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 * @pre_ts: system timestamp before capturing PHC
49 * @post_ts: system timestamp after capturing PHC
50 */
51 struct ptp_system_timestamp {
52 struct timespec64 pre_ts;
53 struct timespec64 post_ts;
54 };
55
56 /**
57 * struct ptp_clock_info - describes a PTP hardware clock
58 *
59 * @owner: The clock driver should set to THIS_MODULE.
60 * @name: A short "friendly name" to identify the clock and to
61 * help distinguish PHY based devices from MAC based ones.
62 * The string is not meant to be a unique id.
63 * @max_adj: The maximum possible frequency adjustment, in parts per billon.
64 * @n_alarm: The number of programmable alarms.
65 * @n_ext_ts: The number of external time stamp channels.
66 * @n_per_out: The number of programmable periodic signals.
67 * @n_pins: The number of programmable pins.
68 * @pps: Indicates whether the clock supports a PPS callback.
69 * @pin_config: Array of length 'n_pins'. If the number of
70 * programmable pins is nonzero, then drivers must
71 * allocate and initialize this array.
72 *
73 * clock operations
74 *
75 * @adjfine: Adjusts the frequency of the hardware clock.
76 * parameter scaled_ppm: Desired frequency offset from
77 * nominal frequency in parts per million, but with a
78 * 16 bit binary fractional field.
79 *
80 * @adjphase: Indicates that the PHC should use an internal servo
81 * algorithm to correct the provided phase offset.
82 * parameter delta: PHC servo phase adjustment target
83 * in nanoseconds.
84 *
85 * @getmaxphase: Advertises maximum offset that can be provided
86 * to the hardware clock's phase control functionality
87 * through adjphase.
88 *
89 * @adjtime: Shifts the time of the hardware clock.
90 * parameter delta: Desired change in nanoseconds.
91 *
92 * @gettime64: Reads the current time from the hardware clock.
93 * This method is deprecated. New drivers should implement
94 * the @gettimex64 method instead.
95 * parameter ts: Holds the result.
96 *
97 * @gettimex64: Reads the current time from the hardware clock and optionally
98 * also the system clock.
99 * parameter ts: Holds the PHC timestamp.
100 * parameter sts: If not NULL, it holds a pair of timestamps from
101 * the system clock. The first reading is made right before
102 * reading the lowest bits of the PHC timestamp and the second
103 * reading immediately follows that.
104 *
105 * @getcrosststamp: Reads the current time from the hardware clock and
106 * system clock simultaneously.
107 * parameter cts: Contains timestamp (device,system) pair,
108 * where system time is realtime and monotonic.
109 *
110 * @settime64: Set the current time on the hardware clock.
111 * parameter ts: Time value to set.
112 *
113 * @getcycles64: Reads the current free running cycle counter from the hardware
114 * clock.
115 * If @getcycles64 and @getcyclesx64 are not supported, then
116 * @gettime64 or @gettimex64 will be used as default
117 * implementation.
118 * parameter ts: Holds the result.
119 *
120 * @getcyclesx64: Reads the current free running cycle counter from the
121 * hardware clock and optionally also the system clock.
122 * If @getcycles64 and @getcyclesx64 are not supported, then
123 * @gettimex64 will be used as default implementation if
124 * available.
125 * parameter ts: Holds the PHC timestamp.
126 * parameter sts: If not NULL, it holds a pair of timestamps
127 * from the system clock. The first reading is made right before
128 * reading the lowest bits of the PHC timestamp and the second
129 * reading immediately follows that.
130 *
131 * @getcrosscycles: Reads the current free running cycle counter from the
132 * hardware clock and system clock simultaneously.
133 * If @getcycles64 and @getcyclesx64 are not supported, then
134 * @getcrosststamp will be used as default implementation if
135 * available.
136 * parameter cts: Contains timestamp (device,system) pair,
137 * where system time is realtime and monotonic.
138 *
139 * @enable: Request driver to enable or disable an ancillary feature.
140 * parameter request: Desired resource to enable or disable.
141 * parameter on: Caller passes one to enable or zero to disable.
142 *
143 * @verify: Confirm that a pin can perform a given function. The PTP
144 * Hardware Clock subsystem maintains the 'pin_config'
145 * array on behalf of the drivers, but the PHC subsystem
146 * assumes that every pin can perform every function. This
147 * hook gives drivers a way of telling the core about
148 * limitations on specific pins. This function must return
149 * zero if the function can be assigned to this pin, and
150 * nonzero otherwise.
151 * parameter pin: index of the pin in question.
152 * parameter func: the desired function to use.
153 * parameter chan: the function channel index to use.
154 *
155 * @do_aux_work: Request driver to perform auxiliary (periodic) operations
156 * Driver should return delay of the next auxiliary work
157 * scheduling time (>=0) or negative value in case further
158 * scheduling is not required.
159 *
160 * Drivers should embed their ptp_clock_info within a private
161 * structure, obtaining a reference to it using container_of().
162 *
163 * The callbacks must all return zero on success, non-zero otherwise.
