2 * Copyright © 2014 Red Hat
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission. The copyright holders make no representations
11 * about the suitability of this software for any purpose. It is provided "as
12 * is" without express or implied warranty.
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
23 #include <linux/kernel.h>
24 #include <linux/delay.h>
25 #include <linux/init.h>
26 #include <linux/errno.h>
27 #include <linux/sched.h>
28 #include <linux/seq_file.h>
29 #include <linux/i2c.h>
30 #include <drm/drm_dp_mst_helper.h>
33 #include <drm/drm_fixed.h>
38 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
39 * protocol. The helpers contain a topology manager and bandwidth manager.
40 * The helpers encapsulate the sending and received of sideband msgs.
42 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
44 static int test_calc_pbn_mode(void);
46 static void drm_dp_put_port(struct drm_dp_mst_port *port);
48 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
50 struct drm_dp_payload *payload);
52 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
53 struct drm_dp_mst_port *port,
54 int offset, int size, u8 *bytes);
56 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
57 struct drm_dp_mst_branch *mstb);
58 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
59 struct drm_dp_mst_branch *mstb,
60 struct drm_dp_mst_port *port);
61 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
64 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
65 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
66 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
67 /* sideband msg handling */
68 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
73 int number_of_bits = num_nibbles * 4;
76 while (number_of_bits != 0) {
79 remainder |= (data[array_index] & bitmask) >> bitshift;
87 if ((remainder & 0x10) == 0x10)
92 while (number_of_bits != 0) {
95 if ((remainder & 0x10) != 0)
102 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
107 int number_of_bits = number_of_bytes * 8;
110 while (number_of_bits != 0) {
113 remainder |= (data[array_index] & bitmask) >> bitshift;
121 if ((remainder & 0x100) == 0x100)
126 while (number_of_bits != 0) {
129 if ((remainder & 0x100) != 0)
133 return remainder & 0xff;
135 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
138 size += (hdr->lct / 2);
142 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
148 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
149 for (i = 0; i < (hdr->lct / 2); i++)
150 buf[idx++] = hdr->rad[i];
151 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
152 (hdr->msg_len & 0x3f);
153 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
155 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
156 buf[idx - 1] |= (crc4 & 0xf);
161 static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
162 u8 *buf, int buflen, u8 *hdrlen)
171 len += ((buf[0] & 0xf0) >> 4) / 2;
174 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
176 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
177 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
181 hdr->lct = (buf[0] & 0xf0) >> 4;
182 hdr->lcr = (buf[0] & 0xf);
184 for (i = 0; i < (hdr->lct / 2); i++)
185 hdr->rad[i] = buf[idx++];
186 hdr->broadcast = (buf[idx] >> 7) & 0x1;
187 hdr->path_msg = (buf[idx] >> 6) & 0x1;
188 hdr->msg_len = buf[idx] & 0x3f;
190 hdr->somt = (buf[idx] >> 7) & 0x1;
191 hdr->eomt = (buf[idx] >> 6) & 0x1;
192 hdr->seqno = (buf[idx] >> 4) & 0x1;
198 static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req,
199 struct drm_dp_sideband_msg_tx *raw)
204 buf[idx++] = req->req_type & 0x7f;
206 switch (req->req_type) {
207 case DP_ENUM_PATH_RESOURCES:
208 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
211 case DP_ALLOCATE_PAYLOAD:
212 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
213 (req->u.allocate_payload.number_sdp_streams & 0xf);
215 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
217 buf[idx] = (req->u.allocate_payload.pbn >> 8);
219 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
221 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
222 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
223 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
226 if (req->u.allocate_payload.number_sdp_streams & 1) {
227 i = req->u.allocate_payload.number_sdp_streams - 1;
228 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
232 case DP_QUERY_PAYLOAD:
233 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
235 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
238 case DP_REMOTE_DPCD_READ:
239 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
240 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
242 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
244 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
246 buf[idx] = (req->u.dpcd_read.num_bytes);
250 case DP_REMOTE_DPCD_WRITE:
251 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
252 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
254 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
256 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
258 buf[idx] = (req->u.dpcd_write.num_bytes);
260 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
261 idx += req->u.dpcd_write.num_bytes;
263 case DP_REMOTE_I2C_READ:
264 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
265 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
267 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
268 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
270 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
272 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
273 idx += req->u.i2c_read.transactions[i].num_bytes;
275 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
276 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
279 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
281 buf[idx] = (req->u.i2c_read.num_bytes_read);
285 case DP_REMOTE_I2C_WRITE:
286 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
288 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
290 buf[idx] = (req->u.i2c_write.num_bytes);
292 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
293 idx += req->u.i2c_write.num_bytes;
299 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
302 crc4 = drm_dp_msg_data_crc4(msg, len);
306 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
307 struct drm_dp_sideband_msg_tx *raw)
312 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
317 /* this adds a chunk of msg to the builder to get the final msg */
318 static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
319 u8 *replybuf, u8 replybuflen, bool hdr)
326 struct drm_dp_sideband_msg_hdr recv_hdr;
327 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
329 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
333 /* get length contained in this portion */
334 msg->curchunk_len = recv_hdr.msg_len;
335 msg->curchunk_hdrlen = hdrlen;
337 /* we have already gotten an somt - don't bother parsing */
338 if (recv_hdr.somt && msg->have_somt)
342 memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
343 msg->have_somt = true;
346 msg->have_eomt = true;
348 /* copy the bytes for the remainder of this header chunk */
349 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
350 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
352 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
353 msg->curchunk_idx += replybuflen;
356 if (msg->curchunk_idx >= msg->curchunk_len) {
358 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
359 /* copy chunk into bigger msg */
360 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
361 msg->curlen += msg->curchunk_len - 1;
366 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
367 struct drm_dp_sideband_msg_reply_body *repmsg)
371 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
373 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
375 if (idx > raw->curlen)
377 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
378 if (raw->msg[idx] & 0x80)
379 repmsg->u.link_addr.ports[i].input_port = 1;
381 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
382 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
385 if (idx > raw->curlen)
387 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
388 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
389 if (repmsg->u.link_addr.ports[i].input_port == 0)
390 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
392 if (idx > raw->curlen)
394 if (repmsg->u.link_addr.ports[i].input_port == 0) {
395 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
397 if (idx > raw->curlen)
399 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
401 if (idx > raw->curlen)
403 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
404 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
408 if (idx > raw->curlen)
