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drm/dp/mst: reply with ACK for UP reqs
[mirror_ubuntu-artful-kernel.git] / drivers / gpu / drm / drm_dp_mst_topology.c
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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>
34
35/**
36 * DOC: dp mst helper
37 *
38 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
39 * protocol. The helpers contain a topology manager and bandwidth manager.
40 * The helpers encapsulate the sending and received of sideband msgs.
41 */
42static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
43 char *buf);
44static int test_calc_pbn_mode(void);
45
46static void drm_dp_put_port(struct drm_dp_mst_port *port);
47
48static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
49 int id,
50 struct drm_dp_payload *payload);
51
52static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
53 struct drm_dp_mst_port *port,
54 int offset, int size, u8 *bytes);
55
68d8c9fc
DA		 56static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
57 struct drm_dp_mst_branch *mstb);
ad7f8a1f
DA		 58static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
59 struct drm_dp_mst_branch *mstb,
60 struct drm_dp_mst_port *port);
61static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
62 u8 *guid);
63
64static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
65static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
66static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
67/* sideband msg handling */
68static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
69{
70 u8 bitmask = 0x80;
71 u8 bitshift = 7;
72 u8 array_index = 0;
73 int number_of_bits = num_nibbles * 4;
74 u8 remainder = 0;
75
76 while (number_of_bits != 0) {
77 number_of_bits--;
78 remainder <<= 1;
79 remainder |= (data[array_index] & bitmask) >> bitshift;
80 bitmask >>= 1;
81 bitshift--;
82 if (bitmask == 0) {
83 bitmask = 0x80;
84 bitshift = 7;
85 array_index++;
86 }
87 if ((remainder & 0x10) == 0x10)
88 remainder ^= 0x13;
89 }
90
91 number_of_bits = 4;
92 while (number_of_bits != 0) {
93 number_of_bits--;
94 remainder <<= 1;
95 if ((remainder & 0x10) != 0)
96 remainder ^= 0x13;
97 }
98
99 return remainder;
100}
101
102static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
103{
104 u8 bitmask = 0x80;
105 u8 bitshift = 7;
106 u8 array_index = 0;
107 int number_of_bits = number_of_bytes * 8;
108 u16 remainder = 0;
109
110 while (number_of_bits != 0) {
111 number_of_bits--;
112 remainder <<= 1;
113 remainder |= (data[array_index] & bitmask) >> bitshift;
114 bitmask >>= 1;
115 bitshift--;
116 if (bitmask == 0) {
117 bitmask = 0x80;
118 bitshift = 7;
119 array_index++;
120 }
121 if ((remainder & 0x100) == 0x100)
122 remainder ^= 0xd5;
123 }
124
125 number_of_bits = 8;
126 while (number_of_bits != 0) {
127 number_of_bits--;
128 remainder <<= 1;
129 if ((remainder & 0x100) != 0)
130 remainder ^= 0xd5;
131 }
132
133 return remainder & 0xff;
134}
135static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
136{
137 u8 size = 3;
138 size += (hdr->lct / 2);
139 return size;
140}
141
142static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
143 u8 *buf, int *len)
144{
145 int idx = 0;
146 int i;
147 u8 crc4;
148 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
149 for (i = 0; i < (hdr->lct / 2); i++)
150 buf[idx++] = hdr->rad[i];
151 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
152 (hdr->msg_len & 0x3f);
153 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
154
155 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
156 buf[idx - 1] |= (crc4 & 0xf);
157
158 *len = idx;
159}
160
161static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
162 u8 *buf, int buflen, u8 *hdrlen)
163{
164 u8 crc4;
165 u8 len;
166 int i;
167 u8 idx;
168 if (buf[0] == 0)
169 return false;
170 len = 3;
171 len += ((buf[0] & 0xf0) >> 4) / 2;
172 if (len > buflen)
173 return false;
174 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
175
176 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
177 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
178 return false;
179 }
180
181 hdr->lct = (buf[0] & 0xf0) >> 4;
182 hdr->lcr = (buf[0] & 0xf);
183 idx = 1;
184 for (i = 0; i < (hdr->lct / 2); i++)
185 hdr->rad[i] = buf[idx++];
186 hdr->broadcast = (buf[idx] >> 7) & 0x1;
187 hdr->path_msg = (buf[idx] >> 6) & 0x1;
188 hdr->msg_len = buf[idx] & 0x3f;
189 idx++;
190 hdr->somt = (buf[idx] >> 7) & 0x1;
191 hdr->eomt = (buf[idx] >> 6) & 0x1;
192 hdr->seqno = (buf[idx] >> 4) & 0x1;
193 idx++;
194 *hdrlen = idx;
195 return true;
196}
197
198static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req,
199 struct drm_dp_sideband_msg_tx *raw)
200{
201 int idx = 0;
202 int i;
203 u8 *buf = raw->msg;
204 buf[idx++] = req->req_type & 0x7f;
205
206 switch (req->req_type) {
207 case DP_ENUM_PATH_RESOURCES:
208 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
209 idx++;
210 break;
211 case DP_ALLOCATE_PAYLOAD:
212 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
213 (req->u.allocate_payload.number_sdp_streams & 0xf);
214 idx++;
215 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
216 idx++;
217 buf[idx] = (req->u.allocate_payload.pbn >> 8);
218 idx++;
219 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
220 idx++;
221 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
222 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
223 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
224 idx++;
225 }
226 if (req->u.allocate_payload.number_sdp_streams & 1) {
227 i = req->u.allocate_payload.number_sdp_streams - 1;
228 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
229 idx++;
230 }
231 break;
232 case DP_QUERY_PAYLOAD:
233 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
234 idx++;
235 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
236 idx++;
237 break;
238 case DP_REMOTE_DPCD_READ:
239 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
240 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
241 idx++;
242 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
243 idx++;
244 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
245 idx++;
246 buf[idx] = (req->u.dpcd_read.num_bytes);
247 idx++;
248 break;
249
250 case DP_REMOTE_DPCD_WRITE:
251 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
252 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
253 idx++;
254 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
255 idx++;
256 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
257 idx++;
258 buf[idx] = (req->u.dpcd_write.num_bytes);
259 idx++;
260 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
261 idx += req->u.dpcd_write.num_bytes;
262 break;
263 case DP_REMOTE_I2C_READ:
264 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
265 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
266 idx++;
267 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
268 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
269 idx++;
270 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
271 idx++;
272 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
273 idx += req->u.i2c_read.transactions[i].num_bytes;
274
275 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
276 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
277 idx++;
278 }
279 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
280 idx++;
281 buf[idx] = (req->u.i2c_read.num_bytes_read);
282 idx++;
283 break;
284
285 case DP_REMOTE_I2C_WRITE:
286 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
287 idx++;
288 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
289 idx++;
290 buf[idx] = (req->u.i2c_write.num_bytes);
291 idx++;
292 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
293 idx += req->u.i2c_write.num_bytes;
294 break;
295 }
296 raw->cur_len = idx;
297}
298
299static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
300{
301 u8 crc4;
302 crc4 = drm_dp_msg_data_crc4(msg, len);
303 msg[len] = crc4;
304}
305
306static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
307 struct drm_dp_sideband_msg_tx *raw)
308{
309 int idx = 0;
310 u8 *buf = raw->msg;
311
312 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
313
314 raw->cur_len = idx;
315}
316
317/* this adds a chunk of msg to the builder to get the final msg */
318static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
319 u8 *replybuf, u8 replybuflen, bool hdr)
320{
321 int ret;
322 u8 crc4;
323
324 if (hdr) {
325 u8 hdrlen;
326 struct drm_dp_sideband_msg_hdr recv_hdr;
327 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
328 if (ret == false) {
329 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
330 return false;
331 }
332
333 /* get length contained in this portion */
334 msg->curchunk_len = recv_hdr.msg_len;
335 msg->curchunk_hdrlen = hdrlen;
336
337 /* we have already gotten an somt - don't bother parsing */
338 if (recv_hdr.somt && msg->have_somt)
339 return false;
340
341 if (recv_hdr.somt) {
342 memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
343 msg->have_somt = true;
344 }
345 if (recv_hdr.eomt)
346 msg->have_eomt = true;
347
348 /* copy the bytes for the remainder of this header chunk */
349 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
350 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
351 } else {
352 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
353 msg->curchunk_idx += replybuflen;
354 }
355
356 if (msg->curchunk_idx >= msg->curchunk_len) {
357 /* do CRC */
358 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
359 /* copy chunk into bigger msg */
360 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
361 msg->curlen += msg->curchunk_len - 1;
362 }
363 return true;
364}
365
366static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
367 struct drm_dp_sideband_msg_reply_body *repmsg)
368{
369 int idx = 1;
370 int i;
371 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
372 idx += 16;
373 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
374 idx++;
375 if (idx > raw->curlen)
376 goto fail_len;
377 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
378 if (raw->msg[idx] & 0x80)
379 repmsg->u.link_addr.ports[i].input_port = 1;
380
381 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
382 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
383
384 idx++;
385 if (idx > raw->curlen)
386 goto fail_len;
387 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
388 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
389 if (repmsg->u.link_addr.ports[i].input_port == 0)
390 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
391 idx++;
392 if (idx > raw->curlen)
393 goto fail_len;
394 if (repmsg->u.link_addr.ports[i].input_port == 0) {
395 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
396 idx++;
397 if (idx > raw->curlen)
398 goto fail_len;
399 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
400 idx += 16;
401 if (idx > raw->curlen)
402 goto fail_len;
403 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
404 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
405 idx++;
406
407 }
408 if (idx > raw->curlen)
409 goto fail_len;
410 }
411
412 return true;
413fail_len:
414 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
415 return false;
416}
417
418static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
419 struct drm_dp_sideband_msg_reply_body *repmsg)
420{
421 int idx = 1;
422 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
423 idx++;
424 if (idx > raw->curlen)
425 goto fail_len;
426 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
427 if (idx > raw->curlen)
428 goto fail_len;
429
430 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
431 return true;
432fail_len:
433 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
434 return false;
435}
436
437static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
438 struct drm_dp_sideband_msg_reply_body *repmsg)
439{
440 int idx = 1;
441 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
442 idx++;
443 if (idx > raw->curlen)
444 goto fail_len;
445 return true;
446fail_len:
447 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
