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_DISCOVERY 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