USB: UDC: Expand device model API interface

The routines used by the UDC core to interface with the kernel's
device model, namely usb_add_gadget_udc(),
usb_add_gadget_udc_release(), and usb_del_gadget_udc(), provide access
to only a subset of the device model's full API.  They include
functionality equivalent to device_register() and device_unregister()
for gadgets, but they omit device_initialize(), device_add(),
device_del(), get_device(), and put_device().

This patch expands the UDC API by adding usb_initialize_gadget(),
usb_add_gadget(), usb_del_gadget(), usb_get_gadget(), and
usb_put_gadget() to fill in the gap.  It rewrites the existing
routines to call the new ones.

CC: Anton Vasilyev <vasilyev@ispras.ru>
CC: Evgeny Novikov <novikov@ispras.ru>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
index 4f82bcd31fd3f662201e96b7a1647bced1af692e..2b6770d9fb3f02beadc3506437c10f178960b1a2 100644 (file)
--- a/drivers/usb/gadget/udc/core.c
+++ b/drivers/usb/gadget/udc/core.c
@@ -1164,21 +1164,18 @@ static int check_pending_gadget_drivers(struct usb_udc *udc)
 }
 
 /**
- * usb_add_gadget_udc_release - adds a new gadget to the udc class driver list
+ * usb_initialize_gadget - initialize a gadget and its embedded struct device
  * @parent: the parent device to this udc. Usually the controller driver's
  * device.
- * @gadget: the gadget to be added to the list.
+ * @gadget: the gadget to be initialized.
  * @release: a gadget release function.
  *
  * Returns zero on success, negative errno otherwise.
  * Calls the gadget release function in the latter case.
  */
-int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
+void usb_initialize_gadget(struct device *parent, struct usb_gadget *gadget,
                void (*release)(struct device *dev))
 {
-       struct usb_udc          *udc;
-       int                     ret = -ENOMEM;
-
        dev_set_name(&gadget->dev, "gadget");
        INIT_WORK(&gadget->work, usb_gadget_state_work);
        gadget->dev.parent = parent;
@@ -1189,17 +1186,32 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
                gadget->dev.release = usb_udc_nop_release;
 
        device_initialize(&gadget->dev);
+}
+EXPORT_SYMBOL_GPL(usb_initialize_gadget);
+
+/**
+ * usb_add_gadget - adds a new gadget to the udc class driver list
+ * @gadget: the gadget to be added to the list.
+ *
+ * Returns zero on success, negative errno otherwise.
+ * Does not do a final usb_put_gadget() if an error occurs.
+ */
+int usb_add_gadget(struct usb_gadget *gadget)
+{
+       struct usb_udc          *udc;
+       int                     ret = -ENOMEM;
 
        udc = kzalloc(sizeof(*udc), GFP_KERNEL);
        if (!udc)
-               goto err_put_gadget;
+               goto error;
 
        device_initialize(&udc->dev);
        udc->dev.release = usb_udc_release;
        udc->dev.class = udc_class;
        udc->dev.groups = usb_udc_attr_groups;
-       udc->dev.parent = parent;
-       ret = dev_set_name(&udc->dev, "%s", kobject_name(&parent->kobj));
+       udc->dev.parent = gadget->dev.parent;
+       ret = dev_set_name(&udc->dev, "%s",
+                       kobject_name(&gadget->dev.parent->kobj));
        if (ret)
                goto err_put_udc;
 
@@ -1242,8 +1254,30 @@ int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
  err_put_udc:
        put_device(&udc->dev);
 
- err_put_gadget:
-       put_device(&gadget->dev);
+ error:
+       return ret;
+}
+EXPORT_SYMBOL_GPL(usb_add_gadget);
+
+/**
+ * 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.
+ * Calls the gadget release function in the latter case.
+ */
+int usb_add_gadget_udc_release(struct device *parent, struct usb_gadget *gadget,
+               void (*release)(struct device *dev))
+{
+       int     ret;
+
+       usb_initialize_gadget(parent, gadget, release);
+       ret = usb_add_gadget(gadget);
+       if (ret)
+               usb_put_gadget(gadget);
        return ret;
 }
 EXPORT_SYMBOL_GPL(usb_add_gadget_udc_release);
@@ -1311,13 +1345,14 @@ static void usb_gadget_remove_driver(struct usb_udc *udc)
 }
 
 /**
- * usb_del_gadget_udc - deletes @udc from udc_list
+ * usb_del_gadget - deletes @udc from udc_list
  * @gadget: the gadget to be removed.
  *
- * This, will call usb_gadget_unregister_driver() if
+ * This will call usb_gadget_unregister_driver() if
  * the @udc is still busy.
+ * It will not do a final usb_put_gadget().
  */
-void usb_del_gadget_udc(struct usb_gadget *gadget)
+void usb_del_gadget(struct usb_gadget *gadget)
 {
        struct usb_udc *udc = gadget->udc;
 
@@ -1340,7 +1375,20 @@ void usb_del_gadget_udc(struct usb_gadget *gadget)
        kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE);
        flush_work(&gadget->work);
        device_unregister(&udc->dev);
-       device_unregister(&gadget->dev);
+       device_del(&gadget->dev);
+}
+EXPORT_SYMBOL_GPL(usb_del_gadget);
+
+/**
+ * usb_del_gadget_udc - deletes @udc from udc_list
+ * @gadget: the gadget to be removed.
+ *
+ * Calls usb_del_gadget() and does a final usb_put_gadget().
+ */
+void usb_del_gadget_udc(struct usb_gadget *gadget)
+{
+       usb_del_gadget(gadget);
+       usb_put_gadget(gadget);
        memset(&gadget->dev, 0x00, sizeof(gadget->dev));
 }
 EXPORT_SYMBOL_GPL(usb_del_gadget_udc);

diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 52ce1f6b8f833404d702cc8cefef7773fb2a834f..e7351d64f11fac7e8806d8a4cfdd3e9cbf811624 100644 (file)
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -436,6 +436,7 @@ struct usb_gadget {
 };
 #define work_to_gadget(w)      (container_of((w), struct usb_gadget, work))
 
+/* Interface to the device model */
 static inline void set_gadget_data(struct usb_gadget *gadget, void *data)
        { dev_set_drvdata(&gadget->dev, data); }
 static inline void *get_gadget_data(struct usb_gadget *gadget)
@@ -444,6 +445,26 @@ static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
 {
        return container_of(dev, struct usb_gadget, dev);
 }
+static inline struct usb_gadget *usb_get_gadget(struct usb_gadget *gadget)
+{
+       get_device(&gadget->dev);
+       return gadget;
+}
+static inline void usb_put_gadget(struct usb_gadget *gadget)
+{
+       put_device(&gadget->dev);
+}
+extern void usb_initialize_gadget(struct device *parent,
+               struct usb_gadget *gadget, void (*release)(struct device *dev));
+extern int usb_add_gadget(struct usb_gadget *gadget);
+extern void usb_del_gadget(struct usb_gadget *gadget);
+
+/* Legacy device-model interface */
+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 char *usb_get_gadget_udc_name(void);
 
 /* iterates the non-control endpoints; 'tmp' is a struct usb_ep pointer */
 #define gadget_for_each_ep(tmp, gadget) \
@@ -735,12 +756,6 @@ 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 char *usb_get_gadget_udc_name(void);
-
 /*-------------------------------------------------------------------------*/
 
 /* utility to simplify dealing with string descriptors */