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3b6627dde9ffdff3c52c4b62eb46b183ae790976
[deliverable/linux.git] / drivers / gpu / drm / drm_dp_mst_topology.c
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 {
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
682 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
683 struct drm_dp_vcpi *vcpi)
684 {
685 int ret, vcpi_ret;
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
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
702 set_bit(ret, &mgr->payload_mask);
703 set_bit(vcpi_ret, &mgr->vcpi_mask);
704 vcpi->vcpi = vcpi_ret + 1;
705 mgr->proposed_vcpis[ret - 1] = vcpi;
706 out_unlock:
707 mutex_unlock(&mgr->payload_lock);
708 return ret;
709 }
710
711 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
712 int vcpi)
713 {
714 int i;
715 if (vcpi == 0)
716 return;
717
718 mutex_lock(&mgr->payload_lock);
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 }
729 mutex_unlock(&mgr->payload_lock);
730 }
731
732 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
733 struct drm_dp_sideband_msg_tx *txmsg)
734 {
735 bool ret;
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 */
742 ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
743 txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
744 return ret;
745 }
746
747 static 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 }
779 out:
780 mutex_unlock(&mgr->qlock);
781
782 return ret;
783 }
784
785 static 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
801 static 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
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
836 static 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
842 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
843 {
844 struct drm_dp_mst_branch *mstb;
845
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:
853 mstb = port->mstb;
854 port->mstb = NULL;
855 drm_dp_put_mst_branch_device(mstb);
856 break;
857 }
858 }
859
860 static 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;
864
865 if (!port->input) {
866 port->vcpi.num_slots = 0;
867
868 kfree(port->cached_edid);
869
870 /*
871 * The only time we don't have a connector
872 * on an output port is if the connector init
873 * fails.
874 */
875 if (port->connector) {
876 /* we can't destroy the connector here, as
877 * we might be holding the mode_config.mutex
878 * from an EDID retrieval */
879
880 mutex_lock(&mgr->destroy_connector_lock);
881 list_add(&port->next, &mgr->destroy_connector_list);
882 mutex_unlock(&mgr->destroy_connector_lock);
883 schedule_work(&mgr->destroy_connector_work);
884 return;
885 }
886 /* no need to clean up vcpi
887 * as if we have no connector we never setup a vcpi */
888 drm_dp_port_teardown_pdt(port, port->pdt);
889 }
890 kfree(port);
891 }
892
893 static void drm_dp_put_port(struct drm_dp_mst_port *port)
894 {
895 kref_put(&port->kref, drm_dp_destroy_port);
896 }
897
898 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)
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
916 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)
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
926 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)
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
944 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)
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
954 static 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 */
973 static 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 */
992 static 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
1016 static 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
1032 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1033 int pnum,
1034 char *proppath,
1035 size_t proppath_size)
1036 {
1037 int i;
1038 char temp[8];
1039 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
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;
1043 snprintf(temp, sizeof(temp), "-%d", port_num);
1044 strlcat(proppath, temp, proppath_size);
1045 }
1046 snprintf(temp, sizeof(temp), "-%d", pnum);
1047 strlcat(proppath, temp, proppath_size);
1048 }
1049
1050 static 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);
1110 if (ret == true)
1111 drm_dp_send_link_address(mstb->mgr, port->mstb);
1112 }
1113
1114 if (created && !port->input) {
1115 char proppath[255];
1116
1117 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
1118 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
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 }
1128 if (port->port_num >= DP_MST_LOGICAL_PORT_0) {
1129 port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1130 drm_mode_connector_set_tile_property(port->connector);
1131 }
1132 (*mstb->mgr->cbs->register_connector)(port->connector);
1133 }
1134
1135 out:
1136 /* put reference to this port */
1137 drm_dp_put_port(port);
1138 }
1139
1140 static 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
1180 static 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 */
1187
1188 mutex_lock(&mgr->lock);
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) {
1197 mstb = port->mstb;
1198 if (!mstb) {
1199 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1200 goto out;
1201 }
1202
1203 break;
1204 }
1205 }
1206 }
1207 kref_get(&mstb->kref);
1208 out:
1209 mutex_unlock(&mgr->lock);
1210 return mstb;
1211 }
1212
1213 static 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;
1217 struct drm_dp_mst_branch *mstb_child;
1218 if (!mstb->link_address_sent)
1219 drm_dp_send_link_address(mgr, mstb);
1220
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
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 }
1238 }
1239 }
1240
1241 static 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);
1244 struct drm_dp_mst_branch *mstb;
1245
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 }
1256 }
1257
1258 static 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
1273 static 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
1287 static 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
1295 retry:
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);
1310
1311 return -EIO;
1312 }
1313 offset += tosend;
1314 total -= tosend;
1315 } while (total > 0);
1316 return 0;
1317 }
1318
1319 static 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 */
1351 static 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
1360 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1361
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
1407 static 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
1412 WARN_ON(!mutex_is_locked(&mgr->qlock));
1413
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 */
1441 static 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
1463 static 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
1473 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1474 struct drm_dp_mst_branch *mstb)
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)
1482 return;
1483
1484 txmsg->dst = mstb;
1485 len = build_link_address(txmsg);
1486
1487 mstb->link_address_sent = true;
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 }
