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 struct system_device_crosststamp;
42 /**
43  * struct ptp_clock_info - decribes a PTP hardware clock
44  *
45  * @owner:     The clock driver should set to THIS_MODULE.
46  * @name:      A short "friendly name" to identify the clock and to
47  *             help distinguish PHY based devices from MAC based ones.
48  *             The string is not meant to be a unique id.
49  * @max_adj:   The maximum possible frequency adjustment, in parts per billon.
50  * @n_alarm:   The number of programmable alarms.
51  * @n_ext_ts:  The number of external time stamp channels.
52  * @n_per_out: The number of programmable periodic signals.
53  * @n_pins:    The number of programmable pins.
54  * @pps:       Indicates whether the clock supports a PPS callback.
55  * @pin_config: Array of length 'n_pins'. If the number of
56  *              programmable pins is nonzero, then drivers must
57  *              allocate and initialize this array.
58  *
59  * clock operations
60  *
61  * @adjfreq:  Adjusts the frequency of the hardware clock.
62  *            parameter delta: Desired frequency offset from nominal frequency
63  *            in parts per billion
64  *
65  * @adjtime:  Shifts the time of the hardware clock.
66  *            parameter delta: Desired change in nanoseconds.
67  *
68  * @gettime64:  Reads the current time from the hardware clock.
69  *              parameter ts: Holds the result.
70  *
71  * @getcrosststamp:  Reads the current time from the hardware clock and
72  *                   system clock simultaneously.
73  *                   parameter cts: Contains timestamp (device,system) pair,
74  *                   where system time is realtime and monotonic.
75  *
76  * @settime64:  Set the current time on the hardware clock.
77  *              parameter ts: Time value to set.
78  *
79  * @enable:   Request driver to enable or disable an ancillary feature.
80  *            parameter request: Desired resource to enable or disable.
81  *            parameter on: Caller passes one to enable or zero to disable.
82  *
83  * @verify:   Confirm that a pin can perform a given function. The PTP
84  *            Hardware Clock subsystem maintains the 'pin_config'
85  *            array on behalf of the drivers, but the PHC subsystem
86  *            assumes that every pin can perform every function. This
87  *            hook gives drivers a way of telling the core about
88  *            limitations on specific pins. This function must return
89  *            zero if the function can be assigned to this pin, and
90  *            nonzero otherwise.
91  *            parameter pin: index of the pin in question.
92  *            parameter func: the desired function to use.
93  *            parameter chan: the function channel index to use.
94  *
95  * Drivers should embed their ptp_clock_info within a private
96  * structure, obtaining a reference to it using container_of().
97  *
98  * The callbacks must all return zero on success, non-zero otherwise.
99  */
100 
101 struct ptp_clock_info {
102 	struct module *owner;
103 	char name[16];
104 	s32 max_adj;
105 	int n_alarm;
106 	int n_ext_ts;
107 	int n_per_out;
108 	int n_pins;
109 	int pps;
110 	struct ptp_pin_desc *pin_config;
111 	int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
112 	int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
113 	int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
114 	int (*getcrosststamp)(struct ptp_clock_info *ptp,
115 			      struct system_device_crosststamp *cts);
116 	int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts);
117 	int (*enable)(struct ptp_clock_info *ptp,
118 		      struct ptp_clock_request *request, int on);
119 	int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
120 		      enum ptp_pin_function func, unsigned int chan);
121 };
122 
123 struct ptp_clock;
124 
125 /**
126  * ptp_clock_register() - register a PTP hardware clock driver
127  *
128  * @info:   Structure describing the new clock.
129  * @parent: Pointer to the parent device of the new clock.
130  */
131 
132 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
133 					    struct device *parent);
134 
135 /**
136  * ptp_clock_unregister() - unregister a PTP hardware clock driver
137  *
138  * @ptp:  The clock to remove from service.
139  */
140 
141 extern int ptp_clock_unregister(struct ptp_clock *ptp);
142 
143 
144 enum ptp_clock_events {
145 	PTP_CLOCK_ALARM,
146 	PTP_CLOCK_EXTTS,
147 	PTP_CLOCK_PPS,
148 	PTP_CLOCK_PPSUSR,
149 };
150 
151 /**
152  * struct ptp_clock_event - decribes a PTP hardware clock event
153  *
154  * @type:  One of the ptp_clock_events enumeration values.
155  * @index: Identifies the source of the event.
156  * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
157  * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
158  */
159 
160 struct ptp_clock_event {
161 	int type;
162 	int index;
163 	union {
164 		u64 timestamp;
165 		struct pps_event_time pps_times;
166 	};
167 };
168 
169 /**
170  * ptp_clock_event() - notify the PTP layer about an event
171  *
172  * @ptp:    The clock obtained from ptp_clock_register().
173  * @event:  Message structure describing the event.
174  */
175 
176 extern void ptp_clock_event(struct ptp_clock *ptp,
177 			    struct ptp_clock_event *event);
178 
179 /**
180  * ptp_clock_index() - obtain the device index of a PTP clock
181  *
182  * @ptp:    The clock obtained from ptp_clock_register().
183  */
184 
185 extern int ptp_clock_index(struct ptp_clock *ptp);
186 
187 /**
188  * ptp_find_pin() - obtain the pin index of a given auxiliary function
189  *
190  * @ptp:    The clock obtained from ptp_clock_register().
191  * @func:   One of the ptp_pin_function enumerated values.
192  * @chan:   The particular functional channel to find.
193  * Return:  Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
194  *          or -1 if the auxiliary function cannot be found.
195  */
196 
197 int ptp_find_pin(struct ptp_clock *ptp,
198 		 enum ptp_pin_function func, unsigned int chan);
199 
200 #endif
201