interface/vchiq_arm/vchiq_shim.c

/**
 * Copyright (c) 2010-2012 Broadcom. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The names of the above-listed copyright holders may not be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * ALTERNATIVELY, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2, as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <interface/compat/vchi_bsd.h>

#include "interface/vchi/vchi.h"
#include "vchiq.h"
#include "vchiq_core.h"

#include "vchiq_util.h"

#define vchiq_status_to_vchi(status) ((int32_t)status)

typedef struct {
	VCHIQ_SERVICE_HANDLE_T handle;

	VCHIU_QUEUE_T queue;

	VCHI_CALLBACK_T callback;
	void *callback_param;
} SHIM_SERVICE_T;

/* ----------------------------------------------------------------------
 * return pointer to the mphi message driver function table
 * -------------------------------------------------------------------- */
const VCHI_MESSAGE_DRIVER_T *
vchi_mphi_message_driver_func_table(void)
{
	return NULL;
}

/* ----------------------------------------------------------------------
 * return a pointer to the 'single' connection driver fops
 * -------------------------------------------------------------------- */
const VCHI_CONNECTION_API_T *
single_get_func_table(void)
{
	return NULL;
}

VCHI_CONNECTION_T *vchi_create_connection(
	const VCHI_CONNECTION_API_T *function_table,
	const VCHI_MESSAGE_DRIVER_T *low_level)
{
	(void)function_table;
	(void)low_level;
	return NULL;
}

/***********************************************************
 * Name: vchi_msg_peek
 *
 * Arguments:  const VCHI_SERVICE_HANDLE_T handle,
 *             void **data,
 *             uint32_t *msg_size,


 *             VCHI_FLAGS_T flags
 *
 * Description: Routine to return a pointer to the current message (to allow in
 *              place processing). The message can be removed using
 *              vchi_msg_remove when you're finished
 *
 * Returns: int32_t - success == 0
 *
 ***********************************************************/
int32_t vchi_msg_peek(VCHI_SERVICE_HANDLE_T handle,
	void **data,
	uint32_t *msg_size,
	VCHI_FLAGS_T flags)
{
	SHIM_SERVICE_T *service = (SHIM_SERVICE_T *)handle;
	VCHIQ_HEADER_T *header;

	WARN_ON((flags != VCHI_FLAGS_NONE) &&
		(flags != VCHI_FLAGS_BLOCK_UNTIL_OP_COMPLETE));

	if (flags == VCHI_FLAGS_NONE)
		if (vchiu_queue_is_empty(&service->queue))
			return -1;

	header = vchiu_queue_peek(&service->queue);

	*data = header->data;
	*msg_size = header->size;

	return 0;
}
EXPORT_SYMBOL(vchi_msg_peek);

/***********************************************************
 * Name: vchi_msg_remove
 *
 * Arguments:  const VCHI_SERVICE_HANDLE_T handle,
 *
 * Description: Routine to remove a message (after it has been read with
 *              vchi_msg_peek)
 *
 * Returns: int32_t - success == 0
 *
 ***********************************************************/
int32_t vchi_msg_remove(VCHI_SERVICE_HANDLE_T handle)
{
	SHIM_SERVICE_T *service = (SHIM_SERVICE_T *)handle;
	VCHIQ_HEADER_T *header;

	header = vchiu_queue_pop(&service->queue);

	vchiq_release_message(service->handle, header);

	return 0;
}
EXPORT_SYMBOL(vchi_msg_remove);

/***********************************************************
 * Name: vchi_msg_queue
 *
 * Arguments:  VCHI_SERVICE_HANDLE_T handle,
 *             const void *data,
 *             uint32_t data_size,
 *             VCHI_FLAGS_T flags,
 *             void *msg_handle,
 *
 * Description: Thin wrapper to queue a message onto a connection
 *
 * Returns: int32_t - success == 0
 *
 ***********************************************************/
int32_t vchi_msg_queue(VCHI_SERVICE_HANDLE_T handle,
	const void *data,
	uint32_t data_size,
	VCHI_FLAGS_T flags,
	void *msg_handle)
{
	SHIM_SERVICE_T *service = (SHIM_SERVICE_T *)handle;
	VCHIQ_ELEMENT_T element = {data, data_size};
	VCHIQ_STATUS_T status;

	(void)msg_handle;

	WARN_ON(flags != VCHI_FLAGS_BLOCK_UNTIL_QUEUED);

	status = vchiq_queue_message(service->handle, &element, 1);

