msg->port_number; 1112 port->mgr = mstb->mgr; 1113 port->aux.name = "DPMST"; 1114 port->aux.dev = dev; 1115 created = true; 1116 } else { 1117 old_pdt = port->pdt; 1118 old_ddps = port->ddps; 1119 } 1120 1121 port->pdt = port_msg->peer_device_type; 1122 port->input = port_msg->input_port; 1123 port->mcs = port_msg->mcs; 1124 port->ddps = port_msg->ddps; 1125 port->ldps = port_msg->legacy_device_plug_status; 1126 port->dpcd_rev = port_msg->dpcd_revision; 1127 port->num_sdp_streams = port_msg->num_sdp_streams; 1128 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks; 1129 1130 /* manage mstb port lists with mgr lock - take a reference 1131 for this list */ 1132 if (created) { 1133 mutex_lock(&mstb->mgr->lock); 1134 kref_get(&port->kref); 1135 list_add(&port->next, &mstb->ports); 1136 mutex_unlock(&mstb->mgr->lock); 1137 } 1138 1139 if (old_ddps != port->ddps) { 1140 if (port->ddps) { 1141 if (!port->input) 1142 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port); 1143 } else { 1144 port->available_pbn = 0; 1145 } 1146 } 1147 1148 if (old_pdt != port->pdt && !port->input) { 1149 drm_dp_port_teardown_pdt(port, old_pdt); 1150 1151 ret = drm_dp_port_setup_pdt(port); 1152 if (ret == true) 1153 drm_dp_send_link_address(mstb->mgr, port->mstb); 1154 } 1155 1156 if (created && !port->input) { 1157 char proppath[255]; 1158 1159 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath)); 1160 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath); 1161 if (!port->connector) { 1162 /* remove it from the port list */ 1163 mutex_lock(&mstb->mgr->lock); 1164 list_del(&port->next); 1165 mutex_unlock(&mstb->mgr->lock); 1166 /* drop port list reference */ 1167 drm_dp_put_port(port); 1168 goto out; 1169 } 1170 if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV || 1171 port->pdt == DP_PEER_DEVICE_SST_SINK) && 1172 port->port_num >= DP_MST_LOGICAL_PORT_0) { 1173 port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc); 1174 drm_mode_connector_set_tile_property(port->connector); 1175 } 1176 (*mstb->mgr->cbs->register_connector)(port->connector); 1177 } 1178 1179 out: 1180 /* put reference to this port */ 1181 drm_dp_put_port(port); 1182 } 1183 1184 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb, 1185 struct drm_dp_connection_status_notify *conn_stat) 1186 { 1187 struct drm_dp_mst_port *port; 1188 int old_pdt; 1189 int old_ddps; 1190 bool dowork = false; 1191 port = drm_dp_get_port(mstb, conn_stat->port_number); 1192 if (!port) 1193 return; 1194 1195 old_ddps = port->ddps; 1196 old_pdt = port->pdt; 1197 port->pdt = conn_stat->peer_device_type; 1198 port->mcs = conn_stat->message_capability_status; 1199 port->ldps = conn_stat->legacy_device_plug_status; 1200 port->ddps = conn_stat->displayport_device_plug_status; 1201 1202 if (old_ddps != port->ddps) { 1203 if (port->ddps) { 1204 dowork = true; 1205 } else { 1206 port->available_pbn = 0; 1207 } 1208 } 1209 if (old_pdt != port->pdt && !port->input) { 1210 drm_dp_port_teardown_pdt(port, old_pdt); 1211 1212 if (drm_dp_port_setup_pdt(port)) 1213 dowork = true; 1214 } 1215 1216 drm_dp_put_port(port); 1217 if (dowork) 1218 queue_work(system_long_wq, &mstb->mgr->work); 1219 1220 } 1221 1222 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr, 1223 u8 lct, u8 *rad) 1224 { 1225 struct drm_dp_mst_branch *mstb; 1226 struct drm_dp_mst_port *port; 1227 int i; 1228 /* find the port by iterating down */ 1229 1230 mutex_lock(&mgr->lock); 1231 mstb = mgr->mst_primary; 1232 1233 for (i = 0; i < lct - 1; i++) { 1234 int shift = (i % 2) ? 0 : 4; 1235 int port_num = (rad[i / 2] >> shift) & 0xf; 1236 1237 list_for_each_entry(port, &mstb->ports, next) { 1238 if (port->port_num == port_num) { 1239 mstb = port->mstb; 1240 if (!mstb) { 1241 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]); 1242 goto out; 1243 } 1244 1245 break; 1246 } 1247 } 1248 } 1249 kref_get(&mstb->kref); 1250 out: 1251 mutex_unlock(&mgr->lock); 1252 return mstb; 1253 } 1254 1255 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper( 1256 struct drm_dp_mst_branch *mstb, 1257 uint8_t *guid) 1258 { 1259 struct drm_dp_mst_branch *found_mstb; 1260 struct drm_dp_mst_port *port; 1261 1262 if (memcmp(mstb->guid, guid, 16) == 0) 1263 return mstb; 1264 1265 1266 list_for_each_entry(port, &mstb->ports, next) { 1267 if (!port->mstb) 1268 continue; 1269 1270 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid); 1271 1272 if (found_mstb) 1273 return found_mstb; 1274 } 1275 1276 return NULL; 1277 } 1278 1279 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid( 1280 struct drm_dp_mst_topology_mgr *mgr, 1281 uint8_t *guid) 1282 { 1283 struct drm_dp_mst_branch *mstb; 1284 1285 /* find the port by iterating down */ 1286 mutex_lock(&mgr->lock); 1287 1288 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid); 1289 1290 if (mstb) 1291 kref_get(&mstb->kref); 1292 1293 mutex_unlock(&mgr->lock); 1294 return mstb; 1295 } 1296 1297 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 1298 struct drm_dp_mst_branch *mstb) 1299 { 1300 struct drm_dp_mst_port *port; 1301 struct drm_dp_mst_branch *mstb_child; 1302 if (!mstb->link_address_sent) 1303 drm_dp_send_link_address(mgr, mstb); 1304 1305 list_for_each_entry(port, &mstb->ports, next) { 1306 if (port->input) 1307 continue; 1308 1309 if (!port->ddps) 1310 continue; 1311 1312 if (!port->available_pbn) 1313 drm_dp_send_enum_path_resources(mgr, mstb, port); 1314 1315 if (port->mstb) { 1316 mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb); 1317 if (mstb_child) { 1318 drm_dp_check_and_send_link_address(mgr, mstb_child); 1319 drm_dp_put_mst_branch_device(mstb_child); 1320 } 1321 } 1322 } 1323 } 1324 1325 static void drm_dp_mst_link_probe_work(struct work_struct *work) 1326 { 1327 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work); 1328 struct drm_dp_mst_branch *mstb; 1329 1330 mutex_lock(&mgr->lock); 1331 mstb = mgr->mst_primary; 1332 if (mstb) { 1333 kref_get(&mstb->kref); 1334 } 1335 mutex_unlock(&mgr->lock); 1336 if (mstb) { 1337 drm_dp_check_and_send_link_address(mgr, mstb); 1338 drm_dp_put_mst_branch_device(mstb); 1339 } 1340 } 1341 1342 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, 1343 u8 *guid) 1344 { 1345 static u8 zero_guid[16]; 1346 1347 if (!memcmp(guid, zero_guid, 16)) { 1348 u64 salt = get_jiffies_64(); 1349 memcpy(&guid[0], &salt, sizeof(u64)); 1350 memcpy(&guid[8], &salt, sizeof(u64)); 1351 return false; 1352 } 1353 return true; 1354 } 1355 1356 #if 0 1357 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes) 1358 { 1359 struct drm_dp_sideband_msg_req_body req; 1360 1361 req.req_type = DP_REMOTE_DPCD_READ; 1362 req.u.dpcd_read.port_number = port_num; 1363 req.u.dpcd_read.dpcd_address = offset; 1364 req.u.dpcd_read.num_bytes = num_bytes; 1365 drm_dp_encode_sideband_req(&req, msg); 1366 1367 return 0; 1368 } 1369 #endif 1370 1371 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr, 1372 bool up, u8 *msg, int len) 1373 { 1374 int ret; 1375 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE; 1376 int tosend, total, offset; 1377 int retries = 0; 1378 1379 retry: 1380 total = len; 1381 offset = 0; 1382 do { 1383 