| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* |
| * System Control and Management Interface (SCMI) Message Protocol |
| * protocols common header file containing some definitions, structures |
| * and function prototypes used in all the different SCMI protocols. |
| * |
| * Copyright (C) 2022 ARM Ltd. |
| */ |
| #ifndef _SCMI_PROTOCOLS_H |
| #define _SCMI_PROTOCOLS_H |
| |
| #include <linux/bitfield.h> |
| #include <linux/completion.h> |
| #include <linux/device.h> |
| #include <linux/errno.h> |
| #include <linux/kernel.h> |
| #include <linux/hashtable.h> |
| #include <linux/list.h> |
| #include <linux/module.h> |
| #include <linux/refcount.h> |
| #include <linux/scmi_protocol.h> |
| #include <linux/spinlock.h> |
| #include <linux/types.h> |
| |
| #include <asm/unaligned.h> |
| |
| #define PROTOCOL_REV_MINOR_MASK GENMASK(15, 0) |
| #define PROTOCOL_REV_MAJOR_MASK GENMASK(31, 16) |
| #define PROTOCOL_REV_MAJOR(x) ((u16)(FIELD_GET(PROTOCOL_REV_MAJOR_MASK, (x)))) |
| #define PROTOCOL_REV_MINOR(x) ((u16)(FIELD_GET(PROTOCOL_REV_MINOR_MASK, (x)))) |
| |
| enum scmi_common_cmd { |
| PROTOCOL_VERSION = 0x0, |
| PROTOCOL_ATTRIBUTES = 0x1, |
| PROTOCOL_MESSAGE_ATTRIBUTES = 0x2, |
| }; |
| |
| /** |
| * struct scmi_msg_resp_prot_version - Response for a message |
| * |
| * @minor_version: Minor version of the ABI that firmware supports |
| * @major_version: Major version of the ABI that firmware supports |
| * |
| * In general, ABI version changes follow the rule that minor version increments |
| * are backward compatible. Major revision changes in ABI may not be |
| * backward compatible. |
| * |
| * Response to a generic message with message type SCMI_MSG_VERSION |
| */ |
| struct scmi_msg_resp_prot_version { |
| __le16 minor_version; |
| __le16 major_version; |
| }; |
| |
| /** |
| * struct scmi_msg - Message(Tx/Rx) structure |
| * |
| * @buf: Buffer pointer |
| * @len: Length of data in the Buffer |
| */ |
| struct scmi_msg { |
| void *buf; |
| size_t len; |
| }; |
| |
| /** |
| * struct scmi_msg_hdr - Message(Tx/Rx) header |
| * |
| * @id: The identifier of the message being sent |
| * @protocol_id: The identifier of the protocol used to send @id message |
| * @type: The SCMI type for this message |
| * @seq: The token to identify the message. When a message returns, the |
| * platform returns the whole message header unmodified including the |
| * token |
| * @status: Status of the transfer once it's complete |
| * @poll_completion: Indicate if the transfer needs to be polled for |
| * completion or interrupt mode is used |
| */ |
| struct scmi_msg_hdr { |
| u8 id; |
| u8 protocol_id; |
| u8 type; |
| u16 seq; |
| u32 status; |
| bool poll_completion; |
| }; |
| |
| /** |
| * struct scmi_xfer - Structure representing a message flow |
| * |
| * @transfer_id: Unique ID for debug & profiling purpose |
| * @hdr: Transmit message header |
| * @tx: Transmit message |
| * @rx: Receive message, the buffer should be pre-allocated to store |
| * message. If request-ACK protocol is used, we can reuse the same |
| * buffer for the rx path as we use for the tx path. |
| * @done: command message transmit completion event |
| * @async_done: pointer to delayed response message received event completion |
| * @pending: True for xfers added to @pending_xfers hashtable |
| * @node: An hlist_node reference used to store this xfer, alternatively, on |
| * the free list @free_xfers or in the @pending_xfers hashtable |
| * @users: A refcount to track the active users for this xfer. |
| * This is meant to protect against the possibility that, when a command |
| * transaction times out concurrently with the reception of a valid |
| * response message, the xfer could be finally put on the TX path, and |
| * so vanish, while on the RX path scmi_rx_callback() is still |
| * processing it: in such a case this refcounting will ensure that, even |
| * though the timed-out transaction will anyway cause the command |
| * request to be reported as failed by time-out, the underlying xfer |
| * cannot be discarded and possibly reused until the last one user on |
| * the RX path has released it. |
| * @busy: An atomic flag to ensure exclusive write access to this xfer |
| * @state: The current state of this transfer, with states transitions deemed |
| * valid being: |
| * - SCMI_XFER_SENT_OK -> SCMI_XFER_RESP_OK [ -> SCMI_XFER_DRESP_OK ] |
| * - SCMI_XFER_SENT_OK -> SCMI_XFER_DRESP_OK |
| * (Missing synchronous response is assumed OK and ignored) |
| * @lock: A spinlock to protect state and busy fields. |
