text: /*
   * 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);
  
  #endif
  