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 #include <linux/iopoll.h>
33
34 #include <drm/drm_fixed.h>
35
36 /**
37 * DOC: dp mst helper
38 *
39 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
40 * protocol. The helpers contain a topology manager and bandwidth manager.
41 * The helpers encapsulate the sending and received of sideband msgs.
42 */
43 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
44 char *buf);
45 static int test_calc_pbn_mode(void);
46
47 static void drm_dp_put_port(struct drm_dp_mst_port *port);
48
49 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
50 int id,
51 struct drm_dp_payload *payload);
52
53 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
54 struct drm_dp_mst_port *port,
55 int offset, int size, u8 *bytes);
56
57 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
58 struct drm_dp_mst_branch *mstb);
59 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
60 struct drm_dp_mst_branch *mstb,
61 struct drm_dp_mst_port *port);
62 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
63 u8 *guid);
64
65 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
66 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
67 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
68 /* sideband msg handling */
drm_dp_msg_header_crc4(const uint8_t * data,size_t num_nibbles)69 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
70 {
71 u8 bitmask = 0x80;
72 u8 bitshift = 7;
73 u8 array_index = 0;
74 int number_of_bits = num_nibbles * 4;
75 u8 remainder = 0;
76
77 while (number_of_bits != 0) {
78 number_of_bits--;
79 remainder <<= 1;
80 remainder |= (data[array_index] & bitmask) >> bitshift;
81 bitmask >>= 1;
82 bitshift--;
83 if (bitmask == 0) {
84 bitmask = 0x80;
85 bitshift = 7;
86 array_index++;
87 }
88 if ((remainder & 0x10) == 0x10)
89 remainder ^= 0x13;
90 }
91
92 number_of_bits = 4;
93 while (number_of_bits != 0) {
94 number_of_bits--;
95 remainder <<= 1;
96 if ((remainder & 0x10) != 0)
97 remainder ^= 0x13;
98 }
99
100 return remainder;
101 }
102
drm_dp_msg_data_crc4(const uint8_t * data,u8 number_of_bytes)103 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
104 {
105 u8 bitmask = 0x80;
106 u8 bitshift = 7;
107 u8 array_index = 0;
108 int number_of_bits = number_of_bytes * 8;
109 u16 remainder = 0;
110
111 while (number_of_bits != 0) {
112 number_of_bits--;
113 remainder <<= 1;
114 remainder |= (data[array_index] & bitmask) >> bitshift;
115 bitmask >>= 1;
116 bitshift--;
117 if (bitmask == 0) {
118 bitmask = 0x80;
119 bitshift = 7;
120 array_index++;
121 }
122 if ((remainder & 0x100) == 0x100)
123 remainder ^= 0xd5;
124 }
125
126 number_of_bits = 8;
127 while (number_of_bits != 0) {
128 number_of_bits--;
129 remainder <<= 1;
130 if ((remainder & 0x100) != 0)
131 remainder ^= 0xd5;
132 }
133
134 return remainder & 0xff;
135 }
drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr * hdr)136 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
137 {
138 u8 size = 3;
139 size += (hdr->lct / 2);
140 return size;
141 }
142
drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr * hdr,u8 * buf,int * len)143 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
144 u8 *buf, int *len)
145 {
146 int idx = 0;
147 int i;
148 u8 crc4;
149 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
150 for (i = 0; i < (hdr->lct / 2); i++)
151 buf[idx++] = hdr->rad[i];
152 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
153 (hdr->msg_len & 0x3f);
154 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
155
156 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
157 buf[idx - 1] |= (crc4 & 0xf);
158
159 *len = idx;
160 }
161
drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr * hdr,u8 * buf,int buflen,u8 * hdrlen)162 static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
163 u8 *buf, int buflen, u8 *hdrlen)
164 {
165 u8 crc4;
166 u8 len;
167 int i;
168 u8 idx;
169 if (buf[0] == 0)
170 return false;
171 len = 3;
172 len += ((buf[0] & 0xf0) >> 4) / 2;
173 if (len > buflen)
174 return false;
175 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
176
177 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
178 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
179 return false;
180 }
181
182 hdr->lct = (buf[0] & 0xf0) >> 4;
183 hdr->lcr = (buf[0] & 0xf);
184 idx = 1;
185 for (i = 0; i < (hdr->lct / 2); i++)
186 hdr->rad[i] = buf[idx++];
187 hdr->broadcast = (buf[idx] >> 7) & 0x1;
188 hdr->path_msg = (buf[idx] >> 6) & 0x1;
189 hdr->msg_len = buf[idx] & 0x3f;
190 idx++;
191 hdr->somt = (buf[idx] >> 7) & 0x1;
192 hdr->eomt = (buf[idx] >> 6) & 0x1;
193 hdr->seqno = (buf[idx] >> 4) & 0x1;
194 idx++;
195 *hdrlen = idx;
196 return true;
197 }
198
drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body * req,struct drm_dp_sideband_msg_tx * raw)199 static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req,
200 struct drm_dp_sideband_msg_tx *raw)
201 {
202 int idx = 0;
203 int i;
204 u8 *buf = raw->msg;
205 buf[idx++] = req->req_type & 0x7f;
206
207 switch (req->req_type) {
208 case DP_ENUM_PATH_RESOURCES:
209 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
210 idx++;
211 break;
212 case DP_ALLOCATE_PAYLOAD:
213 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
214 (req->u.allocate_payload.number_sdp_streams & 0xf);
215 idx++;
216 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
217 idx++;
218 buf[idx] = (req->u.allocate_payload.pbn >> 8);
219 idx++;
220 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
221 idx++;
222 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
223 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
224 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
225 idx++;
226 }
227 if (req->u.allocate_payload.number_sdp_streams & 1) {
228 i = req->u.allocate_payload.number_sdp_streams - 1;
229 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
230 idx++;
231 }
232 break;
233 case DP_QUERY_PAYLOAD:
234 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
235 idx++;
236 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
237 idx++;
238 break;
239 case DP_REMOTE_DPCD_READ:
240 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
241 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
242 idx++;
243 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
244 idx++;
245 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
246 idx++;
247 buf[idx] = (req->u.dpcd_read.num_bytes);
248 idx++;
249 break;
250
251 case DP_REMOTE_DPCD_WRITE:
252 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
253 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
254 idx++;
255 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
256 idx++;
257 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
258 idx++;
259 buf[idx] = (req->u.dpcd_write.num_bytes);
260 idx++;
261 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
262 idx += req->u.dpcd_write.num_bytes;
263 break;
264 case DP_REMOTE_I2C_READ:
265 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
266 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
267 idx++;
268 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
269 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
270 idx++;
271 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
272 idx++;
273 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
274 idx += req->u.i2c_read.transactions[i].num_bytes;
275
276 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4;
277 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
278 idx++;
279 }
280 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
281 idx++;
282 buf[idx] = (req->u.i2c_read.num_bytes_read);
283 idx++;
284 break;
285
286 case DP_REMOTE_I2C_WRITE:
287 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
288 idx++;
289 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
290 idx++;
291 buf[idx] = (req->u.i2c_write.num_bytes);
292 idx++;
293 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
294 idx += req->u.i2c_write.num_bytes;
295 break;
296 }
297 raw->cur_len = idx;
298 }
299
drm_dp_crc_sideband_chunk_req(u8 * msg,u8 len)300 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
301 {
302 u8 crc4;
303 crc4 = drm_dp_msg_data_crc4(msg, len);
304 msg[len] = crc4;
305 }
306
drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body * rep,struct drm_dp_sideband_msg_tx * raw)307 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
308 struct drm_dp_sideband_msg_tx *raw)
309 {
310 int idx = 0;
311 u8 *buf = raw->msg;
312
313 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
314
315 raw->cur_len = idx;
316 }
317
318 /* 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)319 static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
320 u8 *replybuf, u8 replybuflen, bool hdr)
321 {
322 int ret;
323 u8 crc4;
324
325 if (hdr) {
326 u8 hdrlen;
327 struct drm_dp_sideband_msg_hdr recv_hdr;
328 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
329 if (ret == false) {
330 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
331 return false;
332 }
333
334 /*
335 * ignore out-of-order messages or messages that are part of a
336 * failed transaction
337 */
338 if (!recv_hdr.somt && !msg->have_somt)
339 return false;
340
341 /* get length contained in this portion */
342 msg->curchunk_len = recv_hdr.msg_len;
343 msg->curchunk_hdrlen = hdrlen;
344
345 /* we have already gotten an somt - don't bother parsing */
346 if (recv_hdr.somt && msg->have_somt)
347 return false;
348
349 if (recv_hdr.somt) {
350 memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
351 msg->have_somt = true;
352 }
353 if (recv_hdr.eomt)
354 msg->have_eomt = true;
355
356 /* copy the bytes for the remainder of this header chunk */
357 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
358 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
359 } else {
360 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
361 msg->curchunk_idx += replybuflen;
362 }
363
364 if (msg->curchunk_idx >= msg->curchunk_len) {
365 /* do CRC */
366 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
367 /* copy chunk into bigger msg */
368 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
369 msg->curlen += msg->curchunk_len - 1;
370 }
371 return true;
372 }
373
drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)374 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
375 struct drm_dp_sideband_msg_reply_body *repmsg)
376 {
377 int idx = 1;
378 int i;
379 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
380 idx += 16;
381 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
382 idx++;
383 if (idx > raw->curlen)
384 goto fail_len;
385 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
386 if (raw->msg[idx] & 0x80)
387 repmsg->u.link_addr.ports[i].input_port = 1;
388
389 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
390 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
391
392 idx++;
393 if (idx > raw->curlen)
394 goto fail_len;
395 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
396 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
397 if (repmsg->u.link_addr.ports[i].input_port == 0)
398 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
399 idx++;
400 if (idx > raw->curlen)
401 goto fail_len;
402 if (repmsg->u.link_addr.ports[i].input_port == 0) {
403 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
404 idx++;
405 if (idx > raw->curlen)
406 goto fail_len;
407 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
408 idx += 16;
409 if (idx > raw->curlen)
410 goto fail_len;
411 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
412 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
413 idx++;
414
415 }
416 if (idx > raw->curlen)
417 goto fail_len;
418 }
419
420 return true;
421 fail_len:
422 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
423 return false;
424 }
425
drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)426 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
427 struct drm_dp_sideband_msg_reply_body *repmsg)
428 {
429 int idx = 1;
430 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
431 idx++;
432 if (idx > raw->curlen)
433 goto fail_len;
434 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
435 idx++;
436 if (idx > raw->curlen)
437 goto fail_len;
438
439 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
440 return true;
441 fail_len:
442 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
443 return false;
444 }
445
drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)446 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
447 struct drm_dp_sideband_msg_reply_body *repmsg)
448 {
449 int idx = 1;
450 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
451 idx++;
452 if (idx > raw->curlen)
453 goto fail_len;
454 return true;
455 fail_len:
456 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
457 return false;
458 }
459
drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)460 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
461 struct drm_dp_sideband_msg_reply_body *repmsg)
462 {
463 int idx = 1;
464
465 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
466 idx++;
467 if (idx > raw->curlen)
468 goto fail_len;
469 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
470 idx++;
471 /* TODO check */
472 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
473 return true;
