1/*
2 * PTP 1588 clock support
3 *
4 * Copyright (C) 2010 OMICRON electronics GmbH
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21#ifndef _PTP_CLOCK_KERNEL_H_
22#define _PTP_CLOCK_KERNEL_H_
23
24#include <linux/device.h>
25#include <linux/pps_kernel.h>
26#include <linux/ptp_clock.h>
27
28
29struct ptp_clock_request {
30 enum {
31 PTP_CLK_REQ_EXTTS,
32 PTP_CLK_REQ_PEROUT,
33 PTP_CLK_REQ_PPS,
34 } type;
35 union {
36 struct ptp_extts_request extts;
37 struct ptp_perout_request perout;
38 };
39};
40
41struct system_device_crosststamp;
42
43/**
44 * struct ptp_system_timestamp - system time corresponding to a PHC timestamp
45 */
46struct ptp_system_timestamp {
47 struct timespec64 pre_ts;
48 struct timespec64 post_ts;
49};
50
51/**
52 * struct ptp_clock_info - decribes a PTP hardware clock
53 *
54 * @owner: The clock driver should set to THIS_MODULE.
55 * @name: A short "friendly name" to identify the clock and to
56 * help distinguish PHY based devices from MAC based ones.
57 * The string is not meant to be a unique id.
58 * @max_adj: The maximum possible frequency adjustment, in parts per billon.
59 * @n_alarm: The number of programmable alarms.
60 * @n_ext_ts: The number of external time stamp channels.
61 * @n_per_out: The number of programmable periodic signals.
62 * @n_pins: The number of programmable pins.
63 * @pps: Indicates whether the clock supports a PPS callback.
64 * @pin_config: Array of length 'n_pins'. If the number of
65 * programmable pins is nonzero, then drivers must
66 * allocate and initialize this array.
67 *
68 * clock operations
69 *
70 * @adjfine: Adjusts the frequency of the hardware clock.
71 * parameter scaled_ppm: Desired frequency offset from
72 * nominal frequency in parts per million, but with a
73 * 16 bit binary fractional field.
74 *
75 * @adjfreq: Adjusts the frequency of the hardware clock.
76 * This method is deprecated. New drivers should implement
77 * the @adjfine method instead.
78 * parameter delta: Desired frequency offset from nominal frequency
79 * in parts per billion
80 *
81 * @adjtime: Shifts the time of the hardware clock.
82 * parameter delta: Desired change in nanoseconds.
83 *
84 * @gettime64: Reads the current time from the hardware clock.
85 * This method is deprecated. New drivers should implement
86 * the @gettimex64 method instead.
87 * parameter ts: Holds the result.
88 *
89 * @gettimex64: Reads the current time from the hardware clock and optionally
90 * also the system clock.
91 * parameter ts: Holds the PHC timestamp.
92 * parameter sts: If not NULL, it holds a pair of timestamps from
93 * the system clock. The first reading is made right before
94 * reading the lowest bits of the PHC timestamp and the second
95 * reading immediately follows that.
96 *
97 * @getcrosststamp: Reads the current time from the hardware clock and
98 * system clock simultaneously.
99 * parameter cts: Contains timestamp (device,system) pair,
100 * where system time is realtime and monotonic.
101 *
102 * @settime64: Set the current time on the hardware clock.
103 * parameter ts: Time value to set.
104 *
105 * @enable: Request driver to enable or disable an ancillary feature.
106 * parameter request: Desired resource to enable or disable.
107 * parameter on: Caller passes one to enable or zero to disable.
108 *
109 * @verify: Confirm that a pin can perform a given function. The PTP
110 * Hardware Clock subsystem maintains the 'pin_config'
111 * array on behalf of the drivers, but the PHC subsystem
112 * assumes that every pin can perform every function. This
113 * hook gives drivers a way of telling the core about
114 * limitations on specific pins. This function must return
115 * zero if the function can be assigned to this pin, and
116 * nonzero otherwise.
117 * parameter pin: index of the pin in question.
118 * parameter func: the desired function to use.
119 * parameter chan: the function channel index to use.
120 *
121 * @do_work: Request driver to perform auxiliary (periodic) operations
122 * Driver should return delay of the next auxiliary work scheduling
123 * time (>=0) or negative value in case further scheduling
124 * is not required.
125 *
126 * Drivers should embed their ptp_clock_info within a private
127 * structure, obtaining a reference to it using container_of().
128 *
129 * The callbacks must all return zero on success, non-zero otherwise.