1515 } else {
1516 mstb->link_address_sent = false;
1517 DRM_DEBUG_KMS("link address failed %d\n", ret);
1518 }
1519
1520 kfree(txmsg);
1521 }
1522
1523 static 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
1557 static 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)
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);
1591 fail_put:
1592 drm_dp_put_mst_branch_device(mstb);
1593 return ret;
1594 }
1595
1596 static 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
1611 static 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)
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
1624 static 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)
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);
1636 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1637 return 0;
1638 }
1639
1640 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1641 int id,
1642 struct drm_dp_payload *payload)
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 */
1661 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1662 {
1663 int i, j;
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 req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi;
1677 } else {
1678 port = NULL;
1679 req_payload.num_slots = 0;
1680 }
1681
1682 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1683 mgr->payloads[i].start_slot = req_payload.start_slot;
1684 }
1685 /* work out what is required to happen with this payload */
1686 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1687
1688 /* need to push an update for this payload */
1689 if (req_payload.num_slots) {
1690 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1691 mgr->payloads[i].num_slots = req_payload.num_slots;
1692 mgr->payloads[i].vcpi = req_payload.vcpi;
1693 } else if (mgr->payloads[i].num_slots) {
1694 mgr->payloads[i].num_slots = 0;
1695 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
1696 req_payload.payload_state = mgr->payloads[i].payload_state;
1697 mgr->payloads[i].start_slot = 0;
1698 }
1699 mgr->payloads[i].payload_state = req_payload.payload_state;
1700 }
1701 cur_slots += req_payload.num_slots;
1702 }
1703
1704 for (i = 0; i < mgr->max_payloads; i++) {
1705 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1706 DRM_DEBUG_KMS("removing payload %d\n", i);
1707 for (j = i; j < mgr->max_payloads - 1; j++) {
1708 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1709 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1710 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1711 set_bit(j + 1, &mgr->payload_mask);
1712 } else {
1713 clear_bit(j + 1, &mgr->payload_mask);
1714 }
1715 }
1716 memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1717 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1718 clear_bit(mgr->max_payloads, &mgr->payload_mask);
1719
1720 }
1721 }
1722 mutex_unlock(&mgr->payload_lock);
1723
1724 return 0;
1725 }
1726 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1727
1728 /**
1729 * drm_dp_update_payload_part2() - Execute payload update part 2
1730 * @mgr: manager to use.
1731 *
1732 * This iterates over all proposed virtual channels, and tries to
1733 * allocate space in the link for them. For 0->slots transitions,
1734 * this step writes the remote VC payload commands. For slots->0
1735 * this just resets some internal state.
1736 */
1737 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1738 {
1739 struct drm_dp_mst_port *port;
1740 int i;
1741 int ret = 0;
1742 mutex_lock(&mgr->payload_lock);
1743 for (i = 0; i < mgr->max_payloads; i++) {
1744
1745 if (!mgr->proposed_vcpis[i])
1746 continue;
1747
1748 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1749
1750 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1751 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1752 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1753 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1754 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1755 }
1756 if (ret) {
1757 mutex_unlock(&mgr->payload_lock);
1758 return ret;
1759 }
1760 }
1761 mutex_unlock(&mgr->payload_lock);
1762 return 0;
1763 }
1764 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1765
1766 #if 0 /* unused as of yet */
1767 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1768 struct drm_dp_mst_port *port,
1769 int offset, int size)
1770 {
1771 int len;
1772 struct drm_dp_sideband_msg_tx *txmsg;
1773
1774 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1775 if (!txmsg)
1776 return -ENOMEM;
1777
1778 len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1779 txmsg->dst = port->parent;
1780
1781 drm_dp_queue_down_tx(mgr, txmsg);
1782
1783 return 0;
1784 }
1785 #endif
1786
1787 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1788 struct drm_dp_mst_port *port,
1789 int offset, int size, u8 *bytes)
1790 {
1791 int len;
1792 int ret;
1793 struct drm_dp_sideband_msg_tx *txmsg;
1794 struct drm_dp_mst_branch *mstb;
1795
1796 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1797 if (!mstb)
1798 return -EINVAL;
1799
1800 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1801 if (!txmsg) {
1802 ret = -ENOMEM;
1803 goto fail_put;
1804 }
1805
1806 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1807 txmsg->dst = mstb;
1808
1809 drm_dp_queue_down_tx(mgr, txmsg);
1810
1811 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1812 if (ret > 0) {
1813 if (txmsg->reply.reply_type == 1) {
1814 ret = -EINVAL;
1815 } else
1816 ret = 0;
1817 }
1818 kfree(txmsg);
1819 fail_put:
1820 drm_dp_put_mst_branch_device(mstb);
1821 return ret;
1822 }
1823
1824 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1825 {
1826 struct drm_dp_sideband_msg_reply_body reply;
1827
1828 reply.reply_type = 0;
1829 reply.req_type = req_type;
1830 drm_dp_encode_sideband_reply(&reply, msg);
1831 return 0;
1832 }
1833
1834 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1835 struct drm_dp_mst_branch *mstb,
1836 int req_type, int seqno, bool broadcast)
1837 {
1838 struct drm_dp_sideband_msg_tx *txmsg;
1839
1840 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1841 if (!txmsg)
1842 return -ENOMEM;
1843
1844 txmsg->dst = mstb;
1845 txmsg->seqno = seqno;
1846 drm_dp_encode_up_ack_reply(txmsg, req_type);
1847
1848 mutex_lock(&mgr->qlock);
1849 list_add_tail(&txmsg->next, &mgr->tx_msg_upq);
1850 if (!mgr->tx_up_in_progress) {
1851 process_single_up_tx_qlock(mgr);
1852 }
1853 mutex_unlock(&mgr->qlock);
1854 return 0;
1855 }
1856
1857 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1858 int dp_link_count,
1859 int *out)
1860 {
1861 switch (dp_link_bw) {
1862 default:
1863 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1864 dp_link_bw, dp_link_count);
1865 return false;
1866
1867 case DP_LINK_BW_1_62:
1868 *out = 3 * dp_link_count;
1869 break;
1870 case DP_LINK_BW_2_7:
1871 *out = 5 * dp_link_count;
1872 break;
1873 case DP_LINK_BW_5_4:
1874 *out = 10 * dp_link_count;
1875 break;
1876 }
1877 return true;
1878 }
1879
1880 /**
1881 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
1882 * @mgr: manager to set state for
1883 * @mst_state: true to enable MST on this connector - false to disable.