474 fail_len:
475 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
476 return false;
477 }
478
drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)479 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
480 struct drm_dp_sideband_msg_reply_body *repmsg)
481 {
482 int idx = 1;
483 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
484 idx++;
485 if (idx > raw->curlen)
486 goto fail_len;
487 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
488 idx += 2;
489 if (idx > raw->curlen)
490 goto fail_len;
491 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
492 idx += 2;
493 if (idx > raw->curlen)
494 goto fail_len;
495 return true;
496 fail_len:
497 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
498 return false;
499 }
500
drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)501 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
502 struct drm_dp_sideband_msg_reply_body *repmsg)
503 {
504 int idx = 1;
505 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
506 idx++;
507 if (idx > raw->curlen)
508 goto fail_len;
509 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
510 idx++;
511 if (idx > raw->curlen)
512 goto fail_len;
513 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
514 idx += 2;
515 if (idx > raw->curlen)
516 goto fail_len;
517 return true;
518 fail_len:
519 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
520 return false;
521 }
522
drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)523 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
524 struct drm_dp_sideband_msg_reply_body *repmsg)
525 {
526 int idx = 1;
527 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
528 idx++;
529 if (idx > raw->curlen)
530 goto fail_len;
531 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
532 idx += 2;
533 if (idx > raw->curlen)
534 goto fail_len;
535 return true;
536 fail_len:
537 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
538 return false;
539 }
540
drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * msg)541 static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
542 struct drm_dp_sideband_msg_reply_body *msg)
543 {
544 memset(msg, 0, sizeof(*msg));
545 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
546 msg->req_type = (raw->msg[0] & 0x7f);
547
548 if (msg->reply_type) {
549 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
550 msg->u.nak.reason = raw->msg[17];
551 msg->u.nak.nak_data = raw->msg[18];
552 return false;
553 }
554
555 switch (msg->req_type) {
556 case DP_LINK_ADDRESS:
557 return drm_dp_sideband_parse_link_address(raw, msg);
558 case DP_QUERY_PAYLOAD:
559 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
560 case DP_REMOTE_DPCD_READ:
561 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
562 case DP_REMOTE_DPCD_WRITE:
563 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
564 case DP_REMOTE_I2C_READ:
565 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
566 case DP_ENUM_PATH_RESOURCES:
567 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
568 case DP_ALLOCATE_PAYLOAD:
569 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
570 default:
571 DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
572 return false;
573 }
574 }
575
drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_req_body * msg)576 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
577 struct drm_dp_sideband_msg_req_body *msg)
578 {
579 int idx = 1;
580
581 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
582 idx++;
583 if (idx > raw->curlen)
584 goto fail_len;
585
586 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
587 idx += 16;
588 if (idx > raw->curlen)
589 goto fail_len;
590
591 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
592 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
593 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
594 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
595 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
596 idx++;
597 return true;
598 fail_len:
599 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
600 return false;
601 }
602
drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_req_body * msg)603 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
604 struct drm_dp_sideband_msg_req_body *msg)
605 {
606 int idx = 1;
607
608 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
609 idx++;
610 if (idx > raw->curlen)
611 goto fail_len;
612
613 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
614 idx += 16;
615 if (idx > raw->curlen)
616 goto fail_len;
617
618 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
619 idx++;
620 return true;
621 fail_len:
622 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
623 return false;
624 }
625
drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_req_body * msg)626 static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
627 struct drm_dp_sideband_msg_req_body *msg)
628 {
629 memset(msg, 0, sizeof(*msg));
630 msg->req_type = (raw->msg[0] & 0x7f);
631
632 switch (msg->req_type) {
633 case DP_CONNECTION_STATUS_NOTIFY:
634 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
635 case DP_RESOURCE_STATUS_NOTIFY:
636 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
637 default:
638 DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
639 return false;
640 }
641 }
642
build_dpcd_write(struct drm_dp_sideband_msg_tx * msg,u8 port_num,u32 offset,u8 num_bytes,u8 * bytes)643 static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
644 {
645 struct drm_dp_sideband_msg_req_body req;
646
647 req.req_type = DP_REMOTE_DPCD_WRITE;
648 req.u.dpcd_write.port_number = port_num;
649 req.u.dpcd_write.dpcd_address = offset;
650 req.u.dpcd_write.num_bytes = num_bytes;
651 req.u.dpcd_write.bytes = bytes;
652 drm_dp_encode_sideband_req(&req, msg);
653
654 return 0;
655 }
656
build_link_address(struct drm_dp_sideband_msg_tx * msg)657 static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
658 {
659 struct drm_dp_sideband_msg_req_body req;
660
661 req.req_type = DP_LINK_ADDRESS;
662 drm_dp_encode_sideband_req(&req, msg);
663 return 0;
664 }
665
build_enum_path_resources(struct drm_dp_sideband_msg_tx * msg,int port_num)666 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
667 {
668 struct drm_dp_sideband_msg_req_body req;
669
670 req.req_type = DP_ENUM_PATH_RESOURCES;
671 req.u.port_num.port_number = port_num;
672 drm_dp_encode_sideband_req(&req, msg);
673 msg->path_msg = true;
674 return 0;
675 }
676
build_allocate_payload(struct drm_dp_sideband_msg_tx * msg,int port_num,u8 vcpi,uint16_t pbn)677 static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
678 u8 vcpi, uint16_t pbn)
679 {
680 struct drm_dp_sideband_msg_req_body req;
681 memset(&req, 0, sizeof(req));
682 req.req_type = DP_ALLOCATE_PAYLOAD;
683 req.u.allocate_payload.port_number = port_num;
684 req.u.allocate_payload.vcpi = vcpi;
685 req.u.allocate_payload.pbn = pbn;
686 drm_dp_encode_sideband_req(&req, msg);
687 msg->path_msg = true;
688 return 0;
689 }
690
drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_vcpi * vcpi)691 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
692 struct drm_dp_vcpi *vcpi)
693 {
694 int ret, vcpi_ret;
695
696 mutex_lock(&mgr->payload_lock);
697 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
698 if (ret > mgr->max_payloads) {
699 ret = -EINVAL;
700 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
701 goto out_unlock;
702 }
703
704 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
705 if (vcpi_ret > mgr->max_payloads) {
706 ret = -EINVAL;
707 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
708 goto out_unlock;
709 }
710
711 set_bit(ret, &mgr->payload_mask);
712 set_bit(vcpi_ret, &mgr->vcpi_mask);
713 vcpi->vcpi = vcpi_ret + 1;
714 mgr->proposed_vcpis[ret - 1] = vcpi;
715 out_unlock:
716 mutex_unlock(&mgr->payload_lock);
717 return ret;
718 }
719
drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr * mgr,int vcpi)720 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
721 int vcpi)
722 {
723 int i;
724 if (vcpi == 0)
725 return;
726
727 mutex_lock(&mgr->payload_lock);
728 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
729 clear_bit(vcpi - 1, &mgr->vcpi_mask);
730
731 for (i = 0; i < mgr->max_payloads; i++) {
732 if (mgr->proposed_vcpis[i])
733 if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
734 mgr->proposed_vcpis[i] = NULL;
735 clear_bit(i + 1, &mgr->payload_mask);
736 }
737 }
738 mutex_unlock(&mgr->payload_lock);
739 }
740
check_txmsg_state(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg)741 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
742 struct drm_dp_sideband_msg_tx *txmsg)
743 {
744 bool ret;
745
746 /*
747 * All updates to txmsg->state are protected by mgr->qlock, and the two
748 * cases we check here are terminal states. For those the barriers
749 * provided by the wake_up/wait_event pair are enough.
750 */
751 ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
752 txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
753 return ret;
754 }
755
drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch * mstb,struct drm_dp_sideband_msg_tx * txmsg)756 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
757 struct drm_dp_sideband_msg_tx *txmsg)
758 {
759 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
760 int ret;
761
762 ret = wait_event_timeout(mgr->tx_waitq,
763 check_txmsg_state(mgr, txmsg),
764 (4 * HZ));
765 mutex_lock(&mstb->mgr->qlock);
766 if (ret > 0) {
767 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
768 ret = -EIO;
769 goto out;
770 }
771 } else {
772 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
773
774 /* dump some state */
775 ret = -EIO;
776
777 /* remove from q */
778 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
779 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
780 list_del(&txmsg->next);
781 }
782
783 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
784 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
785 mstb->tx_slots[txmsg->seqno] = NULL;
786 }
787 }
788 out:
789 mutex_unlock(&mgr->qlock);
790
791 return ret;
792 }
793
drm_dp_add_mst_branch_device(u8 lct,u8 * rad)794 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
795 {
796 struct drm_dp_mst_branch *mstb;
797
798 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
799 if (!mstb)
800 return NULL;
801
802 mstb->lct = lct;
803 if (lct > 1)
804 memcpy(mstb->rad, rad, lct / 2);
805 INIT_LIST_HEAD(&mstb->ports);
806 kref_init(&mstb->kref);
807 return mstb;
808 }
809
810 static void drm_dp_free_mst_port(struct kref *kref);
811
drm_dp_free_mst_branch_device(struct kref * kref)812 static void drm_dp_free_mst_branch_device(struct kref *kref)
813 {
814 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
815 if (mstb->port_parent) {
816 if (list_empty(&mstb->port_parent->next))
817 kref_put(&mstb->port_parent->kref, drm_dp_free_mst_port);
818 }
819 kfree(mstb);
820 }
821
drm_dp_destroy_mst_branch_device(struct kref * kref)822 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
823 {
824 struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
825 struct drm_dp_mst_port *port, *tmp;
826 bool wake_tx = false;
827
828 /*
829 * init kref again to be used by ports to remove mst branch when it is
830 * not needed anymore
831 */
832 kref_init(kref);
833
834 if (mstb->port_parent && list_empty(&mstb->port_parent->next))
835 kref_get(&mstb->port_parent->kref);
836
837 /*
838 * destroy all ports - don't need lock
839 * as there are no more references to the mst branch
840 * device at this point.
841 */
842 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
843 list_del(&port->next);
844 drm_dp_put_port(port);
845 }
846
847 /* drop any tx slots msg */
848 mutex_lock(&mstb->mgr->qlock);
849 if (mstb->tx_slots[0]) {
850 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
851 mstb->tx_slots[0] = NULL;
852 wake_tx = true;
853 }
854 if (mstb->tx_slots[1]) {
855 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
856 mstb->tx_slots[1] = NULL;
857 wake_tx = true;
858 }
859 mutex_unlock(&mstb->mgr->qlock);
860
861 if (wake_tx)
862 wake_up(&mstb->mgr->tx_waitq);
863
864 kref_put(kref, drm_dp_free_mst_branch_device);
865 }
866
drm_dp_put_mst_branch_device(struct drm_dp_mst_branch * mstb)867 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
868 {
869 kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
870 }
871
872
drm_dp_port_teardown_pdt(struct drm_dp_mst_port * port,int old_pdt)873 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
874 {
875 struct drm_dp_mst_branch *mstb;
876
877 switch (old_pdt) {
878 case DP_PEER_DEVICE_DP_LEGACY_CONV:
879 case DP_PEER_DEVICE_SST_SINK:
880 /* remove i2c over sideband */
881 drm_dp_mst_unregister_i2c_bus(&port->aux);
882 break;
883 case DP_PEER_DEVICE_MST_BRANCHING:
884 mstb = port->mstb;
885 port->mstb = NULL;
886 drm_dp_put_mst_branch_device(mstb);
887 break;
888 }
889 }
890
drm_dp_destroy_port(struct kref * kref)891 static void drm_dp_destroy_port(struct kref *kref)
892 {
893 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
894 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
895
896 if (!port->input) {
897 port->vcpi.num_slots = 0;
898
899 kfree(port->cached_edid);
900
901 /*
902 * The only time we don't have a connector
903 * on an output port is if the connector init
904 * fails.
