xref: /openbmc/linux/include/drm/display/drm_dp_mst_helper.h (revision b694e3c604e999343258c49e574abd7be012e726)
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 	/**
219 	 * @rad: Relative Address of the MST branch.
220 	 * For &drm_dp_mst_topology_mgr.mst_primary, it's rad[8] are all 0,
221 	 * unset and unused. For MST branches connected after mst_primary,
222 	 * in each element of rad[] the nibbles are ordered by the most
223 	 * signifcant 4 bits first and the least significant 4 bits second.
224 	 */
225 	u8 rad[8];
226 	u8 lct;
227 	int num_ports;
228 
229 	/**
230 	 * @ports: the list of ports on this branch device. This should be
231 	 * considered protected for reading by &drm_dp_mst_topology_mgr.lock.
232 	 * There are two exceptions to this:
233 	 * &drm_dp_mst_topology_mgr.up_req_work and
234 	 * &drm_dp_mst_topology_mgr.work, which do not grab
235 	 * &drm_dp_mst_topology_mgr.lock during reads but are the only
236 	 * updaters of this list and are protected from updating the list
237 	 * concurrently by @drm_dp_mst_topology_mgr.probe_lock
238 	 */
239 	struct list_head ports;
240 
241 	struct drm_dp_mst_port *port_parent;
242 	struct drm_dp_mst_topology_mgr *mgr;
243 
244 	bool link_address_sent;
245 
246 	/* global unique identifier to identify branch devices */
247 	u8 guid[16];
248 };
249 
250 
251 struct drm_dp_nak_reply {
252 	u8 guid[16];
253 	u8 reason;
254 	u8 nak_data;
255 };
256 
257 struct drm_dp_link_address_ack_reply {
258 	u8 guid[16];
259 	u8 nports;
260 	struct drm_dp_link_addr_reply_port {
261 		bool input_port;
262 		u8 peer_device_type;
263 		u8 port_number;
264 		bool mcs;
265 		bool ddps;
266 		bool legacy_device_plug_status;
267 		u8 dpcd_revision;
268 		u8 peer_guid[16];
269 		u8 num_sdp_streams;
270 		u8 num_sdp_stream_sinks;
271 	} ports[16];
272 };
273 
274 struct drm_dp_remote_dpcd_read_ack_reply {
275 	u8 port_number;
276 	u8 num_bytes;
277 	u8 bytes[255];
278 };
279 
280 struct drm_dp_remote_dpcd_write_ack_reply {
281 	u8 port_number;
282 };
283 
284 struct drm_dp_remote_dpcd_write_nak_reply {
285 	u8 port_number;
286 	u8 reason;
287 	u8 bytes_written_before_failure;
288 };
289 
290 struct drm_dp_remote_i2c_read_ack_reply {
291 	u8 port_number;
292 	u8 num_bytes;
293 	u8 bytes[255];
294 };
295 
296 struct drm_dp_remote_i2c_read_nak_reply {
297 	u8 port_number;
298 	u8 nak_reason;
299 	u8 i2c_nak_transaction;
300 };
301 
302 struct drm_dp_remote_i2c_write_ack_reply {
303 	u8 port_number;
304 };
305 
306 struct drm_dp_query_stream_enc_status_ack_reply {
307 	/* Bit[23:16]- Stream Id */
308 	u8 stream_id;
309 
310 	/* Bit[15]- Signed */
311 	bool reply_signed;
312 
313 	/* Bit[10:8]- Stream Output Sink Type */
314 	bool unauthorizable_device_present;
315 	bool legacy_device_present;
316 	bool query_capable_device_present;
317 
318 	/* Bit[12:11]- Stream Output CP Type */
319 	bool hdcp_1x_device_present;
320 	bool hdcp_2x_device_present;
321 
322 	/* Bit[4]- Stream Authentication */
323 	bool auth_completed;
324 
325 	/* Bit[3]- Stream Encryption */
326 	bool encryption_enabled;
327 
328 	/* Bit[2]- Stream Repeater Function Present */
329 	bool repeater_present;
