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 *
72 * @supported_perout_flags: The set of flags the driver supports for the
73 * PTP_PEROUT_REQUEST ioctl. The PTP core will
74 * reject a request with any flag not specified
75 * here.
76 *
77 * @supported_extts_flags: The set of flags the driver supports for the
78 * PTP_EXTTS_REQUEST ioctl. The PTP core will use
79 * this list to reject unsupported requests.
80 * PTP_ENABLE_FEATURE is assumed and does not need to
81 * be included. If PTP_STRICT_FLAGS is *not* set,
82 * then both PTP_RISING_EDGE and PTP_FALLING_EDGE
83 * will be assumed. Note that PTP_STRICT_FLAGS must
84 * be set if the drivers wants to honor
85 * PTP_EXTTS_REQUEST2 and any future flags.
86 *
87 * @pin_config: Array of length 'n_pins'. If the number of
88 * programmable pins is nonzero, then drivers must
89 * allocate and initialize this array.
90 *
91 * clock operations
92 *
93 * @adjfine: Adjusts the frequency of the hardware clock.
94 * parameter scaled_ppm: Desired frequency offset from
95 * nominal frequency in parts per million, but with a
96 * 16 bit binary fractional field.
97 *
98 * @adjphase: Indicates that the PHC should use an internal servo
99 * algorithm to correct the provided phase offset.
100 * parameter delta: PHC servo phase adjustment target
101 * in nanoseconds.
102 *
103 * @getmaxphase: Advertises maximum offset that can be provided
104 * to the hardware clock's phase control functionality
105 * through adjphase.
106 *
107 * @adjtime: Shifts the time of the hardware clock.
108 * parameter delta: Desired change in nanoseconds.
109 *
110 * @gettime64: Reads the current time from the hardware clock.
111 * This method is deprecated. New drivers should implement
112 * the @gettimex64 method instead.
113 * parameter ts: Holds the result.
114 *
115 * @gettimex64: Reads the current time from the hardware clock and optionally
116 * also the system clock.
117 * parameter ts: Holds the PHC timestamp.
118 * parameter sts: If not NULL, it holds a pair of timestamps from
119 * the system clock. The first reading is made right before
120 * reading the lowest bits of the PHC timestamp and the second
121 * reading immediately follows that.
122 *
123 * @getcrosststamp: Reads the current time from the hardware clock and
124 * system clock simultaneously.
125 * parameter cts: Contains timestamp (device,system) pair,
126 * where system time is realtime and monotonic.
127 *
128 * @settime64: Set the current time on the hardware clock.
129 * parameter ts: Time value to set.
130 *
131 * @getcycles64: Reads the current free running cycle counter from the hardware
132 * clock.
133 * If @getcycles64 and @getcyclesx64 are not supported, then
134 * @gettime64 or @gettimex64 will be used as default
135 * implementation.
136 * parameter ts: Holds the result.
137 *
138 * @getcyclesx64: Reads the current free running cycle counter from the
139 * hardware clock and optionally also the system clock.
140 * If @getcycles64 and @getcyclesx64 are not supported, then
141 * @gettimex64 will be used as default implementation if
142 * available.
143 * parameter ts: Holds the PHC timestamp.
144 * parameter sts: If not NULL, it holds a pair of timestamps
145 * from the system clock. The first reading is made right before
146 * reading the lowest bits of the PHC timestamp and the second
147 * reading immediately follows that.
148 *
149 * @getcrosscycles: Reads the current free running cycle counter from the
150 * hardware clock and system clock simultaneously.
151 * If @getcycles64 and @getcyclesx64 are not supported, then
152 * @getcrosststamp will be used as default implementation if
153 * available.
154 * parameter cts: Contains timestamp (device,system) pair,
155 * where system time is realtime and monotonic.
156 *
157 * @enable: Request driver to enable or disable an ancillary feature.
158 * parameter request: Desired resource to enable or disable.
159 * parameter on: Caller passes one to enable or zero to disable.
