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
15
16 struct ptp_clock_request {
17 enum {
18 PTP_CLK_REQ_EXTTS,
19 PTP_CLK_REQ_PEROUT,
20 PTP_CLK_REQ_PPS,
21 } type;
22 union {
23 struct ptp_extts_request extts;
24 struct ptp_perout_request perout;
25 };
26 };
27
28 struct system_device_crosststamp;
29
30 /**
31 * struct ptp_system_timestamp - system time corresponding to a PHC timestamp
32 */
33 struct ptp_system_timestamp {
34 struct timespec64 pre_ts;
35 struct timespec64 post_ts;
36 };
37
38 /**
39 * struct ptp_clock_info - describes a PTP hardware clock
40 *
41 * @owner: The clock driver should set to THIS_MODULE.
42 * @name: A short "friendly name" to identify the clock and to
43 * help distinguish PHY based devices from MAC based ones.
44 * The string is not meant to be a unique id.
45 * @max_adj: The maximum possible frequency adjustment, in parts per billon.
46 * @n_alarm: The number of programmable alarms.
47 * @n_ext_ts: The number of external time stamp channels.
48 * @n_per_out: The number of programmable periodic signals.
49 * @n_pins: The number of programmable pins.
50 * @pps: Indicates whether the clock supports a PPS callback.
51 * @pin_config: Array of length 'n_pins'. If the number of
52 * programmable pins is nonzero, then drivers must
53 * allocate and initialize this array.
54 *
55 * clock operations
56 *
57 * @adjfine: Adjusts the frequency of the hardware clock.
58 * parameter scaled_ppm: Desired frequency offset from
59 * nominal frequency in parts per million, but with a
60 * 16 bit binary fractional field.
61 *
62 * @adjfreq: Adjusts the frequency of the hardware clock.
63 * This method is deprecated. New drivers should implement
64 * the @adjfine method instead.
65 * parameter delta: Desired frequency offset from nominal frequency
66 * in parts per billion
67 *
68 * @adjphase: Adjusts the phase offset of the hardware clock.
69 * parameter delta: Desired change in nanoseconds.
70 *
71 * @adjtime: Shifts the time of the hardware clock.
72 * parameter delta: Desired change in nanoseconds.
73 *
74 * @gettime64: Reads the current time from the hardware clock.
75 * This method is deprecated. New drivers should implement
76 * the @gettimex64 method instead.
77 * parameter ts: Holds the result.
78 *
79 * @gettimex64: Reads the current time from the hardware clock and optionally
80 * also the system clock.
81 * parameter ts: Holds the PHC timestamp.
82 * parameter sts: If not NULL, it holds a pair of timestamps from
83 * the system clock. The first reading is made right before
84 * reading the lowest bits of the PHC timestamp and the second
85 * reading immediately follows that.
86 *
87 * @getcrosststamp: Reads the current time from the hardware clock and
88 * system clock simultaneously.
89 * parameter cts: Contains timestamp (device,system) pair,
90 * where system time is realtime and monotonic.
91 *
92 * @settime64: Set the current time on the hardware clock.
93 * parameter ts: Time value to set.
94 *
95 * @enable: Request driver to enable or disable an ancillary feature.
96 * parameter request: Desired resource to enable or disable.
97 * parameter on: Caller passes one to enable or zero to disable.
98 *
99 * @verify: Confirm that a pin can perform a given function. The PTP
100 * Hardware Clock subsystem maintains the 'pin_config'
101 * array on behalf of the drivers, but the PHC subsystem
102 * assumes that every pin can perform every function. This
103 * hook gives drivers a way of telling the core about
104 * limitations on specific pins. This function must return
105 * zero if the function can be assigned to this pin, and
106 * nonzero otherwise.
107 * parameter pin: index of the pin in question.
108 * parameter func: the desired function to use.
109 * parameter chan: the function channel index to use.
110 *
111 * @do_aux_work: Request driver to perform auxiliary (periodic) operations
112 * Driver should return delay of the next auxiliary work
113 * scheduling time (>=0) or negative value in case further
114 * scheduling is not required.
115 *
116 * Drivers should embed their ptp_clock_info within a private
117 * structure, obtaining a reference to it using container_of().
118 *
119 * The callbacks must all return zero on success, non-zero otherwise.
120 */
121
122 struct ptp_clock_info {
123 struct module *owner;
124 char name[16];
125 s32 max_adj;
126 int n_alarm;
127 int n_ext_ts;
128 int n_per_out;
129 int n_pins;
130 int pps;
131 struct ptp_pin_desc *pin_config;
132 int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm);
133 int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
134 int (*adjphase)(struct ptp_clock_info *ptp, s32 phase);
135 int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
136 int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
137 int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
138 struct ptp_system_timestamp *sts);
139 int (*getcrosststamp)(struct ptp_clock_info *ptp,
140 struct system_device_crosststamp *cts);
141 int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts);
142 int (*enable)(struct ptp_clock_info *ptp,
143 struct ptp_clock_request *request, int on);
144 int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
145 enum ptp_pin_function func, unsigned int chan);
146 long (*do_aux_work)(struct ptp_clock_info *ptp);
147 };
148
149 struct ptp_clock;
150
151 enum ptp_clock_events {
152 PTP_CLOCK_ALARM,
153 PTP_CLOCK_EXTTS,
154 PTP_CLOCK_PPS,
155 PTP_CLOCK_PPSUSR,
156 };
157
158 /**
159 * struct ptp_clock_event - decribes a PTP hardware clock event
160 *
161 * @type: One of the ptp_clock_events enumeration values.
