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 int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
57 struct drm_dp_mst_branch *mstb);
58 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
59 struct drm_dp_mst_branch *mstb,
60 struct drm_dp_mst_port *port);
61 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
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_free_mst_port(struct kref *kref);
803 static void drm_dp_free_mst_branch_device(struct kref *kref)
805 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
806 if (mstb->port_parent) {
807 if (list_empty(&mstb->port_parent->next))
808 kref_put(&mstb->port_parent->kref, drm_dp_free_mst_port);
813 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
815 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
816 struct drm_dp_mst_port *port, *tmp;
817 bool wake_tx = false;
820 * init kref again to be used by ports to remove mst branch when it is
825 if (mstb->port_parent && list_empty(&mstb->port_parent->next))
826 kref_get(&mstb->port_parent->kref);
829 * destroy all ports - don't need lock
830 * as there are no more references to the mst branch
831 * device at this point.
833 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
834 list_del(&port->next);
835 drm_dp_put_port(port);
838 /* drop any tx slots msg */
839 mutex_lock(&mstb->mgr->qlock);
840 if (mstb->tx_slots[0]) {
841 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
842 mstb->tx_slots[0] = NULL;
845 if (mstb->tx_slots[1]) {
846 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
847 mstb->tx_slots[1] = NULL;
850 mutex_unlock(&mstb->mgr->qlock);
853 wake_up(&mstb->mgr->tx_waitq);
855 kref_put(kref, drm_dp_free_mst_branch_device);
858 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
860 kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
864 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
866 struct drm_dp_mst_branch *mstb;
869 case DP_PEER_DEVICE_DP_LEGACY_CONV:
870 case DP_PEER_DEVICE_SST_SINK:
871 /* remove i2c over sideband */
872 drm_dp_mst_unregister_i2c_bus(&port->aux);
874 case DP_PEER_DEVICE_MST_BRANCHING:
877 drm_dp_put_mst_branch_device(mstb);
882 static void drm_dp_destroy_port(struct kref *kref)
884 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
885 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
888 port->vcpi.num_slots = 0;
890 kfree(port->cached_edid);
893 * The only time we don't have a connector
894 * on an output port is if the connector init
897 if (port->connector) {
898 /* we can't destroy the connector here, as
899 * we might be holding the mode_config.mutex
900 * from an EDID retrieval */
902 mutex_lock(&mgr->destroy_connector_lock);
903 kref_get(&port->parent->kref);
904 list_add(&port->next, &mgr->destroy_connector_list);
905 mutex_unlock(&mgr->destroy_connector_lock);
906 schedule_work(&mgr->destroy_connector_work);
909 /* no need to clean up vcpi
910 * as if we have no connector we never setup a vcpi */
911 drm_dp_port_teardown_pdt(port, port->pdt);
916 static void drm_dp_put_port(struct drm_dp_mst_port *port)
918 kref_put(&port->kref, drm_dp_destroy_port);
921 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)
923 struct drm_dp_mst_port *port;
924 struct drm_dp_mst_branch *rmstb;
925 if (to_find == mstb) {
926 kref_get(&mstb->kref);
929 list_for_each_entry(port, &mstb->ports, next) {
931 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
939 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)
941 struct drm_dp_mst_branch *rmstb = NULL;
942 mutex_lock(&mgr->lock);
943 if (mgr->mst_primary)
944 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
945 mutex_unlock(&mgr->lock);
949 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)
951 struct drm_dp_mst_port *port, *mport;
953 list_for_each_entry(port, &mstb->ports, next) {
954 if (port == to_find) {
955 kref_get(&port->kref);
959 mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
967 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)
969 struct drm_dp_mst_port *rport = NULL;
970 mutex_lock(&mgr->lock);
971 if (mgr->mst_primary)
972 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
973 mutex_unlock(&mgr->lock);
977 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
979 struct drm_dp_mst_port *port;
981 list_for_each_entry(port, &mstb->ports, next) {
982 if (port->port_num == port_num) {
983 kref_get(&port->kref);
992 * calculate a new RAD for this MST branch device
993 * if parent has an LCT of 2 then it has 1 nibble of RAD,
994 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
996 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
999 int parent_lct = port->parent->lct;
1001 int idx = (parent_lct - 1) / 2;
1002 if (parent_lct > 1) {
1003 memcpy(rad, port->parent->rad, idx + 1);
1004 shift = (parent_lct % 2) ? 4 : 0;
1008 rad[idx] |= port->port_num << shift;
1009 return parent_lct + 1;
1013 * return sends link address for new mstb
1015 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
1019 bool send_link = false;
1020 switch (port->pdt) {
1021 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1022 case DP_PEER_DEVICE_SST_SINK:
1023 /* add i2c over sideband */
1024 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1026 case DP_PEER_DEVICE_MST_BRANCHING:
1027 lct = drm_dp_calculate_rad(port, rad);
1029 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
1030 port->mstb->mgr = port->mgr;
1031 port->mstb->port_parent = port;
1039 static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
1043 memcpy(mstb->guid, guid, 16);
1045 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
1046 if (mstb->port_parent) {
1047 ret = drm_dp_send_dpcd_write(
1055 ret = drm_dp_dpcd_write(
1064 static void build_mst_prop_path(struct drm_dp_mst_port *port,
1065 struct drm_dp_mst_branch *mstb,
1067 size_t proppath_size)
1071 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1072 for (i = 0; i < (mstb->lct - 1); i++) {
