2014-10-02 02:54:14 +00:00
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/*
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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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2014-10-02 02:54:15 +00:00
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#include <linux/atomic.h>
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#include "kernel_ver.h"
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2014-10-02 02:54:14 +00:00
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#include "greybus.h"
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2014-10-03 19:14:22 +00:00
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static DEFINE_SPINLOCK(gb_connections_lock);
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2014-10-06 11:53:08 +00:00
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static void _gb_hd_connection_insert(struct greybus_host_device *hd,
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struct gb_connection *connection)
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{
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struct rb_root *root = &hd->connections;
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struct rb_node *node = &connection->hd_node;
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struct rb_node **link = &root->rb_node;
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struct rb_node *above = NULL;
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u16 cport_id = connection->hd_cport_id;
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while (*link) {
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struct gb_connection *connection;
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above = *link;
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connection = rb_entry(above, struct gb_connection, hd_node);
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if (connection->hd_cport_id > cport_id)
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link = &above->rb_left;
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else if (connection->hd_cport_id < cport_id)
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link = &above->rb_right;
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}
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rb_link_node(node, above, link);
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rb_insert_color(node, root);
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}
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static void _gb_hd_connection_remove(struct gb_connection *connection)
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{
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rb_erase(&connection->hd_node, &connection->hd->connections);
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}
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struct gb_connection *gb_hd_connection_find(struct greybus_host_device *hd,
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u16 cport_id)
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{
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struct gb_connection *connection = NULL;
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struct rb_node *node;
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spin_lock_irq(&gb_connections_lock);
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node = hd->connections.rb_node;
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while (node) {
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connection = rb_entry(node, struct gb_connection, hd_node);
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if (connection->hd_cport_id > cport_id)
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node = node->rb_left;
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else if (connection->hd_cport_id < cport_id)
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node = node->rb_right;
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else
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2014-10-06 17:26:02 +00:00
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goto found;
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2014-10-06 11:53:08 +00:00
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}
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2014-10-06 17:26:02 +00:00
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connection = NULL;
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found:
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2014-10-06 11:53:08 +00:00
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spin_unlock_irq(&gb_connections_lock);
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return connection;
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}
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2014-10-03 19:14:24 +00:00
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/*
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* Allocate an available CPort Id for use for the host side of the
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* given connection. The lowest-available id is returned, so the
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* first call is guaranteed to allocate CPort Id 0.
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*
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* Assigns the connection's hd_cport_id and returns true if successful.
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* Returns false otherwise.
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*/
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2014-10-06 11:53:06 +00:00
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static bool gb_connection_hd_cport_id_alloc(struct gb_connection *connection)
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2014-10-03 19:14:24 +00:00
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{
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struct ida *ida = &connection->hd->cport_id_map;
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int id;
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2014-10-07 03:29:40 +00:00
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spin_lock(&connection->hd->cport_id_map_lock);
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2014-10-03 19:14:24 +00:00
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id = ida_simple_get(ida, 0, HOST_DEV_CPORT_ID_MAX, GFP_KERNEL);
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2014-10-07 03:29:40 +00:00
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spin_unlock(&connection->hd->cport_id_map_lock);
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2014-10-03 19:14:24 +00:00
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if (id < 0)
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return false;
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connection->hd_cport_id = (u16)id;
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return true;
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}
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/*
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* Free a previously-allocated CPort Id on the given host device.
