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 	const struct drm_edid *cached_edid;
142 
143 	/**
144 	 * @fec_capable: bool indicating if FEC can be supported up to that
145 	 * point in the MST topology.
146 	 */
147 	bool fec_capable;
148 };
149 
150 /* sideband msg header - not bit struct */
151 struct drm_dp_sideband_msg_hdr {
152 	u8 lct;
153 	u8 lcr;
154 	u8 rad[8];
155 	bool broadcast;
156 	bool path_msg;
157 	u8 msg_len;
158 	bool somt;
159 	bool eomt;
160 	bool seqno;
161 };
162 
163 struct drm_dp_sideband_msg_rx {
164 	u8 chunk[48];
165 	u8 msg[256];
166 	u8 curchunk_len;
167 	u8 curchunk_idx; /* chunk we are parsing now */
168 	u8 curchunk_hdrlen;
169 	u8 curlen; /* total length of the msg */
170 	bool have_somt;
171 	bool have_eomt;
172 	struct drm_dp_sideband_msg_hdr initial_hdr;
173 };
174 
175 /**
176  * struct drm_dp_mst_branch - MST branch device.
177  * @rad: Relative Address to talk to this branch device.
178  * @lct: Link count total to talk to this branch device.
179  * @num_ports: number of ports on the branch.
180  * @port_parent: pointer to the port parent, NULL if toplevel.
181  * @mgr: topology manager for this branch device.
182  * @link_address_sent: if a link address message has been sent to this device yet.
183  * @guid: guid for DP 1.2 branch device. port under this branch can be
184  * identified by port #.
185  *
186  * This structure represents an MST branch device, there is one
187  * primary branch device at the root, along with any other branches connected
188  * to downstream port of parent branches.
189  */
190 struct drm_dp_mst_branch {
191 	/**
192 	 * @topology_kref: refcount for this branch device's lifetime in the
193 	 * topology, only the DP MST helpers should need to touch this
194 	 */
195 	struct kref topology_kref;
196 
197 	/**
198 	 * @malloc_kref: refcount for the memory allocation containing this
199 	 * structure. See drm_dp_mst_get_mstb_malloc() and
200 	 * drm_dp_mst_put_mstb_malloc().
201 	 */
202 	struct kref malloc_kref;
203 
204 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
205 	/**
206 	 * @topology_ref_history: A history of each topology
207 	 * reference/dereference. See CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS.
208 	 */
209 	struct drm_dp_mst_topology_ref_history topology_ref_history;
210 #endif
211 
212 	/**
213 	 * @destroy_next: linked-list entry used by
214 	 * drm_dp_delayed_destroy_work()
215 	 */
216 	struct list_head destroy_next;
217 
218 	u8 rad[8];
219 	u8 lct;
220 	int num_ports;
221 
222 	/**
223 	 * @ports: the list of ports on this branch device. This should be
224 	 * considered protected for reading by &drm_dp_mst_topology_mgr.lock.
225 	 * There are two exceptions to this:
226 	 * &drm_dp_mst_topology_mgr.up_req_work and
227 	 * &drm_dp_mst_topology_mgr.work, which do not grab
228 	 * &drm_dp_mst_topology_mgr.lock during reads but are the only
229 	 * updaters of this list and are protected from updating the list
230 	 * concurrently by @drm_dp_mst_topology_mgr.probe_lock
231 	 */
232 	struct list_head ports;
233 
234 	struct drm_dp_mst_port *port_parent;
235 	struct drm_dp_mst_topology_mgr *mgr;
236 
237 	bool link_address_sent;
238 
239 	/* global unique identifier to identify branch devices */
240 	u8 guid[16];
241 };
242 
243 
244 struct drm_dp_nak_reply {
245 	u8 guid[16];
246 	u8 reason;
247 	u8 nak_data;
248 };
249 
250 struct drm_dp_link_address_ack_reply {
