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23136bff CM |
1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* | |
3 | * System Control and Management Interface (SCMI) Message Protocol | |
4 | * protocols common header file containing some definitions, structures | |
5 | * and function prototypes used in all the different SCMI protocols. | |
6 | * | |
7 | * Copyright (C) 2022 ARM Ltd. | |
8 | */ | |
9 | #ifndef _SCMI_PROTOCOLS_H | |
10 | #define _SCMI_PROTOCOLS_H | |
11 | ||
12 | #include <linux/bitfield.h> | |
13 | #include <linux/completion.h> | |
14 | #include <linux/device.h> | |
15 | #include <linux/errno.h> | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/hashtable.h> | |
18 | #include <linux/list.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/refcount.h> | |
21 | #include <linux/scmi_protocol.h> | |
22 | #include <linux/spinlock.h> | |
23 | #include <linux/types.h> | |
24 | ||
25 | #include <asm/unaligned.h> | |
26 | ||
27 | #define PROTOCOL_REV_MINOR_MASK GENMASK(15, 0) | |
28 | #define PROTOCOL_REV_MAJOR_MASK GENMASK(31, 16) | |
29 | #define PROTOCOL_REV_MAJOR(x) ((u16)(FIELD_GET(PROTOCOL_REV_MAJOR_MASK, (x)))) | |
30 | #define PROTOCOL_REV_MINOR(x) ((u16)(FIELD_GET(PROTOCOL_REV_MINOR_MASK, (x)))) | |
31 | ||
fc110108 CM |
32 | #define SCMI_PROTOCOL_VENDOR_BASE 0x80 |
33 | ||
23136bff CM |
34 | enum scmi_common_cmd { |
35 | PROTOCOL_VERSION = 0x0, | |
36 | PROTOCOL_ATTRIBUTES = 0x1, | |
37 | PROTOCOL_MESSAGE_ATTRIBUTES = 0x2, | |
8c80c42a | 38 | NEGOTIATE_PROTOCOL_VERSION = 0x10, |
23136bff CM |
39 | }; |
40 | ||
41 | /** | |
42 | * struct scmi_msg_resp_prot_version - Response for a message | |
43 | * | |
44 | * @minor_version: Minor version of the ABI that firmware supports | |
45 | * @major_version: Major version of the ABI that firmware supports | |
46 | * | |
47 | * In general, ABI version changes follow the rule that minor version increments | |
48 | * are backward compatible. Major revision changes in ABI may not be | |
49 | * backward compatible. | |
50 | * | |
51 | * Response to a generic message with message type SCMI_MSG_VERSION | |
52 | */ | |
53 | struct scmi_msg_resp_prot_version { | |
54 | __le16 minor_version; | |
55 | __le16 major_version; | |
56 | }; | |
57 | ||
58 | /** | |
59 | * struct scmi_msg - Message(Tx/Rx) structure | |
60 | * | |
61 | * @buf: Buffer pointer | |
62 | * @len: Length of data in the Buffer | |
63 | */ | |
64 | struct scmi_msg { | |
65 | void *buf; | |
66 | size_t len; | |
67 | }; | |
68 | ||
69 | /** | |
70 | * struct scmi_msg_hdr - Message(Tx/Rx) header | |
71 | * | |
72 | * @id: The identifier of the message being sent | |
73 | * @protocol_id: The identifier of the protocol used to send @id message | |
74 | * @type: The SCMI type for this message | |
75 | * @seq: The token to identify the message. When a message returns, the | |
76 | * platform returns the whole message header unmodified including the | |
77 | * token | |
78 | * @status: Status of the transfer once it's complete | |
79 | * @poll_completion: Indicate if the transfer needs to be polled for | |
80 | * completion or interrupt mode is used | |
81 | */ | |
82 | struct scmi_msg_hdr { | |
83 | u8 id; | |
84 | u8 protocol_id; | |
85 | u8 type; | |
86 | u16 seq; | |
87 | u32 status; | |
88 | bool poll_completion; | |
89 | }; | |
90 | ||
91 | /** | |
92 | * struct scmi_xfer - Structure representing a message flow | |
93 | * | |
94 | * @transfer_id: Unique ID for debug & profiling purpose | |
95 | * @hdr: Transmit message header | |
96 | * @tx: Transmit message | |
97 | * @rx: Receive message, the buffer should be pre-allocated to store | |