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total); 1384 1385 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset, 1386 &msg[offset], 1387 tosend); 1388 if (ret != tosend) { 1389 if (ret == -EIO && retries < 5) { 1390 retries++; 1391 goto retry; 1392 } 1393 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret); 1394 1395 return -EIO; 1396 } 1397 offset += tosend; 1398 total -= tosend; 1399 } while (total > 0); 1400 return 0; 1401 } 1402 1403 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr, 1404 struct drm_dp_sideband_msg_tx *txmsg) 1405 { 1406 struct drm_dp_mst_branch *mstb = txmsg->dst; 1407 u8 req_type; 1408 1409 /* both msg slots are full */ 1410 if (txmsg->seqno == -1) { 1411 if (mstb->tx_slots[0] && mstb->tx_slots[1]) { 1412 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__); 1413 return -EAGAIN; 1414 } 1415 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) { 1416 txmsg->seqno = mstb->last_seqno; 1417 mstb->last_seqno ^= 1; 1418 } else if (mstb->tx_slots[0] == NULL) 1419 txmsg->seqno = 0; 1420 else 1421 txmsg->seqno = 1; 1422 mstb->tx_slots[txmsg->seqno] = txmsg; 1423 } 1424 1425 req_type = txmsg->msg[0] & 0x7f; 1426 if (req_type == DP_CONNECTION_STATUS_NOTIFY || 1427 req_type == DP_RESOURCE_STATUS_NOTIFY) 1428 hdr->broadcast = 1; 1429 else 1430 hdr->broadcast = 0; 1431 hdr->path_msg = txmsg->path_msg; 1432 hdr->lct = mstb->lct; 1433 hdr->lcr = mstb->lct - 1; 1434 if (mstb->lct > 1) 1435 memcpy(hdr->rad, mstb->rad, mstb->lct / 2); 1436 hdr->seqno = txmsg->seqno; 1437 return 0; 1438 } 1439 /* 1440 * process a single block of the next message in the sideband queue 1441 */ 1442 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr, 1443 struct drm_dp_sideband_msg_tx *txmsg, 1444 bool up) 1445 { 1446 u8 chunk[48]; 1447 struct drm_dp_sideband_msg_hdr hdr; 1448 int len, space, idx, tosend; 1449 int ret; 1450 1451 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr)); 1452 1453 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) { 1454 txmsg->seqno = -1; 1455 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND; 1456 } 1457 1458 /* make hdr from dst mst - for replies use seqno 1459 otherwise assign one */ 1460 ret = set_hdr_from_dst_qlock(&hdr, txmsg); 1461 if (ret < 0) 1462 return ret; 1463 1464 /* amount left to send in this message */ 1465 len = txmsg->cur_len - txmsg->cur_offset; 1466 1467 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */ 1468 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr); 1469 1470 tosend = min(len, space); 1471 if (len == txmsg->cur_len) 1472 hdr.somt = 1; 1473 if (space >= len) 1474 hdr.eomt = 1; 1475 1476 1477 hdr.msg_len = tosend + 1; 1478 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx); 1479 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend); 1480 /* add crc at end */ 1481 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend); 1482 idx += tosend + 1; 1483 1484 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx); 1485 if (ret) { 1486 DRM_DEBUG_KMS("sideband msg failed to send\n"); 1487 return ret; 1488 } 1489 1490 txmsg->cur_offset += tosend; 1491 if (txmsg->cur_offset == txmsg->cur_len) { 1492 txmsg->state = DRM_DP_SIDEBAND_TX_SENT; 1493 return 1; 1494 } 1495 return 0; 1496 } 1497 1498 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr) 1499 { 1500 struct drm_dp_sideband_msg_tx *txmsg; 1501 int ret; 1502 1503 WARN_ON(!mutex_is_locked(&mgr->qlock)); 1504 1505 /* construct a chunk from the first msg in the tx_msg queue */ 1506 if (list_empty(&mgr->tx_msg_downq)) { 1507 mgr->tx_down_in_progress = false; 1508 return; 1509 } 1510 mgr->tx_down_in_progress = true; 1511 1512 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next); 1513 ret = process_single_tx_qlock(mgr, txmsg, false); 1514 if (ret == 1) { 1515 /* txmsg is sent it should be in the slots now */ 1516 list_del(&txmsg->next); 1517 } else if (ret) { 1518 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret); 1519 list_del(&txmsg->next); 1520 if (txmsg->seqno != -1) 1521 txmsg->dst->tx_slots[txmsg->seqno] = NULL; 1522 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 1523 wake_up(&mgr->tx_waitq); 1524 } 1525 if (list_empty(&mgr->tx_msg_downq)) { 1526 mgr->tx_down_in_progress = false; 1527 return; 1528 } 1529 } 1530 1531 /* called holding qlock */ 1532 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr, 1533 struct drm_dp_sideband_msg_tx *txmsg) 1534 { 1535 int ret; 1536 1537 /* construct a chunk from the first msg in the tx_msg queue */ 1538 ret = process_single_tx_qlock(mgr, txmsg, true); 1539 1540 if (ret != 1) 1541 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret); 1542 1543 txmsg->dst->tx_slots[txmsg->seqno] = NULL; 1544 } 1545 1546 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr, 1547 struct drm_dp_sideband_msg_tx *txmsg) 1548 { 1549 mutex_lock(&mgr->qlock); 1550 list_add_tail(&txmsg->next, &mgr->tx_msg_downq); 1551 if (!mgr->tx_down_in_progress) 1552 process_single_down_tx_qlock(mgr); 1553 mutex_unlock(&mgr->qlock); 1554 } 1555 1556 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 1557 struct drm_dp_mst_branch *mstb) 1558 { 1559 int len; 1560 struct drm_dp_sideband_msg_tx *txmsg; 1561 int ret; 1562 1563 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 1564 if (!txmsg) 1565 return; 1566 1567 txmsg->dst = mstb; 1568 len = build_link_address(txmsg); 1569 1570 mstb->link_address_sent = true; 1571 drm_dp_queue_down_tx(mgr, txmsg); 1572 1573 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 1574 if (ret > 0) { 1575 int i; 1576 1577 if (txmsg->reply.reply_type == 1) 1578 DRM_DEBUG_KMS("link address nak received\n"); 1579 else { 1580 DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports); 1581 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) { 1582 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, 1583 txmsg->reply.u.link_addr.ports[i].input_port, 1584 txmsg->reply.u.link_addr.ports[i].peer_device_type, 1585 txmsg->reply.u.link_addr.ports[i].port_number, 1586 txmsg->reply.u.link_addr.ports[i].dpcd_revision, 1587 txmsg->reply.u.link_addr.ports[i].mcs, 1588 txmsg->reply.u.link_addr.ports[i].ddps, 1589 txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status, 1590 txmsg->reply.u.link_addr.ports[i].num_sdp_streams, 1591 txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks); 1592 } 1593 1594 drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid); 1595 1596 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) { 1597 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]); 1598 } 1599 (*mgr->cbs->hotplug)(mgr); 1600 } 1601 } else { 1602 mstb->link_address_sent = false; 1603 DRM_DEBUG_KMS("link address failed %d\n", ret); 1604 } 1605 1606 kfree(txmsg); 1607 } 1608 1609 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, 1610 struct drm_dp_mst_branch *mstb, 1611 struct drm_dp_mst_port *port) 1612 { 1613 int len; 1614 struct drm_dp_sideband_msg_tx *txmsg; 1615 int ret; 1616 1617 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 1618 if (!txmsg) 1619 return -ENOMEM; 1620 1621 txmsg->dst = mstb; 1622 len = build_enum_path_resources(txmsg, port->port_num); 1623 1624 drm_dp_queue_down_tx(mgr, txmsg); 1625 1626 