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 * @clockid: clock-base used for capturing the system timestamps
51 */
52 struct ptp_system_timestamp {
53 struct timespec64 pre_ts;
54 struct timespec64 post_ts;
55 clockid_t clockid;
56 };
57
58 /**
59 * struct ptp_clock_info - describes a PTP hardware clock
60 *
61 * @owner: The clock driver should set to THIS_MODULE.
62 * @name: A short "friendly name" to identify the clock and to
63 * help distinguish PHY based devices from MAC based ones.
64 * The string is not meant to be a unique id.
65 * @max_adj: The maximum possible frequency adjustment, in parts per billon.
66 * @n_alarm: The number of programmable alarms.
67 * @n_ext_ts: The number of external time stamp channels.
68 * @n_per_out: The number of programmable periodic signals.
69 * @n_pins: The number of programmable pins.
70 * @pps: Indicates whether the clock supports a PPS callback.
71 * @pin_config: Array of length 'n_pins'. If the number of
72 * programmable pins is nonzero, then drivers must
73 * allocate and initialize this array.
74 *
75 * clock operations
76 *
77 * @adjfine: Adjusts the frequency of the hardware clock.
78 * parameter scaled_ppm: Desired frequency offset from
79 * nominal frequency in parts per million, but with a
80 * 16 bit binary fractional field.
81 *
82 * @adjphase: Indicates that the PHC should use an internal servo
83 * algorithm to correct the provided phase offset.
84 * parameter delta: PHC servo phase adjustment target
85 * in nanoseconds.
86 *
87 * @getmaxphase: Advertises maximum offset that can be provided
88 * to the hardware clock's phase control functionality
89 * through adjphase.
90 *
91 * @adjtime: Shifts the time of the hardware clock.
92 * parameter delta: Desired change in nanoseconds.
93 *
94 * @gettime64: Reads the current time from the hardware clock.
95 * This method is deprecated. New drivers should implement
96 * the @gettimex64 method instead.
97 * parameter ts: Holds the result.
98 *
99 * @gettimex64: Reads the current time from the hardware clock and optionally
100 * also the system clock.
101 * parameter ts: Holds the PHC timestamp.
102 * parameter sts: If not NULL, it holds a pair of timestamps from
103 * the system clock. The first reading is made right before
104 * reading the lowest bits of the PHC timestamp and the second
105 * reading immediately follows that.
106 *
107 * @getcrosststamp: Reads the current time from the hardware clock and
108 * system clock simultaneously.
109 * parameter cts: Contains timestamp (device,system) pair,
110 * where system time is realtime and monotonic.
111 *
112 * @settime64: Set the current time on the hardware clock.
113 * parameter ts: Time value to set.
114 *
115 * @getcycles64: Reads the current free running cycle counter from the hardware
116 * clock.
117 * If @getcycles64 and @getcyclesx64 are not supported, then
118 * @gettime64 or @gettimex64 will be used as default
119 * implementation.
120 * parameter ts: Holds the result.
121 *
122 * @getcyclesx64: Reads the current free running cycle counter from the
123 * hardware clock and optionally also the system clock.
124 * If @getcycles64 and @getcyclesx64 are not supported, then
125 * @gettimex64 will be used as default implementation if
126 * available.
127 * parameter ts: Holds the PHC timestamp.
128 * parameter sts: If not NULL, it holds a pair of timestamps
129 * from the system clock. The first reading is made right before
130 * reading the lowest bits of the PHC timestamp and the second
131 * reading immediately follows that.
132 *
133 * @getcrosscycles: Reads the current free running cycle counter from the
134 * hardware clock and system clock simultaneously.
135 * If @getcycles64 and @getcyclesx64 are not supported, then
136 * @getcrosststamp will be used as default implementation if
137 * available.
138 * parameter cts: Contains timestamp (device,system) pair,
139 * where system time is realtime and monotonic.
140 *
141 * @enable: Request driver to enable or disable an ancillary feature.
142 * parameter request: Desired resource to enable or disable.
143 * parameter on: Caller passes one to enable or zero to disable.
144 *
145 * @verify: Confirm that a pin can perform a given function. The PTP
146 * Hardware Clock subsystem maintains the 'pin_config'
147 * array on behalf of the drivers, but the PHC subsystem
148 * assumes that every pin can perform every function. This
149 * hook gives drivers a way of telling the core about
150 * limitations on specific pins. This function must return
151 * zero if the function can be assigned to this pin, and
152 * nonzero otherwise.