330 
331 	/* Bit[1:0]- Stream State */
332 	u8 state;
333 };
334 
335 #define DRM_DP_MAX_SDP_STREAMS 16
336 struct drm_dp_allocate_payload {
337 	u8 port_number;
338 	u8 number_sdp_streams;
339 	u8 vcpi;
340 	u16 pbn;
341 	u8 sdp_stream_sink[DRM_DP_MAX_SDP_STREAMS];
342 };
343 
344 struct drm_dp_allocate_payload_ack_reply {
345 	u8 port_number;
346 	u8 vcpi;
347 	u16 allocated_pbn;
348 };
349 
350 struct drm_dp_connection_status_notify {
351 	u8 guid[16];
352 	u8 port_number;
353 	bool legacy_device_plug_status;
354 	bool displayport_device_plug_status;
355 	bool message_capability_status;
356 	bool input_port;
357 	u8 peer_device_type;
358 };
359 
360 struct drm_dp_remote_dpcd_read {
361 	u8 port_number;
362 	u32 dpcd_address;
363 	u8 num_bytes;
364 };
365 
366 struct drm_dp_remote_dpcd_write {
367 	u8 port_number;
368 	u32 dpcd_address;
369 	u8 num_bytes;
370 	u8 *bytes;
371 };
372 
373 #define DP_REMOTE_I2C_READ_MAX_TRANSACTIONS 4
374 struct drm_dp_remote_i2c_read {
375 	u8 num_transactions;
376 	u8 port_number;
377 	struct drm_dp_remote_i2c_read_tx {
378 		u8 i2c_dev_id;
379 		u8 num_bytes;
380 		u8 *bytes;
381 		u8 no_stop_bit;
382 		u8 i2c_transaction_delay;
383 	} transactions[DP_REMOTE_I2C_READ_MAX_TRANSACTIONS];
384 	u8 read_i2c_device_id;
385 	u8 num_bytes_read;
386 };
387 
388 struct drm_dp_remote_i2c_write {
389 	u8 port_number;
390 	u8 write_i2c_device_id;
391 	u8 num_bytes;
392 	u8 *bytes;
393 };
394 
395 struct drm_dp_query_stream_enc_status {
396 	u8 stream_id;
397 	u8 client_id[7];	/* 56-bit nonce */
398 	u8 stream_event;
399 	bool valid_stream_event;
400 	u8 stream_behavior;
401 	u8 valid_stream_behavior;
402 };
403 
404 /* this covers ENUM_RESOURCES, POWER_DOWN_PHY, POWER_UP_PHY */
405 struct drm_dp_port_number_req {
406 	u8 port_number;
407 };
408 
409 struct drm_dp_enum_path_resources_ack_reply {
410 	u8 port_number;
411 	bool fec_capable;
412 	u16 full_payload_bw_number;
413 	u16 avail_payload_bw_number;
414 };
415 
416 /* covers POWER_DOWN_PHY, POWER_UP_PHY */
417 struct drm_dp_port_number_rep {
418 	u8 port_number;
419 };
420 
421 struct drm_dp_query_payload {
422 	u8 port_number;
423 	u8 vcpi;
424 };
425 
426 struct drm_dp_resource_status_notify {
427 	u8 port_number;
428 	u8 guid[16];
429 	u16 available_pbn;
430 };
431 
432 struct drm_dp_query_payload_ack_reply {
433 	u8 port_number;
434 	u16 allocated_pbn;
435 };
436 
437 struct drm_dp_sideband_msg_req_body {
438 	u8 req_type;
439 	union ack_req {
440 		struct drm_dp_connection_status_notify conn_stat;
441 		struct drm_dp_port_number_req port_num;
442 		struct drm_dp_resource_status_notify resource_stat;
443 
444 		struct drm_dp_query_payload query_payload;
445 		struct drm_dp_allocate_payload allocate_payload;
446 
447 		struct drm_dp_remote_dpcd_read dpcd_read;
448 		struct drm_dp_remote_dpcd_write dpcd_write;
449 
450 		struct drm_dp_remote_i2c_read i2c_read;
451 		struct drm_dp_remote_i2c_write i2c_write;
452 
453 		struct drm_dp_query_stream_enc_status enc_status;
454 	} u;
455 };
456 
457 struct drm_dp_sideband_msg_reply_body {
458 	u8 reply_type;
459 	u8 req_type;
460 	union ack_replies {
461 		struct drm_dp_nak_reply nak;
