1 /*
2  * Copyright (c) 2022 The Chromium OS Authors
3  *
4  * SPDX-License-Identifier: Apache-2.0
5  */
6 
7 #ifndef ZEPHYR_SUBSYS_USBC_PE_COMMON_INTERNAL_H_
8 #define ZEPHYR_SUBSYS_USBC_PE_COMMON_INTERNAL_H_
9 
10 #include <zephyr/kernel.h>
11 #include <zephyr/usb_c/usbc.h>
12 #include <zephyr/drivers/usb_c/usbc_pd.h>
13 #include <zephyr/drivers/usb_c/usbc_tc.h>
14 #include <zephyr/smf.h>
15 #include "usbc_timer.h"
16 
17 /**
18  * @brief Used in sub-machines for message transmit and receive operation
19  */
20 enum sm_msg_xmit {
21 	/* Wait for a message transmission sub-machine state */
22 	SM_WAIT_FOR_TX,
23 	/* Wait for a message reception sub-machine state */
24 	SM_WAIT_FOR_RX,
25 };
26 
27 /**
28  * @brief Used in sub-machines for message source hard reset operation
29  */
30 enum sm_hard_reset {
31 	/* Start the hard-reset sub-machine state */
32 	SM_HARD_RESET_START,
33 	/* Wait for hard-reset to complete sub-machine state */
34 	SM_HARD_RESET_WAIT,
35 };
36 
37 /**
38  * @brief Policy Engine Errors
39  */
40 enum pe_error {
41 	/** Transmit error */
42 	ERR_XMIT,
43 };
44 
45 /**
46  * @brief Policy Engine Layer States
47  */
48 enum usbc_pe_state {
49 	/** PE_SNK_Startup */
50 	PE_SNK_STARTUP,
51 	/** PE_SNK_Discovery */
52 	PE_SNK_DISCOVERY,
53 	/** PE_SNK_Wait_for_Capabilities */
54 	PE_SNK_WAIT_FOR_CAPABILITIES,
55 	/** PE_SNK_Evaluate_Capability */
56 	PE_SNK_EVALUATE_CAPABILITY,
57 	/** PE_SNK_Select_Capability */
58 	PE_SNK_SELECT_CAPABILITY,
59 	/** PE_SNK_Transition_Sink */
60 	PE_SNK_TRANSITION_SINK,
61 	/** PE_SNK_Ready */
62 	PE_SNK_READY,
63 	/** PE_SNK_Hard_Reset */
64 	PE_SNK_HARD_RESET,
65 	/** PE_SNK_Transition_to_default */
66 	PE_SNK_TRANSITION_TO_DEFAULT,
67 	/** PE_SNK_Give_Sink_Cap */
68 	PE_SNK_GIVE_SINK_CAP,
69 	/** PE_SNK_Get_Source_Cap */
70 	PE_SNK_GET_SOURCE_CAP,
71 
72 	/** PE_SRC_Startup */
73 	PE_SRC_STARTUP,
74 	/** PE_SRC_Discovery */
75 	PE_SRC_DISCOVERY,
76 	/** PE_SRC_Send_Capabilities */
77 	PE_SRC_SEND_CAPABILITIES,
78 	/** PE_SRC_Negotiate_capability */
79 	PE_SRC_NEGOTIATE_CAPABILITY,
80 	/** PE_SRC_Capability_Response */
81 	PE_SRC_CAPABILITY_RESPONSE,
82 	/** PE_SRC_Transition_Supply */
83 	PE_SRC_TRANSITION_SUPPLY,
84 	/** PE_SRC_Ready */
85 	PE_SRC_READY,
86 	/** PE_SRC_Hard_Reset */
87 	PE_SRC_HARD_RESET,
88 	/** PE_SRC_Hard_Reset_Received */
89 	PE_SRC_HARD_RESET_RECEIVED,
90 	/** PE_SRC_Transition_To_Default */
91 	PE_SRC_TRANSITION_TO_DEFAULT,
92 
93 	/** PE_SNK_Soft_Reset and PE_SRC_Soft_Reset */
94 	PE_SOFT_RESET,
95 	/** PE_SNK_Chunk_Received or PE_SRC_Chunk_Received */
96 	PE_CHUNK_RECEIVED,
97 	/**PE_Send_Soft_Reset */
98 	PE_SEND_SOFT_RESET,
99 
100 	/** PE_Send_Not_Supported */
101 	PE_SEND_NOT_SUPPORTED,
102 	/** PE_DRS_Evaluate_Swap */
103 	PE_DRS_EVALUATE_SWAP,
104 	/** PE_DRS_Send_Swap */
105 	PE_DRS_SEND_SWAP,
106 	/** PE_Get_Sink_Cap */
107 	PE_GET_SINK_CAP,
108 
109 	/** PE_Suspend. Not part of the PD specification. */
110 	PE_SUSPEND,
111 
112 	/**
113 	 * NOTE: The states below should not be called directly. They're used
114 	 * internally by the state machine.
