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 #ifndef _DRM_DP_MST_HELPER_H_
23 #define _DRM_DP_MST_HELPER_H_
24 
25 #include <linux/types.h>
26 #include <drm/drm_dp_helper.h>
27 #include <drm/drm_atomic.h>
28 
29 struct drm_dp_mst_branch;
30 
31 /**
32  * struct drm_dp_vcpi - Virtual Channel Payload Identifier
33  * @vcpi: Virtual channel ID.
34  * @pbn: Payload Bandwidth Number for this channel
35  * @aligned_pbn: PBN aligned with slot size
36  * @num_slots: number of slots for this PBN
37  */
38 struct drm_dp_vcpi {
39 	int vcpi;
40 	int pbn;
41 	int aligned_pbn;
42 	int num_slots;
43 };
44 
45 /**
46  * struct drm_dp_mst_port - MST port
47  * @kref: reference count for this port.
48  * @port_num: port number
49  * @input: if this port is an input port.
50  * @mcs: message capability status - DP 1.2 spec.
51  * @ddps: DisplayPort Device Plug Status - DP 1.2
52  * @pdt: Peer Device Type
53  * @ldps: Legacy Device Plug Status
54  * @dpcd_rev: DPCD revision of device on this port
55  * @num_sdp_streams: Number of simultaneous streams
56  * @num_sdp_stream_sinks: Number of stream sinks
57  * @available_pbn: Available bandwidth for this port.
58  * @next: link to next port on this branch device
59  * @mstb: branch device attach below this port
60  * @aux: i2c aux transport to talk to device connected to this port.
61  * @parent: branch device parent of this port
62  * @vcpi: Virtual Channel Payload info for this port.
63  * @connector: DRM connector this port is connected to.
64  * @mgr: topology manager this port lives under.
65  *
66  * This structure represents an MST port endpoint on a device somewhere
67  * in the MST topology.
68  */
69 struct drm_dp_mst_port {
70 	struct kref kref;
71 
72 	u8 port_num;
73 	bool input;
74 	bool mcs;
75 	bool ddps;
76 	u8 pdt;
77 	bool ldps;
78 	u8 dpcd_rev;
79 	u8 num_sdp_streams;
80 	u8 num_sdp_stream_sinks;
81 	uint16_t available_pbn;
82 	struct list_head next;
83 	struct drm_dp_mst_branch *mstb; /* pointer to an mstb if this port has one */
84 	struct drm_dp_aux aux; /* i2c bus for this port? */
85 	struct drm_dp_mst_branch *parent;
86 
87 	struct drm_dp_vcpi vcpi;
88 	struct drm_connector *connector;
89 	struct drm_dp_mst_topology_mgr *mgr;
90 
91 	/**
92 	 * @cached_edid: for DP logical ports - make tiling work by ensuring
93 	 * that the EDID for all connectors is read immediately.
94 	 */
95 	struct edid *cached_edid;
96 	/**
97 	 * @has_audio: Tracks whether the sink connector to this port is
98 	 * audio-capable.
99 	 */
100 	bool has_audio;
101 };
102 
103 /**
104  * struct drm_dp_mst_branch - MST branch device.
105  * @kref: reference count for this port.
106  * @rad: Relative Address to talk to this branch device.
107  * @lct: Link count total to talk to this branch device.
108  * @num_ports: number of ports on the branch.
109  * @msg_slots: one bit per transmitted msg slot.
110  * @ports: linked list of ports on this branch.
111  * @port_parent: pointer to the port parent, NULL if toplevel.
112  * @mgr: topology manager for this branch device.
113  * @tx_slots: transmission slots for this device.
114  * @last_seqno: last sequence number used to talk to this.
115  * @link_address_sent: if a link address message has been sent to this device yet.
116  * @guid: guid for DP 1.2 branch device. port under this branch can be
117  * identified by port #.
118  *
119  * This structure represents an MST branch device, there is one
120  * primary branch device at the root, along with any other branches connected
121  * to downstream port of parent branches.
