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 #include <linux/timecounter.h>
15 #include <linux/skbuff.h>
16
17 #define PTP_CLOCK_NAME_LEN 32
18 /**
19 * struct ptp_clock_request - request PTP clock event
20 *
21 * @type: The type of the request.
22 * EXTTS: Configure external trigger timestamping
23 * PEROUT: Configure periodic output signal (e.g. PPS)
24 * PPS: trigger internal PPS event for input
25 * into kernel PPS subsystem
26 * @extts: describes configuration for external trigger timestamping.
27 * This is only valid when event == PTP_CLK_REQ_EXTTS.
28 * @perout: describes configuration for periodic output.
29 * This is only valid when event == PTP_CLK_REQ_PEROUT.
30 */
31
32 struct ptp_clock_request {
33 enum {
34 PTP_CLK_REQ_EXTTS,
35 PTP_CLK_REQ_PEROUT,
36 PTP_CLK_REQ_PPS,
37 } type;
38 union {
39 struct ptp_extts_request extts;
40 struct ptp_perout_request perout;
41 };
42 };
43
44 struct system_device_crosststamp;
45
46 /**
47 * struct ptp_system_timestamp - system time corresponding to a PHC timestamp
48 */
49 struct ptp_system_timestamp {
50 struct timespec64 pre_ts;
51 struct timespec64 post_ts;
52 };
53
54 /**
55 * struct ptp_clock_info - describes a PTP hardware clock
56 *
57 * @owner: The clock driver should set to THIS_MODULE.
58 * @name: A short "friendly name" to identify the clock and to
59 * help distinguish PHY based devices from MAC based ones.
60 * The string is not meant to be a unique id.
61 * @max_adj: The maximum possible frequency adjustment, in parts per billon.
62 * @n_alarm: The number of programmable alarms.
63 * @n_ext_ts: The number of external time stamp channels.
64 * @n_per_out: The number of programmable periodic signals.
65 * @n_pins: The number of programmable pins.
66 * @pps: Indicates whether the clock supports a PPS callback.
67 * @pin_config: Array of length 'n_pins'. If the number of
68 * programmable pins is nonzero, then drivers must
69 * allocate and initialize this array.
70 *
71 * clock operations
72 *
73 * @adjfine: Adjusts the frequency of the hardware clock.
74 * parameter scaled_ppm: Desired frequency offset from
75 * nominal frequency in parts per million, but with a
76 * 16 bit binary fractional field.
77 *
78 * @adjfreq: Adjusts the frequency of the hardware clock.
79 * This method is deprecated. New drivers should implement
80 * the @adjfine method instead.
81 * parameter delta: Desired frequency offset from nominal frequency
82 * in parts per billion
83 *
84 * @adjphase: Adjusts the phase offset of the hardware clock.
85 * parameter delta: Desired change in nanoseconds.
86 *
87 * @adjtime: Shifts the time of the hardware clock.
88 * parameter delta: Desired change in nanoseconds.
89 *
90 * @gettime64: Reads the current time from the hardware clock.
91 * This method is deprecated. New drivers should implement
92 * the @gettimex64 method instead.
93 * parameter ts: Holds the result.
94 *
95 * @gettimex64: Reads the current time from the hardware clock and optionally
96 * also the system clock.
97 * parameter ts: Holds the PHC timestamp.
98 * parameter sts: If not NULL, it holds a pair of timestamps from
99 * the system clock. The first reading is made right before
100 * reading the lowest bits of the PHC timestamp and the second
101 * reading immediately follows that.
102 *
103 * @getcrosststamp: Reads the current time from the hardware clock and
104 * system clock simultaneously.
105 * parameter cts: Contains timestamp (device,system) pair,
106 * where system time is realtime and monotonic.
107 *
108 * @settime64: Set the current time on the hardware clock.
109 * parameter ts: Time value to set.
110 *
111 * @getcycles64: Reads the current free running cycle counter from the hardware
112 * clock.
113 * If @getcycles64 and @getcyclesx64 are not supported, then
114 * @gettime64 or @gettimex64 will be used as default
115 * implementation.
116 * parameter ts: Holds the result.
117 *
118 * @getcyclesx64: Reads the current free running cycle counter from the
119 * hardware clock and optionally also the system clock.
120 * If @getcycles64 and @getcyclesx64 are not supported, then
121 * @gettimex64 will be used as default implementation if
122 * available.
123 * parameter ts: Holds the PHC timestamp.
124 * parameter sts: If not NULL, it holds a pair of timestamps
125 * from the system clock. The first reading is made right before
126 * reading the lowest bits of the PHC timestamp and the second
127 * reading immediately follows that.
128 *
129 * @getcrosscycles: Reads the current free running cycle counter from the
130 * hardware clock and system clock simultaneously.
131 * If @getcycles64 and @getcyclesx64 are not supported, then
132 * @getcrosststamp will be used as default implementation if
133 * available.
134 * parameter cts: Contains timestamp (device,system) pair,
135 * where system time is realtime and monotonic.
136 *
137 * @enable: Request driver to enable or disable an ancillary feature.
138 * parameter request: Desired resource to enable or disable.