115 	 */
116 
117 	/** PE_SENDER_RESPONSE_PARENT. Not part of the PD specification. */
118 	PE_SENDER_RESPONSE_PARENT,
119 	/** PE_SRC_HARD_RESET_PARENT. Not part of the PD specification. */
120 	PE_SRC_HARD_RESET_PARENT,
121 	/** Number of PE States */
122 	PE_STATE_COUNT
123 };
124 
125 /**
126  * @brief Policy Engine Layer Flags
127  */
128 enum pe_flags {
129 	/** Accept message received from port partner */
130 	PE_FLAGS_ACCEPT = 0,
131 	/** A message we requested to be sent has been transmitted */
132 	PE_FLAGS_TX_COMPLETE = 1,
133 	/** A message sent by a port partner has been received */
134 	PE_FLAGS_MSG_RECEIVED = 2,
135 	/**
136 	 * A hard reset has been requested by the DPM but has not been sent,
137 	 * not currently used
138 	 */
139 	PE_FLAGS_HARD_RESET_PENDING = 3,
140 	/** An explicit contract is in place with our port partner */
141 	PE_FLAGS_EXPLICIT_CONTRACT = 4,
142 	/**
143 	 * Waiting for Sink Capabailities timed out.  Used for retry error
144 	 * handling
145 	 */
146 	PE_FLAGS_SNK_WAIT_CAP_TIMEOUT = 5,
147 	/**
148 	 * Flag to note current Atomic Message Sequence (AMS) is interruptible.
149 	 * If this flag is not set the AMS is non-interruptible. This flag must
150 	 * be set in the interruptible's message state entry.
151 	 */
152 	PE_FLAGS_INTERRUPTIBLE_AMS = 6,
153 	/** Flag to trigger sending a Data Role Swap */
154 	PE_FLAGS_DR_SWAP_TO_DFP = 7,
155 	/** Flag is set when an AMS is initiated by the Device Policy Manager */
156 	PE_FLAGS_DPM_INITIATED_AMS = 8,
157 	/** Flag to note message was discarded due to incoming message */
158 	PE_FLAGS_MSG_DISCARDED = 9,
159 	/** Flag to trigger sending a soft reset */
160 	PE_FLAGS_SEND_SOFT_RESET = 10,
161 	/**
162 	 * This flag is set when a Wait message is received in response to a
163 	 * Sink REQUEST
164 	 */
165 	PE_FLAGS_WAIT_SINK_REQUEST = 11,
166 	/**
167 	 * This flag is set when a Wait message is received in response to a
168 	 * Data Role Swap
169 	 */
170 	PE_FLAGS_WAIT_DATA_ROLE_SWAP = 12,
171 	/**
172 	 * This flag is set when a protocol error occurs.
