greybus: endo: hook up endos into the device tree

This hooks up the endo, and modules, into the device tree.  All modules
for a specific endo are created when the host device is initialized.
When an interface is registered, the correct module for it is found and
that module is used for the sysfs tree.  When the interface is removed,
the reference on the module is dropped.

When the host device goes away, the whole endo and modules are removed
at once.

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Reviewed-by: Alex Elder <elder@linaro.org>

1 files changed, 28 insertions, 24 deletions

diff --git a/drivers/staging/greybus/module.c b/drivers/staging/greybus/module.c
index 780d163b3e00..202f141c7fe3 100644
--- a/drivers/staging/greybus/module.c
+++ b/drivers/staging/greybus/module.c
@@ -94,16 +94,22 @@ u8 get_module_id(u8 interface_id)
 	return interface_id;
 }
 
+struct module_find {
+	struct gb_endo *endo;
+	u8 module_id;
+};
+
 static int module_find(struct device *dev, void *data)
 {
 	struct gb_module *module;
-	u8 *module_id = data;
+	struct module_find *find = data;
 
 	if (!is_gb_module(dev))
 		return 0;
 
 	module = to_gb_module(dev);
-	if (module->module_id == *module_id)
+	if ((module->module_id == find->module_id) &&
+	    (module->dev.parent == &find->endo->dev))
 		return 1;
 
 	return 0;
@@ -113,21 +119,24 @@ static int module_find(struct device *dev, void *data)
  * Search the list of modules in the system.  If one is found, return it, with
  * the reference count incremented.
  */
-static struct gb_module *gb_module_find(u8 module_id)
+struct gb_module *gb_module_find(struct greybus_host_device *hd, u8 module_id)
 {
 	struct device *dev;
 	struct gb_module *module = NULL;
+	struct module_find find;
+
+	find.module_id = module_id;
+	find.endo = hd->endo;
 
 	dev = bus_find_device(&greybus_bus_type, NULL,
-			      &module_id, module_find);
+			      &find, module_find);
 	if (dev)
 		module = to_gb_module(dev);
 
 	return module;
 }
 
-static struct gb_module *gb_module_create(struct greybus_host_device *hd,
-					  u8 module_id)
+struct gb_module *gb_module_create(struct device *parent, u8 module_id)
 {
 	struct gb_module *module;
 	int retval;
@@ -137,12 +146,11 @@ static struct gb_module *gb_module_create(struct greybus_host_device *hd,
 		return NULL;
 
 	module->module_id = module_id;
-	module->refcount = 1;
-	module->dev.parent = hd->parent;
+	module->dev.parent = parent;
 	module->dev.bus = &greybus_bus_type;
 	module->dev.type = &greybus_module_type;
 	module->dev.groups = module_groups;
-	module->dev.dma_mask = hd->parent->dma_mask;
+	module->dev.dma_mask = parent->dma_mask;
 	device_initialize(&module->dev);
 	dev_set_name(&module->dev, "%d", module_id);
 
@@ -158,26 +166,22 @@ static struct gb_module *gb_module_create(struct greybus_host_device *hd,
 	return module;
 }
 
-struct gb_module *gb_module_find_or_create(struct greybus_host_device *hd,
-					   u8 module_id)
+static int module_remove(struct device *dev, void *data)
 {
 	struct gb_module *module;
+	struct gb_endo *endo = data;
 
-	module = gb_module_find(module_id);
-	if (module) {
-		module->refcount++;
-		return module;
-	}
+	if (!is_gb_module(dev))
+		return 0;
+
+	module = to_gb_module(dev);
+	if (module->dev.parent == &endo->dev)
+		device_unregister(&module->dev);
 
-	return gb_module_create(hd, module_id);
+	return 0;
 }
 
-void gb_module_remove(struct gb_module *module)
+void gb_module_remove_all(struct gb_endo *endo)
 {
-	if (!module)
-		return;
-
-	if (!--module->refcount)
-		device_unregister(&module->dev);
+	bus_for_each_dev(&greybus_bus_type, NULL, endo, module_remove);
 }
-