xref: /linux/include/linux/ptp_clock_kernel.h (revision be709d48329a500621d2a05835283150ae137b45)
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 /**
44  * struct ptp_system_timestamp - system time corresponding to a PHC timestamp
45  */
46 struct ptp_system_timestamp {
47 	struct timespec64 pre_ts;
48 	struct timespec64 post_ts;
49 };
50 
51 /**
52  * struct ptp_clock_info - decribes a PTP hardware clock
53  *
54  * @owner:     The clock driver should set to THIS_MODULE.
55  * @name:      A short "friendly name" to identify the clock and to
56  *             help distinguish PHY based devices from MAC based ones.
57  *             The string is not meant to be a unique id.
58  * @max_adj:   The maximum possible frequency adjustment, in parts per billon.
59  * @n_alarm:   The number of programmable alarms.
60  * @n_ext_ts:  The number of external time stamp channels.
61  * @n_per_out: The number of programmable periodic signals.
62  * @n_pins:    The number of programmable pins.
63  * @pps:       Indicates whether the clock supports a PPS callback.
64  * @pin_config: Array of length 'n_pins'. If the number of
65  *              programmable pins is nonzero, then drivers must
66  *              allocate and initialize this array.
67  *
68  * clock operations
69  *
70  * @adjfine:  Adjusts the frequency of the hardware clock.
71  *            parameter scaled_ppm: Desired frequency offset from
72  *            nominal frequency in parts per million, but with a
73  *            16 bit binary fractional field.
74  *
75  * @adjfreq:  Adjusts the frequency of the hardware clock.
76  *            This method is deprecated.  New drivers should implement
77  *            the @adjfine method instead.
78  *            parameter delta: Desired frequency offset from nominal frequency
79  *            in parts per billion
80  *
81  * @adjtime:  Shifts the time of the hardware clock.
82  *            parameter delta: Desired change in nanoseconds.
83  *
84  * @gettime64:  Reads the current time from the hardware clock.
85  *              This method is deprecated.  New drivers should implement
86  *              the @gettimex64 method instead.
87  *              parameter ts: Holds the result.
88  *
89  * @gettimex64:  Reads the current time from the hardware clock and optionally
90  *               also the system clock.
91  *               parameter ts: Holds the PHC timestamp.
92  *               parameter sts: If not NULL, it holds a pair of timestamps from
93  *               the system clock. The first reading is made right before
94  *               reading the lowest bits of the PHC timestamp and the second
95  *               reading immediately follows that.
96  *
97  * @getcrosststamp:  Reads the current time from the hardware clock and
98  *                   system clock simultaneously.
99  *                   parameter cts: Contains timestamp (device,system) pair,
100  *                   where system time is realtime and monotonic.
101  *
102  * @settime64:  Set the current time on the hardware clock.
103  *              parameter ts: Time value to set.
104  *
105  * @enable:   Request driver to enable or disable an ancillary feature.
106  *            parameter request: Desired resource to enable or disable.
107  *            parameter on: Caller passes one to enable or zero to disable.
108  *
109  * @verify:   Confirm that a pin can perform a given function. The PTP
110  *            Hardware Clock subsystem maintains the 'pin_config'
111  *            array on behalf of the drivers, but the PHC subsystem
112  *            assumes that every pin can perform every function. This
113  *            hook gives drivers a way of telling the core about
114  *            limitations on specific pins. This function must return
115  *            zero if the function can be assigned to this pin, and
116  *            nonzero otherwise.
117  *            parameter pin: index of the pin in question.
118  *            parameter func: the desired function to use.
119  *            parameter chan: the function channel index to use.
120  *
121  * @do_work:  Request driver to perform auxiliary (periodic) operations
122  *	      Driver should return delay of the next auxiliary work scheduling
123  *	      time (>=0) or negative value in case further scheduling
124  *	      is not required.
125  *
126  * Drivers should embed their ptp_clock_info within a private
127  * structure, obtaining a reference to it using container_of().
128  *
129  * The callbacks must all return zero on success, non-zero otherwise.