122  */
123 struct drm_dp_mst_branch {
124 	struct kref kref;
125 	u8 rad[8];
126 	u8 lct;
127 	int num_ports;
128 
129 	int msg_slots;
130 	struct list_head ports;
131 
132 	/* list of tx ops queue for this port */
133 	struct drm_dp_mst_port *port_parent;
134 	struct drm_dp_mst_topology_mgr *mgr;
135 
136 	/* slots are protected by mstb->mgr->qlock */
137 	struct drm_dp_sideband_msg_tx *tx_slots[2];
138 	int last_seqno;
139 	bool link_address_sent;
140 
141 	/* global unique identifier to identify branch devices */
142 	u8 guid[16];
143 };
144 
145 
146 /* sideband msg header - not bit struct */
147 struct drm_dp_sideband_msg_hdr {
148 	u8 lct;
149 	u8 lcr;
150 	u8 rad[8];
151 	bool broadcast;
152 	bool path_msg;
153 	u8 msg_len;
154 	bool somt;
155 	bool eomt;
156 	bool seqno;
157 };
158 
159 struct drm_dp_nak_reply {
160 	u8 guid[16];
161 	u8 reason;
162 	u8 nak_data;
163 };
164 
165 struct drm_dp_link_address_ack_reply {
166 	u8 guid[16];
167 	u8 nports;
168 	struct drm_dp_link_addr_reply_port {
169 		bool input_port;
170 		u8 peer_device_type;
171 		u8 port_number;
172 		bool mcs;
173 		bool ddps;
174 		bool legacy_device_plug_status;
175 		u8 dpcd_revision;
176 		u8 peer_guid[16];
177 		u8 num_sdp_streams;
178 		u8 num_sdp_stream_sinks;
179 	} ports[16];
180 };
181 
182 struct drm_dp_remote_dpcd_read_ack_reply {
183 	u8 port_number;
184 	u8 num_bytes;
185 	u8 bytes[255];
186 };
187 
188 struct drm_dp_remote_dpcd_write_ack_reply {
189 	u8 port_number;
190 };
191 
192 struct drm_dp_remote_dpcd_write_nak_reply {
193 	u8 port_number;
194 	u8 reason;
195 	u8 bytes_written_before_failure;
196 };
197 
198 struct drm_dp_remote_i2c_read_ack_reply {
199 	u8 port_number;
200 	u8 num_bytes;
201 	u8 bytes[255];
202 };
203 
204 struct drm_dp_remote_i2c_read_nak_reply {
205 	u8 port_number;
206 	u8 nak_reason;
207 	u8 i2c_nak_transaction;
208 };
209 
210 struct drm_dp_remote_i2c_write_ack_reply {
211 	u8 port_number;
212 };
213 
214 
215 struct drm_dp_sideband_msg_rx {
216 	u8 chunk[48];
217 	u8 msg[256];
218 	u8 curchunk_len;
219 	u8 curchunk_idx; /* chunk we are parsing now */
220 	u8 curchunk_hdrlen;
221 	u8 curlen; /* total length of the msg */
222 	bool have_somt;
223 	bool have_eomt;
224 	struct drm_dp_sideband_msg_hdr initial_hdr;
225 };
226 
227 #define DRM_DP_MAX_SDP_STREAMS 16
228 struct drm_dp_allocate_payload {
229 	u8 port_number;
230 	u8 number_sdp_streams;
231 	u8 vcpi;
232 	u16 pbn;
233 	u8 sdp_stream_sink[DRM_DP_MAX_SDP_STREAMS];
234 };
235 
236 struct drm_dp_allocate_payload_ack_reply {
237 	u8 port_number;
238 	u8 vcpi;
239 	u16 allocated_pbn;
240 };
241 
242 struct drm_dp_connection_status_notify {
243 	u8 guid[16];
244 	u8 port_number;
245 	bool legacy_device_plug_status;
246 	bool displayport_device_plug_status;
247 	bool message_capability_status;
248 	bool input_port;
249 	u8 peer_device_type;
250 };
251 
252 struct drm_dp_remote_dpcd_read {
253 	u8 port_number;
254 	u32 dpcd_address;
255 	u8 num_bytes;
256 };
257 
258 struct drm_dp_remote_dpcd_write {
259 	u8 port_number;
260 	u32 dpcd_address;
261 	u8 num_bytes;
262 	u8 *bytes;
263 };
264 
265 #define DP_REMOTE_I2C_READ_MAX_TRANSACTIONS 4
266 struct drm_dp_remote_i2c_read {
267 	u8 num_transactions;
268 	u8 port_number;
269 	struct {
270 		u8 i2c_dev_id;
