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,
670 u8 number_sdp_streams,
673 struct drm_dp_sideband_msg_req_body req;
674 memset(&req, 0, sizeof(req));
675 req.req_type = DP_ALLOCATE_PAYLOAD;
676 req.u.allocate_payload.port_number = port_num;
677 req.u.allocate_payload.vcpi = vcpi;
678 req.u.allocate_payload.pbn = pbn;
679 req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
680 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
682 drm_dp_encode_sideband_req(&req, msg);
683 msg->path_msg = true;
687 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
688 struct drm_dp_vcpi *vcpi)
692 mutex_lock(&mgr->payload_lock);
693 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
694 if (ret > mgr->max_payloads) {
696 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
700 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
701 if (vcpi_ret > mgr->max_payloads) {
703 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
707 set_bit(ret, &mgr->payload_mask);
708 set_bit(vcpi_ret, &mgr->vcpi_mask);
709 vcpi->vcpi = vcpi_ret + 1;
710 mgr->proposed_vcpis[ret - 1] = vcpi;
712 mutex_unlock(&mgr->payload_lock);
716 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
723 mutex_lock(&mgr->payload_lock);
724 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
725 clear_bit(vcpi - 1, &mgr->vcpi_mask);
727 for (i = 0; i < mgr->max_payloads; i++) {
728 if (mgr->proposed_vcpis[i])
729 if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
730 mgr->proposed_vcpis[i] = NULL;
731 clear_bit(i + 1, &mgr->payload_mask);
734 mutex_unlock(&mgr->payload_lock);
737 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
738 struct drm_dp_sideband_msg_tx *txmsg)
743 * All updates to txmsg->state are protected by mgr->qlock, and the two
744 * cases we check here are terminal states. For those the barriers
745 * provided by the wake_up/wait_event pair are enough.
747 ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
748 txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
752 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
753 struct drm_dp_sideband_msg_tx *txmsg)
755 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
758 ret = wait_event_timeout(mgr->tx_waitq,
759 check_txmsg_state(mgr, txmsg),
761 mutex_lock(&mstb->mgr->qlock);
763 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
768 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
770 /* dump some state */
774 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
775 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
776 list_del(&txmsg->next);
779 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
780 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
781 mstb->tx_slots[txmsg->seqno] = NULL;
785 mutex_unlock(&mgr->qlock);
790 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
792 struct drm_dp_mst_branch *mstb;
794 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
800 memcpy(mstb->rad, rad, lct / 2);
801 INIT_LIST_HEAD(&mstb->ports);
802 kref_init(&mstb->kref);
806 static void drm_dp_free_mst_port(struct kref *kref);
808 static void drm_dp_free_mst_branch_device(struct kref *kref)
810 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
811 if (mstb->port_parent) {
812 if (list_empty(&mstb->port_parent->next))
813 kref_put(&mstb->port_parent->kref, drm_dp_free_mst_port);
818 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
820 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
821 struct drm_dp_mst_port *port, *tmp;
822 bool wake_tx = false;
825 * init kref again to be used by ports to remove mst branch when it is
830 if (mstb->port_parent && list_empty(&mstb->port_parent->next))
831 kref_get(&mstb->port_parent->kref);
834 * destroy all ports - don't need lock
835 * as there are no more references to the mst branch
836 * device at this point.
838 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
839 list_del(&port->next);
840 drm_dp_put_port(port);
843 /* drop any tx slots msg */
844 mutex_lock(&mstb->mgr->qlock);
845 if (mstb->tx_slots[0]) {
846 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
847 mstb->tx_slots[0] = NULL;
850 if (mstb->tx_slots[1]) {
851 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
852 mstb->tx_slots[1] = NULL;
855 mutex_unlock(&mstb->mgr->qlock);
858 wake_up(&mstb->mgr->tx_waitq);
860 kref_put(kref, drm_dp_free_mst_branch_device);
863 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
865 kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
869 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
871 struct drm_dp_mst_branch *mstb;
874 case DP_PEER_DEVICE_DP_LEGACY_CONV:
875 case DP_PEER_DEVICE_SST_SINK:
876 /* remove i2c over sideband */
877 drm_dp_mst_unregister_i2c_bus(&port->aux);
879 case DP_PEER_DEVICE_MST_BRANCHING:
882 drm_dp_put_mst_branch_device(mstb);
887 static void drm_dp_destroy_port(struct kref *kref)
889 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
890 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
893 port->vcpi.num_slots = 0;
895 kfree(port->cached_edid);
898 * The only time we don't have a connector
899 * on an output port is if the connector init
902 if (port->connector) {
903 /* we can't destroy the connector here, as
904 * we might be holding the mode_config.mutex
905 * from an EDID retrieval */
907 mutex_lock(&mgr->destroy_connector_lock);
908 kref_get(&port->parent->kref);
909 list_add(&port->next, &mgr->destroy_connector_list);
910 mutex_unlock(&mgr->destroy_connector_lock);
911 schedule_work(&mgr->destroy_connector_work);
914 /* no need to clean up vcpi
915 * as if we have no connector we never setup a vcpi */
916 drm_dp_port_teardown_pdt(port, port->pdt);
921 static void drm_dp_put_port(struct drm_dp_mst_port *port)
923 kref_put(&port->kref, drm_dp_destroy_port);
926 static struct drm_dp_mst_branch *drm_dp_mst_get_validated_mstb_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_branch *to_find)
928 struct drm_dp_mst_port *port;
929 struct drm_dp_mst_branch *rmstb;
930 if (to_find == mstb) {
931 kref_get(&mstb->kref);
934 list_for_each_entry(port, &mstb->ports, next) {
936 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
944 static struct drm_dp_mst_branch *drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb)
946 struct drm_dp_mst_branch *rmstb = NULL;
947 mutex_lock(&mgr->lock);
948 if (mgr->mst_primary)
949 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
950 mutex_unlock(&mgr->lock);
954 static struct drm_dp_mst_port *drm_dp_mst_get_port_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_port *to_find)