	/* vchiq_queue_message() may return VCHIQ_RETRY, so we need to
	** implement a retry mechanism since this function is supposed
	** to block until queued
	*/
	while (status == VCHIQ_RETRY) {
		msleep(1);
		status = vchiq_queue_message(service->handle, &element, 1);
	}

	return vchiq_status_to_vchi(status);
}
EXPORT_SYMBOL(vchi_msg_queue);

/***********************************************************
 * Name: vchi_bulk_queue_receive
 *
 * Arguments:  VCHI_BULK_HANDLE_T handle,
 *             void *data_dst,
 *             const uint32_t data_size,
 *             VCHI_FLAGS_T flags
 *             void *bulk_handle
 *
 * Description: Routine to setup a rcv buffer
 *
 * Returns: int32_t - success == 0
 *
 ***********************************************************/
int32_t vchi_bulk_queue_receive(VCHI_SERVICE_HANDLE_T handle,
	void *data_dst,
	uint32_t data_size,
	VCHI_FLAGS_T flags,
	void *bulk_handle)
{
	SHIM_SERVICE_T *service = (SHIM_SERVICE_T *)handle;
	VCHIQ_BULK_MODE_T mode;
	VCHIQ_STATUS_T status;

	switch ((int)flags) {
	case VCHI_FLAGS_CALLBACK_WHEN_OP_COMPLETE
		| VCHI_FLAGS_BLOCK_UNTIL_QUEUED:
		WARN_ON(!service->callback);
		mode = VCHIQ_BULK_MODE_CALLBACK;
		break;
	case VCHI_FLAGS_BLOCK_UNTIL_OP_COMPLETE:
		mode = VCHIQ_BULK_MODE_BLOCKING;
		break;
	case VCHI_FLAGS_BLOCK_UNTIL_QUEUED:
	case VCHI_FLAGS_NONE:
		mode = VCHIQ_BULK_MODE_NOCALLBACK;
		break;
	default:
		WARN(1, "unsupported message\n");
		return vchiq_status_to_vchi(VCHIQ_ERROR);
	}

	status = vchiq_bulk_receive(service->handle, data_dst, data_size,
		bulk_handle, mode);

	/* vchiq_bulk_receive() may return VCHIQ_RETRY, so we need to
	** implement a retry mechanism since this function is supposed
	** to block until queued
	*/
	while (status == VCHIQ_RETRY) {
		msleep(1);
		status = vchiq_bulk_receive(service->handle, data_dst,
			data_size, bulk_handle, mode);
	}

	return vchiq_status_to_vchi(status);
}
EXPORT_SYMBOL(vchi_bulk_queue_receive);

/***********************************************************
 * Name: vchi_bulk_queue_transmit
 *
 * Arguments:  VCHI_BULK_HANDLE_T handle,
 *             void *data_src,
 *             uint32_t data_size,
 *             VCHI_FLAGS_T flags,
 *             void *bulk_handle
 *
 * Description: Routine to transmit some data
 *
 * Returns: int32_t - success == 0
 *
 ***********************************************************/
int32_t vchi_bulk_queue_transmit(VCHI_SERVICE_HANDLE_T handle,
	void *data_src,
	uint32_t data_size,
	VCHI_FLAGS_T flags,
	void *bulk_handle)
{
	SHIM_SERVICE_T *service = (SHIM_SERVICE_T *)handle;
	VCHIQ_BULK_MODE_T mode;
	VCHIQ_STATUS_T status;

	switch ((int)flags) {
	case VCHI_FLAGS_CALLBACK_WHEN_OP_COMPLETE
		| VCHI_FLAGS_BLOCK_UNTIL_QUEUED:
		WARN_ON(!service->callback);
		mode = VCHIQ_BULK_MODE_CALLBACK;
		break;
	case VCHI_FLAGS_BLOCK_UNTIL_DATA_READ:
	case VCHI_FLAGS_BLOCK_UNTIL_OP_COMPLETE:
		mode = VCHIQ_BULK_MODE_BLOCKING;
		break;
	case VCHI_FLAGS_BLOCK_UNTIL_QUEUED:
	case VCHI_FLAGS_NONE:
		mode = VCHIQ_BULK_MODE_NOCALLBACK;
		break;
	default:
		WARN(1, "unsupported message\n");
		return vchiq_status_to_vchi(VCHIQ_ERROR);
	}

	status = vchiq_bulk_transmit(service->handle, data_src, data_size,
		bulk_handle, mode);