414 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
418 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
419 struct drm_dp_sideband_msg_reply_body *repmsg)
422 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
424 if (idx > raw->curlen)
426 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
427 if (idx > raw->curlen)
430 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
433 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
437 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
438 struct drm_dp_sideband_msg_reply_body *repmsg)
441 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
443 if (idx > raw->curlen)
447 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
451 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
452 struct drm_dp_sideband_msg_reply_body *repmsg)
456 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
458 if (idx > raw->curlen)
460 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
463 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
466 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
470 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
471 struct drm_dp_sideband_msg_reply_body *repmsg)
474 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
476 if (idx > raw->curlen)
478 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
480 if (idx > raw->curlen)
482 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
484 if (idx > raw->curlen)
488 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
492 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
493 struct drm_dp_sideband_msg_reply_body *repmsg)
496 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
498 if (idx > raw->curlen)
500 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
502 if (idx > raw->curlen)
504 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
506 if (idx > raw->curlen)
510 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
514 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
515 struct drm_dp_sideband_msg_reply_body *repmsg)
518 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
520 if (idx > raw->curlen)
522 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
524 if (idx > raw->curlen)
528 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
532 static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
533 struct drm_dp_sideband_msg_reply_body *msg)
535 memset(msg, 0, sizeof(*msg));
536 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
537 msg->req_type = (raw->msg[0] & 0x7f);
539 if (msg->reply_type) {
540 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
541 msg->u.nak.reason = raw->msg[17];
542 msg->u.nak.nak_data = raw->msg[18];
546 switch (msg->req_type) {
547 case DP_LINK_ADDRESS:
548 return drm_dp_sideband_parse_link_address(raw, msg);
549 case DP_QUERY_PAYLOAD:
550 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
551 case DP_REMOTE_DPCD_READ:
552 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
553 case DP_REMOTE_DPCD_WRITE:
554 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
555 case DP_REMOTE_I2C_READ:
556 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
557 case DP_ENUM_PATH_RESOURCES:
558 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
559 case DP_ALLOCATE_PAYLOAD:
560 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
562 DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
567 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
568 struct drm_dp_sideband_msg_req_body *msg)
572 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
574 if (idx > raw->curlen)
577 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
579 if (idx > raw->curlen)
582 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
583 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
584 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
585 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
586 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
590 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
594 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
595 struct drm_dp_sideband_msg_req_body *msg)
599 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
601 if (idx > raw->curlen)
604 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
606 if (idx > raw->curlen)
609 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
613 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
617 static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
618 struct drm_dp_sideband_msg_req_body *msg)
620 memset(msg, 0, sizeof(*msg));
621 msg->req_type = (raw->msg[0] & 0x7f);
623 switch (msg->req_type) {
624 case DP_CONNECTION_STATUS_NOTIFY:
625 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
626 case DP_RESOURCE_STATUS_NOTIFY:
627 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
629 DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
634 static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
636 struct drm_dp_sideband_msg_req_body req;
638 req.req_type = DP_REMOTE_DPCD_WRITE;
639 req.u.dpcd_write.port_number = port_num;
640 req.u.dpcd_write.dpcd_address = offset;
641 req.u.dpcd_write.num_bytes = num_bytes;
642 req.u.dpcd_write.bytes = bytes;
643 drm_dp_encode_sideband_req(&req, msg);
648 static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
650 struct drm_dp_sideband_msg_req_body req;
652 req.req_type = DP_LINK_ADDRESS;
653 drm_dp_encode_sideband_req(&req, msg);
657 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
659 struct drm_dp_sideband_msg_req_body req;
661 req.req_type = DP_ENUM_PATH_RESOURCES;
662 req.u.port_num.port_number = port_num;
663 drm_dp_encode_sideband_req(&req, msg);
664 msg->path_msg = true;
668 static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
669 u8 vcpi, uint16_t pbn)
671 struct drm_dp_sideband_msg_req_body req;
672 memset(&req, 0, sizeof(req));
673 req.req_type = DP_ALLOCATE_PAYLOAD;
674 req.u.allocate_payload.port_number = port_num;
675 req.u.allocate_payload.vcpi = vcpi;
676 req.u.allocate_payload.pbn = pbn;
677 drm_dp_encode_sideband_req(&req, msg);
678 msg->path_msg = true;
682 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
683 struct drm_dp_vcpi *vcpi)
687 mutex_lock(&mgr->payload_lock);
688 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
689 if (ret > mgr->max_payloads) {
691 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
695 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
696 if (vcpi_ret > mgr->max_payloads) {
698 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
702 set_bit(ret, &mgr->payload_mask);
703 set_bit(vcpi_ret, &mgr->vcpi_mask);
704 vcpi->vcpi = vcpi_ret + 1;
705 mgr->proposed_vcpis[ret - 1] = vcpi;
707 mutex_unlock(&mgr->payload_lock);
711 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
718 mutex_lock(&mgr->payload_lock);
719 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
720 clear_bit(vcpi - 1, &mgr->vcpi_mask);
722 for (i = 0; i < mgr->max_payloads; i++) {
723 if (mgr->proposed_vcpis[i])
724 if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
725 mgr->proposed_vcpis[i] = NULL;
726 clear_bit(i + 1, &mgr->payload_mask);
729 mutex_unlock(&mgr->payload_lock);
732 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
733 struct drm_dp_sideband_msg_tx *txmsg)
738 * All updates to txmsg->state are protected by mgr->qlock, and the two
739 * cases we check here are terminal states. For those the barriers
740 * provided by the wake_up/wait_event pair are enough.
742 ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
743 txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
747 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
748 struct drm_dp_sideband_msg_tx *txmsg)
750 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
753 ret = wait_event_timeout(mgr->tx_waitq,
754 check_txmsg_state(mgr, txmsg),
756 mutex_lock(&mstb->mgr->qlock);
758 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
763 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
765 /* dump some state */
769 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
770 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
771 list_del(&txmsg->next);
774 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
775 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
776 mstb->tx_slots[txmsg->seqno] = NULL;
780 mutex_unlock(&mgr->qlock);
785 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
787 struct drm_dp_mst_branch *mstb;
789 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
795 memcpy(mstb->rad, rad, lct / 2);
796 INIT_LIST_HEAD(&mstb->ports);
797 kref_init(&mstb->kref);
801 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
803 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
804 struct drm_dp_mst_port *port, *tmp;
805 bool wake_tx = false;
808 * destroy all ports - don't need lock
809 * as there are no more references to the mst branch
810 * device at this point.
