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drm: fix missing reference counting decrease
[linux/fpc-iii.git] / drivers / gpu / drm / drm_dp_mst_topology.c
blobfe273b681fe50a78292713b3b89e2847e15f57b9
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>
28 #include <linux/seq_file.h>
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 */
42 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
43 char *buf);
44 static int test_calc_pbn_mode(void);
45
46 static void drm_dp_put_port(struct drm_dp_mst_port *port);
47
48 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
49 int id,
50 struct drm_dp_payload *payload);
51
52 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
53 struct drm_dp_mst_port *port,
54 int offset, int size, u8 *bytes);
55
56 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
57 struct drm_dp_mst_branch *mstb);
58 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
59 struct drm_dp_mst_branch *mstb,
60 struct drm_dp_mst_port *port);
61 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
62 u8 *guid);
63
64 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
65 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
66 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
67 /* sideband msg handling */
68 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
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
102 static 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 }
135 static 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
142 static 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
161 static 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
198 static 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
299 static 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
306 static 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 */
318 static 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
366 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
367 struct drm_dp_sideband_msg_reply_body *repmsg)
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;
413 fail_len:
414 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
415 return false;
416 }
417
418 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
419 struct drm_dp_sideband_msg_reply_body *repmsg)
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;
432 fail_len:
433 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
434 return false;
435 }
436
437 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
438 struct drm_dp_sideband_msg_reply_body *repmsg)
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;
446 fail_len:
447 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
448 return false;
449 }
450
451 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
452 struct drm_dp_sideband_msg_reply_body *repmsg)
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;
465 fail_len:
466 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
467 return false;
468 }
469
470 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
471 struct drm_dp_sideband_msg_reply_body *repmsg)
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;
487 fail_len:
488 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
489 return false;
490 }
491
492 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
493 struct drm_dp_sideband_msg_reply_body *repmsg)
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;
509 fail_len:
510 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
511 return false;
512 }
513
514 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
515 struct drm_dp_sideband_msg_reply_body *repmsg)
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;
527 fail_len:
528 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
529 return false;
530 }
531
532 static 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
567 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
568 struct drm_dp_sideband_msg_req_body *msg)
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;
589 fail_len:
590 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
591 return false;
592 }
593
594 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
595 struct drm_dp_sideband_msg_req_body *msg)
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;
612 fail_len:
613 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
614 return false;
615 }
616
617 static 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
634 static 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
648 static 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
657 static 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
668 static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
669 u8 vcpi, uint16_t pbn,
670 u8 number_sdp_streams,
671 u8 *sdp_stream_sink)
672 {
673 struct drm_dp_sideband_msg_req_body req;
674 memset(&req, 0, sizeof(req));
675 req.req_type = DP_ALLOCATE_PAYLOAD;
676 req.u.allocate_payload.port_number = port_num;
677 req.u.allocate_payload.vcpi = vcpi;
678 req.u.allocate_payload.pbn = pbn;
679 req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
680 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
681 number_sdp_streams);
682 drm_dp_encode_sideband_req(&req, msg);
683 msg->path_msg = true;
684 return 0;
685 }
686
687 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
688 struct drm_dp_vcpi *vcpi)
689 {
690 int ret, vcpi_ret;
691
692 mutex_lock(&mgr->payload_lock);
693 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
694 if (ret > mgr->max_payloads) {
695 ret = -EINVAL;
696 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
697 goto out_unlock;
698 }
699
700 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
701 if (vcpi_ret > mgr->max_payloads) {
702 ret = -EINVAL;
703 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
704 goto out_unlock;
705 }
706
707 set_bit(ret, &mgr->payload_mask);
708 set_bit(vcpi_ret, &mgr->vcpi_mask);
709 vcpi->vcpi = vcpi_ret + 1;
710 mgr->proposed_vcpis[ret - 1] = vcpi;
711 out_unlock:
712 mutex_unlock(&mgr->payload_lock);
713 return ret;
714 }
715
716 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
717 int vcpi)
718 {
719 int i;
720 if (vcpi == 0)
721 return;
722
723 mutex_lock(&mgr->payload_lock);
724 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
725 clear_bit(vcpi - 1, &mgr->vcpi_mask);
726
727 for (i = 0; i < mgr->max_payloads; i++) {
728 if (mgr->proposed_vcpis[i])
729 if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
730 mgr->proposed_vcpis[i] = NULL;
731 clear_bit(i + 1, &mgr->payload_mask);
732 }
733 }
734 mutex_unlock(&mgr->payload_lock);
735 }
736
737 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
738 struct drm_dp_sideband_msg_tx *txmsg)
739 {
740 bool ret;
741
742 /*
743 * All updates to txmsg->state are protected by mgr->qlock, and the two
744 * cases we check here are terminal states. For those the barriers
745 * provided by the wake_up/wait_event pair are enough.
746 */
747 ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
748 txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
749 return ret;
750 }
751
752 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
753 struct drm_dp_sideband_msg_tx *txmsg)
754 {
755 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
756 int ret;
757
758 ret = wait_event_timeout(mgr->tx_waitq,
759 check_txmsg_state(mgr, txmsg),
760 (4 * HZ));
761 mutex_lock(&mstb->mgr->qlock);
762 if (ret > 0) {
763 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
764 ret = -EIO;
765 goto out;
766 }
767 } else {
768 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
769
770 /* dump some state */
771 ret = -EIO;
772
773 /* remove from q */
774 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
775 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
776 list_del(&txmsg->next);
777 }
778
779 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
780 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
781 mstb->tx_slots[txmsg->seqno] = NULL;
782 }
783 }
784 out:
785 mutex_unlock(&mgr->qlock);
786
787 return ret;
788 }
789
790 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
791 {
792 struct drm_dp_mst_branch *mstb;
793
794 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
795 if (!mstb)
796 return NULL;
797
798 mstb->lct = lct;
799 if (lct > 1)
800 memcpy(mstb->rad, rad, lct / 2);
801 INIT_LIST_HEAD(&mstb->ports);
802 kref_init(&mstb->kref);
803 return mstb;
804 }
805
806 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
807 {
808 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
809 struct drm_dp_mst_port *port, *tmp;
810 bool wake_tx = false;
811
812 /*
813 * destroy all ports - don't need lock
814 * as there are no more references to the mst branch
815 * device at this point.
816 */
817 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
818 list_del(&port->next);
819 drm_dp_put_port(port);
820 }
821
822 /* drop any tx slots msg */
823 mutex_lock(&mstb->mgr->qlock);
824 if (mstb->tx_slots[0]) {
825 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
826 mstb->tx_slots[0] = NULL;
827 wake_tx = true;
828 }
829 if (mstb->tx_slots[1]) {
830 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
831 mstb->tx_slots[1] = NULL;
832 wake_tx = true;
833 }
834 mutex_unlock(&mstb->mgr->qlock);
835
836 if (wake_tx)
837 wake_up(&mstb->mgr->tx_waitq);
838 kfree(mstb);
839 }
840
841 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
842 {
843 kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
844 }
845
846
847 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
848 {
849 struct drm_dp_mst_branch *mstb;
850
851 switch (old_pdt) {
852 case DP_PEER_DEVICE_DP_LEGACY_CONV:
853 case DP_PEER_DEVICE_SST_SINK:
854 /* remove i2c over sideband */
855 drm_dp_mst_unregister_i2c_bus(&port->aux);
856 break;
857 case DP_PEER_DEVICE_MST_BRANCHING:
858 mstb = port->mstb;
859 port->mstb = NULL;
860 drm_dp_put_mst_branch_device(mstb);
861 break;
862 }
863 }
864
865 static void drm_dp_destroy_port(struct kref *kref)
866 {
867 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
868 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
869
870 if (!port->input) {
871 port->vcpi.num_slots = 0;
872
873 kfree(port->cached_edid);
874
875 /*
876 * The only time we don't have a connector
877 * on an output port is if the connector init
878 * fails.