462 		struct drm_dp_link_address_ack_reply link_addr;
463 		struct drm_dp_port_number_rep port_number;
464 
465 		struct drm_dp_enum_path_resources_ack_reply path_resources;
466 		struct drm_dp_allocate_payload_ack_reply allocate_payload;
467 		struct drm_dp_query_payload_ack_reply query_payload;
468 
469 		struct drm_dp_remote_dpcd_read_ack_reply remote_dpcd_read_ack;
470 		struct drm_dp_remote_dpcd_write_ack_reply remote_dpcd_write_ack;
471 		struct drm_dp_remote_dpcd_write_nak_reply remote_dpcd_write_nack;
472 
473 		struct drm_dp_remote_i2c_read_ack_reply remote_i2c_read_ack;
474 		struct drm_dp_remote_i2c_read_nak_reply remote_i2c_read_nack;
475 		struct drm_dp_remote_i2c_write_ack_reply remote_i2c_write_ack;
476 
477 		struct drm_dp_query_stream_enc_status_ack_reply enc_status;
478 	} u;
479 };
480 
481 /* msg is queued to be put into a slot */
482 #define DRM_DP_SIDEBAND_TX_QUEUED 0
483 /* msg has started transmitting on a slot - still on msgq */
484 #define DRM_DP_SIDEBAND_TX_START_SEND 1
485 /* msg has finished transmitting on a slot - removed from msgq only in slot */
486 #define DRM_DP_SIDEBAND_TX_SENT 2
487 /* msg has received a response - removed from slot */
488 #define DRM_DP_SIDEBAND_TX_RX 3
489 #define DRM_DP_SIDEBAND_TX_TIMEOUT 4
490 
491 struct drm_dp_sideband_msg_tx {
492 	u8 msg[256];
493 	u8 chunk[48];
494 	u8 cur_offset;
495 	u8 cur_len;
496 	struct drm_dp_mst_branch *dst;
497 	struct list_head next;
498 	int seqno;
499 	int state;
500 	bool path_msg;
501 	struct drm_dp_sideband_msg_reply_body reply;
502 };
503 
504 /* sideband msg handler */
505 struct drm_dp_mst_topology_mgr;
506 struct drm_dp_mst_topology_cbs {
507 	/* create a connector for a port */
508 	struct drm_connector *(*add_connector)(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, const char *path);
509 	/*
510 	 * Checks for any pending MST interrupts, passing them to MST core for
511 	 * processing, the same way an HPD IRQ pulse handler would do this.
512 	 * If provided MST core calls this callback from a poll-waiting loop
513 	 * when waiting for MST down message replies. The driver is expected
514 	 * to guard against a race between this callback and the driver's HPD
515 	 * IRQ pulse handler.
516 	 */
517 	void (*poll_hpd_irq)(struct drm_dp_mst_topology_mgr *mgr);
518 };
519 
520 #define to_dp_mst_topology_state(x) container_of(x, struct drm_dp_mst_topology_state, base)
521 
522 /**
523  * struct drm_dp_mst_atomic_payload - Atomic state struct for an MST payload
524  *
525  * The primary atomic state structure for a given MST payload. Stores information like current
526  * bandwidth allocation, intended action for this payload, etc.
527  */
528 struct drm_dp_mst_atomic_payload {
529 	/** @port: The MST port assigned to this payload */
530 	struct drm_dp_mst_port *port;
531 
532 	/**
533 	 * @vc_start_slot: The time slot that this payload starts on. Because payload start slots
534 	 * can't be determined ahead of time, the contents of this value are UNDEFINED at atomic
535 	 * check time. This shouldn't usually matter, as the start slot should never be relevant for
536 	 * atomic state computations.