812 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
813 list_del(&port->next);
814 drm_dp_put_port(port);
817 /* drop any tx slots msg */
818 mutex_lock(&mstb->mgr->qlock);
819 if (mstb->tx_slots[0]) {
820 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
821 mstb->tx_slots[0] = NULL;
824 if (mstb->tx_slots[1]) {
825 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
826 mstb->tx_slots[1] = NULL;
829 mutex_unlock(&mstb->mgr->qlock);
832 wake_up(&mstb->mgr->tx_waitq);
836 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
838 kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
842 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
844 struct drm_dp_mst_branch *mstb;
847 case DP_PEER_DEVICE_DP_LEGACY_CONV:
848 case DP_PEER_DEVICE_SST_SINK:
849 /* remove i2c over sideband */
850 drm_dp_mst_unregister_i2c_bus(&port->aux);
852 case DP_PEER_DEVICE_MST_BRANCHING:
855 drm_dp_put_mst_branch_device(mstb);
860 static void drm_dp_destroy_port(struct kref *kref)
862 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
863 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
866 port->vcpi.num_slots = 0;
868 kfree(port->cached_edid);
871 * The only time we don't have a connector
872 * on an output port is if the connector init
875 if (port->connector) {
876 /* we can't destroy the connector here, as
877 * we might be holding the mode_config.mutex
878 * from an EDID retrieval */
880 mutex_lock(&mgr->destroy_connector_lock);
881 list_add(&port->next, &mgr->destroy_connector_list);
882 mutex_unlock(&mgr->destroy_connector_lock);
883 schedule_work(&mgr->destroy_connector_work);
886 /* no need to clean up vcpi
887 * as if we have no connector we never setup a vcpi */
888 drm_dp_port_teardown_pdt(port, port->pdt);
893 static void drm_dp_put_port(struct drm_dp_mst_port *port)
895 kref_put(&port->kref, drm_dp_destroy_port);
898 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)
900 struct drm_dp_mst_port *port;
901 struct drm_dp_mst_branch *rmstb;
902 if (to_find == mstb) {
903 kref_get(&mstb->kref);
906 list_for_each_entry(port, &mstb->ports, next) {
908 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
916 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)
918 struct drm_dp_mst_branch *rmstb = NULL;
919 mutex_lock(&mgr->lock);
920 if (mgr->mst_primary)
921 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
922 mutex_unlock(&mgr->lock);
926 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)
928 struct drm_dp_mst_port *port, *mport;
930 list_for_each_entry(port, &mstb->ports, next) {
931 if (port == to_find) {
932 kref_get(&port->kref);
936 mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
944 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)
946 struct drm_dp_mst_port *rport = NULL;
947 mutex_lock(&mgr->lock);
948 if (mgr->mst_primary)
949 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
950 mutex_unlock(&mgr->lock);
954 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
956 struct drm_dp_mst_port *port;
958 list_for_each_entry(port, &mstb->ports, next) {
959 if (port->port_num == port_num) {
960 kref_get(&port->kref);
969 * calculate a new RAD for this MST branch device
970 * if parent has an LCT of 2 then it has 1 nibble of RAD,
971 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
973 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
976 int lct = port->parent->lct;
980 memcpy(rad, port->parent->rad, idx);
981 shift = (lct % 2) ? 4 : 0;
985 rad[idx] |= port->port_num << shift;
990 * return sends link address for new mstb
992 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
996 bool send_link = false;
998 case DP_PEER_DEVICE_DP_LEGACY_CONV:
999 case DP_PEER_DEVICE_SST_SINK:
1000 /* add i2c over sideband */
1001 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1003 case DP_PEER_DEVICE_MST_BRANCHING:
1004 lct = drm_dp_calculate_rad(port, rad);
1006 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
1007 port->mstb->mgr = port->mgr;
1008 port->mstb->port_parent = port;
1016 static void drm_dp_check_port_guid(struct drm_dp_mst_branch *mstb,
1017 struct drm_dp_mst_port *port)
1020 if (port->dpcd_rev >= 0x12) {
1021 port->guid_valid = drm_dp_validate_guid(mstb->mgr, port->guid);
1022 if (!port->guid_valid) {
1023 ret = drm_dp_send_dpcd_write(mstb->mgr,
1027 port->guid_valid = true;
1032 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1035 size_t proppath_size)
1039 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1040 for (i = 0; i < (mstb->lct - 1); i++) {
1041 int shift = (i % 2) ? 0 : 4;
1042 int port_num = mstb->rad[i / 2] >> shift;
1043 snprintf(temp, sizeof(temp), "-%d", port_num);
1044 strlcat(proppath, temp, proppath_size);
1046 snprintf(temp, sizeof(temp), "-%d", pnum);
1047 strlcat(proppath, temp, proppath_size);
1050 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1052 struct drm_dp_link_addr_reply_port *port_msg)
1054 struct drm_dp_mst_port *port;
1056 bool created = false;
1059 port = drm_dp_get_port(mstb, port_msg->port_number);
1061 port = kzalloc(sizeof(*port), GFP_KERNEL);
1064 kref_init(&port->kref);
1065 port->parent = mstb;
1066 port->port_num = port_msg->port_number;
1067 port->mgr = mstb->mgr;
1068 port->aux.name = "DPMST";
1069 port->aux.dev = dev;
1072 old_pdt = port->pdt;
1073 old_ddps = port->ddps;
1076 port->pdt = port_msg->peer_device_type;
1077 port->input = port_msg->input_port;
1078 port->mcs = port_msg->mcs;
1079 port->ddps = port_msg->ddps;
1080 port->ldps = port_msg->legacy_device_plug_status;
1081 port->dpcd_rev = port_msg->dpcd_revision;
1082 port->num_sdp_streams = port_msg->num_sdp_streams;
1083 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1084 memcpy(port->guid, port_msg->peer_guid, 16);
1086 /* manage mstb port lists with mgr lock - take a reference
1089 mutex_lock(&mstb->mgr->lock);
1090 kref_get(&port->kref);
1091 list_add(&port->next, &mstb->ports);
1092 mutex_unlock(&mstb->mgr->lock);
1095 if (old_ddps != port->ddps) {
1097 drm_dp_check_port_guid(mstb, port);
1099 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1101 port->guid_valid = false;
1102 port->available_pbn = 0;
1106 if (old_pdt != port->pdt && !port->input) {
1107 drm_dp_port_teardown_pdt(port, old_pdt);
1109 ret = drm_dp_port_setup_pdt(port);
1111 drm_dp_send_link_address(mstb->mgr, port->mstb);
1114 if (created && !port->input) {
1117 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
1118 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1119 if (!port->connector) {
1120 /* remove it from the port list */
1121 mutex_lock(&mstb->mgr->lock);
1122 list_del(&port->next);
1123 mutex_unlock(&mstb->mgr->lock);
1124 /* drop port list reference */
1125 drm_dp_put_port(port);
1128 if (port->port_num >= DP_MST_LOGICAL_PORT_0) {
1129 port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1130 drm_mode_connector_set_tile_property(port->connector);
1132 (*mstb->mgr->cbs->register_connector)(port->connector);
1136 /* put reference to this port */
1137 drm_dp_put_port(port);
1140 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1141 struct drm_dp_connection_status_notify *conn_stat)
1143 struct drm_dp_mst_port *port;
1146 bool dowork = false;
1147 port = drm_dp_get_port(mstb, conn_stat->port_number);
1151 old_ddps = port->ddps;
1152 old_pdt = port->pdt;
1153 port->pdt = conn_stat->peer_device_type;
1154 port->mcs = conn_stat->message_capability_status;
1155 port->ldps = conn_stat->legacy_device_plug_status;
1156 port->ddps = conn_stat->displayport_device_plug_status;
1158 if (old_ddps != port->ddps) {
1160 drm_dp_check_port_guid(mstb, port);
1163 port->guid_valid = false;
1164 port->available_pbn = 0;
1167 if (old_pdt != port->pdt && !port->input) {
1168 drm_dp_port_teardown_pdt(port, old_pdt);
1170 if (drm_dp_port_setup_pdt(port))
1174 drm_dp_put_port(port);
1176 queue_work(system_long_wq, &mstb->mgr->work);
1180 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1183 struct drm_dp_mst_branch *mstb;
1184 struct drm_dp_mst_port *port;
1186 /* find the port by iterating down */
1188 mutex_lock(&mgr->lock);
1189 mstb = mgr->mst_primary;
1191 for (i = 0; i < lct - 1; i++) {