1073 int shift = (i % 2) ? 0 : 4;
1074 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
1075 snprintf(temp, sizeof(temp), "-%d", port_num);
1076 strlcat(proppath, temp, proppath_size);
1078 snprintf(temp, sizeof(temp), "-%d", port->port_num);
1079 strlcat(proppath, temp, proppath_size);
1082 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1084 struct drm_dp_link_addr_reply_port *port_msg)
1086 struct drm_dp_mst_port *port;
1088 bool created = false;
1091 port = drm_dp_get_port(mstb, port_msg->port_number);
1093 port = kzalloc(sizeof(*port), GFP_KERNEL);
1096 kref_init(&port->kref);
1097 port->parent = mstb;
1098 port->port_num = port_msg->port_number;
1099 port->mgr = mstb->mgr;
1100 port->aux.name = "DPMST";
1101 port->aux.dev = dev;
1104 old_pdt = port->pdt;
1105 old_ddps = port->ddps;
1108 port->pdt = port_msg->peer_device_type;
1109 port->input = port_msg->input_port;
1110 port->mcs = port_msg->mcs;
1111 port->ddps = port_msg->ddps;
1112 port->ldps = port_msg->legacy_device_plug_status;
1113 port->dpcd_rev = port_msg->dpcd_revision;
1114 port->num_sdp_streams = port_msg->num_sdp_streams;
1115 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1117 /* manage mstb port lists with mgr lock - take a reference
1120 mutex_lock(&mstb->mgr->lock);
1121 kref_get(&port->kref);
1122 list_add(&port->next, &mstb->ports);
1123 mutex_unlock(&mstb->mgr->lock);
1126 if (old_ddps != port->ddps) {
1129 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1131 port->available_pbn = 0;
1135 if (old_pdt != port->pdt && !port->input) {
1136 drm_dp_port_teardown_pdt(port, old_pdt);
1138 ret = drm_dp_port_setup_pdt(port);
1140 drm_dp_send_link_address(mstb->mgr, port->mstb);
1141 port->mstb->link_address_sent = true;
1145 if (created && !port->input) {
1147 build_mst_prop_path(port, mstb, proppath, sizeof(proppath));
1148 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1149 if (!port->connector) {
1150 /* remove it from the port list */
1151 mutex_lock(&mstb->mgr->lock);
1152 list_del(&port->next);
1153 mutex_unlock(&mstb->mgr->lock);
1154 /* drop port list reference */
1155 drm_dp_put_port(port);
1158 if (port->port_num >= 8) {
1159 port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1164 /* put reference to this port */
1165 drm_dp_put_port(port);
1168 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1169 struct drm_dp_connection_status_notify *conn_stat)
1171 struct drm_dp_mst_port *port;
1174 bool dowork = false;
1175 port = drm_dp_get_port(mstb, conn_stat->port_number);
1179 old_ddps = port->ddps;
1180 old_pdt = port->pdt;
1181 port->pdt = conn_stat->peer_device_type;
1182 port->mcs = conn_stat->message_capability_status;
1183 port->ldps = conn_stat->legacy_device_plug_status;
1184 port->ddps = conn_stat->displayport_device_plug_status;
1186 if (old_ddps != port->ddps) {
1190 port->available_pbn = 0;
1193 if (old_pdt != port->pdt && !port->input) {
1194 drm_dp_port_teardown_pdt(port, old_pdt);
1196 if (drm_dp_port_setup_pdt(port))
1200 drm_dp_put_port(port);
1202 queue_work(system_long_wq, &mstb->mgr->work);
1206 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1209 struct drm_dp_mst_branch *mstb;
1210 struct drm_dp_mst_port *port;
1212 /* find the port by iterating down */
1214 mutex_lock(&mgr->lock);
1215 mstb = mgr->mst_primary;
1217 for (i = 0; i < lct - 1; i++) {
1218 int shift = (i % 2) ? 0 : 4;
1219 int port_num = (rad[i / 2] >> shift) & 0xf;
1221 list_for_each_entry(port, &mstb->ports, next) {
1222 if (port->port_num == port_num) {
1225 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1233 kref_get(&mstb->kref);
1235 mutex_unlock(&mgr->lock);
1239 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1240 struct drm_dp_mst_branch *mstb,
1243 struct drm_dp_mst_branch *found_mstb;
1244 struct drm_dp_mst_port *port;
1246 if (memcmp(mstb->guid, guid, 16) == 0)
1250 list_for_each_entry(port, &mstb->ports, next) {
1254 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1263 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
1264 struct drm_dp_mst_topology_mgr *mgr,
1267 struct drm_dp_mst_branch *mstb;
1269 /* find the port by iterating down */
1270 mutex_lock(&mgr->lock);
1272 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
1275 kref_get(&mstb->kref);
1277 mutex_unlock(&mgr->lock);
1281 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1282 struct drm_dp_mst_branch *mstb)
1284 struct drm_dp_mst_port *port;
1285 struct drm_dp_mst_branch *mstb_child;
1286 if (!mstb->link_address_sent) {
1287 drm_dp_send_link_address(mgr, mstb);
1288 mstb->link_address_sent = true;
1290 list_for_each_entry(port, &mstb->ports, next) {
1297 if (!port->available_pbn)
1298 drm_dp_send_enum_path_resources(mgr, mstb, port);
1301 mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1303 drm_dp_check_and_send_link_address(mgr, mstb_child);
1304 drm_dp_put_mst_branch_device(mstb_child);
1310 static void drm_dp_mst_link_probe_work(struct work_struct *work)
1312 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1313 struct drm_dp_mst_branch *mstb;
1315 mutex_lock(&mgr->lock);
1316 mstb = mgr->mst_primary;
1318 kref_get(&mstb->kref);
1320 mutex_unlock(&mgr->lock);
1322 drm_dp_check_and_send_link_address(mgr, mstb);
1323 drm_dp_put_mst_branch_device(mstb);
1327 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1330 static u8 zero_guid[16];
1332 if (!memcmp(guid, zero_guid, 16)) {
1333 u64 salt = get_jiffies_64();
1334 memcpy(&guid[0], &salt, sizeof(u64));
1335 memcpy(&guid[8], &salt, sizeof(u64));
1342 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1344 struct drm_dp_sideband_msg_req_body req;
1346 req.req_type = DP_REMOTE_DPCD_READ;
1347 req.u.dpcd_read.port_number = port_num;
1348 req.u.dpcd_read.dpcd_address = offset;
1349 req.u.dpcd_read.num_bytes = num_bytes;
1350 drm_dp_encode_sideband_req(&req, msg);
