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drm/dp/mst: make sure mst_primary mstb is valid in work function
[linux-2.6-block.git] / drivers / gpu / drm / drm_dp_mst_topology.c
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ad7f8a1f
DA		 1/*
2 * Copyright © 2014 Red Hat
3 *
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission. The copyright holders make no representations
11 * about the suitability of this software for any purpose. It is provided "as
12 * is" without express or implied warranty.
13 *
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20 * OF THIS SOFTWARE.
21 */
22
23#include <linux/kernel.h>
24#include <linux/delay.h>
25#include <linux/init.h>
26#include <linux/errno.h>
27#include <linux/sched.h>
75bc08ab 28#include <linux/seq_file.h>
ad7f8a1f
DA		 29#include <linux/i2c.h>
30#include <drm/drm_dp_mst_helper.h>
31#include <drm/drmP.h>
32
33#include <drm/drm_fixed.h>
34
35/**
36 * DOC: dp mst helper
37 *
38 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
39 * protocol. The helpers contain a topology manager and bandwidth manager.
40 * The helpers encapsulate the sending and received of sideband msgs.
41 */
42static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
43 char *buf);
44static int test_calc_pbn_mode(void);
45
46static void drm_dp_put_port(struct drm_dp_mst_port *port);
47
48static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
49 int id,
50 struct drm_dp_payload *payload);
51
52static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
53 struct drm_dp_mst_port *port,
54 int offset, int size, u8 *bytes);
55
56static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
57 struct drm_dp_mst_branch *mstb);
58static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
59 struct drm_dp_mst_branch *mstb,
60 struct drm_dp_mst_port *port);
61static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
62 u8 *guid);
63
64static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
65static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
66static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
67/* sideband msg handling */
68static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
69{
70 u8 bitmask = 0x80;
71 u8 bitshift = 7;
72 u8 array_index = 0;
73 int number_of_bits = num_nibbles * 4;
74 u8 remainder = 0;
75
76 while (number_of_bits != 0) {
77 number_of_bits--;
78 remainder <<= 1;
79 remainder |= (data[array_index] & bitmask) >> bitshift;
80 bitmask >>= 1;
81 bitshift--;
82 if (bitmask == 0) {
83 bitmask = 0x80;
84 bitshift = 7;
85 array_index++;
86 }
87 if ((remainder & 0x10) == 0x10)
88 remainder ^= 0x13;
89 }
90
91 number_of_bits = 4;
92 while (number_of_bits != 0) {
93 number_of_bits--;
94 remainder <<= 1;
95 if ((remainder & 0x10) != 0)
96 remainder ^= 0x13;
97 }
98
99 return remainder;
100}
101
102static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
103{
104 u8 bitmask = 0x80;
105 u8 bitshift = 7;
106 u8 array_index = 0;
107 int number_of_bits = number_of_bytes * 8;
108 u16 remainder = 0;
109
110 while (number_of_bits != 0) {
111 number_of_bits--;
112 remainder <<= 1;
113 remainder |= (data[array_index] & bitmask) >> bitshift;
114 bitmask >>= 1;
115 bitshift--;
116 if (bitmask == 0) {
117 bitmask = 0x80;
118 bitshift = 7;
119 array_index++;
120 }
121 if ((remainder & 0x100) == 0x100)
122 remainder ^= 0xd5;
123 }
124
125 number_of_bits = 8;
126 while (number_of_bits != 0) {
127 number_of_bits--;
128 remainder <<= 1;
129 if ((remainder & 0x100) != 0)
130 remainder ^= 0xd5;
131 }
132
133 return remainder & 0xff;
134}
135static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
136{
137 u8 size = 3;
138 size += (hdr->lct / 2);
139 return size;
140}
141
142static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
143 u8 *buf, int *len)
144{
145 int idx = 0;
146 int i;
147 u8 crc4;
148 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
149 for (i = 0; i < (hdr->lct / 2); i++)
150 buf[idx++] = hdr->rad[i];
151 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
152 (hdr->msg_len & 0x3f);
153 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
154
155 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
156 buf[idx - 1] |= (crc4 & 0xf);
157
158 *len = idx;
159}
160
161static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
162 u8 *buf, int buflen, u8 *hdrlen)
163{
164 u8 crc4;
165 u8 len;
166 int i;
167 u8 idx;
168 if (buf[0] == 0)
169 return false;
170 len = 3;
171 len += ((buf[0] & 0xf0) >> 4) / 2;
172 if (len > buflen)
173 return false;
174 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
175
176 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
177 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
178 return false;
179 }
180
181 hdr->lct = (buf[0] & 0xf0) >> 4;
182 hdr->lcr = (buf[0] & 0xf);
183 idx = 1;
184 for (i = 0; i < (hdr->lct / 2); i++)
185 hdr->rad[i] = buf[idx++];
186 hdr->broadcast = (buf[idx] >> 7) & 0x1;
187 hdr->path_msg = (buf[idx] >> 6) & 0x1;
188 hdr->msg_len = buf[idx] & 0x3f;
189 idx++;
190 hdr->somt = (buf[idx] >> 7) & 0x1;
191 hdr->eomt = (buf[idx] >> 6) & 0x1;
192 hdr->seqno = (buf[idx] >> 4) & 0x1;
193 idx++;
194 *hdrlen = idx;
195 return true;
196}
197
198static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req,
199 struct drm_dp_sideband_msg_tx *raw)
200{
201 int idx = 0;
202 int i;
203 u8 *buf = raw->msg;
204 buf[idx++] = req->req_type & 0x7f;
205
206 switch (req->req_type) {
207 case DP_ENUM_PATH_RESOURCES:
208 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
209 idx++;
210 break;
211 case DP_ALLOCATE_PAYLOAD:
212 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
213 (req->u.allocate_payload.number_sdp_streams & 0xf);
214 idx++;
215 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
216 idx++;
217 buf[idx] = (req->u.allocate_payload.pbn >> 8);
218 idx++;
219 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
220 idx++;
221 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
222 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
223 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
224 idx++;
225 }
226 if (req->u.allocate_payload.number_sdp_streams & 1) {
227 i = req->u.allocate_payload.number_sdp_streams - 1;
228 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
229 idx++;
230 }
231 break;
232 case DP_QUERY_PAYLOAD:
233 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
234 idx++;
235 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
236 idx++;
237 break;
238 case DP_REMOTE_DPCD_READ:
239 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
240 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
241 idx++;
242 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
243 idx++;
244 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
245 idx++;
246 buf[idx] = (req->u.dpcd_read.num_bytes);
247 idx++;
248 break;
249
250 case DP_REMOTE_DPCD_WRITE:
251 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
252 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
253 idx++;
254 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
255 idx++;
256 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
257 idx++;
258 buf[idx] = (req->u.dpcd_write.num_bytes);
259 idx++;
260 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
261 idx += req->u.dpcd_write.num_bytes;
262 break;
263 case DP_REMOTE_I2C_READ:
264 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
265 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
266 idx++;
267 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
268 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
269 idx++;
270 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
271 idx++;
272 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
273 idx += req->u.i2c_read.transactions[i].num_bytes;
274
275 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
276 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
277 idx++;
278 }
279 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
280 idx++;
281 buf[idx] = (req->u.i2c_read.num_bytes_read);
282 idx++;
283 break;
284
285 case DP_REMOTE_I2C_WRITE:
286 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
287 idx++;
288 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
289 idx++;
290 buf[idx] = (req->u.i2c_write.num_bytes);
291 idx++;
292 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
293 idx += req->u.i2c_write.num_bytes;
294 break;
295 }
296 raw->cur_len = idx;
297}
298
299static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
300{
301 u8 crc4;
302 crc4 = drm_dp_msg_data_crc4(msg, len);
303 msg[len] = crc4;
304}
305
306static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
307 struct drm_dp_sideband_msg_tx *raw)
308{
309 int idx = 0;
310 u8 *buf = raw->msg;
311
312 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
313
314 raw->cur_len = idx;
315}
316
317/* this adds a chunk of msg to the builder to get the final msg */
318static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
319 u8 *replybuf, u8 replybuflen, bool hdr)
320{
321 int ret;
322 u8 crc4;
323
324 if (hdr) {
325 u8 hdrlen;
326 struct drm_dp_sideband_msg_hdr recv_hdr;
327 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
328 if (ret == false) {
329 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
330 return false;
331 }
332
333 /* get length contained in this portion */
334 msg->curchunk_len = recv_hdr.msg_len;
335 msg->curchunk_hdrlen = hdrlen;
336
337 /* we have already gotten an somt - don't bother parsing */
338 if (recv_hdr.somt && msg->have_somt)
339 return false;
340
341 if (recv_hdr.somt) {
342 memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
343 msg->have_somt = true;
344 }
345 if (recv_hdr.eomt)
346 msg->have_eomt = true;
347
348 /* copy the bytes for the remainder of this header chunk */
349 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
350 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
351 } else {
352 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
353 msg->curchunk_idx += replybuflen;
354 }
355
356 if (msg->curchunk_idx >= msg->curchunk_len) {
357 /* do CRC */
358 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
359 /* copy chunk into bigger msg */
360 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
361 msg->curlen += msg->curchunk_len - 1;
362 }
363 return true;
364}
365
366static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
367 struct drm_dp_sideband_msg_reply_body *repmsg)
368{
369 int idx = 1;
370 int i;
371 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
372 idx += 16;
373 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
374 idx++;
375 if (idx > raw->curlen)
376 goto fail_len;
377 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
378 if (raw->msg[idx] & 0x80)
379 repmsg->u.link_addr.ports[i].input_port = 1;
380
381 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
382 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
383
384 idx++;
385 if (idx > raw->curlen)
386 goto fail_len;
387 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
388 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
389 if (repmsg->u.link_addr.ports[i].input_port == 0)
390 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
391 idx++;
392 if (idx > raw->curlen)
393 goto fail_len;
394 if (repmsg->u.link_addr.ports[i].input_port == 0) {
395 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
396 idx++;
397 if (idx > raw->curlen)
398 goto fail_len;
399 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
400 idx += 16;
401 if (idx > raw->curlen)
402 goto fail_len;