271 		u8 num_bytes;
272 		u8 *bytes;
273 		u8 no_stop_bit;
274 		u8 i2c_transaction_delay;
275 	} transactions[DP_REMOTE_I2C_READ_MAX_TRANSACTIONS];
276 	u8 read_i2c_device_id;
277 	u8 num_bytes_read;
278 };
279 
280 struct drm_dp_remote_i2c_write {
281 	u8 port_number;
282 	u8 write_i2c_device_id;
283 	u8 num_bytes;
284 	u8 *bytes;
285 };
286 
287 /* this covers ENUM_RESOURCES, POWER_DOWN_PHY, POWER_UP_PHY */
288 struct drm_dp_port_number_req {
289 	u8 port_number;
290 };
291 
292 struct drm_dp_enum_path_resources_ack_reply {
293 	u8 port_number;
294 	u16 full_payload_bw_number;
295 	u16 avail_payload_bw_number;
296 };
297 
298 /* covers POWER_DOWN_PHY, POWER_UP_PHY */
299 struct drm_dp_port_number_rep {
300 	u8 port_number;
301 };
302 
303 struct drm_dp_query_payload {
304 	u8 port_number;
305 	u8 vcpi;
306 };
307 
308 struct drm_dp_resource_status_notify {
309 	u8 port_number;
310 	u8 guid[16];
311 	u16 available_pbn;
312 };
313 
314 struct drm_dp_query_payload_ack_reply {
315 	u8 port_number;
316 	u8 allocated_pbn;
317 };
318 
319 struct drm_dp_sideband_msg_req_body {
320 	u8 req_type;
321 	union ack_req {
322 		struct drm_dp_connection_status_notify conn_stat;
323 		struct drm_dp_port_number_req port_num;
324 		struct drm_dp_resource_status_notify resource_stat;
325 
326 		struct drm_dp_query_payload query_payload;
327 		struct drm_dp_allocate_payload allocate_payload;
328 
329 		struct drm_dp_remote_dpcd_read dpcd_read;
330 		struct drm_dp_remote_dpcd_write dpcd_write;
331 
332 		struct drm_dp_remote_i2c_read i2c_read;
333 		struct drm_dp_remote_i2c_write i2c_write;
334 	} u;
335 };
336 
337 struct drm_dp_sideband_msg_reply_body {
338 	u8 reply_type;
339 	u8 req_type;
340 	union ack_replies {
341 		struct drm_dp_nak_reply nak;
342 		struct drm_dp_link_address_ack_reply link_addr;
343 		struct drm_dp_port_number_rep port_number;
344 
345 		struct drm_dp_enum_path_resources_ack_reply path_resources;
346 		struct drm_dp_allocate_payload_ack_reply allocate_payload;
347 		struct drm_dp_query_payload_ack_reply query_payload;
348 
349 		struct drm_dp_remote_dpcd_read_ack_reply remote_dpcd_read_ack;
350 		struct drm_dp_remote_dpcd_write_ack_reply remote_dpcd_write_ack;
351 		struct drm_dp_remote_dpcd_write_nak_reply remote_dpcd_write_nack;
352 
353 		struct drm_dp_remote_i2c_read_ack_reply remote_i2c_read_ack;
354 		struct drm_dp_remote_i2c_read_nak_reply remote_i2c_read_nack;
355 		struct drm_dp_remote_i2c_write_ack_reply remote_i2c_write_ack;
356 	} u;
357 };
358 
359 /* msg is queued to be put into a slot */
360 #define DRM_DP_SIDEBAND_TX_QUEUED 0
361 /* msg has started transmitting on a slot - still on msgq */
362 #define DRM_DP_SIDEBAND_TX_START_SEND 1
363 /* msg has finished transmitting on a slot - removed from msgq only in slot */
364 #define DRM_DP_SIDEBAND_TX_SENT 2
365 /* msg has received a response - removed from slot */
366 #define DRM_DP_SIDEBAND_TX_RX 3
367 #define DRM_DP_SIDEBAND_TX_TIMEOUT 4
368 
369 struct drm_dp_sideband_msg_tx {
370 	u8 msg[256];
371 	u8 chunk[48];
372 	u8 cur_offset;
373 	u8 cur_len;
374 	struct drm_dp_mst_branch *dst;
375 	struct list_head next;
376 	int seqno;
377 	int state;
378 	bool path_msg;
379 	struct drm_dp_sideband_msg_reply_body reply;
380 };
381 
382 /* sideband msg handler */
