From d94ba80ebbea17f036cecb104398fbcd788aa742 Mon Sep 17 00:00:00 2001 From: Richard Cochran Date: Fri, 22 Apr 2011 12:03:08 +0200 Subject: ptp: Added a brand new class driver for ptp clocks. This patch adds an infrastructure for hardware clocks that implement IEEE 1588, the Precision Time Protocol (PTP). A class driver offers a registration method to particular hardware clock drivers. Each clock is presented as a standard POSIX clock. The ancillary clock features are exposed in two different ways, via the sysfs and by a character device. Signed-off-by: Richard Cochran Acked-by: Arnd Bergmann Acked-by: David S. Miller Signed-off-by: John Stultz --- Documentation/ABI/testing/sysfs-ptp | 98 +++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-ptp (limited to 'Documentation/ABI') diff --git a/Documentation/ABI/testing/sysfs-ptp b/Documentation/ABI/testing/sysfs-ptp new file mode 100644 index 000000000000..d40d2b550502 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-ptp @@ -0,0 +1,98 @@ +What: /sys/class/ptp/ +Date: September 2010 +Contact: Richard Cochran +Description: + This directory contains files and directories + providing a standardized interface to the ancillary + features of PTP hardware clocks. + +What: /sys/class/ptp/ptpN/ +Date: September 2010 +Contact: Richard Cochran +Description: + This directory contains the attributes of the Nth PTP + hardware clock registered into the PTP class driver + subsystem. + +What: /sys/class/ptp/ptpN/clock_name +Date: September 2010 +Contact: Richard Cochran +Description: + This file contains the name of the PTP hardware clock + as a human readable string. + +What: /sys/class/ptp/ptpN/max_adjustment +Date: September 2010 +Contact: Richard Cochran +Description: + This file contains the PTP hardware clock's maximum + frequency adjustment value (a positive integer) in + parts per billion. + +What: /sys/class/ptp/ptpN/n_alarms +Date: September 2010 +Contact: Richard Cochran +Description: + This file contains the number of periodic or one shot + alarms offer by the PTP hardware clock. + +What: /sys/class/ptp/ptpN/n_external_timestamps +Date: September 2010 +Contact: Richard Cochran +Description: + This file contains the number of external timestamp + channels offered by the PTP hardware clock. + +What: /sys/class/ptp/ptpN/n_periodic_outputs +Date: September 2010 +Contact: Richard Cochran +Description: + This file contains the number of programmable periodic + output channels offered by the PTP hardware clock. + +What: /sys/class/ptp/ptpN/pps_avaiable +Date: September 2010 +Contact: Richard Cochran +Description: + This file indicates whether the PTP hardware clock + supports a Pulse Per Second to the host CPU. Reading + "1" means that the PPS is supported, while "0" means + not supported. + +What: /sys/class/ptp/ptpN/extts_enable +Date: September 2010 +Contact: Richard Cochran +Description: + This write-only file enables or disables external + timestamps. To enable external timestamps, write the + channel index followed by a "1" into the file. + To disable external timestamps, write the channel + index followed by a "0" into the file. + +What: /sys/class/ptp/ptpN/fifo +Date: September 2010 +Contact: Richard Cochran +Description: + This file provides timestamps on external events, in + the form of three integers: channel index, seconds, + and nanoseconds. + +What: /sys/class/ptp/ptpN/period +Date: September 2010 +Contact: Richard Cochran +Description: + This write-only file enables or disables periodic + outputs. To enable a periodic output, write five + integers into the file: channel index, start time + seconds, start time nanoseconds, period seconds, and + period nanoseconds. To disable a periodic output, set + all the seconds and nanoseconds values to zero. + +What: /sys/class/ptp/ptpN/pps_enable +Date: September 2010 +Contact: Richard Cochran +Description: + This write-only file enables or disables delivery of + PPS events to the Linux PPS subsystem. To enable PPS + events, write a "1" into the file. To disable events, + write a "0" into the file. -- cgit v1.2.2