greybus: get rid of functions now...

We decided yesterday that we would no longer support the notion of a
"function."  Instead, a connection will simply exist between the AP
and an interface on a module (and a CPort Id on each end).  What
was previously considered the "function type" will now be handled
as the "protocol" associated with the connection.

Update gb_connection_create() to take just the interface and a cport
id associated with that interface.

Right now every module points back to a host device, so for now
we'll establish the connection back to that.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/staging/greybus/Makefile

@@ -6,7 +6,6 @@ greybus-y :=	core.o		\
 		manifest.o	\
 		module.o	\
 		interface.o	\
-		function.o	\
 		connection.o	\
 		operation.o	\
 		i2c-gb.o	\

drivers/staging/greybus/connection.c

@@ -22,23 +22,25 @@
  * Returns a pointer to the new connection if successful, or a null
  * pointer otherwise.
  */
-struct gb_connection *gb_connection_create(struct greybus_host_device *hd,
-				struct gb_function *function)
+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;
 
-	connection->cport_id = greybus_hd_cport_id_alloc(hd);
-	if (connection->cport_id == CPORT_ID_BAD) {
+	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->function = function;	/* XXX refcount? */
+	connection->interface = interface;	/* XXX refcount? */
+	connection->interface_cport_id = cport_id;
 	INIT_LIST_HEAD(&connection->operations);
 	atomic_set(&connection->op_cycle, 0);
 
@@ -56,9 +58,9 @@ void gb_connection_destroy(struct gb_connection *connection)
 	/* XXX Need to wait for any outstanding requests to complete */
 	WARN_ON(!list_empty(&connection->operations));
 
-	greybus_hd_cport_id_free(connection->hd, connection->cport_id);
-	/* kref_put(function); */
-	/* kref_put(hd); */
+	greybus_hd_cport_id_free(connection->hd, connection->hd_cport_id);
+	/* kref_put(connection->interface); */
+	/* kref_put(connection->hd); */
 	kfree(connection);
 }
 

drivers/staging/greybus/connection.h

@@ -14,18 +14,21 @@
 #include "greybus.h"
 
 struct gb_connection {
-	struct gb_function		*function;
 	struct greybus_host_device	*hd;
-	u16				cport_id;	/* Host side */
+	struct gb_interface		*interface;
+	u16				hd_cport_id;
+	u16				interface_cport_id;
 
-	struct list_head		host_links;
+	struct list_head		hd_links;
+	struct list_head		interface_links;
+	/* protocol */
 
 	struct list_head		operations;
 	atomic_t			op_cycle;
 };
 
-struct gb_connection *gb_connection_create(struct greybus_host_device *hd,
-					struct gb_function *function);
+struct gb_connection *gb_connection_create(struct gb_interface *interface,
+						u16 cport_id);
 void gb_connection_destroy(struct gb_connection *connection);
 
 u16 gb_connection_op_id(struct gb_connection *connection);

drivers/staging/greybus/function.c

-/*
- * Greybus functions
- *
- * Copyright 2014 Google Inc.
- *
- * Released under the GPLv2 only.
- */
-
-#include "greybus.h"
-
-/* XXX This could be per-host device or per-module or per-interface */
-static DEFINE_SPINLOCK(gb_functions_lock);
-
-/*
- * A Greybus function generically defines an entity associated with
- * a CPort within a module.  Each function has a type (e.g. i2c,
- * GPIO, etc.) that defines how it behaves and how the AP interacts
- * with it.
- *
- * Create a gb_function structure to represent a discovered
- * function.  Returns a pointer to the new function or a null
- * pointer if a failure occurs due to memory exhaustion.
- */
-struct gb_function *gb_function_create(struct gb_interface *interface,
-					u16 cport_id)
-{
-	struct gb_function *function;
-
-	function = kzalloc(sizeof(*function), GFP_KERNEL);
-	if (!function)
-		return NULL;
-
-	function->interface = interface;	/* XXX refcount? */
-	function->cport_id = cport_id;
-
-	spin_lock_irq(&gb_functions_lock);
-	list_add_tail(&function->links, &interface->functions);
-	spin_unlock_irq(&gb_functions_lock);
-
-	return function;
-}
-
-/*
- * Tear down a previously set up function.
- */
-void gb_function_destroy(struct gb_function *function)
-{
-	if (WARN_ON(!function))
-		return;
-
-	spin_lock_irq(&gb_functions_lock);
-	list_del(&function->links);
-	spin_unlock_irq(&gb_functions_lock);
-
-	/* kref_put(gmod); */
-	kfree(function);
-}

drivers/staging/greybus/function.h

-/*
- * Greybus functions
- *
- * Copyright 2014 Google Inc.
- *
- * Released under the GPLv2 only.
- */
-
-#ifndef __FUNCTION_H
-#define __FUNCTION_H
-
-struct gb_function {
-	struct gb_interface		*interface;
-	u16				cport_id;
-
-	struct list_head		links;	/* interface->functions */
-};
-
-struct gb_function *gb_function_create(struct gb_interface *interface,
-					u16 cport_id);
-void gb_function_destroy(struct gb_function *function);
-
-#endif /* __FUNCTION_H */

drivers/staging/greybus/greybus.h

@@ -24,7 +24,6 @@
 #include "manifest.h"
 #include "module.h"
 #include "interface.h"
-#include "function.h"
 #include "connection.h"
 #include "operation.h"
 

drivers/staging/greybus/manifest.c

@@ -204,7 +204,7 @@ u32 gb_manifest_parse_cports(struct gb_interface *interface)
 		/* Found one.  Set up its function structure */
 		protocol = (enum greybus_protocol)desc_cport->protocol;
 		cport_id = le16_to_cpu(desc_cport->id);
-		if (!gb_function_create(interface, cport_id))
+		if (!gb_connection_create(interface, cport_id))
 			return 0;	/* Error */
 
 		count++;

drivers/staging/greybus/operation.c

@@ -124,8 +124,8 @@ struct gb_operation *gb_operation_create(struct gb_connection *connection,
 
 	/* Our buffer holds a header in addition to the requested payload */
 	size += sizeof(*header);
-	gbuf = greybus_alloc_gbuf(connection->function->interface->gmod,
-				connection->cport_id,
+	gbuf = greybus_alloc_gbuf(connection->interface->gmod,
+				connection->hd_cport_id,
 				gbuf_out_callback, size,
 				GFP_KERNEL, operation);
 	if (gbuf) {