1 /*
2  * Copyright © 2014 Red Hat.
3  *
4  * Permission to use, copy, modify, distribute, and sell this software and its
5  * documentation for any purpose is hereby granted without fee, provided that
6  * the above copyright notice appear in all copies and that both that copyright
7  * notice and this permission notice appear in supporting documentation, and
8  * that the name of the copyright holders not be used in advertising or
9  * publicity pertaining to distribution of the software without specific,
10  * written prior permission.  The copyright holders make no representations
11  * about the suitability of this software for any purpose.  It is provided "as
12  * is" without express or implied warranty.
13  *
14  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20  * OF THIS SOFTWARE.
21  */
22 #ifndef _DRM_DP_MST_HELPER_H_
23 #define _DRM_DP_MST_HELPER_H_
24 
25 #include <linux/types.h>
26 #include <drm/drm_dp_helper.h>
27 
28 struct drm_dp_mst_branch;
29 
30 /**
31  * struct drm_dp_vcpi - Virtual Channel Payload Identifer
32  * @vcpi: Virtual channel ID.
33  * @pbn: Payload Bandwidth Number for this channel
34  * @aligned_pbn: PBN aligned with slot size
35  * @num_slots: number of slots for this PBN
36  */
37 struct drm_dp_vcpi {
38 	int vcpi;
39 	int pbn;
40 	int aligned_pbn;
41 	int num_slots;
42 };
43 
44 /**
45  * struct drm_dp_mst_port - MST port
46  * @kref: reference count for this port.
47  * @guid_valid: for DP 1.2 devices if we have validated the GUID.
48  * @guid: guid for DP 1.2 device on this port.
49  * @port_num: port number
50  * @input: if this port is an input port.
51  * @mcs: message capability status - DP 1.2 spec.
52  * @ddps: DisplayPort Device Plug Status - DP 1.2
53  * @pdt: Peer Device Type
54  * @ldps: Legacy Device Plug Status
55  * @dpcd_rev: DPCD revision of device on this port
56  * @num_sdp_streams: Number of simultaneous streams
57  * @num_sdp_stream_sinks: Number of stream sinks
58  * @available_pbn: Available bandwidth for this port.
59  * @next: link to next port on this branch device
60  * @mstb: branch device attach below this port
61  * @aux: i2c aux transport to talk to device connected to this port.
62  * @parent: branch device parent of this port
63  * @vcpi: Virtual Channel Payload info for this port.
64  * @connector: DRM connector this port is connected to.
65  * @mgr: topology manager this port lives under.
66  *
67  * This structure represents an MST port endpoint on a device somewhere
68  * in the MST topology.
69  */
70 struct drm_dp_mst_port {
71 	struct kref kref;
72 
73 	/* if dpcd 1.2 device is on this port - its GUID info */
74 	bool guid_valid;
75 	u8 guid[16];
76 
77 	u8 port_num;
78 	bool input;
79 	bool mcs;
80 	bool ddps;
81 	u8 pdt;
82 	bool ldps;
83 	u8 dpcd_rev;
84 	u8 num_sdp_streams;
85 	u8 num_sdp_stream_sinks;
86 	uint16_t available_pbn;
87 	struct list_head next;
88 	struct drm_dp_mst_branch *mstb; /* pointer to an mstb if this port has one */
89 	struct drm_dp_aux aux; /* i2c bus for this port? */
90 	struct drm_dp_mst_branch *parent;
91 
92 	struct drm_dp_vcpi vcpi;
93 	struct drm_connector *connector;
94 	struct drm_dp_mst_topology_mgr *mgr;
95 };
96 
97 /**
98  * struct drm_dp_mst_branch - MST branch device.
99  * @kref: reference count for this port.
100  * @rad: Relative Address to talk to this branch device.
101  * @lct: Link count total to talk to this branch device.
102  * @num_ports: number of ports on the branch.
103  * @msg_slots: one bit per transmitted msg slot.
104  * @ports: linked list of ports on this branch.
105  * @port_parent: pointer to the port parent, NULL if toplevel.
106  * @mgr: topology manager for this branch device.
107  * @tx_slots: transmission slots for this device.
108  * @last_seqno: last sequence number used to talk to this.
109  * @link_address_sent: if a link address message has been sent to this device yet.
