1*4882a593Smuzhiyun# SPDX-License-Identifier: GPL-2.0-only 2*4882a593Smuzhiyun# 3*4882a593Smuzhiyun# PPS support configuration 4*4882a593Smuzhiyun# 5*4882a593Smuzhiyun 6*4882a593Smuzhiyunmenuconfig PPS 7*4882a593Smuzhiyun tristate "PPS support" 8*4882a593Smuzhiyun help 9*4882a593Smuzhiyun PPS (Pulse Per Second) is a special pulse provided by some GPS 10*4882a593Smuzhiyun antennae. Userland can use it to get a high-precision time 11*4882a593Smuzhiyun reference. 12*4882a593Smuzhiyun 13*4882a593Smuzhiyun Some antennae's PPS signals are connected with the CD (Carrier 14*4882a593Smuzhiyun Detect) pin of the serial line they use to communicate with the 15*4882a593Smuzhiyun host. In this case use the SERIAL_LINE client support. 16*4882a593Smuzhiyun 17*4882a593Smuzhiyun Some antennae's PPS signals are connected with some special host 18*4882a593Smuzhiyun inputs so you have to enable the corresponding client support. 19*4882a593Smuzhiyun 20*4882a593Smuzhiyun To compile this driver as a module, choose M here: the module 21*4882a593Smuzhiyun will be called pps_core.ko. 22*4882a593Smuzhiyun 23*4882a593Smuzhiyunif PPS 24*4882a593Smuzhiyun 25*4882a593Smuzhiyunconfig PPS_DEBUG 26*4882a593Smuzhiyun bool "PPS debugging messages" 27*4882a593Smuzhiyun help 28*4882a593Smuzhiyun Say Y here if you want the PPS support to produce a bunch of debug 29*4882a593Smuzhiyun messages to the system log. Select this if you are having a 30*4882a593Smuzhiyun problem with PPS support and want to see more of what is going on. 31*4882a593Smuzhiyun 32*4882a593Smuzhiyunconfig NTP_PPS 33*4882a593Smuzhiyun bool "PPS kernel consumer support" 34*4882a593Smuzhiyun depends on !NO_HZ_COMMON 35*4882a593Smuzhiyun help 36*4882a593Smuzhiyun This option adds support for direct in-kernel time 37*4882a593Smuzhiyun synchronization using an external PPS signal. 38*4882a593Smuzhiyun 39*4882a593Smuzhiyun It doesn't work on tickless systems at the moment. 40*4882a593Smuzhiyun 41*4882a593Smuzhiyunsource "drivers/pps/clients/Kconfig" 42*4882a593Smuzhiyun 43*4882a593Smuzhiyunsource "drivers/pps/generators/Kconfig" 44*4882a593Smuzhiyun 45*4882a593Smuzhiyunendif # PPS 46