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 1627 if (ret > 0) { 1628 if (txmsg->reply.reply_type == 1) 1629 DRM_DEBUG_KMS("enum path resources nak received\n"); 1630 else { 1631 if (port->port_num != txmsg->reply.u.path_resources.port_number) 1632 DRM_ERROR("got incorrect port in response\n"); 1633 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, 1634 txmsg->reply.u.path_resources.avail_payload_bw_number); 1635 port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number; 1636 } 1637 } 1638 1639 kfree(txmsg); 1640 return 0; 1641 } 1642 1643 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb) 1644 { 1645 if (!mstb->port_parent) 1646 return NULL; 1647 1648 if (mstb->port_parent->mstb != mstb) 1649 return mstb->port_parent; 1650 1651 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent); 1652 } 1653 1654 static struct drm_dp_mst_branch *drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr, 1655 struct drm_dp_mst_branch *mstb, 1656 int *port_num) 1657 { 1658 struct drm_dp_mst_branch *rmstb = NULL; 1659 struct drm_dp_mst_port *found_port; 1660 mutex_lock(&mgr->lock); 1661 if (mgr->mst_primary) { 1662 found_port = drm_dp_get_last_connected_port_to_mstb(mstb); 1663 1664 if (found_port) { 1665 rmstb = found_port->parent; 1666 kref_get(&rmstb->kref); 1667 *port_num = found_port->port_num; 1668 } 1669 } 1670 mutex_unlock(&mgr->lock); 1671 return rmstb; 1672 } 1673 1674 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr, 1675 struct drm_dp_mst_port *port, 1676 int id, 1677 int pbn) 1678 { 1679 struct drm_dp_sideband_msg_tx *txmsg; 1680 struct drm_dp_mst_branch *mstb; 1681 int len, ret, port_num; 1682 1683 port = drm_dp_get_validated_port_ref(mgr, port); 1684 if (!port) 1685 return -EINVAL; 1686 1687 port_num = port->port_num; 1688 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent); 1689 if (!mstb) { 1690 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, port->parent, &port_num); 1691 1692 if (!mstb) { 1693 drm_dp_put_port(port); 1694 return -EINVAL; 1695 } 1696 } 1697 1698 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 1699 if (!txmsg) { 1700 ret = -ENOMEM; 1701 goto fail_put; 1702 } 1703 1704 txmsg->dst = mstb; 1705 len = build_allocate_payload(txmsg, port_num, 1706 id, 1707 pbn); 1708 1709 drm_dp_queue_down_tx(mgr, txmsg); 1710 1711 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 1712 if (ret > 0) { 1713 if (txmsg->reply.reply_type == 1) { 1714 ret = -EINVAL; 1715 } else 1716 ret = 0; 1717 } 1718 kfree(txmsg); 1719 fail_put: 1720 drm_dp_put_mst_branch_device(mstb); 1721 drm_dp_put_port(port); 1722 return ret; 1723 } 1724 1725 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr, 1726 int id, 1727 struct drm_dp_payload *payload) 1728 { 1729 int ret; 1730 1731 ret = drm_dp_dpcd_write_payload(mgr, id, payload); 1732 if (ret < 0) { 1733 payload->payload_state = 0; 1734 return ret; 1735 } 1736 payload->payload_state = DP_PAYLOAD_LOCAL; 1737 return 0; 1738 } 1739 1740 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr, 1741 struct drm_dp_mst_port *port, 1742 int id, 1743 struct drm_dp_payload *payload) 1744 { 1745 int ret; 1746 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn); 1747 if (ret < 0) 1748 return ret; 1749 payload->payload_state = DP_PAYLOAD_REMOTE; 1750 return ret; 1751 } 1752 1753 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr, 1754 struct drm_dp_mst_port *port, 1755 int id, 1756 struct drm_dp_payload *payload) 1757 { 1758 DRM_DEBUG_KMS("\n"); 1759 /* its okay for these to fail */ 1760 if (port) { 1761 drm_dp_payload_send_msg(mgr, port, id, 0); 1762 } 1763 1764 drm_dp_dpcd_write_payload(mgr, id, payload); 1765 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL; 1766 return 0; 1767 } 1768 1769 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr, 1770 int id, 1771 struct drm_dp_payload *payload) 1772 { 1773 payload->payload_state = 0; 1774 return 0; 1775 } 1776 1777 /** 1778 * drm_dp_update_payload_part1() - Execute payload update part 1 1779 * @mgr: manager to use. 1780 * 1781 * This iterates over all proposed virtual channels, and tries to 1782 * allocate space in the link for them. For 0->slots transitions, 1783 * this step just writes the VCPI to the MST device. For slots->0 1784 * transitions, this writes the updated VCPIs and removes the 1785 * remote VC payloads. 1786 * 1787 * after calling this the driver should generate ACT and payload 1788 * packets. 1789 */ 1790 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr) 1791 { 1792 int i, j; 1793 int cur_slots = 1; 1794 struct drm_dp_payload req_payload; 1795 struct drm_dp_mst_port *port; 1796 1797 mutex_lock(&mgr->payload_lock); 1798 for (i = 0; i < mgr->max_payloads; i++) { 1799 /* solve the current payloads - compare to the hw ones 1800 - update the hw view */ 1801 req_payload.start_slot = cur_slots; 1802 if (mgr->proposed_vcpis[i]) { 1803 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi); 1804 port = drm_dp_get_validated_port_ref(mgr, port); 1805 if (!port) { 1806 mutex_unlock(&mgr->payload_lock); 1807 return -EINVAL; 1808 } 1809 req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots; 1810 req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi; 1811 } else { 1812 port = NULL; 1813 req_payload.num_slots = 0; 1814 } 1815 1816 if (mgr->payloads[i].start_slot != req_payload.start_slot) { 1817 mgr->payloads[i].start_slot = req_payload.start_slot; 1818 } 1819 /* work out what is required to happen with this payload */ 1820 if (mgr->payloads[i].num_slots != req_payload.num_slots) { 1821 1822 /* need to push an update for this payload */ 1823 if (req_payload.num_slots) { 1824 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload); 1825 mgr->payloads[i].num_slots = req_payload.num_slots; 1826 mgr->payloads[i].vcpi = req_payload.vcpi; 1827 } else if (mgr->payloads[i].num_slots) { 1828 mgr->payloads[i].num_slots = 0; 1829 drm_dp_destroy_payload_step1(mgr, port, mgr->payloads[i].vcpi, &mgr->payloads[i]); 1830 req_payload.payload_state = mgr->payloads[i].payload_state; 1831 mgr->payloads[i].start_slot = 0; 1832 } 1833 mgr->payloads[i].payload_state = req_payload.payload_state; 1834 } 1835 cur_slots += req_payload.num_slots; 1836 1837 if (port) 1838 drm_dp_put_port(port); 1839 } 1840 1841 for (i = 0; i < mgr->max_payloads; i++) { 1842 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) { 1843 DRM_DEBUG_KMS("removing payload %d\n", i); 1844 for (j = i; j < mgr->max_payloads - 1; j++) { 1845 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload)); 1846 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1]; 1847 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) { 1848 set_bit(j + 1, &mgr->payload_mask); 1849 } else { 1850 clear_bit(j + 1, &mgr->payload_mask); 1851 } 1852 } 1853 memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload)); 1854 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL; 1855 clear_bit(mgr->max_payloads, &mgr->payload_mask); 1856 1857 } 1858 } 1859 mutex_unlock(&mgr->payload_lock); 1860 1861 return 0; 1862 } 1863 EXPORT_SYMBOL(drm_dp_update_payload_part1); 1864 1865 /** 1866 * drm_dp_update_payload_part2() - Execute payload update part 2 1867 * @mgr: manager to use. 1868 * 1869 * This iterates over all proposed virtual channels, and tries to 1870 * allocate space in the link for them. For 0->slots transitions, 1871 * this step writes the remote VC payload commands. For slots->0 1872 * this just resets some internal state. 