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/display/drm_dp_helper.h>
27 #include <drm/drm_atomic.h>
28 
29 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
30 #include <linux/stackdepot.h>
31 #include <linux/timekeeping.h>
32 
33 enum drm_dp_mst_topology_ref_type {
34 	DRM_DP_MST_TOPOLOGY_REF_GET,
35 	DRM_DP_MST_TOPOLOGY_REF_PUT,
36 };
37 
38 struct drm_dp_mst_topology_ref_history {
39 	struct drm_dp_mst_topology_ref_entry {
40 		enum drm_dp_mst_topology_ref_type type;
41 		int count;
42 		ktime_t ts_nsec;
43 		depot_stack_handle_t backtrace;
44 	} *entries;
45 	int len;
46 };
47 #endif /* IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) */
48 
49 struct drm_dp_mst_branch;
50 
51 /**
52  * struct drm_dp_mst_port - MST port
53  * @port_num: port number
54  * @input: if this port is an input port. Protected by
55  * &drm_dp_mst_topology_mgr.base.lock.
56  * @mcs: message capability status - DP 1.2 spec. Protected by
57  * &drm_dp_mst_topology_mgr.base.lock.
58  * @ddps: DisplayPort Device Plug Status - DP 1.2. Protected by
59  * &drm_dp_mst_topology_mgr.base.lock.
60  * @pdt: Peer Device Type. Protected by
61  * &drm_dp_mst_topology_mgr.base.lock.
62  * @ldps: Legacy Device Plug Status. Protected by
63  * &drm_dp_mst_topology_mgr.base.lock.
64  * @dpcd_rev: DPCD revision of device on this port. Protected by
65  * &drm_dp_mst_topology_mgr.base.lock.
66  * @num_sdp_streams: Number of simultaneous streams. Protected by
67  * &drm_dp_mst_topology_mgr.base.lock.
68  * @num_sdp_stream_sinks: Number of stream sinks. Protected by
69  * &drm_dp_mst_topology_mgr.base.lock.
70  * @full_pbn: Max possible bandwidth for this port. Protected by
71  * &drm_dp_mst_topology_mgr.base.lock.
72  * @next: link to next port on this branch device
73  * @aux: i2c aux transport to talk to device connected to this port, protected
74  * by &drm_dp_mst_topology_mgr.base.lock.
75  * @passthrough_aux: parent aux to which DSC pass-through requests should be
76  * sent, only set if DSC pass-through is possible.
77  * @parent: branch device parent of this port
78  * @vcpi: Virtual Channel Payload info for this port.
79  * @connector: DRM connector this port is connected to. Protected by
80  * &drm_dp_mst_topology_mgr.base.lock.
81  * @mgr: topology manager this port lives under.
82  *
83  * This structure represents an MST port endpoint on a device somewhere
84  * in the MST topology.
85  */
86 struct drm_dp_mst_port {
87 	/**
88 	 * @topology_kref: refcount for this port's lifetime in the topology,
89 	 * only the DP MST helpers should need to touch this
90 	 */
91 	struct kref topology_kref;
92 
93 	/**
94 	 * @malloc_kref: refcount for the memory allocation containing this
95 	 * structure. See drm_dp_mst_get_port_malloc() and
96 	 * drm_dp_mst_put_port_malloc().
97 	 */
98 	struct kref malloc_kref;
99 
100 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
101 	/**
102 	 * @topology_ref_history: A history of each topology
103 	 * reference/dereference. See CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS.
104 	 */
105 	struct drm_dp_mst_topology_ref_history topology_ref_history;
106 #endif
107 
108 	u8 port_num;
109 	bool input;
110 	bool mcs;
111 	bool ddps;
112 	u8 pdt;
113 	bool ldps;
114 	u8 dpcd_rev;
115 	u8 num_sdp_streams;
116 	u8 num_sdp_stream_sinks;
117 	uint16_t full_pbn;
118 	struct list_head next;
119 	/**
120 	 * @mstb: the branch device connected to this port, if there is one.
121 	 * This should be considered protected for reading by
122 	 * &drm_dp_mst_topology_mgr.lock. There are two exceptions to this:
123 	 * &drm_dp_mst_topology_mgr.up_req_work and
124 	 * &drm_dp_mst_topology_mgr.work, which do not grab
125 	 * &drm_dp_mst_topology_mgr.lock during reads but are the only
126 	 * updaters of this list and are protected from writing concurrently
127 	 * by &drm_dp_mst_topology_mgr.probe_lock.
128 	 */
129 	struct drm_dp_mst_branch *mstb;
130 	struct drm_dp_aux aux; /* i2c bus for this port? */
131 	struct drm_dp_aux *passthrough_aux;
132 	struct drm_dp_mst_branch *parent;
133 
134 	struct drm_connector *connector;
135 	struct drm_dp_mst_topology_mgr *mgr;
136 
137 	/**
138 	 * @cached_edid: for DP logical ports - make tiling work by ensuring
139 	 * that the EDID for all connectors is read immediately.
