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) << 5;
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 case DP_POWER_DOWN_PHY:
299 case DP_POWER_UP_PHY:
300 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
301 idx++;
302 break;
303 }
304 raw->cur_len = idx;
305 }
306
drm_dp_crc_sideband_chunk_req(u8 * msg,u8 len)307 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
308 {
309 u8 crc4;
310 crc4 = drm_dp_msg_data_crc4(msg, len);
311 msg[len] = crc4;
312 }
313
drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body * rep,struct drm_dp_sideband_msg_tx * raw)314 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
315 struct drm_dp_sideband_msg_tx *raw)
316 {
317 int idx = 0;
318 u8 *buf = raw->msg;
319
320 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
321
322 raw->cur_len = idx;
323 }
324
325 /* 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)326 static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
327 u8 *replybuf, u8 replybuflen, bool hdr)
328 {
329 int ret;
330 u8 crc4;
331
332 if (hdr) {
333 u8 hdrlen;
334 struct drm_dp_sideband_msg_hdr recv_hdr;
335 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
336 if (ret == false) {
337 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
338 return false;
339 }
340
341 /*
342 * ignore out-of-order messages or messages that are part of a
343 * failed transaction
344 */
345 if (!recv_hdr.somt && !msg->have_somt)
346 return false;
347
348 /* get length contained in this portion */
349 msg->curchunk_len = recv_hdr.msg_len;
350 msg->curchunk_hdrlen = hdrlen;
351
352 /* we have already gotten an somt - don't bother parsing */
353 if (recv_hdr.somt && msg->have_somt)
354 return false;
355
356 if (recv_hdr.somt) {
357 memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
358 msg->have_somt = true;
359 }
360 if (recv_hdr.eomt)
361 msg->have_eomt = true;
362
363 /* copy the bytes for the remainder of this header chunk */
364 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
365 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
366 } else {
367 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
368 msg->curchunk_idx += replybuflen;
369 }
370
371 if (msg->curchunk_idx >= msg->curchunk_len) {
372 /* do CRC */
373 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
374 /* copy chunk into bigger msg */
375 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
376 msg->curlen += msg->curchunk_len - 1;
377 }
378 return true;
379 }
380
drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)381 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
382 struct drm_dp_sideband_msg_reply_body *repmsg)
383 {
384 int idx = 1;
385 int i;
386 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
387 idx += 16;
388 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
389 idx++;
390 if (idx > raw->curlen)
391 goto fail_len;
392 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
393 if (raw->msg[idx] & 0x80)
394 repmsg->u.link_addr.ports[i].input_port = 1;
395
396 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
397 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
398
399 idx++;
400 if (idx > raw->curlen)
401 goto fail_len;
402 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
403 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
404 if (repmsg->u.link_addr.ports[i].input_port == 0)
405 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
406 idx++;
407 if (idx > raw->curlen)
408 goto fail_len;
409 if (repmsg->u.link_addr.ports[i].input_port == 0) {
410 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
411 idx++;
412 if (idx > raw->curlen)
413 goto fail_len;
414 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
415 idx += 16;
416 if (idx > raw->curlen)
417 goto fail_len;
418 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
419 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
420 idx++;
421
422 }
423 if (idx > raw->curlen)
424 goto fail_len;
425 }
426
427 return true;
428 fail_len:
429 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
430 return false;
431 }
432
drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)433 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
434 struct drm_dp_sideband_msg_reply_body *repmsg)
435 {
436 int idx = 1;
437 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
438 idx++;
439 if (idx > raw->curlen)
440 goto fail_len;
441 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
442 if (idx > raw->curlen)
443 goto fail_len;
444
445 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
446 return true;
447 fail_len:
448 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
449 return false;
450 }
451
drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)452 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
453 struct drm_dp_sideband_msg_reply_body *repmsg)
454 {
455 int idx = 1;
456 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
457 idx++;
458 if (idx > raw->curlen)
459 goto fail_len;
460 return true;
461 fail_len:
462 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
463 return false;
464 }
465
drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)466 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
467 struct drm_dp_sideband_msg_reply_body *repmsg)
468 {
469 int idx = 1;
470
471 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
472 idx++;
473 if (idx > raw->curlen)
474 goto fail_len;
475 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
476 idx++;
477 /* TODO check */
478 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
479 return true;
480 fail_len:
481 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
482 return false;
483 }
484
drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)485 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
486 struct drm_dp_sideband_msg_reply_body *repmsg)
487 {
488 int idx = 1;
489 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
490 idx++;
491 if (idx > raw->curlen)
492 goto fail_len;
493 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
494 idx += 2;
495 if (idx > raw->curlen)
496 goto fail_len;
497 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
498 idx += 2;
499 if (idx > raw->curlen)
500 goto fail_len;
501 return true;
502 fail_len:
503 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
504 return false;
505 }
506
drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)507 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
508 struct drm_dp_sideband_msg_reply_body *repmsg)
509 {
510 int idx = 1;
511 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
512 idx++;
513 if (idx > raw->curlen)
514 goto fail_len;
515 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
516 idx++;
517 if (idx > raw->curlen)
518 goto fail_len;
519 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
520 idx += 2;
521 if (idx > raw->curlen)
522 goto fail_len;
523 return true;
524 fail_len:
525 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
526 return false;
527 }
528
drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)529 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
530 struct drm_dp_sideband_msg_reply_body *repmsg)
531 {
532 int idx = 1;
533 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
534 idx++;
535 if (idx > raw->curlen)
536 goto fail_len;
537 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
538 idx += 2;
539 if (idx > raw->curlen)
540 goto fail_len;
541 return true;
542 fail_len:
543 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
544 return false;
545 }
546
drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)547 static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
548 struct drm_dp_sideband_msg_reply_body *repmsg)
549 {
550 int idx = 1;
551
552 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
553 idx++;
554 if (idx > raw->curlen) {
555 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
556 idx, raw->curlen);
557 return false;
558 }
559 return true;
560 }
561
drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * msg)562 static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
563 struct drm_dp_sideband_msg_reply_body *msg)
564 {
565 memset(msg, 0, sizeof(*msg));
566 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
567 msg->req_type = (raw->msg[0] & 0x7f);
568
569 if (msg->reply_type) {
570 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
571 msg->u.nak.reason = raw->msg[17];
572 msg->u.nak.nak_data = raw->msg[18];
573 return false;
574 }
575
576 switch (msg->req_type) {
577 case DP_LINK_ADDRESS:
578 return drm_dp_sideband_parse_link_address(raw, msg);
579 case DP_QUERY_PAYLOAD:
580 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
581 case DP_REMOTE_DPCD_READ:
582 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
583 case DP_REMOTE_DPCD_WRITE:
584 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
585 case DP_REMOTE_I2C_READ:
586 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
587 case DP_ENUM_PATH_RESOURCES:
588 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
589 case DP_ALLOCATE_PAYLOAD:
590 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
591 case DP_POWER_DOWN_PHY:
592 case DP_POWER_UP_PHY:
593 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
594 default:
595 DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
596 return false;
597 }
598 }
599
drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_req_body * msg)600 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
601 struct drm_dp_sideband_msg_req_body *msg)
602 {
603 int idx = 1;
604
605 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
606 idx++;
607 if (idx > raw->curlen)
608 goto fail_len;
609
610 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
611 idx += 16;
612 if (idx > raw->curlen)
613 goto fail_len;
614
615 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
616 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
617 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
618 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
619 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
620 idx++;
621 return true;
622 fail_len:
623 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
624 return false;
625 }
626
drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_req_body * msg)627 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
628 struct drm_dp_sideband_msg_req_body *msg)
629 {
630 int idx = 1;
631
632 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
633 idx++;
634 if (idx > raw->curlen)
635 goto fail_len;
636
637 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
638 idx += 16;
639 if (idx > raw->curlen)
640 goto fail_len;
641
642 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
643 idx++;
644 return true;
645 fail_len:
646 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
647 return false;
648 }
649
drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_req_body * msg)650 static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
651 struct drm_dp_sideband_msg_req_body *msg)
652 {
653 memset(msg, 0, sizeof(*msg));
654 msg->req_type = (raw->msg[0] & 0x7f);
655
656 switch (msg->req_type) {
657 case DP_CONNECTION_STATUS_NOTIFY:
658 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
659 case DP_RESOURCE_STATUS_NOTIFY:
660 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
661 default:
662 DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
663 return false;
664 }
665 }
666
build_dpcd_write(struct drm_dp_sideband_msg_tx * msg,u8 port_num,u32 offset,u8 num_bytes,u8 * bytes)667 static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
668 {
669 struct drm_dp_sideband_msg_req_body req;
670
671 req.req_type = DP_REMOTE_DPCD_WRITE;
672 req.u.dpcd_write.port_number = port_num;
673 req.u.dpcd_write.dpcd_address = offset;
674 req.u.dpcd_write.num_bytes = num_bytes;
675 req.u.dpcd_write.bytes = bytes;
676 drm_dp_encode_sideband_req(&req, msg);
677
678 return 0;
679 }
680
build_link_address(struct drm_dp_sideband_msg_tx * msg)681 static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
682 {
683 struct drm_dp_sideband_msg_req_body req;
684
685 req.req_type = DP_LINK_ADDRESS;
686 drm_dp_encode_sideband_req(&req, msg);
687 return 0;
688 }
689
build_enum_path_resources(struct drm_dp_sideband_msg_tx * msg,int port_num)690 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
691 {
692 struct drm_dp_sideband_msg_req_body req;
693
694 req.req_type = DP_ENUM_PATH_RESOURCES;
695 req.u.port_num.port_number = port_num;
696 drm_dp_encode_sideband_req(&req, msg);
697 msg->path_msg = true;
698 return 0;
699 }
700
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)701 static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
702 u8 vcpi, uint16_t pbn,
703 u8 number_sdp_streams,
704 u8 *sdp_stream_sink)
705 {
706 struct drm_dp_sideband_msg_req_body req;
707 memset(&req, 0, sizeof(req));
708 req.req_type = DP_ALLOCATE_PAYLOAD;
709 req.u.allocate_payload.port_number = port_num;
710 req.u.allocate_payload.vcpi = vcpi;
711 req.u.allocate_payload.pbn = pbn;
712 req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
713 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
714 number_sdp_streams);
715 drm_dp_encode_sideband_req(&req, msg);
716 msg->path_msg = true;
717 return 0;
718 }
719
build_power_updown_phy(struct drm_dp_sideband_msg_tx * msg,int port_num,bool power_up)720 static int build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
721 int port_num, bool power_up)
722 {
723 struct drm_dp_sideband_msg_req_body req;
724
725 if (power_up)
726 req.req_type = DP_POWER_UP_PHY;
727 else
728 req.req_type = DP_POWER_DOWN_PHY;
729
730 req.u.port_num.port_number = port_num;
731 drm_dp_encode_sideband_req(&req, msg);
732 msg->path_msg = true;
733 return 0;
734 }
735
drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_vcpi * vcpi)736 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
737 struct drm_dp_vcpi *vcpi)
738 {
739 int ret, vcpi_ret;
740
741 mutex_lock(&mgr->payload_lock);
742 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
743 if (ret > mgr->max_payloads) {
744 ret = -EINVAL;
745 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
746 goto out_unlock;
747 }
748
749 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
750 if (vcpi_ret > mgr->max_payloads) {
751 ret = -EINVAL;
752 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
753 goto out_unlock;
754 }
755
756 set_bit(ret, &mgr->payload_mask);
757 set_bit(vcpi_ret, &mgr->vcpi_mask);
758 vcpi->vcpi = vcpi_ret + 1;
759 mgr->proposed_vcpis[ret - 1] = vcpi;
760 out_unlock:
761 mutex_unlock(&mgr->payload_lock);
762 return ret;
763 }
764
drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr * mgr,int vcpi)765 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
766 int vcpi)
767 {
768 int i;
769 if (vcpi == 0)
770 return;
771
772 mutex_lock(&mgr->payload_lock);
773 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
774 clear_bit(vcpi - 1, &mgr->vcpi_mask);
775
776 for (i = 0; i < mgr->max_payloads; i++) {
777 if (mgr->proposed_vcpis[i])
778 if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
779 mgr->proposed_vcpis[i] = NULL;
780 clear_bit(i + 1, &mgr->payload_mask);
781 }
782 }
783 mutex_unlock(&mgr->payload_lock);
784 }
785
check_txmsg_state(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg)786 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
787 struct drm_dp_sideband_msg_tx *txmsg)
788 {
789 unsigned int state;
790
791 /*
792 * All updates to txmsg->state are protected by mgr->qlock, and the two
793 * cases we check here are terminal states. For those the barriers
794 * provided by the wake_up/wait_event pair are enough.