905 */
906 if (port->connector) {
907 /* we can't destroy the connector here, as
908 * we might be holding the mode_config.mutex
909 * from an EDID retrieval */
910
911 mutex_lock(&mgr->destroy_connector_lock);
912 kref_get(&port->parent->kref);
913 list_add(&port->next, &mgr->destroy_connector_list);
914 mutex_unlock(&mgr->destroy_connector_lock);
915 schedule_work(&mgr->destroy_connector_work);
916 return;
917 }
918 /* no need to clean up vcpi
919 * as if we have no connector we never setup a vcpi */
920 drm_dp_port_teardown_pdt(port, port->pdt);
921 port->pdt = DP_PEER_DEVICE_NONE;
922 }
923 kfree(port);
924 }
925
drm_dp_put_port(struct drm_dp_mst_port * port)926 static void drm_dp_put_port(struct drm_dp_mst_port *port)
927 {
928 kref_put(&port->kref, drm_dp_destroy_port);
929 }
930
drm_dp_mst_get_validated_mstb_ref_locked(struct drm_dp_mst_branch * mstb,struct drm_dp_mst_branch * to_find)931 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)
932 {
933 struct drm_dp_mst_port *port;
934 struct drm_dp_mst_branch *rmstb;
935 if (to_find == mstb) {
936 kref_get(&mstb->kref);
937 return mstb;
938 }
939 list_for_each_entry(port, &mstb->ports, next) {
940 if (port->mstb) {
941 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
942 if (rmstb)
943 return rmstb;
944 }
945 }
946 return NULL;
947 }
948
drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb)949 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)
950 {
951 struct drm_dp_mst_branch *rmstb = NULL;
952 mutex_lock(&mgr->lock);
953 if (mgr->mst_primary)
954 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
955 mutex_unlock(&mgr->lock);
956 return rmstb;
957 }
958
drm_dp_mst_get_port_ref_locked(struct drm_dp_mst_branch * mstb,struct drm_dp_mst_port * to_find)959 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)
960 {
961 struct drm_dp_mst_port *port, *mport;
962
963 list_for_each_entry(port, &mstb->ports, next) {
964 if (port == to_find) {
965 kref_get(&port->kref);
966 return port;
967 }
968 if (port->mstb) {
969 mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
970 if (mport)
971 return mport;
972 }
973 }
974 return NULL;
975 }
976
drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)977 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)
978 {
979 struct drm_dp_mst_port *rport = NULL;
980 mutex_lock(&mgr->lock);
981 if (mgr->mst_primary)
982 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
983 mutex_unlock(&mgr->lock);
984 return rport;
985 }
986
drm_dp_get_port(struct drm_dp_mst_branch * mstb,u8 port_num)987 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
988 {
989 struct drm_dp_mst_port *port;
990
991 list_for_each_entry(port, &mstb->ports, next) {
992 if (port->port_num == port_num) {
993 kref_get(&port->kref);
994 return port;
995 }
996 }
997
998 return NULL;
999 }
1000
1001 /*
1002 * calculate a new RAD for this MST branch device
1003 * if parent has an LCT of 2 then it has 1 nibble of RAD,
1004 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1005 */
drm_dp_calculate_rad(struct drm_dp_mst_port * port,u8 * rad)1006 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1007 u8 *rad)
1008 {
1009 int parent_lct = port->parent->lct;
1010 int shift = 4;
1011 int idx = (parent_lct - 1) / 2;
1012 if (parent_lct > 1) {
1013 memcpy(rad, port->parent->rad, idx + 1);
1014 shift = (parent_lct % 2) ? 4 : 0;
1015 } else
1016 rad[0] = 0;
1017
1018 rad[idx] |= port->port_num << shift;
1019 return parent_lct + 1;
1020 }
1021
1022 /*
1023 * return sends link address for new mstb
1024 */
drm_dp_port_setup_pdt(struct drm_dp_mst_port * port)1025 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
1026 {
1027 int ret;
1028 u8 rad[6], lct;
1029 bool send_link = false;
1030 switch (port->pdt) {
1031 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1032 case DP_PEER_DEVICE_SST_SINK:
1033 /* add i2c over sideband */
1034 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1035 break;
1036 case DP_PEER_DEVICE_MST_BRANCHING:
1037 lct = drm_dp_calculate_rad(port, rad);
1038
1039 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
1040 if (port->mstb) {
1041 port->mstb->mgr = port->mgr;
1042 port->mstb->port_parent = port;
1043
1044 send_link = true;
1045 }
1046 break;
1047 }
1048 return send_link;
1049 }
1050
drm_dp_check_mstb_guid(struct drm_dp_mst_branch * mstb,u8 * guid)1051 static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
1052 {
1053 int ret;
1054
1055 memcpy(mstb->guid, guid, 16);
1056
1057 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
1058 if (mstb->port_parent) {
1059 ret = drm_dp_send_dpcd_write(
1060 mstb->mgr,
1061 mstb->port_parent,
1062 DP_GUID,
1063 16,
1064 mstb->guid);
1065 } else {
1066
1067 ret = drm_dp_dpcd_write(
1068 mstb->mgr->aux,
1069 DP_GUID,
1070 mstb->guid,
1071 16);
1072 }
1073 }
1074 }
1075
build_mst_prop_path(const struct drm_dp_mst_branch * mstb,int pnum,char * proppath,size_t proppath_size)1076 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1077 int pnum,
1078 char *proppath,
1079 size_t proppath_size)
1080 {
1081 int i;
1082 char temp[8];
1083 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1084 for (i = 0; i < (mstb->lct - 1); i++) {
1085 int shift = (i % 2) ? 0 : 4;
1086 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
1087 snprintf(temp, sizeof(temp), "-%d", port_num);
1088 strlcat(proppath, temp, proppath_size);
1089 }
1090 snprintf(temp, sizeof(temp), "-%d", pnum);
1091 strlcat(proppath, temp, proppath_size);
1092 }
1093
drm_dp_add_port(struct drm_dp_mst_branch * mstb,struct device * dev,struct drm_dp_link_addr_reply_port * port_msg)1094 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1095 struct device *dev,
1096 struct drm_dp_link_addr_reply_port *port_msg)
1097 {
1098 struct drm_dp_mst_port *port;
1099 bool ret;
1100 bool created = false;
1101 int old_pdt = 0;
1102 int old_ddps = 0;
1103 port = drm_dp_get_port(mstb, port_msg->port_number);
1104 if (!port) {
1105 port = kzalloc(sizeof(*port), GFP_KERNEL);
1106 if (!port)
1107 return;
1108 kref_init(&port->kref);
1109 port->parent = mstb;
1110 port->port_num = port_msg->port_number;
1111 port->mgr = mstb->mgr;
1112 port->aux.name = "DPMST";
1113 port->aux.dev = dev;
1114 created = true;
1115 } else {
1116 old_pdt = port->pdt;
1117 old_ddps = port->ddps;
1118 }
1119
1120 port->pdt = port_msg->peer_device_type;
1121 port->input = port_msg->input_port;
1122 port->mcs = port_msg->mcs;
1123 port->ddps = port_msg->ddps;
1124 port->ldps = port_msg->legacy_device_plug_status;
1125 port->dpcd_rev = port_msg->dpcd_revision;
1126 port->num_sdp_streams = port_msg->num_sdp_streams;
1127 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1128
1129 /* manage mstb port lists with mgr lock - take a reference
1130 for this list */
1131 if (created) {
1132 mutex_lock(&mstb->mgr->lock);
1133 kref_get(&port->kref);
1134 list_add(&port->next, &mstb->ports);
1135 mutex_unlock(&mstb->mgr->lock);
1136 }
1137
1138 if (old_ddps != port->ddps) {
1139 if (port->ddps) {
1140 if (!port->input)
1141 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1142 } else {
1143 port->available_pbn = 0;
1144 }
1145 }
1146
1147 if (old_pdt != port->pdt && !port->input) {
1148 drm_dp_port_teardown_pdt(port, old_pdt);
1149
1150 ret = drm_dp_port_setup_pdt(port);
1151 if (ret == true)
1152 drm_dp_send_link_address(mstb->mgr, port->mstb);
1153 }
1154
1155 if (created && !port->input) {
1156 char proppath[255];
1157
1158 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
1159 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1160 if (!port->connector) {
1161 /* remove it from the port list */
1162 mutex_lock(&mstb->mgr->lock);
1163 list_del(&port->next);
1164 mutex_unlock(&mstb->mgr->lock);
1165 /* drop port list reference */
1166 drm_dp_put_port(port);
1167 goto out;
1168 }
1169 if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
1170 port->pdt == DP_PEER_DEVICE_SST_SINK) &&
1171 port->port_num >= DP_MST_LOGICAL_PORT_0) {
1172 port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1173 drm_mode_connector_set_tile_property(port->connector);
1174 }
1175 (*mstb->mgr->cbs->register_connector)(port->connector);
1176 }
1177
1178 out:
1179 /* put reference to this port */
1180 drm_dp_put_port(port);
1181 }
1182
drm_dp_update_port(struct drm_dp_mst_branch * mstb,struct drm_dp_connection_status_notify * conn_stat)1183 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1184 struct drm_dp_connection_status_notify *conn_stat)
1185 {
1186 struct drm_dp_mst_port *port;
1187 int old_pdt;
1188 int old_ddps;
1189 bool dowork = false;
1190 port = drm_dp_get_port(mstb, conn_stat->port_number);
1191 if (!port)
1192 return;
1193
1194 old_ddps = port->ddps;
1195 old_pdt = port->pdt;
1196 port->pdt = conn_stat->peer_device_type;
1197 port->mcs = conn_stat->message_capability_status;
1198 port->ldps = conn_stat->legacy_device_plug_status;
1199 port->ddps = conn_stat->displayport_device_plug_status;
1200
1201 if (old_ddps != port->ddps) {
1202 if (port->ddps) {
1203 dowork = true;
1204 } else {
1205 port->available_pbn = 0;
1206 }
1207 }
1208 if (old_pdt != port->pdt && !port->input) {
1209 drm_dp_port_teardown_pdt(port, old_pdt);
1210
1211 if (drm_dp_port_setup_pdt(port))
1212 dowork = true;
1213 }
1214
1215 drm_dp_put_port(port);
1216 if (dowork)
1217 queue_work(system_long_wq, &mstb->mgr->work);
1218
1219 }
1220
drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr * mgr,u8 lct,u8 * rad)1221 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1222 u8 lct, u8 *rad)
1223 {
1224 struct drm_dp_mst_branch *mstb;
1225 struct drm_dp_mst_port *port;
1226 int i;
1227 /* find the port by iterating down */
1228
1229 mutex_lock(&mgr->lock);
1230 mstb = mgr->mst_primary;
1231
1232 if (!mstb)
1233 goto out;
1234
1235 for (i = 0; i < lct - 1; i++) {
1236 int shift = (i % 2) ? 0 : 4;
1237 int port_num = (rad[i / 2] >> shift) & 0xf;
1238
1239 list_for_each_entry(port, &mstb->ports, next) {
1240 if (port->port_num == port_num) {
1241 mstb = port->mstb;
1242 if (!mstb) {
1243 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1244 goto out;
1245 }
1246
1247 break;
1248 }
1249 }
1250 }
1251 kref_get(&mstb->kref);
1252 out:
1253 mutex_unlock(&mgr->lock);
1254 return mstb;
1255 }
1256
get_mst_branch_device_by_guid_helper(struct drm_dp_mst_branch * mstb,uint8_t * guid)1257 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1258 struct drm_dp_mst_branch *mstb,
1259 uint8_t *guid)
1260 {
1261 struct drm_dp_mst_branch *found_mstb;
1262 struct drm_dp_mst_port *port;
1263
1264 if (memcmp(mstb->guid, guid, 16) == 0)
1265 return mstb;
1266
1267
1268 list_for_each_entry(port, &mstb->ports, next) {
1269 if (!port->mstb)
1270 continue;
1271
1272 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1273
1274 if (found_mstb)
1275 return found_mstb;
1276 }
1277
1278 return NULL;
1279 }
1280
drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr * mgr,uint8_t * guid)1281 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
1282 struct drm_dp_mst_topology_mgr *mgr,
1283 uint8_t *guid)
1284 {
1285 struct drm_dp_mst_branch *mstb;
1286
1287 /* find the port by iterating down */
1288 mutex_lock(&mgr->lock);
1289
1290 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
