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 #include <drm/drm_atomic.h>
35 #include <drm/drm_atomic_helper.h>
36
37 /**
38 * DOC: dp mst helper
39 *
40 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
41 * protocol. The helpers contain a topology manager and bandwidth manager.
42 * The helpers encapsulate the sending and received of sideband msgs.
43 */
44 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
45 char *buf);
46 static int test_calc_pbn_mode(void);
47
48 static void drm_dp_put_port(struct drm_dp_mst_port *port);
49
50 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
51 int id,
52 struct drm_dp_payload *payload);
53
54 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
55 struct drm_dp_mst_port *port,
56 int offset, int size, u8 *bytes);
57
58 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
59 struct drm_dp_mst_branch *mstb);
60 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
61 struct drm_dp_mst_branch *mstb,
62 struct drm_dp_mst_port *port);
63 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
64 u8 *guid);
65
66 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
67 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
68 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
69 /* sideband msg handling */
drm_dp_msg_header_crc4(const uint8_t * data,size_t num_nibbles)70 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
71 {
72 u8 bitmask = 0x80;
73 u8 bitshift = 7;
74 u8 array_index = 0;
75 int number_of_bits = num_nibbles * 4;
76 u8 remainder = 0;
77
78 while (number_of_bits != 0) {
79 number_of_bits--;
80 remainder <<= 1;
81 remainder |= (data[array_index] & bitmask) >> bitshift;
82 bitmask >>= 1;
83 bitshift--;
84 if (bitmask == 0) {
85 bitmask = 0x80;
86 bitshift = 7;
87 array_index++;
88 }
89 if ((remainder & 0x10) == 0x10)
90 remainder ^= 0x13;
91 }
92
93 number_of_bits = 4;
94 while (number_of_bits != 0) {
95 number_of_bits--;
96 remainder <<= 1;
97 if ((remainder & 0x10) != 0)
98 remainder ^= 0x13;
99 }
100
101 return remainder;
102 }
103
drm_dp_msg_data_crc4(const uint8_t * data,u8 number_of_bytes)104 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
105 {
106 u8 bitmask = 0x80;
107 u8 bitshift = 7;
108 u8 array_index = 0;
109 int number_of_bits = number_of_bytes * 8;
110 u16 remainder = 0;
111
112 while (number_of_bits != 0) {
113 number_of_bits--;
114 remainder <<= 1;
115 remainder |= (data[array_index] & bitmask) >> bitshift;
116 bitmask >>= 1;
117 bitshift--;
118 if (bitmask == 0) {
119 bitmask = 0x80;
120 bitshift = 7;
121 array_index++;
122 }
123 if ((remainder & 0x100) == 0x100)
124 remainder ^= 0xd5;
125 }
126
127 number_of_bits = 8;
128 while (number_of_bits != 0) {
129 number_of_bits--;
130 remainder <<= 1;
131 if ((remainder & 0x100) != 0)
132 remainder ^= 0xd5;
133 }
134
135 return remainder & 0xff;
136 }
drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr * hdr)137 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
138 {
139 u8 size = 3;
140 size += (hdr->lct / 2);
141 return size;
142 }
143
drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr * hdr,u8 * buf,int * len)144 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
145 u8 *buf, int *len)
146 {
147 int idx = 0;
148 int i;
149 u8 crc4;
150 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
151 for (i = 0; i < (hdr->lct / 2); i++)
152 buf[idx++] = hdr->rad[i];
153 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
154 (hdr->msg_len & 0x3f);
155 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
156
157 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
158 buf[idx - 1] |= (crc4 & 0xf);
159
160 *len = idx;
161 }
162
drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr * hdr,u8 * buf,int buflen,u8 * hdrlen)163 static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
164 u8 *buf, int buflen, u8 *hdrlen)
165 {
166 u8 crc4;
167 u8 len;
168 int i;
169 u8 idx;
170 if (buf[0] == 0)
171 return false;
172 len = 3;
173 len += ((buf[0] & 0xf0) >> 4) / 2;
174 if (len > buflen)
175 return false;
176 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
177
178 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
179 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
180 return false;
181 }
182
183 hdr->lct = (buf[0] & 0xf0) >> 4;
184 hdr->lcr = (buf[0] & 0xf);
185 idx = 1;
186 for (i = 0; i < (hdr->lct / 2); i++)
187 hdr->rad[i] = buf[idx++];
188 hdr->broadcast = (buf[idx] >> 7) & 0x1;
189 hdr->path_msg = (buf[idx] >> 6) & 0x1;
190 hdr->msg_len = buf[idx] & 0x3f;
191 idx++;
192 hdr->somt = (buf[idx] >> 7) & 0x1;
193 hdr->eomt = (buf[idx] >> 6) & 0x1;
194 hdr->seqno = (buf[idx] >> 4) & 0x1;
195 idx++;
196 *hdrlen = idx;
197 return true;
198 }
199
drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body * req,struct drm_dp_sideband_msg_tx * raw)200 static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req,
201 struct drm_dp_sideband_msg_tx *raw)
202 {
203 int idx = 0;
204 int i;
205 u8 *buf = raw->msg;
206 buf[idx++] = req->req_type & 0x7f;
207
208 switch (req->req_type) {
209 case DP_ENUM_PATH_RESOURCES:
210 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
211 idx++;
212 break;
213 case DP_ALLOCATE_PAYLOAD:
214 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
215 (req->u.allocate_payload.number_sdp_streams & 0xf);
216 idx++;
217 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
218 idx++;
219 buf[idx] = (req->u.allocate_payload.pbn >> 8);
220 idx++;
221 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
222 idx++;
223 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
224 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
225 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
226 idx++;
227 }
228 if (req->u.allocate_payload.number_sdp_streams & 1) {
229 i = req->u.allocate_payload.number_sdp_streams - 1;
230 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
231 idx++;
232 }
233 break;
234 case DP_QUERY_PAYLOAD:
235 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
236 idx++;
237 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
238 idx++;
239 break;
240 case DP_REMOTE_DPCD_READ:
241 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
242 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
243 idx++;
244 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
245 idx++;
246 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
247 idx++;
248 buf[idx] = (req->u.dpcd_read.num_bytes);
249 idx++;
250 break;
251
252 case DP_REMOTE_DPCD_WRITE:
253 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
254 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
255 idx++;
256 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
257 idx++;
258 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
259 idx++;
260 buf[idx] = (req->u.dpcd_write.num_bytes);
261 idx++;
262 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
263 idx += req->u.dpcd_write.num_bytes;
264 break;
265 case DP_REMOTE_I2C_READ:
266 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
267 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
268 idx++;
269 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
270 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
271 idx++;
272 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
273 idx++;
274 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
275 idx += req->u.i2c_read.transactions[i].num_bytes;
276
277 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4;
278 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
279 idx++;
280 }
281 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
282 idx++;
283 buf[idx] = (req->u.i2c_read.num_bytes_read);
284 idx++;
285 break;
286
287 case DP_REMOTE_I2C_WRITE:
288 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
289 idx++;
290 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
291 idx++;
292 buf[idx] = (req->u.i2c_write.num_bytes);
293 idx++;
294 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
295 idx += req->u.i2c_write.num_bytes;
296 break;
297 }
298 raw->cur_len = idx;
299 }
300
drm_dp_crc_sideband_chunk_req(u8 * msg,u8 len)301 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
302 {
303 u8 crc4;
304 crc4 = drm_dp_msg_data_crc4(msg, len);
305 msg[len] = crc4;
306 }
307
drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body * rep,struct drm_dp_sideband_msg_tx * raw)308 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
309 struct drm_dp_sideband_msg_tx *raw)
310 {
311 int idx = 0;
312 u8 *buf = raw->msg;
313
314 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
315
316 raw->cur_len = idx;
317 }
318
319 /* this adds a chunk of msg to the builder to get the final msg */
drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx * msg,u8 * replybuf,u8 replybuflen,bool hdr)320 static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
321 u8 *replybuf, u8 replybuflen, bool hdr)
322 {
323 int ret;
324 u8 crc4;
325
326 if (hdr) {
327 u8 hdrlen;
328 struct drm_dp_sideband_msg_hdr recv_hdr;
329 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
330 if (ret == false) {
331 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
332 return false;
333 }
334
335 /*
336 * ignore out-of-order messages or messages that are part of a
337 * failed transaction
338 */
339 if (!recv_hdr.somt && !msg->have_somt)
340 return false;
341
342 /* get length contained in this portion */
343 msg->curchunk_len = recv_hdr.msg_len;
344 msg->curchunk_hdrlen = hdrlen;
345
346 /* we have already gotten an somt - don't bother parsing */
347 if (recv_hdr.somt && msg->have_somt)
348 return false;
349
350 if (recv_hdr.somt) {
351 memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
352 msg->have_somt = true;
353 }
354 if (recv_hdr.eomt)
355 msg->have_eomt = true;
356
357 /* copy the bytes for the remainder of this header chunk */
358 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
359 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
360 } else {
361 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
362 msg->curchunk_idx += replybuflen;
363 }
364
365 if (msg->curchunk_idx >= msg->curchunk_len) {
366 /* do CRC */
367 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
368 /* copy chunk into bigger msg */
369 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
370 msg->curlen += msg->curchunk_len - 1;
371 }
372 return true;
373 }
374
drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)375 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
376 struct drm_dp_sideband_msg_reply_body *repmsg)
377 {
378 int idx = 1;
379 int i;
380 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
381 idx += 16;
382 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
383 idx++;
384 if (idx > raw->curlen)
385 goto fail_len;
386 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
387 if (raw->msg[idx] & 0x80)
388 repmsg->u.link_addr.ports[i].input_port = 1;
389
390 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
391 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
392
393 idx++;
394 if (idx > raw->curlen)
395 goto fail_len;
396 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
397 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
398 if (repmsg->u.link_addr.ports[i].input_port == 0)
399 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
400 idx++;
401 if (idx > raw->curlen)
402 goto fail_len;
403 if (repmsg->u.link_addr.ports[i].input_port == 0) {
404 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
405 idx++;
406 if (idx > raw->curlen)
407 goto fail_len;
408 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
409 idx += 16;
410 if (idx > raw->curlen)
411 goto fail_len;
412 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
413 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
414 idx++;
415
416 }
417 if (idx > raw->curlen)
418 goto fail_len;
419 }
420
421 return true;
422 fail_len:
423 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
424 return false;
425 }
426
drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)427 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
428 struct drm_dp_sideband_msg_reply_body *repmsg)
429 {
430 int idx = 1;
431 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
432 idx++;
433 if (idx > raw->curlen)
434 goto fail_len;
435 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
436 if (idx > raw->curlen)
437 goto fail_len;
438
439 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
440 return true;
441 fail_len:
442 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
443 return false;
444 }
445
drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)446 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
447 struct drm_dp_sideband_msg_reply_body *repmsg)
448 {
449 int idx = 1;
450 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
451 idx++;
452 if (idx > raw->curlen)
453 goto fail_len;
454 return true;
455 fail_len:
456 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
457 return false;
458 }
459
drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)460 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
461 struct drm_dp_sideband_msg_reply_body *repmsg)
462 {
463 int idx = 1;
464
465 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
466 idx++;
467 if (idx > raw->curlen)
468 goto fail_len;
469 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
470 idx++;
471 /* TODO check */
472 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
473 return true;
474 fail_len:
475 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