1884 *
1885 * This is called by the driver when it detects an MST capable device plugged
1886 * into a DP MST capable port, or when a DP MST capable device is unplugged.
1887 */
1888 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
1889 {
1890 int ret = 0;
1891 struct drm_dp_mst_branch *mstb = NULL;
1892
1893 mutex_lock(&mgr->lock);
1894 if (mst_state == mgr->mst_state)
1895 goto out_unlock;
1896
1897 mgr->mst_state = mst_state;
1898 /* set the device into MST mode */
1899 if (mst_state) {
1900 WARN_ON(mgr->mst_primary);
1901
1902 /* get dpcd info */
1903 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
1904 if (ret != DP_RECEIVER_CAP_SIZE) {
1905 DRM_DEBUG_KMS("failed to read DPCD\n");
1906 goto out_unlock;
1907 }
1908
1909 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
1910 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
1911 &mgr->pbn_div)) {
1912 ret = -EINVAL;
1913 goto out_unlock;
1914 }
1915
1916 mgr->total_pbn = 2560;
1917 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
1918 mgr->avail_slots = mgr->total_slots;
1919
1920 /* add initial branch device at LCT 1 */
1921 mstb = drm_dp_add_mst_branch_device(1, NULL);
1922 if (mstb == NULL) {
1923 ret = -ENOMEM;
1924 goto out_unlock;
1925 }
1926 mstb->mgr = mgr;
1927
1928 /* give this the main reference */
1929 mgr->mst_primary = mstb;
1930 kref_get(&mgr->mst_primary->kref);
1931
1932 {
1933 struct drm_dp_payload reset_pay;
1934 reset_pay.start_slot = 0;
1935 reset_pay.num_slots = 0x3f;
1936 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
1937 }
1938
1939 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1940 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
1941 if (ret < 0) {
1942 goto out_unlock;
1943 }
1944
1945
1946 /* sort out guid */
1947 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
1948 if (ret != 16) {
1949 DRM_DEBUG_KMS("failed to read DP GUID %d\n", ret);
1950 goto out_unlock;
1951 }
1952
1953 mgr->guid_valid = drm_dp_validate_guid(mgr, mgr->guid);
1954 if (!mgr->guid_valid) {
1955 ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, mgr->guid, 16);
1956 mgr->guid_valid = true;
1957 }
1958
1959 queue_work(system_long_wq, &mgr->work);
1960
1961 ret = 0;
1962 } else {
1963 /* disable MST on the device */
1964 mstb = mgr->mst_primary;
1965 mgr->mst_primary = NULL;
1966 /* this can fail if the device is gone */
1967 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
1968 ret = 0;
1969 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
1970 mgr->payload_mask = 0;
1971 set_bit(0, &mgr->payload_mask);
1972 mgr->vcpi_mask = 0;
1973 }
1974
1975 out_unlock:
1976 mutex_unlock(&mgr->lock);
1977 if (mstb)
1978 drm_dp_put_mst_branch_device(mstb);
1979 return ret;
1980
1981 }
1982 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
1983
1984 /**
1985 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
1986 * @mgr: manager to suspend
1987 *
1988 * This function tells the MST device that we can't handle UP messages
1989 * anymore. This should stop it from sending any since we are suspended.
1990 */
1991 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
1992 {
1993 mutex_lock(&mgr->lock);
1994 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1995 DP_MST_EN | DP_UPSTREAM_IS_SRC);
1996 mutex_unlock(&mgr->lock);
1997 flush_work(&mgr->work);
1998 flush_work(&mgr->destroy_connector_work);
1999 }
2000 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2001
2002 /**
2003 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2004 * @mgr: manager to resume
2005 *
2006 * This will fetch DPCD and see if the device is still there,
2007 * if it is, it will rewrite the MSTM control bits, and return.