879 */
880 if (port->connector) {
881 /* we can't destroy the connector here, as
882 * we might be holding the mode_config.mutex
883 * from an EDID retrieval */
884
885 mutex_lock(&mgr->destroy_connector_lock);
886 list_add(&port->next, &mgr->destroy_connector_list);
887 mutex_unlock(&mgr->destroy_connector_lock);
888 schedule_work(&mgr->destroy_connector_work);
889 return;
890 }
891 /* no need to clean up vcpi
892 * as if we have no connector we never setup a vcpi */
893 drm_dp_port_teardown_pdt(port, port->pdt);
894 }
895 kfree(port);
896 }
897
898 static void drm_dp_put_port(struct drm_dp_mst_port *port)
899 {
900 kref_put(&port->kref, drm_dp_destroy_port);
901 }
902
903 static struct drm_dp_mst_branch *drm_dp_mst_get_validated_mstb_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_branch *to_find)
904 {
905 struct drm_dp_mst_port *port;
906 struct drm_dp_mst_branch *rmstb;
907 if (to_find == mstb) {
908 kref_get(&mstb->kref);
909 return mstb;
910 }
911 list_for_each_entry(port, &mstb->ports, next) {
912 if (port->mstb) {
913 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
914 if (rmstb)
915 return rmstb;
916 }
917 }
918 return NULL;
919 }
920
921 static struct drm_dp_mst_branch *drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb)
922 {
923 struct drm_dp_mst_branch *rmstb = NULL;
924 mutex_lock(&mgr->lock);
925 if (mgr->mst_primary)
926 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
927 mutex_unlock(&mgr->lock);
928 return rmstb;
929 }
930
931 static struct drm_dp_mst_port *drm_dp_mst_get_port_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_port *to_find)
932 {
933 struct drm_dp_mst_port *port, *mport;
934
935 list_for_each_entry(port, &mstb->ports, next) {
936 if (port == to_find) {
937 kref_get(&port->kref);
938 return port;
939 }
940 if (port->mstb) {
941 mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
942 if (mport)
943 return mport;
944 }
945 }
946 return NULL;
947 }
948
949 static struct drm_dp_mst_port *drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
950 {
951 struct drm_dp_mst_port *rport = NULL;
952 mutex_lock(&mgr->lock);
953 if (mgr->mst_primary)
954 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
955 mutex_unlock(&mgr->lock);
956 return rport;
957 }
958
959 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
960 {
961 struct drm_dp_mst_port *port;
962
963 list_for_each_entry(port, &mstb->ports, next) {
964 if (port->port_num == port_num) {
965 kref_get(&port->kref);
966 return port;
967 }
968 }
969
970 return NULL;
971 }
972
973 /*
974 * calculate a new RAD for this MST branch device
975 * if parent has an LCT of 2 then it has 1 nibble of RAD,
976 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
977 */
978 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
979 u8 *rad)
980 {
981 int parent_lct = port->parent->lct;
982 int shift = 4;
983 int idx = (parent_lct - 1) / 2;
984 if (parent_lct > 1) {
985 memcpy(rad, port->parent->rad, idx + 1);
986 shift = (parent_lct % 2) ? 4 : 0;
987 } else
988 rad[0] = 0;
989
990 rad[idx] |= port->port_num << shift;
991 return parent_lct + 1;
992 }
993
994 /*
995 * return sends link address for new mstb
996 */
997 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
998 {
999 int ret;
1000 u8 rad[6], lct;
1001 bool send_link = false;
1002 switch (port->pdt) {
1003 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1004 case DP_PEER_DEVICE_SST_SINK:
1005 /* add i2c over sideband */
1006 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1007 break;
1008 case DP_PEER_DEVICE_MST_BRANCHING:
1009 lct = drm_dp_calculate_rad(port, rad);
1010
1011 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
1012 port->mstb->mgr = port->mgr;
1013 port->mstb->port_parent = port;
1014
1015 send_link = true;
1016 break;
1017 }
1018 return send_link;
1019 }
1020
1021 static void drm_dp_check_port_guid(struct drm_dp_mst_branch *mstb,
1022 struct drm_dp_mst_port *port)
1023 {
1024 int ret;
1025 if (port->dpcd_rev >= 0x12) {
1026 port->guid_valid = drm_dp_validate_guid(mstb->mgr, port->guid);
1027 if (!port->guid_valid) {
1028 ret = drm_dp_send_dpcd_write(mstb->mgr,
1029 port,
1030 DP_GUID,
1031 16, port->guid);
1032 port->guid_valid = true;
1033 }
1034 }
1035 }
1036
1037 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1038 int pnum,
1039 char *proppath,
1040 size_t proppath_size)
1041 {
1042 int i;
1043 char temp[8];
1044 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1045 for (i = 0; i < (mstb->lct - 1); i++) {
1046 int shift = (i % 2) ? 0 : 4;
1047 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
1048 snprintf(temp, sizeof(temp), "-%d", port_num);
1049 strlcat(proppath, temp, proppath_size);
1050 }
1051 snprintf(temp, sizeof(temp), "-%d", pnum);
1052 strlcat(proppath, temp, proppath_size);
1053 }
1054
1055 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1056 struct device *dev,
1057 struct drm_dp_link_addr_reply_port *port_msg)
1058 {
1059 struct drm_dp_mst_port *port;
1060 bool ret;
1061 bool created = false;
1062 int old_pdt = 0;
1063 int old_ddps = 0;
1064 port = drm_dp_get_port(mstb, port_msg->port_number);
1065 if (!port) {
1066 port = kzalloc(sizeof(*port), GFP_KERNEL);
1067 if (!port)
1068 return;
1069 kref_init(&port->kref);
1070 port->parent = mstb;
1071 port->port_num = port_msg->port_number;
1072 port->mgr = mstb->mgr;
1073 port->aux.name = "DPMST";
1074 port->aux.dev = dev;
1075 created = true;
1076 } else {
1077 old_pdt = port->pdt;
1078 old_ddps = port->ddps;
1079 }
1080
1081 port->pdt = port_msg->peer_device_type;
1082 port->input = port_msg->input_port;
1083 port->mcs = port_msg->mcs;
1084 port->ddps = port_msg->ddps;
1085 port->ldps = port_msg->legacy_device_plug_status;
1086 port->dpcd_rev = port_msg->dpcd_revision;
1087 port->num_sdp_streams = port_msg->num_sdp_streams;
1088 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1089 memcpy(port->guid, port_msg->peer_guid, 16);
1090
1091 /* manage mstb port lists with mgr lock - take a reference
1092 for this list */
1093 if (created) {
1094 mutex_lock(&mstb->mgr->lock);
1095 kref_get(&port->kref);
1096 list_add(&port->next, &mstb->ports);
1097 mutex_unlock(&mstb->mgr->lock);
1098 }
1099
1100 if (old_ddps != port->ddps) {
1101 if (port->ddps) {
1102 drm_dp_check_port_guid(mstb, port);
1103 if (!port->input)
1104 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1105 } else {
1106 port->guid_valid = false;
1107 port->available_pbn = 0;
1108 }
1109 }
1110
1111 if (old_pdt != port->pdt && !port->input) {
1112 drm_dp_port_teardown_pdt(port, old_pdt);
1113
1114 ret = drm_dp_port_setup_pdt(port);
1115 if (ret == true)
1116 drm_dp_send_link_address(mstb->mgr, port->mstb);
1117 }
1118
1119 if (created && !port->input) {
1120 char proppath[255];
1121
1122 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
1123 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1124 if (!port->connector) {
1125 /* remove it from the port list */
1126 mutex_lock(&mstb->mgr->lock);
1127 list_del(&port->next);
1128 mutex_unlock(&mstb->mgr->lock);
1129 /* drop port list reference */
1130 drm_dp_put_port(port);
1131 goto out;
1132 }
1133 if (port->port_num >= DP_MST_LOGICAL_PORT_0) {
1134 port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1135 drm_mode_connector_set_tile_property(port->connector);
1136 }
1137 (*mstb->mgr->cbs->register_connector)(port->connector);
1138 }
1139
1140 out:
1141 /* put reference to this port */
1142 drm_dp_put_port(port);
1143 }
1144
1145 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1146 struct drm_dp_connection_status_notify *conn_stat)
1147 {
1148 struct drm_dp_mst_port *port;
1149 int old_pdt;
1150 int old_ddps;
1151 bool dowork = false;
1152 port = drm_dp_get_port(mstb, conn_stat->port_number);
1153 if (!port)
1154 return;
1155
1156 old_ddps = port->ddps;
1157 old_pdt = port->pdt;
1158 port->pdt = conn_stat->peer_device_type;
1159 port->mcs = conn_stat->message_capability_status;
1160 port->ldps = conn_stat->legacy_device_plug_status;
1161 port->ddps = conn_stat->displayport_device_plug_status;
1162
1163 if (old_ddps != port->ddps) {
1164 if (port->ddps) {
1165 drm_dp_check_port_guid(mstb, port);
1166 dowork = true;
1167 } else {
1168 port->guid_valid = false;
1169 port->available_pbn = 0;
1170 }
1171 }
1172 if (old_pdt != port->pdt && !port->input) {
1173 drm_dp_port_teardown_pdt(port, old_pdt);
1174
1175 if (drm_dp_port_setup_pdt(port))
1176 dowork = true;
1177 }
1178
1179 drm_dp_put_port(port);
1180 if (dowork)