476 return false;
477 }
478
drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)479 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
480 struct drm_dp_sideband_msg_reply_body *repmsg)
481 {
482 int idx = 1;
483 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
484 idx++;
485 if (idx > raw->curlen)
486 goto fail_len;
487 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
488 idx += 2;
489 if (idx > raw->curlen)
490 goto fail_len;
491 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
492 idx += 2;
493 if (idx > raw->curlen)
494 goto fail_len;
495 return true;
496 fail_len:
497 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
498 return false;
499 }
500
drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)501 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
502 struct drm_dp_sideband_msg_reply_body *repmsg)
503 {
504 int idx = 1;
505 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
506 idx++;
507 if (idx > raw->curlen)
508 goto fail_len;
509 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
510 idx++;
511 if (idx > raw->curlen)
512 goto fail_len;
513 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
514 idx += 2;
515 if (idx > raw->curlen)
516 goto fail_len;
517 return true;
518 fail_len:
519 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
520 return false;
521 }
522
drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)523 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
524 struct drm_dp_sideband_msg_reply_body *repmsg)
525 {
526 int idx = 1;
527 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
528 idx++;
529 if (idx > raw->curlen)
530 goto fail_len;
531 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
532 idx += 2;
533 if (idx > raw->curlen)
534 goto fail_len;
535 return true;
536 fail_len:
537 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
538 return false;
539 }
540
drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * msg)541 static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
542 struct drm_dp_sideband_msg_reply_body *msg)
543 {
544 memset(msg, 0, sizeof(*msg));
545 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
546 msg->req_type = (raw->msg[0] & 0x7f);
547
548 if (msg->reply_type) {
549 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
550 msg->u.nak.reason = raw->msg[17];
551 msg->u.nak.nak_data = raw->msg[18];
552 return false;
553 }
554
555 switch (msg->req_type) {
556 case DP_LINK_ADDRESS:
557 return drm_dp_sideband_parse_link_address(raw, msg);
558 case DP_QUERY_PAYLOAD:
559 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
560 case DP_REMOTE_DPCD_READ:
561 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
562 case DP_REMOTE_DPCD_WRITE:
563 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
564 case DP_REMOTE_I2C_READ:
565 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
566 case DP_ENUM_PATH_RESOURCES:
567 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
568 case DP_ALLOCATE_PAYLOAD:
569 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
570 default:
571 DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
572 return false;
573 }
574 }
575
drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_req_body * msg)576 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
577 struct drm_dp_sideband_msg_req_body *msg)
578 {
579 int idx = 1;
580
581 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
582 idx++;
583 if (idx > raw->curlen)
584 goto fail_len;
585
586 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
587 idx += 16;
588 if (idx > raw->curlen)
589 goto fail_len;
590
591 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
592 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
593 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
594 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
595 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
596 idx++;
597 return true;
598 fail_len:
599 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
600 return false;
601 }
602
drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_req_body * msg)603 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
604 struct drm_dp_sideband_msg_req_body *msg)
605 {
606 int idx = 1;
607
608 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
609 idx++;
610 if (idx > raw->curlen)
611 goto fail_len;
612
613 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
614 idx += 16;
615 if (idx > raw->curlen)
616 goto fail_len;
617
618 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
619 idx++;
620 return true;
621 fail_len:
622 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
623 return false;
624 }
625
drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_req_body * msg)626 static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
627 struct drm_dp_sideband_msg_req_body *msg)
628 {
629 memset(msg, 0, sizeof(*msg));
630 msg->req_type = (raw->msg[0] & 0x7f);
631
632 switch (msg->req_type) {
633 case DP_CONNECTION_STATUS_NOTIFY:
634 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
635 case DP_RESOURCE_STATUS_NOTIFY:
636 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
637 default:
638 DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
639 return false;
640 }
641 }
642
build_dpcd_write(struct drm_dp_sideband_msg_tx * msg,u8 port_num,u32 offset,u8 num_bytes,u8 * bytes)643 static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
644 {
645 struct drm_dp_sideband_msg_req_body req;
646
647 req.req_type = DP_REMOTE_DPCD_WRITE;
648 req.u.dpcd_write.port_number = port_num;
649 req.u.dpcd_write.dpcd_address = offset;
650 req.u.dpcd_write.num_bytes = num_bytes;
651 req.u.dpcd_write.bytes = bytes;
652 drm_dp_encode_sideband_req(&req, msg);
653
654 return 0;
655 }
656
build_link_address(struct drm_dp_sideband_msg_tx * msg)657 static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
658 {
659 struct drm_dp_sideband_msg_req_body req;
660
661 req.req_type = DP_LINK_ADDRESS;
662 drm_dp_encode_sideband_req(&req, msg);
663 return 0;
664 }
665
build_enum_path_resources(struct drm_dp_sideband_msg_tx * msg,int port_num)666 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
667 {
668 struct drm_dp_sideband_msg_req_body req;
669
670 req.req_type = DP_ENUM_PATH_RESOURCES;
671 req.u.port_num.port_number = port_num;
672 drm_dp_encode_sideband_req(&req, msg);
673 msg->path_msg = true;
674 return 0;
675 }
676
build_allocate_payload(struct drm_dp_sideband_msg_tx * msg,int port_num,u8 vcpi,uint16_t pbn,u8 number_sdp_streams,u8 * sdp_stream_sink)677 static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
678 u8 vcpi, uint16_t pbn,
679 u8 number_sdp_streams,
680 u8 *sdp_stream_sink)
681 {
682 struct drm_dp_sideband_msg_req_body req;
683 memset(&req, 0, sizeof(req));
684 req.req_type = DP_ALLOCATE_PAYLOAD;
685 req.u.allocate_payload.port_number = port_num;
686 req.u.allocate_payload.vcpi = vcpi;
687 req.u.allocate_payload.pbn = pbn;
688 req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
689 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
690 number_sdp_streams);
691 drm_dp_encode_sideband_req(&req, msg);
692 msg->path_msg = true;
693 return 0;
694 }
695
drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_vcpi * vcpi)696 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
697 struct drm_dp_vcpi *vcpi)
698 {
699 int ret, vcpi_ret;
700
701 mutex_lock(&mgr->payload_lock);
702 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
703 if (ret > mgr->max_payloads) {
704 ret = -EINVAL;
705 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
706 goto out_unlock;
707 }
708
709 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
710 if (vcpi_ret > mgr->max_payloads) {
711 ret = -EINVAL;
712 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
713 goto out_unlock;
714 }
715
716 set_bit(ret, &mgr->payload_mask);
717 set_bit(vcpi_ret, &mgr->vcpi_mask);
718 vcpi->vcpi = vcpi_ret + 1;
719 mgr->proposed_vcpis[ret - 1] = vcpi;
720 out_unlock:
721 mutex_unlock(&mgr->payload_lock);
722 return ret;
723 }
724
drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr * mgr,int vcpi)725 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
726 int vcpi)
727 {
728 int i;
729 if (vcpi == 0)
730 return;
731
732 mutex_lock(&mgr->payload_lock);
733 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
734 clear_bit(vcpi - 1, &mgr->vcpi_mask);
735
736 for (i = 0; i < mgr->max_payloads; i++) {
737 if (mgr->proposed_vcpis[i])
738 if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
739 mgr->proposed_vcpis[i] = NULL;
740 clear_bit(i + 1, &mgr->payload_mask);
741 }
742 }
743 mutex_unlock(&mgr->payload_lock);
744 }
745
check_txmsg_state(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg)746 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
747 struct drm_dp_sideband_msg_tx *txmsg)
748 {
749 unsigned int state;
750
751 /*
752 * All updates to txmsg->state are protected by mgr->qlock, and the two
753 * cases we check here are terminal states. For those the barriers
754 * provided by the wake_up/wait_event pair are enough.
755 */
756 state = READ_ONCE(txmsg->state);
757 return (state == DRM_DP_SIDEBAND_TX_RX ||
758 state == DRM_DP_SIDEBAND_TX_TIMEOUT);
759 }
760
drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch * mstb,struct drm_dp_sideband_msg_tx * txmsg)761 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
762 struct drm_dp_sideband_msg_tx *txmsg)
763 {
764 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
765 int ret;
766
767 ret = wait_event_timeout(mgr->tx_waitq,
768 check_txmsg_state(mgr, txmsg),
769 (4 * HZ));
770 mutex_lock(&mstb->mgr->qlock);
771 if (ret > 0) {
772 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
773 ret = -EIO;
774 goto out;
775 }
776 } else {
777 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
778
779 /* dump some state */
780 ret = -EIO;
781
782 /* remove from q */
783 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
784 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
785 list_del(&txmsg->next);
786 }
787
788 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
789 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
790 mstb->tx_slots[txmsg->seqno] = NULL;
791 }
792 }
793 out:
794 mutex_unlock(&mgr->qlock);
795
796 return ret;
797 }
798
drm_dp_add_mst_branch_device(u8 lct,u8 * rad)799 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
800 {
801 struct drm_dp_mst_branch *mstb;
802
803 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
804 if (!mstb)
805 return NULL;
806
807 mstb->lct = lct;
808 if (lct > 1)
809 memcpy(mstb->rad, rad, lct / 2);
810 INIT_LIST_HEAD(&mstb->ports);
811 kref_init(&mstb->kref);
812 return mstb;
813 }
814
815 static void drm_dp_free_mst_port(struct kref *kref);
816
drm_dp_free_mst_branch_device(struct kref * kref)817 static void drm_dp_free_mst_branch_device(struct kref *kref)
818 {
819 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
820 if (mstb->port_parent) {
821 if (list_empty(&mstb->port_parent->next))
822 kref_put(&mstb->port_parent->kref, drm_dp_free_mst_port);
823 }
824 kfree(mstb);
825 }
826
drm_dp_destroy_mst_branch_device(struct kref * kref)827 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
828 {
829 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
830 struct drm_dp_mst_port *port, *tmp;
831 bool wake_tx = false;
832
833 /*
834 * init kref again to be used by ports to remove mst branch when it is
835 * not needed anymore
836 */
837 kref_init(kref);
838
839 if (mstb->port_parent && list_empty(&mstb->port_parent->next))
840 kref_get(&mstb->port_parent->kref);
841
842 /*
843 * destroy all ports - don't need lock
844 * as there are no more references to the mst branch
845 * device at this point.
846 */
847 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
848 list_del(&port->next);
849 drm_dp_put_port(port);
850 }
851
852 /* drop any tx slots msg */
853 mutex_lock(&mstb->mgr->qlock);
854 if (mstb->tx_slots[0]) {
855 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
856 mstb->tx_slots[0] = NULL;
857 wake_tx = true;
858 }
859 if (mstb->tx_slots[1]) {
860 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
861 mstb->tx_slots[1] = NULL;
862 wake_tx = true;
863 }
864 mutex_unlock(&mstb->mgr->qlock);
865
866 if (wake_tx)
867 wake_up_all(&mstb->mgr->tx_waitq);
868
869 kref_put(kref, drm_dp_free_mst_branch_device);
870 }
871
drm_dp_put_mst_branch_device(struct drm_dp_mst_branch * mstb)872 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
873 {
874 kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
875 }
876
877
drm_dp_port_teardown_pdt(struct drm_dp_mst_port * port,int old_pdt)878 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
879 {
880 struct drm_dp_mst_branch *mstb;
881
882 switch (old_pdt) {
883 case DP_PEER_DEVICE_DP_LEGACY_CONV:
884 case DP_PEER_DEVICE_SST_SINK:
885 /* remove i2c over sideband */
886 drm_dp_mst_unregister_i2c_bus(&port->aux);
887 break;
888 case DP_PEER_DEVICE_MST_BRANCHING:
889 mstb = port->mstb;
890 port->mstb = NULL;
891 drm_dp_put_mst_branch_device(mstb);
892 break;
893 }
894 }
895
drm_dp_destroy_port(struct kref * kref)896 static void drm_dp_destroy_port(struct kref *kref)
897 {
898 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
899 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
900
901 if (!port->input) {
902 port->vcpi.num_slots = 0;
903
904 kfree(port->cached_edid);
905
906 /*
907 * The only time we don't have a connector
908 * on an output port is if the connector init
909 * fails.