537 	 *
538 	 * Since this value is determined at commit time instead of check time, this value is
539 	 * protected by the MST helpers ensuring that async commits operating on the given topology
540 	 * never run in parallel. In the event that a driver does need to read this value (e.g. to
541 	 * inform hardware of the starting timeslot for a payload), the driver may either:
542 	 *
543 	 * * Read this field during the atomic commit after
544 	 *   drm_dp_mst_atomic_wait_for_dependencies() has been called, which will ensure the
545 	 *   previous MST states payload start slots have been copied over to the new state. Note
546 	 *   that a new start slot won't be assigned/removed from this payload until
547 	 *   drm_dp_add_payload_part1()/drm_dp_remove_payload() have been called.
548 	 * * Acquire the MST modesetting lock, and then wait for any pending MST-related commits to
549 	 *   get committed to hardware by calling drm_crtc_commit_wait() on each of the
550 	 *   &drm_crtc_commit structs in &drm_dp_mst_topology_state.commit_deps.
551 	 *
552 	 * If neither of the two above solutions suffice (e.g. the driver needs to read the start
553 	 * slot in the middle of an atomic commit without waiting for some reason), then drivers
554 	 * should cache this value themselves after changing payloads.
555 	 */
556 	s8 vc_start_slot;
557 
558 	/** @vcpi: The Virtual Channel Payload Identifier */
559 	u8 vcpi;
560 	/**
561 	 * @time_slots:
562 	 * The number of timeslots allocated to this payload from the source DP Tx to
563 	 * the immediate downstream DP Rx
564 	 */
565 	int time_slots;
566 	/** @pbn: The payload bandwidth for this payload */
567 	int pbn;
568 
569 	/** @delete: Whether or not we intend to delete this payload during this atomic commit */
570 	bool delete : 1;
571 	/** @dsc_enabled: Whether or not this payload has DSC enabled */
572 	bool dsc_enabled : 1;
573 
574 	/** @next: The list node for this payload */
575 	struct list_head next;
576 };
577 
578 /**
579  * struct drm_dp_mst_topology_state - DisplayPort MST topology atomic state
580  *
581  * This struct represents the atomic state of the toplevel DisplayPort MST manager
582  */
583 struct drm_dp_mst_topology_state {
584 	/** @base: Base private state for atomic */
585 	struct drm_private_state base;
586 
587 	/** @mgr: The topology manager */
588 	struct drm_dp_mst_topology_mgr *mgr;
589 
590 	/**
591 	 * @pending_crtc_mask: A bitmask of all CRTCs this topology state touches, drivers may
592 	 * modify this to add additional dependencies if needed.
593 	 */
594 	u32 pending_crtc_mask;
595 	/**
596 	 * @commit_deps: A list of all CRTC commits affecting this topology, this field isn't
597 	 * populated until drm_dp_mst_atomic_wait_for_dependencies() is called.
598 	 */
599 	struct drm_crtc_commit **commit_deps;
600 	/** @num_commit_deps: The number of CRTC commits in @commit_deps */
601 	size_t num_commit_deps;
602 
603 	/** @payload_mask: A bitmask of allocated VCPIs, used for VCPI assignments */
604 	u32 payload_mask;
605 	/** @payloads: The list of payloads being created/destroyed in this state */
606 	struct list_head payloads;
607 
608 	/** @total_avail_slots: The total number of slots this topology can handle (63 or 64) */
609 	u8 total_avail_slots;
610 	/** @start_slot: The first usable time slot in this topology (1 or 0) */
611 	u8 start_slot;
612 
613 	/**
614 	 * @pbn_div: The current PBN divisor for this topology. The driver is expected to fill this
615 	 * out itself.
616 	 */
617 	int pbn_div;
618 };
619 
620 #define to_dp_mst_topology_mgr(x) container_of(x, struct drm_dp_mst_topology_mgr, base)
621 
622 /**
623  * struct drm_dp_mst_topology_mgr - DisplayPort MST manager
624  *
625  * This struct represents the toplevel displayport MST topology manager.
626  * There should be one instance of this for every MST capable DP connector
627  * on the GPU.
628  */
629 struct drm_dp_mst_topology_mgr {
630 	/**
631 	 * @base: Base private object for atomic
632 	 */
633 	struct drm_private_obj base;
634 
635 	/**
636 	 * @dev: device pointer for adding i2c devices etc.
