usb: gadget: udc-core: allow udc class register gadget device

Currently all UDC drivers are calling
device_register() before calling
usb_add_gadget_udc(). In order to avoid
code duplication, we can allow udc-core.c
register that device.

However that would become a really large patch,
so to cope with the meanwhile and allow us
to write bite-sized patches, we're adding
a flag which will be set by UDC driver once
it removes the code for registering the
gadget device.

Once all are converted, the new flag will
be removed.

Reviewed-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

2 files changed, 23 insertions, 4 deletions

diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c
index 2a9cd369f71c..919505426ec1 100644
--- a/drivers/usb/gadget/udc-core.c
+++ b/drivers/usb/gadget/udc-core.c
@@ -173,6 +173,14 @@ int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
         if (!udc)
                 goto err1;
 
+        if (gadget->register_my_device) {
+                dev_set_name(&gadget->dev, "gadget");
+
+                ret = device_register(&gadget->dev);
+                if (ret)
+                        goto err2;
+        }
+
         device_initialize(&udc->dev);
         udc->dev.release = usb_udc_release;
         udc->dev.class = udc_class;
@@ -180,7 +188,7 @@ int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
         udc->dev.parent = parent;
         ret = dev_set_name(&udc->dev, "%s", kobject_name(&parent->kobj));
         if (ret)
-                goto err2;
+                goto err3;
 
         udc->gadget = gadget;
 
@@ -189,18 +197,22 @@ int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
 
         ret = device_add(&udc->dev);
         if (ret)
-                goto err3;
+                goto err4;
 
         mutex_unlock(&udc_lock);
 
         return 0;
-err3:
+
+err4:
         list_del(&udc->list);
         mutex_unlock(&udc_lock);
 
-err2:
+err3:
         put_device(&udc->dev);
 
+err2:
+        if (gadget->register_my_device)
+                put_device(&gadget->dev);
 err1:
         return ret;
 }
@@ -254,6 +266,9 @@ found:
 
         kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
         device_unregister(&udc->dev);
+
+        if (gadget->register_my_device)
+                device_unregister(&gadget->dev);
 }
 EXPORT_SYMBOL_GPL(usb_del_gadget_udc);
 
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 2e297e80d59a..fcd9ef8d3f70 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -494,6 +494,9 @@ struct usb_gadget_ops {
  *      only supports HNP on a different root port.
  * @b_hnp_enable: OTG device feature flag, indicating that the A-Host
  *      enabled HNP support.
+ * @register_my_device: Flag telling udc-core that UDC driver didn't
+ *      register the gadget device to the driver model. Temporary until
+ *      all UDC drivers are fixed up properly.
  * @name: Identifies the controller hardware type.  Used in diagnostics
  *      and sometimes configuration.
  * @dev: Driver model state for this abstract device.
@@ -531,6 +534,7 @@ struct usb_gadget {
         unsigned                        b_hnp_enable:1;
         unsigned                        a_hnp_support:1;
         unsigned                        a_alt_hnp_support:1;
+        unsigned                        register_my_device:1;
         const char                      *name;
         struct device                   dev;
         unsigned                        out_epnum;