| * @priv: A pointer for transport private usage. |
| */ |
| struct scmi_xfer { |
| int transfer_id; |
| struct scmi_msg_hdr hdr; |
| struct scmi_msg tx; |
| struct scmi_msg rx; |
| struct completion done; |
| struct completion *async_done; |
| bool pending; |
| struct hlist_node node; |
| refcount_t users; |
| #define SCMI_XFER_FREE 0 |
| #define SCMI_XFER_BUSY 1 |
| atomic_t busy; |
| #define SCMI_XFER_SENT_OK 0 |
| #define SCMI_XFER_RESP_OK 1 |
| #define SCMI_XFER_DRESP_OK 2 |
| int state; |
| /* A lock to protect state and busy fields */ |
| spinlock_t lock; |
| void *priv; |
| }; |
| |
| struct scmi_xfer_ops; |
| struct scmi_proto_helpers_ops; |
| |
| /** |
| * struct scmi_protocol_handle - Reference to an initialized protocol instance |
| * |
| * @dev: A reference to the associated SCMI instance device (handle->dev). |
| * @xops: A reference to a struct holding refs to the core xfer operations that |
| * can be used by the protocol implementation to generate SCMI messages. |
| * @set_priv: A method to set protocol private data for this instance. |
| * @get_priv: A method to get protocol private data previously set. |
| * |
| * This structure represents a protocol initialized against specific SCMI |
| * instance and it will be used as follows: |
| * - as a parameter fed from the core to the protocol initialization code so |
| * that it can access the core xfer operations to build and generate SCMI |
| * messages exclusively for the specific underlying protocol instance. |
| * - as an opaque handle fed by an SCMI driver user when it tries to access |
| * this protocol through its own protocol operations. |
| * In this case this handle will be returned as an opaque object together |
| * with the related protocol operations when the SCMI driver tries to access |
| * the protocol. |
| */ |
| struct scmi_protocol_handle { |
| struct device *dev; |
| const struct scmi_xfer_ops *xops; |
| const struct scmi_proto_helpers_ops *hops; |
| int (*set_priv)(const struct scmi_protocol_handle *ph, void *priv); |
| void *(*get_priv)(const struct scmi_protocol_handle *ph); |
| }; |
| |
| /** |
| * struct scmi_iterator_state - Iterator current state descriptor |
| * @desc_index: Starting index for the current mulit-part request. |
| * @num_returned: Number of returned items in the last multi-part reply. |
| * @num_remaining: Number of remaining items in the multi-part message. |
| * @max_resources: Maximum acceptable number of items, configured by the caller |
| * depending on the underlying resources that it is querying. |
| * @loop_idx: The iterator loop index in the current multi-part reply. |
| * @rx_len: Size in bytes of the currenly processed message; it can be used by |
| * the user of the iterator to verify a reply size. |
| * @priv: Optional pointer to some additional state-related private data setup |
| * by the caller during the iterations. |
| */ |
| struct scmi_iterator_state { |
| unsigned int desc_index; |
| unsigned int num_returned; |
| unsigned int num_remaining; |
| unsigned int max_resources; |
| unsigned int loop_idx; |
| size_t rx_len; |
| void *priv; |
| }; |
| |
| /** |
| * struct scmi_iterator_ops - Custom iterator operations |
| * @prepare_message: An operation to provide the custom logic to fill in the |
| * SCMI command request pointed by @message. @desc_index is |
| * a reference to the next index to use in the multi-part |
| * request. |
| * @update_state: An operation to provide the custom logic to update the |
| * iterator state from the actual message response. |
| * @process_response: An operation to provide the custom logic needed to process |
| * each chunk of the multi-part message. |
| */ |
| struct scmi_iterator_ops { |
| void (*prepare_message)(void *message, unsigned int desc_index, |
| const void *priv); |
| int (*update_state)(struct scmi_iterator_state *st, |
| const void *response, void *priv); |
| int (*process_response)(const struct scmi_protocol_handle *ph, |
| const void *response, |
| struct scmi_iterator_state *st, void *priv); |
| }; |
| |
| struct scmi_fc_db_info { |
| int width; |
| u64 set; |
| u64 mask; |
| void __iomem *addr; |
| }; |
| |
| struct scmi_fc_info { |
| void __iomem *set_addr; |
| void __iomem *get_addr; |
| struct scmi_fc_db_info *set_db; |
| }; |
| |
| /** |
| * struct scmi_proto_helpers_ops - References to common protocol helpers |
| * @extended_name_get: A common helper function to retrieve extended naming |
| * for the specified resource using the specified command. |