139 * parameter on: Caller passes one to enable or zero to disable.
140 *
141 * @verify: Confirm that a pin can perform a given function. The PTP
142 * Hardware Clock subsystem maintains the 'pin_config'
143 * array on behalf of the drivers, but the PHC subsystem
144 * assumes that every pin can perform every function. This
145 * hook gives drivers a way of telling the core about
146 * limitations on specific pins. This function must return
147 * zero if the function can be assigned to this pin, and
148 * nonzero otherwise.
149 * parameter pin: index of the pin in question.
150 * parameter func: the desired function to use.
151 * parameter chan: the function channel index to use.
152 *
153 * @do_aux_work: Request driver to perform auxiliary (periodic) operations
154 * Driver should return delay of the next auxiliary work
155 * scheduling time (>=0) or negative value in case further
156 * scheduling is not required.
157 *
158 * Drivers should embed their ptp_clock_info within a private
159 * structure, obtaining a reference to it using container_of().
160 *
161 * The callbacks must all return zero on success, non-zero otherwise.
162 */
163
164 struct ptp_clock_info {
165 struct module *owner;
166 char name[PTP_CLOCK_NAME_LEN];
167 s32 max_adj;
168 int n_alarm;
169 int n_ext_ts;
170 int n_per_out;
171 int n_pins;
172 int pps;
173 struct ptp_pin_desc *pin_config;
174 int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm);
175 int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
176 int (*adjphase)(struct ptp_clock_info *ptp, s32 phase);
177 int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
178 int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
179 int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
180 struct ptp_system_timestamp *sts);
181 int (*getcrosststamp)(struct ptp_clock_info *ptp,
182 struct system_device_crosststamp *cts);
183 int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts);
184 int (*getcycles64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
185 int (*getcyclesx64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
186 struct ptp_system_timestamp *sts);
187 int (*getcrosscycles)(struct ptp_clock_info *ptp,
188 struct system_device_crosststamp *cts);
189 int (*enable)(struct ptp_clock_info *ptp,
190 struct ptp_clock_request *request, int on);
191 int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
192 enum ptp_pin_function func, unsigned int chan);
193 long (*do_aux_work)(struct ptp_clock_info *ptp);
194 };
195
196 struct ptp_clock;
197
198 enum ptp_clock_events {
199 PTP_CLOCK_ALARM,
200 PTP_CLOCK_EXTTS,
201 PTP_CLOCK_PPS,
202 PTP_CLOCK_PPSUSR,
203 };
204
205 /**
206 * struct ptp_clock_event - decribes a PTP hardware clock event
207 *
208 * @type: One of the ptp_clock_events enumeration values.
209 * @index: Identifies the source of the event.
210 * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
211 * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
212 */
213
214 struct ptp_clock_event {
215 int type;
216 int index;
217 union {
218 u64 timestamp;
219 struct pps_event_time pps_times;
220 };
221 };
222
223 /**
224 * scaled_ppm_to_ppb() - convert scaled ppm to ppb
225 *
226 * @ppm: Parts per million, but with a 16 bit binary fractional field
227 */
scaled_ppm_to_ppb(long ppm)228 static inline long scaled_ppm_to_ppb(long ppm)
229 {
230 /*
231 * The 'freq' field in the 'struct timex' is in parts per
232 * million, but with a 16 bit binary fractional field.
233 *
234 * We want to calculate
235 *
236 * ppb = scaled_ppm * 1000 / 2^16
237 *
238 * which simplifies to
239 *
240 * ppb = scaled_ppm * 125 / 2^13
241 */
242 s64 ppb = 1 + ppm;
243
244 ppb *= 125;
245 ppb >>= 13;
246 return (long)ppb;
247 }
248
249 #if IS_ENABLED(CONFIG_PTP_1588_CLOCK)
250
251 /**
252 * ptp_clock_register() - register a PTP hardware clock driver
253 *
254 * @info: Structure describing the new clock.
255 * @parent: Pointer to the parent device of the new clock.
256 *
257 * Returns a valid pointer on success or PTR_ERR on failure. If PHC
258 * support is missing at the configuration level, this function
259 * returns NULL, and drivers are expected to gracefully handle that
260 * case separately.
261 */
262
263 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
264 struct device *parent);
265
266 /**
267 * ptp_clock_unregister() - unregister a PTP hardware clock driver
268 *
269 * @ptp: The clock to remove from service.
270 */
271
272 extern int ptp_clock_unregister(struct ptp_clock *ptp);
273
274 /**
275 * ptp_clock_event() - notify the PTP layer about an event
276 *
277 * @ptp: The clock obtained from ptp_clock_register().
278 * @event: Message structure describing the event.
279 */
280
281 extern void ptp_clock_event(struct ptp_clock *ptp,
282 struct ptp_clock_event *event);
283
284 /**
285 * ptp_clock_index() - obtain the device index of a PTP clock
286 *
287 * @ptp: The clock obtained from ptp_clock_register().
