summaryrefslogtreecommitdiff
path: root/include/linux/ptp_clock_kernel.h
blob: 92b44161408efc06549e6925464c2f5694503a0b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * PTP 1588 clock support
 *
 * Copyright (C) 2010 OMICRON electronics GmbH
 */

#ifndef _PTP_CLOCK_KERNEL_H_
#define _PTP_CLOCK_KERNEL_H_

#include <linux/device.h>
#include <linux/pps_kernel.h>
#include <linux/ptp_clock.h>
#include <linux/timecounter.h>
#include <linux/skbuff.h>

#define PTP_CLOCK_NAME_LEN	32
/**
 * struct ptp_clock_request - request PTP clock event
 *
 * @type:   The type of the request.
 *	    EXTTS:  Configure external trigger timestamping
 *	    PEROUT: Configure periodic output signal (e.g. PPS)
 *	    PPS:    trigger internal PPS event for input
 *	            into kernel PPS subsystem
 * @extts:  describes configuration for external trigger timestamping.
 *          This is only valid when event == PTP_CLK_REQ_EXTTS.
 * @perout: describes configuration for periodic output.
 *	    This is only valid when event == PTP_CLK_REQ_PEROUT.
 */

struct ptp_clock_request {
	enum {
		PTP_CLK_REQ_EXTTS,
		PTP_CLK_REQ_PEROUT,
		PTP_CLK_REQ_PPS,
	} type;
	union {
		struct ptp_extts_request extts;
		struct ptp_perout_request perout;
	};
};

struct system_device_crosststamp;

/**
 * struct ptp_system_timestamp - system time corresponding to a PHC timestamp
 */
struct ptp_system_timestamp {
	struct timespec64 pre_ts;
	struct timespec64 post_ts;
};

/**
 * struct ptp_clock_info - describes a PTP hardware clock
 *
 * @owner:     The clock driver should set to THIS_MODULE.
 * @name:      A short "friendly name" to identify the clock and to
 *             help distinguish PHY based devices from MAC based ones.
 *             The string is not meant to be a unique id.
 * @max_adj:   The maximum possible frequency adjustment, in parts per billon.
 * @n_alarm:   The number of programmable alarms.
 * @n_ext_ts:  The number of external time stamp channels.
 * @n_per_out: The number of programmable periodic signals.
 * @n_pins:    The number of programmable pins.
 * @pps:       Indicates whether the clock supports a PPS callback.
 * @pin_config: Array of length 'n_pins'. If the number of
 *              programmable pins is nonzero, then drivers must
 *              allocate and initialize this array.
 *
 * clock operations
 *
 * @adjfine:  Adjusts the frequency of the hardware clock.
 *            parameter scaled_ppm: Desired frequency offset from
 *            nominal frequency in parts per million, but with a
 *            16 bit binary fractional field.
 *
 * @adjfreq:  Adjusts the frequency of the hardware clock.
 *            This method is deprecated.  New drivers should implement
 *            the @adjfine method instead.
 *            parameter delta: Desired frequency offset from nominal frequency
 *            in parts per billion
 *
 * @adjphase:  Adjusts the phase offset of the hardware clock.
 *             parameter delta: Desired change in nanoseconds.
 *
 * @adjtime:  Shifts the time of the hardware clock.
 *            parameter delta: Desired change in nanoseconds.
 *
 * @gettime64:  Reads the current time from the hardware clock.
 *              This method is deprecated.  New drivers should implement
 *              the @gettimex64 method instead.
 *              parameter ts: Holds the result.
 *
 * @gettimex64:  Reads the current time from the hardware clock and optionally
 *               also the system clock.
 *               parameter ts: Holds the PHC timestamp.
 *               parameter sts: If not NULL, it holds a pair of timestamps from
 *               the system clock. The first reading is made right before
 *               reading the lowest bits of the PHC timestamp and the second
 *               reading immediately follows that.
 *
 * @getcrosststamp:  Reads the current time from the hardware clock and
 *                   system clock simultaneously.
 *                   parameter cts: Contains timestamp (device,system) pair,
 *                   where system time is realtime and monotonic.
 *
 * @settime64:  Set the current time on the hardware clock.
 *              parameter ts: Time value to set.
 *
 * @getcycles64:  Reads the current free running cycle counter from the hardware
 *                clock.
 *                If @getcycles64 and @getcyclesx64 are not supported, then
 *                @gettime64 or @gettimex64 will be used as default
 *                implementation.
 *                parameter ts: Holds the result.
 *
 * @getcyclesx64:  Reads the current free running cycle counter from the
 *                 hardware clock and optionally also the system clock.
 *                 If @getcycles64 and @getcyclesx64 are not supported, then
 *                 @gettimex64 will be used as default implementation if
 *                 available.
 *                 parameter ts: Holds the PHC timestamp.
 *                 parameter sts: If not NULL, it holds a pair of timestamps
 *                 from the system clock. The first reading is made right before
 *                 reading the lowest bits of the PHC timestamp and the second
 *                 reading immediately follows that.
 *
 * @getcrosscycles:  Reads the current free running cycle counter from the
 *                   hardware clock and system clock simultaneously.
 *                   If @getcycles64 and @getcyclesx64 are not supported, then
 *                   @getcrosststamp will be used as default implementation if
 *                   available.
 *                   parameter cts: Contains timestamp (device,system) pair,
 *                   where system time is realtime and monotonic.
 *
 * @enable:   Request driver to enable or disable an ancillary feature.
 *            parameter request: Desired resource to enable or disable.
 *            parameter on: Caller passes one to enable or zero to disable.
 *
 * @verify:   Confirm that a pin can perform a given function. The PTP
 *            Hardware Clock subsystem maintains the 'pin_config'
 *            array on behalf of the drivers, but the PHC subsystem
 *            assumes that every pin can perform every function. This
 *            hook gives drivers a way of telling the core about
 *            limitations on specific pins. This function must return
 *            zero if the function can be assigned to this pin, and
 *            nonzero otherwise.
 *            parameter pin: index of the pin in question.
 *            parameter func: the desired function to use.
 *            parameter chan: the function channel index to use.
 *
 * @do_aux_work:  Request driver to perform auxiliary (periodic) operations
 *                Driver should return delay of the next auxiliary work
 *                scheduling time (>=0) or negative value in case further
 *                scheduling is not required.
 *
 * Drivers should embed their ptp_clock_info within a private
 * structure, obtaining a reference to it using container_of().
 *
 * The callbacks must all return zero on success, non-zero otherwise.
 */