448 return false;
449}
450
451static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
452 struct drm_dp_sideband_msg_reply_body *repmsg)
453{
454 int idx = 1;
455
456 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
457 idx++;
458 if (idx > raw->curlen)
459 goto fail_len;
460 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
461 idx++;
462 /* TODO check */
463 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
464 return true;
465fail_len:
466 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
467 return false;
468}
469
470static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
471 struct drm_dp_sideband_msg_reply_body *repmsg)
472{
473 int idx = 1;
474 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
475 idx++;
476 if (idx > raw->curlen)
477 goto fail_len;
478 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
479 idx += 2;
480 if (idx > raw->curlen)
481 goto fail_len;
482 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
483 idx += 2;
484 if (idx > raw->curlen)
485 goto fail_len;
486 return true;
487fail_len:
488 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
489 return false;
490}
491
492static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
493 struct drm_dp_sideband_msg_reply_body *repmsg)
494{
495 int idx = 1;
496 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
497 idx++;
498 if (idx > raw->curlen)
499 goto fail_len;
500 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
501 idx++;
502 if (idx > raw->curlen)
503 goto fail_len;
504 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
505 idx += 2;
506 if (idx > raw->curlen)
507 goto fail_len;
508 return true;
509fail_len:
510 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
511 return false;
512}
513
514static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
515 struct drm_dp_sideband_msg_reply_body *repmsg)
516{
517 int idx = 1;
518 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
519 idx++;
520 if (idx > raw->curlen)
521 goto fail_len;
522 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
523 idx += 2;
524 if (idx > raw->curlen)
525 goto fail_len;
526 return true;
527fail_len:
528 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
529 return false;
530}
531
532static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
533 struct drm_dp_sideband_msg_reply_body *msg)
534{
535 memset(msg, 0, sizeof(*msg));
536 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
537 msg->req_type = (raw->msg[0] & 0x7f);
538
539 if (msg->reply_type) {
540 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
541 msg->u.nak.reason = raw->msg[17];
542 msg->u.nak.nak_data = raw->msg[18];
543 return false;
544 }
545
546 switch (msg->req_type) {
547 case DP_LINK_ADDRESS:
548 return drm_dp_sideband_parse_link_address(raw, msg);
549 case DP_QUERY_PAYLOAD:
550 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
551 case DP_REMOTE_DPCD_READ:
552 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
553 case DP_REMOTE_DPCD_WRITE:
554 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
555 case DP_REMOTE_I2C_READ:
556 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
557 case DP_ENUM_PATH_RESOURCES:
558 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
559 case DP_ALLOCATE_PAYLOAD:
560 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
561 default:
562 DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
563 return false;
564 }
565}
566
567static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
568 struct drm_dp_sideband_msg_req_body *msg)
569{
570 int idx = 1;
571
572 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
573 idx++;
574 if (idx > raw->curlen)
575 goto fail_len;
576
577 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
578 idx += 16;
579 if (idx > raw->curlen)
580 goto fail_len;
581
582 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
583 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
584 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
585 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
586 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
587 idx++;
588 return true;
589fail_len:
590 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
591 return false;
592}
593
594static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
595 struct drm_dp_sideband_msg_req_body *msg)
596{
597 int idx = 1;
598
599 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
600 idx++;
601 if (idx > raw->curlen)
602 goto fail_len;
603
604 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
605 idx += 16;
606 if (idx > raw->curlen)
607 goto fail_len;
608
609 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
610 idx++;
611 return true;
612fail_len:
613 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
614 return false;
615}
616
617static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
618 struct drm_dp_sideband_msg_req_body *msg)
619{
620 memset(msg, 0, sizeof(*msg));
621 msg->req_type = (raw->msg[0] & 0x7f);
622
623 switch (msg->req_type) {
624 case DP_CONNECTION_STATUS_NOTIFY:
625 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
626 case DP_RESOURCE_STATUS_NOTIFY:
627 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
628 default:
629 DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
630 return false;
631 }
632}
633
634static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
635{
636 struct drm_dp_sideband_msg_req_body req;
637
638 req.req_type = DP_REMOTE_DPCD_WRITE;
639 req.u.dpcd_write.port_number = port_num;
640 req.u.dpcd_write.dpcd_address = offset;
641 req.u.dpcd_write.num_bytes = num_bytes;
642 req.u.dpcd_write.bytes = bytes;
643 drm_dp_encode_sideband_req(&req, msg);
644
645 return 0;
646}
647
648static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
649{
650 struct drm_dp_sideband_msg_req_body req;
651
652 req.req_type = DP_LINK_ADDRESS;
653 drm_dp_encode_sideband_req(&req, msg);
654 return 0;
655}
656
657static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
658{
659 struct drm_dp_sideband_msg_req_body req;
660
661 req.req_type = DP_ENUM_PATH_RESOURCES;
662 req.u.port_num.port_number = port_num;
663 drm_dp_encode_sideband_req(&req, msg);
664 msg->path_msg = true;
665 return 0;
666}
667
668static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
669 u8 vcpi, uint16_t pbn)
670{
671 struct drm_dp_sideband_msg_req_body req;
672 memset(&req, 0, sizeof(req));
673 req.req_type = DP_ALLOCATE_PAYLOAD;
674 req.u.allocate_payload.port_number = port_num;
675 req.u.allocate_payload.vcpi = vcpi;
676 req.u.allocate_payload.pbn = pbn;
677 drm_dp_encode_sideband_req(&req, msg);
678 msg->path_msg = true;
679 return 0;
680}
681
682static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
683 struct drm_dp_vcpi *vcpi)
684{
dfda0df3 685 int ret, vcpi_ret;
ad7f8a1f
DA		 686
687 mutex_lock(&mgr->payload_lock);
688 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
689 if (ret > mgr->max_payloads) {
690 ret = -EINVAL;
691 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
692 goto out_unlock;
693 }
694
dfda0df3
DA		 695 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
696 if (vcpi_ret > mgr->max_payloads) {
697 ret = -EINVAL;
698 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
699 goto out_unlock;
700 }
701
ad7f8a1f 702 set_bit(ret, &mgr->payload_mask);
dfda0df3
DA		 703 set_bit(vcpi_ret, &mgr->vcpi_mask);
704 vcpi->vcpi = vcpi_ret + 1;
ad7f8a1f
DA		 705 mgr->proposed_vcpis[ret - 1] = vcpi;
706out_unlock:
707 mutex_unlock(&mgr->payload_lock);
708 return ret;
709}
710
711static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
dfda0df3 712 int vcpi)
ad7f8a1f 713{
dfda0df3
DA		 714 int i;
715 if (vcpi == 0)
ad7f8a1f
DA		 716 return;
717
718 mutex_lock(&mgr->payload_lock);
dfda0df3
DA		 719 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
720 clear_bit(vcpi - 1, &mgr->vcpi_mask);
721
722 for (i = 0; i < mgr->max_payloads; i++) {
723 if (mgr->proposed_vcpis[i])
724 if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
725 mgr->proposed_vcpis[i] = NULL;
726 clear_bit(i + 1, &mgr->payload_mask);
727 }
728 }
ad7f8a1f
DA		 729 mutex_unlock(&mgr->payload_lock);
730}
731
732static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
733 struct drm_dp_sideband_msg_tx *txmsg)
734{
735 bool ret;
cd961bb9
DV		 736
737 /*
738 * All updates to txmsg->state are protected by mgr->qlock, and the two
739 * cases we check here are terminal states. For those the barriers
740 * provided by the wake_up/wait_event pair are enough.
741 */
ad7f8a1f
DA		 742 ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
743 txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
ad7f8a1f
DA		 744 return ret;
745}
746
747static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
748 struct drm_dp_sideband_msg_tx *txmsg)
749{
750 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
751 int ret;
752
753 ret = wait_event_timeout(mgr->tx_waitq,
754 check_txmsg_state(mgr, txmsg),
755 (4 * HZ));
756 mutex_lock(&mstb->mgr->qlock);
757 if (ret > 0) {
758 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
759 ret = -EIO;
760 goto out;
761 }
762 } else {
763 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
764
765 /* dump some state */
766 ret = -EIO;
767
768 /* remove from q */
769 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
770 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
771 list_del(&txmsg->next);
772 }
773
774 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
775 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
776 mstb->tx_slots[txmsg->seqno] = NULL;
777 }
778 }
779out:
780 mutex_unlock(&mgr->qlock);
781
782 return ret;
783}
784
785static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
786{
787 struct drm_dp_mst_branch *mstb;
788
789 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
790 if (!mstb)
791 return NULL;
792
793 mstb->lct = lct;
794 if (lct > 1)
795 memcpy(mstb->rad, rad, lct / 2);
796 INIT_LIST_HEAD(&mstb->ports);
797 kref_init(&mstb->kref);
798 return mstb;
799}
800
801static void drm_dp_destroy_mst_branch_device(struct kref *kref)
802{
803 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
804 struct drm_dp_mst_port *port, *tmp;
805 bool wake_tx = false;
806
ad7f8a1f
DA		 807 /*
808 * destroy all ports - don't need lock
809 * as there are no more references to the mst branch
810 * device at this point.
811 */
812 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
813 list_del(&port->next);
814 drm_dp_put_port(port);
815 }
816
817 /* drop any tx slots msg */
818 mutex_lock(&mstb->mgr->qlock);
819 if (mstb->tx_slots[0]) {
820 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
821 mstb->tx_slots[0] = NULL;
822 wake_tx = true;
823 }
824 if (mstb->tx_slots[1]) {
825 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
826 mstb->tx_slots[1] = NULL;
827 wake_tx = true;
828 }
829 mutex_unlock(&mstb->mgr->qlock);
830
831 if (wake_tx)
832 wake_up(&mstb->mgr->tx_waitq);
833 kfree(mstb);
834}
835
836static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
837{
838 kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
839}
840
841
842static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
843{
0391359d
DV		 844 struct drm_dp_mst_branch *mstb;
845
ad7f8a1f
DA		 846 switch (old_pdt) {
847 case DP_PEER_DEVICE_DP_LEGACY_CONV:
848 case DP_PEER_DEVICE_SST_SINK:
849 /* remove i2c over sideband */
850 drm_dp_mst_unregister_i2c_bus(&port->aux);
851 break;
852 case DP_PEER_DEVICE_MST_BRANCHING:
0391359d 853 mstb = port->mstb;
ad7f8a1f 854 port->mstb = NULL;
0391359d 855 drm_dp_put_mst_branch_device(mstb);
ad7f8a1f
DA		 856 break;
857 }
858}
859
860static void drm_dp_destroy_port(struct kref *kref)
861{
862 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
863 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
df4839fd 864
ad7f8a1f
DA		 865 if (!port->input) {
866 port->vcpi.num_slots = 0;
c6a0aed4
DA		 867
868 kfree(port->cached_edid);
6b8eeca6 869
df4839fd
DA		 870 /*
871 * The only time we don't have a connector
872 * on an output port is if the connector init
873 * fails.