288 */
289
290 extern int ptp_clock_index(struct ptp_clock *ptp);
291
292 /**
293 * ptp_find_pin() - obtain the pin index of a given auxiliary function
294 *
295 * The caller must hold ptp_clock::pincfg_mux. Drivers do not have
296 * access to that mutex as ptp_clock is an opaque type. However, the
297 * core code acquires the mutex before invoking the driver's
298 * ptp_clock_info::enable() callback, and so drivers may call this
299 * function from that context.
300 *
301 * @ptp: The clock obtained from ptp_clock_register().
302 * @func: One of the ptp_pin_function enumerated values.
303 * @chan: The particular functional channel to find.
304 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
305 * or -1 if the auxiliary function cannot be found.
306 */
307
308 int ptp_find_pin(struct ptp_clock *ptp,
309 enum ptp_pin_function func, unsigned int chan);
310
311 /**
312 * ptp_find_pin_unlocked() - wrapper for ptp_find_pin()
313 *
314 * This function acquires the ptp_clock::pincfg_mux mutex before
315 * invoking ptp_find_pin(). Instead of using this function, drivers
316 * should most likely call ptp_find_pin() directly from their
317 * ptp_clock_info::enable() method.
318 *
319 */
320
321 int ptp_find_pin_unlocked(struct ptp_clock *ptp,
322 enum ptp_pin_function func, unsigned int chan);
323
324 /**
325 * ptp_schedule_worker() - schedule ptp auxiliary work
326 *
327 * @ptp: The clock obtained from ptp_clock_register().
328 * @delay: number of jiffies to wait before queuing
329 * See kthread_queue_delayed_work() for more info.
330 */
331
332 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay);
333
334 /**
335 * ptp_cancel_worker_sync() - cancel ptp auxiliary clock
336 *
337 * @ptp: The clock obtained from ptp_clock_register().
338 */
339 void ptp_cancel_worker_sync(struct ptp_clock *ptp);
340
341 #else
ptp_clock_register(struct ptp_clock_info * info,struct device * parent)342 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
343 struct device *parent)
344 { return NULL; }
ptp_clock_unregister(struct ptp_clock * ptp)345 static inline int ptp_clock_unregister(struct ptp_clock *ptp)
346 { return 0; }
ptp_clock_event(struct ptp_clock * ptp,struct ptp_clock_event * event)347 static inline void ptp_clock_event(struct ptp_clock *ptp,
348 struct ptp_clock_event *event)
349 { }
ptp_clock_index(struct ptp_clock * ptp)350 static inline int ptp_clock_index(struct ptp_clock *ptp)
351 { return -1; }
ptp_find_pin(struct ptp_clock * ptp,enum ptp_pin_function func,unsigned int chan)352 static inline int ptp_find_pin(struct ptp_clock *ptp,
353 enum ptp_pin_function func, unsigned int chan)
354 { return -1; }
ptp_find_pin_unlocked(struct ptp_clock * ptp,enum ptp_pin_function func,unsigned int chan)355 static inline int ptp_find_pin_unlocked(struct ptp_clock *ptp,
356 enum ptp_pin_function func,
357 unsigned int chan)
358 { return -1; }
ptp_schedule_worker(struct ptp_clock * ptp,unsigned long delay)359 static inline int ptp_schedule_worker(struct ptp_clock *ptp,
360 unsigned long delay)
361 { return -EOPNOTSUPP; }
ptp_cancel_worker_sync(struct ptp_clock * ptp)362 static inline void ptp_cancel_worker_sync(struct ptp_clock *ptp)
363 { }
364 #endif
365
366 #if IS_BUILTIN(CONFIG_PTP_1588_CLOCK)
367 /*
368 * These are called by the network core, and don't work if PTP is in
369 * a loadable module.
370 */
371
372 /**
373 * ptp_get_vclocks_index() - get all vclocks index on pclock, and
374 * caller is responsible to free memory
375 * of vclock_index
376 *
377 * @pclock_index: phc index of ptp pclock.
378 * @vclock_index: pointer to pointer of vclock index.
379 *
380 * return number of vclocks.
381 */
382 int ptp_get_vclocks_index(int pclock_index, int **vclock_index);
383
384 /**
385 * ptp_convert_timestamp() - convert timestamp to a ptp vclock time
386 *
387 * @hwtstamp: timestamp
388 * @vclock_index: phc index of ptp vclock.
389 *
390 * Returns converted timestamp, or 0 on error.
391 */
392 ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, int vclock_index);
393 #else
ptp_get_vclocks_index(int pclock_index,int ** vclock_index)394 static inline int ptp_get_vclocks_index(int pclock_index, int **vclock_index)
395 { return 0; }
ptp_convert_timestamp(const ktime_t * hwtstamp,int vclock_index)396 static inline ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp,
397 int vclock_index)
398 { return 0; }
399
400 #endif
401
ptp_read_system_prets(struct ptp_system_timestamp * sts)402 static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts)
403 {
404 if (sts)
405 ktime_get_real_ts64(&sts->pre_ts);
406 }
407
ptp_read_system_postts(struct ptp_system_timestamp * sts)408 static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts)
409 {
410 if (sts)
411 ktime_get_real_ts64(&sts->post_ts);
412 }
413
414 #endif
415