1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * System Control and Management Interface (SCMI) Message Protocol
4 * driver common header file containing some definitions, structures
5 * and function prototypes used in all the different SCMI protocols.
6 *
7 * Copyright (C) 2018-2021 ARM Ltd.
8 */
9 #ifndef _SCMI_COMMON_H
10 #define _SCMI_COMMON_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/module.h>
18 #include <linux/scmi_protocol.h>
19 #include <linux/types.h>
20
21 #include <asm/unaligned.h>
22
23 #include "notify.h"
24
25 #define PROTOCOL_REV_MINOR_MASK GENMASK(15, 0)
26 #define PROTOCOL_REV_MAJOR_MASK GENMASK(31, 16)
27 #define PROTOCOL_REV_MAJOR(x) (u16)(FIELD_GET(PROTOCOL_REV_MAJOR_MASK, (x)))
28 #define PROTOCOL_REV_MINOR(x) (u16)(FIELD_GET(PROTOCOL_REV_MINOR_MASK, (x)))
29 #define MAX_PROTOCOLS_IMP 16
30 #define MAX_OPPS 16
31
32 enum scmi_common_cmd {
33 PROTOCOL_VERSION = 0x0,
34 PROTOCOL_ATTRIBUTES = 0x1,
35 PROTOCOL_MESSAGE_ATTRIBUTES = 0x2,
36 };
37
38 /**
39 * struct scmi_msg_resp_prot_version - Response for a message
40 *
41 * @minor_version: Minor version of the ABI that firmware supports
42 * @major_version: Major version of the ABI that firmware supports
43 *
44 * In general, ABI version changes follow the rule that minor version increments
45 * are backward compatible. Major revision changes in ABI may not be
46 * backward compatible.
47 *
48 * Response to a generic message with message type SCMI_MSG_VERSION
49 */
50 struct scmi_msg_resp_prot_version {
51 __le16 minor_version;
52 __le16 major_version;
53 };
54
55 #define MSG_ID_MASK GENMASK(7, 0)
56 #define MSG_XTRACT_ID(hdr) FIELD_GET(MSG_ID_MASK, (hdr))
57 #define MSG_TYPE_MASK GENMASK(9, 8)
58 #define MSG_XTRACT_TYPE(hdr) FIELD_GET(MSG_TYPE_MASK, (hdr))
59 #define MSG_TYPE_COMMAND 0
60 #define MSG_TYPE_DELAYED_RESP 2
61 #define MSG_TYPE_NOTIFICATION 3
62 #define MSG_PROTOCOL_ID_MASK GENMASK(17, 10)
63 #define MSG_XTRACT_PROT_ID(hdr) FIELD_GET(MSG_PROTOCOL_ID_MASK, (hdr))
64 #define MSG_TOKEN_ID_MASK GENMASK(27, 18)
65 #define MSG_XTRACT_TOKEN(hdr) FIELD_GET(MSG_TOKEN_ID_MASK, (hdr))
66 #define MSG_TOKEN_MAX (MSG_XTRACT_TOKEN(MSG_TOKEN_ID_MASK) + 1)
67
68 /**
69 * struct scmi_msg_hdr - Message(Tx/Rx) header
70 *
71 * @id: The identifier of the message being sent
72 * @protocol_id: The identifier of the protocol used to send @id message
73 * @seq: The token to identify the message. When a message returns, the
74 * platform returns the whole message header unmodified including the
75 * token
76 * @status: Status of the transfer once it's complete
77 * @poll_completion: Indicate if the transfer needs to be polled for
78 * completion or interrupt mode is used
79 */
80 struct scmi_msg_hdr {
81 u8 id;
82 u8 protocol_id;
83 u16 seq;
84 u32 status;
85 bool poll_completion;
86 };
87
88 /**
89 * pack_scmi_header() - packs and returns 32-bit header
90 *
91 * @hdr: pointer to header containing all the information on message id,
92 * protocol id and sequence id.
93 *
94 * Return: 32-bit packed message header to be sent to the platform.
95 */
pack_scmi_header(struct scmi_msg_hdr * hdr)96 static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr)
97 {
98 return FIELD_PREP(MSG_ID_MASK, hdr->id) |
99 FIELD_PREP(MSG_TOKEN_ID_MASK, hdr->seq) |
100 FIELD_PREP(MSG_PROTOCOL_ID_MASK, hdr->protocol_id);
101 }
102
103 /**
104 * unpack_scmi_header() - unpacks and records message and protocol id
105 *
106 * @msg_hdr: 32-bit packed message header sent from the platform
107 * @hdr: pointer to header to fetch message and protocol id.
