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