164 */
165
166 struct ptp_clock_info {
167 struct module *owner;
168 char name[PTP_CLOCK_NAME_LEN];
169 s32 max_adj;
170 int n_alarm;
171 int n_ext_ts;
172 int n_per_out;
173 int n_pins;
174 int pps;
175 struct ptp_pin_desc *pin_config;
176 int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm);
177 int (*adjphase)(struct ptp_clock_info *ptp, s32 phase);
178 s32 (*getmaxphase)(struct ptp_clock_info *ptp);
179 int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
180 int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
181 int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
182 struct ptp_system_timestamp *sts);
183 int (*getcrosststamp)(struct ptp_clock_info *ptp,
184 struct system_device_crosststamp *cts);
185 int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts);
186 int (*getcycles64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
187 int (*getcyclesx64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
188 struct ptp_system_timestamp *sts);
189 int (*getcrosscycles)(struct ptp_clock_info *ptp,
190 struct system_device_crosststamp *cts);
191 int (*enable)(struct ptp_clock_info *ptp,
192 struct ptp_clock_request *request, int on);
193 int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
194 enum ptp_pin_function func, unsigned int chan);
195 long (*do_aux_work)(struct ptp_clock_info *ptp);
196 };
197
198 struct ptp_clock;
199
200 enum ptp_clock_events {
201 PTP_CLOCK_ALARM,
202 PTP_CLOCK_EXTTS,
203 PTP_CLOCK_EXTOFF,
204 PTP_CLOCK_PPS,
205 PTP_CLOCK_PPSUSR,
206 };
207
208 /**
209 * struct ptp_clock_event - decribes a PTP hardware clock event
210 *
211 * @type: One of the ptp_clock_events enumeration values.
212 * @index: Identifies the source of the event.
213 * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
214 * @offset: When the event occurred (%PTP_CLOCK_EXTOFF only).
215 * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
216 */
217
218 struct ptp_clock_event {
219 int type;
220 int index;
221 union {
222 u64 timestamp;
223 s64 offset;
224 struct pps_event_time pps_times;
225 };
226 };
227
228 /**
229 * scaled_ppm_to_ppb() - convert scaled ppm to ppb
230 *
231 * @ppm: Parts per million, but with a 16 bit binary fractional field
232 */
233 static inline long scaled_ppm_to_ppb(long ppm)
234 {
235 /*
236 * The 'freq' field in the 'struct timex' is in parts per
237 * million, but with a 16 bit binary fractional field.
238 *
239 * We want to calculate
240 *
241 * ppb = scaled_ppm * 1000 / 2^16
242 *
243 * which simplifies to
244 *
245 * ppb = scaled_ppm * 125 / 2^13
246 */
247 s64 ppb = 1 + ppm;
248
249 ppb *= 125;
250 ppb >>= 13;
251 return (long)ppb;
252 }
253
254 /**
255 * diff_by_scaled_ppm - Calculate difference using scaled ppm
256 * @base: the base increment value to adjust
257 * @scaled_ppm: scaled parts per million to adjust by
258 * @diff: on return, the absolute value of calculated diff
259 *
260 * Calculate the difference to adjust the base increment using scaled parts
261 * per million.
262 *
263 * Use mul_u64_u64_div_u64 to perform the difference calculation in avoid
264 * possible overflow.
265 *
266 * Returns: true if scaled_ppm is negative, false otherwise
267 */
268 static inline bool diff_by_scaled_ppm(u64 base, long scaled_ppm, u64 *diff)
269 {
270 bool negative = false;
271
272 if (scaled_ppm < 0) {
273 negative = true;
274 scaled_ppm = -scaled_ppm;
275 }
276
277 *diff = mul_u64_u64_div_u64(base, (u64)scaled_ppm, 1000000ULL << 16);
278
279 return negative;
280 }
281
282 /**
283 * adjust_by_scaled_ppm - Adjust a base increment by scaled parts per million
284 * @base: the base increment value to adjust
285 * @scaled_ppm: scaled parts per million frequency adjustment
286 *
287 * Helper function which calculates a new increment value based on the
288 * requested scaled parts per million adjustment.
289 */
290 static inline u64 adjust_by_scaled_ppm(u64 base, long scaled_ppm)
291 {
292 u64 diff;
293
294 if (diff_by_scaled_ppm(base, scaled_ppm, &diff))
295 return base - diff;
296
297 return base + diff;
298 }
299
300 #if IS_ENABLED(CONFIG_PTP_1588_CLOCK)
301
302 /**
303 * ptp_clock_register() - register a PTP hardware clock driver
304 *
305 * @info: Structure describing the new clock.
306 * @parent: Pointer to the parent device of the new clock.
307 *
308 * Returns a valid pointer on success or PTR_ERR on failure. If PHC
309 * support is missing at the configuration level, this function
310 * returns NULL, and drivers are expected to gracefully handle that
311 * case separately.
312 */
313
314 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
315 struct device *parent);
316
317 /**
318 * ptp_clock_unregister() - unregister a PTP hardware clock driver
319 *
320 * @ptp: The clock to remove from service.