874 */
6b8eeca6 875 if (port->connector) {
df4839fd
DA		 876 /* we can't destroy the connector here, as
877 * we might be holding the mode_config.mutex
878 * from an EDID retrieval */
879
6b8eeca6 880 mutex_lock(&mgr->destroy_connector_lock);
4772ff03 881 list_add(&port->next, &mgr->destroy_connector_list);
6b8eeca6
DA		 882 mutex_unlock(&mgr->destroy_connector_lock);
883 schedule_work(&mgr->destroy_connector_work);
4772ff03 884 return;
6b8eeca6 885 }
df4839fd
DA		 886 /* no need to clean up vcpi
887 * as if we have no connector we never setup a vcpi */
ad7f8a1f 888 drm_dp_port_teardown_pdt(port, port->pdt);
ad7f8a1f
DA		 889 }
890 kfree(port);
ad7f8a1f
DA		 891}
892
893static void drm_dp_put_port(struct drm_dp_mst_port *port)
894{
895 kref_put(&port->kref, drm_dp_destroy_port);
896}
897
898static 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)
899{
900 struct drm_dp_mst_port *port;
901 struct drm_dp_mst_branch *rmstb;
902 if (to_find == mstb) {
903 kref_get(&mstb->kref);
904 return mstb;
905 }
906 list_for_each_entry(port, &mstb->ports, next) {
907 if (port->mstb) {
908 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
909 if (rmstb)
910 return rmstb;
911 }
912 }
913 return NULL;
914}
915
916static struct drm_dp_mst_branch *drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb)
917{
918 struct drm_dp_mst_branch *rmstb = NULL;
919 mutex_lock(&mgr->lock);
920 if (mgr->mst_primary)
921 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
922 mutex_unlock(&mgr->lock);
923 return rmstb;
924}
925
926static 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)
927{
928 struct drm_dp_mst_port *port, *mport;
929
930 list_for_each_entry(port, &mstb->ports, next) {
931 if (port == to_find) {
932 kref_get(&port->kref);
933 return port;
934 }
935 if (port->mstb) {
936 mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
937 if (mport)
938 return mport;
939 }
940 }
941 return NULL;
942}
943
944static struct drm_dp_mst_port *drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
945{
946 struct drm_dp_mst_port *rport = NULL;
947 mutex_lock(&mgr->lock);
948 if (mgr->mst_primary)
949 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
950 mutex_unlock(&mgr->lock);
951 return rport;
952}
953
954static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
955{
956 struct drm_dp_mst_port *port;
957
958 list_for_each_entry(port, &mstb->ports, next) {
959 if (port->port_num == port_num) {
960 kref_get(&port->kref);
961 return port;
962 }
963 }
964
965 return NULL;
966}
967
968/*
969 * calculate a new RAD for this MST branch device
970 * if parent has an LCT of 2 then it has 1 nibble of RAD,
971 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
972 */
973static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
974 u8 *rad)
975{
976 int lct = port->parent->lct;
977 int shift = 4;
978 int idx = lct / 2;
979 if (lct > 1) {
980 memcpy(rad, port->parent->rad, idx);
981 shift = (lct % 2) ? 4 : 0;
982 } else
983 rad[0] = 0;
984
985 rad[idx] |= port->port_num << shift;
986 return lct + 1;
987}
988
989/*
990 * return sends link address for new mstb
991 */
992static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
993{
994 int ret;
995 u8 rad[6], lct;
996 bool send_link = false;
997 switch (port->pdt) {
998 case DP_PEER_DEVICE_DP_LEGACY_CONV:
999 case DP_PEER_DEVICE_SST_SINK:
1000 /* add i2c over sideband */
1001 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1002 break;
1003 case DP_PEER_DEVICE_MST_BRANCHING:
1004 lct = drm_dp_calculate_rad(port, rad);
1005
1006 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
1007 port->mstb->mgr = port->mgr;
1008 port->mstb->port_parent = port;
1009
1010 send_link = true;
1011 break;
1012 }
1013 return send_link;
1014}
1015
1016static void drm_dp_check_port_guid(struct drm_dp_mst_branch *mstb,
1017 struct drm_dp_mst_port *port)
1018{
1019 int ret;
1020 if (port->dpcd_rev >= 0x12) {
1021 port->guid_valid = drm_dp_validate_guid(mstb->mgr, port->guid);
1022 if (!port->guid_valid) {
1023 ret = drm_dp_send_dpcd_write(mstb->mgr,
1024 port,
1025 DP_GUID,
1026 16, port->guid);
1027 port->guid_valid = true;
1028 }
1029 }
1030}
1031
1c960876
DA		 1032static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1033 int pnum,
d87af4d1
RS		 1034 char *proppath,
1035 size_t proppath_size)
ad7f8a1f
DA		 1036{
1037 int i;
1038 char temp[8];
d87af4d1 1039 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
ad7f8a1f
DA		 1040 for (i = 0; i < (mstb->lct - 1); i++) {
1041 int shift = (i % 2) ? 0 : 4;
1042 int port_num = mstb->rad[i / 2] >> shift;
d87af4d1
RS		 1043 snprintf(temp, sizeof(temp), "-%d", port_num);
1044 strlcat(proppath, temp, proppath_size);
ad7f8a1f 1045 }
1c960876 1046 snprintf(temp, sizeof(temp), "-%d", pnum);
d87af4d1 1047 strlcat(proppath, temp, proppath_size);
ad7f8a1f
DA		 1048}
1049
1050static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1051 struct device *dev,
1052 struct drm_dp_link_addr_reply_port *port_msg)
1053{
1054 struct drm_dp_mst_port *port;
1055 bool ret;
1056 bool created = false;
1057 int old_pdt = 0;
1058 int old_ddps = 0;
1059 port = drm_dp_get_port(mstb, port_msg->port_number);
1060 if (!port) {
1061 port = kzalloc(sizeof(*port), GFP_KERNEL);
1062 if (!port)
1063 return;
1064 kref_init(&port->kref);
1065 port->parent = mstb;
1066 port->port_num = port_msg->port_number;
1067 port->mgr = mstb->mgr;
1068 port->aux.name = "DPMST";
1069 port->aux.dev = dev;
1070 created = true;
1071 } else {
1072 old_pdt = port->pdt;
1073 old_ddps = port->ddps;
1074 }
1075
1076 port->pdt = port_msg->peer_device_type;
1077 port->input = port_msg->input_port;
1078 port->mcs = port_msg->mcs;
1079 port->ddps = port_msg->ddps;
1080 port->ldps = port_msg->legacy_device_plug_status;
1081 port->dpcd_rev = port_msg->dpcd_revision;
1082 port->num_sdp_streams = port_msg->num_sdp_streams;
1083 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1084 memcpy(port->guid, port_msg->peer_guid, 16);
1085
1086 /* manage mstb port lists with mgr lock - take a reference
1087 for this list */
1088 if (created) {
1089 mutex_lock(&mstb->mgr->lock);
1090 kref_get(&port->kref);
1091 list_add(&port->next, &mstb->ports);
1092 mutex_unlock(&mstb->mgr->lock);
1093 }
1094
1095 if (old_ddps != port->ddps) {
1096 if (port->ddps) {
1097 drm_dp_check_port_guid(mstb, port);
1098 if (!port->input)
1099 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1100 } else {
1101 port->guid_valid = false;
1102 port->available_pbn = 0;
1103 }
1104 }
1105
1106 if (old_pdt != port->pdt && !port->input) {
1107 drm_dp_port_teardown_pdt(port, old_pdt);
1108
1109 ret = drm_dp_port_setup_pdt(port);
68d8c9fc 1110 if (ret == true)
ad7f8a1f 1111 drm_dp_send_link_address(mstb->mgr, port->mstb);
ad7f8a1f
DA		 1112 }
1113
1114 if (created && !port->input) {
1115 char proppath[255];
1c960876
DA		 1116
1117 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
ad7f8a1f 1118 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
df4839fd
DA		 1119 if (!port->connector) {
1120 /* remove it from the port list */
1121 mutex_lock(&mstb->mgr->lock);
1122 list_del(&port->next);
1123 mutex_unlock(&mstb->mgr->lock);
1124 /* drop port list reference */
1125 drm_dp_put_port(port);
1126 goto out;
1127 }
ccf03d69 1128 if (port->port_num >= DP_MST_LOGICAL_PORT_0) {
c6a0aed4 1129 port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
d9515c5e 1130 drm_mode_connector_set_tile_property(port->connector);
c6a0aed4 1131 }
d9515c5e 1132 (*mstb->mgr->cbs->register_connector)(port->connector);
ad7f8a1f
DA		 1133 }
1134
df4839fd 1135out:
ad7f8a1f
DA		 1136 /* put reference to this port */
1137 drm_dp_put_port(port);
1138}
1139
1140static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1141 struct drm_dp_connection_status_notify *conn_stat)
1142{
1143 struct drm_dp_mst_port *port;
1144 int old_pdt;
1145 int old_ddps;
1146 bool dowork = false;
1147 port = drm_dp_get_port(mstb, conn_stat->port_number);
1148 if (!port)
1149 return;
1150
1151 old_ddps = port->ddps;
1152 old_pdt = port->pdt;
1153 port->pdt = conn_stat->peer_device_type;
1154 port->mcs = conn_stat->message_capability_status;
1155 port->ldps = conn_stat->legacy_device_plug_status;
1156 port->ddps = conn_stat->displayport_device_plug_status;
1157
1158 if (old_ddps != port->ddps) {
1159 if (port->ddps) {
1160 drm_dp_check_port_guid(mstb, port);
1161 dowork = true;
1162 } else {
1163 port->guid_valid = false;
1164 port->available_pbn = 0;
1165 }
1166 }
1167 if (old_pdt != port->pdt && !port->input) {
1168 drm_dp_port_teardown_pdt(port, old_pdt);
1169
1170 if (drm_dp_port_setup_pdt(port))
1171 dowork = true;
1172 }
1173
1174 drm_dp_put_port(port);
1175 if (dowork)
1176 queue_work(system_long_wq, &mstb->mgr->work);
1177
1178}
1179
1180static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1181 u8 lct, u8 *rad)
1182{
1183 struct drm_dp_mst_branch *mstb;
1184 struct drm_dp_mst_port *port;
1185 int i;
1186 /* find the port by iterating down */
9eb1e57f
DA		 1187
1188 mutex_lock(&mgr->lock);
ad7f8a1f
DA		 1189 mstb = mgr->mst_primary;
1190
1191 for (i = 0; i < lct - 1; i++) {
1192 int shift = (i % 2) ? 0 : 4;
1193 int port_num = rad[i / 2] >> shift;
1194
1195 list_for_each_entry(port, &mstb->ports, next) {
1196 if (port->port_num == port_num) {
30730c7f
AR		 1197 mstb = port->mstb;
1198 if (!mstb) {
ad7f8a1f 1199 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
30730c7f 1200 goto out;
ad7f8a1f
DA		 1201 }
1202
ad7f8a1f
DA		 1203 break;
1204 }
1205 }
1206 }
1207 kref_get(&mstb->kref);
30730c7f 1208out:
9eb1e57f 1209 mutex_unlock(&mgr->lock);
ad7f8a1f
DA		 1210 return mstb;
1211}
1212
1213static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1214 struct drm_dp_mst_branch *mstb)
1215{
1216 struct drm_dp_mst_port *port;
9254ec49 1217 struct drm_dp_mst_branch *mstb_child;
68d8c9fc 1218 if (!mstb->link_address_sent)