140 	 */
141 	struct edid *cached_edid;
142 	/**
143 	 * @has_audio: Tracks whether the sink connector to this port is
144 	 * audio-capable.
145 	 */
146 	bool has_audio;
147 
148 	/**
149 	 * @fec_capable: bool indicating if FEC can be supported up to that
150 	 * point in the MST topology.
151 	 */
152 	bool fec_capable;
153 };
154 
155 /* sideband msg header - not bit struct */
156 struct drm_dp_sideband_msg_hdr {
157 	u8 lct;
158 	u8 lcr;
159 	u8 rad[8];
160 	bool broadcast;
161 	bool path_msg;
162 	u8 msg_len;
163 	bool somt;
164 	bool eomt;
165 	bool seqno;
166 };
167 
168 struct drm_dp_sideband_msg_rx {
169 	u8 chunk[48];
170 	u8 msg[256];
171 	u8 curchunk_len;
172 	u8 curchunk_idx; /* chunk we are parsing now */
173 	u8 curchunk_hdrlen;
174 	u8 curlen; /* total length of the msg */
175 	bool have_somt;
176 	bool have_eomt;
177 	struct drm_dp_sideband_msg_hdr initial_hdr;
178 };
179 
180 /**
181  * struct drm_dp_mst_branch - MST branch device.
182  * @rad: Relative Address to talk to this branch device.
183  * @lct: Link count total to talk to this branch device.
184  * @num_ports: number of ports on the branch.
185  * @port_parent: pointer to the port parent, NULL if toplevel.
186  * @mgr: topology manager for this branch device.
187  * @link_address_sent: if a link address message has been sent to this device yet.
188  * @guid: guid for DP 1.2 branch device. port under this branch can be
189  * identified by port #.
190  *
191  * This structure represents an MST branch device, there is one
192  * primary branch device at the root, along with any other branches connected
193  * to downstream port of parent branches.
194  */
195 struct drm_dp_mst_branch {
196 	/**
197 	 * @topology_kref: refcount for this branch device's lifetime in the
198 	 * topology, only the DP MST helpers should need to touch this
199 	 */
200 	struct kref topology_kref;
201 
202 	/**
203 	 * @malloc_kref: refcount for the memory allocation containing this
204 	 * structure. See drm_dp_mst_get_mstb_malloc() and
205 	 * drm_dp_mst_put_mstb_malloc().
206 	 */
207 	struct kref malloc_kref;
208 
209 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
210 	/**
211 	 * @topology_ref_history: A history of each topology
212 	 * reference/dereference. See CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS.
213 	 */
214 	struct drm_dp_mst_topology_ref_history topology_ref_history;
215 #endif
216 
217 	/**
218 	 * @destroy_next: linked-list entry used by
219 	 * drm_dp_delayed_destroy_work()
220 	 */
221 	struct list_head destroy_next;
222 
223 	u8 rad[8];
224 	u8 lct;
225 	int num_ports;
226 
227 	/**
228 	 * @ports: the list of ports on this branch device. This should be
229 	 * considered protected for reading by &drm_dp_mst_topology_mgr.lock.
230 	 * There are two exceptions to this:
231 	 * &drm_dp_mst_topology_mgr.up_req_work and
232 	 * &drm_dp_mst_topology_mgr.work, which do not grab
233 	 * &drm_dp_mst_topology_mgr.lock during reads but are the only
234 	 * updaters of this list and are protected from updating the list
235 	 * concurrently by @drm_dp_mst_topology_mgr.probe_lock
236 	 */
237 	struct list_head ports;
238 
239 	struct drm_dp_mst_port *port_parent;
240 	struct drm_dp_mst_topology_mgr *mgr;
241 
242 	bool link_address_sent;
243 
244 	/* global unique identifier to identify branch devices */
245 	u8 guid[16];
246 };
247 
248 
249 struct drm_dp_nak_reply {
250 	u8 guid[16];
251 	u8 reason;
252 	u8 nak_data;
253 };
254 
255 struct drm_dp_link_address_ack_reply {
256 	u8 guid[16];
257 	u8 nports;
258 	struct drm_dp_link_addr_reply_port {
259 		bool input_port;
260 		u8 peer_device_type;
261 		u8 port_number;
262 		bool mcs;
263 		bool ddps;
264 		bool legacy_device_plug_status;
265 		u8 dpcd_revision;
266 		u8 peer_guid[16];
267 		u8 num_sdp_streams;
268 		u8 num_sdp_stream_sinks;