160 *
161 * @verify: Confirm that a pin can perform a given function. The PTP
162 * Hardware Clock subsystem maintains the 'pin_config'
163 * array on behalf of the drivers, but the PHC subsystem
164 * assumes that every pin can perform every function. This
165 * hook gives drivers a way of telling the core about
166 * limitations on specific pins. This function must return
167 * zero if the function can be assigned to this pin, and
168 * nonzero otherwise.
169 * parameter pin: index of the pin in question.
170 * parameter func: the desired function to use.
171 * parameter chan: the function channel index to use.
172 *
173 * @do_aux_work: Request driver to perform auxiliary (periodic) operations
174 * Driver should return delay of the next auxiliary work
175 * scheduling time (>=0) or negative value in case further
176 * scheduling is not required.
177 *
178 * Drivers should embed their ptp_clock_info within a private
179 * structure, obtaining a reference to it using container_of().
180 *
181 * The callbacks must all return zero on success, non-zero otherwise.
182 */
183
184 struct ptp_clock_info {
185 struct module *owner;
186 char name[PTP_CLOCK_NAME_LEN];
187 s32 max_adj;
188 int n_alarm;
189 int n_ext_ts;
190 int n_per_out;
191 int n_pins;
192 int pps;
193 unsigned int supported_perout_flags;
194 unsigned int supported_extts_flags;
195 struct ptp_pin_desc *pin_config;
196 int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm);
197 int (*adjphase)(struct ptp_clock_info *ptp, s32 phase);
198 s32 (*getmaxphase)(struct ptp_clock_info *ptp);
199 int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
200 int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
201 int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
202 struct ptp_system_timestamp *sts);
203 int (*getcrosststamp)(struct ptp_clock_info *ptp,
204 struct system_device_crosststamp *cts);
205 int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts);
206 int (*getcycles64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
207 int (*getcyclesx64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
208 struct ptp_system_timestamp *sts);
209 int (*getcrosscycles)(struct ptp_clock_info *ptp,
210 struct system_device_crosststamp *cts);
211 int (*enable)(struct ptp_clock_info *ptp,
212 struct ptp_clock_request *request, int on);
213 int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
214 enum ptp_pin_function func, unsigned int chan);
215 long (*do_aux_work)(struct ptp_clock_info *ptp);
216 };
217
218 struct ptp_clock;
219
220 enum ptp_clock_events {
221 PTP_CLOCK_ALARM,
222 PTP_CLOCK_EXTTS,
223 PTP_CLOCK_EXTOFF,
224 PTP_CLOCK_PPS,
225 PTP_CLOCK_PPSUSR,
226 };
227
228 /**
229 * struct ptp_clock_event - decribes a PTP hardware clock event
230 *
231 * @type: One of the ptp_clock_events enumeration values.
232 * @index: Identifies the source of the event.
233 * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
234 * @offset: When the event occurred (%PTP_CLOCK_EXTOFF only).
235 * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
236 */
237
238 struct ptp_clock_event {
239 int type;
240 int index;
241 union {
242 u64 timestamp;
243 s64 offset;
244 struct pps_event_time pps_times;
245 };
246 };
247
248 /**
249 * scaled_ppm_to_ppb() - convert scaled ppm to ppb
250 *
251 * @ppm: Parts per million, but with a 16 bit binary fractional field
252 */
scaled_ppm_to_ppb(long ppm)253 static inline long scaled_ppm_to_ppb(long ppm)
254 {
255 /*
256 * The 'freq' field in the 'struct timex' is in parts per
257 * million, but with a 16 bit binary fractional field.
258 *
259 * We want to calculate
260 *
261 * ppb = scaled_ppm * 1000 / 2^16
262 *
263 * which simplifies to
264 *
265 * ppb = scaled_ppm * 125 / 2^13
266 */
267 s64 ppb = 1 + ppm;
268
269 ppb *= 125;
270 ppb >>= 13;
271 return (long)ppb;
272 }
273
274 /**
275 * diff_by_scaled_ppm - Calculate difference using scaled ppm
276 * @base: the base increment value to adjust
277 * @scaled_ppm: scaled parts per million to adjust by
278 * @diff: on return, the absolute value of calculated diff
279 *
280 * Calculate the difference to adjust the base increment using scaled parts
281 * per million.