108 */
unpack_scmi_header(u32 msg_hdr,struct scmi_msg_hdr * hdr)109 static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr)
110 {
111 hdr->id = MSG_XTRACT_ID(msg_hdr);
112 hdr->protocol_id = MSG_XTRACT_PROT_ID(msg_hdr);
113 }
114
115 /**
116 * struct scmi_msg - Message(Tx/Rx) structure
117 *
118 * @buf: Buffer pointer
119 * @len: Length of data in the Buffer
120 */
121 struct scmi_msg {
122 void *buf;
123 size_t len;
124 };
125
126 /**
127 * struct scmi_xfer - Structure representing a message flow
128 *
129 * @transfer_id: Unique ID for debug & profiling purpose
130 * @hdr: Transmit message header
131 * @tx: Transmit message
132 * @rx: Receive message, the buffer should be pre-allocated to store
133 * message. If request-ACK protocol is used, we can reuse the same
134 * buffer for the rx path as we use for the tx path.
135 * @done: command message transmit completion event
136 * @async_done: pointer to delayed response message received event completion
137 */
138 struct scmi_xfer {
139 int transfer_id;
140 struct scmi_msg_hdr hdr;
141 struct scmi_msg tx;
142 struct scmi_msg rx;
143 struct completion done;
144 struct completion *async_done;
145 };
146
147 struct scmi_xfer_ops;
148
149 /**
150 * struct scmi_protocol_handle - Reference to an initialized protocol instance
151 *
152 * @dev: A reference to the associated SCMI instance device (handle->dev).
153 * @xops: A reference to a struct holding refs to the core xfer operations that
154 * can be used by the protocol implementation to generate SCMI messages.
155 * @set_priv: A method to set protocol private data for this instance.
156 * @get_priv: A method to get protocol private data previously set.
157 *
158 * This structure represents a protocol initialized against specific SCMI
159 * instance and it will be used as follows:
160 * - as a parameter fed from the core to the protocol initialization code so
161 * that it can access the core xfer operations to build and generate SCMI
162 * messages exclusively for the specific underlying protocol instance.
163 * - as an opaque handle fed by an SCMI driver user when it tries to access
164 * this protocol through its own protocol operations.
165 * In this case this handle will be returned as an opaque object together
166 * with the related protocol operations when the SCMI driver tries to access
167 * the protocol.
168 */
169 struct scmi_protocol_handle {
170 struct device *dev;
171 const struct scmi_xfer_ops *xops;
172 int (*set_priv)(const struct scmi_protocol_handle *ph, void *priv);
173 void *(*get_priv)(const struct scmi_protocol_handle *ph);
174 };
175
176 /**
177 * struct scmi_xfer_ops - References to the core SCMI xfer operations.
178 * @version_get: Get this version protocol.
179 * @xfer_get_init: Initialize one struct xfer if any xfer slot is free.
180 * @reset_rx_to_maxsz: Reset rx size to max transport size.
181 * @do_xfer: Do the SCMI transfer.
182 * @do_xfer_with_response: Do the SCMI transfer waiting for a response.
183 * @xfer_put: Free the xfer slot.
184 *
185 * Note that all this operations expect a protocol handle as first parameter;
186 * they then internally use it to infer the underlying protocol number: this
187 * way is not possible for a protocol implementation to forge messages for
188 * another protocol.
189 */
190 struct scmi_xfer_ops {
191 int (*version_get)(const struct scmi_protocol_handle *ph, u32 *version);
192 int (*xfer_get_init)(const struct scmi_protocol_handle *ph, u8 msg_id,
193 size_t tx_size, size_t rx_size,
194 struct scmi_xfer **p);
195 void (*reset_rx_to_maxsz)(const struct scmi_protocol_handle *ph,
196 struct scmi_xfer *xfer);
197 int (*do_xfer)(const struct scmi_protocol_handle *ph,
198 struct scmi_xfer *xfer);
199 int (*do_xfer_with_response)(const struct scmi_protocol_handle *ph,
200 struct scmi_xfer *xfer);
201 void (*xfer_put)(const struct scmi_protocol_handle *ph,
202 struct scmi_xfer *xfer);
203 };
204
205 struct scmi_revision_info *
206 scmi_revision_area_get(const struct scmi_protocol_handle *ph);
207 int scmi_handle_put(const struct scmi_handle *handle);
208 struct scmi_handle *scmi_handle_get(struct device *dev);
209 void scmi_set_handle(struct scmi_device *scmi_dev);
210 void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph,
211 u8 *prot_imp);
212
213 typedef int (*scmi_prot_init_ph_fn_t)(const struct scmi_protocol_handle *);
214
215 /**
216 * struct scmi_protocol - Protocol descriptor
217 * @id: Protocol ID.
218 * @owner: Module reference if any.
219 * @instance_init: Mandatory protocol initialization function.
220 * @instance_deinit: Optional protocol de-initialization function.
221 * @ops: Optional reference to the operations provided by the protocol and
222 * exposed in scmi_protocol.h.
223 * @events: An optional reference to the events supported by this protocol.