173 	 */
174 	PE_FLAGS_PROTOCOL_ERROR = 13,
175 	/** This flag is set when a transmit error occurs. */
176 	PE_FLAGS_MSG_XMIT_ERROR = 14,
177 
178 	/* The Port Partner is PD connected */
179 	PE_FLAGS_PD_CONNECTED = 15,
180 	/* The Port partner has been PD connected at least once */
181 	PE_FLAGS_HAS_BEEN_PD_CONNECTED = 16,
182 	/* A Protocol Error didn't generate a Soft Reset */
183 	PE_FLAGS_PROTOCOL_ERROR_NO_SOFT_RESET = 17,
184 	/* This flag is set when the first AMS message is sent */
185 	PE_FLAGS_FIRST_MSG_SENT = 18,
186 	/** Number of PE Flags */
187 	PE_FLAGS_COUNT
188 };
189 
190 /**
191  * @brief Policy Engine State Machine Object
192  */
193 struct policy_engine {
194 	/** state machine context */
195 	struct smf_ctx ctx;
196 	/** Port device */
197 	const struct device *dev;
198 	/** state machine flags */
199 	ATOMIC_DEFINE(flags, PE_FLAGS_COUNT);
200 	/** current port power role (SOURCE or SINK) */
201 	enum tc_power_role power_role;
202 	/** current port data role (DFP or UFP) */
203 	enum tc_data_role data_role;
204 	/** port address where soft resets are sent */
205 	enum pd_packet_type soft_reset_sop;
206 	/** DPM request */
207 	enum usbc_policy_request_t dpm_request;
208 	/** generic variable used for simple in state statemachines */
209 	uint32_t submachine;
210 #ifdef CONFIG_USBC_CSM_SOURCE_ONLY
211 	/** The Sink made a valid request of the Source if true */
212 	bool snk_request_can_be_met;
213 	/** Outcome of the Sink request */
214 	enum usbc_snk_req_reply_t snk_request_reply;
215 	/** Save Sink Request Object */
216 	uint32_t snk_request;
217 	/** Present Contract stores the current Sink Request */
218 	uint32_t present_contract;
219 #endif
220 	/* Counters */
221 
222 	/**
223 	 * This counter is used to retry the Hard Reset whenever there is no
224 	 * response from the remote device.
225 	 */
226 	uint32_t hard_reset_counter;
227 
228 #ifdef CONFIG_USBC_CSM_SOURCE_ONLY
229 	/**
230 	 * This counter tracks the number of times a Source Caps message was
231 	 * sent.
232 	 */
233 	uint32_t caps_counter;
234 #endif
235 
236 	/* Timers */
237 
238 	/** tSenderResponse timer */
239 	struct usbc_timer_t pd_t_sender_response;
240 	/** tChunkingNotSupported timer */
241 	struct usbc_timer_t pd_t_chunking_not_supported;
242 	/** Time to wait before resending message after WAIT reception */
243 	struct usbc_timer_t pd_t_wait_to_resend;
244 
245 #ifdef CONFIG_USBC_CSM_SINK_ONLY
246 	/** tTypeCSinkWaitCap timer */
247 	struct usbc_timer_t pd_t_typec_sink_wait_cap;
248 	/** tPSTransition timer */
249 	struct usbc_timer_t pd_t_ps_transition;
250 	/** tSinkRequest timer */
251 	struct usbc_timer_t pd_t_sink_request;
252 #else
253 	/** tTypeCSendSourceCap timer */
254 	struct usbc_timer_t pd_t_typec_send_source_cap;
255 	/** tNoResponse timer */
256 	struct usbc_timer_t pd_t_no_response;
257 	/** tPSHardReset timer */
258 	struct usbc_timer_t pd_t_ps_hard_reset;
259 #endif /* CONFIG_USBC_CSM_SINK_ONLY */
260 };
261 
262 /**
263  * @brief First message in AMS has been sent
264  *
265  * @param dev Pointer to the device structure for the driver instance
266  */
267 void pe_first_msg_sent(const struct device *dev);
268 
269 /**
270  * @brief Sets a Policy Engine state
271  *
272  * @param dev Pointer to the device structure for the driver instance
273  * @param state next PE State to enter
274  */
275 void pe_set_state(const struct device *dev, const enum usbc_pe_state state);
276 
277 /**
278  * @brief Get the Policy Engine's current state
279  *
280  * @param dev Pointer to the device structure for the driver instance
281  * @retval current PE state
282  */
283 enum usbc_pe_state pe_get_state(const struct device *dev);
284 
285 /**
286  * @brief Get the Policy Engine's previous state
287  *
288  * @param dev Pointer to the device structure for the driver instance
289  * @retval last PE state
290  */
291 enum usbc_pe_state pe_get_last_state(const struct device *dev);
292 
293 /**
294  * @brief Send a soft reset message
295  *