383 struct drm_dp_mst_topology_mgr;
384 struct drm_dp_mst_topology_cbs {
385 	/* create a connector for a port */
386 	struct drm_connector *(*add_connector)(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, const char *path);
387 	void (*register_connector)(struct drm_connector *connector);
388 	void (*destroy_connector)(struct drm_dp_mst_topology_mgr *mgr,
389 				  struct drm_connector *connector);
390 	void (*hotplug)(struct drm_dp_mst_topology_mgr *mgr);
391 
392 };
393 
394 #define DP_MAX_PAYLOAD (sizeof(unsigned long) * 8)
395 
396 #define DP_PAYLOAD_LOCAL 1
397 #define DP_PAYLOAD_REMOTE 2
398 #define DP_PAYLOAD_DELETE_LOCAL 3
399 
400 struct drm_dp_payload {
401 	int payload_state;
402 	int start_slot;
403 	int num_slots;
404 	int vcpi;
405 };
406 
407 #define to_dp_mst_topology_state(x) container_of(x, struct drm_dp_mst_topology_state, base)
408 
409 struct drm_dp_mst_topology_state {
410 	struct drm_private_state base;
411 	int avail_slots;
412 	struct drm_atomic_state *state;
413 	struct drm_dp_mst_topology_mgr *mgr;
414 };
415 
416 #define to_dp_mst_topology_mgr(x) container_of(x, struct drm_dp_mst_topology_mgr, base)
417 
418 /**
419  * struct drm_dp_mst_topology_mgr - DisplayPort MST manager
420  *
421  * This struct represents the toplevel displayport MST topology manager.
422  * There should be one instance of this for every MST capable DP connector
423  * on the GPU.
424  */
425 struct drm_dp_mst_topology_mgr {
426 	/**
427 	 * @base: Base private object for atomic
428 	 */
429 	struct drm_private_obj base;
430 
431 	/**
432 	 * @dev: device pointer for adding i2c devices etc.
433 	 */
434 	struct drm_device *dev;
435 	/**
436 	 * @cbs: callbacks for connector addition and destruction.
437 	 */
438 	const struct drm_dp_mst_topology_cbs *cbs;
439 	/**
440 	 * @max_dpcd_transaction_bytes: maximum number of bytes to read/write
441 	 * in one go.
442 	 */
443 	int max_dpcd_transaction_bytes;
444 	/**
445 	 * @aux: AUX channel for the DP MST connector this topolgy mgr is
446 	 * controlling.
447 	 */
448 	struct drm_dp_aux *aux;
449 	/**
450 	 * @max_payloads: maximum number of payloads the GPU can generate.
451 	 */
452 	int max_payloads;
453 	/**
454 	 * @conn_base_id: DRM connector ID this mgr is connected to. Only used
455 	 * to build the MST connector path value.
456 	 */
457 	int conn_base_id;
458 
459 	/**
460 	 * @down_rep_recv: Message receiver state for down replies. This and
461 	 * @up_req_recv are only ever access from the work item, which is
462 	 * serialised.
463 	 */
464 	struct drm_dp_sideband_msg_rx down_rep_recv;
465 	/**
466 	 * @up_req_recv: Message receiver state for up requests. This and
467 	 * @down_rep_recv are only ever access from the work item, which is
468 	 * serialised.
469 	 */
470 	struct drm_dp_sideband_msg_rx up_req_recv;
471 
472 	/**
473 	 * @lock: protects mst state, primary, dpcd.
474 	 */
475 	struct mutex lock;
476 
477 	/**
478 	 * @mst_state: If this manager is enabled for an MST capable port. False
479 	 * if no MST sink/branch devices is connected.
480 	 */
481 	bool mst_state;
482 	/**
483 	 * @mst_primary: Pointer to the primary/first branch device.
484 	 */
485 	struct drm_dp_mst_branch *mst_primary;
486 
487 	/**
488 	 * @dpcd: Cache of DPCD for primary port.