1291
1292 if (mstb)
1293 kref_get(&mstb->kref);
1294
1295 mutex_unlock(&mgr->lock);
1296 return mstb;
1297 }
1298
drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb)1299 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1300 struct drm_dp_mst_branch *mstb)
1301 {
1302 struct drm_dp_mst_port *port;
1303 struct drm_dp_mst_branch *mstb_child;
1304 if (!mstb->link_address_sent)
1305 drm_dp_send_link_address(mgr, mstb);
1306
1307 list_for_each_entry(port, &mstb->ports, next) {
1308 if (port->input)
1309 continue;
1310
1311 if (!port->ddps)
1312 continue;
1313
1314 if (!port->available_pbn)
1315 drm_dp_send_enum_path_resources(mgr, mstb, port);
1316
1317 if (port->mstb) {
1318 mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1319 if (mstb_child) {
1320 drm_dp_check_and_send_link_address(mgr, mstb_child);
1321 drm_dp_put_mst_branch_device(mstb_child);
1322 }
1323 }
1324 }
1325 }
1326
drm_dp_mst_link_probe_work(struct work_struct * work)1327 static void drm_dp_mst_link_probe_work(struct work_struct *work)
1328 {
1329 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1330 struct drm_dp_mst_branch *mstb;
1331
1332 mutex_lock(&mgr->lock);
1333 mstb = mgr->mst_primary;
1334 if (mstb) {
1335 kref_get(&mstb->kref);
1336 }
1337 mutex_unlock(&mgr->lock);
1338 if (mstb) {
1339 drm_dp_check_and_send_link_address(mgr, mstb);
1340 drm_dp_put_mst_branch_device(mstb);
1341 }
1342 }
1343
drm_dp_validate_guid(struct drm_dp_mst_topology_mgr * mgr,u8 * guid)1344 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1345 u8 *guid)
1346 {
1347 static u8 zero_guid[16];
1348
1349 if (!memcmp(guid, zero_guid, 16)) {
1350 u64 salt = get_jiffies_64();
1351 memcpy(&guid[0], &salt, sizeof(u64));
1352 memcpy(&guid[8], &salt, sizeof(u64));
1353 return false;
1354 }
1355 return true;
1356 }
1357
1358 #if 0
1359 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1360 {
1361 struct drm_dp_sideband_msg_req_body req;
1362
1363 req.req_type = DP_REMOTE_DPCD_READ;
1364 req.u.dpcd_read.port_number = port_num;
1365 req.u.dpcd_read.dpcd_address = offset;
1366 req.u.dpcd_read.num_bytes = num_bytes;
1367 drm_dp_encode_sideband_req(&req, msg);
1368
1369 return 0;
1370 }
1371 #endif
1372
drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr * mgr,bool up,u8 * msg,int len)1373 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1374 bool up, u8 *msg, int len)
1375 {
1376 int ret;
1377 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1378 int tosend, total, offset;
1379 int retries = 0;
1380
1381 retry:
1382 total = len;
1383 offset = 0;
1384 do {
1385 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1386
1387 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1388 &msg[offset],
1389 tosend);
1390 if (ret != tosend) {
1391 if (ret == -EIO && retries < 5) {
1392 retries++;
1393 goto retry;
1394 }
1395 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1396
1397 return -EIO;
1398 }
1399 offset += tosend;
1400 total -= tosend;
1401 } while (total > 0);
1402 return 0;
1403 }
1404
set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr * hdr,struct drm_dp_sideband_msg_tx * txmsg)1405 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1406 struct drm_dp_sideband_msg_tx *txmsg)
1407 {
1408 struct drm_dp_mst_branch *mstb = txmsg->dst;
1409 u8 req_type;
1410
1411 /* both msg slots are full */
1412 if (txmsg->seqno == -1) {
1413 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1414 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1415 return -EAGAIN;
1416 }
1417 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1418 txmsg->seqno = mstb->last_seqno;
1419 mstb->last_seqno ^= 1;
1420 } else if (mstb->tx_slots[0] == NULL)
1421 txmsg->seqno = 0;
1422 else
1423 txmsg->seqno = 1;
1424 mstb->tx_slots[txmsg->seqno] = txmsg;
1425 }
1426
1427 req_type = txmsg->msg[0] & 0x7f;
1428 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1429 req_type == DP_RESOURCE_STATUS_NOTIFY)
1430 hdr->broadcast = 1;
1431 else
1432 hdr->broadcast = 0;
1433 hdr->path_msg = txmsg->path_msg;
1434 hdr->lct = mstb->lct;
1435 hdr->lcr = mstb->lct - 1;
1436 if (mstb->lct > 1)
1437 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1438 hdr->seqno = txmsg->seqno;
1439 return 0;
1440 }
1441 /*
1442 * process a single block of the next message in the sideband queue
1443 */
process_single_tx_qlock(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg,bool up)1444 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1445 struct drm_dp_sideband_msg_tx *txmsg,
1446 bool up)
1447 {
1448 u8 chunk[48];
1449 struct drm_dp_sideband_msg_hdr hdr;
1450 int len, space, idx, tosend;
1451 int ret;
1452
1453 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1454
1455 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1456 txmsg->seqno = -1;
1457 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1458 }
1459
1460 /* make hdr from dst mst - for replies use seqno
1461 otherwise assign one */
1462 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1463 if (ret < 0)
1464 return ret;
1465
1466 /* amount left to send in this message */
1467 len = txmsg->cur_len - txmsg->cur_offset;
1468
1469 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1470 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1471
1472 tosend = min(len, space);
1473 if (len == txmsg->cur_len)
1474 hdr.somt = 1;
1475 if (space >= len)
1476 hdr.eomt = 1;
1477
1478
1479 hdr.msg_len = tosend + 1;
1480 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1481 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1482 /* add crc at end */
1483 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1484 idx += tosend + 1;
1485
1486 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1487 if (ret) {
1488 DRM_DEBUG_KMS("sideband msg failed to send\n");
1489 return ret;
1490 }
1491
1492 txmsg->cur_offset += tosend;
1493 if (txmsg->cur_offset == txmsg->cur_len) {
1494 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1495 return 1;
1496 }
1497 return 0;
1498 }
1499
process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr * mgr)1500 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1501 {
1502 struct drm_dp_sideband_msg_tx *txmsg;
1503 int ret;
1504
1505 WARN_ON(!mutex_is_locked(&mgr->qlock));
1506
1507 /* construct a chunk from the first msg in the tx_msg queue */
1508 if (list_empty(&mgr->tx_msg_downq)) {
1509 mgr->tx_down_in_progress = false;
1510 return;
1511 }
1512 mgr->tx_down_in_progress = true;
1513
1514 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1515 ret = process_single_tx_qlock(mgr, txmsg, false);
1516 if (ret == 1) {
1517 /* txmsg is sent it should be in the slots now */
1518 list_del(&txmsg->next);
1519 } else if (ret) {
1520 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1521 list_del(&txmsg->next);
1522 if (txmsg->seqno != -1)
1523 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1524 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1525 wake_up(&mgr->tx_waitq);
1526 }
1527 if (list_empty(&mgr->tx_msg_downq)) {
1528 mgr->tx_down_in_progress = false;
1529 return;
1530 }
1531 }
1532
1533 /* called holding qlock */
process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg)1534 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1535 struct drm_dp_sideband_msg_tx *txmsg)
1536 {
1537 int ret;
1538
1539 /* construct a chunk from the first msg in the tx_msg queue */
1540 ret = process_single_tx_qlock(mgr, txmsg, true);
1541
1542 if (ret != 1)
1543 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1544
1545 if (txmsg->seqno != -1) {
1546 WARN_ON((unsigned int)txmsg->seqno >
1547 ARRAY_SIZE(txmsg->dst->tx_slots));
1548 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1549 }
1550 }
1551
drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg)1552 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1553 struct drm_dp_sideband_msg_tx *txmsg)
1554 {
1555 mutex_lock(&mgr->qlock);
1556 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1557 if (!mgr->tx_down_in_progress)
1558 process_single_down_tx_qlock(mgr);
1559 mutex_unlock(&mgr->qlock);
1560 }
1561
drm_dp_send_link_address(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb)1562 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1563 struct drm_dp_mst_branch *mstb)
1564 {
1565 int len;
1566 struct drm_dp_sideband_msg_tx *txmsg;
1567 int ret;
1568
1569 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1570 if (!txmsg)
1571 return;
1572
1573 txmsg->dst = mstb;
1574 len = build_link_address(txmsg);
1575
1576 mstb->link_address_sent = true;
1577 drm_dp_queue_down_tx(mgr, txmsg);
1578
1579 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1580 if (ret > 0) {
1581 int i;
1582
1583 if (txmsg->reply.reply_type == 1)
1584 DRM_DEBUG_KMS("link address nak received\n");
1585 else {
1586 DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1587 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1588 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,
1589 txmsg->reply.u.link_addr.ports[i].input_port,
1590 txmsg->reply.u.link_addr.ports[i].peer_device_type,
1591 txmsg->reply.u.link_addr.ports[i].port_number,
1592 txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1593 txmsg->reply.u.link_addr.ports[i].mcs,
1594 txmsg->reply.u.link_addr.ports[i].ddps,
1595 txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1596 txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1597 txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1598 }
1599
1600 drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);
1601
1602 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1603 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1604 }
1605 (*mgr->cbs->hotplug)(mgr);
1606 }
1607 } else {
1608 mstb->link_address_sent = false;
1609 DRM_DEBUG_KMS("link address failed %d\n", ret);
1610 }
1611
1612 kfree(txmsg);
1613 }
1614
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)1615 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1616 struct drm_dp_mst_branch *mstb,
1617 struct drm_dp_mst_port *port)
1618 {
1619 int len;
1620 struct drm_dp_sideband_msg_tx *txmsg;
1621 int ret;
1622
1623 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1624 if (!txmsg)
1625 return -ENOMEM;
1626
1627 txmsg->dst = mstb;
1628 len = build_enum_path_resources(txmsg, port->port_num);
1629
1630 drm_dp_queue_down_tx(mgr, txmsg);
1631
1632 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1633 if (ret > 0) {
1634 if (txmsg->reply.reply_type == 1)
1635 DRM_DEBUG_KMS("enum path resources nak received\n");
1636 else {
1637 if (port->port_num != txmsg->reply.u.path_resources.port_number)
1638 DRM_ERROR("got incorrect port in response\n");
1639 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,
1640 txmsg->reply.u.path_resources.avail_payload_bw_number);
1641 port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1642 }
1643 }
1644
1645 kfree(txmsg);
1646 return 0;
1647 }
1648
drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch * mstb)1649 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
1650 {
1651 if (!mstb->port_parent)
1652 return NULL;
1653
1654 if (mstb->port_parent->mstb != mstb)
1655 return mstb->port_parent;
1656
1657 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
