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, 40 insertions, 43 deletions

diff --git a/drivers/staging/greybus/svc.c b/drivers/staging/greybus/svc.c
index cde59d02400b..94016954a6ab 100644
--- a/drivers/staging/greybus/svc.c
+++ b/drivers/staging/greybus/svc.c
@@ -665,6 +665,19 @@ static int gb_svc_hello(struct gb_operation *op)
 	return 0;
 }
 
+static struct gb_module *gb_svc_module_lookup(struct gb_svc *svc, u8 module_id)
+{
+	struct gb_host_device *hd = svc->hd;
+	struct gb_module *module;
+
+	list_for_each_entry(module, &hd->modules, hd_node) {
+		if (module->module_id == module_id)
+			return module;
+	}
+
+	return NULL;
+}
+
 static void gb_svc_intf_reenable(struct gb_svc *svc, struct gb_interface *intf)
 {
 	int ret;
@@ -689,7 +702,7 @@ static void gb_svc_process_intf_hotplug(struct gb_operation *operation)
 	struct gb_connection *connection = operation->connection;
 	struct gb_svc *svc = gb_connection_get_data(connection);
 	struct gb_host_device *hd = connection->hd;
-	struct gb_interface *intf;
+	struct gb_module *module;
 	u8 intf_id;
 	int ret;
 
@@ -699,52 +712,35 @@ static void gb_svc_process_intf_hotplug(struct gb_operation *operation)
 
 	dev_dbg(&svc->dev, "%s - id = %u\n", __func__, intf_id);
 
-	intf = gb_interface_find(hd, intf_id);
-	if (intf) {
+	/* All modules are considered 1x2 for now */
+	module = gb_svc_module_lookup(svc, intf_id);
+	if (module) {
 		dev_info(&svc->dev, "mode switch detected on interface %u\n",
 				intf_id);
 
-		return gb_svc_intf_reenable(svc, intf);
+		return gb_svc_intf_reenable(svc, module->interfaces[0]);
 	}
 
-	intf = gb_interface_create(hd, intf_id);
-	if (!intf) {
-		dev_err(&svc->dev, "failed to create interface %u\n",
-				intf_id);
+	module = gb_module_create(hd, intf_id, 1);
+	if (!module) {
+		dev_err(&svc->dev, "failed to create module\n");
 		return;
 	}
 
-	ret = gb_interface_activate(intf);
+	ret = gb_module_add(module);
 	if (ret) {
-		dev_err(&svc->dev, "failed to activate interface %u: %d\n",
-				intf_id, ret);
-		gb_interface_add(intf);
+		gb_module_put(module);
 		return;
 	}
 
-	ret = gb_interface_add(intf);
-	if (ret)
-		goto err_interface_deactivate;
-
-	ret = gb_interface_enable(intf);
-	if (ret) {
-		dev_err(&svc->dev, "failed to enable interface %u: %d\n",
-				intf_id, ret);
-		goto err_interface_deactivate;
-	}
-
-	return;
-
-err_interface_deactivate:
-	gb_interface_deactivate(intf);
+	list_add(&module->hd_node, &hd->modules);
 }
 
 static void gb_svc_process_intf_hot_unplug(struct gb_operation *operation)
 {
 	struct gb_svc *svc = gb_connection_get_data(operation->connection);
 	struct gb_svc_intf_hot_unplug_request *request;
-	struct gb_host_device *hd = operation->connection->hd;
-	struct gb_interface *intf;
+	struct gb_module *module;
 	u8 intf_id;
 
 	/* The request message size has already been verified. */
@@ -753,19 +749,19 @@ static void gb_svc_process_intf_hot_unplug(struct gb_operation *operation)
 
 	dev_dbg(&svc->dev, "%s - id = %u\n", __func__, intf_id);
 
-	intf = gb_interface_find(hd, intf_id);
-	if (!intf) {
+	/* All modules are considered 1x2 for now */
+	module = gb_svc_module_lookup(svc, intf_id);
+	if (!module) {
 		dev_warn(&svc->dev, "could not find hot-unplug interface %u\n",
 				intf_id);
 		return;
 	}
 
-	/* Mark as disconnected to prevent I/O during disable. */
-	intf->disconnected = true;
+	module->disconnected = true;
 
-	gb_interface_disable(intf);
-	gb_interface_deactivate(intf);
-	gb_interface_remove(intf);
+	gb_module_del(module);
+	list_del(&module->hd_node);
+	gb_module_put(module);
 }
 
 static void gb_svc_process_deferred_request(struct work_struct *work)
@@ -1104,14 +1100,15 @@ int gb_svc_add(struct gb_svc *svc)
 	return 0;
 }
 
-static void gb_svc_remove_interfaces(struct gb_svc *svc)
+static void gb_svc_remove_modules(struct gb_svc *svc)
 {
-	struct gb_interface *intf, *tmp;
+	struct gb_host_device *hd = svc->hd;
+	struct gb_module *module, *tmp;
 
-	list_for_each_entry_safe(intf, tmp, &svc->hd->interfaces, links) {
-		gb_interface_disable(intf);
-		gb_interface_deactivate(intf);
-		gb_interface_remove(intf);
+	list_for_each_entry_safe(module, tmp, &hd->modules, hd_node) {
+		gb_module_del(module);
+		list_del(&module->hd_node);
+		gb_module_put(module);
 	}
 }
 
@@ -1132,7 +1129,7 @@ void gb_svc_del(struct gb_svc *svc)
 
 	flush_workqueue(svc->wq);
 
-	gb_svc_remove_interfaces(svc);
+	gb_svc_remove_modules(svc);
 }
 
 void gb_svc_put(struct gb_svc *svc)