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drm/i915: Parse VBT PSR block.
[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 switch (old_pdt) {
843 case DP_PEER_DEVICE_DP_LEGACY_CONV:
844 case DP_PEER_DEVICE_SST_SINK:
845 /* remove i2c over sideband */
846 drm_dp_mst_unregister_i2c_bus(&port->aux);
847 break;
848 case DP_PEER_DEVICE_MST_BRANCHING:
849 drm_dp_put_mst_branch_device(port->mstb);
850 port->mstb = NULL;
851 break;
852 }
853 }
854
855 static void drm_dp_destroy_port(struct kref *kref)
856 {
857 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
858 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
859 if (!port->input) {
860 port->vcpi.num_slots = 0;
861 if (port->connector)
862 (*port->mgr->cbs->destroy_connector)(mgr, port->connector);
863 drm_dp_port_teardown_pdt(port, port->pdt);
864
865 if (!port->input && port->vcpi.vcpi > 0)
866 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
867 }
868 kfree(port);
869
870 (*mgr->cbs->hotplug)(mgr);
871 }
872
873 static void drm_dp_put_port(struct drm_dp_mst_port *port)
874 {
875 kref_put(&port->kref, drm_dp_destroy_port);
876 }
877
878 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)
879 {
880 struct drm_dp_mst_port *port;
881 struct drm_dp_mst_branch *rmstb;
882 if (to_find == mstb) {
883 kref_get(&mstb->kref);
884 return mstb;
885 }
886 list_for_each_entry(port, &mstb->ports, next) {
887 if (port->mstb) {
888 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
889 if (rmstb)
890 return rmstb;
891 }
892 }
893 return NULL;
894 }
895
896 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)
897 {
898 struct drm_dp_mst_branch *rmstb = NULL;
899 mutex_lock(&mgr->lock);
900 if (mgr->mst_primary)
901 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
902 mutex_unlock(&mgr->lock);
903 return rmstb;
904 }
905
906 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)
907 {
908 struct drm_dp_mst_port *port, *mport;
909
910 list_for_each_entry(port, &mstb->ports, next) {
911 if (port == to_find) {
912 kref_get(&port->kref);
913 return port;
914 }
915 if (port->mstb) {
916 mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
917 if (mport)
918 return mport;
919 }
920 }
921 return NULL;
922 }
923
924 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)
925 {
926 struct drm_dp_mst_port *rport = NULL;
927 mutex_lock(&mgr->lock);
928 if (mgr->mst_primary)
929 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
930 mutex_unlock(&mgr->lock);
931 return rport;
932 }
933
934 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
935 {
936 struct drm_dp_mst_port *port;
937
938 list_for_each_entry(port, &mstb->ports, next) {
939 if (port->port_num == port_num) {
940 kref_get(&port->kref);
941 return port;
942 }
943 }
944
945 return NULL;
946 }
947
948 /*
949 * calculate a new RAD for this MST branch device
950 * if parent has an LCT of 2 then it has 1 nibble of RAD,
951 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
952 */
953 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
954 u8 *rad)
955 {
956 int lct = port->parent->lct;
957 int shift = 4;
958 int idx = lct / 2;
959 if (lct > 1) {
960 memcpy(rad, port->parent->rad, idx);
961 shift = (lct % 2) ? 4 : 0;
962 } else
963 rad[0] = 0;
964
965 rad[idx] |= port->port_num << shift;
966 return lct + 1;
967 }
968
969 /*
970 * return sends link address for new mstb
971 */
972 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
973 {
974 int ret;
975 u8 rad[6], lct;
976 bool send_link = false;
977 switch (port->pdt) {
978 case DP_PEER_DEVICE_DP_LEGACY_CONV:
979 case DP_PEER_DEVICE_SST_SINK:
980 /* add i2c over sideband */
981 ret = drm_dp_mst_register_i2c_bus(&port->aux);
982 break;
983 case DP_PEER_DEVICE_MST_BRANCHING:
984 lct = drm_dp_calculate_rad(port, rad);
985
986 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
987 port->mstb->mgr = port->mgr;
988 port->mstb->port_parent = port;
989
990 send_link = true;
991 break;
992 }
993 return send_link;
994 }
995
996 static void drm_dp_check_port_guid(struct drm_dp_mst_branch *mstb,
997 struct drm_dp_mst_port *port)
998 {
999 int ret;
1000 if (port->dpcd_rev >= 0x12) {
1001 port->guid_valid = drm_dp_validate_guid(mstb->mgr, port->guid);
1002 if (!port->guid_valid) {
1003 ret = drm_dp_send_dpcd_write(mstb->mgr,
1004 port,
1005 DP_GUID,
1006 16, port->guid);
1007 port->guid_valid = true;
1008 }
1009 }
1010 }
1011
1012 static void build_mst_prop_path(struct drm_dp_mst_port *port,
1013 struct drm_dp_mst_branch *mstb,
1014 char *proppath,
1015 size_t proppath_size)
1016 {
1017 int i;
1018 char temp[8];
1019 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1020 for (i = 0; i < (mstb->lct - 1); i++) {
1021 int shift = (i % 2) ? 0 : 4;
1022 int port_num = mstb->rad[i / 2] >> shift;
1023 snprintf(temp, sizeof(temp), "-%d", port_num);
1024 strlcat(proppath, temp, proppath_size);
1025 }
1026 snprintf(temp, sizeof(temp), "-%d", port->port_num);
1027 strlcat(proppath, temp, proppath_size);
1028 }
1029
1030 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1031 struct device *dev,
1032 struct drm_dp_link_addr_reply_port *port_msg)
1033 {
1034 struct drm_dp_mst_port *port;
1035 bool ret;
1036 bool created = false;
1037 int old_pdt = 0;
1038 int old_ddps = 0;
1039 port = drm_dp_get_port(mstb, port_msg->port_number);
1040 if (!port) {
1041 port = kzalloc(sizeof(*port), GFP_KERNEL);
1042 if (!port)
1043 return;
1044 kref_init(&port->kref);
1045 port->parent = mstb;
1046 port->port_num = port_msg->port_number;
1047 port->mgr = mstb->mgr;
1048 port->aux.name = "DPMST";
1049 port->aux.dev = dev;
1050 created = true;
1051 } else {
1052 old_pdt = port->pdt;
1053 old_ddps = port->ddps;
1054 }
1055
1056 port->pdt = port_msg->peer_device_type;
1057 port->input = port_msg->input_port;
1058 port->mcs = port_msg->mcs;
1059 port->ddps = port_msg->ddps;
1060 port->ldps = port_msg->legacy_device_plug_status;
1061 port->dpcd_rev = port_msg->dpcd_revision;
1062 port->num_sdp_streams = port_msg->num_sdp_streams;
1063 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1064 memcpy(port->guid, port_msg->peer_guid, 16);
1065
1066 /* manage mstb port lists with mgr lock - take a reference
1067 for this list */
1068 if (created) {
1069 mutex_lock(&mstb->mgr->lock);
1070 kref_get(&port->kref);
1071 list_add(&port->next, &mstb->ports);
1072 mutex_unlock(&mstb->mgr->lock);
1073 }
1074
1075 if (old_ddps != port->ddps) {
1076 if (port->ddps) {
1077 drm_dp_check_port_guid(mstb, port);
1078 if (!port->input)
1079 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1080 } else {
1081 port->guid_valid = false;
1082 port->available_pbn = 0;
1083 }
1084 }
1085
1086 if (old_pdt != port->pdt && !port->input) {
1087 drm_dp_port_teardown_pdt(port, old_pdt);
1088
1089 ret = drm_dp_port_setup_pdt(port);
1090 if (ret == true) {
1091 drm_dp_send_link_address(mstb->mgr, port->mstb);
1092 port->mstb->link_address_sent = true;
1093 }