2008 *
2009 * if the device fails this returns -1, and the driver should do
2010 * a full MST reprobe, in case we were undocked.
2011 */
2012 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2013 {
2014 int ret = 0;
2015
2016 mutex_lock(&mgr->lock);
2017
2018 if (mgr->mst_primary) {
2019 int sret;
2020 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2021 if (sret != DP_RECEIVER_CAP_SIZE) {
2022 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2023 ret = -1;
2024 goto out_unlock;
2025 }
2026
2027 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2028 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2029 if (ret < 0) {
2030 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2031 ret = -1;
2032 goto out_unlock;
2033 }
2034 ret = 0;
2035 } else
2036 ret = -1;
2037
2038 out_unlock:
2039 mutex_unlock(&mgr->lock);
2040 return ret;
2041 }
2042 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2043
2044 static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2045 {
2046 int len;
2047 u8 replyblock[32];
2048 int replylen, origlen, curreply;
2049 int ret;
2050 struct drm_dp_sideband_msg_rx *msg;
2051 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2052 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2053
2054 len = min(mgr->max_dpcd_transaction_bytes, 16);
2055 ret = drm_dp_dpcd_read(mgr->aux, basereg,
2056 replyblock, len);
2057 if (ret != len) {
2058 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2059 return;
2060 }
2061 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2062 if (!ret) {
2063 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2064 return;
2065 }
2066 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2067
2068 origlen = replylen;
2069 replylen -= len;
2070 curreply = len;
2071 while (replylen > 0) {
2072 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2073 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2074 replyblock, len);
2075 if (ret != len) {
2076 DRM_DEBUG_KMS("failed to read a chunk\n");
2077 }
2078 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2079 if (ret == false)
2080 DRM_DEBUG_KMS("failed to build sideband msg\n");
2081 curreply += len;
2082 replylen -= len;
2083 }
2084 }
2085
2086 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2087 {
2088 int ret = 0;
2089
2090 drm_dp_get_one_sb_msg(mgr, false);
2091
2092 if (mgr->down_rep_recv.have_eomt) {
2093 struct drm_dp_sideband_msg_tx *txmsg;
2094 struct drm_dp_mst_branch *mstb;
2095 int slot = -1;
2096 mstb = drm_dp_get_mst_branch_device(mgr,
2097 mgr->down_rep_recv.initial_hdr.lct,
2098 mgr->down_rep_recv.initial_hdr.rad);
2099
2100 if (!mstb) {
2101 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2102 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2103 return 0;
2104 }
2105
2106 /* find the message */
2107 slot = mgr->down_rep_recv.initial_hdr.seqno;
2108 mutex_lock(&mgr->qlock);
2109 txmsg = mstb->tx_slots[slot];
2110 /* remove from slots */
2111 mutex_unlock(&mgr->qlock);
2112
2113 if (!txmsg) {
2114 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2115 mstb,
2116 mgr->down_rep_recv.initial_hdr.seqno,
2117 mgr->down_rep_recv.initial_hdr.lct,
2118 mgr->down_rep_recv.initial_hdr.rad[0],
2119 mgr->down_rep_recv.msg[0]);
2120 drm_dp_put_mst_branch_device(mstb);
2121 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2122 return 0;
2123 }
2124
2125 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2126 if (txmsg->reply.reply_type == 1) {
2127 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);
2128 }
2129
2130 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2131 drm_dp_put_mst_branch_device(mstb);
2132
2133 mutex_lock(&mgr->qlock);
2134 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2135 mstb->tx_slots[slot] = NULL;
2136 mutex_unlock(&mgr->qlock);
2137
2138 wake_up(&mgr->tx_waitq);
2139 }
2140 return ret;
2141 }
2142
2143 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2144 {
2145 int ret = 0;
2146 drm_dp_get_one_sb_msg(mgr, true);
2147
2148 if (mgr->up_req_recv.have_eomt) {
2149 struct drm_dp_sideband_msg_req_body msg;
2150 struct drm_dp_mst_branch *mstb;
2151 bool seqno;
2152 mstb = drm_dp_get_mst_branch_device(mgr,
2153 mgr->up_req_recv.initial_hdr.lct,
2154 mgr->up_req_recv.initial_hdr.rad);
2155 if (!mstb) {
2156 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2157 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2158 return 0;
2159 }
2160
2161 seqno = mgr->up_req_recv.initial_hdr.seqno;
2162 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2163
2164 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2165 drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
2166 drm_dp_update_port(mstb, &msg.u.conn_stat);
2167 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);
2168 (*mgr->cbs->hotplug)(mgr);
2169
2170 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2171 drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
2172 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2173 }
2174
2175 drm_dp_put_mst_branch_device(mstb);
2176 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2177 }
2178 return ret;
2179 }
2180
2181 /**
2182 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2183 * @mgr: manager to notify irq for.
2184 * @esi: 4 bytes from SINK_COUNT_ESI
2185 * @handled: whether the hpd interrupt was consumed or not
2186 *
2187 * This should be called from the driver when it detects a short IRQ,
2188 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2189 * topology manager will process the sideband messages received as a result
2190 * of this.
