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Merge tag 'sound-fix-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai...
[linux.git] / drivers / gpu / drm / drm_dp_mst_topology.c
CommitLineData
ad7f8a1f
DA		 1/*
2 * Copyright © 2014 Red Hat
3 *
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission. The copyright holders make no representations
11 * about the suitability of this software for any purpose. It is provided "as
12 * is" without express or implied warranty.
13 *
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20 * OF THIS SOFTWARE.
21 */
22
23#include <linux/kernel.h>
24#include <linux/delay.h>
25#include <linux/init.h>
26#include <linux/errno.h>
27#include <linux/sched.h>
75bc08ab 28#include <linux/seq_file.h>
ad7f8a1f
DA		 29#include <linux/i2c.h>
30#include <drm/drm_dp_mst_helper.h>
31#include <drm/drmP.h>
32
33#include <drm/drm_fixed.h>
a4370c77
VS		 34#include <drm/drm_atomic.h>
35#include <drm/drm_atomic_helper.h>
ad7f8a1f
DA		 36
37/**
38 * DOC: dp mst helper
39 *
40 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
41 * protocol. The helpers contain a topology manager and bandwidth manager.
42 * The helpers encapsulate the sending and received of sideband msgs.
43 */
44static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
45 char *buf);
46static int test_calc_pbn_mode(void);
47
48static void drm_dp_put_port(struct drm_dp_mst_port *port);
49
50static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
51 int id,
52 struct drm_dp_payload *payload);
53
54static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
55 struct drm_dp_mst_port *port,
56 int offset, int size, u8 *bytes);
57
68d8c9fc
DA		 58static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
59 struct drm_dp_mst_branch *mstb);
ad7f8a1f
DA		 60static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
61 struct drm_dp_mst_branch *mstb,
62 struct drm_dp_mst_port *port);
63static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
64 u8 *guid);
65
66static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
67static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
68static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
69/* sideband msg handling */
70static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
71{
72 u8 bitmask = 0x80;
73 u8 bitshift = 7;
74 u8 array_index = 0;
75 int number_of_bits = num_nibbles * 4;
76 u8 remainder = 0;
77
78 while (number_of_bits != 0) {
79 number_of_bits--;
80 remainder <<= 1;
81 remainder |= (data[array_index] & bitmask) >> bitshift;
82 bitmask >>= 1;
83 bitshift--;
84 if (bitmask == 0) {
85 bitmask = 0x80;
86 bitshift = 7;
87 array_index++;
88 }
89 if ((remainder & 0x10) == 0x10)
90 remainder ^= 0x13;
91 }
92
93 number_of_bits = 4;
94 while (number_of_bits != 0) {
95 number_of_bits--;
96 remainder <<= 1;
97 if ((remainder & 0x10) != 0)
98 remainder ^= 0x13;
99 }
100
101 return remainder;
102}
103
104static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
105{
106 u8 bitmask = 0x80;
107 u8 bitshift = 7;
108 u8 array_index = 0;
109 int number_of_bits = number_of_bytes * 8;
110 u16 remainder = 0;
111
112 while (number_of_bits != 0) {
113 number_of_bits--;
114 remainder <<= 1;
115 remainder |= (data[array_index] & bitmask) >> bitshift;
116 bitmask >>= 1;
117 bitshift--;
118 if (bitmask == 0) {
119 bitmask = 0x80;
120 bitshift = 7;
121 array_index++;
122 }
123 if ((remainder & 0x100) == 0x100)
124 remainder ^= 0xd5;
125 }
126
127 number_of_bits = 8;
128 while (number_of_bits != 0) {
129 number_of_bits--;
130 remainder <<= 1;
131 if ((remainder & 0x100) != 0)
132 remainder ^= 0xd5;
133 }
134
135 return remainder & 0xff;
136}
137static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
138{
139 u8 size = 3;
140 size += (hdr->lct / 2);
141 return size;
142}
143
144static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
145 u8 *buf, int *len)
146{
147 int idx = 0;
148 int i;
149 u8 crc4;
150 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
151 for (i = 0; i < (hdr->lct / 2); i++)
152 buf[idx++] = hdr->rad[i];
153 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
154 (hdr->msg_len & 0x3f);
155 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
156
157 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
158 buf[idx - 1] |= (crc4 & 0xf);
159
160 *len = idx;
161}
162
163static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
164 u8 *buf, int buflen, u8 *hdrlen)
165{
166 u8 crc4;
167 u8 len;
168 int i;
169 u8 idx;
170 if (buf[0] == 0)
171 return false;
172 len = 3;
173 len += ((buf[0] & 0xf0) >> 4) / 2;
174 if (len > buflen)
175 return false;
176 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
177
178 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
179 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
180 return false;
181 }
182
183 hdr->lct = (buf[0] & 0xf0) >> 4;
184 hdr->lcr = (buf[0] & 0xf);
185 idx = 1;
186 for (i = 0; i < (hdr->lct / 2); i++)
187 hdr->rad[i] = buf[idx++];
188 hdr->broadcast = (buf[idx] >> 7) & 0x1;
189 hdr->path_msg = (buf[idx] >> 6) & 0x1;
190 hdr->msg_len = buf[idx] & 0x3f;
191 idx++;
192 hdr->somt = (buf[idx] >> 7) & 0x1;
193 hdr->eomt = (buf[idx] >> 6) & 0x1;
194 hdr->seqno = (buf[idx] >> 4) & 0x1;
195 idx++;
196 *hdrlen = idx;
197 return true;
198}
199
200static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req,
201 struct drm_dp_sideband_msg_tx *raw)
202{
203 int idx = 0;
204 int i;
205 u8 *buf = raw->msg;
206 buf[idx++] = req->req_type & 0x7f;
207
208 switch (req->req_type) {
209 case DP_ENUM_PATH_RESOURCES:
210 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
211 idx++;
212 break;
213 case DP_ALLOCATE_PAYLOAD:
214 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
215 (req->u.allocate_payload.number_sdp_streams & 0xf);
216 idx++;
217 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
218 idx++;
219 buf[idx] = (req->u.allocate_payload.pbn >> 8);
220 idx++;
221 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
222 idx++;
223 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
224 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
225 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
226 idx++;
227 }
228 if (req->u.allocate_payload.number_sdp_streams & 1) {
229 i = req->u.allocate_payload.number_sdp_streams - 1;
230 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
231 idx++;
232 }
233 break;
234 case DP_QUERY_PAYLOAD:
235 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
236 idx++;
237 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
238 idx++;
239 break;
240 case DP_REMOTE_DPCD_READ:
241 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
242 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
243 idx++;
244 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
245 idx++;
246 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
247 idx++;
248 buf[idx] = (req->u.dpcd_read.num_bytes);
249 idx++;
250 break;
251
252 case DP_REMOTE_DPCD_WRITE:
253 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
254 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
255 idx++;
256 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
257 idx++;
258 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
259 idx++;
260 buf[idx] = (req->u.dpcd_write.num_bytes);
261 idx++;
262 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
263 idx += req->u.dpcd_write.num_bytes;
264 break;
265 case DP_REMOTE_I2C_READ:
266 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
267 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
268 idx++;
269 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
270 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
271 idx++;
272 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
273 idx++;
274 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
275 idx += req->u.i2c_read.transactions[i].num_bytes;
276
277 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
278 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
279 idx++;
280 }
281 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
282 idx++;
283 buf[idx] = (req->u.i2c_read.num_bytes_read);
284 idx++;
285 break;
286
287 case DP_REMOTE_I2C_WRITE:
288 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
289 idx++;
290 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
291 idx++;
292 buf[idx] = (req->u.i2c_write.num_bytes);
293 idx++;
294 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
295 idx += req->u.i2c_write.num_bytes;
296 break;
0bb9c2b2
DP		 297
298 case DP_POWER_DOWN_PHY:
299 case DP_POWER_UP_PHY:
300 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
301 idx++;
302 break;
ad7f8a1f
DA		 303 }
304 raw->cur_len = idx;
305}
306
307static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
308{
309 u8 crc4;
310 crc4 = drm_dp_msg_data_crc4(msg, len);
311 msg[len] = crc4;
312}
313
314static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
315 struct drm_dp_sideband_msg_tx *raw)
316{
317 int idx = 0;
318 u8 *buf = raw->msg;
319
320 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
321
322 raw->cur_len = idx;
323}
324
325/* this adds a chunk of msg to the builder to get the final msg */
326static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
327 u8 *replybuf, u8 replybuflen, bool hdr)
328{
329 int ret;
330 u8 crc4;
331
332 if (hdr) {
333 u8 hdrlen;
334 struct drm_dp_sideband_msg_hdr recv_hdr;
335 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
336 if (ret == false) {
337 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
338 return false;
339 }
340
636c4c3e
ID		 341 /*
342 * ignore out-of-order messages or messages that are part of a
343 * failed transaction
344 */
345 if (!recv_hdr.somt && !msg->have_somt)
346 return false;
347
ad7f8a1f
DA		 348 /* get length contained in this portion */
349 msg->curchunk_len = recv_hdr.msg_len;
350 msg->curchunk_hdrlen = hdrlen;
351
352 /* we have already gotten an somt - don't bother parsing */
353 if (recv_hdr.somt && msg->have_somt)
354 return false;
355
356 if (recv_hdr.somt) {
357 memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
358 msg->have_somt = true;
359 }
360 if (recv_hdr.eomt)
361 msg->have_eomt = true;
362
363 /* copy the bytes for the remainder of this header chunk */
364 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
365 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
366 } else {
367 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
368 msg->curchunk_idx += replybuflen;
369 }
370
371 if (msg->curchunk_idx >= msg->curchunk_len) {
372 /* do CRC */
373 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
374 /* copy chunk into bigger msg */
375 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
376 msg->curlen += msg->curchunk_len - 1;
377 }
378 return true;
379}
380
381static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
382 struct drm_dp_sideband_msg_reply_body *repmsg)
383{
384 int idx = 1;
385 int i;
386 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
387 idx += 16;
388 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
389 idx++;
390 if (idx > raw->curlen)
391 goto fail_len;
392 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
393 if (raw->msg[idx] & 0x80)
394 repmsg->u.link_addr.ports[i].input_port = 1;
395
396 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
397 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
398
399 idx++;
400 if (idx > raw->curlen)
401 goto fail_len;
402 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
403 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
404 if (repmsg->u.link_addr.ports[i].input_port == 0)
405 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
406 idx++;
407 if (idx > raw->curlen)
408 goto fail_len;
409 if (repmsg->u.link_addr.ports[i].input_port == 0) {
410 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
411 idx++;
412 if (idx > raw->curlen)
413 goto fail_len;
414 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
415 idx += 16;
416 if (idx > raw->curlen)
417 goto fail_len;
418 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
419 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
420 idx++;
421
422 }
423 if (idx > raw->curlen)
424 goto fail_len;
425 }
426
427 return true;
428fail_len:
429 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
430 return false;
431}
432
433static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
434 struct drm_dp_sideband_msg_reply_body *repmsg)
435{
436 int idx = 1;
437 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
438 idx++;
439 if (idx > raw->curlen)
440 goto fail_len;
441 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
a4c30a48 442 idx++;
ad7f8a1f
DA		 443 if (idx > raw->curlen)
444 goto fail_len;
445
446 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
447 return true;
448fail_len:
449 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
450 return false;
451}
452
453static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
454 struct drm_dp_sideband_msg_reply_body *repmsg)
455{
456 int idx = 1;
457 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
458 idx++;
459 if (idx > raw->curlen)
460 goto fail_len;
461 return true;
462fail_len:
463 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
464 return false;
465}
466
467static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
468 struct drm_dp_sideband_msg_reply_body *repmsg)
469{
470 int idx = 1;
471
472 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
473 idx++;
474 if (idx > raw->curlen)
475 goto fail_len;
476 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
477 idx++;
478 /* TODO check */
479 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