251 	u8 guid[16];
252 	u8 nports;
253 	struct drm_dp_link_addr_reply_port {
254 		bool input_port;
255 		u8 peer_device_type;
256 		u8 port_number;
257 		bool mcs;
258 		bool ddps;
259 		bool legacy_device_plug_status;
260 		u8 dpcd_revision;
261 		u8 peer_guid[16];
262 		u8 num_sdp_streams;
263 		u8 num_sdp_stream_sinks;
264 	} ports[16];
265 };
266 
267 struct drm_dp_remote_dpcd_read_ack_reply {
268 	u8 port_number;
269 	u8 num_bytes;
270 	u8 bytes[255];
271 };
272 
273 struct drm_dp_remote_dpcd_write_ack_reply {
274 	u8 port_number;
275 };
276 
277 struct drm_dp_remote_dpcd_write_nak_reply {
278 	u8 port_number;
279 	u8 reason;
280 	u8 bytes_written_before_failure;
281 };
282 
283 struct drm_dp_remote_i2c_read_ack_reply {
284 	u8 port_number;
285 	u8 num_bytes;
286 	u8 bytes[255];
287 };
288 
289 struct drm_dp_remote_i2c_read_nak_reply {
290 	u8 port_number;
291 	u8 nak_reason;
292 	u8 i2c_nak_transaction;
293 };
294 
295 struct drm_dp_remote_i2c_write_ack_reply {
296 	u8 port_number;
297 };
298 
299 struct drm_dp_query_stream_enc_status_ack_reply {
300 	/* Bit[23:16]- Stream Id */
301 	u8 stream_id;
302 
303 	/* Bit[15]- Signed */
304 	bool reply_signed;
305 
306 	/* Bit[10:8]- Stream Output Sink Type */
307 	bool unauthorizable_device_present;
308 	bool legacy_device_present;
309 	bool query_capable_device_present;
310 
311 	/* Bit[12:11]- Stream Output CP Type */
312 	bool hdcp_1x_device_present;
313 	bool hdcp_2x_device_present;
314 
315 	/* Bit[4]- Stream Authentication */
316 	bool auth_completed;
317 
318 	/* Bit[3]- Stream Encryption */
319 	bool encryption_enabled;
320 
321 	/* Bit[2]- Stream Repeater Function Present */
322 	bool repeater_present;
323 
324 	/* Bit[1:0]- Stream State */
325 	u8 state;
326 };
327 
328 #define DRM_DP_MAX_SDP_STREAMS 16
329 struct drm_dp_allocate_payload {
330 	u8 port_number;
331 	u8 number_sdp_streams;
332 	u8 vcpi;
333 	u16 pbn;
334 	u8 sdp_stream_sink[DRM_DP_MAX_SDP_STREAMS];
335 };
336 
337 struct drm_dp_allocate_payload_ack_reply {
338 	u8 port_number;
339 	u8 vcpi;
340 	u16 allocated_pbn;
341 };
342 
343 struct drm_dp_connection_status_notify {
344 	u8 guid[16];
345 	u8 port_number;
346 	bool legacy_device_plug_status;
347 	bool displayport_device_plug_status;
348 	bool message_capability_status;
349 	bool input_port;
350 	u8 peer_device_type;
351 };
352 
353 struct drm_dp_remote_dpcd_read {
354 	u8 port_number;
355 	u32 dpcd_address;
356 	u8 num_bytes;
357 };
358 
359 struct drm_dp_remote_dpcd_write {
360 	u8 port_number;
361 	u32 dpcd_address;
362 	u8 num_bytes;
363 	u8 *bytes;
364 };
365 
366 #define DP_REMOTE_I2C_READ_MAX_TRANSACTIONS 4
367 struct drm_dp_remote_i2c_read {
368 	u8 num_transactions;
369 	u8 port_number;
370 	struct drm_dp_remote_i2c_read_tx {
371 		u8 i2c_dev_id;
372 		u8 num_bytes;
373 		u8 *bytes;
374 		u8 no_stop_bit;
375 		u8 i2c_transaction_delay;
376 	} transactions[DP_REMOTE_I2C_READ_MAX_TRANSACTIONS];
377 	u8 read_i2c_device_id;
378 	u8 num_bytes_read;
379 };
380 
381 struct drm_dp_remote_i2c_write {
382 	u8 port_number;
383 	u8 write_i2c_device_id;
384 	u8 num_bytes;
385 	u8 *bytes;
386 };
387 
388 struct drm_dp_query_stream_enc_status {
389 	u8 stream_id;
390 	u8 client_id[7];	/* 56-bit nonce */
391 	u8 stream_event;
392 	bool valid_stream_event;
393 	u8 stream_behavior;
394 	u8 valid_stream_behavior;
395 };
396 
397 /* this covers ENUM_RESOURCES, POWER_DOWN_PHY, POWER_UP_PHY */