ad7f8a1f 1219 drm_dp_send_link_address(mgr, mstb);
68d8c9fc 1220
ad7f8a1f
DA		 1221 list_for_each_entry(port, &mstb->ports, next) {
1222 if (port->input)
1223 continue;
1224
1225 if (!port->ddps)
1226 continue;
1227
1228 if (!port->available_pbn)
1229 drm_dp_send_enum_path_resources(mgr, mstb, port);
1230
9254ec49
DV		 1231 if (port->mstb) {
1232 mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1233 if (mstb_child) {
1234 drm_dp_check_and_send_link_address(mgr, mstb_child);
1235 drm_dp_put_mst_branch_device(mstb_child);
1236 }
1237 }
ad7f8a1f
DA		 1238 }
1239}
1240
1241static void drm_dp_mst_link_probe_work(struct work_struct *work)
1242{
1243 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
9254ec49 1244 struct drm_dp_mst_branch *mstb;
ad7f8a1f 1245
9254ec49
DV		 1246 mutex_lock(&mgr->lock);
1247 mstb = mgr->mst_primary;
1248 if (mstb) {
1249 kref_get(&mstb->kref);
1250 }
1251 mutex_unlock(&mgr->lock);
1252 if (mstb) {
1253 drm_dp_check_and_send_link_address(mgr, mstb);
1254 drm_dp_put_mst_branch_device(mstb);
1255 }
ad7f8a1f
DA		 1256}
1257
1258static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1259 u8 *guid)
1260{
1261 static u8 zero_guid[16];
1262
1263 if (!memcmp(guid, zero_guid, 16)) {
1264 u64 salt = get_jiffies_64();
1265 memcpy(&guid[0], &salt, sizeof(u64));
1266 memcpy(&guid[8], &salt, sizeof(u64));
1267 return false;
1268 }
1269 return true;
1270}
1271
1272#if 0
1273static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1274{
1275 struct drm_dp_sideband_msg_req_body req;
1276
1277 req.req_type = DP_REMOTE_DPCD_READ;
1278 req.u.dpcd_read.port_number = port_num;
1279 req.u.dpcd_read.dpcd_address = offset;
1280 req.u.dpcd_read.num_bytes = num_bytes;
1281 drm_dp_encode_sideband_req(&req, msg);
1282
1283 return 0;
1284}
1285#endif
1286
1287static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1288 bool up, u8 *msg, int len)
1289{
1290 int ret;
1291 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1292 int tosend, total, offset;
1293 int retries = 0;
1294
1295retry:
1296 total = len;
1297 offset = 0;
1298 do {
1299 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1300
1301 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1302 &msg[offset],
1303 tosend);
1304 if (ret != tosend) {
1305 if (ret == -EIO && retries < 5) {
1306 retries++;
1307 goto retry;
1308 }
1309 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
ad7f8a1f
DA		 1310
1311 return -EIO;
1312 }
1313 offset += tosend;
1314 total -= tosend;
1315 } while (total > 0);
1316 return 0;
1317}
1318
1319static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1320 struct drm_dp_sideband_msg_tx *txmsg)
1321{
1322 struct drm_dp_mst_branch *mstb = txmsg->dst;
1323
1324 /* both msg slots are full */
1325 if (txmsg->seqno == -1) {
1326 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1327 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1328 return -EAGAIN;
1329 }
1330 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1331 txmsg->seqno = mstb->last_seqno;
1332 mstb->last_seqno ^= 1;
1333 } else if (mstb->tx_slots[0] == NULL)
1334 txmsg->seqno = 0;
1335 else
1336 txmsg->seqno = 1;
1337 mstb->tx_slots[txmsg->seqno] = txmsg;
1338 }
1339 hdr->broadcast = 0;
1340 hdr->path_msg = txmsg->path_msg;
1341 hdr->lct = mstb->lct;
1342 hdr->lcr = mstb->lct - 1;
1343 if (mstb->lct > 1)
1344 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1345 hdr->seqno = txmsg->seqno;
1346 return 0;
1347}
1348/*
1349 * process a single block of the next message in the sideband queue
1350 */
1351static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1352 struct drm_dp_sideband_msg_tx *txmsg,
1353 bool up)
1354{
1355 u8 chunk[48];
1356 struct drm_dp_sideband_msg_hdr hdr;
1357 int len, space, idx, tosend;
1358 int ret;
1359
bf3719c0
DL		 1360 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1361
ad7f8a1f
DA		 1362 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1363 txmsg->seqno = -1;
1364 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1365 }
1366
1367 /* make hdr from dst mst - for replies use seqno
1368 otherwise assign one */
1369 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1370 if (ret < 0)
1371 return ret;
1372
1373 /* amount left to send in this message */
1374 len = txmsg->cur_len - txmsg->cur_offset;
1375
1376 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1377 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1378
1379 tosend = min(len, space);
1380 if (len == txmsg->cur_len)
1381 hdr.somt = 1;
1382 if (space >= len)
1383 hdr.eomt = 1;
1384
1385
1386 hdr.msg_len = tosend + 1;
1387 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1388 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1389 /* add crc at end */
1390 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1391 idx += tosend + 1;
1392
1393 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1394 if (ret) {
1395 DRM_DEBUG_KMS("sideband msg failed to send\n");
1396 return ret;
1397 }
1398
1399 txmsg->cur_offset += tosend;
1400 if (txmsg->cur_offset == txmsg->cur_len) {
1401 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1402 return 1;
1403 }
1404 return 0;
1405}
1406
ad7f8a1f
DA		 1407static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1408{
1409 struct drm_dp_sideband_msg_tx *txmsg;
1410 int ret;
1411
cd961bb9
DV		 1412 WARN_ON(!mutex_is_locked(&mgr->qlock));
1413
ad7f8a1f
DA		 1414 /* construct a chunk from the first msg in the tx_msg queue */
1415 if (list_empty(&mgr->tx_msg_downq)) {
1416 mgr->tx_down_in_progress = false;
1417 return;
1418 }
1419 mgr->tx_down_in_progress = true;
1420
1421 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1422 ret = process_single_tx_qlock(mgr, txmsg, false);
1423 if (ret == 1) {
1424 /* txmsg is sent it should be in the slots now */
1425 list_del(&txmsg->next);
1426 } else if (ret) {
1427 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1428 list_del(&txmsg->next);
1429 if (txmsg->seqno != -1)
1430 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1431 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1432 wake_up(&mgr->tx_waitq);
1433 }
1434 if (list_empty(&mgr->tx_msg_downq)) {
1435 mgr->tx_down_in_progress = false;
1436 return;
1437 }
1438}
1439
1440/* called holding qlock */
1441static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1442{
1443 struct drm_dp_sideband_msg_tx *txmsg;
1444 int ret;
1445
1446 /* construct a chunk from the first msg in the tx_msg queue */
1447 if (list_empty(&mgr->tx_msg_upq)) {
1448 mgr->tx_up_in_progress = false;
1449 return;
1450 }
1451
1452 txmsg = list_first_entry(&mgr->tx_msg_upq, struct drm_dp_sideband_msg_tx, next);
1453 ret = process_single_tx_qlock(mgr, txmsg, true);
1454 if (ret == 1) {
1455 /* up txmsgs aren't put in slots - so free after we send it */
1456 list_del(&txmsg->next);
1457 kfree(txmsg);
1458 } else if (ret)
1459 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1460 mgr->tx_up_in_progress = true;
1461}
1462
1463static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1464 struct drm_dp_sideband_msg_tx *txmsg)
1465{
1466 mutex_lock(&mgr->qlock);
1467 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1468 if (!mgr->tx_down_in_progress)
1469 process_single_down_tx_qlock(mgr);
1470 mutex_unlock(&mgr->qlock);
1471}
1472
68d8c9fc
DA		 1473static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1474 struct drm_dp_mst_branch *mstb)
ad7f8a1f
DA		 1475{
1476 int len;
1477 struct drm_dp_sideband_msg_tx *txmsg;
1478 int ret;
1479
1480 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1481 if (!txmsg)
68d8c9fc 1482 return;
ad7f8a1f
DA		 1483
1484 txmsg->dst = mstb;
1485 len = build_link_address(txmsg);
1486
68d8c9fc 1487 mstb->link_address_sent = true;
ad7f8a1f
DA		 1488 drm_dp_queue_down_tx(mgr, txmsg);
1489
1490 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1491 if (ret > 0) {
1492 int i;
1493
1494 if (txmsg->reply.reply_type == 1)
1495 DRM_DEBUG_KMS("link address nak received\n");
1496 else {
1497 DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1498 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1499 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,
1500 txmsg->reply.u.link_addr.ports[i].input_port,
1501 txmsg->reply.u.link_addr.ports[i].peer_device_type,
1502 txmsg->reply.u.link_addr.ports[i].port_number,
1503 txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1504 txmsg->reply.u.link_addr.ports[i].mcs,
1505 txmsg->reply.u.link_addr.ports[i].ddps,
1506 txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1507 txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1508 txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1509 }
1510 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1511 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1512 }
1513 (*mgr->cbs->hotplug)(mgr);
1514 }
68d8c9fc
DA		 1515 } else {
1516 mstb->link_address_sent = false;
ad7f8a1f 1517 DRM_DEBUG_KMS("link address failed %d\n", ret);
68d8c9fc 1518 }
ad7f8a1f
DA		 1519
1520 kfree(txmsg);
ad7f8a1f
DA		 1521}
1522
1523static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1524 struct drm_dp_mst_branch *mstb,
1525 struct drm_dp_mst_port *port)
1526{
1527 int len;
1528 struct drm_dp_sideband_msg_tx *txmsg;
1529 int ret;
1530
1531 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1532 if (!txmsg)
1533 return -ENOMEM;
1534
1535 txmsg->dst = mstb;
1536 len = build_enum_path_resources(txmsg, port->port_num);
1537
1538 drm_dp_queue_down_tx(mgr, txmsg);
1539
1540 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1541 if (ret > 0) {
1542 if (txmsg->reply.reply_type == 1)
1543 DRM_DEBUG_KMS("enum path resources nak received\n");
1544 else {
1545 if (port->port_num != txmsg->reply.u.path_resources.port_number)
1546 DRM_ERROR("got incorrect port in response\n");
1547 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,