98 | * message. If request-ACK protocol is used, we can reuse the same | |
99 | * buffer for the rx path as we use for the tx path. | |
100 | * @done: command message transmit completion event | |
101 | * @async_done: pointer to delayed response message received event completion | |
102 | * @pending: True for xfers added to @pending_xfers hashtable | |
103 | * @node: An hlist_node reference used to store this xfer, alternatively, on | |
104 | * the free list @free_xfers or in the @pending_xfers hashtable | |
105 | * @users: A refcount to track the active users for this xfer. | |
106 | * This is meant to protect against the possibility that, when a command | |
107 | * transaction times out concurrently with the reception of a valid | |
108 | * response message, the xfer could be finally put on the TX path, and | |
109 | * so vanish, while on the RX path scmi_rx_callback() is still | |
110 | * processing it: in such a case this refcounting will ensure that, even | |
111 | * though the timed-out transaction will anyway cause the command | |
112 | * request to be reported as failed by time-out, the underlying xfer | |
113 | * cannot be discarded and possibly reused until the last one user on | |
114 | * the RX path has released it. | |
115 | * @busy: An atomic flag to ensure exclusive write access to this xfer | |
116 | * @state: The current state of this transfer, with states transitions deemed | |
117 | * valid being: | |
118 | * - SCMI_XFER_SENT_OK -> SCMI_XFER_RESP_OK [ -> SCMI_XFER_DRESP_OK ] | |
119 | * - SCMI_XFER_SENT_OK -> SCMI_XFER_DRESP_OK | |
120 | * (Missing synchronous response is assumed OK and ignored) | |
37057bf2 | 121 | * @flags: Optional flags associated to this xfer. |
23136bff CM |
122 | * @lock: A spinlock to protect state and busy fields. |
123 | * @priv: A pointer for transport private usage. | |
124 | */ | |
125 | struct scmi_xfer { | |
126 | int transfer_id; | |
127 | struct scmi_msg_hdr hdr; | |
128 | struct scmi_msg tx; | |
129 | struct scmi_msg rx; | |
130 | struct completion done; | |
131 | struct completion *async_done; | |
132 | bool pending; | |
133 | struct hlist_node node; | |
134 | refcount_t users; | |
135 | #define SCMI_XFER_FREE 0 | |
136 | #define SCMI_XFER_BUSY 1 | |
137 | atomic_t busy; | |
138 | #define SCMI_XFER_SENT_OK 0 | |
139 | #define SCMI_XFER_RESP_OK 1 | |
140 | #define SCMI_XFER_DRESP_OK 2 | |
141 | int state; | |
37057bf2 CM |
142 | #define SCMI_XFER_FLAG_IS_RAW BIT(0) |
143 | #define SCMI_XFER_IS_RAW(x) ((x)->flags & SCMI_XFER_FLAG_IS_RAW) | |
7860701d CM |
144 | #define SCMI_XFER_FLAG_CHAN_SET BIT(1) |
145 | #define SCMI_XFER_IS_CHAN_SET(x) \ | |
146 | ((x)->flags & SCMI_XFER_FLAG_CHAN_SET) | |
37057bf2 | 147 | int flags; |
23136bff CM |
148 | /* A lock to protect state and busy fields */ |
149 | spinlock_t lock; | |
150 | void *priv; | |
151 | }; | |
152 | ||
153 | struct scmi_xfer_ops; | |
5c873d12 | 154 | struct scmi_proto_helpers_ops; |
23136bff CM |
155 | |
156 | /** | |
157 | * struct scmi_protocol_handle - Reference to an initialized protocol instance | |
158 | * | |
159 | * @dev: A reference to the associated SCMI instance device (handle->dev). | |
160 | * @xops: A reference to a struct holding refs to the core xfer operations that | |
161 | * can be used by the protocol implementation to generate SCMI messages. | |
162 | * @set_priv: A method to set protocol private data for this instance. | |
163 | * @get_priv: A method to get protocol private data previously set. | |
164 | * | |
165 | * This structure represents a protocol initialized against specific SCMI | |
