include/linux/ptp_clock_kernel.h

   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  * ptp_find_pin() - obtain the pin index of a given auxiliary function
 209  *
 210  * @ptp:    The clock obtained from ptp_clock_register().
 211  * @func:   One of the ptp_pin_function enumerated values.
 212  * @chan:   The particular functional channel to find.
 213  * Return:  Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
 214  *          or -1 if the auxiliary function cannot be found.
 215  */
 216
 217 int ptp_find_pin(struct ptp_clock *ptp,
 218                  enum ptp_pin_function func, unsigned int chan);
 219
 220 /**
 221  * ptp_schedule_worker() - schedule ptp auxiliary work
 222  *
 223  * @ptp:    The clock obtained from ptp_clock_register().
 224  * @delay:  number of jiffies to wait before queuing
 225  *          See kthread_queue_delayed_work() for more info.
 226  */
 227
 228 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay);
 229
 230 #else
 231 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 232                                                    struct device *parent)
 233 { return NULL; }
 234 static inline int ptp_clock_unregister(struct ptp_clock *ptp)
 235 { return 0; }
 236 static inline void ptp_clock_event(struct ptp_clock *ptp,
 237                                    struct ptp_clock_event *event)
 238 { }
 239 static inline int ptp_clock_index(struct ptp_clock *ptp)
 240 { return -1; }
 241 static inline int ptp_find_pin(struct ptp_clock *ptp,
 242                                enum ptp_pin_function func, unsigned int chan)
 243 { return -1; }
 244 static inline int ptp_schedule_worker(struct ptp_clock *ptp,
 245                                       unsigned long delay)
 246 { return -EOPNOTSUPP; }
 247
 248 #endif
 249
 250 #endif