403 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
404 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
405 idx++;
406
407 }
408 if (idx > raw->curlen)
409 goto fail_len;
410 }
411
412 return true;
413fail_len:
414 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
415 return false;
416}
417
418static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
419 struct drm_dp_sideband_msg_reply_body *repmsg)
420{
421 int idx = 1;
422 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
423 idx++;
424 if (idx > raw->curlen)
425 goto fail_len;
426 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
427 if (idx > raw->curlen)
428 goto fail_len;
429
430 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
431 return true;
432fail_len:
433 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
434 return false;
435}
436
437static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
438 struct drm_dp_sideband_msg_reply_body *repmsg)
439{
440 int idx = 1;
441 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
442 idx++;
443 if (idx > raw->curlen)
444 goto fail_len;
445 return true;
446fail_len:
447 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
448 return false;
449}
450
451static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
452 struct drm_dp_sideband_msg_reply_body *repmsg)
453{
454 int idx = 1;
455
456 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
457 idx++;
458 if (idx > raw->curlen)
459 goto fail_len;
460 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
461 idx++;
462 /* TODO check */
463 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
464 return true;
465fail_len:
466 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
467 return false;
468}
469
470static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
471 struct drm_dp_sideband_msg_reply_body *repmsg)
472{
473 int idx = 1;
474 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
475 idx++;
476 if (idx > raw->curlen)
477 goto fail_len;
478 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
479 idx += 2;
480 if (idx > raw->curlen)
481 goto fail_len;
482 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
483 idx += 2;
484 if (idx > raw->curlen)
485 goto fail_len;
486 return true;
487fail_len:
488 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
489 return false;
490}
491
492static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
493 struct drm_dp_sideband_msg_reply_body *repmsg)
494{
495 int idx = 1;
496 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
497 idx++;
498 if (idx > raw->curlen)
499 goto fail_len;
500 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
501 idx++;
502 if (idx > raw->curlen)
503 goto fail_len;
504 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
505 idx += 2;
506 if (idx > raw->curlen)
507 goto fail_len;
508 return true;
509fail_len:
510 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
511 return false;
512}
513
514static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
515 struct drm_dp_sideband_msg_reply_body *repmsg)
516{
517 int idx = 1;
518 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
519 idx++;
520 if (idx > raw->curlen)
521 goto fail_len;
522 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
523 idx += 2;
524 if (idx > raw->curlen)
525 goto fail_len;
526 return true;
527fail_len:
528 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
529 return false;
530}
531
532static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
533 struct drm_dp_sideband_msg_reply_body *msg)
534{
535 memset(msg, 0, sizeof(*msg));
536 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
537 msg->req_type = (raw->msg[0] & 0x7f);
538
539 if (msg->reply_type) {
540 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
541 msg->u.nak.reason = raw->msg[17];
542 msg->u.nak.nak_data = raw->msg[18];
543 return false;
544 }
545
546 switch (msg->req_type) {
547 case DP_LINK_ADDRESS:
548 return drm_dp_sideband_parse_link_address(raw, msg);
549 case DP_QUERY_PAYLOAD:
550 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
551 case DP_REMOTE_DPCD_READ:
552 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
553 case DP_REMOTE_DPCD_WRITE:
554 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
555 case DP_REMOTE_I2C_READ:
556 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
557 case DP_ENUM_PATH_RESOURCES:
558 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
559 case DP_ALLOCATE_PAYLOAD:
560 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
561 default:
562 DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
563 return false;
564 }
565}
566
567static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
568 struct drm_dp_sideband_msg_req_body *msg)
569{
570 int idx = 1;
571
572 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
573 idx++;
574 if (idx > raw->curlen)
575 goto fail_len;
576
577 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
578 idx += 16;
579 if (idx > raw->curlen)
580 goto fail_len;
581
582 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
583 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
584 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
585 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
586 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
587 idx++;
588 return true;
589fail_len:
590 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
591 return false;
592}
593
594static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
595 struct drm_dp_sideband_msg_req_body *msg)
596{
597 int idx = 1;
598
599 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
600 idx++;
601 if (idx > raw->curlen)
602 goto fail_len;
603
604 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
605 idx += 16;
606 if (idx > raw->curlen)
607 goto fail_len;
608
609 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
610 idx++;
611 return true;
612fail_len:
613 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
614 return false;
615}
616
617static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
618 struct drm_dp_sideband_msg_req_body *msg)
619{
620 memset(msg, 0, sizeof(*msg));
621 msg->req_type = (raw->msg[0] & 0x7f);
622
623 switch (msg->req_type) {
624 case DP_CONNECTION_STATUS_NOTIFY:
625 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
626 case DP_RESOURCE_STATUS_NOTIFY:
627 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
628 default:
629 DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
630 return false;
631 }
632}
633
634static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
635{
636 struct drm_dp_sideband_msg_req_body req;
637
638 req.req_type = DP_REMOTE_DPCD_WRITE;
639 req.u.dpcd_write.port_number = port_num;
640 req.u.dpcd_write.dpcd_address = offset;
641 req.u.dpcd_write.num_bytes = num_bytes;
642 req.u.dpcd_write.bytes = bytes;
643 drm_dp_encode_sideband_req(&req, msg);
644
645 return 0;
646}
647
648static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
649{
650 struct drm_dp_sideband_msg_req_body req;
651
652 req.req_type = DP_LINK_ADDRESS;
653 drm_dp_encode_sideband_req(&req, msg);
654 return 0;
655}
656
657static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
658{
659 struct drm_dp_sideband_msg_req_body req;
660
661 req.req_type = DP_ENUM_PATH_RESOURCES;
662 req.u.port_num.port_number = port_num;
663 drm_dp_encode_sideband_req(&req, msg);
664 msg->path_msg = true;
665 return 0;
666}
667
668static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
669 u8 vcpi, uint16_t pbn)
670{
671 struct drm_dp_sideband_msg_req_body req;
672 memset(&req, 0, sizeof(req));
673 req.req_type = DP_ALLOCATE_PAYLOAD;
674 req.u.allocate_payload.port_number = port_num;
675 req.u.allocate_payload.vcpi = vcpi;
676 req.u.allocate_payload.pbn = pbn;
677 drm_dp_encode_sideband_req(&req, msg);
678 msg->path_msg = true;
679 return 0;
680}
681
682static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
683 struct drm_dp_vcpi *vcpi)
684{
dfda0df3 685 int ret, vcpi_ret;
ad7f8a1f
DA		 686
687 mutex_lock(&mgr->payload_lock);
688 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
689 if (ret > mgr->max_payloads) {
690 ret = -EINVAL;
691 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
692 goto out_unlock;
693 }
694
dfda0df3
DA		 695 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
696 if (vcpi_ret > mgr->max_payloads) {
697 ret = -EINVAL;
698 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
699 goto out_unlock;
700 }
701
ad7f8a1f 702 set_bit(ret, &mgr->payload_mask);
dfda0df3
DA		 703 set_bit(vcpi_ret, &mgr->vcpi_mask);
704 vcpi->vcpi = vcpi_ret + 1;
ad7f8a1f
DA		 705 mgr->proposed_vcpis[ret - 1] = vcpi;
706out_unlock:
707 mutex_unlock(&mgr->payload_lock);
708 return ret;
709}
710
711static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
dfda0df3 712 int vcpi)
ad7f8a1f 713{
dfda0df3
DA		 714 int i;
715 if (vcpi == 0)
ad7f8a1f
DA		 716 return;
717
718 mutex_lock(&mgr->payload_lock);
dfda0df3
DA		 719 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
720 clear_bit(vcpi - 1, &mgr->vcpi_mask);
721
722 for (i = 0; i < mgr->max_payloads; i++) {
723 if (mgr->proposed_vcpis[i])
724 if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
725 mgr->proposed_vcpis[i] = NULL;
726 clear_bit(i + 1, &mgr->payload_mask);
727 }
728 }
ad7f8a1f
DA		 729 mutex_unlock(&mgr->payload_lock);
730}
731
732static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
733 struct drm_dp_sideband_msg_tx *txmsg)
734{
735 bool ret;
cd961bb9
DV		 736
737 /*
738 * All updates to txmsg->state are protected by mgr->qlock, and the two
739 * cases we check here are terminal states. For those the barriers
740 * provided by the wake_up/wait_event pair are enough.
741 */
ad7f8a1f
DA		 742 ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
743 txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
ad7f8a1f
DA		 744 return ret;
745}
746
747static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
748 struct drm_dp_sideband_msg_tx *txmsg)
749{
750 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
751 int ret;
752
753 ret = wait_event_timeout(mgr->tx_waitq,
754 check_txmsg_state(mgr, txmsg),
755 (4 * HZ));
756 mutex_lock(&mstb->mgr->qlock);
757 if (ret > 0) {
758 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
759 ret = -EIO;
760 goto out;
761 }
762 } else {
763 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
764
765 /* dump some state */
766 ret = -EIO;
767
768 /* remove from q */
769 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
770 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
771 list_del(&txmsg->next);
772 }
773
774 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
775 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
776 mstb->tx_slots[txmsg->seqno] = NULL;
777 }
778 }
779out:
780 mutex_unlock(&mgr->qlock);
781
782 return ret;
783}
784
785static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
786{
787 struct drm_dp_mst_branch *mstb;
788
789 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
790 if (!mstb)
791 return NULL;
792
793 mstb->lct = lct;
794 if (lct > 1)
795 memcpy(mstb->rad, rad, lct / 2);
796 INIT_LIST_HEAD(&mstb->ports);
797 kref_init(&mstb->kref);
798 return mstb;
799}
800
801static void drm_dp_destroy_mst_branch_device(struct kref *kref)
802{
803 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
804 struct drm_dp_mst_port *port, *tmp;
805 bool wake_tx = false;
806
807 cancel_work_sync(&mstb->mgr->work);
808
809 /*
810 * destroy all ports - don't need lock
811 * as there are no more references to the mst branch
812 * device at this point.