1873 */ 1874 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr) 1875 { 1876 struct drm_dp_mst_port *port; 1877 int i; 1878 int ret = 0; 1879 mutex_lock(&mgr->payload_lock); 1880 for (i = 0; i < mgr->max_payloads; i++) { 1881 1882 if (!mgr->proposed_vcpis[i]) 1883 continue; 1884 1885 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi); 1886 1887 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state); 1888 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) { 1889 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]); 1890 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) { 1891 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]); 1892 } 1893 if (ret) { 1894 mutex_unlock(&mgr->payload_lock); 1895 return ret; 1896 } 1897 } 1898 mutex_unlock(&mgr->payload_lock); 1899 return 0; 1900 } 1901 EXPORT_SYMBOL(drm_dp_update_payload_part2); 1902 1903 #if 0 /* unused as of yet */ 1904 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr, 1905 struct drm_dp_mst_port *port, 1906 int offset, int size) 1907 { 1908 int len; 1909 struct drm_dp_sideband_msg_tx *txmsg; 1910 1911 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 1912 if (!txmsg) 1913 return -ENOMEM; 1914 1915 len = build_dpcd_read(txmsg, port->port_num, 0, 8); 1916 txmsg->dst = port->parent; 1917 1918 drm_dp_queue_down_tx(mgr, txmsg); 1919 1920 return 0; 1921 } 1922 #endif 1923 1924 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, 1925 struct drm_dp_mst_port *port, 1926 int offset, int size, u8 *bytes) 1927 { 1928 int len; 1929 int ret; 1930 struct drm_dp_sideband_msg_tx *txmsg; 1931 struct drm_dp_mst_branch *mstb; 1932 1933 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent); 1934 if (!mstb) 1935 return -EINVAL; 1936 1937 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 1938 if (!txmsg) { 1939 ret = -ENOMEM; 1940 goto fail_put; 1941 } 1942 1943 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes); 1944 txmsg->dst = mstb; 1945 1946 drm_dp_queue_down_tx(mgr, txmsg); 1947 1948 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 1949 if (ret > 0) { 1950 if (txmsg->reply.reply_type == 1) { 1951 ret = -EINVAL; 1952 } else 1953 ret = 0; 1954 } 1955 kfree(txmsg); 1956 fail_put: 1957 drm_dp_put_mst_branch_device(mstb); 1958 return ret; 1959 } 1960 1961 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type) 1962 { 1963 struct drm_dp_sideband_msg_reply_body reply; 1964 1965 reply.reply_type = 1; 1966 reply.req_type = req_type; 1967 drm_dp_encode_sideband_reply(&reply, msg); 1968 return 0; 1969 } 1970 1971 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr, 1972 struct drm_dp_mst_branch *mstb, 1973 int req_type, int seqno, bool broadcast) 1974 { 1975 struct drm_dp_sideband_msg_tx *txmsg; 1976 1977 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 1978 if (!txmsg) 1979 return -ENOMEM; 1980 1981 txmsg->dst = mstb; 1982 txmsg->seqno = seqno; 1983 drm_dp_encode_up_ack_reply(txmsg, req_type); 1984 1985 mutex_lock(&mgr->qlock); 1986 1987 process_single_up_tx_qlock(mgr, txmsg); 1988 1989 mutex_unlock(&mgr->qlock); 1990 1991 kfree(txmsg); 1992 return 0; 1993 } 1994 1995 static bool drm_dp_get_vc_payload_bw(int dp_link_bw, 1996 int dp_link_count, 1997 int *out) 1998 { 1999 switch (dp_link_bw) { 2000 default: 2001 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n", 2002 dp_link_bw, dp_link_count); 2003 return false; 2004 2005 case DP_LINK_BW_1_62: 2006 *out = 3 * dp_link_count; 2007 break; 2008 case DP_LINK_BW_2_7: 2009 *out = 5 * dp_link_count; 2010 break; 2011 case DP_LINK_BW_5_4: 2012 *out = 10 * dp_link_count; 2013 break; 2014 } 2015 return true; 2016 } 2017 2018 /** 2019 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager 2020 * @mgr: manager to set state for 2021 * @mst_state: true to enable MST on this connector - false to disable. 2022 * 2023 * This is called by the driver when it detects an MST capable device plugged 2024 * into a DP MST capable port, or when a DP MST capable device is unplugged. 2025 */ 2026 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state) 2027 { 2028 int ret = 0; 2029 struct drm_dp_mst_branch *mstb = NULL; 2030 2031 mutex_lock(&mgr->lock); 2032 if (mst_state == mgr->mst_state) 2033 goto out_unlock; 2034 2035 mgr->mst_state = mst_state; 2036 /* set the device into MST mode */ 2037 if (mst_state) { 2038 WARN_ON(mgr->mst_primary); 2039 2040 /* get dpcd info */ 2041 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE); 2042 if (ret != DP_RECEIVER_CAP_SIZE) { 2043 DRM_DEBUG_KMS("failed to read DPCD\n"); 2044 goto out_unlock; 2045 } 2046 2047 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1], 2048 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK, 2049 &mgr->pbn_div)) { 2050 ret = -EINVAL; 2051 goto out_unlock; 2052 } 2053 2054 mgr->total_pbn = 2560; 2055 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div); 2056 mgr->avail_slots = mgr->total_slots; 2057 2058 /* add initial branch device at LCT 1 */ 2059 mstb = drm_dp_add_mst_branch_device(1, NULL); 2060 if (mstb == NULL) { 2061 ret = -ENOMEM; 2062 goto out_unlock; 2063 } 2064 mstb->mgr = mgr; 2065 2066 /* give this the main reference */ 2067 mgr->mst_primary = mstb; 2068 kref_get(&mgr->mst_primary->kref); 2069 2070 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 2071 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC); 2072 if (ret < 0) { 2073 goto out_unlock; 2074 } 2075 2076 { 2077 struct drm_dp_payload reset_pay; 2078 reset_pay.start_slot = 0; 2079 reset_pay.num_slots = 0x3f; 2080 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay); 2081 } 2082 2083 queue_work(system_long_wq, &mgr->work); 2084 2085 ret = 0; 2086 } else { 2087 /* disable MST on the device */ 2088 mstb = mgr->mst_primary; 2089 mgr->mst_primary = NULL; 2090 /* this can fail if the device is gone */ 2091 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0); 2092 ret = 0; 2093 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload)); 2094 mgr->payload_mask = 0; 2095 set_bit(0, &mgr->payload_mask); 2096 mgr->vcpi_mask = 0; 2097 } 2098 2099 out_unlock: 2100 mutex_unlock(&mgr->lock); 2101 if (mstb) 2102 drm_dp_put_mst_branch_device(mstb); 2103 return ret; 2104 2105 } 2106 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst); 2107 2108 /** 2109 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager 2110 * @mgr: manager to suspend 2111 * 2112 * This function tells the MST device that we can't handle UP messages 2113 * anymore. This should stop it from sending any since we are suspended. 2114 */ 2115 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr) 2116 { 2117 mutex_lock(&mgr->lock); 2118 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 2119 DP_MST_EN | DP_UPSTREAM_IS_SRC); 2120 mutex_unlock(&mgr->lock); 2121 flush_work(&mgr->work); 2122 flush_work(&mgr->destroy_connector_work); 2123 } 2124 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend); 2125 2126 /** 2127 * drm_dp_mst_topology_mgr_resume() - resume the MST manager 2128 * @mgr: manager to resume 2129 * 2130 * This will fetch DPCD and see if the device is still there, 2131 * if it is, it will rewrite the MSTM control bits, and return. 