637 	 */
638 	struct drm_device *dev;
639 	/**
640 	 * @cbs: callbacks for connector addition and destruction.
641 	 */
642 	const struct drm_dp_mst_topology_cbs *cbs;
643 	/**
644 	 * @max_dpcd_transaction_bytes: maximum number of bytes to read/write
645 	 * in one go.
646 	 */
647 	int max_dpcd_transaction_bytes;
648 	/**
649 	 * @aux: AUX channel for the DP MST connector this topolgy mgr is
650 	 * controlling.
651 	 */
652 	struct drm_dp_aux *aux;
653 	/**
654 	 * @max_payloads: maximum number of payloads the GPU can generate.
655 	 */
656 	int max_payloads;
657 	/**
658 	 * @conn_base_id: DRM connector ID this mgr is connected to. Only used
659 	 * to build the MST connector path value.
660 	 */
661 	int conn_base_id;
662 
663 	/**
664 	 * @up_req_recv: Message receiver state for up requests.
665 	 */
666 	struct drm_dp_sideband_msg_rx up_req_recv;
667 
668 	/**
669 	 * @down_rep_recv: Message receiver state for replies to down
670 	 * requests.
671 	 */
672 	struct drm_dp_sideband_msg_rx down_rep_recv;
673 
674 	/**
675 	 * @lock: protects @mst_state, @mst_primary, @dpcd, and
676 	 * @payload_id_table_cleared.
677 	 */
678 	struct mutex lock;
679 
680 	/**
681 	 * @probe_lock: Prevents @work and @up_req_work, the only writers of
682 	 * &drm_dp_mst_port.mstb and &drm_dp_mst_branch.ports, from racing
683 	 * while they update the topology.
684 	 */
685 	struct mutex probe_lock;
686 
687 	/**
688 	 * @mst_state: If this manager is enabled for an MST capable port. False
689 	 * if no MST sink/branch devices is connected.
690 	 */
691 	bool mst_state : 1;
692 
693 	/**
694 	 * @payload_id_table_cleared: Whether or not we've cleared the payload
695 	 * ID table for @mst_primary. Protected by @lock.
696 	 */
697 	bool payload_id_table_cleared : 1;
698 
699 	/**
700 	 * @reset_rx_state: The down request's reply and up request message
701 	 * receiver state must be reset, after the topology manager got
702 	 * removed. Protected by @lock.
703 	 */
704 	bool reset_rx_state : 1;
705 
706 	/**
707 	 * @payload_count: The number of currently active payloads in hardware. This value is only
708 	 * intended to be used internally by MST helpers for payload tracking, and is only safe to
709 	 * read/write from the atomic commit (not check) context.
710 	 */
711 	u8 payload_count;
712 
713 	/**
714 	 * @next_start_slot: The starting timeslot to use for new VC payloads. This value is used
715 	 * internally by MST helpers for payload tracking, and is only safe to read/write from the
716 	 * atomic commit (not check) context.
717 	 */
718 	u8 next_start_slot;
719 
720 	/**
721 	 * @mst_primary: Pointer to the primary/first branch device.
722 	 */
723 	struct drm_dp_mst_branch *mst_primary;
724 
725 	/**
726 	 * @dpcd: Cache of DPCD for primary port.
727 	 */
728 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
729 	/**
730 	 * @sink_count: Sink count from DEVICE_SERVICE_IRQ_VECTOR_ESI0.
731 	 */
732 	u8 sink_count;
733 
734 	/**
735 	 * @funcs: Atomic helper callbacks
736 	 */
737 	const struct drm_private_state_funcs *funcs;
738 
739 	/**
740 	 * @qlock: protects @tx_msg_downq and &drm_dp_sideband_msg_tx.state
741 	 */
742 	struct mutex qlock;
743 
744 	/**
745 	 * @tx_msg_downq: List of pending down requests
746 	 */
747 	struct list_head tx_msg_downq;
748 
749 	/**
750 	 * @tx_waitq: Wait to queue stall for the tx worker.
751 	 */
752 	wait_queue_head_t tx_waitq;
753 	/**
754 	 * @work: Probe work.
