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
41/**
42 * struct ptp_clock_info - decribes a PTP hardware clock
43 *
44 * @owner:     The clock driver should set to THIS_MODULE.
45 * @name:      A short "friendly name" to identify the clock and to
46 *             help distinguish PHY based devices from MAC based ones.
47 *             The string is not meant to be a unique id.
48 * @max_adj:   The maximum possible frequency adjustment, in parts per billon.
49 * @n_alarm:   The number of programmable alarms.
50 * @n_ext_ts:  The number of external time stamp channels.
51 * @n_per_out: The number of programmable periodic signals.
52 * @n_pins:    The number of programmable pins.
53 * @pps:       Indicates whether the clock supports a PPS callback.
54 * @pin_config: Array of length 'n_pins'. If the number of
55 *              programmable pins is nonzero, then drivers must
56 *              allocate and initialize this array.
57 *
58 * clock operations
59 *
60 * @adjfreq:  Adjusts the frequency of the hardware clock.
61 *            parameter delta: Desired frequency offset from nominal frequency
62 *            in parts per billion
63 *
64 * @adjtime:  Shifts the time of the hardware clock.
65 *            parameter delta: Desired change in nanoseconds.
66 *
67 * @gettime:  Reads the current time from the hardware clock.
68 *            parameter ts: Holds the result.
69 *
70 * @settime:  Set the current time on the hardware clock.
71 *            parameter ts: Time value to set.
72 *
73 * @enable:   Request driver to enable or disable an ancillary feature.
74 *            parameter request: Desired resource to enable or disable.
75 *            parameter on: Caller passes one to enable or zero to disable.
76 *
77 * @verify:   Confirm that a pin can perform a given function. The PTP
78 *            Hardware Clock subsystem maintains the 'pin_config'
79 *            array on behalf of the drivers, but the PHC subsystem
80 *            assumes that every pin can perform every function. This
81 *            hook gives drivers a way of telling the core about
82 *            limitations on specific pins. This function must return
83 *            zero if the function can be assigned to this pin, and
84 *            nonzero otherwise.
85 *            parameter pin: index of the pin in question.
86 *            parameter func: the desired function to use.
87 *            parameter chan: the function channel index to use.
88 *
89 * Drivers should embed their ptp_clock_info within a private
90 * structure, obtaining a reference to it using container_of().
91 *
92 * The callbacks must all return zero on success, non-zero otherwise.
93 */
94
95struct ptp_clock_info {
96	struct module *owner;
97	char name[16];
98	s32 max_adj;
99	int n_alarm;
100	int n_ext_ts;
101	int n_per_out;
102	int n_pins;
103	int pps;
104	struct ptp_pin_desc *pin_config;
105	int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
106	int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
107	int (*gettime)(struct ptp_clock_info *ptp, struct timespec *ts);
108	int (*settime)(struct ptp_clock_info *ptp, const struct timespec *ts);
109	int (*enable)(struct ptp_clock_info *ptp,
110		      struct ptp_clock_request *request, int on);
111	int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
112		      enum ptp_pin_function func, unsigned int chan);
113};
114
115struct ptp_clock;
116
117/**
118 * ptp_clock_register() - register a PTP hardware clock driver
119 *
120 * @info:   Structure describing the new clock.
121 * @parent: Pointer to the parent device of the new clock.
122 */
123
124extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
125					    struct device *parent);
126
127/**
128 * ptp_clock_unregister() - unregister a PTP hardware clock driver
129 *
130 * @ptp:  The clock to remove from service.
131 */
132
133extern int ptp_clock_unregister(struct ptp_clock *ptp);
134
135
136enum ptp_clock_events {
137	PTP_CLOCK_ALARM,
138	PTP_CLOCK_EXTTS,
139	PTP_CLOCK_PPS,
140	PTP_CLOCK_PPSUSR,
141};
142
143/**
144 * struct ptp_clock_event - decribes a PTP hardware clock event
145 *
146 * @type:  One of the ptp_clock_events enumeration values.
147 * @index: Identifies the source of the event.
148 * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
149 * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
150 */
151
152struct ptp_clock_event {
153	int type;
154	int index;
155	union {
156		u64 timestamp;
157		struct pps_event_time pps_times;
158	};
159};
160
161/**
162 * ptp_clock_event() - notify the PTP layer about an event
163 *
164 * @ptp:    The clock obtained from ptp_clock_register().
165 * @event:  Message structure describing the event.
166 */
167
168extern void ptp_clock_event(struct ptp_clock *ptp,
169			    struct ptp_clock_event *event);
170
171/**
172 * ptp_clock_index() - obtain the device index of a PTP clock
173 *
174 * @ptp:    The clock obtained from ptp_clock_register().
175 */
176
177extern int ptp_clock_index(struct ptp_clock *ptp);
178
179/**
180 * ptp_find_pin() - obtain the pin index of a given auxiliary function
181 *
182 * @ptp:    The clock obtained from ptp_clock_register().
183 * @func:   One of the ptp_pin_function enumerated values.
184 * @chan:   The particular functional channel to find.
185 * Return:  Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
186 *          or -1 if the auxiliary function cannot be found.
187 */
188
189int ptp_find_pin(struct ptp_clock *ptp,
190		 enum ptp_pin_function func, unsigned int chan);
191
192#endif
193