795 */
796 state = READ_ONCE(txmsg->state);
797 return (state == DRM_DP_SIDEBAND_TX_RX ||
798 state == DRM_DP_SIDEBAND_TX_TIMEOUT);
799 }
800
drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch * mstb,struct drm_dp_sideband_msg_tx * txmsg)801 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
802 struct drm_dp_sideband_msg_tx *txmsg)
803 {
804 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
805 int ret;
806
807 ret = wait_event_timeout(mgr->tx_waitq,
808 check_txmsg_state(mgr, txmsg),
809 (4 * HZ));
810 mutex_lock(&mstb->mgr->qlock);
811 if (ret > 0) {
812 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
813 ret = -EIO;
814 goto out;
815 }
816 } else {
817 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
818
819 /* dump some state */
820 ret = -EIO;
821
822 /* remove from q */
823 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
824 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
825 list_del(&txmsg->next);
826 }
827
828 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
829 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
830 mstb->tx_slots[txmsg->seqno] = NULL;
831 }
832 }
833 out:
834 mutex_unlock(&mgr->qlock);
835
836 return ret;
837 }
838
drm_dp_add_mst_branch_device(u8 lct,u8 * rad)839 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
840 {
841 struct drm_dp_mst_branch *mstb;
842
843 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
844 if (!mstb)
845 return NULL;
846
847 mstb->lct = lct;
848 if (lct > 1)
849 memcpy(mstb->rad, rad, lct / 2);
850 INIT_LIST_HEAD(&mstb->ports);
851 kref_init(&mstb->kref);
852 return mstb;
853 }
854
855 static void drm_dp_free_mst_port(struct kref *kref);
856
drm_dp_free_mst_branch_device(struct kref * kref)857 static void drm_dp_free_mst_branch_device(struct kref *kref)
858 {
859 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
860 if (mstb->port_parent) {
861 if (list_empty(&mstb->port_parent->next))
862 kref_put(&mstb->port_parent->kref, drm_dp_free_mst_port);
863 }
864 kfree(mstb);
865 }
866
drm_dp_destroy_mst_branch_device(struct kref * kref)867 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
868 {
869 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
870 struct drm_dp_mst_port *port, *tmp;
871 bool wake_tx = false;
872
873 /*
874 * init kref again to be used by ports to remove mst branch when it is
875 * not needed anymore
876 */
877 kref_init(kref);
878
879 if (mstb->port_parent && list_empty(&mstb->port_parent->next))
880 kref_get(&mstb->port_parent->kref);
881
882 /*
883 * destroy all ports - don't need lock
884 * as there are no more references to the mst branch
885 * device at this point.
886 */
887 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
888 list_del(&port->next);
889 drm_dp_put_port(port);
890 }
891
892 /* drop any tx slots msg */
893 mutex_lock(&mstb->mgr->qlock);
894 if (mstb->tx_slots[0]) {
895 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
896 mstb->tx_slots[0] = NULL;
897 wake_tx = true;
898 }
899 if (mstb->tx_slots[1]) {
900 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
901 mstb->tx_slots[1] = NULL;
902 wake_tx = true;
903 }
904 mutex_unlock(&mstb->mgr->qlock);
905
906 if (wake_tx)
907 wake_up_all(&mstb->mgr->tx_waitq);
908
909 kref_put(kref, drm_dp_free_mst_branch_device);
910 }
911
drm_dp_put_mst_branch_device(struct drm_dp_mst_branch * mstb)912 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
913 {
914 kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
915 }
916
917
drm_dp_port_teardown_pdt(struct drm_dp_mst_port * port,int old_pdt)918 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
919 {
920 struct drm_dp_mst_branch *mstb;
921
922 switch (old_pdt) {
923 case DP_PEER_DEVICE_DP_LEGACY_CONV:
924 case DP_PEER_DEVICE_SST_SINK:
925 /* remove i2c over sideband */
926 drm_dp_mst_unregister_i2c_bus(&port->aux);
927 break;
928 case DP_PEER_DEVICE_MST_BRANCHING:
929 mstb = port->mstb;
930 port->mstb = NULL;
931 drm_dp_put_mst_branch_device(mstb);
932 break;
933 }
934 }
935
drm_dp_destroy_port(struct kref * kref)936 static void drm_dp_destroy_port(struct kref *kref)
937 {
938 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
939 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
940
941 if (!port->input) {
942 port->vcpi.num_slots = 0;
943
944 kfree(port->cached_edid);
945
946 /*
947 * The only time we don't have a connector
948 * on an output port is if the connector init
949 * fails.
950 */
951 if (port->connector) {
952 /* we can't destroy the connector here, as
953 * we might be holding the mode_config.mutex
954 * from an EDID retrieval */
955
956 mutex_lock(&mgr->destroy_connector_lock);
957 kref_get(&port->parent->kref);
958 list_add(&port->next, &mgr->destroy_connector_list);
959 mutex_unlock(&mgr->destroy_connector_lock);
960 schedule_work(&mgr->destroy_connector_work);
961 return;
962 }
963 /* no need to clean up vcpi
964 * as if we have no connector we never setup a vcpi */
965 drm_dp_port_teardown_pdt(port, port->pdt);
966 port->pdt = DP_PEER_DEVICE_NONE;
967 }
968 kfree(port);
969 }
970
drm_dp_put_port(struct drm_dp_mst_port * port)971 static void drm_dp_put_port(struct drm_dp_mst_port *port)
972 {
973 kref_put(&port->kref, drm_dp_destroy_port);
974 }
975
drm_dp_mst_get_validated_mstb_ref_locked(struct drm_dp_mst_branch * mstb,struct drm_dp_mst_branch * to_find)976 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)
977 {
978 struct drm_dp_mst_port *port;
979 struct drm_dp_mst_branch *rmstb;
980 if (to_find == mstb) {
981 kref_get(&mstb->kref);
982 return mstb;
983 }
984 list_for_each_entry(port, &mstb->ports, next) {
985 if (port->mstb) {
986 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
987 if (rmstb)
988 return rmstb;
989 }
990 }
991 return NULL;
992 }
993
drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb)994 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)
995 {
996 struct drm_dp_mst_branch *rmstb = NULL;
997 mutex_lock(&mgr->lock);
998 if (mgr->mst_primary)
999 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
1000 mutex_unlock(&mgr->lock);
1001 return rmstb;
1002 }
1003
drm_dp_mst_get_port_ref_locked(struct drm_dp_mst_branch * mstb,struct drm_dp_mst_port * to_find)1004 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)
1005 {
1006 struct drm_dp_mst_port *port, *mport;
1007
1008 list_for_each_entry(port, &mstb->ports, next) {
1009 if (port == to_find) {
1010 kref_get(&port->kref);
1011 return port;
1012 }
1013 if (port->mstb) {
1014 mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
1015 if (mport)
1016 return mport;
1017 }
1018 }
1019 return NULL;
1020 }
1021
drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)1022 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)
1023 {
1024 struct drm_dp_mst_port *rport = NULL;
1025 mutex_lock(&mgr->lock);
1026 if (mgr->mst_primary)
1027 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
1028 mutex_unlock(&mgr->lock);
1029 return rport;
1030 }
1031
drm_dp_get_port(struct drm_dp_mst_branch * mstb,u8 port_num)1032 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
1033 {
1034 struct drm_dp_mst_port *port;
1035
1036 list_for_each_entry(port, &mstb->ports, next) {
1037 if (port->port_num == port_num) {
1038 kref_get(&port->kref);
1039 return port;
1040 }
1041 }
1042
1043 return NULL;
1044 }
1045
1046 /*
1047 * calculate a new RAD for this MST branch device
1048 * if parent has an LCT of 2 then it has 1 nibble of RAD,
1049 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1050 */
drm_dp_calculate_rad(struct drm_dp_mst_port * port,u8 * rad)1051 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1052 u8 *rad)
1053 {
1054 int parent_lct = port->parent->lct;
1055 int shift = 4;
1056 int idx = (parent_lct - 1) / 2;
1057 if (parent_lct > 1) {
1058 memcpy(rad, port->parent->rad, idx + 1);
1059 shift = (parent_lct % 2) ? 4 : 0;
1060 } else
1061 rad[0] = 0;
1062
1063 rad[idx] |= port->port_num << shift;
1064 return parent_lct + 1;
1065 }
1066
1067 /*
1068 * return sends link address for new mstb
1069 */
drm_dp_port_setup_pdt(struct drm_dp_mst_port * port)1070 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
1071 {
1072 int ret;
1073 u8 rad[6], lct;
1074 bool send_link = false;
1075 switch (port->pdt) {
1076 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1077 case DP_PEER_DEVICE_SST_SINK:
1078 /* add i2c over sideband */
1079 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1080 break;
1081 case DP_PEER_DEVICE_MST_BRANCHING:
1082 lct = drm_dp_calculate_rad(port, rad);
1083
1084 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
1085 port->mstb->mgr = port->mgr;
1086 port->mstb->port_parent = port;
1087
1088 send_link = true;
1089 break;
1090 }
1091 return send_link;
1092 }
1093
drm_dp_check_mstb_guid(struct drm_dp_mst_branch * mstb,u8 * guid)1094 static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
1095 {
1096 int ret;
1097
1098 memcpy(mstb->guid, guid, 16);
1099
1100 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
1101 if (mstb->port_parent) {
1102 ret = drm_dp_send_dpcd_write(
1103 mstb->mgr,
1104 mstb->port_parent,
1105 DP_GUID,
1106 16,
1107 mstb->guid);
1108 } else {
1109
1110 ret = drm_dp_dpcd_write(
1111 mstb->mgr->aux,
1112 DP_GUID,
1113 mstb->guid,
1114 16);
1115 }
1116 }
1117 }
1118
build_mst_prop_path(const struct drm_dp_mst_branch * mstb,int pnum,char * proppath,size_t proppath_size)1119 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1120 int pnum,
1121 char *proppath,
1122 size_t proppath_size)
1123 {
1124 int i;
1125 char temp[8];
1126 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1127 for (i = 0; i < (mstb->lct - 1); i++) {
1128 int shift = (i % 2) ? 0 : 4;
1129 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
1130 snprintf(temp, sizeof(temp), "-%d", port_num);
1131 strlcat(proppath, temp, proppath_size);
1132 }
1133 snprintf(temp, sizeof(temp), "-%d", pnum);
1134 strlcat(proppath, temp, proppath_size);
1135 }
1136
drm_dp_add_port(struct drm_dp_mst_branch * mstb,struct drm_device * dev,struct drm_dp_link_addr_reply_port * port_msg)1137 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1138 struct drm_device *dev,
1139 struct drm_dp_link_addr_reply_port *port_msg)
1140 {
1141 struct drm_dp_mst_port *port;
1142 bool ret;
1143 bool created = false;
1144 int old_pdt = 0;
1145 int old_ddps = 0;
1146 port = drm_dp_get_port(mstb, port_msg->port_number);
1147 if (!port) {
1148 port = kzalloc(sizeof(*port), GFP_KERNEL);