480 return true;
481fail_len:
482 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
483 return false;
484}
485
486static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
487 struct drm_dp_sideband_msg_reply_body *repmsg)
488{
489 int idx = 1;
490 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
491 idx++;
492 if (idx > raw->curlen)
493 goto fail_len;
494 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
495 idx += 2;
496 if (idx > raw->curlen)
497 goto fail_len;
498 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
499 idx += 2;
500 if (idx > raw->curlen)
501 goto fail_len;
502 return true;
503fail_len:
504 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
505 return false;
506}
507
508static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
509 struct drm_dp_sideband_msg_reply_body *repmsg)
510{
511 int idx = 1;
512 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
513 idx++;
514 if (idx > raw->curlen)
515 goto fail_len;
516 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
517 idx++;
518 if (idx > raw->curlen)
519 goto fail_len;
520 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
521 idx += 2;
522 if (idx > raw->curlen)
523 goto fail_len;
524 return true;
525fail_len:
526 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
527 return false;
528}
529
530static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
531 struct drm_dp_sideband_msg_reply_body *repmsg)
532{
533 int idx = 1;
534 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
535 idx++;
536 if (idx > raw->curlen)
537 goto fail_len;
538 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
539 idx += 2;
540 if (idx > raw->curlen)
541 goto fail_len;
542 return true;
543fail_len:
544 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
545 return false;
546}
547
0bb9c2b2
DP		 548static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
549 struct drm_dp_sideband_msg_reply_body *repmsg)
550{
551 int idx = 1;
552
553 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
554 idx++;
555 if (idx > raw->curlen) {
556 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
557 idx, raw->curlen);
558 return false;
559 }
560 return true;
561}
562
ad7f8a1f
DA		 563static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
564 struct drm_dp_sideband_msg_reply_body *msg)
565{
566 memset(msg, 0, sizeof(*msg));
567 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
568 msg->req_type = (raw->msg[0] & 0x7f);
569
570 if (msg->reply_type) {
571 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
572 msg->u.nak.reason = raw->msg[17];
573 msg->u.nak.nak_data = raw->msg[18];
574 return false;
575 }
576
577 switch (msg->req_type) {
578 case DP_LINK_ADDRESS:
579 return drm_dp_sideband_parse_link_address(raw, msg);
580 case DP_QUERY_PAYLOAD:
581 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
582 case DP_REMOTE_DPCD_READ:
583 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
584 case DP_REMOTE_DPCD_WRITE:
585 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
586 case DP_REMOTE_I2C_READ:
587 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
588 case DP_ENUM_PATH_RESOURCES:
589 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
590 case DP_ALLOCATE_PAYLOAD:
591 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
0bb9c2b2
DP		 592 case DP_POWER_DOWN_PHY:
593 case DP_POWER_UP_PHY:
594 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
ad7f8a1f
DA		 595 default:
596 DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
597 return false;
598 }
599}
600
601static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
602 struct drm_dp_sideband_msg_req_body *msg)
603{
604 int idx = 1;
605
606 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
607 idx++;
608 if (idx > raw->curlen)
609 goto fail_len;
610
611 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
612 idx += 16;
613 if (idx > raw->curlen)
614 goto fail_len;
615
616 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
617 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
618 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
619 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
620 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
621 idx++;
622 return true;
623fail_len:
624 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
625 return false;
626}
627
628static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
629 struct drm_dp_sideband_msg_req_body *msg)
630{
631 int idx = 1;
632
633 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
634 idx++;
635 if (idx > raw->curlen)
636 goto fail_len;
637
638 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
639 idx += 16;
640 if (idx > raw->curlen)
641 goto fail_len;
642
643 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
644 idx++;
645 return true;
646fail_len:
647 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
648 return false;
649}
650
651static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
652 struct drm_dp_sideband_msg_req_body *msg)
653{
654 memset(msg, 0, sizeof(*msg));
655 msg->req_type = (raw->msg[0] & 0x7f);
656
657 switch (msg->req_type) {
658 case DP_CONNECTION_STATUS_NOTIFY:
659 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
660 case DP_RESOURCE_STATUS_NOTIFY:
661 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
662 default:
663 DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
664 return false;
665 }
666}
667
668static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
669{
670 struct drm_dp_sideband_msg_req_body req;
671
672 req.req_type = DP_REMOTE_DPCD_WRITE;
673 req.u.dpcd_write.port_number = port_num;
674 req.u.dpcd_write.dpcd_address = offset;
675 req.u.dpcd_write.num_bytes = num_bytes;
676 req.u.dpcd_write.bytes = bytes;
677 drm_dp_encode_sideband_req(&req, msg);
678
679 return 0;
680}
681
682static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
683{
684 struct drm_dp_sideband_msg_req_body req;
685
686 req.req_type = DP_LINK_ADDRESS;
687 drm_dp_encode_sideband_req(&req, msg);
688 return 0;
689}
690
691static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
692{
693 struct drm_dp_sideband_msg_req_body req;
694
695 req.req_type = DP_ENUM_PATH_RESOURCES;
696 req.u.port_num.port_number = port_num;
697 drm_dp_encode_sideband_req(&req, msg);
698 msg->path_msg = true;
699 return 0;
700}
701
702static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
ef8f9bea
LY		 703 u8 vcpi, uint16_t pbn,
704 u8 number_sdp_streams,
705 u8 *sdp_stream_sink)
ad7f8a1f
DA		 706{
707 struct drm_dp_sideband_msg_req_body req;
708 memset(&req, 0, sizeof(req));
709 req.req_type = DP_ALLOCATE_PAYLOAD;
710 req.u.allocate_payload.port_number = port_num;
711 req.u.allocate_payload.vcpi = vcpi;
712 req.u.allocate_payload.pbn = pbn;
ef8f9bea
LY		 713 req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
714 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
715 number_sdp_streams);
ad7f8a1f
DA		 716 drm_dp_encode_sideband_req(&req, msg);
717 msg->path_msg = true;
718 return 0;
719}
720
0bb9c2b2
DP		 721static int build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
722 int port_num, bool power_up)
723{
724 struct drm_dp_sideband_msg_req_body req;
725
726 if (power_up)
727 req.req_type = DP_POWER_UP_PHY;
728 else
729 req.req_type = DP_POWER_DOWN_PHY;
730
731 req.u.port_num.port_number = port_num;
732 drm_dp_encode_sideband_req(&req, msg);
733 msg->path_msg = true;
734 return 0;
735}
736
ad7f8a1f
DA		 737static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
738 struct drm_dp_vcpi *vcpi)
739{
dfda0df3 740 int ret, vcpi_ret;
ad7f8a1f
DA		 741
742 mutex_lock(&mgr->payload_lock);
743 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
744 if (ret > mgr->max_payloads) {
745 ret = -EINVAL;
746 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
747 goto out_unlock;
748 }
749
dfda0df3
DA		 750 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
751 if (vcpi_ret > mgr->max_payloads) {
752 ret = -EINVAL;
753 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
754 goto out_unlock;
755 }
756
ad7f8a1f 757 set_bit(ret, &mgr->payload_mask);
dfda0df3
DA		 758 set_bit(vcpi_ret, &mgr->vcpi_mask);
759 vcpi->vcpi = vcpi_ret + 1;
ad7f8a1f
DA		 760 mgr->proposed_vcpis[ret - 1] = vcpi;
761out_unlock:
762 mutex_unlock(&mgr->payload_lock);
763 return ret;
764}
765
766static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
dfda0df3 767 int vcpi)
ad7f8a1f 768{
dfda0df3
DA		 769 int i;
770 if (vcpi == 0)
ad7f8a1f
DA		 771 return;
772
773 mutex_lock(&mgr->payload_lock);
dfda0df3
DA		 774 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
775 clear_bit(vcpi - 1, &mgr->vcpi_mask);
776
777 for (i = 0; i < mgr->max_payloads; i++) {
778 if (mgr->proposed_vcpis[i])
779 if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
780 mgr->proposed_vcpis[i] = NULL;
781 clear_bit(i + 1, &mgr->payload_mask);
782 }
783 }
ad7f8a1f
DA		 784 mutex_unlock(&mgr->payload_lock);
785}
786
787static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
788 struct drm_dp_sideband_msg_tx *txmsg)
789{
992d38cc 790 unsigned int state;
cd961bb9
SV		 791
792 /*
793 * All updates to txmsg->state are protected by mgr->qlock, and the two
794 * cases we check here are terminal states. For those the barriers
795 * provided by the wake_up/wait_event pair are enough.
796 */
992d38cc
CW		 797 state = READ_ONCE(txmsg->state);
798 return (state == DRM_DP_SIDEBAND_TX_RX ||
799 state == DRM_DP_SIDEBAND_TX_TIMEOUT);
ad7f8a1f
DA		 800}
801
802static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
803 struct drm_dp_sideband_msg_tx *txmsg)
804{
805 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
806 int ret;
807
808 ret = wait_event_timeout(mgr->tx_waitq,
809 check_txmsg_state(mgr, txmsg),
810 (4 * HZ));
811 mutex_lock(&mstb->mgr->qlock);
812 if (ret > 0) {
813 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
814 ret = -EIO;
815 goto out;
816 }
817 } else {
818 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
819
820 /* dump some state */
821 ret = -EIO;
822
823 /* remove from q */
824 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
825 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
826 list_del(&txmsg->next);
827 }
828
829 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
830 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
831 mstb->tx_slots[txmsg->seqno] = NULL;
832 }
833 }
834out:
835 mutex_unlock(&mgr->qlock);
836
837 return ret;
838}
839
840static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
841{
842 struct drm_dp_mst_branch *mstb;
843
844 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
845 if (!mstb)
846 return NULL;
847
848 mstb->lct = lct;
849 if (lct > 1)
850 memcpy(mstb->rad, rad, lct / 2);
851 INIT_LIST_HEAD(&mstb->ports);
852 kref_init(&mstb->kref);
853 return mstb;
854}
855
91a25e46
ML		 856static void drm_dp_free_mst_port(struct kref *kref);
857
858static void drm_dp_free_mst_branch_device(struct kref *kref)
859{
860 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
861 if (mstb->port_parent) {
862 if (list_empty(&mstb->port_parent->next))
863 kref_put(&mstb->port_parent->kref, drm_dp_free_mst_port);
864 }
865 kfree(mstb);
866}
867
ad7f8a1f
DA		 868static void drm_dp_destroy_mst_branch_device(struct kref *kref)
869{
870 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
871 struct drm_dp_mst_port *port, *tmp;
872 bool wake_tx = false;
873
91a25e46
ML		 874 /*
875 * init kref again to be used by ports to remove mst branch when it is
876 * not needed anymore
877 */
878 kref_init(kref);
879
880 if (mstb->port_parent && list_empty(&mstb->port_parent->next))
881 kref_get(&mstb->port_parent->kref);
882
ad7f8a1f
DA		 883 /*
884 * destroy all ports - don't need lock
885 * as there are no more references to the mst branch
886 * device at this point.
887 */
888 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
889 list_del(&port->next);
890 drm_dp_put_port(port);
891 }
892
893 /* drop any tx slots msg */
894 mutex_lock(&mstb->mgr->qlock);
895 if (mstb->tx_slots[0]) {
896 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
897 mstb->tx_slots[0] = NULL;
898 wake_tx = true;
899 }
900 if (mstb->tx_slots[1]) {
901 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
902 mstb->tx_slots[1] = NULL;
903 wake_tx = true;
904 }
905 mutex_unlock(&mstb->mgr->qlock);
906
907 if (wake_tx)
68e989dc 908 wake_up_all(&mstb->mgr->tx_waitq);
91a25e46
ML		 909
910 kref_put(kref, drm_dp_free_mst_branch_device);
ad7f8a1f
DA		 911}
912
913static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
914{
915 kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
916}
917
918
919static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
920{
0391359d
SV		 921 struct drm_dp_mst_branch *mstb;
922
ad7f8a1f
DA		 923 switch (old_pdt) {
924 case DP_PEER_DEVICE_DP_LEGACY_CONV:
925 case DP_PEER_DEVICE_SST_SINK:
926 /* remove i2c over sideband */
927 drm_dp_mst_unregister_i2c_bus(&port->aux);
928 break;
929 case DP_PEER_DEVICE_MST_BRANCHING:
0391359d 930 mstb = port->mstb;
ad7f8a1f 931 port->mstb = NULL;
0391359d 932 drm_dp_put_mst_branch_device(mstb);
ad7f8a1f
DA		 933 break;
934 }
935}
936
937static void drm_dp_destroy_port(struct kref *kref)
938{
939 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
940 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
df4839fd 941
ad7f8a1f
DA		 942 if (!port->input) {
943 port->vcpi.num_slots = 0;
c6a0aed4
DA		 944
945 kfree(port->cached_edid);
6b8eeca6 946
df4839fd
DA		 947 /*
948 * The only time we don't have a connector
949 * on an output port is if the connector init
950 * fails.