956 struct drm_dp_mst_port *port, *mport;
958 list_for_each_entry(port, &mstb->ports, next) {
959 if (port == to_find) {
960 kref_get(&port->kref);
964 mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
972 static struct drm_dp_mst_port *drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
974 struct drm_dp_mst_port *rport = NULL;
975 mutex_lock(&mgr->lock);
976 if (mgr->mst_primary)
977 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
978 mutex_unlock(&mgr->lock);
982 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
984 struct drm_dp_mst_port *port;
986 list_for_each_entry(port, &mstb->ports, next) {
987 if (port->port_num == port_num) {
988 kref_get(&port->kref);
997 * calculate a new RAD for this MST branch device
998 * if parent has an LCT of 2 then it has 1 nibble of RAD,
999 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1001 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1004 int parent_lct = port->parent->lct;
1006 int idx = (parent_lct - 1) / 2;
1007 if (parent_lct > 1) {
1008 memcpy(rad, port->parent->rad, idx + 1);
1009 shift = (parent_lct % 2) ? 4 : 0;
1013 rad[idx] |= port->port_num << shift;
1014 return parent_lct + 1;
1018 * return sends link address for new mstb
1020 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
1024 bool send_link = false;
1025 switch (port->pdt) {
1026 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1027 case DP_PEER_DEVICE_SST_SINK:
1028 /* add i2c over sideband */
1029 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1031 case DP_PEER_DEVICE_MST_BRANCHING:
1032 lct = drm_dp_calculate_rad(port, rad);
1034 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
1035 port->mstb->mgr = port->mgr;
1036 port->mstb->port_parent = port;
1044 static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
1048 memcpy(mstb->guid, guid, 16);
1050 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
1051 if (mstb->port_parent) {
1052 ret = drm_dp_send_dpcd_write(
1060 ret = drm_dp_dpcd_write(
1069 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1072 size_t proppath_size)
1076 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1077 for (i = 0; i < (mstb->lct - 1); i++) {
1078 int shift = (i % 2) ? 0 : 4;
1079 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
1080 snprintf(temp, sizeof(temp), "-%d", port_num);
1081 strlcat(proppath, temp, proppath_size);
1083 snprintf(temp, sizeof(temp), "-%d", pnum);
1084 strlcat(proppath, temp, proppath_size);
1087 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1089 struct drm_dp_link_addr_reply_port *port_msg)
1091 struct drm_dp_mst_port *port;
1093 bool created = false;
1096 port = drm_dp_get_port(mstb, port_msg->port_number);
1098 port = kzalloc(sizeof(*port), GFP_KERNEL);
1101 kref_init(&port->kref);
1102 port->parent = mstb;
1103 port->port_num = port_msg->port_number;
1104 port->mgr = mstb->mgr;
1105 port->aux.name = "DPMST";
1106 port->aux.dev = dev;
1109 old_pdt = port->pdt;
1110 old_ddps = port->ddps;
1113 port->pdt = port_msg->peer_device_type;
1114 port->input = port_msg->input_port;
1115 port->mcs = port_msg->mcs;
1116 port->ddps = port_msg->ddps;
1117 port->ldps = port_msg->legacy_device_plug_status;
1118 port->dpcd_rev = port_msg->dpcd_revision;
1119 port->num_sdp_streams = port_msg->num_sdp_streams;
1120 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1122 /* manage mstb port lists with mgr lock - take a reference
1125 mutex_lock(&mstb->mgr->lock);
1126 kref_get(&port->kref);
1127 list_add(&port->next, &mstb->ports);
1128 mutex_unlock(&mstb->mgr->lock);
1131 if (old_ddps != port->ddps) {
1134 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1136 port->available_pbn = 0;
1140 if (old_pdt != port->pdt && !port->input) {
1141 drm_dp_port_teardown_pdt(port, old_pdt);
1143 ret = drm_dp_port_setup_pdt(port);
1145 drm_dp_send_link_address(mstb->mgr, port->mstb);
1148 if (created && !port->input) {
1151 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
1152 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1153 if (!port->connector) {
1154 /* remove it from the port list */
1155 mutex_lock(&mstb->mgr->lock);
1156 list_del(&port->next);
1157 mutex_unlock(&mstb->mgr->lock);
1158 /* drop port list reference */
1159 drm_dp_put_port(port);
1162 if (port->port_num >= DP_MST_LOGICAL_PORT_0) {
1163 port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1164 drm_mode_connector_set_tile_property(port->connector);
1166 (*mstb->mgr->cbs->register_connector)(port->connector);
1170 /* put reference to this port */
1171 drm_dp_put_port(port);
1174 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1175 struct drm_dp_connection_status_notify *conn_stat)
1177 struct drm_dp_mst_port *port;
1180 bool dowork = false;
1181 port = drm_dp_get_port(mstb, conn_stat->port_number);
1185 old_ddps = port->ddps;
1186 old_pdt = port->pdt;
1187 port->pdt = conn_stat->peer_device_type;
1188 port->mcs = conn_stat->message_capability_status;
1189 port->ldps = conn_stat->legacy_device_plug_status;
1190 port->ddps = conn_stat->displayport_device_plug_status;
1192 if (old_ddps != port->ddps) {
1196 port->available_pbn = 0;
1199 if (old_pdt != port->pdt && !port->input) {
1200 drm_dp_port_teardown_pdt(port, old_pdt);
1202 if (drm_dp_port_setup_pdt(port))
1206 drm_dp_put_port(port);
1208 queue_work(system_long_wq, &mstb->mgr->work);
1212 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1215 struct drm_dp_mst_branch *mstb;
1216 struct drm_dp_mst_port *port;
1218 /* find the port by iterating down */
1220 mutex_lock(&mgr->lock);
1221 mstb = mgr->mst_primary;
1223 for (i = 0; i < lct - 1; i++) {
1224 int shift = (i % 2) ? 0 : 4;
1225 int port_num = (rad[i / 2] >> shift) & 0xf;
1227 list_for_each_entry(port, &mstb->ports, next) {
1228 if (port->port_num == port_num) {
1231 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1239 kref_get(&mstb->kref);
1241 mutex_unlock(&mgr->lock);
1245 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1246 struct drm_dp_mst_branch *mstb,
1249 struct drm_dp_mst_branch *found_mstb;
1250 struct drm_dp_mst_port *port;
1252 if (memcmp(mstb->guid, guid, 16) == 0)
1256 list_for_each_entry(port, &mstb->ports, next) {
1260 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1269 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
1270 struct drm_dp_mst_topology_mgr *mgr,
1273 struct drm_dp_mst_branch *mstb;
1275 /* find the port by iterating down */
1276 mutex_lock(&mgr->lock);
1278 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
1281 kref_get(&mstb->kref);
1283 mutex_unlock(&mgr->lock);