2132 * 2133 * if the device fails this returns -1, and the driver should do 2134 * a full MST reprobe, in case we were undocked. 2135 */ 2136 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr) 2137 { 2138 int ret = 0; 2139 2140 mutex_lock(&mgr->lock); 2141 2142 if (mgr->mst_primary) { 2143 int sret; 2144 u8 guid[16]; 2145 2146 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE); 2147 if (sret != DP_RECEIVER_CAP_SIZE) { 2148 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n"); 2149 ret = -1; 2150 goto out_unlock; 2151 } 2152 2153 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 2154 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC); 2155 if (ret < 0) { 2156 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n"); 2157 ret = -1; 2158 goto out_unlock; 2159 } 2160 2161 /* Some hubs forget their guids after they resume */ 2162 sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16); 2163 if (sret != 16) { 2164 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n"); 2165 ret = -1; 2166 goto out_unlock; 2167 } 2168 drm_dp_check_mstb_guid(mgr->mst_primary, guid); 2169 2170 ret = 0; 2171 } else 2172 ret = -1; 2173 2174 out_unlock: 2175 mutex_unlock(&mgr->lock); 2176 return ret; 2177 } 2178 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume); 2179 2180 static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up) 2181 { 2182 int len; 2183 u8 replyblock[32]; 2184 int replylen, origlen, curreply; 2185 int ret; 2186 struct drm_dp_sideband_msg_rx *msg; 2187 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE; 2188 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv; 2189 2190 len = min(mgr->max_dpcd_transaction_bytes, 16); 2191 ret = drm_dp_dpcd_read(mgr->aux, basereg, 2192 replyblock, len); 2193 if (ret != len) { 2194 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret); 2195 return false; 2196 } 2197 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true); 2198 if (!ret) { 2199 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]); 2200 return false; 2201 } 2202 replylen = msg->curchunk_len + msg->curchunk_hdrlen; 2203 2204 origlen = replylen; 2205 replylen -= len; 2206 curreply = len; 2207 while (replylen > 0) { 2208 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16); 2209 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply, 2210 replyblock, len); 2211 if (ret != len) { 2212 DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n", 2213 len, ret); 2214 return false; 2215 } 2216 2217 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false); 2218 if (!ret) { 2219 DRM_DEBUG_KMS("failed to build sideband msg\n"); 2220 return false; 2221 } 2222 2223 curreply += len; 2224 replylen -= len; 2225 } 2226 return true; 2227 } 2228 2229 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr) 2230 { 2231 int ret = 0; 2232 2233 if (!drm_dp_get_one_sb_msg(mgr, false)) { 2234 memset(&mgr->down_rep_recv, 0, 2235 sizeof(struct drm_dp_sideband_msg_rx)); 2236 return 0; 2237 } 2238 2239 if (mgr->down_rep_recv.have_eomt) { 2240 struct drm_dp_sideband_msg_tx *txmsg; 2241 struct drm_dp_mst_branch *mstb; 2242 int slot = -1; 2243 mstb = drm_dp_get_mst_branch_device(mgr, 2244 mgr->down_rep_recv.initial_hdr.lct, 2245 mgr->down_rep_recv.initial_hdr.rad); 2246 2247 if (!mstb) { 2248 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct); 2249 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 2250 return 0; 2251 } 2252 2253 /* find the message */ 2254 slot = mgr->down_rep_recv.initial_hdr.seqno; 2255 mutex_lock(&mgr->qlock); 2256 txmsg = mstb->tx_slots[slot]; 2257 /* remove from slots */ 2258 mutex_unlock(&mgr->qlock); 2259 2260 if (!txmsg) { 2261 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n", 2262 mstb, 2263 mgr->down_rep_recv.initial_hdr.seqno, 2264 mgr->down_rep_recv.initial_hdr.lct, 2265 mgr->down_rep_recv.initial_hdr.rad[0], 2266 mgr->down_rep_recv.msg[0]); 2267 drm_dp_put_mst_branch_device(mstb); 2268 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 2269 return 0; 2270 } 2271 2272 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply); 2273 if (txmsg->reply.reply_type == 1) { 2274 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); 2275 } 2276 2277 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 2278 drm_dp_put_mst_branch_device(mstb); 2279 2280 mutex_lock(&mgr->qlock); 2281 txmsg->state = DRM_DP_SIDEBAND_TX_RX; 2282 mstb->tx_slots[slot] = NULL; 2283 mutex_unlock(&mgr->qlock); 2284 2285 wake_up(&mgr->tx_waitq); 2286 } 2287 return ret; 2288 } 2289 2290 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr) 2291 { 2292 int ret = 0; 2293 2294 if (!drm_dp_get_one_sb_msg(mgr, true)) { 2295 memset(&mgr->up_req_recv, 0, 2296 sizeof(struct drm_dp_sideband_msg_rx)); 2297 return 0; 2298 } 2299 2300 if (mgr->up_req_recv.have_eomt) { 2301 struct drm_dp_sideband_msg_req_body msg; 2302 struct drm_dp_mst_branch *mstb = NULL; 2303 bool seqno; 2304 2305 if (!mgr->up_req_recv.initial_hdr.broadcast) { 2306 mstb = drm_dp_get_mst_branch_device(mgr, 2307 mgr->up_req_recv.initial_hdr.lct, 2308 mgr->up_req_recv.initial_hdr.rad); 2309 if (!mstb) { 2310 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct); 2311 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 2312 return 0; 2313 } 2314 } 2315 2316 seqno = mgr->up_req_recv.initial_hdr.seqno; 2317 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg); 2318 2319 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) { 2320 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false); 2321 2322 if (!mstb) 2323 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid); 2324 2325 if (!mstb) { 2326 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct); 2327 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 2328 return 0; 2329 } 2330 2331 drm_dp_update_port(mstb, &msg.u.conn_stat); 2332 2333 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); 2334 (*mgr->cbs->hotplug)(mgr); 2335 2336 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) { 2337 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false); 2338 if (!mstb) 2339 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid); 2340 2341 if (!mstb) { 2342 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct); 2343 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 2344 return 0; 2345 } 2346 2347 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn); 2348 } 2349 2350 if (mstb) 2351 drm_dp_put_mst_branch_device(mstb); 2352 2353 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 2354 } 2355 return ret; 2356 } 2357 2358 /** 2359 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify 2360 * @mgr: manager to notify irq for. 2361 * @esi: 4 bytes from SINK_COUNT_ESI 2362 * @handled: whether the hpd interrupt was consumed or not 2363 * 2364 * This should be called from the driver when it detects a short IRQ, 2365 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The 2366 * topology manager will process the sideband