usb:gadget:Add "state" attribute to android_device

Added a device attribute to android_device to
determine USB_GADGET's state

Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Change-Id: I17f8903120df96bf2f4bf441940b53a87b818230

diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 38077becbf2c074fe2e3ae71bc13479fe6e656a9..d0196637b693c29ebf999639f0d3e8b969c103d1 100644 (file)
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -1559,11 +1559,49 @@ static const struct usb_gadget_driver configfs_driver_template = {
        },
 };
 
+#ifdef CONFIG_USB_CONFIGFS_UEVENT
+static ssize_t state_show(struct device *pdev, struct device_attribute *attr,
+                       char *buf)
+{
+       struct gadget_info *dev = dev_get_drvdata(pdev);
+       struct usb_composite_dev *cdev;
+       char *state = "DISCONNECTED";
+       unsigned long flags;
+
+       if (!dev)
+               goto out;
+
+       cdev = &dev->cdev;
+
+       if (!cdev)
+               goto out;
+
+       spin_lock_irqsave(&cdev->lock, flags);
+       if (cdev->config)
+               state = "CONFIGURED";
+       else if (dev->connected)
+               state = "CONNECTED";
+       spin_unlock_irqrestore(&cdev->lock, flags);
+out:
+       return sprintf(buf, "%s\n", state);
+}
+
+static DEVICE_ATTR(state, S_IRUGO, state_show, NULL);
+
+static struct device_attribute *android_usb_attributes[] = {
+       &dev_attr_state,
+       NULL
+};
+#endif
+
 static struct config_group *gadgets_make(
                struct config_group *group,
                const char *name)
 {
        struct gadget_info *gi;
+       struct device_attribute **attrs;
+       struct device_attribute *attr;
+       int err;
 
        gi = kzalloc(sizeof(*gi), GFP_KERNEL);
        if (!gi)
@@ -1609,14 +1647,33 @@ static struct config_group *gadgets_make(
                                MKDEV(0, 0), NULL, "android0");
        if (IS_ERR(android_device))
                goto err;
+
+       dev_set_drvdata(android_device, gi);
+
+       attrs = android_usb_attributes;
+       while ((attr = *attrs++)) {
+               err = device_create_file(android_device, attr);
+               if (err)
+                       goto err1;
+       }
 #endif
 
        if (!gi->composite.gadget_driver.function)
-               goto err;
+               goto err1;
 
        config_group_init_type_name(&gi->group, name,
                                &gadget_root_type);
        return &gi->group;
+
+err1:
+#ifdef CONFIG_USB_CONFIGFS_UEVENT
+       attrs = android_usb_attributes;
+       while ((attr = *attrs++))
+               device_remove_file(android_device, attr);
+
+       device_destroy(android_device->class,
+                               android_device->devt);
+#endif
 err:
        kfree(gi);
        return ERR_PTR(-ENOMEM);
@@ -1624,8 +1681,15 @@ err:
 
 static void gadgets_drop(struct config_group *group, struct config_item *item)
 {
+       struct device_attribute **attrs;
+       struct device_attribute *attr;
+
        config_item_put(item);
+
 #ifdef CONFIG_USB_CONFIGFS_UEVENT
+       attrs = android_usb_attributes;
+       while ((attr = *attrs++))
+               device_remove_file(android_device, attr);
        device_destroy(android_device->class, android_device->devt);
 #endif
 }