1287 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1288 struct drm_dp_mst_branch *mstb)
1290 struct drm_dp_mst_port *port;
1291 struct drm_dp_mst_branch *mstb_child;
1292 if (!mstb->link_address_sent)
1293 drm_dp_send_link_address(mgr, mstb);
1295 list_for_each_entry(port, &mstb->ports, next) {
1302 if (!port->available_pbn)
1303 drm_dp_send_enum_path_resources(mgr, mstb, port);
1306 mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1308 drm_dp_check_and_send_link_address(mgr, mstb_child);
1309 drm_dp_put_mst_branch_device(mstb_child);
1315 static void drm_dp_mst_link_probe_work(struct work_struct *work)
1317 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1318 struct drm_dp_mst_branch *mstb;
1320 mutex_lock(&mgr->lock);
1321 mstb = mgr->mst_primary;
1323 kref_get(&mstb->kref);
1325 mutex_unlock(&mgr->lock);
1327 drm_dp_check_and_send_link_address(mgr, mstb);
1328 drm_dp_put_mst_branch_device(mstb);
1332 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1335 static u8 zero_guid[16];
1337 if (!memcmp(guid, zero_guid, 16)) {
1338 u64 salt = get_jiffies_64();
1339 memcpy(&guid[0], &salt, sizeof(u64));
1340 memcpy(&guid[8], &salt, sizeof(u64));
1347 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1349 struct drm_dp_sideband_msg_req_body req;
1351 req.req_type = DP_REMOTE_DPCD_READ;
1352 req.u.dpcd_read.port_number = port_num;
1353 req.u.dpcd_read.dpcd_address = offset;
1354 req.u.dpcd_read.num_bytes = num_bytes;
1355 drm_dp_encode_sideband_req(&req, msg);
1361 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1362 bool up, u8 *msg, int len)
1365 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1366 int tosend, total, offset;
1373 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1375 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1378 if (ret != tosend) {
1379 if (ret == -EIO && retries < 5) {
1383 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1389 } while (total > 0);
1393 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1394 struct drm_dp_sideband_msg_tx *txmsg)
1396 struct drm_dp_mst_branch *mstb = txmsg->dst;
1399 /* both msg slots are full */
1400 if (txmsg->seqno == -1) {
1401 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1402 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1405 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1406 txmsg->seqno = mstb->last_seqno;
1407 mstb->last_seqno ^= 1;
1408 } else if (mstb->tx_slots[0] == NULL)
1412 mstb->tx_slots[txmsg->seqno] = txmsg;
1415 req_type = txmsg->msg[0] & 0x7f;
1416 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1417 req_type == DP_RESOURCE_STATUS_NOTIFY)
1421 hdr->path_msg = txmsg->path_msg;
1422 hdr->lct = mstb->lct;
1423 hdr->lcr = mstb->lct - 1;
1425 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1426 hdr->seqno = txmsg->seqno;
1430 * process a single block of the next message in the sideband queue
1432 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1433 struct drm_dp_sideband_msg_tx *txmsg,
1437 struct drm_dp_sideband_msg_hdr hdr;
1438 int len, space, idx, tosend;
1441 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1443 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1445 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1448 /* make hdr from dst mst - for replies use seqno
1449 otherwise assign one */
1450 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1454 /* amount left to send in this message */
1455 len = txmsg->cur_len - txmsg->cur_offset;
1457 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1458 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1460 tosend = min(len, space);
1461 if (len == txmsg->cur_len)
1467 hdr.msg_len = tosend + 1;
1468 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1469 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1470 /* add crc at end */
1471 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1474 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1476 DRM_DEBUG_KMS("sideband msg failed to send\n");
1480 txmsg->cur_offset += tosend;
1481 if (txmsg->cur_offset == txmsg->cur_len) {
1482 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1488 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1490 struct drm_dp_sideband_msg_tx *txmsg;
1493 WARN_ON(!mutex_is_locked(&mgr->qlock));
1495 /* construct a chunk from the first msg in the tx_msg queue */
1496 if (list_empty(&mgr->tx_msg_downq)) {
1497 mgr->tx_down_in_progress = false;
1500 mgr->tx_down_in_progress = true;
1502 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1503 ret = process_single_tx_qlock(mgr, txmsg, false);
1505 /* txmsg is sent it should be in the slots now */
1506 list_del(&txmsg->next);
1508 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1509 list_del(&txmsg->next);
1510 if (txmsg->seqno != -1)
1511 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1512 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1513 wake_up(&mgr->tx_waitq);
1515 if (list_empty(&mgr->tx_msg_downq)) {
1516 mgr->tx_down_in_progress = false;
1521 /* called holding qlock */
1522 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1523 struct drm_dp_sideband_msg_tx *txmsg)
1527 /* construct a chunk from the first msg in the tx_msg queue */
1528 ret = process_single_tx_qlock(mgr, txmsg, true);
1531 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1533 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1536 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1537 struct drm_dp_sideband_msg_tx *txmsg)
1539 mutex_lock(&mgr->qlock);
1540 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1541 if (!mgr->tx_down_in_progress)
1542 process_single_down_tx_qlock(mgr);
1543 mutex_unlock(&mgr->qlock);
1546 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1547 struct drm_dp_mst_branch *mstb)
1550 struct drm_dp_sideband_msg_tx *txmsg;
1553 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1558 len = build_link_address(txmsg);
1560 mstb->link_address_sent = true;
1561 drm_dp_queue_down_tx(mgr, txmsg);
1563 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1567 if (txmsg->reply.reply_type == 1)
1568 DRM_DEBUG_KMS("link address nak received\n");
1570 DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1571 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1572 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,
1573 txmsg->reply.u.link_addr.ports[i].input_port,
1574 txmsg->reply.u.link_addr.ports[i].peer_device_type,
1575 txmsg->reply.u.link_addr.ports[i].port_number,
1576 txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1577 txmsg->reply.u.link_addr.ports[i].mcs,
