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  */
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  */
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