110  *
111  * This structure represents an MST branch device, there is one
112  * primary branch device at the root, along with any others connected
113  * to downstream ports
114  */
115 struct drm_dp_mst_branch {
116 	struct kref kref;
117 	u8 rad[8];
118 	u8 lct;
119 	int num_ports;
120 
121 	int msg_slots;
122 	struct list_head ports;
123 
124 	/* list of tx ops queue for this port */
125 	struct drm_dp_mst_port *port_parent;
126 	struct drm_dp_mst_topology_mgr *mgr;
127 
128 	/* slots are protected by mstb->mgr->qlock */
129 	struct drm_dp_sideband_msg_tx *tx_slots[2];
130 	int last_seqno;
131 	bool link_address_sent;
132 };
133 
134 
135 /* sideband msg header - not bit struct */
136 struct drm_dp_sideband_msg_hdr {
137 	u8 lct;
138 	u8 lcr;
139 	u8 rad[8];
140 	bool broadcast;
141 	bool path_msg;
142 	u8 msg_len;
143 	bool somt;
144 	bool eomt;
145 	bool seqno;
146 };
147 
148 struct drm_dp_nak_reply {
149 	u8 guid[16];
150 	u8 reason;
151 	u8 nak_data;
152 };
153 
154 struct drm_dp_link_address_ack_reply {
155 	u8 guid[16];
156 	u8 nports;
157 	struct drm_dp_link_addr_reply_port {
158 		bool input_port;
159 		u8 peer_device_type;
160 		u8 port_number;
161 		bool mcs;
162 		bool ddps;
163 		bool legacy_device_plug_status;
164 		u8 dpcd_revision;
165 		u8 peer_guid[16];
166 		u8 num_sdp_streams;
167 		u8 num_sdp_stream_sinks;
168 	} ports[16];
169 };
170 
171 struct drm_dp_remote_dpcd_read_ack_reply {
172 	u8 port_number;
173 	u8 num_bytes;
174 	u8 bytes[255];
175 };
176 
177 struct drm_dp_remote_dpcd_write_ack_reply {
178 	u8 port_number;
179 };
180 
181 struct drm_dp_remote_dpcd_write_nak_reply {
182 	u8 port_number;
183 	u8 reason;
184 	u8 bytes_written_before_failure;
185 };
186 
187 struct drm_dp_remote_i2c_read_ack_reply {
188 	u8 port_number;
189 	u8 num_bytes;
190 	u8 bytes[255];
191 };
192 
193 struct drm_dp_remote_i2c_read_nak_reply {
194 	u8 port_number;
195 	u8 nak_reason;
196 	u8 i2c_nak_transaction;
197 };
198 
199 struct drm_dp_remote_i2c_write_ack_reply {
200 	u8 port_number;
201 };
202 
203 
204 struct drm_dp_sideband_msg_rx {
205 	u8 chunk[48];
206 	u8 msg[256];
207 	u8 curchunk_len;
208 	u8 curchunk_idx; /* chunk we are parsing now */
209 	u8 curchunk_hdrlen;
210 	u8 curlen; /* total length of the msg */
211 	bool have_somt;
212 	bool have_eomt;
213 	struct drm_dp_sideband_msg_hdr initial_hdr;
214 };
215 
216 
217 struct drm_dp_allocate_payload {
218 	u8 port_number;
219 	u8 number_sdp_streams;
220 	u8 vcpi;
221 	u16 pbn;
222 	u8 sdp_stream_sink[8];
223 };
224 
225 struct drm_dp_allocate_payload_ack_reply {
226 	u8 port_number;
227 	u8 vcpi;
228 	u16 allocated_pbn;
229 };
230 
231 struct drm_dp_connection_status_notify {
232 	u8 guid[16];
233 	u8 port_number;
234 	bool legacy_device_plug_status;
235 	bool displayport_device_plug_status;
236 	bool message_capability_status;
237 	bool input_port;
238 	u8 peer_device_type;
239 };
240 
241 struct drm_dp_remote_dpcd_read {
242 	u8 port_number;
243 	u32 dpcd_address;
244 	u8 num_bytes;
245 };
246 
247 struct drm_dp_remote_dpcd_write {
248 	u8 port_number;
249 	u32 dpcd_address;
250 	u8 num_bytes;
251 	u8 *bytes;
252 };
253 
254 struct drm_dp_remote_i2c_read {
255 	u8 num_transactions;
256 	u8 port_number;
257 	struct {
258 		u8 i2c_dev_id;
259 		u8 num_bytes;
260 		u8 *bytes;
261 		u8 no_stop_bit;
262 		u8 i2c_transaction_delay;
263 	} transactions[4];
264 	u8 read_i2c_device_id;
265 	u8 num_bytes_read;
266 };
267 
268 struct drm_dp_remote_i2c_write {
269 	u8 port_number;
270 	u8 write_i2c_device_id;
271 	u8 num_bytes;
272 	u8 *bytes;
273 };
274 
275 /* this covers ENUM_RESOURCES, POWER_DOWN_PHY, POWER_UP_PHY */