1181 queue_work(system_long_wq, &mstb->mgr->work);
1182
1183 }
1184
1185 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1186 u8 lct, u8 *rad)
1187 {
1188 struct drm_dp_mst_branch *mstb;
1189 struct drm_dp_mst_port *port;
1190 int i;
1191 /* find the port by iterating down */
1192
1193 mutex_lock(&mgr->lock);
1194 mstb = mgr->mst_primary;
1195
1196 for (i = 0; i < lct - 1; i++) {
1197 int shift = (i % 2) ? 0 : 4;
1198 int port_num = (rad[i / 2] >> shift) & 0xf;
1199
1200 list_for_each_entry(port, &mstb->ports, next) {
1201 if (port->port_num == port_num) {
1202 mstb = port->mstb;
1203 if (!mstb) {
1204 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1205 goto out;
1206 }
1207
1208 break;
1209 }
1210 }
1211 }
1212 kref_get(&mstb->kref);
1213 out:
1214 mutex_unlock(&mgr->lock);
1215 return mstb;
1216 }
1217
1218 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1219 struct drm_dp_mst_branch *mstb,
1220 uint8_t *guid)
1221 {
1222 struct drm_dp_mst_branch *found_mstb;
1223 struct drm_dp_mst_port *port;
1224
1225 list_for_each_entry(port, &mstb->ports, next) {
1226 if (!port->mstb)
1227 continue;
1228
1229 if (port->guid_valid && memcmp(port->guid, guid, 16) == 0)
1230 return port->mstb;
1231
1232 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1233
1234 if (found_mstb)
1235 return found_mstb;
1236 }
1237
1238 return NULL;
1239 }
1240
1241 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
1242 struct drm_dp_mst_topology_mgr *mgr,
1243 uint8_t *guid)
1244 {
1245 struct drm_dp_mst_branch *mstb;
1246
1247 /* find the port by iterating down */
1248 mutex_lock(&mgr->lock);
1249
1250 if (mgr->guid_valid && memcmp(mgr->guid, guid, 16) == 0)
1251 mstb = mgr->mst_primary;
1252 else
1253 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
1254
1255 if (mstb)
1256 kref_get(&mstb->kref);
1257
1258 mutex_unlock(&mgr->lock);
1259 return mstb;
1260 }
1261
1262 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1263 struct drm_dp_mst_branch *mstb)
1264 {
1265 struct drm_dp_mst_port *port;
1266 struct drm_dp_mst_branch *mstb_child;
1267 if (!mstb->link_address_sent)
1268 drm_dp_send_link_address(mgr, mstb);
1269
1270 list_for_each_entry(port, &mstb->ports, next) {
1271 if (port->input)
1272 continue;
1273
1274 if (!port->ddps)
1275 continue;
1276
1277 if (!port->available_pbn)
1278 drm_dp_send_enum_path_resources(mgr, mstb, port);
1279
1280 if (port->mstb) {
1281 mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1282 if (mstb_child) {
1283 drm_dp_check_and_send_link_address(mgr, mstb_child);
1284 drm_dp_put_mst_branch_device(mstb_child);
1285 }
1286 }
1287 }
1288 }
1289
1290 static void drm_dp_mst_link_probe_work(struct work_struct *work)
1291 {
1292 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1293 struct drm_dp_mst_branch *mstb;
1294
1295 mutex_lock(&mgr->lock);
1296 mstb = mgr->mst_primary;
1297 if (mstb) {
1298 kref_get(&mstb->kref);
1299 }
1300 mutex_unlock(&mgr->lock);
1301 if (mstb) {
1302 drm_dp_check_and_send_link_address(mgr, mstb);
1303 drm_dp_put_mst_branch_device(mstb);
1304 }
1305 }
1306
1307 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1308 u8 *guid)
1309 {
1310 static u8 zero_guid[16];
1311
1312 if (!memcmp(guid, zero_guid, 16)) {
1313 u64 salt = get_jiffies_64();
1314 memcpy(&guid[0], &salt, sizeof(u64));
1315 memcpy(&guid[8], &salt, sizeof(u64));
1316 return false;
1317 }
1318 return true;
1319 }
1320
1321 #if 0
1322 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1323 {
1324 struct drm_dp_sideband_msg_req_body req;
1325
1326 req.req_type = DP_REMOTE_DPCD_READ;
1327 req.u.dpcd_read.port_number = port_num;
1328 req.u.dpcd_read.dpcd_address = offset;
1329 req.u.dpcd_read.num_bytes = num_bytes;
1330 drm_dp_encode_sideband_req(&req, msg);
1331
1332 return 0;
1333 }
1334 #endif
1335
1336 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1337 bool up, u8 *msg, int len)
1338 {
1339 int ret;
1340 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1341 int tosend, total, offset;
1342 int retries = 0;
1343
1344 retry:
1345 total = len;
1346 offset = 0;
1347 do {
1348 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1349
1350 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1351 &msg[offset],
1352 tosend);
1353 if (ret != tosend) {
1354 if (ret == -EIO && retries < 5) {
1355 retries++;
1356 goto retry;
1357 }
1358 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1359
1360 return -EIO;
1361 }
1362 offset += tosend;
1363 total -= tosend;
1364 } while (total > 0);
1365 return 0;
1366 }
1367
1368 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1369 struct drm_dp_sideband_msg_tx *txmsg)
1370 {
1371 struct drm_dp_mst_branch *mstb = txmsg->dst;
1372 u8 req_type;
1373
1374 /* both msg slots are full */
1375 if (txmsg->seqno == -1) {
1376 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1377 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1378 return -EAGAIN;
1379 }
1380 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1381 txmsg->seqno = mstb->last_seqno;
1382 mstb->last_seqno ^= 1;
1383 } else if (mstb->tx_slots[0] == NULL)
1384 txmsg->seqno = 0;
1385 else
1386 txmsg->seqno = 1;
1387 mstb->tx_slots[txmsg->seqno] = txmsg;
1388 }
1389
1390 req_type = txmsg->msg[0] & 0x7f;
1391 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1392 req_type == DP_RESOURCE_STATUS_NOTIFY)
1393 hdr->broadcast = 1;
1394 else
1395 hdr->broadcast = 0;
1396 hdr->path_msg = txmsg->path_msg;
1397 hdr->lct = mstb->lct;
1398 hdr->lcr = mstb->lct - 1;
1399 if (mstb->lct > 1)
1400 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1401 hdr->seqno = txmsg->seqno;
1402 return 0;
1403 }
1404 /*
1405 * process a single block of the next message in the sideband queue
1406 */
1407 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1408 struct drm_dp_sideband_msg_tx *txmsg,
1409 bool up)
1410 {
1411 u8 chunk[48];
1412 struct drm_dp_sideband_msg_hdr hdr;
1413 int len, space, idx, tosend;
1414 int ret;
1415
1416 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1417
1418 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1419 txmsg->seqno = -1;
1420 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1421 }
1422
1423 /* make hdr from dst mst - for replies use seqno
1424 otherwise assign one */
1425 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1426 if (ret < 0)
1427 return ret;
1428
1429 /* amount left to send in this message */
1430 len = txmsg->cur_len - txmsg->cur_offset;
1431
1432 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1433 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1434
1435 tosend = min(len, space);
1436 if (len == txmsg->cur_len)
1437 hdr.somt = 1;
1438 if (space >= len)
1439 hdr.eomt = 1;
1440
1441
1442 hdr.msg_len = tosend + 1;
1443 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1444 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1445 /* add crc at end */
1446 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1447 idx += tosend + 1;
1448
1449 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1450 if (ret) {
1451 DRM_DEBUG_KMS("sideband msg failed to send\n");
1452 return ret;
1453 }
1454
1455 txmsg->cur_offset += tosend;
1456 if (txmsg->cur_offset == txmsg->cur_len) {
1457 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1458 return 1;
1459 }
1460 return 0;
1461 }
1462
1463 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1464 {
1465 struct drm_dp_sideband_msg_tx *txmsg;
1466 int ret;
1467
1468 WARN_ON(!mutex_is_locked(&mgr->qlock));
1469
1470 /* construct a chunk from the first msg in the tx_msg queue */
1471 if (list_empty(&mgr->tx_msg_downq)) {
1472 mgr->tx_down_in_progress = false;
1473 return;
1474 }
1475 mgr->tx_down_in_progress = true;
1476
1477 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1478 ret = process_single_tx_qlock(mgr, txmsg, false);
1479 if (ret == 1) {
1480 /* txmsg is sent it should be in the slots now */
1481 list_del(&txmsg->next);
1482 } else if (ret) {
1483 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1484 list_del(&txmsg->next);
1485 if (txmsg->seqno != -1)
1486 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1487 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1488 wake_up(&mgr->tx_waitq);
1489 }
1490 if (list_empty(&mgr->tx_msg_downq)) {
1491 mgr->tx_down_in_progress = false;
1492 return;
1493 }
1494 }
1495
1496 /* called holding qlock */
1497 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1498 struct drm_dp_sideband_msg_tx *txmsg)
1499 {
1500 int ret;
1501
1502 /* construct a chunk from the first msg in the tx_msg queue */