269 	} ports[16];
270 };
271 
272 struct drm_dp_remote_dpcd_read_ack_reply {
273 	u8 port_number;
274 	u8 num_bytes;
275 	u8 bytes[255];
276 };
277 
278 struct drm_dp_remote_dpcd_write_ack_reply {
279 	u8 port_number;
280 };
281 
282 struct drm_dp_remote_dpcd_write_nak_reply {
283 	u8 port_number;
284 	u8 reason;
285 	u8 bytes_written_before_failure;
286 };
287 
288 struct drm_dp_remote_i2c_read_ack_reply {
289 	u8 port_number;
290 	u8 num_bytes;
291 	u8 bytes[255];
292 };
293 
294 struct drm_dp_remote_i2c_read_nak_reply {
295 	u8 port_number;
296 	u8 nak_reason;
297 	u8 i2c_nak_transaction;
298 };
299 
300 struct drm_dp_remote_i2c_write_ack_reply {
301 	u8 port_number;
302 };
303 
304 struct drm_dp_query_stream_enc_status_ack_reply {
305 	/* Bit[23:16]- Stream Id */
306 	u8 stream_id;
307 
308 	/* Bit[15]- Signed */
309 	bool reply_signed;
310 
311 	/* Bit[10:8]- Stream Output Sink Type */
312 	bool unauthorizable_device_present;
313 	bool legacy_device_present;
314 	bool query_capable_device_present;
315 
316 	/* Bit[12:11]- Stream Output CP Type */
317 	bool hdcp_1x_device_present;
318 	bool hdcp_2x_device_present;
319 
320 	/* Bit[4]- Stream Authentication */
321 	bool auth_completed;
322 
323 	/* Bit[3]- Stream Encryption */
324 	bool encryption_enabled;
325 
326 	/* Bit[2]- Stream Repeater Function Present */
327 	bool repeater_present;
328 
329 	/* Bit[1:0]- Stream State */
330 	u8 state;
331 };
332 
333 #define DRM_DP_MAX_SDP_STREAMS 16
334 struct drm_dp_allocate_payload {
335 	u8 port_number;
336 	u8 number_sdp_streams;
337 	u8 vcpi;
338 	u16 pbn;
339 	u8 sdp_stream_sink[DRM_DP_MAX_SDP_STREAMS];
340 };
341 
342 struct drm_dp_allocate_payload_ack_reply {
343 	u8 port_number;
344 	u8 vcpi;
345 	u16 allocated_pbn;
346 };
347 
348 struct drm_dp_connection_status_notify {
349 	u8 guid[16];
350 	u8 port_number;
351 	bool legacy_device_plug_status;
352 	bool displayport_device_plug_status;
353 	bool message_capability_status;
354 	bool input_port;
355 	u8 peer_device_type;
356 };
357 
358 struct drm_dp_remote_dpcd_read {
359 	u8 port_number;
360 	u32 dpcd_address;
361 	u8 num_bytes;
362 };
363 
364 struct drm_dp_remote_dpcd_write {
365 	u8 port_number;
366 	u32 dpcd_address;
367 	u8 num_bytes;
368 	u8 *bytes;
369 };
370 
371 #define DP_REMOTE_I2C_READ_MAX_TRANSACTIONS 4
372 struct drm_dp_remote_i2c_read {
373 	u8 num_transactions;
374 	u8 port_number;
375 	struct drm_dp_remote_i2c_read_tx {
376 		u8 i2c_dev_id;
377 		u8 num_bytes;
378 		u8 *bytes;
379 		u8 no_stop_bit;
380 		u8 i2c_transaction_delay;
381 	} transactions[DP_REMOTE_I2C_READ_MAX_TRANSACTIONS];
382 	u8 read_i2c_device_id;
383 	u8 num_bytes_read;
384 };
385 
386 struct drm_dp_remote_i2c_write {
387 	u8 port_number;
388 	u8 write_i2c_device_id;
389 	u8 num_bytes;
390 	u8 *bytes;
391 };
392 
393 struct drm_dp_query_stream_enc_status {
394 	u8 stream_id;
395 	u8 client_id[7];	/* 56-bit nonce */
396 	u8 stream_event;
397 	bool valid_stream_event;
398 	u8 stream_behavior;
399 	u8 valid_stream_behavior;
400 };
401 
402 /* this covers ENUM_RESOURCES, POWER_DOWN_PHY, POWER_UP_PHY */
403 struct drm_dp_port_number_req {
404 	u8 port_number;
405 };
406 
407 struct drm_dp_enum_path_resources_ack_reply {
408 	u8 port_number;
409 	bool fec_capable;
410 	u16 full_payload_bw_number;
411 	u16 avail_payload_bw_number;
412 };
413 
414 /* covers POWER_DOWN_PHY, POWER_UP_PHY */
415 struct drm_dp_port_number_rep {
416 	u8 port_number;
417 };
418 
419 struct drm_dp_query_payload {
420 	u8 port_number;
421 	u8 vcpi;
422 };
423 
424 struct drm_dp_resource_status_notify {
425 	u8 port_number;
426 	u8 guid[16];
427 	u16 available_pbn;
428 };
429 
430 struct drm_dp_query_payload_ack_reply {
431 	u8 port_number;
432 	u16 allocated_pbn;
433 };
434 
435 struct drm_dp_sideband_msg_req_body {
436 	u8 req_type;
437 	union ack_req {