755 	 */
756 	struct work_struct work;
757 	/**
758 	 * @tx_work: Sideband transmit worker. This can nest within the main
759 	 * @work worker for each transaction @work launches.
760 	 */
761 	struct work_struct tx_work;
762 
763 	/**
764 	 * @destroy_port_list: List of to be destroyed connectors.
765 	 */
766 	struct list_head destroy_port_list;
767 	/**
768 	 * @destroy_branch_device_list: List of to be destroyed branch
769 	 * devices.
770 	 */
771 	struct list_head destroy_branch_device_list;
772 	/**
773 	 * @delayed_destroy_lock: Protects @destroy_port_list and
774 	 * @destroy_branch_device_list.
775 	 */
776 	struct mutex delayed_destroy_lock;
777 
778 	/**
779 	 * @delayed_destroy_wq: Workqueue used for delayed_destroy_work items.
780 	 * A dedicated WQ makes it possible to drain any requeued work items
781 	 * on it.
782 	 */
783 	struct workqueue_struct *delayed_destroy_wq;
784 
785 	/**
786 	 * @delayed_destroy_work: Work item to destroy MST port and branch
787 	 * devices, needed to avoid locking inversion.
788 	 */
789 	struct work_struct delayed_destroy_work;
790 
791 	/**
792 	 * @up_req_list: List of pending up requests from the topology that
793 	 * need to be processed, in chronological order.
794 	 */
795 	struct list_head up_req_list;
796 	/**
797 	 * @up_req_lock: Protects @up_req_list
798 	 */
799 	struct mutex up_req_lock;
800 	/**
801 	 * @up_req_work: Work item to process up requests received from the
802 	 * topology. Needed to avoid blocking hotplug handling and sideband
803 	 * transmissions.
804 	 */
805 	struct work_struct up_req_work;
806 
807 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
808 	/**
809 	 * @topology_ref_history_lock: protects
810 	 * &drm_dp_mst_port.topology_ref_history and
811 	 * &drm_dp_mst_branch.topology_ref_history.
812 	 */
813 	struct mutex topology_ref_history_lock;
814 #endif
815 };
816 
817 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
818 				 struct drm_device *dev, struct drm_dp_aux *aux,
819 				 int max_dpcd_transaction_bytes,
820 				 int max_payloads, int conn_base_id);
821 
822 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr);
823 
824 bool drm_dp_read_mst_cap(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
825 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state);
826 
827 int drm_dp_mst_hpd_irq_handle_event(struct drm_dp_mst_topology_mgr *mgr,
828 				    const u8 *esi,
829 				    u8 *ack,
830 				    bool *handled);
831 void drm_dp_mst_hpd_irq_send_new_request(struct drm_dp_mst_topology_mgr *mgr);
832 
833 int
834 drm_dp_mst_detect_port(struct drm_connector *connector,
835 		       struct drm_modeset_acquire_ctx *ctx,
836 		       struct drm_dp_mst_topology_mgr *mgr,
837 		       struct drm_dp_mst_port *port);
838 
839 const struct drm_edid *drm_dp_mst_edid_read(struct drm_connector *connector,
840 					    struct drm_dp_mst_topology_mgr *mgr,
841 					    struct drm_dp_mst_port *port);
842 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector,
843 				 struct drm_dp_mst_topology_mgr *mgr,
844 				 struct drm_dp_mst_port *port);
845 
846 int drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr,
847 			     int link_rate, int link_lane_count);
848 
849 int drm_dp_calc_pbn_mode(int clock, int bpp);
850 
851 void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap);
852 
853 int drm_dp_add_payload_part1(struct drm_dp_mst_topology_mgr *mgr,
854 			     struct drm_dp_mst_topology_state *mst_state,
855 			     struct drm_dp_mst_atomic_payload *payload);
856 int drm_dp_add_payload_part2(struct drm_dp_mst_topology_mgr *mgr,
857 			     struct drm_atomic_state *state,
858 			     struct drm_dp_mst_atomic_payload *payload);
859 void drm_dp_remove_payload(struct drm_dp_mst_topology_mgr *mgr,
860 			   struct drm_dp_mst_topology_state *mst_state,
861 			   const struct drm_dp_mst_atomic_payload *old_payload,
862 			   struct drm_dp_mst_atomic_payload *new_payload);
863 
864 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr);
865 