1503 ret = process_single_tx_qlock(mgr, txmsg, true);
1504
1505 if (ret != 1)
1506 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1507
1508 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1509 }
1510
1511 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1512 struct drm_dp_sideband_msg_tx *txmsg)
1513 {
1514 mutex_lock(&mgr->qlock);
1515 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1516 if (!mgr->tx_down_in_progress)
1517 process_single_down_tx_qlock(mgr);
1518 mutex_unlock(&mgr->qlock);
1519 }
1520
1521 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1522 struct drm_dp_mst_branch *mstb)
1523 {
1524 int len;
1525 struct drm_dp_sideband_msg_tx *txmsg;
1526 int ret;
1527
1528 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1529 if (!txmsg)
1530 return;
1531
1532 txmsg->dst = mstb;
1533 len = build_link_address(txmsg);
1534
1535 mstb->link_address_sent = true;
1536 drm_dp_queue_down_tx(mgr, txmsg);
1537
1538 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1539 if (ret > 0) {
1540 int i;
1541
1542 if (txmsg->reply.reply_type == 1)
1543 DRM_DEBUG_KMS("link address nak received\n");
1544 else {
1545 DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1546 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1547 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,
1548 txmsg->reply.u.link_addr.ports[i].input_port,
1549 txmsg->reply.u.link_addr.ports[i].peer_device_type,
1550 txmsg->reply.u.link_addr.ports[i].port_number,
1551 txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1552 txmsg->reply.u.link_addr.ports[i].mcs,
1553 txmsg->reply.u.link_addr.ports[i].ddps,
1554 txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1555 txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1556 txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1557 }
1558 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1559 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1560 }
1561 (*mgr->cbs->hotplug)(mgr);
1562 }
1563 } else {
1564 mstb->link_address_sent = false;
1565 DRM_DEBUG_KMS("link address failed %d\n", ret);
1566 }
1567
1568 kfree(txmsg);
1569 }
1570
1571 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1572 struct drm_dp_mst_branch *mstb,
1573 struct drm_dp_mst_port *port)
1574 {
1575 int len;
1576 struct drm_dp_sideband_msg_tx *txmsg;
1577 int ret;
1578
1579 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1580 if (!txmsg)
1581 return -ENOMEM;
1582
1583 txmsg->dst = mstb;
1584 len = build_enum_path_resources(txmsg, port->port_num);
1585
1586 drm_dp_queue_down_tx(mgr, txmsg);
1587
1588 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1589 if (ret > 0) {
1590 if (txmsg->reply.reply_type == 1)
1591 DRM_DEBUG_KMS("enum path resources nak received\n");
1592 else {
1593 if (port->port_num != txmsg->reply.u.path_resources.port_number)
1594 DRM_ERROR("got incorrect port in response\n");
1595 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,
1596 txmsg->reply.u.path_resources.avail_payload_bw_number);
1597 port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1598 }
1599 }
1600
1601 kfree(txmsg);
1602 return 0;
1603 }
1604
1605 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1606 struct drm_dp_mst_port *port,
1607 int id,
1608 int pbn)
1609 {
1610 struct drm_dp_sideband_msg_tx *txmsg;
1611 struct drm_dp_mst_branch *mstb;
1612 int len, ret;
1613 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
1614 int i;
1615
1616 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1617 if (!mstb)
1618 return -EINVAL;
1619
1620 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1621 if (!txmsg) {
1622 ret = -ENOMEM;
1623 goto fail_put;
1624 }
1625
1626 for (i = 0; i < port->num_sdp_streams; i++)
1627 sinks[i] = i;
1628
1629 txmsg->dst = mstb;
1630 len = build_allocate_payload(txmsg, port->port_num,
1631 id,
1632 pbn, port->num_sdp_streams, sinks);
1633
1634 drm_dp_queue_down_tx(mgr, txmsg);
1635
1636 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1637 if (ret > 0) {
1638 if (txmsg->reply.reply_type == 1) {
1639 ret = -EINVAL;
1640 } else
1641 ret = 0;
1642 }
1643 kfree(txmsg);
1644 fail_put:
1645 drm_dp_put_mst_branch_device(mstb);
1646 return ret;
1647 }
1648
1649 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1650 int id,
1651 struct drm_dp_payload *payload)
1652 {
1653 int ret;
1654
1655 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1656 if (ret < 0) {
1657 payload->payload_state = 0;
1658 return ret;
1659 }
1660 payload->payload_state = DP_PAYLOAD_LOCAL;
1661 return 0;
1662 }
1663
1664 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1665 struct drm_dp_mst_port *port,
1666 int id,
1667 struct drm_dp_payload *payload)
1668 {
1669 int ret;
1670 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1671 if (ret < 0)
1672 return ret;
1673 payload->payload_state = DP_PAYLOAD_REMOTE;
1674 return ret;
1675 }
1676
1677 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1678 struct drm_dp_mst_port *port,
1679 int id,
1680 struct drm_dp_payload *payload)
1681 {
1682 DRM_DEBUG_KMS("\n");
1683 /* its okay for these to fail */
1684 if (port) {
1685 drm_dp_payload_send_msg(mgr, port, id, 0);
1686 }
1687
1688 drm_dp_dpcd_write_payload(mgr, id, payload);
1689 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1690 return 0;
1691 }
1692
1693 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1694 int id,
1695 struct drm_dp_payload *payload)
1696 {
1697 payload->payload_state = 0;
1698 return 0;
1699 }
1700
1701 /**
1702 * drm_dp_update_payload_part1() - Execute payload update part 1
1703 * @mgr: manager to use.
1704 *
1705 * This iterates over all proposed virtual channels, and tries to
1706 * allocate space in the link for them. For 0->slots transitions,
1707 * this step just writes the VCPI to the MST device. For slots->0
1708 * transitions, this writes the updated VCPIs and removes the
1709 * remote VC payloads.
1710 *
1711 * after calling this the driver should generate ACT and payload
1712 * packets.
1713 */
1714 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1715 {
1716 int i, j;
1717 int cur_slots = 1;
1718 struct drm_dp_payload req_payload;
1719 struct drm_dp_mst_port *port;
1720
1721 mutex_lock(&mgr->payload_lock);
1722 for (i = 0; i < mgr->max_payloads; i++) {
1723 /* solve the current payloads - compare to the hw ones
1724 - update the hw view */
1725 req_payload.start_slot = cur_slots;
1726 if (mgr->proposed_vcpis[i]) {
1727 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1728 req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1729 req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi;
1730 } else {
1731 port = NULL;
1732 req_payload.num_slots = 0;
1733 }
1734
1735 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1736 mgr->payloads[i].start_slot = req_payload.start_slot;
1737 }
1738 /* work out what is required to happen with this payload */
1739 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1740
1741 /* need to push an update for this payload */
1742 if (req_payload.num_slots) {
1743 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1744 mgr->payloads[i].num_slots = req_payload.num_slots;
1745 mgr->payloads[i].vcpi = req_payload.vcpi;
1746 } else if (mgr->payloads[i].num_slots) {
1747 mgr->payloads[i].num_slots = 0;
1748 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
1749 req_payload.payload_state = mgr->payloads[i].payload_state;
1750 mgr->payloads[i].start_slot = 0;
1751 }
1752 mgr->payloads[i].payload_state = req_payload.payload_state;
1753 }
1754 cur_slots += req_payload.num_slots;
1755 }
1756
1757 for (i = 0; i < mgr->max_payloads; i++) {
1758 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1759 DRM_DEBUG_KMS("removing payload %d\n", i);
1760 for (j = i; j < mgr->max_payloads - 1; j++) {
1761 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1762 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1763 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1764 set_bit(j + 1, &mgr->payload_mask);
1765 } else {
1766 clear_bit(j + 1, &mgr->payload_mask);
1767 }
1768 }
1769 memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1770 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1771 clear_bit(mgr->max_payloads, &mgr->payload_mask);
1772
1773 }
1774 }
1775 mutex_unlock(&mgr->payload_lock);
1776
1777 return 0;
1778 }
1779 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1780
1781 /**
1782 * drm_dp_update_payload_part2() - Execute payload update part 2
1783 * @mgr: manager to use.