951 */
6b8eeca6 952 if (port->connector) {
df4839fd
DA		 953 /* we can't destroy the connector here, as
954 * we might be holding the mode_config.mutex
955 * from an EDID retrieval */
956
6b8eeca6 957 mutex_lock(&mgr->destroy_connector_lock);
91a25e46 958 kref_get(&port->parent->kref);
4772ff03 959 list_add(&port->next, &mgr->destroy_connector_list);
6b8eeca6
DA		 960 mutex_unlock(&mgr->destroy_connector_lock);
961 schedule_work(&mgr->destroy_connector_work);
4772ff03 962 return;
6b8eeca6 963 }
df4839fd
DA		 964 /* no need to clean up vcpi
965 * as if we have no connector we never setup a vcpi */
ad7f8a1f 966 drm_dp_port_teardown_pdt(port, port->pdt);
36e3fa6a 967 port->pdt = DP_PEER_DEVICE_NONE;
ad7f8a1f
DA		 968 }
969 kfree(port);
ad7f8a1f
DA		 970}
971
972static void drm_dp_put_port(struct drm_dp_mst_port *port)
973{
974 kref_put(&port->kref, drm_dp_destroy_port);
975}
976
977static 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)
978{
979 struct drm_dp_mst_port *port;
980 struct drm_dp_mst_branch *rmstb;
981 if (to_find == mstb) {
982 kref_get(&mstb->kref);
983 return mstb;
984 }
985 list_for_each_entry(port, &mstb->ports, next) {
986 if (port->mstb) {
987 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
988 if (rmstb)
989 return rmstb;
990 }
991 }
992 return NULL;
993}
994
995static struct drm_dp_mst_branch *drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb)
996{
997 struct drm_dp_mst_branch *rmstb = NULL;
998 mutex_lock(&mgr->lock);
999 if (mgr->mst_primary)
1000 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
1001 mutex_unlock(&mgr->lock);
1002 return rmstb;
1003}
1004
1005static 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)
1006{
1007 struct drm_dp_mst_port *port, *mport;
1008
1009 list_for_each_entry(port, &mstb->ports, next) {
1010 if (port == to_find) {
1011 kref_get(&port->kref);
1012 return port;
1013 }
1014 if (port->mstb) {
1015 mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
1016 if (mport)
1017 return mport;
1018 }
1019 }
1020 return NULL;
1021}
1022
1023static struct drm_dp_mst_port *drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
1024{
1025 struct drm_dp_mst_port *rport = NULL;
1026 mutex_lock(&mgr->lock);
1027 if (mgr->mst_primary)
1028 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
1029 mutex_unlock(&mgr->lock);
1030 return rport;
1031}
1032
1033static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
1034{
1035 struct drm_dp_mst_port *port;
1036
1037 list_for_each_entry(port, &mstb->ports, next) {
1038 if (port->port_num == port_num) {
1039 kref_get(&port->kref);
1040 return port;
1041 }
1042 }
1043
1044 return NULL;
1045}
1046
1047/*
1048 * calculate a new RAD for this MST branch device
1049 * if parent has an LCT of 2 then it has 1 nibble of RAD,
1050 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1051 */
1052static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1053 u8 *rad)
1054{
75af4c8c 1055 int parent_lct = port->parent->lct;
ad7f8a1f 1056 int shift = 4;
75af4c8c
ML		 1057 int idx = (parent_lct - 1) / 2;
1058 if (parent_lct > 1) {
1059 memcpy(rad, port->parent->rad, idx + 1);
1060 shift = (parent_lct % 2) ? 4 : 0;
ad7f8a1f
DA		 1061 } else
1062 rad[0] = 0;
1063
1064 rad[idx] |= port->port_num << shift;
75af4c8c 1065 return parent_lct + 1;
ad7f8a1f
DA		 1066}
1067
1068/*
1069 * return sends link address for new mstb
1070 */
1071static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
1072{
1073 int ret;
1074 u8 rad[6], lct;
1075 bool send_link = false;
1076 switch (port->pdt) {
1077 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1078 case DP_PEER_DEVICE_SST_SINK:
1079 /* add i2c over sideband */
1080 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1081 break;
1082 case DP_PEER_DEVICE_MST_BRANCHING:
1083 lct = drm_dp_calculate_rad(port, rad);
1084
1085 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
22a07038
JM		 1086 if (port->mstb) {
1087 port->mstb->mgr = port->mgr;
1088 port->mstb->port_parent = port;
ad7f8a1f 1089
22a07038
JM		 1090 send_link = true;
1091 }
ad7f8a1f
DA		 1092 break;
1093 }
1094 return send_link;
1095}
1096
5e93b820 1097static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
ad7f8a1f
DA		 1098{
1099 int ret;
5e93b820
HW		 1100
1101 memcpy(mstb->guid, guid, 16);
1102
1103 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
1104 if (mstb->port_parent) {
1105 ret = drm_dp_send_dpcd_write(
1106 mstb->mgr,
1107 mstb->port_parent,
1108 DP_GUID,
1109 16,
1110 mstb->guid);
1111 } else {
1112
1113 ret = drm_dp_dpcd_write(
1114 mstb->mgr->aux,
1115 DP_GUID,
1116 mstb->guid,
1117 16);
ad7f8a1f
DA		 1118 }
1119 }
1120}
1121
1c960876
DA		 1122static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1123 int pnum,
d87af4d1
RS		 1124 char *proppath,
1125 size_t proppath_size)
ad7f8a1f
DA		 1126{
1127 int i;
1128 char temp[8];
d87af4d1 1129 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
ad7f8a1f
DA		 1130 for (i = 0; i < (mstb->lct - 1); i++) {
1131 int shift = (i % 2) ? 0 : 4;
7a11a334 1132 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
d87af4d1
RS		 1133 snprintf(temp, sizeof(temp), "-%d", port_num);
1134 strlcat(proppath, temp, proppath_size);
ad7f8a1f 1135 }
1c960876 1136 snprintf(temp, sizeof(temp), "-%d", pnum);
d87af4d1 1137 strlcat(proppath, temp, proppath_size);
ad7f8a1f
DA		 1138}
1139
1140static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
7b0a89a6 1141 struct drm_device *dev,
ad7f8a1f
DA		 1142 struct drm_dp_link_addr_reply_port *port_msg)
1143{
1144 struct drm_dp_mst_port *port;
1145 bool ret;
1146 bool created = false;
1147 int old_pdt = 0;
1148 int old_ddps = 0;
1149 port = drm_dp_get_port(mstb, port_msg->port_number);
1150 if (!port) {
1151 port = kzalloc(sizeof(*port), GFP_KERNEL);
1152 if (!port)
1153 return;
1154 kref_init(&port->kref);
1155 port->parent = mstb;
1156 port->port_num = port_msg->port_number;
1157 port->mgr = mstb->mgr;
1158 port->aux.name = "DPMST";
7b0a89a6 1159 port->aux.dev = dev->dev;
ad7f8a1f
DA		 1160 created = true;
1161 } else {
1162 old_pdt = port->pdt;
1163 old_ddps = port->ddps;
1164 }
1165
1166 port->pdt = port_msg->peer_device_type;
1167 port->input = port_msg->input_port;
1168 port->mcs = port_msg->mcs;
1169 port->ddps = port_msg->ddps;
1170 port->ldps = port_msg->legacy_device_plug_status;
1171 port->dpcd_rev = port_msg->dpcd_revision;
1172 port->num_sdp_streams = port_msg->num_sdp_streams;
1173 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
ad7f8a1f
DA		 1174
1175 /* manage mstb port lists with mgr lock - take a reference
1176 for this list */
1177 if (created) {
1178 mutex_lock(&mstb->mgr->lock);
1179 kref_get(&port->kref);
1180 list_add(&port->next, &mstb->ports);
1181 mutex_unlock(&mstb->mgr->lock);
1182 }
1183
1184 if (old_ddps != port->ddps) {
1185 if (port->ddps) {
ad7f8a1f
DA		 1186 if (!port->input)
1187 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1188 } else {
ad7f8a1f
DA		 1189 port->available_pbn = 0;
1190 }
1191 }
1192
1193 if (old_pdt != port->pdt && !port->input) {
1194 drm_dp_port_teardown_pdt(port, old_pdt);
1195
1196 ret = drm_dp_port_setup_pdt(port);
68d8c9fc 1197 if (ret == true)
ad7f8a1f 1198 drm_dp_send_link_address(mstb->mgr, port->mstb);
ad7f8a1f
DA		 1199 }
1200
1201 if (created && !port->input) {
1202 char proppath[255];
1c960876
DA		 1203
1204 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
ad7f8a1f 1205 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
df4839fd
DA		 1206 if (!port->connector) {
1207 /* remove it from the port list */
1208 mutex_lock(&mstb->mgr->lock);
1209 list_del(&port->next);
1210 mutex_unlock(&mstb->mgr->lock);
1211 /* drop port list reference */
1212 drm_dp_put_port(port);
1213 goto out;
1214 }
4da5caa6
VS		 1215 if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
1216 port->pdt == DP_PEER_DEVICE_SST_SINK) &&
1217 port->port_num >= DP_MST_LOGICAL_PORT_0) {
8ae22cb4 1218 port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
97e14fbe 1219 drm_connector_set_tile_property(port->connector);
8ae22cb4 1220 }
d9515c5e 1221 (*mstb->mgr->cbs->register_connector)(port->connector);
ad7f8a1f 1222 }
8ae22cb4 1223
df4839fd 1224out:
ad7f8a1f
DA		 1225 /* put reference to this port */
1226 drm_dp_put_port(port);
1227}
1228
1229static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1230 struct drm_dp_connection_status_notify *conn_stat)
1231{
1232 struct drm_dp_mst_port *port;
1233 int old_pdt;
1234 int old_ddps;
1235 bool dowork = false;
1236 port = drm_dp_get_port(mstb, conn_stat->port_number);
1237 if (!port)
1238 return;
1239
1240 old_ddps = port->ddps;
1241 old_pdt = port->pdt;
1242 port->pdt = conn_stat->peer_device_type;
1243 port->mcs = conn_stat->message_capability_status;
1244 port->ldps = conn_stat->legacy_device_plug_status;
1245 port->ddps = conn_stat->displayport_device_plug_status;
1246
1247 if (old_ddps != port->ddps) {
1248 if (port->ddps) {
8ae22cb4 1249 dowork = true;
ad7f8a1f 1250 } else {
ad7f8a1f
DA		 1251 port->available_pbn = 0;
1252 }
1253 }
1254 if (old_pdt != port->pdt && !port->input) {
1255 drm_dp_port_teardown_pdt(port, old_pdt);
1256
1257 if (drm_dp_port_setup_pdt(port))
1258 dowork = true;
1259 }
1260
1261 drm_dp_put_port(port);
1262 if (dowork)
1263 queue_work(system_long_wq, &mstb->mgr->work);
1264
1265}
1266
1267static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1268 u8 lct, u8 *rad)
1269{
1270 struct drm_dp_mst_branch *mstb;
1271 struct drm_dp_mst_port *port;
1272 int i;
1273 /* find the port by iterating down */
9eb1e57f
DA		 1274
1275 mutex_lock(&mgr->lock);
ad7f8a1f
DA		 1276 mstb = mgr->mst_primary;
1277
1278 for (i = 0; i < lct - 1; i++) {
1279 int shift = (i % 2) ? 0 : 4;
7a11a334 1280 int port_num = (rad[i / 2] >> shift) & 0xf;
ad7f8a1f
DA		 1281
1282 list_for_each_entry(port, &mstb->ports, next) {
1283 if (port->port_num == port_num) {
30730c7f
AR		 1284 mstb = port->mstb;
1285 if (!mstb) {
ad7f8a1f 1286 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
30730c7f 1287 goto out;
ad7f8a1f
DA		 1288 }
1289
ad7f8a1f
DA		 1290 break;
1291 }
1292 }
1293 }
1294 kref_get(&mstb->kref);
30730c7f 1295out:
9eb1e57f 1296 mutex_unlock(&mgr->lock);
ad7f8a1f
DA		 1297 return mstb;
1298}
1299
bd934320
ML		 1300static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1301 struct drm_dp_mst_branch *mstb,
1302 uint8_t *guid)
1303{
1304 struct drm_dp_mst_branch *found_mstb;
1305 struct drm_dp_mst_port *port;
1306
5e93b820
HW		 1307 if (memcmp(mstb->guid, guid, 16) == 0)
1308 return mstb;
1309
1310
bd934320
ML		 1311 list_for_each_entry(port, &mstb->ports, next) {
1312 if (!port->mstb)
1313 continue;
1314
bd934320
ML		 1315 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1316
1317 if (found_mstb)
1318 return found_mstb;
1319 }
1320
1321 return NULL;
1322}
1323
1324static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
1325 struct drm_dp_mst_topology_mgr *mgr,
1326 uint8_t *guid)
1327{
1328 struct drm_dp_mst_branch *mstb;
1329
1330 /* find the port by iterating down */
1331 mutex_lock(&mgr->lock);
1332
5e93b820 1333 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
bd934320
ML		 1334
1335 if (mstb)
1336 kref_get(&mstb->kref);
1337
1338 mutex_unlock(&mgr->lock);
1339 return mstb;
1340}
1341
ad7f8a1f
DA		 1342static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1343 struct drm_dp_mst_branch *mstb)
1344{
1345 struct drm_dp_mst_port *port;
9254ec49 1346 struct drm_dp_mst_branch *mstb_child;
68d8c9fc 1347 if (!mstb->link_address_sent)
ad7f8a1f 1348 drm_dp_send_link_address(mgr, mstb);
68d8c9fc 1349
ad7f8a1f
DA		 1350 list_for_each_entry(port, &mstb->ports, next) {
1351 if (port->input)
1352 continue;
1353
8ae22cb4 1354 if (!port->ddps)
ad7f8a1f
DA		 1355 continue;
1356
1357 if (!port->available_pbn)
1358 drm_dp_send_enum_path_resources(mgr, mstb, port);
1359
9254ec49
SV		 1360 if (port->mstb) {
1361 mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1362 if (mstb_child) {
1363 drm_dp_check_and_send_link_address(mgr, mstb_child);
1364 drm_dp_put_mst_branch_device(mstb_child);
1365 }
1366 }
ad7f8a1f
DA		 1367 }
1368}
1369
1370static void drm_dp_mst_link_probe_work(struct work_struct *work)
1371{
1372 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
9254ec49 1373 struct drm_dp_mst_branch *mstb;
ad7f8a1f 1374
9254ec49
SV		 1375 mutex_lock(&mgr->lock);
1376 mstb = mgr->mst_primary;
1377 if (mstb) {
1378 kref_get(&mstb->kref);
1379 }
1380 mutex_unlock(&mgr->lock);
1381 if (mstb) {
1382 drm_dp_check_and_send_link_address(mgr, mstb);
1383 drm_dp_put_mst_branch_device(mstb);
1384 }
ad7f8a1f
DA		 1385}
1386
1387static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1388 u8 *guid)
1389{
e38e1289 1390 u64 salt;
ad7f8a1f 1391
e38e1289
VS		 1392 if (memchr_inv(guid, 0, 16))
1393 return true;
1394
1395 salt = get_jiffies_64();
1396
1397 memcpy(&guid[0], &salt, sizeof(u64));
1398 memcpy(&guid[8], &salt, sizeof(u64));
1399
1400 return false;
ad7f8a1f
DA		 1401}
1402
1403#if 0
1404static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1405{
1406 struct drm_dp_sideband_msg_req_body req;
1407
1408 req.req_type = DP_REMOTE_DPCD_READ;
1409 req.u.dpcd_read.port_number = port_num;
1410 req.u.dpcd_read.dpcd_address = offset;
1411 req.u.dpcd_read.num_bytes = num_bytes;