1094 }
1095
1096 if (created && !port->input) {
1097 char proppath[255];
1098 build_mst_prop_path(port, mstb, proppath, sizeof(proppath));
1099 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1100 }
1101
1102 /* put reference to this port */
1103 drm_dp_put_port(port);
1104 }
1105
1106 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1107 struct drm_dp_connection_status_notify *conn_stat)
1108 {
1109 struct drm_dp_mst_port *port;
1110 int old_pdt;
1111 int old_ddps;
1112 bool dowork = false;
1113 port = drm_dp_get_port(mstb, conn_stat->port_number);
1114 if (!port)
1115 return;
1116
1117 old_ddps = port->ddps;
1118 old_pdt = port->pdt;
1119 port->pdt = conn_stat->peer_device_type;
1120 port->mcs = conn_stat->message_capability_status;
1121 port->ldps = conn_stat->legacy_device_plug_status;
1122 port->ddps = conn_stat->displayport_device_plug_status;
1123
1124 if (old_ddps != port->ddps) {
1125 if (port->ddps) {
1126 drm_dp_check_port_guid(mstb, port);
1127 dowork = true;
1128 } else {
1129 port->guid_valid = false;
1130 port->available_pbn = 0;
1131 }
1132 }
1133 if (old_pdt != port->pdt && !port->input) {
1134 drm_dp_port_teardown_pdt(port, old_pdt);
1135
1136 if (drm_dp_port_setup_pdt(port))
1137 dowork = true;
1138 }
1139
1140 drm_dp_put_port(port);
1141 if (dowork)
1142 queue_work(system_long_wq, &mstb->mgr->work);
1143
1144 }
1145
1146 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1147 u8 lct, u8 *rad)
1148 {
1149 struct drm_dp_mst_branch *mstb;
1150 struct drm_dp_mst_port *port;
1151 int i;
1152 /* find the port by iterating down */
1153 mstb = mgr->mst_primary;
1154
1155 for (i = 0; i < lct - 1; i++) {
1156 int shift = (i % 2) ? 0 : 4;
1157 int port_num = rad[i / 2] >> shift;
1158
1159 list_for_each_entry(port, &mstb->ports, next) {
1160 if (port->port_num == port_num) {
1161 if (!port->mstb) {
1162 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1163 return NULL;
1164 }
1165
1166 mstb = port->mstb;
1167 break;
1168 }
1169 }
1170 }
1171 kref_get(&mstb->kref);
1172 return mstb;
1173 }
1174
1175 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1176 struct drm_dp_mst_branch *mstb)
1177 {
1178 struct drm_dp_mst_port *port;
1179
1180 if (!mstb->link_address_sent) {
1181 drm_dp_send_link_address(mgr, mstb);
1182 mstb->link_address_sent = true;
1183 }
1184 list_for_each_entry(port, &mstb->ports, next) {
1185 if (port->input)
1186 continue;
1187
1188 if (!port->ddps)
1189 continue;
1190
1191 if (!port->available_pbn)
1192 drm_dp_send_enum_path_resources(mgr, mstb, port);
1193
1194 if (port->mstb)
1195 drm_dp_check_and_send_link_address(mgr, port->mstb);
1196 }
1197 }
1198
1199 static void drm_dp_mst_link_probe_work(struct work_struct *work)
1200 {
1201 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1202
1203 drm_dp_check_and_send_link_address(mgr, mgr->mst_primary);
1204
1205 }
1206
1207 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1208 u8 *guid)
1209 {
1210 static u8 zero_guid[16];
1211
1212 if (!memcmp(guid, zero_guid, 16)) {
1213 u64 salt = get_jiffies_64();
1214 memcpy(&guid[0], &salt, sizeof(u64));
1215 memcpy(&guid[8], &salt, sizeof(u64));
1216 return false;
1217 }
1218 return true;
1219 }
1220
1221 #if 0
1222 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1223 {
1224 struct drm_dp_sideband_msg_req_body req;
1225
1226 req.req_type = DP_REMOTE_DPCD_READ;
1227 req.u.dpcd_read.port_number = port_num;
1228 req.u.dpcd_read.dpcd_address = offset;
1229 req.u.dpcd_read.num_bytes = num_bytes;
1230 drm_dp_encode_sideband_req(&req, msg);
1231
1232 return 0;
1233 }
1234 #endif
1235
1236 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1237 bool up, u8 *msg, int len)
1238 {
1239 int ret;
1240 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1241 int tosend, total, offset;
1242 int retries = 0;
1243
1244 retry:
1245 total = len;
1246 offset = 0;
1247 do {
1248 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1249
1250 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1251 &msg[offset],
1252 tosend);
1253 if (ret != tosend) {
1254 if (ret == -EIO && retries < 5) {
1255 retries++;
1256 goto retry;
1257 }
1258 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1259 WARN(1, "fail\n");
1260
1261 return -EIO;
1262 }
1263 offset += tosend;
1264 total -= tosend;
1265 } while (total > 0);
1266 return 0;
1267 }
1268
1269 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1270 struct drm_dp_sideband_msg_tx *txmsg)
1271 {
1272 struct drm_dp_mst_branch *mstb = txmsg->dst;
1273
1274 /* both msg slots are full */
1275 if (txmsg->seqno == -1) {
1276 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1277 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1278 return -EAGAIN;
1279 }
1280 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1281 txmsg->seqno = mstb->last_seqno;
1282 mstb->last_seqno ^= 1;
1283 } else if (mstb->tx_slots[0] == NULL)
1284 txmsg->seqno = 0;
1285 else
1286 txmsg->seqno = 1;
1287 mstb->tx_slots[txmsg->seqno] = txmsg;
1288 }
1289 hdr->broadcast = 0;
1290 hdr->path_msg = txmsg->path_msg;
1291 hdr->lct = mstb->lct;
1292 hdr->lcr = mstb->lct - 1;
1293 if (mstb->lct > 1)
1294 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1295 hdr->seqno = txmsg->seqno;
1296 return 0;
1297 }
1298 /*
1299 * process a single block of the next message in the sideband queue
1300 */
1301 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1302 struct drm_dp_sideband_msg_tx *txmsg,
1303 bool up)
1304 {
1305 u8 chunk[48];
1306 struct drm_dp_sideband_msg_hdr hdr;
1307 int len, space, idx, tosend;
1308 int ret;
1309
1310 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1311
1312 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1313 txmsg->seqno = -1;
1314 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1315 }
1316
1317 /* make hdr from dst mst - for replies use seqno
1318 otherwise assign one */
1319 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1320 if (ret < 0)
1321 return ret;
1322
1323 /* amount left to send in this message */
1324 len = txmsg->cur_len - txmsg->cur_offset;
1325
1326 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1327 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1328
1329 tosend = min(len, space);
1330 if (len == txmsg->cur_len)
1331 hdr.somt = 1;
1332 if (space >= len)
1333 hdr.eomt = 1;
1334
1335
1336 hdr.msg_len = tosend + 1;
1337 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1338 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1339 /* add crc at end */
1340 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1341 idx += tosend + 1;
1342
1343 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1344 if (ret) {
1345 DRM_DEBUG_KMS("sideband msg failed to send\n");
1346 return ret;
1347 }
1348
1349 txmsg->cur_offset += tosend;
1350 if (txmsg->cur_offset == txmsg->cur_len) {
1351 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1352 return 1;
1353 }
