blob: f3f774d2ed7b848660dbaf6785e04d4783d5aa3e (
plain) (
tree)
|
|
/*
* Greybus connections
*
* Copyright 2014 Google Inc.
*
* Released under the GPLv2 only.
*/
#include <linux/atomic.h>
#include "kernel_ver.h"
#include "greybus.h"
/*
* Set up a Greybus connection, representing the bidirectional link
* between a CPort on a (local) Greybus host device and a CPort on
* another Greybus module.
*
* A connection also maintains the state of operations sent over the
* connection.
*
* Returns a pointer to the new connection if successful, or a null
* pointer otherwise.
*/
struct gb_connection *gb_connection_create(struct gb_interface *interface,
u16 cport_id)
{
struct gb_connection *connection;
struct greybus_host_device *hd;
connection = kzalloc(sizeof(*connection), GFP_KERNEL);
if (!connection)
return NULL;
hd = interface->gmod->hd;
connection->hd_cport_id = greybus_hd_cport_id_alloc(hd);
if (connection->hd_cport_id == CPORT_ID_BAD) {
kfree(connection);
return NULL;
}
connection->hd = hd; /* XXX refcount? */
connection->interface = interface; /* XXX refcount? */
connection->interface_cport_id = cport_id;
INIT_LIST_HEAD(&connection->operations);
atomic_set(&connection->op_cycle, 0);
return connection;
}
/*
* Tear down a previously set up connection.
*/
void gb_connection_destroy(struct gb_connection *connection)
{
if (WARN_ON(!connection))
return;
/* XXX Need to wait for any outstanding requests to complete */
WARN_ON(!list_empty(&connection->operations));
greybus_hd_cport_id_free(connection->hd, connection->hd_cport_id);
/* kref_put(connection->interface); */
/* kref_put(connection->hd); */
kfree(connection);
}
u16 gb_connection_op_id(struct gb_connection *connection)
{
return (u16)(atomic_inc_return(&connection->op_cycle) % U16_MAX);
}
|