dm thin metadata: fix __udivdi3 undefined on 32-bit
[linux/fpc-iii.git] / Documentation / ABI / testing / sysfs-ptp
blob44806a678f12a21a3ff149bc1b7838a4c14da602
1 What:           /sys/class/ptp/
2 Date:           September 2010
3 Contact:        Richard Cochran <richardcochran@gmail.com>
4 Description:
5                 This directory contains files and directories
6                 providing a standardized interface to the ancillary
7                 features of PTP hardware clocks.
9 What:           /sys/class/ptp/ptpN/
10 Date:           September 2010
11 Contact:        Richard Cochran <richardcochran@gmail.com>
12 Description:
13                 This directory contains the attributes of the Nth PTP
14                 hardware clock registered into the PTP class driver
15                 subsystem.
17 What:           /sys/class/ptp/ptpN/clock_name
18 Date:           September 2010
19 Contact:        Richard Cochran <richardcochran@gmail.com>
20 Description:
21                 This file contains the name of the PTP hardware clock
22                 as a human readable string. The purpose of this
23                 attribute is to provide the user with a "friendly
24                 name" and to help distinguish PHY based devices from
25                 MAC based ones. The string does not necessarily have
26                 to be any kind of unique id.
28 What:           /sys/class/ptp/ptpN/max_adjustment
29 Date:           September 2010
30 Contact:        Richard Cochran <richardcochran@gmail.com>
31 Description:
32                 This file contains the PTP hardware clock's maximum
33                 frequency adjustment value (a positive integer) in
34                 parts per billion.
36 What:           /sys/class/ptp/ptpN/n_alarms
37 Date:           September 2010
38 Contact:        Richard Cochran <richardcochran@gmail.com>
39 Description:
40                 This file contains the number of periodic or one shot
41                 alarms offer by the PTP hardware clock.
43 What:           /sys/class/ptp/ptpN/n_external_timestamps
44 Date:           September 2010
45 Contact:        Richard Cochran <richardcochran@gmail.com>
46 Description:
47                 This file contains the number of external timestamp
48                 channels offered by the PTP hardware clock.
50 What:           /sys/class/ptp/ptpN/n_periodic_outputs
51 Date:           September 2010
52 Contact:        Richard Cochran <richardcochran@gmail.com>
53 Description:
54                 This file contains the number of programmable periodic
55                 output channels offered by the PTP hardware clock.
57 What:           /sys/class/ptp/ptpN/n_pins
58 Date:           March 2014
59 Contact:        Richard Cochran <richardcochran@gmail.com>
60 Description:
61                 This file contains the number of programmable pins
62                 offered by the PTP hardware clock.
64 What:           /sys/class/ptp/ptpN/pins
65 Date:           March 2014
66 Contact:        Richard Cochran <richardcochran@gmail.com>
67 Description:
68                 This directory contains one file for each programmable
69                 pin offered by the PTP hardware clock. The file name
70                 is the hardware dependent pin name. Reading from this
71                 file produces two numbers, the assigned function (see
72                 the PTP_PF_ enumeration values in linux/ptp_clock.h)
73                 and the channel number. The function and channel
74                 assignment may be changed by two writing numbers into
75                 the file.
77 What:           /sys/class/ptp/ptpN/pps_avaiable
78 Date:           September 2010
79 Contact:        Richard Cochran <richardcochran@gmail.com>
80 Description:
81                 This file indicates whether the PTP hardware clock
82                 supports a Pulse Per Second to the host CPU. Reading
83                 "1" means that the PPS is supported, while "0" means
84                 not supported.
86 What:           /sys/class/ptp/ptpN/extts_enable
87 Date:           September 2010
88 Contact:        Richard Cochran <richardcochran@gmail.com>
89 Description:
90                 This write-only file enables or disables external
91                 timestamps. To enable external timestamps, write the
92                 channel index followed by a "1" into the file.
93                 To disable external timestamps, write the channel
94                 index followed by a "0" into the file.
96 What:           /sys/class/ptp/ptpN/fifo
97 Date:           September 2010
98 Contact:        Richard Cochran <richardcochran@gmail.com>
99 Description:
100                 This file provides timestamps on external events, in
101                 the form of three integers: channel index, seconds,
102                 and nanoseconds.
104 What:           /sys/class/ptp/ptpN/period
105 Date:           September 2010
106 Contact:        Richard Cochran <richardcochran@gmail.com>
107 Description:
108                 This write-only file enables or disables periodic
109                 outputs. To enable a periodic output, write five
110                 integers into the file: channel index, start time
111                 seconds, start time nanoseconds, period seconds, and
112                 period nanoseconds. To disable a periodic output, set
113                 all the seconds and nanoseconds values to zero.
115 What:           /sys/class/ptp/ptpN/pps_enable
116 Date:           September 2010
117 Contact:        Richard Cochran <richardcochran@gmail.com>
118 Description:
119                 This write-only file enables or disables delivery of
120                 PPS events to the Linux PPS subsystem. To enable PPS
121                 events, write a "1" into the file. To disable events,
122                 write a "0" into the file.