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*/
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2014-10-06 11:53:06 +00:00
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static void gb_connection_hd_cport_id_free(struct gb_connection *connection)
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2014-10-03 19:14:24 +00:00
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{
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struct ida *ida = &connection->hd->cport_id_map;
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2014-10-07 03:29:40 +00:00
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spin_lock(&connection->hd->cport_id_map_lock);
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2014-10-03 19:14:24 +00:00
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ida_simple_remove(ida, connection->hd_cport_id);
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2014-10-07 03:29:40 +00:00
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spin_unlock(&connection->hd->cport_id_map_lock);
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2014-10-03 19:14:24 +00:00
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connection->hd_cport_id = CPORT_ID_BAD;
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}
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2014-10-02 02:54:14 +00:00
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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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2014-10-02 02:54:15 +00:00
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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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2014-10-02 02:54:14 +00:00
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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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2014-10-02 17:30:05 +00:00
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struct gb_connection *gb_connection_create(struct gb_interface *interface,
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2014-10-02 17:30:06 +00:00
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u16 cport_id, enum greybus_protocol protocol)
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2014-10-02 02:54:14 +00:00
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{
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struct gb_connection *connection;
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2014-10-02 17:30:05 +00:00
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struct greybus_host_device *hd;
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2014-10-02 02:54:14 +00:00
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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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2014-10-02 17:30:05 +00:00
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hd = interface->gmod->hd;
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2014-10-03 19:14:24 +00:00
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connection->hd = hd; /* XXX refcount? */
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2014-10-06 11:53:06 +00:00
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if (!gb_connection_hd_cport_id_alloc(connection)) {
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2014-10-03 19:14:24 +00:00
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/* kref_put(connection->hd); */
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2014-10-02 17:30:04 +00:00
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kfree(connection);
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return NULL;
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}
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2014-10-07 03:29:40 +00:00
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2014-10-02 17:30:05 +00:00
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connection->interface = interface; /* XXX refcount? */
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connection->interface_cport_id = cport_id;
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2014-10-02 17:30:06 +00:00
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connection->protocol = protocol;
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2014-10-03 19:14:22 +00:00
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spin_lock_irq(&gb_connections_lock);
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2014-10-06 11:53:08 +00:00
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_gb_hd_connection_insert(hd, connection);
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2014-10-03 19:14:22 +00:00
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list_add_tail(&connection->interface_links, &interface->connections);
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spin_unlock_irq(&gb_connections_lock);
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2014-10-02 02:54:15 +00:00
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INIT_LIST_HEAD(&connection->operations);
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2014-10-16 11:35:32 +00:00
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connection->pending = RB_ROOT;
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2014-10-02 02:54:15 +00:00
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atomic_set(&connection->op_cycle, 0);
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2014-10-02 02:54:14 +00:00
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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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2014-10-02 02:54:15 +00:00
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WARN_ON(!list_empty(&connection->operations));
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2014-10-02 02:54:14 +00:00
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2014-10-03 19:14:22 +00:00
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spin_lock_irq(&gb_connections_lock);
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list_del(&connection->interface_links);
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2014-10-06 11:53:08 +00:00
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_gb_hd_connection_remove(connection);
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2014-10-03 19:14:22 +00:00
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spin_unlock_irq(&gb_connections_lock);
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2014-10-06 11:53:06 +00:00
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gb_connection_hd_cport_id_free(connection);
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2014-10-02 17:30:05 +00:00
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/* kref_put(connection->interface); */
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/* kref_put(connection->hd); */
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2014-10-02 02:54:14 +00:00
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kfree(connection);
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}
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2014-10-02 02:54:15 +00:00
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2014-10-16 11:35:32 +00:00
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u16 gb_connection_operation_id(struct gb_connection *connection)
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2014-10-02 02:54:15 +00:00
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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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2014-10-03 20:05:22 +00:00
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void gb_connection_err(struct gb_connection *connection, const char *fmt, ...)
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{
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struct va_format vaf;
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va_list args;
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va_start(args, fmt);
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vaf.fmt = fmt;
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vaf.va = &args;
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pr_err("greybus: [%hhu:%hhu:%hu]: %pV\n",
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connection->interface->gmod->module_id,
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connection->interface->id,
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connection->interface_cport_id, &vaf);
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va_end(args);
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}
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2014-10-16 11:35:35 +00:00
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/*
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* XXX Protocols should have a set of function pointers:
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* ->init (called here, to initialize the device)
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* ->input_handler
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* ->exit (reverse of init)
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*/
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int gb_connection_init(struct gb_connection *connection)
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{
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switch (connection->protocol) {
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case GREYBUS_PROTOCOL_I2C:
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2014-10-16 11:35:38 +00:00
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return gb_i2c_device_init(connection);
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2014-10-16 11:35:35 +00:00
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case GREYBUS_PROTOCOL_GPIO:
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2014-10-16 11:35:39 +00:00
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return gb_gpio_controller_init(connection);
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2014-10-20 07:24:57 +00:00
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case GREYBUS_PROTOCOL_BATTERY:
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return gb_battery_device_init(connection);
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case GREYBUS_PROTOCOL_CONTROL:
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case GREYBUS_PROTOCOL_AP:
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2014-10-16 11:35:35 +00:00
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case GREYBUS_PROTOCOL_UART:
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case GREYBUS_PROTOCOL_HID:
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case GREYBUS_PROTOCOL_VENDOR:
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default:
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gb_connection_err(connection, "unimplemented protocol %u",
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(u32)connection->protocol);
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break;
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}
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return -ENXIO;
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}
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