910 */
911 if (port->connector) {
912 /* we can't destroy the connector here, as
913 * we might be holding the mode_config.mutex
914 * from an EDID retrieval */
915
916 mutex_lock(&mgr->destroy_connector_lock);
917 kref_get(&port->parent->kref);
918 list_add(&port->next, &mgr->destroy_connector_list);
919 mutex_unlock(&mgr->destroy_connector_lock);
920 schedule_work(&mgr->destroy_connector_work);
921 return;
922 }
923 /* no need to clean up vcpi
924 * as if we have no connector we never setup a vcpi */
925 drm_dp_port_teardown_pdt(port, port->pdt);
926 port->pdt = DP_PEER_DEVICE_NONE;
927 }
928 kfree(port);
929 }
930
drm_dp_put_port(struct drm_dp_mst_port * port)931 static void drm_dp_put_port(struct drm_dp_mst_port *port)
932 {
933 kref_put(&port->kref, drm_dp_destroy_port);
934 }
935
drm_dp_mst_get_validated_mstb_ref_locked(struct drm_dp_mst_branch * mstb,struct drm_dp_mst_branch * to_find)936 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)
937 {
938 struct drm_dp_mst_port *port;
939 struct drm_dp_mst_branch *rmstb;
940 if (to_find == mstb) {
941 kref_get(&mstb->kref);
942 return mstb;
943 }
944 list_for_each_entry(port, &mstb->ports, next) {
945 if (port->mstb) {
946 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
947 if (rmstb)
948 return rmstb;
949 }
950 }
951 return NULL;
952 }
953
drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb)954 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)
955 {
956 struct drm_dp_mst_branch *rmstb = NULL;
957 mutex_lock(&mgr->lock);
958 if (mgr->mst_primary)
959 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
960 mutex_unlock(&mgr->lock);
961 return rmstb;
962 }
963
drm_dp_mst_get_port_ref_locked(struct drm_dp_mst_branch * mstb,struct drm_dp_mst_port * to_find)964 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)
965 {
966 struct drm_dp_mst_port *port, *mport;
967
968 list_for_each_entry(port, &mstb->ports, next) {
969 if (port == to_find) {
970 kref_get(&port->kref);
971 return port;
972 }
973 if (port->mstb) {
974 mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
975 if (mport)
976 return mport;
977 }
978 }
979 return NULL;
980 }
981
drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)982 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)
983 {
984 struct drm_dp_mst_port *rport = NULL;
985 mutex_lock(&mgr->lock);
986 if (mgr->mst_primary)
987 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
988 mutex_unlock(&mgr->lock);
989 return rport;
990 }
991
drm_dp_get_port(struct drm_dp_mst_branch * mstb,u8 port_num)992 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
993 {
994 struct drm_dp_mst_port *port;
995
996 list_for_each_entry(port, &mstb->ports, next) {
997 if (port->port_num == port_num) {
998 kref_get(&port->kref);
999 return port;
1000 }
1001 }
1002
1003 return NULL;
1004 }
1005
1006 /*
1007 * calculate a new RAD for this MST branch device
1008 * if parent has an LCT of 2 then it has 1 nibble of RAD,
1009 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1010 */
drm_dp_calculate_rad(struct drm_dp_mst_port * port,u8 * rad)1011 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1012 u8 *rad)
1013 {
1014 int parent_lct = port->parent->lct;
1015 int shift = 4;
1016 int idx = (parent_lct - 1) / 2;
1017 if (parent_lct > 1) {
1018 memcpy(rad, port->parent->rad, idx + 1);
1019 shift = (parent_lct % 2) ? 4 : 0;
1020 } else
1021 rad[0] = 0;
1022
1023 rad[idx] |= port->port_num << shift;
1024 return parent_lct + 1;
1025 }
1026
1027 /*
1028 * return sends link address for new mstb
1029 */
drm_dp_port_setup_pdt(struct drm_dp_mst_port * port)1030 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
1031 {
1032 int ret;
1033 u8 rad[6], lct;
1034 bool send_link = false;
1035 switch (port->pdt) {
1036 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1037 case DP_PEER_DEVICE_SST_SINK:
1038 /* add i2c over sideband */
1039 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1040 break;
1041 case DP_PEER_DEVICE_MST_BRANCHING:
1042 lct = drm_dp_calculate_rad(port, rad);
1043
1044 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
1045 port->mstb->mgr = port->mgr;
1046 port->mstb->port_parent = port;
1047
1048 send_link = true;
1049 break;
1050 }
1051 return send_link;
1052 }
1053
drm_dp_check_mstb_guid(struct drm_dp_mst_branch * mstb,u8 * guid)1054 static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
1055 {
1056 int ret;
1057
1058 memcpy(mstb->guid, guid, 16);
1059
1060 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
1061 if (mstb->port_parent) {
1062 ret = drm_dp_send_dpcd_write(
1063 mstb->mgr,
1064 mstb->port_parent,
1065 DP_GUID,
1066 16,
1067 mstb->guid);
1068 } else {
1069
1070 ret = drm_dp_dpcd_write(
1071 mstb->mgr->aux,
1072 DP_GUID,
1073 mstb->guid,
1074 16);
1075 }
1076 }
1077 }
1078
build_mst_prop_path(const struct drm_dp_mst_branch * mstb,int pnum,char * proppath,size_t proppath_size)1079 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1080 int pnum,
1081 char *proppath,
1082 size_t proppath_size)
1083 {
1084 int i;
1085 char temp[8];
1086 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1087 for (i = 0; i < (mstb->lct - 1); i++) {
1088 int shift = (i % 2) ? 0 : 4;
1089 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
1090 snprintf(temp, sizeof(temp), "-%d", port_num);
1091 strlcat(proppath, temp, proppath_size);
1092 }
1093 snprintf(temp, sizeof(temp), "-%d", pnum);
1094 strlcat(proppath, temp, proppath_size);
1095 }
1096
drm_dp_add_port(struct drm_dp_mst_branch * mstb,struct drm_device * dev,struct drm_dp_link_addr_reply_port * port_msg)1097 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1098 struct drm_device *dev,
1099 struct drm_dp_link_addr_reply_port *port_msg)
1100 {
1101 struct drm_dp_mst_port *port;
1102 bool ret;
1103 bool created = false;
1104 int old_pdt = 0;
1105 int old_ddps = 0;
1106 port = drm_dp_get_port(mstb, port_msg->port_number);
1107 if (!port) {
1108 port = kzalloc(sizeof(*port), GFP_KERNEL);
1109 if (!port)
1110 return;
1111 kref_init(&port->kref);
1112 port->parent = mstb;
1113 port->port_num = port_msg->port_number;
1114 port->mgr = mstb->mgr;
1115 port->aux.name = "DPMST";
1116 port->aux.dev = dev->dev;
1117 created = true;
1118 } else {
1119 old_pdt = port->pdt;
1120 old_ddps = port->ddps;
1121 }
1122
1123 port->pdt = port_msg->peer_device_type;
1124 port->input = port_msg->input_port;
1125 port->mcs = port_msg->mcs;
1126 port->ddps = port_msg->ddps;
1127 port->ldps = port_msg->legacy_device_plug_status;
1128 port->dpcd_rev = port_msg->dpcd_revision;
1129 port->num_sdp_streams = port_msg->num_sdp_streams;
1130 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1131
1132 /* manage mstb port lists with mgr lock - take a reference
1133 for this list */
1134 if (created) {
1135 mutex_lock(&mstb->mgr->lock);
1136 kref_get(&port->kref);
1137 list_add(&port->next, &mstb->ports);
1138 mutex_unlock(&mstb->mgr->lock);
1139 }
1140
1141 if (old_ddps != port->ddps) {
1142 if (port->ddps) {
1143 if (!port->input)
1144 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1145 } else {
1146 port->available_pbn = 0;
1147 }
1148 }
1149
1150 if (old_pdt != port->pdt && !port->input) {
1151 drm_dp_port_teardown_pdt(port, old_pdt);
1152
1153 ret = drm_dp_port_setup_pdt(port);
1154 if (ret == true)
1155 drm_dp_send_link_address(mstb->mgr, port->mstb);
1156 }
1157
1158 if (created && !port->input) {
1159 char proppath[255];
1160
1161 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
1162 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1163 if (!port->connector) {
1164 /* remove it from the port list */
1165 mutex_lock(&mstb->mgr->lock);
1166 list_del(&port->next);
1167 mutex_unlock(&mstb->mgr->lock);
1168 /* drop port list reference */
1169 drm_dp_put_port(port);
1170 goto out;
1171 }
1172 if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
1173 port->pdt == DP_PEER_DEVICE_SST_SINK) &&
1174 port->port_num >= DP_MST_LOGICAL_PORT_0) {
1175 port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1176 drm_mode_connector_set_tile_property(port->connector);
1177 }
1178 (*mstb->mgr->cbs->register_connector)(port->connector);
1179 }
1180
1181 out:
1182 /* put reference to this port */
1183 drm_dp_put_port(port);
1184 }
1185
drm_dp_update_port(struct drm_dp_mst_branch * mstb,struct drm_dp_connection_status_notify * conn_stat)1186 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1187 struct drm_dp_connection_status_notify *conn_stat)
1188 {
1189 struct drm_dp_mst_port *port;
1190 int old_pdt;
1191 int old_ddps;
1192 bool dowork = false;
1193 port = drm_dp_get_port(mstb, conn_stat->port_number);
1194 if (!port)
1195 return;
1196
1197 old_ddps = port->ddps;
1198 old_pdt = port->pdt;
1199 port->pdt = conn_stat->peer_device_type;
1200 port->mcs = conn_stat->message_capability_status;
1201 port->ldps = conn_stat->legacy_device_plug_status;
1202 port->ddps = conn_stat->displayport_device_plug_status;
1203
1204 if (old_ddps != port->ddps) {
1205 if (port->ddps) {
1206 dowork = true;
1207 } else {
1208 port->available_pbn = 0;
1209 }
1210 }
1211 if (old_pdt != port->pdt && !port->input) {
1212 drm_dp_port_teardown_pdt(port, old_pdt);
1213
1214 if (drm_dp_port_setup_pdt(port))
1215 dowork = true;
1216 }
1217
1218 drm_dp_put_port(port);
1219 if (dowork)
1220 queue_work(system_long_wq, &mstb->mgr->work);
1221
1222 }
1223
drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr * mgr,u8 lct,u8 * rad)1224 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1225 u8 lct, u8 *rad)
1226 {
1227 struct drm_dp_mst_branch *mstb;
1228 struct drm_dp_mst_port *port;
1229 int i;
1230 /* find the port by iterating down */
1231
1232 mutex_lock(&mgr->lock);
1233 mstb = mgr->mst_primary;
1234
1235 if (!mstb)
1236 goto out;
1237
1238 for (i = 0; i < lct - 1; i++) {
1239 int shift = (i % 2) ? 0 : 4;
1240 int port_num = (rad[i / 2] >> shift) & 0xf;
1241
1242 list_for_each_entry(port, &mstb->ports, next) {
1243 if (port->port_num == port_num) {
1244 mstb = port->mstb;
1245 if (!mstb) {
1246 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1247 goto out;
1248 }
1249
1250 break;
1251 }
1252 }
1253 }
1254 kref_get(&mstb->kref);
1255 out:
1256 mutex_unlock(&mgr->lock);
1257 return mstb;
1258 }
1259
get_mst_branch_device_by_guid_helper(struct drm_dp_mst_branch * mstb,uint8_t * guid)1260 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1261 struct drm_dp_mst_branch *mstb,
1262 uint8_t *guid)
1263 {
1264 struct drm_dp_mst_branch *found_mstb;
1265 struct drm_dp_mst_port *port;
1266
1267 if (memcmp(mstb->guid, guid, 16) == 0)
1268 return mstb;
1269
1270
1271 list_for_each_entry(port, &mstb->ports, next) {
1272 if (!port->mstb)
1273 continue;
1274
1275 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1276
1277 if (found_mstb)
1278 return found_mstb;
1279 }
1280
1281 return NULL;
1282 }
1283
drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr * mgr,uint8_t * guid)1284 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
1285 struct drm_dp_mst_topology_mgr *mgr,
1286 uint8_t *guid)
1287 {
1288 struct drm_dp_mst_branch *mstb;
1289
1290 /* find the port by iterating down */
1291 mutex_lock(&mgr->lock);
1292
1293 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
1294
1295 if (mstb)
1296 kref_get(&mstb->kref);
1297
1298 mutex_unlock(&mgr->lock);
1299 return mstb;
1300 }
1301
drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb)1302 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1303 struct drm_dp_mst_branch *mstb)
1304 {
1305 struct drm_dp_mst_port *port;
1306 struct drm_dp_mst_branch *mstb_child;
1307 if (!mstb->link_address_sent)
1308 drm_dp_send_link_address(mgr, mstb);
1309
1310 list_for_each_entry(port, &mstb->ports, next) {
1311 if (port->input)
1312 continue;
1313
1314 if (!port->ddps)
1315 continue;
1316
1317 if (!port->available_pbn)
1318 drm_dp_send_enum_path_resources(mgr, mstb, port);
1319
1320 if (port->mstb) {
1321 mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1322 if (mstb_child) {
1323 drm_dp_check_and_send_link_address(mgr, mstb_child);
1324 drm_dp_put_mst_branch_device(mstb_child);
1325 }
1326 }
1327 }
1328 }
1329
drm_dp_mst_link_probe_work(struct work_struct * work)1330 static void drm_dp_mst_link_probe_work(struct work_struct *work)
1331 {
1332 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1333 struct drm_dp_mst_branch *mstb;
1334
1335 mutex_lock(&mgr->lock);
1336 mstb = mgr->mst_primary;
1337 if (mstb) {
1338 kref_get(&mstb->kref);
1339 }
1340 mutex_unlock(&mgr->lock);
1341 if (mstb) {
1342 drm_dp_check_and_send_link_address(mgr, mstb);
1343 drm_dp_put_mst_branch_device(mstb);
1344 }
1345 }
1346
drm_dp_validate_guid(struct drm_dp_mst_topology_mgr * mgr,u8 * guid)1347 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1348 u8 *guid)
1349 {
1350 u64 salt;
1351
1352 if (memchr_inv(guid, 0, 16))
1353 return true;
1354
1355 salt = get_jiffies_64();
1356
1357 memcpy(&guid[0], &salt, sizeof(u64));
1358 memcpy(&guid[8], &salt, sizeof(u64));
1359
1360 return false;
1361 }
1362
1363 #if 0
1364 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1365 {