166 | * instance and it will be used as follows: | |
167 | * - as a parameter fed from the core to the protocol initialization code so | |
168 | * that it can access the core xfer operations to build and generate SCMI | |
169 | * messages exclusively for the specific underlying protocol instance. | |
170 | * - as an opaque handle fed by an SCMI driver user when it tries to access | |
171 | * this protocol through its own protocol operations. | |
172 | * In this case this handle will be returned as an opaque object together | |
173 | * with the related protocol operations when the SCMI driver tries to access | |
174 | * the protocol. | |
175 | */ | |
176 | struct scmi_protocol_handle { | |
177 | struct device *dev; | |
178 | const struct scmi_xfer_ops *xops; | |
5c873d12 | 179 | const struct scmi_proto_helpers_ops *hops; |
b5efc28a CM |
180 | int (*set_priv)(const struct scmi_protocol_handle *ph, void *priv, |
181 | u32 version); | |
23136bff CM |
182 | void *(*get_priv)(const struct scmi_protocol_handle *ph); |
183 | }; | |
184 | ||
36b6ea0f CM |
185 | /** |
186 | * struct scmi_iterator_state - Iterator current state descriptor | |
187 | * @desc_index: Starting index for the current mulit-part request. | |
188 | * @num_returned: Number of returned items in the last multi-part reply. | |
189 | * @num_remaining: Number of remaining items in the multi-part message. | |
190 | * @max_resources: Maximum acceptable number of items, configured by the caller | |
191 | * depending on the underlying resources that it is querying. | |
192 | * @loop_idx: The iterator loop index in the current multi-part reply. | |
754f04ca CM |
193 | * @rx_len: Size in bytes of the currenly processed message; it can be used by |
194 | * the user of the iterator to verify a reply size. | |
36b6ea0f CM |
195 | * @priv: Optional pointer to some additional state-related private data setup |
196 | * by the caller during the iterations. | |
197 | */ | |
198 | struct scmi_iterator_state { | |
199 | unsigned int desc_index; | |
200 | unsigned int num_returned; | |
201 | unsigned int num_remaining; | |
202 | unsigned int max_resources; | |
203 | unsigned int loop_idx; | |
754f04ca | 204 | size_t rx_len; |
36b6ea0f CM |
205 | void *priv; |
206 | }; | |
207 | ||
208 | /** | |
209 | * struct scmi_iterator_ops - Custom iterator operations | |
210 | * @prepare_message: An operation to provide the custom logic to fill in the | |
211 | * SCMI command request pointed by @message. @desc_index is | |
212 | * a reference to the next index to use in the multi-part | |
213 | * request. | |
214 | * @update_state: An operation to provide the custom logic to update the | |
215 | * iterator state from the actual message response. | |
216 | * @process_response: An operation to provide the custom logic needed to process | |
217 | * each chunk of the multi-part message. | |
218 | */ | |
219 | struct scmi_iterator_ops { | |
220 | void (*prepare_message)(void *message, unsigned int desc_index, | |
221 | const void *priv); | |
222 | int (*update_state)(struct scmi_iterator_state *st, | |
223 | const void *response, void *priv); | |
224 | int (*process_response)(const struct scmi_protocol_handle *ph, | |
225 | const void *response, | |
226 | struct scmi_iterator_state *st, void *priv); | |
227 | }; | |
228 | ||
6f9ea4da CM |
229 | struct scmi_fc_db_info { |
230 | int width; | |
231 | u64 set; | |
232 | u64 mask; | |
233 | void __iomem *addr; | |
234 | }; | |
235 | ||
236 | struct scmi_fc_info { | |
237 | void __iomem *set_addr; | |
238 | void __iomem *get_addr; | |
239 | struct scmi_fc_db_info *set_db; | |
2441caa8 | 240 | u32 rate_limit; |
