HID: logitech-hidpp: document sysfs interface

Descriptions have been collected from git commit logs.

Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/Documentation/ABI/testing/sysfs-driver-hid-logitech-hidpp b/Documentation/ABI/testing/sysfs-driver-hid-logitech-hidpp
new file mode 100644 (file)
index 0000000..d8f831f
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-hid-logitech-hidpp
@@ -0,0 +1,19 @@
+What:          /sys/bus/hid/drivers/logitech-hidpp-device/<dev>/range
+Date:          Jan, 2016
+KernelVersion: 4.6
+Contact:       linux-input@vger.kernel.org
+Description:
+               (RW) This attribute controls the amount of 'turn' permitted in
+               Logitech G920 wheel. Reading from the file shows the current
+               range of the steering wheel. Writing a value within the min and
+               max boundary sets the range of the wheel.
+
+What:          /sys/bus/hid/drivers/logitech-hidpp-device/<dev>/builtin_power_supply
+Date:          Apr, 2017
+KernelVersion: 4.12
+Contact:       linux-input@vger.kernel.org
+Description:
+               Presence of this file indicates that HID++ driver is capable of
+               handling battery properties in the kernel. This way, upower can
+               add a udev rule to decide whether or not it should use the
+               internal unifying support or the generic kernel one.