2191 */
2192 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2193 {
2194 int ret = 0;
2195 int sc;
2196 *handled = false;
2197 sc = esi[0] & 0x3f;
2198
2199 if (sc != mgr->sink_count) {
2200 mgr->sink_count = sc;
2201 *handled = true;
2202 }
2203
2204 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2205 ret = drm_dp_mst_handle_down_rep(mgr);
2206 *handled = true;
2207 }
2208
2209 if (esi[1] & DP_UP_REQ_MSG_RDY) {
2210 ret |= drm_dp_mst_handle_up_req(mgr);
2211 *handled = true;
2212 }
2213
2214 drm_dp_mst_kick_tx(mgr);
2215 return ret;
2216 }
2217 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2218
2219 /**
2220 * drm_dp_mst_detect_port() - get connection status for an MST port
2221 * @mgr: manager for this port
2222 * @port: unverified pointer to a port
2223 *
2224 * This returns the current connection state for a port. It validates the
2225 * port pointer still exists so the caller doesn't require a reference
2226 */
2227 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2228 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2229 {
2230 enum drm_connector_status status = connector_status_disconnected;
2231
2232 /* we need to search for the port in the mgr in case its gone */
2233 port = drm_dp_get_validated_port_ref(mgr, port);
2234 if (!port)
2235 return connector_status_disconnected;
2236
2237 if (!port->ddps)
2238 goto out;
2239
2240 switch (port->pdt) {
2241 case DP_PEER_DEVICE_NONE:
2242 case DP_PEER_DEVICE_MST_BRANCHING:
2243 break;
2244
2245 case DP_PEER_DEVICE_SST_SINK:
2246 status = connector_status_connected;
2247 /* for logical ports - cache the EDID */
2248 if (port->port_num >= 8 && !port->cached_edid) {
2249 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2250 }
2251 break;
2252 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2253 if (port->ldps)
2254 status = connector_status_connected;
2255 break;
2256 }
2257 out:
2258 drm_dp_put_port(port);
2259 return status;
2260 }
2261 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2262
2263 /**
2264 * drm_dp_mst_get_edid() - get EDID for an MST port
2265 * @connector: toplevel connector to get EDID for
2266 * @mgr: manager for this port
2267 * @port: unverified pointer to a port.
2268 *
2269 * This returns an EDID for the port connected to a connector,
2270 * It validates the pointer still exists so the caller doesn't require a
2271 * reference.
2272 */
2273 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2274 {
2275 struct edid *edid = NULL;
2276
2277 /* we need to search for the port in the mgr in case its gone */
2278 port = drm_dp_get_validated_port_ref(mgr, port);
2279 if (!port)
2280 return NULL;
2281
2282 if (port->cached_edid)
2283 edid = drm_edid_duplicate(port->cached_edid);
2284 else {
2285 edid = drm_get_edid(connector, &port->aux.ddc);
2286 drm_mode_connector_set_tile_property(connector);
2287 }
2288 drm_dp_put_port(port);
2289 return edid;
2290 }
2291 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2292
2293 /**
2294 * drm_dp_find_vcpi_slots() - find slots for this PBN value
2295 * @mgr: manager to use
2296 * @pbn: payload bandwidth to convert into slots.
2297 */
2298 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2299 int pbn)
2300 {
2301 int num_slots;
2302
2303 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2304
2305 if (num_slots > mgr->avail_slots)
2306 return -ENOSPC;
2307 return num_slots;
2308 }
2309 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2310
2311 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2312 struct drm_dp_vcpi *vcpi, int pbn)
2313 {
2314 int num_slots;
2315 int ret;
2316
2317 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2318
2319 if (num_slots > mgr->avail_slots)
2320 return -ENOSPC;
2321
2322 vcpi->pbn = pbn;
2323 vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2324 vcpi->num_slots = num_slots;
2325
2326 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2327 if (ret < 0)
2328 return ret;
2329 return 0;
2330 }
2331
2332 /**
2333 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2334 * @mgr: manager for this port
2335 * @port: port to allocate a virtual channel for.
2336 * @pbn: payload bandwidth number to request
2337 * @slots: returned number of slots for this PBN.
2338 */
2339 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2340 {
2341 int ret;
2342
2343 port = drm_dp_get_validated_port_ref(mgr, port);
2344 if (!port)
2345 return false;
2346
2347 if (port->vcpi.vcpi > 0) {
2348 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2349 if (pbn == port->vcpi.pbn) {
2350 *slots = port->vcpi.num_slots;
2351 return true;
2352 }
2353 }
2354
2355 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2356 if (ret) {
2357 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2358 goto out;
2359 }
2360 DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2361 *slots = port->vcpi.num_slots;
2362
2363 drm_dp_put_port(port);
2364 return true;
2365 out:
2366 return false;
2367 }
2368 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2369
2370 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2371 {
2372 int slots = 0;
2373 port = drm_dp_get_validated_port_ref(mgr, port);
2374 if (!port)
2375 return slots;
2376
2377 slots = port->vcpi.num_slots;
2378 drm_dp_put_port(port);
2379 return slots;
2380 }
2381 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2382
2383 /**
2384 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2385 * @mgr: manager for this port
2386 * @port: unverified pointer to a port.