1784 *
1785 * This iterates over all proposed virtual channels, and tries to
1786 * allocate space in the link for them. For 0->slots transitions,
1787 * this step writes the remote VC payload commands. For slots->0
1788 * this just resets some internal state.
1789 */
1790 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1791 {
1792 struct drm_dp_mst_port *port;
1793 int i;
1794 int ret = 0;
1795 mutex_lock(&mgr->payload_lock);
1796 for (i = 0; i < mgr->max_payloads; i++) {
1797
1798 if (!mgr->proposed_vcpis[i])
1799 continue;
1800
1801 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1802
1803 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1804 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1805 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1806 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1807 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1808 }
1809 if (ret) {
1810 mutex_unlock(&mgr->payload_lock);
1811 return ret;
1812 }
1813 }
1814 mutex_unlock(&mgr->payload_lock);
1815 return 0;
1816 }
1817 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1818
1819 #if 0 /* unused as of yet */
1820 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1821 struct drm_dp_mst_port *port,
1822 int offset, int size)
1823 {
1824 int len;
1825 struct drm_dp_sideband_msg_tx *txmsg;
1826
1827 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1828 if (!txmsg)
1829 return -ENOMEM;
1830
1831 len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1832 txmsg->dst = port->parent;
1833
1834 drm_dp_queue_down_tx(mgr, txmsg);
1835
1836 return 0;
1837 }
1838 #endif
1839
1840 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1841 struct drm_dp_mst_port *port,
1842 int offset, int size, u8 *bytes)
1843 {
1844 int len;
1845 int ret;
1846 struct drm_dp_sideband_msg_tx *txmsg;
1847 struct drm_dp_mst_branch *mstb;
1848
1849 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1850 if (!mstb)
1851 return -EINVAL;
1852
1853 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1854 if (!txmsg) {
1855 ret = -ENOMEM;
1856 goto fail_put;
1857 }
1858
1859 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1860 txmsg->dst = mstb;
1861
1862 drm_dp_queue_down_tx(mgr, txmsg);
1863
1864 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1865 if (ret > 0) {
1866 if (txmsg->reply.reply_type == 1) {
1867 ret = -EINVAL;
1868 } else
1869 ret = 0;
1870 }
1871 kfree(txmsg);
1872 fail_put:
1873 drm_dp_put_mst_branch_device(mstb);
1874 return ret;
1875 }
1876
1877 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1878 {
1879 struct drm_dp_sideband_msg_reply_body reply;
1880
1881 reply.reply_type = 0;
1882 reply.req_type = req_type;
1883 drm_dp_encode_sideband_reply(&reply, msg);
1884 return 0;
1885 }
1886
1887 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1888 struct drm_dp_mst_branch *mstb,
1889 int req_type, int seqno, bool broadcast)
1890 {
1891 struct drm_dp_sideband_msg_tx *txmsg;
1892
1893 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1894 if (!txmsg)
1895 return -ENOMEM;
1896
1897 txmsg->dst = mstb;
1898 txmsg->seqno = seqno;
1899 drm_dp_encode_up_ack_reply(txmsg, req_type);
1900
1901 mutex_lock(&mgr->qlock);
1902
1903 process_single_up_tx_qlock(mgr, txmsg);
1904
1905 mutex_unlock(&mgr->qlock);
1906
1907 kfree(txmsg);
1908 return 0;
1909 }
1910
1911 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1912 int dp_link_count,
1913 int *out)
1914 {
1915 switch (dp_link_bw) {
1916 default:
1917 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1918 dp_link_bw, dp_link_count);
1919 return false;
1920
1921 case DP_LINK_BW_1_62:
1922 *out = 3 * dp_link_count;
1923 break;
1924 case DP_LINK_BW_2_7:
1925 *out = 5 * dp_link_count;
1926 break;
1927 case DP_LINK_BW_5_4:
1928 *out = 10 * dp_link_count;
1929 break;
1930 }
1931 return true;
1932 }
1933
1934 /**
1935 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
1936 * @mgr: manager to set state for
1937 * @mst_state: true to enable MST on this connector - false to disable.
1938 *
1939 * This is called by the driver when it detects an MST capable device plugged
1940 * into a DP MST capable port, or when a DP MST capable device is unplugged.
1941 */
1942 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
1943 {
1944 int ret = 0;
1945 struct drm_dp_mst_branch *mstb = NULL;
1946
1947 mutex_lock(&mgr->lock);
1948 if (mst_state == mgr->mst_state)
1949 goto out_unlock;
1950
1951 mgr->mst_state = mst_state;
1952 /* set the device into MST mode */
1953 if (mst_state) {
1954 WARN_ON(mgr->mst_primary);
1955
1956 /* get dpcd info */
1957 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
1958 if (ret != DP_RECEIVER_CAP_SIZE) {
1959 DRM_DEBUG_KMS("failed to read DPCD\n");
1960 goto out_unlock;
1961 }
1962
1963 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
1964 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
1965 &mgr->pbn_div)) {
1966 ret = -EINVAL;
1967 goto out_unlock;
1968 }
1969
1970 mgr->total_pbn = 2560;
1971 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
1972 mgr->avail_slots = mgr->total_slots;
1973
1974 /* add initial branch device at LCT 1 */
1975 mstb = drm_dp_add_mst_branch_device(1, NULL);
1976 if (mstb == NULL) {
1977 ret = -ENOMEM;
1978 goto out_unlock;
1979 }
1980 mstb->mgr = mgr;
1981
1982 /* give this the main reference */
1983 mgr->mst_primary = mstb;
1984 kref_get(&mgr->mst_primary->kref);
1985
1986 {
1987 struct drm_dp_payload reset_pay;
1988 reset_pay.start_slot = 0;
1989 reset_pay.num_slots = 0x3f;
1990 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
1991 }
1992
1993 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1994 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
1995 if (ret < 0) {
1996 goto out_unlock;
1997 }
1998
1999
2000 /* sort out guid */
2001 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
2002 if (ret != 16) {
2003 DRM_DEBUG_KMS("failed to read DP GUID %d\n", ret);
2004 goto out_unlock;
2005 }
2006
2007 mgr->guid_valid = drm_dp_validate_guid(mgr, mgr->guid);
2008 if (!mgr->guid_valid) {
2009 ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, mgr->guid, 16);
2010 mgr->guid_valid = true;
2011 }
2012
2013 queue_work(system_long_wq, &mgr->work);
2014
2015 ret = 0;
2016 } else {
2017 /* disable MST on the device */
2018 mstb = mgr->mst_primary;
2019 mgr->mst_primary = NULL;
2020 /* this can fail if the device is gone */
2021 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2022 ret = 0;
2023 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2024 mgr->payload_mask = 0;
2025 set_bit(0, &mgr->payload_mask);
2026 mgr->vcpi_mask = 0;
2027 }
2028
2029 out_unlock:
2030 mutex_unlock(&mgr->lock);
2031 if (mstb)
2032 drm_dp_put_mst_branch_device(mstb);
2033 return ret;
2034
2035 }
2036 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2037
2038 /**
2039 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2040 * @mgr: manager to suspend
2041 *
2042 * This function tells the MST device that we can't handle UP messages
2043 * anymore. This should stop it from sending any since we are suspended.
2044 */
2045 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2046 {
2047 mutex_lock(&mgr->lock);
2048 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2049 DP_MST_EN | DP_UPSTREAM_IS_SRC);
2050 mutex_unlock(&mgr->lock);
2051 flush_work(&mgr->work);
2052 flush_work(&mgr->destroy_connector_work);
2053 }
2054 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2055
2056 /**
2057 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2058 * @mgr: manager to resume
2059 *
2060 * This will fetch DPCD and see if the device is still there,
2061 * if it is, it will rewrite the MSTM control bits, and return.
2062 *
2063 * if the device fails this returns -1, and the driver should do
2064 * a full MST reprobe, in case we were undocked.
