drivers/firmware/arm_scmi/notify.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * System Control and Management Interface (SCMI) Message Protocol
   4  * notification header file containing some definitions, structures
   5  * and function prototypes related to SCMI Notification handling.
   6  *
   7  * Copyright (C) 2020-2021 ARM Ltd.
   8  */
   9 #ifndef _SCMI_NOTIFY_H
  10 #define _SCMI_NOTIFY_H
  11
  12 #include <linux/device.h>
  13 #include <linux/ktime.h>
  14 #include <linux/types.h>
  15
  16 #define SCMI_PROTO_QUEUE_SZ     4096
  17
  18 /**
  19  * struct scmi_event  - Describes an event to be supported
  20  * @id: Event ID
  21  * @max_payld_sz: Max possible size for the payload of a notification message
  22  * @max_report_sz: Max possible size for the report of a notification message
  23  *
  24  * Each SCMI protocol, during its initialization phase, can describe the events
  25  * it wishes to support in a few struct scmi_event and pass them to the core
  26  * using scmi_register_protocol_events().
  27  */
  28 struct scmi_event {
  29         u8      id;
  30         size_t  max_payld_sz;
  31         size_t  max_report_sz;
  32 };
  33
  34 struct scmi_protocol_handle;
  35
  36 /**
  37  * struct scmi_event_ops  - Protocol helpers called by the notification core.
  38  * @is_notify_supported: Return 0 if the specified notification for the
  39  *                       specified resource (src_id) is supported.
  40  * @get_num_sources: Returns the number of possible events' sources for this
  41  *                   protocol
  42  * @set_notify_enabled: Enable/disable the required evt_id/src_id notifications
  43  *                      using the proper custom protocol commands.
  44  *                      Return 0 on Success
  45  * @fill_custom_report: fills a custom event report from the provided
  46  *                      event message payld identifying the event
  47  *                      specific src_id.
  48  *                      Return NULL on failure otherwise @report now fully
  49  *                      populated
  50  *
  51  * Context: Helpers described in &struct scmi_event_ops are called only in
  52  *          process context.
  53  */
  54 struct scmi_event_ops {
  55         bool (*is_notify_supported)(const struct scmi_protocol_handle *ph,
  56                                     u8 evt_id, u32 src_id);
  57         int (*get_num_sources)(const struct scmi_protocol_handle *ph);
  58         int (*set_notify_enabled)(const struct scmi_protocol_handle *ph,
  59                                   u8 evt_id, u32 src_id, bool enabled);
  60         void *(*fill_custom_report)(const struct scmi_protocol_handle *ph,
  61                                     u8 evt_id, ktime_t timestamp,
  62                                     const void *payld, size_t payld_sz,
  63                                     void *report, u32 *src_id);
  64 };
  65
  66 /**
  67  * struct scmi_protocol_events  - Per-protocol description of available events
  68  * @queue_sz: Size in bytes of the per-protocol queue to use.
  69  * @ops: Array of protocol-specific events operations.
  70  * @evts: Array of supported protocol's events.
  71  * @num_events: Number of supported protocol's events described in @evts.
  72  * @num_sources: Number of protocol's sources, should be greater than 0; if not
  73  *               available at compile time, it will be provided at run-time via
  74  *               @get_num_sources.
  75  */
  76 struct scmi_protocol_events {
  77         size_t                          queue_sz;
  78         const struct scmi_event_ops     *ops;
  79         const struct scmi_event         *evts;
  80         unsigned int                    num_events;
  81         unsigned int                    num_sources;
  82 };
  83
  84 int scmi_notification_init(struct scmi_handle *handle);
  85 void scmi_notification_exit(struct scmi_handle *handle);
  86 int scmi_register_protocol_events(const struct scmi_handle *handle, u8 proto_id,
  87                                   const struct scmi_protocol_handle *ph,
  88                                   const struct scmi_protocol_events *ee);
  89 void scmi_deregister_protocol_events(const struct scmi_handle *handle,
  90                                      u8 proto_id);
  91 int scmi_notify(const struct scmi_handle *handle, u8 proto_id, u8 evt_id,
  92                 const void *buf, size_t len, ktime_t ts);
  93
  94 #endif /* _SCMI_NOTIFY_H */