1412 drm_dp_encode_sideband_req(&req, msg);
1413
1414 return 0;
1415}
1416#endif
1417
1418static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1419 bool up, u8 *msg, int len)
1420{
1421 int ret;
1422 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1423 int tosend, total, offset;
1424 int retries = 0;
1425
1426retry:
1427 total = len;
1428 offset = 0;
1429 do {
1430 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1431
1432 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1433 &msg[offset],
1434 tosend);
1435 if (ret != tosend) {
1436 if (ret == -EIO && retries < 5) {
1437 retries++;
1438 goto retry;
1439 }
1440 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
ad7f8a1f
DA		 1441
1442 return -EIO;
1443 }
1444 offset += tosend;
1445 total -= tosend;
1446 } while (total > 0);
1447 return 0;
1448}
1449
1450static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1451 struct drm_dp_sideband_msg_tx *txmsg)
1452{
1453 struct drm_dp_mst_branch *mstb = txmsg->dst;
bd934320 1454 u8 req_type;
ad7f8a1f
DA		 1455
1456 /* both msg slots are full */
1457 if (txmsg->seqno == -1) {
1458 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1459 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1460 return -EAGAIN;
1461 }
1462 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1463 txmsg->seqno = mstb->last_seqno;
1464 mstb->last_seqno ^= 1;
1465 } else if (mstb->tx_slots[0] == NULL)
1466 txmsg->seqno = 0;
1467 else
1468 txmsg->seqno = 1;
1469 mstb->tx_slots[txmsg->seqno] = txmsg;
1470 }
bd934320
ML		 1471
1472 req_type = txmsg->msg[0] & 0x7f;
1473 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1474 req_type == DP_RESOURCE_STATUS_NOTIFY)
1475 hdr->broadcast = 1;
1476 else
1477 hdr->broadcast = 0;
ad7f8a1f
DA		 1478 hdr->path_msg = txmsg->path_msg;
1479 hdr->lct = mstb->lct;
1480 hdr->lcr = mstb->lct - 1;
1481 if (mstb->lct > 1)
1482 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1483 hdr->seqno = txmsg->seqno;
1484 return 0;
1485}
1486/*
1487 * process a single block of the next message in the sideband queue
1488 */
1489static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1490 struct drm_dp_sideband_msg_tx *txmsg,
1491 bool up)
1492{
1493 u8 chunk[48];
1494 struct drm_dp_sideband_msg_hdr hdr;
1495 int len, space, idx, tosend;
1496 int ret;
1497
bf3719c0
DL		 1498 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1499
ad7f8a1f
DA		 1500 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1501 txmsg->seqno = -1;
1502 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1503 }
1504
1505 /* make hdr from dst mst - for replies use seqno
1506 otherwise assign one */
1507 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1508 if (ret < 0)
1509 return ret;
1510
1511 /* amount left to send in this message */
1512 len = txmsg->cur_len - txmsg->cur_offset;
1513
1514 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1515 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1516
1517 tosend = min(len, space);
1518 if (len == txmsg->cur_len)
1519 hdr.somt = 1;
1520 if (space >= len)
1521 hdr.eomt = 1;
1522
1523
1524 hdr.msg_len = tosend + 1;
1525 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1526 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1527 /* add crc at end */
1528 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1529 idx += tosend + 1;
1530
1531 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1532 if (ret) {
1533 DRM_DEBUG_KMS("sideband msg failed to send\n");
1534 return ret;
1535 }
1536
1537 txmsg->cur_offset += tosend;
1538 if (txmsg->cur_offset == txmsg->cur_len) {
1539 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1540 return 1;
1541 }
1542 return 0;
1543}
1544
ad7f8a1f
DA		 1545static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1546{
1547 struct drm_dp_sideband_msg_tx *txmsg;
1548 int ret;
1549
cd961bb9
SV		 1550 WARN_ON(!mutex_is_locked(&mgr->qlock));
1551
ad7f8a1f 1552 /* construct a chunk from the first msg in the tx_msg queue */
cb021a3e 1553 if (list_empty(&mgr->tx_msg_downq))
ad7f8a1f 1554 return;
ad7f8a1f
DA		 1555
1556 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1557 ret = process_single_tx_qlock(mgr, txmsg, false);
1558 if (ret == 1) {
1559 /* txmsg is sent it should be in the slots now */
1560 list_del(&txmsg->next);
1561 } else if (ret) {
1562 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1563 list_del(&txmsg->next);
1564 if (txmsg->seqno != -1)
1565 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1566 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
68e989dc 1567 wake_up_all(&mgr->tx_waitq);
ad7f8a1f 1568 }
ad7f8a1f
DA		 1569}
1570
1571/* called holding qlock */
1f16ee7f
ML		 1572static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1573 struct drm_dp_sideband_msg_tx *txmsg)
ad7f8a1f 1574{
ad7f8a1f
DA		 1575 int ret;
1576
1577 /* construct a chunk from the first msg in the tx_msg queue */
ad7f8a1f 1578 ret = process_single_tx_qlock(mgr, txmsg, true);
1f16ee7f
ML		 1579
1580 if (ret != 1)
ad7f8a1f 1581 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1f16ee7f
ML		 1582
1583 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
ad7f8a1f
DA		 1584}
1585
1586static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1587 struct drm_dp_sideband_msg_tx *txmsg)
1588{
1589 mutex_lock(&mgr->qlock);
1590 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
cb021a3e 1591 if (list_is_singular(&mgr->tx_msg_downq))
ad7f8a1f
DA		 1592 process_single_down_tx_qlock(mgr);
1593 mutex_unlock(&mgr->qlock);
1594}
1595
68d8c9fc
DA		 1596static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1597 struct drm_dp_mst_branch *mstb)
ad7f8a1f
DA		 1598{
1599 int len;
1600 struct drm_dp_sideband_msg_tx *txmsg;
1601 int ret;
1602
1603 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1604 if (!txmsg)
68d8c9fc 1605 return;
ad7f8a1f
DA		 1606
1607 txmsg->dst = mstb;
1608 len = build_link_address(txmsg);
1609
68d8c9fc 1610 mstb->link_address_sent = true;
ad7f8a1f
DA		 1611 drm_dp_queue_down_tx(mgr, txmsg);
1612
1613 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1614 if (ret > 0) {
1615 int i;
1616
1617 if (txmsg->reply.reply_type == 1)
1618 DRM_DEBUG_KMS("link address nak received\n");
1619 else {
1620 DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1621 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1622 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,
1623 txmsg->reply.u.link_addr.ports[i].input_port,
1624 txmsg->reply.u.link_addr.ports[i].peer_device_type,
1625 txmsg->reply.u.link_addr.ports[i].port_number,
1626 txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1627 txmsg->reply.u.link_addr.ports[i].mcs,
1628 txmsg->reply.u.link_addr.ports[i].ddps,
1629 txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1630 txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1631 txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1632 }
5e93b820
HW		 1633
1634 drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);
1635
ad7f8a1f
DA		 1636 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1637 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1638 }
8ae22cb4 1639 (*mgr->cbs->hotplug)(mgr);
ad7f8a1f 1640 }
68d8c9fc
DA		 1641 } else {
1642 mstb->link_address_sent = false;
ad7f8a1f 1643 DRM_DEBUG_KMS("link address failed %d\n", ret);
68d8c9fc 1644 }
ad7f8a1f
DA		 1645
1646 kfree(txmsg);
ad7f8a1f
DA		 1647}
1648
1649static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1650 struct drm_dp_mst_branch *mstb,
1651 struct drm_dp_mst_port *port)
1652{
1653 int len;
1654 struct drm_dp_sideband_msg_tx *txmsg;
1655 int ret;
1656
1657 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1658 if (!txmsg)
1659 return -ENOMEM;
1660
1661 txmsg->dst = mstb;
1662 len = build_enum_path_resources(txmsg, port->port_num);
1663
1664 drm_dp_queue_down_tx(mgr, txmsg);
1665
1666 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1667 if (ret > 0) {
1668 if (txmsg->reply.reply_type == 1)
1669 DRM_DEBUG_KMS("enum path resources nak received\n");
1670 else {
1671 if (port->port_num != txmsg->reply.u.path_resources.port_number)
1672 DRM_ERROR("got incorrect port in response\n");
1673 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,
1674 txmsg->reply.u.path_resources.avail_payload_bw_number);
1675 port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1676 }
1677 }
1678
1679 kfree(txmsg);
1680 return 0;
1681}
1682
91a25e46
ML		 1683static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
1684{
1685 if (!mstb->port_parent)
1686 return NULL;
1687
1688 if (mstb->port_parent->mstb != mstb)
1689 return mstb->port_parent;
1690
1691 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
1692}
1693
1694static struct drm_dp_mst_branch *drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
1695 struct drm_dp_mst_branch *mstb,
1696 int *port_num)
1697{
1698 struct drm_dp_mst_branch *rmstb = NULL;
1699 struct drm_dp_mst_port *found_port;
1700 mutex_lock(&mgr->lock);
1701 if (mgr->mst_primary) {
1702 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
1703
1704 if (found_port) {
1705 rmstb = found_port->parent;
1706 kref_get(&rmstb->kref);
1707 *port_num = found_port->port_num;
1708 }
1709 }
1710 mutex_unlock(&mgr->lock);
1711 return rmstb;
1712}
1713
8fa6a425
TR		 1714static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1715 struct drm_dp_mst_port *port,
1716 int id,
1717 int pbn)
ad7f8a1f
DA		 1718{
1719 struct drm_dp_sideband_msg_tx *txmsg;
1720 struct drm_dp_mst_branch *mstb;
91a25e46 1721 int len, ret, port_num;
ef8f9bea
LY		 1722 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
1723 int i;
ad7f8a1f 1724
deba0a2a 1725 port = drm_dp_get_validated_port_ref(mgr, port);
1726 if (!port)
1727 return -EINVAL;
1728
91a25e46 1729 port_num = port->port_num;
ad7f8a1f 1730 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
91a25e46
ML		 1731 if (!mstb) {
1732 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, port->parent, &port_num);
1733
deba0a2a 1734 if (!mstb) {
1735 drm_dp_put_port(port);
91a25e46 1736 return -EINVAL;
deba0a2a 1737 }
91a25e46 1738 }
ad7f8a1f
DA		 1739
1740 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1741 if (!txmsg) {
1742 ret = -ENOMEM;
1743 goto fail_put;
1744 }
1745
ef8f9bea
LY		 1746 for (i = 0; i < port->num_sdp_streams; i++)
1747 sinks[i] = i;
1748
ad7f8a1f 1749 txmsg->dst = mstb;
91a25e46 1750 len = build_allocate_payload(txmsg, port_num,
ad7f8a1f 1751 id,
ef8f9bea 1752 pbn, port->num_sdp_streams, sinks);
ad7f8a1f
DA		 1753
1754 drm_dp_queue_down_tx(mgr, txmsg);
1755
1756 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1757 if (ret > 0) {
1758 if (txmsg->reply.reply_type == 1) {
1759 ret = -EINVAL;
1760 } else
1761 ret = 0;
1762 }
1763 kfree(txmsg);
1764fail_put:
1765 drm_dp_put_mst_branch_device(mstb);
deba0a2a 1766 drm_dp_put_port(port);
ad7f8a1f
DA		 1767 return ret;
1768}
1769
0bb9c2b2
DP		 1770int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
1771 struct drm_dp_mst_port *port, bool power_up)
1772{
1773 struct drm_dp_sideband_msg_tx *txmsg;
1774 int len, ret;
1775
1776 port = drm_dp_get_validated_port_ref(mgr, port);
1777 if (!port)
1778 return -EINVAL;
1779
1780 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1781 if (!txmsg) {
1782 drm_dp_put_port(port);
1783 return -ENOMEM;
1784 }
1785
1786 txmsg->dst = port->parent;
1787 len = build_power_updown_phy(txmsg, port->port_num, power_up);
1788 drm_dp_queue_down_tx(mgr, txmsg);
1789
1790 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
1791 if (ret > 0) {
1792 if (txmsg->reply.reply_type == 1)
1793 ret = -EINVAL;
1794 else
1795 ret = 0;
1796 }
1797 kfree(txmsg);
1798 drm_dp_put_port(port);
1799
1800 return ret;
1801}
1802EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
1803
ad7f8a1f
DA		 1804static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1805 int id,
1806 struct drm_dp_payload *payload)
1807{
1808 int ret;
1809
1810 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1811 if (ret < 0) {
1812 payload->payload_state = 0;
1813 return ret;
1814 }
1815 payload->payload_state = DP_PAYLOAD_LOCAL;
1816 return 0;
1817}
1818
8fa6a425
TR		 1819static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1820 struct drm_dp_mst_port *port,
1821 int id,
1822 struct drm_dp_payload *payload)
ad7f8a1f
DA		 1823{
1824 int ret;
1825 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1826 if (ret < 0)
1827 return ret;
1828 payload->payload_state = DP_PAYLOAD_REMOTE;
1829 return ret;
1830}
1831
8fa6a425
TR		 1832static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1833 struct drm_dp_mst_port *port,
1834 int id,
1835 struct drm_dp_payload *payload)
ad7f8a1f
DA		 1836{
1837 DRM_DEBUG_KMS("\n");
1838 /* its okay for these to fail */
1839 if (port) {
1840 drm_dp_payload_send_msg(mgr, port, id, 0);
1841 }
1842
1843 drm_dp_dpcd_write_payload(mgr, id, payload);
dfda0df3 1844 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
ad7f8a1f
DA		 1845 return 0;
1846}
1847
8fa6a425
TR		 1848static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1849 int id,
1850 struct drm_dp_payload *payload)
ad7f8a1f
DA		 1851{
1852 payload->payload_state = 0;
1853 return 0;
1854}
1855
1856/**
1857 * drm_dp_update_payload_part1() - Execute payload update part 1
1858 * @mgr: manager to use.