1578 txmsg->reply.u.link_addr.ports[i].ddps,
1579 txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1580 txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1581 txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1584 drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);
1586 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1587 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1589 (*mgr->cbs->hotplug)(mgr);
1592 mstb->link_address_sent = false;
1593 DRM_DEBUG_KMS("link address failed %d\n", ret);
1599 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1600 struct drm_dp_mst_branch *mstb,
1601 struct drm_dp_mst_port *port)
1604 struct drm_dp_sideband_msg_tx *txmsg;
1607 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1612 len = build_enum_path_resources(txmsg, port->port_num);
1614 drm_dp_queue_down_tx(mgr, txmsg);
1616 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1618 if (txmsg->reply.reply_type == 1)
1619 DRM_DEBUG_KMS("enum path resources nak received\n");
1621 if (port->port_num != txmsg->reply.u.path_resources.port_number)
1622 DRM_ERROR("got incorrect port in response\n");
1623 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,
1624 txmsg->reply.u.path_resources.avail_payload_bw_number);
1625 port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1633 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
1635 if (!mstb->port_parent)
1638 if (mstb->port_parent->mstb != mstb)
1639 return mstb->port_parent;
1641 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
1644 static struct drm_dp_mst_branch *drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
1645 struct drm_dp_mst_branch *mstb,
1648 struct drm_dp_mst_branch *rmstb = NULL;
1649 struct drm_dp_mst_port *found_port;
1650 mutex_lock(&mgr->lock);
1651 if (mgr->mst_primary) {
1652 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
1655 rmstb = found_port->parent;
1656 kref_get(&rmstb->kref);
1657 *port_num = found_port->port_num;
1660 mutex_unlock(&mgr->lock);
1664 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1665 struct drm_dp_mst_port *port,
1669 struct drm_dp_sideband_msg_tx *txmsg;
1670 struct drm_dp_mst_branch *mstb;
1671 int len, ret, port_num;
1672 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
1675 port_num = port->port_num;
1676 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1678 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, port->parent, &port_num);
1684 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1690 for (i = 0; i < port->num_sdp_streams; i++)
1694 len = build_allocate_payload(txmsg, port_num,
1696 pbn, port->num_sdp_streams, sinks);
1698 drm_dp_queue_down_tx(mgr, txmsg);
1700 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1702 if (txmsg->reply.reply_type == 1) {
1709 drm_dp_put_mst_branch_device(mstb);
1713 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1715 struct drm_dp_payload *payload)
1719 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1721 payload->payload_state = 0;
1724 payload->payload_state = DP_PAYLOAD_LOCAL;
1728 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1729 struct drm_dp_mst_port *port,
1731 struct drm_dp_payload *payload)
1734 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1737 payload->payload_state = DP_PAYLOAD_REMOTE;
1741 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1742 struct drm_dp_mst_port *port,
1744 struct drm_dp_payload *payload)
1746 DRM_DEBUG_KMS("\n");
1747 /* its okay for these to fail */
1749 drm_dp_payload_send_msg(mgr, port, id, 0);
1752 drm_dp_dpcd_write_payload(mgr, id, payload);
1753 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1757 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1759 struct drm_dp_payload *payload)
1761 payload->payload_state = 0;
1766 * drm_dp_update_payload_part1() - Execute payload update part 1
1767 * @mgr: manager to use.
1769 * This iterates over all proposed virtual channels, and tries to
1770 * allocate space in the link for them. For 0->slots transitions,
1771 * this step just writes the VCPI to the MST device. For slots->0
1772 * transitions, this writes the updated VCPIs and removes the
1773 * remote VC payloads.
1775 * after calling this the driver should generate ACT and payload
1778 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1782 struct drm_dp_payload req_payload;
1783 struct drm_dp_mst_port *port;
1785 mutex_lock(&mgr->payload_lock);
1786 for (i = 0; i < mgr->max_payloads; i++) {
1787 /* solve the current payloads - compare to the hw ones
1788 - update the hw view */
1789 req_payload.start_slot = cur_slots;
1790 if (mgr->proposed_vcpis[i]) {
1791 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1792 req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1793 req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi;
1796 req_payload.num_slots = 0;
1799 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1800 mgr->payloads[i].start_slot = req_payload.start_slot;
1802 /* work out what is required to happen with this payload */
1803 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1805 /* need to push an update for this payload */
1806 if (req_payload.num_slots) {
1807 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1808 mgr->payloads[i].num_slots = req_payload.num_slots;
1809 mgr->payloads[i].vcpi = req_payload.vcpi;
1810 } else if (mgr->payloads[i].num_slots) {
1811 mgr->payloads[i].num_slots = 0;
1812 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
1813 req_payload.payload_state = mgr->payloads[i].payload_state;
1814 mgr->payloads[i].start_slot = 0;
1816 mgr->payloads[i].payload_state = req_payload.payload_state;
1818 cur_slots += req_payload.num_slots;
1821 for (i = 0; i < mgr->max_payloads; i++) {
1822 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1823 DRM_DEBUG_KMS("removing payload %d\n", i);
1824 for (j = i; j < mgr->max_payloads - 1; j++) {
1825 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1826 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1827 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1828 set_bit(j + 1, &mgr->payload_mask);
1830 clear_bit(j + 1, &mgr->payload_mask);
1833 memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1834 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1835 clear_bit(mgr->max_payloads, &mgr->payload_mask);
1839 mutex_unlock(&mgr->payload_lock);
1843 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1846 * drm_dp_update_payload_part2() - Execute payload update part 2
1847 * @mgr: manager to use.
