xref: /openbmc/linux/include/uapi/linux/pps.h (revision 4f6cce39)
1 /*
2  * PPS API header
3  *
4  * Copyright (C) 2005-2009   Rodolfo Giometti <giometti@linux.it>
5  *
6  *   This program is free software; you can redistribute it and/or modify
7  *   it under the terms of the GNU General Public License as published by
8  *   the Free Software Foundation; either version 2 of the License, or
9  *   (at your option) any later version.
10  *
11  *   This program is distributed in the hope that it will be useful,
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *   GNU General Public License for more details.
15  *
16  *   You should have received a copy of the GNU General Public License
17  *   along with this program; if not, write to the Free Software
18  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19  */
20 
21 
22 #ifndef _PPS_H_
23 #define _PPS_H_
24 
25 #include <linux/types.h>
26 
27 #define PPS_VERSION		"5.3.6"
28 #define PPS_MAX_SOURCES		16		/* should be enough... */
29 
30 /* Implementation note: the logical states ``assert'' and ``clear''
31  * are implemented in terms of the chip register, i.e. ``assert''
32  * means the bit is set.  */
33 
34 /*
35  * 3.2 New data structures
36  */
37 
38 #define PPS_API_VERS_1		1
39 #define PPS_API_VERS		PPS_API_VERS_1	/* we use API version 1 */
40 #define PPS_MAX_NAME_LEN	32
41 
42 /* 32-bit vs. 64-bit compatibility.
43  *
44  * 0n i386, the alignment of a uint64_t is only 4 bytes, while on most other
45  * architectures it's 8 bytes. On i386, there will be no padding between the
46  * two consecutive 'struct pps_ktime' members of struct pps_kinfo and struct
47  * pps_kparams. But on most platforms there will be padding to ensure correct
48  * alignment.
49  *
50  * The simple fix is probably to add an explicit padding.
51  *					 		[David Woodhouse]
52  */
53 struct pps_ktime {
54 	__s64 sec;
55 	__s32 nsec;
56 	__u32 flags;
57 };
58 #define PPS_TIME_INVALID	(1<<0)	/* used to specify timeout==NULL */
59 
60 struct pps_kinfo {
61 	__u32 assert_sequence;		/* seq. num. of assert event */
62 	__u32 clear_sequence; 		/* seq. num. of clear event */
63 	struct pps_ktime assert_tu;	/* time of assert event */
64 	struct pps_ktime clear_tu;	/* time of clear event */
65 	int current_mode;		/* current mode bits */
66 };
67 
68 struct pps_kparams {
69 	int api_version;		/* API version # */
70 	int mode;			/* mode bits */
71 	struct pps_ktime assert_off_tu;	/* offset compensation for assert */
72 	struct pps_ktime clear_off_tu;	/* offset compensation for clear */
73 };
74 
75 /*
76  * 3.3 Mode bit definitions
77  */
78 
79 /* Device/implementation parameters */
80 #define PPS_CAPTUREASSERT	0x01	/* capture assert events */
81 #define PPS_CAPTURECLEAR	0x02	/* capture clear events */
82 #define PPS_CAPTUREBOTH		0x03	/* capture assert and clear events */
83 
84 #define PPS_OFFSETASSERT	0x10	/* apply compensation for assert ev. */
85 #define PPS_OFFSETCLEAR		0x20	/* apply compensation for clear ev. */
86 
87 #define PPS_CANWAIT		0x100	/* can we wait for an event? */
88 #define PPS_CANPOLL		0x200	/* bit reserved for future use */
89 
90 /* Kernel actions */
91 #define PPS_ECHOASSERT		0x40	/* feed back assert event to output */
92 #define PPS_ECHOCLEAR		0x80	/* feed back clear event to output */
93 
94 /* Timestamp formats */
95 #define PPS_TSFMT_TSPEC		0x1000	/* select timespec format */
96 #define PPS_TSFMT_NTPFP		0x2000	/* select NTP format */
97 
98 /*
99  * 3.4.4 New functions: disciplining the kernel timebase
100  */
101 
102 /* Kernel consumers */
103 #define PPS_KC_HARDPPS		0	/* hardpps() (or equivalent) */
104 #define PPS_KC_HARDPPS_PLL	1	/* hardpps() constrained to
105 					   use a phase-locked loop */
106 #define PPS_KC_HARDPPS_FLL	2	/* hardpps() constrained to
107 					   use a frequency-locked loop */
108 /*
109  * Here begins the implementation-specific part!
110  */
111 
112 struct pps_fdata {
113 	struct pps_kinfo info;
114 	struct pps_ktime timeout;
115 };
116 
117 struct pps_bind_args {
118 	int tsformat;	/* format of time stamps */
119 	int edge;	/* selected event type */
120 	int consumer;	/* selected kernel consumer */
121 };
122 
123 #include <linux/ioctl.h>
124 
125 #define PPS_GETPARAMS		_IOR('p', 0xa1, struct pps_kparams *)
126 #define PPS_SETPARAMS		_IOW('p', 0xa2, struct pps_kparams *)
127 #define PPS_GETCAP		_IOR('p', 0xa3, int *)
128 #define PPS_FETCH		_IOWR('p', 0xa4, struct pps_fdata *)
129 #define PPS_KC_BIND		_IOW('p', 0xa5, struct pps_bind_args *)
130 
131 #endif /* _PPS_H_ */
132