6f9ea4da CM |
241 | }; |
242 | ||
5c873d12 CM |
243 | /** |
244 | * struct scmi_proto_helpers_ops - References to common protocol helpers | |
245 | * @extended_name_get: A common helper function to retrieve extended naming | |
246 | * for the specified resource using the specified command. | |
247 | * Result is returned as a NULL terminated string in the | |
248 | * pre-allocated area pointed to by @name with maximum | |
249 | * capacity of @len bytes. | |
36b6ea0f CM |
250 | * @iter_response_init: A common helper to initialize a generic iterator to |
251 | * parse multi-message responses: when run the iterator | |
252 | * will take care to send the initial command request as | |
253 | * specified by @msg_id and @tx_size and then to parse the | |
254 | * multi-part responses using the custom operations | |
255 | * provided in @ops. | |
256 | * @iter_response_run: A common helper to trigger the run of a previously | |
257 | * initialized iterator. | |
637b6d6c CM |
258 | * @protocol_msg_check: A common helper to check is a specific protocol message |
259 | * is supported. | |
6f9ea4da CM |
260 | * @fastchannel_init: A common helper used to initialize FC descriptors by |
261 | * gathering FC descriptions from the SCMI platform server. | |
262 | * @fastchannel_db_ring: A common helper to ring a FC doorbell. | |
4869b5cc | 263 | * @get_max_msg_size: A common helper to get the maximum message size. |
5c873d12 CM |
264 | */ |
265 | struct scmi_proto_helpers_ops { | |
266 | int (*extended_name_get)(const struct scmi_protocol_handle *ph, | |
e4e6e8f1 CM |
267 | u8 cmd_id, u32 res_id, u32 *flags, char *name, |
268 | size_t len); | |
36b6ea0f CM |
269 | void *(*iter_response_init)(const struct scmi_protocol_handle *ph, |
270 | struct scmi_iterator_ops *ops, | |
271 | unsigned int max_resources, u8 msg_id, | |
272 | size_t tx_size, void *priv); | |
273 | int (*iter_response_run)(void *iter); | |
637b6d6c CM |
274 | int (*protocol_msg_check)(const struct scmi_protocol_handle *ph, |
275 | u32 message_id, u32 *attributes); | |
6f9ea4da CM |
276 | void (*fastchannel_init)(const struct scmi_protocol_handle *ph, |
277 | u8 describe_id, u32 message_id, | |
278 | u32 valid_size, u32 domain, | |
279 | void __iomem **p_addr, | |
2441caa8 PG |
280 | struct scmi_fc_db_info **p_db, |
281 | u32 *rate_limit); | |
6f9ea4da | 282 | void (*fastchannel_db_ring)(struct scmi_fc_db_info *db); |
4869b5cc | 283 | int (*get_max_msg_size)(const struct scmi_protocol_handle *ph); |
5c873d12 CM |
284 | }; |
285 | ||
23136bff CM |
286 | /** |
287 | * struct scmi_xfer_ops - References to the core SCMI xfer operations. | |
288 | * @version_get: Get this version protocol. | |
289 | * @xfer_get_init: Initialize one struct xfer if any xfer slot is free. | |
290 | * @reset_rx_to_maxsz: Reset rx size to max transport size. | |
291 | * @do_xfer: Do the SCMI transfer. | |
292 | * @do_xfer_with_response: Do the SCMI transfer waiting for a response. | |
293 | * @xfer_put: Free the xfer slot. | |
294 | * | |
295 | * Note that all this operations expect a protocol handle as first parameter; | |
296 | * they then internally use it to infer the underlying protocol number: this | |
297 | * way is not possible for a protocol implementation to forge messages for | |
298 | * another protocol. | |
299 | */ | |
300 | struct scmi_xfer_ops { | |
301 | int (*version_get)(const struct scmi_protocol_handle *ph, u32 *version); | |
302 | int (*xfer_get_init)(const struct scmi_protocol_handle *ph, u8 msg_id, | |
303 | size_t tx_size, size_t rx_size, | |
304 | struct scmi_xfer **p); | |