276 struct drm_dp_port_number_req {
277 	u8 port_number;
278 };
279 
280 struct drm_dp_enum_path_resources_ack_reply {
281 	u8 port_number;
282 	u16 full_payload_bw_number;
283 	u16 avail_payload_bw_number;
284 };
285 
286 /* covers POWER_DOWN_PHY, POWER_UP_PHY */
287 struct drm_dp_port_number_rep {
288 	u8 port_number;
289 };
290 
291 struct drm_dp_query_payload {
292 	u8 port_number;
293 	u8 vcpi;
294 };
295 
296 struct drm_dp_resource_status_notify {
297 	u8 port_number;
298 	u8 guid[16];
299 	u16 available_pbn;
300 };
301 
302 struct drm_dp_query_payload_ack_reply {
303 	u8 port_number;
304 	u8 allocated_pbn;
305 };
306 
307 struct drm_dp_sideband_msg_req_body {
308 	u8 req_type;
309 	union ack_req {
310 		struct drm_dp_connection_status_notify conn_stat;
311 		struct drm_dp_port_number_req port_num;
312 		struct drm_dp_resource_status_notify resource_stat;
313 
314 		struct drm_dp_query_payload query_payload;
315 		struct drm_dp_allocate_payload allocate_payload;
316 
317 		struct drm_dp_remote_dpcd_read dpcd_read;
318 		struct drm_dp_remote_dpcd_write dpcd_write;
319 
320 		struct drm_dp_remote_i2c_read i2c_read;
321 		struct drm_dp_remote_i2c_write i2c_write;
322 	} u;
323 };
324 
325 struct drm_dp_sideband_msg_reply_body {
326 	u8 reply_type;
327 	u8 req_type;
328 	union ack_replies {
329 		struct drm_dp_nak_reply nak;
330 		struct drm_dp_link_address_ack_reply link_addr;
331 		struct drm_dp_port_number_rep port_number;
332 
333 		struct drm_dp_enum_path_resources_ack_reply path_resources;
334 		struct drm_dp_allocate_payload_ack_reply allocate_payload;
335 		struct drm_dp_query_payload_ack_reply query_payload;
336 
337 		struct drm_dp_remote_dpcd_read_ack_reply remote_dpcd_read_ack;
338 		struct drm_dp_remote_dpcd_write_ack_reply remote_dpcd_write_ack;
339 		struct drm_dp_remote_dpcd_write_nak_reply remote_dpcd_write_nack;
340 
341 		struct drm_dp_remote_i2c_read_ack_reply remote_i2c_read_ack;
342 		struct drm_dp_remote_i2c_read_nak_reply remote_i2c_read_nack;
343 		struct drm_dp_remote_i2c_write_ack_reply remote_i2c_write_ack;
344 	} u;
345 };
346 
347 /* msg is queued to be put into a slot */
348 #define DRM_DP_SIDEBAND_TX_QUEUED 0
349 /* msg has started transmitting on a slot - still on msgq */
350 #define DRM_DP_SIDEBAND_TX_START_SEND 1
351 /* msg has finished transmitting on a slot - removed from msgq only in slot */
352 #define DRM_DP_SIDEBAND_TX_SENT 2
353 /* msg has received a response - removed from slot */
354 #define DRM_DP_SIDEBAND_TX_RX 3
355 #define DRM_DP_SIDEBAND_TX_TIMEOUT 4
356 
357 struct drm_dp_sideband_msg_tx {
358 	u8 msg[256];
359 	u8 chunk[48];
360 	u8 cur_offset;
361 	u8 cur_len;
362 	struct drm_dp_mst_branch *dst;
363 	struct list_head next;
364 	int seqno;
365 	int state;
366 	bool path_msg;
367 	struct drm_dp_sideband_msg_reply_body reply;
368 };
369 
370 /* sideband msg handler */
371 struct drm_dp_mst_topology_mgr;
372 struct drm_dp_mst_topology_cbs {
373 	/* create a connector for a port */
374 	struct drm_connector *(*add_connector)(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, char *path);
375 	void (*destroy_connector)(struct drm_dp_mst_topology_mgr *mgr,
376 				  struct drm_connector *connector);
377 	void (*hotplug)(struct drm_dp_mst_topology_mgr *mgr);
378 
379 };
380 
381 #define DP_MAX_PAYLOAD (sizeof(unsigned long) * 8)
382 
383 #define DP_PAYLOAD_LOCAL 1
384 #define DP_PAYLOAD_REMOTE 2
385 #define DP_PAYLOAD_DELETE_LOCAL 3
386 
387 struct drm_dp_payload {
388 	int payload_state;
389 	int start_slot;
390 	int num_slots;
391 };
392 
393 /**
394  * struct drm_dp_mst_topology_mgr - DisplayPort MST manager
395  * @dev: device pointer for adding i2c devices etc.