321 */
322
323 extern int ptp_clock_unregister(struct ptp_clock *ptp);
324
325 /**
326 * ptp_clock_event() - notify the PTP layer about an event
327 *
328 * @ptp: The clock obtained from ptp_clock_register().
329 * @event: Message structure describing the event.
330 */
331
332 extern void ptp_clock_event(struct ptp_clock *ptp,
333 struct ptp_clock_event *event);
334
335 /**
336 * ptp_clock_index() - obtain the device index of a PTP clock
337 *
338 * @ptp: The clock obtained from ptp_clock_register().
339 */
340
341 extern int ptp_clock_index(struct ptp_clock *ptp);
342
343 /**
344 * ptp_find_pin() - obtain the pin index of a given auxiliary function
345 *
346 * The caller must hold ptp_clock::pincfg_mux. Drivers do not have
347 * access to that mutex as ptp_clock is an opaque type. However, the
348 * core code acquires the mutex before invoking the driver's
349 * ptp_clock_info::enable() callback, and so drivers may call this
350 * function from that context.
351 *
352 * @ptp: The clock obtained from ptp_clock_register().
353 * @func: One of the ptp_pin_function enumerated values.
354 * @chan: The particular functional channel to find.
355 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
356 * or -1 if the auxiliary function cannot be found.
357 */
358
359 int ptp_find_pin(struct ptp_clock *ptp,
360 enum ptp_pin_function func, unsigned int chan);
361
362 /**
363 * ptp_find_pin_unlocked() - wrapper for ptp_find_pin()
364 *
365 * This function acquires the ptp_clock::pincfg_mux mutex before
366 * invoking ptp_find_pin(). Instead of using this function, drivers
367 * should most likely call ptp_find_pin() directly from their
368 * ptp_clock_info::enable() method.
369 *
370 * @ptp: The clock obtained from ptp_clock_register().
371 * @func: One of the ptp_pin_function enumerated values.
372 * @chan: The particular functional channel to find.
373 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
374 * or -1 if the auxiliary function cannot be found.
375 */
376
377 int ptp_find_pin_unlocked(struct ptp_clock *ptp,
378 enum ptp_pin_function func, unsigned int chan);
379
380 /**
381 * ptp_schedule_worker() - schedule ptp auxiliary work
382 *
383 * @ptp: The clock obtained from ptp_clock_register().
384 * @delay: number of jiffies to wait before queuing
385 * See kthread_queue_delayed_work() for more info.
386 */
387
388 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay);
389
390 /**
391 * ptp_cancel_worker_sync() - cancel ptp auxiliary clock
392 *
393 * @ptp: The clock obtained from ptp_clock_register().
394 */
395 void ptp_cancel_worker_sync(struct ptp_clock *ptp);
396
397 #else
398 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
399 struct device *parent)
400 { return NULL; }
401 static inline int ptp_clock_unregister(struct ptp_clock *ptp)
402 { return 0; }
403 static inline void ptp_clock_event(struct ptp_clock *ptp,
404 struct ptp_clock_event *event)
405 { }
406 static inline int ptp_clock_index(struct ptp_clock *ptp)
407 { return -1; }
408 static inline int ptp_find_pin(struct ptp_clock *ptp,
409 enum ptp_pin_function func, unsigned int chan)
410 { return -1; }
411 static inline int ptp_find_pin_unlocked(struct ptp_clock *ptp,
412 enum ptp_pin_function func,
413 unsigned int chan)
414 { return -1; }
415 static inline int ptp_schedule_worker(struct ptp_clock *ptp,
416 unsigned long delay)
417 { return -EOPNOTSUPP; }
418 static inline void ptp_cancel_worker_sync(struct ptp_clock *ptp)
419 { }
420 #endif
421
422 #if IS_BUILTIN(CONFIG_PTP_1588_CLOCK)
423 /*
424 * These are called by the network core, and don't work if PTP is in
425 * a loadable module.
426 */
427
428 /**
429 * ptp_get_vclocks_index() - get all vclocks index on pclock, and
430 * caller is responsible to free memory
431 * of vclock_index
432 *
433 * @pclock_index: phc index of ptp pclock.
434 * @vclock_index: pointer to pointer of vclock index.
435 *
436 * return number of vclocks.
437 */
438 int ptp_get_vclocks_index(int pclock_index, int **vclock_index);
439
440 /**
441 * ptp_convert_timestamp() - convert timestamp to a ptp vclock time
442 *
443 * @hwtstamp: timestamp
444 * @vclock_index: phc index of ptp vclock.
445 *
446 * Returns converted timestamp, or 0 on error.
447 */
448 ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, int vclock_index);
449 #else
450 static inline int ptp_get_vclocks_index(int pclock_index, int **vclock_index)
451 { return 0; }
452 static inline ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp,
453 int vclock_index)
454 { return 0; }
455
456 #endif
457
458 static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts)
459 {
460 if (sts)
461 ktime_get_real_ts64(&sts->pre_ts);
462 }
463
464 static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts)
465 {
466 if (sts)
467 ktime_get_real_ts64(&sts->post_ts);
468 }
469
470 #endif
471
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