1192 int shift = (i % 2) ? 0 : 4;
1193 int port_num = rad[i / 2] >> shift;
1195 list_for_each_entry(port, &mstb->ports, next) {
1196 if (port->port_num == port_num) {
1199 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1207 kref_get(&mstb->kref);
1209 mutex_unlock(&mgr->lock);
1213 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1214 struct drm_dp_mst_branch *mstb,
1217 struct drm_dp_mst_branch *found_mstb;
1218 struct drm_dp_mst_port *port;
1220 list_for_each_entry(port, &mstb->ports, next) {
1224 if (port->guid_valid && memcmp(port->guid, guid, 16) == 0)
1227 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1236 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
1237 struct drm_dp_mst_topology_mgr *mgr,
1240 struct drm_dp_mst_branch *mstb;
1242 /* find the port by iterating down */
1243 mutex_lock(&mgr->lock);
1245 if (mgr->guid_valid && memcmp(mgr->guid, guid, 16) == 0)
1246 mstb = mgr->mst_primary;
1248 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
1251 kref_get(&mstb->kref);
1253 mutex_unlock(&mgr->lock);
1257 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1258 struct drm_dp_mst_branch *mstb)
1260 struct drm_dp_mst_port *port;
1261 struct drm_dp_mst_branch *mstb_child;
1262 if (!mstb->link_address_sent)
1263 drm_dp_send_link_address(mgr, mstb);
1265 list_for_each_entry(port, &mstb->ports, next) {
1272 if (!port->available_pbn)
1273 drm_dp_send_enum_path_resources(mgr, mstb, port);
1276 mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1278 drm_dp_check_and_send_link_address(mgr, mstb_child);
1279 drm_dp_put_mst_branch_device(mstb_child);
1285 static void drm_dp_mst_link_probe_work(struct work_struct *work)
1287 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1288 struct drm_dp_mst_branch *mstb;
1290 mutex_lock(&mgr->lock);
1291 mstb = mgr->mst_primary;
1293 kref_get(&mstb->kref);
1295 mutex_unlock(&mgr->lock);
1297 drm_dp_check_and_send_link_address(mgr, mstb);
1298 drm_dp_put_mst_branch_device(mstb);
1302 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1305 static u8 zero_guid[16];
1307 if (!memcmp(guid, zero_guid, 16)) {
1308 u64 salt = get_jiffies_64();
1309 memcpy(&guid[0], &salt, sizeof(u64));
1310 memcpy(&guid[8], &salt, sizeof(u64));
1317 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1319 struct drm_dp_sideband_msg_req_body req;
1321 req.req_type = DP_REMOTE_DPCD_READ;
1322 req.u.dpcd_read.port_number = port_num;
1323 req.u.dpcd_read.dpcd_address = offset;
1324 req.u.dpcd_read.num_bytes = num_bytes;
1325 drm_dp_encode_sideband_req(&req, msg);
1331 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1332 bool up, u8 *msg, int len)
1335 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1336 int tosend, total, offset;
1343 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1345 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1348 if (ret != tosend) {
1349 if (ret == -EIO && retries < 5) {
1353 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1359 } while (total > 0);
1363 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1364 struct drm_dp_sideband_msg_tx *txmsg)
1366 struct drm_dp_mst_branch *mstb = txmsg->dst;
1369 /* both msg slots are full */
1370 if (txmsg->seqno == -1) {
1371 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1372 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1375 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1376 txmsg->seqno = mstb->last_seqno;
1377 mstb->last_seqno ^= 1;
1378 } else if (mstb->tx_slots[0] == NULL)
1382 mstb->tx_slots[txmsg->seqno] = txmsg;
1385 req_type = txmsg->msg[0] & 0x7f;
1386 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1387 req_type == DP_RESOURCE_STATUS_NOTIFY)
1391 hdr->path_msg = txmsg->path_msg;
1392 hdr->lct = mstb->lct;
1393 hdr->lcr = mstb->lct - 1;
1395 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1396 hdr->seqno = txmsg->seqno;
1400 * process a single block of the next message in the sideband queue
1402 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1403 struct drm_dp_sideband_msg_tx *txmsg,
1407 struct drm_dp_sideband_msg_hdr hdr;
1408 int len, space, idx, tosend;
1411 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1413 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1415 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1418 /* make hdr from dst mst - for replies use seqno
1419 otherwise assign one */
1420 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1424 /* amount left to send in this message */
1425 len = txmsg->cur_len - txmsg->cur_offset;
1427 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1428 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1430 tosend = min(len, space);
1431 if (len == txmsg->cur_len)
1437 hdr.msg_len = tosend + 1;
1438 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1439 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1440 /* add crc at end */
1441 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1444 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1446 DRM_DEBUG_KMS("sideband msg failed to send\n");
1450 txmsg->cur_offset += tosend;
1451 if (txmsg->cur_offset == txmsg->cur_len) {
1452 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1458 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1460 struct drm_dp_sideband_msg_tx *txmsg;
1463 WARN_ON(!mutex_is_locked(&mgr->qlock));
1465 /* construct a chunk from the first msg in the tx_msg queue */
1466 if (list_empty(&mgr->tx_msg_downq)) {
1467 mgr->tx_down_in_progress = false;
1470 mgr->tx_down_in_progress = true;
1472 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1473 ret = process_single_tx_qlock(mgr, txmsg, false);
1475 /* txmsg is sent it should be in the slots now */
1476 list_del(&txmsg->next);
1478 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1479 list_del(&txmsg->next);
1480 if (txmsg->seqno != -1)
1481 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1482 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1483 wake_up(&mgr->tx_waitq);
1485 if (list_empty(&mgr->tx_msg_downq)) {
1486 mgr->tx_down_in_progress = false;
1491 /* called holding qlock */
1492 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1494 struct drm_dp_sideband_msg_tx *txmsg;
1497 /* construct a chunk from the first msg in the tx_msg queue */
1498 if (list_empty(&mgr->tx_msg_upq)) {
1499 mgr->tx_up_in_progress = false;
1503 txmsg = list_first_entry(&mgr->tx_msg_upq, struct drm_dp_sideband_msg_tx, next);
1504 ret = process_single_tx_qlock(mgr, txmsg, true);
1506 /* up txmsgs aren't put in slots - so free after we send it */
1507 list_del(&txmsg->next);
1510 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1511 mgr->tx_up_in_progress = true;
1514 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1515 struct drm_dp_sideband_msg_tx *txmsg)
1517 mutex_lock(&mgr->qlock);
1518 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1519 if (!mgr->tx_down_in_progress)
1520 process_single_down_tx_qlock(mgr);
1521 mutex_unlock(&mgr->qlock);
1524 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1525 struct drm_dp_mst_branch *mstb)
1528 struct drm_dp_sideband_msg_tx *txmsg;
1531 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1536 len = build_link_address(txmsg);
1538 mstb->link_address_sent = true;
1539 drm_dp_queue_down_tx(mgr, txmsg);
1541 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1545 if (txmsg->reply.reply_type == 1)
1546 DRM_DEBUG_KMS("link address nak received\n");
1548 DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1549 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1550 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,
1551 txmsg->reply.u.link_addr.ports[i].input_port,
1552 txmsg->reply.u.link_addr.ports[i].peer_device_type,
1553 txmsg->reply.u.link_addr.ports[i].port_number,
1554 txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1555 txmsg->reply.u.link_addr.ports[i].mcs,
1556 txmsg->reply.u.link_addr.ports[i].ddps,
1557 txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1558 txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1559 txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1561 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1562 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1564 (*mgr->cbs->hotplug)(mgr);