438 		struct drm_dp_connection_status_notify conn_stat;
439 		struct drm_dp_port_number_req port_num;
440 		struct drm_dp_resource_status_notify resource_stat;
441 
442 		struct drm_dp_query_payload query_payload;
443 		struct drm_dp_allocate_payload allocate_payload;
444 
445 		struct drm_dp_remote_dpcd_read dpcd_read;
446 		struct drm_dp_remote_dpcd_write dpcd_write;
447 
448 		struct drm_dp_remote_i2c_read i2c_read;
449 		struct drm_dp_remote_i2c_write i2c_write;
450 
451 		struct drm_dp_query_stream_enc_status enc_status;
452 	} u;
453 };
454 
455 struct drm_dp_sideband_msg_reply_body {
456 	u8 reply_type;
457 	u8 req_type;
458 	union ack_replies {
459 		struct drm_dp_nak_reply nak;
460 		struct drm_dp_link_address_ack_reply link_addr;
461 		struct drm_dp_port_number_rep port_number;
462 
463 		struct drm_dp_enum_path_resources_ack_reply path_resources;
464 		struct drm_dp_allocate_payload_ack_reply allocate_payload;
465 		struct drm_dp_query_payload_ack_reply query_payload;
466 
467 		struct drm_dp_remote_dpcd_read_ack_reply remote_dpcd_read_ack;
468 		struct drm_dp_remote_dpcd_write_ack_reply remote_dpcd_write_ack;
469 		struct drm_dp_remote_dpcd_write_nak_reply remote_dpcd_write_nack;
470 
471 		struct drm_dp_remote_i2c_read_ack_reply remote_i2c_read_ack;
472 		struct drm_dp_remote_i2c_read_nak_reply remote_i2c_read_nack;
473 		struct drm_dp_remote_i2c_write_ack_reply remote_i2c_write_ack;
474 
475 		struct drm_dp_query_stream_enc_status_ack_reply enc_status;
476 	} u;
477 };
478 
479 /* msg is queued to be put into a slot */
480 #define DRM_DP_SIDEBAND_TX_QUEUED 0
481 /* msg has started transmitting on a slot - still on msgq */
482 #define DRM_DP_SIDEBAND_TX_START_SEND 1
483 /* msg has finished transmitting on a slot - removed from msgq only in slot */
484 #define DRM_DP_SIDEBAND_TX_SENT 2
485 /* msg has received a response - removed from slot */
486 #define DRM_DP_SIDEBAND_TX_RX 3
487 #define DRM_DP_SIDEBAND_TX_TIMEOUT 4
488 
489 struct drm_dp_sideband_msg_tx {
490 	u8 msg[256];
491 	u8 chunk[48];
492 	u8 cur_offset;
493 	u8 cur_len;
494 	struct drm_dp_mst_branch *dst;
495 	struct list_head next;
496 	int seqno;
497 	int state;
498 	bool path_msg;
499 	struct drm_dp_sideband_msg_reply_body reply;
500 };
501 
502 /* sideband msg handler */
503 struct drm_dp_mst_topology_mgr;
504 struct drm_dp_mst_topology_cbs {
505 	/* create a connector for a port */
506 	struct drm_connector *(*add_connector)(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, const char *path);
507 	/*
508 	 * Checks for any pending MST interrupts, passing them to MST core for
509 	 * processing, the same way an HPD IRQ pulse handler would do this.
510 	 * If provided MST core calls this callback from a poll-waiting loop
511 	 * when waiting for MST down message replies. The driver is expected
512 	 * to guard against a race between this callback and the driver's HPD
513 	 * IRQ pulse handler.
514 	 */
515 	void (*poll_hpd_irq)(struct drm_dp_mst_topology_mgr *mgr);
516 };
517 
518 #define to_dp_mst_topology_state(x) container_of(x, struct drm_dp_mst_topology_state, base)
519 
520 /**
521  * struct drm_dp_mst_atomic_payload - Atomic state struct for an MST payload
522  *
523  * The primary atomic state structure for a given MST payload. Stores information like current
524  * bandwidth allocation, intended action for this payload, etc.
525  */
526 struct drm_dp_mst_atomic_payload {
527 	/** @port: The MST port assigned to this payload */
528 	struct drm_dp_mst_port *port;
529 
530 	/**
531 	 * @vc_start_slot: The time slot that this payload starts on. Because payload start slots
532 	 * can't be determined ahead of time, the contents of this value are UNDEFINED at atomic
533 	 * check time. This shouldn't usually matter, as the start slot should never be relevant for
534 	 * atomic state computations.