struct ptp_clock_info {
	struct module *owner;
	char name[PTP_CLOCK_NAME_LEN];
	s32 max_adj;
	int n_alarm;
	int n_ext_ts;
	int n_per_out;
	int n_pins;
	int pps;
	struct ptp_pin_desc *pin_config;
	int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm);
	int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
	int (*adjphase)(struct ptp_clock_info *ptp, s32 phase);
	int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
	int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
	int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
			  struct ptp_system_timestamp *sts);
	int (*getcrosststamp)(struct ptp_clock_info *ptp,
			      struct system_device_crosststamp *cts);
	int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts);
	int (*getcycles64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
	int (*getcyclesx64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
			    struct ptp_system_timestamp *sts);
	int (*getcrosscycles)(struct ptp_clock_info *ptp,
			      struct system_device_crosststamp *cts);
	int (*enable)(struct ptp_clock_info *ptp,
		      struct ptp_clock_request *request, int on);
	int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
		      enum ptp_pin_function func, unsigned int chan);
	long (*do_aux_work)(struct ptp_clock_info *ptp);
};

struct ptp_clock;

enum ptp_clock_events {
	PTP_CLOCK_ALARM,
	PTP_CLOCK_EXTTS,
	PTP_CLOCK_PPS,
	PTP_CLOCK_PPSUSR,
};

/**
 * struct ptp_clock_event - decribes a PTP hardware clock event
 *
 * @type:  One of the ptp_clock_events enumeration values.
 * @index: Identifies the source of the event.
 * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
 * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
 */

struct ptp_clock_event {
	int type;
	int index;
	union {
		u64 timestamp;
		struct pps_event_time pps_times;
	};
};

/**
 * scaled_ppm_to_ppb() - convert scaled ppm to ppb
 *
 * @ppm:    Parts per million, but with a 16 bit binary fractional field
 */
static inline long scaled_ppm_to_ppb(long ppm)
{
	/*
	 * The 'freq' field in the 'struct timex' is in parts per
	 * million, but with a 16 bit binary fractional field.
	 *
	 * We want to calculate
	 *
	 *    ppb = scaled_ppm * 1000 / 2^16
	 *
	 * which simplifies to
	 *
	 *    ppb = scaled_ppm * 125 / 2^13
	 */
	s64 ppb = 1 + ppm;

	ppb *= 125;
	ppb >>= 13;
	return (long)ppb;
}

#if IS_ENABLED(CONFIG_PTP_1588_CLOCK)

/**
 * ptp_clock_register() - register a PTP hardware clock driver
 *
 * @info:   Structure describing the new clock.
 * @parent: Pointer to the parent device of the new clock.
 *
 * Returns a valid pointer on success or PTR_ERR on failure.  If PHC
 * support is missing at the configuration level, this function
 * returns NULL, and drivers are expected to gracefully handle that
 * case separately.
 */

extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
					    struct device *parent);

