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