1366 struct drm_dp_sideband_msg_req_body req;
1367
1368 req.req_type = DP_REMOTE_DPCD_READ;
1369 req.u.dpcd_read.port_number = port_num;
1370 req.u.dpcd_read.dpcd_address = offset;
1371 req.u.dpcd_read.num_bytes = num_bytes;
1372 drm_dp_encode_sideband_req(&req, msg);
1373
1374 return 0;
1375 }
1376 #endif
1377
drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr * mgr,bool up,u8 * msg,int len)1378 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1379 bool up, u8 *msg, int len)
1380 {
1381 int ret;
1382 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1383 int tosend, total, offset;
1384 int retries = 0;
1385
1386 retry:
1387 total = len;
1388 offset = 0;
1389 do {
1390 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1391
1392 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1393 &msg[offset],
1394 tosend);
1395 if (ret != tosend) {
1396 if (ret == -EIO && retries < 5) {
1397 retries++;
1398 goto retry;
1399 }
1400 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1401
1402 return -EIO;
1403 }
1404 offset += tosend;
1405 total -= tosend;
1406 } while (total > 0);
1407 return 0;
1408 }
1409
set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr * hdr,struct drm_dp_sideband_msg_tx * txmsg)1410 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1411 struct drm_dp_sideband_msg_tx *txmsg)
1412 {
1413 struct drm_dp_mst_branch *mstb = txmsg->dst;
1414 u8 req_type;
1415
1416 /* both msg slots are full */
1417 if (txmsg->seqno == -1) {
1418 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1419 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1420 return -EAGAIN;
1421 }
1422 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1423 txmsg->seqno = mstb->last_seqno;
1424 mstb->last_seqno ^= 1;
1425 } else if (mstb->tx_slots[0] == NULL)
1426 txmsg->seqno = 0;
1427 else
1428 txmsg->seqno = 1;
1429 mstb->tx_slots[txmsg->seqno] = txmsg;
1430 }
1431
1432 req_type = txmsg->msg[0] & 0x7f;
1433 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1434 req_type == DP_RESOURCE_STATUS_NOTIFY)
1435 hdr->broadcast = 1;
1436 else
1437 hdr->broadcast = 0;
1438 hdr->path_msg = txmsg->path_msg;
1439 hdr->lct = mstb->lct;
1440 hdr->lcr = mstb->lct - 1;
1441 if (mstb->lct > 1)
1442 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1443 hdr->seqno = txmsg->seqno;
1444 return 0;
1445 }
1446 /*
1447 * process a single block of the next message in the sideband queue
1448 */
process_single_tx_qlock(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg,bool up)1449 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1450 struct drm_dp_sideband_msg_tx *txmsg,
1451 bool up)
1452 {
1453 u8 chunk[48];
1454 struct drm_dp_sideband_msg_hdr hdr;
1455 int len, space, idx, tosend;
1456 int ret;
1457
1458 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1459
1460 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1461 txmsg->seqno = -1;
1462 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1463 }
1464
1465 /* make hdr from dst mst - for replies use seqno
1466 otherwise assign one */
1467 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1468 if (ret < 0)
1469 return ret;
1470
1471 /* amount left to send in this message */
1472 len = txmsg->cur_len - txmsg->cur_offset;
1473
1474 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1475 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1476
1477 tosend = min(len, space);
1478 if (len == txmsg->cur_len)
1479 hdr.somt = 1;
1480 if (space >= len)
1481 hdr.eomt = 1;
1482
1483
1484 hdr.msg_len = tosend + 1;
1485 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1486 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1487 /* add crc at end */
1488 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1489 idx += tosend + 1;
1490
1491 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1492 if (ret) {
1493 DRM_DEBUG_KMS("sideband msg failed to send\n");
1494 return ret;
1495 }
1496
1497 txmsg->cur_offset += tosend;
1498 if (txmsg->cur_offset == txmsg->cur_len) {
1499 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1500 return 1;
1501 }
1502 return 0;
1503 }
1504
process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr * mgr)1505 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1506 {
1507 struct drm_dp_sideband_msg_tx *txmsg;
1508 int ret;
1509
1510 WARN_ON(!mutex_is_locked(&mgr->qlock));
1511
1512 /* construct a chunk from the first msg in the tx_msg queue */
1513 if (list_empty(&mgr->tx_msg_downq))
1514 return;
1515
1516 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1517 ret = process_single_tx_qlock(mgr, txmsg, false);
1518 if (ret == 1) {
1519 /* txmsg is sent it should be in the slots now */
1520 list_del(&txmsg->next);
1521 } else if (ret) {
1522 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1523 list_del(&txmsg->next);
1524 if (txmsg->seqno != -1)
1525 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1526 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1527 wake_up_all(&mgr->tx_waitq);
1528 }
1529 }
1530
1531 /* called holding qlock */
process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg)1532 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1533 struct drm_dp_sideband_msg_tx *txmsg)
1534 {
1535 int ret;
1536
1537 /* construct a chunk from the first msg in the tx_msg queue */
1538 ret = process_single_tx_qlock(mgr, txmsg, true);
1539
1540 if (ret != 1)
1541 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1542
1543 if (txmsg->seqno != -1) {
1544 WARN_ON((unsigned int)txmsg->seqno >
1545 ARRAY_SIZE(txmsg->dst->tx_slots));
1546 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1547 }
1548 }
1549
drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg)1550 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1551 struct drm_dp_sideband_msg_tx *txmsg)
1552 {
1553 mutex_lock(&mgr->qlock);
1554 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1555 if (list_is_singular(&mgr->tx_msg_downq))
1556 process_single_down_tx_qlock(mgr);
1557 mutex_unlock(&mgr->qlock);
1558 }
1559
drm_dp_send_link_address(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb)1560 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1561 struct drm_dp_mst_branch *mstb)
1562 {
1563 int len;
1564 struct drm_dp_sideband_msg_tx *txmsg;
1565 int ret;
1566
1567 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1568 if (!txmsg)
1569 return;
1570
1571 txmsg->dst = mstb;
1572 len = build_link_address(txmsg);
1573
1574 mstb->link_address_sent = true;
1575 drm_dp_queue_down_tx(mgr, txmsg);
1576
1577 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1578 if (ret > 0) {
1579 int i;
1580
1581 if (txmsg->reply.reply_type == 1)
1582 DRM_DEBUG_KMS("link address nak received\n");
1583 else {
1584 DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1585 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1586 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,
1587 txmsg->reply.u.link_addr.ports[i].input_port,
1588 txmsg->reply.u.link_addr.ports[i].peer_device_type,
1589 txmsg->reply.u.link_addr.ports[i].port_number,
1590 txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1591 txmsg->reply.u.link_addr.ports[i].mcs,
1592 txmsg->reply.u.link_addr.ports[i].ddps,
1593 txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1594 txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1595 txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1596 }
1597
1598 drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);
1599
1600 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1601 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1602 }
1603 (*mgr->cbs->hotplug)(mgr);
1604 }
1605 } else {
1606 mstb->link_address_sent = false;
1607 DRM_DEBUG_KMS("link address failed %d\n", ret);
1608 }
1609
1610 kfree(txmsg);
1611 }
1612
drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb,struct drm_dp_mst_port * port)1613 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1614 struct drm_dp_mst_branch *mstb,
1615 struct drm_dp_mst_port *port)
1616 {
1617 int len;
1618 struct drm_dp_sideband_msg_tx *txmsg;
1619 int ret;
1620
1621 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1622 if (!txmsg)
1623 return -ENOMEM;
1624
1625 txmsg->dst = mstb;
1626 len = build_enum_path_resources(txmsg, port->port_num);
1627
1628 drm_dp_queue_down_tx(mgr, txmsg);
1629
1630 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1631 if (ret > 0) {
1632 if (txmsg->reply.reply_type == 1)
1633 DRM_DEBUG_KMS("enum path resources nak received\n");
1634 else {
1635 if (port->port_num != txmsg->reply.u.path_resources.port_number)
1636 DRM_ERROR("got incorrect port in response\n");
1637 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,
1638 txmsg->reply.u.path_resources.avail_payload_bw_number);
1639 port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1640 }
1641 }
1642
1643 kfree(txmsg);
1644 return 0;
1645 }
1646
drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch * mstb)1647 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
1648 {
1649 if (!mstb->port_parent)
1650 return NULL;
1651
1652 if (mstb->port_parent->mstb != mstb)
1653 return mstb->port_parent;
1654
1655 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
1656 }
1657
drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb,int * port_num)1658 static struct drm_dp_mst_branch *drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
1659 struct drm_dp_mst_branch *mstb,
1660 int *port_num)
1661 {
1662 struct drm_dp_mst_branch *rmstb = NULL;
1663 struct drm_dp_mst_port *found_port;
1664 mutex_lock(&mgr->lock);
1665 if (mgr->mst_primary) {
1666 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
1667
1668 if (found_port) {
1669 rmstb = found_port->parent;
1670 kref_get(&rmstb->kref);
1671 *port_num = found_port->port_num;
1672 }
1673 }
1674 mutex_unlock(&mgr->lock);
1675 return rmstb;
1676 }
1677
drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int id,int pbn)1678 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1679 struct drm_dp_mst_port *port,
1680 int id,
1681 int pbn)
1682 {
1683 struct drm_dp_sideband_msg_tx *txmsg;
1684 struct drm_dp_mst_branch *mstb;
1685 int len, ret, port_num;
1686 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
1687 int i;
1688
1689 port = drm_dp_get_validated_port_ref(mgr, port);
1690 if (!port)
1691 return -EINVAL;
1692
1693 port_num = port->port_num;
1694 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1695 if (!mstb) {
1696 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, port->parent, &port_num);
1697
1698 if (!mstb) {
1699 drm_dp_put_port(port);
1700 return -EINVAL;
1701 }
1702 }
1703
1704 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1705 if (!txmsg) {
1706 ret = -ENOMEM;
1707 goto fail_put;
1708 }
1709
1710 for (i = 0; i < port->num_sdp_streams; i++)
1711 sinks[i] = i;
1712
1713 txmsg->dst = mstb;
1714 len = build_allocate_payload(txmsg, port_num,
1715 id,
1716 pbn, port->num_sdp_streams, sinks);
1717
1718 drm_dp_queue_down_tx(mgr, txmsg);
1719
1720 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1721 if (ret > 0) {
1722 if (txmsg->reply.reply_type == 1) {
1723 ret = -EINVAL;
1724 } else
1725 ret = 0;
1726 }
1727 kfree(txmsg);
1728 fail_put:
1729 drm_dp_put_mst_branch_device(mstb);
1730 drm_dp_put_port(port);
1731 return ret;
1732 }
1733
drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr * mgr,int id,struct drm_dp_payload * payload)1734 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1735 int id,
1736 struct drm_dp_payload *payload)
1737 {
1738 int ret;
1739
1740 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1741 if (ret < 0) {
1742 payload->payload_state = 0;
1743 return ret;
1744 }
1745 payload->payload_state = DP_PAYLOAD_LOCAL;
1746 return 0;
1747 }
1748
drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int id,struct drm_dp_payload * payload)1749 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1750 struct drm_dp_mst_port *port,
1751 int id,
1752 struct drm_dp_payload *payload)
1753 {
1754 int ret;
1755 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1756 if (ret < 0)
1757 return ret;
1758 payload->payload_state = DP_PAYLOAD_REMOTE;
1759 return ret;
1760 }
1761
drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int id,struct drm_dp_payload * payload)1762 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1763 struct drm_dp_mst_port *port,
1764 int id,
1765 struct drm_dp_payload *payload)
1766 {
1767 DRM_DEBUG_KMS("\n");
1768 /* its okay for these to fail */
1769 if (port) {
1770 drm_dp_payload_send_msg(mgr, port, id, 0);
1771 }
1772
1773 drm_dp_dpcd_write_payload(mgr, id, payload);
1774 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1775 return 0;
1776 }
1777
drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr * mgr,int id,struct drm_dp_payload * payload)1778 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1779 int id,
1780 struct drm_dp_payload *payload)
1781 {
1782 payload->payload_state = 0;
1783 return 0;
1784 }
1785
1786 /**
1787 * drm_dp_update_payload_part1() - Execute payload update part 1
1788 * @mgr: manager to use.