1356 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1357 bool up, u8 *msg, int len)
1360 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1361 int tosend, total, offset;
1368 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1370 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1373 if (ret != tosend) {
1374 if (ret == -EIO && retries < 5) {
1378 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1384 } while (total > 0);
1388 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1389 struct drm_dp_sideband_msg_tx *txmsg)
1391 struct drm_dp_mst_branch *mstb = txmsg->dst;
1394 /* both msg slots are full */
1395 if (txmsg->seqno == -1) {
1396 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1397 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1400 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1401 txmsg->seqno = mstb->last_seqno;
1402 mstb->last_seqno ^= 1;
1403 } else if (mstb->tx_slots[0] == NULL)
1407 mstb->tx_slots[txmsg->seqno] = txmsg;
1410 req_type = txmsg->msg[0] & 0x7f;
1411 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1412 req_type == DP_RESOURCE_STATUS_NOTIFY)
1416 hdr->path_msg = txmsg->path_msg;
1417 hdr->lct = mstb->lct;
1418 hdr->lcr = mstb->lct - 1;
1420 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1421 hdr->seqno = txmsg->seqno;
1425 * process a single block of the next message in the sideband queue
1427 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1428 struct drm_dp_sideband_msg_tx *txmsg,
1432 struct drm_dp_sideband_msg_hdr hdr;
1433 int len, space, idx, tosend;
1436 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1438 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1440 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1443 /* make hdr from dst mst - for replies use seqno
1444 otherwise assign one */
1445 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1449 /* amount left to send in this message */
1450 len = txmsg->cur_len - txmsg->cur_offset;
1452 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1453 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1455 tosend = min(len, space);
1456 if (len == txmsg->cur_len)
1462 hdr.msg_len = tosend + 1;
1463 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1464 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1465 /* add crc at end */
1466 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1469 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1471 DRM_DEBUG_KMS("sideband msg failed to send\n");
1475 txmsg->cur_offset += tosend;
1476 if (txmsg->cur_offset == txmsg->cur_len) {
1477 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1483 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1485 struct drm_dp_sideband_msg_tx *txmsg;
1488 WARN_ON(!mutex_is_locked(&mgr->qlock));
1490 /* construct a chunk from the first msg in the tx_msg queue */
1491 if (list_empty(&mgr->tx_msg_downq)) {
1492 mgr->tx_down_in_progress = false;
1495 mgr->tx_down_in_progress = true;
1497 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1498 ret = process_single_tx_qlock(mgr, txmsg, false);
1500 /* txmsg is sent it should be in the slots now */
1501 list_del(&txmsg->next);
1503 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1504 list_del(&txmsg->next);
1505 if (txmsg->seqno != -1)
1506 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1507 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1508 wake_up(&mgr->tx_waitq);
1510 if (list_empty(&mgr->tx_msg_downq)) {
1511 mgr->tx_down_in_progress = false;
1516 /* called holding qlock */
1517 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1518 struct drm_dp_sideband_msg_tx *txmsg)
1522 /* construct a chunk from the first msg in the tx_msg queue */
1523 ret = process_single_tx_qlock(mgr, txmsg, true);
1526 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1528 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1531 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1532 struct drm_dp_sideband_msg_tx *txmsg)
1534 mutex_lock(&mgr->qlock);
1535 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1536 if (!mgr->tx_down_in_progress)
1537 process_single_down_tx_qlock(mgr);
1538 mutex_unlock(&mgr->qlock);
1541 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1542 struct drm_dp_mst_branch *mstb)
1545 struct drm_dp_sideband_msg_tx *txmsg;
1548 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1553 len = build_link_address(txmsg);
1555 drm_dp_queue_down_tx(mgr, txmsg);
1557 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1561 if (txmsg->reply.reply_type == 1)
1562 DRM_DEBUG_KMS("link address nak received\n");
1564 DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1565 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1566 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,
1567 txmsg->reply.u.link_addr.ports[i].input_port,
1568 txmsg->reply.u.link_addr.ports[i].peer_device_type,
1569 txmsg->reply.u.link_addr.ports[i].port_number,
1570 txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1571 txmsg->reply.u.link_addr.ports[i].mcs,
1572 txmsg->reply.u.link_addr.ports[i].ddps,
1573 txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1574 txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1575 txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1578 drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);
1580 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1581 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1583 (*mgr->cbs->hotplug)(mgr);
1586 DRM_DEBUG_KMS("link address failed %d\n", ret);
1592 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1593 struct drm_dp_mst_branch *mstb,
1594 struct drm_dp_mst_port *port)
1597 struct drm_dp_sideband_msg_tx *txmsg;
1600 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1605 len = build_enum_path_resources(txmsg, port->port_num);
1607 drm_dp_queue_down_tx(mgr, txmsg);
