xref: /linux/include/linux/ptp_clock_kernel.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * PTP 1588 clock support
3  *
4  * Copyright (C) 2010 OMICRON electronics GmbH
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 #ifndef _PTP_CLOCK_KERNEL_H_
22 #define _PTP_CLOCK_KERNEL_H_
23 
24 #include <linux/device.h>
25 #include <linux/pps_kernel.h>
26 #include <linux/ptp_clock.h>
27 
28 
29 struct ptp_clock_request {
30 	enum {
31 		PTP_CLK_REQ_EXTTS,
32 		PTP_CLK_REQ_PEROUT,
33 		PTP_CLK_REQ_PPS,
34 	} type;
35 	union {
36 		struct ptp_extts_request extts;
37 		struct ptp_perout_request perout;
38 	};
39 };
40 
41 /**
42  * struct ptp_clock_info - decribes a PTP hardware clock
43  *
44  * @owner:     The clock driver should set to THIS_MODULE.
45  * @name:      A short "friendly name" to identify the clock and to
46  *             help distinguish PHY based devices from MAC based ones.
47  *             The string is not meant to be a unique id.
48  * @max_adj:   The maximum possible frequency adjustment, in parts per billon.
49  * @n_alarm:   The number of programmable alarms.
50  * @n_ext_ts:  The number of external time stamp channels.
51  * @n_per_out: The number of programmable periodic signals.
52  * @n_pins:    The number of programmable pins.
53  * @pps:       Indicates whether the clock supports a PPS callback.
54  * @pin_config: Array of length 'n_pins'. If the number of
55  *              programmable pins is nonzero, then drivers must
56  *              allocate and initialize this array.
57  *
58  * clock operations
59  *
60  * @adjfreq:  Adjusts the frequency of the hardware clock.
61  *            parameter delta: Desired frequency offset from nominal frequency
62  *            in parts per billion
63  *
64  * @adjtime:  Shifts the time of the hardware clock.
65  *            parameter delta: Desired change in nanoseconds.
66  *
67  * @gettime64:  Reads the current time from the hardware clock.
68  *              parameter ts: Holds the result.
69  *
70  * @settime64:  Set the current time on the hardware clock.
71  *              parameter ts: Time value to set.
72  *
73  * @enable:   Request driver to enable or disable an ancillary feature.
74  *            parameter request: Desired resource to enable or disable.
75  *            parameter on: Caller passes one to enable or zero to disable.
76  *
77  * @verify:   Confirm that a pin can perform a given function. The PTP
78  *            Hardware Clock subsystem maintains the 'pin_config'
79  *            array on behalf of the drivers, but the PHC subsystem
80  *            assumes that every pin can perform every function. This
81  *            hook gives drivers a way of telling the core about
82  *            limitations on specific pins. This function must return
83  *            zero if the function can be assigned to this pin, and
84  *            nonzero otherwise.
85  *            parameter pin: index of the pin in question.
86  *            parameter func: the desired function to use.
87  *            parameter chan: the function channel index to use.
88  *
89  * Drivers should embed their ptp_clock_info within a private
90  * structure, obtaining a reference to it using container_of().
91  *
92  * The callbacks must all return zero on success, non-zero otherwise.
93  */
94 
95 struct ptp_clock_info {
96 	struct module *owner;
97 	char name[16];
98 	s32 max_adj;
99 	int n_alarm;
100 	int n_ext_ts;
101 	int n_per_out;
102 	int n_pins;
103 	int pps;
104 	struct ptp_pin_desc *pin_config;
105 	int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
106 	int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
107 	int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
108 	int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts);
109 	int (*enable)(struct ptp_clock_info *ptp,
110 		      struct ptp_clock_request *request, int on);
111 	int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
112 		      enum ptp_pin_function func, unsigned int chan);
113 };
114 
115 struct ptp_clock;
116 
117 /**
118  * ptp_clock_register() - register a PTP hardware clock driver
119  *
120  * @info:   Structure describing the new clock.
121  * @parent: Pointer to the parent device of the new clock.
122  */
123 
124 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
125 					    struct device *parent);
126 
127 /**
128  * ptp_clock_unregister() - unregister a PTP hardware clock driver
129  *
130  * @ptp:  The clock to remove from service.
131  */
132 
133 extern int ptp_clock_unregister(struct ptp_clock *ptp);
134 
135 
136 enum ptp_clock_events {
137 	PTP_CLOCK_ALARM,
138 	PTP_CLOCK_EXTTS,
139 	PTP_CLOCK_PPS,
140 	PTP_CLOCK_PPSUSR,
141 };
142 
143 /**
144  * struct ptp_clock_event - decribes a PTP hardware clock event
145  *
146  * @type:  One of the ptp_clock_events enumeration values.
147  * @index: Identifies the source of the event.
148  * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
149  * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
150  */
151 
152 struct ptp_clock_event {
153 	int type;
154 	int index;
155 	union {
156 		u64 timestamp;
157 		struct pps_event_time pps_times;
158 	};
159 };
160 
161 /**
162  * ptp_clock_event() - notify the PTP layer about an event
163  *
164  * @ptp:    The clock obtained from ptp_clock_register().
165  * @event:  Message structure describing the event.
166  */
167 
168 extern void ptp_clock_event(struct ptp_clock *ptp,
169 			    struct ptp_clock_event *event);
170 
171 /**
172  * ptp_clock_index() - obtain the device index of a PTP clock
173  *
174  * @ptp:    The clock obtained from ptp_clock_register().
175  */
176 
177 extern int ptp_clock_index(struct ptp_clock *ptp);
178 
179 /**
180  * ptp_find_pin() - obtain the pin index of a given auxiliary function
181  *
182  * @ptp:    The clock obtained from ptp_clock_register().
183  * @func:   One of the ptp_pin_function enumerated values.
184  * @chan:   The particular functional channel to find.
185  * Return:  Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
186  *          or -1 if the auxiliary function cannot be found.
187  */
188 
189 int ptp_find_pin(struct ptp_clock *ptp,
190 		 enum ptp_pin_function func, unsigned int chan);
191 
192 #endif
193