398 struct drm_dp_port_number_req {
399 	u8 port_number;
400 };
401 
402 struct drm_dp_enum_path_resources_ack_reply {
403 	u8 port_number;
404 	bool fec_capable;
405 	u16 full_payload_bw_number;
406 	u16 avail_payload_bw_number;
407 };
408 
409 /* covers POWER_DOWN_PHY, POWER_UP_PHY */
410 struct drm_dp_port_number_rep {
411 	u8 port_number;
412 };
413 
414 struct drm_dp_query_payload {
415 	u8 port_number;
416 	u8 vcpi;
417 };
418 
419 struct drm_dp_resource_status_notify {
420 	u8 port_number;
421 	u8 guid[16];
422 	u16 available_pbn;
423 };
424 
425 struct drm_dp_query_payload_ack_reply {
426 	u8 port_number;
427 	u16 allocated_pbn;
428 };
429 
430 struct drm_dp_sideband_msg_req_body {
431 	u8 req_type;
432 	union ack_req {
433 		struct drm_dp_connection_status_notify conn_stat;
434 		struct drm_dp_port_number_req port_num;
435 		struct drm_dp_resource_status_notify resource_stat;
436 
437 		struct drm_dp_query_payload query_payload;
438 		struct drm_dp_allocate_payload allocate_payload;
439 
440 		struct drm_dp_remote_dpcd_read dpcd_read;
441 		struct drm_dp_remote_dpcd_write dpcd_write;
442 
443 		struct drm_dp_remote_i2c_read i2c_read;
444 		struct drm_dp_remote_i2c_write i2c_write;
445 
446 		struct drm_dp_query_stream_enc_status enc_status;
447 	} u;
448 };
449 
450 struct drm_dp_sideband_msg_reply_body {
451 	u8 reply_type;
452 	u8 req_type;
453 	union ack_replies {
454 		struct drm_dp_nak_reply nak;
455 		struct drm_dp_link_address_ack_reply link_addr;
456 		struct drm_dp_port_number_rep port_number;
457 
458 		struct drm_dp_enum_path_resources_ack_reply path_resources;
459 		struct drm_dp_allocate_payload_ack_reply allocate_payload;
460 		struct drm_dp_query_payload_ack_reply query_payload;
461 
462 		struct drm_dp_remote_dpcd_read_ack_reply remote_dpcd_read_ack;
463 		struct drm_dp_remote_dpcd_write_ack_reply remote_dpcd_write_ack;
464 		struct drm_dp_remote_dpcd_write_nak_reply remote_dpcd_write_nack;
465 
466 		struct drm_dp_remote_i2c_read_ack_reply remote_i2c_read_ack;
467 		struct drm_dp_remote_i2c_read_nak_reply remote_i2c_read_nack;
468 		struct drm_dp_remote_i2c_write_ack_reply remote_i2c_write_ack;
469 
470 		struct drm_dp_query_stream_enc_status_ack_reply enc_status;
471 	} u;
472 };
473 
474 /* msg is queued to be put into a slot */
475 #define DRM_DP_SIDEBAND_TX_QUEUED 0
476 /* msg has started transmitting on a slot - still on msgq */
477 #define DRM_DP_SIDEBAND_TX_START_SEND 1
478 /* msg has finished transmitting on a slot - removed from msgq only in slot */
479 #define DRM_DP_SIDEBAND_TX_SENT 2
480 /* msg has received a response - removed from slot */
481 #define DRM_DP_SIDEBAND_TX_RX 3
482 #define DRM_DP_SIDEBAND_TX_TIMEOUT 4
483 
484 struct drm_dp_sideband_msg_tx {
485 	u8 msg[256];
486 	u8 chunk[48];
487 	u8 cur_offset;
488 	u8 cur_len;
489 	struct drm_dp_mst_branch *dst;
490 	struct list_head next;
491 	int seqno;
492 	int state;
493 	bool path_msg;
494 	struct drm_dp_sideband_msg_reply_body reply;
495 };
496 
497 /* sideband msg handler */
498 struct drm_dp_mst_topology_mgr;
499 struct drm_dp_mst_topology_cbs {
500 	/* create a connector for a port */
501 	struct drm_connector *(*add_connector)(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, const char *path);
502 	/*
503 	 * Checks for any pending MST interrupts, passing them to MST core for
504 	 * processing, the same way an HPD IRQ pulse handler would do this.