1658 }
1659
drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb,int * port_num)1660 static struct drm_dp_mst_branch *drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
1661 struct drm_dp_mst_branch *mstb,
1662 int *port_num)
1663 {
1664 struct drm_dp_mst_branch *rmstb = NULL;
1665 struct drm_dp_mst_port *found_port;
1666 mutex_lock(&mgr->lock);
1667 if (mgr->mst_primary) {
1668 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
1669
1670 if (found_port) {
1671 rmstb = found_port->parent;
1672 kref_get(&rmstb->kref);
1673 *port_num = found_port->port_num;
1674 }
1675 }
1676 mutex_unlock(&mgr->lock);
1677 return rmstb;
1678 }
1679
drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int id,int pbn)1680 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1681 struct drm_dp_mst_port *port,
1682 int id,
1683 int pbn)
1684 {
1685 struct drm_dp_sideband_msg_tx *txmsg;
1686 struct drm_dp_mst_branch *mstb;
1687 int len, ret, port_num;
1688
1689 port = drm_dp_get_validated_port_ref(mgr, port);
1690 if (!port)
1691 return -EINVAL;
1692
1693 port_num = port->port_num;
1694 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1695 if (!mstb) {
1696 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, port->parent, &port_num);
1697
1698 if (!mstb) {
1699 drm_dp_put_port(port);
1700 return -EINVAL;
1701 }
1702 }
1703
1704 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1705 if (!txmsg) {
1706 ret = -ENOMEM;
1707 goto fail_put;
1708 }
1709
1710 txmsg->dst = mstb;
1711 len = build_allocate_payload(txmsg, port_num,
1712 id,
1713 pbn);
1714
1715 drm_dp_queue_down_tx(mgr, txmsg);
1716
1717 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1718 if (ret > 0) {
1719 if (txmsg->reply.reply_type == 1) {
1720 ret = -EINVAL;
1721 } else
1722 ret = 0;
1723 }
1724 kfree(txmsg);
1725 fail_put:
1726 drm_dp_put_mst_branch_device(mstb);
1727 drm_dp_put_port(port);
1728 return ret;
1729 }
1730
drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr * mgr,int id,struct drm_dp_payload * payload)1731 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1732 int id,
1733 struct drm_dp_payload *payload)
1734 {
1735 int ret;
1736
1737 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1738 if (ret < 0) {
1739 payload->payload_state = 0;
1740 return ret;
1741 }
1742 payload->payload_state = DP_PAYLOAD_LOCAL;
1743 return 0;
1744 }
1745
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)1746 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1747 struct drm_dp_mst_port *port,
1748 int id,
1749 struct drm_dp_payload *payload)
1750 {
1751 int ret;
1752 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1753 if (ret < 0)
1754 return ret;
1755 payload->payload_state = DP_PAYLOAD_REMOTE;
1756 return ret;
1757 }
1758
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)1759 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1760 struct drm_dp_mst_port *port,
1761 int id,
1762 struct drm_dp_payload *payload)
1763 {
1764 DRM_DEBUG_KMS("\n");
1765 /* its okay for these to fail */
1766 if (port) {
1767 drm_dp_payload_send_msg(mgr, port, id, 0);
1768 }
1769
1770 drm_dp_dpcd_write_payload(mgr, id, payload);
1771 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1772 return 0;
1773 }
1774
drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr * mgr,int id,struct drm_dp_payload * payload)1775 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1776 int id,
1777 struct drm_dp_payload *payload)
1778 {
1779 payload->payload_state = 0;
1780 return 0;
1781 }
1782
1783 /**
1784 * drm_dp_update_payload_part1() - Execute payload update part 1
1785 * @mgr: manager to use.
1786 *
1787 * This iterates over all proposed virtual channels, and tries to
1788 * allocate space in the link for them. For 0->slots transitions,
1789 * this step just writes the VCPI to the MST device. For slots->0
1790 * transitions, this writes the updated VCPIs and removes the
1791 * remote VC payloads.
1792 *
1793 * after calling this the driver should generate ACT and payload
1794 * packets.
1795 */
drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr * mgr)1796 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1797 {
1798 int i, j;
1799 int cur_slots = 1;
1800 struct drm_dp_payload req_payload;
1801 struct drm_dp_mst_port *port;
1802
1803 mutex_lock(&mgr->payload_lock);
1804 for (i = 0; i < mgr->max_payloads; i++) {
1805 /* solve the current payloads - compare to the hw ones
1806 - update the hw view */
1807 req_payload.start_slot = cur_slots;
1808 if (mgr->proposed_vcpis[i]) {
1809 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1810 port = drm_dp_get_validated_port_ref(mgr, port);
1811 if (!port) {
1812 mutex_unlock(&mgr->payload_lock);
1813 return -EINVAL;
1814 }
1815 req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1816 req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi;
1817 } else {
1818 port = NULL;
1819 req_payload.num_slots = 0;
1820 }
1821
1822 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1823 mgr->payloads[i].start_slot = req_payload.start_slot;
1824 }
1825 /* work out what is required to happen with this payload */
1826 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1827
1828 /* need to push an update for this payload */
1829 if (req_payload.num_slots) {
1830 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1831 mgr->payloads[i].num_slots = req_payload.num_slots;
1832 mgr->payloads[i].vcpi = req_payload.vcpi;
1833 } else if (mgr->payloads[i].num_slots) {
1834 mgr->payloads[i].num_slots = 0;
1835 drm_dp_destroy_payload_step1(mgr, port, mgr->payloads[i].vcpi, &mgr->payloads[i]);
1836 req_payload.payload_state = mgr->payloads[i].payload_state;
1837 mgr->payloads[i].start_slot = 0;
1838 }
1839 mgr->payloads[i].payload_state = req_payload.payload_state;
1840 }
1841 cur_slots += req_payload.num_slots;
1842
1843 if (port)
1844 drm_dp_put_port(port);
1845 }
1846
1847 for (i = 0; i < mgr->max_payloads; i++) {
1848 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1849 DRM_DEBUG_KMS("removing payload %d\n", i);
1850 for (j = i; j < mgr->max_payloads - 1; j++) {
1851 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1852 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1853 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1854 set_bit(j + 1, &mgr->payload_mask);
1855 } else {
1856 clear_bit(j + 1, &mgr->payload_mask);
1857 }
1858 }
1859 memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1860 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1861 clear_bit(mgr->max_payloads, &mgr->payload_mask);
1862
1863 }
1864 }
1865 mutex_unlock(&mgr->payload_lock);
1866
1867 return 0;
1868 }
1869 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1870
1871 /**
1872 * drm_dp_update_payload_part2() - Execute payload update part 2
1873 * @mgr: manager to use.
1874 *
1875 * This iterates over all proposed virtual channels, and tries to
1876 * allocate space in the link for them. For 0->slots transitions,
1877 * this step writes the remote VC payload commands. For slots->0
1878 * this just resets some internal state.
1879 */
drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr * mgr)1880 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1881 {
1882 struct drm_dp_mst_port *port;
1883 int i;
1884 int ret = 0;
1885 mutex_lock(&mgr->payload_lock);
1886 for (i = 0; i < mgr->max_payloads; i++) {
1887
1888 if (!mgr->proposed_vcpis[i])
1889 continue;
1890
1891 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1892
1893 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1894 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1895 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1896 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1897 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1898 }
1899 if (ret) {
1900 mutex_unlock(&mgr->payload_lock);
1901 return ret;
1902 }
1903 }
1904 mutex_unlock(&mgr->payload_lock);
1905 return 0;
1906 }
1907 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1908
1909 #if 0 /* unused as of yet */
1910 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1911 struct drm_dp_mst_port *port,
1912 int offset, int size)
1913 {
1914 int len;
1915 struct drm_dp_sideband_msg_tx *txmsg;
1916
1917 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1918 if (!txmsg)
1919 return -ENOMEM;
1920
1921 len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1922 txmsg->dst = port->parent;
1923
1924 drm_dp_queue_down_tx(mgr, txmsg);
1925
1926 return 0;
1927 }
1928 #endif
1929
drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int offset,int size,u8 * bytes)1930 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1931 struct drm_dp_mst_port *port,
1932 int offset, int size, u8 *bytes)
1933 {
1934 int len;
1935 int ret;
1936 struct drm_dp_sideband_msg_tx *txmsg;
1937 struct drm_dp_mst_branch *mstb;
1938
1939 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1940 if (!mstb)
1941 return -EINVAL;
1942
1943 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1944 if (!txmsg) {
1945 ret = -ENOMEM;
1946 goto fail_put;
1947 }
1948
1949 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1950 txmsg->dst = mstb;
1951
1952 drm_dp_queue_down_tx(mgr, txmsg);
1953
1954 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1955 if (ret > 0) {
1956 if (txmsg->reply.reply_type == 1) {
1957 ret = -EINVAL;
1958 } else
1959 ret = 0;
1960 }
1961 kfree(txmsg);
1962 fail_put:
1963 drm_dp_put_mst_branch_device(mstb);
1964 return ret;
1965 }
1966
drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx * msg,u8 req_type)1967 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1968 {
1969 struct drm_dp_sideband_msg_reply_body reply;
1970
1971 reply.reply_type = 1;
1972 reply.req_type = req_type;
1973 drm_dp_encode_sideband_reply(&reply, msg);
1974 return 0;
1975 }
1976
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)1977 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1978 struct drm_dp_mst_branch *mstb,
1979 int req_type, int seqno, bool broadcast)
1980 {
1981 struct drm_dp_sideband_msg_tx *txmsg;
1982
1983 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1984 if (!txmsg)
1985 return -ENOMEM;
1986
1987 txmsg->dst = mstb;
1988 txmsg->seqno = seqno;
1989 drm_dp_encode_up_ack_reply(txmsg, req_type);
1990
1991 mutex_lock(&mgr->qlock);
1992
1993 process_single_up_tx_qlock(mgr, txmsg);
1994
1995 mutex_unlock(&mgr->qlock);
1996
1997 kfree(txmsg);
1998 return 0;
1999 }
2000
drm_dp_get_vc_payload_bw(int dp_link_bw,int dp_link_count,int * out)2001 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
2002 int dp_link_count,
2003 int *out)
2004 {
2005 switch (dp_link_bw) {
2006 default:
2007 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
2008 dp_link_bw, dp_link_count);
2009 return false;
2010
2011 case DP_LINK_BW_1_62:
2012 *out = 3 * dp_link_count;
2013 break;
2014 case DP_LINK_BW_2_7:
2015 *out = 5 * dp_link_count;
2016 break;
2017 case DP_LINK_BW_5_4:
2018 *out = 10 * dp_link_count;
2019 break;
2020 }
2021 return true;
2022 }
2023
2024 /**
2025 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
2026 * @mgr: manager to set state for
2027 * @mst_state: true to enable MST on this connector - false to disable.