866 void drm_dp_mst_dump_topology(struct seq_file *m,
867 			      struct drm_dp_mst_topology_mgr *mgr);
868 
869 void drm_dp_mst_topology_queue_probe(struct drm_dp_mst_topology_mgr *mgr);
870 
871 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr);
872 int __must_check
873 drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
874 			       bool sync);
875 
876 ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
877 			     unsigned int offset, void *buffer, size_t size);
878 ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
879 			      unsigned int offset, void *buffer, size_t size);
880 
881 int drm_dp_mst_connector_late_register(struct drm_connector *connector,
882 				       struct drm_dp_mst_port *port);
883 void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
884 					   struct drm_dp_mst_port *port);
885 
886 struct drm_dp_mst_topology_state *
887 drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
888 				  struct drm_dp_mst_topology_mgr *mgr);
889 struct drm_dp_mst_topology_state *
890 drm_atomic_get_old_mst_topology_state(struct drm_atomic_state *state,
891 				      struct drm_dp_mst_topology_mgr *mgr);
892 struct drm_dp_mst_topology_state *
893 drm_atomic_get_new_mst_topology_state(struct drm_atomic_state *state,
894 				      struct drm_dp_mst_topology_mgr *mgr);
895 struct drm_dp_mst_atomic_payload *
896 drm_atomic_get_mst_payload_state(struct drm_dp_mst_topology_state *state,
897 				 struct drm_dp_mst_port *port);
898 int __must_check
899 drm_dp_atomic_find_time_slots(struct drm_atomic_state *state,
900 			      struct drm_dp_mst_topology_mgr *mgr,
901 			      struct drm_dp_mst_port *port, int pbn);
902 int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
903 				 struct drm_dp_mst_port *port,
904 				 int pbn, bool enable);
905 int __must_check
906 drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state,
907 				  struct drm_dp_mst_topology_mgr *mgr);
908 int __must_check
909 drm_dp_atomic_release_time_slots(struct drm_atomic_state *state,
910 				 struct drm_dp_mst_topology_mgr *mgr,
911 				 struct drm_dp_mst_port *port);
912 void drm_dp_mst_atomic_wait_for_dependencies(struct drm_atomic_state *state);
913 int __must_check drm_dp_mst_atomic_setup_commit(struct drm_atomic_state *state);
914 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
915 				 struct drm_dp_mst_port *port, bool power_up);
916 int drm_dp_send_query_stream_enc_status(struct drm_dp_mst_topology_mgr *mgr,
917 		struct drm_dp_mst_port *port,
918 		struct drm_dp_query_stream_enc_status_ack_reply *status);
919 int __must_check drm_dp_mst_atomic_check(struct drm_atomic_state *state);
920 int __must_check drm_dp_mst_root_conn_atomic_check(struct drm_connector_state *new_conn_state,
921 						   struct drm_dp_mst_topology_mgr *mgr);
922 
923 void drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port);
924 void drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port);
925 
926 struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port);
927 
928 static inline struct drm_dp_mst_topology_state *
to_drm_dp_mst_topology_state(struct drm_private_state * state)929 to_drm_dp_mst_topology_state(struct drm_private_state *state)
930 {
931 	return container_of(state, struct drm_dp_mst_topology_state, base);
932 }
933 
934 extern const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs;
935 
936 /**
937  * __drm_dp_mst_state_iter_get - private atomic state iterator function for
938  * macro-internal use
939  * @state: &struct drm_atomic_state pointer
940  * @mgr: pointer to the &struct drm_dp_mst_topology_mgr iteration cursor
941  * @old_state: optional pointer to the old &struct drm_dp_mst_topology_state
942  * iteration cursor
943  * @new_state: optional pointer to the new &struct drm_dp_mst_topology_state
944  * iteration cursor
945  * @i: int iteration cursor, for macro-internal use
946  *
947  * Used by for_each_oldnew_mst_mgr_in_state(),
948  * for_each_old_mst_mgr_in_state(), and for_each_new_mst_mgr_in_state(). Don't
949  * call this directly.