153 * parameter pin: index of the pin in question.
154 * parameter func: the desired function to use.
155 * parameter chan: the function channel index to use.
156 *
157 * @do_aux_work: Request driver to perform auxiliary (periodic) operations
158 * Driver should return delay of the next auxiliary work
159 * scheduling time (>=0) or negative value in case further
160 * scheduling is not required.
161 *
162 * Drivers should embed their ptp_clock_info within a private
163 * structure, obtaining a reference to it using container_of().
164 *
165 * The callbacks must all return zero on success, non-zero otherwise.
166 */
167
168 struct ptp_clock_info {
169 struct module *owner;
170 char name[PTP_CLOCK_NAME_LEN];
171 s32 max_adj;
172 int n_alarm;
173 int n_ext_ts;
174 int n_per_out;
175 int n_pins;
176 int pps;
177 struct ptp_pin_desc *pin_config;
178 int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm);
179 int (*adjphase)(struct ptp_clock_info *ptp, s32 phase);
180 s32 (*getmaxphase)(struct ptp_clock_info *ptp);
181 int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
182 int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
183 int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
184 struct ptp_system_timestamp *sts);
185 int (*getcrosststamp)(struct ptp_clock_info *ptp,
186 struct system_device_crosststamp *cts);
187 int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts);
188 int (*getcycles64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
189 int (*getcyclesx64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
190 struct ptp_system_timestamp *sts);
191 int (*getcrosscycles)(struct ptp_clock_info *ptp,
192 struct system_device_crosststamp *cts);
193 int (*enable)(struct ptp_clock_info *ptp,
194 struct ptp_clock_request *request, int on);
195 int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
196 enum ptp_pin_function func, unsigned int chan);
197 long (*do_aux_work)(struct ptp_clock_info *ptp);
198 };
199
200 struct ptp_clock;
201
202 enum ptp_clock_events {
203 PTP_CLOCK_ALARM,
204 PTP_CLOCK_EXTTS,
205 PTP_CLOCK_EXTOFF,
206 PTP_CLOCK_PPS,
207 PTP_CLOCK_PPSUSR,
208 };
209
210 /**
211 * struct ptp_clock_event - decribes a PTP hardware clock event
212 *
213 * @type: One of the ptp_clock_events enumeration values.
214 * @index: Identifies the source of the event.
215 * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
216 * @offset: When the event occurred (%PTP_CLOCK_EXTOFF only).
217 * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
218 */
219
220 struct ptp_clock_event {
221 int type;
222 int index;
223 union {
224 u64 timestamp;
225 s64 offset;
226 struct pps_event_time pps_times;
227 };
228 };
229
230 /**
231 * scaled_ppm_to_ppb() - convert scaled ppm to ppb
232 *
233 * @ppm: Parts per million, but with a 16 bit binary fractional field
234 */
scaled_ppm_to_ppb(long ppm)235 static inline long scaled_ppm_to_ppb(long ppm)
236 {
237 /*
238 * The 'freq' field in the 'struct timex' is in parts per
239 * million, but with a 16 bit binary fractional field.
240 *
241 * We want to calculate
242 *
243 * ppb = scaled_ppm * 1000 / 2^16
244 *
245 * which simplifies to
246 *
247 * ppb = scaled_ppm * 125 / 2^13
248 */
249 s64 ppb = 1 + ppm;
250
251 ppb *= 125;
252 ppb >>= 13;
253 return (long)ppb;
254 }
255
256 /**
257 * diff_by_scaled_ppm - Calculate difference using scaled ppm
258 * @base: the base increment value to adjust
259 * @scaled_ppm: scaled parts per million to adjust by
260 * @diff: on return, the absolute value of calculated diff
261 *
262 * Calculate the difference to adjust the base increment using scaled parts
263 * per million.
264 *
265 * Use mul_u64_u64_div_u64 to perform the difference calculation in avoid
266 * possible overflow.