296  * @param dev Pointer to the device structure for the driver instance
297  * @param type SOP* to send soft reset message
298  */
299 void pe_send_soft_reset(const struct device *dev, const enum pd_packet_type type);
300 
301 /**
302  * @brief Send a Power Delivery Data Message
303  *
304  * @param dev Pointer to the device structure for the driver instance
305  * @param type SOP* to send message
306  * @param msg PD data message to send
307  */
308 void pe_send_data_msg(const struct device *dev,
309 		   const enum pd_packet_type type,
310 		   const enum pd_data_msg_type msg);
311 
312 /**
313  * @brief Send a Power Delivery Control Message
314  *
315  * @param dev Pointer to the device structure for the driver instance
316  * @param type SOP* to send message
317  * @param msg PD control message to send
318  */
319 void pe_send_ctrl_msg(const struct device *dev,
320 		   const enum pd_packet_type type,
321 		   const enum pd_ctrl_msg_type msg);
322 
323 /**
324  * @brief Request desired voltage from source.
325  *
326  * @param dev Pointer to the device structure for the driver instance
327  * @param rdo Request Data Object to send
328  */
329 void pe_send_request_msg(const struct device *dev, const uint32_t rdo);
330 
331 /**
332  * @brief Transitions state after receiving an extended message.
333  *
334  * @param dev Pointer to the device structure for the driver instance
335  */
336 void extended_message_not_supported(const struct device *dev);
337 
338 /**
339  * @brief Check if a specific control message was received
340  *
341  * @param dev Pointer to the device structure for the driver instance
342  * @param header message header containing the message
343  * @param mt message type to check
344  * @retval true if the header contains the message type, else false
345  */
346 bool received_control_message(const struct device *dev, const union pd_header header,
347 			      const enum pd_ctrl_msg_type mt);
348 
349 /**
350  * @brief Check if a specific data message was received
351  *
352  * @param dev Pointer to the device structure for the driver instance
353  * @param header message header containing the message
354  * @param mt message type to check
355  * @param true if the header contains the message type, else false
356  */
357 bool received_data_message(const struct device *dev, const union pd_header header,
358 			   const enum pd_data_msg_type mt);
359 
360 /**
361  * @brief Check a DPM policy
362  *
363  * @param dev Pointer to the device structure for the driver instance
364  * @param pc The DPM policy to check
365  * @retval true if the DPM approves the check, else false
366  */
367 bool policy_check(const struct device *dev, const enum usbc_policy_check_t pc);
368 
369 /**
370  * @brief Notify the DPM of a policy change
371  *
372  * @param dev Pointer to the device structure for the driver instance
373  * @param notify The notification to send the the DPM
374  */
375 void policy_notify(const struct device *dev, const enum usbc_policy_notify_t notify);
376 
377 /**
378  * @brief Notify the DPM of a WAIT message reception
379  *
380  * @param dev Pointer to the device structure for the driver instance
381  * @param notify Wait message to send to DPM
382  * @retval true if the Policy Engine should wait and try the action again
383  */
384 bool policy_wait_notify(const struct device *dev, const enum usbc_policy_wait_t notify);
385 
386 /**
387  * @brief Send the received source caps to the DPM
388  *
389  * @param dev Pointer to the device structure for the driver instance
390  * @param pdos pointer to pdos to send
391  * @param num_pdos number of pdos to send
392  */
393 void policy_set_src_cap(const struct device *dev, const uint32_t *pdos, const int num_pdos);
394 
395 /**
396  * @brief Check if the sink request can be met by the DPM
397  */
398 enum usbc_snk_req_reply_t policy_check_sink_request(const struct device *dev,
399 						const uint32_t request_msg);
400 
401 /**
402  * @brief Check if the Present Contract is still valid.