535 	 *
536 	 * Since this value is determined at commit time instead of check time, this value is
537 	 * protected by the MST helpers ensuring that async commits operating on the given topology
538 	 * never run in parallel. In the event that a driver does need to read this value (e.g. to
539 	 * inform hardware of the starting timeslot for a payload), the driver may either:
540 	 *
541 	 * * Read this field during the atomic commit after
542 	 *   drm_dp_mst_atomic_wait_for_dependencies() has been called, which will ensure the
543 	 *   previous MST states payload start slots have been copied over to the new state. Note
544 	 *   that a new start slot won't be assigned/removed from this payload until
545 	 *   drm_dp_add_payload_part1()/drm_dp_remove_payload() have been called.
546 	 * * Acquire the MST modesetting lock, and then wait for any pending MST-related commits to
547 	 *   get committed to hardware by calling drm_crtc_commit_wait() on each of the
548 	 *   &drm_crtc_commit structs in &drm_dp_mst_topology_state.commit_deps.
549 	 *
550 	 * If neither of the two above solutions suffice (e.g. the driver needs to read the start
551 	 * slot in the middle of an atomic commit without waiting for some reason), then drivers
552 	 * should cache this value themselves after changing payloads.
553 	 */
554 	s8 vc_start_slot;
555 
556 	/** @vcpi: The Virtual Channel Payload Identifier */
557 	u8 vcpi;
558 	/**
559 	 * @time_slots:
560 	 * The number of timeslots allocated to this payload from the source DP Tx to
561 	 * the immediate downstream DP Rx
562 	 */
563 	int time_slots;
564 	/** @pbn: The payload bandwidth for this payload */
565 	int pbn;
566 
567 	/** @delete: Whether or not we intend to delete this payload during this atomic commit */
568 	bool delete : 1;
569 	/** @dsc_enabled: Whether or not this payload has DSC enabled */
570 	bool dsc_enabled : 1;
571 
572 	/** @next: The list node for this payload */
573 	struct list_head next;
574 };
575 
576 /**
577  * struct drm_dp_mst_topology_state - DisplayPort MST topology atomic state
578  *
579  * This struct represents the atomic state of the toplevel DisplayPort MST manager
580  */
581 struct drm_dp_mst_topology_state {
582 	/** @base: Base private state for atomic */
583 	struct drm_private_state base;
584 
585 	/** @mgr: The topology manager */
586 	struct drm_dp_mst_topology_mgr *mgr;
587 
588 	/**
589 	 * @pending_crtc_mask: A bitmask of all CRTCs this topology state touches, drivers may
590 	 * modify this to add additional dependencies if needed.
591 	 */
592 	u32 pending_crtc_mask;
593 	/**
594 	 * @commit_deps: A list of all CRTC commits affecting this topology, this field isn't
595 	 * populated until drm_dp_mst_atomic_wait_for_dependencies() is called.
596 	 */
597 	struct drm_crtc_commit **commit_deps;
598 	/** @num_commit_deps: The number of CRTC commits in @commit_deps */
599 	size_t num_commit_deps;
600 
601 	/** @payload_mask: A bitmask of allocated VCPIs, used for VCPI assignments */
602 	u32 payload_mask;
603 	/** @payloads: The list of payloads being created/destroyed in this state */
604 	struct list_head payloads;
605 
606 	/** @total_avail_slots: The total number of slots this topology can handle (63 or 64) */
607 	u8 total_avail_slots;
608 	/** @start_slot: The first usable time slot in this topology (1 or 0) */
609 	u8 start_slot;
610 
611 	/**
612 	 * @pbn_div: The current PBN divisor for this topology. The driver is expected to fill this
613 	 * out itself.
614 	 */
615 	int pbn_div;
616 };
617 
618 #define to_dp_mst_topology_mgr(x) container_of(x, struct drm_dp_mst_topology_mgr, base)
619 
620 /**
621  * struct drm_dp_mst_topology_mgr - DisplayPort MST manager
622  *
623  * This struct represents the toplevel displayport MST topology manager.
624  * There should be one instance of this for every MST capable DP connector
625  * on the GPU.
626  */
627 struct drm_dp_mst_topology_mgr {
628 	/**
629 	 * @base: Base private object for atomic
630 	 */
631 	struct drm_private_obj base;
632 
633 	/**
634 	 * @dev: device pointer for adding i2c devices etc.
635 	 */
636 	struct drm_device *dev;
637 	/**
638 	 * @cbs: callbacks for connector addition and destruction.
639 	 */
640 	const struct drm_dp_mst_topology_cbs *cbs;
641 	/**
642 	 * @max_dpcd_transaction_bytes: maximum number of bytes to read/write
643 	 * in one go.
644 	 */
645 	int max_dpcd_transaction_bytes;
646 	/**
647 	 * @aux: AUX channel for the DP MST connector this topolgy mgr is
648 	 * controlling.
649 	 */
650 	struct drm_dp_aux *aux;
651 	/**
652 	 * @max_payloads: maximum number of payloads the GPU can generate.