1149 if (!port)
1150 return;
1151 kref_init(&port->kref);
1152 port->parent = mstb;
1153 port->port_num = port_msg->port_number;
1154 port->mgr = mstb->mgr;
1155 port->aux.name = "DPMST";
1156 port->aux.dev = dev->dev;
1157 created = true;
1158 } else {
1159 old_pdt = port->pdt;
1160 old_ddps = port->ddps;
1161 }
1162
1163 port->pdt = port_msg->peer_device_type;
1164 port->input = port_msg->input_port;
1165 port->mcs = port_msg->mcs;
1166 port->ddps = port_msg->ddps;
1167 port->ldps = port_msg->legacy_device_plug_status;
1168 port->dpcd_rev = port_msg->dpcd_revision;
1169 port->num_sdp_streams = port_msg->num_sdp_streams;
1170 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1171
1172 /* manage mstb port lists with mgr lock - take a reference
1173 for this list */
1174 if (created) {
1175 mutex_lock(&mstb->mgr->lock);
1176 kref_get(&port->kref);
1177 list_add(&port->next, &mstb->ports);
1178 mutex_unlock(&mstb->mgr->lock);
1179 }
1180
1181 if (old_ddps != port->ddps) {
1182 if (port->ddps) {
1183 if (!port->input)
1184 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1185 } else {
1186 port->available_pbn = 0;
1187 }
1188 }
1189
1190 if (old_pdt != port->pdt && !port->input) {
1191 drm_dp_port_teardown_pdt(port, old_pdt);
1192
1193 ret = drm_dp_port_setup_pdt(port);
1194 if (ret == true)
1195 drm_dp_send_link_address(mstb->mgr, port->mstb);
1196 }
1197
1198 if (created && !port->input) {
1199 char proppath[255];
1200
1201 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
1202 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1203 if (!port->connector) {
1204 /* remove it from the port list */
1205 mutex_lock(&mstb->mgr->lock);
1206 list_del(&port->next);
1207 mutex_unlock(&mstb->mgr->lock);
1208 /* drop port list reference */
1209 drm_dp_put_port(port);
1210 goto out;
1211 }
1212 if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
1213 port->pdt == DP_PEER_DEVICE_SST_SINK) &&
1214 port->port_num >= DP_MST_LOGICAL_PORT_0) {
1215 port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1216 drm_mode_connector_set_tile_property(port->connector);
1217 }
1218 (*mstb->mgr->cbs->register_connector)(port->connector);
1219 }
1220
1221 out:
1222 /* put reference to this port */
1223 drm_dp_put_port(port);
1224 }
1225
drm_dp_update_port(struct drm_dp_mst_branch * mstb,struct drm_dp_connection_status_notify * conn_stat)1226 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1227 struct drm_dp_connection_status_notify *conn_stat)
1228 {
1229 struct drm_dp_mst_port *port;
1230 int old_pdt;
1231 int old_ddps;
1232 bool dowork = false;
1233 port = drm_dp_get_port(mstb, conn_stat->port_number);
1234 if (!port)
1235 return;
1236
1237 old_ddps = port->ddps;
1238 old_pdt = port->pdt;
1239 port->pdt = conn_stat->peer_device_type;
1240 port->mcs = conn_stat->message_capability_status;
1241 port->ldps = conn_stat->legacy_device_plug_status;
1242 port->ddps = conn_stat->displayport_device_plug_status;
1243
1244 if (old_ddps != port->ddps) {
1245 if (port->ddps) {
1246 dowork = true;
1247 } else {
1248 port->available_pbn = 0;
1249 }
1250 }
1251 if (old_pdt != port->pdt && !port->input) {
1252 drm_dp_port_teardown_pdt(port, old_pdt);
1253
1254 if (drm_dp_port_setup_pdt(port))
1255 dowork = true;
1256 }
1257
1258 drm_dp_put_port(port);
1259 if (dowork)
1260 queue_work(system_long_wq, &mstb->mgr->work);
1261
1262 }
1263
drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr * mgr,u8 lct,u8 * rad)1264 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1265 u8 lct, u8 *rad)
1266 {
1267 struct drm_dp_mst_branch *mstb;
1268 struct drm_dp_mst_port *port;
1269 int i;
1270 /* find the port by iterating down */
1271
1272 mutex_lock(&mgr->lock);
1273 mstb = mgr->mst_primary;
1274
1275 for (i = 0; i < lct - 1; i++) {
1276 int shift = (i % 2) ? 0 : 4;
1277 int port_num = (rad[i / 2] >> shift) & 0xf;
1278
1279 list_for_each_entry(port, &mstb->ports, next) {
1280 if (port->port_num == port_num) {
1281 mstb = port->mstb;
1282 if (!mstb) {
1283 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1284 goto out;
1285 }
1286
1287 break;
1288 }
1289 }
1290 }
1291 kref_get(&mstb->kref);
1292 out:
1293 mutex_unlock(&mgr->lock);
1294 return mstb;
1295 }
1296
get_mst_branch_device_by_guid_helper(struct drm_dp_mst_branch * mstb,uint8_t * guid)1297 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1298 struct drm_dp_mst_branch *mstb,
1299 uint8_t *guid)
1300 {
1301 struct drm_dp_mst_branch *found_mstb;
1302 struct drm_dp_mst_port *port;
1303
1304 if (memcmp(mstb->guid, guid, 16) == 0)
1305 return mstb;
1306
1307
1308 list_for_each_entry(port, &mstb->ports, next) {
1309 if (!port->mstb)
1310 continue;
1311
1312 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1313
1314 if (found_mstb)
1315 return found_mstb;
1316 }
1317
1318 return NULL;
1319 }
1320
drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr * mgr,uint8_t * guid)1321 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
1322 struct drm_dp_mst_topology_mgr *mgr,
1323 uint8_t *guid)
1324 {
1325 struct drm_dp_mst_branch *mstb;
1326
1327 /* find the port by iterating down */
1328 mutex_lock(&mgr->lock);
1329
1330 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
1331
1332 if (mstb)
1333 kref_get(&mstb->kref);
1334
1335 mutex_unlock(&mgr->lock);
1336 return mstb;
1337 }
1338
drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb)1339 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1340 struct drm_dp_mst_branch *mstb)
1341 {
1342 struct drm_dp_mst_port *port;
1343 struct drm_dp_mst_branch *mstb_child;
1344 if (!mstb->link_address_sent)
1345 drm_dp_send_link_address(mgr, mstb);
1346
1347 list_for_each_entry(port, &mstb->ports, next) {
1348 if (port->input)
1349 continue;
1350
1351 if (!port->ddps)
1352 continue;
1353
1354 if (!port->available_pbn)
1355 drm_dp_send_enum_path_resources(mgr, mstb, port);
1356
1357 if (port->mstb) {
1358 mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1359 if (mstb_child) {
1360 drm_dp_check_and_send_link_address(mgr, mstb_child);
1361 drm_dp_put_mst_branch_device(mstb_child);
1362 }
1363 }
1364 }
1365 }
1366
drm_dp_mst_link_probe_work(struct work_struct * work)1367 static void drm_dp_mst_link_probe_work(struct work_struct *work)
1368 {
1369 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1370 struct drm_dp_mst_branch *mstb;
1371
1372 mutex_lock(&mgr->lock);
1373 mstb = mgr->mst_primary;
1374 if (mstb) {
1375 kref_get(&mstb->kref);
1376 }
1377 mutex_unlock(&mgr->lock);
1378 if (mstb) {
1379 drm_dp_check_and_send_link_address(mgr, mstb);
1380 drm_dp_put_mst_branch_device(mstb);
1381 }
1382 }
1383
drm_dp_validate_guid(struct drm_dp_mst_topology_mgr * mgr,u8 * guid)1384 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1385 u8 *guid)
1386 {
1387 u64 salt;
1388
1389 if (memchr_inv(guid, 0, 16))
1390 return true;
1391
1392 salt = get_jiffies_64();
1393
1394 memcpy(&guid[0], &salt, sizeof(u64));
1395 memcpy(&guid[8], &salt, sizeof(u64));
1396
1397 return false;
1398 }
1399
1400 #if 0
1401 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1402 {
1403 struct drm_dp_sideband_msg_req_body req;
1404
1405 req.req_type = DP_REMOTE_DPCD_READ;
1406 req.u.dpcd_read.port_number = port_num;
1407 req.u.dpcd_read.dpcd_address = offset;
1408 req.u.dpcd_read.num_bytes = num_bytes;
1409 drm_dp_encode_sideband_req(&req, msg);
1410
1411 return 0;
1412 }
1413 #endif
1414
drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr * mgr,bool up,u8 * msg,int len)1415 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1416 bool up, u8 *msg, int len)
1417 {
1418 int ret;
1419 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1420 int tosend, total, offset;
1421 int retries = 0;
1422
1423 retry:
1424 total = len;
1425 offset = 0;
1426 do {
1427 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1428
1429 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1430 &msg[offset],
1431 tosend);
1432 if (ret != tosend) {
1433 if (ret == -EIO && retries < 5) {
1434 retries++;
1435 goto retry;
1436 }
1437 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1438
1439 return -EIO;
1440 }
1441 offset += tosend;
1442 total -= tosend;
1443 } while (total > 0);
1444 return 0;
1445 }
1446
set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr * hdr,struct drm_dp_sideband_msg_tx * txmsg)1447 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1448 struct drm_dp_sideband_msg_tx *txmsg)
1449 {
1450 struct drm_dp_mst_branch *mstb = txmsg->dst;
1451 u8 req_type;
1452
1453 /* both msg slots are full */
1454 if (txmsg->seqno == -1) {
1455 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1456 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1457 return -EAGAIN;
1458 }
1459 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1460 txmsg->seqno = mstb->last_seqno;
1461 mstb->last_seqno ^= 1;
1462 } else if (mstb->tx_slots[0] == NULL)
1463 txmsg->seqno = 0;
1464 else
1465 txmsg->seqno = 1;
1466 mstb->tx_slots[txmsg->seqno] = txmsg;
1467 }
1468
1469 req_type = txmsg->msg[0] & 0x7f;
1470 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1471 req_type == DP_RESOURCE_STATUS_NOTIFY)
1472 hdr->broadcast = 1;
1473 else
1474 hdr->broadcast = 0;
1475 hdr->path_msg = txmsg->path_msg;
1476 hdr->lct = mstb->lct;
1477 hdr->lcr = mstb->lct - 1;
1478 if (mstb->lct > 1)
1479 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1480 hdr->seqno = txmsg->seqno;
1481 return 0;
1482 }
1483 /*
1484 * process a single block of the next message in the sideband queue
1485 */
process_single_tx_qlock(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg,bool up)1486 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1487 struct drm_dp_sideband_msg_tx *txmsg,
1488 bool up)
1489 {
1490 u8 chunk[48];
1491 struct drm_dp_sideband_msg_hdr hdr;
1492 int len, space, idx, tosend;
1493 int ret;
1494
1495 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1496
1497 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1498 txmsg->seqno = -1;
1499 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1500 }
1501
1502 /* make hdr from dst mst - for replies use seqno
1503 otherwise assign one */
1504 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1505 if (ret < 0)
1506 return ret;
1507
1508 /* amount left to send in this message */
1509 len = txmsg->cur_len - txmsg->cur_offset;
1510
1511 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1512 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1513
