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(a: base, mul: (u64)scaled_ppm, div: 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: &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(tv: &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(tv: &sts->post_ts); |
468 | } |
469 | |
470 | #endif |
471 | |