2065 */
2066 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2067 {
2068 int ret = 0;
2069
2070 mutex_lock(&mgr->lock);
2071
2072 if (mgr->mst_primary) {
2073 int sret;
2074 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2075 if (sret != DP_RECEIVER_CAP_SIZE) {
2076 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2077 ret = -1;
2078 goto out_unlock;
2079 }
2080
2081 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2082 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2083 if (ret < 0) {
2084 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2085 ret = -1;
2086 goto out_unlock;
2087 }
2088 ret = 0;
2089 } else
2090 ret = -1;
2091
2092 out_unlock:
2093 mutex_unlock(&mgr->lock);
2094 return ret;
2095 }
2096 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2097
2098 static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2099 {
2100 int len;
2101 u8 replyblock[32];
2102 int replylen, origlen, curreply;
2103 int ret;
2104 struct drm_dp_sideband_msg_rx *msg;
2105 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2106 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2107
2108 len = min(mgr->max_dpcd_transaction_bytes, 16);
2109 ret = drm_dp_dpcd_read(mgr->aux, basereg,
2110 replyblock, len);
2111 if (ret != len) {
2112 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2113 return;
2114 }
2115 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2116 if (!ret) {
2117 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2118 return;
2119 }
2120 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2121
2122 origlen = replylen;
2123 replylen -= len;
2124 curreply = len;
2125 while (replylen > 0) {
2126 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2127 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2128 replyblock, len);
2129 if (ret != len) {
2130 DRM_DEBUG_KMS("failed to read a chunk\n");
2131 }
2132 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2133 if (ret == false)
2134 DRM_DEBUG_KMS("failed to build sideband msg\n");
2135 curreply += len;
2136 replylen -= len;
2137 }
2138 }
2139
2140 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2141 {
2142 int ret = 0;
2143
2144 drm_dp_get_one_sb_msg(mgr, false);
2145
2146 if (mgr->down_rep_recv.have_eomt) {
2147 struct drm_dp_sideband_msg_tx *txmsg;
2148 struct drm_dp_mst_branch *mstb;
2149 int slot = -1;
2150 mstb = drm_dp_get_mst_branch_device(mgr,
2151 mgr->down_rep_recv.initial_hdr.lct,
2152 mgr->down_rep_recv.initial_hdr.rad);
2153
2154 if (!mstb) {
2155 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2156 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2157 return 0;
2158 }
2159
2160 /* find the message */
2161 slot = mgr->down_rep_recv.initial_hdr.seqno;
2162 mutex_lock(&mgr->qlock);
2163 txmsg = mstb->tx_slots[slot];
2164 /* remove from slots */
2165 mutex_unlock(&mgr->qlock);
2166
2167 if (!txmsg) {
2168 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2169 mstb,
2170 mgr->down_rep_recv.initial_hdr.seqno,
2171 mgr->down_rep_recv.initial_hdr.lct,
2172 mgr->down_rep_recv.initial_hdr.rad[0],
2173 mgr->down_rep_recv.msg[0]);
2174 drm_dp_put_mst_branch_device(mstb);
2175 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2176 return 0;
2177 }
2178
2179 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2180 if (txmsg->reply.reply_type == 1) {
2181 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);
2182 }
2183
2184 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2185 drm_dp_put_mst_branch_device(mstb);
2186
2187 mutex_lock(&mgr->qlock);
2188 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2189 mstb->tx_slots[slot] = NULL;
2190 mutex_unlock(&mgr->qlock);
2191
2192 wake_up(&mgr->tx_waitq);
2193 }
2194 return ret;
2195 }
2196
2197 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2198 {
2199 int ret = 0;
2200 drm_dp_get_one_sb_msg(mgr, true);
2201
2202 if (mgr->up_req_recv.have_eomt) {
2203 struct drm_dp_sideband_msg_req_body msg;
2204 struct drm_dp_mst_branch *mstb = NULL;
2205 bool seqno;
2206
2207 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2208 mstb = drm_dp_get_mst_branch_device(mgr,
2209 mgr->up_req_recv.initial_hdr.lct,
2210 mgr->up_req_recv.initial_hdr.rad);
2211 if (!mstb) {
2212 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2213 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2214 return 0;
2215 }
2216 }
2217
2218 seqno = mgr->up_req_recv.initial_hdr.seqno;
2219 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2220
2221 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2222 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2223
2224 if (!mstb)
2225 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2226
2227 if (!mstb) {
2228 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2229 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2230 return 0;
2231 }
2232
2233 drm_dp_update_port(mstb, &msg.u.conn_stat);
2234 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);
2235 (*mgr->cbs->hotplug)(mgr);
2236
2237 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2238 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2239 if (!mstb)
2240 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2241
2242 if (!mstb) {
2243 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2244 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2245 return 0;
2246 }
2247
2248 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2249 }
2250
2251 drm_dp_put_mst_branch_device(mstb);
2252 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2253 }
2254 return ret;
2255 }
2256
2257 /**
2258 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2259 * @mgr: manager to notify irq for.
2260 * @esi: 4 bytes from SINK_COUNT_ESI
2261 * @handled: whether the hpd interrupt was consumed or not
2262 *
2263 * This should be called from the driver when it detects a short IRQ,
2264 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2265 * topology manager will process the sideband messages received as a result
2266 * of this.
2267 */
2268 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2269 {
2270 int ret = 0;
2271 int sc;
2272 *handled = false;
2273 sc = esi[0] & 0x3f;
2274
2275 if (sc != mgr->sink_count) {
2276 mgr->sink_count = sc;
2277 *handled = true;
2278 }
2279
2280 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2281 ret = drm_dp_mst_handle_down_rep(mgr);
2282 *handled = true;
2283 }
2284
2285 if (esi[1] & DP_UP_REQ_MSG_RDY) {
2286 ret |= drm_dp_mst_handle_up_req(mgr);
2287 *handled = true;
2288 }
2289
2290 drm_dp_mst_kick_tx(mgr);
2291 return ret;
2292 }
2293 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2294
2295 /**
2296 * drm_dp_mst_detect_port() - get connection status for an MST port
2297 * @mgr: manager for this port
2298 * @port: unverified pointer to a port
2299 *
2300 * This returns the current connection state for a port. It validates the
2301 * port pointer still exists so the caller doesn't require a reference
2302 */
2303 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2304 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2305 {
2306 enum drm_connector_status status = connector_status_disconnected;
2307
2308 /* we need to search for the port in the mgr in case its gone */
2309 port = drm_dp_get_validated_port_ref(mgr, port);
2310 if (!port)
2311 return connector_status_disconnected;
2312
2313 if (!port->ddps)
2314 goto out;
2315
2316 switch (port->pdt) {
2317 case DP_PEER_DEVICE_NONE:
2318 case DP_PEER_DEVICE_MST_BRANCHING:
2319 break;
2320
2321 case DP_PEER_DEVICE_SST_SINK:
2322 status = connector_status_connected;
2323 /* for logical ports - cache the EDID */
2324 if (port->port_num >= 8 && !port->cached_edid) {
2325 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2326 }
2327 break;
2328 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2329 if (port->ldps)
2330 status = connector_status_connected;
2331 break;
2332 }
2333 out:
2334 drm_dp_put_port(port);
2335 return status;
2336 }
2337 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2338
2339 /**
2340 * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
2341 * @mgr: manager for this port
2342 * @port: unverified pointer to a port.
2343 *
2344 * This returns whether the port supports audio or not.
2345 */
2346 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
2347 struct drm_dp_mst_port *port)
2348 {
2349 bool ret = false;
2350
2351 port = drm_dp_get_validated_port_ref(mgr, port);
2352 if (!port)
2353 return ret;
2354 ret = port->has_audio;
2355 drm_dp_put_port(port);
2356 return ret;
2357 }
2358 EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
2359
2360 /**
2361 * drm_dp_mst_get_edid() - get EDID for an MST port
2362 * @connector: toplevel connector to get EDID for
2363 * @mgr: manager for this port
2364 * @port: unverified pointer to a port.
2365 *
2366 * This returns an EDID for the port connected to a connector,
2367 * It validates the pointer still exists so the caller doesn't require a
2368 * reference.
2369 */
2370 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2371 {
2372 struct edid *edid = NULL;
2373
2374 /* we need to search for the port in the mgr in case its gone */
2375 port = drm_dp_get_validated_port_ref(mgr, port);
2376 if (!port)
2377 return NULL;
2378
2379 if (port->cached_edid)
2380 edid = drm_edid_duplicate(port->cached_edid);
2381 else {
2382 edid = drm_get_edid(connector, &port->aux.ddc);
2383 drm_mode_connector_set_tile_property(connector);
2384 }
2385 port->has_audio = drm_detect_monitor_audio(edid);
2386 drm_dp_put_port(port);
2387 return edid;
2388 }
2389 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2390
2391 /**
2392 * drm_dp_find_vcpi_slots() - find slots for this PBN value
2393 * @mgr: manager to use
2394 * @pbn: payload bandwidth to convert into slots.