2387 *
2388 * This just resets the number of slots for the ports VCPI for later programming.
2389 */
2390 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2391 {
2392 port = drm_dp_get_validated_port_ref(mgr, port);
2393 if (!port)
2394 return;
2395 port->vcpi.num_slots = 0;
2396 drm_dp_put_port(port);
2397 }
2398 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2399
2400 /**
2401 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2402 * @mgr: manager for this port
2403 * @port: unverified port to deallocate vcpi for
2404 */
2405 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2406 {
2407 port = drm_dp_get_validated_port_ref(mgr, port);
2408 if (!port)
2409 return;
2410
2411 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2412 port->vcpi.num_slots = 0;
2413 port->vcpi.pbn = 0;
2414 port->vcpi.aligned_pbn = 0;
2415 port->vcpi.vcpi = 0;
2416 drm_dp_put_port(port);
2417 }
2418 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2419
2420 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2421 int id, struct drm_dp_payload *payload)
2422 {
2423 u8 payload_alloc[3], status;
2424 int ret;
2425 int retries = 0;
2426
2427 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2428 DP_PAYLOAD_TABLE_UPDATED);
2429
2430 payload_alloc[0] = id;
2431 payload_alloc[1] = payload->start_slot;
2432 payload_alloc[2] = payload->num_slots;
2433
2434 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2435 if (ret != 3) {
2436 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2437 goto fail;
2438 }
2439
2440 retry:
2441 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2442 if (ret < 0) {
2443 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2444 goto fail;
2445 }
2446
2447 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2448 retries++;
2449 if (retries < 20) {
2450 usleep_range(10000, 20000);
2451 goto retry;
2452 }
2453 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2454 ret = -EINVAL;
2455 goto fail;
2456 }
2457 ret = 0;
2458 fail:
2459 return ret;
2460 }
2461
2462
2463 /**
2464 * drm_dp_check_act_status() - Check ACT handled status.
2465 * @mgr: manager to use
2466 *
2467 * Check the payload status bits in the DPCD for ACT handled completion.
2468 */
2469 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2470 {
2471 u8 status;
2472 int ret;
2473 int count = 0;
2474
2475 do {
2476 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2477
2478 if (ret < 0) {
2479 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2480 goto fail;
2481 }
2482
2483 if (status & DP_PAYLOAD_ACT_HANDLED)
2484 break;
2485 count++;
2486 udelay(100);
2487
2488 } while (count < 30);
2489
2490 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2491 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2492 ret = -EINVAL;
2493 goto fail;
2494 }
2495 return 0;
2496 fail:
2497 return ret;
2498 }
2499 EXPORT_SYMBOL(drm_dp_check_act_status);
2500
2501 /**
2502 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2503 * @clock: dot clock for the mode
2504 * @bpp: bpp for the mode.
2505 *
2506 * This uses the formula in the spec to calculate the PBN value for a mode.
2507 */
2508 int drm_dp_calc_pbn_mode(int clock, int bpp)
2509 {
2510 fixed20_12 pix_bw;
2511 fixed20_12 fbpp;
2512 fixed20_12 result;
2513 fixed20_12 margin, tmp;
2514 u32 res;
2515
2516 pix_bw.full = dfixed_const(clock);
2517 fbpp.full = dfixed_const(bpp);
2518 tmp.full = dfixed_const(8);
2519 fbpp.full = dfixed_div(fbpp, tmp);
2520
2521 result.full = dfixed_mul(pix_bw, fbpp);
2522 margin.full = dfixed_const(54);
2523 tmp.full = dfixed_const(64);
2524 margin.full = dfixed_div(margin, tmp);
2525 result.full = dfixed_div(result, margin);
2526
2527 margin.full = dfixed_const(1006);
2528 tmp.full = dfixed_const(1000);
2529 margin.full = dfixed_div(margin, tmp);
2530 result.full = dfixed_mul(result, margin);
2531
2532 result.full = dfixed_div(result, tmp);
2533 result.full = dfixed_ceil(result);
2534 res = dfixed_trunc(result);
2535 return res;
2536 }
2537 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2538
2539 static int test_calc_pbn_mode(void)
2540 {
2541 int ret;
2542 ret = drm_dp_calc_pbn_mode(154000, 30);
2543 if (ret != 689)
2544 return -EINVAL;
2545 ret = drm_dp_calc_pbn_mode(234000, 30);
2546 if (ret != 1047)
2547 return -EINVAL;
2548 return 0;
2549 }
2550
2551 /* we want to kick the TX after we've ack the up/down IRQs. */
2552 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2553 {
2554 queue_work(system_long_wq, &mgr->tx_work);
2555 }
2556
2557 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2558 struct drm_dp_mst_branch *mstb)
2559 {
2560 struct drm_dp_mst_port *port;
2561 int tabs = mstb->lct;
2562 char prefix[10];
2563 int i;
2564
2565 for (i = 0; i < tabs; i++)
2566 prefix[i] = '\t';
2567 prefix[i] = '\0';
2568
2569 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2570 list_for_each_entry(port, &mstb->ports, next) {
2571 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port, port->connector);
2572 if (port->mstb)
2573 drm_dp_mst_dump_mstb(m, port->mstb);
2574 }
2575 }
2576
2577 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2578 char *buf)
2579 {
2580 int ret;
2581 int i;
2582 for (i = 0; i < 4; i++) {
2583 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2584 if (ret != 16)
2585 break;
2586 }
2587 if (i == 4)
2588 return true;
2589 return false;
2590 }
2591
2592 /**
2593 * drm_dp_mst_dump_topology(): dump topology to seq file.