813 */
814 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
815 list_del(&port->next);
816 drm_dp_put_port(port);
817 }
818
819 /* drop any tx slots msg */
820 mutex_lock(&mstb->mgr->qlock);
821 if (mstb->tx_slots[0]) {
822 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
823 mstb->tx_slots[0] = NULL;
824 wake_tx = true;
825 }
826 if (mstb->tx_slots[1]) {
827 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
828 mstb->tx_slots[1] = NULL;
829 wake_tx = true;
830 }
831 mutex_unlock(&mstb->mgr->qlock);
832
833 if (wake_tx)
834 wake_up(&mstb->mgr->tx_waitq);
835 kfree(mstb);
836}
837
838static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
839{
840 kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
841}
842
843
844static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
845{
0391359d
DV		 846 struct drm_dp_mst_branch *mstb;
847
ad7f8a1f
DA		 848 switch (old_pdt) {
849 case DP_PEER_DEVICE_DP_LEGACY_CONV:
850 case DP_PEER_DEVICE_SST_SINK:
851 /* remove i2c over sideband */
852 drm_dp_mst_unregister_i2c_bus(&port->aux);
853 break;
854 case DP_PEER_DEVICE_MST_BRANCHING:
0391359d 855 mstb = port->mstb;
ad7f8a1f 856 port->mstb = NULL;
0391359d 857 drm_dp_put_mst_branch_device(mstb);
ad7f8a1f
DA		 858 break;
859 }
860}
861
862static void drm_dp_destroy_port(struct kref *kref)
863{
864 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
865 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
866 if (!port->input) {
867 port->vcpi.num_slots = 0;
c6a0aed4
DA		 868
869 kfree(port->cached_edid);
ad7f8a1f
DA		 870 if (port->connector)
871 (*port->mgr->cbs->destroy_connector)(mgr, port->connector);
872 drm_dp_port_teardown_pdt(port, port->pdt);
873
874 if (!port->input && port->vcpi.vcpi > 0)
875 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
876 }
877 kfree(port);
878
879 (*mgr->cbs->hotplug)(mgr);
880}
881
882static void drm_dp_put_port(struct drm_dp_mst_port *port)
883{
884 kref_put(&port->kref, drm_dp_destroy_port);
885}
886
887static 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)
888{
889 struct drm_dp_mst_port *port;
890 struct drm_dp_mst_branch *rmstb;
891 if (to_find == mstb) {
892 kref_get(&mstb->kref);
893 return mstb;
894 }
895 list_for_each_entry(port, &mstb->ports, next) {
896 if (port->mstb) {
897 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
898 if (rmstb)
899 return rmstb;
900 }
901 }
902 return NULL;
903}
904
905static struct drm_dp_mst_branch *drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb)
906{
907 struct drm_dp_mst_branch *rmstb = NULL;
908 mutex_lock(&mgr->lock);
909 if (mgr->mst_primary)
910 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
911 mutex_unlock(&mgr->lock);
912 return rmstb;
913}
914
915static 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)
916{
917 struct drm_dp_mst_port *port, *mport;
918
919 list_for_each_entry(port, &mstb->ports, next) {
920 if (port == to_find) {
921 kref_get(&port->kref);
922 return port;
923 }
924 if (port->mstb) {
925 mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
926 if (mport)
927 return mport;
928 }
929 }
930 return NULL;
931}
932
933static struct drm_dp_mst_port *drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
934{
935 struct drm_dp_mst_port *rport = NULL;
936 mutex_lock(&mgr->lock);
937 if (mgr->mst_primary)
938 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
939 mutex_unlock(&mgr->lock);
940 return rport;
941}
942
943static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
944{
945 struct drm_dp_mst_port *port;
946
947 list_for_each_entry(port, &mstb->ports, next) {
948 if (port->port_num == port_num) {
949 kref_get(&port->kref);
950 return port;
951 }
952 }
953
954 return NULL;
955}
956
957/*
958 * calculate a new RAD for this MST branch device
959 * if parent has an LCT of 2 then it has 1 nibble of RAD,
960 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
961 */
962static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
963 u8 *rad)
964{
965 int lct = port->parent->lct;
966 int shift = 4;
967 int idx = lct / 2;
968 if (lct > 1) {
969 memcpy(rad, port->parent->rad, idx);
970 shift = (lct % 2) ? 4 : 0;
971 } else
972 rad[0] = 0;
973
974 rad[idx] |= port->port_num << shift;
975 return lct + 1;
976}
977
978/*
979 * return sends link address for new mstb
980 */
981static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
982{
983 int ret;
984 u8 rad[6], lct;
985 bool send_link = false;
986 switch (port->pdt) {
987 case DP_PEER_DEVICE_DP_LEGACY_CONV:
988 case DP_PEER_DEVICE_SST_SINK:
989 /* add i2c over sideband */
990 ret = drm_dp_mst_register_i2c_bus(&port->aux);
991 break;
992 case DP_PEER_DEVICE_MST_BRANCHING:
993 lct = drm_dp_calculate_rad(port, rad);
994
995 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
996 port->mstb->mgr = port->mgr;
997 port->mstb->port_parent = port;
998
999 send_link = true;
1000 break;
1001 }
1002 return send_link;
1003}
1004
1005static void drm_dp_check_port_guid(struct drm_dp_mst_branch *mstb,
1006 struct drm_dp_mst_port *port)
1007{
1008 int ret;
1009 if (port->dpcd_rev >= 0x12) {
1010 port->guid_valid = drm_dp_validate_guid(mstb->mgr, port->guid);
1011 if (!port->guid_valid) {
1012 ret = drm_dp_send_dpcd_write(mstb->mgr,
1013 port,
1014 DP_GUID,
1015 16, port->guid);
1016 port->guid_valid = true;
1017 }
1018 }
1019}
1020
1021static void build_mst_prop_path(struct drm_dp_mst_port *port,
1022 struct drm_dp_mst_branch *mstb,
d87af4d1
RS		 1023 char *proppath,
1024 size_t proppath_size)
ad7f8a1f
DA		 1025{
1026 int i;
1027 char temp[8];
d87af4d1 1028 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
ad7f8a1f
DA		 1029 for (i = 0; i < (mstb->lct - 1); i++) {
1030 int shift = (i % 2) ? 0 : 4;
1031 int port_num = mstb->rad[i / 2] >> shift;
d87af4d1
RS		 1032 snprintf(temp, sizeof(temp), "-%d", port_num);
1033 strlcat(proppath, temp, proppath_size);
ad7f8a1f 1034 }
d87af4d1
RS		 1035 snprintf(temp, sizeof(temp), "-%d", port->port_num);
1036 strlcat(proppath, temp, proppath_size);
ad7f8a1f
DA		 1037}
1038
1039static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1040 struct device *dev,
1041 struct drm_dp_link_addr_reply_port *port_msg)
1042{
1043 struct drm_dp_mst_port *port;
1044 bool ret;
1045 bool created = false;
1046 int old_pdt = 0;
1047 int old_ddps = 0;
1048 port = drm_dp_get_port(mstb, port_msg->port_number);
1049 if (!port) {
1050 port = kzalloc(sizeof(*port), GFP_KERNEL);
1051 if (!port)
1052 return;
1053 kref_init(&port->kref);
1054 port->parent = mstb;
1055 port->port_num = port_msg->port_number;
1056 port->mgr = mstb->mgr;
1057 port->aux.name = "DPMST";
1058 port->aux.dev = dev;
1059 created = true;
1060 } else {
1061 old_pdt = port->pdt;
1062 old_ddps = port->ddps;
1063 }
1064
1065 port->pdt = port_msg->peer_device_type;
1066 port->input = port_msg->input_port;
1067 port->mcs = port_msg->mcs;
1068 port->ddps = port_msg->ddps;
1069 port->ldps = port_msg->legacy_device_plug_status;
1070 port->dpcd_rev = port_msg->dpcd_revision;
1071 port->num_sdp_streams = port_msg->num_sdp_streams;
1072 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1073 memcpy(port->guid, port_msg->peer_guid, 16);
1074
1075 /* manage mstb port lists with mgr lock - take a reference
1076 for this list */
1077 if (created) {
1078 mutex_lock(&mstb->mgr->lock);
1079 kref_get(&port->kref);
1080 list_add(&port->next, &mstb->ports);
1081 mutex_unlock(&mstb->mgr->lock);
1082 }
1083
1084 if (old_ddps != port->ddps) {
1085 if (port->ddps) {
1086 drm_dp_check_port_guid(mstb, port);
1087 if (!port->input)
1088 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1089 } else {
1090 port->guid_valid = false;
1091 port->available_pbn = 0;
1092 }
1093 }
1094
1095 if (old_pdt != port->pdt && !port->input) {
1096 drm_dp_port_teardown_pdt(port, old_pdt);
1097
1098 ret = drm_dp_port_setup_pdt(port);
1099 if (ret == true) {
1100 drm_dp_send_link_address(mstb->mgr, port->mstb);
1101 port->mstb->link_address_sent = true;
1102 }
1103 }
1104
1105 if (created && !port->input) {
1106 char proppath[255];
d87af4d1 1107 build_mst_prop_path(port, mstb, proppath, sizeof(proppath));
ad7f8a1f 1108 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
c6a0aed4
DA		 1109
1110 if (port->port_num >= 8) {
1111 port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1112 }
ad7f8a1f
DA		 1113 }
1114
1115 /* put reference to this port */
1116 drm_dp_put_port(port);
1117}
1118
1119static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1120 struct drm_dp_connection_status_notify *conn_stat)
1121{
1122 struct drm_dp_mst_port *port;
1123 int old_pdt;
1124 int old_ddps;
1125 bool dowork = false;
