/* Copyright (c) 2022 Intel Corporation
 * SPDX-License-Identifier: Apache-2.0
 */
#ifndef ZEPHYR_INCLUDE_CAVS_IPC_H
#define ZEPHYR_INCLUDE_CAVS_IPC_H

#include <zephyr/kernel.h>
#include <zephyr/device.h>

struct cavs_ipc_config {
	volatile struct cavs_ipc *regs;
};

/** @brief cAVS IPC Message Handler Callback
 *
 * This function, once registered via cavs_ipc_set_message_handler(),
 * is invoked in interrupt context to service messages sent from the
 * foreign/connected IPC context.  The message contents of the TDR and
 * TDD registers are provided in the data/ext_data argument.
 *
 * The function should return true if processing of the message is
 * complete and return notification to the other side (via the TDA
 * register) is desired immediately.  Returning false means that no
 * return "DONE" interrupt will occur until cavs_ipc_complete() is
 * called on this device at some point in the future.
 *
 * @note Further messages on the link will not be transmitted or
 * received while an in-progress message remains incomplete!
 *
 * @param dev IPC device
 * @param arg Registered argument from cavs_ipc_set_message_handler()
 * @param data Message data from other side (low bits of TDR register)
 * @param ext_dat Extended message data (TDD register)
 * @return true if the message is completely handled
 */
typedef bool (*cavs_ipc_handler_t)(const struct device *dev, void *arg,
				   uint32_t data, uint32_t ext_data);

/** @brief cAVS IPC Message Complete Callback
 *
 * This function, once registered via cavs_ipc_set_done_handler(), is
 * invoked in interrupt context when a "DONE" return interrupt is
 * received from the other side of the connection (indicating that a
 * previously sent message is finished processing).
 *
 * @note On cAVS hardware the DONE interrupt is transmitted
 * synchronously with the interrupt being cleared on the remote
 * device.  It is not possible to delay processing.  This callback
 * will still occur, but protocols which rely on notification of
 * asynchronous command processing will need modification.
 *
 * @param dev IPC device
 * @param arg Registered argument from cavs_ipc_set_done_handler()
 */
typedef void (*cavs_ipc_done_t)(const struct device *dev, void *arg);

struct cavs_ipc_data {
	struct k_sem sem;
	struct k_spinlock lock;
	cavs_ipc_handler_t handle_message;
	void *handler_arg;
	cavs_ipc_done_t done_notify;
	void *done_arg;
};

void z_cavs_ipc_isr(const void *devarg);

/** @brief Register message callback handler
 *
 * This function registers a handler function for received messages.
 *
 * @param dev IPC device
 * @param fn Callback function
 * @param arg Value to pass as the "arg" parameter to the function
 */
void cavs_ipc_set_message_handler(const struct device *dev,
				  cavs_ipc_handler_t fn, void *arg);

/** @brief Register done callback handler
 *
 * This function registers a handler function for message completion
 * notifications
 *
 * @param dev IPC device
 * @param fn Callback function
 * @param arg Value to pass as the "arg" parameter to the function
 */
void cavs_ipc_set_done_handler(const struct device *dev,
			       cavs_ipc_done_t fn, void *arg);

/** @brief Initialize cavs_ipc device
 *
 * Initialize the device.  Must be called before any API calls or
 * interrupts can be serviced.
 *
 * @param dev IPC device
 * @return Zero on success, negative codes for error
 */
int cavs_ipc_init(const struct device *dev);

/** @brief Complete an in-progress message
 *
 * Notify the other side that the current in-progress message is
 * complete.  This is a noop if no message is in progress.
 *
 * @note Further messages on the link will not be transmitted or
 * received while an in-progress message remains incomplete!
 *
 * @param dev IPC device
 */
void cavs_ipc_complete(const struct device *dev);

/** @brief Message-in-progress predicate
 *
 * Returns false if a message has been received but not yet completed
 * via cavs_ipc_complete(), true otherwise.
 *
 * @param dev IPC device
 * @return True if no message is in progress
 */
bool cavs_ipc_is_complete(const struct device *dev);


/** @brief Send an IPC message
 *
 * Sends a message to the other side of an IPC link.  The data and
 * ext_data parameters are passed using the IDR/IDD registers.
 * Returns true if the message was sent, false if a current message is
 * in progress (in the sense of cavs_ipc_is_complete()).
 *
 * @param dev IPC device
 * @param data 30 bits value to transmit with the message (IDR register)
 * @param ext_data Extended value to transmit with the message (IDD register)
 * @return message successfully transmitted
 */
bool cavs_ipc_send_message(const struct device *dev,
			   uint32_t data, uint32_t ext_data);

/** @brief Send an IPC message, block until completion
 *
 * As for cavs_ipc_send_message(), but blocks the current thread until
 * the completion of the message or the expiration of the provided
 * timeout.
 *
 * @param dev IPC device
 * @param data 30 bits value to transmit with the message (IDR register)
 * @param ext_data Extended value to transmit with the message (IDD register)
 * @param timeout Maximum time to wait, or K_FOREVER, or K_NO_WAIT
 * @return message successfully transmitted
 */
bool cavs_ipc_send_message_sync(const struct device *dev,
				uint32_t data, uint32_t ext_data,
				k_timeout_t timeout);

#define CAVS_HOST_DTNODE DT_NODELABEL(cavs_host_ipc)

/** @brief Host IPC device pointer
 *
 * This macro expands to the registered host IPC device from
 * devicetree (if one exists!).  The device will be initialized and
 * ready at system startup.
 */
#define CAVS_HOST_DEV DEVICE_DT_GET(CAVS_HOST_DTNODE)

#endif /* ZEPHYR_INCLUDE_CAVS_IPC_H */