greybus: core: add module abstraction

Add Greybus module abstraction that will be used to implement controlled
module removal (eject) and represent module geometry.

Greybus module devices correspond to physical modules and have one or
more interfaces. Modules have an id that is identical to the id of their
primary interface, which in turn is the interface with lowest numbered
id. The module name is constructed from the bus and module id:

        <bus_id>-<module_id>

Interfaces, bundles, and control devices are consequently renamed as

        <bus_id>-<module_id>.<interface_id>
        <bus_id>-<module_id>.<interface_id>.<bundle_id>
        <bus_id>-<module_id>.<interface_id>.ctrl

As before, interface ids (and therefore in a sense now also module ids)
correspond to physical interface positions on the frame.

Modules have the following attributes:

        module_id
        num_interfaces

where module_id is the id of the module and num_interface the number of
interfaces the module has.

Note that until SVC module-size detection has been implemented, all
interfaces are considered to be part of 1x2 modules. Specifically, the
two interfaces of a 2x2 module will be presented as two 1x2 modules for
now.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

1 files changed, 12 insertions, 28 deletions

diff --git a/drivers/staging/greybus/interface.c b/drivers/staging/greybus/interface.c
index 89fe901cb0a3..d51c5635f22b 100644
--- a/drivers/staging/greybus/interface.c
+++ b/drivers/staging/greybus/interface.c
@@ -333,21 +333,6 @@ static struct attribute *interface_attrs[] = {
 };
 ATTRIBUTE_GROUPS(interface);
 
-
-// FIXME, odds are you don't want to call this function, rework the caller to
-// not need it please.
-struct gb_interface *gb_interface_find(struct gb_host_device *hd,
-				       u8 interface_id)
-{
-	struct gb_interface *intf;
-
-	list_for_each_entry(intf, &hd->interfaces, links)
-		if (intf->interface_id == interface_id)
-			return intf;
-
-	return NULL;
-}
-
 static void gb_interface_release(struct device *dev)
 {
 	struct gb_interface *intf = to_gb_interface(dev);
@@ -371,13 +356,11 @@ struct device_type greybus_interface_type = {
  *
  * Returns a pointer to the new interfce or a null pointer if a
  * failure occurs due to memory exhaustion.
- *
- * Locking: Caller ensures serialisation with gb_interface_remove and
- * gb_interface_find.
  */
-struct gb_interface *gb_interface_create(struct gb_host_device *hd,
+struct gb_interface *gb_interface_create(struct gb_module *module,
 					 u8 interface_id)
 {
+	struct gb_host_device *hd = module->hd;
 	struct gb_interface *intf;
 
 	intf = kzalloc(sizeof(*intf), GFP_KERNEL);
@@ -385,6 +368,7 @@ struct gb_interface *gb_interface_create(struct gb_host_device *hd,
 		return NULL;
 
 	intf->hd = hd;		/* XXX refcount? */
+	intf->module = module;
 	intf->interface_id = interface_id;
 	INIT_LIST_HEAD(&intf->bundles);
 	INIT_LIST_HEAD(&intf->manifest_descs);
@@ -392,15 +376,14 @@ struct gb_interface *gb_interface_create(struct gb_host_device *hd,
 	/* Invalid device id to start with */
 	intf->device_id = GB_INTERFACE_DEVICE_ID_BAD;
 
-	intf->dev.parent = &hd->dev;
+	intf->dev.parent = &module->dev;
 	intf->dev.bus = &greybus_bus_type;
 	intf->dev.type = &greybus_interface_type;
 	intf->dev.groups = interface_groups;
-	intf->dev.dma_mask = hd->dev.dma_mask;
+	intf->dev.dma_mask = module->dev.dma_mask;
 	device_initialize(&intf->dev);
-	dev_set_name(&intf->dev, "%d-%d", hd->bus_id, interface_id);
-
-	list_add(&intf->links, &hd->interfaces);
+	dev_set_name(&intf->dev, "%s.%u", dev_name(&module->dev),
+			interface_id);
 
 	return intf;
 }
@@ -579,15 +562,16 @@ int gb_interface_add(struct gb_interface *intf)
 	return 0;
 }
 
-/* Deregister an interface and drop its reference. */
-void gb_interface_remove(struct gb_interface *intf)
+/* Deregister an interface. */
+void gb_interface_del(struct gb_interface *intf)
 {
 	if (device_is_registered(&intf->dev)) {
 		device_del(&intf->dev);
 		dev_info(&intf->dev, "Interface removed\n");
 	}
+}
 
-	list_del(&intf->links);
-
+void gb_interface_put(struct gb_interface *intf)
+{
 	put_device(&intf->dev);
 }