130  */
131 
132 struct ptp_clock_info {
133 	struct module *owner;
134 	char name[16];
135 	s32 max_adj;
136 	int n_alarm;
137 	int n_ext_ts;
138 	int n_per_out;
139 	int n_pins;
140 	int pps;
141 	struct ptp_pin_desc *pin_config;
142 	int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm);
143 	int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
144 	int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
145 	int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
146 	int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
147 			  struct ptp_system_timestamp *sts);
148 	int (*getcrosststamp)(struct ptp_clock_info *ptp,
149 			      struct system_device_crosststamp *cts);
150 	int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts);
151 	int (*enable)(struct ptp_clock_info *ptp,
152 		      struct ptp_clock_request *request, int on);
153 	int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
154 		      enum ptp_pin_function func, unsigned int chan);
155 	long (*do_aux_work)(struct ptp_clock_info *ptp);
156 };
157 
158 struct ptp_clock;
159 
160 enum ptp_clock_events {
161 	PTP_CLOCK_ALARM,
162 	PTP_CLOCK_EXTTS,
163 	PTP_CLOCK_PPS,
164 	PTP_CLOCK_PPSUSR,
165 };
166 
167 /**
168  * struct ptp_clock_event - decribes a PTP hardware clock event
169  *
170  * @type:  One of the ptp_clock_events enumeration values.
171  * @index: Identifies the source of the event.
172  * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
173  * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
174  */
175 
176 struct ptp_clock_event {
177 	int type;
178 	int index;
179 	union {
180 		u64 timestamp;
181 		struct pps_event_time pps_times;
182 	};
183 };
184 
185 #if IS_REACHABLE(CONFIG_PTP_1588_CLOCK)
186 
187 /**
188  * ptp_clock_register() - register a PTP hardware clock driver
189  *
190  * @info:   Structure describing the new clock.
191  * @parent: Pointer to the parent device of the new clock.
192  *
193  * Returns a valid pointer on success or PTR_ERR on failure.  If PHC
194  * support is missing at the configuration level, this function
195  * returns NULL, and drivers are expected to gracefully handle that
196  * case separately.
197  */
198 
199 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
200 					    struct device *parent);
201 
202 /**
203  * ptp_clock_unregister() - unregister a PTP hardware clock driver
204  *
205  * @ptp:  The clock to remove from service.
206  */
207 
208 extern int ptp_clock_unregister(struct ptp_clock *ptp);
209 
210 /**
211  * ptp_clock_event() - notify the PTP layer about an event
212  *
213  * @ptp:    The clock obtained from ptp_clock_register().
214  * @event:  Message structure describing the event.
215  */
216 
217 extern void ptp_clock_event(struct ptp_clock *ptp,
218 			    struct ptp_clock_event *event);
219 
220 /**
221  * ptp_clock_index() - obtain the device index of a PTP clock
222  *
223  * @ptp:    The clock obtained from ptp_clock_register().
224  */
225 
226 extern int ptp_clock_index(struct ptp_clock *ptp);
227 
228 /**
229  * ptp_find_pin() - obtain the pin index of a given auxiliary function
230  *
231  * @ptp:    The clock obtained from ptp_clock_register().
232  * @func:   One of the ptp_pin_function enumerated values.
233  * @chan:   The particular functional channel to find.
234  * Return:  Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
235  *          or -1 if the auxiliary function cannot be found.
236  */
237 
238 int ptp_find_pin(struct ptp_clock *ptp,
239 		 enum ptp_pin_function func, unsigned int chan);
240 
241 /**
242  * ptp_schedule_worker() - schedule ptp auxiliary work
243  *
244  * @ptp:    The clock obtained from ptp_clock_register().
245  * @delay:  number of jiffies to wait before queuing
246  *          See kthread_queue_delayed_work() for more info.
247  */
248 
249 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay);
250 
251 #else
252 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
253 						   struct device *parent)
254 { return NULL; }
255 static inline int ptp_clock_unregister(struct ptp_clock *ptp)
256 { return 0; }
257 static inline void ptp_clock_event(struct ptp_clock *ptp,
258 				   struct ptp_clock_event *event)
259 { }
260 static inline int ptp_clock_index(struct ptp_clock *ptp)
261 { return -1; }
262 static inline int ptp_find_pin(struct ptp_clock *ptp,
263 			       enum ptp_pin_function func, unsigned int chan)
264 { return -1; }
265 static inline int ptp_schedule_worker(struct ptp_clock *ptp,
266 				      unsigned long delay)
267 { return -EOPNOTSUPP; }
268 
269 #endif
270 
271 static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts)
272 {
273 	if (sts)
274 		ktime_get_real_ts64(&sts->pre_ts);
275 }
276 
277 static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts)
278 {
279 	if (sts)
280 		ktime_get_real_ts64(&sts->post_ts);
281 }
282 
283 #endif
284