	/* vchiq_bulk_transmit() may return VCHIQ_RETRY, so we need to
	** implement a retry mechanism since this function is supposed
	** to block until queued
	*/
	while (status == VCHIQ_RETRY) {
		msleep(1);
		status = vchiq_bulk_transmit(service->handle, data_src,
			data_size, bulk_handle, mode);
	}

	return vchiq_status_to_vchi(status);
}
EXPORT_SYMBOL(vchi_bulk_queue_transmit);

/***********************************************************
 * Name: vchi_msg_dequeue
 *
 * Arguments:  VCHI_SERVICE_HANDLE_T handle,
 *             void *data,
 *             uint32_t max_data_size_to_read,
 *             uint32_t *actual_msg_size
 *             VCHI_FLAGS_T flags
 *
 * Description: Routine to dequeue a message into the supplied buffer
 *
 * Returns: int32_t - success == 0
 *
 ***********************************************************/
int32_t vchi_msg_dequeue(VCHI_SERVICE_HANDLE_T handle,
	void *data,
	uint32_t max_data_size_to_read,
	uint32_t *actual_msg_size,
	VCHI_FLAGS_T flags)
{
	SHIM_SERVICE_T *service = (SHIM_SERVICE_T *)handle;
	VCHIQ_HEADER_T *header;

	WARN_ON((flags != VCHI_FLAGS_NONE) &&
		(flags != VCHI_FLAGS_BLOCK_UNTIL_OP_COMPLETE));

	if (flags == VCHI_FLAGS_NONE)
		if (vchiu_queue_is_empty(&service->queue))
			return -1;

	header = vchiu_queue_pop(&service->queue);

	memcpy(data, header->data, header->size < max_data_size_to_read ?
		header->size : max_data_size_to_read);

	*actual_msg_size = header->size;

	vchiq_release_message(service->handle, header);

	return 0;
}
EXPORT_SYMBOL(vchi_msg_dequeue);

/***********************************************************
 * Name: vchi_msg_queuev
 *
 * Arguments:  VCHI_SERVICE_HANDLE_T handle,
 *             VCHI_MSG_VECTOR_T *vector,
 *             uint32_t count,
 *             VCHI_FLAGS_T flags,
 *             void *msg_handle
 *
 * Description: Thin wrapper to queue a message onto a connection
 *
 * Returns: int32_t - success == 0
 *
 ***********************************************************/

vchiq_static_assert(sizeof(VCHI_MSG_VECTOR_T) == sizeof(VCHIQ_ELEMENT_T));
vchiq_static_assert(offsetof(VCHI_MSG_VECTOR_T, vec_base) ==
	offsetof(VCHIQ_ELEMENT_T, data));
vchiq_static_assert(offsetof(VCHI_MSG_VECTOR_T, vec_len) ==
	offsetof(VCHIQ_ELEMENT_T, size));

int32_t vchi_msg_queuev(VCHI_SERVICE_HANDLE_T handle,
	VCHI_MSG_VECTOR_T *vector,
	uint32_t count,
	VCHI_FLAGS_T flags,
	void *msg_handle)
{
	SHIM_SERVICE_T *service = (SHIM_SERVICE_T *)handle;

	(void)msg_handle;

	WARN_ON(flags != VCHI_FLAGS_BLOCK_UNTIL_QUEUED);

	return vchiq_status_to_vchi(vchiq_queue_message(service->handle,
		(const VCHIQ_ELEMENT_T *)vector, count));
}
EXPORT_SYMBOL(vchi_msg_queuev);

/***********************************************************
 * Name: vchi_held_msg_release
 *
 * Arguments:  VCHI_HELD_MSG_T *message
 *
 * Description: Routine to release a held message (after it has been read with
 *              vchi_msg_hold)
 *
 * Returns: int32_t - success == 0
 *
 ***********************************************************/
int32_t vchi_held_msg_release(VCHI_HELD_MSG_T *message)
{
	vchiq_release_message((VCHIQ_SERVICE_HANDLE_T)message->service,
		(VCHIQ_HEADER_T *)message->message);