653 	 */
654 	int max_payloads;
655 	/**
656 	 * @conn_base_id: DRM connector ID this mgr is connected to. Only used
657 	 * to build the MST connector path value.
658 	 */
659 	int conn_base_id;
660 
661 	/**
662 	 * @up_req_recv: Message receiver state for up requests.
663 	 */
664 	struct drm_dp_sideband_msg_rx up_req_recv;
665 
666 	/**
667 	 * @down_rep_recv: Message receiver state for replies to down
668 	 * requests.
669 	 */
670 	struct drm_dp_sideband_msg_rx down_rep_recv;
671 
672 	/**
673 	 * @lock: protects @mst_state, @mst_primary, @dpcd, and
674 	 * @payload_id_table_cleared.
675 	 */
676 	struct mutex lock;
677 
678 	/**
679 	 * @probe_lock: Prevents @work and @up_req_work, the only writers of
680 	 * &drm_dp_mst_port.mstb and &drm_dp_mst_branch.ports, from racing
681 	 * while they update the topology.
682 	 */
683 	struct mutex probe_lock;
684 
685 	/**
686 	 * @mst_state: If this manager is enabled for an MST capable port. False
687 	 * if no MST sink/branch devices is connected.
688 	 */
689 	bool mst_state : 1;
690 
691 	/**
692 	 * @payload_id_table_cleared: Whether or not we've cleared the payload
693 	 * ID table for @mst_primary. Protected by @lock.
694 	 */
695 	bool payload_id_table_cleared : 1;
696 
697 	/**
698 	 * @payload_count: The number of currently active payloads in hardware. This value is only
699 	 * intended to be used internally by MST helpers for payload tracking, and is only safe to
700 	 * read/write from the atomic commit (not check) context.
701 	 */
702 	u8 payload_count;
703 
704 	/**
705 	 * @next_start_slot: The starting timeslot to use for new VC payloads. This value is used
706 	 * internally by MST helpers for payload tracking, and is only safe to read/write from the
707 	 * atomic commit (not check) context.
708 	 */
709 	u8 next_start_slot;
710 
711 	/**
712 	 * @mst_primary: Pointer to the primary/first branch device.
713 	 */
714 	struct drm_dp_mst_branch *mst_primary;
715 
716 	/**
717 	 * @dpcd: Cache of DPCD for primary port.
718 	 */
719 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
720 	/**
721 	 * @sink_count: Sink count from DEVICE_SERVICE_IRQ_VECTOR_ESI0.
722 	 */
723 	u8 sink_count;
724 
725 	/**
726 	 * @funcs: Atomic helper callbacks
727 	 */
728 	const struct drm_private_state_funcs *funcs;
729 
730 	/**
731 	 * @qlock: protects @tx_msg_downq and &drm_dp_sideband_msg_tx.state
732 	 */
733 	struct mutex qlock;
734 
735 	/**
736 	 * @tx_msg_downq: List of pending down requests
737 	 */
738 	struct list_head tx_msg_downq;
739 
740 	/**
741 	 * @tx_waitq: Wait to queue stall for the tx worker.
742 	 */
743 	wait_queue_head_t tx_waitq;
744 	/**
745 	 * @work: Probe work.
746 	 */
747 	struct work_struct work;
748 	/**
749 	 * @tx_work: Sideband transmit worker. This can nest within the main
750 	 * @work worker for each transaction @work launches.
751 	 */
752 	struct work_struct tx_work;
753 
754 	/**
755 	 * @destroy_port_list: List of to be destroyed connectors.
756 	 */
757 	struct list_head destroy_port_list;
758 	/**
759 	 * @destroy_branch_device_list: List of to be destroyed branch
760 	 * devices.
761 	 */
762 	struct list_head destroy_branch_device_list;
763 	/**
764 	 * @delayed_destroy_lock: Protects @destroy_port_list and
765 	 * @destroy_branch_device_list.
766 	 */
767 	struct mutex delayed_destroy_lock;
768 
769 	/**
770 	 * @delayed_destroy_wq: Workqueue used for delayed_destroy_work items.
771 	 * A dedicated WQ makes it possible to drain any requeued work items
772 	 * on it.
773 	 */
774 	struct workqueue_struct *delayed_destroy_wq;
775 
776 	/**
777 	 * @delayed_destroy_work: Work item to destroy MST port and branch
778 	 * devices, needed to avoid locking inversion.
779 	 */
780 	struct work_struct delayed_destroy_work;
781 
782 	/**
783 	 * @up_req_list: List of pending up requests from the topology that
784 	 * need to be processed, in chronological order.
785 	 */
786 	struct list_head up_req_list;
787 	/**
788 	 * @up_req_lock: Protects @up_req_list
789 	 */
790 	struct mutex up_req_lock;
791 	/**
792 	 * @up_req_work: Work item to process up requests received from the
793 	 * topology. Needed to avoid blocking hotplug handling and sideband
794 	 * transmissions.