2594 * @m: seq_file to dump output to
2595 * @mgr: manager to dump current topology for.
2596 *
2597 * helper to dump MST topology to a seq file for debugfs.
2598 */
2599 void drm_dp_mst_dump_topology(struct seq_file *m,
2600 struct drm_dp_mst_topology_mgr *mgr)
2601 {
2602 int i;
2603 struct drm_dp_mst_port *port;
2604 mutex_lock(&mgr->lock);
2605 if (mgr->mst_primary)
2606 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2607
2608 /* dump VCPIs */
2609 mutex_unlock(&mgr->lock);
2610
2611 mutex_lock(&mgr->payload_lock);
2612 seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
2613
2614 for (i = 0; i < mgr->max_payloads; i++) {
2615 if (mgr->proposed_vcpis[i]) {
2616 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2617 seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2618 } else
2619 seq_printf(m, "vcpi %d:unsed\n", i);
2620 }
2621 for (i = 0; i < mgr->max_payloads; i++) {
2622 seq_printf(m, "payload %d: %d, %d, %d\n",
2623 i,
2624 mgr->payloads[i].payload_state,
2625 mgr->payloads[i].start_slot,
2626 mgr->payloads[i].num_slots);
2627
2628
2629 }
2630 mutex_unlock(&mgr->payload_lock);
2631
2632 mutex_lock(&mgr->lock);
2633 if (mgr->mst_primary) {
2634 u8 buf[64];
2635 bool bret;
2636 int ret;
2637 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2638 seq_printf(m, "dpcd: ");
2639 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2640 seq_printf(m, "%02x ", buf[i]);
2641 seq_printf(m, "\n");
2642 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2643 seq_printf(m, "faux/mst: ");
2644 for (i = 0; i < 2; i++)
2645 seq_printf(m, "%02x ", buf[i]);
2646 seq_printf(m, "\n");
2647 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2648 seq_printf(m, "mst ctrl: ");
2649 for (i = 0; i < 1; i++)
2650 seq_printf(m, "%02x ", buf[i]);
2651 seq_printf(m, "\n");
2652
2653 /* dump the standard OUI branch header */
2654 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
2655 seq_printf(m, "branch oui: ");
2656 for (i = 0; i < 0x3; i++)
2657 seq_printf(m, "%02x", buf[i]);
2658 seq_printf(m, " devid: ");
2659 for (i = 0x3; i < 0x8; i++)
2660 seq_printf(m, "%c", buf[i]);
2661 seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
2662 seq_printf(m, "\n");
2663 bret = dump_dp_payload_table(mgr, buf);
2664 if (bret == true) {
2665 seq_printf(m, "payload table: ");
2666 for (i = 0; i < 63; i++)
2667 seq_printf(m, "%02x ", buf[i]);
2668 seq_printf(m, "\n");
2669 }
2670
2671 }
2672
2673 mutex_unlock(&mgr->lock);
2674
2675 }
2676 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2677
2678 static void drm_dp_tx_work(struct work_struct *work)
2679 {
2680 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2681
2682 mutex_lock(&mgr->qlock);
2683 if (mgr->tx_down_in_progress)
2684 process_single_down_tx_qlock(mgr);
2685 mutex_unlock(&mgr->qlock);
2686 }
2687
2688 static void drm_dp_destroy_connector_work(struct work_struct *work)
2689 {
2690 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
2691 struct drm_dp_mst_port *port;
2692 bool send_hotplug = false;
2693 /*
2694 * Not a regular list traverse as we have to drop the destroy
2695 * connector lock before destroying the connector, to avoid AB->BA
2696 * ordering between this lock and the config mutex.
2697 */
2698 for (;;) {
2699 mutex_lock(&mgr->destroy_connector_lock);
2700 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
2701 if (!port) {
2702 mutex_unlock(&mgr->destroy_connector_lock);
2703 break;
2704 }
2705 list_del(&port->next);
2706 mutex_unlock(&mgr->destroy_connector_lock);
2707
2708 mgr->cbs->destroy_connector(mgr, port->connector);
2709
2710 drm_dp_port_teardown_pdt(port, port->pdt);
2711
2712 if (!port->input && port->vcpi.vcpi > 0)
2713 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2714 kfree(port);
2715 send_hotplug = true;
2716 }
2717 if (send_hotplug)
2718 (*mgr->cbs->hotplug)(mgr);
2719 }
2720
2721 /**
2722 * drm_dp_mst_topology_mgr_init - initialise a topology manager
2723 * @mgr: manager struct to initialise
2724 * @dev: device providing this structure - for i2c addition.
2725 * @aux: DP helper aux channel to talk to this device
2726 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2727 * @max_payloads: maximum number of payloads this GPU can source
2728 * @conn_base_id: the connector object ID the MST device is connected to.