396  * @cbs: callbacks for connector addition and destruction.
397  * @max_dpcd_transaction_bytes - maximum number of bytes to read/write in one go.
398  * @aux: aux channel for the DP connector.
399  * @max_payloads: maximum number of payloads the GPU can generate.
400  * @conn_base_id: DRM connector ID this mgr is connected to.
401  * @down_rep_recv: msg receiver state for down replies.
402  * @up_req_recv: msg receiver state for up requests.
403  * @lock: protects mst state, primary, guid, dpcd.
404  * @mst_state: if this manager is enabled for an MST capable port.
405  * @mst_primary: pointer to the primary branch device.
406  * @guid_valid: GUID valid for the primary branch device.
407  * @guid: GUID for primary port.
408  * @dpcd: cache of DPCD for primary port.
409  * @pbn_div: PBN to slots divisor.
410  *
411  * This struct represents the toplevel displayport MST topology manager.
412  * There should be one instance of this for every MST capable DP connector
413  * on the GPU.
414  */
415 struct drm_dp_mst_topology_mgr {
416 
417 	struct device *dev;
418 	struct drm_dp_mst_topology_cbs *cbs;
419 	int max_dpcd_transaction_bytes;
420 	struct drm_dp_aux *aux; /* auxch for this topology mgr to use */
421 	int max_payloads;
422 	int conn_base_id;
423 
424 	/* only ever accessed from the workqueue - which should be serialised */
425 	struct drm_dp_sideband_msg_rx down_rep_recv;
426 	struct drm_dp_sideband_msg_rx up_req_recv;
427 
428 	/* pointer to info about the initial MST device */
429 	struct lock lock; /* protects mst_state + primary + guid + dpcd */
430 
431 	bool mst_state;
432 	struct drm_dp_mst_branch *mst_primary;
433 	/* primary MST device GUID */
434 	bool guid_valid;
435 	u8 guid[16];
436 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
437 	u8 sink_count;
438 	int pbn_div;
439 	int total_slots;
440 	int avail_slots;
441 	int total_pbn;
442 
443 	/* messages to be transmitted */
444 	/* qlock protects the upq/downq and in_progress,
445 	   the mstb tx_slots and txmsg->state once they are queued */
446 	struct lock qlock;
447 	struct list_head tx_msg_downq;
448 	struct list_head tx_msg_upq;
449 	bool tx_down_in_progress;
450 	bool tx_up_in_progress;
451 
452 	/* payload info + lock for it */
453 	struct lock payload_lock;
454 	struct drm_dp_vcpi **proposed_vcpis;
455 	struct drm_dp_payload *payloads;
456 	unsigned long payload_mask;
457 
458 	wait_queue_head_t tx_waitq;
459 	struct work_struct work;
460 
461 	struct work_struct tx_work;
462 };
463 
464 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr, struct device *dev, struct drm_dp_aux *aux, int max_dpcd_transaction_bytes, int max_payloads, int conn_base_id);
465 
466 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr);
467 
468 
469 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state);
470 
471 
472 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled);
473 
474 
475 enum drm_connector_status drm_dp_mst_detect_port(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
476 
477 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
478 
479 
480 int drm_dp_calc_pbn_mode(int clock, int bpp);
481 
482 
483 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots);
484 
485 
486 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
487 
488 
489 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
490 				struct drm_dp_mst_port *port);
491 
492 
493 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
494 			   int pbn);
495 
496 
497 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr);
498 
499 
500 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr);
501 
502 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr);
503 
504 void drm_dp_mst_dump_topology(struct seq_file *m,
505 			      struct drm_dp_mst_topology_mgr *mgr);
506 
507 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr);
508 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr);
509 #endif
510