1859 *
1860 * This iterates over all proposed virtual channels, and tries to
1861 * allocate space in the link for them. For 0->slots transitions,
1862 * this step just writes the VCPI to the MST device. For slots->0
1863 * transitions, this writes the updated VCPIs and removes the
1864 * remote VC payloads.
1865 *
1866 * after calling this the driver should generate ACT and payload
1867 * packets.
1868 */
1869int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1870{
dfda0df3 1871 int i, j;
ad7f8a1f
DA		 1872 int cur_slots = 1;
1873 struct drm_dp_payload req_payload;
1874 struct drm_dp_mst_port *port;
1875
1876 mutex_lock(&mgr->payload_lock);
1877 for (i = 0; i < mgr->max_payloads; i++) {
1878 /* solve the current payloads - compare to the hw ones
1879 - update the hw view */
1880 req_payload.start_slot = cur_slots;
1881 if (mgr->proposed_vcpis[i]) {
1882 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
263efde3 1883 port = drm_dp_get_validated_port_ref(mgr, port);
1884 if (!port) {
1885 mutex_unlock(&mgr->payload_lock);
1886 return -EINVAL;
1887 }
ad7f8a1f 1888 req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
6cecdf7a 1889 req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi;
ad7f8a1f
DA		 1890 } else {
1891 port = NULL;
1892 req_payload.num_slots = 0;
1893 }
dfda0df3
DA		 1894
1895 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1896 mgr->payloads[i].start_slot = req_payload.start_slot;
1897 }
ad7f8a1f 1898 /* work out what is required to happen with this payload */
dfda0df3 1899 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
ad7f8a1f
DA		 1900
1901 /* need to push an update for this payload */
1902 if (req_payload.num_slots) {
dfda0df3 1903 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
ad7f8a1f 1904 mgr->payloads[i].num_slots = req_payload.num_slots;
6cecdf7a 1905 mgr->payloads[i].vcpi = req_payload.vcpi;
ad7f8a1f
DA		 1906 } else if (mgr->payloads[i].num_slots) {
1907 mgr->payloads[i].num_slots = 0;
bb08c04d 1908 drm_dp_destroy_payload_step1(mgr, port, mgr->payloads[i].vcpi, &mgr->payloads[i]);
ad7f8a1f 1909 req_payload.payload_state = mgr->payloads[i].payload_state;
dfda0df3
DA		 1910 mgr->payloads[i].start_slot = 0;
1911 }
ad7f8a1f
DA		 1912 mgr->payloads[i].payload_state = req_payload.payload_state;
1913 }
1914 cur_slots += req_payload.num_slots;
263efde3 1915
1916 if (port)
1917 drm_dp_put_port(port);
ad7f8a1f 1918 }
dfda0df3
DA		 1919
1920 for (i = 0; i < mgr->max_payloads; i++) {
1921 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1922 DRM_DEBUG_KMS("removing payload %d\n", i);
1923 for (j = i; j < mgr->max_payloads - 1; j++) {
1924 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1925 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1926 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1927 set_bit(j + 1, &mgr->payload_mask);
1928 } else {
1929 clear_bit(j + 1, &mgr->payload_mask);
1930 }
1931 }
1932 memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1933 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1934 clear_bit(mgr->max_payloads, &mgr->payload_mask);
1935
1936 }
1937 }
ad7f8a1f
DA		 1938 mutex_unlock(&mgr->payload_lock);
1939
1940 return 0;
1941}
1942EXPORT_SYMBOL(drm_dp_update_payload_part1);
1943
1944/**
1945 * drm_dp_update_payload_part2() - Execute payload update part 2
1946 * @mgr: manager to use.
1947 *
1948 * This iterates over all proposed virtual channels, and tries to
1949 * allocate space in the link for them. For 0->slots transitions,
1950 * this step writes the remote VC payload commands. For slots->0
1951 * this just resets some internal state.
1952 */
1953int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1954{
1955 struct drm_dp_mst_port *port;
1956 int i;
7389ad4b 1957 int ret = 0;
ad7f8a1f
DA		 1958 mutex_lock(&mgr->payload_lock);
1959 for (i = 0; i < mgr->max_payloads; i++) {
1960
1961 if (!mgr->proposed_vcpis[i])
1962 continue;
1963
1964 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1965
1966 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1967 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
dfda0df3 1968 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
ad7f8a1f 1969 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
dfda0df3 1970 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
ad7f8a1f
DA		 1971 }
1972 if (ret) {
1973 mutex_unlock(&mgr->payload_lock);
1974 return ret;
1975 }
1976 }
1977 mutex_unlock(&mgr->payload_lock);
1978 return 0;
1979}
1980EXPORT_SYMBOL(drm_dp_update_payload_part2);
1981
1982#if 0 /* unused as of yet */
1983static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1984 struct drm_dp_mst_port *port,
1985 int offset, int size)
1986{
1987 int len;
1988 struct drm_dp_sideband_msg_tx *txmsg;
1989
1990 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1991 if (!txmsg)
1992 return -ENOMEM;
1993
1994 len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1995 txmsg->dst = port->parent;
1996
1997 drm_dp_queue_down_tx(mgr, txmsg);
1998
1999 return 0;
2000}
2001#endif
2002
2003static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
2004 struct drm_dp_mst_port *port,
2005 int offset, int size, u8 *bytes)
2006{
2007 int len;
2008 int ret;
2009 struct drm_dp_sideband_msg_tx *txmsg;
2010 struct drm_dp_mst_branch *mstb;
2011
2012 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2013 if (!mstb)
2014 return -EINVAL;
2015
2016 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2017 if (!txmsg) {
2018 ret = -ENOMEM;
2019 goto fail_put;
2020 }
2021
2022 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
2023 txmsg->dst = mstb;
2024
2025 drm_dp_queue_down_tx(mgr, txmsg);
2026
2027 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2028 if (ret > 0) {
2029 if (txmsg->reply.reply_type == 1) {
2030 ret = -EINVAL;
2031 } else
2032 ret = 0;
2033 }
2034 kfree(txmsg);
2035fail_put:
2036 drm_dp_put_mst_branch_device(mstb);
2037 return ret;
2038}
2039
2040static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
2041{
2042 struct drm_dp_sideband_msg_reply_body reply;
2043
a68d2437 2044 reply.reply_type = 0;
ad7f8a1f
DA		 2045 reply.req_type = req_type;
2046 drm_dp_encode_sideband_reply(&reply, msg);
2047 return 0;
2048}
2049
2050static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
2051 struct drm_dp_mst_branch *mstb,
2052 int req_type, int seqno, bool broadcast)
2053{
2054 struct drm_dp_sideband_msg_tx *txmsg;
2055
2056 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2057 if (!txmsg)
2058 return -ENOMEM;
2059
2060 txmsg->dst = mstb;
2061 txmsg->seqno = seqno;
2062 drm_dp_encode_up_ack_reply(txmsg, req_type);
2063
2064 mutex_lock(&mgr->qlock);
1f16ee7f
ML		 2065
2066 process_single_up_tx_qlock(mgr, txmsg);
2067
ad7f8a1f 2068 mutex_unlock(&mgr->qlock);
1f16ee7f
ML		 2069
2070 kfree(txmsg);
ad7f8a1f
DA		 2071 return 0;
2072}
2073
b853fdb3
CW		 2074static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
2075 int dp_link_count,
2076 int *out)
ad7f8a1f
DA		 2077{
2078 switch (dp_link_bw) {
b853fdb3
CW		 2079 default:
2080 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
2081 dp_link_bw, dp_link_count);
2082 return false;
2083
ad7f8a1f 2084 case DP_LINK_BW_1_62:
b853fdb3
CW		 2085 *out = 3 * dp_link_count;
2086 break;
ad7f8a1f 2087 case DP_LINK_BW_2_7:
b853fdb3
CW		 2088 *out = 5 * dp_link_count;
2089 break;
ad7f8a1f 2090 case DP_LINK_BW_5_4:
b853fdb3
CW		 2091 *out = 10 * dp_link_count;
2092 break;
e0bd878a
MN		 2093 case DP_LINK_BW_8_1:
2094 *out = 15 * dp_link_count;
2095 break;
ad7f8a1f 2096 }
b853fdb3 2097 return true;
ad7f8a1f
DA		 2098}
2099
2100/**
2101 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
2102 * @mgr: manager to set state for
2103 * @mst_state: true to enable MST on this connector - false to disable.
2104 *
2105 * This is called by the driver when it detects an MST capable device plugged
2106 * into a DP MST capable port, or when a DP MST capable device is unplugged.
2107 */
2108int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
2109{
2110 int ret = 0;
2111 struct drm_dp_mst_branch *mstb = NULL;
2112
2113 mutex_lock(&mgr->lock);
2114 if (mst_state == mgr->mst_state)
2115 goto out_unlock;
2116
2117 mgr->mst_state = mst_state;
2118 /* set the device into MST mode */
2119 if (mst_state) {
2120 WARN_ON(mgr->mst_primary);
2121
2122 /* get dpcd info */
2123 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2124 if (ret != DP_RECEIVER_CAP_SIZE) {
2125 DRM_DEBUG_KMS("failed to read DPCD\n");
2126 goto out_unlock;
2127 }
2128
b853fdb3
CW		 2129 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
2130 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
2131 &mgr->pbn_div)) {
2132 ret = -EINVAL;
2133 goto out_unlock;
2134 }
2135
ad7f8a1f
DA		 2136 /* add initial branch device at LCT 1 */
2137 mstb = drm_dp_add_mst_branch_device(1, NULL);
2138 if (mstb == NULL) {
2139 ret = -ENOMEM;
2140 goto out_unlock;
2141 }
2142 mstb->mgr = mgr;
2143
2144 /* give this the main reference */
2145 mgr->mst_primary = mstb;
2146 kref_get(&mgr->mst_primary->kref);
2147
c175cd16
AG		 2148 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2149 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2150 if (ret < 0) {
2151 goto out_unlock;
2152 }
2153
ad7f8a1f
DA		 2154 {
2155 struct drm_dp_payload reset_pay;
2156 reset_pay.start_slot = 0;
2157 reset_pay.num_slots = 0x3f;
2158 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
2159 }
2160
ad7f8a1f
DA		 2161 queue_work(system_long_wq, &mgr->work);
2162
2163 ret = 0;
2164 } else {
2165 /* disable MST on the device */
2166 mstb = mgr->mst_primary;
2167 mgr->mst_primary = NULL;
2168 /* this can fail if the device is gone */
2169 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2170 ret = 0;
2171 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2172 mgr->payload_mask = 0;
2173 set_bit(0, &mgr->payload_mask);
dfda0df3 2174 mgr->vcpi_mask = 0;
ad7f8a1f
DA		 2175 }
2176
2177out_unlock:
2178 mutex_unlock(&mgr->lock);
2179 if (mstb)
2180 drm_dp_put_mst_branch_device(mstb);
2181 return ret;
2182
2183}
2184EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2185
2186/**
2187 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2188 * @mgr: manager to suspend
2189 *
2190 * This function tells the MST device that we can't handle UP messages
2191 * anymore. This should stop it from sending any since we are suspended.