1354 return 0;
1355 }
1356
1357 /* must be called holding qlock */
1358 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1359 {
1360 struct drm_dp_sideband_msg_tx *txmsg;
1361 int ret;
1362
1363 /* construct a chunk from the first msg in the tx_msg queue */
1364 if (list_empty(&mgr->tx_msg_downq)) {
1365 mgr->tx_down_in_progress = false;
1366 return;
1367 }
1368 mgr->tx_down_in_progress = true;
1369
1370 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1371 ret = process_single_tx_qlock(mgr, txmsg, false);
1372 if (ret == 1) {
1373 /* txmsg is sent it should be in the slots now */
1374 list_del(&txmsg->next);
1375 } else if (ret) {
1376 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1377 list_del(&txmsg->next);
1378 if (txmsg->seqno != -1)
1379 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1380 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1381 wake_up(&mgr->tx_waitq);
1382 }
1383 if (list_empty(&mgr->tx_msg_downq)) {
1384 mgr->tx_down_in_progress = false;
1385 return;
1386 }
1387 }
1388
1389 /* called holding qlock */
1390 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1391 {
1392 struct drm_dp_sideband_msg_tx *txmsg;
1393 int ret;
1394
1395 /* construct a chunk from the first msg in the tx_msg queue */
1396 if (list_empty(&mgr->tx_msg_upq)) {
1397 mgr->tx_up_in_progress = false;
1398 return;
1399 }
1400
1401 txmsg = list_first_entry(&mgr->tx_msg_upq, struct drm_dp_sideband_msg_tx, next);
1402 ret = process_single_tx_qlock(mgr, txmsg, true);
1403 if (ret == 1) {
1404 /* up txmsgs aren't put in slots - so free after we send it */
1405 list_del(&txmsg->next);
1406 kfree(txmsg);
1407 } else if (ret)
1408 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1409 mgr->tx_up_in_progress = true;
1410 }
1411
1412 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1413 struct drm_dp_sideband_msg_tx *txmsg)
1414 {
1415 mutex_lock(&mgr->qlock);
1416 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1417 if (!mgr->tx_down_in_progress)
1418 process_single_down_tx_qlock(mgr);
1419 mutex_unlock(&mgr->qlock);
1420 }
1421
1422 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1423 struct drm_dp_mst_branch *mstb)
1424 {
1425 int len;
1426 struct drm_dp_sideband_msg_tx *txmsg;
1427 int ret;
1428
1429 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1430 if (!txmsg)
1431 return -ENOMEM;
1432
1433 txmsg->dst = mstb;
1434 len = build_link_address(txmsg);
1435
1436 drm_dp_queue_down_tx(mgr, txmsg);
1437
1438 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1439 if (ret > 0) {
1440 int i;
1441
1442 if (txmsg->reply.reply_type == 1)
1443 DRM_DEBUG_KMS("link address nak received\n");
1444 else {
1445 DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1446 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1447 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,
1448 txmsg->reply.u.link_addr.ports[i].input_port,
1449 txmsg->reply.u.link_addr.ports[i].peer_device_type,
1450 txmsg->reply.u.link_addr.ports[i].port_number,
1451 txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1452 txmsg->reply.u.link_addr.ports[i].mcs,
1453 txmsg->reply.u.link_addr.ports[i].ddps,
1454 txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1455 txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1456 txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1457 }
1458 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1459 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1460 }
1461 (*mgr->cbs->hotplug)(mgr);
1462 }
1463 } else
1464 DRM_DEBUG_KMS("link address failed %d\n", ret);
1465
1466 kfree(txmsg);
1467 return 0;
1468 }
1469
1470 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1471 struct drm_dp_mst_branch *mstb,
1472 struct drm_dp_mst_port *port)
1473 {
1474 int len;
1475 struct drm_dp_sideband_msg_tx *txmsg;
1476 int ret;
1477
1478 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1479 if (!txmsg)
1480 return -ENOMEM;
1481
1482 txmsg->dst = mstb;
1483 len = build_enum_path_resources(txmsg, port->port_num);
1484
1485 drm_dp_queue_down_tx(mgr, txmsg);
1486
1487 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1488 if (ret > 0) {
1489 if (txmsg->reply.reply_type == 1)
1490 DRM_DEBUG_KMS("enum path resources nak received\n");
1491 else {
1492 if (port->port_num != txmsg->reply.u.path_resources.port_number)
1493 DRM_ERROR("got incorrect port in response\n");
1494 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,
1495 txmsg->reply.u.path_resources.avail_payload_bw_number);
1496 port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1497 }
1498 }
1499
1500 kfree(txmsg);
1501 return 0;
1502 }
1503
1504 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1505 struct drm_dp_mst_port *port,
1506 int id,
1507 int pbn)
1508 {
1509 struct drm_dp_sideband_msg_tx *txmsg;
1510 struct drm_dp_mst_branch *mstb;
1511 int len, ret;
1512
1513 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1514 if (!mstb)
1515 return -EINVAL;
1516
1517 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1518 if (!txmsg) {
1519 ret = -ENOMEM;
1520 goto fail_put;
1521 }
1522
1523 txmsg->dst = mstb;
1524 len = build_allocate_payload(txmsg, port->port_num,
1525 id,
1526 pbn);
1527
1528 drm_dp_queue_down_tx(mgr, txmsg);
1529
1530 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1531 if (ret > 0) {
1532 if (txmsg->reply.reply_type == 1) {
1533 ret = -EINVAL;
1534 } else
1535 ret = 0;
1536 }
1537 kfree(txmsg);
1538 fail_put:
1539 drm_dp_put_mst_branch_device(mstb);
1540 return ret;
1541 }
1542
1543 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1544 int id,
1545 struct drm_dp_payload *payload)
1546 {
1547 int ret;
1548
1549 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1550 if (ret < 0) {
1551 payload->payload_state = 0;
1552 return ret;
1553 }
1554 payload->payload_state = DP_PAYLOAD_LOCAL;
1555 return 0;
1556 }
1557
1558 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1559 struct drm_dp_mst_port *port,
1560 int id,
1561 struct drm_dp_payload *payload)
1562 {
1563 int ret;
1564 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1565 if (ret < 0)
1566 return ret;
1567 payload->payload_state = DP_PAYLOAD_REMOTE;
1568 return ret;
1569 }
1570
1571 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1572 struct drm_dp_mst_port *port,
1573 int id,
1574 struct drm_dp_payload *payload)
1575 {
1576 DRM_DEBUG_KMS("\n");
1577 /* its okay for these to fail */
1578 if (port) {
1579 drm_dp_payload_send_msg(mgr, port, id, 0);
1580 }
1581
1582 drm_dp_dpcd_write_payload(mgr, id, payload);
1583 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1584 return 0;
1585 }
1586
1587 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1588 int id,
1589 struct drm_dp_payload *payload)
1590 {
1591 payload->payload_state = 0;
1592 return 0;
1593 }
1594
1595 /**
1596 * drm_dp_update_payload_part1() - Execute payload update part 1
1597 * @mgr: manager to use.