1609 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1611 if (txmsg->reply.reply_type == 1)
1612 DRM_DEBUG_KMS("enum path resources nak received\n");
1614 if (port->port_num != txmsg->reply.u.path_resources.port_number)
1615 DRM_ERROR("got incorrect port in response\n");
1616 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,
1617 txmsg->reply.u.path_resources.avail_payload_bw_number);
1618 port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1626 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
1628 if (!mstb->port_parent)
1631 if (mstb->port_parent->mstb != mstb)
1632 return mstb->port_parent;
1634 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
1637 static struct drm_dp_mst_branch *drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
1638 struct drm_dp_mst_branch *mstb,
1641 struct drm_dp_mst_branch *rmstb = NULL;
1642 struct drm_dp_mst_port *found_port;
1643 mutex_lock(&mgr->lock);
1644 if (mgr->mst_primary) {
1645 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
1648 rmstb = found_port->parent;
1649 kref_get(&rmstb->kref);
1650 *port_num = found_port->port_num;
1653 mutex_unlock(&mgr->lock);
1657 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1658 struct drm_dp_mst_port *port,
1662 struct drm_dp_sideband_msg_tx *txmsg;
1663 struct drm_dp_mst_branch *mstb;
1664 int len, ret, port_num;
1666 port = drm_dp_get_validated_port_ref(mgr, port);
1670 port_num = port->port_num;
1671 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1673 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, port->parent, &port_num);
1676 drm_dp_put_port(port);
1681 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1688 len = build_allocate_payload(txmsg, port_num,
1692 drm_dp_queue_down_tx(mgr, txmsg);
1694 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1696 if (txmsg->reply.reply_type == 1) {
1703 drm_dp_put_mst_branch_device(mstb);
1704 drm_dp_put_port(port);
1708 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1710 struct drm_dp_payload *payload)
1714 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1716 payload->payload_state = 0;
1719 payload->payload_state = DP_PAYLOAD_LOCAL;
1723 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1724 struct drm_dp_mst_port *port,
1726 struct drm_dp_payload *payload)
1729 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1732 payload->payload_state = DP_PAYLOAD_REMOTE;
1736 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1737 struct drm_dp_mst_port *port,
1739 struct drm_dp_payload *payload)
1741 DRM_DEBUG_KMS("\n");
1742 /* its okay for these to fail */
1744 drm_dp_payload_send_msg(mgr, port, id, 0);
1747 drm_dp_dpcd_write_payload(mgr, id, payload);
1748 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1752 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1754 struct drm_dp_payload *payload)
1756 payload->payload_state = 0;
1761 * drm_dp_update_payload_part1() - Execute payload update part 1
1762 * @mgr: manager to use.
1764 * This iterates over all proposed virtual channels, and tries to
1765 * allocate space in the link for them. For 0->slots transitions,
1766 * this step just writes the VCPI to the MST device. For slots->0
1767 * transitions, this writes the updated VCPIs and removes the
1768 * remote VC payloads.
1770 * after calling this the driver should generate ACT and payload
1773 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1777 struct drm_dp_payload req_payload;
1778 struct drm_dp_mst_port *port;
1780 mutex_lock(&mgr->payload_lock);
1781 for (i = 0; i < mgr->max_payloads; i++) {
1782 /* solve the current payloads - compare to the hw ones
1783 - update the hw view */
1784 req_payload.start_slot = cur_slots;
1785 if (mgr->proposed_vcpis[i]) {
1786 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1787 port = drm_dp_get_validated_port_ref(mgr, port);
1789 mutex_unlock(&mgr->payload_lock);
1792 req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1795 req_payload.num_slots = 0;
1798 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1799 mgr->payloads[i].start_slot = req_payload.start_slot;
1801 /* work out what is required to happen with this payload */
1802 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1804 /* need to push an update for this payload */
1805 if (req_payload.num_slots) {
1806 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1807 mgr->payloads[i].num_slots = req_payload.num_slots;
1808 } else if (mgr->payloads[i].num_slots) {
1809 mgr->payloads[i].num_slots = 0;
1810 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
1811 req_payload.payload_state = mgr->payloads[i].payload_state;
1812 mgr->payloads[i].start_slot = 0;
1814 mgr->payloads[i].payload_state = req_payload.payload_state;
1816 cur_slots += req_payload.num_slots;
1819 drm_dp_put_port(port);
1822 for (i = 0; i < mgr->max_payloads; i++) {
1823 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1824 DRM_DEBUG_KMS("removing payload %d\n", i);
1825 for (j = i; j < mgr->max_payloads - 1; j++) {
1826 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1827 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1828 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1829 set_bit(j + 1, &mgr->payload_mask);
1831 clear_bit(j + 1, &mgr->payload_mask);
1834 memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1835 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1836 clear_bit(mgr->max_payloads, &mgr->payload_mask);
1840 mutex_unlock(&mgr->payload_lock);
1844 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1847 * drm_dp_update_payload_part2() - Execute payload update part 2
1848 * @mgr: manager to use.
1850 * This iterates over all proposed virtual channels, and tries to
1851 * allocate space in the link for them. For 0->slots transitions,
1852 * this step writes the remote VC payload commands. For slots->0
1853 * this just resets some internal state.