| * Result is returned as a NULL terminated string in the |
| * pre-allocated area pointed to by @name with maximum |
| * capacity of @len bytes. |
| * @iter_response_init: A common helper to initialize a generic iterator to |
| * parse multi-message responses: when run the iterator |
| * will take care to send the initial command request as |
| * specified by @msg_id and @tx_size and then to parse the |
| * multi-part responses using the custom operations |
| * provided in @ops. |
| * @iter_response_run: A common helper to trigger the run of a previously |
| * initialized iterator. |
| * @fastchannel_init: A common helper used to initialize FC descriptors by |
| * gathering FC descriptions from the SCMI platform server. |
| * @fastchannel_db_ring: A common helper to ring a FC doorbell. |
| */ |
| struct scmi_proto_helpers_ops { |
| int (*extended_name_get)(const struct scmi_protocol_handle *ph, |
| u8 cmd_id, u32 res_id, char *name, size_t len); |
| void *(*iter_response_init)(const struct scmi_protocol_handle *ph, |
| struct scmi_iterator_ops *ops, |
| unsigned int max_resources, u8 msg_id, |
| size_t tx_size, void *priv); |
| int (*iter_response_run)(void *iter); |
| void (*fastchannel_init)(const struct scmi_protocol_handle *ph, |
| u8 describe_id, u32 message_id, |
| u32 valid_size, u32 domain, |
| void __iomem **p_addr, |
| struct scmi_fc_db_info **p_db); |
| void (*fastchannel_db_ring)(struct scmi_fc_db_info *db); |
| }; |
| |
| /** |
| * struct scmi_xfer_ops - References to the core SCMI xfer operations. |
| * @version_get: Get this version protocol. |
| * @xfer_get_init: Initialize one struct xfer if any xfer slot is free. |
| * @reset_rx_to_maxsz: Reset rx size to max transport size. |
| * @do_xfer: Do the SCMI transfer. |
| * @do_xfer_with_response: Do the SCMI transfer waiting for a response. |
| * @xfer_put: Free the xfer slot. |
| * |
| * Note that all this operations expect a protocol handle as first parameter; |
| * they then internally use it to infer the underlying protocol number: this |
| * way is not possible for a protocol implementation to forge messages for |
| * another protocol. |
| */ |
| struct scmi_xfer_ops { |
| int (*version_get)(const struct scmi_protocol_handle *ph, u32 *version); |
| int (*xfer_get_init)(const struct scmi_protocol_handle *ph, u8 msg_id, |
| size_t tx_size, size_t rx_size, |
| struct scmi_xfer **p); |
| void (*reset_rx_to_maxsz)(const struct scmi_protocol_handle *ph, |
| struct scmi_xfer *xfer); |
| int (*do_xfer)(const struct scmi_protocol_handle *ph, |
| struct scmi_xfer *xfer); |
| int (*do_xfer_with_response)(const struct scmi_protocol_handle *ph, |
| struct scmi_xfer *xfer); |
| void (*xfer_put)(const struct scmi_protocol_handle *ph, |
| struct scmi_xfer *xfer); |
| }; |
| |
| typedef int (*scmi_prot_init_ph_fn_t)(const struct scmi_protocol_handle *); |
| |
| /** |
| * struct scmi_protocol - Protocol descriptor |
| * @id: Protocol ID. |
| * @owner: Module reference if any. |
| * @instance_init: Mandatory protocol initialization function. |
| * @instance_deinit: Optional protocol de-initialization function. |
| * @ops: Optional reference to the operations provided by the protocol and |
| * exposed in scmi_protocol.h. |
| * @events: An optional reference to the events supported by this protocol. |
| */ |
| struct scmi_protocol { |
| const u8 id; |
| struct module *owner; |
| const scmi_prot_init_ph_fn_t instance_init; |
| const scmi_prot_init_ph_fn_t instance_deinit; |
| const void *ops; |
| const struct scmi_protocol_events *events; |
| }; |
| |
| #define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(name, proto) \ |
| static const struct scmi_protocol *__this_proto = &(proto); \ |
| \ |
| int __init scmi_##name##_register(void) \ |
| { \ |
| return scmi_protocol_register(__this_proto); \ |
| } \ |
| \ |
| void __exit scmi_##name##_unregister(void) \ |
| { \ |
| scmi_protocol_unregister(__this_proto); \ |
| } |
| |
| #define DECLARE_SCMI_REGISTER_UNREGISTER(func) \ |
| int __init scmi_##func##_register(void); \ |
| void __exit scmi_##func##_unregister(void) |
| DECLARE_SCMI_REGISTER_UNREGISTER(base); |
| DECLARE_SCMI_REGISTER_UNREGISTER(clock); |
| DECLARE_SCMI_REGISTER_UNREGISTER(perf); |
| DECLARE_SCMI_REGISTER_UNREGISTER(power); |
| DECLARE_SCMI_REGISTER_UNREGISTER(reset); |
| DECLARE_SCMI_REGISTER_UNREGISTER(sensors); |
| DECLARE_SCMI_REGISTER_UNREGISTER(voltage); |
| DECLARE_SCMI_REGISTER_UNREGISTER(system); |
| DECLARE_SCMI_REGISTER_UNREGISTER(powercap); |
| |
| #endif /* _SCMI_PROTOCOLS_H */ |