[PATCH] usb: udc: add gadget state kobject uevent

[Rong Wang]

    usb: udc: add gadget state kobject uevent

    Add USB_UDC_STATE environment variable in udc uevent
    callback and trigger kobject_uevent in usb_gadget_set_state
    to inform the user-space the state of the gadget.

    Signed-off-by: Rong Wang <Rong.Wang@xxxxxxx>

diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c
index ffd8fa5..05715d1 100644
--- a/drivers/usb/gadget/udc-core.c
+++ b/drivers/usb/gadget/udc-core.c
@@ -101,11 +101,32 @@ EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);

 /* ------------------------------------------------------------------------- */

+/**
+ * usb_gadget_set_state - set usb gadget state
+ * @gadget: gadget device
+ * @state: state defined in USB specification ch9
+ * Context: !in_interrupt()
+ */
 void usb_gadget_set_state(struct usb_gadget *gadget,
                enum usb_device_state state)
 {
+       struct usb_udc          *udc = NULL;
+
        gadget->state = state;
        sysfs_notify(&gadget->dev.kobj, NULL, "status");
+
+       mutex_lock(&udc_lock);
+       list_for_each_entry(udc, &udc_list, list)
+               if (udc->gadget == gadget)
+                       goto found;
+
+       dev_err(gadget->dev.parent, "gadget not registered.\n");
+       mutex_unlock(&udc_lock);
+       return;
+
+found:
+       mutex_unlock(&udc_lock);
+       kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE);
 }
 EXPORT_SYMBOL_GPL(usb_gadget_set_state);

@@ -538,6 +559,15 @@ static int usb_udc_uevent(struct device *dev,
struct kobj_uevent_env *env)
                }
        }

+       if (udc->gadget) {
+               ret = add_uevent_var(env, "USB_UDC_STATE=%s",
+                               usb_state_string(udc->gadget->state));
+               if (ret) {
+                       dev_err(dev, "failed to add uevent USB_UDC_STATE\n");
+                       return ret;
+               }
+       }
+
        return 0;
 }
--
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