/*
 * Copyright (c) 2017-2021, ARM Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#ifndef SCMI_H
#define SCMI_H

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

#include <lib/bakery_lock.h>
#include <lib/psci/psci.h>
#include <lib/spinlock.h>

/* Supported SCMI Protocol Versions */
#define SCMI_AP_CORE_PROTO_VER			MAKE_SCMI_VERSION(1, 0)
#define SCMI_PWR_DMN_PROTO_VER			MAKE_SCMI_VERSION(2, 0)
#define SCMI_SYS_PWR_PROTO_VER			MAKE_SCMI_VERSION(1, 0)

#define GET_SCMI_MAJOR_VER(ver)			(((ver) >> 16) & 0xffff)
#define GET_SCMI_MINOR_VER(ver)			((ver) & 0xffff)

#define MAKE_SCMI_VERSION(maj, min)	\
			((((maj) & 0xffff) << 16) | ((min) & 0xffff))

/*
 * Check that the driver's version is same or higher than the reported SCMI
 * version. We accept lower major version numbers, as all affected protocols
 * so far stay backwards compatible. This might need to be revisited in the
 * future.
 */
#define is_scmi_version_compatible(drv, scmi)				\
	((GET_SCMI_MAJOR_VER(drv) > GET_SCMI_MAJOR_VER(scmi)) ||	\
	((GET_SCMI_MAJOR_VER(drv) == GET_SCMI_MAJOR_VER(scmi)) &&	\
	(GET_SCMI_MINOR_VER(drv) <= GET_SCMI_MINOR_VER(scmi))))

/* SCMI Protocol identifiers */
#define SCMI_PWR_DMN_PROTO_ID			0x11
#define SCMI_SYS_PWR_PROTO_ID			0x12
/* The AP core protocol is a CSS platform-specific extension */
#define SCMI_AP_CORE_PROTO_ID			0x90

/* Mandatory messages IDs for all SCMI protocols */
#define SCMI_PROTO_VERSION_MSG			0x0
#define SCMI_PROTO_ATTR_MSG			0x1
#define SCMI_PROTO_MSG_ATTR_MSG			0x2

/* SCMI power domain management protocol message IDs */
#define SCMI_PWR_STATE_SET_MSG			0x4
#define SCMI_PWR_STATE_GET_MSG			0x5

/* SCMI system power management protocol message IDs */
#define SCMI_SYS_PWR_STATE_SET_MSG		0x3
#define SCMI_SYS_PWR_STATE_GET_MSG		0x4

/* SCMI AP core protocol message IDs */
#define SCMI_AP_CORE_RESET_ADDR_SET_MSG		0x3
#define SCMI_AP_CORE_RESET_ADDR_GET_MSG		0x4

/* Helper macros for system power management protocol commands */

/*
 * Macros to describe the bit-fields of the `attribute` of system power domain
 * protocol PROTOCOL_MSG_ATTRIBUTE message.
 */
#define SYS_PWR_ATTR_WARM_RESET_SHIFT		31
#define SCMI_SYS_PWR_WARM_RESET_SUPPORTED	(1U << SYS_PWR_ATTR_WARM_RESET_SHIFT)

#define SYS_PWR_ATTR_SUSPEND_SHIFT		30
#define SCMI_SYS_PWR_SUSPEND_SUPPORTED		(1 << SYS_PWR_ATTR_SUSPEND_SHIFT)

/*
 * Macros to describe the bit-fields of the `flags` parameter of system power
 * domain protocol SYSTEM_POWER_STATE_SET message.
 */
#define SYS_PWR_SET_GRACEFUL_REQ_SHIFT		0
#define SCMI_SYS_PWR_GRACEFUL_REQ		(1 << SYS_PWR_SET_GRACEFUL_REQ_SHIFT)
#define SCMI_SYS_PWR_FORCEFUL_REQ		(0 << SYS_PWR_SET_GRACEFUL_REQ_SHIFT)