messages received as a result 2367 * of this. 2368 */ 2369 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled) 2370 { 2371 int ret = 0; 2372 int sc; 2373 *handled = false; 2374 sc = esi[0] & 0x3f; 2375 2376 if (sc != mgr->sink_count) { 2377 mgr->sink_count = sc; 2378 *handled = true; 2379 } 2380 2381 if (esi[1] & DP_DOWN_REP_MSG_RDY) { 2382 ret = drm_dp_mst_handle_down_rep(mgr); 2383 *handled = true; 2384 } 2385 2386 if (esi[1] & DP_UP_REQ_MSG_RDY) { 2387 ret |= drm_dp_mst_handle_up_req(mgr); 2388 *handled = true; 2389 } 2390 2391 drm_dp_mst_kick_tx(mgr); 2392 return ret; 2393 } 2394 EXPORT_SYMBOL(drm_dp_mst_hpd_irq); 2395 2396 /** 2397 * drm_dp_mst_detect_port() - get connection status for an MST port 2398 * @mgr: manager for this port 2399 * @port: unverified pointer to a port 2400 * 2401 * This returns the current connection state for a port. It validates the 2402 * port pointer still exists so the caller doesn't require a reference 2403 */ 2404 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector, 2405 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) 2406 { 2407 enum drm_connector_status status = connector_status_disconnected; 2408 2409 /* we need to search for the port in the mgr in case its gone */ 2410 port = drm_dp_get_validated_port_ref(mgr, port); 2411 if (!port) 2412 return connector_status_disconnected; 2413 2414 if (!port->ddps) 2415 goto out; 2416 2417 switch (port->pdt) { 2418 case DP_PEER_DEVICE_NONE: 2419 case DP_PEER_DEVICE_MST_BRANCHING: 2420 break; 2421 2422 case DP_PEER_DEVICE_SST_SINK: 2423 status = connector_status_connected; 2424 /* for logical ports - cache the EDID */ 2425 if (port->port_num >= 8 && !port->cached_edid) { 2426 port->cached_edid = drm_get_edid(connector, &port->aux.ddc); 2427 } 2428 break; 2429 case DP_PEER_DEVICE_DP_LEGACY_CONV: 2430 if (port->ldps) 2431 status = connector_status_connected; 2432 break; 2433 } 2434 out: 2435 drm_dp_put_port(port); 2436 return status; 2437 } 2438 EXPORT_SYMBOL(drm_dp_mst_detect_port); 2439 2440 /** 2441 * drm_dp_mst_get_edid() - get EDID for an MST port 2442 * @connector: toplevel connector to get EDID for 2443 * @mgr: manager for this port 2444 * @port: unverified pointer to a port. 2445 * 2446 * This returns an EDID for the port connected to a connector, 2447 * It validates the pointer still exists so the caller doesn't require a 2448 * reference. 2449 */ 2450 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) 2451 { 2452 struct edid *edid = NULL; 2453 2454 /* we need to search for the port in the mgr in case its gone */ 2455 port = drm_dp_get_validated_port_ref(mgr, port); 2456 if (!port) 2457 return NULL; 2458 2459 if (port->cached_edid) 2460 edid = drm_edid_duplicate(port->cached_edid); 2461 else { 2462 edid = drm_get_edid(connector, &port->aux.ddc); 2463 drm_mode_connector_set_tile_property(connector); 2464 } 2465 drm_dp_put_port(port); 2466 return edid; 2467 } 2468 EXPORT_SYMBOL(drm_dp_mst_get_edid); 2469 2470 /** 2471 * drm_dp_find_vcpi_slots() - find slots for this PBN value 2472 * @mgr: manager to use 2473 * @pbn: payload bandwidth to convert into slots. 2474 */ 2475 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, 2476 int pbn) 2477 { 2478 int num_slots; 2479 2480 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div); 2481 2482 if (num_slots > mgr->avail_slots) 2483 return -ENOSPC; 2484 return num_slots; 2485 } 2486 EXPORT_SYMBOL(drm_dp_find_vcpi_slots); 2487 2488 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr, 2489 struct drm_dp_vcpi *vcpi, int pbn) 2490 { 2491 int num_slots; 2492 int ret; 2493 2494 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div); 2495 2496 if (num_slots > mgr->avail_slots) 2497 return -ENOSPC; 2498 2499 vcpi->pbn = pbn; 2500 vcpi->aligned_pbn = num_slots * mgr->pbn_div; 2501 vcpi->num_slots = num_slots; 2502 2503 ret = drm_dp_mst_assign_payload_id(mgr, vcpi); 2504 if (ret < 0) 2505 return ret; 2506 return 0; 2507 } 2508 2509 /** 2510 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel 2511 * @mgr: manager for this port 2512 * @port: port to allocate a virtual channel for. 2513 * @pbn: payload bandwidth number to request 2514 * @slots: returned number of slots for this PBN. 2515 */ 2516 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots) 2517 { 2518 int ret; 2519 2520 port = drm_dp_get_validated_port_ref(mgr, port); 2521 if (!port) 2522 return false; 2523 2524 if (port->vcpi.vcpi > 0) { 2525 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn); 2526 if (pbn == port->vcpi.pbn) { 2527 *slots = port->vcpi.num_slots; 2528 drm_dp_put_port(port); 2529 return true; 2530 } 2531 } 2532 2533 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn); 2534 if (ret) { 2535 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret); 2536 goto out; 2537 } 2538 DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots); 2539 *slots = port->vcpi.num_slots; 2540 2541 drm_dp_put_port(port); 2542 return true; 2543 out: 2544 return false; 2545 } 2546 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi); 2547 2548 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) 2549 { 2550 int slots = 0; 2551 port = drm_dp_get_validated_port_ref(mgr, port); 2552 if (!port) 2553 return slots; 2554 2555 slots = port->vcpi.num_slots; 2556 drm_dp_put_port(port); 2557 return slots; 2558 } 2559 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots); 2560 2561 /** 2562 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI 2563 * @mgr: manager for this port 2564 * @port: unverified pointer to a port. 2565 * 2566 * This just resets the number of slots for the ports VCPI for later programming. 2567 */ 2568 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) 2569 { 2570 port = drm_dp_get_validated_port_ref(mgr, port); 2571 if (!port) 2572 return; 2573 port->vcpi.num_slots = 0; 2574 drm_dp_put_port(port); 2575 } 2576 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots); 2577 2578 /** 2579 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI 2580 * @mgr: manager for this port 2581 * @port: unverified port to deallocate vcpi for 2582 */ 2583 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) 2584 { 2585 port = drm_dp_get_validated_port_ref(mgr, port); 2586 if (!port) 2587 return; 2588 2589 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi); 2590 port->vcpi.num_slots = 0; 2591 port->vcpi.pbn = 0; 2592 port->vcpi.aligned_pbn = 0; 2593 port->vcpi.vcpi = 0; 2594 drm_dp_put_port(port); 2595 } 2596 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi); 2597 2598 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, 2599 int id, struct drm_dp_payload *payload) 2600 { 2601 u8 payload_alloc[3], status; 2602 int ret; 2603 int retries = 0; 2604 2605 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, 2606 DP_PAYLOAD_TABLE_UPDATED); 2607 2608 payload_alloc[0] = id; 2609 payload_alloc[1] = payload->start_slot; 2610 payload_alloc[2] = payload->num_slots; 2611 2612 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3); 2613 if (ret != 3) { 2614 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret); 2615 goto fail; 2616 } 2617 2618 retry: 2619 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); 2620 if (ret < 0) { 2621 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret); 2622 goto fail; 2623 } 2624 2625 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) { 2626 retries++; 2627 if (retries < 20) { 2628 usleep_range(10000, 20000); 2629 goto retry; 2630 } 2631 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status); 2632 ret = -EINVAL; 2633 goto fail; 2634 } 2635 ret = 0; 2636 fail: 2637 return ret; 2638 } 2639 2640 2641 /** 2642 * drm_dp_check_act_status() - Check ACT handled status. 