usb: gadget: factor out two helper functions from composite_bind()

This patch factors out two helper functions from composite_bind()
that is composite_dev_prepare() and its counterpart
composite_dev_cleanup().

This will be used by the configfs which requries a slightly different
bind/setup code because part of its configurations (i.e. config
descripts, cdev, …) are setup in advance and VID/PID and so one should
not be overwritten. Also the setup of ep0 endpoint can be delayed until
the UDC is assigned.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

2 files changed, 59 insertions, 31 deletions

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 366facccf4f6..9083ec93f38e 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1394,11 +1394,8 @@ static void __composite_unbind(struct usb_gadget *gadget, bool unbind_driver)
         if (cdev->driver->unbind && unbind_driver)
                 cdev->driver->unbind(cdev);
 
-        if (cdev->req) {
-                kfree(cdev->req->buf);
-                usb_ep_free_request(gadget->ep0, cdev->req);
-        }
-        device_remove_file(&gadget->dev, &dev_attr_suspended);
+        composite_dev_cleanup(cdev);
+
         kfree(cdev->def_manufacturer);
         kfree(cdev);
         set_gadget_data(gadget, NULL);
@@ -1447,34 +1444,25 @@ static void update_unchanged_dev_desc(struct usb_device_descriptor *new,
                 new->iProduct = iProduct;
 }
 
-static struct usb_composite_driver *to_cdriver(struct usb_gadget_driver *gdrv)
+int composite_dev_prepare(struct usb_composite_driver *composite,
+                struct usb_composite_dev *cdev)
 {
-        return container_of(gdrv, struct usb_composite_driver, gadget_driver);
-}
-
-static int composite_bind(struct usb_gadget *gadget,
-                struct usb_gadget_driver *gdriver)
-{
-        struct usb_composite_dev        *cdev;
-        struct usb_composite_driver     *composite = to_cdriver(gdriver);
-        int                             status = -ENOMEM;
-
-        cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
-        if (!cdev)
-                return status;
-
-        spin_lock_init(&cdev->lock);
-        cdev->gadget = gadget;
-        set_gadget_data(gadget, cdev);
-        INIT_LIST_HEAD(&cdev->configs);
+        struct usb_gadget *gadget = cdev->gadget;
+        int ret = -ENOMEM;
 
         /* preallocate control response and buffer */
         cdev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
         if (!cdev->req)
-                goto fail;
+                return -ENOMEM;
+
         cdev->req->buf = kmalloc(USB_COMP_EP0_BUFSIZ, GFP_KERNEL);
         if (!cdev->req->buf)
                 goto fail;
+
+        ret = device_create_file(&gadget->dev, &dev_attr_suspended);
+        if (ret)
+                goto fail_dev;
+
         cdev->req->complete = composite_setup_complete;
         gadget->ep0->driver_data = cdev;
 
@@ -1492,7 +1480,44 @@ static int composite_bind(struct usb_gadget *gadget,
          * we force endpoints to start unassigned; few controller
          * drivers will zero ep->driver_data.
          */
-        usb_ep_autoconfig_reset(cdev->gadget);
+        usb_ep_autoconfig_reset(gadget);
+        return 0;
+fail_dev:
+        kfree(cdev->req->buf);
+fail:
+        usb_ep_free_request(gadget->ep0, cdev->req);
+        cdev->req = NULL;
+        return ret;
+}
+
+void composite_dev_cleanup(struct usb_composite_dev *cdev)
+{
+        if (cdev->req) {
+                kfree(cdev->req->buf);
+                usb_ep_free_request(cdev->gadget->ep0, cdev->req);
+        }
+        device_remove_file(&cdev->gadget->dev, &dev_attr_suspended);
+}
+
+static int composite_bind(struct usb_gadget *gadget,
+                struct usb_gadget_driver *gdriver)
+{
+        struct usb_composite_dev        *cdev;
+        struct usb_composite_driver     *composite = to_cdriver(gdriver);
+        int                             status = -ENOMEM;
+
+        cdev = kzalloc(sizeof *cdev, GFP_KERNEL);
+        if (!cdev)
+                return status;
+
+        spin_lock_init(&cdev->lock);
+        cdev->gadget = gadget;
+        set_gadget_data(gadget, cdev);
+        INIT_LIST_HEAD(&cdev->configs);
+
+        status = composite_dev_prepare(composite, cdev);
+        if (status)
+                goto fail;
 
         /* composite gadget needs to assign strings for whole device (like
          * serial number), register function drivers, potentially update
@@ -1508,11 +1533,6 @@ static int composite_bind(struct usb_gadget *gadget,
         if (composite->needs_serial && !cdev->desc.iSerialNumber)
                 WARNING(cdev, "userspace failed to provide iSerialNumber\n");
 
-        /* finish up */
-        status = device_create_file(&gadget->dev, &dev_attr_suspended);
-        if (status)
-                goto fail;
-
         INFO(cdev, "%s ready\n", composite->name);
         return 0;
 
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index 771de7acf8dd..bd6d857c12f4 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -323,7 +323,15 @@ struct usb_composite_driver {
 extern int usb_composite_probe(struct usb_composite_driver *driver);
 extern void usb_composite_unregister(struct usb_composite_driver *driver);
 extern void usb_composite_setup_continue(struct usb_composite_dev *cdev);
+extern int composite_dev_prepare(struct usb_composite_driver *composite,
+                struct usb_composite_dev *cdev);
+void composite_dev_cleanup(struct usb_composite_dev *cdev);
 
+static inline struct usb_composite_driver *to_cdriver(
+                struct usb_gadget_driver *gdrv)
+{
+        return container_of(gdrv, struct usb_composite_driver, gadget_driver);
+}
 
 /**
  * struct usb_composite_device - represents one composite usb gadget