1849 * This iterates over all proposed virtual channels, and tries to
1850 * allocate space in the link for them. For 0->slots transitions,
1851 * this step writes the remote VC payload commands. For slots->0
1852 * this just resets some internal state.
1854 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1856 struct drm_dp_mst_port *port;
1859 mutex_lock(&mgr->payload_lock);
1860 for (i = 0; i < mgr->max_payloads; i++) {
1862 if (!mgr->proposed_vcpis[i])
1865 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1867 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1868 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1869 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1870 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1871 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1874 mutex_unlock(&mgr->payload_lock);
1878 mutex_unlock(&mgr->payload_lock);
1881 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1883 #if 0 /* unused as of yet */
1884 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1885 struct drm_dp_mst_port *port,
1886 int offset, int size)
1889 struct drm_dp_sideband_msg_tx *txmsg;
1891 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1895 len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1896 txmsg->dst = port->parent;
1898 drm_dp_queue_down_tx(mgr, txmsg);
1904 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1905 struct drm_dp_mst_port *port,
1906 int offset, int size, u8 *bytes)
1910 struct drm_dp_sideband_msg_tx *txmsg;
1911 struct drm_dp_mst_branch *mstb;
1913 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1917 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1923 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1926 drm_dp_queue_down_tx(mgr, txmsg);
1928 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1930 if (txmsg->reply.reply_type == 1) {
1937 drm_dp_put_mst_branch_device(mstb);
1941 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1943 struct drm_dp_sideband_msg_reply_body reply;
1945 reply.reply_type = 0;
1946 reply.req_type = req_type;
1947 drm_dp_encode_sideband_reply(&reply, msg);
1951 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1952 struct drm_dp_mst_branch *mstb,
1953 int req_type, int seqno, bool broadcast)
1955 struct drm_dp_sideband_msg_tx *txmsg;
1957 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1962 txmsg->seqno = seqno;
1963 drm_dp_encode_up_ack_reply(txmsg, req_type);
1965 mutex_lock(&mgr->qlock);
1967 process_single_up_tx_qlock(mgr, txmsg);
1969 mutex_unlock(&mgr->qlock);
1975 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1979 switch (dp_link_bw) {
1981 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1982 dp_link_bw, dp_link_count);
1985 case DP_LINK_BW_1_62:
1986 *out = 3 * dp_link_count;
1988 case DP_LINK_BW_2_7:
1989 *out = 5 * dp_link_count;
1991 case DP_LINK_BW_5_4:
1992 *out = 10 * dp_link_count;
1999 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
2000 * @mgr: manager to set state for
2001 * @mst_state: true to enable MST on this connector - false to disable.
2003 * This is called by the driver when it detects an MST capable device plugged
2004 * into a DP MST capable port, or when a DP MST capable device is unplugged.
2006 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
2009 struct drm_dp_mst_branch *mstb = NULL;
2011 mutex_lock(&mgr->lock);
2012 if (mst_state == mgr->mst_state)
2015 mgr->mst_state = mst_state;
2016 /* set the device into MST mode */
2018 WARN_ON(mgr->mst_primary);
2021 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2022 if (ret != DP_RECEIVER_CAP_SIZE) {
2023 DRM_DEBUG_KMS("failed to read DPCD\n");
2027 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
2028 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
2034 mgr->total_pbn = 2560;
2035 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
2036 mgr->avail_slots = mgr->total_slots;
2038 /* add initial branch device at LCT 1 */
2039 mstb = drm_dp_add_mst_branch_device(1, NULL);
2046 /* give this the main reference */
2047 mgr->mst_primary = mstb;
2048 kref_get(&mgr->mst_primary->kref);
2050 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2051 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2057 struct drm_dp_payload reset_pay;
2058 reset_pay.start_slot = 0;
2059 reset_pay.num_slots = 0x3f;
2060 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
2063 queue_work(system_long_wq, &mgr->work);
2067 /* disable MST on the device */
2068 mstb = mgr->mst_primary;
2069 mgr->mst_primary = NULL;
2070 /* this can fail if the device is gone */
2071 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2073 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2074 mgr->payload_mask = 0;
2075 set_bit(0, &mgr->payload_mask);
2080 mutex_unlock(&mgr->lock);
2082 drm_dp_put_mst_branch_device(mstb);
2086 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2089 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2090 * @mgr: manager to suspend
2092 * This function tells the MST device that we can't handle UP messages
2093 * anymore. This should stop it from sending any since we are suspended.
2095 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2097 mutex_lock(&mgr->lock);
2098 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2099 DP_MST_EN | DP_UPSTREAM_IS_SRC);
2100 mutex_unlock(&mgr->lock);
2101 flush_work(&mgr->work);
2102 flush_work(&mgr->destroy_connector_work);
2104 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2107 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2108 * @mgr: manager to resume
2110 * This will fetch DPCD and see if the device is still there,
2111 * if it is, it will rewrite the MSTM control bits, and return.
2113 * if the device fails this returns -1, and the driver should do
2114 * a full MST reprobe, in case we were undocked.