305 | void (*reset_rx_to_maxsz)(const struct scmi_protocol_handle *ph, | |
306 | struct scmi_xfer *xfer); | |
307 | int (*do_xfer)(const struct scmi_protocol_handle *ph, | |
308 | struct scmi_xfer *xfer); | |
309 | int (*do_xfer_with_response)(const struct scmi_protocol_handle *ph, | |
310 | struct scmi_xfer *xfer); | |
311 | void (*xfer_put)(const struct scmi_protocol_handle *ph, | |
312 | struct scmi_xfer *xfer); | |
313 | }; | |
314 | ||
315 | typedef int (*scmi_prot_init_ph_fn_t)(const struct scmi_protocol_handle *); | |
316 | ||
317 | /** | |
318 | * struct scmi_protocol - Protocol descriptor | |
319 | * @id: Protocol ID. | |
320 | * @owner: Module reference if any. | |
321 | * @instance_init: Mandatory protocol initialization function. | |
322 | * @instance_deinit: Optional protocol de-initialization function. | |
323 | * @ops: Optional reference to the operations provided by the protocol and | |
324 | * exposed in scmi_protocol.h. | |
325 | * @events: An optional reference to the events supported by this protocol. | |
b5efc28a CM |
326 | * @supported_version: The highest version currently supported for this |
327 | * protocol by the agent. Each protocol implementation | |
328 | * in the agent is supposed to downgrade to match the | |
329 | * protocol version supported by the platform. | |
fc110108 CM |
330 | * @vendor_id: A firmware vendor string for vendor protocols matching. |
331 | * Ignored when @id identifies a standard protocol, cannot be NULL | |
332 | * otherwise. | |
333 | * @sub_vendor_id: A firmware sub_vendor string for vendor protocols matching. | |
334 | * Ignored if NULL or when @id identifies a standard protocol. | |
335 | * @impl_ver: A firmware implementation version for vendor protocols matching. | |
336 | * Ignored if zero or if @id identifies a standard protocol. | |
337 | * | |
338 | * Note that vendor protocols matching at load time is performed by attempting | |
339 | * the closest match first against the tuple (vendor, sub_vendor, impl_ver) | |
23136bff CM |
340 | */ |
341 | struct scmi_protocol { | |
342 | const u8 id; | |
343 | struct module *owner; | |
344 | const scmi_prot_init_ph_fn_t instance_init; | |
345 | const scmi_prot_init_ph_fn_t instance_deinit; | |
346 | const void *ops; | |
347 | const struct scmi_protocol_events *events; | |
b5efc28a | 348 | unsigned int supported_version; |
fc110108 CM |
349 | char *vendor_id; |
350 | char *sub_vendor_id; | |
351 | u32 impl_ver; | |
23136bff CM |
352 | }; |
353 | ||
354 | #define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(name, proto) \ | |
355 | static const struct scmi_protocol *__this_proto = &(proto); \ | |
356 | \ | |
357 | int __init scmi_##name##_register(void) \ | |
358 | { \ | |
359 | return scmi_protocol_register(__this_proto); \ | |
360 | } \ | |
361 | \ | |
362 | void __exit scmi_##name##_unregister(void) \ | |
363 | { \ | |
364 | scmi_protocol_unregister(__this_proto); \ | |
365 | } | |
366 | ||
367 | #define DECLARE_SCMI_REGISTER_UNREGISTER(func) \ | |
368 | int __init scmi_##func##_register(void); \ | |
369 | void __exit scmi_##func##_unregister(void) | |
370 | DECLARE_SCMI_REGISTER_UNREGISTER(base); | |
371 | DECLARE_SCMI_REGISTER_UNREGISTER(clock); | |
372 | DECLARE_SCMI_REGISTER_UNREGISTER(perf); | |
373 | DECLARE_SCMI_REGISTER_UNREGISTER(power); | |
374 | DECLARE_SCMI_REGISTER_UNREGISTER(reset); | |
375 | DECLARE_SCMI_REGISTER_UNREGISTER(sensors); | |
376 | DECLARE_SCMI_REGISTER_UNREGISTER(voltage); | |
377 | DECLARE_SCMI_REGISTER_UNREGISTER(system); | |
0316f99c | 378 | DECLARE_SCMI_REGISTER_UNREGISTER(powercap); |
23136bff CM |
379 | |
380 | #endif /* _SCMI_PROTOCOLS_H */ |