1567 mstb->link_address_sent = false;
1568 DRM_DEBUG_KMS("link address failed %d\n", ret);
1574 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1575 struct drm_dp_mst_branch *mstb,
1576 struct drm_dp_mst_port *port)
1579 struct drm_dp_sideband_msg_tx *txmsg;
1582 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1587 len = build_enum_path_resources(txmsg, port->port_num);
1589 drm_dp_queue_down_tx(mgr, txmsg);
1591 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1593 if (txmsg->reply.reply_type == 1)
1594 DRM_DEBUG_KMS("enum path resources nak received\n");
1596 if (port->port_num != txmsg->reply.u.path_resources.port_number)
1597 DRM_ERROR("got incorrect port in response\n");
1598 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,
1599 txmsg->reply.u.path_resources.avail_payload_bw_number);
1600 port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1608 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1609 struct drm_dp_mst_port *port,
1613 struct drm_dp_sideband_msg_tx *txmsg;
1614 struct drm_dp_mst_branch *mstb;
1617 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1621 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1628 len = build_allocate_payload(txmsg, port->port_num,
1632 drm_dp_queue_down_tx(mgr, txmsg);
1634 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1636 if (txmsg->reply.reply_type == 1) {
1643 drm_dp_put_mst_branch_device(mstb);
1647 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1649 struct drm_dp_payload *payload)
1653 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1655 payload->payload_state = 0;
1658 payload->payload_state = DP_PAYLOAD_LOCAL;
1662 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1663 struct drm_dp_mst_port *port,
1665 struct drm_dp_payload *payload)
1668 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1671 payload->payload_state = DP_PAYLOAD_REMOTE;
1675 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1676 struct drm_dp_mst_port *port,
1678 struct drm_dp_payload *payload)
1680 DRM_DEBUG_KMS("\n");
1681 /* its okay for these to fail */
1683 drm_dp_payload_send_msg(mgr, port, id, 0);
1686 drm_dp_dpcd_write_payload(mgr, id, payload);
1687 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1691 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1693 struct drm_dp_payload *payload)
1695 payload->payload_state = 0;
1700 * drm_dp_update_payload_part1() - Execute payload update part 1
1701 * @mgr: manager to use.
1703 * This iterates over all proposed virtual channels, and tries to
1704 * allocate space in the link for them. For 0->slots transitions,
1705 * this step just writes the VCPI to the MST device. For slots->0
1706 * transitions, this writes the updated VCPIs and removes the
1707 * remote VC payloads.
1709 * after calling this the driver should generate ACT and payload
1712 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1716 struct drm_dp_payload req_payload;
1717 struct drm_dp_mst_port *port;
1719 mutex_lock(&mgr->payload_lock);
1720 for (i = 0; i < mgr->max_payloads; i++) {
1721 /* solve the current payloads - compare to the hw ones
1722 - update the hw view */
1723 req_payload.start_slot = cur_slots;
1724 if (mgr->proposed_vcpis[i]) {
1725 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1726 req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1729 req_payload.num_slots = 0;
1732 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1733 mgr->payloads[i].start_slot = req_payload.start_slot;
1735 /* work out what is required to happen with this payload */
1736 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1738 /* need to push an update for this payload */
1739 if (req_payload.num_slots) {
1740 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1741 mgr->payloads[i].num_slots = req_payload.num_slots;
1742 } else if (mgr->payloads[i].num_slots) {
1743 mgr->payloads[i].num_slots = 0;
1744 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
1745 req_payload.payload_state = mgr->payloads[i].payload_state;
1746 mgr->payloads[i].start_slot = 0;
1748 mgr->payloads[i].payload_state = req_payload.payload_state;
1750 cur_slots += req_payload.num_slots;
1753 for (i = 0; i < mgr->max_payloads; i++) {
1754 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1755 DRM_DEBUG_KMS("removing payload %d\n", i);
1756 for (j = i; j < mgr->max_payloads - 1; j++) {
1757 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1758 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1759 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1760 set_bit(j + 1, &mgr->payload_mask);
1762 clear_bit(j + 1, &mgr->payload_mask);
1765 memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1766 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1767 clear_bit(mgr->max_payloads, &mgr->payload_mask);
1771 mutex_unlock(&mgr->payload_lock);
1775 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1778 * drm_dp_update_payload_part2() - Execute payload update part 2
1779 * @mgr: manager to use.
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 writes the remote VC payload commands. For slots->0
1784 * this just resets some internal state.
1786 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1788 struct drm_dp_mst_port *port;
1791 mutex_lock(&mgr->payload_lock);
1792 for (i = 0; i < mgr->max_payloads; i++) {
1794 if (!mgr->proposed_vcpis[i])
1797 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1799 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1800 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1801 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1802 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1803 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1806 mutex_unlock(&mgr->payload_lock);
1810 mutex_unlock(&mgr->payload_lock);
1813 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1815 #if 0 /* unused as of yet */
1816 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1817 struct drm_dp_mst_port *port,
1818 int offset, int size)
1821 struct drm_dp_sideband_msg_tx *txmsg;
1823 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1827 len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1828 txmsg->dst = port->parent;
1830 drm_dp_queue_down_tx(mgr, txmsg);
1836 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1837 struct drm_dp_mst_port *port,
1838 int offset, int size, u8 *bytes)
1842 struct drm_dp_sideband_msg_tx *txmsg;
1843 struct drm_dp_mst_branch *mstb;
1845 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1849 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1855 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1858 drm_dp_queue_down_tx(mgr, txmsg);
1860 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1862 if (txmsg->reply.reply_type == 1) {
1869 drm_dp_put_mst_branch_device(mstb);
1873 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1875 struct drm_dp_sideband_msg_reply_body reply;
1877 reply.reply_type = 1;
1878 reply.req_type = req_type;
1879 drm_dp_encode_sideband_reply(&reply, msg);
1883 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1884 struct drm_dp_mst_branch *mstb,
1885 int req_type, int seqno, bool broadcast)
1887 struct drm_dp_sideband_msg_tx *txmsg;
1889 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1894 txmsg->seqno = seqno;
1895 drm_dp_encode_up_ack_reply(txmsg, req_type);
1897 mutex_lock(&mgr->qlock);
1898 list_add_tail(&txmsg->next, &mgr->tx_msg_upq);
1899 if (!mgr->tx_up_in_progress) {
1900 process_single_up_tx_qlock(mgr);
1902 mutex_unlock(&mgr->qlock);
1906 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1910 switch (dp_link_bw) {
1912 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1913 dp_link_bw, dp_link_count);
1916 case DP_LINK_BW_1_62:
1917 *out = 3 * dp_link_count;
1919 case DP_LINK_BW_2_7:
1920 *out = 5 * dp_link_count;
1922 case DP_LINK_BW_5_4:
1923 *out = 10 * dp_link_count;
1930 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
1931 * @mgr: manager to set state for
1932 * @mst_state: true to enable MST on this connector - false to disable.