130 */
131
132struct ptp_clock_info {
133 struct module *owner;
134 char name[16];
135 s32 max_adj;
136 int n_alarm;
137 int n_ext_ts;
138 int n_per_out;
139 int n_pins;
140 int pps;
141 struct ptp_pin_desc *pin_config;
142 int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm);
143 int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
144 int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
145 int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
146 int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
147 struct ptp_system_timestamp *sts);
148 int (*getcrosststamp)(struct ptp_clock_info *ptp,
149 struct system_device_crosststamp *cts);
150 int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts);
151 int (*enable)(struct ptp_clock_info *ptp,
152 struct ptp_clock_request *request, int on);
153 int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
154 enum ptp_pin_function func, unsigned int chan);
155 long (*do_aux_work)(struct ptp_clock_info *ptp);
156};
157
158struct ptp_clock;
159
160enum ptp_clock_events {
161 PTP_CLOCK_ALARM,
162 PTP_CLOCK_EXTTS,
163 PTP_CLOCK_PPS,
164 PTP_CLOCK_PPSUSR,
165};
166
167/**
168 * struct ptp_clock_event - decribes a PTP hardware clock event
169 *
170 * @type: One of the ptp_clock_events enumeration values.
171 * @index: Identifies the source of the event.
172 * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
173 * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
174 */
175
176struct ptp_clock_event {
177 int type;
178 int index;
179 union {
180 u64 timestamp;
181 struct pps_event_time pps_times;
182 };
183};
184
185#if IS_REACHABLE(CONFIG_PTP_1588_CLOCK)
186
187/**
188 * ptp_clock_register() - register a PTP hardware clock driver
189 *
190 * @info: Structure describing the new clock.
191 * @parent: Pointer to the parent device of the new clock.
192 *
193 * Returns a valid pointer on success or PTR_ERR on failure. If PHC
194 * support is missing at the configuration level, this function
195 * returns NULL, and drivers are expected to gracefully handle that
196 * case separately.
197 */
198
199extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
200 struct device *parent);
201
202/**
203 * ptp_clock_unregister() - unregister a PTP hardware clock driver
204 *
205 * @ptp: The clock to remove from service.
206 */
207
208extern int ptp_clock_unregister(struct ptp_clock *ptp);
209
210/**
211 * ptp_clock_event() - notify the PTP layer about an event
212 *
213 * @ptp: The clock obtained from ptp_clock_register().
214 * @event: Message structure describing the event.
215 */
216
217extern void ptp_clock_event(struct ptp_clock *ptp,
218 struct ptp_clock_event *event);
219
220/**
221 * ptp_clock_index() - obtain the device index of a PTP clock
222 *
223 * @ptp: The clock obtained from ptp_clock_register().
224 */
225
226extern int ptp_clock_index(struct ptp_clock *ptp);
227
228/**
229 * ptp_find_pin() - obtain the pin index of a given auxiliary function
230 *
231 * @ptp: The clock obtained from ptp_clock_register().
232 * @func: One of the ptp_pin_function enumerated values.
233 * @chan: The particular functional channel to find.
234 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
235 * or -1 if the auxiliary function cannot be found.
236 */
237
238int ptp_find_pin(struct ptp_clock *ptp,
239 enum ptp_pin_function func, unsigned int chan);
240
241/**
242 * ptp_schedule_worker() - schedule ptp auxiliary work
243 *
244 * @ptp: The clock obtained from ptp_clock_register().
245 * @delay: number of jiffies to wait before queuing
246 * See kthread_queue_delayed_work() for more info.
247 */
248
249int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay);
250
251#else
252static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
253 struct device *parent)
254{ return NULL; }
255static inline int ptp_clock_unregister(struct ptp_clock *ptp)
256{ return 0; }
257static inline void ptp_clock_event(struct ptp_clock *ptp,
258 struct ptp_clock_event *event)
259{ }
260static inline int ptp_clock_index(struct ptp_clock *ptp)
261{ return -1; }
262static inline int ptp_find_pin(struct ptp_clock *ptp,
263 enum ptp_pin_function func, unsigned int chan)
264{ return -1; }
265static inline int ptp_schedule_worker(struct ptp_clock *ptp,
266 unsigned long delay)
267{ return -EOPNOTSUPP; }
268
269#endif
270
271static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts)
272{
273 if (sts)
274 ktime_get_real_ts64(&sts->pre_ts);
275}
276
277static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts)
278{
279 if (sts)
280 ktime_get_real_ts64(&sts->post_ts);
281}
282
283#endif
284