1855 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1857 struct drm_dp_mst_port *port;
1860 mutex_lock(&mgr->payload_lock);
1861 for (i = 0; i < mgr->max_payloads; i++) {
1863 if (!mgr->proposed_vcpis[i])
1866 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1868 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1869 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1870 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1871 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1872 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1875 mutex_unlock(&mgr->payload_lock);
1879 mutex_unlock(&mgr->payload_lock);
1882 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1884 #if 0 /* unused as of yet */
1885 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1886 struct drm_dp_mst_port *port,
1887 int offset, int size)
1890 struct drm_dp_sideband_msg_tx *txmsg;
1892 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1896 len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1897 txmsg->dst = port->parent;
1899 drm_dp_queue_down_tx(mgr, txmsg);
1905 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1906 struct drm_dp_mst_port *port,
1907 int offset, int size, u8 *bytes)
1911 struct drm_dp_sideband_msg_tx *txmsg;
1912 struct drm_dp_mst_branch *mstb;
1914 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1918 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1924 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1927 drm_dp_queue_down_tx(mgr, txmsg);
1929 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1931 if (txmsg->reply.reply_type == 1) {
1938 drm_dp_put_mst_branch_device(mstb);
1942 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1944 struct drm_dp_sideband_msg_reply_body reply;
1946 reply.reply_type = 1;
1947 reply.req_type = req_type;
1948 drm_dp_encode_sideband_reply(&reply, msg);
1952 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1953 struct drm_dp_mst_branch *mstb,
1954 int req_type, int seqno, bool broadcast)
1956 struct drm_dp_sideband_msg_tx *txmsg;
1958 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1963 txmsg->seqno = seqno;
1964 drm_dp_encode_up_ack_reply(txmsg, req_type);
1966 mutex_lock(&mgr->qlock);
1968 process_single_up_tx_qlock(mgr, txmsg);
1970 mutex_unlock(&mgr->qlock);
1976 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1980 switch (dp_link_bw) {
1982 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1983 dp_link_bw, dp_link_count);
1986 case DP_LINK_BW_1_62:
1987 *out = 3 * dp_link_count;
1989 case DP_LINK_BW_2_7:
1990 *out = 5 * dp_link_count;
1992 case DP_LINK_BW_5_4:
1993 *out = 10 * dp_link_count;
2000 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
2001 * @mgr: manager to set state for
2002 * @mst_state: true to enable MST on this connector - false to disable.
2004 * This is called by the driver when it detects an MST capable device plugged
2005 * into a DP MST capable port, or when a DP MST capable device is unplugged.
2007 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
2010 struct drm_dp_mst_branch *mstb = NULL;
2012 mutex_lock(&mgr->lock);
2013 if (mst_state == mgr->mst_state)
2016 mgr->mst_state = mst_state;
2017 /* set the device into MST mode */
2019 WARN_ON(mgr->mst_primary);
2022 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2023 if (ret != DP_RECEIVER_CAP_SIZE) {
2024 DRM_DEBUG_KMS("failed to read DPCD\n");
2028 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
2029 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
2035 mgr->total_pbn = 2560;
2036 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
2037 mgr->avail_slots = mgr->total_slots;
2039 /* add initial branch device at LCT 1 */
2040 mstb = drm_dp_add_mst_branch_device(1, NULL);
2047 /* give this the main reference */
2048 mgr->mst_primary = mstb;
2049 kref_get(&mgr->mst_primary->kref);
2051 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2052 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2058 struct drm_dp_payload reset_pay;
2059 reset_pay.start_slot = 0;
2060 reset_pay.num_slots = 0x3f;
2061 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
2064 queue_work(system_long_wq, &mgr->work);
2068 /* disable MST on the device */
2069 mstb = mgr->mst_primary;
2070 mgr->mst_primary = NULL;
2071 /* this can fail if the device is gone */
2072 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2074 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2075 mgr->payload_mask = 0;
2076 set_bit(0, &mgr->payload_mask);
2081 mutex_unlock(&mgr->lock);
2083 drm_dp_put_mst_branch_device(mstb);
2087 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2090 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2091 * @mgr: manager to suspend
2093 * This function tells the MST device that we can't handle UP messages
2094 * anymore. This should stop it from sending any since we are suspended.
2096 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2098 mutex_lock(&mgr->lock);
2099 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2100 DP_MST_EN | DP_UPSTREAM_IS_SRC);
2101 mutex_unlock(&mgr->lock);
2102 flush_work(&mgr->work);
2103 flush_work(&mgr->destroy_connector_work);
2105 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2108 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2109 * @mgr: manager to resume
2111 * This will fetch DPCD and see if the device is still there,
2112 * if it is, it will rewrite the MSTM control bits, and return.
2114 * if the device fails this returns -1, and the driver should do
2115 * a full MST reprobe, in case we were undocked.