1126 port = drm_dp_get_port(mstb, conn_stat->port_number);
1127 if (!port)
1128 return;
1129
1130 old_ddps = port->ddps;
1131 old_pdt = port->pdt;
1132 port->pdt = conn_stat->peer_device_type;
1133 port->mcs = conn_stat->message_capability_status;
1134 port->ldps = conn_stat->legacy_device_plug_status;
1135 port->ddps = conn_stat->displayport_device_plug_status;
1136
1137 if (old_ddps != port->ddps) {
1138 if (port->ddps) {
1139 drm_dp_check_port_guid(mstb, port);
1140 dowork = true;
1141 } else {
1142 port->guid_valid = false;
1143 port->available_pbn = 0;
1144 }
1145 }
1146 if (old_pdt != port->pdt && !port->input) {
1147 drm_dp_port_teardown_pdt(port, old_pdt);
1148
1149 if (drm_dp_port_setup_pdt(port))
1150 dowork = true;
1151 }
1152
1153 drm_dp_put_port(port);
1154 if (dowork)
1155 queue_work(system_long_wq, &mstb->mgr->work);
1156
1157}
1158
1159static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1160 u8 lct, u8 *rad)
1161{
1162 struct drm_dp_mst_branch *mstb;
1163 struct drm_dp_mst_port *port;
1164 int i;
1165 /* find the port by iterating down */
1166 mstb = mgr->mst_primary;
1167
1168 for (i = 0; i < lct - 1; i++) {
1169 int shift = (i % 2) ? 0 : 4;
1170 int port_num = rad[i / 2] >> shift;
1171
1172 list_for_each_entry(port, &mstb->ports, next) {
1173 if (port->port_num == port_num) {
1174 if (!port->mstb) {
1175 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1176 return NULL;
1177 }
1178
1179 mstb = port->mstb;
1180 break;
1181 }
1182 }
1183 }
1184 kref_get(&mstb->kref);
1185 return mstb;
1186}
1187
1188static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1189 struct drm_dp_mst_branch *mstb)
1190{
1191 struct drm_dp_mst_port *port;
9254ec49 1192 struct drm_dp_mst_branch *mstb_child;
ad7f8a1f
DA		 1193 if (!mstb->link_address_sent) {
1194 drm_dp_send_link_address(mgr, mstb);
1195 mstb->link_address_sent = true;
1196 }
1197 list_for_each_entry(port, &mstb->ports, next) {
1198 if (port->input)
1199 continue;
1200
1201 if (!port->ddps)
1202 continue;
1203
1204 if (!port->available_pbn)
1205 drm_dp_send_enum_path_resources(mgr, mstb, port);
1206
9254ec49
DV		 1207 if (port->mstb) {
1208 mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1209 if (mstb_child) {
1210 drm_dp_check_and_send_link_address(mgr, mstb_child);
1211 drm_dp_put_mst_branch_device(mstb_child);
1212 }
1213 }
ad7f8a1f
DA		 1214 }
1215}
1216
1217static void drm_dp_mst_link_probe_work(struct work_struct *work)
1218{
1219 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
9254ec49 1220 struct drm_dp_mst_branch *mstb;
ad7f8a1f 1221
9254ec49
DV		 1222 mutex_lock(&mgr->lock);
1223 mstb = mgr->mst_primary;
1224 if (mstb) {
1225 kref_get(&mstb->kref);
1226 }
1227 mutex_unlock(&mgr->lock);
1228 if (mstb) {
1229 drm_dp_check_and_send_link_address(mgr, mstb);
1230 drm_dp_put_mst_branch_device(mstb);
1231 }
ad7f8a1f
DA		 1232}
1233
1234static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1235 u8 *guid)
1236{
1237 static u8 zero_guid[16];
1238
1239 if (!memcmp(guid, zero_guid, 16)) {
1240 u64 salt = get_jiffies_64();
1241 memcpy(&guid[0], &salt, sizeof(u64));
1242 memcpy(&guid[8], &salt, sizeof(u64));
1243 return false;
1244 }
1245 return true;
1246}
1247
1248#if 0
1249static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1250{
1251 struct drm_dp_sideband_msg_req_body req;
1252
1253 req.req_type = DP_REMOTE_DPCD_READ;
1254 req.u.dpcd_read.port_number = port_num;
1255 req.u.dpcd_read.dpcd_address = offset;
1256 req.u.dpcd_read.num_bytes = num_bytes;
1257 drm_dp_encode_sideband_req(&req, msg);
1258
1259 return 0;
1260}
1261#endif
1262
1263static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1264 bool up, u8 *msg, int len)
1265{
1266 int ret;
1267 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1268 int tosend, total, offset;
1269 int retries = 0;
1270
1271retry:
1272 total = len;
1273 offset = 0;
1274 do {
1275 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1276
1277 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1278 &msg[offset],
1279 tosend);
1280 if (ret != tosend) {
1281 if (ret == -EIO && retries < 5) {
1282 retries++;
1283 goto retry;
1284 }
1285 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1286 WARN(1, "fail\n");
1287
1288 return -EIO;
1289 }
1290 offset += tosend;
1291 total -= tosend;
1292 } while (total > 0);
1293 return 0;
1294}
1295
1296static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1297 struct drm_dp_sideband_msg_tx *txmsg)
1298{
1299 struct drm_dp_mst_branch *mstb = txmsg->dst;
1300
1301 /* both msg slots are full */
1302 if (txmsg->seqno == -1) {
1303 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1304 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1305 return -EAGAIN;
1306 }
1307 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1308 txmsg->seqno = mstb->last_seqno;
1309 mstb->last_seqno ^= 1;
1310 } else if (mstb->tx_slots[0] == NULL)
1311 txmsg->seqno = 0;
1312 else
1313 txmsg->seqno = 1;
1314 mstb->tx_slots[txmsg->seqno] = txmsg;
1315 }
1316 hdr->broadcast = 0;
1317 hdr->path_msg = txmsg->path_msg;
1318 hdr->lct = mstb->lct;
1319 hdr->lcr = mstb->lct - 1;
1320 if (mstb->lct > 1)
1321 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1322 hdr->seqno = txmsg->seqno;
1323 return 0;
1324}
1325/*
1326 * process a single block of the next message in the sideband queue
1327 */
1328static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1329 struct drm_dp_sideband_msg_tx *txmsg,
1330 bool up)
1331{
1332 u8 chunk[48];
1333 struct drm_dp_sideband_msg_hdr hdr;
1334 int len, space, idx, tosend;
1335 int ret;
1336
bf3719c0
DL		 1337 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1338
ad7f8a1f
DA		 1339 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1340 txmsg->seqno = -1;
1341 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1342 }
1343
1344 /* make hdr from dst mst - for replies use seqno
1345 otherwise assign one */
1346 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1347 if (ret < 0)
1348 return ret;
1349
1350 /* amount left to send in this message */
1351 len = txmsg->cur_len - txmsg->cur_offset;
1352
1353 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1354 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1355
1356 tosend = min(len, space);
1357 if (len == txmsg->cur_len)
1358 hdr.somt = 1;
1359 if (space >= len)
1360 hdr.eomt = 1;
1361
1362
1363 hdr.msg_len = tosend + 1;
1364 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1365 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1366 /* add crc at end */
1367 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1368 idx += tosend + 1;
1369
1370 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1371 if (ret) {
1372 DRM_DEBUG_KMS("sideband msg failed to send\n");
1373 return ret;
1374 }
1375
1376 txmsg->cur_offset += tosend;
1377 if (txmsg->cur_offset == txmsg->cur_len) {
1378 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1379 return 1;
1380 }
1381 return 0;
1382}
1383
ad7f8a1f
DA		 1384static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1385{
1386 struct drm_dp_sideband_msg_tx *txmsg;
1387 int ret;
1388
cd961bb9
DV		 1389 WARN_ON(!mutex_is_locked(&mgr->qlock));
1390
ad7f8a1f
DA		 1391 /* construct a chunk from the first msg in the tx_msg queue */
1392 if (list_empty(&mgr->tx_msg_downq)) {
1393 mgr->tx_down_in_progress = false;
1394 return;
1395 }
1396 mgr->tx_down_in_progress = true;
1397
1398 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1399 ret = process_single_tx_qlock(mgr, txmsg, false);
1400 if (ret == 1) {
1401 /* txmsg is sent it should be in the slots now */
1402 list_del(&txmsg->next);
1403 } else if (ret) {
1404 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1405 list_del(&txmsg->next);
1406 if (txmsg->seqno != -1)
1407 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1408 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1409 wake_up(&mgr->tx_waitq);
1410 }
1411 if (list_empty(&mgr->tx_msg_downq)) {
1412 mgr->tx_down_in_progress = false;
1413 return;
1414 }
1415}
1416
1417/* called holding qlock */
1418static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1419{
1420 struct drm_dp_sideband_msg_tx *txmsg;
1421 int ret;
1422
1423 /* construct a chunk from the first msg in the tx_msg queue */
1424 if (list_empty(&mgr->tx_msg_upq)) {
1425 mgr->tx_up_in_progress = false;
1426 return;
1427 }
1428
1429 txmsg = list_first_entry(&mgr->tx_msg_upq, struct drm_dp_sideband_msg_tx, next);
1430 ret = process_single_tx_qlock(mgr, txmsg, true);
1431 if (ret == 1) {
1432 /* up txmsgs aren't put in slots - so free after we send it */
1433 list_del(&txmsg->next);
1434 kfree(txmsg);