505 	 * If provided MST core calls this callback from a poll-waiting loop
506 	 * when waiting for MST down message replies. The driver is expected
507 	 * to guard against a race between this callback and the driver's HPD
508 	 * IRQ pulse handler.
509 	 */
510 	void (*poll_hpd_irq)(struct drm_dp_mst_topology_mgr *mgr);
511 };
512 
513 #define to_dp_mst_topology_state(x) container_of(x, struct drm_dp_mst_topology_state, base)
514 
515 /**
516  * struct drm_dp_mst_atomic_payload - Atomic state struct for an MST payload
517  *
518  * The primary atomic state structure for a given MST payload. Stores information like current
519  * bandwidth allocation, intended action for this payload, etc.
520  */
521 struct drm_dp_mst_atomic_payload {
522 	/** @port: The MST port assigned to this payload */
523 	struct drm_dp_mst_port *port;
524 
525 	/**
526 	 * @vc_start_slot: The time slot that this payload starts on. Because payload start slots
527 	 * can't be determined ahead of time, the contents of this value are UNDEFINED at atomic
528 	 * check time. This shouldn't usually matter, as the start slot should never be relevant for
529 	 * atomic state computations.
530 	 *
531 	 * Since this value is determined at commit time instead of check time, this value is
532 	 * protected by the MST helpers ensuring that async commits operating on the given topology
533 	 * never run in parallel. In the event that a driver does need to read this value (e.g. to
534 	 * inform hardware of the starting timeslot for a payload), the driver may either:
535 	 *
536 	 * * Read this field during the atomic commit after
537 	 *   drm_dp_mst_atomic_wait_for_dependencies() has been called, which will ensure the
538 	 *   previous MST states payload start slots have been copied over to the new state. Note
539 	 *   that a new start slot won't be assigned/removed from this payload until
540 	 *   drm_dp_add_payload_part1()/drm_dp_remove_payload() have been called.
541 	 * * Acquire the MST modesetting lock, and then wait for any pending MST-related commits to
542 	 *   get committed to hardware by calling drm_crtc_commit_wait() on each of the
543 	 *   &drm_crtc_commit structs in &drm_dp_mst_topology_state.commit_deps.
544 	 *
545 	 * If neither of the two above solutions suffice (e.g. the driver needs to read the start
546 	 * slot in the middle of an atomic commit without waiting for some reason), then drivers
547 	 * should cache this value themselves after changing payloads.
548 	 */
549 	s8 vc_start_slot;
550 
551 	/** @vcpi: The Virtual Channel Payload Identifier */
552 	u8 vcpi;
553 	/**
554 	 * @time_slots:
555 	 * The number of timeslots allocated to this payload from the source DP Tx to
556 	 * the immediate downstream DP Rx
557 	 */
558 	int time_slots;
559 	/** @pbn: The payload bandwidth for this payload */
560 	int pbn;
561 
562 	/** @delete: Whether or not we intend to delete this payload during this atomic commit */
563 	bool delete : 1;
564 	/** @dsc_enabled: Whether or not this payload has DSC enabled */
565 	bool dsc_enabled : 1;
566 
567 	/** @next: The list node for this payload */
568 	struct list_head next;
569 };
570 
571 /**
572  * struct drm_dp_mst_topology_state - DisplayPort MST topology atomic state
573  *
574  * This struct represents the atomic state of the toplevel DisplayPort MST manager
575  */
576 struct drm_dp_mst_topology_state {
577 	/** @base: Base private state for atomic */
578 	struct drm_private_state base;
579 
580 	/** @mgr: The topology manager */
581 	struct drm_dp_mst_topology_mgr *mgr;
582 
583 	/**
584 	 * @pending_crtc_mask: A bitmask of all CRTCs this topology state touches, drivers may
585 	 * modify this to add additional dependencies if needed.
586 	 */
587 	u32 pending_crtc_mask;
588 	/**
589 	 * @commit_deps: A list of all CRTC commits affecting this topology, this field isn't
590 	 * populated until drm_dp_mst_atomic_wait_for_dependencies() is called.