224 */
225 struct scmi_protocol {
226 const u8 id;
227 struct module *owner;
228 const scmi_prot_init_ph_fn_t instance_init;
229 const scmi_prot_init_ph_fn_t instance_deinit;
230 const void *ops;
231 const struct scmi_protocol_events *events;
232 };
233
234 int __init scmi_bus_init(void);
235 void __exit scmi_bus_exit(void);
236
237 #define DECLARE_SCMI_REGISTER_UNREGISTER(func) \
238 int __init scmi_##func##_register(void); \
239 void __exit scmi_##func##_unregister(void)
240 DECLARE_SCMI_REGISTER_UNREGISTER(base);
241 DECLARE_SCMI_REGISTER_UNREGISTER(clock);
242 DECLARE_SCMI_REGISTER_UNREGISTER(perf);
243 DECLARE_SCMI_REGISTER_UNREGISTER(power);
244 DECLARE_SCMI_REGISTER_UNREGISTER(reset);
245 DECLARE_SCMI_REGISTER_UNREGISTER(sensors);
246 DECLARE_SCMI_REGISTER_UNREGISTER(voltage);
247 DECLARE_SCMI_REGISTER_UNREGISTER(system);
248
249 #define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(name, proto) \
250 static const struct scmi_protocol *__this_proto = &(proto); \
251 \
252 int __init scmi_##name##_register(void) \
253 { \
254 return scmi_protocol_register(__this_proto); \
255 } \
256 \
257 void __exit scmi_##name##_unregister(void) \
258 { \
259 scmi_protocol_unregister(__this_proto); \
260 }
261
262 const struct scmi_protocol *scmi_protocol_get(int protocol_id);
263 void scmi_protocol_put(int protocol_id);
264
265 int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id);
266 void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id);
267
268 /* SCMI Transport */
269 /**
270 * struct scmi_chan_info - Structure representing a SCMI channel information
271 *
272 * @dev: Reference to device in the SCMI hierarchy corresponding to this
273 * channel
274 * @handle: Pointer to SCMI entity handle
275 * @transport_info: Transport layer related information
276 */
277 struct scmi_chan_info {
278 struct device *dev;
279 struct scmi_handle *handle;
280 void *transport_info;
281 };
282
283 /**
284 * struct scmi_transport_ops - Structure representing a SCMI transport ops
285 *
286 * @chan_available: Callback to check if channel is available or not
287 * @chan_setup: Callback to allocate and setup a channel
288 * @chan_free: Callback to free a channel
289 * @send_message: Callback to send a message
290 * @mark_txdone: Callback to mark tx as done
291 * @fetch_response: Callback to fetch response
292 * @fetch_notification: Callback to fetch notification
293 * @clear_channel: Callback to clear a channel
294 * @poll_done: Callback to poll transfer status
295 */
296 struct scmi_transport_ops {
297 bool (*chan_available)(struct device *dev, int idx);
298 int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev,
299 bool tx);
300 int (*chan_free)(int id, void *p, void *data);
301 int (*send_message)(struct scmi_chan_info *cinfo,
302 struct scmi_xfer *xfer);
303 void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret);
304 void (*fetch_response)(struct scmi_chan_info *cinfo,
305 struct scmi_xfer *xfer);
306 void (*fetch_notification)(struct scmi_chan_info *cinfo,
307 size_t max_len, struct scmi_xfer *xfer);
308 void (*clear_channel)(struct scmi_chan_info *cinfo);
309 bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer);
310 };
311
312 int scmi_protocol_device_request(const struct scmi_device_id *id_table);
313 void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table);
314 struct scmi_device *scmi_child_dev_find(struct device *parent,
315 int prot_id, const char *name);
316
317 /**
318 * struct scmi_desc - Description of SoC integration
319 *
320 * @ops: Pointer to the transport specific ops structure
321 * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)
322 * @max_msg: Maximum number of messages that can be pending
323 * simultaneously in the system
324 * @max_msg_size: Maximum size of data per message that can be handled.
325 */
326 struct scmi_desc {
327 const struct scmi_transport_ops *ops;
328 int max_rx_timeout_ms;
329 int max_msg;
330 int max_msg_size;
331 };
332
333 extern const struct scmi_desc scmi_mailbox_desc;
334 #ifdef CONFIG_HAVE_ARM_SMCCC
335 extern const struct scmi_desc scmi_smc_desc;
336 #endif
337
338 void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr);
339 void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id);
340
341 /* shmem related declarations */
342 struct scmi_shared_mem;
343
344 void shmem_tx_prepare(struct scmi_shared_mem __iomem *shmem,
345 struct scmi_xfer *xfer);
346 u32 shmem_read_header(struct scmi_shared_mem __iomem *shmem);
347 void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem,
348 struct scmi_xfer *xfer);
349 void shmem_fetch_notification(struct scmi_shared_mem __iomem *shmem,
350 size_t max_len, struct scmi_xfer *xfer);
351 void shmem_clear_channel(struct scmi_shared_mem __iomem *shmem);
352 bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem,
353 struct scmi_xfer *xfer);
354
355 void scmi_notification_instance_data_set(const struct scmi_handle *handle,
356 void *priv);
357 void *scmi_notification_instance_data_get(const struct scmi_handle *handle);
358
359 #endif /* _SCMI_COMMON_H */
360