1514 tosend = min(len, space);
1515 if (len == txmsg->cur_len)
1516 hdr.somt = 1;
1517 if (space >= len)
1518 hdr.eomt = 1;
1519
1520
1521 hdr.msg_len = tosend + 1;
1522 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1523 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1524 /* add crc at end */
1525 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1526 idx += tosend + 1;
1527
1528 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1529 if (ret) {
1530 DRM_DEBUG_KMS("sideband msg failed to send\n");
1531 return ret;
1532 }
1533
1534 txmsg->cur_offset += tosend;
1535 if (txmsg->cur_offset == txmsg->cur_len) {
1536 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1537 return 1;
1538 }
1539 return 0;
1540 }
1541
process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr * mgr)1542 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1543 {
1544 struct drm_dp_sideband_msg_tx *txmsg;
1545 int ret;
1546
1547 WARN_ON(!mutex_is_locked(&mgr->qlock));
1548
1549 /* construct a chunk from the first msg in the tx_msg queue */
1550 if (list_empty(&mgr->tx_msg_downq))
1551 return;
1552
1553 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1554 ret = process_single_tx_qlock(mgr, txmsg, false);
1555 if (ret == 1) {
1556 /* txmsg is sent it should be in the slots now */
1557 list_del(&txmsg->next);
1558 } else if (ret) {
1559 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1560 list_del(&txmsg->next);
1561 if (txmsg->seqno != -1)
1562 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1563 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1564 wake_up_all(&mgr->tx_waitq);
1565 }
1566 }
1567
1568 /* called holding qlock */
process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg)1569 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1570 struct drm_dp_sideband_msg_tx *txmsg)
1571 {
1572 int ret;
1573
1574 /* construct a chunk from the first msg in the tx_msg queue */
1575 ret = process_single_tx_qlock(mgr, txmsg, true);
1576
1577 if (ret != 1)
1578 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1579
1580 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1581 }
1582
drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg)1583 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1584 struct drm_dp_sideband_msg_tx *txmsg)
1585 {
1586 mutex_lock(&mgr->qlock);
1587 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1588 if (list_is_singular(&mgr->tx_msg_downq))
1589 process_single_down_tx_qlock(mgr);
1590 mutex_unlock(&mgr->qlock);
1591 }
1592
drm_dp_send_link_address(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb)1593 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1594 struct drm_dp_mst_branch *mstb)
1595 {
1596 int len;
1597 struct drm_dp_sideband_msg_tx *txmsg;
1598 int ret;
1599
1600 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1601 if (!txmsg)
1602 return;
1603
1604 txmsg->dst = mstb;
1605 len = build_link_address(txmsg);
1606
1607 mstb->link_address_sent = true;
1608 drm_dp_queue_down_tx(mgr, txmsg);
1609
1610 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1611 if (ret > 0) {
1612 int i;
1613
1614 if (txmsg->reply.reply_type == 1)
1615 DRM_DEBUG_KMS("link address nak received\n");
1616 else {
1617 DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1618 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1619 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,
1620 txmsg->reply.u.link_addr.ports[i].input_port,
1621 txmsg->reply.u.link_addr.ports[i].peer_device_type,
1622 txmsg->reply.u.link_addr.ports[i].port_number,
1623 txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1624 txmsg->reply.u.link_addr.ports[i].mcs,
1625 txmsg->reply.u.link_addr.ports[i].ddps,
1626 txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1627 txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1628 txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1629 }
1630
1631 drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);
1632
1633 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1634 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1635 }
1636 (*mgr->cbs->hotplug)(mgr);
1637 }
1638 } else {
1639 mstb->link_address_sent = false;
1640 DRM_DEBUG_KMS("link address failed %d\n", ret);
1641 }
1642
1643 kfree(txmsg);
1644 }
1645
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)1646 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1647 struct drm_dp_mst_branch *mstb,
1648 struct drm_dp_mst_port *port)
1649 {
1650 int len;
1651 struct drm_dp_sideband_msg_tx *txmsg;
1652 int ret;
1653
1654 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1655 if (!txmsg)
1656 return -ENOMEM;
1657
1658 txmsg->dst = mstb;
1659 len = build_enum_path_resources(txmsg, port->port_num);
1660
1661 drm_dp_queue_down_tx(mgr, txmsg);
1662
1663 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1664 if (ret > 0) {
1665 if (txmsg->reply.reply_type == 1)
1666 DRM_DEBUG_KMS("enum path resources nak received\n");
1667 else {
1668 if (port->port_num != txmsg->reply.u.path_resources.port_number)
1669 DRM_ERROR("got incorrect port in response\n");
1670 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,
1671 txmsg->reply.u.path_resources.avail_payload_bw_number);
1672 port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1673 }
1674 }
1675
1676 kfree(txmsg);
1677 return 0;
1678 }
1679
drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch * mstb)1680 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
1681 {
1682 if (!mstb->port_parent)
1683 return NULL;
1684
1685 if (mstb->port_parent->mstb != mstb)
1686 return mstb->port_parent;
1687
1688 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
1689 }
1690
drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb,int * port_num)1691 static struct drm_dp_mst_branch *drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
1692 struct drm_dp_mst_branch *mstb,
1693 int *port_num)
1694 {
1695 struct drm_dp_mst_branch *rmstb = NULL;
1696 struct drm_dp_mst_port *found_port;
1697 mutex_lock(&mgr->lock);
1698 if (mgr->mst_primary) {
1699 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
1700
1701 if (found_port) {
1702 rmstb = found_port->parent;
1703 kref_get(&rmstb->kref);
1704 *port_num = found_port->port_num;
1705 }
1706 }
1707 mutex_unlock(&mgr->lock);
1708 return rmstb;
1709 }
1710
drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int id,int pbn)1711 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1712 struct drm_dp_mst_port *port,
1713 int id,
1714 int pbn)
1715 {
1716 struct drm_dp_sideband_msg_tx *txmsg;
1717 struct drm_dp_mst_branch *mstb;
1718 int len, ret, port_num;
1719 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
1720 int i;
1721
1722 port = drm_dp_get_validated_port_ref(mgr, port);
1723 if (!port)
1724 return -EINVAL;
1725
1726 port_num = port->port_num;
1727 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1728 if (!mstb) {
1729 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, port->parent, &port_num);
1730
1731 if (!mstb) {
1732 drm_dp_put_port(port);
1733 return -EINVAL;
1734 }
1735 }
1736
1737 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1738 if (!txmsg) {
1739 ret = -ENOMEM;
1740 goto fail_put;
1741 }
1742
1743 for (i = 0; i < port->num_sdp_streams; i++)
1744 sinks[i] = i;
1745
1746 txmsg->dst = mstb;
1747 len = build_allocate_payload(txmsg, port_num,
1748 id,
1749 pbn, port->num_sdp_streams, sinks);
1750
1751 drm_dp_queue_down_tx(mgr, txmsg);
1752
1753 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1754 if (ret > 0) {
1755 if (txmsg->reply.reply_type == 1) {
1756 ret = -EINVAL;
1757 } else
1758 ret = 0;
1759 }
1760 kfree(txmsg);
1761 fail_put:
1762 drm_dp_put_mst_branch_device(mstb);
1763 drm_dp_put_port(port);
1764 return ret;
1765 }
1766
drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,bool power_up)1767 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
1768 struct drm_dp_mst_port *port, bool power_up)
1769 {
1770 struct drm_dp_sideband_msg_tx *txmsg;
1771 int len, ret;
1772
1773 port = drm_dp_get_validated_port_ref(mgr, port);
1774 if (!port)
1775 return -EINVAL;
1776
1777 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1778 if (!txmsg) {
1779 drm_dp_put_port(port);
1780 return -ENOMEM;
1781 }
1782
1783 txmsg->dst = port->parent;
1784 len = build_power_updown_phy(txmsg, port->port_num, power_up);
1785 drm_dp_queue_down_tx(mgr, txmsg);
1786
1787 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
1788 if (ret > 0) {
1789 if (txmsg->reply.reply_type == 1)
1790 ret = -EINVAL;
1791 else
1792 ret = 0;
1793 }
1794 kfree(txmsg);
1795 drm_dp_put_port(port);
1796
1797 return ret;
1798 }
1799 EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
1800
drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr * mgr,int id,struct drm_dp_payload * payload)1801 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1802 int id,
1803 struct drm_dp_payload *payload)
1804 {
1805 int ret;
1806
1807 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1808 if (ret < 0) {
1809 payload->payload_state = 0;
1810 return ret;
1811 }
1812 payload->payload_state = DP_PAYLOAD_LOCAL;
1813 return 0;
1814 }
1815
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)1816 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1817 struct drm_dp_mst_port *port,
1818 int id,
1819 struct drm_dp_payload *payload)
1820 {
1821 int ret;
1822 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1823 if (ret < 0)
1824 return ret;
1825 payload->payload_state = DP_PAYLOAD_REMOTE;
1826 return ret;
1827 }
1828
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)1829 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1830 struct drm_dp_mst_port *port,
1831 int id,
1832 struct drm_dp_payload *payload)
1833 {
1834 DRM_DEBUG_KMS("\n");
1835 /* its okay for these to fail */
1836 if (port) {
1837 drm_dp_payload_send_msg(mgr, port, id, 0);
1838 }
1839
1840 drm_dp_dpcd_write_payload(mgr, id, payload);
1841 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1842 return 0;
1843 }
1844
drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr * mgr,int id,struct drm_dp_payload * payload)1845 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1846 int id,
1847 struct drm_dp_payload *payload)
1848 {
1849 payload->payload_state = 0;
1850 return 0;
1851 }
1852
1853 /**
1854 * drm_dp_update_payload_part1() - Execute payload update part 1
1855 * @mgr: manager to use.