162 * @index: Identifies the source of the event.
163 * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
164 * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
165 */
166
167 struct ptp_clock_event {
168 int type;
169 int index;
170 union {
171 u64 timestamp;
172 struct pps_event_time pps_times;
173 };
174 };
175
176 #if IS_REACHABLE(CONFIG_PTP_1588_CLOCK)
177
178 /**
179 * ptp_clock_register() - register a PTP hardware clock driver
180 *
181 * @info: Structure describing the new clock.
182 * @parent: Pointer to the parent device of the new clock.
183 *
184 * Returns a valid pointer on success or PTR_ERR on failure. If PHC
185 * support is missing at the configuration level, this function
186 * returns NULL, and drivers are expected to gracefully handle that
187 * case separately.
188 */
189
190 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
191 struct device *parent);
192
193 /**
194 * ptp_clock_unregister() - unregister a PTP hardware clock driver
195 *
196 * @ptp: The clock to remove from service.
197 */
198
199 extern int ptp_clock_unregister(struct ptp_clock *ptp);
200
201 /**
202 * ptp_clock_event() - notify the PTP layer about an event
203 *
204 * @ptp: The clock obtained from ptp_clock_register().
205 * @event: Message structure describing the event.
206 */
207
208 extern void ptp_clock_event(struct ptp_clock *ptp,
209 struct ptp_clock_event *event);
210
211 /**
212 * ptp_clock_index() - obtain the device index of a PTP clock
213 *
214 * @ptp: The clock obtained from ptp_clock_register().
215 */
216
217 extern int ptp_clock_index(struct ptp_clock *ptp);
218
219 /**
220 * scaled_ppm_to_ppb() - convert scaled ppm to ppb
221 *
222 * @ppm: Parts per million, but with a 16 bit binary fractional field
223 */
224
225 extern long scaled_ppm_to_ppb(long ppm);
226
227 /**
228 * ptp_find_pin() - obtain the pin index of a given auxiliary function
229 *
230 * The caller must hold ptp_clock::pincfg_mux. Drivers do not have
231 * access to that mutex as ptp_clock is an opaque type. However, the
232 * core code acquires the mutex before invoking the driver's
233 * ptp_clock_info::enable() callback, and so drivers may call this
234 * function from that context.
235 *
236 * @ptp: The clock obtained from ptp_clock_register().
237 * @func: One of the ptp_pin_function enumerated values.
238 * @chan: The particular functional channel to find.
239 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
240 * or -1 if the auxiliary function cannot be found.
241 */
242
243 int ptp_find_pin(struct ptp_clock *ptp,
244 enum ptp_pin_function func, unsigned int chan);
245
246 /**
247 * ptp_find_pin_unlocked() - wrapper for ptp_find_pin()
248 *
249 * This function acquires the ptp_clock::pincfg_mux mutex before
250 * invoking ptp_find_pin(). Instead of using this function, drivers
251 * should most likely call ptp_find_pin() directly from their
252 * ptp_clock_info::enable() method.
253 *
254 */
255
256 int ptp_find_pin_unlocked(struct ptp_clock *ptp,
257 enum ptp_pin_function func, unsigned int chan);
258
259 /**
260 * ptp_schedule_worker() - schedule ptp auxiliary work
261 *
262 * @ptp: The clock obtained from ptp_clock_register().
263 * @delay: number of jiffies to wait before queuing
264 * See kthread_queue_delayed_work() for more info.
265 */
266
267 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay);
268
269 /**
270 * ptp_cancel_worker_sync() - cancel ptp auxiliary clock
271 *
272 * @ptp: The clock obtained from ptp_clock_register().
273 */
274 void ptp_cancel_worker_sync(struct ptp_clock *ptp);
275
276 #else
ptp_clock_register(struct ptp_clock_info * info,struct device * parent)277 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
278 struct device *parent)
279 { return NULL; }
ptp_clock_unregister(struct ptp_clock * ptp)280 static inline int ptp_clock_unregister(struct ptp_clock *ptp)
281 { return 0; }
ptp_clock_event(struct ptp_clock * ptp,struct ptp_clock_event * event)282 static inline void ptp_clock_event(struct ptp_clock *ptp,
283 struct ptp_clock_event *event)
284 { }
ptp_clock_index(struct ptp_clock * ptp)285 static inline int ptp_clock_index(struct ptp_clock *ptp)
286 { return -1; }
ptp_find_pin(struct ptp_clock * ptp,enum ptp_pin_function func,unsigned int chan)287 static inline int ptp_find_pin(struct ptp_clock *ptp,
288 enum ptp_pin_function func, unsigned int chan)
289 { return -1; }
ptp_schedule_worker(struct ptp_clock * ptp,unsigned long delay)290 static inline int ptp_schedule_worker(struct ptp_clock *ptp,
291 unsigned long delay)
292 { return -EOPNOTSUPP; }
ptp_cancel_worker_sync(struct ptp_clock * ptp)293 static inline void ptp_cancel_worker_sync(struct ptp_clock *ptp)
294 { }
295
296 #endif
297
ptp_read_system_prets(struct ptp_system_timestamp * sts)298 static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts)
299 {
300 if (sts)
301 ktime_get_real_ts64(&sts->pre_ts);
302 }
303
ptp_read_system_postts(struct ptp_system_timestamp * sts)304 static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts)
305 {
306 if (sts)
307 ktime_get_real_ts64(&sts->post_ts);
308 }
309
310 #endif
311