	return 0;
}

/***********************************************************
 * Name: vchi_msg_hold
 *
 * Arguments:  VCHI_SERVICE_HANDLE_T handle,
 *             void **data,
 *             uint32_t *msg_size,
 *             VCHI_FLAGS_T flags,
 *             VCHI_HELD_MSG_T *message_handle
 *
 * Description: Routine to return a pointer to the current message (to allow
 *              in place processing). The message is dequeued - don't forget
 *              to release the message using vchi_held_msg_release when you're
 *              finished.
 *
 * Returns: int32_t - success == 0
 *
 ***********************************************************/
int32_t vchi_msg_hold(VCHI_SERVICE_HANDLE_T handle,
	void **data,
	uint32_t *msg_size,
	VCHI_FLAGS_T flags,
	VCHI_HELD_MSG_T *message_handle)
{
	SHIM_SERVICE_T *service = (SHIM_SERVICE_T *)handle;
	VCHIQ_HEADER_T *header;

	WARN_ON((flags != VCHI_FLAGS_NONE) &&
		(flags != VCHI_FLAGS_BLOCK_UNTIL_OP_COMPLETE));

	if (flags == VCHI_FLAGS_NONE)
		if (vchiu_queue_is_empty(&service->queue))
			return -1;

	header = vchiu_queue_pop(&service->queue);

	*data = header->data;
	*msg_size = header->size;

	message_handle->service =
		(struct opaque_vchi_service_t *)service->handle;
	message_handle->message = header;

	return 0;
}

/***********************************************************
 * Name: vchi_initialise
 *
 * Arguments: VCHI_INSTANCE_T *instance_handle
 *            VCHI_CONNECTION_T **connections
 *            const uint32_t num_connections
 *
 * Description: Initialises the hardware but does not transmit anything
 *              When run as a Host App this will be called twice hence the need
 *              to malloc the state information
 *
 * Returns: 0 if successful, failure otherwise
 *
 ***********************************************************/

int32_t vchi_initialise(VCHI_INSTANCE_T *instance_handle)
{
	VCHIQ_INSTANCE_T instance;
	VCHIQ_STATUS_T status;

	status = vchiq_initialise(&instance);

	*instance_handle = (VCHI_INSTANCE_T)instance;

	return vchiq_status_to_vchi(status);
}
EXPORT_SYMBOL(vchi_initialise);

/***********************************************************
 * Name: vchi_connect
 *
 * Arguments: VCHI_CONNECTION_T **connections
 *            const uint32_t num_connections
 *            VCHI_INSTANCE_T instance_handle)
 *
 * Description: Starts the command service on each connection,
 *              causing INIT messages to be pinged back and forth
 *
 * Returns: 0 if successful, failure otherwise
 *
 ***********************************************************/
int32_t vchi_connect(VCHI_CONNECTION_T **connections,
	const uint32_t num_connections,
	VCHI_INSTANCE_T instance_handle)
{
	VCHIQ_INSTANCE_T instance = (VCHIQ_INSTANCE_T)instance_handle;

	(void)connections;
	(void)num_connections;

	return vchiq_connect(instance);
}
EXPORT_SYMBOL(vchi_connect);


/***********************************************************
 * Name: vchi_disconnect
 *
 * Arguments: VCHI_INSTANCE_T instance_handle
 *
 * Description: Stops the command service on each connection,
 *              causing DE-INIT messages to be pinged back and forth
 *
 * Returns: 0 if successful, failure otherwise
 *
 ***********************************************************/
int32_t vchi_disconnect(VCHI_INSTANCE_T instance_handle)
{
	VCHIQ_INSTANCE_T instance = (VCHIQ_INSTANCE_T)instance_handle;
	return vchiq_status_to_vchi(vchiq_shutdown(instance));
}
EXPORT_SYMBOL(vchi_disconnect);


/***********************************************************
 * Name: vchi_service_open
 * Name: vchi_service_create
 *
 * Arguments: VCHI_INSTANCE_T *instance_handle
 *            SERVICE_CREATION_T *setup,
 *            VCHI_SERVICE_HANDLE_T *handle
 *
 * Description: Routine to open a service
 *
 * Returns: int32_t - success == 0
 *
 ***********************************************************/

static VCHIQ_STATUS_T shim_callback(VCHIQ_REASON_T reason,
	VCHIQ_HEADER_T *header, VCHIQ_SERVICE_HANDLE_T handle, void *bulk_user)
{
	SHIM_SERVICE_T *service =
		(SHIM_SERVICE_T *)VCHIQ_GET_SERVICE_USERDATA(handle);

        if (!service->callback)
		goto release;

	switch (reason) {
	case VCHIQ_MESSAGE_AVAILABLE:
		vchiu_queue_push(&service->queue, header);