2116 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2120 mutex_lock(&mgr->lock);
2122 if (mgr->mst_primary) {
2124 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2125 if (sret != DP_RECEIVER_CAP_SIZE) {
2126 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2131 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2132 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2134 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2143 mutex_unlock(&mgr->lock);
2146 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2148 static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2152 int replylen, origlen, curreply;
2154 struct drm_dp_sideband_msg_rx *msg;
2155 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2156 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2158 len = min(mgr->max_dpcd_transaction_bytes, 16);
2159 ret = drm_dp_dpcd_read(mgr->aux, basereg,
2162 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2165 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2167 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2170 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2175 while (replylen > 0) {
2176 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2177 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2180 DRM_DEBUG_KMS("failed to read a chunk\n");
2182 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2184 DRM_DEBUG_KMS("failed to build sideband msg\n");
2190 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2194 drm_dp_get_one_sb_msg(mgr, false);
2196 if (mgr->down_rep_recv.have_eomt) {
2197 struct drm_dp_sideband_msg_tx *txmsg;
2198 struct drm_dp_mst_branch *mstb;
2200 mstb = drm_dp_get_mst_branch_device(mgr,
2201 mgr->down_rep_recv.initial_hdr.lct,
2202 mgr->down_rep_recv.initial_hdr.rad);
2205 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2206 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2210 /* find the message */
2211 slot = mgr->down_rep_recv.initial_hdr.seqno;
2212 mutex_lock(&mgr->qlock);
2213 txmsg = mstb->tx_slots[slot];
2214 /* remove from slots */
2215 mutex_unlock(&mgr->qlock);
2218 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2220 mgr->down_rep_recv.initial_hdr.seqno,
2221 mgr->down_rep_recv.initial_hdr.lct,
2222 mgr->down_rep_recv.initial_hdr.rad[0],
2223 mgr->down_rep_recv.msg[0]);
2224 drm_dp_put_mst_branch_device(mstb);
2225 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2229 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2230 if (txmsg->reply.reply_type == 1) {
2231 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);
2234 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2235 drm_dp_put_mst_branch_device(mstb);
2237 mutex_lock(&mgr->qlock);
2238 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2239 mstb->tx_slots[slot] = NULL;
2240 mutex_unlock(&mgr->qlock);
2242 wake_up(&mgr->tx_waitq);
2247 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2250 drm_dp_get_one_sb_msg(mgr, true);
2252 if (mgr->up_req_recv.have_eomt) {
2253 struct drm_dp_sideband_msg_req_body msg;
2254 struct drm_dp_mst_branch *mstb = NULL;
2257 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2258 mstb = drm_dp_get_mst_branch_device(mgr,
2259 mgr->up_req_recv.initial_hdr.lct,
2260 mgr->up_req_recv.initial_hdr.rad);
2262 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2263 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2268 seqno = mgr->up_req_recv.initial_hdr.seqno;
2269 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2271 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2272 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2275 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2278 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2279 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2283 drm_dp_update_port(mstb, &msg.u.conn_stat);
2285 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);
2286 (*mgr->cbs->hotplug)(mgr);
2288 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2289 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2291 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2294 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2295 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2299 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2302 drm_dp_put_mst_branch_device(mstb);
2303 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2309 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2310 * @mgr: manager to notify irq for.
2311 * @esi: 4 bytes from SINK_COUNT_ESI
2312 * @handled: whether the hpd interrupt was consumed or not
2314 * This should be called from the driver when it detects a short IRQ,
2315 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2316 * topology manager will process the sideband messages received as a result
2319 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2326 if (sc != mgr->sink_count) {
2327 mgr->sink_count = sc;
2331 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2332 ret = drm_dp_mst_handle_down_rep(mgr);
2336 if (esi[1] & DP_UP_REQ_MSG_RDY) {
2337 ret |= drm_dp_mst_handle_up_req(mgr);
2341 drm_dp_mst_kick_tx(mgr);
2344 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2347 * drm_dp_mst_detect_port() - get connection status for an MST port
2348 * @mgr: manager for this port
2349 * @port: unverified pointer to a port
2351 * This returns the current connection state for a port. It validates the
2352 * port pointer still exists so the caller doesn't require a reference
2354 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2355 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2357 enum drm_connector_status status = connector_status_disconnected;
2359 /* we need to search for the port in the mgr in case its gone */
2360 port = drm_dp_get_validated_port_ref(mgr, port);
2362 return connector_status_disconnected;
2367 switch (port->pdt) {
2368 case DP_PEER_DEVICE_NONE:
2369 case DP_PEER_DEVICE_MST_BRANCHING:
2372 case DP_PEER_DEVICE_SST_SINK:
2373 status = connector_status_connected;
2374 /* for logical ports - cache the EDID */
2375 if (port->port_num >= 8 && !port->cached_edid) {
2376 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2379 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2381 status = connector_status_connected;
2385 drm_dp_put_port(port);
2388 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2391 * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
2392 * @mgr: manager for this port
2393 * @port: unverified pointer to a port.
2395 * This returns whether the port supports audio or not.
2397 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
2398 struct drm_dp_mst_port *port)
2402 port = drm_dp_get_validated_port_ref(mgr, port);
2405 ret = port->has_audio;
2406 drm_dp_put_port(port);
2409 EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
2412 * drm_dp_mst_get_edid() - get EDID for an MST port
2413 * @connector: toplevel connector to get EDID for
2414 * @mgr: manager for this port
2415 * @port: unverified pointer to a port.
2417 * This returns an EDID for the port connected to a connector,
2418 * It validates the pointer still exists so the caller doesn't require a
2421 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2423 struct edid *edid = NULL;
2425 /* we need to search for the port in the mgr in case its gone */
2426 port = drm_dp_get_validated_port_ref(mgr, port);
2430 if (port->cached_edid)
2431 edid = drm_edid_duplicate(port->cached_edid);
2433 edid = drm_get_edid(connector, &port->aux.ddc);
2434 drm_mode_connector_set_tile_property(connector);
2436 port->has_audio = drm_detect_monitor_audio(edid);
2437 drm_dp_put_port(port);
2440 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2443 * drm_dp_find_vcpi_slots() - find slots for this PBN value
2444 * @mgr: manager to use
2445 * @pbn: payload bandwidth to convert into slots.
2447 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2452 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2454 if (num_slots > mgr->avail_slots)
2458 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2460 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2461 struct drm_dp_vcpi *vcpi, int pbn)
2466 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2468 if (num_slots > mgr->avail_slots)
2472 vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2473 vcpi->num_slots = num_slots;
2475 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2482 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2483 * @mgr: manager for this port
2484 * @port: port to allocate a virtual channel for.
2485 * @pbn: payload bandwidth number to request
2486 * @slots: returned number of slots for this PBN.
