usb: gadget: udc-core: introduce usb_add_gadget_udc_release()

not all UDC drivers need a proper release function,
for those which don't need it, we udc-core will provide
a no-op release method so we can remove "redefinition"
of such methods in almost every UDC driver.

Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c
index 2423d024654f139d922a085f639b54eb21f01230..a50811e35bdbe6a99bd0ff8a7b9791fd5e36d6e1 100644 (file)
--- a/drivers/usb/gadget/udc-core.c
+++ b/drivers/usb/gadget/udc-core.c
@@ -166,15 +166,23 @@ static void usb_udc_release(struct device *dev)
 }
 
 static const struct attribute_group *usb_udc_attr_groups[];
+
+static void usb_udc_nop_release(struct device *dev)
+{
+       dev_vdbg(dev, "%s\n", __func__);
+}
+
 /**
- * usb_add_gadget_udc - adds a new gadget to the udc class driver list
- * @parent: the parent device to this udc. Usually the controller
- * driver's device.
- * @gadget: the gadget to be added to the list
+ * usb_add_gadget_udc_release - adds a new gadget to the udc class driver list
+ * @parent: the parent device to this udc. Usually the controller driver's
+ * device.
+ * @gadget: the gadget to be added to the list.
+ * @release: a gadget release function.
  *
  * Returns zero on success, negative errno otherwise.
  */
-int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
+int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
+               void (*release)(struct device *dev))
 {
        struct usb_udc          *udc;
        int                     ret = -ENOMEM;
@@ -190,6 +198,13 @@ int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
        gadget->dev.dma_parms = parent->dma_parms;
        gadget->dev.dma_mask = parent->dma_mask;
 
+       if (release) {
+               gadget->dev.release = release;
+       } else {
+               if (!gadget->dev.release)
+                       gadget->dev.release = usb_udc_nop_release;
+       }
+
        ret = device_register(&gadget->dev);
        if (ret)
                goto err2;
@@ -231,6 +246,20 @@ err2:
 err1:
        return ret;
 }
+EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
+
+/**
+ * usb_add_gadget_udc - adds a new gadget to the udc class driver list
+ * @parent: the parent device to this udc. Usually the controller
+ * driver's device.
+ * @gadget: the gadget to be added to the list
+ *
+ * Returns zero on success, negative errno otherwise.
+ */
+int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget)
+{
+       return usb_add_gadget_udc_release(parent, gadget, NULL);
+}
 EXPORT_SYMBOL_GPL(usb_add_gadget_udc);
 
 static void usb_gadget_remove_driver(struct usb_udc *udc)

diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 32b734d88d6bb3cdd601e4e8da33d6ca7083def4..c454a88abf2e6fed7adda903a7d2e0626613e29f 100644 (file)
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -874,6 +874,8 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver);
  */
 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver);
 
+extern int usb_add_gadget_udc_release(struct device *parent,
+               struct usb_gadget *gadget, void (*release)(struct device *dev));
 extern int usb_add_gadget_udc(struct device *parent, struct usb_gadget *gadget);
 extern void usb_del_gadget_udc(struct usb_gadget *gadget);
 extern int udc_attach_driver(const char *name,