282 *
283 * Use mul_u64_u64_div_u64 to perform the difference calculation in avoid
284 * possible overflow.
285 *
286 * Returns: true if scaled_ppm is negative, false otherwise
287 */
diff_by_scaled_ppm(u64 base,long scaled_ppm,u64 * diff)288 static inline bool diff_by_scaled_ppm(u64 base, long scaled_ppm, u64 *diff)
289 {
290 bool negative = false;
291
292 if (scaled_ppm < 0) {
293 negative = true;
294 scaled_ppm = -scaled_ppm;
295 }
296
297 *diff = mul_u64_u64_div_u64(base, (u64)scaled_ppm, 1000000ULL << 16);
298
299 return negative;
300 }
301
302 /**
303 * adjust_by_scaled_ppm - Adjust a base increment by scaled parts per million
304 * @base: the base increment value to adjust
305 * @scaled_ppm: scaled parts per million frequency adjustment
306 *
307 * Helper function which calculates a new increment value based on the
308 * requested scaled parts per million adjustment.
309 */
adjust_by_scaled_ppm(u64 base,long scaled_ppm)310 static inline u64 adjust_by_scaled_ppm(u64 base, long scaled_ppm)
311 {
312 u64 diff;
313
314 if (diff_by_scaled_ppm(base, scaled_ppm, &diff))
315 return base - diff;
316
317 return base + diff;
318 }
319
320 #if IS_ENABLED(CONFIG_PTP_1588_CLOCK)
321
322 /**
323 * ptp_clock_register() - register a PTP hardware clock driver
324 *
325 * @info: Structure describing the new clock.
326 * @parent: Pointer to the parent device of the new clock.
327 *
328 * Returns: a valid pointer on success or PTR_ERR on failure. If PHC
329 * support is missing at the configuration level, this function
330 * returns NULL, and drivers are expected to gracefully handle that
331 * case separately.
332 */
333
334 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
335 struct device *parent);
336
337 /**
338 * ptp_clock_unregister() - unregister a PTP hardware clock driver
339 *
340 * @ptp: The clock to remove from service.
341 */
342
343 extern int ptp_clock_unregister(struct ptp_clock *ptp);
344
345 /**
346 * ptp_clock_event() - notify the PTP layer about an event
347 *
348 * @ptp: The clock obtained from ptp_clock_register().
349 * @event: Message structure describing the event.
350 */
351
352 extern void ptp_clock_event(struct ptp_clock *ptp,
353 struct ptp_clock_event *event);
354
355 /**
356 * ptp_clock_index() - obtain the device index of a PTP clock
357 *
358 * @ptp: The clock obtained from ptp_clock_register().
359 */
360
361 extern int ptp_clock_index(struct ptp_clock *ptp);
362
363 /**
364 * ptp_find_pin() - obtain the pin index of a given auxiliary function
365 *
366 * The caller must hold ptp_clock::pincfg_mux. Drivers do not have
367 * access to that mutex as ptp_clock is an opaque type. However, the
368 * core code acquires the mutex before invoking the driver's
369 * ptp_clock_info::enable() callback, and so drivers may call this
370 * function from that context.
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(struct ptp_clock *ptp,
380 enum ptp_pin_function func, unsigned int chan);
381
382 /**
383 * ptp_find_pin_unlocked() - wrapper for ptp_find_pin()
384 *
385 * This function acquires the ptp_clock::pincfg_mux mutex before
386 * invoking ptp_find_pin(). Instead of using this function, drivers
387 * should most likely call ptp_find_pin() directly from their
388 * ptp_clock_info::enable() method.
389 *
390 * @ptp: The clock obtained from ptp_clock_register().
391 * @func: One of the ptp_pin_function enumerated values.
392 * @chan: The particular functional channel to find.
393 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
394 * or -1 if the auxiliary function cannot be found.
