/*
 * PTP 1588 clock support
 *
 * Copyright (C) 2010 OMICRON electronics GmbH
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifndef _PTP_CLOCK_KERNEL_H_
#define _PTP_CLOCK_KERNEL_H_

#include <linux/ptp_clock.h>


struct ptp_clock_request {
	enum {
		PTP_CLK_REQ_EXTTS,
		PTP_CLK_REQ_PEROUT,
		PTP_CLK_REQ_PPS,
	} type;
	union {
		struct ptp_extts_request extts;
		struct ptp_perout_request perout;
	};
};

/**
 * struct ptp_clock_info - decribes a PTP hardware clock
 *
 * @owner:     The clock driver should set to THIS_MODULE.
 * @name:      A short name to identify the clock.
 * @max_adj:   The maximum possible frequency adjustment, in parts per billon.
 * @n_alarm:   The number of programmable alarms.
 * @n_ext_ts:  The number of external time stamp channels.
 * @n_per_out: The number of programmable periodic signals.
 * @pps:       Indicates whether the clock supports a PPS callback.
 *
 * clock operations
 *
 * @adjfreq:  Adjusts the frequency of the hardware clock.
 *            parameter delta: Desired period change in parts per billion.
 *
 * @adjtime:  Shifts the time of the hardware clock.
 *            parameter delta: Desired change in nanoseconds.
 *
 * @gettime:  Reads the current time from the hardware clock.
 *            parameter ts: Holds the result.
 *
 * @settime:  Set the current time on the hardware clock.
 *            parameter ts: Time value to set.
 *
 * @enable:   Request driver to enable or disable an ancillary feature.
 *            parameter request: Desired resource to enable or disable.
 *            parameter on: Caller passes one to enable or zero to disable.
 *
 * Drivers should embed their ptp_clock_info within a private
 * structure, obtaining a reference to it using container_of().
 *
 * The callbacks must all return zero on success, non-zero otherwise.
 */

struct ptp_clock_info {
	struct module *owner;
	char name[16];
	s32 max_adj;
	int n_alarm;
	int n_ext_ts;
	int n_per_out;
	int pps;
	int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
	int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
	int (*gettime)(struct ptp_clock_info *ptp, struct timespec *ts);
	int (*settime)(struct ptp_clock_info *ptp, const struct timespec *ts);
	int (*enable)(struct ptp_clock_info *ptp,
		      struct ptp_clock_request *request, int on);
};

struct ptp_clock;

/**
 * ptp_clock_register() - register a PTP hardware clock driver
 *
 * @info:  Structure describing the new clock.
 */

extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info);

/**
 * ptp_clock_unregister() - unregister a PTP hardware clock driver
 *
 * @ptp:  The clock to remove from service.
 */

extern int ptp_clock_unregister(struct ptp_clock *ptp);


enum ptp_clock_events {
	PTP_CLOCK_ALARM,
	PTP_CLOCK_EXTTS,
	PTP_CLOCK_PPS,
};

/**
 * struct ptp_clock_event - decribes a PTP hardware clock event
 *
 * @type:  One of the ptp_clock_events enumeration values.
 * @index: Identifies the source of the event.
 * @timestamp: When the event occured.
 */

struct ptp_clock_event {
	int type;
	int index;
	u64 timestamp;
};

/**
 * ptp_clock_event() - notify the PTP layer about an event
 *
 * @ptp:    The clock obtained from ptp_clock_register().
 * @event:  Message structure describing the event.
 */

extern void ptp_clock_event(struct ptp_clock *ptp,
			    struct ptp_clock_event *event);

/**
 * ptp_clock_index() - obtain the device index of a PTP clock
 *
 * @ptp:    The clock obtained from ptp_clock_register().
 */

extern int ptp_clock_index(struct ptp_clock *ptp);

#endif