1598 *
1599 * This iterates over all proposed virtual channels, and tries to
1600 * allocate space in the link for them. For 0->slots transitions,
1601 * this step just writes the VCPI to the MST device. For slots->0
1602 * transitions, this writes the updated VCPIs and removes the
1603 * remote VC payloads.
1604 *
1605 * after calling this the driver should generate ACT and payload
1606 * packets.
1607 */
1608 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1609 {
1610 int i, j;
1611 int cur_slots = 1;
1612 struct drm_dp_payload req_payload;
1613 struct drm_dp_mst_port *port;
1614
1615 mutex_lock(&mgr->payload_lock);
1616 for (i = 0; i < mgr->max_payloads; i++) {
1617 /* solve the current payloads - compare to the hw ones
1618 - update the hw view */
1619 req_payload.start_slot = cur_slots;
1620 if (mgr->proposed_vcpis[i]) {
1621 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1622 req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1623 } else {
1624 port = NULL;
1625 req_payload.num_slots = 0;
1626 }
1627
1628 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1629 mgr->payloads[i].start_slot = req_payload.start_slot;
1630 }
1631 /* work out what is required to happen with this payload */
1632 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1633
1634 /* need to push an update for this payload */
1635 if (req_payload.num_slots) {
1636 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1637 mgr->payloads[i].num_slots = req_payload.num_slots;
1638 } else if (mgr->payloads[i].num_slots) {
1639 mgr->payloads[i].num_slots = 0;
1640 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
1641 req_payload.payload_state = mgr->payloads[i].payload_state;
1642 mgr->payloads[i].start_slot = 0;
1643 }
1644 mgr->payloads[i].payload_state = req_payload.payload_state;
1645 }
1646 cur_slots += req_payload.num_slots;
1647 }
1648
1649 for (i = 0; i < mgr->max_payloads; i++) {
1650 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1651 DRM_DEBUG_KMS("removing payload %d\n", i);
1652 for (j = i; j < mgr->max_payloads - 1; j++) {
1653 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1654 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1655 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1656 set_bit(j + 1, &mgr->payload_mask);
1657 } else {
1658 clear_bit(j + 1, &mgr->payload_mask);
1659 }
1660 }
1661 memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1662 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1663 clear_bit(mgr->max_payloads, &mgr->payload_mask);
1664
1665 }
1666 }
1667 mutex_unlock(&mgr->payload_lock);
1668
1669 return 0;
1670 }
1671 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1672
1673 /**
1674 * drm_dp_update_payload_part2() - Execute payload update part 2
1675 * @mgr: manager to use.
1676 *
1677 * This iterates over all proposed virtual channels, and tries to
1678 * allocate space in the link for them. For 0->slots transitions,
1679 * this step writes the remote VC payload commands. For slots->0
1680 * this just resets some internal state.
1681 */
1682 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1683 {
1684 struct drm_dp_mst_port *port;
1685 int i;
1686 int ret = 0;
1687 mutex_lock(&mgr->payload_lock);
1688 for (i = 0; i < mgr->max_payloads; i++) {
1689
1690 if (!mgr->proposed_vcpis[i])
1691 continue;
1692
1693 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1694
1695 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1696 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1697 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1698 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1699 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1700 }
1701 if (ret) {
1702 mutex_unlock(&mgr->payload_lock);
1703 return ret;
1704 }
1705 }
1706 mutex_unlock(&mgr->payload_lock);
1707 return 0;
1708 }
1709 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1710
1711 #if 0 /* unused as of yet */
1712 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1713 struct drm_dp_mst_port *port,
1714 int offset, int size)
1715 {
1716 int len;
1717 struct drm_dp_sideband_msg_tx *txmsg;
1718
1719 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1720 if (!txmsg)
1721 return -ENOMEM;
1722
1723 len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1724 txmsg->dst = port->parent;
1725
1726 drm_dp_queue_down_tx(mgr, txmsg);
1727
1728 return 0;
1729 }
1730 #endif
1731
1732 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1733 struct drm_dp_mst_port *port,
1734 int offset, int size, u8 *bytes)
1735 {
1736 int len;
1737 int ret;
1738 struct drm_dp_sideband_msg_tx *txmsg;
1739 struct drm_dp_mst_branch *mstb;
1740
1741 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1742 if (!mstb)
1743 return -EINVAL;
1744
1745 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1746 if (!txmsg) {
1747 ret = -ENOMEM;
1748 goto fail_put;
1749 }
1750
1751 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1752 txmsg->dst = mstb;
1753
1754 drm_dp_queue_down_tx(mgr, txmsg);
1755
1756 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1757 if (ret > 0) {
1758 if (txmsg->reply.reply_type == 1) {
1759 ret = -EINVAL;
1760 } else
1761 ret = 0;
1762 }
1763 kfree(txmsg);
1764 fail_put:
1765 drm_dp_put_mst_branch_device(mstb);
1766 return ret;
1767 }
1768
1769 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1770 {
1771 struct drm_dp_sideband_msg_reply_body reply;
1772
1773 reply.reply_type = 1;
1774 reply.req_type = req_type;
1775 drm_dp_encode_sideband_reply(&reply, msg);
1776 return 0;
1777 }
1778
1779 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1780 struct drm_dp_mst_branch *mstb,
1781 int req_type, int seqno, bool broadcast)
1782 {
1783 struct drm_dp_sideband_msg_tx *txmsg;
1784
1785 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1786 if (!txmsg)
1787 return -ENOMEM;
1788
1789 txmsg->dst = mstb;
1790 txmsg->seqno = seqno;
1791 drm_dp_encode_up_ack_reply(txmsg, req_type);
1792
1793 mutex_lock(&mgr->qlock);
1794 list_add_tail(&txmsg->next, &mgr->tx_msg_upq);
1795 if (!mgr->tx_up_in_progress) {
1796 process_single_up_tx_qlock(mgr);
1797 }
1798 mutex_unlock(&mgr->qlock);
1799 return 0;
1800 }
1801
1802 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1803 int dp_link_count,
1804 int *out)
1805 {
1806 switch (dp_link_bw) {
1807 default:
1808 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1809 dp_link_bw, dp_link_count);
1810 return false;
1811
1812 case DP_LINK_BW_1_62:
1813 *out = 3 * dp_link_count;
1814 break;
1815 case DP_LINK_BW_2_7:
1816 *out = 5 * dp_link_count;
1817 break;
1818 case DP_LINK_BW_5_4:
1819 *out = 10 * dp_link_count;
1820 break;
1821 }
1822 return true;
1823 }
1824
1825 /**
1826 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
1827 * @mgr: manager to set state for
1828 * @mst_state: true to enable MST on this connector - false to disable.