1934 * This is called by the driver when it detects an MST capable device plugged
1935 * into a DP MST capable port, or when a DP MST capable device is unplugged.
1937 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
1940 struct drm_dp_mst_branch *mstb = NULL;
1942 mutex_lock(&mgr->lock);
1943 if (mst_state == mgr->mst_state)
1946 mgr->mst_state = mst_state;
1947 /* set the device into MST mode */
1949 WARN_ON(mgr->mst_primary);
1952 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
1953 if (ret != DP_RECEIVER_CAP_SIZE) {
1954 DRM_DEBUG_KMS("failed to read DPCD\n");
1958 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
1959 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
1965 mgr->total_pbn = 2560;
1966 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
1967 mgr->avail_slots = mgr->total_slots;
1969 /* add initial branch device at LCT 1 */
1970 mstb = drm_dp_add_mst_branch_device(1, NULL);
1977 /* give this the main reference */
1978 mgr->mst_primary = mstb;
1979 kref_get(&mgr->mst_primary->kref);
1982 struct drm_dp_payload reset_pay;
1983 reset_pay.start_slot = 0;
1984 reset_pay.num_slots = 0x3f;
1985 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
1988 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1989 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
1996 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
1998 DRM_DEBUG_KMS("failed to read DP GUID %d\n", ret);
2002 mgr->guid_valid = drm_dp_validate_guid(mgr, mgr->guid);
2003 if (!mgr->guid_valid) {
2004 ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, mgr->guid, 16);
2005 mgr->guid_valid = true;
2008 queue_work(system_long_wq, &mgr->work);
2012 /* disable MST on the device */
2013 mstb = mgr->mst_primary;
2014 mgr->mst_primary = NULL;
2015 /* this can fail if the device is gone */
2016 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2018 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2019 mgr->payload_mask = 0;
2020 set_bit(0, &mgr->payload_mask);
2025 mutex_unlock(&mgr->lock);
2027 drm_dp_put_mst_branch_device(mstb);
2031 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2034 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2035 * @mgr: manager to suspend
2037 * This function tells the MST device that we can't handle UP messages
2038 * anymore. This should stop it from sending any since we are suspended.
2040 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2042 mutex_lock(&mgr->lock);
2043 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2044 DP_MST_EN | DP_UPSTREAM_IS_SRC);
2045 mutex_unlock(&mgr->lock);
2046 flush_work(&mgr->work);
2047 flush_work(&mgr->destroy_connector_work);
2049 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2052 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2053 * @mgr: manager to resume
2055 * This will fetch DPCD and see if the device is still there,
2056 * if it is, it will rewrite the MSTM control bits, and return.
2058 * if the device fails this returns -1, and the driver should do
2059 * a full MST reprobe, in case we were undocked.
2061 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2065 mutex_lock(&mgr->lock);
2067 if (mgr->mst_primary) {
2069 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2070 if (sret != DP_RECEIVER_CAP_SIZE) {
2071 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2076 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2077 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2079 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2088 mutex_unlock(&mgr->lock);
2091 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2093 static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2097 int replylen, origlen, curreply;
2099 struct drm_dp_sideband_msg_rx *msg;
2100 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2101 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2103 len = min(mgr->max_dpcd_transaction_bytes, 16);
2104 ret = drm_dp_dpcd_read(mgr->aux, basereg,
2107 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2110 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2112 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2115 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2120 while (replylen > 0) {
2121 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2122 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2125 DRM_DEBUG_KMS("failed to read a chunk\n");
2127 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2129 DRM_DEBUG_KMS("failed to build sideband msg\n");
2135 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2139 drm_dp_get_one_sb_msg(mgr, false);
2141 if (mgr->down_rep_recv.have_eomt) {
2142 struct drm_dp_sideband_msg_tx *txmsg;
2143 struct drm_dp_mst_branch *mstb;
2145 mstb = drm_dp_get_mst_branch_device(mgr,
2146 mgr->down_rep_recv.initial_hdr.lct,
2147 mgr->down_rep_recv.initial_hdr.rad);
2150 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2151 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2155 /* find the message */
2156 slot = mgr->down_rep_recv.initial_hdr.seqno;
2157 mutex_lock(&mgr->qlock);
2158 txmsg = mstb->tx_slots[slot];
2159 /* remove from slots */
2160 mutex_unlock(&mgr->qlock);
2163 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2165 mgr->down_rep_recv.initial_hdr.seqno,
2166 mgr->down_rep_recv.initial_hdr.lct,
2167 mgr->down_rep_recv.initial_hdr.rad[0],
2168 mgr->down_rep_recv.msg[0]);
2169 drm_dp_put_mst_branch_device(mstb);
2170 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2174 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2175 if (txmsg->reply.reply_type == 1) {
2176 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);
2179 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2180 drm_dp_put_mst_branch_device(mstb);
2182 mutex_lock(&mgr->qlock);
2183 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2184 mstb->tx_slots[slot] = NULL;
2185 mutex_unlock(&mgr->qlock);
2187 wake_up(&mgr->tx_waitq);
2192 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2195 drm_dp_get_one_sb_msg(mgr, true);
2197 if (mgr->up_req_recv.have_eomt) {
2198 struct drm_dp_sideband_msg_req_body msg;
2199 struct drm_dp_mst_branch *mstb = NULL;
2202 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2203 mstb = drm_dp_get_mst_branch_device(mgr,
2204 mgr->up_req_recv.initial_hdr.lct,
2205 mgr->up_req_recv.initial_hdr.rad);
2207 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2208 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2213 seqno = mgr->up_req_recv.initial_hdr.seqno;
2214 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2216 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2217 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2220 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2223 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2224 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2228 drm_dp_update_port(mstb, &msg.u.conn_stat);
2229 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);
2230 (*mgr->cbs->hotplug)(mgr);
2232 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2233 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2235 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2238 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2239 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2243 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2246 drm_dp_put_mst_branch_device(mstb);
2247 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2253 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2254 * @mgr: manager to notify irq for.