2395 */
2396 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2397 int pbn)
2398 {
2399 int num_slots;
2400
2401 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2402
2403 if (num_slots > mgr->avail_slots)
2404 return -ENOSPC;
2405 return num_slots;
2406 }
2407 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2408
2409 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2410 struct drm_dp_vcpi *vcpi, int pbn)
2411 {
2412 int num_slots;
2413 int ret;
2414
2415 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2416
2417 if (num_slots > mgr->avail_slots)
2418 return -ENOSPC;
2419
2420 vcpi->pbn = pbn;
2421 vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2422 vcpi->num_slots = num_slots;
2423
2424 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2425 if (ret < 0)
2426 return ret;
2427 return 0;
2428 }
2429
2430 /**
2431 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2432 * @mgr: manager for this port
2433 * @port: port to allocate a virtual channel for.
2434 * @pbn: payload bandwidth number to request
2435 * @slots: returned number of slots for this PBN.
2436 */
2437 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2438 {
2439 int ret;
2440
2441 port = drm_dp_get_validated_port_ref(mgr, port);
2442 if (!port)
2443 return false;
2444
2445 if (port->vcpi.vcpi > 0) {
2446 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2447 if (pbn == port->vcpi.pbn) {
2448 *slots = port->vcpi.num_slots;
2449 drm_dp_put_port(port);
2450 return true;
2451 }
2452 }
2453
2454 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2455 if (ret) {
2456 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2457 goto out;
2458 }
2459 DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2460 *slots = port->vcpi.num_slots;
2461
2462 drm_dp_put_port(port);
2463 return true;
2464 out:
2465 return false;
2466 }
2467 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2468
2469 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2470 {
2471 int slots = 0;
2472 port = drm_dp_get_validated_port_ref(mgr, port);
2473 if (!port)
2474 return slots;
2475
2476 slots = port->vcpi.num_slots;
2477 drm_dp_put_port(port);
2478 return slots;
2479 }
2480 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2481
2482 /**
2483 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2484 * @mgr: manager for this port
2485 * @port: unverified pointer to a port.
2486 *
2487 * This just resets the number of slots for the ports VCPI for later programming.
2488 */
2489 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2490 {
2491 port = drm_dp_get_validated_port_ref(mgr, port);
2492 if (!port)
2493 return;
2494 port->vcpi.num_slots = 0;
2495 drm_dp_put_port(port);
2496 }
2497 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2498
2499 /**
2500 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2501 * @mgr: manager for this port
2502 * @port: unverified port to deallocate vcpi for
2503 */
2504 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2505 {
2506 port = drm_dp_get_validated_port_ref(mgr, port);
2507 if (!port)
2508 return;
2509
2510 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2511 port->vcpi.num_slots = 0;
2512 port->vcpi.pbn = 0;
2513 port->vcpi.aligned_pbn = 0;
2514 port->vcpi.vcpi = 0;
2515 drm_dp_put_port(port);
2516 }
2517 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2518
2519 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2520 int id, struct drm_dp_payload *payload)
2521 {
2522 u8 payload_alloc[3], status;
2523 int ret;
2524 int retries = 0;
2525
2526 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2527 DP_PAYLOAD_TABLE_UPDATED);
2528
2529 payload_alloc[0] = id;
2530 payload_alloc[1] = payload->start_slot;
2531 payload_alloc[2] = payload->num_slots;
2532
2533 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2534 if (ret != 3) {
2535 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2536 goto fail;
2537 }
2538
2539 retry:
2540 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2541 if (ret < 0) {
2542 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2543 goto fail;
2544 }
2545
2546 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2547 retries++;
2548 if (retries < 20) {
2549 usleep_range(10000, 20000);
2550 goto retry;
2551 }
2552 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2553 ret = -EINVAL;
2554 goto fail;
2555 }
2556 ret = 0;
2557 fail:
2558 return ret;
2559 }
2560
2561
2562 /**
2563 * drm_dp_check_act_status() - Check ACT handled status.
2564 * @mgr: manager to use
2565 *
2566 * Check the payload status bits in the DPCD for ACT handled completion.
2567 */
2568 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2569 {
2570 u8 status;
2571 int ret;
2572 int count = 0;
2573
2574 do {
2575 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2576
2577 if (ret < 0) {
2578 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2579 goto fail;
2580 }
2581
2582 if (status & DP_PAYLOAD_ACT_HANDLED)
2583 break;
2584 count++;
2585 udelay(100);
2586
2587 } while (count < 30);
2588
2589 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2590 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2591 ret = -EINVAL;
2592 goto fail;
2593 }
2594 return 0;
2595 fail:
2596 return ret;
2597 }
2598 EXPORT_SYMBOL(drm_dp_check_act_status);
2599
2600 /**
2601 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2602 * @clock: dot clock for the mode
2603 * @bpp: bpp for the mode.
2604 *
2605 * This uses the formula in the spec to calculate the PBN value for a mode.
2606 */
2607 int drm_dp_calc_pbn_mode(int clock, int bpp)
2608 {
2609 fixed20_12 pix_bw;
2610 fixed20_12 fbpp;
2611 fixed20_12 result;
2612 fixed20_12 margin, tmp;
2613 u32 res;
2614
2615 pix_bw.full = dfixed_const(clock);
2616 fbpp.full = dfixed_const(bpp);
2617 tmp.full = dfixed_const(8);
2618 fbpp.full = dfixed_div(fbpp, tmp);
2619
2620 result.full = dfixed_mul(pix_bw, fbpp);
2621 margin.full = dfixed_const(54);
2622 tmp.full = dfixed_const(64);
2623 margin.full = dfixed_div(margin, tmp);
2624 result.full = dfixed_div(result, margin);
2625
2626 margin.full = dfixed_const(1006);
2627 tmp.full = dfixed_const(1000);
2628 margin.full = dfixed_div(margin, tmp);
2629 result.full = dfixed_mul(result, margin);
2630
2631 result.full = dfixed_div(result, tmp);
2632 result.full = dfixed_ceil(result);
2633 res = dfixed_trunc(result);
2634 return res;
2635 }
2636 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2637
2638 static int test_calc_pbn_mode(void)
2639 {
2640 int ret;
2641 ret = drm_dp_calc_pbn_mode(154000, 30);
2642 if (ret != 689)
2643 return -EINVAL;
2644 ret = drm_dp_calc_pbn_mode(234000, 30);
2645 if (ret != 1047)
2646 return -EINVAL;
2647 return 0;
2648 }
2649
2650 /* we want to kick the TX after we've ack the up/down IRQs. */
2651 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2652 {
2653 queue_work(system_long_wq, &mgr->tx_work);
2654 }
2655
2656 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2657 struct drm_dp_mst_branch *mstb)
2658 {
2659 struct drm_dp_mst_port *port;
2660 int tabs = mstb->lct;
2661 char prefix[10];
2662 int i;
2663
2664 for (i = 0; i < tabs; i++)
2665 prefix[i] = '\t';
2666 prefix[i] = '\0';
2667
2668 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2669 list_for_each_entry(port, &mstb->ports, next) {
2670 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
2671 if (port->mstb)
2672 drm_dp_mst_dump_mstb(m, port->mstb);
2673 }
2674 }
2675
2676 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2677 char *buf)
2678 {
2679 int ret;
2680 int i;
2681 for (i = 0; i < 4; i++) {
2682 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2683 if (ret != 16)
2684 break;
2685 }
2686 if (i == 4)
2687 return true;
2688 return false;
2689 }
2690
2691 /**
2692 * drm_dp_mst_dump_topology(): dump topology to seq file.
2693 * @m: seq_file to dump output to
2694 * @mgr: manager to dump current topology for.
2695 *
2696 * helper to dump MST topology to a seq file for debugfs.