1856 *
1857 * This iterates over all proposed virtual channels, and tries to
1858 * allocate space in the link for them. For 0->slots transitions,
1859 * this step just writes the VCPI to the MST device. For slots->0
1860 * transitions, this writes the updated VCPIs and removes the
1861 * remote VC payloads.
1862 *
1863 * after calling this the driver should generate ACT and payload
1864 * packets.
1865 */
drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr * mgr)1866 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1867 {
1868 int i, j;
1869 int cur_slots = 1;
1870 struct drm_dp_payload req_payload;
1871 struct drm_dp_mst_port *port;
1872
1873 mutex_lock(&mgr->payload_lock);
1874 for (i = 0; i < mgr->max_payloads; i++) {
1875 /* solve the current payloads - compare to the hw ones
1876 - update the hw view */
1877 req_payload.start_slot = cur_slots;
1878 if (mgr->proposed_vcpis[i]) {
1879 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1880 port = drm_dp_get_validated_port_ref(mgr, port);
1881 if (!port) {
1882 mutex_unlock(&mgr->payload_lock);
1883 return -EINVAL;
1884 }
1885 req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1886 req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi;
1887 } else {
1888 port = NULL;
1889 req_payload.num_slots = 0;
1890 }
1891
1892 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1893 mgr->payloads[i].start_slot = req_payload.start_slot;
1894 }
1895 /* work out what is required to happen with this payload */
1896 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1897
1898 /* need to push an update for this payload */
1899 if (req_payload.num_slots) {
1900 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1901 mgr->payloads[i].num_slots = req_payload.num_slots;
1902 mgr->payloads[i].vcpi = req_payload.vcpi;
1903 } else if (mgr->payloads[i].num_slots) {
1904 mgr->payloads[i].num_slots = 0;
1905 drm_dp_destroy_payload_step1(mgr, port, mgr->payloads[i].vcpi, &mgr->payloads[i]);
1906 req_payload.payload_state = mgr->payloads[i].payload_state;
1907 mgr->payloads[i].start_slot = 0;
1908 }
1909 mgr->payloads[i].payload_state = req_payload.payload_state;
1910 }
1911 cur_slots += req_payload.num_slots;
1912
1913 if (port)
1914 drm_dp_put_port(port);
1915 }
1916
1917 for (i = 0; i < mgr->max_payloads; i++) {
1918 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1919 DRM_DEBUG_KMS("removing payload %d\n", i);
1920 for (j = i; j < mgr->max_payloads - 1; j++) {
1921 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1922 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1923 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1924 set_bit(j + 1, &mgr->payload_mask);
1925 } else {
1926 clear_bit(j + 1, &mgr->payload_mask);
1927 }
1928 }
1929 memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1930 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1931 clear_bit(mgr->max_payloads, &mgr->payload_mask);
1932
1933 }
1934 }
1935 mutex_unlock(&mgr->payload_lock);
1936
1937 return 0;
1938 }
1939 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1940
1941 /**
1942 * drm_dp_update_payload_part2() - Execute payload update part 2
1943 * @mgr: manager to use.
1944 *
1945 * This iterates over all proposed virtual channels, and tries to
1946 * allocate space in the link for them. For 0->slots transitions,
1947 * this step writes the remote VC payload commands. For slots->0
1948 * this just resets some internal state.
1949 */
drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr * mgr)1950 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1951 {
1952 struct drm_dp_mst_port *port;
1953 int i;
1954 int ret = 0;
1955 mutex_lock(&mgr->payload_lock);
1956 for (i = 0; i < mgr->max_payloads; i++) {
1957
1958 if (!mgr->proposed_vcpis[i])
1959 continue;
1960
1961 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1962
1963 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1964 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1965 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1966 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1967 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1968 }
1969 if (ret) {
1970 mutex_unlock(&mgr->payload_lock);
1971 return ret;
1972 }
1973 }
1974 mutex_unlock(&mgr->payload_lock);
1975 return 0;
1976 }
1977 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1978
1979 #if 0 /* unused as of yet */
1980 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1981 struct drm_dp_mst_port *port,
1982 int offset, int size)
1983 {
1984 int len;
1985 struct drm_dp_sideband_msg_tx *txmsg;
1986
1987 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1988 if (!txmsg)
1989 return -ENOMEM;
1990
1991 len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1992 txmsg->dst = port->parent;
1993
1994 drm_dp_queue_down_tx(mgr, txmsg);
1995
1996 return 0;
1997 }
1998 #endif
1999
drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int offset,int size,u8 * bytes)2000 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
2001 struct drm_dp_mst_port *port,
2002 int offset, int size, u8 *bytes)
2003 {
2004 int len;
2005 int ret;
2006 struct drm_dp_sideband_msg_tx *txmsg;
2007 struct drm_dp_mst_branch *mstb;
2008
2009 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2010 if (!mstb)
2011 return -EINVAL;
2012
2013 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2014 if (!txmsg) {
2015 ret = -ENOMEM;
2016 goto fail_put;
2017 }
2018
2019 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
2020 txmsg->dst = mstb;
2021
2022 drm_dp_queue_down_tx(mgr, txmsg);
2023
2024 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2025 if (ret > 0) {
2026 if (txmsg->reply.reply_type == 1) {
2027 ret = -EINVAL;
2028 } else
2029 ret = 0;
2030 }
2031 kfree(txmsg);
2032 fail_put:
2033 drm_dp_put_mst_branch_device(mstb);
2034 return ret;
2035 }
2036
drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx * msg,u8 req_type)2037 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
2038 {
2039 struct drm_dp_sideband_msg_reply_body reply;
2040
2041 reply.reply_type = 0;
2042 reply.req_type = req_type;
2043 drm_dp_encode_sideband_reply(&reply, msg);
2044 return 0;
2045 }
2046
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)2047 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
2048 struct drm_dp_mst_branch *mstb,
2049 int req_type, int seqno, bool broadcast)
2050 {
2051 struct drm_dp_sideband_msg_tx *txmsg;
2052
2053 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2054 if (!txmsg)
2055 return -ENOMEM;
2056
2057 txmsg->dst = mstb;
2058 txmsg->seqno = seqno;
2059 drm_dp_encode_up_ack_reply(txmsg, req_type);
2060
2061 mutex_lock(&mgr->qlock);
2062
2063 process_single_up_tx_qlock(mgr, txmsg);
2064
2065 mutex_unlock(&mgr->qlock);
2066
2067 kfree(txmsg);
2068 return 0;
2069 }
2070
drm_dp_get_vc_payload_bw(int dp_link_bw,int dp_link_count,int * out)2071 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
2072 int dp_link_count,
2073 int *out)
2074 {
2075 switch (dp_link_bw) {
2076 default:
2077 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
2078 dp_link_bw, dp_link_count);
2079 return false;
2080
2081 case DP_LINK_BW_1_62:
2082 *out = 3 * dp_link_count;
2083 break;
2084 case DP_LINK_BW_2_7:
2085 *out = 5 * dp_link_count;
2086 break;
2087 case DP_LINK_BW_5_4:
2088 *out = 10 * dp_link_count;
2089 break;
2090 }
2091 return true;
2092 }
2093
2094 /**
2095 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
2096 * @mgr: manager to set state for
2097 * @mst_state: true to enable MST on this connector - false to disable.
2098 *
2099 * This is called by the driver when it detects an MST capable device plugged
2100 * into a DP MST capable port, or when a DP MST capable device is unplugged.
2101 */
drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr * mgr,bool mst_state)2102 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
2103 {
2104 int ret = 0;
2105 struct drm_dp_mst_branch *mstb = NULL;
2106
2107 mutex_lock(&mgr->lock);
2108 if (mst_state == mgr->mst_state)
2109 goto out_unlock;
2110
2111 mgr->mst_state = mst_state;
2112 /* set the device into MST mode */
2113 if (mst_state) {
2114 WARN_ON(mgr->mst_primary);
2115
2116 /* get dpcd info */
2117 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2118 if (ret != DP_RECEIVER_CAP_SIZE) {
2119 DRM_DEBUG_KMS("failed to read DPCD\n");
2120 goto out_unlock;
2121 }
2122
2123 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
2124 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
2125 &mgr->pbn_div)) {
2126 ret = -EINVAL;
2127 goto out_unlock;
2128 }
2129
2130 /* add initial branch device at LCT 1 */
2131 mstb = drm_dp_add_mst_branch_device(1, NULL);
2132 if (mstb == NULL) {
2133 ret = -ENOMEM;
2134 goto out_unlock;
2135 }
2136 mstb->mgr = mgr;
2137
2138 /* give this the main reference */
2139 mgr->mst_primary = mstb;
2140 kref_get(&mgr->mst_primary->kref);
2141
2142 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2143 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2144 if (ret < 0) {
2145 goto out_unlock;
2146 }
2147
2148 {
2149 struct drm_dp_payload reset_pay;
2150 reset_pay.start_slot = 0;
2151 reset_pay.num_slots = 0x3f;
2152 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
2153 }
2154
2155 queue_work(system_long_wq, &mgr->work);
2156
2157 ret = 0;
2158 } else {
2159 /* disable MST on the device */
2160 mstb = mgr->mst_primary;
2161 mgr->mst_primary = NULL;
2162 /* this can fail if the device is gone */
2163 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2164 ret = 0;
2165 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2166 mgr->payload_mask = 0;
2167 set_bit(0, &mgr->payload_mask);
2168 mgr->vcpi_mask = 0;
2169 }
2170
2171 out_unlock:
2172 mutex_unlock(&mgr->lock);
2173 if (mstb)
2174 drm_dp_put_mst_branch_device(mstb);
2175 return ret;
2176
2177 }
2178 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2179
2180 /**
2181 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2182 * @mgr: manager to suspend
2183 *
2184 * This function tells the MST device that we can't handle UP messages
2185 * anymore. This should stop it from sending any since we are suspended.
2186 */
drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr * mgr)2187 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2188 {
2189 mutex_lock(&mgr->lock);
2190 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2191 DP_MST_EN | DP_UPSTREAM_IS_SRC);
2192 mutex_unlock(&mgr->lock);
2193 flush_work(&mgr->work);
2194 flush_work(&mgr->destroy_connector_work);
2195 }
2196 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2197
2198 /**
2199 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2200 * @mgr: manager to resume
2201 *
2202 * This will fetch DPCD and see if the device is still there,
2203 * if it is, it will rewrite the MSTM control bits, and return.
2204 *
2205 * if the device fails this returns -1, and the driver should do
2206 * a full MST reprobe, in case we were undocked.