591 	 */
592 	struct drm_crtc_commit **commit_deps;
593 	/** @num_commit_deps: The number of CRTC commits in @commit_deps */
594 	size_t num_commit_deps;
595 
596 	/** @payload_mask: A bitmask of allocated VCPIs, used for VCPI assignments */
597 	u32 payload_mask;
598 	/** @payloads: The list of payloads being created/destroyed in this state */
599 	struct list_head payloads;
600 
601 	/** @total_avail_slots: The total number of slots this topology can handle (63 or 64) */
602 	u8 total_avail_slots;
603 	/** @start_slot: The first usable time slot in this topology (1 or 0) */
604 	u8 start_slot;
605 
606 	/**
607 	 * @pbn_div: The current PBN divisor for this topology. The driver is expected to fill this
608 	 * out itself.
609 	 */
610 	int pbn_div;
611 };
612 
613 #define to_dp_mst_topology_mgr(x) container_of(x, struct drm_dp_mst_topology_mgr, base)
614 
615 /**
616  * struct drm_dp_mst_topology_mgr - DisplayPort MST manager
617  *
618  * This struct represents the toplevel displayport MST topology manager.
619  * There should be one instance of this for every MST capable DP connector
620  * on the GPU.
621  */
622 struct drm_dp_mst_topology_mgr {
623 	/**
624 	 * @base: Base private object for atomic
625 	 */
626 	struct drm_private_obj base;
627 
628 	/**
629 	 * @dev: device pointer for adding i2c devices etc.
630 	 */
631 	struct drm_device *dev;
632 	/**
633 	 * @cbs: callbacks for connector addition and destruction.
634 	 */
635 	const struct drm_dp_mst_topology_cbs *cbs;
636 	/**
637 	 * @max_dpcd_transaction_bytes: maximum number of bytes to read/write
638 	 * in one go.
639 	 */
640 	int max_dpcd_transaction_bytes;
641 	/**
642 	 * @aux: AUX channel for the DP MST connector this topolgy mgr is
643 	 * controlling.
644 	 */
645 	struct drm_dp_aux *aux;
646 	/**
647 	 * @max_payloads: maximum number of payloads the GPU can generate.
648 	 */
649 	int max_payloads;
650 	/**
651 	 * @conn_base_id: DRM connector ID this mgr is connected to. Only used
652 	 * to build the MST connector path value.
653 	 */
654 	int conn_base_id;
655 
656 	/**
657 	 * @up_req_recv: Message receiver state for up requests.
658 	 */
659 	struct drm_dp_sideband_msg_rx up_req_recv;
660 
661 	/**
662 	 * @down_rep_recv: Message receiver state for replies to down
663 	 * requests.
664 	 */
665 	struct drm_dp_sideband_msg_rx down_rep_recv;
666 
667 	/**
668 	 * @lock: protects @mst_state, @mst_primary, @dpcd, and
669 	 * @payload_id_table_cleared.
670 	 */
671 	struct mutex lock;
672 
673 	/**
674 	 * @probe_lock: Prevents @work and @up_req_work, the only writers of
675 	 * &drm_dp_mst_port.mstb and &drm_dp_mst_branch.ports, from racing
676 	 * while they update the topology.
677 	 */
678 	struct mutex probe_lock;
679 
680 	/**
681 	 * @mst_state: If this manager is enabled for an MST capable port. False
682 	 * if no MST sink/branch devices is connected.
683 	 */
684 	bool mst_state : 1;
685 
686 	/**
687 	 * @payload_id_table_cleared: Whether or not we've cleared the payload
688 	 * ID table for @mst_primary. Protected by @lock.
689 	 */
690 	bool payload_id_table_cleared : 1;
691 
692 	/**
693 	 * @reset_rx_state: The down request's reply and up request message
694 	 * receiver state must be reset, after the topology manager got
695 	 * removed. Protected by @lock.
696 	 */
697 	bool reset_rx_state : 1;
698 
699 	/**
700 	 * @payload_count: The number of currently active payloads in hardware. This value is only
701 	 * intended to be used internally by MST helpers for payload tracking, and is only safe to
702 	 * read/write from the atomic commit (not check) context.
703 	 */
704 	u8 payload_count;
705 
706 	/**
707 	 * @next_start_slot: The starting timeslot to use for new VC payloads. This value is used
708 	 * internally by MST helpers for payload tracking, and is only safe to read/write from the
709 	 * atomic commit (not check) context.
710 	 */
711 	u8 next_start_slot;
712 
713 	/**
714 	 * @mst_primary: Pointer to the primary/first branch device.
715 	 */
716 	struct drm_dp_mst_branch *mst_primary;
717 
718 	/**
719 	 * @dpcd: Cache of DPCD for primary port.