1548 txmsg->reply.u.path_resources.avail_payload_bw_number);
1549 port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1550 }
1551 }
1552
1553 kfree(txmsg);
1554 return 0;
1555}
1556
8fa6a425
TR		 1557static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1558 struct drm_dp_mst_port *port,
1559 int id,
1560 int pbn)
ad7f8a1f
DA		 1561{
1562 struct drm_dp_sideband_msg_tx *txmsg;
1563 struct drm_dp_mst_branch *mstb;
1564 int len, ret;
1565
1566 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1567 if (!mstb)
1568 return -EINVAL;
1569
1570 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1571 if (!txmsg) {
1572 ret = -ENOMEM;
1573 goto fail_put;
1574 }
1575
1576 txmsg->dst = mstb;
1577 len = build_allocate_payload(txmsg, port->port_num,
1578 id,
1579 pbn);
1580
1581 drm_dp_queue_down_tx(mgr, txmsg);
1582
1583 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1584 if (ret > 0) {
1585 if (txmsg->reply.reply_type == 1) {
1586 ret = -EINVAL;
1587 } else
1588 ret = 0;
1589 }
1590 kfree(txmsg);
1591fail_put:
1592 drm_dp_put_mst_branch_device(mstb);
1593 return ret;
1594}
1595
1596static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1597 int id,
1598 struct drm_dp_payload *payload)
1599{
1600 int ret;
1601
1602 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1603 if (ret < 0) {
1604 payload->payload_state = 0;
1605 return ret;
1606 }
1607 payload->payload_state = DP_PAYLOAD_LOCAL;
1608 return 0;
1609}
1610
8fa6a425
TR		 1611static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1612 struct drm_dp_mst_port *port,
1613 int id,
1614 struct drm_dp_payload *payload)
ad7f8a1f
DA		 1615{
1616 int ret;
1617 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1618 if (ret < 0)
1619 return ret;
1620 payload->payload_state = DP_PAYLOAD_REMOTE;
1621 return ret;
1622}
1623
8fa6a425
TR		 1624static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1625 struct drm_dp_mst_port *port,
1626 int id,
1627 struct drm_dp_payload *payload)
ad7f8a1f
DA		 1628{
1629 DRM_DEBUG_KMS("\n");
1630 /* its okay for these to fail */
1631 if (port) {
1632 drm_dp_payload_send_msg(mgr, port, id, 0);
1633 }
1634
1635 drm_dp_dpcd_write_payload(mgr, id, payload);
dfda0df3 1636 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
ad7f8a1f
DA		 1637 return 0;
1638}
1639
8fa6a425
TR		 1640static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1641 int id,
1642 struct drm_dp_payload *payload)
ad7f8a1f
DA		 1643{
1644 payload->payload_state = 0;
1645 return 0;
1646}
1647
1648/**
1649 * drm_dp_update_payload_part1() - Execute payload update part 1
1650 * @mgr: manager to use.
1651 *
1652 * This iterates over all proposed virtual channels, and tries to
1653 * allocate space in the link for them. For 0->slots transitions,
1654 * this step just writes the VCPI to the MST device. For slots->0
1655 * transitions, this writes the updated VCPIs and removes the
1656 * remote VC payloads.
1657 *
1658 * after calling this the driver should generate ACT and payload
1659 * packets.
1660 */
1661int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1662{
dfda0df3 1663 int i, j;
ad7f8a1f
DA		 1664 int cur_slots = 1;
1665 struct drm_dp_payload req_payload;
1666 struct drm_dp_mst_port *port;
1667
1668 mutex_lock(&mgr->payload_lock);
1669 for (i = 0; i < mgr->max_payloads; i++) {
1670 /* solve the current payloads - compare to the hw ones
1671 - update the hw view */
1672 req_payload.start_slot = cur_slots;
1673 if (mgr->proposed_vcpis[i]) {
1674 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1675 req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1676 } else {
1677 port = NULL;
1678 req_payload.num_slots = 0;
1679 }
dfda0df3
DA		 1680
1681 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1682 mgr->payloads[i].start_slot = req_payload.start_slot;
1683 }
ad7f8a1f 1684 /* work out what is required to happen with this payload */
dfda0df3 1685 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
ad7f8a1f
DA		 1686
1687 /* need to push an update for this payload */
1688 if (req_payload.num_slots) {
dfda0df3 1689 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
ad7f8a1f
DA		 1690 mgr->payloads[i].num_slots = req_payload.num_slots;
1691 } else if (mgr->payloads[i].num_slots) {
1692 mgr->payloads[i].num_slots = 0;
dfda0df3 1693 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
ad7f8a1f 1694 req_payload.payload_state = mgr->payloads[i].payload_state;
dfda0df3
DA		 1695 mgr->payloads[i].start_slot = 0;
1696 }
ad7f8a1f
DA		 1697 mgr->payloads[i].payload_state = req_payload.payload_state;
1698 }
1699 cur_slots += req_payload.num_slots;
1700 }
dfda0df3
DA		 1701
1702 for (i = 0; i < mgr->max_payloads; i++) {
1703 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1704 DRM_DEBUG_KMS("removing payload %d\n", i);
1705 for (j = i; j < mgr->max_payloads - 1; j++) {
1706 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1707 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1708 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1709 set_bit(j + 1, &mgr->payload_mask);
1710 } else {
1711 clear_bit(j + 1, &mgr->payload_mask);
1712 }
1713 }
1714 memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1715 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1716 clear_bit(mgr->max_payloads, &mgr->payload_mask);
1717
1718 }
1719 }
ad7f8a1f
DA		 1720 mutex_unlock(&mgr->payload_lock);
1721
1722 return 0;
1723}
1724EXPORT_SYMBOL(drm_dp_update_payload_part1);
1725
1726/**
1727 * drm_dp_update_payload_part2() - Execute payload update part 2
1728 * @mgr: manager to use.
1729 *
1730 * This iterates over all proposed virtual channels, and tries to
1731 * allocate space in the link for them. For 0->slots transitions,
1732 * this step writes the remote VC payload commands. For slots->0
1733 * this just resets some internal state.
1734 */
1735int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1736{
1737 struct drm_dp_mst_port *port;
1738 int i;
7389ad4b 1739 int ret = 0;
ad7f8a1f
DA		 1740 mutex_lock(&mgr->payload_lock);
1741 for (i = 0; i < mgr->max_payloads; i++) {
1742
1743 if (!mgr->proposed_vcpis[i])
1744 continue;
1745
1746 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1747
1748 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1749 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
dfda0df3 1750 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
ad7f8a1f 1751 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
dfda0df3 1752 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
ad7f8a1f
DA		 1753 }
1754 if (ret) {
1755 mutex_unlock(&mgr->payload_lock);
1756 return ret;
1757 }
1758 }
1759 mutex_unlock(&mgr->payload_lock);
1760 return 0;
1761}
1762EXPORT_SYMBOL(drm_dp_update_payload_part2);
1763
1764#if 0 /* unused as of yet */
1765static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1766 struct drm_dp_mst_port *port,
1767 int offset, int size)
1768{
1769 int len;
1770 struct drm_dp_sideband_msg_tx *txmsg;
1771
1772 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1773 if (!txmsg)
1774 return -ENOMEM;
1775
1776 len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1777 txmsg->dst = port->parent;
1778
1779 drm_dp_queue_down_tx(mgr, txmsg);
1780
1781 return 0;
1782}
1783#endif
1784
1785static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1786 struct drm_dp_mst_port *port,
1787 int offset, int size, u8 *bytes)
1788{
1789 int len;
1790 int ret;
1791 struct drm_dp_sideband_msg_tx *txmsg;
1792 struct drm_dp_mst_branch *mstb;
1793
1794 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1795 if (!mstb)
1796 return -EINVAL;
1797
1798 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1799 if (!txmsg) {
1800 ret = -ENOMEM;
1801 goto fail_put;
1802 }
1803
1804 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1805 txmsg->dst = mstb;
1806
1807 drm_dp_queue_down_tx(mgr, txmsg);
1808
1809 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1810 if (ret > 0) {
1811 if (txmsg->reply.reply_type == 1) {
1812 ret = -EINVAL;
1813 } else
1814 ret = 0;
1815 }
1816 kfree(txmsg);
1817fail_put:
1818 drm_dp_put_mst_branch_device(mstb);
1819 return ret;
1820}
1821
1822static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1823{
1824 struct drm_dp_sideband_msg_reply_body reply;
1825
a68d2437 1826 reply.reply_type = 0;
ad7f8a1f
DA		 1827 reply.req_type = req_type;
1828 drm_dp_encode_sideband_reply(&reply, msg);
1829 return 0;
1830}
1831
1832static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1833 struct drm_dp_mst_branch *mstb,
1834 int req_type, int seqno, bool broadcast)
1835{
1836 struct drm_dp_sideband_msg_tx *txmsg;
1837
1838 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1839 if (!txmsg)
1840 return -ENOMEM;
1841
1842 txmsg->dst = mstb;
1843 txmsg->seqno = seqno;
1844 drm_dp_encode_up_ack_reply(txmsg, req_type);
1845
1846 mutex_lock(&mgr->qlock);
1847 list_add_tail(&txmsg->next, &mgr->tx_msg_upq);
1848 if (!mgr->tx_up_in_progress) {
1849 process_single_up_tx_qlock(mgr);
1850 }
1851 mutex_unlock(&mgr->qlock);
1852 return 0;
1853}
1854
b853fdb3
CW		 1855static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1856 int dp_link_count,
1857 int *out)
ad7f8a1f
DA		 1858{
1859 switch (dp_link_bw) {
b853fdb3
CW		 1860 default:
1861 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1862 dp_link_bw, dp_link_count);
1863 return false;
1864
ad7f8a1f 1865 case DP_LINK_BW_1_62:
b853fdb3
CW		 1866 *out = 3 * dp_link_count;
1867 break;
ad7f8a1f 1868 case DP_LINK_BW_2_7:
b853fdb3
CW		 1869 *out = 5 * dp_link_count;
1870 break;
ad7f8a1f 1871 case DP_LINK_BW_5_4:
b853fdb3
CW		 1872 *out = 10 * dp_link_count;
1873 break;
ad7f8a1f 1874 }
b853fdb3 1875 return true;
ad7f8a1f
DA		 1876}
1877
1878/**
1879 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
1880 * @mgr: manager to set state for
1881 * @mst_state: true to enable MST on this connector - false to disable.