2028 *
2029 * This is called by the driver when it detects an MST capable device plugged
2030 * into a DP MST capable port, or when a DP MST capable device is unplugged.
2031 */
drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr * mgr,bool mst_state)2032 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
2033 {
2034 int ret = 0;
2035 struct drm_dp_mst_branch *mstb = NULL;
2036
2037 mutex_lock(&mgr->payload_lock);
2038 mutex_lock(&mgr->lock);
2039 if (mst_state == mgr->mst_state)
2040 goto out_unlock;
2041
2042 mgr->mst_state = mst_state;
2043 /* set the device into MST mode */
2044 if (mst_state) {
2045 WARN_ON(mgr->mst_primary);
2046
2047 /* get dpcd info */
2048 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2049 if (ret != DP_RECEIVER_CAP_SIZE) {
2050 DRM_DEBUG_KMS("failed to read DPCD\n");
2051 goto out_unlock;
2052 }
2053
2054 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
2055 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
2056 &mgr->pbn_div)) {
2057 ret = -EINVAL;
2058 goto out_unlock;
2059 }
2060
2061 mgr->total_pbn = 2560;
2062 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
2063 mgr->avail_slots = mgr->total_slots;
2064
2065 /* add initial branch device at LCT 1 */
2066 mstb = drm_dp_add_mst_branch_device(1, NULL);
2067 if (mstb == NULL) {
2068 ret = -ENOMEM;
2069 goto out_unlock;
2070 }
2071 mstb->mgr = mgr;
2072
2073 /* give this the main reference */
2074 mgr->mst_primary = mstb;
2075 kref_get(&mgr->mst_primary->kref);
2076
2077 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2078 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2079 if (ret < 0) {
2080 goto out_unlock;
2081 }
2082
2083 {
2084 struct drm_dp_payload reset_pay;
2085 reset_pay.start_slot = 0;
2086 reset_pay.num_slots = 0x3f;
2087 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
2088 }
2089
2090 queue_work(system_long_wq, &mgr->work);
2091
2092 ret = 0;
2093 } else {
2094 /* disable MST on the device */
2095 mstb = mgr->mst_primary;
2096 mgr->mst_primary = NULL;
2097 /* this can fail if the device is gone */
2098 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2099 ret = 0;
2100 memset(mgr->payloads, 0,
2101 mgr->max_payloads * sizeof(mgr->payloads[0]));
2102 memset(mgr->proposed_vcpis, 0,
2103 mgr->max_payloads * sizeof(mgr->proposed_vcpis[0]));
2104 mgr->payload_mask = 0;
2105 set_bit(0, &mgr->payload_mask);
2106 mgr->vcpi_mask = 0;
2107 }
2108
2109 out_unlock:
2110 mutex_unlock(&mgr->lock);
2111 mutex_unlock(&mgr->payload_lock);
2112 if (mstb)
2113 drm_dp_put_mst_branch_device(mstb);
2114 return ret;
2115
2116 }
2117 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2118
2119 /**
2120 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2121 * @mgr: manager to suspend
2122 *
2123 * This function tells the MST device that we can't handle UP messages
2124 * anymore. This should stop it from sending any since we are suspended.
2125 */
drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr * mgr)2126 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2127 {
2128 mutex_lock(&mgr->lock);
2129 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2130 DP_MST_EN | DP_UPSTREAM_IS_SRC);
2131 mutex_unlock(&mgr->lock);
2132 flush_work(&mgr->work);
2133 flush_work(&mgr->destroy_connector_work);
2134 }
2135 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2136
2137 /**
2138 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2139 * @mgr: manager to resume
2140 *
2141 * This will fetch DPCD and see if the device is still there,
2142 * if it is, it will rewrite the MSTM control bits, and return.
2143 *
2144 * if the device fails this returns -1, and the driver should do
2145 * a full MST reprobe, in case we were undocked.
2146 */
drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr * mgr)2147 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2148 {
2149 int ret = 0;
2150
2151 mutex_lock(&mgr->lock);
2152
2153 if (mgr->mst_primary) {
2154 int sret;
2155 u8 guid[16];
2156
2157 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2158 if (sret != DP_RECEIVER_CAP_SIZE) {
2159 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2160 ret = -1;
2161 goto out_unlock;
2162 }
2163
2164 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2165 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2166 if (ret < 0) {
2167 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2168 ret = -1;
2169 goto out_unlock;
2170 }
2171
2172 /* Some hubs forget their guids after they resume */
2173 sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
2174 if (sret != 16) {
2175 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2176 ret = -1;
2177 goto out_unlock;
2178 }
2179 drm_dp_check_mstb_guid(mgr->mst_primary, guid);
2180
2181 ret = 0;
2182 } else
2183 ret = -1;
2184
2185 out_unlock:
2186 mutex_unlock(&mgr->lock);
2187 return ret;
2188 }
2189 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2190
drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr * mgr,bool up)2191 static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2192 {
2193 int len;
2194 u8 replyblock[32];
2195 int replylen, origlen, curreply;
2196 int ret;
2197 struct drm_dp_sideband_msg_rx *msg;
2198 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2199 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2200
2201 len = min(mgr->max_dpcd_transaction_bytes, 16);
2202 ret = drm_dp_dpcd_read(mgr->aux, basereg,
2203 replyblock, len);
2204 if (ret != len) {
2205 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2206 return false;
2207 }
2208 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2209 if (!ret) {
2210 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2211 return false;
2212 }
2213 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2214
2215 origlen = replylen;
2216 replylen -= len;
2217 curreply = len;
2218 while (replylen > 0) {
2219 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2220 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2221 replyblock, len);
2222 if (ret != len) {
2223 DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
2224 len, ret);
2225 return false;
2226 }
2227
2228 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2229 if (!ret) {
2230 DRM_DEBUG_KMS("failed to build sideband msg\n");
2231 return false;
2232 }
2233
2234 curreply += len;
2235 replylen -= len;
2236 }
2237 return true;
2238 }
2239
drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr * mgr)2240 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2241 {
2242 int ret = 0;
2243
2244 if (!drm_dp_get_one_sb_msg(mgr, false)) {
2245 memset(&mgr->down_rep_recv, 0,
2246 sizeof(struct drm_dp_sideband_msg_rx));
2247 return 0;
2248 }
2249
2250 if (mgr->down_rep_recv.have_eomt) {
2251 struct drm_dp_sideband_msg_tx *txmsg;
2252 struct drm_dp_mst_branch *mstb;
2253 int slot = -1;
2254 mstb = drm_dp_get_mst_branch_device(mgr,
2255 mgr->down_rep_recv.initial_hdr.lct,
2256 mgr->down_rep_recv.initial_hdr.rad);
2257
2258 if (!mstb) {
2259 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2260 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2261 return 0;
2262 }
2263
2264 /* find the message */
2265 slot = mgr->down_rep_recv.initial_hdr.seqno;
2266 mutex_lock(&mgr->qlock);
2267 txmsg = mstb->tx_slots[slot];
2268 /* remove from slots */
2269 mutex_unlock(&mgr->qlock);
2270
2271 if (!txmsg) {
2272 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2273 mstb,
2274 mgr->down_rep_recv.initial_hdr.seqno,
2275 mgr->down_rep_recv.initial_hdr.lct,
2276 mgr->down_rep_recv.initial_hdr.rad[0],
2277 mgr->down_rep_recv.msg[0]);
2278 drm_dp_put_mst_branch_device(mstb);
2279 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2280 return 0;
2281 }
2282
2283 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2284 if (txmsg->reply.reply_type == 1) {
2285 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);
2286 }
2287
2288 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2289 drm_dp_put_mst_branch_device(mstb);
2290
2291 mutex_lock(&mgr->qlock);
2292 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2293 mstb->tx_slots[slot] = NULL;
2294 mutex_unlock(&mgr->qlock);
2295
2296 wake_up(&mgr->tx_waitq);
2297 }
2298 return ret;
2299 }
2300
drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr * mgr)2301 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2302 {
2303 int ret = 0;
2304
2305 if (!drm_dp_get_one_sb_msg(mgr, true)) {
2306 memset(&mgr->up_req_recv, 0,
2307 sizeof(struct drm_dp_sideband_msg_rx));
2308 return 0;
2309 }
2310
2311 if (mgr->up_req_recv.have_eomt) {
2312 struct drm_dp_sideband_msg_req_body msg;
2313 struct drm_dp_mst_branch *mstb = NULL;
2314 bool seqno;
2315
2316 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2317 mstb = drm_dp_get_mst_branch_device(mgr,
2318 mgr->up_req_recv.initial_hdr.lct,
2319 mgr->up_req_recv.initial_hdr.rad);
2320 if (!mstb) {
2321 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2322 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2323 return 0;
2324 }
2325 }
2326
2327 seqno = mgr->up_req_recv.initial_hdr.seqno;
2328 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2329
2330 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2331 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2332
2333 if (!mstb)
2334 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2335
2336 if (!mstb) {
2337 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2338 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2339 return 0;
2340 }
2341
2342 drm_dp_update_port(mstb, &msg.u.conn_stat);
2343
2344 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);
2345 (*mgr->cbs->hotplug)(mgr);
2346
2347 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2348 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2349 if (!mstb)
2350 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2351
2352 if (!mstb) {
2353 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2354 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2355 return 0;
2356 }
2357
2358 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2359 }
2360
2361 if (mstb)
2362 drm_dp_put_mst_branch_device(mstb);
2363
2364 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2365 }
2366 return ret;
2367 }
2368
2369 /**
2370 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2371 * @mgr: manager to notify irq for.
2372 * @esi: 4 bytes from SINK_COUNT_ESI
2373 * @handled: whether the hpd interrupt was consumed or not
2374 *
2375 * This should be called from the driver when it detects a short IRQ,
2376 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2377 * topology manager will process the sideband messages received as a result
2378 * of this.