		service->callback(service->callback_param,
				  VCHI_CALLBACK_MSG_AVAILABLE, NULL);

		goto done;
		break;

	case VCHIQ_BULK_TRANSMIT_DONE:
		service->callback(service->callback_param,
				  VCHI_CALLBACK_BULK_SENT, bulk_user);
		break;

	case VCHIQ_BULK_RECEIVE_DONE:
		service->callback(service->callback_param,
				  VCHI_CALLBACK_BULK_RECEIVED, bulk_user);
		break;

	case VCHIQ_SERVICE_CLOSED:
		service->callback(service->callback_param,
				  VCHI_CALLBACK_SERVICE_CLOSED, NULL);
		break;

	case VCHIQ_SERVICE_OPENED:
		/* No equivalent VCHI reason */
		break;

	case VCHIQ_BULK_TRANSMIT_ABORTED:
		service->callback(service->callback_param,
				  VCHI_CALLBACK_BULK_TRANSMIT_ABORTED,
				  bulk_user);
		break;

	case VCHIQ_BULK_RECEIVE_ABORTED:
		service->callback(service->callback_param,
				  VCHI_CALLBACK_BULK_RECEIVE_ABORTED,
				  bulk_user);
		break;

	default:
		WARN(1, "not supported\n");
		break;
	}

release:
        vchiq_release_message(service->handle, header);
done:
	return VCHIQ_SUCCESS;
}

static SHIM_SERVICE_T *service_alloc(VCHIQ_INSTANCE_T instance,
	SERVICE_CREATION_T *setup)
{
	SHIM_SERVICE_T *service = kzalloc(sizeof(SHIM_SERVICE_T), GFP_KERNEL);

	(void)instance;

	if (service) {
		if (vchiu_queue_init(&service->queue, 64)) {
			service->callback = setup->callback;
			service->callback_param = setup->callback_param;
		} else {
			kfree(service);
			service = NULL;
		}
	}

	return service;
}

static void service_free(SHIM_SERVICE_T *service)
{
	if (service) {
		vchiu_queue_delete(&service->queue);
		kfree(service);
	}
}

int32_t vchi_service_open(VCHI_INSTANCE_T instance_handle,
	SERVICE_CREATION_T *setup,
	VCHI_SERVICE_HANDLE_T *handle)
{
	VCHIQ_INSTANCE_T instance = (VCHIQ_INSTANCE_T)instance_handle;
	SHIM_SERVICE_T *service = service_alloc(instance, setup);
	if (service) {
		VCHIQ_SERVICE_PARAMS_T params;
		VCHIQ_STATUS_T status;

		memset(&params, 0, sizeof(params));
		params.fourcc = setup->service_id;
		params.callback = shim_callback;
		params.userdata = service;
		params.version = setup->version.version;
		params.version_min = setup->version.version_min;

		status = vchiq_open_service(instance, &params,
			&service->handle);
		if (status != VCHIQ_SUCCESS) {
			service_free(service);
			service = NULL;
		}
	}

	*handle = (VCHI_SERVICE_HANDLE_T)service;

	return (service != NULL) ? 0 : -1;
}
EXPORT_SYMBOL(vchi_service_open);

int32_t vchi_service_create(VCHI_INSTANCE_T instance_handle,
	SERVICE_CREATION_T *setup,
	VCHI_SERVICE_HANDLE_T *handle)
{
	VCHIQ_INSTANCE_T instance = (VCHIQ_INSTANCE_T)instance_handle;
	SHIM_SERVICE_T *service = service_alloc(instance, setup);
	if (service) {
		VCHIQ_SERVICE_PARAMS_T params;
		VCHIQ_STATUS_T status;

		memset(&params, 0, sizeof(params));
		params.fourcc = setup->service_id;
		params.callback = shim_callback;
		params.userdata = service;
		params.version = setup->version.version;
		params.version_min = setup->version.version_min;
		status = vchiq_add_service(instance, &params, &service->handle);

		if (status != VCHIQ_SUCCESS) {
			service_free(service);
			service = NULL;
		}
	}