1882 *
1883 * This is called by the driver when it detects an MST capable device plugged
1884 * into a DP MST capable port, or when a DP MST capable device is unplugged.
1885 */
1886int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
1887{
1888 int ret = 0;
1889 struct drm_dp_mst_branch *mstb = NULL;
1890
1891 mutex_lock(&mgr->lock);
1892 if (mst_state == mgr->mst_state)
1893 goto out_unlock;
1894
1895 mgr->mst_state = mst_state;
1896 /* set the device into MST mode */
1897 if (mst_state) {
1898 WARN_ON(mgr->mst_primary);
1899
1900 /* get dpcd info */
1901 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
1902 if (ret != DP_RECEIVER_CAP_SIZE) {
1903 DRM_DEBUG_KMS("failed to read DPCD\n");
1904 goto out_unlock;
1905 }
1906
b853fdb3
CW		 1907 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
1908 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
1909 &mgr->pbn_div)) {
1910 ret = -EINVAL;
1911 goto out_unlock;
1912 }
1913
ad7f8a1f
DA		 1914 mgr->total_pbn = 2560;
1915 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
1916 mgr->avail_slots = mgr->total_slots;
1917
1918 /* add initial branch device at LCT 1 */
1919 mstb = drm_dp_add_mst_branch_device(1, NULL);
1920 if (mstb == NULL) {
1921 ret = -ENOMEM;
1922 goto out_unlock;
1923 }
1924 mstb->mgr = mgr;
1925
1926 /* give this the main reference */
1927 mgr->mst_primary = mstb;
1928 kref_get(&mgr->mst_primary->kref);
1929
1930 {
1931 struct drm_dp_payload reset_pay;
1932 reset_pay.start_slot = 0;
1933 reset_pay.num_slots = 0x3f;
1934 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
1935 }
1936
1937 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1938 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
1939 if (ret < 0) {
1940 goto out_unlock;
1941 }
1942
1943
1944 /* sort out guid */
1945 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
1946 if (ret != 16) {
1947 DRM_DEBUG_KMS("failed to read DP GUID %d\n", ret);
1948 goto out_unlock;
1949 }
1950
1951 mgr->guid_valid = drm_dp_validate_guid(mgr, mgr->guid);
1952 if (!mgr->guid_valid) {
1953 ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, mgr->guid, 16);
1954 mgr->guid_valid = true;
1955 }
1956
1957 queue_work(system_long_wq, &mgr->work);
1958
1959 ret = 0;
1960 } else {
1961 /* disable MST on the device */
1962 mstb = mgr->mst_primary;
1963 mgr->mst_primary = NULL;
1964 /* this can fail if the device is gone */
1965 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
1966 ret = 0;
1967 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
1968 mgr->payload_mask = 0;
1969 set_bit(0, &mgr->payload_mask);
dfda0df3 1970 mgr->vcpi_mask = 0;
ad7f8a1f
DA		 1971 }
1972
1973out_unlock:
1974 mutex_unlock(&mgr->lock);
1975 if (mstb)
1976 drm_dp_put_mst_branch_device(mstb);
1977 return ret;
1978
1979}
1980EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
1981
1982/**
1983 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
1984 * @mgr: manager to suspend
1985 *
1986 * This function tells the MST device that we can't handle UP messages
1987 * anymore. This should stop it from sending any since we are suspended.
1988 */
1989void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
1990{
1991 mutex_lock(&mgr->lock);
1992 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1993 DP_MST_EN | DP_UPSTREAM_IS_SRC);
1994 mutex_unlock(&mgr->lock);
274d8352
DA		 1995 flush_work(&mgr->work);
1996 flush_work(&mgr->destroy_connector_work);
ad7f8a1f
DA		 1997}
1998EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
1999
2000/**
2001 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2002 * @mgr: manager to resume
2003 *
2004 * This will fetch DPCD and see if the device is still there,
2005 * if it is, it will rewrite the MSTM control bits, and return.
2006 *
2007 * if the device fails this returns -1, and the driver should do
2008 * a full MST reprobe, in case we were undocked.
2009 */
2010int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2011{
2012 int ret = 0;
2013
2014 mutex_lock(&mgr->lock);
2015
2016 if (mgr->mst_primary) {
2017 int sret;
2018 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2019 if (sret != DP_RECEIVER_CAP_SIZE) {
2020 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2021 ret = -1;
2022 goto out_unlock;
2023 }
2024
2025 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2026 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2027 if (ret < 0) {
2028 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2029 ret = -1;
2030 goto out_unlock;
2031 }
2032 ret = 0;
2033 } else
2034 ret = -1;
2035
2036out_unlock:
2037 mutex_unlock(&mgr->lock);
2038 return ret;
2039}
2040EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2041
2042static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2043{
2044 int len;
2045 u8 replyblock[32];
2046 int replylen, origlen, curreply;
2047 int ret;
2048 struct drm_dp_sideband_msg_rx *msg;
2049 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2050 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2051
2052 len = min(mgr->max_dpcd_transaction_bytes, 16);
2053 ret = drm_dp_dpcd_read(mgr->aux, basereg,
2054 replyblock, len);
2055 if (ret != len) {
2056 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2057 return;
2058 }
2059 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2060 if (!ret) {
2061 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2062 return;
2063 }
2064 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2065
2066 origlen = replylen;
2067 replylen -= len;
2068 curreply = len;
2069 while (replylen > 0) {
2070 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2071 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2072 replyblock, len);
2073 if (ret != len) {
2074 DRM_DEBUG_KMS("failed to read a chunk\n");
2075 }
2076 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2077 if (ret == false)
2078 DRM_DEBUG_KMS("failed to build sideband msg\n");
2079 curreply += len;
2080 replylen -= len;
2081 }
2082}
2083
2084static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2085{
2086 int ret = 0;
2087
2088 drm_dp_get_one_sb_msg(mgr, false);
2089
2090 if (mgr->down_rep_recv.have_eomt) {
2091 struct drm_dp_sideband_msg_tx *txmsg;
2092 struct drm_dp_mst_branch *mstb;
2093 int slot = -1;
2094 mstb = drm_dp_get_mst_branch_device(mgr,
2095 mgr->down_rep_recv.initial_hdr.lct,
2096 mgr->down_rep_recv.initial_hdr.rad);
2097
2098 if (!mstb) {
2099 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2100 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2101 return 0;
2102 }
2103
2104 /* find the message */
2105 slot = mgr->down_rep_recv.initial_hdr.seqno;
2106 mutex_lock(&mgr->qlock);
2107 txmsg = mstb->tx_slots[slot];
2108 /* remove from slots */
2109 mutex_unlock(&mgr->qlock);
2110
2111 if (!txmsg) {
2112 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2113 mstb,
2114 mgr->down_rep_recv.initial_hdr.seqno,
2115 mgr->down_rep_recv.initial_hdr.lct,
2116 mgr->down_rep_recv.initial_hdr.rad[0],
2117 mgr->down_rep_recv.msg[0]);
2118 drm_dp_put_mst_branch_device(mstb);
2119 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2120 return 0;
2121 }
2122
2123 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2124 if (txmsg->reply.reply_type == 1) {
2125 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);
2126 }
2127
2128 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2129 drm_dp_put_mst_branch_device(mstb);
2130
2131 mutex_lock(&mgr->qlock);
2132 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2133 mstb->tx_slots[slot] = NULL;
2134 mutex_unlock(&mgr->qlock);
2135
2136 wake_up(&mgr->tx_waitq);
2137 }
2138 return ret;
2139}
2140
2141static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2142{
2143 int ret = 0;
2144 drm_dp_get_one_sb_msg(mgr, true);
2145
2146 if (mgr->up_req_recv.have_eomt) {
2147 struct drm_dp_sideband_msg_req_body msg;
2148 struct drm_dp_mst_branch *mstb;
2149 bool seqno;
2150 mstb = drm_dp_get_mst_branch_device(mgr,
2151 mgr->up_req_recv.initial_hdr.lct,
2152 mgr->up_req_recv.initial_hdr.rad);
2153 if (!mstb) {
2154 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2155 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2156 return 0;
2157 }
2158
2159 seqno = mgr->up_req_recv.initial_hdr.seqno;
2160 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2161
2162 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2163 drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
2164 drm_dp_update_port(mstb, &msg.u.conn_stat);
2165 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);
2166 (*mgr->cbs->hotplug)(mgr);
2167
2168 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2169 drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
2170 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2171 }
2172
2173 drm_dp_put_mst_branch_device(mstb);
2174 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2175 }
2176 return ret;
2177}
2178
2179/**
2180 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2181 * @mgr: manager to notify irq for.
2182 * @esi: 4 bytes from SINK_COUNT_ESI
295ee853 2183 * @handled: whether the hpd interrupt was consumed or not
ad7f8a1f
DA		 2184 *
2185 * This should be called from the driver when it detects a short IRQ,
2186 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2187 * topology manager will process the sideband messages received as a result
2188 * of this.
