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