2192 */
2193void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2194{
2195 mutex_lock(&mgr->lock);
2196 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2197 DP_MST_EN | DP_UPSTREAM_IS_SRC);
2198 mutex_unlock(&mgr->lock);
274d8352
DA		 2199 flush_work(&mgr->work);
2200 flush_work(&mgr->destroy_connector_work);
ad7f8a1f
DA		 2201}
2202EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2203
2204/**
2205 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2206 * @mgr: manager to resume
2207 *
2208 * This will fetch DPCD and see if the device is still there,
2209 * if it is, it will rewrite the MSTM control bits, and return.
2210 *
2211 * if the device fails this returns -1, and the driver should do
2212 * a full MST reprobe, in case we were undocked.
2213 */
2214int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2215{
2216 int ret = 0;
2217
2218 mutex_lock(&mgr->lock);
2219
2220 if (mgr->mst_primary) {
2221 int sret;
1652fce6
L		 2222 u8 guid[16];
2223
ad7f8a1f
DA		 2224 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2225 if (sret != DP_RECEIVER_CAP_SIZE) {
2226 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2227 ret = -1;
2228 goto out_unlock;
2229 }
2230
2231 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2232 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2233 if (ret < 0) {
2234 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2235 ret = -1;
2236 goto out_unlock;
2237 }
1652fce6
L		 2238
2239 /* Some hubs forget their guids after they resume */
2240 sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
2241 if (sret != 16) {
2242 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2243 ret = -1;
2244 goto out_unlock;
2245 }
2246 drm_dp_check_mstb_guid(mgr->mst_primary, guid);
2247
ad7f8a1f
DA		 2248 ret = 0;
2249 } else
2250 ret = -1;
2251
2252out_unlock:
2253 mutex_unlock(&mgr->lock);
2254 return ret;
2255}
2256EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2257
636c4c3e 2258static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
ad7f8a1f
DA		 2259{
2260 int len;
2261 u8 replyblock[32];
2262 int replylen, origlen, curreply;
2263 int ret;
2264 struct drm_dp_sideband_msg_rx *msg;
2265 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2266 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2267
2268 len = min(mgr->max_dpcd_transaction_bytes, 16);
2269 ret = drm_dp_dpcd_read(mgr->aux, basereg,
2270 replyblock, len);
2271 if (ret != len) {
2272 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
636c4c3e 2273 return false;
ad7f8a1f
DA		 2274 }
2275 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2276 if (!ret) {
2277 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
636c4c3e 2278 return false;
ad7f8a1f
DA		 2279 }
2280 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2281
2282 origlen = replylen;
2283 replylen -= len;
2284 curreply = len;
2285 while (replylen > 0) {
2286 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2287 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2288 replyblock, len);
2289 if (ret != len) {
448421b5
ID		 2290 DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
2291 len, ret);
636c4c3e 2292 return false;
ad7f8a1f 2293 }
448421b5 2294
ad7f8a1f 2295 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
448421b5 2296 if (!ret) {
ad7f8a1f 2297 DRM_DEBUG_KMS("failed to build sideband msg\n");
636c4c3e 2298 return false;
448421b5
ID		 2299 }
2300
ad7f8a1f
DA		 2301 curreply += len;
2302 replylen -= len;
2303 }
636c4c3e 2304 return true;
ad7f8a1f
DA		 2305}
2306
2307static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2308{
2309 int ret = 0;
2310
636c4c3e
ID		 2311 if (!drm_dp_get_one_sb_msg(mgr, false)) {
2312 memset(&mgr->down_rep_recv, 0,
2313 sizeof(struct drm_dp_sideband_msg_rx));
2314 return 0;
2315 }
ad7f8a1f
DA		 2316
2317 if (mgr->down_rep_recv.have_eomt) {
2318 struct drm_dp_sideband_msg_tx *txmsg;
2319 struct drm_dp_mst_branch *mstb;
2320 int slot = -1;
2321 mstb = drm_dp_get_mst_branch_device(mgr,
2322 mgr->down_rep_recv.initial_hdr.lct,
2323 mgr->down_rep_recv.initial_hdr.rad);
2324
2325 if (!mstb) {
2326 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2327 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2328 return 0;
2329 }
2330
2331 /* find the message */
2332 slot = mgr->down_rep_recv.initial_hdr.seqno;
2333 mutex_lock(&mgr->qlock);
2334 txmsg = mstb->tx_slots[slot];
2335 /* remove from slots */
2336 mutex_unlock(&mgr->qlock);
2337
2338 if (!txmsg) {
2339 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2340 mstb,
2341 mgr->down_rep_recv.initial_hdr.seqno,
2342 mgr->down_rep_recv.initial_hdr.lct,
2343 mgr->down_rep_recv.initial_hdr.rad[0],
2344 mgr->down_rep_recv.msg[0]);
2345 drm_dp_put_mst_branch_device(mstb);
2346 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2347 return 0;
2348 }
2349
2350 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2351 if (txmsg->reply.reply_type == 1) {
2352 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);
2353 }
2354
2355 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2356 drm_dp_put_mst_branch_device(mstb);
2357
2358 mutex_lock(&mgr->qlock);
2359 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2360 mstb->tx_slots[slot] = NULL;
2361 mutex_unlock(&mgr->qlock);
2362
68e989dc 2363 wake_up_all(&mgr->tx_waitq);
ad7f8a1f
DA		 2364 }
2365 return ret;
2366}
2367
2368static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2369{
2370 int ret = 0;
636c4c3e
ID		 2371
2372 if (!drm_dp_get_one_sb_msg(mgr, true)) {
2373 memset(&mgr->up_req_recv, 0,
2374 sizeof(struct drm_dp_sideband_msg_rx));
2375 return 0;
2376 }
ad7f8a1f
DA		 2377
2378 if (mgr->up_req_recv.have_eomt) {
2379 struct drm_dp_sideband_msg_req_body msg;
bd934320 2380 struct drm_dp_mst_branch *mstb = NULL;
ad7f8a1f 2381 bool seqno;
bd934320
ML		 2382
2383 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2384 mstb = drm_dp_get_mst_branch_device(mgr,
2385 mgr->up_req_recv.initial_hdr.lct,
2386 mgr->up_req_recv.initial_hdr.rad);
2387 if (!mstb) {
2388 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2389 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2390 return 0;
2391 }
ad7f8a1f
DA		 2392 }
2393
2394 seqno = mgr->up_req_recv.initial_hdr.seqno;
2395 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2396
2397 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
bd934320
ML		 2398 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2399
2400 if (!mstb)
2401 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2402
2403 if (!mstb) {
2404 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2405 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2406 return 0;
2407 }
2408
ad7f8a1f 2409 drm_dp_update_port(mstb, &msg.u.conn_stat);
5e93b820 2410
ad7f8a1f 2411 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);
8ae22cb4
DA		 2412 (*mgr->cbs->hotplug)(mgr);
2413
ad7f8a1f 2414 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
bd934320
ML		 2415 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2416 if (!mstb)
2417 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2418
2419 if (!mstb) {
2420 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2421 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2422 return 0;
2423 }
2424
ad7f8a1f
DA		 2425 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2426 }
2427
7f8b3987
ID		 2428 if (mstb)
2429 drm_dp_put_mst_branch_device(mstb);
2430
ad7f8a1f
DA		 2431 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2432 }
2433 return ret;
2434}
2435
2436/**
2437 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2438 * @mgr: manager to notify irq for.
2439 * @esi: 4 bytes from SINK_COUNT_ESI
295ee853 2440 * @handled: whether the hpd interrupt was consumed or not
ad7f8a1f
DA		 2441 *
2442 * This should be called from the driver when it detects a short IRQ,
2443 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2444 * topology manager will process the sideband messages received as a result
2445 * of this.
2446 */
2447int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2448{
2449 int ret = 0;
2450 int sc;
2451 *handled = false;
2452 sc = esi[0] & 0x3f;
2453
2454 if (sc != mgr->sink_count) {
2455 mgr->sink_count = sc;
2456 *handled = true;
2457 }
2458
2459 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2460 ret = drm_dp_mst_handle_down_rep(mgr);
2461 *handled = true;
2462 }
2463
2464 if (esi[1] & DP_UP_REQ_MSG_RDY) {
2465 ret |= drm_dp_mst_handle_up_req(mgr);
2466 *handled = true;
2467 }
2468
2469 drm_dp_mst_kick_tx(mgr);
2470 return ret;
2471}
2472EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2473
2474/**
2475 * drm_dp_mst_detect_port() - get connection status for an MST port
132d49d7 2476 * @connector: DRM connector for this port
ad7f8a1f
DA		 2477 * @mgr: manager for this port
2478 * @port: unverified pointer to a port
2479 *
2480 * This returns the current connection state for a port. It validates the
2481 * port pointer still exists so the caller doesn't require a reference
2482 */
c6a0aed4
DA		 2483enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2484 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
ad7f8a1f
DA		 2485{
2486 enum drm_connector_status status = connector_status_disconnected;
2487
2488 /* we need to search for the port in the mgr in case its gone */
2489 port = drm_dp_get_validated_port_ref(mgr, port);
2490 if (!port)
2491 return connector_status_disconnected;
2492
2493 if (!port->ddps)
2494 goto out;
2495
2496 switch (port->pdt) {
2497 case DP_PEER_DEVICE_NONE:
2498 case DP_PEER_DEVICE_MST_BRANCHING:
2499 break;
2500
2501 case DP_PEER_DEVICE_SST_SINK:
2502 status = connector_status_connected;
8ae22cb4
DA		 2503 /* for logical ports - cache the EDID */
2504 if (port->port_num >= 8 && !port->cached_edid) {
2505 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2506 }
ad7f8a1f
DA		 2507 break;
2508 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2509 if (port->ldps)
2510 status = connector_status_connected;
2511 break;
2512 }
2513out:
2514 drm_dp_put_port(port);
2515 return status;
2516}
2517EXPORT_SYMBOL(drm_dp_mst_detect_port);
2518
ef8f9bea
LY		 2519/**
2520 * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
2521 * @mgr: manager for this port
2522 * @port: unverified pointer to a port.
2523 *
2524 * This returns whether the port supports audio or not.
2525 */
2526bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
2527 struct drm_dp_mst_port *port)
2528{
2529 bool ret = false;
2530
2531 port = drm_dp_get_validated_port_ref(mgr, port);
2532 if (!port)
2533 return ret;
2534 ret = port->has_audio;
2535 drm_dp_put_port(port);
2536 return ret;
2537}
2538EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
2539
ad7f8a1f
DA		 2540/**
2541 * drm_dp_mst_get_edid() - get EDID for an MST port
2542 * @connector: toplevel connector to get EDID for
2543 * @mgr: manager for this port
2544 * @port: unverified pointer to a port.
2545 *
2546 * This returns an EDID for the port connected to a connector,
2547 * It validates the pointer still exists so the caller doesn't require a
2548 * reference.
2549 */
2550struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2551{
2552 struct edid *edid = NULL;
2553
2554 /* we need to search for the port in the mgr in case its gone */
2555 port = drm_dp_get_validated_port_ref(mgr, port);
2556 if (!port)
2557 return NULL;
2558
c6a0aed4
DA		 2559 if (port->cached_edid)
2560 edid = drm_edid_duplicate(port->cached_edid);
8ae22cb4
DA		 2561 else {
2562 edid = drm_get_edid(connector, &port->aux.ddc);
97e14fbe 2563 drm_connector_set_tile_property(connector);
8ae22cb4 2564 }
ef8f9bea 2565 port->has_audio = drm_detect_monitor_audio(edid);
ad7f8a1f
DA		 2566 drm_dp_put_port(port);
2567 return edid;
2568}
2569EXPORT_SYMBOL(drm_dp_mst_get_edid);
2570
2571/**
2572 * drm_dp_find_vcpi_slots() - find slots for this PBN value
2573 * @mgr: manager to use
2574 * @pbn: payload bandwidth to convert into slots.