1829 *
1830 * This is called by the driver when it detects an MST capable device plugged
1831 * into a DP MST capable port, or when a DP MST capable device is unplugged.
1832 */
1833 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
1834 {
1835 int ret = 0;
1836 struct drm_dp_mst_branch *mstb = NULL;
1837
1838 mutex_lock(&mgr->lock);
1839 if (mst_state == mgr->mst_state)
1840 goto out_unlock;
1841
1842 mgr->mst_state = mst_state;
1843 /* set the device into MST mode */
1844 if (mst_state) {
1845 WARN_ON(mgr->mst_primary);
1846
1847 /* get dpcd info */
1848 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
1849 if (ret != DP_RECEIVER_CAP_SIZE) {
1850 DRM_DEBUG_KMS("failed to read DPCD\n");
1851 goto out_unlock;
1852 }
1853
1854 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
1855 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
1856 &mgr->pbn_div)) {
1857 ret = -EINVAL;
1858 goto out_unlock;
1859 }
1860
1861 mgr->total_pbn = 2560;
1862 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
1863 mgr->avail_slots = mgr->total_slots;
1864
1865 /* add initial branch device at LCT 1 */
1866 mstb = drm_dp_add_mst_branch_device(1, NULL);
1867 if (mstb == NULL) {
1868 ret = -ENOMEM;
1869 goto out_unlock;
1870 }
1871 mstb->mgr = mgr;
1872
1873 /* give this the main reference */
1874 mgr->mst_primary = mstb;
1875 kref_get(&mgr->mst_primary->kref);
1876
1877 {
1878 struct drm_dp_payload reset_pay;
1879 reset_pay.start_slot = 0;
1880 reset_pay.num_slots = 0x3f;
1881 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
1882 }
1883
1884 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1885 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
1886 if (ret < 0) {
1887 goto out_unlock;
1888 }
1889
1890
1891 /* sort out guid */
1892 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
1893 if (ret != 16) {
1894 DRM_DEBUG_KMS("failed to read DP GUID %d\n", ret);
1895 goto out_unlock;
1896 }
1897
1898 mgr->guid_valid = drm_dp_validate_guid(mgr, mgr->guid);
1899 if (!mgr->guid_valid) {
1900 ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, mgr->guid, 16);
1901 mgr->guid_valid = true;
1902 }
1903
1904 queue_work(system_long_wq, &mgr->work);
1905
1906 ret = 0;
1907 } else {
1908 /* disable MST on the device */
1909 mstb = mgr->mst_primary;
1910 mgr->mst_primary = NULL;
1911 /* this can fail if the device is gone */
1912 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
1913 ret = 0;
1914 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
1915 mgr->payload_mask = 0;
1916 set_bit(0, &mgr->payload_mask);
1917 mgr->vcpi_mask = 0;
1918 }
1919
1920 out_unlock:
1921 mutex_unlock(&mgr->lock);
1922 if (mstb)
1923 drm_dp_put_mst_branch_device(mstb);
1924 return ret;
1925
1926 }
1927 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
1928
1929 /**
1930 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
1931 * @mgr: manager to suspend
1932 *
1933 * This function tells the MST device that we can't handle UP messages
1934 * anymore. This should stop it from sending any since we are suspended.
1935 */
1936 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
1937 {
1938 mutex_lock(&mgr->lock);
1939 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1940 DP_MST_EN | DP_UPSTREAM_IS_SRC);
1941 mutex_unlock(&mgr->lock);
1942 }
1943 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
1944
1945 /**
1946 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
1947 * @mgr: manager to resume
1948 *
1949 * This will fetch DPCD and see if the device is still there,
1950 * if it is, it will rewrite the MSTM control bits, and return.
1951 *
1952 * if the device fails this returns -1, and the driver should do
1953 * a full MST reprobe, in case we were undocked.
1954 */
1955 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
1956 {
1957 int ret = 0;
1958
1959 mutex_lock(&mgr->lock);
1960
1961 if (mgr->mst_primary) {
1962 int sret;
1963 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
1964 if (sret != DP_RECEIVER_CAP_SIZE) {
1965 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
1966 ret = -1;
1967 goto out_unlock;
1968 }
1969
1970 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1971 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
1972 if (ret < 0) {
1973 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
1974 ret = -1;
1975 goto out_unlock;
1976 }
1977 ret = 0;
1978 } else
1979 ret = -1;
1980
1981 out_unlock:
1982 mutex_unlock(&mgr->lock);
1983 return ret;
1984 }
1985 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
1986
1987 static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
1988 {
1989 int len;
1990 u8 replyblock[32];
1991 int replylen, origlen, curreply;
1992 int ret;
1993 struct drm_dp_sideband_msg_rx *msg;
1994 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
1995 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
1996
1997 len = min(mgr->max_dpcd_transaction_bytes, 16);
1998 ret = drm_dp_dpcd_read(mgr->aux, basereg,
1999 replyblock, len);
2000 if (ret != len) {
2001 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2002 return;
2003 }
2004 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2005 if (!ret) {
2006 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2007 return;
2008 }
2009 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2010
2011 origlen = replylen;
2012 replylen -= len;
2013 curreply = len;
2014 while (replylen > 0) {
2015 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2016 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2017 replyblock, len);
2018 if (ret != len) {
2019 DRM_DEBUG_KMS("failed to read a chunk\n");
2020 }
2021 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2022 if (ret == false)
2023 DRM_DEBUG_KMS("failed to build sideband msg\n");
2024 curreply += len;
2025 replylen -= len;
2026 }
2027 }
2028
2029 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2030 {
2031 int ret = 0;
2032
2033 drm_dp_get_one_sb_msg(mgr, false);
2034
2035 if (mgr->down_rep_recv.have_eomt) {
2036 struct drm_dp_sideband_msg_tx *txmsg;
2037 struct drm_dp_mst_branch *mstb;
2038 int slot = -1;
2039 mstb = drm_dp_get_mst_branch_device(mgr,
2040 mgr->down_rep_recv.initial_hdr.lct,
2041 mgr->down_rep_recv.initial_hdr.rad);
2042
2043 if (!mstb) {
2044 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2045 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2046 return 0;
2047 }
2048
2049 /* find the message */
2050 slot = mgr->down_rep_recv.initial_hdr.seqno;
2051 mutex_lock(&mgr->qlock);
2052 txmsg = mstb->tx_slots[slot];