2379 */
drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr * mgr,u8 * esi,bool * handled)2380 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2381 {
2382 int ret = 0;
2383 int sc;
2384 *handled = false;
2385 sc = esi[0] & 0x3f;
2386
2387 if (sc != mgr->sink_count) {
2388 mgr->sink_count = sc;
2389 *handled = true;
2390 }
2391
2392 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2393 ret = drm_dp_mst_handle_down_rep(mgr);
2394 *handled = true;
2395 }
2396
2397 if (esi[1] & DP_UP_REQ_MSG_RDY) {
2398 ret |= drm_dp_mst_handle_up_req(mgr);
2399 *handled = true;
2400 }
2401
2402 drm_dp_mst_kick_tx(mgr);
2403 return ret;
2404 }
2405 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2406
2407 /**
2408 * drm_dp_mst_detect_port() - get connection status for an MST port
2409 * @mgr: manager for this port
2410 * @port: unverified pointer to a port
2411 *
2412 * This returns the current connection state for a port. It validates the
2413 * port pointer still exists so the caller doesn't require a reference
2414 */
drm_dp_mst_detect_port(struct drm_connector * connector,struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2415 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2416 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2417 {
2418 enum drm_connector_status status = connector_status_disconnected;
2419
2420 /* we need to search for the port in the mgr in case its gone */
2421 port = drm_dp_get_validated_port_ref(mgr, port);
2422 if (!port)
2423 return connector_status_disconnected;
2424
2425 if (!port->ddps)
2426 goto out;
2427
2428 switch (port->pdt) {
2429 case DP_PEER_DEVICE_NONE:
2430 case DP_PEER_DEVICE_MST_BRANCHING:
2431 break;
2432
2433 case DP_PEER_DEVICE_SST_SINK:
2434 status = connector_status_connected;
2435 /* for logical ports - cache the EDID */
2436 if (port->port_num >= 8 && !port->cached_edid) {
2437 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2438 }
2439 break;
2440 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2441 if (port->ldps)
2442 status = connector_status_connected;
2443 break;
2444 }
2445 out:
2446 drm_dp_put_port(port);
2447 return status;
2448 }
2449 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2450
2451 /**
2452 * drm_dp_mst_get_edid() - get EDID for an MST port
2453 * @connector: toplevel connector to get EDID for
2454 * @mgr: manager for this port
2455 * @port: unverified pointer to a port.
2456 *
2457 * This returns an EDID for the port connected to a connector,
2458 * It validates the pointer still exists so the caller doesn't require a
2459 * reference.
2460 */
drm_dp_mst_get_edid(struct drm_connector * connector,struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2461 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2462 {
2463 struct edid *edid = NULL;
2464
2465 /* we need to search for the port in the mgr in case its gone */
2466 port = drm_dp_get_validated_port_ref(mgr, port);
2467 if (!port)
2468 return NULL;
2469
2470 if (port->cached_edid)
2471 edid = drm_edid_duplicate(port->cached_edid);
2472 else {
2473 edid = drm_get_edid(connector, &port->aux.ddc);
2474 drm_mode_connector_set_tile_property(connector);
2475 }
2476 drm_dp_put_port(port);
2477 return edid;
2478 }
2479 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2480
2481 /**
2482 * drm_dp_find_vcpi_slots() - find slots for this PBN value
2483 * @mgr: manager to use
2484 * @pbn: payload bandwidth to convert into slots.
2485 */
drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr * mgr,int pbn)2486 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2487 int pbn)
2488 {
2489 int num_slots;
2490
2491 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2492
2493 if (num_slots > mgr->avail_slots)
2494 return -ENOSPC;
2495 return num_slots;
2496 }
2497 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2498
drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_vcpi * vcpi,int pbn)2499 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2500 struct drm_dp_vcpi *vcpi, int pbn)
2501 {
2502 int num_slots;
2503 int ret;
2504
2505 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2506
2507 if (num_slots > mgr->avail_slots)
2508 return -ENOSPC;
2509
2510 vcpi->pbn = pbn;
2511 vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2512 vcpi->num_slots = num_slots;
2513
2514 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2515 if (ret < 0)
2516 return ret;
2517 return 0;
2518 }
2519
2520 /**
2521 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2522 * @mgr: manager for this port
2523 * @port: port to allocate a virtual channel for.
2524 * @pbn: payload bandwidth number to request
2525 * @slots: returned number of slots for this PBN.
2526 */
drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int pbn,int * slots)2527 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2528 {
2529 int ret;
2530
2531 port = drm_dp_get_validated_port_ref(mgr, port);
2532 if (!port)
2533 return false;
2534
2535 if (port->vcpi.vcpi > 0) {
2536 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2537 if (pbn == port->vcpi.pbn) {
2538 *slots = port->vcpi.num_slots;
2539 drm_dp_put_port(port);
2540 return true;
2541 }
2542 }
2543
2544 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2545 if (ret) {
2546 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2547 goto out;
2548 }
2549 DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2550 *slots = port->vcpi.num_slots;
2551
2552 drm_dp_put_port(port);
2553 return true;
2554 out:
2555 return false;
2556 }
2557 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2558
drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2559 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2560 {
2561 int slots = 0;
2562 port = drm_dp_get_validated_port_ref(mgr, port);
2563 if (!port)
2564 return slots;
2565
2566 slots = port->vcpi.num_slots;
2567 drm_dp_put_port(port);
2568 return slots;
2569 }
2570 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2571
2572 /**
2573 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2574 * @mgr: manager for this port
2575 * @port: unverified pointer to a port.
2576 *
2577 * This just resets the number of slots for the ports VCPI for later programming.
2578 */
drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2579 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2580 {
2581 port = drm_dp_get_validated_port_ref(mgr, port);
2582 if (!port)
2583 return;
2584 port->vcpi.num_slots = 0;
2585 drm_dp_put_port(port);
2586 }
2587 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2588
2589 /**
2590 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2591 * @mgr: manager for this port
2592 * @port: unverified port to deallocate vcpi for
2593 */
drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2594 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2595 {
2596 port = drm_dp_get_validated_port_ref(mgr, port);
2597 if (!port)
2598 return;
2599
2600 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2601 port->vcpi.num_slots = 0;
2602 port->vcpi.pbn = 0;
2603 port->vcpi.aligned_pbn = 0;
2604 port->vcpi.vcpi = 0;
2605 drm_dp_put_port(port);
2606 }
2607 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2608
drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr * mgr,int id,struct drm_dp_payload * payload)2609 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2610 int id, struct drm_dp_payload *payload)
2611 {
2612 u8 payload_alloc[3], status;
2613 int ret;
2614 int retries = 0;
2615
2616 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2617 DP_PAYLOAD_TABLE_UPDATED);
2618
2619 payload_alloc[0] = id;
2620 payload_alloc[1] = payload->start_slot;
2621 payload_alloc[2] = payload->num_slots;
2622
2623 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2624 if (ret != 3) {
2625 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2626 goto fail;
2627 }
2628
2629 retry:
2630 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2631 if (ret < 0) {
2632 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2633 goto fail;
2634 }
2635
2636 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2637 retries++;
2638 if (retries < 20) {
2639 usleep_range(10000, 20000);
2640 goto retry;
2641 }
2642 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2643 ret = -EINVAL;
2644 goto fail;
2645 }
2646 ret = 0;
2647 fail:
2648 return ret;
2649 }
2650
do_get_act_status(struct drm_dp_aux * aux)2651 static int do_get_act_status(struct drm_dp_aux *aux)
2652 {
2653 int ret;
2654 u8 status;
2655
2656 ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2657 if (ret < 0)
2658 return ret;
2659
2660 return status;
2661 }
2662
2663 /**
2664 * drm_dp_check_act_status() - Check ACT handled status.
2665 * @mgr: manager to use
2666 *
2667 * Check the payload status bits in the DPCD for ACT handled completion.
2668 */
drm_dp_check_act_status(struct drm_dp_mst_topology_mgr * mgr)2669 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2670 {
2671 /*
2672 * There doesn't seem to be any recommended retry count or timeout in
2673 * the MST specification. Since some hubs have been observed to take
2674 * over 1 second to update their payload allocations under certain
2675 * conditions, we use a rather large timeout value.
2676 */
2677 const int timeout_ms = 3000;
2678 int ret, status;
2679
2680 ret = readx_poll_timeout(do_get_act_status, mgr->aux, status,
2681 status & DP_PAYLOAD_ACT_HANDLED || status < 0,
2682 200, timeout_ms * USEC_PER_MSEC);
2683 if (ret < 0 && status >= 0) {
2684 DRM_DEBUG_KMS("Failed to get ACT after %dms, last status: %02x\n",
2685 timeout_ms, status);
2686 return -EINVAL;
2687 } else if (status < 0) {
2688 DRM_DEBUG_KMS("Failed to read payload table status: %d\n",
2689 status);
2690 return status;
2691 }
2692
2693 return 0;
2694 }
2695 EXPORT_SYMBOL(drm_dp_check_act_status);
2696
2697 /**
2698 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2699 * @clock: dot clock for the mode
2700 * @bpp: bpp for the mode.
2701 *
2702 * This uses the formula in the spec to calculate the PBN value for a mode.
2703 */
drm_dp_calc_pbn_mode(int clock,int bpp)2704 int drm_dp_calc_pbn_mode(int clock, int bpp)
2705 {
2706 u64 kbps;
2707 s64 peak_kbps;
2708 u32 numerator;
2709 u32 denominator;
2710
2711 kbps = clock * bpp;
2712
2713 /*
2714 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
2715 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
2716 * common multiplier to render an integer PBN for all link rate/lane
2717 * counts combinations
2718 * calculate
2719 * peak_kbps *= (1006/1000)
2720 * peak_kbps *= (64/54)
2721 * peak_kbps *= 8 convert to bytes
2722 */
2723
2724 numerator = 64 * 1006;
2725 denominator = 54 * 8 * 1000 * 1000;
2726
2727 kbps *= numerator;
2728 peak_kbps = drm_fixp_from_fraction(kbps, denominator);
2729
2730 return drm_fixp2int_ceil(peak_kbps);
2731 }
2732 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2733
test_calc_pbn_mode(void)2734 static int test_calc_pbn_mode(void)
2735 {
2736 int ret;
2737 ret = drm_dp_calc_pbn_mode(154000, 30);
2738 if (ret != 689) {
2739 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2740 154000, 30, 689, ret);
2741 return -EINVAL;
2742 }
2743 ret = drm_dp_calc_pbn_mode(234000, 30);
2744 if (ret != 1047) {
2745 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2746 234000, 30, 1047, ret);
2747 return -EINVAL;
2748 }
2749 ret = drm_dp_calc_pbn_mode(297000, 24);
2750 if (ret != 1063) {
2751 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2752 297000, 24, 1063, ret);
2753 return -EINVAL;
2754 }
2755 return 0;
2756 }
2757
2758 /* 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)2759 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2760 {
2761 queue_work(system_long_wq, &mgr->tx_work);
2762 }
2763
drm_dp_mst_dump_mstb(struct seq_file * m,struct drm_dp_mst_branch * mstb)2764 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2765 struct drm_dp_mst_branch *mstb)
2766 {
2767 struct drm_dp_mst_port *port;
2768 int tabs = mstb->lct;
2769 char prefix[10];
2770 int i;
2771
2772 for (i = 0; i < tabs; i++)
2773 prefix[i] = '\t';
2774 prefix[i] = '\0';
2775
2776 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2777 list_for_each_entry(port, &mstb->ports, next) {
2778 seq_printf(m, "%sport: %d: ddps: %d ldps: %d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port, port->connector);
2779 if (port->mstb)
2780 drm_dp_mst_dump_mstb(m, port->mstb);
2781 }
2782 }
2783
dump_dp_payload_table(struct drm_dp_mst_topology_mgr * mgr,char * buf)2784 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2785 char *buf)
2786 {
2787 int ret;
2788 int i;
2789 for (i = 0; i < 4; i++) {
2790 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2791 if (ret != 16)
2792 break;
2793 }
2794 if (i == 4)
2795 return true;
2796 return false;
2797 }
2798
2799 /**
2800 * drm_dp_mst_dump_topology(): dump topology to seq file.