403  *
404  * @note The contract is considered "invalid" if the previous current/voltage
405  *	 are no longer available AND the sink fails to make a valid request.
406  */
407 bool policy_present_contract_is_valid(const struct device *dev, const uint32_t present_contract);
408 
409 /**
410  * @brief Get a Request Data Object from the DPM
411  *
412  * @param dev Pointer to the device structure for the driver instance
413  * @retval the RDO from the DPM
414  */
415 uint32_t policy_get_request_data_object(const struct device *dev);
416 
417 /**
418  * @brief Check if the sink is a default level
419  *
420  * @param dev Pointer to the device structure for the driver instance
421  * @retval true if sink is at default value, else false
422  */
423 bool policy_is_snk_at_default(const struct device *dev);
424 
425 /**
426  * @brief Get sink caps from the DPM
427  *
428  * @param dev Pointer to the device structure for the driver instance
429  * @param pdos pointer to pdo sink caps
430  * @param num_pdos number of pdo sink caps
431  */
432 void policy_get_snk_cap(const struct device *dev, uint32_t **pdos, int *num_pdos);
433 
434 /**
435  * @brief Check if Source Power Supply is ready
436  */
437 bool policy_is_ps_ready(const struct device *dev);
438 
439 /**
440  * @brief Informs the Device Policy Manager that the Sink
441  *	  is unable to use the current Source Caps and should
442  *	  should enable a different set of Source Caps. True
443  *	  is returned if new Source Caps are available, else
444  *	  false.
445  */
446 bool policy_change_src_caps(const struct device *dev);
447 
448 /**
449  * @brief End and atomic messaging sequence
450  */
451 void pe_dpm_end_ams(const struct device *dev);
452 
453 /**
454  * @brief Handle common DPM requests
455  *
456  * @param dev Pointer to the device structure for the driver instance
457  * @retval true if request was handled, else false
458  */
459 bool common_dpm_requests(const struct device *dev);
460 
461 /**
462  * @brief This function must only be called in the subsystem init function.
463  *
464  * @param dev Pointer to the device structure for the driver instance.
465  */
466 void pe_subsys_init(const struct device *dev);
467 
468 /**
469  * @brief Start the Policy Engine Layer state machine. This is only called
470  *	  from the Type-C state machine.
471  *
472  * @param dev Pointer to the device structure for the driver instance
473  */
474 void pe_start(const struct device *dev);
475 
476 /**
477  * @brief Suspend the Policy Engine Layer state machine. This is only called
478  *	  from the Type-C state machine.
479  *
480  * @param dev Pointer to the device structure for the driver instance
481  */
482 void pe_suspend(const struct device *dev);
483 
484 /**
485  * @brief Run the Policy Engine Layer state machine. This is called from the
486  *	  subsystems port stack thread
487  *
488  * @param dev Pointer to the device structure for the driver instance
489  * @param dpm_request Device Policy Manager request
490  */
491 void pe_run(const struct device *dev,
492 	    const int32_t dpm_request);
493 
494 /**
495  * @brief Query if the Policy Engine is running
496  *
497  * @param dev Pointer to the device structure for the driver instance
498  *
499  * @retval TRUE if the Policy Engine is running
500  * @retval FALSE if the Policy Engine is not running
501  */
502 bool pe_is_running(const struct device *dev);
503 
504 /**
505  * @brief Informs the Policy Engine that a message was successfully sent
506  *
507  * @param dev Pointer to the device structure for the driver instance
508  */
509 void pe_message_sent(const struct device *dev);
510 
511 /**
512  * @brief Informs the Policy Engine of an error.