1789 *
1790 * This iterates over all proposed virtual channels, and tries to
1791 * allocate space in the link for them. For 0->slots transitions,
1792 * this step just writes the VCPI to the MST device. For slots->0
1793 * transitions, this writes the updated VCPIs and removes the
1794 * remote VC payloads.
1795 *
1796 * after calling this the driver should generate ACT and payload
1797 * packets.
1798 */
drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr * mgr)1799 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1800 {
1801 int i, j;
1802 int cur_slots = 1;
1803 struct drm_dp_payload req_payload;
1804 struct drm_dp_mst_port *port;
1805
1806 mutex_lock(&mgr->payload_lock);
1807 for (i = 0; i < mgr->max_payloads; i++) {
1808 /* solve the current payloads - compare to the hw ones
1809 - update the hw view */
1810 req_payload.start_slot = cur_slots;
1811 if (mgr->proposed_vcpis[i]) {
1812 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1813 port = drm_dp_get_validated_port_ref(mgr, port);
1814 if (!port) {
1815 mutex_unlock(&mgr->payload_lock);
1816 return -EINVAL;
1817 }
1818 req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1819 req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi;
1820 } else {
1821 port = NULL;
1822 req_payload.num_slots = 0;
1823 }
1824
1825 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1826 mgr->payloads[i].start_slot = req_payload.start_slot;
1827 }
1828 /* work out what is required to happen with this payload */
1829 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1830
1831 /* need to push an update for this payload */
1832 if (req_payload.num_slots) {
1833 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1834 mgr->payloads[i].num_slots = req_payload.num_slots;
1835 mgr->payloads[i].vcpi = req_payload.vcpi;
1836 } else if (mgr->payloads[i].num_slots) {
1837 mgr->payloads[i].num_slots = 0;
1838 drm_dp_destroy_payload_step1(mgr, port, mgr->payloads[i].vcpi, &mgr->payloads[i]);
1839 req_payload.payload_state = mgr->payloads[i].payload_state;
1840 mgr->payloads[i].start_slot = 0;
1841 }
1842 mgr->payloads[i].payload_state = req_payload.payload_state;
1843 }
1844 cur_slots += req_payload.num_slots;
1845
1846 if (port)
1847 drm_dp_put_port(port);
1848 }
1849
1850 for (i = 0; i < mgr->max_payloads; i++) {
1851 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1852 DRM_DEBUG_KMS("removing payload %d\n", i);
1853 for (j = i; j < mgr->max_payloads - 1; j++) {
1854 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1855 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1856 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1857 set_bit(j + 1, &mgr->payload_mask);
1858 } else {
1859 clear_bit(j + 1, &mgr->payload_mask);
1860 }
1861 }
1862 memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1863 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1864 clear_bit(mgr->max_payloads, &mgr->payload_mask);
1865
1866 }
1867 }
1868 mutex_unlock(&mgr->payload_lock);
1869
1870 return 0;
1871 }
1872 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1873
1874 /**
1875 * drm_dp_update_payload_part2() - Execute payload update part 2
1876 * @mgr: manager to use.
1877 *
1878 * This iterates over all proposed virtual channels, and tries to
1879 * allocate space in the link for them. For 0->slots transitions,
1880 * this step writes the remote VC payload commands. For slots->0
1881 * this just resets some internal state.
1882 */
drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr * mgr)1883 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1884 {
1885 struct drm_dp_mst_port *port;
1886 int i;
1887 int ret = 0;
1888 mutex_lock(&mgr->payload_lock);
1889 for (i = 0; i < mgr->max_payloads; i++) {
1890
1891 if (!mgr->proposed_vcpis[i])
1892 continue;
1893
1894 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1895
1896 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1897 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1898 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1899 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1900 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1901 }
1902 if (ret) {
1903 mutex_unlock(&mgr->payload_lock);
1904 return ret;
1905 }
1906 }
1907 mutex_unlock(&mgr->payload_lock);
1908 return 0;
1909 }
1910 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1911
1912 #if 0 /* unused as of yet */
1913 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1914 struct drm_dp_mst_port *port,
1915 int offset, int size)
1916 {
1917 int len;
1918 struct drm_dp_sideband_msg_tx *txmsg;
1919
1920 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1921 if (!txmsg)
1922 return -ENOMEM;
1923
1924 len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1925 txmsg->dst = port->parent;
1926
1927 drm_dp_queue_down_tx(mgr, txmsg);
1928
1929 return 0;
1930 }
1931 #endif
1932
drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int offset,int size,u8 * bytes)1933 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1934 struct drm_dp_mst_port *port,
1935 int offset, int size, u8 *bytes)
1936 {
1937 int len;
1938 int ret;
1939 struct drm_dp_sideband_msg_tx *txmsg;
1940 struct drm_dp_mst_branch *mstb;
1941
1942 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1943 if (!mstb)
1944 return -EINVAL;
1945
1946 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1947 if (!txmsg) {
1948 ret = -ENOMEM;
1949 goto fail_put;
1950 }
1951
1952 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1953 txmsg->dst = mstb;
1954
1955 drm_dp_queue_down_tx(mgr, txmsg);
1956
1957 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1958 if (ret > 0) {
1959 if (txmsg->reply.reply_type == 1) {
1960 ret = -EINVAL;
1961 } else
1962 ret = 0;
1963 }
1964 kfree(txmsg);
1965 fail_put:
1966 drm_dp_put_mst_branch_device(mstb);
1967 return ret;
1968 }
1969
drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx * msg,u8 req_type)1970 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1971 {
1972 struct drm_dp_sideband_msg_reply_body reply;
1973
1974 reply.reply_type = 0;
1975 reply.req_type = req_type;
1976 drm_dp_encode_sideband_reply(&reply, msg);
1977 return 0;
1978 }
1979
drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb,int req_type,int seqno,bool broadcast)1980 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1981 struct drm_dp_mst_branch *mstb,
1982 int req_type, int seqno, bool broadcast)
1983 {
1984 struct drm_dp_sideband_msg_tx *txmsg;
1985
1986 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1987 if (!txmsg)
1988 return -ENOMEM;
1989
1990 txmsg->dst = mstb;
1991 txmsg->seqno = seqno;
1992 drm_dp_encode_up_ack_reply(txmsg, req_type);
1993
1994 mutex_lock(&mgr->qlock);
1995
1996 process_single_up_tx_qlock(mgr, txmsg);
1997
1998 mutex_unlock(&mgr->qlock);
1999
2000 kfree(txmsg);
2001 return 0;
2002 }
2003
drm_dp_get_vc_payload_bw(int dp_link_bw,int dp_link_count,int * out)2004 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
2005 int dp_link_count,
2006 int *out)
2007 {
2008 switch (dp_link_bw) {
2009 default:
2010 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
2011 dp_link_bw, dp_link_count);
2012 return false;
2013
2014 case DP_LINK_BW_1_62:
2015 *out = 3 * dp_link_count;
2016 break;
2017 case DP_LINK_BW_2_7:
2018 *out = 5 * dp_link_count;
2019 break;
2020 case DP_LINK_BW_5_4:
2021 *out = 10 * dp_link_count;
2022 break;
2023 }
2024 return true;
2025 }
2026
2027 /**
2028 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
2029 * @mgr: manager to set state for
2030 * @mst_state: true to enable MST on this connector - false to disable.
2031 *
2032 * This is called by the driver when it detects an MST capable device plugged
2033 * into a DP MST capable port, or when a DP MST capable device is unplugged.
2034 */
drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr * mgr,bool mst_state)2035 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
2036 {
2037 int ret = 0;
2038 struct drm_dp_mst_branch *mstb = NULL;
2039
2040 mutex_lock(&mgr->lock);
2041 if (mst_state == mgr->mst_state)
2042 goto out_unlock;
2043
2044 mgr->mst_state = mst_state;
2045 /* set the device into MST mode */
2046 if (mst_state) {
2047 WARN_ON(mgr->mst_primary);
2048
2049 /* get dpcd info */
2050 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2051 if (ret != DP_RECEIVER_CAP_SIZE) {
2052 DRM_DEBUG_KMS("failed to read DPCD\n");
2053 goto out_unlock;
2054 }
2055
2056 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
2057 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
2058 &mgr->pbn_div)) {
2059 ret = -EINVAL;
2060 goto out_unlock;
2061 }
2062
2063 /* add initial branch device at LCT 1 */
2064 mstb = drm_dp_add_mst_branch_device(1, NULL);
2065 if (mstb == NULL) {
2066 ret = -ENOMEM;
2067 goto out_unlock;
2068 }
2069 mstb->mgr = mgr;
2070
2071 /* give this the main reference */
2072 mgr->mst_primary = mstb;
2073 kref_get(&mgr->mst_primary->kref);
2074
2075 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2076 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2077 if (ret < 0) {
2078 goto out_unlock;
2079 }
2080
2081 {
2082 struct drm_dp_payload reset_pay;
2083 reset_pay.start_slot = 0;
2084 reset_pay.num_slots = 0x3f;
2085 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
2086 }
2087
2088 queue_work(system_long_wq, &mgr->work);
2089
2090 ret = 0;
2091 } else {
2092 /* disable MST on the device */
2093 mstb = mgr->mst_primary;
2094 mgr->mst_primary = NULL;
2095 /* this can fail if the device is gone */
2096 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2097 ret = 0;
2098 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2099 mgr->payload_mask = 0;
2100 set_bit(0, &mgr->payload_mask);
2101 mgr->vcpi_mask = 0;
2102 }
2103
2104 out_unlock:
2105 mutex_unlock(&mgr->lock);
2106 if (mstb)
2107 drm_dp_put_mst_branch_device(mstb);
2108 return ret;
2109
2110 }
2111 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2112
2113 /**
2114 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2115 * @mgr: manager to suspend
2116 *
2117 * This function tells the MST device that we can't handle UP messages
2118 * anymore. This should stop it from sending any since we are suspended.
