xref: /openbmc/linux/include/uapi/linux/pps.h (revision e2be04c7)
1 /* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
2 /*
3  * PPS API header
4  *
5  * Copyright (C) 2005-2009   Rodolfo Giometti <giometti@linux.it>
6  *
7  *   This program is free software; you can redistribute it and/or modify
8  *   it under the terms of the GNU General Public License as published by
9  *   the Free Software Foundation; either version 2 of the License, or
10  *   (at your option) any later version.
11  *
12  *   This program is distributed in the hope that it will be useful,
13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *   GNU General Public License for more details.
16  *
17  *   You should have received a copy of the GNU General Public License
18  *   along with this program; if not, write to the Free Software
19  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20  */
21 
22 
23 #ifndef _PPS_H_
24 #define _PPS_H_
25 
26 #include <linux/types.h>
27 
28 #define PPS_VERSION		"5.3.6"
29 #define PPS_MAX_SOURCES		16		/* should be enough... */
30 
31 /* Implementation note: the logical states ``assert'' and ``clear''
32  * are implemented in terms of the chip register, i.e. ``assert''
33  * means the bit is set.  */
34 
35 /*
36  * 3.2 New data structures
37  */
38 
39 #define PPS_API_VERS_1		1
40 #define PPS_API_VERS		PPS_API_VERS_1	/* we use API version 1 */
41 #define PPS_MAX_NAME_LEN	32
42 
43 /* 32-bit vs. 64-bit compatibility.
44  *
45  * 0n i386, the alignment of a uint64_t is only 4 bytes, while on most other
46  * architectures it's 8 bytes. On i386, there will be no padding between the
47  * two consecutive 'struct pps_ktime' members of struct pps_kinfo and struct
48  * pps_kparams. But on most platforms there will be padding to ensure correct
49  * alignment.
50  *
51  * The simple fix is probably to add an explicit padding.
52  *					 		[David Woodhouse]
53  */
54 struct pps_ktime {
55 	__s64 sec;
56 	__s32 nsec;
57 	__u32 flags;
58 };
59 
60 struct pps_ktime_compat {
61 	__s64 sec;
62 	__s32 nsec;
63 	__u32 flags;
64 } __attribute__((packed, aligned(4)));
65 #define PPS_TIME_INVALID	(1<<0)	/* used to specify timeout==NULL */
66 
67 struct pps_kinfo {
68 	__u32 assert_sequence;		/* seq. num. of assert event */
69 	__u32 clear_sequence; 		/* seq. num. of clear event */
70 	struct pps_ktime assert_tu;	/* time of assert event */
71 	struct pps_ktime clear_tu;	/* time of clear event */
72 	int current_mode;		/* current mode bits */
73 };
74 
75 struct pps_kinfo_compat {
76 	__u32 assert_sequence;			/* seq. num. of assert event */
77 	__u32 clear_sequence;			/* seq. num. of clear event */
78 	struct pps_ktime_compat assert_tu;	/* time of assert event */
79 	struct pps_ktime_compat clear_tu;	/* time of clear event */
80 	int current_mode;			/* current mode bits */
81 };
82 
83 struct pps_kparams {
84 	int api_version;		/* API version # */
85 	int mode;			/* mode bits */
86 	struct pps_ktime assert_off_tu;	/* offset compensation for assert */
87 	struct pps_ktime clear_off_tu;	/* offset compensation for clear */
88 };
89 
90 /*
91  * 3.3 Mode bit definitions
92  */
93 
94 /* Device/implementation parameters */
95 #define PPS_CAPTUREASSERT	0x01	/* capture assert events */
96 #define PPS_CAPTURECLEAR	0x02	/* capture clear events */
97 #define PPS_CAPTUREBOTH		0x03	/* capture assert and clear events */
98 
99 #define PPS_OFFSETASSERT	0x10	/* apply compensation for assert event */
100 #define PPS_OFFSETCLEAR		0x20	/* apply compensation for clear event */
101 
102 #define PPS_CANWAIT		0x100	/* can we wait for an event? */
103 #define PPS_CANPOLL		0x200	/* bit reserved for future use */
104 
105 /* Kernel actions */
106 #define PPS_ECHOASSERT		0x40	/* feed back assert event to output */
107 #define PPS_ECHOCLEAR		0x80	/* feed back clear event to output */
108 
109 /* Timestamp formats */
110 #define PPS_TSFMT_TSPEC		0x1000	/* select timespec format */
111 #define PPS_TSFMT_NTPFP		0x2000	/* select NTP format */
112 
113 /*
114  * 3.4.4 New functions: disciplining the kernel timebase
115  */
116 
117 /* Kernel consumers */
118 #define PPS_KC_HARDPPS		0	/* hardpps() (or equivalent) */
119 #define PPS_KC_HARDPPS_PLL	1	/* hardpps() constrained to
120 					   use a phase-locked loop */
121 #define PPS_KC_HARDPPS_FLL	2	/* hardpps() constrained to
122 					   use a frequency-locked loop */
123 /*
124  * Here begins the implementation-specific part!
125  */
126 
127 struct pps_fdata {
128 	struct pps_kinfo info;
129 	struct pps_ktime timeout;
130 };
131 
132 struct pps_fdata_compat {
133 	struct pps_kinfo_compat info;
134 	struct pps_ktime_compat timeout;
135 };
136 
137 struct pps_bind_args {
138 	int tsformat;	/* format of time stamps */
139 	int edge;	/* selected event type */
140 	int consumer;	/* selected kernel consumer */
141 };
142 
143 #include <linux/ioctl.h>
144 
145 #define PPS_GETPARAMS		_IOR('p', 0xa1, struct pps_kparams *)
146 #define PPS_SETPARAMS		_IOW('p', 0xa2, struct pps_kparams *)
147 #define PPS_GETCAP		_IOR('p', 0xa3, int *)
148 #define PPS_FETCH		_IOWR('p', 0xa4, struct pps_fdata *)
149 #define PPS_KC_BIND		_IOW('p', 0xa5, struct pps_bind_args *)
150 
151 #endif /* _PPS_H_ */
152