USB: gadget: core: create sysfs link between udc and gadget
PATCH 1/1 USB: gadget: core: create sysfs link between udc and gadget
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 <[email protected]>
--- drivers/usb/gadget/udc/core.c | 9 +++++++++ 1 file changed, 9 insertions(+)
drivers/usb/gadget/udc/core.c +9 -0
@@ -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
Signature · 1 line
2.44.0.278.ge034bb2e1d-goog