489 	 */
490 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
491 	/**
492 	 * @sink_count: Sink count from DEVICE_SERVICE_IRQ_VECTOR_ESI0.
493 	 */
494 	u8 sink_count;
495 	/**
496 	 * @pbn_div: PBN to slots divisor.
497 	 */
498 	int pbn_div;
499 
500 	/**
501 	 * @state: State information for topology manager
502 	 */
503 	struct drm_dp_mst_topology_state *state;
504 
505 	/**
506 	 * @funcs: Atomic helper callbacks
507 	 */
508 	const struct drm_private_state_funcs *funcs;
509 
510 	/**
511 	 * @qlock: protects @tx_msg_downq, the &drm_dp_mst_branch.txslost and
512 	 * &drm_dp_sideband_msg_tx.state once they are queued
513 	 */
514 	struct mutex qlock;
515 	/**
516 	 * @tx_msg_downq: List of pending down replies.
517 	 */
518 	struct list_head tx_msg_downq;
519 
520 	/**
521 	 * @payload_lock: Protect payload information.
522 	 */
523 	struct mutex payload_lock;
524 	/**
525 	 * @proposed_vcpis: Array of pointers for the new VCPI allocation. The
526 	 * VCPI structure itself is &drm_dp_mst_port.vcpi.
527 	 */
528 	struct drm_dp_vcpi **proposed_vcpis;
529 	/**
530 	 * @payloads: Array of payloads.
531 	 */
532 	struct drm_dp_payload *payloads;
533 	/**
534 	 * @payload_mask: Elements of @payloads actually in use. Since
535 	 * reallocation of active outputs isn't possible gaps can be created by
536 	 * disabling outputs out of order compared to how they've been enabled.
537 	 */
538 	unsigned long payload_mask;
539 	/**
540 	 * @vcpi_mask: Similar to @payload_mask, but for @proposed_vcpis.
541 	 */
542 	unsigned long vcpi_mask;
543 
544 	/**
545 	 * @tx_waitq: Wait to queue stall for the tx worker.
546 	 */
547 	wait_queue_head_t tx_waitq;
548 	/**
549 	 * @work: Probe work.
550 	 */
551 	struct work_struct work;
552 	/**
553 	 * @tx_work: Sideband transmit worker. This can nest within the main
554 	 * @work worker for each transaction @work launches.
555 	 */
556 	struct work_struct tx_work;
557 
558 	/**
559 	 * @destroy_connector_list: List of to be destroyed connectors.
560 	 */
561 	struct list_head destroy_connector_list;
562 	/**
563 	 * @destroy_connector_lock: Protects @connector_list.
564 	 */
565 	struct mutex destroy_connector_lock;
566 	/**
567 	 * @destroy_connector_work: Work item to destroy connectors. Needed to
568 	 * avoid locking inversion.
569 	 */
570 	struct work_struct destroy_connector_work;
571 };
572 
573 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
574 				 struct drm_device *dev, struct drm_dp_aux *aux,
575 				 int max_dpcd_transaction_bytes,
576 				 int max_payloads, int conn_base_id);
577 
578 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr);
579 
580 
581 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state);
582 
583 
584 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled);
585 
586 
587 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
588 
589 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
590 					struct drm_dp_mst_port *port);
591 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
592 
593 
594 int drm_dp_calc_pbn_mode(int clock, int bpp);
595 
596 
597 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
598 			      struct drm_dp_mst_port *port, int pbn, int slots);
599 
600 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
601 
602 
603 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
604 
605 
606 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
607 				struct drm_dp_mst_port *port);
608 
609 
610 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
611 			   int pbn);
612 
613 
614 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr);
615 
616 
617 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr);
618 
619 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr);
620 
621 void drm_dp_mst_dump_topology(struct seq_file *m,
622 			      struct drm_dp_mst_topology_mgr *mgr);
623 
624 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr);
625 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr);
626 struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
627 								    struct drm_dp_mst_topology_mgr *mgr);
628 int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
629 				  struct drm_dp_mst_topology_mgr *mgr,
630 				  struct drm_dp_mst_port *port, int pbn);
631 int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
632 				     struct drm_dp_mst_topology_mgr *mgr,
633 				     int slots);
634 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
635 				 struct drm_dp_mst_port *port, bool power_up);
636 
637 #endif
638