xref: /linux/include/linux/ptp_clock_kernel.h (revision 71e2f4dd5a65bd8dbca0b77661e75eea471168f8)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * PTP 1588 clock support
4  *
5  * Copyright (C) 2010 OMICRON electronics GmbH
6  */
7 
8 #ifndef _PTP_CLOCK_KERNEL_H_
9 #define _PTP_CLOCK_KERNEL_H_
10 
11 #include <linux/device.h>
12 #include <linux/pps_kernel.h>
13 #include <linux/ptp_clock.h>
14 
15 
16 struct ptp_clock_request {
17 	enum {
18 		PTP_CLK_REQ_EXTTS,
19 		PTP_CLK_REQ_PEROUT,
20 		PTP_CLK_REQ_PPS,
21 	} type;
22 	union {
23 		struct ptp_extts_request extts;
24 		struct ptp_perout_request perout;
25 	};
26 };
27 
28 struct system_device_crosststamp;
29 
30 /**
31  * struct ptp_system_timestamp - system time corresponding to a PHC timestamp
32  */
33 struct ptp_system_timestamp {
34 	struct timespec64 pre_ts;
35 	struct timespec64 post_ts;
36 };
37 
38 /**
39  * struct ptp_clock_info - decribes a PTP hardware clock
40  *
41  * @owner:     The clock driver should set to THIS_MODULE.
42  * @name:      A short "friendly name" to identify the clock and to
43  *             help distinguish PHY based devices from MAC based ones.
44  *             The string is not meant to be a unique id.
45  * @max_adj:   The maximum possible frequency adjustment, in parts per billon.
46  * @n_alarm:   The number of programmable alarms.
47  * @n_ext_ts:  The number of external time stamp channels.
48  * @n_per_out: The number of programmable periodic signals.
49  * @n_pins:    The number of programmable pins.
50  * @pps:       Indicates whether the clock supports a PPS callback.
51  * @pin_config: Array of length 'n_pins'. If the number of
52  *              programmable pins is nonzero, then drivers must
53  *              allocate and initialize this array.
54  *
55  * clock operations
56  *
57  * @adjfine:  Adjusts the frequency of the hardware clock.
58  *            parameter scaled_ppm: Desired frequency offset from
59  *            nominal frequency in parts per million, but with a
60  *            16 bit binary fractional field.
61  *
62  * @adjfreq:  Adjusts the frequency of the hardware clock.
63  *            This method is deprecated.  New drivers should implement
64  *            the @adjfine method instead.
65  *            parameter delta: Desired frequency offset from nominal frequency
66  *            in parts per billion
67  *
68  * @adjtime:  Shifts the time of the hardware clock.
69  *            parameter delta: Desired change in nanoseconds.
70  *
71  * @gettime64:  Reads the current time from the hardware clock.
72  *              This method is deprecated.  New drivers should implement
73  *              the @gettimex64 method instead.
74  *              parameter ts: Holds the result.
75  *
76  * @gettimex64:  Reads the current time from the hardware clock and optionally
77  *               also the system clock.
78  *               parameter ts: Holds the PHC timestamp.
79  *               parameter sts: If not NULL, it holds a pair of timestamps from
80  *               the system clock. The first reading is made right before
81  *               reading the lowest bits of the PHC timestamp and the second
82  *               reading immediately follows that.
83  *
84  * @getcrosststamp:  Reads the current time from the hardware clock and
85  *                   system clock simultaneously.
86  *                   parameter cts: Contains timestamp (device,system) pair,
87  *                   where system time is realtime and monotonic.
88  *
89  * @settime64:  Set the current time on the hardware clock.
90  *              parameter ts: Time value to set.
91  *
92  * @enable:   Request driver to enable or disable an ancillary feature.
93  *            parameter request: Desired resource to enable or disable.
94  *            parameter on: Caller passes one to enable or zero to disable.
95  *
96  * @verify:   Confirm that a pin can perform a given function. The PTP
97  *            Hardware Clock subsystem maintains the 'pin_config'
98  *            array on behalf of the drivers, but the PHC subsystem
99  *            assumes that every pin can perform every function. This
100  *            hook gives drivers a way of telling the core about
101  *            limitations on specific pins. This function must return
102  *            zero if the function can be assigned to this pin, and
103  *            nonzero otherwise.
104  *            parameter pin: index of the pin in question.
105  *            parameter func: the desired function to use.
106  *            parameter chan: the function channel index to use.
107  *
108  * @do_work:  Request driver to perform auxiliary (periodic) operations
109  *	      Driver should return delay of the next auxiliary work scheduling
110  *	      time (>=0) or negative value in case further scheduling
111  *	      is not required.
112  *
113  * Drivers should embed their ptp_clock_info within a private
114  * structure, obtaining a reference to it using container_of().
115  *
116  * The callbacks must all return zero on success, non-zero otherwise.