	*handle = (VCHI_SERVICE_HANDLE_T)service;

	return (service != NULL) ? 0 : -1;
}
EXPORT_SYMBOL(vchi_service_create);

int32_t vchi_service_close(const VCHI_SERVICE_HANDLE_T handle)
{
	int32_t ret = -1;
	SHIM_SERVICE_T *service = (SHIM_SERVICE_T *)handle;
	if (service) {
		VCHIQ_STATUS_T status = vchiq_close_service(service->handle);
		if (status == VCHIQ_SUCCESS) {
			service_free(service);
			service = NULL;
		}

		ret = vchiq_status_to_vchi(status);
	}
	return ret;
}
EXPORT_SYMBOL(vchi_service_close);

int32_t vchi_service_destroy(const VCHI_SERVICE_HANDLE_T handle)
{
	int32_t ret = -1;
	SHIM_SERVICE_T *service = (SHIM_SERVICE_T *)handle;
	if (service) {
		VCHIQ_STATUS_T status = vchiq_remove_service(service->handle);
		if (status == VCHIQ_SUCCESS) {
			service_free(service);
			service = NULL;
		}

		ret = vchiq_status_to_vchi(status);
	}
	return ret;
}
EXPORT_SYMBOL(vchi_service_destroy);

#ifdef notyet
int32_t vchi_get_peer_version( const VCHI_SERVICE_HANDLE_T handle, short *peer_version )
{
   int32_t ret = -1;
   SHIM_SERVICE_T *service = (SHIM_SERVICE_T *)handle;
   if(service)
   {
      VCHIQ_STATUS_T status = vchiq_get_peer_version(service->handle, peer_version);
      ret = vchiq_status_to_vchi( status );
   }
   return ret;
}
EXPORT_SYMBOL(vchi_get_peer_version);

/* ----------------------------------------------------------------------
 * read a uint32_t from buffer.
 * network format is defined to be little endian
 * -------------------------------------------------------------------- */
uint32_t
vchi_readbuf_uint32(const void *_ptr)
{
	const unsigned char *ptr = _ptr;
	return ptr[0] | (ptr[1] << 8) | (ptr[2] << 16) | (ptr[3] << 24);
}

/* ----------------------------------------------------------------------
 * write a uint32_t to buffer.
 * network format is defined to be little endian
 * -------------------------------------------------------------------- */
void
vchi_writebuf_uint32(void *_ptr, uint32_t value)
{
	unsigned char *ptr = _ptr;
	ptr[0] = (unsigned char)((value >> 0)  & 0xFF);
	ptr[1] = (unsigned char)((value >> 8)  & 0xFF);
	ptr[2] = (unsigned char)((value >> 16) & 0xFF);
	ptr[3] = (unsigned char)((value >> 24) & 0xFF);
}

/* ----------------------------------------------------------------------
 * read a uint16_t from buffer.
 * network format is defined to be little endian
 * -------------------------------------------------------------------- */
uint16_t
vchi_readbuf_uint16(const void *_ptr)
{
	const unsigned char *ptr = _ptr;
	return ptr[0] | (ptr[1] << 8);
}

/* ----------------------------------------------------------------------
 * write a uint16_t into the buffer.
 * network format is defined to be little endian
 * -------------------------------------------------------------------- */
void
vchi_writebuf_uint16(void *_ptr, uint16_t value)
{
	unsigned char *ptr = _ptr;
	ptr[0] = (value >> 0)  & 0xFF;
	ptr[1] = (value >> 8)  & 0xFF;
}
#endif

/***********************************************************
 * Name: vchi_service_use
 *
 * Arguments: const VCHI_SERVICE_HANDLE_T handle
 *
 * Description: Routine to increment refcount on a service
 *
 * Returns: void
 *
 ***********************************************************/
int32_t vchi_service_use(const VCHI_SERVICE_HANDLE_T handle)
{
	int32_t ret = -1;
	SHIM_SERVICE_T *service = (SHIM_SERVICE_T *)handle;
	if (service)
		ret = vchiq_status_to_vchi(vchiq_use_service(service->handle));
	return ret;
}
EXPORT_SYMBOL(vchi_service_use);

/***********************************************************
 * Name: vchi_service_release
 *
 * Arguments: const VCHI_SERVICE_HANDLE_T handle
 *
 * Description: Routine to decrement refcount on a service
 *
 * Returns: void
 *
 ***********************************************************/
int32_t vchi_service_release(const VCHI_SERVICE_HANDLE_T handle)
{
	int32_t ret = -1;
	SHIM_SERVICE_T *service = (SHIM_SERVICE_T *)handle;
	if (service)
		ret = vchiq_status_to_vchi(
			vchiq_release_service(service->handle));
	return ret;
}
EXPORT_SYMBOL(vchi_service_release);