2117 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2121 mutex_lock(&mgr->lock);
2123 if (mgr->mst_primary) {
2127 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2128 if (sret != DP_RECEIVER_CAP_SIZE) {
2129 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2134 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2135 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2137 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2142 /* Some hubs forget their guids after they resume */
2143 sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
2145 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2149 drm_dp_check_mstb_guid(mgr->mst_primary, guid);
2156 mutex_unlock(&mgr->lock);
2159 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2161 static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2165 int replylen, origlen, curreply;
2167 struct drm_dp_sideband_msg_rx *msg;
2168 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2169 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2171 len = min(mgr->max_dpcd_transaction_bytes, 16);
2172 ret = drm_dp_dpcd_read(mgr->aux, basereg,
2175 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2178 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2180 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2183 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2188 while (replylen > 0) {
2189 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2190 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2193 DRM_DEBUG_KMS("failed to read a chunk\n");
2195 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2197 DRM_DEBUG_KMS("failed to build sideband msg\n");
2203 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2207 drm_dp_get_one_sb_msg(mgr, false);
2209 if (mgr->down_rep_recv.have_eomt) {
2210 struct drm_dp_sideband_msg_tx *txmsg;
2211 struct drm_dp_mst_branch *mstb;
2213 mstb = drm_dp_get_mst_branch_device(mgr,
2214 mgr->down_rep_recv.initial_hdr.lct,
2215 mgr->down_rep_recv.initial_hdr.rad);
2218 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2219 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2223 /* find the message */
2224 slot = mgr->down_rep_recv.initial_hdr.seqno;
2225 mutex_lock(&mgr->qlock);
2226 txmsg = mstb->tx_slots[slot];
2227 /* remove from slots */
2228 mutex_unlock(&mgr->qlock);
2231 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2233 mgr->down_rep_recv.initial_hdr.seqno,
2234 mgr->down_rep_recv.initial_hdr.lct,
2235 mgr->down_rep_recv.initial_hdr.rad[0],
2236 mgr->down_rep_recv.msg[0]);
2237 drm_dp_put_mst_branch_device(mstb);
2238 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2242 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2243 if (txmsg->reply.reply_type == 1) {
2244 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);
2247 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2248 drm_dp_put_mst_branch_device(mstb);
2250 mutex_lock(&mgr->qlock);
2251 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2252 mstb->tx_slots[slot] = NULL;
2253 mutex_unlock(&mgr->qlock);
2255 wake_up(&mgr->tx_waitq);
2260 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2263 drm_dp_get_one_sb_msg(mgr, true);
2265 if (mgr->up_req_recv.have_eomt) {
2266 struct drm_dp_sideband_msg_req_body msg;
2267 struct drm_dp_mst_branch *mstb = NULL;
2270 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2271 mstb = drm_dp_get_mst_branch_device(mgr,
2272 mgr->up_req_recv.initial_hdr.lct,
2273 mgr->up_req_recv.initial_hdr.rad);
2275 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2276 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2281 seqno = mgr->up_req_recv.initial_hdr.seqno;
2282 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2284 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2285 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2288 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2291 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2292 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2296 drm_dp_update_port(mstb, &msg.u.conn_stat);
2298 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);
2299 (*mgr->cbs->hotplug)(mgr);
2301 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2302 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2304 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2307 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2308 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2312 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2315 drm_dp_put_mst_branch_device(mstb);
2316 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2322 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2323 * @mgr: manager to notify irq for.
2324 * @esi: 4 bytes from SINK_COUNT_ESI
2325 * @handled: whether the hpd interrupt was consumed or not
2327 * This should be called from the driver when it detects a short IRQ,
2328 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2329 * topology manager will process the sideband messages received as a result
2332 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2339 if (sc != mgr->sink_count) {
2340 mgr->sink_count = sc;
2344 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2345 ret = drm_dp_mst_handle_down_rep(mgr);
2349 if (esi[1] & DP_UP_REQ_MSG_RDY) {
2350 ret |= drm_dp_mst_handle_up_req(mgr);
2354 drm_dp_mst_kick_tx(mgr);
2357 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2360 * drm_dp_mst_detect_port() - get connection status for an MST port
2361 * @mgr: manager for this port
2362 * @port: unverified pointer to a port
2364 * This returns the current connection state for a port. It validates the
2365 * port pointer still exists so the caller doesn't require a reference
2367 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2368 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2370 enum drm_connector_status status = connector_status_disconnected;
2372 /* we need to search for the port in the mgr in case its gone */
2373 port = drm_dp_get_validated_port_ref(mgr, port);
2375 return connector_status_disconnected;
2380 switch (port->pdt) {
2381 case DP_PEER_DEVICE_NONE:
2382 case DP_PEER_DEVICE_MST_BRANCHING:
2385 case DP_PEER_DEVICE_SST_SINK:
2386 status = connector_status_connected;
2387 /* for logical ports - cache the EDID */
2388 if (port->port_num >= 8 && !port->cached_edid) {
2389 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2392 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2394 status = connector_status_connected;
2398 drm_dp_put_port(port);
2401 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2404 * drm_dp_mst_get_edid() - get EDID for an MST port
2405 * @connector: toplevel connector to get EDID for
2406 * @mgr: manager for this port
2407 * @port: unverified pointer to a port.
2409 * This returns an EDID for the port connected to a connector,
2410 * It validates the pointer still exists so the caller doesn't require a
2413 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2415 struct edid *edid = NULL;
2417 /* we need to search for the port in the mgr in case its gone */
2418 port = drm_dp_get_validated_port_ref(mgr, port);
2422 if (port->cached_edid)
2423 edid = drm_edid_duplicate(port->cached_edid);
2425 edid = drm_get_edid(connector, &port->aux.ddc);
2427 drm_mode_connector_set_tile_property(connector);
2428 drm_dp_put_port(port);
2431 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2434 * drm_dp_find_vcpi_slots() - find slots for this PBN value
2435 * @mgr: manager to use
2436 * @pbn: payload bandwidth to convert into slots.
2438 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2443 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2445 if (num_slots > mgr->avail_slots)
2449 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2451 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2452 struct drm_dp_vcpi *vcpi, int pbn)
2457 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2459 if (num_slots > mgr->avail_slots)
2463 vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2464 vcpi->num_slots = num_slots;
2466 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2473 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2474 * @mgr: manager for this port
2475 * @port: port to allocate a virtual channel for.
2476 * @pbn: payload bandwidth number to request
2477 * @slots: returned number of slots for this PBN.
2479 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2483 port = drm_dp_get_validated_port_ref(mgr, port);
2487 if (port->vcpi.vcpi > 0) {
2488 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2489 if (pbn == port->vcpi.pbn) {
2490 *slots = port->vcpi.num_slots;
2491 drm_dp_put_port(port);
2496 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2498 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2501 DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2502 *slots = port->vcpi.num_slots;
2504 drm_dp_put_port(port);
2509 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2511 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2514 port = drm_dp_get_validated_port_ref(mgr, port);
2518 slots = port->vcpi.num_slots;
2519 drm_dp_put_port(port);
2522 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2525 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2526 * @mgr: manager for this port
2527 * @port: unverified pointer to a port.
