drivers/staging/vc04_services/interface/vchi/vchi_common.h

/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
/* Copyright (c) 2010-2012 Broadcom. All rights reserved. */

#ifndef VCHI_COMMON_H_
#define VCHI_COMMON_H_

//flags used when sending messages (must be bitmapped)
enum vchi_flags {
	VCHI_FLAGS_NONE                      = 0x0,
	VCHI_FLAGS_BLOCK_UNTIL_OP_COMPLETE   = 0x1,   // waits for message to be received, or sent (NB. not the same as being seen on other side)
	VCHI_FLAGS_CALLBACK_WHEN_OP_COMPLETE = 0x2,   // run a callback when message sent
	VCHI_FLAGS_BLOCK_UNTIL_QUEUED        = 0x4,   // return once the transfer is in a queue ready to go
	VCHI_FLAGS_ALLOW_PARTIAL             = 0x8,
	VCHI_FLAGS_BLOCK_UNTIL_DATA_READ     = 0x10,
	VCHI_FLAGS_CALLBACK_WHEN_DATA_READ   = 0x20,

	VCHI_FLAGS_ALIGN_SLOT            = 0x000080,  // internal use only
	VCHI_FLAGS_BULK_AUX_QUEUED       = 0x010000,  // internal use only
	VCHI_FLAGS_BULK_AUX_COMPLETE     = 0x020000,  // internal use only
	VCHI_FLAGS_BULK_DATA_QUEUED      = 0x040000,  // internal use only
	VCHI_FLAGS_BULK_DATA_COMPLETE    = 0x080000,  // internal use only
	VCHI_FLAGS_INTERNAL              = 0xFF0000
};

// constants for vchi_crc_control()
enum vchi_crc_control {
	VCHI_CRC_NOTHING = -1,
	VCHI_CRC_PER_SERVICE = 0,
	VCHI_CRC_EVERYTHING = 1,
};

//callback reasons when an event occurs on a service
enum vchi_callback_reason {
	VCHI_CALLBACK_REASON_MIN,

	//This indicates that there is data available
	//handle is the msg id that was transmitted with the data
	//    When a message is received and there was no FULL message available previously, send callback
	//    Tasks get kicked by the callback, reset their event and try and read from the fifo until it fails
	VCHI_CALLBACK_MSG_AVAILABLE,
	VCHI_CALLBACK_MSG_SENT,
	VCHI_CALLBACK_MSG_SPACE_AVAILABLE, // XXX not yet implemented

	// This indicates that a transfer from the other side has completed
	VCHI_CALLBACK_BULK_RECEIVED,
	//This indicates that data queued up to be sent has now gone
	//handle is the msg id that was used when sending the data
	VCHI_CALLBACK_BULK_SENT,
	VCHI_CALLBACK_BULK_RX_SPACE_AVAILABLE, // XXX not yet implemented
	VCHI_CALLBACK_BULK_TX_SPACE_AVAILABLE, // XXX not yet implemented

	VCHI_CALLBACK_SERVICE_CLOSED,

	// this side has sent XOFF to peer due to lack of data consumption by service
	// (suggests the service may need to take some recovery action if it has
	// been deliberately holding off consuming data)
	VCHI_CALLBACK_SENT_XOFF,
	VCHI_CALLBACK_SENT_XON,

	// indicates that a bulk transfer has finished reading the source buffer
	VCHI_CALLBACK_BULK_DATA_READ,

	// power notification events (currently host side only)
	VCHI_CALLBACK_PEER_OFF,
	VCHI_CALLBACK_PEER_SUSPENDED,
	VCHI_CALLBACK_PEER_ON,
	VCHI_CALLBACK_PEER_RESUMED,
	VCHI_CALLBACK_FORCED_POWER_OFF,

	// some extra notifications provided by vchiq_arm
	VCHI_CALLBACK_SERVICE_OPENED,
	VCHI_CALLBACK_BULK_RECEIVE_ABORTED,
	VCHI_CALLBACK_BULK_TRANSMIT_ABORTED,

	VCHI_CALLBACK_REASON_MAX
};

// service control options
enum vchi_service_option {
	VCHI_SERVICE_OPTION_MIN,

	VCHI_SERVICE_OPTION_TRACE,
	VCHI_SERVICE_OPTION_SYNCHRONOUS,

	VCHI_SERVICE_OPTION_MAX
};

//Callback used by all services / bulk transfers
typedef void (*vchi_callback)(void *callback_param, //my service local param
			      enum vchi_callback_reason reason,
			      void *handle); //for transmitting msg's only

/*
 * Define vector struct for scatter-gather (vector) operations
 * Vectors can be nested - if a vector element has negative length, then
 * the data pointer is treated as pointing to another vector array, with
 * '-vec_len' elements. Thus to append a header onto an existing vector,
 * you can do this:
 *
 * void foo(const struct vchi_msg_vector *v, int n)
 * {
 *    struct vchi_msg_vector nv[2];
 *    nv[0].vec_base = my_header;
 *    nv[0].vec_len = sizeof my_header;
 *    nv[1].vec_base = v;
 *    nv[1].vec_len = -n;
 *    ...
 *
 */
struct vchi_msg_vector {
	const void *vec_base;
	int32_t vec_len;
};

// Iterator structure for reading ahead through received message queue. Allocated by client,
// initialised by vchi_msg_look_ahead. Fields are for internal VCHI use only.
// Iterates over messages in queue at the instant of the call to vchi_msg_lookahead -
// will not proceed to messages received since. Behaviour is undefined if an iterator
// is used again after messages for that service are removed/dequeued by any
// means other than vchi_msg_iter_... calls on the iterator itself.
struct vchi_msg_iter {
	struct opaque_vchi_service_t *service;
	void *last;
	void *next;
	void *remove;
};

#endif // VCHI_COMMON_H_