2575 */
2576int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2577 int pbn)
2578{
2579 int num_slots;
2580
2581 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2582
feb2c3bc
PD		 2583 /* max. time slots - one slot for MTP header */
2584 if (num_slots > 63)
ad7f8a1f
DA		 2585 return -ENOSPC;
2586 return num_slots;
2587}
2588EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2589
2590static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
1e797f55 2591 struct drm_dp_vcpi *vcpi, int pbn, int slots)
ad7f8a1f 2592{
ad7f8a1f
DA		 2593 int ret;
2594
feb2c3bc 2595 /* max. time slots - one slot for MTP header */
1e797f55 2596 if (slots > 63)
ad7f8a1f
DA		 2597 return -ENOSPC;
2598
2599 vcpi->pbn = pbn;
1e797f55
PD		 2600 vcpi->aligned_pbn = slots * mgr->pbn_div;
2601 vcpi->num_slots = slots;
ad7f8a1f
DA		 2602
2603 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2604 if (ret < 0)
2605 return ret;
2606 return 0;
2607}
2608
edb1ed1a
PD		 2609/**
2610 * drm_dp_atomic_find_vcpi_slots() - Find and add vcpi slots to the state
2611 * @state: global atomic state
2612 * @mgr: MST topology manager for the port
2613 * @port: port to find vcpi slots for
2614 * @pbn: bandwidth required for the mode in PBN
2615 *
2616 * RETURNS:
2617 * Total slots in the atomic state assigned for this port or error
2618 */
2619int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
2620 struct drm_dp_mst_topology_mgr *mgr,
2621 struct drm_dp_mst_port *port, int pbn)
2622{
2623 struct drm_dp_mst_topology_state *topology_state;
2624 int req_slots;
2625
2626 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
56a91c49
VS		 2627 if (IS_ERR(topology_state))
2628 return PTR_ERR(topology_state);
edb1ed1a
PD		 2629
2630 port = drm_dp_get_validated_port_ref(mgr, port);
2631 if (port == NULL)
2632 return -EINVAL;
2633 req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2634 DRM_DEBUG_KMS("vcpi slots req=%d, avail=%d\n",
2635 req_slots, topology_state->avail_slots);
2636
2637 if (req_slots > topology_state->avail_slots) {
2638 drm_dp_put_port(port);
2639 return -ENOSPC;
2640 }
2641
2642 topology_state->avail_slots -= req_slots;
2643 DRM_DEBUG_KMS("vcpi slots avail=%d", topology_state->avail_slots);
2644
2645 drm_dp_put_port(port);
2646 return req_slots;
2647}
2648EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
2649
2650/**
2651 * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
2652 * @state: global atomic state
2653 * @mgr: MST topology manager for the port
2654 * @slots: number of vcpi slots to release
2655 *
2656 * RETURNS:
2657 * 0 if @slots were added back to &drm_dp_mst_topology_state->avail_slots or
2658 * negative error code
2659 */
2660int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
2661 struct drm_dp_mst_topology_mgr *mgr,
2662 int slots)
2663{
2664 struct drm_dp_mst_topology_state *topology_state;
2665
2666 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
56a91c49
VS		 2667 if (IS_ERR(topology_state))
2668 return PTR_ERR(topology_state);
edb1ed1a
PD		 2669
2670 /* We cannot rely on port->vcpi.num_slots to update
2671 * topology_state->avail_slots as the port may not exist if the parent
2672 * branch device was unplugged. This should be fixed by tracking
2673 * per-port slot allocation in drm_dp_mst_topology_state instead of
2674 * depending on the caller to tell us how many slots to release.
2675 */
2676 topology_state->avail_slots += slots;
2677 DRM_DEBUG_KMS("vcpi slots released=%d, avail=%d\n",
2678 slots, topology_state->avail_slots);
2679
2680 return 0;
2681}
2682EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
2683
ad7f8a1f
DA		 2684/**
2685 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2686 * @mgr: manager for this port
2687 * @port: port to allocate a virtual channel for.
2688 * @pbn: payload bandwidth number to request
2689 * @slots: returned number of slots for this PBN.
2690 */
1e797f55
PD		 2691bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2692 struct drm_dp_mst_port *port, int pbn, int slots)
ad7f8a1f
DA		 2693{
2694 int ret;
2695
2696 port = drm_dp_get_validated_port_ref(mgr, port);
2697 if (!port)
2698 return false;
2699
1e797f55
PD		 2700 if (slots < 0)
2701 return false;
2702
ad7f8a1f
DA		 2703 if (port->vcpi.vcpi > 0) {
2704 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2705 if (pbn == port->vcpi.pbn) {
dabe1954 2706 drm_dp_put_port(port);
ad7f8a1f
DA		 2707 return true;
2708 }
2709 }
2710
1e797f55 2711 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
ad7f8a1f 2712 if (ret) {
feb2c3bc
PD		 2713 DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
2714 DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
ad7f8a1f
DA		 2715 goto out;
2716 }
feb2c3bc
PD		 2717 DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
2718 pbn, port->vcpi.num_slots);
ad7f8a1f
DA		 2719
2720 drm_dp_put_port(port);
2721 return true;
2722out:
2723 return false;
2724}
2725EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2726
87f5942d
DA		 2727int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2728{
2729 int slots = 0;
2730 port = drm_dp_get_validated_port_ref(mgr, port);
2731 if (!port)
2732 return slots;
2733
2734 slots = port->vcpi.num_slots;
2735 drm_dp_put_port(port);
2736 return slots;
2737}
2738EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2739
ad7f8a1f
DA		 2740/**
2741 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2742 * @mgr: manager for this port
2743 * @port: unverified pointer to a port.
2744 *
2745 * This just resets the number of slots for the ports VCPI for later programming.
2746 */
2747void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2748{
2749 port = drm_dp_get_validated_port_ref(mgr, port);
2750 if (!port)
2751 return;
2752 port->vcpi.num_slots = 0;
2753 drm_dp_put_port(port);
2754}
2755EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2756
2757/**
2758 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2759 * @mgr: manager for this port
2760 * @port: unverified port to deallocate vcpi for
2761 */
2762void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2763{
2764 port = drm_dp_get_validated_port_ref(mgr, port);
2765 if (!port)
2766 return;
2767
2768 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2769 port->vcpi.num_slots = 0;
2770 port->vcpi.pbn = 0;
2771 port->vcpi.aligned_pbn = 0;
2772 port->vcpi.vcpi = 0;
2773 drm_dp_put_port(port);
2774}
2775EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2776
2777static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2778 int id, struct drm_dp_payload *payload)
2779{
2780 u8 payload_alloc[3], status;
2781 int ret;
2782 int retries = 0;
2783
2784 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2785 DP_PAYLOAD_TABLE_UPDATED);
2786
2787 payload_alloc[0] = id;
2788 payload_alloc[1] = payload->start_slot;
2789 payload_alloc[2] = payload->num_slots;
2790
2791 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2792 if (ret != 3) {
2793 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2794 goto fail;
2795 }
2796
2797retry:
2798 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2799 if (ret < 0) {
2800 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2801 goto fail;
2802 }
2803
2804 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2805 retries++;
2806 if (retries < 20) {
2807 usleep_range(10000, 20000);
2808 goto retry;
2809 }
2810 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2811 ret = -EINVAL;
2812 goto fail;
2813 }
2814 ret = 0;
2815fail:
2816 return ret;
2817}
2818
2819
2820/**
2821 * drm_dp_check_act_status() - Check ACT handled status.
2822 * @mgr: manager to use
2823 *
2824 * Check the payload status bits in the DPCD for ACT handled completion.
2825 */
2826int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2827{
2828 u8 status;
2829 int ret;
2830 int count = 0;
2831
2832 do {
2833 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2834
2835 if (ret < 0) {
2836 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2837 goto fail;
2838 }
2839
2840 if (status & DP_PAYLOAD_ACT_HANDLED)
2841 break;
2842 count++;
2843 udelay(100);
2844
2845 } while (count < 30);
2846
2847 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2848 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2849 ret = -EINVAL;
2850 goto fail;
2851 }
2852 return 0;
2853fail:
2854 return ret;
2855}
2856EXPORT_SYMBOL(drm_dp_check_act_status);
2857
2858/**
2859 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2860 * @clock: dot clock for the mode
2861 * @bpp: bpp for the mode.
2862 *
2863 * This uses the formula in the spec to calculate the PBN value for a mode.
2864 */
2865int drm_dp_calc_pbn_mode(int clock, int bpp)
2866{
a9ebb3e4
HW		 2867 u64 kbps;
2868 s64 peak_kbps;
2869 u32 numerator;
2870 u32 denominator;
2871
2872 kbps = clock * bpp;
2873
2874 /*
2875 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
2876 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
2877 * common multiplier to render an integer PBN for all link rate/lane
2878 * counts combinations
2879 * calculate
2880 * peak_kbps *= (1006/1000)
2881 * peak_kbps *= (64/54)
2882 * peak_kbps *= 8 convert to bytes
2883 */
2884
2885 numerator = 64 * 1006;
2886 denominator = 54 * 8 * 1000 * 1000;
2887
2888 kbps *= numerator;
2889 peak_kbps = drm_fixp_from_fraction(kbps, denominator);
2890
2891 return drm_fixp2int_ceil(peak_kbps);
ad7f8a1f
DA		 2892}
2893EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2894
2895static int test_calc_pbn_mode(void)
2896{
2897 int ret;
2898 ret = drm_dp_calc_pbn_mode(154000, 30);
a9ebb3e4
HW		 2899 if (ret != 689) {
2900 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2901 154000, 30, 689, ret);
ad7f8a1f 2902 return -EINVAL;
a9ebb3e4 2903 }
ad7f8a1f 2904 ret = drm_dp_calc_pbn_mode(234000, 30);
a9ebb3e4
HW		 2905 if (ret != 1047) {
2906 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2907 234000, 30, 1047, ret);
ad7f8a1f 2908 return -EINVAL;
a9ebb3e4
HW		 2909 }
2910 ret = drm_dp_calc_pbn_mode(297000, 24);
2911 if (ret != 1063) {
2912 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2913 297000, 24, 1063, ret);
2914 return -EINVAL;
2915 }
ad7f8a1f
DA		 2916 return 0;
2917}
2918
2919/* we want to kick the TX after we've ack the up/down IRQs. */
2920static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2921{
2922 queue_work(system_long_wq, &mgr->tx_work);
2923}
2924
2925static void drm_dp_mst_dump_mstb(struct seq_file *m,
2926 struct drm_dp_mst_branch *mstb)
2927{
2928 struct drm_dp_mst_port *port;
2929 int tabs = mstb->lct;
2930 char prefix[10];
2931 int i;
2932
2933 for (i = 0; i < tabs; i++)
2934 prefix[i] = '\t';
2935 prefix[i] = '\0';
2936
2937 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2938 list_for_each_entry(port, &mstb->ports, next) {
51108f25 2939 seq_printf(m, "%sport: %d: input: %d: pdt: %d, ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->input, port->pdt, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
ad7f8a1f
DA		 2940 if (port->mstb)
2941 drm_dp_mst_dump_mstb(m, port->mstb);
2942 }
2943}
2944
7056a2bc
AS		 2945#define DP_PAYLOAD_TABLE_SIZE 64
2946
ad7f8a1f
DA		 2947static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2948 char *buf)
2949{
ad7f8a1f 2950 int i;
46466b0d 2951
7056a2bc 2952 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
46466b0d
JP		 2953 if (drm_dp_dpcd_read(mgr->aux,
2954 DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
2955 &buf[i], 16) != 16)
2956 return false;
ad7f8a1f 2957 }
46466b0d 2958 return true;
ad7f8a1f
DA		 2959}
2960
51108f25
JB		 2961static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
2962 struct drm_dp_mst_port *port, char *name,
2963 int namelen)
2964{
2965 struct edid *mst_edid;
2966
2967 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
2968 drm_edid_get_monitor_name(mst_edid, name, namelen);
2969}
2970
ad7f8a1f
DA		 2971/**
2972 * drm_dp_mst_dump_topology(): dump topology to seq file.
2973 * @m: seq_file to dump output to
2974 * @mgr: manager to dump current topology for.
2975 *
2976 * helper to dump MST topology to a seq file for debugfs.