267 *
268 * Returns: true if scaled_ppm is negative, false otherwise
269 */
diff_by_scaled_ppm(u64 base,long scaled_ppm,u64 * diff)270 static inline bool diff_by_scaled_ppm(u64 base, long scaled_ppm, u64 *diff)
271 {
272 bool negative = false;
273
274 if (scaled_ppm < 0) {
275 negative = true;
276 scaled_ppm = -scaled_ppm;
277 }
278
279 *diff = mul_u64_u64_div_u64(base, (u64)scaled_ppm, 1000000ULL << 16);
280
281 return negative;
282 }
283
284 /**
285 * adjust_by_scaled_ppm - Adjust a base increment by scaled parts per million
286 * @base: the base increment value to adjust
287 * @scaled_ppm: scaled parts per million frequency adjustment
288 *
289 * Helper function which calculates a new increment value based on the
290 * requested scaled parts per million adjustment.
291 */
adjust_by_scaled_ppm(u64 base,long scaled_ppm)292 static inline u64 adjust_by_scaled_ppm(u64 base, long scaled_ppm)
293 {
294 u64 diff;
295
296 if (diff_by_scaled_ppm(base, scaled_ppm, &diff))
297 return base - diff;
298
299 return base + diff;
300 }
301
302 #if IS_ENABLED(CONFIG_PTP_1588_CLOCK)
303
304 /**
305 * ptp_clock_register() - register a PTP hardware clock driver
306 *
307 * @info: Structure describing the new clock.
308 * @parent: Pointer to the parent device of the new clock.
309 *
310 * Returns a valid pointer on success or PTR_ERR on failure. If PHC
311 * support is missing at the configuration level, this function
312 * returns NULL, and drivers are expected to gracefully handle that
313 * case separately.
314 */
315
316 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
317 struct device *parent);
318
319 /**
320 * ptp_clock_unregister() - unregister a PTP hardware clock driver
321 *
322 * @ptp: The clock to remove from service.
323 */
324
325 extern int ptp_clock_unregister(struct ptp_clock *ptp);
326
327 /**
328 * ptp_clock_event() - notify the PTP layer about an event
329 *
330 * @ptp: The clock obtained from ptp_clock_register().
331 * @event: Message structure describing the event.
332 */
333
334 extern void ptp_clock_event(struct ptp_clock *ptp,
335 struct ptp_clock_event *event);
336
337 /**
338 * ptp_clock_index() - obtain the device index of a PTP clock
339 *
340 * @ptp: The clock obtained from ptp_clock_register().
341 */
342
343 extern int ptp_clock_index(struct ptp_clock *ptp);
344
345 /**
346 * ptp_find_pin() - obtain the pin index of a given auxiliary function
347 *
348 * The caller must hold ptp_clock::pincfg_mux. Drivers do not have
349 * access to that mutex as ptp_clock is an opaque type. However, the
350 * core code acquires the mutex before invoking the driver's
351 * ptp_clock_info::enable() callback, and so drivers may call this
352 * function from that context.
353 *
354 * @ptp: The clock obtained from ptp_clock_register().
355 * @func: One of the ptp_pin_function enumerated values.
356 * @chan: The particular functional channel to find.
357 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
358 * or -1 if the auxiliary function cannot be found.
359 */
360
361 int ptp_find_pin(struct ptp_clock *ptp,
362 enum ptp_pin_function func, unsigned int chan);
363
364 /**
365 * ptp_find_pin_unlocked() - wrapper for ptp_find_pin()
366 *
367 * This function acquires the ptp_clock::pincfg_mux mutex before
368 * invoking ptp_find_pin(). Instead of using this function, drivers
369 * should most likely call ptp_find_pin() directly from their
370 * ptp_clock_info::enable() method.
371 *
372 * @ptp: The clock obtained from ptp_clock_register().
373 * @func: One of the ptp_pin_function enumerated values.
374 * @chan: The particular functional channel to find.
375 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
376 * or -1 if the auxiliary function cannot be found.
377 */
378
379 int ptp_find_pin_unlocked(struct ptp_clock *ptp,
380 enum ptp_pin_function func, unsigned int chan);
381
382 /**
383 * ptp_schedule_worker() - schedule ptp auxiliary work
384 *
385 * @ptp: The clock obtained from ptp_clock_register().
386 * @delay: number of jiffies to wait before queuing
387 * See kthread_queue_delayed_work() for more info.
388 */
389
390 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay);
391
392 /**
393 * ptp_cancel_worker_sync() - cancel ptp auxiliary clock
394 *
395 * @ptp: The clock obtained from ptp_clock_register().