2529 * This just resets the number of slots for the ports VCPI for later programming.
2531 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2533 port = drm_dp_get_validated_port_ref(mgr, port);
2536 port->vcpi.num_slots = 0;
2537 drm_dp_put_port(port);
2539 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2542 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2543 * @mgr: manager for this port
2544 * @port: unverified port to deallocate vcpi for
2546 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2548 port = drm_dp_get_validated_port_ref(mgr, port);
2552 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2553 port->vcpi.num_slots = 0;
2555 port->vcpi.aligned_pbn = 0;
2556 port->vcpi.vcpi = 0;
2557 drm_dp_put_port(port);
2559 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2561 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2562 int id, struct drm_dp_payload *payload)
2564 u8 payload_alloc[3], status;
2568 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2569 DP_PAYLOAD_TABLE_UPDATED);
2571 payload_alloc[0] = id;
2572 payload_alloc[1] = payload->start_slot;
2573 payload_alloc[2] = payload->num_slots;
2575 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2577 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2582 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2584 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2588 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2591 usleep_range(10000, 20000);
2594 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2605 * drm_dp_check_act_status() - Check ACT handled status.
2606 * @mgr: manager to use
2608 * Check the payload status bits in the DPCD for ACT handled completion.
2610 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2617 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2620 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2624 if (status & DP_PAYLOAD_ACT_HANDLED)
2629 } while (count < 30);
2631 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2632 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2640 EXPORT_SYMBOL(drm_dp_check_act_status);
2643 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2644 * @clock: dot clock for the mode
2645 * @bpp: bpp for the mode.
2647 * This uses the formula in the spec to calculate the PBN value for a mode.
2649 int drm_dp_calc_pbn_mode(int clock, int bpp)
2659 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
2660 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
2661 * common multiplier to render an integer PBN for all link rate/lane
2662 * counts combinations
2664 * peak_kbps *= (1006/1000)
2665 * peak_kbps *= (64/54)
2666 * peak_kbps *= 8 convert to bytes
2669 numerator = 64 * 1006;
2670 denominator = 54 * 8 * 1000 * 1000;
2673 peak_kbps = drm_fixp_from_fraction(kbps, denominator);
2675 return drm_fixp2int_ceil(peak_kbps);
2677 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2679 static int test_calc_pbn_mode(void)
2682 ret = drm_dp_calc_pbn_mode(154000, 30);
2684 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2685 154000, 30, 689, ret);
2688 ret = drm_dp_calc_pbn_mode(234000, 30);
2690 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2691 234000, 30, 1047, ret);
2694 ret = drm_dp_calc_pbn_mode(297000, 24);
2696 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2697 297000, 24, 1063, ret);
2703 /* we want to kick the TX after we've ack the up/down IRQs. */
2704 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2706 queue_work(system_long_wq, &mgr->tx_work);
2709 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2710 struct drm_dp_mst_branch *mstb)
2712 struct drm_dp_mst_port *port;
2713 int tabs = mstb->lct;
2717 for (i = 0; i < tabs; i++)
2721 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2722 list_for_each_entry(port, &mstb->ports, next) {
2723 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port, port->connector);
2725 drm_dp_mst_dump_mstb(m, port->mstb);
2729 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2734 for (i = 0; i < 4; i++) {
2735 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2745 * drm_dp_mst_dump_topology(): dump topology to seq file.
2746 * @m: seq_file to dump output to
2747 * @mgr: manager to dump current topology for.
2749 * helper to dump MST topology to a seq file for debugfs.
2751 void drm_dp_mst_dump_topology(struct seq_file *m,
2752 struct drm_dp_mst_topology_mgr *mgr)
2755 struct drm_dp_mst_port *port;
2756 mutex_lock(&mgr->lock);
2757 if (mgr->mst_primary)
2758 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2761 mutex_unlock(&mgr->lock);
2763 mutex_lock(&mgr->payload_lock);
2764 seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
2766 for (i = 0; i < mgr->max_payloads; i++) {
2767 if (mgr->proposed_vcpis[i]) {
2768 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2769 seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2771 seq_printf(m, "vcpi %d:unsed\n", i);
2773 for (i = 0; i < mgr->max_payloads; i++) {
2774 seq_printf(m, "payload %d: %d, %d, %d\n",
2776 mgr->payloads[i].payload_state,
2777 mgr->payloads[i].start_slot,
2778 mgr->payloads[i].num_slots);
2782 mutex_unlock(&mgr->payload_lock);
2784 mutex_lock(&mgr->lock);
2785 if (mgr->mst_primary) {
2789 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2790 seq_printf(m, "dpcd: ");
2791 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2792 seq_printf(m, "%02x ", buf[i]);
2793 seq_printf(m, "\n");
2794 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2795 seq_printf(m, "faux/mst: ");
2796 for (i = 0; i < 2; i++)
2797 seq_printf(m, "%02x ", buf[i]);
2798 seq_printf(m, "\n");
2799 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2800 seq_printf(m, "mst ctrl: ");
2801 for (i = 0; i < 1; i++)
2802 seq_printf(m, "%02x ", buf[i]);
2803 seq_printf(m, "\n");
2805 bret = dump_dp_payload_table(mgr, buf);
2807 seq_printf(m, "payload table: ");
2808 for (i = 0; i < 63; i++)
2809 seq_printf(m, "%02x ", buf[i]);
2810 seq_printf(m, "\n");
2815 mutex_unlock(&mgr->lock);
2818 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2820 static void drm_dp_tx_work(struct work_struct *work)
2822 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2824 mutex_lock(&mgr->qlock);
2825 if (mgr->tx_down_in_progress)
2826 process_single_down_tx_qlock(mgr);
2827 mutex_unlock(&mgr->qlock);
2830 static void drm_dp_free_mst_port(struct kref *kref)
2832 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
2833 kref_put(&port->parent->kref, drm_dp_free_mst_branch_device);
2837 static void drm_dp_destroy_connector_work(struct work_struct *work)
2839 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
2840 struct drm_dp_mst_port *port;
2841 bool send_hotplug = false;
2843 * Not a regular list traverse as we have to drop the destroy
2844 * connector lock before destroying the connector, to avoid AB->BA
2845 * ordering between this lock and the config mutex.