/**
 * ptp_clock_unregister() - unregister a PTP hardware clock driver
 *
 * @ptp:  The clock to remove from service.
 */

extern int ptp_clock_unregister(struct ptp_clock *ptp);

/**
 * ptp_clock_event() - notify the PTP layer about an event
 *
 * @ptp:    The clock obtained from ptp_clock_register().
 * @event:  Message structure describing the event.
 */

extern void ptp_clock_event(struct ptp_clock *ptp,
			    struct ptp_clock_event *event);

/**
 * ptp_clock_index() - obtain the device index of a PTP clock
 *
 * @ptp:    The clock obtained from ptp_clock_register().
 */

extern int ptp_clock_index(struct ptp_clock *ptp);

/**
 * ptp_find_pin() - obtain the pin index of a given auxiliary function
 *
 * The caller must hold ptp_clock::pincfg_mux.  Drivers do not have
 * access to that mutex as ptp_clock is an opaque type.  However, the
 * core code acquires the mutex before invoking the driver's
 * ptp_clock_info::enable() callback, and so drivers may call this
 * function from that context.
 *
 * @ptp:    The clock obtained from ptp_clock_register().
 * @func:   One of the ptp_pin_function enumerated values.
 * @chan:   The particular functional channel to find.
 * Return:  Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
 *          or -1 if the auxiliary function cannot be found.
 */

int ptp_find_pin(struct ptp_clock *ptp,
		 enum ptp_pin_function func, unsigned int chan);

/**
 * ptp_find_pin_unlocked() - wrapper for ptp_find_pin()
 *
 * This function acquires the ptp_clock::pincfg_mux mutex before
 * invoking ptp_find_pin().  Instead of using this function, drivers
 * should most likely call ptp_find_pin() directly from their
 * ptp_clock_info::enable() method.
 *
 */

int ptp_find_pin_unlocked(struct ptp_clock *ptp,
			  enum ptp_pin_function func, unsigned int chan);

/**
 * ptp_schedule_worker() - schedule ptp auxiliary work
 *
 * @ptp:    The clock obtained from ptp_clock_register().
 * @delay:  number of jiffies to wait before queuing
 *          See kthread_queue_delayed_work() for more info.
 */

int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay);

/**
 * ptp_cancel_worker_sync() - cancel ptp auxiliary clock
 *
 * @ptp:     The clock obtained from ptp_clock_register().
 */
void ptp_cancel_worker_sync(struct ptp_clock *ptp);

#else
static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
						   struct device *parent)
{ return NULL; }
static inline int ptp_clock_unregister(struct ptp_clock *ptp)
{ return 0; }
static inline void ptp_clock_event(struct ptp_clock *ptp,
				   struct ptp_clock_event *event)
{ }
static inline int ptp_clock_index(struct ptp_clock *ptp)
{ return -1; }
static inline int ptp_find_pin(struct ptp_clock *ptp,
			       enum ptp_pin_function func, unsigned int chan)
{ return -1; }
static inline int ptp_find_pin_unlocked(struct ptp_clock *ptp,
					enum ptp_pin_function func,
					unsigned int chan)
{ return -1; }
static inline int ptp_schedule_worker(struct ptp_clock *ptp,
				      unsigned long delay)
{ return -EOPNOTSUPP; }
static inline void ptp_cancel_worker_sync(struct ptp_clock *ptp)
{ }
#endif

#if IS_BUILTIN(CONFIG_PTP_1588_CLOCK)
/*
 * These are called by the network core, and don't work if PTP is in
 * a loadable module.
 */

/**
 * ptp_get_vclocks_index() - get all vclocks index on pclock, and
 *                           caller is responsible to free memory
 *                           of vclock_index
 *
 * @pclock_index: phc index of ptp pclock.
 * @vclock_index: pointer to pointer of vclock index.
 *
 * return number of vclocks.
 */
int ptp_get_vclocks_index(int pclock_index, int **vclock_index);

/**
 * ptp_convert_timestamp() - convert timestamp to a ptp vclock time
 *
 * @hwtstamp:     timestamp
 * @vclock_index: phc index of ptp vclock.
 *
 * Returns converted timestamp, or 0 on error.
 */
ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, int vclock_index);
#else
static inline int ptp_get_vclocks_index(int pclock_index, int **vclock_index)
{ return 0; }
static inline ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp,
					    int vclock_index)
{ return 0; }

#endif

static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts)
{
	if (sts)
		ktime_get_real_ts64(&sts->pre_ts);
}

static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts)
{
	if (sts)
		ktime_get_real_ts64(&sts->post_ts);
}

#endif