/*
 * Macros to describe the `system_state` parameter of system power
 * domain protocol SYSTEM_POWER_STATE_SET message.
 */
#define SCMI_SYS_PWR_SHUTDOWN			0x0
#define SCMI_SYS_PWR_COLD_RESET			0x1
#define SCMI_SYS_PWR_WARM_RESET			0x2
#define SCMI_SYS_PWR_POWER_UP			0x3
#define SCMI_SYS_PWR_SUSPEND			0x4

/*
 * Macros to describe the bit-fields of the `attribute` of AP core protocol
 * AP_CORE_RESET_ADDR set/get messages.
 */
#define SCMI_AP_CORE_LOCK_ATTR_SHIFT		0x0
#define SCMI_AP_CORE_LOCK_ATTR			(1U << SCMI_AP_CORE_LOCK_ATTR_SHIFT)

/* SCMI Error code definitions */
#define SCMI_E_QUEUED			1
#define SCMI_E_SUCCESS			0
#define SCMI_E_NOT_SUPPORTED		-1
#define SCMI_E_INVALID_PARAM		-2
#define SCMI_E_DENIED			-3
#define SCMI_E_NOT_FOUND		-4
#define SCMI_E_OUT_OF_RANGE		-5
#define SCMI_E_BUSY			-6

/*
 * SCMI driver platform information. The details of the doorbell mechanism
 * can be found in the SCMI specification.
 */
typedef struct scmi_channel_plat_info {
	/* SCMI mailbox memory */
	uintptr_t scmi_mbx_mem;
	/* The door bell register address */
	uintptr_t db_reg_addr;
	/* The bit mask that need to be preserved when ringing doorbell */
	uint32_t db_preserve_mask;
	/* The bit mask that need to be set to ring doorbell */
	uint32_t db_modify_mask;
	/* The handler for ringing doorbell */
	void (*ring_doorbell)(struct scmi_channel_plat_info *plat_info);
	/* cookie is unused now. But added for future enhancements. */
	void *cookie;
} scmi_channel_plat_info_t;


#if HW_ASSISTED_COHERENCY
typedef spinlock_t scmi_lock_t;
#else
typedef bakery_lock_t scmi_lock_t;
#endif

/*
 * Structure to represent an SCMI channel.
 */
typedef struct scmi_channel {
	scmi_channel_plat_info_t *info;
	 /* The lock for channel access */
	scmi_lock_t *lock;
	/* Indicate whether the channel is initialized */
	int is_initialized;
} scmi_channel_t;

/* External Common API */
void *scmi_init(scmi_channel_t *ch);
int scmi_proto_msg_attr(void *p, uint32_t proto_id, uint32_t command_id,
						uint32_t *attr);
int scmi_proto_version(void *p, uint32_t proto_id, uint32_t *version);

/*
 * Power domain protocol commands. Refer to the SCMI specification for more
 * details on these commands.
 */
int scmi_pwr_state_set(void *p, uint32_t domain_id, uint32_t scmi_pwr_state);
int scmi_pwr_state_get(void *p, uint32_t domain_id, uint32_t *scmi_pwr_state);

/*
 * System power management protocol commands. Refer SCMI specification for more
 * details on these commands.
 */
int scmi_sys_pwr_state_set(void *p, uint32_t flags, uint32_t system_state);
int scmi_sys_pwr_state_get(void *p, uint32_t *system_state);

/* SCMI AP core configuration protocol commands. */
int scmi_ap_core_set_reset_addr(void *p, uint64_t reset_addr, uint32_t attr);
int scmi_ap_core_get_reset_addr(void *p, uint64_t *reset_addr, uint32_t *attr);

/* API to get the platform specific SCMI channel information. */
scmi_channel_plat_info_t *plat_css_get_scmi_info(int channel_id);

/* API to override default PSCI callbacks for platforms that support SCMI. */
const plat_psci_ops_t *css_scmi_override_pm_ops(plat_psci_ops_t *ops);

#endif /* SCMI_H */