795 	 */
796 	struct work_struct up_req_work;
797 
798 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
799 	/**
800 	 * @topology_ref_history_lock: protects
801 	 * &drm_dp_mst_port.topology_ref_history and
802 	 * &drm_dp_mst_branch.topology_ref_history.
803 	 */
804 	struct mutex topology_ref_history_lock;
805 #endif
806 };
807 
808 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
809 				 struct drm_device *dev, struct drm_dp_aux *aux,
810 				 int max_dpcd_transaction_bytes,
811 				 int max_payloads, int conn_base_id);
812 
813 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr);
814 
815 bool drm_dp_read_mst_cap(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
816 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state);
817 
818 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled);
819 
820 
821 int
822 drm_dp_mst_detect_port(struct drm_connector *connector,
823 		       struct drm_modeset_acquire_ctx *ctx,
824 		       struct drm_dp_mst_topology_mgr *mgr,
825 		       struct drm_dp_mst_port *port);
826 
827 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
828 
829 int drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr,
830 			     int link_rate, int link_lane_count);
831 
832 int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc);
833 
834 void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap);
835 
836 int drm_dp_add_payload_part1(struct drm_dp_mst_topology_mgr *mgr,
837 			     struct drm_dp_mst_topology_state *mst_state,
838 			     struct drm_dp_mst_atomic_payload *payload);
839 int drm_dp_add_payload_part2(struct drm_dp_mst_topology_mgr *mgr,
840 			     struct drm_atomic_state *state,
841 			     struct drm_dp_mst_atomic_payload *payload);
842 void drm_dp_remove_payload(struct drm_dp_mst_topology_mgr *mgr,
843 			   struct drm_dp_mst_topology_state *mst_state,
844 			   const struct drm_dp_mst_atomic_payload *old_payload,
845 			   struct drm_dp_mst_atomic_payload *new_payload);
846 
847 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr);
848 
849 void drm_dp_mst_dump_topology(struct seq_file *m,
850 			      struct drm_dp_mst_topology_mgr *mgr);
851 
852 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr);
853 int __must_check
854 drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
855 			       bool sync);
856 
857 ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
858 			     unsigned int offset, void *buffer, size_t size);
859 ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
860 			      unsigned int offset, void *buffer, size_t size);
861 
862 int drm_dp_mst_connector_late_register(struct drm_connector *connector,
863 				       struct drm_dp_mst_port *port);
864 void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
865 					   struct drm_dp_mst_port *port);
866 
867 struct drm_dp_mst_topology_state *
868 drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
869 				  struct drm_dp_mst_topology_mgr *mgr);
870 struct drm_dp_mst_topology_state *
871 drm_atomic_get_old_mst_topology_state(struct drm_atomic_state *state,
872 				      struct drm_dp_mst_topology_mgr *mgr);
873 struct drm_dp_mst_topology_state *
874 drm_atomic_get_new_mst_topology_state(struct drm_atomic_state *state,
875 				      struct drm_dp_mst_topology_mgr *mgr);
876 struct drm_dp_mst_atomic_payload *
877 drm_atomic_get_mst_payload_state(struct drm_dp_mst_topology_state *state,
878 				 struct drm_dp_mst_port *port);
879 int __must_check
880 drm_dp_atomic_find_time_slots(struct drm_atomic_state *state,
881 			      struct drm_dp_mst_topology_mgr *mgr,
882 			      struct drm_dp_mst_port *port, int pbn);
883 int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
884 				 struct drm_dp_mst_port *port,
885 				 int pbn, bool enable);
886 int __must_check
887 drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state,
888 				  struct drm_dp_mst_topology_mgr *mgr);
889 int __must_check
890 drm_dp_atomic_release_time_slots(struct drm_atomic_state *state,
891 				 struct drm_dp_mst_topology_mgr *mgr,
892 				 struct drm_dp_mst_port *port);
893 void drm_dp_mst_atomic_wait_for_dependencies(struct drm_atomic_state *state);
894 int __must_check drm_dp_mst_atomic_setup_commit(struct drm_atomic_state *state);
895 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
896 				 struct drm_dp_mst_port *port, bool power_up);
897 int drm_dp_send_query_stream_enc_status(struct drm_dp_mst_topology_mgr *mgr,
898 		struct drm_dp_mst_port *port,
899 		struct drm_dp_query_stream_enc_status_ack_reply *status);
900 int __must_check drm_dp_mst_atomic_check(struct drm_atomic_state *state);
901 int __must_check drm_dp_mst_root_conn_atomic_check(struct drm_connector_state *new_conn_state,
902 						   struct drm_dp_mst_topology_mgr *mgr);
903 
904 void drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port);
905 void drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port);
906 
907 struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port);
908 
909 static inline struct drm_dp_mst_topology_state *
910 to_drm_dp_mst_topology_state(struct drm_private_state *state)
911 {
912 	return container_of(state, struct drm_dp_mst_topology_state, base);
913 }
914 
915 extern const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs;
916 
917 /**
918  * __drm_dp_mst_state_iter_get - private atomic state iterator function for
919  * macro-internal use
920  * @state: &struct drm_atomic_state pointer
921  * @mgr: pointer to the &struct drm_dp_mst_topology_mgr iteration cursor
922  * @old_state: optional pointer to the old &struct drm_dp_mst_topology_state
923  * iteration cursor
924  * @new_state: optional pointer to the new &struct drm_dp_mst_topology_state
925  * iteration cursor
926  * @i: int iteration cursor, for macro-internal use
927  *
928  * Used by for_each_oldnew_mst_mgr_in_state(),
929  * for_each_old_mst_mgr_in_state(), and for_each_new_mst_mgr_in_state(). Don't
930  * call this directly.