2643 * @mgr: manager to use 2644 * 2645 * Check the payload status bits in the DPCD for ACT handled completion. 2646 */ 2647 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr) 2648 { 2649 u8 status; 2650 int ret; 2651 int count = 0; 2652 2653 do { 2654 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); 2655 2656 if (ret < 0) { 2657 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret); 2658 goto fail; 2659 } 2660 2661 if (status & DP_PAYLOAD_ACT_HANDLED) 2662 break; 2663 count++; 2664 udelay(100); 2665 2666 } while (count < 30); 2667 2668 if (!(status & DP_PAYLOAD_ACT_HANDLED)) { 2669 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count); 2670 ret = -EINVAL; 2671 goto fail; 2672 } 2673 return 0; 2674 fail: 2675 return ret; 2676 } 2677 EXPORT_SYMBOL(drm_dp_check_act_status); 2678 2679 /** 2680 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode. 2681 * @clock: dot clock for the mode 2682 * @bpp: bpp for the mode. 2683 * 2684 * This uses the formula in the spec to calculate the PBN value for a mode. 2685 */ 2686 int drm_dp_calc_pbn_mode(int clock, int bpp) 2687 { 2688 u64 kbps; 2689 s64 peak_kbps; 2690 u32 numerator; 2691 u32 denominator; 2692 2693 kbps = clock * bpp; 2694 2695 /* 2696 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006 2697 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on 2698 * common multiplier to render an integer PBN for all link rate/lane 2699 * counts combinations 2700 * calculate 2701 * peak_kbps *= (1006/1000) 2702 * peak_kbps *= (64/54) 2703 * peak_kbps *= 8 convert to bytes 2704 */ 2705 2706 numerator = 64 * 1006; 2707 denominator = 54 * 8 * 1000 * 1000; 2708 2709 kbps *= numerator; 2710 peak_kbps = drm_fixp_from_fraction(kbps, denominator); 2711 2712 return drm_fixp2int_ceil(peak_kbps); 2713 } 2714 EXPORT_SYMBOL(drm_dp_calc_pbn_mode); 2715 2716 static int test_calc_pbn_mode(void) 2717 { 2718 int ret; 2719 ret = drm_dp_calc_pbn_mode(154000, 30); 2720 if (ret != 689) { 2721 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n", 2722 154000, 30, 689, ret); 2723 return -EINVAL; 2724 } 2725 ret = drm_dp_calc_pbn_mode(234000, 30); 2726 if (ret != 1047) { 2727 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n", 2728 234000, 30, 1047, ret); 2729 return -EINVAL; 2730 } 2731 ret = drm_dp_calc_pbn_mode(297000, 24); 2732 if (ret != 1063) { 2733 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n", 2734 297000, 24, 1063, ret); 2735 return -EINVAL; 2736 } 2737 return 0; 2738 } 2739 2740 /* we want to kick the TX after we've ack the up/down IRQs. */ 2741 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr) 2742 { 2743 queue_work(system_long_wq, &mgr->tx_work); 2744 } 2745 2746 static void drm_dp_mst_dump_mstb(struct seq_file *m, 2747 struct drm_dp_mst_branch *mstb) 2748 { 2749 struct drm_dp_mst_port *port; 2750 int tabs = mstb->lct; 2751 char prefix[10]; 2752 int i; 2753 2754 for (i = 0; i < tabs; i++) 2755 prefix[i] = '\t'; 2756 prefix[i] = '\0'; 2757 2758 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports); 2759 list_for_each_entry(port, &mstb->ports, next) { 2760 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port, port->connector); 2761 if (port->mstb) 2762 drm_dp_mst_dump_mstb(m, port->mstb); 2763 } 2764 } 2765 2766 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, 2767 char *buf) 2768 { 2769 int ret; 2770 int i; 2771 for (i = 0; i < 4; i++) { 2772 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16); 2773 if (ret != 16) 2774 break; 2775 } 2776 if (i == 4) 2777 return true; 2778 return false; 2779 } 2780 2781 /** 2782 * drm_dp_mst_dump_topology(): dump topology to seq file. 2783 * @m: seq_file to dump output to 2784 * @mgr: manager to dump current topology for. 2785 * 2786 * helper to dump MST topology to a seq file for debugfs. 2787 */ 2788 void drm_dp_mst_dump_topology(struct seq_file *m, 2789 struct drm_dp_mst_topology_mgr *mgr) 2790 { 2791 int i; 2792 struct drm_dp_mst_port *port; 2793 mutex_lock(&mgr->lock); 2794 if (mgr->mst_primary) 2795 drm_dp_mst_dump_mstb(m, mgr->mst_primary); 2796 2797 /* dump VCPIs */ 2798 mutex_unlock(&mgr->lock); 2799 2800 mutex_lock(&mgr->payload_lock); 2801 seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask); 2802 2803 for (i = 0; i < mgr->max_payloads; i++) { 2804 if (mgr->proposed_vcpis[i]) { 2805 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi); 2806 seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots); 2807 } else 2808 seq_printf(m, "vcpi %d:unsed\n", i); 2809 } 2810 for (i = 0; i < mgr->max_payloads; i++) { 2811 seq_printf(m, "payload %d: %d, %d, %d\n", 2812 i, 2813 mgr->payloads[i].payload_state, 2814 mgr->payloads[i].start_slot, 2815 mgr->payloads[i].num_slots); 2816 2817 2818 } 2819 mutex_unlock(&mgr->payload_lock); 2820 2821 mutex_lock(&mgr->lock); 2822 if (mgr->mst_primary) { 2823 u8 buf[64]; 2824 bool bret; 2825 int ret; 2826 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE); 2827 seq_printf(m, "dpcd: "); 2828 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++) 2829 seq_printf(m, "%02x ", buf[i]); 2830 seq_printf(m, "\n"); 2831 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2); 2832 seq_printf(m, "faux/mst: "); 2833 for (i = 0; i < 2; i++) 2834 seq_printf(m, "%02x ", buf[i]); 2835 seq_printf(m, "\n"); 2836 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1); 2837 seq_printf(m, "mst ctrl: "); 2838 for (i = 0; i < 1; i++) 2839 seq_printf(m, "%02x ", buf[i]); 2840 seq_printf(m, "\n"); 2841 2842 /* dump the standard OUI branch header */ 2843 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE); 2844 seq_printf(m, "branch oui: "); 2845 for (i = 0; i < 0x3; i++) 2846 seq_printf(m, "%02x", buf[i]); 2847 seq_printf(m, " devid: "); 2848 for (i = 0x3; i < 0x8; i++) 2849 seq_printf(m, "%c", buf[i]); 2850 seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]); 2851 seq_printf(m, "\n"); 2852 bret = dump_dp_payload_table(mgr, buf); 2853 if (bret == true) { 2854 seq_printf(m, "payload table: "); 2855 for (i = 0; i < 63; i++) 2856 seq_printf(m, "%02x ", buf[i]); 2857 seq_printf(m, "\n"); 2858 } 2859 2860 } 2861 2862 mutex_unlock(&mgr->lock); 2863 2864 } 2865 EXPORT_SYMBOL(drm_dp_mst_dump_topology); 2866 2867 static void drm_dp_tx_work(struct work_struct *work) 2868 { 2869 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work); 2870 2871 mutex_lock(&mgr->qlock); 2872 if (mgr->tx_down_in_progress) 2873 process_single_down_tx_qlock(mgr); 2874 mutex_unlock(&mgr->qlock); 2875 } 2876 2877 static void drm_dp_free_mst_port(struct kref *kref) 2878 { 2879 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref); 2880 kref_put(&port->parent->kref, drm_dp_free_mst_branch_device); 2881 kfree(port); 2882 } 2883 2884 static void drm_dp_destroy_connector_work(struct work_struct *work) 2885 { 2886 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work); 2887 struct drm_dp_mst_port *port; 2888 bool send_hotplug = false; 2889 /* 2890 * Not a regular list traverse as we have to drop the destroy 2891 * connector lock before destroying the connector, to avoid AB->BA 2892 * ordering between this lock and the config mutex. 