2119 */
drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr * mgr)2120 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2121 {
2122 mutex_lock(&mgr->lock);
2123 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2124 DP_MST_EN | DP_UPSTREAM_IS_SRC);
2125 mutex_unlock(&mgr->lock);
2126 flush_work(&mgr->work);
2127 flush_work(&mgr->destroy_connector_work);
2128 }
2129 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2130
2131 /**
2132 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2133 * @mgr: manager to resume
2134 *
2135 * This will fetch DPCD and see if the device is still there,
2136 * if it is, it will rewrite the MSTM control bits, and return.
2137 *
2138 * if the device fails this returns -1, and the driver should do
2139 * a full MST reprobe, in case we were undocked.
2140 */
drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr * mgr)2141 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2142 {
2143 int ret = 0;
2144
2145 mutex_lock(&mgr->lock);
2146
2147 if (mgr->mst_primary) {
2148 int sret;
2149 u8 guid[16];
2150
2151 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2152 if (sret != DP_RECEIVER_CAP_SIZE) {
2153 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2154 ret = -1;
2155 goto out_unlock;
2156 }
2157
2158 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2159 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2160 if (ret < 0) {
2161 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2162 ret = -1;
2163 goto out_unlock;
2164 }
2165
2166 /* Some hubs forget their guids after they resume */
2167 sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
2168 if (sret != 16) {
2169 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2170 ret = -1;
2171 goto out_unlock;
2172 }
2173 drm_dp_check_mstb_guid(mgr->mst_primary, guid);
2174
2175 ret = 0;
2176 } else
2177 ret = -1;
2178
2179 out_unlock:
2180 mutex_unlock(&mgr->lock);
2181 return ret;
2182 }
2183 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2184
drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr * mgr,bool up)2185 static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2186 {
2187 int len;
2188 u8 replyblock[32];
2189 int replylen, origlen, curreply;
2190 int ret;
2191 struct drm_dp_sideband_msg_rx *msg;
2192 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2193 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2194
2195 len = min(mgr->max_dpcd_transaction_bytes, 16);
2196 ret = drm_dp_dpcd_read(mgr->aux, basereg,
2197 replyblock, len);
2198 if (ret != len) {
2199 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2200 return false;
2201 }
2202 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2203 if (!ret) {
2204 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2205 return false;
2206 }
2207 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2208
2209 origlen = replylen;
2210 replylen -= len;
2211 curreply = len;
2212 while (replylen > 0) {
2213 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2214 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2215 replyblock, len);
2216 if (ret != len) {
2217 DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
2218 len, ret);
2219 return false;
2220 }
2221
2222 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2223 if (!ret) {
2224 DRM_DEBUG_KMS("failed to build sideband msg\n");
2225 return false;
2226 }
2227
2228 curreply += len;
2229 replylen -= len;
2230 }
2231 return true;
2232 }
2233
drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr * mgr)2234 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2235 {
2236 int ret = 0;
2237
2238 if (!drm_dp_get_one_sb_msg(mgr, false)) {
2239 memset(&mgr->down_rep_recv, 0,
2240 sizeof(struct drm_dp_sideband_msg_rx));
2241 return 0;
2242 }
2243
2244 if (mgr->down_rep_recv.have_eomt) {
2245 struct drm_dp_sideband_msg_tx *txmsg;
2246 struct drm_dp_mst_branch *mstb;
2247 int slot = -1;
2248 mstb = drm_dp_get_mst_branch_device(mgr,
2249 mgr->down_rep_recv.initial_hdr.lct,
2250 mgr->down_rep_recv.initial_hdr.rad);
2251
2252 if (!mstb) {
2253 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2254 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2255 return 0;
2256 }
2257
2258 /* find the message */
2259 slot = mgr->down_rep_recv.initial_hdr.seqno;
2260 mutex_lock(&mgr->qlock);
2261 txmsg = mstb->tx_slots[slot];
2262 /* remove from slots */
2263 mutex_unlock(&mgr->qlock);
2264
2265 if (!txmsg) {
2266 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2267 mstb,
2268 mgr->down_rep_recv.initial_hdr.seqno,
2269 mgr->down_rep_recv.initial_hdr.lct,
2270 mgr->down_rep_recv.initial_hdr.rad[0],
2271 mgr->down_rep_recv.msg[0]);
2272 drm_dp_put_mst_branch_device(mstb);
2273 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2274 return 0;
2275 }
2276
2277 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2278 if (txmsg->reply.reply_type == 1) {
2279 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);
2280 }
2281
2282 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2283 drm_dp_put_mst_branch_device(mstb);
2284
2285 mutex_lock(&mgr->qlock);
2286 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2287 mstb->tx_slots[slot] = NULL;
2288 mutex_unlock(&mgr->qlock);
2289
2290 wake_up_all(&mgr->tx_waitq);
2291 }
2292 return ret;
2293 }
2294
drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr * mgr)2295 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2296 {
2297 int ret = 0;
2298
2299 if (!drm_dp_get_one_sb_msg(mgr, true)) {
2300 memset(&mgr->up_req_recv, 0,
2301 sizeof(struct drm_dp_sideband_msg_rx));
2302 return 0;
2303 }
2304
2305 if (mgr->up_req_recv.have_eomt) {
2306 struct drm_dp_sideband_msg_req_body msg;
2307 struct drm_dp_mst_branch *mstb = NULL;
2308 bool seqno;
2309
2310 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2311 mstb = drm_dp_get_mst_branch_device(mgr,
2312 mgr->up_req_recv.initial_hdr.lct,
2313 mgr->up_req_recv.initial_hdr.rad);
2314 if (!mstb) {
2315 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2316 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2317 return 0;
2318 }
2319 }
2320
2321 seqno = mgr->up_req_recv.initial_hdr.seqno;
2322 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2323
2324 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2325 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2326
2327 if (!mstb)
2328 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2329
2330 if (!mstb) {
2331 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2332 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2333 return 0;
2334 }
2335
2336 drm_dp_update_port(mstb, &msg.u.conn_stat);
2337
2338 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);
2339 (*mgr->cbs->hotplug)(mgr);
2340
2341 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2342 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2343 if (!mstb)
2344 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2345
2346 if (!mstb) {
2347 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2348 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2349 return 0;
2350 }
2351
2352 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2353 }
2354
2355 if (mstb)
2356 drm_dp_put_mst_branch_device(mstb);
2357
2358 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2359 }
2360 return ret;
2361 }
2362
2363 /**
2364 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2365 * @mgr: manager to notify irq for.
2366 * @esi: 4 bytes from SINK_COUNT_ESI
2367 * @handled: whether the hpd interrupt was consumed or not
2368 *
2369 * This should be called from the driver when it detects a short IRQ,
2370 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2371 * topology manager will process the sideband messages received as a result
2372 * of this.
2373 */
drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr * mgr,u8 * esi,bool * handled)2374 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2375 {
2376 int ret = 0;
2377 int sc;
2378 *handled = false;
2379 sc = esi[0] & 0x3f;
2380
2381 if (sc != mgr->sink_count) {
2382 mgr->sink_count = sc;
2383 *handled = true;
2384 }
2385
2386 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2387 ret = drm_dp_mst_handle_down_rep(mgr);
2388 *handled = true;
2389 }
2390
2391 if (esi[1] & DP_UP_REQ_MSG_RDY) {
2392 ret |= drm_dp_mst_handle_up_req(mgr);
2393 *handled = true;
2394 }
2395
2396 drm_dp_mst_kick_tx(mgr);
2397 return ret;
2398 }
2399 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2400
2401 /**
2402 * drm_dp_mst_detect_port() - get connection status for an MST port
2403 * @connector: DRM connector for this port
2404 * @mgr: manager for this port
2405 * @port: unverified pointer to a port
2406 *
2407 * This returns the current connection state for a port. It validates the
2408 * port pointer still exists so the caller doesn't require a reference
2409 */
drm_dp_mst_detect_port(struct drm_connector * connector,struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2410 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2411 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2412 {
2413 enum drm_connector_status status = connector_status_disconnected;
2414
2415 /* we need to search for the port in the mgr in case its gone */
2416 port = drm_dp_get_validated_port_ref(mgr, port);
2417 if (!port)
2418 return connector_status_disconnected;
2419
2420 if (!port->ddps)
2421 goto out;
2422
2423 switch (port->pdt) {
2424 case DP_PEER_DEVICE_NONE:
2425 case DP_PEER_DEVICE_MST_BRANCHING:
2426 break;
2427
2428 case DP_PEER_DEVICE_SST_SINK:
2429 status = connector_status_connected;
2430 /* for logical ports - cache the EDID */
2431 if (port->port_num >= 8 && !port->cached_edid) {
2432 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2433 }
2434 break;
2435 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2436 if (port->ldps)
2437 status = connector_status_connected;
2438 break;
2439 }
2440 out:
2441 drm_dp_put_port(port);
2442 return status;
2443 }
2444 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2445
2446 /**
2447 * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
2448 * @mgr: manager for this port
2449 * @port: unverified pointer to a port.
2450 *
2451 * This returns whether the port supports audio or not.
2452 */
drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2453 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
2454 struct drm_dp_mst_port *port)
2455 {
2456 bool ret = false;
2457
2458 port = drm_dp_get_validated_port_ref(mgr, port);
2459 if (!port)
2460 return ret;
2461 ret = port->has_audio;
2462 drm_dp_put_port(port);
2463 return ret;
2464 }
2465 EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
2466
2467 /**
2468 * drm_dp_mst_get_edid() - get EDID for an MST port
2469 * @connector: toplevel connector to get EDID for
2470 * @mgr: manager for this port
2471 * @port: unverified pointer to a port.
2472 *
2473 * This returns an EDID for the port connected to a connector,
2474 * It validates the pointer still exists so the caller doesn't require a
2475 * reference.
2476 */
drm_dp_mst_get_edid(struct drm_connector * connector,struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2477 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2478 {
2479 struct edid *edid = NULL;
2480
2481 /* we need to search for the port in the mgr in case its gone */
2482 port = drm_dp_get_validated_port_ref(mgr, port);
2483 if (!port)
2484 return NULL;
2485
2486 if (port->cached_edid)
2487 edid = drm_edid_duplicate(port->cached_edid);
2488 else {
2489 edid = drm_get_edid(connector, &port->aux.ddc);
2490 drm_mode_connector_set_tile_property(connector);
2491 }
2492 port->has_audio = drm_detect_monitor_audio(edid);
2493 drm_dp_put_port(port);
2494 return edid;
2495 }
2496 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2497
2498 /**
2499 * drm_dp_find_vcpi_slots() - find slots for this PBN value
2500 * @mgr: manager to use
2501 * @pbn: payload bandwidth to convert into slots.