513  *
514  * @param dev Pointer to the device structure for the driver instance
515  * @param  e policy error
516  * @param type port partner address where error was generated
517  */
518 void pe_report_error(const struct device *dev,
519 		     const enum pe_error e,
520 		     const enum pd_packet_type type);
521 
522 /**
523  * @brief Informs the Policy Engine that a transmit message was discarded
524  *	  because of an incoming message.
525  *
526  * @param dev Pointer to the device structure for the driver instance
527  */
528 void pe_report_discard(const struct device *dev);
529 
530 /**
531  * @brief Called by the Protocol Layer to informs the Policy Engine
532  *	  that a message has been received.
533  *
534  * @param dev Pointer to the device structure for the driver instance
535  */
536 void pe_message_received(const struct device *dev);
537 
538 /**
539  * @brief Informs the Policy Engine that a hard reset was received.
540  *
541  * @param dev Pointer to the device structure for the driver instance
542  */
543 void pe_got_hard_reset(const struct device *dev);
544 
545 /**
546  * @brief Informs the Policy Engine that a soft reset was received.
547  *
548  * @param dev Pointer to the device structure for the driver instance
549  */
550 void pe_got_soft_reset(const struct device *dev);
551 
552 /**
553  * @brief Informs the Policy Engine that a hard reset was sent.
554  *
555  * @param dev Pointer to the device structure for the driver instance
556  */
557 void pe_hard_reset_sent(const struct device *dev);
558 
559 /**
560  * @brief Indicates if an explicit contract is in place
561  *
562  * @param dev Pointer to the device structure for the driver instance
563  *
564  * @retval true if an explicit contract is in place, else false
565  */
566 bool pe_is_explicit_contract(const struct device *dev);
567 
568 /*
569  * @brief Informs the Policy Engine that it should invalidate the
570  *	  explicit contract.
571  *
572  * @param dev Pointer to the device structure for the driver instance
573  */
574 void pe_invalidate_explicit_contract(const struct device *dev);
575 
576 /**
577  * @brief Return true if the PE is is within an atomic messaging sequence
578  *	  that it initiated with a SOP* port partner.
579  *
580  * @note The PRL layer polls this instead of using AMS_START and AMS_END
581  *	  notification from the PE that is called out by the spec
582  *
583  * @param dev Pointer to the device structure for the driver instance
584  */
585 bool pe_dpm_initiated_ams(const struct device *dev);
586 
587 /**
588  * @brief Get the current data role
589  *
590  * @param dev Pointer to the device structure for the driver instance
591  *
592  * @retval data role
593  */
594 enum tc_data_role pe_get_data_role(const struct device *dev);
595 
596 /**
597  * @brief Sets the data role and updates the TCPC
598  *
599  * @param dev Pointer to the device structure for the driver instance
600  * @param dr Data Role to be set
601  */
602 void pe_set_data_role(const struct device *dev, enum tc_data_role dr);
603 
604 /**
605  * @brief Get the current power role
606  *
607  * @param dev Pointer to the device structure for the driver instance
608  *
609  * @retval power role
610  */
611 enum tc_power_role pe_get_power_role(const struct device *dev);
612 
613 /**
614  * @brief Get cable plug role
615  *
616  * @param dev Pointer to the device structure for the driver instance
617  *
618  * @retval cable plug role
619  */
620 enum tc_cable_plug pe_get_cable_plug(const struct device *dev);
621 
622 #endif /* ZEPHYR_SUBSYS_USBC_PE_COMMON_INTERNAL_H_ */
623