1435 } else if (ret)
1436 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1437 mgr->tx_up_in_progress = true;
1438}
1439
1440static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1441 struct drm_dp_sideband_msg_tx *txmsg)
1442{
1443 mutex_lock(&mgr->qlock);
1444 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1445 if (!mgr->tx_down_in_progress)
1446 process_single_down_tx_qlock(mgr);
1447 mutex_unlock(&mgr->qlock);
1448}
1449
1450static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1451 struct drm_dp_mst_branch *mstb)
1452{
1453 int len;
1454 struct drm_dp_sideband_msg_tx *txmsg;
1455 int ret;
1456
1457 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1458 if (!txmsg)
1459 return -ENOMEM;
1460
1461 txmsg->dst = mstb;
1462 len = build_link_address(txmsg);
1463
1464 drm_dp_queue_down_tx(mgr, txmsg);
1465
1466 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1467 if (ret > 0) {
1468 int i;
1469
1470 if (txmsg->reply.reply_type == 1)
1471 DRM_DEBUG_KMS("link address nak received\n");
1472 else {
1473 DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1474 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1475 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,
1476 txmsg->reply.u.link_addr.ports[i].input_port,
1477 txmsg->reply.u.link_addr.ports[i].peer_device_type,
1478 txmsg->reply.u.link_addr.ports[i].port_number,
1479 txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1480 txmsg->reply.u.link_addr.ports[i].mcs,
1481 txmsg->reply.u.link_addr.ports[i].ddps,
1482 txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1483 txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1484 txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1485 }
1486 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1487 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1488 }
1489 (*mgr->cbs->hotplug)(mgr);
1490 }
1491 } else
1492 DRM_DEBUG_KMS("link address failed %d\n", ret);
1493
1494 kfree(txmsg);
1495 return 0;
1496}
1497
1498static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1499 struct drm_dp_mst_branch *mstb,
1500 struct drm_dp_mst_port *port)
1501{
1502 int len;
1503 struct drm_dp_sideband_msg_tx *txmsg;
1504 int ret;
1505
1506 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1507 if (!txmsg)
1508 return -ENOMEM;
1509
1510 txmsg->dst = mstb;
1511 len = build_enum_path_resources(txmsg, port->port_num);
1512
1513 drm_dp_queue_down_tx(mgr, txmsg);
1514
1515 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1516 if (ret > 0) {
1517 if (txmsg->reply.reply_type == 1)
1518 DRM_DEBUG_KMS("enum path resources nak received\n");
1519 else {
1520 if (port->port_num != txmsg->reply.u.path_resources.port_number)
1521 DRM_ERROR("got incorrect port in response\n");
1522 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,
1523 txmsg->reply.u.path_resources.avail_payload_bw_number);
1524 port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1525 }
1526 }
1527
1528 kfree(txmsg);
1529 return 0;
1530}
1531
8fa6a425
TR		 1532static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1533 struct drm_dp_mst_port *port,
1534 int id,
1535 int pbn)
ad7f8a1f
DA		 1536{
1537 struct drm_dp_sideband_msg_tx *txmsg;
1538 struct drm_dp_mst_branch *mstb;
1539 int len, ret;
1540
1541 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1542 if (!mstb)
1543 return -EINVAL;
1544
1545 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1546 if (!txmsg) {
1547 ret = -ENOMEM;
1548 goto fail_put;
1549 }
1550
1551 txmsg->dst = mstb;
1552 len = build_allocate_payload(txmsg, port->port_num,
1553 id,
1554 pbn);
1555
1556 drm_dp_queue_down_tx(mgr, txmsg);
1557
1558 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1559 if (ret > 0) {
1560 if (txmsg->reply.reply_type == 1) {
1561 ret = -EINVAL;
1562 } else
1563 ret = 0;
1564 }
1565 kfree(txmsg);
1566fail_put:
1567 drm_dp_put_mst_branch_device(mstb);
1568 return ret;
1569}
1570
1571static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1572 int id,
1573 struct drm_dp_payload *payload)
1574{
1575 int ret;
1576
1577 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1578 if (ret < 0) {
1579 payload->payload_state = 0;
1580 return ret;
1581 }
1582 payload->payload_state = DP_PAYLOAD_LOCAL;
1583 return 0;
1584}
1585
8fa6a425
TR		 1586static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1587 struct drm_dp_mst_port *port,
1588 int id,
1589 struct drm_dp_payload *payload)
ad7f8a1f
DA		 1590{
1591 int ret;
1592 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1593 if (ret < 0)
1594 return ret;
1595 payload->payload_state = DP_PAYLOAD_REMOTE;
1596 return ret;
1597}
1598
8fa6a425
TR		 1599static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1600 struct drm_dp_mst_port *port,
1601 int id,
1602 struct drm_dp_payload *payload)
ad7f8a1f
DA		 1603{
1604 DRM_DEBUG_KMS("\n");
1605 /* its okay for these to fail */
1606 if (port) {
1607 drm_dp_payload_send_msg(mgr, port, id, 0);
1608 }
1609
1610 drm_dp_dpcd_write_payload(mgr, id, payload);
dfda0df3 1611 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
ad7f8a1f
DA		 1612 return 0;
1613}
1614
8fa6a425
TR		 1615static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1616 int id,
1617 struct drm_dp_payload *payload)
ad7f8a1f
DA		 1618{
1619 payload->payload_state = 0;
1620 return 0;
1621}
1622
1623/**
1624 * drm_dp_update_payload_part1() - Execute payload update part 1
1625 * @mgr: manager to use.
1626 *
1627 * This iterates over all proposed virtual channels, and tries to
1628 * allocate space in the link for them. For 0->slots transitions,
1629 * this step just writes the VCPI to the MST device. For slots->0
1630 * transitions, this writes the updated VCPIs and removes the
1631 * remote VC payloads.
1632 *
1633 * after calling this the driver should generate ACT and payload
1634 * packets.
1635 */
1636int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1637{
dfda0df3 1638 int i, j;
ad7f8a1f
DA		 1639 int cur_slots = 1;
1640 struct drm_dp_payload req_payload;
1641 struct drm_dp_mst_port *port;
1642
1643 mutex_lock(&mgr->payload_lock);
1644 for (i = 0; i < mgr->max_payloads; i++) {
1645 /* solve the current payloads - compare to the hw ones
1646 - update the hw view */
1647 req_payload.start_slot = cur_slots;
1648 if (mgr->proposed_vcpis[i]) {
1649 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1650 req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1651 } else {
1652 port = NULL;
1653 req_payload.num_slots = 0;
1654 }
dfda0df3
DA		 1655
1656 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1657 mgr->payloads[i].start_slot = req_payload.start_slot;
1658 }
ad7f8a1f 1659 /* work out what is required to happen with this payload */
dfda0df3 1660 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
ad7f8a1f
DA		 1661
1662 /* need to push an update for this payload */
1663 if (req_payload.num_slots) {
dfda0df3 1664 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
ad7f8a1f
DA		 1665 mgr->payloads[i].num_slots = req_payload.num_slots;
1666 } else if (mgr->payloads[i].num_slots) {
1667 mgr->payloads[i].num_slots = 0;
dfda0df3 1668 drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
ad7f8a1f 1669 req_payload.payload_state = mgr->payloads[i].payload_state;
dfda0df3
DA		 1670 mgr->payloads[i].start_slot = 0;
1671 }
ad7f8a1f
DA		 1672 mgr->payloads[i].payload_state = req_payload.payload_state;
1673 }
1674 cur_slots += req_payload.num_slots;
1675 }
dfda0df3
DA		 1676
1677 for (i = 0; i < mgr->max_payloads; i++) {
1678 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1679 DRM_DEBUG_KMS("removing payload %d\n", i);
1680 for (j = i; j < mgr->max_payloads - 1; j++) {
1681 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1682 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1683 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1684 set_bit(j + 1, &mgr->payload_mask);
1685 } else {
1686 clear_bit(j + 1, &mgr->payload_mask);
1687 }
1688 }
1689 memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1690 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1691 clear_bit(mgr->max_payloads, &mgr->payload_mask);
1692
1693 }
1694 }
ad7f8a1f
DA		 1695 mutex_unlock(&mgr->payload_lock);
1696
1697 return 0;
1698}
1699EXPORT_SYMBOL(drm_dp_update_payload_part1);
1700
1701/**
1702 * drm_dp_update_payload_part2() - Execute payload update part 2
1703 * @mgr: manager to use.
1704 *
1705 * This iterates over all proposed virtual channels, and tries to
1706 * allocate space in the link for them. For 0->slots transitions,
1707 * this step writes the remote VC payload commands. For slots->0
1708 * this just resets some internal state.