931  *
932  * Returns:
933  * True if the current &struct drm_private_obj is a &struct
934  * drm_dp_mst_topology_mgr, false otherwise.
935  */
936 static inline bool
937 __drm_dp_mst_state_iter_get(struct drm_atomic_state *state,
938 			    struct drm_dp_mst_topology_mgr **mgr,
939 			    struct drm_dp_mst_topology_state **old_state,
940 			    struct drm_dp_mst_topology_state **new_state,
941 			    int i)
942 {
943 	struct __drm_private_objs_state *objs_state = &state->private_objs[i];
944 
945 	if (objs_state->ptr->funcs != &drm_dp_mst_topology_state_funcs)
946 		return false;
947 
948 	*mgr = to_dp_mst_topology_mgr(objs_state->ptr);
949 	if (old_state)
950 		*old_state = to_dp_mst_topology_state(objs_state->old_state);
951 	if (new_state)
952 		*new_state = to_dp_mst_topology_state(objs_state->new_state);
953 
954 	return true;
955 }
956 
957 /**
958  * for_each_oldnew_mst_mgr_in_state - iterate over all DP MST topology
959  * managers in an atomic update
960  * @__state: &struct drm_atomic_state pointer
961  * @mgr: &struct drm_dp_mst_topology_mgr iteration cursor
962  * @old_state: &struct drm_dp_mst_topology_state iteration cursor for the old
963  * state
964  * @new_state: &struct drm_dp_mst_topology_state iteration cursor for the new
965  * state
966  * @__i: int iteration cursor, for macro-internal use
967  *
968  * This iterates over all DRM DP MST topology managers in an atomic update,
969  * tracking both old and new state. This is useful in places where the state
970  * delta needs to be considered, for example in atomic check functions.
971  */
972 #define for_each_oldnew_mst_mgr_in_state(__state, mgr, old_state, new_state, __i) \
973 	for ((__i) = 0; (__i) < (__state)->num_private_objs; (__i)++) \
974 		for_each_if(__drm_dp_mst_state_iter_get((__state), &(mgr), &(old_state), &(new_state), (__i)))
975 
976 /**
977  * for_each_old_mst_mgr_in_state - iterate over all DP MST topology managers
978  * in an atomic update
979  * @__state: &struct drm_atomic_state pointer
980  * @mgr: &struct drm_dp_mst_topology_mgr iteration cursor
981  * @old_state: &struct drm_dp_mst_topology_state iteration cursor for the old
982  * state
983  * @__i: int iteration cursor, for macro-internal use
984  *
985  * This iterates over all DRM DP MST topology managers in an atomic update,
986  * tracking only the old state. This is useful in disable functions, where we
987  * need the old state the hardware is still in.
988  */
989 #define for_each_old_mst_mgr_in_state(__state, mgr, old_state, __i) \
990 	for ((__i) = 0; (__i) < (__state)->num_private_objs; (__i)++) \
991 		for_each_if(__drm_dp_mst_state_iter_get((__state), &(mgr), &(old_state), NULL, (__i)))
992 
993 /**
994  * for_each_new_mst_mgr_in_state - iterate over all DP MST topology managers
995  * in an atomic update
996  * @__state: &struct drm_atomic_state pointer
997  * @mgr: &struct drm_dp_mst_topology_mgr iteration cursor
998  * @new_state: &struct drm_dp_mst_topology_state iteration cursor for the new
999  * state
1000  * @__i: int iteration cursor, for macro-internal use
1001  *
1002  * This iterates over all DRM DP MST topology managers in an atomic update,
1003  * tracking only the new state. This is useful in enable functions, where we
1004  * need the new state the hardware should be in when the atomic commit
1005  * operation has completed.
1006  */
1007 #define for_each_new_mst_mgr_in_state(__state, mgr, new_state, __i) \
1008 	for ((__i) = 0; (__i) < (__state)->num_private_objs; (__i)++) \
1009 		for_each_if(__drm_dp_mst_state_iter_get((__state), &(mgr), NULL, &(new_state), (__i)))
1010 
1011 #endif
1012