2053 /* remove from slots */
2054 mutex_unlock(&mgr->qlock);
2055
2056 if (!txmsg) {
2057 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2058 mstb,
2059 mgr->down_rep_recv.initial_hdr.seqno,
2060 mgr->down_rep_recv.initial_hdr.lct,
2061 mgr->down_rep_recv.initial_hdr.rad[0],
2062 mgr->down_rep_recv.msg[0]);
2063 drm_dp_put_mst_branch_device(mstb);
2064 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2065 return 0;
2066 }
2067
2068 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2069 if (txmsg->reply.reply_type == 1) {
2070 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);
2071 }
2072
2073 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2074 drm_dp_put_mst_branch_device(mstb);
2075
2076 mutex_lock(&mgr->qlock);
2077 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2078 mstb->tx_slots[slot] = NULL;
2079 mutex_unlock(&mgr->qlock);
2080
2081 wake_up(&mgr->tx_waitq);
2082 }
2083 return ret;
2084 }
2085
2086 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2087 {
2088 int ret = 0;
2089 drm_dp_get_one_sb_msg(mgr, true);
2090
2091 if (mgr->up_req_recv.have_eomt) {
2092 struct drm_dp_sideband_msg_req_body msg;
2093 struct drm_dp_mst_branch *mstb;
2094 bool seqno;
2095 mstb = drm_dp_get_mst_branch_device(mgr,
2096 mgr->up_req_recv.initial_hdr.lct,
2097 mgr->up_req_recv.initial_hdr.rad);
2098 if (!mstb) {
2099 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2100 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2101 return 0;
2102 }
2103
2104 seqno = mgr->up_req_recv.initial_hdr.seqno;
2105 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2106
2107 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2108 drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
2109 drm_dp_update_port(mstb, &msg.u.conn_stat);
2110 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);
2111 (*mgr->cbs->hotplug)(mgr);
2112
2113 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2114 drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
2115 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2116 }
2117
2118 drm_dp_put_mst_branch_device(mstb);
2119 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2120 }
2121 return ret;
2122 }
2123
2124 /**
2125 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2126 * @mgr: manager to notify irq for.
2127 * @esi: 4 bytes from SINK_COUNT_ESI
2128 * @handled: whether the hpd interrupt was consumed or not
2129 *
2130 * This should be called from the driver when it detects a short IRQ,
2131 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2132 * topology manager will process the sideband messages received as a result
2133 * of this.
2134 */
2135 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2136 {
2137 int ret = 0;
2138 int sc;
2139 *handled = false;
2140 sc = esi[0] & 0x3f;
2141
2142 if (sc != mgr->sink_count) {
2143 mgr->sink_count = sc;
2144 *handled = true;
2145 }
2146
2147 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2148 ret = drm_dp_mst_handle_down_rep(mgr);
2149 *handled = true;
2150 }
2151
2152 if (esi[1] & DP_UP_REQ_MSG_RDY) {
2153 ret |= drm_dp_mst_handle_up_req(mgr);
2154 *handled = true;
2155 }
2156
2157 drm_dp_mst_kick_tx(mgr);
2158 return ret;
2159 }
2160 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2161
2162 /**
2163 * drm_dp_mst_detect_port() - get connection status for an MST port
2164 * @mgr: manager for this port
2165 * @port: unverified pointer to a port
2166 *
2167 * This returns the current connection state for a port. It validates the
2168 * port pointer still exists so the caller doesn't require a reference
2169 */
2170 enum drm_connector_status drm_dp_mst_detect_port(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2171 {
2172 enum drm_connector_status status = connector_status_disconnected;
2173
2174 /* we need to search for the port in the mgr in case its gone */
2175 port = drm_dp_get_validated_port_ref(mgr, port);
2176 if (!port)
2177 return connector_status_disconnected;
2178
2179 if (!port->ddps)
2180 goto out;
2181
2182 switch (port->pdt) {
2183 case DP_PEER_DEVICE_NONE:
2184 case DP_PEER_DEVICE_MST_BRANCHING:
2185 break;
2186
2187 case DP_PEER_DEVICE_SST_SINK:
2188 status = connector_status_connected;
2189 break;
2190 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2191 if (port->ldps)
2192 status = connector_status_connected;
2193 break;
2194 }
2195 out:
2196 drm_dp_put_port(port);
2197 return status;
2198 }
2199 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2200
2201 /**
2202 * drm_dp_mst_get_edid() - get EDID for an MST port
2203 * @connector: toplevel connector to get EDID for
2204 * @mgr: manager for this port
2205 * @port: unverified pointer to a port.
2206 *
2207 * This returns an EDID for the port connected to a connector,
2208 * It validates the pointer still exists so the caller doesn't require a
2209 * reference.
2210 */
2211 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2212 {
2213 struct edid *edid = NULL;
2214
2215 /* we need to search for the port in the mgr in case its gone */
2216 port = drm_dp_get_validated_port_ref(mgr, port);
2217 if (!port)
2218 return NULL;
2219
2220 edid = drm_get_edid(connector, &port->aux.ddc);
2221 drm_dp_put_port(port);
2222 return edid;
2223 }
2224 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2225
2226 /**
2227 * drm_dp_find_vcpi_slots() - find slots for this PBN value
2228 * @mgr: manager to use
2229 * @pbn: payload bandwidth to convert into slots.
2230 */
2231 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2232 int pbn)
2233 {
2234 int num_slots;
2235
2236 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2237
2238 if (num_slots > mgr->avail_slots)
2239 return -ENOSPC;
2240 return num_slots;
2241 }
2242 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2243
2244 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2245 struct drm_dp_vcpi *vcpi, int pbn)
2246 {
2247 int num_slots;
2248 int ret;
2249
2250 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2251
2252 if (num_slots > mgr->avail_slots)
2253 return -ENOSPC;
2254
2255 vcpi->pbn = pbn;
2256 vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2257 vcpi->num_slots = num_slots;
2258
2259 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2260 if (ret < 0)
2261 return ret;
2262 return 0;
2263 }
2264
2265 /**
2266 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2267 * @mgr: manager for this port
2268 * @port: port to allocate a virtual channel for.
2269 * @pbn: payload bandwidth number to request
2270 * @slots: returned number of slots for this PBN.