1709 */
1710int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1711{
1712 struct drm_dp_mst_port *port;
1713 int i;
7389ad4b 1714 int ret = 0;
ad7f8a1f
DA		 1715 mutex_lock(&mgr->payload_lock);
1716 for (i = 0; i < mgr->max_payloads; i++) {
1717
1718 if (!mgr->proposed_vcpis[i])
1719 continue;
1720
1721 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1722
1723 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1724 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
dfda0df3 1725 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
ad7f8a1f 1726 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
dfda0df3 1727 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
ad7f8a1f
DA		 1728 }
1729 if (ret) {
1730 mutex_unlock(&mgr->payload_lock);
1731 return ret;
1732 }
1733 }
1734 mutex_unlock(&mgr->payload_lock);
1735 return 0;
1736}
1737EXPORT_SYMBOL(drm_dp_update_payload_part2);
1738
1739#if 0 /* unused as of yet */
1740static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1741 struct drm_dp_mst_port *port,
1742 int offset, int size)
1743{
1744 int len;
1745 struct drm_dp_sideband_msg_tx *txmsg;
1746
1747 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1748 if (!txmsg)
1749 return -ENOMEM;
1750
1751 len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1752 txmsg->dst = port->parent;
1753
1754 drm_dp_queue_down_tx(mgr, txmsg);
1755
1756 return 0;
1757}
1758#endif
1759
1760static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1761 struct drm_dp_mst_port *port,
1762 int offset, int size, u8 *bytes)
1763{
1764 int len;
1765 int ret;
1766 struct drm_dp_sideband_msg_tx *txmsg;
1767 struct drm_dp_mst_branch *mstb;
1768
1769 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1770 if (!mstb)
1771 return -EINVAL;
1772
1773 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1774 if (!txmsg) {
1775 ret = -ENOMEM;
1776 goto fail_put;
1777 }
1778
1779 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1780 txmsg->dst = mstb;
1781
1782 drm_dp_queue_down_tx(mgr, txmsg);
1783
1784 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1785 if (ret > 0) {
1786 if (txmsg->reply.reply_type == 1) {
1787 ret = -EINVAL;
1788 } else
1789 ret = 0;
1790 }
1791 kfree(txmsg);
1792fail_put:
1793 drm_dp_put_mst_branch_device(mstb);
1794 return ret;
1795}
1796
1797static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1798{
1799 struct drm_dp_sideband_msg_reply_body reply;
1800
1801 reply.reply_type = 1;
1802 reply.req_type = req_type;
1803 drm_dp_encode_sideband_reply(&reply, msg);
1804 return 0;
1805}
1806
1807static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1808 struct drm_dp_mst_branch *mstb,
1809 int req_type, int seqno, bool broadcast)
1810{
1811 struct drm_dp_sideband_msg_tx *txmsg;
1812
1813 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1814 if (!txmsg)
1815 return -ENOMEM;
1816
1817 txmsg->dst = mstb;
1818 txmsg->seqno = seqno;
1819 drm_dp_encode_up_ack_reply(txmsg, req_type);
1820
1821 mutex_lock(&mgr->qlock);
1822 list_add_tail(&txmsg->next, &mgr->tx_msg_upq);
1823 if (!mgr->tx_up_in_progress) {
1824 process_single_up_tx_qlock(mgr);
1825 }
1826 mutex_unlock(&mgr->qlock);
1827 return 0;
1828}
1829
b853fdb3
CW		 1830static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1831 int dp_link_count,
1832 int *out)
ad7f8a1f
DA		 1833{
1834 switch (dp_link_bw) {
b853fdb3
CW		 1835 default:
1836 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
1837 dp_link_bw, dp_link_count);
1838 return false;
1839
ad7f8a1f 1840 case DP_LINK_BW_1_62:
b853fdb3
CW		 1841 *out = 3 * dp_link_count;
1842 break;
ad7f8a1f 1843 case DP_LINK_BW_2_7:
b853fdb3
CW		 1844 *out = 5 * dp_link_count;
1845 break;
ad7f8a1f 1846 case DP_LINK_BW_5_4:
b853fdb3
CW		 1847 *out = 10 * dp_link_count;
1848 break;
ad7f8a1f 1849 }
b853fdb3 1850 return true;
ad7f8a1f
DA		 1851}
1852
1853/**
1854 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
1855 * @mgr: manager to set state for
1856 * @mst_state: true to enable MST on this connector - false to disable.
1857 *
1858 * This is called by the driver when it detects an MST capable device plugged
1859 * into a DP MST capable port, or when a DP MST capable device is unplugged.
1860 */
1861int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
1862{
1863 int ret = 0;
1864 struct drm_dp_mst_branch *mstb = NULL;
1865
1866 mutex_lock(&mgr->lock);
1867 if (mst_state == mgr->mst_state)
1868 goto out_unlock;
1869
1870 mgr->mst_state = mst_state;
1871 /* set the device into MST mode */
1872 if (mst_state) {
1873 WARN_ON(mgr->mst_primary);
1874
1875 /* get dpcd info */
1876 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
1877 if (ret != DP_RECEIVER_CAP_SIZE) {
1878 DRM_DEBUG_KMS("failed to read DPCD\n");
1879 goto out_unlock;
1880 }
1881
b853fdb3
CW		 1882 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
1883 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
1884 &mgr->pbn_div)) {
1885 ret = -EINVAL;
1886 goto out_unlock;
1887 }
1888
ad7f8a1f
DA		 1889 mgr->total_pbn = 2560;
1890 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
1891 mgr->avail_slots = mgr->total_slots;
1892
1893 /* add initial branch device at LCT 1 */
1894 mstb = drm_dp_add_mst_branch_device(1, NULL);
1895 if (mstb == NULL) {
1896 ret = -ENOMEM;
1897 goto out_unlock;
1898 }
1899 mstb->mgr = mgr;
1900
1901 /* give this the main reference */
1902 mgr->mst_primary = mstb;
1903 kref_get(&mgr->mst_primary->kref);
1904
1905 {
1906 struct drm_dp_payload reset_pay;
1907 reset_pay.start_slot = 0;
1908 reset_pay.num_slots = 0x3f;
1909 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
1910 }
1911
1912 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1913 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
1914 if (ret < 0) {
1915 goto out_unlock;
1916 }
1917
1918
1919 /* sort out guid */
1920 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
1921 if (ret != 16) {
1922 DRM_DEBUG_KMS("failed to read DP GUID %d\n", ret);
1923 goto out_unlock;
1924 }
1925
1926 mgr->guid_valid = drm_dp_validate_guid(mgr, mgr->guid);
1927 if (!mgr->guid_valid) {
1928 ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, mgr->guid, 16);
1929 mgr->guid_valid = true;
1930 }
1931
1932 queue_work(system_long_wq, &mgr->work);
1933
1934 ret = 0;
1935 } else {
1936 /* disable MST on the device */
1937 mstb = mgr->mst_primary;
1938 mgr->mst_primary = NULL;
1939 /* this can fail if the device is gone */
1940 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
1941 ret = 0;
1942 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
1943 mgr->payload_mask = 0;
1944 set_bit(0, &mgr->payload_mask);
dfda0df3 1945 mgr->vcpi_mask = 0;
ad7f8a1f
DA		 1946 }
1947
1948out_unlock:
1949 mutex_unlock(&mgr->lock);
1950 if (mstb)
1951 drm_dp_put_mst_branch_device(mstb);
1952 return ret;
1953
1954}
1955EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
1956
1957/**
1958 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
1959 * @mgr: manager to suspend
1960 *
1961 * This function tells the MST device that we can't handle UP messages
1962 * anymore. This should stop it from sending any since we are suspended.
1963 */
1964void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
1965{
1966 mutex_lock(&mgr->lock);
1967 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1968 DP_MST_EN | DP_UPSTREAM_IS_SRC);
1969 mutex_unlock(&mgr->lock);
1970}
1971EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
1972
1973/**
1974 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
1975 * @mgr: manager to resume
1976 *
1977 * This will fetch DPCD and see if the device is still there,
1978 * if it is, it will rewrite the MSTM control bits, and return.
1979 *
1980 * if the device fails this returns -1, and the driver should do
1981 * a full MST reprobe, in case we were undocked.
1982 */
1983int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
1984{
1985 int ret = 0;
1986
1987 mutex_lock(&mgr->lock);
1988
1989 if (mgr->mst_primary) {
1990 int sret;
1991 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
1992 if (sret != DP_RECEIVER_CAP_SIZE) {
1993 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
1994 ret = -1;
1995 goto out_unlock;
1996 }
1997
1998 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
1999 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2000 if (ret < 0) {
2001 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2002 ret = -1;
2003 goto out_unlock;
2004 }
2005 ret = 0;
2006 } else
2007 ret = -1;
2008
2009out_unlock:
2010 mutex_unlock(&mgr->lock);
2011 return ret;
2012}
2013EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2014
2015static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2016{
2017 int len;
2018 u8 replyblock[32];
2019 int replylen, origlen, curreply;
2020 int ret;
2021 struct drm_dp_sideband_msg_rx *msg;
2022 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2023 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2024
2025 len = min(mgr->max_dpcd_transaction_bytes, 16);
2026 ret = drm_dp_dpcd_read(mgr->aux, basereg,
2027 replyblock, len);
2028 if (ret != len) {
2029 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2030 return;
2031 }
2032 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2033 if (!ret) {
2034 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2035 return;
2036 }
2037 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2038
2039 origlen = replylen;
2040 replylen -= len;
2041 curreply = len;
2042 while (replylen > 0) {
2043 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2044 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2045 replyblock, len);
2046 if (ret != len) {
2047 DRM_DEBUG_KMS("failed to read a chunk\n");
2048 }
2049 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2050 if (ret == false)
2051 DRM_DEBUG_KMS("failed to build sideband msg\n");
2052 curreply += len;
2053 replylen -= len;
2054 }
2055}
2056
2057static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2058{
2059 int ret = 0;
2060
2061 drm_dp_get_one_sb_msg(mgr, false);
2062
2063 if (mgr->down_rep_recv.have_eomt) {
2064 struct drm_dp_sideband_msg_tx *txmsg;
2065 struct drm_dp_mst_branch *mstb;
2066 int slot = -1;
2067 mstb = drm_dp_get_mst_branch_device(mgr,
2068 mgr->down_rep_recv.initial_hdr.lct,
2069 mgr->down_rep_recv.initial_hdr.rad);
2070
2071 if (!mstb) {
2072 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2073 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2074 return 0;
2075 }
2076
2077 /* find the message */
2078 slot = mgr->down_rep_recv.initial_hdr.seqno;
2079 mutex_lock(&mgr->qlock);
2080 txmsg = mstb->tx_slots[slot];
2081 /* remove from slots */
2082 mutex_unlock(&mgr->qlock);
2083
2084 if (!txmsg) {
2085 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2086 mstb,
2087 mgr->down_rep_recv.initial_hdr.seqno,
2088 mgr->down_rep_recv.initial_hdr.lct,
2089 mgr->down_rep_recv.initial_hdr.rad[0],
2090 mgr->down_rep_recv.msg[0]);
2091 drm_dp_put_mst_branch_device(mstb);
2092 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2093 return 0;
2094 }
2095
2096 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2097 if (txmsg->reply.reply_type == 1) {
2098 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);
2099 }
2100
2101 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2102 drm_dp_put_mst_branch_device(mstb);
2103
2104 mutex_lock(&mgr->qlock);
2105 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2106 mstb->tx_slots[slot] = NULL;
2107 mutex_unlock(&mgr->qlock);
2108
2109 wake_up(&mgr->tx_waitq);
2110 }
2111 return ret;
2112}
2113
2114static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2115{
2116 int ret = 0;
2117 drm_dp_get_one_sb_msg(mgr, true);
2118
2119 if (mgr->up_req_recv.have_eomt) {
2120 struct drm_dp_sideband_msg_req_body msg;
2121 struct drm_dp_mst_branch *mstb;
2122 bool seqno;
2123 mstb = drm_dp_get_mst_branch_device(mgr,
2124 mgr->up_req_recv.initial_hdr.lct,
2125 mgr->up_req_recv.initial_hdr.rad);
2126 if (!mstb) {
2127 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2128 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2129 return 0;
2130 }
2131
2132 seqno = mgr->up_req_recv.initial_hdr.seqno;
2133 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2134
2135 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2136 drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
2137 drm_dp_update_port(mstb, &msg.u.conn_stat);
2138 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);
2139 (*mgr->cbs->hotplug)(mgr);
2140
2141 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2142 drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
2143 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2144 }
2145
2146 drm_dp_put_mst_branch_device(mstb);
2147 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2148 }
2149 return ret;
2150}
2151
2152/**
2153 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2154 * @mgr: manager to notify irq for.
