Implement TSINFO_GET request to get timestamping information for a network
device. This is traditionally available via ETHTOOL_GET_TS_INFO ioctl
request.
Move part of ethtool_get_ts_info() into common.c so that ioctl and netlink
code use the same logic to get timestamping information from the device.
v3: use "TSINFO" rather than "TIMESTAMP", suggested by Richard Cochran
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