2502 */
drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr * mgr,int pbn)2503 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2504 int pbn)
2505 {
2506 int num_slots;
2507
2508 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2509
2510 /* max. time slots - one slot for MTP header */
2511 if (num_slots > 63)
2512 return -ENOSPC;
2513 return num_slots;
2514 }
2515 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2516
drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_vcpi * vcpi,int pbn,int slots)2517 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2518 struct drm_dp_vcpi *vcpi, int pbn, int slots)
2519 {
2520 int ret;
2521
2522 /* max. time slots - one slot for MTP header */
2523 if (slots > 63)
2524 return -ENOSPC;
2525
2526 vcpi->pbn = pbn;
2527 vcpi->aligned_pbn = slots * mgr->pbn_div;
2528 vcpi->num_slots = slots;
2529
2530 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2531 if (ret < 0)
2532 return ret;
2533 return 0;
2534 }
2535
2536 /**
2537 * drm_dp_atomic_find_vcpi_slots() - Find and add vcpi slots to the state
2538 * @state: global atomic state
2539 * @mgr: MST topology manager for the port
2540 * @port: port to find vcpi slots for
2541 * @pbn: bandwidth required for the mode in PBN
2542 *
2543 * RETURNS:
2544 * Total slots in the atomic state assigned for this port or error
2545 */
drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state * state,struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int pbn)2546 int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
2547 struct drm_dp_mst_topology_mgr *mgr,
2548 struct drm_dp_mst_port *port, int pbn)
2549 {
2550 struct drm_dp_mst_topology_state *topology_state;
2551 int req_slots;
2552
2553 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
2554 if (IS_ERR(topology_state))
2555 return PTR_ERR(topology_state);
2556
2557 port = drm_dp_get_validated_port_ref(mgr, port);
2558 if (port == NULL)
2559 return -EINVAL;
2560 req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2561 DRM_DEBUG_KMS("vcpi slots req=%d, avail=%d\n",
2562 req_slots, topology_state->avail_slots);
2563
2564 if (req_slots > topology_state->avail_slots) {
2565 drm_dp_put_port(port);
2566 return -ENOSPC;
2567 }
2568
2569 topology_state->avail_slots -= req_slots;
2570 DRM_DEBUG_KMS("vcpi slots avail=%d", topology_state->avail_slots);
2571
2572 drm_dp_put_port(port);
2573 return req_slots;
2574 }
2575 EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
2576
2577 /**
2578 * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
2579 * @state: global atomic state
2580 * @mgr: MST topology manager for the port
2581 * @slots: number of vcpi slots to release
2582 *
2583 * RETURNS:
2584 * 0 if @slots were added back to &drm_dp_mst_topology_state->avail_slots or
2585 * negative error code
2586 */
drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state * state,struct drm_dp_mst_topology_mgr * mgr,int slots)2587 int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
2588 struct drm_dp_mst_topology_mgr *mgr,
2589 int slots)
2590 {
2591 struct drm_dp_mst_topology_state *topology_state;
2592
2593 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
2594 if (IS_ERR(topology_state))
2595 return PTR_ERR(topology_state);
2596
2597 /* We cannot rely on port->vcpi.num_slots to update
2598 * topology_state->avail_slots as the port may not exist if the parent
2599 * branch device was unplugged. This should be fixed by tracking
2600 * per-port slot allocation in drm_dp_mst_topology_state instead of
2601 * depending on the caller to tell us how many slots to release.
2602 */
2603 topology_state->avail_slots += slots;
2604 DRM_DEBUG_KMS("vcpi slots released=%d, avail=%d\n",
2605 slots, topology_state->avail_slots);
2606
2607 return 0;
2608 }
2609 EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
2610
2611 /**
2612 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2613 * @mgr: manager for this port
2614 * @port: port to allocate a virtual channel for.
2615 * @pbn: payload bandwidth number to request
2616 * @slots: returned number of slots for this PBN.
2617 */
drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int pbn,int slots)2618 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2619 struct drm_dp_mst_port *port, int pbn, int slots)
2620 {
2621 int ret;
2622
2623 port = drm_dp_get_validated_port_ref(mgr, port);
2624 if (!port)
2625 return false;
2626
2627 if (slots < 0)
2628 return false;
2629
2630 if (port->vcpi.vcpi > 0) {
2631 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2632 if (pbn == port->vcpi.pbn) {
2633 drm_dp_put_port(port);
2634 return true;
2635 }
2636 }
2637
2638 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
2639 if (ret) {
2640 DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
2641 DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
2642 goto out;
2643 }
2644 DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
2645 pbn, port->vcpi.num_slots);
2646
2647 drm_dp_put_port(port);
2648 return true;
2649 out:
2650 return false;
2651 }
2652 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2653
drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2654 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2655 {
2656 int slots = 0;
2657 port = drm_dp_get_validated_port_ref(mgr, port);
2658 if (!port)
2659 return slots;
2660
2661 slots = port->vcpi.num_slots;
2662 drm_dp_put_port(port);
2663 return slots;
2664 }
2665 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2666
2667 /**
2668 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2669 * @mgr: manager for this port
2670 * @port: unverified pointer to a port.
2671 *
2672 * This just resets the number of slots for the ports VCPI for later programming.
2673 */
drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2674 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2675 {
2676 port = drm_dp_get_validated_port_ref(mgr, port);
2677 if (!port)
2678 return;
2679 port->vcpi.num_slots = 0;
2680 drm_dp_put_port(port);
2681 }
2682 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2683
2684 /**
2685 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2686 * @mgr: manager for this port
2687 * @port: unverified port to deallocate vcpi for
2688 */
drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2689 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2690 {
2691 port = drm_dp_get_validated_port_ref(mgr, port);
2692 if (!port)
2693 return;
2694
2695 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2696 port->vcpi.num_slots = 0;
2697 port->vcpi.pbn = 0;
2698 port->vcpi.aligned_pbn = 0;
2699 port->vcpi.vcpi = 0;
2700 drm_dp_put_port(port);
2701 }
2702 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2703
drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr * mgr,int id,struct drm_dp_payload * payload)2704 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2705 int id, struct drm_dp_payload *payload)
2706 {
2707 u8 payload_alloc[3], status;
2708 int ret;
2709 int retries = 0;
2710
2711 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2712 DP_PAYLOAD_TABLE_UPDATED);
2713
2714 payload_alloc[0] = id;
2715 payload_alloc[1] = payload->start_slot;
2716 payload_alloc[2] = payload->num_slots;
2717
2718 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2719 if (ret != 3) {
2720 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2721 goto fail;
2722 }
2723
2724 retry:
2725 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2726 if (ret < 0) {
2727 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2728 goto fail;
2729 }
2730
2731 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2732 retries++;
2733 if (retries < 20) {
2734 usleep_range(10000, 20000);
2735 goto retry;
2736 }
2737 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2738 ret = -EINVAL;
2739 goto fail;
2740 }
2741 ret = 0;
2742 fail:
2743 return ret;
2744 }
2745
2746
2747 /**
2748 * drm_dp_check_act_status() - Check ACT handled status.
2749 * @mgr: manager to use
2750 *
2751 * Check the payload status bits in the DPCD for ACT handled completion.
2752 */
drm_dp_check_act_status(struct drm_dp_mst_topology_mgr * mgr)2753 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2754 {
2755 u8 status;
2756 int ret;
2757 int count = 0;
2758
2759 do {
2760 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2761
2762 if (ret < 0) {
2763 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2764 goto fail;
2765 }
2766
2767 if (status & DP_PAYLOAD_ACT_HANDLED)
2768 break;
2769 count++;
2770 udelay(100);
2771
2772 } while (count < 30);
2773
2774 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2775 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2776 ret = -EINVAL;
2777 goto fail;
2778 }
2779 return 0;
2780 fail:
2781 return ret;
2782 }
2783 EXPORT_SYMBOL(drm_dp_check_act_status);
2784
2785 /**
2786 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2787 * @clock: dot clock for the mode
2788 * @bpp: bpp for the mode.
2789 *
2790 * This uses the formula in the spec to calculate the PBN value for a mode.
2791 */
drm_dp_calc_pbn_mode(int clock,int bpp)2792 int drm_dp_calc_pbn_mode(int clock, int bpp)
2793 {
2794 u64 kbps;
2795 s64 peak_kbps;
2796 u32 numerator;
2797 u32 denominator;
2798
2799 kbps = clock * bpp;
2800
2801 /*
2802 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
2803 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
2804 * common multiplier to render an integer PBN for all link rate/lane
2805 * counts combinations
2806 * calculate
2807 * peak_kbps *= (1006/1000)
2808 * peak_kbps *= (64/54)
2809 * peak_kbps *= 8 convert to bytes
2810 */
2811
2812 numerator = 64 * 1006;
2813 denominator = 54 * 8 * 1000 * 1000;
2814
2815 kbps *= numerator;
2816 peak_kbps = drm_fixp_from_fraction(kbps, denominator);
2817
2818 return drm_fixp2int_ceil(peak_kbps);
2819 }
2820 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2821
test_calc_pbn_mode(void)2822 static int test_calc_pbn_mode(void)
2823 {
2824 int ret;
2825 ret = drm_dp_calc_pbn_mode(154000, 30);
2826 if (ret != 689) {
2827 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2828 154000, 30, 689, ret);
2829 return -EINVAL;
2830 }
2831 ret = drm_dp_calc_pbn_mode(234000, 30);
2832 if (ret != 1047) {
2833 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2834 234000, 30, 1047, ret);
2835 return -EINVAL;
2836 }
2837 ret = drm_dp_calc_pbn_mode(297000, 24);
2838 if (ret != 1063) {
2839 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2840 297000, 24, 1063, ret);
2841 return -EINVAL;
2842 }
2843 return 0;
2844 }
2845
2846 /* we want to kick the TX after we've ack the up/down IRQs. */
drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr * mgr)2847 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2848 {
2849 queue_work(system_long_wq, &mgr->tx_work);
2850 }
2851
drm_dp_mst_dump_mstb(struct seq_file * m,struct drm_dp_mst_branch * mstb)2852 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2853 struct drm_dp_mst_branch *mstb)
2854 {
2855 struct drm_dp_mst_port *port;
2856 int tabs = mstb->lct;
2857 char prefix[10];
2858 int i;
2859
2860 for (i = 0; i < tabs; i++)
2861 prefix[i] = '\t';
2862 prefix[i] = '\0';
2863
2864 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2865 list_for_each_entry(port, &mstb->ports, next) {
2866 seq_printf(m, "%sport: %d: input: %d: pdt: %d, ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->input, port->pdt, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
2867 if (port->mstb)
2868 drm_dp_mst_dump_mstb(m, port->mstb);
2869 }
2870 }
2871
2872 #define DP_PAYLOAD_TABLE_SIZE 64
2873
dump_dp_payload_table(struct drm_dp_mst_topology_mgr * mgr,char * buf)2874 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2875 char *buf)
2876 {
2877 int i;
2878
2879 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
2880 if (drm_dp_dpcd_read(mgr->aux,
2881 DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
2882 &buf[i], 16) != 16)
2883 return false;
2884 }
2885 return true;
2886 }
2887
fetch_monitor_name(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,char * name,int namelen)2888 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
2889 struct drm_dp_mst_port *port, char *name,
2890 int namelen)
2891 {
2892 struct edid *mst_edid;
2893
2894 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
2895 drm_edid_get_monitor_name(mst_edid, name, namelen);
2896 }
2897
2898 /**
2899 * drm_dp_mst_dump_topology(): dump topology to seq file.
2900 * @m: seq_file to dump output to
2901 * @mgr: manager to dump current topology for.
2902 *
2903 * helper to dump MST topology to a seq file for debugfs.