2155 * @esi: 4 bytes from SINK_COUNT_ESI
295ee853 2156 * @handled: whether the hpd interrupt was consumed or not
ad7f8a1f
DA		 2157 *
2158 * This should be called from the driver when it detects a short IRQ,
2159 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2160 * topology manager will process the sideband messages received as a result
2161 * of this.
2162 */
2163int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2164{
2165 int ret = 0;
2166 int sc;
2167 *handled = false;
2168 sc = esi[0] & 0x3f;
2169
2170 if (sc != mgr->sink_count) {
2171 mgr->sink_count = sc;
2172 *handled = true;
2173 }
2174
2175 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2176 ret = drm_dp_mst_handle_down_rep(mgr);
2177 *handled = true;
2178 }
2179
2180 if (esi[1] & DP_UP_REQ_MSG_RDY) {
2181 ret |= drm_dp_mst_handle_up_req(mgr);
2182 *handled = true;
2183 }
2184
2185 drm_dp_mst_kick_tx(mgr);
2186 return ret;
2187}
2188EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2189
2190/**
2191 * drm_dp_mst_detect_port() - get connection status for an MST port
2192 * @mgr: manager for this port
2193 * @port: unverified pointer to a port
2194 *
2195 * This returns the current connection state for a port. It validates the
2196 * port pointer still exists so the caller doesn't require a reference
2197 */
c6a0aed4
DA		 2198enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2199 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
ad7f8a1f
DA		 2200{
2201 enum drm_connector_status status = connector_status_disconnected;
2202
2203 /* we need to search for the port in the mgr in case its gone */
2204 port = drm_dp_get_validated_port_ref(mgr, port);
2205 if (!port)
2206 return connector_status_disconnected;
2207
2208 if (!port->ddps)
2209 goto out;
2210
2211 switch (port->pdt) {
2212 case DP_PEER_DEVICE_NONE:
2213 case DP_PEER_DEVICE_MST_BRANCHING:
2214 break;
2215
2216 case DP_PEER_DEVICE_SST_SINK:
2217 status = connector_status_connected;
c6a0aed4
DA		 2218 /* for logical ports - cache the EDID */
2219 if (port->port_num >= 8 && !port->cached_edid) {
2220 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2221 }
ad7f8a1f
DA		 2222 break;
2223 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2224 if (port->ldps)
2225 status = connector_status_connected;
2226 break;
2227 }
2228out:
2229 drm_dp_put_port(port);
2230 return status;
2231}
2232EXPORT_SYMBOL(drm_dp_mst_detect_port);
2233
2234/**
2235 * drm_dp_mst_get_edid() - get EDID for an MST port
2236 * @connector: toplevel connector to get EDID for
2237 * @mgr: manager for this port
2238 * @port: unverified pointer to a port.
2239 *
2240 * This returns an EDID for the port connected to a connector,
2241 * It validates the pointer still exists so the caller doesn't require a
2242 * reference.
2243 */
2244struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2245{
2246 struct edid *edid = NULL;
2247
2248 /* we need to search for the port in the mgr in case its gone */
2249 port = drm_dp_get_validated_port_ref(mgr, port);
2250 if (!port)
2251 return NULL;
2252
c6a0aed4
DA		 2253 if (port->cached_edid)
2254 edid = drm_edid_duplicate(port->cached_edid);
2255 else
2256 edid = drm_get_edid(connector, &port->aux.ddc);
2257
6f134d7b 2258 drm_mode_connector_set_tile_property(connector);
ad7f8a1f
DA		 2259 drm_dp_put_port(port);
2260 return edid;
2261}
2262EXPORT_SYMBOL(drm_dp_mst_get_edid);
2263
2264/**
2265 * drm_dp_find_vcpi_slots() - find slots for this PBN value
2266 * @mgr: manager to use
2267 * @pbn: payload bandwidth to convert into slots.
2268 */
2269int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2270 int pbn)
2271{
2272 int num_slots;
2273
2274 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2275
2276 if (num_slots > mgr->avail_slots)
2277 return -ENOSPC;
2278 return num_slots;
2279}
2280EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2281
2282static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2283 struct drm_dp_vcpi *vcpi, int pbn)
2284{
2285 int num_slots;
2286 int ret;
2287
2288 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2289
2290 if (num_slots > mgr->avail_slots)
2291 return -ENOSPC;
2292
2293 vcpi->pbn = pbn;
2294 vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2295 vcpi->num_slots = num_slots;
2296
2297 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2298 if (ret < 0)
2299 return ret;
2300 return 0;
2301}
2302
2303/**
2304 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2305 * @mgr: manager for this port
2306 * @port: port to allocate a virtual channel for.
2307 * @pbn: payload bandwidth number to request
2308 * @slots: returned number of slots for this PBN.
2309 */
2310bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2311{
2312 int ret;
2313
2314 port = drm_dp_get_validated_port_ref(mgr, port);
2315 if (!port)
2316 return false;
2317
2318 if (port->vcpi.vcpi > 0) {
2319 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2320 if (pbn == port->vcpi.pbn) {
2321 *slots = port->vcpi.num_slots;
2322 return true;
2323 }
2324 }
2325
2326 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2327 if (ret) {
2328 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2329 goto out;
2330 }
2331 DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2332 *slots = port->vcpi.num_slots;
2333
2334 drm_dp_put_port(port);
2335 return true;
2336out:
2337 return false;
2338}
2339EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2340
87f5942d
DA		 2341int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2342{
2343 int slots = 0;
2344 port = drm_dp_get_validated_port_ref(mgr, port);
2345 if (!port)
2346 return slots;
2347
2348 slots = port->vcpi.num_slots;
2349 drm_dp_put_port(port);
2350 return slots;
2351}
2352EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2353
ad7f8a1f
DA		 2354/**
2355 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2356 * @mgr: manager for this port
2357 * @port: unverified pointer to a port.
2358 *
2359 * This just resets the number of slots for the ports VCPI for later programming.
2360 */
2361void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2362{
2363 port = drm_dp_get_validated_port_ref(mgr, port);
2364 if (!port)
2365 return;
2366 port->vcpi.num_slots = 0;
2367 drm_dp_put_port(port);
2368}
2369EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2370
2371/**
2372 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2373 * @mgr: manager for this port
2374 * @port: unverified port to deallocate vcpi for
2375 */
2376void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2377{
2378 port = drm_dp_get_validated_port_ref(mgr, port);
2379 if (!port)
2380 return;
2381
2382 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2383 port->vcpi.num_slots = 0;
2384 port->vcpi.pbn = 0;
2385 port->vcpi.aligned_pbn = 0;
2386 port->vcpi.vcpi = 0;
2387 drm_dp_put_port(port);
2388}
2389EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2390
2391static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2392 int id, struct drm_dp_payload *payload)
2393{
2394 u8 payload_alloc[3], status;
2395 int ret;
2396 int retries = 0;
2397
2398 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2399 DP_PAYLOAD_TABLE_UPDATED);
2400
2401 payload_alloc[0] = id;
2402 payload_alloc[1] = payload->start_slot;
2403 payload_alloc[2] = payload->num_slots;
2404
2405 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2406 if (ret != 3) {
2407 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2408 goto fail;
2409 }
2410
2411retry:
2412 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2413 if (ret < 0) {
2414 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2415 goto fail;
2416 }
2417
2418 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2419 retries++;
2420 if (retries < 20) {
2421 usleep_range(10000, 20000);
2422 goto retry;
2423 }
2424 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2425 ret = -EINVAL;
2426 goto fail;
2427 }
2428 ret = 0;
2429fail:
2430 return ret;
2431}
2432
2433
2434/**
2435 * drm_dp_check_act_status() - Check ACT handled status.
2436 * @mgr: manager to use
2437 *
2438 * Check the payload status bits in the DPCD for ACT handled completion.
2439 */
2440int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2441{
2442 u8 status;
2443 int ret;
2444 int count = 0;
2445
2446 do {
2447 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2448
2449 if (ret < 0) {
2450 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2451 goto fail;
2452 }
2453
2454 if (status & DP_PAYLOAD_ACT_HANDLED)
2455 break;
2456 count++;
2457 udelay(100);
2458
2459 } while (count < 30);
2460
2461 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2462 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2463 ret = -EINVAL;
2464 goto fail;
2465 }
2466 return 0;
2467fail:
2468 return ret;
2469}
2470EXPORT_SYMBOL(drm_dp_check_act_status);
2471
2472/**
2473 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2474 * @clock: dot clock for the mode
2475 * @bpp: bpp for the mode.
2476 *
2477 * This uses the formula in the spec to calculate the PBN value for a mode.