117  */
118 
119 struct ptp_clock_info {
120 	struct module *owner;
121 	char name[16];
122 	s32 max_adj;
123 	int n_alarm;
124 	int n_ext_ts;
125 	int n_per_out;
126 	int n_pins;
127 	int pps;
128 	struct ptp_pin_desc *pin_config;
129 	int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm);
130 	int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
131 	int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
132 	int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
133 	int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
134 			  struct ptp_system_timestamp *sts);
135 	int (*getcrosststamp)(struct ptp_clock_info *ptp,
136 			      struct system_device_crosststamp *cts);
137 	int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts);
138 	int (*enable)(struct ptp_clock_info *ptp,
139 		      struct ptp_clock_request *request, int on);
140 	int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
141 		      enum ptp_pin_function func, unsigned int chan);
142 	long (*do_aux_work)(struct ptp_clock_info *ptp);
143 };
144 
145 struct ptp_clock;
146 
147 enum ptp_clock_events {
148 	PTP_CLOCK_ALARM,
149 	PTP_CLOCK_EXTTS,
150 	PTP_CLOCK_PPS,
151 	PTP_CLOCK_PPSUSR,
152 };
153 
154 /**
155  * struct ptp_clock_event - decribes a PTP hardware clock event
156  *
157  * @type:  One of the ptp_clock_events enumeration values.
158  * @index: Identifies the source of the event.
159  * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
160  * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
161  */
162 
163 struct ptp_clock_event {
164 	int type;
165 	int index;
166 	union {
167 		u64 timestamp;
168 		struct pps_event_time pps_times;
169 	};
170 };
171 
172 #if IS_REACHABLE(CONFIG_PTP_1588_CLOCK)
173 
174 /**
175  * ptp_clock_register() - register a PTP hardware clock driver
176  *
177  * @info:   Structure describing the new clock.
178  * @parent: Pointer to the parent device of the new clock.
179  *
180  * Returns a valid pointer on success or PTR_ERR on failure.  If PHC
181  * support is missing at the configuration level, this function
182  * returns NULL, and drivers are expected to gracefully handle that
183  * case separately.
184  */
185 
186 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
187 					    struct device *parent);
188 
189 /**
190  * ptp_clock_unregister() - unregister a PTP hardware clock driver
191  *
192  * @ptp:  The clock to remove from service.
193  */
194 
195 extern int ptp_clock_unregister(struct ptp_clock *ptp);
196 
197 /**
198  * ptp_clock_event() - notify the PTP layer about an event
199  *
200  * @ptp:    The clock obtained from ptp_clock_register().
201  * @event:  Message structure describing the event.
202  */
203 
204 extern void ptp_clock_event(struct ptp_clock *ptp,
205 			    struct ptp_clock_event *event);
206 
207 /**
208  * ptp_clock_index() - obtain the device index of a PTP clock
209  *
210  * @ptp:    The clock obtained from ptp_clock_register().
211  */
212 
213 extern int ptp_clock_index(struct ptp_clock *ptp);
214 
215 /**
216  * scaled_ppm_to_ppb() - convert scaled ppm to ppb
217  *
218  * @ppm:    Parts per million, but with a 16 bit binary fractional field
219  */
220 
221 extern s32 scaled_ppm_to_ppb(long ppm);
222 
223 /**
224  * ptp_find_pin() - obtain the pin index of a given auxiliary function
225  *
226  * @ptp:    The clock obtained from ptp_clock_register().
227  * @func:   One of the ptp_pin_function enumerated values.
228  * @chan:   The particular functional channel to find.
229  * Return:  Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
230  *          or -1 if the auxiliary function cannot be found.
231  */
232 
233 int ptp_find_pin(struct ptp_clock *ptp,
234 		 enum ptp_pin_function func, unsigned int chan);
235 
236 /**
237  * ptp_schedule_worker() - schedule ptp auxiliary work
238  *
239  * @ptp:    The clock obtained from ptp_clock_register().
240  * @delay:  number of jiffies to wait before queuing
241  *          See kthread_queue_delayed_work() for more info.
242  */
243 
244 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay);
245 
246 #else
247 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
248 						   struct device *parent)
249 { return NULL; }
250 static inline int ptp_clock_unregister(struct ptp_clock *ptp)
251 { return 0; }
252 static inline void ptp_clock_event(struct ptp_clock *ptp,
253 				   struct ptp_clock_event *event)
254 { }
255 static inline int ptp_clock_index(struct ptp_clock *ptp)
256 { return -1; }
257 static inline int ptp_find_pin(struct ptp_clock *ptp,
258 			       enum ptp_pin_function func, unsigned int chan)
259 { return -1; }
260 static inline int ptp_schedule_worker(struct ptp_clock *ptp,
261 				      unsigned long delay)
262 { return -EOPNOTSUPP; }
263 
264 #endif
265 
266 static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts)
267 {
268 	if (sts)
269 		ktime_get_real_ts64(&sts->pre_ts);
270 }
271 
272 static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts)
273 {
274 	if (sts)
275 		ktime_get_real_ts64(&sts->post_ts);
276 }
277 
278 #endif
279