2904 */
drm_dp_mst_dump_topology(struct seq_file * m,struct drm_dp_mst_topology_mgr * mgr)2905 void drm_dp_mst_dump_topology(struct seq_file *m,
2906 struct drm_dp_mst_topology_mgr *mgr)
2907 {
2908 int i;
2909 struct drm_dp_mst_port *port;
2910
2911 mutex_lock(&mgr->lock);
2912 if (mgr->mst_primary)
2913 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2914
2915 /* dump VCPIs */
2916 mutex_unlock(&mgr->lock);
2917
2918 mutex_lock(&mgr->payload_lock);
2919 seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
2920 mgr->max_payloads);
2921
2922 for (i = 0; i < mgr->max_payloads; i++) {
2923 if (mgr->proposed_vcpis[i]) {
2924 char name[14];
2925
2926 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2927 fetch_monitor_name(mgr, port, name, sizeof(name));
2928 seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
2929 port->port_num, port->vcpi.vcpi,
2930 port->vcpi.num_slots,
2931 (*name != 0) ? name : "Unknown");
2932 } else
2933 seq_printf(m, "vcpi %d:unused\n", i);
2934 }
2935 for (i = 0; i < mgr->max_payloads; i++) {
2936 seq_printf(m, "payload %d: %d, %d, %d\n",
2937 i,
2938 mgr->payloads[i].payload_state,
2939 mgr->payloads[i].start_slot,
2940 mgr->payloads[i].num_slots);
2941
2942
2943 }
2944 mutex_unlock(&mgr->payload_lock);
2945
2946 mutex_lock(&mgr->lock);
2947 if (mgr->mst_primary) {
2948 u8 buf[DP_PAYLOAD_TABLE_SIZE];
2949 int ret;
2950
2951 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2952 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
2953 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2954 seq_printf(m, "faux/mst: %*ph\n", 2, buf);
2955 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2956 seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
2957
2958 /* dump the standard OUI branch header */
2959 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
2960 seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
2961 for (i = 0x3; i < 0x8 && buf[i]; i++)
2962 seq_printf(m, "%c", buf[i]);
2963 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
2964 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
2965 if (dump_dp_payload_table(mgr, buf))
2966 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
2967 }
2968
2969 mutex_unlock(&mgr->lock);
2970
2971 }
2972 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2973
drm_dp_tx_work(struct work_struct * work)2974 static void drm_dp_tx_work(struct work_struct *work)
2975 {
2976 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2977
2978 mutex_lock(&mgr->qlock);
2979 if (!list_empty(&mgr->tx_msg_downq))
2980 process_single_down_tx_qlock(mgr);
2981 mutex_unlock(&mgr->qlock);
2982 }
2983
drm_dp_free_mst_port(struct kref * kref)2984 static void drm_dp_free_mst_port(struct kref *kref)
2985 {
2986 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
2987 kref_put(&port->parent->kref, drm_dp_free_mst_branch_device);
2988 kfree(port);
2989 }
2990
drm_dp_destroy_connector_work(struct work_struct * work)2991 static void drm_dp_destroy_connector_work(struct work_struct *work)
2992 {
2993 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
2994 struct drm_dp_mst_port *port;
2995 bool send_hotplug = false;
2996 /*
2997 * Not a regular list traverse as we have to drop the destroy
2998 * connector lock before destroying the connector, to avoid AB->BA
2999 * ordering between this lock and the config mutex.
3000 */
3001 for (;;) {
3002 mutex_lock(&mgr->destroy_connector_lock);
3003 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
3004 if (!port) {
3005 mutex_unlock(&mgr->destroy_connector_lock);
3006 break;
3007 }
3008 list_del(&port->next);
3009 mutex_unlock(&mgr->destroy_connector_lock);
3010
3011 kref_init(&port->kref);
3012 INIT_LIST_HEAD(&port->next);
3013
3014 mgr->cbs->destroy_connector(mgr, port->connector);
3015
3016 drm_dp_port_teardown_pdt(port, port->pdt);
3017 port->pdt = DP_PEER_DEVICE_NONE;
3018
3019 if (!port->input && port->vcpi.vcpi > 0) {
3020 drm_dp_mst_reset_vcpi_slots(mgr, port);
3021 drm_dp_update_payload_part1(mgr);
3022 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
3023 }
3024
3025 kref_put(&port->kref, drm_dp_free_mst_port);
3026 send_hotplug = true;
3027 }
3028 if (send_hotplug)
3029 (*mgr->cbs->hotplug)(mgr);
3030 }
3031
3032 static struct drm_private_state *
drm_dp_mst_duplicate_state(struct drm_private_obj * obj)3033 drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
3034 {
3035 struct drm_dp_mst_topology_state *state;
3036
3037 state = kmemdup(obj->state, sizeof(*state), GFP_KERNEL);
3038 if (!state)
3039 return NULL;
3040
3041 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
3042
3043 return &state->base;
3044 }
3045
drm_dp_mst_destroy_state(struct drm_private_obj * obj,struct drm_private_state * state)3046 static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
3047 struct drm_private_state *state)
3048 {
3049 struct drm_dp_mst_topology_state *mst_state =
3050 to_dp_mst_topology_state(state);
3051
3052 kfree(mst_state);
3053 }
3054
3055 static const struct drm_private_state_funcs mst_state_funcs = {
3056 .atomic_duplicate_state = drm_dp_mst_duplicate_state,
3057 .atomic_destroy_state = drm_dp_mst_destroy_state,
3058 };
3059
3060 /**
3061 * drm_atomic_get_mst_topology_state: get MST topology state
3062 *
3063 * @state: global atomic state
3064 * @mgr: MST topology manager, also the private object in this case
3065 *
3066 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
3067 * state vtable so that the private object state returned is that of a MST
3068 * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
3069 * to care of the locking, so warn if don't hold the connection_mutex.
3070 *
3071 * RETURNS:
3072 *
3073 * The MST topology state or error pointer.
3074 */
drm_atomic_get_mst_topology_state(struct drm_atomic_state * state,struct drm_dp_mst_topology_mgr * mgr)3075 struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
3076 struct drm_dp_mst_topology_mgr *mgr)
3077 {
3078 struct drm_device *dev = mgr->dev;
3079
3080 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
3081 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
3082 }
3083 EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
3084
3085 /**
3086 * drm_dp_mst_topology_mgr_init - initialise a topology manager
3087 * @mgr: manager struct to initialise
3088 * @dev: device providing this structure - for i2c addition.
3089 * @aux: DP helper aux channel to talk to this device
3090 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
3091 * @max_payloads: maximum number of payloads this GPU can source
3092 * @conn_base_id: the connector object ID the MST device is connected to.
3093 *
3094 * Return 0 for success, or negative error code on failure
3095 */
drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr * mgr,struct drm_device * dev,struct drm_dp_aux * aux,int max_dpcd_transaction_bytes,int max_payloads,int conn_base_id)3096 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
3097 struct drm_device *dev, struct drm_dp_aux *aux,
3098 int max_dpcd_transaction_bytes,
3099 int max_payloads, int conn_base_id)
3100 {
3101 struct drm_dp_mst_topology_state *mst_state;
3102
3103 mutex_init(&mgr->lock);
3104 mutex_init(&mgr->qlock);
3105 mutex_init(&mgr->payload_lock);
3106 mutex_init(&mgr->destroy_connector_lock);
3107 INIT_LIST_HEAD(&mgr->tx_msg_downq);
3108 INIT_LIST_HEAD(&mgr->destroy_connector_list);
3109 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
3110 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
3111 INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
3112 init_waitqueue_head(&mgr->tx_waitq);
3113 mgr->dev = dev;
3114 mgr->aux = aux;
3115 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
3116 mgr->max_payloads = max_payloads;
3117 mgr->conn_base_id = conn_base_id;
3118 if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
3119 max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
3120 return -EINVAL;
3121 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
3122 if (!mgr->payloads)
3123 return -ENOMEM;
3124 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
3125 if (!mgr->proposed_vcpis)
3126 return -ENOMEM;
3127 set_bit(0, &mgr->payload_mask);
3128 if (test_calc_pbn_mode() < 0)
3129 DRM_ERROR("MST PBN self-test failed\n");
3130
3131 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
3132 if (mst_state == NULL)
3133 return -ENOMEM;
3134
3135 mst_state->mgr = mgr;
3136
3137 /* max. time slots - one slot for MTP header */
3138 mst_state->avail_slots = 63;
3139
3140 drm_atomic_private_obj_init(&mgr->base,
3141 &mst_state->base,
3142 &mst_state_funcs);
3143
3144 return 0;
3145 }
3146 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
3147
3148 /**
3149 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
3150 * @mgr: manager to destroy
3151 */
drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr * mgr)3152 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
3153 {
3154 flush_work(&mgr->work);
3155 flush_work(&mgr->destroy_connector_work);
3156 mutex_lock(&mgr->payload_lock);
3157 kfree(mgr->payloads);
3158 mgr->payloads = NULL;
3159 kfree(mgr->proposed_vcpis);
3160 mgr->proposed_vcpis = NULL;
3161 mutex_unlock(&mgr->payload_lock);
3162 mgr->dev = NULL;
3163 mgr->aux = NULL;
3164 drm_atomic_private_obj_fini(&mgr->base);
3165 mgr->funcs = NULL;
3166 }
3167 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
3168
3169 /* I2C device */
drm_dp_mst_i2c_xfer(struct i2c_adapter * adapter,struct i2c_msg * msgs,int num)3170 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
3171 int num)
3172 {
3173 struct drm_dp_aux *aux = adapter->algo_data;
3174 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
3175 struct drm_dp_mst_branch *mstb;
3176 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
3177 unsigned int i;
3178 bool reading = false;
3179 struct drm_dp_sideband_msg_req_body msg;
3180 struct drm_dp_sideband_msg_tx *txmsg = NULL;
3181 int ret;
3182
3183 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
3184 if (!mstb)
3185 return -EREMOTEIO;
3186
3187 /* construct i2c msg */
3188 /* see if last msg is a read */
3189 if (msgs[num - 1].flags & I2C_M_RD)
3190 reading = true;
3191
3192 if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
3193 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
3194 ret = -EIO;
3195 goto out;
3196 }
3197
3198 memset(&msg, 0, sizeof(msg));
3199 msg.req_type = DP_REMOTE_I2C_READ;
3200 msg.u.i2c_read.num_transactions = num - 1;
3201 msg.u.i2c_read.port_number = port->port_num;
3202 for (i = 0; i < num - 1; i++) {
3203 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
3204 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
3205 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
3206 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
3207 }
3208 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
3209 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
3210
3211 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3212 if (!txmsg) {
3213 ret = -ENOMEM;
3214 goto out;
3215 }
3216
3217 txmsg->dst = mstb;
3218 drm_dp_encode_sideband_req(&msg, txmsg);
3219
3220 drm_dp_queue_down_tx(mgr, txmsg);
3221
3222 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3223 if (ret > 0) {
3224
3225 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
3226 ret = -EREMOTEIO;
3227 goto out;
3228 }
3229 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
3230 ret = -EIO;
3231 goto out;
3232 }
3233 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
3234 ret = num;
3235 }
3236 out:
3237 kfree(txmsg);
3238 drm_dp_put_mst_branch_device(mstb);
3239 return ret;
3240 }
3241
drm_dp_mst_i2c_functionality(struct i2c_adapter * adapter)3242 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
3243 {
3244 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
3245 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
3246 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
3247 I2C_FUNC_10BIT_ADDR;
3248 }
3249
3250 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
3251 .functionality = drm_dp_mst_i2c_functionality,
3252 .master_xfer = drm_dp_mst_i2c_xfer,
3253 };
3254
3255 /**
3256 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
3257 * @aux: DisplayPort AUX channel
3258 *
3259 * Returns 0 on success or a negative error code on failure.
3260 */
drm_dp_mst_register_i2c_bus(struct drm_dp_aux * aux)3261 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
3262 {
3263 aux->ddc.algo = &drm_dp_mst_i2c_algo;
3264 aux->ddc.algo_data = aux;
3265 aux->ddc.retries = 3;
3266
3267 aux->ddc.class = I2C_CLASS_DDC;
3268 aux->ddc.owner = THIS_MODULE;
3269 aux->ddc.dev.parent = aux->dev;
3270 aux->ddc.dev.of_node = aux->dev->of_node;
3271
3272 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
3273 sizeof(aux->ddc.name));
3274
3275 return i2c_add_adapter(&aux->ddc);
3276 }
3277
3278 /**
3279 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
3280 * @aux: DisplayPort AUX channel
3281 */
drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux * aux)3282 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
3283 {
3284 i2c_del_adapter(&aux->ddc);
3285 }
3286