2478 */
2479int drm_dp_calc_pbn_mode(int clock, int bpp)
2480{
2481 fixed20_12 pix_bw;
2482 fixed20_12 fbpp;
2483 fixed20_12 result;
2484 fixed20_12 margin, tmp;
2485 u32 res;
2486
2487 pix_bw.full = dfixed_const(clock);
2488 fbpp.full = dfixed_const(bpp);
2489 tmp.full = dfixed_const(8);
2490 fbpp.full = dfixed_div(fbpp, tmp);
2491
2492 result.full = dfixed_mul(pix_bw, fbpp);
2493 margin.full = dfixed_const(54);
2494 tmp.full = dfixed_const(64);
2495 margin.full = dfixed_div(margin, tmp);
2496 result.full = dfixed_div(result, margin);
2497
2498 margin.full = dfixed_const(1006);
2499 tmp.full = dfixed_const(1000);
2500 margin.full = dfixed_div(margin, tmp);
2501 result.full = dfixed_mul(result, margin);
2502
2503 result.full = dfixed_div(result, tmp);
2504 result.full = dfixed_ceil(result);
2505 res = dfixed_trunc(result);
2506 return res;
2507}
2508EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2509
2510static int test_calc_pbn_mode(void)
2511{
2512 int ret;
2513 ret = drm_dp_calc_pbn_mode(154000, 30);
2514 if (ret != 689)
2515 return -EINVAL;
2516 ret = drm_dp_calc_pbn_mode(234000, 30);
2517 if (ret != 1047)
2518 return -EINVAL;
2519 return 0;
2520}
2521
2522/* we want to kick the TX after we've ack the up/down IRQs. */
2523static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2524{
2525 queue_work(system_long_wq, &mgr->tx_work);
2526}
2527
2528static void drm_dp_mst_dump_mstb(struct seq_file *m,
2529 struct drm_dp_mst_branch *mstb)
2530{
2531 struct drm_dp_mst_port *port;
2532 int tabs = mstb->lct;
2533 char prefix[10];
2534 int i;
2535
2536 for (i = 0; i < tabs; i++)
2537 prefix[i] = '\t';
2538 prefix[i] = '\0';
2539
2540 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2541 list_for_each_entry(port, &mstb->ports, next) {
2542 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port, port->connector);
2543 if (port->mstb)
2544 drm_dp_mst_dump_mstb(m, port->mstb);
2545 }
2546}
2547
2548static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2549 char *buf)
2550{
2551 int ret;
2552 int i;
2553 for (i = 0; i < 4; i++) {
2554 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2555 if (ret != 16)
2556 break;
2557 }
2558 if (i == 4)
2559 return true;
2560 return false;
2561}
2562
2563/**
2564 * drm_dp_mst_dump_topology(): dump topology to seq file.
2565 * @m: seq_file to dump output to
2566 * @mgr: manager to dump current topology for.
2567 *
2568 * helper to dump MST topology to a seq file for debugfs.
2569 */
2570void drm_dp_mst_dump_topology(struct seq_file *m,
2571 struct drm_dp_mst_topology_mgr *mgr)
2572{
2573 int i;
2574 struct drm_dp_mst_port *port;
2575 mutex_lock(&mgr->lock);
2576 if (mgr->mst_primary)
2577 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2578
2579 /* dump VCPIs */
2580 mutex_unlock(&mgr->lock);
2581
2582 mutex_lock(&mgr->payload_lock);
dfda0df3 2583 seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
ad7f8a1f
DA		 2584
2585 for (i = 0; i < mgr->max_payloads; i++) {
2586 if (mgr->proposed_vcpis[i]) {
2587 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2588 seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2589 } else
2590 seq_printf(m, "vcpi %d:unsed\n", i);
2591 }
2592 for (i = 0; i < mgr->max_payloads; i++) {
2593 seq_printf(m, "payload %d: %d, %d, %d\n",
2594 i,
2595 mgr->payloads[i].payload_state,
2596 mgr->payloads[i].start_slot,
2597 mgr->payloads[i].num_slots);
2598
2599
2600 }
2601 mutex_unlock(&mgr->payload_lock);
2602
2603 mutex_lock(&mgr->lock);
2604 if (mgr->mst_primary) {
2605 u8 buf[64];
2606 bool bret;
2607 int ret;
2608 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2609 seq_printf(m, "dpcd: ");
2610 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2611 seq_printf(m, "%02x ", buf[i]);
2612 seq_printf(m, "\n");
2613 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2614 seq_printf(m, "faux/mst: ");
2615 for (i = 0; i < 2; i++)
2616 seq_printf(m, "%02x ", buf[i]);
2617 seq_printf(m, "\n");
2618 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2619 seq_printf(m, "mst ctrl: ");
2620 for (i = 0; i < 1; i++)
2621 seq_printf(m, "%02x ", buf[i]);
2622 seq_printf(m, "\n");
2623
2624 bret = dump_dp_payload_table(mgr, buf);
2625 if (bret == true) {
2626 seq_printf(m, "payload table: ");
2627 for (i = 0; i < 63; i++)
2628 seq_printf(m, "%02x ", buf[i]);
2629 seq_printf(m, "\n");
2630 }
2631
2632 }
2633
2634 mutex_unlock(&mgr->lock);
2635
2636}
2637EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2638
2639static void drm_dp_tx_work(struct work_struct *work)
2640{
2641 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2642
2643 mutex_lock(&mgr->qlock);
2644 if (mgr->tx_down_in_progress)
2645 process_single_down_tx_qlock(mgr);
2646 mutex_unlock(&mgr->qlock);
2647}
2648
2649/**
2650 * drm_dp_mst_topology_mgr_init - initialise a topology manager
2651 * @mgr: manager struct to initialise
2652 * @dev: device providing this structure - for i2c addition.
2653 * @aux: DP helper aux channel to talk to this device
2654 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2655 * @max_payloads: maximum number of payloads this GPU can source
2656 * @conn_base_id: the connector object ID the MST device is connected to.
2657 *
2658 * Return 0 for success, or negative error code on failure
2659 */
2660int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2661 struct device *dev, struct drm_dp_aux *aux,
2662 int max_dpcd_transaction_bytes,
2663 int max_payloads, int conn_base_id)
2664{
2665 mutex_init(&mgr->lock);
2666 mutex_init(&mgr->qlock);
2667 mutex_init(&mgr->payload_lock);
2668 INIT_LIST_HEAD(&mgr->tx_msg_upq);
2669 INIT_LIST_HEAD(&mgr->tx_msg_downq);
2670 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2671 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2672 init_waitqueue_head(&mgr->tx_waitq);
2673 mgr->dev = dev;
2674 mgr->aux = aux;
2675 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2676 mgr->max_payloads = max_payloads;
2677 mgr->conn_base_id = conn_base_id;
2678 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2679 if (!mgr->payloads)
2680 return -ENOMEM;
2681 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2682 if (!mgr->proposed_vcpis)
2683 return -ENOMEM;
2684 set_bit(0, &mgr->payload_mask);
2685 test_calc_pbn_mode();
2686 return 0;
2687}
2688EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2689
2690/**
2691 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2692 * @mgr: manager to destroy
2693 */
2694void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2695{
2696 mutex_lock(&mgr->payload_lock);
2697 kfree(mgr->payloads);
2698 mgr->payloads = NULL;
2699 kfree(mgr->proposed_vcpis);
2700 mgr->proposed_vcpis = NULL;
2701 mutex_unlock(&mgr->payload_lock);
2702 mgr->dev = NULL;
2703 mgr->aux = NULL;
2704}
2705EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
2706
2707/* I2C device */
2708static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
2709 int num)
2710{
2711 struct drm_dp_aux *aux = adapter->algo_data;
2712 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
2713 struct drm_dp_mst_branch *mstb;
2714 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2715 unsigned int i;
2716 bool reading = false;
2717 struct drm_dp_sideband_msg_req_body msg;
2718 struct drm_dp_sideband_msg_tx *txmsg = NULL;
2719 int ret;
2720
2721 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2722 if (!mstb)
2723 return -EREMOTEIO;
2724
2725 /* construct i2c msg */
2726 /* see if last msg is a read */
2727 if (msgs[num - 1].flags & I2C_M_RD)
2728 reading = true;
2729
2730 if (!reading) {
2731 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
2732 ret = -EIO;
2733 goto out;
2734 }
2735
2736 msg.req_type = DP_REMOTE_I2C_READ;
2737 msg.u.i2c_read.num_transactions = num - 1;
2738 msg.u.i2c_read.port_number = port->port_num;
2739 for (i = 0; i < num - 1; i++) {
2740 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
2741 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
2742 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
2743 }
2744 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
2745 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
2746
2747 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2748 if (!txmsg) {
2749 ret = -ENOMEM;
2750 goto out;
2751 }
2752
2753 txmsg->dst = mstb;
2754 drm_dp_encode_sideband_req(&msg, txmsg);
2755
2756 drm_dp_queue_down_tx(mgr, txmsg);
2757
2758 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2759 if (ret > 0) {
2760
2761 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
2762 ret = -EREMOTEIO;
2763 goto out;
2764 }
2765 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
2766 ret = -EIO;
2767 goto out;
2768 }
2769 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
2770 ret = num;
2771 }
2772out:
2773 kfree(txmsg);
2774 drm_dp_put_mst_branch_device(mstb);
2775 return ret;
2776}
2777
2778static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
2779{
2780 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
2781 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
2782 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
2783 I2C_FUNC_10BIT_ADDR;
2784}
2785
2786static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
2787 .functionality = drm_dp_mst_i2c_functionality,
2788 .master_xfer = drm_dp_mst_i2c_xfer,
2789};
2790
2791/**
2792 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
2793 * @aux: DisplayPort AUX channel
2794 *
2795 * Returns 0 on success or a negative error code on failure.
2796 */
2797static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
2798{
2799 aux->ddc.algo = &drm_dp_mst_i2c_algo;
2800 aux->ddc.algo_data = aux;
2801 aux->ddc.retries = 3;
2802
2803 aux->ddc.class = I2C_CLASS_DDC;
2804 aux->ddc.owner = THIS_MODULE;
2805 aux->ddc.dev.parent = aux->dev;
2806 aux->ddc.dev.of_node = aux->dev->of_node;
2807
2808 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
2809 sizeof(aux->ddc.name));
2810
2811 return i2c_add_adapter(&aux->ddc);
2812}
2813
2814/**
2815 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
2816 * @aux: DisplayPort AUX channel
2817 */
2818static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
2819{
2820 i2c_del_adapter(&aux->ddc);
2821}
Linux 6.x block layer and io_uring tree(s)