396 */
397 void ptp_cancel_worker_sync(struct ptp_clock *ptp);
398
399 #else
ptp_clock_register(struct ptp_clock_info * info,struct device * parent)400 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
401 struct device *parent)
402 { return NULL; }
ptp_clock_unregister(struct ptp_clock * ptp)403 static inline int ptp_clock_unregister(struct ptp_clock *ptp)
404 { return 0; }
ptp_clock_event(struct ptp_clock * ptp,struct ptp_clock_event * event)405 static inline void ptp_clock_event(struct ptp_clock *ptp,
406 struct ptp_clock_event *event)
407 { }
ptp_clock_index(struct ptp_clock * ptp)408 static inline int ptp_clock_index(struct ptp_clock *ptp)
409 { return -1; }
ptp_find_pin(struct ptp_clock * ptp,enum ptp_pin_function func,unsigned int chan)410 static inline int ptp_find_pin(struct ptp_clock *ptp,
411 enum ptp_pin_function func, unsigned int chan)
412 { return -1; }
ptp_find_pin_unlocked(struct ptp_clock * ptp,enum ptp_pin_function func,unsigned int chan)413 static inline int ptp_find_pin_unlocked(struct ptp_clock *ptp,
414 enum ptp_pin_function func,
415 unsigned int chan)
416 { return -1; }
ptp_schedule_worker(struct ptp_clock * ptp,unsigned long delay)417 static inline int ptp_schedule_worker(struct ptp_clock *ptp,
418 unsigned long delay)
419 { return -EOPNOTSUPP; }
ptp_cancel_worker_sync(struct ptp_clock * ptp)420 static inline void ptp_cancel_worker_sync(struct ptp_clock *ptp)
421 { }
422 #endif
423
424 #if IS_BUILTIN(CONFIG_PTP_1588_CLOCK)
425 /*
426 * These are called by the network core, and don't work if PTP is in
427 * a loadable module.
428 */
429
430 /**
431 * ptp_get_vclocks_index() - get all vclocks index on pclock, and
432 * caller is responsible to free memory
433 * of vclock_index
434 *
435 * @pclock_index: phc index of ptp pclock.
436 * @vclock_index: pointer to pointer of vclock index.
437 *
438 * return number of vclocks.
439 */
440 int ptp_get_vclocks_index(int pclock_index, int **vclock_index);
441
442 /**
443 * ptp_convert_timestamp() - convert timestamp to a ptp vclock time
444 *
445 * @hwtstamp: timestamp
446 * @vclock_index: phc index of ptp vclock.
447 *
448 * Returns converted timestamp, or 0 on error.
449 */
450 ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, int vclock_index);
451 #else
ptp_get_vclocks_index(int pclock_index,int ** vclock_index)452 static inline int ptp_get_vclocks_index(int pclock_index, int **vclock_index)
453 { return 0; }
ptp_convert_timestamp(const ktime_t * hwtstamp,int vclock_index)454 static inline ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp,
455 int vclock_index)
456 { return 0; }
457
458 #endif
459
ptp_read_system_prets(struct ptp_system_timestamp * sts)460 static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts)
461 {
462 if (sts) {
463 switch (sts->clockid) {
464 case CLOCK_REALTIME:
465 ktime_get_real_ts64(&sts->pre_ts);
466 break;
467 case CLOCK_MONOTONIC:
468 ktime_get_ts64(&sts->pre_ts);
469 break;
470 case CLOCK_MONOTONIC_RAW:
471 ktime_get_raw_ts64(&sts->pre_ts);
472 break;
473 default:
474 break;
475 }
476 }
477 }
478
ptp_read_system_postts(struct ptp_system_timestamp * sts)479 static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts)
480 {
481 if (sts) {
482 switch (sts->clockid) {
483 case CLOCK_REALTIME:
484 ktime_get_real_ts64(&sts->post_ts);
485 break;
486 case CLOCK_MONOTONIC:
487 ktime_get_ts64(&sts->post_ts);
488 break;
489 case CLOCK_MONOTONIC_RAW:
490 ktime_get_raw_ts64(&sts->post_ts);
491 break;
492 default:
493 break;
494 }
495 }
496 }
497
498 #endif
499