2207 */
drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr * mgr)2208 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2209 {
2210 int ret = 0;
2211
2212 mutex_lock(&mgr->lock);
2213
2214 if (mgr->mst_primary) {
2215 int sret;
2216 u8 guid[16];
2217
2218 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2219 if (sret != DP_RECEIVER_CAP_SIZE) {
2220 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2221 ret = -1;
2222 goto out_unlock;
2223 }
2224
2225 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2226 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2227 if (ret < 0) {
2228 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2229 ret = -1;
2230 goto out_unlock;
2231 }
2232
2233 /* Some hubs forget their guids after they resume */
2234 sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
2235 if (sret != 16) {
2236 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2237 ret = -1;
2238 goto out_unlock;
2239 }
2240 drm_dp_check_mstb_guid(mgr->mst_primary, guid);
2241
2242 ret = 0;
2243 } else
2244 ret = -1;
2245
2246 out_unlock:
2247 mutex_unlock(&mgr->lock);
2248 return ret;
2249 }
2250 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2251
drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr * mgr,bool up)2252 static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2253 {
2254 int len;
2255 u8 replyblock[32];
2256 int replylen, origlen, curreply;
2257 int ret;
2258 struct drm_dp_sideband_msg_rx *msg;
2259 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2260 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2261
2262 len = min(mgr->max_dpcd_transaction_bytes, 16);
2263 ret = drm_dp_dpcd_read(mgr->aux, basereg,
2264 replyblock, len);
2265 if (ret != len) {
2266 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2267 return false;
2268 }
2269 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2270 if (!ret) {
2271 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2272 return false;
2273 }
2274 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2275
2276 origlen = replylen;
2277 replylen -= len;
2278 curreply = len;
2279 while (replylen > 0) {
2280 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2281 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2282 replyblock, len);
2283 if (ret != len) {
2284 DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
2285 len, ret);
2286 return false;
2287 }
2288
2289 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2290 if (!ret) {
2291 DRM_DEBUG_KMS("failed to build sideband msg\n");
2292 return false;
2293 }
2294
2295 curreply += len;
2296 replylen -= len;
2297 }
2298 return true;
2299 }
2300
drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr * mgr)2301 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2302 {
2303 int ret = 0;
2304
2305 if (!drm_dp_get_one_sb_msg(mgr, false)) {
2306 memset(&mgr->down_rep_recv, 0,
2307 sizeof(struct drm_dp_sideband_msg_rx));
2308 return 0;
2309 }
2310
2311 if (mgr->down_rep_recv.have_eomt) {
2312 struct drm_dp_sideband_msg_tx *txmsg;
2313 struct drm_dp_mst_branch *mstb;
2314 int slot = -1;
2315 mstb = drm_dp_get_mst_branch_device(mgr,
2316 mgr->down_rep_recv.initial_hdr.lct,
2317 mgr->down_rep_recv.initial_hdr.rad);
2318
2319 if (!mstb) {
2320 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2321 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2322 return 0;
2323 }
2324
2325 /* find the message */
2326 slot = mgr->down_rep_recv.initial_hdr.seqno;
2327 mutex_lock(&mgr->qlock);
2328 txmsg = mstb->tx_slots[slot];
2329 /* remove from slots */
2330 mutex_unlock(&mgr->qlock);
2331
2332 if (!txmsg) {
2333 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2334 mstb,
2335 mgr->down_rep_recv.initial_hdr.seqno,
2336 mgr->down_rep_recv.initial_hdr.lct,
2337 mgr->down_rep_recv.initial_hdr.rad[0],
2338 mgr->down_rep_recv.msg[0]);
2339 drm_dp_put_mst_branch_device(mstb);
2340 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2341 return 0;
2342 }
2343
2344 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2345 if (txmsg->reply.reply_type == 1) {
2346 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);
2347 }
2348
2349 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2350 drm_dp_put_mst_branch_device(mstb);
2351
2352 mutex_lock(&mgr->qlock);
2353 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2354 mstb->tx_slots[slot] = NULL;
2355 mutex_unlock(&mgr->qlock);
2356
2357 wake_up_all(&mgr->tx_waitq);
2358 }
2359 return ret;
2360 }
2361
drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr * mgr)2362 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2363 {
2364 int ret = 0;
2365
2366 if (!drm_dp_get_one_sb_msg(mgr, true)) {
2367 memset(&mgr->up_req_recv, 0,
2368 sizeof(struct drm_dp_sideband_msg_rx));
2369 return 0;
2370 }
2371
2372 if (mgr->up_req_recv.have_eomt) {
2373 struct drm_dp_sideband_msg_req_body msg;
2374 struct drm_dp_mst_branch *mstb = NULL;
2375 bool seqno;
2376
2377 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2378 mstb = drm_dp_get_mst_branch_device(mgr,
2379 mgr->up_req_recv.initial_hdr.lct,
2380 mgr->up_req_recv.initial_hdr.rad);
2381 if (!mstb) {
2382 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2383 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2384 return 0;
2385 }
2386 }
2387
2388 seqno = mgr->up_req_recv.initial_hdr.seqno;
2389 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2390
2391 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2392 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2393
2394 if (!mstb)
2395 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2396
2397 if (!mstb) {
2398 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2399 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2400 return 0;
2401 }
2402
2403 drm_dp_update_port(mstb, &msg.u.conn_stat);
2404
2405 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);
2406 (*mgr->cbs->hotplug)(mgr);
2407
2408 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2409 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2410 if (!mstb)
2411 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2412
2413 if (!mstb) {
2414 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2415 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2416 return 0;
2417 }
2418
2419 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2420 }
2421
2422 if (mstb)
2423 drm_dp_put_mst_branch_device(mstb);
2424
2425 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2426 }
2427 return ret;
2428 }
2429
2430 /**
2431 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2432 * @mgr: manager to notify irq for.
2433 * @esi: 4 bytes from SINK_COUNT_ESI
2434 * @handled: whether the hpd interrupt was consumed or not
2435 *
2436 * This should be called from the driver when it detects a short IRQ,
2437 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2438 * topology manager will process the sideband messages received as a result
2439 * of this.
2440 */
drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr * mgr,u8 * esi,bool * handled)2441 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2442 {
2443 int ret = 0;
2444 int sc;
2445 *handled = false;
2446 sc = esi[0] & 0x3f;
2447
2448 if (sc != mgr->sink_count) {
2449 mgr->sink_count = sc;
2450 *handled = true;
2451 }
2452
2453 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2454 ret = drm_dp_mst_handle_down_rep(mgr);
2455 *handled = true;
2456 }
2457
2458 if (esi[1] & DP_UP_REQ_MSG_RDY) {
2459 ret |= drm_dp_mst_handle_up_req(mgr);
2460 *handled = true;
2461 }
2462
2463 drm_dp_mst_kick_tx(mgr);
2464 return ret;
2465 }
2466 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2467
2468 /**
2469 * drm_dp_mst_detect_port() - get connection status for an MST port
2470 * @connector: DRM connector for this port
2471 * @mgr: manager for this port
2472 * @port: unverified pointer to a port
2473 *
2474 * This returns the current connection state for a port. It validates the
2475 * port pointer still exists so the caller doesn't require a reference
2476 */
drm_dp_mst_detect_port(struct drm_connector * connector,struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2477 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2478 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2479 {
2480 enum drm_connector_status status = connector_status_disconnected;
2481
2482 /* we need to search for the port in the mgr in case its gone */
2483 port = drm_dp_get_validated_port_ref(mgr, port);
2484 if (!port)
2485 return connector_status_disconnected;
2486
2487 if (!port->ddps)
2488 goto out;
2489
2490 switch (port->pdt) {
2491 case DP_PEER_DEVICE_NONE:
2492 case DP_PEER_DEVICE_MST_BRANCHING:
2493 break;
2494
2495 case DP_PEER_DEVICE_SST_SINK:
2496 status = connector_status_connected;
2497 /* for logical ports - cache the EDID */
2498 if (port->port_num >= 8 && !port->cached_edid) {
2499 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2500 }
2501 break;
2502 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2503 if (port->ldps)
2504 status = connector_status_connected;
2505 break;
2506 }
2507 out:
2508 drm_dp_put_port(port);
2509 return status;
2510 }
2511 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2512
2513 /**
2514 * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
2515 * @mgr: manager for this port
2516 * @port: unverified pointer to a port.
2517 *
2518 * This returns whether the port supports audio or not.
2519 */
drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2520 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
2521 struct drm_dp_mst_port *port)
2522 {
2523 bool ret = false;
2524
2525 port = drm_dp_get_validated_port_ref(mgr, port);
2526 if (!port)
2527 return ret;
2528 ret = port->has_audio;
2529 drm_dp_put_port(port);
2530 return ret;
2531 }
2532 EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
2533
2534 /**
2535 * drm_dp_mst_get_edid() - get EDID for an MST port
2536 * @connector: toplevel connector to get EDID for
2537 * @mgr: manager for this port
2538 * @port: unverified pointer to a port.
2539 *
2540 * This returns an EDID for the port connected to a connector,
2541 * It validates the pointer still exists so the caller doesn't require a
2542 * reference.
2543 */
drm_dp_mst_get_edid(struct drm_connector * connector,struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2544 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2545 {
2546 struct edid *edid = NULL;
2547
2548 /* we need to search for the port in the mgr in case its gone */
2549 port = drm_dp_get_validated_port_ref(mgr, port);
2550 if (!port)
2551 return NULL;
2552
2553 if (port->cached_edid)
2554 edid = drm_edid_duplicate(port->cached_edid);
2555 else {
2556 edid = drm_get_edid(connector, &port->aux.ddc);
2557 drm_mode_connector_set_tile_property(connector);
2558 }
2559 port->has_audio = drm_detect_monitor_audio(edid);
2560 drm_dp_put_port(port);
2561 return edid;
2562 }
2563 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2564
2565 /**
2566 * drm_dp_find_vcpi_slots() - find slots for this PBN value
2567 * @mgr: manager to use
2568 * @pbn: payload bandwidth to convert into slots.
2569 */
drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr * mgr,int pbn)2570 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2571 int pbn)
2572 {
2573 int num_slots;
2574
2575 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2576
2577 /* max. time slots - one slot for MTP header */
2578 if (num_slots > 63)
2579 return -ENOSPC;
2580 return num_slots;
2581 }
2582 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2583
drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_vcpi * vcpi,int pbn,int slots)2584 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2585 struct drm_dp_vcpi *vcpi, int pbn, int slots)
2586 {
2587 int ret;
2588
2589 /* max. time slots - one slot for MTP header */
2590 if (slots > 63)
2591 return -ENOSPC;
2592
2593 vcpi->pbn = pbn;
2594 vcpi->aligned_pbn = slots * mgr->pbn_div;
2595 vcpi->num_slots = slots;
2596
2597 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2598 if (ret < 0)
2599 return ret;
2600 return 0;
2601 }
2602
2603 /**
2604 * drm_dp_atomic_find_vcpi_slots() - Find and add vcpi slots to the state
2605 * @state: global atomic state
2606 * @mgr: MST topology manager for the port
2607 * @port: port to find vcpi slots for
2608 * @pbn: bandwidth required for the mode in PBN
2609 *
2610 * RETURNS:
2611 * Total slots in the atomic state assigned for this port or error
2612 */
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)2613 int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
2614 struct drm_dp_mst_topology_mgr *mgr,
2615 struct drm_dp_mst_port *port, int pbn)
2616 {
2617 struct drm_dp_mst_topology_state *topology_state;
2618 int req_slots;
2619
2620 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
2621 if (IS_ERR(topology_state))
2622 return PTR_ERR(topology_state);
2623
2624 port = drm_dp_get_validated_port_ref(mgr, port);
2625 if (port == NULL)
2626 return -EINVAL;
2627 req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2628 DRM_DEBUG_KMS("vcpi slots req=%d, avail=%d\n",
2629 req_slots, topology_state->avail_slots);
2630
2631 if (req_slots > topology_state->avail_slots) {
2632 drm_dp_put_port(port);
2633 return -ENOSPC;
2634 }
2635
2636 topology_state->avail_slots -= req_slots;
2637 DRM_DEBUG_KMS("vcpi slots avail=%d", topology_state->avail_slots);
2638
2639 drm_dp_put_port(port);
2640 return req_slots;
2641 }
2642 EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
2643
2644 /**
2645 * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
2646 * @state: global atomic state
2647 * @mgr: MST topology manager for the port
2648 * @slots: number of vcpi slots to release
2649 *
2650 * RETURNS:
2651 * 0 if @slots were added back to &drm_dp_mst_topology_state->avail_slots or
2652 * negative error code
2653 */
drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state * state,struct drm_dp_mst_topology_mgr * mgr,int slots)2654 int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
2655 struct drm_dp_mst_topology_mgr *mgr,
2656 int slots)
2657 {
2658 struct drm_dp_mst_topology_state *topology_state;
2659
2660 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
2661 if (IS_ERR(topology_state))
2662 return PTR_ERR(topology_state);
2663
2664 /* We cannot rely on port->vcpi.num_slots to update
2665 * topology_state->avail_slots as the port may not exist if the parent
2666 * branch device was unplugged. This should be fixed by tracking
2667 * per-port slot allocation in drm_dp_mst_topology_state instead of
2668 * depending on the caller to tell us how many slots to release.
