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path: root/drivers/usb/roles
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-rw-r--r--drivers/usb/roles/class.c29
1 files changed, 21 insertions, 8 deletions
diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
index 32e6d19f7..a327f8bc5 100644
--- a/drivers/usb/roles/class.c
+++ b/drivers/usb/roles/class.c
@@ -19,7 +19,9 @@ static struct class *role_class;
struct usb_role_switch {
struct device dev;
struct mutex lock; /* device lock*/
+ struct module *module; /* the module this device depends on */
enum usb_role role;
+ bool registered;
/* From descriptor */
struct device *usb2_port;
@@ -46,6 +48,9 @@ int usb_role_switch_set_role(struct usb_role_switch *sw, enum usb_role role)
if (IS_ERR_OR_NULL(sw))
return 0;
+ if (!sw->registered)
+ return -EOPNOTSUPP;
+
mutex_lock(&sw->lock);
ret = sw->set(sw, role);
@@ -71,7 +76,7 @@ enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw)
{
enum usb_role role;
- if (IS_ERR_OR_NULL(sw))
+ if (IS_ERR_OR_NULL(sw) || !sw->registered)
return USB_ROLE_NONE;
mutex_lock(&sw->lock);
@@ -133,7 +138,7 @@ struct usb_role_switch *usb_role_switch_get(struct device *dev)
usb_role_switch_match);
if (!IS_ERR_OR_NULL(sw))
- WARN_ON(!try_module_get(sw->dev.parent->driver->owner));
+ WARN_ON(!try_module_get(sw->module));
return sw;
}
@@ -155,7 +160,7 @@ struct usb_role_switch *fwnode_usb_role_switch_get(struct fwnode_handle *fwnode)
sw = fwnode_connection_find_match(fwnode, "usb-role-switch",
NULL, usb_role_switch_match);
if (!IS_ERR_OR_NULL(sw))
- WARN_ON(!try_module_get(sw->dev.parent->driver->owner));
+ WARN_ON(!try_module_get(sw->module));
return sw;
}
@@ -170,7 +175,7 @@ EXPORT_SYMBOL_GPL(fwnode_usb_role_switch_get);
void usb_role_switch_put(struct usb_role_switch *sw)
{
if (!IS_ERR_OR_NULL(sw)) {
- module_put(sw->dev.parent->driver->owner);
+ module_put(sw->module);
put_device(&sw->dev);
}
}
@@ -187,15 +192,18 @@ struct usb_role_switch *
usb_role_switch_find_by_fwnode(const struct fwnode_handle *fwnode)
{
struct device *dev;
+ struct usb_role_switch *sw = NULL;
if (!fwnode)
return NULL;
dev = class_find_device_by_fwnode(role_class, fwnode);
- if (dev)
- WARN_ON(!try_module_get(dev->parent->driver->owner));
+ if (dev) {
+ sw = to_role_switch(dev);
+ WARN_ON(!try_module_get(sw->module));
+ }
- return dev ? to_role_switch(dev) : NULL;
+ return sw;
}
EXPORT_SYMBOL_GPL(usb_role_switch_find_by_fwnode);
@@ -337,6 +345,7 @@ usb_role_switch_register(struct device *parent,
sw->set = desc->set;
sw->get = desc->get;
+ sw->module = parent->driver->owner;
sw->dev.parent = parent;
sw->dev.fwnode = desc->fwnode;
sw->dev.class = role_class;
@@ -351,6 +360,8 @@ usb_role_switch_register(struct device *parent,
return ERR_PTR(ret);
}
+ sw->registered = true;
+
/* TODO: Symlinks for the host port and the device controller. */
return sw;
@@ -365,8 +376,10 @@ EXPORT_SYMBOL_GPL(usb_role_switch_register);
*/
void usb_role_switch_unregister(struct usb_role_switch *sw)
{
- if (!IS_ERR_OR_NULL(sw))
+ if (!IS_ERR_OR_NULL(sw)) {
+ sw->registered = false;
device_unregister(&sw->dev);
+ }
}
EXPORT_SYMBOL_GPL(usb_role_switch_unregister);