2271 */
2272 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2273 {
2274 int ret;
2275
2276 port = drm_dp_get_validated_port_ref(mgr, port);
2277 if (!port)
2278 return false;
2279
2280 if (port->vcpi.vcpi > 0) {
2281 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2282 if (pbn == port->vcpi.pbn) {
2283 *slots = port->vcpi.num_slots;
2284 return true;
2285 }
2286 }
2287
2288 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2289 if (ret) {
2290 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2291 goto out;
2292 }
2293 DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2294 *slots = port->vcpi.num_slots;
2295
2296 drm_dp_put_port(port);
2297 return true;
2298 out:
2299 return false;
2300 }
2301 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2302
2303 /**
2304 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2305 * @mgr: manager for this port
2306 * @port: unverified pointer to a port.
2307 *
2308 * This just resets the number of slots for the ports VCPI for later programming.
2309 */
2310 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2311 {
2312 port = drm_dp_get_validated_port_ref(mgr, port);
2313 if (!port)
2314 return;
2315 port->vcpi.num_slots = 0;
2316 drm_dp_put_port(port);
2317 }
2318 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2319
2320 /**
2321 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2322 * @mgr: manager for this port
2323 * @port: unverified port to deallocate vcpi for
2324 */
2325 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2326 {
2327 port = drm_dp_get_validated_port_ref(mgr, port);
2328 if (!port)
2329 return;
2330
2331 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2332 port->vcpi.num_slots = 0;
2333 port->vcpi.pbn = 0;
2334 port->vcpi.aligned_pbn = 0;
2335 port->vcpi.vcpi = 0;
2336 drm_dp_put_port(port);
2337 }
2338 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2339
2340 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2341 int id, struct drm_dp_payload *payload)
2342 {
2343 u8 payload_alloc[3], status;
2344 int ret;
2345 int retries = 0;
2346
2347 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2348 DP_PAYLOAD_TABLE_UPDATED);
2349
2350 payload_alloc[0] = id;
2351 payload_alloc[1] = payload->start_slot;
2352 payload_alloc[2] = payload->num_slots;
2353
2354 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2355 if (ret != 3) {
2356 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2357 goto fail;
2358 }
2359
2360 retry:
2361 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2362 if (ret < 0) {
2363 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2364 goto fail;
2365 }
2366
2367 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2368 retries++;
2369 if (retries < 20) {
2370 usleep_range(10000, 20000);
2371 goto retry;
2372 }
2373 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2374 ret = -EINVAL;
2375 goto fail;
2376 }
2377 ret = 0;
2378 fail:
2379 return ret;
2380 }
2381
2382
2383 /**
2384 * drm_dp_check_act_status() - Check ACT handled status.
2385 * @mgr: manager to use
2386 *
2387 * Check the payload status bits in the DPCD for ACT handled completion.
2388 */
2389 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2390 {
2391 u8 status;
2392 int ret;
2393 int count = 0;
2394
2395 do {
2396 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2397
2398 if (ret < 0) {
2399 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2400 goto fail;
2401 }
2402
2403 if (status & DP_PAYLOAD_ACT_HANDLED)
2404 break;
2405 count++;
2406 udelay(100);
2407
2408 } while (count < 30);
2409
2410 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2411 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2412 ret = -EINVAL;
2413 goto fail;
2414 }
2415 return 0;
2416 fail:
2417 return ret;
2418 }
2419 EXPORT_SYMBOL(drm_dp_check_act_status);
2420
2421 /**
2422 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2423 * @clock: dot clock for the mode
2424 * @bpp: bpp for the mode.
2425 *
2426 * This uses the formula in the spec to calculate the PBN value for a mode.
2427 */
2428 int drm_dp_calc_pbn_mode(int clock, int bpp)
2429 {
2430 fixed20_12 pix_bw;
2431 fixed20_12 fbpp;
2432 fixed20_12 result;
2433 fixed20_12 margin, tmp;
2434 u32 res;
2435
2436 pix_bw.full = dfixed_const(clock);
2437 fbpp.full = dfixed_const(bpp);
2438 tmp.full = dfixed_const(8);
2439 fbpp.full = dfixed_div(fbpp, tmp);
2440
2441 result.full = dfixed_mul(pix_bw, fbpp);
2442 margin.full = dfixed_const(54);
2443 tmp.full = dfixed_const(64);
2444 margin.full = dfixed_div(margin, tmp);
2445 result.full = dfixed_div(result, margin);
2446
2447 margin.full = dfixed_const(1006);
2448 tmp.full = dfixed_const(1000);
2449 margin.full = dfixed_div(margin, tmp);
2450 result.full = dfixed_mul(result, margin);
2451
2452 result.full = dfixed_div(result, tmp);
2453 result.full = dfixed_ceil(result);
2454 res = dfixed_trunc(result);
2455 return res;
2456 }
2457 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2458
2459 static int test_calc_pbn_mode(void)
2460 {
2461 int ret;
2462 ret = drm_dp_calc_pbn_mode(154000, 30);
2463 if (ret != 689)
2464 return -EINVAL;
2465 ret = drm_dp_calc_pbn_mode(234000, 30);
2466 if (ret != 1047)
2467 return -EINVAL;
2468 return 0;
2469 }
2470
2471 /* we want to kick the TX after we've ack the up/down IRQs. */
2472 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2473 {
2474 queue_work(system_long_wq, &mgr->tx_work);
2475 }
2476
2477 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2478 struct drm_dp_mst_branch *mstb)
2479 {
2480 struct drm_dp_mst_port *port;
2481 int tabs = mstb->lct;
2482 char prefix[10];
2483 int i;
2484
2485 for (i = 0; i < tabs; i++)
2486 prefix[i] = '\t';
2487 prefix[i] = '\0';
2488
2489 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2490 list_for_each_entry(port, &mstb->ports, next) {
2491 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port, port->connector);
2492 if (port->mstb)
2493 drm_dp_mst_dump_mstb(m, port->mstb);
2494 }
2495 }
2496
2497 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2498 char *buf)
2499 {
2500 int ret;
2501 int i;
2502 for (i = 0; i < 4; i++) {
2503 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2504 if (ret != 16)
2505 break;
2506 }
2507 if (i == 4)
2508 return true;
2509 return false;
2510 }
2511
2512 /**
2513 * drm_dp_mst_dump_topology(): dump topology to seq file.
2514 * @m: seq_file to dump output to
2515 * @mgr: manager to dump current topology for.
2516 *
2517 * helper to dump MST topology to a seq file for debugfs.