2669 */
2670 topology_state->avail_slots += slots;
2671 DRM_DEBUG_KMS("vcpi slots released=%d, avail=%d\n",
2672 slots, topology_state->avail_slots);
2673
2674 return 0;
2675 }
2676 EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
2677
2678 /**
2679 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2680 * @mgr: manager for this port
2681 * @port: port to allocate a virtual channel for.
2682 * @pbn: payload bandwidth number to request
2683 * @slots: returned number of slots for this PBN.
2684 */
drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int pbn,int slots)2685 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2686 struct drm_dp_mst_port *port, int pbn, int slots)
2687 {
2688 int ret;
2689
2690 port = drm_dp_get_validated_port_ref(mgr, port);
2691 if (!port)
2692 return false;
2693
2694 if (slots < 0)
2695 return false;
2696
2697 if (port->vcpi.vcpi > 0) {
2698 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2699 if (pbn == port->vcpi.pbn) {
2700 drm_dp_put_port(port);
2701 return true;
2702 }
2703 }
2704
2705 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
2706 if (ret) {
2707 DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
2708 DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
2709 goto out;
2710 }
2711 DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
2712 pbn, port->vcpi.num_slots);
2713
2714 drm_dp_put_port(port);
2715 return true;
2716 out:
2717 return false;
2718 }
2719 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2720
drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2721 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2722 {
2723 int slots = 0;
2724 port = drm_dp_get_validated_port_ref(mgr, port);
2725 if (!port)
2726 return slots;
2727
2728 slots = port->vcpi.num_slots;
2729 drm_dp_put_port(port);
2730 return slots;
2731 }
2732 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2733
2734 /**
2735 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2736 * @mgr: manager for this port
2737 * @port: unverified pointer to a port.
2738 *
2739 * This just resets the number of slots for the ports VCPI for later programming.
2740 */
drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2741 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2742 {
2743 port = drm_dp_get_validated_port_ref(mgr, port);
2744 if (!port)
2745 return;
2746 port->vcpi.num_slots = 0;
2747 drm_dp_put_port(port);
2748 }
2749 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2750
2751 /**
2752 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2753 * @mgr: manager for this port
2754 * @port: unverified port to deallocate vcpi for
2755 */
drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2756 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2757 {
2758 port = drm_dp_get_validated_port_ref(mgr, port);
2759 if (!port)
2760 return;
2761
2762 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2763 port->vcpi.num_slots = 0;
2764 port->vcpi.pbn = 0;
2765 port->vcpi.aligned_pbn = 0;
2766 port->vcpi.vcpi = 0;
2767 drm_dp_put_port(port);
2768 }
2769 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2770
drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr * mgr,int id,struct drm_dp_payload * payload)2771 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2772 int id, struct drm_dp_payload *payload)
2773 {
2774 u8 payload_alloc[3], status;
2775 int ret;
2776 int retries = 0;
2777
2778 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2779 DP_PAYLOAD_TABLE_UPDATED);
2780
2781 payload_alloc[0] = id;
2782 payload_alloc[1] = payload->start_slot;
2783 payload_alloc[2] = payload->num_slots;
2784
2785 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2786 if (ret != 3) {
2787 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2788 goto fail;
2789 }
2790
2791 retry:
2792 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2793 if (ret < 0) {
2794 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2795 goto fail;
2796 }
2797
2798 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2799 retries++;
2800 if (retries < 20) {
2801 usleep_range(10000, 20000);
2802 goto retry;
2803 }
2804 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2805 ret = -EINVAL;
2806 goto fail;
2807 }
2808 ret = 0;
2809 fail:
2810 return ret;
2811 }
2812
2813
2814 /**
2815 * drm_dp_check_act_status() - Check ACT handled status.
2816 * @mgr: manager to use
2817 *
2818 * Check the payload status bits in the DPCD for ACT handled completion.
2819 */
drm_dp_check_act_status(struct drm_dp_mst_topology_mgr * mgr)2820 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2821 {
2822 u8 status;
2823 int ret;
2824 int count = 0;
2825
2826 do {
2827 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2828
2829 if (ret < 0) {
2830 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2831 goto fail;
2832 }
2833
2834 if (status & DP_PAYLOAD_ACT_HANDLED)
2835 break;
2836 count++;
2837 udelay(100);
2838
2839 } while (count < 30);
2840
2841 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2842 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2843 ret = -EINVAL;
2844 goto fail;
2845 }
2846 return 0;
2847 fail:
2848 return ret;
2849 }
2850 EXPORT_SYMBOL(drm_dp_check_act_status);
2851
2852 /**
2853 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2854 * @clock: dot clock for the mode
2855 * @bpp: bpp for the mode.
2856 *
2857 * This uses the formula in the spec to calculate the PBN value for a mode.
2858 */
drm_dp_calc_pbn_mode(int clock,int bpp)2859 int drm_dp_calc_pbn_mode(int clock, int bpp)
2860 {
2861 u64 kbps;
2862 s64 peak_kbps;
2863 u32 numerator;
2864 u32 denominator;
2865
2866 kbps = clock * bpp;
2867
2868 /*
2869 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
2870 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
2871 * common multiplier to render an integer PBN for all link rate/lane
2872 * counts combinations
2873 * calculate
2874 * peak_kbps *= (1006/1000)
2875 * peak_kbps *= (64/54)
2876 * peak_kbps *= 8 convert to bytes
2877 */
2878
2879 numerator = 64 * 1006;
2880 denominator = 54 * 8 * 1000 * 1000;
2881
2882 kbps *= numerator;
2883 peak_kbps = drm_fixp_from_fraction(kbps, denominator);
2884
2885 return drm_fixp2int_ceil(peak_kbps);
2886 }
2887 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2888
test_calc_pbn_mode(void)2889 static int test_calc_pbn_mode(void)
2890 {
2891 int ret;
2892 ret = drm_dp_calc_pbn_mode(154000, 30);
2893 if (ret != 689) {
2894 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2895 154000, 30, 689, ret);
2896 return -EINVAL;
2897 }
2898 ret = drm_dp_calc_pbn_mode(234000, 30);
2899 if (ret != 1047) {
2900 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2901 234000, 30, 1047, ret);
2902 return -EINVAL;
2903 }
2904 ret = drm_dp_calc_pbn_mode(297000, 24);
2905 if (ret != 1063) {
2906 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2907 297000, 24, 1063, ret);
2908 return -EINVAL;
2909 }
2910 return 0;
2911 }
2912
2913 /* 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)2914 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2915 {
2916 queue_work(system_long_wq, &mgr->tx_work);
2917 }
2918
drm_dp_mst_dump_mstb(struct seq_file * m,struct drm_dp_mst_branch * mstb)2919 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2920 struct drm_dp_mst_branch *mstb)
2921 {
2922 struct drm_dp_mst_port *port;
2923 int tabs = mstb->lct;
2924 char prefix[10];
2925 int i;
2926
2927 for (i = 0; i < tabs; i++)
2928 prefix[i] = '\t';
2929 prefix[i] = '\0';
2930
2931 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2932 list_for_each_entry(port, &mstb->ports, next) {
2933 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);
2934 if (port->mstb)
2935 drm_dp_mst_dump_mstb(m, port->mstb);
2936 }
2937 }
2938
dump_dp_payload_table(struct drm_dp_mst_topology_mgr * mgr,char * buf)2939 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2940 char *buf)
2941 {
2942 int i;
2943
2944 for (i = 0; i < 64; i += 16) {
2945 if (drm_dp_dpcd_read(mgr->aux,
2946 DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
2947 &buf[i], 16) != 16)
2948 return false;
2949 }
2950 return true;
2951 }
2952
fetch_monitor_name(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,char * name,int namelen)2953 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
2954 struct drm_dp_mst_port *port, char *name,
2955 int namelen)
2956 {
2957 struct edid *mst_edid;
2958
2959 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
2960 drm_edid_get_monitor_name(mst_edid, name, namelen);
2961 }
2962
2963 /**
2964 * drm_dp_mst_dump_topology(): dump topology to seq file.
2965 * @m: seq_file to dump output to
2966 * @mgr: manager to dump current topology for.
2967 *
2968 * helper to dump MST topology to a seq file for debugfs.