720 	 */
721 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
722 	/**
723 	 * @sink_count: Sink count from DEVICE_SERVICE_IRQ_VECTOR_ESI0.
724 	 */
725 	u8 sink_count;
726 
727 	/**
728 	 * @funcs: Atomic helper callbacks
729 	 */
730 	const struct drm_private_state_funcs *funcs;
731 
732 	/**
733 	 * @qlock: protects @tx_msg_downq and &drm_dp_sideband_msg_tx.state
734 	 */
735 	struct mutex qlock;
736 
737 	/**
738 	 * @tx_msg_downq: List of pending down requests
739 	 */
740 	struct list_head tx_msg_downq;
741 
742 	/**
743 	 * @tx_waitq: Wait to queue stall for the tx worker.
744 	 */
745 	wait_queue_head_t tx_waitq;
746 	/**
747 	 * @work: Probe work.
748 	 */
749 	struct work_struct work;
750 	/**
751 	 * @tx_work: Sideband transmit worker. This can nest within the main
752 	 * @work worker for each transaction @work launches.
753 	 */
754 	struct work_struct tx_work;
755 
756 	/**
757 	 * @destroy_port_list: List of to be destroyed connectors.
758 	 */
759 	struct list_head destroy_port_list;
760 	/**
761 	 * @destroy_branch_device_list: List of to be destroyed branch
762 	 * devices.
763 	 */
764 	struct list_head destroy_branch_device_list;
765 	/**
766 	 * @delayed_destroy_lock: Protects @destroy_port_list and
767 	 * @destroy_branch_device_list.
768 	 */
769 	struct mutex delayed_destroy_lock;
770 
771 	/**
772 	 * @delayed_destroy_wq: Workqueue used for delayed_destroy_work items.
773 	 * A dedicated WQ makes it possible to drain any requeued work items
774 	 * on it.
775 	 */
776 	struct workqueue_struct *delayed_destroy_wq;
777 
778 	/**
779 	 * @delayed_destroy_work: Work item to destroy MST port and branch
780 	 * devices, needed to avoid locking inversion.
781 	 */
782 	struct work_struct delayed_destroy_work;
783 
784 	/**
785 	 * @up_req_list: List of pending up requests from the topology that
786 	 * need to be processed, in chronological order.
787 	 */
788 	struct list_head up_req_list;
789 	/**
790 	 * @up_req_lock: Protects @up_req_list
791 	 */
792 	struct mutex up_req_lock;
793 	/**
794 	 * @up_req_work: Work item to process up requests received from the
795 	 * topology. Needed to avoid blocking hotplug handling and sideband
796 	 * transmissions.
797 	 */
798 	struct work_struct up_req_work;
799 
800 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
801 	/**
802 	 * @topology_ref_history_lock: protects
803 	 * &drm_dp_mst_port.topology_ref_history and
804 	 * &drm_dp_mst_branch.topology_ref_history.
805 	 */
806 	struct mutex topology_ref_history_lock;
807 #endif
808 };
809 
810 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
811 				 struct drm_device *dev, struct drm_dp_aux *aux,
812 				 int max_dpcd_transaction_bytes,
813 				 int max_payloads, int conn_base_id);
814 
815 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr);
816 
817 bool drm_dp_read_mst_cap(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
818 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state);
819 
820 int drm_dp_mst_hpd_irq_handle_event(struct drm_dp_mst_topology_mgr *mgr,
821 				    const u8 *esi,
822 				    u8 *ack,
823 				    bool *handled);
824 void drm_dp_mst_hpd_irq_send_new_request(struct drm_dp_mst_topology_mgr *mgr);
825 
826 int
827 drm_dp_mst_detect_port(struct drm_connector *connector,
828 		       struct drm_modeset_acquire_ctx *ctx,
829 		       struct drm_dp_mst_topology_mgr *mgr,
830 		       struct drm_dp_mst_port *port);
831 
832 const struct drm_edid *drm_dp_mst_edid_read(struct drm_connector *connector,
833 					    struct drm_dp_mst_topology_mgr *mgr,
834 					    struct drm_dp_mst_port *port);
835 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector,
836 				 struct drm_dp_mst_topology_mgr *mgr,
837 				 struct drm_dp_mst_port *port);
838 
839 int drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr,
840 			     int link_rate, int link_lane_count);
841 
842 int drm_dp_calc_pbn_mode(int clock, int bpp);
843 
844 void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap);
845 
846 int drm_dp_add_payload_part1(struct drm_dp_mst_topology_mgr *mgr,
847 			     struct drm_dp_mst_topology_state *mst_state,
848 			     struct drm_dp_mst_atomic_payload *payload);
849 int drm_dp_add_payload_part2(struct drm_dp_mst_topology_mgr *mgr,