2488 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2492 port = drm_dp_get_validated_port_ref(mgr, port);
2496 if (port->vcpi.vcpi > 0) {
2497 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2498 if (pbn == port->vcpi.pbn) {
2499 *slots = port->vcpi.num_slots;
2500 drm_dp_put_port(port);
2505 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2507 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2510 DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2511 *slots = port->vcpi.num_slots;
2513 drm_dp_put_port(port);
2518 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2520 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2523 port = drm_dp_get_validated_port_ref(mgr, port);
2527 slots = port->vcpi.num_slots;
2528 drm_dp_put_port(port);
2531 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2534 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2535 * @mgr: manager for this port
2536 * @port: unverified pointer to a port.
2538 * This just resets the number of slots for the ports VCPI for later programming.
2540 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2542 port = drm_dp_get_validated_port_ref(mgr, port);
2545 port->vcpi.num_slots = 0;
2546 drm_dp_put_port(port);
2548 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2551 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2552 * @mgr: manager for this port
2553 * @port: unverified port to deallocate vcpi for
2555 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2557 port = drm_dp_get_validated_port_ref(mgr, port);
2561 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2562 port->vcpi.num_slots = 0;
2564 port->vcpi.aligned_pbn = 0;
2565 port->vcpi.vcpi = 0;
2566 drm_dp_put_port(port);
2568 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2570 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2571 int id, struct drm_dp_payload *payload)
2573 u8 payload_alloc[3], status;
2577 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2578 DP_PAYLOAD_TABLE_UPDATED);
2580 payload_alloc[0] = id;
2581 payload_alloc[1] = payload->start_slot;
2582 payload_alloc[2] = payload->num_slots;
2584 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2586 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2591 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2593 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2597 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2600 usleep_range(10000, 20000);
2603 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2614 * drm_dp_check_act_status() - Check ACT handled status.
2615 * @mgr: manager to use
2617 * Check the payload status bits in the DPCD for ACT handled completion.
2619 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2626 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2629 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2633 if (status & DP_PAYLOAD_ACT_HANDLED)
2638 } while (count < 30);
2640 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2641 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2649 EXPORT_SYMBOL(drm_dp_check_act_status);
2652 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2653 * @clock: dot clock for the mode
2654 * @bpp: bpp for the mode.
2656 * This uses the formula in the spec to calculate the PBN value for a mode.
2658 int drm_dp_calc_pbn_mode(int clock, int bpp)
2668 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
2669 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
2670 * common multiplier to render an integer PBN for all link rate/lane
2671 * counts combinations
2673 * peak_kbps *= (1006/1000)
2674 * peak_kbps *= (64/54)
2675 * peak_kbps *= 8 convert to bytes
2678 numerator = 64 * 1006;
2679 denominator = 54 * 8 * 1000 * 1000;
2682 peak_kbps = drm_fixp_from_fraction(kbps, denominator);
2684 return drm_fixp2int_ceil(peak_kbps);
2686 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2688 static int test_calc_pbn_mode(void)
2691 ret = drm_dp_calc_pbn_mode(154000, 30);
2693 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2694 154000, 30, 689, ret);
2697 ret = drm_dp_calc_pbn_mode(234000, 30);
2699 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2700 234000, 30, 1047, ret);
2703 ret = drm_dp_calc_pbn_mode(297000, 24);
2705 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2706 297000, 24, 1063, ret);
2712 /* we want to kick the TX after we've ack the up/down IRQs. */
2713 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2715 queue_work(system_long_wq, &mgr->tx_work);
2718 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2719 struct drm_dp_mst_branch *mstb)
2721 struct drm_dp_mst_port *port;
2722 int tabs = mstb->lct;
2726 for (i = 0; i < tabs; i++)
2730 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2731 list_for_each_entry(port, &mstb->ports, next) {
2732 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
2734 drm_dp_mst_dump_mstb(m, port->mstb);
2738 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2743 for (i = 0; i < 4; i++) {
2744 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2754 * drm_dp_mst_dump_topology(): dump topology to seq file.
2755 * @m: seq_file to dump output to
2756 * @mgr: manager to dump current topology for.
2758 * helper to dump MST topology to a seq file for debugfs.
2760 void drm_dp_mst_dump_topology(struct seq_file *m,
2761 struct drm_dp_mst_topology_mgr *mgr)
2764 struct drm_dp_mst_port *port;
2765 mutex_lock(&mgr->lock);
2766 if (mgr->mst_primary)
2767 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2770 mutex_unlock(&mgr->lock);
2772 mutex_lock(&mgr->payload_lock);
2773 seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
2775 for (i = 0; i < mgr->max_payloads; i++) {
2776 if (mgr->proposed_vcpis[i]) {
2777 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2778 seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2780 seq_printf(m, "vcpi %d:unsed\n", i);
2782 for (i = 0; i < mgr->max_payloads; i++) {
2783 seq_printf(m, "payload %d: %d, %d, %d\n",
2785 mgr->payloads[i].payload_state,
2786 mgr->payloads[i].start_slot,
2787 mgr->payloads[i].num_slots);
2791 mutex_unlock(&mgr->payload_lock);
2793 mutex_lock(&mgr->lock);
2794 if (mgr->mst_primary) {
2798 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2799 seq_printf(m, "dpcd: ");
2800 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2801 seq_printf(m, "%02x ", buf[i]);
2802 seq_printf(m, "\n");
2803 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2804 seq_printf(m, "faux/mst: ");
2805 for (i = 0; i < 2; i++)
2806 seq_printf(m, "%02x ", buf[i]);
2807 seq_printf(m, "\n");
2808 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2809 seq_printf(m, "mst ctrl: ");
2810 for (i = 0; i < 1; i++)
2811 seq_printf(m, "%02x ", buf[i]);
2812 seq_printf(m, "\n");
2814 /* dump the standard OUI branch header */
2815 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
2816 seq_printf(m, "branch oui: ");
2817 for (i = 0; i < 0x3; i++)
2818 seq_printf(m, "%02x", buf[i]);
2819 seq_printf(m, " devid: ");
2820 for (i = 0x3; i < 0x8; i++)
2821 seq_printf(m, "%c", buf[i]);
2822 seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
2823 seq_printf(m, "\n");
2824 bret = dump_dp_payload_table(mgr, buf);
2826 seq_printf(m, "payload table: ");
2827 for (i = 0; i < 63; i++)
2828 seq_printf(m, "%02x ", buf[i]);
2829 seq_printf(m, "\n");
2834 mutex_unlock(&mgr->lock);
2837 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2839 static void drm_dp_tx_work(struct work_struct *work)
2841 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2843 mutex_lock(&mgr->qlock);
2844 if (mgr->tx_down_in_progress)
2845 process_single_down_tx_qlock(mgr);
2846 mutex_unlock(&mgr->qlock);
2849 static void drm_dp_free_mst_port(struct kref *kref)
2851 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
2852 kref_put(&port->parent->kref, drm_dp_free_mst_branch_device);
2856 static void drm_dp_destroy_connector_work(struct work_struct *work)
2858 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
2859 struct drm_dp_mst_port *port;
2860 bool send_hotplug = false;
2862 * Not a regular list traverse as we have to drop the destroy
2863 * connector lock before destroying the connector, to avoid AB->BA
2864 * ordering between this lock and the config mutex.