395 */
396
397 int ptp_find_pin_unlocked(struct ptp_clock *ptp,
398 enum ptp_pin_function func, unsigned int chan);
399
400 /**
401 * ptp_schedule_worker() - schedule ptp auxiliary work
402 *
403 * @ptp: The clock obtained from ptp_clock_register().
404 * @delay: number of jiffies to wait before queuing
405 * See kthread_queue_delayed_work() for more info.
406 */
407
408 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay);
409
410 /**
411 * ptp_cancel_worker_sync() - cancel ptp auxiliary clock
412 *
413 * @ptp: The clock obtained from ptp_clock_register().
414 */
415 void ptp_cancel_worker_sync(struct ptp_clock *ptp);
416
417 #else
ptp_clock_register(struct ptp_clock_info * info,struct device * parent)418 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
419 struct device *parent)
420 { return NULL; }
ptp_clock_unregister(struct ptp_clock * ptp)421 static inline int ptp_clock_unregister(struct ptp_clock *ptp)
422 { return 0; }
ptp_clock_event(struct ptp_clock * ptp,struct ptp_clock_event * event)423 static inline void ptp_clock_event(struct ptp_clock *ptp,
424 struct ptp_clock_event *event)
425 { }
ptp_clock_index(struct ptp_clock * ptp)426 static inline int ptp_clock_index(struct ptp_clock *ptp)
427 { return -1; }
ptp_find_pin(struct ptp_clock * ptp,enum ptp_pin_function func,unsigned int chan)428 static inline int ptp_find_pin(struct ptp_clock *ptp,
429 enum ptp_pin_function func, unsigned int chan)
430 { return -1; }
ptp_find_pin_unlocked(struct ptp_clock * ptp,enum ptp_pin_function func,unsigned int chan)431 static inline int ptp_find_pin_unlocked(struct ptp_clock *ptp,
432 enum ptp_pin_function func,
433 unsigned int chan)
434 { return -1; }
ptp_schedule_worker(struct ptp_clock * ptp,unsigned long delay)435 static inline int ptp_schedule_worker(struct ptp_clock *ptp,
436 unsigned long delay)
437 { return -EOPNOTSUPP; }
ptp_cancel_worker_sync(struct ptp_clock * ptp)438 static inline void ptp_cancel_worker_sync(struct ptp_clock *ptp)
439 { }
440 #endif
441
442 #if IS_BUILTIN(CONFIG_PTP_1588_CLOCK)
443 /*
444 * These are called by the network core, and don't work if PTP is in
445 * a loadable module.
446 */
447
448 /**
449 * ptp_get_vclocks_index() - get all vclocks index on pclock, and
450 * caller is responsible to free memory
451 * of vclock_index
452 *
453 * @pclock_index: phc index of ptp pclock.
454 * @vclock_index: pointer to pointer of vclock index.
455 *
456 * return number of vclocks.
457 */
458 int ptp_get_vclocks_index(int pclock_index, int **vclock_index);
459
460 /**
461 * ptp_convert_timestamp() - convert timestamp to a ptp vclock time
462 *
463 * @hwtstamp: timestamp
464 * @vclock_index: phc index of ptp vclock.
465 *
466 * Returns: converted timestamp, or 0 on error.
467 */
468 ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, int vclock_index);
469 #else
ptp_get_vclocks_index(int pclock_index,int ** vclock_index)470 static inline int ptp_get_vclocks_index(int pclock_index, int **vclock_index)
471 { return 0; }
ptp_convert_timestamp(const ktime_t * hwtstamp,int vclock_index)472 static inline ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp,
473 int vclock_index)
474 { return 0; }
475
476 #endif
477
ptp_read_system_prets(struct ptp_system_timestamp * sts)478 static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts)
479 {
480 if (sts)
481 ktime_get_clock_ts64(sts->clockid, &sts->pre_ts);
482 }
483
ptp_read_system_postts(struct ptp_system_timestamp * sts)484 static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts)
485 {
486 if (sts)
487 ktime_get_clock_ts64(sts->clockid, &sts->post_ts);
488 }
489
490 #endif
491