2729 *
2730 * Return 0 for success, or negative error code on failure
2731 */
2732 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2733 struct device *dev, struct drm_dp_aux *aux,
2734 int max_dpcd_transaction_bytes,
2735 int max_payloads, int conn_base_id)
2736 {
2737 mutex_init(&mgr->lock);
2738 mutex_init(&mgr->qlock);
2739 mutex_init(&mgr->payload_lock);
2740 mutex_init(&mgr->destroy_connector_lock);
2741 INIT_LIST_HEAD(&mgr->tx_msg_upq);
2742 INIT_LIST_HEAD(&mgr->tx_msg_downq);
2743 INIT_LIST_HEAD(&mgr->destroy_connector_list);
2744 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2745 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2746 INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
2747 init_waitqueue_head(&mgr->tx_waitq);
2748 mgr->dev = dev;
2749 mgr->aux = aux;
2750 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2751 mgr->max_payloads = max_payloads;
2752 mgr->conn_base_id = conn_base_id;
2753 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2754 if (!mgr->payloads)
2755 return -ENOMEM;
2756 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2757 if (!mgr->proposed_vcpis)
2758 return -ENOMEM;
2759 set_bit(0, &mgr->payload_mask);
2760 test_calc_pbn_mode();
2761 return 0;
2762 }
2763 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2764
2765 /**
2766 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2767 * @mgr: manager to destroy
2768 */
2769 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2770 {
2771 flush_work(&mgr->work);
2772 flush_work(&mgr->destroy_connector_work);
2773 mutex_lock(&mgr->payload_lock);
2774 kfree(mgr->payloads);
2775 mgr->payloads = NULL;
2776 kfree(mgr->proposed_vcpis);
2777 mgr->proposed_vcpis = NULL;
2778 mutex_unlock(&mgr->payload_lock);
2779 mgr->dev = NULL;
2780 mgr->aux = NULL;
2781 }
2782 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
2783
2784 /* I2C device */
2785 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
2786 int num)
2787 {
2788 struct drm_dp_aux *aux = adapter->algo_data;
2789 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
2790 struct drm_dp_mst_branch *mstb;
2791 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2792 unsigned int i;
2793 bool reading = false;
2794 struct drm_dp_sideband_msg_req_body msg;
2795 struct drm_dp_sideband_msg_tx *txmsg = NULL;
2796 int ret;
2797
2798 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2799 if (!mstb)
2800 return -EREMOTEIO;
2801
2802 /* construct i2c msg */
2803 /* see if last msg is a read */
2804 if (msgs[num - 1].flags & I2C_M_RD)
2805 reading = true;
2806
2807 if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
2808 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
2809 ret = -EIO;
2810 goto out;
2811 }
2812
2813 memset(&msg, 0, sizeof(msg));
2814 msg.req_type = DP_REMOTE_I2C_READ;
2815 msg.u.i2c_read.num_transactions = num - 1;
2816 msg.u.i2c_read.port_number = port->port_num;
2817 for (i = 0; i < num - 1; i++) {
2818 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
2819 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
2820 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
2821 }
2822 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
2823 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
2824
2825 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2826 if (!txmsg) {
2827 ret = -ENOMEM;
2828 goto out;
2829 }
2830
2831 txmsg->dst = mstb;
2832 drm_dp_encode_sideband_req(&msg, txmsg);
2833
2834 drm_dp_queue_down_tx(mgr, txmsg);
2835
2836 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2837 if (ret > 0) {
2838
2839 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
2840 ret = -EREMOTEIO;
2841 goto out;
2842 }
2843 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
2844 ret = -EIO;
2845 goto out;
2846 }
2847 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
2848 ret = num;
2849 }
2850 out:
2851 kfree(txmsg);
2852 drm_dp_put_mst_branch_device(mstb);
2853 return ret;
2854 }
2855
2856 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
2857 {
2858 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
2859 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
2860 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
2861 I2C_FUNC_10BIT_ADDR;
2862 }
2863
2864 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
2865 .functionality = drm_dp_mst_i2c_functionality,
2866 .master_xfer = drm_dp_mst_i2c_xfer,
2867 };
2868
2869 /**
2870 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
2871 * @aux: DisplayPort AUX channel
2872 *
2873 * Returns 0 on success or a negative error code on failure.
2874 */
2875 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
2876 {
2877 aux->ddc.algo = &drm_dp_mst_i2c_algo;
2878 aux->ddc.algo_data = aux;
2879 aux->ddc.retries = 3;
2880
2881 aux->ddc.class = I2C_CLASS_DDC;
2882 aux->ddc.owner = THIS_MODULE;
2883 aux->ddc.dev.parent = aux->dev;
2884 aux->ddc.dev.of_node = aux->dev->of_node;
2885
2886 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
2887 sizeof(aux->ddc.name));
2888
2889 return i2c_add_adapter(&aux->ddc);
2890 }
2891
2892 /**
2893 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
2894 * @aux: DisplayPort AUX channel
2895 */
2896 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
2897 {
2898 i2c_del_adapter(&aux->ddc);
2899 }
Linux kernel - Deliverables
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