2977 */
2978void drm_dp_mst_dump_topology(struct seq_file *m,
2979 struct drm_dp_mst_topology_mgr *mgr)
2980{
2981 int i;
2982 struct drm_dp_mst_port *port;
51108f25 2983
ad7f8a1f
DA		 2984 mutex_lock(&mgr->lock);
2985 if (mgr->mst_primary)
2986 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2987
2988 /* dump VCPIs */
2989 mutex_unlock(&mgr->lock);
2990
2991 mutex_lock(&mgr->payload_lock);
51108f25
JB		 2992 seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
2993 mgr->max_payloads);
ad7f8a1f
DA		 2994
2995 for (i = 0; i < mgr->max_payloads; i++) {
2996 if (mgr->proposed_vcpis[i]) {
51108f25
JB		 2997 char name[14];
2998
ad7f8a1f 2999 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
51108f25
JB		 3000 fetch_monitor_name(mgr, port, name, sizeof(name));
3001 seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
3002 port->port_num, port->vcpi.vcpi,
3003 port->vcpi.num_slots,
3004 (*name != 0) ? name : "Unknown");
ad7f8a1f 3005 } else
51108f25 3006 seq_printf(m, "vcpi %d:unused\n", i);
ad7f8a1f
DA		 3007 }
3008 for (i = 0; i < mgr->max_payloads; i++) {
3009 seq_printf(m, "payload %d: %d, %d, %d\n",
3010 i,
3011 mgr->payloads[i].payload_state,
3012 mgr->payloads[i].start_slot,
3013 mgr->payloads[i].num_slots);
3014
3015
3016 }
3017 mutex_unlock(&mgr->payload_lock);
3018
3019 mutex_lock(&mgr->lock);
3020 if (mgr->mst_primary) {
7056a2bc 3021 u8 buf[DP_PAYLOAD_TABLE_SIZE];
ad7f8a1f 3022 int ret;
46466b0d 3023
ad7f8a1f 3024 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
46466b0d 3025 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
ad7f8a1f 3026 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
46466b0d 3027 seq_printf(m, "faux/mst: %*ph\n", 2, buf);
ad7f8a1f 3028 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
46466b0d 3029 seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
ad7f8a1f 3030
44790462
DA		 3031 /* dump the standard OUI branch header */
3032 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
46466b0d 3033 seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
51108f25 3034 for (i = 0x3; i < 0x8 && buf[i]; i++)
44790462 3035 seq_printf(m, "%c", buf[i]);
46466b0d
JP		 3036 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
3037 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
3038 if (dump_dp_payload_table(mgr, buf))
7056a2bc 3039 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
ad7f8a1f
DA		 3040 }
3041
3042 mutex_unlock(&mgr->lock);
3043
3044}
3045EXPORT_SYMBOL(drm_dp_mst_dump_topology);
3046
3047static void drm_dp_tx_work(struct work_struct *work)
3048{
3049 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
3050
3051 mutex_lock(&mgr->qlock);
cb021a3e 3052 if (!list_empty(&mgr->tx_msg_downq))
ad7f8a1f
DA		 3053 process_single_down_tx_qlock(mgr);
3054 mutex_unlock(&mgr->qlock);
3055}
3056
91a25e46
ML		 3057static void drm_dp_free_mst_port(struct kref *kref)
3058{
3059 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
3060 kref_put(&port->parent->kref, drm_dp_free_mst_branch_device);
3061 kfree(port);
3062}
3063
6b8eeca6
DA		 3064static void drm_dp_destroy_connector_work(struct work_struct *work)
3065{
3066 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
4772ff03 3067 struct drm_dp_mst_port *port;
df4839fd 3068 bool send_hotplug = false;
6b8eeca6
DA		 3069 /*
3070 * Not a regular list traverse as we have to drop the destroy
3071 * connector lock before destroying the connector, to avoid AB->BA
3072 * ordering between this lock and the config mutex.
3073 */
3074 for (;;) {
3075 mutex_lock(&mgr->destroy_connector_lock);
4772ff03
ML		 3076 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
3077 if (!port) {
6b8eeca6
DA		 3078 mutex_unlock(&mgr->destroy_connector_lock);
3079 break;
3080 }
4772ff03 3081 list_del(&port->next);
6b8eeca6
DA		 3082 mutex_unlock(&mgr->destroy_connector_lock);
3083
91a25e46
ML		 3084 kref_init(&port->kref);
3085 INIT_LIST_HEAD(&port->next);
3086
4772ff03
ML		 3087 mgr->cbs->destroy_connector(mgr, port->connector);
3088
3089 drm_dp_port_teardown_pdt(port, port->pdt);
36e3fa6a 3090 port->pdt = DP_PEER_DEVICE_NONE;
4772ff03 3091
91a25e46 3092 if (!port->input && port->vcpi.vcpi > 0) {
fd2d2bac
AG		 3093 drm_dp_mst_reset_vcpi_slots(mgr, port);
3094 drm_dp_update_payload_part1(mgr);
3095 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
91a25e46
ML		 3096 }
3097
3098 kref_put(&port->kref, drm_dp_free_mst_port);
df4839fd 3099 send_hotplug = true;
6b8eeca6 3100 }
df4839fd
DA		 3101 if (send_hotplug)
3102 (*mgr->cbs->hotplug)(mgr);
6b8eeca6
DA		 3103}
3104
a4370c77
VS		 3105static struct drm_private_state *
3106drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
3f3353b7 3107{
a4370c77 3108 struct drm_dp_mst_topology_state *state;
3f3353b7 3109
a4370c77
VS		 3110 state = kmemdup(obj->state, sizeof(*state), GFP_KERNEL);
3111 if (!state)
3f3353b7
PD		 3112 return NULL;
3113
a4370c77 3114 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
3f3353b7 3115
a4370c77 3116 return &state->base;
3f3353b7
PD		 3117}
3118
a4370c77
VS		 3119static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
3120 struct drm_private_state *state)
3f3353b7 3121{
a4370c77
VS		 3122 struct drm_dp_mst_topology_state *mst_state =
3123 to_dp_mst_topology_state(state);
3124
3125 kfree(mst_state);
3f3353b7
PD		 3126}
3127
3128static const struct drm_private_state_funcs mst_state_funcs = {
a4370c77
VS		 3129 .atomic_duplicate_state = drm_dp_mst_duplicate_state,
3130 .atomic_destroy_state = drm_dp_mst_destroy_state,
3f3353b7
PD		 3131};
3132
3133/**
3134 * drm_atomic_get_mst_topology_state: get MST topology state
3135 *
3136 * @state: global atomic state
3137 * @mgr: MST topology manager, also the private object in this case
3138 *
3139 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
3140 * state vtable so that the private object state returned is that of a MST
3141 * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
3142 * to care of the locking, so warn if don't hold the connection_mutex.
3143 *
3144 * RETURNS:
3145 *
3146 * The MST topology state or error pointer.
3147 */
3148struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
3149 struct drm_dp_mst_topology_mgr *mgr)
3150{
3151 struct drm_device *dev = mgr->dev;
3152
3153 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
a4370c77 3154 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
3f3353b7
PD		 3155}
3156EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
3157
ad7f8a1f
DA		 3158/**
3159 * drm_dp_mst_topology_mgr_init - initialise a topology manager
3160 * @mgr: manager struct to initialise
3161 * @dev: device providing this structure - for i2c addition.
3162 * @aux: DP helper aux channel to talk to this device
3163 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
3164 * @max_payloads: maximum number of payloads this GPU can source
3165 * @conn_base_id: the connector object ID the MST device is connected to.
3166 *
3167 * Return 0 for success, or negative error code on failure
3168 */
3169int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
7b0a89a6 3170 struct drm_device *dev, struct drm_dp_aux *aux,
ad7f8a1f
DA		 3171 int max_dpcd_transaction_bytes,
3172 int max_payloads, int conn_base_id)
3173{
a4370c77
VS		 3174 struct drm_dp_mst_topology_state *mst_state;
3175
ad7f8a1f
DA		 3176 mutex_init(&mgr->lock);
3177 mutex_init(&mgr->qlock);
3178 mutex_init(&mgr->payload_lock);
6b8eeca6 3179 mutex_init(&mgr->destroy_connector_lock);
ad7f8a1f 3180 INIT_LIST_HEAD(&mgr->tx_msg_downq);
6b8eeca6 3181 INIT_LIST_HEAD(&mgr->destroy_connector_list);
ad7f8a1f
DA		 3182 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
3183 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
6b8eeca6 3184 INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
ad7f8a1f
DA		 3185 init_waitqueue_head(&mgr->tx_waitq);
3186 mgr->dev = dev;
3187 mgr->aux = aux;
3188 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
3189 mgr->max_payloads = max_payloads;
3190 mgr->conn_base_id = conn_base_id;
4d6a10da
ID		 3191 if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
3192 max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
3193 return -EINVAL;
ad7f8a1f
DA		 3194 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
3195 if (!mgr->payloads)
3196 return -ENOMEM;
3197 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
3198 if (!mgr->proposed_vcpis)
3199 return -ENOMEM;
3200 set_bit(0, &mgr->payload_mask);
441388a8
ID		 3201 if (test_calc_pbn_mode() < 0)
3202 DRM_ERROR("MST PBN self-test failed\n");
3203
a4370c77
VS		 3204 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
3205 if (mst_state == NULL)
3f3353b7 3206 return -ENOMEM;
a4370c77
VS		 3207
3208 mst_state->mgr = mgr;
3f3353b7
PD		 3209
3210 /* max. time slots - one slot for MTP header */
a4370c77
VS		 3211 mst_state->avail_slots = 63;
3212
3213 drm_atomic_private_obj_init(&mgr->base,
3214 &mst_state->base,
3215 &mst_state_funcs);
3f3353b7 3216
ad7f8a1f
DA		 3217 return 0;
3218}
3219EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
3220
3221/**
3222 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
3223 * @mgr: manager to destroy
3224 */
3225void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
3226{
274d8352 3227 flush_work(&mgr->work);
6b8eeca6 3228 flush_work(&mgr->destroy_connector_work);
ad7f8a1f
DA		 3229 mutex_lock(&mgr->payload_lock);
3230 kfree(mgr->payloads);
3231 mgr->payloads = NULL;
3232 kfree(mgr->proposed_vcpis);
3233 mgr->proposed_vcpis = NULL;
3234 mutex_unlock(&mgr->payload_lock);
3235 mgr->dev = NULL;
3236 mgr->aux = NULL;
a4370c77 3237 drm_atomic_private_obj_fini(&mgr->base);
3f3353b7 3238 mgr->funcs = NULL;
ad7f8a1f
DA		 3239}
3240EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
3241
3242/* I2C device */
3243static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
3244 int num)
3245{
3246 struct drm_dp_aux *aux = adapter->algo_data;
3247 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
3248 struct drm_dp_mst_branch *mstb;
3249 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
3250 unsigned int i;
3251 bool reading = false;
3252 struct drm_dp_sideband_msg_req_body msg;
3253 struct drm_dp_sideband_msg_tx *txmsg = NULL;
3254 int ret;
3255
3256 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
3257 if (!mstb)
3258 return -EREMOTEIO;
3259
3260 /* construct i2c msg */
3261 /* see if last msg is a read */
3262 if (msgs[num - 1].flags & I2C_M_RD)
3263 reading = true;
3264
ae491542 3265 if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
ad7f8a1f
DA		 3266 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
3267 ret = -EIO;
3268 goto out;
3269 }
3270
ae491542 3271 memset(&msg, 0, sizeof(msg));
ad7f8a1f
DA		 3272 msg.req_type = DP_REMOTE_I2C_READ;
3273 msg.u.i2c_read.num_transactions = num - 1;
3274 msg.u.i2c_read.port_number = port->port_num;
3275 for (i = 0; i < num - 1; i++) {
3276 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
3277 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
3278 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
3279 }
3280 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
3281 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
3282
3283 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3284 if (!txmsg) {
3285 ret = -ENOMEM;
3286 goto out;
3287 }
3288
3289 txmsg->dst = mstb;
3290 drm_dp_encode_sideband_req(&msg, txmsg);
3291
3292 drm_dp_queue_down_tx(mgr, txmsg);
3293
3294 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3295 if (ret > 0) {
3296
3297 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
3298 ret = -EREMOTEIO;
3299 goto out;
3300 }
3301 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
3302 ret = -EIO;
3303 goto out;
3304 }
3305 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
3306 ret = num;
3307 }
3308out:
3309 kfree(txmsg);
3310 drm_dp_put_mst_branch_device(mstb);
3311 return ret;
3312}
3313
3314static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
3315{
3316 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
3317 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
3318 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
3319 I2C_FUNC_10BIT_ADDR;
3320}
3321
3322static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
3323 .functionality = drm_dp_mst_i2c_functionality,
3324 .master_xfer = drm_dp_mst_i2c_xfer,
3325};
3326
3327/**
3328 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
3329 * @aux: DisplayPort AUX channel
3330 *
3331 * Returns 0 on success or a negative error code on failure.
3332 */
3333static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
3334{
3335 aux->ddc.algo = &drm_dp_mst_i2c_algo;
3336 aux->ddc.algo_data = aux;
3337 aux->ddc.retries = 3;
3338
3339 aux->ddc.class = I2C_CLASS_DDC;
3340 aux->ddc.owner = THIS_MODULE;
3341 aux->ddc.dev.parent = aux->dev;
3342 aux->ddc.dev.of_node = aux->dev->of_node;
3343
3344 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
3345 sizeof(aux->ddc.name));
3346
3347 return i2c_add_adapter(&aux->ddc);
3348}
3349
3350/**
3351 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
3352 * @aux: DisplayPort AUX channel
3353 */
3354static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
3355{
3356 i2c_del_adapter(&aux->ddc);
3357}
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