2697 */
2698 void drm_dp_mst_dump_topology(struct seq_file *m,
2699 struct drm_dp_mst_topology_mgr *mgr)
2700 {
2701 int i;
2702 struct drm_dp_mst_port *port;
2703 mutex_lock(&mgr->lock);
2704 if (mgr->mst_primary)
2705 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2706
2707 /* dump VCPIs */
2708 mutex_unlock(&mgr->lock);
2709
2710 mutex_lock(&mgr->payload_lock);
2711 seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
2712
2713 for (i = 0; i < mgr->max_payloads; i++) {
2714 if (mgr->proposed_vcpis[i]) {
2715 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2716 seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2717 } else
2718 seq_printf(m, "vcpi %d:unsed\n", i);
2719 }
2720 for (i = 0; i < mgr->max_payloads; i++) {
2721 seq_printf(m, "payload %d: %d, %d, %d\n",
2722 i,
2723 mgr->payloads[i].payload_state,
2724 mgr->payloads[i].start_slot,
2725 mgr->payloads[i].num_slots);
2726
2727
2728 }
2729 mutex_unlock(&mgr->payload_lock);
2730
2731 mutex_lock(&mgr->lock);
2732 if (mgr->mst_primary) {
2733 u8 buf[64];
2734 bool bret;
2735 int ret;
2736 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2737 seq_printf(m, "dpcd: ");
2738 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2739 seq_printf(m, "%02x ", buf[i]);
2740 seq_printf(m, "\n");
2741 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2742 seq_printf(m, "faux/mst: ");
2743 for (i = 0; i < 2; i++)
2744 seq_printf(m, "%02x ", buf[i]);
2745 seq_printf(m, "\n");
2746 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2747 seq_printf(m, "mst ctrl: ");
2748 for (i = 0; i < 1; i++)
2749 seq_printf(m, "%02x ", buf[i]);
2750 seq_printf(m, "\n");
2751
2752 /* dump the standard OUI branch header */
2753 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
2754 seq_printf(m, "branch oui: ");
2755 for (i = 0; i < 0x3; i++)
2756 seq_printf(m, "%02x", buf[i]);
2757 seq_printf(m, " devid: ");
2758 for (i = 0x3; i < 0x8; i++)
2759 seq_printf(m, "%c", buf[i]);
2760 seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
2761 seq_printf(m, "\n");
2762 bret = dump_dp_payload_table(mgr, buf);
2763 if (bret == true) {
2764 seq_printf(m, "payload table: ");
2765 for (i = 0; i < 63; i++)
2766 seq_printf(m, "%02x ", buf[i]);
2767 seq_printf(m, "\n");
2768 }
2769
2770 }
2771
2772 mutex_unlock(&mgr->lock);
2773
2774 }
2775 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2776
2777 static void drm_dp_tx_work(struct work_struct *work)
2778 {
2779 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2780
2781 mutex_lock(&mgr->qlock);
2782 if (mgr->tx_down_in_progress)
2783 process_single_down_tx_qlock(mgr);
2784 mutex_unlock(&mgr->qlock);
2785 }
2786
2787 static void drm_dp_destroy_connector_work(struct work_struct *work)
2788 {
2789 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
2790 struct drm_dp_mst_port *port;
2791 bool send_hotplug = false;
2792 /*
2793 * Not a regular list traverse as we have to drop the destroy
2794 * connector lock before destroying the connector, to avoid AB->BA
2795 * ordering between this lock and the config mutex.
2796 */
2797 for (;;) {
2798 mutex_lock(&mgr->destroy_connector_lock);
2799 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
2800 if (!port) {
2801 mutex_unlock(&mgr->destroy_connector_lock);
2802 break;
2803 }
2804 list_del(&port->next);
2805 mutex_unlock(&mgr->destroy_connector_lock);
2806
2807 mgr->cbs->destroy_connector(mgr, port->connector);
2808
2809 drm_dp_port_teardown_pdt(port, port->pdt);
2810
2811 if (!port->input && port->vcpi.vcpi > 0)
2812 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2813 kfree(port);
2814 send_hotplug = true;
2815 }
2816 if (send_hotplug)
2817 (*mgr->cbs->hotplug)(mgr);
2818 }
2819
2820 /**
2821 * drm_dp_mst_topology_mgr_init - initialise a topology manager
2822 * @mgr: manager struct to initialise
2823 * @dev: device providing this structure - for i2c addition.
2824 * @aux: DP helper aux channel to talk to this device
2825 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2826 * @max_payloads: maximum number of payloads this GPU can source
2827 * @conn_base_id: the connector object ID the MST device is connected to.
2828 *
2829 * Return 0 for success, or negative error code on failure
2830 */
2831 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2832 struct device *dev, struct drm_dp_aux *aux,
2833 int max_dpcd_transaction_bytes,
2834 int max_payloads, int conn_base_id)
2835 {
2836 mutex_init(&mgr->lock);
2837 mutex_init(&mgr->qlock);
2838 mutex_init(&mgr->payload_lock);
2839 mutex_init(&mgr->destroy_connector_lock);
2840 INIT_LIST_HEAD(&mgr->tx_msg_downq);
2841 INIT_LIST_HEAD(&mgr->destroy_connector_list);
2842 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2843 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2844 INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
2845 init_waitqueue_head(&mgr->tx_waitq);
2846 mgr->dev = dev;
2847 mgr->aux = aux;
2848 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2849 mgr->max_payloads = max_payloads;
2850 mgr->conn_base_id = conn_base_id;
2851 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2852 if (!mgr->payloads)
2853 return -ENOMEM;
2854 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2855 if (!mgr->proposed_vcpis)
2856 return -ENOMEM;
2857 set_bit(0, &mgr->payload_mask);
2858 test_calc_pbn_mode();
2859 return 0;
2860 }
2861 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2862
2863 /**
2864 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2865 * @mgr: manager to destroy
2866 */
2867 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2868 {
2869 flush_work(&mgr->work);
2870 flush_work(&mgr->destroy_connector_work);
2871 mutex_lock(&mgr->payload_lock);
2872 kfree(mgr->payloads);
2873 mgr->payloads = NULL;
2874 kfree(mgr->proposed_vcpis);
2875 mgr->proposed_vcpis = NULL;
2876 mutex_unlock(&mgr->payload_lock);
2877 mgr->dev = NULL;
2878 mgr->aux = NULL;
2879 }
2880 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
2881
2882 /* I2C device */
2883 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
2884 int num)
2885 {
2886 struct drm_dp_aux *aux = adapter->algo_data;
2887 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
2888 struct drm_dp_mst_branch *mstb;
2889 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2890 unsigned int i;
2891 bool reading = false;
2892 struct drm_dp_sideband_msg_req_body msg;
2893 struct drm_dp_sideband_msg_tx *txmsg = NULL;
2894 int ret;
2895
2896 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2897 if (!mstb)
2898 return -EREMOTEIO;
2899
2900 /* construct i2c msg */
2901 /* see if last msg is a read */
2902 if (msgs[num - 1].flags & I2C_M_RD)
2903 reading = true;
2904
2905 if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
2906 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
2907 ret = -EIO;
2908 goto out;
2909 }
2910
2911 memset(&msg, 0, sizeof(msg));
2912 msg.req_type = DP_REMOTE_I2C_READ;
2913 msg.u.i2c_read.num_transactions = num - 1;
2914 msg.u.i2c_read.port_number = port->port_num;
2915 for (i = 0; i < num - 1; i++) {
2916 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
2917 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
2918 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
2919 }
2920 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
2921 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
2922
2923 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2924 if (!txmsg) {
2925 ret = -ENOMEM;
2926 goto out;
2927 }
2928
2929 txmsg->dst = mstb;
2930 drm_dp_encode_sideband_req(&msg, txmsg);
2931
2932 drm_dp_queue_down_tx(mgr, txmsg);
2933
2934 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2935 if (ret > 0) {
2936
2937 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
2938 ret = -EREMOTEIO;
2939 goto out;
2940 }
2941 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
2942 ret = -EIO;
2943 goto out;
2944 }
2945 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
2946 ret = num;
2947 }
2948 out:
2949 kfree(txmsg);
2950 drm_dp_put_mst_branch_device(mstb);
2951 return ret;
2952 }
2953
2954 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
2955 {
2956 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
2957 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
2958 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
2959 I2C_FUNC_10BIT_ADDR;
2960 }
2961
2962 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
2963 .functionality = drm_dp_mst_i2c_functionality,
2964 .master_xfer = drm_dp_mst_i2c_xfer,
2965 };
2966
2967 /**
2968 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
2969 * @aux: DisplayPort AUX channel
2970 *
2971 * Returns 0 on success or a negative error code on failure.
2972 */
2973 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
2974 {
2975 aux->ddc.algo = &drm_dp_mst_i2c_algo;
2976 aux->ddc.algo_data = aux;
2977 aux->ddc.retries = 3;
2978
2979 aux->ddc.class = I2C_CLASS_DDC;
2980 aux->ddc.owner = THIS_MODULE;
2981 aux->ddc.dev.parent = aux->dev;
2982 aux->ddc.dev.of_node = aux->dev->of_node;
2983
2984 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
2985 sizeof(aux->ddc.name));
2986
2987 return i2c_add_adapter(&aux->ddc);
2988 }
2989
2990 /**
2991 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
2992 * @aux: DisplayPort AUX channel
2993 */
2994 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
2995 {
2996 i2c_del_adapter(&aux->ddc);
2997 }
Linux with added FPC-III support