850 			     struct drm_atomic_state *state,
851 			     struct drm_dp_mst_atomic_payload *payload);
852 void drm_dp_remove_payload(struct drm_dp_mst_topology_mgr *mgr,
853 			   struct drm_dp_mst_topology_state *mst_state,
854 			   const struct drm_dp_mst_atomic_payload *old_payload,
855 			   struct drm_dp_mst_atomic_payload *new_payload);
856 
857 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr);
858 
859 void drm_dp_mst_dump_topology(struct seq_file *m,
860 			      struct drm_dp_mst_topology_mgr *mgr);
861 
862 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr);
863 int __must_check
864 drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
865 			       bool sync);
866 
867 ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
868 			     unsigned int offset, void *buffer, size_t size);
869 ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
870 			      unsigned int offset, void *buffer, size_t size);
871 
872 int drm_dp_mst_connector_late_register(struct drm_connector *connector,
873 				       struct drm_dp_mst_port *port);
874 void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
875 					   struct drm_dp_mst_port *port);
876 
877 struct drm_dp_mst_topology_state *
878 drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
879 				  struct drm_dp_mst_topology_mgr *mgr);
880 struct drm_dp_mst_topology_state *
881 drm_atomic_get_old_mst_topology_state(struct drm_atomic_state *state,
882 				      struct drm_dp_mst_topology_mgr *mgr);
883 struct drm_dp_mst_topology_state *
884 drm_atomic_get_new_mst_topology_state(struct drm_atomic_state *state,
885 				      struct drm_dp_mst_topology_mgr *mgr);
886 struct drm_dp_mst_atomic_payload *
887 drm_atomic_get_mst_payload_state(struct drm_dp_mst_topology_state *state,
888 				 struct drm_dp_mst_port *port);
889 int __must_check
890 drm_dp_atomic_find_time_slots(struct drm_atomic_state *state,
891 			      struct drm_dp_mst_topology_mgr *mgr,
892 			      struct drm_dp_mst_port *port, int pbn);
893 int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
894 				 struct drm_dp_mst_port *port,
895 				 int pbn, bool enable);
896 int __must_check
897 drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state,
898 				  struct drm_dp_mst_topology_mgr *mgr);
899 int __must_check
900 drm_dp_atomic_release_time_slots(struct drm_atomic_state *state,
901 				 struct drm_dp_mst_topology_mgr *mgr,
902 				 struct drm_dp_mst_port *port);
903 void drm_dp_mst_atomic_wait_for_dependencies(struct drm_atomic_state *state);
904 int __must_check drm_dp_mst_atomic_setup_commit(struct drm_atomic_state *state);
905 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
906 				 struct drm_dp_mst_port *port, bool power_up);
907 int drm_dp_send_query_stream_enc_status(struct drm_dp_mst_topology_mgr *mgr,
908 		struct drm_dp_mst_port *port,
909 		struct drm_dp_query_stream_enc_status_ack_reply *status);
910 int __must_check drm_dp_mst_atomic_check(struct drm_atomic_state *state);
911 int __must_check drm_dp_mst_root_conn_atomic_check(struct drm_connector_state *new_conn_state,
912 						   struct drm_dp_mst_topology_mgr *mgr);
913 
914 void drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port);
915 void drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port);
916 
917 struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port);
918 
919 static inline struct drm_dp_mst_topology_state *
920 to_drm_dp_mst_topology_state(struct drm_private_state *state)
921 {
922 	return container_of(state, struct drm_dp_mst_topology_state, base);
923 }
924 
925 extern const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs;
926 
927 /**
928  * __drm_dp_mst_state_iter_get - private atomic state iterator function for
929  * macro-internal use
930  * @state: &struct drm_atomic_state pointer
931  * @mgr: pointer to the &struct drm_dp_mst_topology_mgr iteration cursor
932  * @old_state: optional pointer to the old &struct drm_dp_mst_topology_state
933  * iteration cursor
934  * @new_state: optional pointer to the new &struct drm_dp_mst_topology_state
935  * iteration cursor
936  * @i: int iteration cursor, for macro-internal use
937  *
938  * Used by for_each_oldnew_mst_mgr_in_state(),
939  * for_each_old_mst_mgr_in_state(), and for_each_new_mst_mgr_in_state(). Don't
940  * call this directly.