2189 */
2190int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2191{
2192 int ret = 0;
2193 int sc;
2194 *handled = false;
2195 sc = esi[0] & 0x3f;
2196
2197 if (sc != mgr->sink_count) {
2198 mgr->sink_count = sc;
2199 *handled = true;
2200 }
2201
2202 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2203 ret = drm_dp_mst_handle_down_rep(mgr);
2204 *handled = true;
2205 }
2206
2207 if (esi[1] & DP_UP_REQ_MSG_RDY) {
2208 ret |= drm_dp_mst_handle_up_req(mgr);
2209 *handled = true;
2210 }
2211
2212 drm_dp_mst_kick_tx(mgr);
2213 return ret;
2214}
2215EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2216
2217/**
2218 * drm_dp_mst_detect_port() - get connection status for an MST port
2219 * @mgr: manager for this port
2220 * @port: unverified pointer to a port
2221 *
2222 * This returns the current connection state for a port. It validates the
2223 * port pointer still exists so the caller doesn't require a reference
2224 */
c6a0aed4
DA		 2225enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2226 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
ad7f8a1f
DA		 2227{
2228 enum drm_connector_status status = connector_status_disconnected;
2229
2230 /* we need to search for the port in the mgr in case its gone */
2231 port = drm_dp_get_validated_port_ref(mgr, port);
2232 if (!port)
2233 return connector_status_disconnected;
2234
2235 if (!port->ddps)
2236 goto out;
2237
2238 switch (port->pdt) {
2239 case DP_PEER_DEVICE_NONE:
2240 case DP_PEER_DEVICE_MST_BRANCHING:
2241 break;
2242
2243 case DP_PEER_DEVICE_SST_SINK:
2244 status = connector_status_connected;
c6a0aed4
DA		 2245 /* for logical ports - cache the EDID */
2246 if (port->port_num >= 8 && !port->cached_edid) {
2247 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2248 }
ad7f8a1f
DA		 2249 break;
2250 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2251 if (port->ldps)
2252 status = connector_status_connected;
2253 break;
2254 }
2255out:
2256 drm_dp_put_port(port);
2257 return status;
2258}
2259EXPORT_SYMBOL(drm_dp_mst_detect_port);
2260
2261/**
2262 * drm_dp_mst_get_edid() - get EDID for an MST port
2263 * @connector: toplevel connector to get EDID for
2264 * @mgr: manager for this port
2265 * @port: unverified pointer to a port.
2266 *
2267 * This returns an EDID for the port connected to a connector,
2268 * It validates the pointer still exists so the caller doesn't require a
2269 * reference.
2270 */
2271struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2272{
2273 struct edid *edid = NULL;
2274
2275 /* we need to search for the port in the mgr in case its gone */
2276 port = drm_dp_get_validated_port_ref(mgr, port);
2277 if (!port)
2278 return NULL;
2279
c6a0aed4
DA		 2280 if (port->cached_edid)
2281 edid = drm_edid_duplicate(port->cached_edid);
d9515c5e 2282 else {
c6a0aed4 2283 edid = drm_get_edid(connector, &port->aux.ddc);
d9515c5e
DA		 2284 drm_mode_connector_set_tile_property(connector);
2285 }
ad7f8a1f
DA		 2286 drm_dp_put_port(port);
2287 return edid;
2288}
2289EXPORT_SYMBOL(drm_dp_mst_get_edid);
2290
2291/**
2292 * drm_dp_find_vcpi_slots() - find slots for this PBN value
2293 * @mgr: manager to use
2294 * @pbn: payload bandwidth to convert into slots.
2295 */
2296int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2297 int pbn)
2298{
2299 int num_slots;
2300
2301 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2302
2303 if (num_slots > mgr->avail_slots)
2304 return -ENOSPC;
2305 return num_slots;
2306}
2307EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2308
2309static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2310 struct drm_dp_vcpi *vcpi, int pbn)
2311{
2312 int num_slots;
2313 int ret;
2314
2315 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2316
2317 if (num_slots > mgr->avail_slots)
2318 return -ENOSPC;
2319
2320 vcpi->pbn = pbn;
2321 vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2322 vcpi->num_slots = num_slots;
2323
2324 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2325 if (ret < 0)
2326 return ret;
2327 return 0;
2328}
2329
2330/**
2331 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2332 * @mgr: manager for this port
2333 * @port: port to allocate a virtual channel for.
2334 * @pbn: payload bandwidth number to request
2335 * @slots: returned number of slots for this PBN.
2336 */
2337bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2338{
2339 int ret;
2340
2341 port = drm_dp_get_validated_port_ref(mgr, port);
2342 if (!port)
2343 return false;
2344
2345 if (port->vcpi.vcpi > 0) {
2346 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2347 if (pbn == port->vcpi.pbn) {
2348 *slots = port->vcpi.num_slots;
2349 return true;
2350 }
2351 }
2352
2353 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2354 if (ret) {
2355 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2356 goto out;
2357 }
2358 DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2359 *slots = port->vcpi.num_slots;
2360
2361 drm_dp_put_port(port);
2362 return true;
2363out:
2364 return false;
2365}
2366EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2367
87f5942d
DA		 2368int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2369{
2370 int slots = 0;
2371 port = drm_dp_get_validated_port_ref(mgr, port);
2372 if (!port)
2373 return slots;
2374
2375 slots = port->vcpi.num_slots;
2376 drm_dp_put_port(port);
2377 return slots;
2378}
2379EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2380
ad7f8a1f
DA		 2381/**
2382 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2383 * @mgr: manager for this port
2384 * @port: unverified pointer to a port.
2385 *
2386 * This just resets the number of slots for the ports VCPI for later programming.
2387 */
2388void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2389{
2390 port = drm_dp_get_validated_port_ref(mgr, port);
2391 if (!port)
2392 return;
2393 port->vcpi.num_slots = 0;
2394 drm_dp_put_port(port);
2395}
2396EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2397
2398/**
2399 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2400 * @mgr: manager for this port
2401 * @port: unverified port to deallocate vcpi for
2402 */
2403void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2404{
2405 port = drm_dp_get_validated_port_ref(mgr, port);
2406 if (!port)
2407 return;
2408
2409 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2410 port->vcpi.num_slots = 0;
2411 port->vcpi.pbn = 0;
2412 port->vcpi.aligned_pbn = 0;
2413 port->vcpi.vcpi = 0;
2414 drm_dp_put_port(port);
2415}
2416EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2417
2418static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2419 int id, struct drm_dp_payload *payload)
2420{
2421 u8 payload_alloc[3], status;
2422 int ret;
2423 int retries = 0;
2424
2425 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2426 DP_PAYLOAD_TABLE_UPDATED);
2427
2428 payload_alloc[0] = id;
2429 payload_alloc[1] = payload->start_slot;
2430 payload_alloc[2] = payload->num_slots;
2431
2432 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2433 if (ret != 3) {
2434 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2435 goto fail;
2436 }
2437
2438retry:
2439 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2440 if (ret < 0) {
2441 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2442 goto fail;
2443 }
2444
2445 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2446 retries++;
2447 if (retries < 20) {
2448 usleep_range(10000, 20000);
2449 goto retry;
2450 }
2451 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2452 ret = -EINVAL;
2453 goto fail;
2454 }
2455 ret = 0;
2456fail:
2457 return ret;
2458}
2459
2460
2461/**
2462 * drm_dp_check_act_status() - Check ACT handled status.
2463 * @mgr: manager to use
2464 *
2465 * Check the payload status bits in the DPCD for ACT handled completion.
2466 */
2467int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2468{
2469 u8 status;
2470 int ret;
2471 int count = 0;
2472
2473 do {
2474 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2475
2476 if (ret < 0) {
2477 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2478 goto fail;
2479 }
2480
2481 if (status & DP_PAYLOAD_ACT_HANDLED)
2482 break;
2483 count++;
2484 udelay(100);
2485
2486 } while (count < 30);
2487
2488 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2489 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2490 ret = -EINVAL;
2491 goto fail;
2492 }
2493 return 0;
2494fail:
2495 return ret;
2496}
2497EXPORT_SYMBOL(drm_dp_check_act_status);
2498
2499/**
2500 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2501 * @clock: dot clock for the mode
2502 * @bpp: bpp for the mode.
2503 *
2504 * This uses the formula in the spec to calculate the PBN value for a mode.
2505 */
2506int drm_dp_calc_pbn_mode(int clock, int bpp)
2507{
2508 fixed20_12 pix_bw;
2509 fixed20_12 fbpp;
2510 fixed20_12 result;
2511 fixed20_12 margin, tmp;
2512 u32 res;
2513
2514 pix_bw.full = dfixed_const(clock);
2515 fbpp.full = dfixed_const(bpp);
2516 tmp.full = dfixed_const(8);
2517 fbpp.full = dfixed_div(fbpp, tmp);
2518
2519 result.full = dfixed_mul(pix_bw, fbpp);
2520 margin.full = dfixed_const(54);
2521 tmp.full = dfixed_const(64);
2522 margin.full = dfixed_div(margin, tmp);
2523 result.full = dfixed_div(result, margin);
2524
2525 margin.full = dfixed_const(1006);
2526 tmp.full = dfixed_const(1000);
2527 margin.full = dfixed_div(margin, tmp);
2528 result.full = dfixed_mul(result, margin);
2529
2530 result.full = dfixed_div(result, tmp);
2531 result.full = dfixed_ceil(result);
2532 res = dfixed_trunc(result);
2533 return res;
2534}
2535EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2536
2537static int test_calc_pbn_mode(void)
2538{
2539 int ret;
2540 ret = drm_dp_calc_pbn_mode(154000, 30);
2541 if (ret != 689)
2542 return -EINVAL;
2543 ret = drm_dp_calc_pbn_mode(234000, 30);
2544 if (ret != 1047)
2545 return -EINVAL;
2546 return 0;
2547}
2548
2549/* we want to kick the TX after we've ack the up/down IRQs. */
2550static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2551{
2552 queue_work(system_long_wq, &mgr->tx_work);
2553}
2554
2555static void drm_dp_mst_dump_mstb(struct seq_file *m,
2556 struct drm_dp_mst_branch *mstb)
2557{
2558 struct drm_dp_mst_port *port;
2559 int tabs = mstb->lct;
2560 char prefix[10];
2561 int i;
2562
2563 for (i = 0; i < tabs; i++)
2564 prefix[i] = '\t';
2565 prefix[i] = '\0';
2566
2567 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2568 list_for_each_entry(port, &mstb->ports, next) {
2569 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port, port->connector);
2570 if (port->mstb)
2571 drm_dp_mst_dump_mstb(m, port->mstb);
2572 }
2573}
2574
2575static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2576 char *buf)
2577{
2578 int ret;
2579 int i;
2580 for (i = 0; i < 4; i++) {
2581 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2582 if (ret != 16)
2583 break;
2584 }
2585 if (i == 4)
2586 return true;
2587 return false;
2588}
2589
2590/**
2591 * drm_dp_mst_dump_topology(): dump topology to seq file.
