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 - decribes 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 * @adjtime: Shifts the time of the hardware clock.
69 * parameter delta: Desired change in nanoseconds.
70 *
71 * @gettime64: Reads the current time from the hardware clock.
72 * This method is deprecated. New drivers should implement
73 * the @gettimex64 method instead.
74 * parameter ts: Holds the result.
75 *
76 * @gettimex64: Reads the current time from the hardware clock and optionally
77 * also the system clock.
78 * parameter ts: Holds the PHC timestamp.
79 * parameter sts: If not NULL, it holds a pair of timestamps from
80 * the system clock. The first reading is made right before
81 * reading the lowest bits of the PHC timestamp and the second
82 * reading immediately follows that.
83 *
84 * @getcrosststamp: Reads the current time from the hardware clock and
85 * system clock simultaneously.
86 * parameter cts: Contains timestamp (device,system) pair,
87 * where system time is realtime and monotonic.
88 *
89 * @settime64: Set the current time on the hardware clock.
90 * parameter ts: Time value to set.
91 *
92 * @enable: Request driver to enable or disable an ancillary feature.
93 * parameter request: Desired resource to enable or disable.
94 * parameter on: Caller passes one to enable or zero to disable.
95 *
96 * @verify: Confirm that a pin can perform a given function. The PTP
97 * Hardware Clock subsystem maintains the 'pin_config'
98 * array on behalf of the drivers, but the PHC subsystem
99 * assumes that every pin can perform every function. This
100 * hook gives drivers a way of telling the core about
101 * limitations on specific pins. This function must return
102 * zero if the function can be assigned to this pin, and
103 * nonzero otherwise.
104 * parameter pin: index of the pin in question.
105 * parameter func: the desired function to use.
106 * parameter chan: the function channel index to use.
107 *
108 * @do_work: Request driver to perform auxiliary (periodic) operations
109 * Driver should return delay of the next auxiliary work scheduling
110 * time (>=0) or negative value in case further scheduling
111 * is not required.
112 *
113 * Drivers should embed their ptp_clock_info within a private
114 * structure, obtaining a reference to it using container_of().
115 *
116 * The callbacks must all return zero on success, non-zero otherwise.
117 */
118
119 struct ptp_clock_info {
120 struct module *owner;
121 char name[16];
122 s32 max_adj;
123 int n_alarm;
124 int n_ext_ts;
125 int n_per_out;
126 int n_pins;
127 int pps;
128 struct ptp_pin_desc *pin_config;
129 int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm);
130 int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
131 int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
132 int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
133 int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
134 struct ptp_system_timestamp *sts);
135 int (*getcrosststamp)(struct ptp_clock_info *ptp,
136 struct system_device_crosststamp *cts);
137 int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts);
138 int (*enable)(struct ptp_clock_info *ptp,
139 struct ptp_clock_request *request, int on);
140 int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
141 enum ptp_pin_function func, unsigned int chan);
142 long (*do_aux_work)(struct ptp_clock_info *ptp);
143 };
144
145 struct ptp_clock;
146
147 enum ptp_clock_events {
148 PTP_CLOCK_ALARM,
149 PTP_CLOCK_EXTTS,
150 PTP_CLOCK_PPS,
151 PTP_CLOCK_PPSUSR,
152 };
153
154 /**
155 * struct ptp_clock_event - decribes a PTP hardware clock event
156 *
157 * @type: One of the ptp_clock_events enumeration values.
158 * @index: Identifies the source of the event.
159 * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
160 * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
161 */
162
163 struct ptp_clock_event {
164 int type;
165 int index;
166 union {
167 u64 timestamp;
168 struct pps_event_time pps_times;
169 };
170 };
171
172 #if IS_REACHABLE(CONFIG_PTP_1588_CLOCK)
173
174 /**
175 * ptp_clock_register() - register a PTP hardware clock driver
176 *
177 * @info: Structure describing the new clock.
178 * @parent: Pointer to the parent device of the new clock.
179 *
180 * Returns a valid pointer on success or PTR_ERR on failure. If PHC
181 * support is missing at the configuration level, this function
182 * returns NULL, and drivers are expected to gracefully handle that
183 * case separately.
184 */
185
186 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
187 struct device *parent);
188
189 /**
190 * ptp_clock_unregister() - unregister a PTP hardware clock driver
191 *
192 * @ptp: The clock to remove from service.
193 */
194
195 extern int ptp_clock_unregister(struct ptp_clock *ptp);
196
197 /**
198 * ptp_clock_event() - notify the PTP layer about an event
199 *
200 * @ptp: The clock obtained from ptp_clock_register().
201 * @event: Message structure describing the event.
202 */
203
204 extern void ptp_clock_event(struct ptp_clock *ptp,
205 struct ptp_clock_event *event);
206
207 /**
208 * ptp_clock_index() - obtain the device index of a PTP clock
209 *
210 * @ptp: The clock obtained from ptp_clock_register().
211 */
212
213 extern int ptp_clock_index(struct ptp_clock *ptp);
214
215 /**
216 * scaled_ppm_to_ppb() - convert scaled ppm to ppb
217 *
218 * @ppm: Parts per million, but with a 16 bit binary fractional field
219 */
220
221 extern s32 scaled_ppm_to_ppb(long ppm);
222
223 /**
224 * ptp_find_pin() - obtain the pin index of a given auxiliary function
225 *
226 * @ptp: The clock obtained from ptp_clock_register().
227 * @func: One of the ptp_pin_function enumerated values.
228 * @chan: The particular functional channel to find.
229 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
230 * or -1 if the auxiliary function cannot be found.
231 */
232
233 int ptp_find_pin(struct ptp_clock *ptp,
234 enum ptp_pin_function func, unsigned int chan);
235
236 /**
237 * ptp_schedule_worker() - schedule ptp auxiliary work
238 *
239 * @ptp: The clock obtained from ptp_clock_register().
240 * @delay: number of jiffies to wait before queuing
241 * See kthread_queue_delayed_work() for more info.
242 */
243
244 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay);
245
246 #else
247 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
248 struct device *parent)
249 { return NULL; }
250 static inline int ptp_clock_unregister(struct ptp_clock *ptp)
251 { return 0; }
252 static inline void ptp_clock_event(struct ptp_clock *ptp,
253 struct ptp_clock_event *event)
254 { }
255 static inline int ptp_clock_index(struct ptp_clock *ptp)
256 { return -1; }
257 static inline int ptp_find_pin(struct ptp_clock *ptp,
258 enum ptp_pin_function func, unsigned int chan)
259 { return -1; }
260 static inline int ptp_schedule_worker(struct ptp_clock *ptp,
261 unsigned long delay)
262 { return -EOPNOTSUPP; }
263
264 #endif
265
266 static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts)
267 {
268 if (sts)
269 ktime_get_real_ts64(&sts->pre_ts);
270 }
271
272 static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts)
273 {
274 if (sts)
275 ktime_get_real_ts64(&sts->post_ts);
276 }
277
278 #endif