include/drivers/st/scmi-msg.h

/* SPDX-License-Identifier: BSD-3-Clause */
/*
 * Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.
 * Copyright (c) 2019, Linaro Limited
 */

#ifndef SCMI_MSG_H
#define SCMI_MSG_H

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

/* Minimum size expected for SMT based shared memory message buffers */
#define SMT_BUF_SLOT_SIZE	128U

/* A channel abstract a communication path between agent and server */
struct scmi_msg_channel;

/*
 * struct scmi_msg_channel - Shared memory buffer for a agent-to-server channel
 *
 * @shm_addr: Address of the shared memory for the SCMI channel
 * @shm_size: Byte size of the shared memory for the SCMI channel
 * @busy: True when channel is busy, flase when channel is free
 * @agent_name: Agent name, SCMI protocol exposes 16 bytes max, or NULL
 */
struct scmi_msg_channel {
	uintptr_t shm_addr;
	size_t shm_size;
	bool busy;
	const char *agent_name;
};

/* Platform callback functions */

/*
 * Return the SCMI channel related to an agent
 * @agent_id: SCMI agent ID
 * Return a pointer to channel on success, NULL otherwise
 */
struct scmi_msg_channel *plat_scmi_get_channel(unsigned int agent_id);

/*
 * Return how many SCMI protocols supported by the platform
 * According to the SCMI specification, this function does not target
 * a specific agent ID and shall return all platform known capabilities.
 */
size_t plat_scmi_protocol_count(void);

/*
 * Get the count and list of SCMI protocols (but base) supported for an agent
 *
 * @agent_id: SCMI agent ID
 * Return a pointer to a null terminated array supported protocol IDs.
 */
const uint8_t *plat_scmi_protocol_list(unsigned int agent_id);

/* Get the name of the SCMI vendor for the platform */
const char *plat_scmi_vendor_name(void);

/* Get the name of the SCMI sub-vendor for the platform */
const char *plat_scmi_sub_vendor_name(void);

/* Handlers for SCMI Clock protocol services */

/*
 * Return number of clock controllers for an agent
 * @agent_id: SCMI agent ID
 * Return number of clock controllers
 */
size_t plat_scmi_clock_count(unsigned int agent_id);

/*
 * Get clock controller string ID (aka name)
 * @agent_id: SCMI agent ID
 * @scmi_id: SCMI clock ID
 * Return pointer to name or NULL
 */
const char *plat_scmi_clock_get_name(unsigned int agent_id,
				     unsigned int scmi_id);

/*
 * Get clock possible rate as an array of frequencies in Hertz.
 *
 * @agent_id: SCMI agent ID
 * @scmi_id: SCMI clock ID
 * @rates: If NULL, function returns, else output rates array
 * @nb_elts: Array size of @rates.
 * Return an SCMI compliant error code
 */
int32_t plat_scmi_clock_rates_array(unsigned int agent_id, unsigned int scmi_id,
				    unsigned long *rates, size_t *nb_elts);

/*
 * Get clock possible rate as range with regular steps in Hertz
 *
 * @agent_id: SCMI agent ID
 * @scmi_id: SCMI clock ID
 * @min_max_step: 3 cell array for min, max and step rate data
 * Return an SCMI compliant error code
 */
int32_t plat_scmi_clock_rates_by_step(unsigned int agent_id,
				      unsigned int scmi_id,
				      unsigned long *min_max_step);

/*
 * Get clock rate in Hertz
 * @agent_id: SCMI agent ID
 * @scmi_id: SCMI clock ID
 * Return clock rate or 0 if not supported
 */
unsigned long plat_scmi_clock_get_rate(unsigned int agent_id,
				       unsigned int scmi_id);

/*
 * Set clock rate in Hertz
 * @agent_id: SCMI agent ID
 * @scmi_id: SCMI clock ID
 * @rate: Target clock frequency in Hertz
 * Return a compliant SCMI error code
 */
int32_t plat_scmi_clock_set_rate(unsigned int agent_id, unsigned int scmi_id,
				 unsigned long rate);

/*
 * Get clock state (enabled or disabled)
 * @agent_id: SCMI agent ID
 * @scmi_id: SCMI clock ID
 * Return 1 if clock is enabled, 0 if disables, or a negative SCMI error code
 */
int32_t plat_scmi_clock_get_state(unsigned int agent_id, unsigned int scmi_id);

/*
 * Get clock state (enabled or disabled)
 * @agent_id: SCMI agent ID
 * @scmi_id: SCMI clock ID
 * @enable_not_disable: Enable clock if true, disable clock otherwise
 * Return a compliant SCMI error code
 */
int32_t plat_scmi_clock_set_state(unsigned int agent_id, unsigned int scmi_id,
				  bool enable_not_disable);

#endif /* SCMI_MSG_H */