2255 * @esi: 4 bytes from SINK_COUNT_ESI
2256 * @handled: whether the hpd interrupt was consumed or not
2258 * This should be called from the driver when it detects a short IRQ,
2259 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2260 * topology manager will process the sideband messages received as a result
2263 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2270 if (sc != mgr->sink_count) {
2271 mgr->sink_count = sc;
2275 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2276 ret = drm_dp_mst_handle_down_rep(mgr);
2280 if (esi[1] & DP_UP_REQ_MSG_RDY) {
2281 ret |= drm_dp_mst_handle_up_req(mgr);
2285 drm_dp_mst_kick_tx(mgr);
2288 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2291 * drm_dp_mst_detect_port() - get connection status for an MST port
2292 * @mgr: manager for this port
2293 * @port: unverified pointer to a port
2295 * This returns the current connection state for a port. It validates the
2296 * port pointer still exists so the caller doesn't require a reference
2298 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2299 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2301 enum drm_connector_status status = connector_status_disconnected;
2303 /* we need to search for the port in the mgr in case its gone */
2304 port = drm_dp_get_validated_port_ref(mgr, port);
2306 return connector_status_disconnected;
2311 switch (port->pdt) {
2312 case DP_PEER_DEVICE_NONE:
2313 case DP_PEER_DEVICE_MST_BRANCHING:
2316 case DP_PEER_DEVICE_SST_SINK:
2317 status = connector_status_connected;
2318 /* for logical ports - cache the EDID */
2319 if (port->port_num >= 8 && !port->cached_edid) {
2320 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2323 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2325 status = connector_status_connected;
2329 drm_dp_put_port(port);
2332 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2335 * drm_dp_mst_get_edid() - get EDID for an MST port
2336 * @connector: toplevel connector to get EDID for
2337 * @mgr: manager for this port
2338 * @port: unverified pointer to a port.
2340 * This returns an EDID for the port connected to a connector,
2341 * It validates the pointer still exists so the caller doesn't require a
2344 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2346 struct edid *edid = NULL;
2348 /* we need to search for the port in the mgr in case its gone */
2349 port = drm_dp_get_validated_port_ref(mgr, port);
2353 if (port->cached_edid)
2354 edid = drm_edid_duplicate(port->cached_edid);
2356 edid = drm_get_edid(connector, &port->aux.ddc);
2357 drm_mode_connector_set_tile_property(connector);
2359 drm_dp_put_port(port);
2362 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2365 * drm_dp_find_vcpi_slots() - find slots for this PBN value
2366 * @mgr: manager to use
2367 * @pbn: payload bandwidth to convert into slots.
2369 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2374 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2376 if (num_slots > mgr->avail_slots)
2380 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2382 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2383 struct drm_dp_vcpi *vcpi, int pbn)
2388 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2390 if (num_slots > mgr->avail_slots)
2394 vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2395 vcpi->num_slots = num_slots;
2397 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2404 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2405 * @mgr: manager for this port
2406 * @port: port to allocate a virtual channel for.
2407 * @pbn: payload bandwidth number to request
2408 * @slots: returned number of slots for this PBN.
2410 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2414 port = drm_dp_get_validated_port_ref(mgr, port);
2418 if (port->vcpi.vcpi > 0) {
2419 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2420 if (pbn == port->vcpi.pbn) {
2421 *slots = port->vcpi.num_slots;
2426 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2428 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2431 DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2432 *slots = port->vcpi.num_slots;
2434 drm_dp_put_port(port);
2439 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2441 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2444 port = drm_dp_get_validated_port_ref(mgr, port);
2448 slots = port->vcpi.num_slots;
2449 drm_dp_put_port(port);
2452 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2455 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2456 * @mgr: manager for this port
2457 * @port: unverified pointer to a port.
2459 * This just resets the number of slots for the ports VCPI for later programming.
2461 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2463 port = drm_dp_get_validated_port_ref(mgr, port);
2466 port->vcpi.num_slots = 0;
2467 drm_dp_put_port(port);
2469 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2472 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2473 * @mgr: manager for this port
2474 * @port: unverified port to deallocate vcpi for
2476 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2478 port = drm_dp_get_validated_port_ref(mgr, port);
2482 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2483 port->vcpi.num_slots = 0;
2485 port->vcpi.aligned_pbn = 0;
2486 port->vcpi.vcpi = 0;
2487 drm_dp_put_port(port);
2489 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2491 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2492 int id, struct drm_dp_payload *payload)
2494 u8 payload_alloc[3], status;
2498 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2499 DP_PAYLOAD_TABLE_UPDATED);
2501 payload_alloc[0] = id;
2502 payload_alloc[1] = payload->start_slot;
2503 payload_alloc[2] = payload->num_slots;
2505 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2507 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2512 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2514 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2518 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2521 usleep_range(10000, 20000);
2524 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2535 * drm_dp_check_act_status() - Check ACT handled status.
2536 * @mgr: manager to use
2538 * Check the payload status bits in the DPCD for ACT handled completion.
2540 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2547 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2550 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2554 if (status & DP_PAYLOAD_ACT_HANDLED)
2559 } while (count < 30);
2561 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2562 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2570 EXPORT_SYMBOL(drm_dp_check_act_status);
2573 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2574 * @clock: dot clock for the mode
2575 * @bpp: bpp for the mode.
2577 * This uses the formula in the spec to calculate the PBN value for a mode.
2579 int drm_dp_calc_pbn_mode(int clock, int bpp)
2584 fixed20_12 margin, tmp;
2587 pix_bw.full = dfixed_const(clock);
2588 fbpp.full = dfixed_const(bpp);
2589 tmp.full = dfixed_const(8);
2590 fbpp.full = dfixed_div(fbpp, tmp);
2592 result.full = dfixed_mul(pix_bw, fbpp);
2593 margin.full = dfixed_const(54);
2594 tmp.full = dfixed_const(64);
2595 margin.full = dfixed_div(margin, tmp);
2596 result.full = dfixed_div(result, margin);
2598 margin.full = dfixed_const(1006);
2599 tmp.full = dfixed_const(1000);
2600 margin.full = dfixed_div(margin, tmp);
2601 result.full = dfixed_mul(result, margin);
2603 result.full = dfixed_div(result, tmp);
2604 result.full = dfixed_ceil(result);
2605 res = dfixed_trunc(result);
2608 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2610 static int test_calc_pbn_mode(void)
2613 ret = drm_dp_calc_pbn_mode(154000, 30);
2616 ret = drm_dp_calc_pbn_mode(234000, 30);
2622 /* we want to kick the TX after we've ack the up/down IRQs. */
2623 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2625 queue_work(system_long_wq, &mgr->tx_work);
2628 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2629 struct drm_dp_mst_branch *mstb)
2631 struct drm_dp_mst_port *port;
2632 int tabs = mstb->lct;
2636 for (i = 0; i < tabs; i++)
2640 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2641 list_for_each_entry(port, &mstb->ports, next) {
2642 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port, port->connector);
2644 drm_dp_mst_dump_mstb(m, port->mstb);
2648 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2653 for (i = 0; i < 4; i++) {
2654 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2664 * drm_dp_mst_dump_topology(): dump topology to seq file.
2665 * @m: seq_file to dump output to
2666 * @mgr: manager to dump current topology for.
2668 * helper to dump MST topology to a seq file for debugfs.