2592 * @m: seq_file to dump output to
2593 * @mgr: manager to dump current topology for.
2594 *
2595 * helper to dump MST topology to a seq file for debugfs.
2596 */
2597void drm_dp_mst_dump_topology(struct seq_file *m,
2598 struct drm_dp_mst_topology_mgr *mgr)
2599{
2600 int i;
2601 struct drm_dp_mst_port *port;
2602 mutex_lock(&mgr->lock);
2603 if (mgr->mst_primary)
2604 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2605
2606 /* dump VCPIs */
2607 mutex_unlock(&mgr->lock);
2608
2609 mutex_lock(&mgr->payload_lock);
dfda0df3 2610 seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
ad7f8a1f
DA		 2611
2612 for (i = 0; i < mgr->max_payloads; i++) {
2613 if (mgr->proposed_vcpis[i]) {
2614 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2615 seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2616 } else
2617 seq_printf(m, "vcpi %d:unsed\n", i);
2618 }
2619 for (i = 0; i < mgr->max_payloads; i++) {
2620 seq_printf(m, "payload %d: %d, %d, %d\n",
2621 i,
2622 mgr->payloads[i].payload_state,
2623 mgr->payloads[i].start_slot,
2624 mgr->payloads[i].num_slots);
2625
2626
2627 }
2628 mutex_unlock(&mgr->payload_lock);
2629
2630 mutex_lock(&mgr->lock);
2631 if (mgr->mst_primary) {
2632 u8 buf[64];
2633 bool bret;
2634 int ret;
2635 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2636 seq_printf(m, "dpcd: ");
2637 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2638 seq_printf(m, "%02x ", buf[i]);
2639 seq_printf(m, "\n");
2640 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2641 seq_printf(m, "faux/mst: ");
2642 for (i = 0; i < 2; i++)
2643 seq_printf(m, "%02x ", buf[i]);
2644 seq_printf(m, "\n");
2645 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2646 seq_printf(m, "mst ctrl: ");
2647 for (i = 0; i < 1; i++)
2648 seq_printf(m, "%02x ", buf[i]);
2649 seq_printf(m, "\n");
2650
44790462
DA		 2651 /* dump the standard OUI branch header */
2652 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
2653 seq_printf(m, "branch oui: ");
2654 for (i = 0; i < 0x3; i++)
2655 seq_printf(m, "%02x", buf[i]);
2656 seq_printf(m, " devid: ");
2657 for (i = 0x3; i < 0x8; i++)
2658 seq_printf(m, "%c", buf[i]);
2659 seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
2660 seq_printf(m, "\n");
ad7f8a1f
DA		 2661 bret = dump_dp_payload_table(mgr, buf);
2662 if (bret == true) {
2663 seq_printf(m, "payload table: ");
2664 for (i = 0; i < 63; i++)
2665 seq_printf(m, "%02x ", buf[i]);
2666 seq_printf(m, "\n");
2667 }
2668
2669 }
2670
2671 mutex_unlock(&mgr->lock);
2672
2673}
2674EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2675
2676static void drm_dp_tx_work(struct work_struct *work)
2677{
2678 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2679
2680 mutex_lock(&mgr->qlock);
2681 if (mgr->tx_down_in_progress)
2682 process_single_down_tx_qlock(mgr);
2683 mutex_unlock(&mgr->qlock);
2684}
2685
6b8eeca6
DA		 2686static void drm_dp_destroy_connector_work(struct work_struct *work)
2687{
2688 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
4772ff03 2689 struct drm_dp_mst_port *port;
df4839fd 2690 bool send_hotplug = false;
6b8eeca6
DA		 2691 /*
2692 * Not a regular list traverse as we have to drop the destroy
2693 * connector lock before destroying the connector, to avoid AB->BA
2694 * ordering between this lock and the config mutex.
2695 */
2696 for (;;) {
2697 mutex_lock(&mgr->destroy_connector_lock);
4772ff03
ML		 2698 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
2699 if (!port) {
6b8eeca6
DA		 2700 mutex_unlock(&mgr->destroy_connector_lock);
2701 break;
2702 }
4772ff03 2703 list_del(&port->next);
6b8eeca6
DA		 2704 mutex_unlock(&mgr->destroy_connector_lock);
2705
4772ff03
ML		 2706 mgr->cbs->destroy_connector(mgr, port->connector);
2707
2708 drm_dp_port_teardown_pdt(port, port->pdt);
2709
2710 if (!port->input && port->vcpi.vcpi > 0)
2711 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2712 kfree(port);
df4839fd 2713 send_hotplug = true;
6b8eeca6 2714 }
df4839fd
DA		 2715 if (send_hotplug)
2716 (*mgr->cbs->hotplug)(mgr);
6b8eeca6
DA		 2717}
2718
ad7f8a1f
DA		 2719/**
2720 * drm_dp_mst_topology_mgr_init - initialise a topology manager
2721 * @mgr: manager struct to initialise
2722 * @dev: device providing this structure - for i2c addition.
2723 * @aux: DP helper aux channel to talk to this device
2724 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2725 * @max_payloads: maximum number of payloads this GPU can source
2726 * @conn_base_id: the connector object ID the MST device is connected to.
2727 *
2728 * Return 0 for success, or negative error code on failure
2729 */
2730int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2731 struct device *dev, struct drm_dp_aux *aux,
2732 int max_dpcd_transaction_bytes,
2733 int max_payloads, int conn_base_id)
2734{
2735 mutex_init(&mgr->lock);
2736 mutex_init(&mgr->qlock);
2737 mutex_init(&mgr->payload_lock);
6b8eeca6 2738 mutex_init(&mgr->destroy_connector_lock);
ad7f8a1f
DA		 2739 INIT_LIST_HEAD(&mgr->tx_msg_upq);
2740 INIT_LIST_HEAD(&mgr->tx_msg_downq);
6b8eeca6 2741 INIT_LIST_HEAD(&mgr->destroy_connector_list);
ad7f8a1f
DA		 2742 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2743 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
6b8eeca6 2744 INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
ad7f8a1f
DA		 2745 init_waitqueue_head(&mgr->tx_waitq);
2746 mgr->dev = dev;
2747 mgr->aux = aux;
2748 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2749 mgr->max_payloads = max_payloads;
2750 mgr->conn_base_id = conn_base_id;
2751 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2752 if (!mgr->payloads)
2753 return -ENOMEM;
2754 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2755 if (!mgr->proposed_vcpis)
2756 return -ENOMEM;
2757 set_bit(0, &mgr->payload_mask);
2758 test_calc_pbn_mode();
2759 return 0;
2760}
2761EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2762
2763/**
2764 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2765 * @mgr: manager to destroy
2766 */
2767void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2768{
274d8352 2769 flush_work(&mgr->work);
6b8eeca6 2770 flush_work(&mgr->destroy_connector_work);
ad7f8a1f
DA		 2771 mutex_lock(&mgr->payload_lock);
2772 kfree(mgr->payloads);
2773 mgr->payloads = NULL;
2774 kfree(mgr->proposed_vcpis);
2775 mgr->proposed_vcpis = NULL;
2776 mutex_unlock(&mgr->payload_lock);
2777 mgr->dev = NULL;
2778 mgr->aux = NULL;
2779}
2780EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
2781
2782/* I2C device */
2783static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
2784 int num)
2785{
2786 struct drm_dp_aux *aux = adapter->algo_data;
2787 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
2788 struct drm_dp_mst_branch *mstb;
2789 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2790 unsigned int i;
2791 bool reading = false;
2792 struct drm_dp_sideband_msg_req_body msg;
2793 struct drm_dp_sideband_msg_tx *txmsg = NULL;
2794 int ret;
2795
2796 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2797 if (!mstb)
2798 return -EREMOTEIO;
2799
2800 /* construct i2c msg */
2801 /* see if last msg is a read */
2802 if (msgs[num - 1].flags & I2C_M_RD)
2803 reading = true;
2804
ae491542 2805 if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
ad7f8a1f
DA		 2806 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
2807 ret = -EIO;
2808 goto out;
2809 }
2810
ae491542 2811 memset(&msg, 0, sizeof(msg));
ad7f8a1f
DA		 2812 msg.req_type = DP_REMOTE_I2C_READ;
2813 msg.u.i2c_read.num_transactions = num - 1;
2814 msg.u.i2c_read.port_number = port->port_num;
2815 for (i = 0; i < num - 1; i++) {
2816 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
2817 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
2818 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
2819 }
2820 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
2821 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
2822
2823 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2824 if (!txmsg) {
2825 ret = -ENOMEM;
2826 goto out;
2827 }
2828
2829 txmsg->dst = mstb;
2830 drm_dp_encode_sideband_req(&msg, txmsg);
2831
2832 drm_dp_queue_down_tx(mgr, txmsg);
2833
2834 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2835 if (ret > 0) {
2836
2837 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
2838 ret = -EREMOTEIO;
2839 goto out;
2840 }
2841 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
2842 ret = -EIO;
2843 goto out;
2844 }
2845 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
2846 ret = num;
2847 }
2848out:
2849 kfree(txmsg);
2850 drm_dp_put_mst_branch_device(mstb);
2851 return ret;
2852}
2853
2854static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
2855{
2856 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
2857 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
2858 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
2859 I2C_FUNC_10BIT_ADDR;
2860}
2861
2862static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
2863 .functionality = drm_dp_mst_i2c_functionality,
2864 .master_xfer = drm_dp_mst_i2c_xfer,
2865};
2866
2867/**
2868 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
2869 * @aux: DisplayPort AUX channel
2870 *
2871 * Returns 0 on success or a negative error code on failure.
2872 */
2873static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
2874{
2875 aux->ddc.algo = &drm_dp_mst_i2c_algo;
2876 aux->ddc.algo_data = aux;
2877 aux->ddc.retries = 3;
2878
2879 aux->ddc.class = I2C_CLASS_DDC;
2880 aux->ddc.owner = THIS_MODULE;
2881 aux->ddc.dev.parent = aux->dev;
2882 aux->ddc.dev.of_node = aux->dev->of_node;
2883
2884 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
2885 sizeof(aux->ddc.name));
2886
2887 return i2c_add_adapter(&aux->ddc);
2888}
2889
2890/**
2891 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
2892 * @aux: DisplayPort AUX channel
2893 */
2894static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
2895{
2896 i2c_del_adapter(&aux->ddc);
2897}
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