941  *
942  * Returns:
943  * True if the current &struct drm_private_obj is a &struct
944  * drm_dp_mst_topology_mgr, false otherwise.
945  */
946 static inline bool
947 __drm_dp_mst_state_iter_get(struct drm_atomic_state *state,
948 			    struct drm_dp_mst_topology_mgr **mgr,
949 			    struct drm_dp_mst_topology_state **old_state,
950 			    struct drm_dp_mst_topology_state **new_state,
951 			    int i)
952 {
953 	struct __drm_private_objs_state *objs_state = &state->private_objs[i];
954 
955 	if (objs_state->ptr->funcs != &drm_dp_mst_topology_state_funcs)
956 		return false;
957 
958 	*mgr = to_dp_mst_topology_mgr(objs_state->ptr);
959 	if (old_state)
960 		*old_state = to_dp_mst_topology_state(objs_state->old_state);
961 	if (new_state)
962 		*new_state = to_dp_mst_topology_state(objs_state->new_state);
963 
964 	return true;
965 }
966 
967 /**
968  * for_each_oldnew_mst_mgr_in_state - iterate over all DP MST topology
969  * managers in an atomic update
970  * @__state: &struct drm_atomic_state pointer
971  * @mgr: &struct drm_dp_mst_topology_mgr iteration cursor
972  * @old_state: &struct drm_dp_mst_topology_state iteration cursor for the old
973  * state
974  * @new_state: &struct drm_dp_mst_topology_state iteration cursor for the new
975  * state
976  * @__i: int iteration cursor, for macro-internal use
977  *
978  * This iterates over all DRM DP MST topology managers in an atomic update,
979  * tracking both old and new state. This is useful in places where the state
980  * delta needs to be considered, for example in atomic check functions.
981  */
982 #define for_each_oldnew_mst_mgr_in_state(__state, mgr, old_state, new_state, __i) \
983 	for ((__i) = 0; (__i) < (__state)->num_private_objs; (__i)++) \
984 		for_each_if(__drm_dp_mst_state_iter_get((__state), &(mgr), &(old_state), &(new_state), (__i)))
985 
986 /**
987  * for_each_old_mst_mgr_in_state - iterate over all DP MST topology managers
988  * in an atomic update
989  * @__state: &struct drm_atomic_state pointer
990  * @mgr: &struct drm_dp_mst_topology_mgr iteration cursor
991  * @old_state: &struct drm_dp_mst_topology_state iteration cursor for the old
992  * state
993  * @__i: int iteration cursor, for macro-internal use
994  *
995  * This iterates over all DRM DP MST topology managers in an atomic update,
996  * tracking only the old state. This is useful in disable functions, where we
997  * need the old state the hardware is still in.
998  */
999 #define for_each_old_mst_mgr_in_state(__state, mgr, old_state, __i) \
1000 	for ((__i) = 0; (__i) < (__state)->num_private_objs; (__i)++) \
1001 		for_each_if(__drm_dp_mst_state_iter_get((__state), &(mgr), &(old_state), NULL, (__i)))
1002 
1003 /**
1004  * for_each_new_mst_mgr_in_state - iterate over all DP MST topology managers
1005  * in an atomic update
1006  * @__state: &struct drm_atomic_state pointer
1007  * @mgr: &struct drm_dp_mst_topology_mgr iteration cursor
1008  * @new_state: &struct drm_dp_mst_topology_state iteration cursor for the new
1009  * state
1010  * @__i: int iteration cursor, for macro-internal use
1011  *
1012  * This iterates over all DRM DP MST topology managers in an atomic update,
1013  * tracking only the new state. This is useful in enable functions, where we
1014  * need the new state the hardware should be in when the atomic commit
1015  * operation has completed.
1016  */
1017 #define for_each_new_mst_mgr_in_state(__state, mgr, new_state, __i) \
1018 	for ((__i) = 0; (__i) < (__state)->num_private_objs; (__i)++) \
1019 		for_each_if(__drm_dp_mst_state_iter_get((__state), &(mgr), NULL, &(new_state), (__i)))
1020 
1021 #endif
1022