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