2518 */
2519 void drm_dp_mst_dump_topology(struct seq_file *m,
2520 struct drm_dp_mst_topology_mgr *mgr)
2521 {
2522 int i;
2523 struct drm_dp_mst_port *port;
2524 mutex_lock(&mgr->lock);
2525 if (mgr->mst_primary)
2526 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2527
2528 /* dump VCPIs */
2529 mutex_unlock(&mgr->lock);
2530
2531 mutex_lock(&mgr->payload_lock);
2532 seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
2533
2534 for (i = 0; i < mgr->max_payloads; i++) {
2535 if (mgr->proposed_vcpis[i]) {
2536 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2537 seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2538 } else
2539 seq_printf(m, "vcpi %d:unsed\n", i);
2540 }
2541 for (i = 0; i < mgr->max_payloads; i++) {
2542 seq_printf(m, "payload %d: %d, %d, %d\n",
2543 i,
2544 mgr->payloads[i].payload_state,
2545 mgr->payloads[i].start_slot,
2546 mgr->payloads[i].num_slots);
2547
2548
2549 }
2550 mutex_unlock(&mgr->payload_lock);
2551
2552 mutex_lock(&mgr->lock);
2553 if (mgr->mst_primary) {
2554 u8 buf[64];
2555 bool bret;
2556 int ret;
2557 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2558 seq_printf(m, "dpcd: ");
2559 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2560 seq_printf(m, "%02x ", buf[i]);
2561 seq_printf(m, "\n");
2562 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2563 seq_printf(m, "faux/mst: ");
2564 for (i = 0; i < 2; i++)
2565 seq_printf(m, "%02x ", buf[i]);
2566 seq_printf(m, "\n");
2567 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2568 seq_printf(m, "mst ctrl: ");
2569 for (i = 0; i < 1; i++)
2570 seq_printf(m, "%02x ", buf[i]);
2571 seq_printf(m, "\n");
2572
2573 bret = dump_dp_payload_table(mgr, buf);
2574 if (bret == true) {
2575 seq_printf(m, "payload table: ");
2576 for (i = 0; i < 63; i++)
2577 seq_printf(m, "%02x ", buf[i]);
2578 seq_printf(m, "\n");
2579 }
2580
2581 }
2582
2583 mutex_unlock(&mgr->lock);
2584
2585 }
2586 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2587
2588 static void drm_dp_tx_work(struct work_struct *work)
2589 {
2590 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2591
2592 mutex_lock(&mgr->qlock);
2593 if (mgr->tx_down_in_progress)
2594 process_single_down_tx_qlock(mgr);
2595 mutex_unlock(&mgr->qlock);
2596 }
2597
2598 /**
2599 * drm_dp_mst_topology_mgr_init - initialise a topology manager
2600 * @mgr: manager struct to initialise
2601 * @dev: device providing this structure - for i2c addition.
2602 * @aux: DP helper aux channel to talk to this device
2603 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2604 * @max_payloads: maximum number of payloads this GPU can source
2605 * @conn_base_id: the connector object ID the MST device is connected to.
2606 *
2607 * Return 0 for success, or negative error code on failure
2608 */
2609 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2610 struct device *dev, struct drm_dp_aux *aux,
2611 int max_dpcd_transaction_bytes,
2612 int max_payloads, int conn_base_id)
2613 {
2614 mutex_init(&mgr->lock);
2615 mutex_init(&mgr->qlock);
2616 mutex_init(&mgr->payload_lock);
2617 INIT_LIST_HEAD(&mgr->tx_msg_upq);
2618 INIT_LIST_HEAD(&mgr->tx_msg_downq);
2619 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2620 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2621 init_waitqueue_head(&mgr->tx_waitq);
2622 mgr->dev = dev;
2623 mgr->aux = aux;
2624 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2625 mgr->max_payloads = max_payloads;
2626 mgr->conn_base_id = conn_base_id;
2627 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2628 if (!mgr->payloads)
2629 return -ENOMEM;
2630 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2631 if (!mgr->proposed_vcpis)
2632 return -ENOMEM;
2633 set_bit(0, &mgr->payload_mask);
2634 test_calc_pbn_mode();
2635 return 0;
2636 }
2637 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2638
2639 /**
2640 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2641 * @mgr: manager to destroy
2642 */
2643 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2644 {
2645 mutex_lock(&mgr->payload_lock);
2646 kfree(mgr->payloads);
2647 mgr->payloads = NULL;
2648 kfree(mgr->proposed_vcpis);
2649 mgr->proposed_vcpis = NULL;
2650 mutex_unlock(&mgr->payload_lock);
2651 mgr->dev = NULL;
2652 mgr->aux = NULL;
2653 }
2654 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
2655
2656 /* I2C device */
2657 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
2658 int num)
2659 {
2660 struct drm_dp_aux *aux = adapter->algo_data;
2661 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
2662 struct drm_dp_mst_branch *mstb;
2663 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2664 unsigned int i;
2665 bool reading = false;
2666 struct drm_dp_sideband_msg_req_body msg;
2667 struct drm_dp_sideband_msg_tx *txmsg = NULL;
2668 int ret;
2669
2670 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2671 if (!mstb)
2672 return -EREMOTEIO;
2673
2674 /* construct i2c msg */
2675 /* see if last msg is a read */
2676 if (msgs[num - 1].flags & I2C_M_RD)
2677 reading = true;
2678
2679 if (!reading) {
2680 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
2681 ret = -EIO;
2682 goto out;
2683 }
2684
2685 msg.req_type = DP_REMOTE_I2C_READ;
2686 msg.u.i2c_read.num_transactions = num - 1;
2687 msg.u.i2c_read.port_number = port->port_num;
2688 for (i = 0; i < num - 1; i++) {
2689 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
2690 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
2691 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
2692 }
2693 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
2694 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
2695
2696 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2697 if (!txmsg) {
2698 ret = -ENOMEM;
2699 goto out;
2700 }
2701
2702 txmsg->dst = mstb;
2703 drm_dp_encode_sideband_req(&msg, txmsg);
2704
2705 drm_dp_queue_down_tx(mgr, txmsg);
2706
2707 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2708 if (ret > 0) {
2709
2710 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
2711 ret = -EREMOTEIO;
2712 goto out;
2713 }
2714 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
2715 ret = -EIO;
2716 goto out;
2717 }
2718 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
2719 ret = num;
2720 }
2721 out:
2722 kfree(txmsg);
2723 drm_dp_put_mst_branch_device(mstb);
2724 return ret;
2725 }
2726
2727 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
2728 {
2729 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
2730 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
2731 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
2732 I2C_FUNC_10BIT_ADDR;
2733 }
2734
2735 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
2736 .functionality = drm_dp_mst_i2c_functionality,
2737 .master_xfer = drm_dp_mst_i2c_xfer,
2738 };
2739
2740 /**
2741 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
2742 * @aux: DisplayPort AUX channel
2743 *
2744 * Returns 0 on success or a negative error code on failure.
2745 */
2746 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
2747 {
2748 aux->ddc.algo = &drm_dp_mst_i2c_algo;
2749 aux->ddc.algo_data = aux;
2750 aux->ddc.retries = 3;
2751
2752 aux->ddc.class = I2C_CLASS_DDC;
2753 aux->ddc.owner = THIS_MODULE;
2754 aux->ddc.dev.parent = aux->dev;
2755 aux->ddc.dev.of_node = aux->dev->of_node;
2756
2757 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
2758 sizeof(aux->ddc.name));
2759
2760 return i2c_add_adapter(&aux->ddc);
2761 }
2762
2763 /**
2764 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
2765 * @aux: DisplayPort AUX channel
2766 */
2767 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
2768 {
2769 i2c_del_adapter(&aux->ddc);
2770 }
Linux kernel - Deliverables
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