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