2848 mutex_lock(&mgr->destroy_connector_lock);
2849 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
2851 mutex_unlock(&mgr->destroy_connector_lock);
2854 list_del(&port->next);
2855 mutex_unlock(&mgr->destroy_connector_lock);
2857 kref_init(&port->kref);
2858 INIT_LIST_HEAD(&port->next);
2860 mgr->cbs->destroy_connector(mgr, port->connector);
2862 drm_dp_port_teardown_pdt(port, port->pdt);
2864 if (!port->input && port->vcpi.vcpi > 0) {
2865 drm_dp_mst_reset_vcpi_slots(mgr, port);
2866 drm_dp_update_payload_part1(mgr);
2867 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2870 kref_put(&port->kref, drm_dp_free_mst_port);
2871 send_hotplug = true;
2874 (*mgr->cbs->hotplug)(mgr);
2878 * drm_dp_mst_topology_mgr_init - initialise a topology manager
2879 * @mgr: manager struct to initialise
2880 * @dev: device providing this structure - for i2c addition.
2881 * @aux: DP helper aux channel to talk to this device
2882 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2883 * @max_payloads: maximum number of payloads this GPU can source
2884 * @conn_base_id: the connector object ID the MST device is connected to.
2886 * Return 0 for success, or negative error code on failure
2888 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2889 struct device *dev, struct drm_dp_aux *aux,
2890 int max_dpcd_transaction_bytes,
2891 int max_payloads, int conn_base_id)
2893 mutex_init(&mgr->lock);
2894 mutex_init(&mgr->qlock);
2895 mutex_init(&mgr->payload_lock);
2896 mutex_init(&mgr->destroy_connector_lock);
2897 INIT_LIST_HEAD(&mgr->tx_msg_downq);
2898 INIT_LIST_HEAD(&mgr->destroy_connector_list);
2899 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2900 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2901 INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
2902 init_waitqueue_head(&mgr->tx_waitq);
2905 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2906 mgr->max_payloads = max_payloads;
2907 mgr->conn_base_id = conn_base_id;
2908 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2911 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2912 if (!mgr->proposed_vcpis)
2914 set_bit(0, &mgr->payload_mask);
2915 test_calc_pbn_mode();
2918 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2921 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2922 * @mgr: manager to destroy
2924 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2926 flush_work(&mgr->work);
2927 flush_work(&mgr->destroy_connector_work);
2928 mutex_lock(&mgr->payload_lock);
2929 kfree(mgr->payloads);
2930 mgr->payloads = NULL;
2931 kfree(mgr->proposed_vcpis);
2932 mgr->proposed_vcpis = NULL;
2933 mutex_unlock(&mgr->payload_lock);
2937 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
2940 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
2943 struct drm_dp_aux *aux = adapter->algo_data;
2944 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
2945 struct drm_dp_mst_branch *mstb;
2946 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2948 bool reading = false;
2949 struct drm_dp_sideband_msg_req_body msg;
2950 struct drm_dp_sideband_msg_tx *txmsg = NULL;
2953 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2957 /* construct i2c msg */
2958 /* see if last msg is a read */
2959 if (msgs[num - 1].flags & I2C_M_RD)
2962 if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
2963 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
2968 memset(&msg, 0, sizeof(msg));
2969 msg.req_type = DP_REMOTE_I2C_READ;
2970 msg.u.i2c_read.num_transactions = num - 1;
2971 msg.u.i2c_read.port_number = port->port_num;
2972 for (i = 0; i < num - 1; i++) {
2973 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
2974 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
2975 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
2977 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
2978 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
2980 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2987 drm_dp_encode_sideband_req(&msg, txmsg);
2989 drm_dp_queue_down_tx(mgr, txmsg);
2991 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2994 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
2998 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
3002 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
3007 drm_dp_put_mst_branch_device(mstb);
3011 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
3013 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
3014 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
3015 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
3016 I2C_FUNC_10BIT_ADDR;
3019 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
3020 .functionality = drm_dp_mst_i2c_functionality,
3021 .master_xfer = drm_dp_mst_i2c_xfer,
3025 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
3026 * @aux: DisplayPort AUX channel
3028 * Returns 0 on success or a negative error code on failure.
3030 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
3032 aux->ddc.algo = &drm_dp_mst_i2c_algo;
3033 aux->ddc.algo_data = aux;
3034 aux->ddc.retries = 3;
3036 aux->ddc.class = I2C_CLASS_DDC;
3037 aux->ddc.owner = THIS_MODULE;
3038 aux->ddc.dev.parent = aux->dev;
3039 aux->ddc.dev.of_node = aux->dev->of_node;
3041 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
3042 sizeof(aux->ddc.name));
3044 return i2c_add_adapter(&aux->ddc);
3048 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
3049 * @aux: DisplayPort AUX channel
3051 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
3053 i2c_del_adapter(&aux->ddc);