950  *
951  * Returns:
952  * True if the current &struct drm_private_obj is a &struct
953  * drm_dp_mst_topology_mgr, false otherwise.
954  */
955 static inline bool
__drm_dp_mst_state_iter_get(struct drm_atomic_state * state,struct drm_dp_mst_topology_mgr ** mgr,struct drm_dp_mst_topology_state ** old_state,struct drm_dp_mst_topology_state ** new_state,int i)956 __drm_dp_mst_state_iter_get(struct drm_atomic_state *state,
957 			    struct drm_dp_mst_topology_mgr **mgr,
958 			    struct drm_dp_mst_topology_state **old_state,
959 			    struct drm_dp_mst_topology_state **new_state,
960 			    int i)
961 {
962 	struct __drm_private_objs_state *objs_state = &state->private_objs[i];
963 
964 	if (objs_state->ptr->funcs != &drm_dp_mst_topology_state_funcs)
965 		return false;
966 
967 	*mgr = to_dp_mst_topology_mgr(objs_state->ptr);
968 	if (old_state)
969 		*old_state = to_dp_mst_topology_state(objs_state->old_state);
970 	if (new_state)
971 		*new_state = to_dp_mst_topology_state(objs_state->new_state);
972 
973 	return true;
974 }
975 
976 /**
977  * for_each_oldnew_mst_mgr_in_state - iterate over all DP MST topology
978  * managers 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  * @new_state: &struct drm_dp_mst_topology_state iteration cursor for the new
984  * state
985  * @__i: int iteration cursor, for macro-internal use
986  *
987  * This iterates over all DRM DP MST topology managers in an atomic update,
988  * tracking both old and new state. This is useful in places where the state
989  * delta needs to be considered, for example in atomic check functions.
990  */
991 #define for_each_oldnew_mst_mgr_in_state(__state, mgr, old_state, new_state, __i) \
992 	for ((__i) = 0; (__i) < (__state)->num_private_objs; (__i)++) \
993 		for_each_if(__drm_dp_mst_state_iter_get((__state), &(mgr), &(old_state), &(new_state), (__i)))
994 
995 /**
996  * for_each_old_mst_mgr_in_state - iterate over all DP MST topology managers
997  * in an atomic update
998  * @__state: &struct drm_atomic_state pointer
999  * @mgr: &struct drm_dp_mst_topology_mgr iteration cursor
1000  * @old_state: &struct drm_dp_mst_topology_state iteration cursor for the old
1001  * state
1002  * @__i: int iteration cursor, for macro-internal use
1003  *
1004  * This iterates over all DRM DP MST topology managers in an atomic update,
1005  * tracking only the old state. This is useful in disable functions, where we
1006  * need the old state the hardware is still in.
1007  */
1008 #define for_each_old_mst_mgr_in_state(__state, mgr, old_state, __i) \
1009 	for ((__i) = 0; (__i) < (__state)->num_private_objs; (__i)++) \
1010 		for_each_if(__drm_dp_mst_state_iter_get((__state), &(mgr), &(old_state), NULL, (__i)))
1011 
1012 /**
1013  * for_each_new_mst_mgr_in_state - iterate over all DP MST topology managers
1014  * in an atomic update
1015  * @__state: &struct drm_atomic_state pointer
1016  * @mgr: &struct drm_dp_mst_topology_mgr iteration cursor
1017  * @new_state: &struct drm_dp_mst_topology_state iteration cursor for the new
1018  * state
1019  * @__i: int iteration cursor, for macro-internal use
1020  *
1021  * This iterates over all DRM DP MST topology managers in an atomic update,
1022  * tracking only the new state. This is useful in enable functions, where we
1023  * need the new state the hardware should be in when the atomic commit
1024  * operation has completed.
1025  */
1026 #define for_each_new_mst_mgr_in_state(__state, mgr, new_state, __i) \
1027 	for ((__i) = 0; (__i) < (__state)->num_private_objs; (__i)++) \
1028 		for_each_if(__drm_dp_mst_state_iter_get((__state), &(mgr), NULL, &(new_state), (__i)))
1029 
1030 #endif
1031