HID: introduce hid_is_using_ll_driver
Although HID itself is transport-agnostic, occasionally a driver may
want to interact with the low-level transport that a device is connected
through. To do this, we need to know what kind of bus is in use. The
first guess may be to look at the 'bus' field of the 'struct hid_device',
but this field may be emulated in some cases (e.g. uhid).
More ideally, we can check which ll_driver a device is using. This
function introduces a 'hid_is_using_ll_driver' function and makes the
'struct hid_ll_driver' of the four most common transports accessible
through hid.h.
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Acked-By: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 5006f9b..3853408 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -777,6 +777,17 @@
int (*idle)(struct hid_device *hdev, int report, int idle, int reqtype);
};
+extern struct hid_ll_driver i2c_hid_ll_driver;
+extern struct hid_ll_driver hidp_hid_driver;
+extern struct hid_ll_driver uhid_hid_driver;
+extern struct hid_ll_driver usb_hid_driver;
+
+static inline bool hid_is_using_ll_driver(struct hid_device *hdev,
+ struct hid_ll_driver *driver)
+{
+ return hdev->ll_driver == driver;
+}
+
#define PM_HINT_FULLON 1<<5
#define PM_HINT_NORMAL 1<<1