2969 */
drm_dp_mst_dump_topology(struct seq_file * m,struct drm_dp_mst_topology_mgr * mgr)2970 void drm_dp_mst_dump_topology(struct seq_file *m,
2971 struct drm_dp_mst_topology_mgr *mgr)
2972 {
2973 int i;
2974 struct drm_dp_mst_port *port;
2975
2976 mutex_lock(&mgr->lock);
2977 if (mgr->mst_primary)
2978 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2979
2980 /* dump VCPIs */
2981 mutex_unlock(&mgr->lock);
2982
2983 mutex_lock(&mgr->payload_lock);
2984 seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
2985 mgr->max_payloads);
2986
2987 for (i = 0; i < mgr->max_payloads; i++) {
2988 if (mgr->proposed_vcpis[i]) {
2989 char name[14];
2990
2991 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2992 fetch_monitor_name(mgr, port, name, sizeof(name));
2993 seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
2994 port->port_num, port->vcpi.vcpi,
2995 port->vcpi.num_slots,
2996 (*name != 0) ? name : "Unknown");
2997 } else
2998 seq_printf(m, "vcpi %d:unused\n", i);
2999 }
3000 for (i = 0; i < mgr->max_payloads; i++) {
3001 seq_printf(m, "payload %d: %d, %d, %d\n",
3002 i,
3003 mgr->payloads[i].payload_state,
3004 mgr->payloads[i].start_slot,
3005 mgr->payloads[i].num_slots);
3006
3007
3008 }
3009 mutex_unlock(&mgr->payload_lock);
3010
3011 mutex_lock(&mgr->lock);
3012 if (mgr->mst_primary) {
3013 u8 buf[64];
3014 int ret;
3015
3016 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
3017 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
3018 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
3019 seq_printf(m, "faux/mst: %*ph\n", 2, buf);
3020 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
3021 seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
3022
3023 /* dump the standard OUI branch header */
3024 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
3025 seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
3026 for (i = 0x3; i < 0x8 && buf[i]; i++)
3027 seq_printf(m, "%c", buf[i]);
3028 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
3029 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
3030 if (dump_dp_payload_table(mgr, buf))
3031 seq_printf(m, "payload table: %*ph\n", 63, buf);
3032
3033 }
3034
3035 mutex_unlock(&mgr->lock);
3036
3037 }
3038 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
3039
drm_dp_tx_work(struct work_struct * work)3040 static void drm_dp_tx_work(struct work_struct *work)
3041 {
3042 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
3043
3044 mutex_lock(&mgr->qlock);
3045 if (!list_empty(&mgr->tx_msg_downq))
3046 process_single_down_tx_qlock(mgr);
3047 mutex_unlock(&mgr->qlock);
3048 }
3049
drm_dp_free_mst_port(struct kref * kref)3050 static void drm_dp_free_mst_port(struct kref *kref)
3051 {
3052 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
3053 kref_put(&port->parent->kref, drm_dp_free_mst_branch_device);
3054 kfree(port);
3055 }
3056
drm_dp_destroy_connector_work(struct work_struct * work)3057 static void drm_dp_destroy_connector_work(struct work_struct *work)
3058 {
3059 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
3060 struct drm_dp_mst_port *port;
3061 bool send_hotplug = false;
3062 /*
3063 * Not a regular list traverse as we have to drop the destroy
3064 * connector lock before destroying the connector, to avoid AB->BA
3065 * ordering between this lock and the config mutex.
3066 */
3067 for (;;) {
3068 mutex_lock(&mgr->destroy_connector_lock);
3069 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
3070 if (!port) {
3071 mutex_unlock(&mgr->destroy_connector_lock);
3072 break;
3073 }
3074 list_del(&port->next);
3075 mutex_unlock(&mgr->destroy_connector_lock);
3076
3077 kref_init(&port->kref);
3078 INIT_LIST_HEAD(&port->next);
3079
3080 mgr->cbs->destroy_connector(mgr, port->connector);
3081
3082 drm_dp_port_teardown_pdt(port, port->pdt);
3083 port->pdt = DP_PEER_DEVICE_NONE;
3084
3085 if (!port->input && port->vcpi.vcpi > 0) {
3086 drm_dp_mst_reset_vcpi_slots(mgr, port);
3087 drm_dp_update_payload_part1(mgr);
3088 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
3089 }
3090
3091 kref_put(&port->kref, drm_dp_free_mst_port);
3092 send_hotplug = true;
3093 }
3094 if (send_hotplug)
3095 (*mgr->cbs->hotplug)(mgr);
3096 }
3097
3098 static struct drm_private_state *
drm_dp_mst_duplicate_state(struct drm_private_obj * obj)3099 drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
3100 {
3101 struct drm_dp_mst_topology_state *state;
3102
3103 state = kmemdup(obj->state, sizeof(*state), GFP_KERNEL);
3104 if (!state)
3105 return NULL;
3106
3107 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
3108
3109 return &state->base;
3110 }
3111
drm_dp_mst_destroy_state(struct drm_private_obj * obj,struct drm_private_state * state)3112 static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
3113 struct drm_private_state *state)
3114 {
3115 struct drm_dp_mst_topology_state *mst_state =
3116 to_dp_mst_topology_state(state);
3117
3118 kfree(mst_state);
3119 }
3120
3121 static const struct drm_private_state_funcs mst_state_funcs = {
3122 .atomic_duplicate_state = drm_dp_mst_duplicate_state,
3123 .atomic_destroy_state = drm_dp_mst_destroy_state,
3124 };
3125
3126 /**
3127 * drm_atomic_get_mst_topology_state: get MST topology state
3128 *
3129 * @state: global atomic state
3130 * @mgr: MST topology manager, also the private object in this case
3131 *
3132 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
3133 * state vtable so that the private object state returned is that of a MST
3134 * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
3135 * to care of the locking, so warn if don't hold the connection_mutex.
3136 *
3137 * RETURNS:
3138 *
3139 * The MST topology state or error pointer.
3140 */
drm_atomic_get_mst_topology_state(struct drm_atomic_state * state,struct drm_dp_mst_topology_mgr * mgr)3141 struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
3142 struct drm_dp_mst_topology_mgr *mgr)
3143 {
3144 struct drm_device *dev = mgr->dev;
3145
3146 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
3147 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
3148 }
3149 EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
3150
3151 /**
3152 * drm_dp_mst_topology_mgr_init - initialise a topology manager
3153 * @mgr: manager struct to initialise
3154 * @dev: device providing this structure - for i2c addition.
3155 * @aux: DP helper aux channel to talk to this device
3156 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
3157 * @max_payloads: maximum number of payloads this GPU can source
3158 * @conn_base_id: the connector object ID the MST device is connected to.
3159 *
3160 * Return 0 for success, or negative error code on failure
3161 */
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)3162 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
3163 struct drm_device *dev, struct drm_dp_aux *aux,
3164 int max_dpcd_transaction_bytes,
3165 int max_payloads, int conn_base_id)
3166 {
3167 struct drm_dp_mst_topology_state *mst_state;
3168
3169 lockinit(&mgr->lock, "drmml", 0, LK_CANRECURSE);
3170 lockinit(&mgr->qlock, "drmmql", 0, LK_CANRECURSE);
3171 lockinit(&mgr->payload_lock, "drmmpl", 0, LK_CANRECURSE);
3172 lockinit(&mgr->destroy_connector_lock, "drmmdcl", 0, LK_CANRECURSE);
3173 INIT_LIST_HEAD(&mgr->tx_msg_downq);
3174 INIT_LIST_HEAD(&mgr->destroy_connector_list);
3175 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
3176 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
3177 INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
3178 init_waitqueue_head(&mgr->tx_waitq);
3179 mgr->dev = dev;
3180 mgr->aux = aux;
3181 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
3182 mgr->max_payloads = max_payloads;
3183 mgr->conn_base_id = conn_base_id;
3184 if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
3185 max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
3186 return -EINVAL;
3187 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
3188 if (!mgr->payloads)
3189 return -ENOMEM;
3190 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
3191 if (!mgr->proposed_vcpis)
3192 return -ENOMEM;
3193 set_bit(0, &mgr->payload_mask);
3194 if (test_calc_pbn_mode() < 0)
3195 DRM_ERROR("MST PBN self-test failed\n");
3196
3197 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
3198 if (mst_state == NULL)
3199 return -ENOMEM;
3200
3201 mst_state->mgr = mgr;
3202
3203 /* max. time slots - one slot for MTP header */
3204 mst_state->avail_slots = 63;
3205
3206 drm_atomic_private_obj_init(&mgr->base,
3207 &mst_state->base,
3208 &mst_state_funcs);
3209
3210 return 0;
3211 }
3212 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
3213
3214 /**
3215 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
3216 * @mgr: manager to destroy
3217 */
drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr * mgr)3218 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
3219 {
3220 flush_work(&mgr->work);
3221 flush_work(&mgr->destroy_connector_work);
3222 mutex_lock(&mgr->payload_lock);
3223 kfree(mgr->payloads);
3224 mgr->payloads = NULL;
3225 kfree(mgr->proposed_vcpis);
3226 mgr->proposed_vcpis = NULL;
3227 mutex_unlock(&mgr->payload_lock);
3228 mgr->dev = NULL;
3229 mgr->aux = NULL;
3230 drm_atomic_private_obj_fini(&mgr->base);
3231 mgr->funcs = NULL;
3232 }
3233 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
3234
3235 /* I2C device */
drm_dp_mst_i2c_xfer(struct i2c_adapter * adapter,struct i2c_msg * msgs,int num)3236 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
3237 int num)
3238 {
3239 struct drm_dp_aux *aux = adapter->algo_data;
3240 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
3241 struct drm_dp_mst_branch *mstb;
3242 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
3243 unsigned int i;
3244 bool reading = false;
3245 struct drm_dp_sideband_msg_req_body msg;
3246 struct drm_dp_sideband_msg_tx *txmsg = NULL;
3247 int ret;
3248
3249 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
3250 if (!mstb)
3251 return -EREMOTEIO;
3252
3253 /* construct i2c msg */
3254 /* see if last msg is a read */
3255 if (msgs[num - 1].flags & I2C_M_RD)
3256 reading = true;
3257
3258 if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
3259 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
3260 ret = -EIO;
3261 goto out;
3262 }
3263
3264 memset(&msg, 0, sizeof(msg));
3265 msg.req_type = DP_REMOTE_I2C_READ;
3266 msg.u.i2c_read.num_transactions = num - 1;
3267 msg.u.i2c_read.port_number = port->port_num;
3268 for (i = 0; i < num - 1; i++) {
3269 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
3270 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
3271 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
3272 }
3273 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
3274 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
3275
3276 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3277 if (!txmsg) {
3278 ret = -ENOMEM;
3279 goto out;
3280 }
3281
3282 txmsg->dst = mstb;
3283 drm_dp_encode_sideband_req(&msg, txmsg);
3284
3285 drm_dp_queue_down_tx(mgr, txmsg);
3286
3287 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3288 if (ret > 0) {
3289
3290 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
3291 ret = -EREMOTEIO;
3292 goto out;
3293 }
3294 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
3295 ret = -EIO;
3296 goto out;
3297 }
3298 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
3299 ret = num;
3300 }
3301 out:
3302 kfree(txmsg);
3303 drm_dp_put_mst_branch_device(mstb);
3304 return ret;
3305 }
3306
drm_dp_mst_i2c_functionality(struct i2c_adapter * adapter)3307 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
3308 {
3309 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
3310 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
3311 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
3312 I2C_FUNC_10BIT_ADDR;
3313 }
3314
3315 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
3316 .functionality = drm_dp_mst_i2c_functionality,
3317 .master_xfer = drm_dp_mst_i2c_xfer,
3318 };
3319
3320 /**
3321 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
3322 * @aux: DisplayPort AUX channel
3323 *
3324 * Returns 0 on success or a negative error code on failure.
3325 */
drm_dp_mst_register_i2c_bus(struct drm_dp_aux * aux)3326 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
3327 {
3328 aux->ddc.algo = &drm_dp_mst_i2c_algo;
3329 aux->ddc.algo_data = aux;
3330 aux->ddc.retries = 3;
3331
3332 #if 0
3333 aux->ddc.class = I2C_CLASS_DDC;
3334 aux->ddc.owner = THIS_MODULE;
3335 #endif
3336 aux->ddc.dev.parent = aux->dev;
3337 #if 0
3338 aux->ddc.dev.of_node = aux->dev->of_node;
3339 #endif
3340
3341 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
3342 sizeof(aux->ddc.name));
3343
3344 return i2c_add_adapter(&aux->ddc);
3345 }
3346
3347 /**
3348 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
3349 * @aux: DisplayPort AUX channel
3350 */
drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux * aux)3351 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
3352 {
3353 i2c_del_adapter(&aux->ddc);
3354 }
3355