2893 */ 2894 for (;;) { 2895 mutex_lock(&mgr->destroy_connector_lock); 2896 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next); 2897 if (!port) { 2898 mutex_unlock(&mgr->destroy_connector_lock); 2899 break; 2900 } 2901 list_del(&port->next); 2902 mutex_unlock(&mgr->destroy_connector_lock); 2903 2904 kref_init(&port->kref); 2905 INIT_LIST_HEAD(&port->next); 2906 2907 mgr->cbs->destroy_connector(mgr, port->connector); 2908 2909 drm_dp_port_teardown_pdt(port, port->pdt); 2910 port->pdt = DP_PEER_DEVICE_NONE; 2911 2912 if (!port->input && port->vcpi.vcpi > 0) { 2913 drm_dp_mst_reset_vcpi_slots(mgr, port); 2914 drm_dp_update_payload_part1(mgr); 2915 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi); 2916 } 2917 2918 kref_put(&port->kref, drm_dp_free_mst_port); 2919 send_hotplug = true; 2920 } 2921 if (send_hotplug) 2922 (*mgr->cbs->hotplug)(mgr); 2923 } 2924 2925 /** 2926 * drm_dp_mst_topology_mgr_init - initialise a topology manager 2927 * @mgr: manager struct to initialise 2928 * @dev: device providing this structure - for i2c addition. 2929 * @aux: DP helper aux channel to talk to this device 2930 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit 2931 * @max_payloads: maximum number of payloads this GPU can source 2932 * @conn_base_id: the connector object ID the MST device is connected to. 2933 * 2934 * Return 0 for success, or negative error code on failure 2935 */ 2936 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr, 2937 struct device *dev, struct drm_dp_aux *aux, 2938 int max_dpcd_transaction_bytes, 2939 int max_payloads, int conn_base_id) 2940 { 2941 mutex_init(&mgr->lock); 2942 mutex_init(&mgr->qlock); 2943 mutex_init(&mgr->payload_lock); 2944 mutex_init(&mgr->destroy_connector_lock); 2945 INIT_LIST_HEAD(&mgr->tx_msg_downq); 2946 INIT_LIST_HEAD(&mgr->destroy_connector_list); 2947 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work); 2948 INIT_WORK(&mgr->tx_work, drm_dp_tx_work); 2949 INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work); 2950 init_waitqueue_head(&mgr->tx_waitq); 2951 mgr->dev = dev; 2952 mgr->aux = aux; 2953 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes; 2954 mgr->max_payloads = max_payloads; 2955 mgr->conn_base_id = conn_base_id; 2956 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL); 2957 if (!mgr->payloads) 2958 return -ENOMEM; 2959 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL); 2960 if (!mgr->proposed_vcpis) 2961 return -ENOMEM; 2962 set_bit(0, &mgr->payload_mask); 2963 test_calc_pbn_mode(); 2964 return 0; 2965 } 2966 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init); 2967 2968 /** 2969 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager. 2970 * @mgr: manager to destroy 2971 */ 2972 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr) 2973 { 2974 flush_work(&mgr->work); 2975 flush_work(&mgr->destroy_connector_work); 2976 mutex_lock(&mgr->payload_lock); 2977 kfree(mgr->payloads); 2978 mgr->payloads = NULL; 2979 kfree(mgr->proposed_vcpis); 2980 mgr->proposed_vcpis = NULL; 2981 mutex_unlock(&mgr->payload_lock); 2982 mgr->dev = NULL; 2983 mgr->aux = NULL; 2984 } 2985 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy); 2986 2987 /* I2C device */ 2988 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, 2989 int num) 2990 { 2991 struct drm_dp_aux *aux = adapter->algo_data; 2992 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux); 2993 struct drm_dp_mst_branch *mstb; 2994 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 2995 unsigned int i; 2996 bool reading = false; 2997 struct drm_dp_sideband_msg_req_body msg; 2998 struct drm_dp_sideband_msg_tx *txmsg = NULL; 2999 int ret; 3000 3001 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent); 3002 if (!mstb) 3003 return -EREMOTEIO; 3004 3005 /* construct i2c msg */ 3006 /* see if last msg is a read */ 3007 if (msgs[num - 1].flags & I2C_M_RD) 3008 reading = true; 3009 3010 if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) { 3011 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n"); 3012 ret = -EIO; 3013 goto out; 3014 } 3015 3016 memset(&msg, 0, sizeof(msg)); 3017 msg.req_type = DP_REMOTE_I2C_READ; 3018 msg.u.i2c_read.num_transactions = num - 1; 3019 msg.u.i2c_read.port_number = port->port_num; 3020 for (i = 0; i < num - 1; i++) { 3021 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr; 3022 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len; 3023 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf; 3024 } 3025 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr; 3026 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len; 3027 3028 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3029 if (!txmsg) { 3030 ret = -ENOMEM; 3031 goto out; 3032 } 3033 3034 txmsg->dst = mstb; 3035 drm_dp_encode_sideband_req(&msg, txmsg); 3036 3037 drm_dp_queue_down_tx(mgr, txmsg); 3038 3039 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3040 if (ret > 0) { 3041 3042 if (txmsg->reply.reply_type == 1) { /* got a NAK back */ 3043 ret = -EREMOTEIO; 3044 goto out; 3045 } 3046 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) { 3047 ret = -EIO; 3048 goto out; 3049 } 3050 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len); 3051 ret = num; 3052 } 3053 out: 3054 kfree(txmsg); 3055 drm_dp_put_mst_branch_device(mstb); 3056 return ret; 3057 } 3058 3059 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter) 3060 { 3061 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | 3062 I2C_FUNC_SMBUS_READ_BLOCK_DATA | 3063 I2C_FUNC_SMBUS_BLOCK_PROC_CALL | 3064 I2C_FUNC_10BIT_ADDR; 3065 } 3066 3067 static const struct i2c_algorithm drm_dp_mst_i2c_algo = { 3068 .functionality = drm_dp_mst_i2c_functionality, 3069 .master_xfer = drm_dp_mst_i2c_xfer, 3070 }; 3071 3072 /** 3073 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX 3074 * @aux: DisplayPort AUX channel 3075 * 3076 * Returns 0 on success or a negative error code on failure. 3077 */ 3078 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux) 3079 { 3080 aux->ddc.algo = &drm_dp_mst_i2c_algo; 3081 aux->ddc.algo_data = aux; 3082 aux->ddc.retries = 3; 3083 3084 aux->ddc.class = I2C_CLASS_DDC; 3085 aux->ddc.owner = THIS_MODULE; 3086 aux->ddc.dev.parent = aux->dev; 3087 aux->ddc.dev.of_node = aux->dev->of_node; 3088 3089 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev), 3090 sizeof(aux->ddc.name)); 3091 3092 return i2c_add_adapter(&aux->ddc); 3093 } 3094 3095 /** 3096 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter 3097 * @aux: DisplayPort AUX channel 3098 */ 3099 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux) 3100 { 3101 i2c_del_adapter(&aux->ddc); 3102 } 3103
Indexes created Wed Oct 01 18:09:54 GMT 2025