2867 mutex_lock(&mgr->destroy_connector_lock);
2868 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
2870 mutex_unlock(&mgr->destroy_connector_lock);
2873 list_del(&port->next);
2874 mutex_unlock(&mgr->destroy_connector_lock);
2876 kref_init(&port->kref);
2877 INIT_LIST_HEAD(&port->next);
2879 mgr->cbs->destroy_connector(mgr, port->connector);
2881 drm_dp_port_teardown_pdt(port, port->pdt);
2883 if (!port->input && port->vcpi.vcpi > 0) {
2884 if (mgr->mst_state) {
2885 drm_dp_mst_reset_vcpi_slots(mgr, port);
2886 drm_dp_update_payload_part1(mgr);
2887 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2891 kref_put(&port->kref, drm_dp_free_mst_port);
2892 send_hotplug = true;
2895 (*mgr->cbs->hotplug)(mgr);
2899 * drm_dp_mst_topology_mgr_init - initialise a topology manager
2900 * @mgr: manager struct to initialise
2901 * @dev: device providing this structure - for i2c addition.
2902 * @aux: DP helper aux channel to talk to this device
2903 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2904 * @max_payloads: maximum number of payloads this GPU can source
2905 * @conn_base_id: the connector object ID the MST device is connected to.
2907 * Return 0 for success, or negative error code on failure
2909 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2910 struct device *dev, struct drm_dp_aux *aux,
2911 int max_dpcd_transaction_bytes,
2912 int max_payloads, int conn_base_id)
2914 mutex_init(&mgr->lock);
2915 mutex_init(&mgr->qlock);
2916 mutex_init(&mgr->payload_lock);
2917 mutex_init(&mgr->destroy_connector_lock);
2918 INIT_LIST_HEAD(&mgr->tx_msg_downq);
2919 INIT_LIST_HEAD(&mgr->destroy_connector_list);
2920 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2921 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2922 INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
2923 init_waitqueue_head(&mgr->tx_waitq);
2926 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2927 mgr->max_payloads = max_payloads;
2928 mgr->conn_base_id = conn_base_id;
2929 if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
2930 max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
2932 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2935 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2936 if (!mgr->proposed_vcpis)
2938 set_bit(0, &mgr->payload_mask);
2939 if (test_calc_pbn_mode() < 0)
2940 DRM_ERROR("MST PBN self-test failed\n");
2944 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2947 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2948 * @mgr: manager to destroy
2950 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2952 flush_work(&mgr->work);
2953 flush_work(&mgr->destroy_connector_work);
2954 mutex_lock(&mgr->payload_lock);
2955 kfree(mgr->payloads);
2956 mgr->payloads = NULL;
2957 kfree(mgr->proposed_vcpis);
2958 mgr->proposed_vcpis = NULL;
2959 mutex_unlock(&mgr->payload_lock);
2963 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
2966 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
2969 struct drm_dp_aux *aux = adapter->algo_data;
2970 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
2971 struct drm_dp_mst_branch *mstb;
2972 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2974 bool reading = false;
2975 struct drm_dp_sideband_msg_req_body msg;
2976 struct drm_dp_sideband_msg_tx *txmsg = NULL;
2979 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2983 /* construct i2c msg */
2984 /* see if last msg is a read */
2985 if (msgs[num - 1].flags & I2C_M_RD)
2988 if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
2989 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
2994 memset(&msg, 0, sizeof(msg));
2995 msg.req_type = DP_REMOTE_I2C_READ;
2996 msg.u.i2c_read.num_transactions = num - 1;
2997 msg.u.i2c_read.port_number = port->port_num;
2998 for (i = 0; i < num - 1; i++) {
2999 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
3000 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
3001 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
3003 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
3004 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
3006 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3013 drm_dp_encode_sideband_req(&msg, txmsg);
3015 drm_dp_queue_down_tx(mgr, txmsg);
3017 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3020 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
3024 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
3028 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
3033 drm_dp_put_mst_branch_device(mstb);
3037 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
3039 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
3040 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
3041 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
3042 I2C_FUNC_10BIT_ADDR;
3045 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
3046 .functionality = drm_dp_mst_i2c_functionality,
3047 .master_xfer = drm_dp_mst_i2c_xfer,
3051 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
3052 * @aux: DisplayPort AUX channel
3054 * Returns 0 on success or a negative error code on failure.
3056 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
3058 aux->ddc.algo = &drm_dp_mst_i2c_algo;
3059 aux->ddc.algo_data = aux;
3060 aux->ddc.retries = 3;
3062 aux->ddc.class = I2C_CLASS_DDC;
3063 aux->ddc.owner = THIS_MODULE;
3064 aux->ddc.dev.parent = aux->dev;
3065 aux->ddc.dev.of_node = aux->dev->of_node;
3067 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
3068 sizeof(aux->ddc.name));
3070 return i2c_add_adapter(&aux->ddc);
3074 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
3075 * @aux: DisplayPort AUX channel
3077 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
3079 i2c_del_adapter(&aux->ddc);