udc device and gadget device are tightly coupled, yet there's no good way to corelate the two. Add a sysfs link in udc that points to the corresponding gadget device. An example use case: userspace configures a f_midi configfs driver and bind the udc device, then it tries to locate the corresponding midi device, which is a child device of the gadget device. The gadget device that's associated to the udc device has to be identified in order to index the midi device. Having a sysfs link would make things much easier. Signed-off-by: Roy Luo <royluo@xxxxxxxxxx> --- drivers/usb/gadget/udc/core.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index d59f94464b87..876b8635b16f 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -1419,8 +1419,16 @@ int usb_add_gadget(struct usb_gadget *gadget) if (ret) goto err_free_id; + ret = sysfs_create_link(&udc->dev.kobj, + &gadget->dev.kobj, "gadget"); + if (ret) + goto err_del_gadget; + return 0; + err_del_gadget: + device_del(&gadget->dev); + err_free_id: ida_free(&gadget_id_numbers, gadget->id_number); @@ -1529,6 +1537,7 @@ void usb_del_gadget(struct usb_gadget *gadget) mutex_unlock(&udc_lock); kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE); + sysfs_remove_link(&udc->dev.kobj, "gadget"); flush_work(&gadget->work); device_del(&gadget->dev); ida_free(&gadget_id_numbers, gadget->id_number); base-commit: 67be068d31d423b857ffd8c34dbcc093f8dfff76 -- 2.44.0.278.ge034bb2e1d-goog
