drivers/firmware/arm_scmi/notify.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * System Control and Management Interface (SCMI) Message Protocol
 * notification header file containing some definitions, structures
 * and function prototypes related to SCMI Notification handling.
 *
 * Copyright (C) 2020 ARM Ltd.
 */
#ifndef _SCMI_NOTIFY_H
#define _SCMI_NOTIFY_H

#include <linux/device.h>
#include <linux/ktime.h>
#include <linux/types.h>

#define SCMI_PROTO_QUEUE_SZ	4096

/**
 * struct scmi_event  - Describes an event to be supported
 * @id: Event ID
 * @max_payld_sz: Max possible size for the payload of a notification message
 * @max_report_sz: Max possible size for the report of a notification message
 *
 * Each SCMI protocol, during its initialization phase, can describe the events
 * it wishes to support in a few struct scmi_event and pass them to the core
 * using scmi_register_protocol_events().
 */
struct scmi_event {
	u8	id;
	size_t	max_payld_sz;
	size_t	max_report_sz;
};

/**
 * struct scmi_event_ops  - Protocol helpers called by the notification core.
 * @set_notify_enabled: Enable/disable the required evt_id/src_id notifications
 *			using the proper custom protocol commands.
 *			Return 0 on Success
 * @fill_custom_report: fills a custom event report from the provided
 *			event message payld identifying the event
 *			specific src_id.
 *			Return NULL on failure otherwise @report now fully
 *			populated
 *
 * Context: Helpers described in &struct scmi_event_ops are called only in
 *	    process context.
 */
struct scmi_event_ops {
	int (*set_notify_enabled)(const struct scmi_handle *handle,
				  u8 evt_id, u32 src_id, bool enabled);
	void *(*fill_custom_report)(const struct scmi_handle *handle,
				    u8 evt_id, ktime_t timestamp,
				    const void *payld, size_t payld_sz,
				    void *report, u32 *src_id);
};

int scmi_notification_init(struct scmi_handle *handle);
void scmi_notification_exit(struct scmi_handle *handle);

int scmi_register_protocol_events(const struct scmi_handle *handle,
				  u8 proto_id, size_t queue_sz,
				  const struct scmi_event_ops *ops,
				  const struct scmi_event *evt, int num_events,
				  int num_sources);
int scmi_notify(const struct scmi_handle *handle, u8 proto_id, u8 evt_id,
		const void *buf, size_t len, ktime_t ts);

#endif /* _SCMI_NOTIFY_H */