2670 void drm_dp_mst_dump_topology(struct seq_file *m,
2671 struct drm_dp_mst_topology_mgr *mgr)
2674 struct drm_dp_mst_port *port;
2675 mutex_lock(&mgr->lock);
2676 if (mgr->mst_primary)
2677 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2680 mutex_unlock(&mgr->lock);
2682 mutex_lock(&mgr->payload_lock);
2683 seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
2685 for (i = 0; i < mgr->max_payloads; i++) {
2686 if (mgr->proposed_vcpis[i]) {
2687 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2688 seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2690 seq_printf(m, "vcpi %d:unsed\n", i);
2692 for (i = 0; i < mgr->max_payloads; i++) {
2693 seq_printf(m, "payload %d: %d, %d, %d\n",
2695 mgr->payloads[i].payload_state,
2696 mgr->payloads[i].start_slot,
2697 mgr->payloads[i].num_slots);
2701 mutex_unlock(&mgr->payload_lock);
2703 mutex_lock(&mgr->lock);
2704 if (mgr->mst_primary) {
2708 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2709 seq_printf(m, "dpcd: ");
2710 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2711 seq_printf(m, "%02x ", buf[i]);
2712 seq_printf(m, "\n");
2713 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2714 seq_printf(m, "faux/mst: ");
2715 for (i = 0; i < 2; i++)
2716 seq_printf(m, "%02x ", buf[i]);
2717 seq_printf(m, "\n");
2718 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2719 seq_printf(m, "mst ctrl: ");
2720 for (i = 0; i < 1; i++)
2721 seq_printf(m, "%02x ", buf[i]);
2722 seq_printf(m, "\n");
2724 /* dump the standard OUI branch header */
2725 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
2726 seq_printf(m, "branch oui: ");
2727 for (i = 0; i < 0x3; i++)
2728 seq_printf(m, "%02x", buf[i]);
2729 seq_printf(m, " devid: ");
2730 for (i = 0x3; i < 0x8; i++)
2731 seq_printf(m, "%c", buf[i]);
2732 seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
2733 seq_printf(m, "\n");
2734 bret = dump_dp_payload_table(mgr, buf);
2736 seq_printf(m, "payload table: ");
2737 for (i = 0; i < 63; i++)
2738 seq_printf(m, "%02x ", buf[i]);
2739 seq_printf(m, "\n");
2744 mutex_unlock(&mgr->lock);
2747 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2749 static void drm_dp_tx_work(struct work_struct *work)
2751 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2753 mutex_lock(&mgr->qlock);
2754 if (mgr->tx_down_in_progress)
2755 process_single_down_tx_qlock(mgr);
2756 mutex_unlock(&mgr->qlock);
2759 static void drm_dp_destroy_connector_work(struct work_struct *work)
2761 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
2762 struct drm_dp_mst_port *port;
2763 bool send_hotplug = false;
2765 * Not a regular list traverse as we have to drop the destroy
2766 * connector lock before destroying the connector, to avoid AB->BA
2767 * ordering between this lock and the config mutex.
2770 mutex_lock(&mgr->destroy_connector_lock);
2771 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
2773 mutex_unlock(&mgr->destroy_connector_lock);
2776 list_del(&port->next);
2777 mutex_unlock(&mgr->destroy_connector_lock);
2779 mgr->cbs->destroy_connector(mgr, port->connector);
2781 drm_dp_port_teardown_pdt(port, port->pdt);
2783 if (!port->input && port->vcpi.vcpi > 0)
2784 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2786 send_hotplug = true;
2789 (*mgr->cbs->hotplug)(mgr);
2793 * drm_dp_mst_topology_mgr_init - initialise a topology manager
2794 * @mgr: manager struct to initialise
2795 * @dev: device providing this structure - for i2c addition.
2796 * @aux: DP helper aux channel to talk to this device
2797 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2798 * @max_payloads: maximum number of payloads this GPU can source
2799 * @conn_base_id: the connector object ID the MST device is connected to.
2801 * Return 0 for success, or negative error code on failure
2803 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2804 struct device *dev, struct drm_dp_aux *aux,
2805 int max_dpcd_transaction_bytes,
2806 int max_payloads, int conn_base_id)
2808 mutex_init(&mgr->lock);
2809 mutex_init(&mgr->qlock);
2810 mutex_init(&mgr->payload_lock);
2811 mutex_init(&mgr->destroy_connector_lock);
2812 INIT_LIST_HEAD(&mgr->tx_msg_upq);
2813 INIT_LIST_HEAD(&mgr->tx_msg_downq);
2814 INIT_LIST_HEAD(&mgr->destroy_connector_list);
2815 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2816 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2817 INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
2818 init_waitqueue_head(&mgr->tx_waitq);
2821 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2822 mgr->max_payloads = max_payloads;
2823 mgr->conn_base_id = conn_base_id;
2824 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2827 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2828 if (!mgr->proposed_vcpis)
2830 set_bit(0, &mgr->payload_mask);
2831 test_calc_pbn_mode();
2834 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2837 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2838 * @mgr: manager to destroy
2840 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2842 flush_work(&mgr->work);
2843 flush_work(&mgr->destroy_connector_work);
2844 mutex_lock(&mgr->payload_lock);
2845 kfree(mgr->payloads);
2846 mgr->payloads = NULL;
2847 kfree(mgr->proposed_vcpis);
2848 mgr->proposed_vcpis = NULL;
2849 mutex_unlock(&mgr->payload_lock);
2853 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
2856 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
2859 struct drm_dp_aux *aux = adapter->algo_data;
2860 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
2861 struct drm_dp_mst_branch *mstb;
2862 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2864 bool reading = false;
2865 struct drm_dp_sideband_msg_req_body msg;
2866 struct drm_dp_sideband_msg_tx *txmsg = NULL;
2869 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2873 /* construct i2c msg */
2874 /* see if last msg is a read */
2875 if (msgs[num - 1].flags & I2C_M_RD)
2878 if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
2879 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
2884 memset(&msg, 0, sizeof(msg));
2885 msg.req_type = DP_REMOTE_I2C_READ;
2886 msg.u.i2c_read.num_transactions = num - 1;
2887 msg.u.i2c_read.port_number = port->port_num;
2888 for (i = 0; i < num - 1; i++) {
2889 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
2890 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
2891 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
2893 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
2894 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
2896 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2903 drm_dp_encode_sideband_req(&msg, txmsg);
2905 drm_dp_queue_down_tx(mgr, txmsg);
2907 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2910 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
2914 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
2918 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
2923 drm_dp_put_mst_branch_device(mstb);
2927 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
2929 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
2930 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
2931 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
2932 I2C_FUNC_10BIT_ADDR;
2935 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
2936 .functionality = drm_dp_mst_i2c_functionality,
2937 .master_xfer = drm_dp_mst_i2c_xfer,
2941 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
2942 * @aux: DisplayPort AUX channel
2944 * Returns 0 on success or a negative error code on failure.
2946 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
2948 aux->ddc.algo = &drm_dp_mst_i2c_algo;
2949 aux->ddc.algo_data = aux;
2950 aux->ddc.retries = 3;
2952 aux->ddc.class = I2C_CLASS_DDC;
2953 aux->ddc.owner = THIS_MODULE;
2954 aux->ddc.dev.parent = aux->dev;
2955 aux->ddc.dev.of_node = aux->dev->of_node;
2957 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
2958 sizeof(aux->ddc.name));
2960 return i2c_add_adapter(&aux->ddc);
2964 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
2965 * @aux: DisplayPort AUX channel
2967 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
2969 i2c_del_adapter(&aux->ddc);