2801 * @m: seq_file to dump output to
2802 * @mgr: manager to dump current topology for.
2803 *
2804 * helper to dump MST topology to a seq file for debugfs.
2805 */
drm_dp_mst_dump_topology(struct seq_file * m,struct drm_dp_mst_topology_mgr * mgr)2806 void drm_dp_mst_dump_topology(struct seq_file *m,
2807 struct drm_dp_mst_topology_mgr *mgr)
2808 {
2809 int i;
2810 struct drm_dp_mst_port *port;
2811 mutex_lock(&mgr->lock);
2812 if (mgr->mst_primary)
2813 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2814
2815 /* dump VCPIs */
2816 mutex_unlock(&mgr->lock);
2817
2818 mutex_lock(&mgr->payload_lock);
2819 seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
2820
2821 for (i = 0; i < mgr->max_payloads; i++) {
2822 if (mgr->proposed_vcpis[i]) {
2823 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2824 seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
2825 } else
2826 seq_printf(m, "vcpi %d:unsed\n", i);
2827 }
2828 for (i = 0; i < mgr->max_payloads; i++) {
2829 seq_printf(m, "payload %d: %d, %d, %d\n",
2830 i,
2831 mgr->payloads[i].payload_state,
2832 mgr->payloads[i].start_slot,
2833 mgr->payloads[i].num_slots);
2834
2835
2836 }
2837 mutex_unlock(&mgr->payload_lock);
2838
2839 mutex_lock(&mgr->lock);
2840 if (mgr->mst_primary) {
2841 u8 buf[64];
2842 bool bret;
2843 int ret;
2844 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2845 seq_printf(m, "dpcd: ");
2846 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2847 seq_printf(m, "%02x ", buf[i]);
2848 seq_printf(m, "\n");
2849 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2850 seq_printf(m, "faux/mst: ");
2851 for (i = 0; i < 2; i++)
2852 seq_printf(m, "%02x ", buf[i]);
2853 seq_printf(m, "\n");
2854 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2855 seq_printf(m, "mst ctrl: ");
2856 for (i = 0; i < 1; i++)
2857 seq_printf(m, "%02x ", buf[i]);
2858 seq_printf(m, "\n");
2859
2860 /* dump the standard OUI branch header */
2861 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
2862 seq_printf(m, "branch oui: ");
2863 for (i = 0; i < 0x3; i++)
2864 seq_printf(m, "%02x", buf[i]);
2865 seq_printf(m, " devid: ");
2866 for (i = 0x3; i < 0x8; i++)
2867 seq_printf(m, "%c", buf[i]);
2868 seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
2869 seq_printf(m, "\n");
2870 bret = dump_dp_payload_table(mgr, buf);
2871 if (bret == true) {
2872 seq_printf(m, "payload table: ");
2873 for (i = 0; i < 63; i++)
2874 seq_printf(m, "%02x ", buf[i]);
2875 seq_printf(m, "\n");
2876 }
2877
2878 }
2879
2880 mutex_unlock(&mgr->lock);
2881
2882 }
2883 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2884
drm_dp_tx_work(struct work_struct * work)2885 static void drm_dp_tx_work(struct work_struct *work)
2886 {
2887 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2888
2889 mutex_lock(&mgr->qlock);
2890 if (mgr->tx_down_in_progress)
2891 process_single_down_tx_qlock(mgr);
2892 mutex_unlock(&mgr->qlock);
2893 }
2894
drm_dp_free_mst_port(struct kref * kref)2895 static void drm_dp_free_mst_port(struct kref *kref)
2896 {
2897 struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
2898 kref_put(&port->parent->kref, drm_dp_free_mst_branch_device);
2899 kfree(port);
2900 }
2901
drm_dp_destroy_connector_work(struct work_struct * work)2902 static void drm_dp_destroy_connector_work(struct work_struct *work)
2903 {
2904 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
2905 struct drm_dp_mst_port *port;
2906 bool send_hotplug = false;
2907 /*
2908 * Not a regular list traverse as we have to drop the destroy
2909 * connector lock before destroying the connector, to avoid AB->BA
2910 * ordering between this lock and the config mutex.
2911 */
2912 for (;;) {
2913 mutex_lock(&mgr->destroy_connector_lock);
2914 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
2915 if (!port) {
2916 mutex_unlock(&mgr->destroy_connector_lock);
2917 break;
2918 }
2919 list_del(&port->next);
2920 mutex_unlock(&mgr->destroy_connector_lock);
2921
2922 kref_init(&port->kref);
2923 INIT_LIST_HEAD(&port->next);
2924
2925 mgr->cbs->destroy_connector(mgr, port->connector);
2926
2927 drm_dp_port_teardown_pdt(port, port->pdt);
2928 port->pdt = DP_PEER_DEVICE_NONE;
2929
2930 if (!port->input && port->vcpi.vcpi > 0) {
2931 drm_dp_mst_reset_vcpi_slots(mgr, port);
2932 drm_dp_update_payload_part1(mgr);
2933 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2934 }
2935
2936 kref_put(&port->kref, drm_dp_free_mst_port);
2937 send_hotplug = true;
2938 }
2939 if (send_hotplug)
2940 (*mgr->cbs->hotplug)(mgr);
2941 }
2942
2943 /**
2944 * drm_dp_mst_topology_mgr_init - initialise a topology manager
2945 * @mgr: manager struct to initialise
2946 * @dev: device providing this structure - for i2c addition.
2947 * @aux: DP helper aux channel to talk to this device
2948 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2949 * @max_payloads: maximum number of payloads this GPU can source
2950 * @conn_base_id: the connector object ID the MST device is connected to.
2951 *
2952 * Return 0 for success, or negative error code on failure
2953 */
drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr * mgr,struct device * dev,struct drm_dp_aux * aux,int max_dpcd_transaction_bytes,int max_payloads,int conn_base_id)2954 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2955 struct device *dev, struct drm_dp_aux *aux,
2956 int max_dpcd_transaction_bytes,
2957 int max_payloads, int conn_base_id)
2958 {
2959 mutex_init(&mgr->lock);
2960 mutex_init(&mgr->qlock);
2961 mutex_init(&mgr->payload_lock);
2962 mutex_init(&mgr->destroy_connector_lock);
2963 INIT_LIST_HEAD(&mgr->tx_msg_downq);
2964 INIT_LIST_HEAD(&mgr->destroy_connector_list);
2965 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2966 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2967 INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
2968 init_waitqueue_head(&mgr->tx_waitq);
2969 mgr->dev = dev;
2970 mgr->aux = aux;
2971 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2972 mgr->max_payloads = max_payloads;
2973 mgr->conn_base_id = conn_base_id;
2974 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
2975 if (!mgr->payloads)
2976 return -ENOMEM;
2977 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
2978 if (!mgr->proposed_vcpis)
2979 return -ENOMEM;
2980 set_bit(0, &mgr->payload_mask);
2981 test_calc_pbn_mode();
2982 return 0;
2983 }
2984 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
2985
2986 /**
2987 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
2988 * @mgr: manager to destroy
2989 */
drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr * mgr)2990 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
2991 {
2992 flush_work(&mgr->work);
2993 flush_work(&mgr->destroy_connector_work);
2994 mutex_lock(&mgr->payload_lock);
2995 kfree(mgr->payloads);
2996 mgr->payloads = NULL;
2997 kfree(mgr->proposed_vcpis);
2998 mgr->proposed_vcpis = NULL;
2999 mutex_unlock(&mgr->payload_lock);
3000 mgr->dev = NULL;
3001 mgr->aux = NULL;
3002 }
3003 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
3004
3005 /* I2C device */
drm_dp_mst_i2c_xfer(struct i2c_adapter * adapter,struct i2c_msg * msgs,int num)3006 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
3007 int num)
3008 {
3009 struct drm_dp_aux *aux = adapter->algo_data;
3010 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
3011 struct drm_dp_mst_branch *mstb;
3012 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
3013 unsigned int i;
3014 bool reading = false;
3015 struct drm_dp_sideband_msg_req_body msg;
3016 struct drm_dp_sideband_msg_tx *txmsg = NULL;
3017 int ret;
3018
3019 mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
3020 if (!mstb)
3021 return -EREMOTEIO;
3022
3023 /* construct i2c msg */
3024 /* see if last msg is a read */
3025 if (msgs[num - 1].flags & I2C_M_RD)
3026 reading = true;
3027
3028 if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
3029 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
3030 ret = -EIO;
3031 goto out;
3032 }
3033
3034 memset(&msg, 0, sizeof(msg));
3035 msg.req_type = DP_REMOTE_I2C_READ;
3036 msg.u.i2c_read.num_transactions = num - 1;
3037 msg.u.i2c_read.port_number = port->port_num;
3038 for (i = 0; i < num - 1; i++) {
3039 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
3040 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
3041 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
3042 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
3043 }
3044 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
3045 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
3046
3047 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3048 if (!txmsg) {
3049 ret = -ENOMEM;
3050 goto out;
3051 }
3052
3053 txmsg->dst = mstb;
3054 drm_dp_encode_sideband_req(&msg, txmsg);
3055
3056 drm_dp_queue_down_tx(mgr, txmsg);
3057
3058 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3059 if (ret > 0) {
3060
3061 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
3062 ret = -EREMOTEIO;
3063 goto out;
3064 }
3065 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
3066 ret = -EIO;
3067 goto out;
3068 }
3069 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
3070 ret = num;
3071 }
3072 out:
3073 kfree(txmsg);
3074 drm_dp_put_mst_branch_device(mstb);
3075 return ret;
3076 }
3077
drm_dp_mst_i2c_functionality(struct i2c_adapter * adapter)3078 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
3079 {
3080 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
3081 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
3082 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
3083 I2C_FUNC_10BIT_ADDR;
3084 }
3085
3086 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
3087 .functionality = drm_dp_mst_i2c_functionality,
3088 .master_xfer = drm_dp_mst_i2c_xfer,
3089 };
3090
3091 /**
3092 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
3093 * @aux: DisplayPort AUX channel
3094 *
3095 * Returns 0 on success or a negative error code on failure.
3096 */
drm_dp_mst_register_i2c_bus(struct drm_dp_aux * aux)3097 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
3098 {
3099 aux->ddc.algo = &drm_dp_mst_i2c_algo;
3100 aux->ddc.algo_data = aux;
3101 aux->ddc.retries = 3;
3102
3103 aux->ddc.class = I2C_CLASS_DDC;
3104 aux->ddc.owner = THIS_MODULE;
3105 aux->ddc.dev.parent = aux->dev;
3106 aux->ddc.dev.of_node = aux->dev->of_node;
3107
3108 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
3109 sizeof(aux->ddc.name));
3110
3111 return i2c_add_adapter(&aux->ddc);
3112 }
3113
3114 /**
3115 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
3116 * @aux: DisplayPort AUX channel
3117 */
drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux * aux)3118 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
3119 {
3120 i2c_del_adapter(&aux->ddc);
3121 }
3122