/*
   * 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/device.h>

  #include <linux/pps_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 system_device_crosststamp;

  /**
   * struct ptp_clock_info - decribes a PTP hardware clock
   *
   * @owner:     The clock driver should set to THIS_MODULE.

   * @name:      A short "friendly name" to identify the clock and to
   *             help distinguish PHY based devices from MAC based ones.
   *             The string is not meant to be a unique id.

   * @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.

   * @n_pins:    The number of programmable pins.

   * @pps:       Indicates whether the clock supports a PPS callback.

   * @pin_config: Array of length 'n_pins'. If the number of
   *              programmable pins is nonzero, then drivers must
   *              allocate and initialize this array.

   *
   * clock operations
   *

   * @adjfine:  Adjusts the frequency of the hardware clock.
   *            parameter scaled_ppm: Desired frequency offset from
   *            nominal frequency in parts per million, but with a
   *            16 bit binary fractional field.
   *

   * @adjfreq:  Adjusts the frequency of the hardware clock.

   *            This method is deprecated.  New drivers should implement
   *            the @adjfine method instead.

   *            parameter delta: Desired frequency offset from nominal frequency
   *            in parts per billion

   *
   * @adjtime:  Shifts the time of the hardware clock.
   *            parameter delta: Desired change in nanoseconds.
   *

   * @gettime64:  Reads the current time from the hardware clock.
   *              parameter ts: Holds the result.
   *

   * @getcrosststamp:  Reads the current time from the hardware clock and
   *                   system clock simultaneously.
   *                   parameter cts: Contains timestamp (device,system) pair,
   *                   where system time is realtime and monotonic.
   *

   * @settime64:  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.
   *

   * @verify:   Confirm that a pin can perform a given function. The PTP
   *            Hardware Clock subsystem maintains the 'pin_config'
   *            array on behalf of the drivers, but the PHC subsystem
   *            assumes that every pin can perform every function. This
   *            hook gives drivers a way of telling the core about
   *            limitations on specific pins. This function must return
   *            zero if the function can be assigned to this pin, and
   *            nonzero otherwise.
   *            parameter pin: index of the pin in question.
   *            parameter func: the desired function to use.
   *            parameter chan: the function channel index to use.
   *

   * @do_work:  Request driver to perform auxiliary (periodic) operations
   *	      Driver should return delay of the next auxiliary work scheduling
   *	      time (>=0) or negative value in case further scheduling
   *	      is not required.
   *

   * 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 n_pins;

  	int pps;

  	struct ptp_pin_desc *pin_config;

  	int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm);

  	int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
  	int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);

  	int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);

  	int (*getcrosststamp)(struct ptp_clock_info *ptp,
  			      struct system_device_crosststamp *cts);

  	int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts);

  	int (*enable)(struct ptp_clock_info *ptp,
  		      struct ptp_clock_request *request, int on);

  	int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
  		      enum ptp_pin_function func, unsigned int chan);

  	long (*do_aux_work)(struct ptp_clock_info *ptp);

  };
  
  struct ptp_clock;

  enum ptp_clock_events {
  	PTP_CLOCK_ALARM,
  	PTP_CLOCK_EXTTS,
  	PTP_CLOCK_PPS,

  	PTP_CLOCK_PPSUSR,

  };
  
  /**
   * 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 occurred (%PTP_CLOCK_EXTTS only).
   * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).

   */
  
  struct ptp_clock_event {
  	int type;
  	int index;

  	union {
  		u64 timestamp;
  		struct pps_event_time pps_times;
  	};

  };

  #if IS_REACHABLE(CONFIG_PTP_1588_CLOCK)
  
  /**
   * ptp_clock_register() - register a PTP hardware clock driver
   *
   * @info:   Structure describing the new clock.
   * @parent: Pointer to the parent device of the new clock.
   *
   * Returns a valid pointer on success or PTR_ERR on failure.  If PHC
   * support is missing at the configuration level, this function
   * returns NULL, and drivers are expected to gracefully handle that
   * case separately.
   */
  
  extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
  					    struct device *parent);
  
  /**
   * 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);

  /**
   * 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);

  /**
   * ptp_find_pin() - obtain the pin index of a given auxiliary function
   *
   * @ptp:    The clock obtained from ptp_clock_register().
   * @func:   One of the ptp_pin_function enumerated values.
   * @chan:   The particular functional channel to find.
   * Return:  Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
   *          or -1 if the auxiliary function cannot be found.
   */
  
  int ptp_find_pin(struct ptp_clock *ptp,
  		 enum ptp_pin_function func, unsigned int chan);

  /**
   * ptp_schedule_worker() - schedule ptp auxiliary work
   *
   * @ptp:    The clock obtained from ptp_clock_register().
   * @delay:  number of jiffies to wait before queuing
   *          See kthread_queue_delayed_work() for more info.
   */
  
  int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay);

  #else
  static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
  						   struct device *parent)
  { return NULL; }
  static inline int ptp_clock_unregister(struct ptp_clock *ptp)
  { return 0; }
  static inline void ptp_clock_event(struct ptp_clock *ptp,
  				   struct ptp_clock_event *event)
  { }
  static inline int ptp_clock_index(struct ptp_clock *ptp)
  { return -1; }
  static inline int ptp_find_pin(struct ptp_clock *ptp,
  			       enum ptp_pin_function func, unsigned int chan)
  { return -1; }

  static inline int ptp_schedule_worker(struct ptp_clock *ptp,
  				      unsigned long delay)
  { return -EOPNOTSUPP; }

  #endif

  #endif