include/linux/ptp_clock_kernel.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * PTP 1588 clock support
   4  *
   5  * Copyright (C) 2010 OMICRON electronics GmbH
   6  */
   7
   8 #ifndef _PTP_CLOCK_KERNEL_H_
   9 #define _PTP_CLOCK_KERNEL_H_
  10
  11 #include <linux/device.h>
  12 #include <linux/pps_kernel.h>
  13 #include <linux/ptp_clock.h>
  14
  15
  16 struct ptp_clock_request {
  17         enum {
  18                 PTP_CLK_REQ_EXTTS,
  19                 PTP_CLK_REQ_PEROUT,
  20                 PTP_CLK_REQ_PPS,
  21         } type;
  22         union {
  23                 struct ptp_extts_request extts;
  24                 struct ptp_perout_request perout;
  25         };
  26 };
  27
  28 struct system_device_crosststamp;
  29
  30 /**
  31  * struct ptp_system_timestamp - system time corresponding to a PHC timestamp
  32  */
  33 struct ptp_system_timestamp {
  34         struct timespec64 pre_ts;
  35         struct timespec64 post_ts;
  36 };
  37
  38 /**
  39  * struct ptp_clock_info - decribes a PTP hardware clock
  40  *
  41  * @owner:     The clock driver should set to THIS_MODULE.
  42  * @name:      A short "friendly name" to identify the clock and to
  43  *             help distinguish PHY based devices from MAC based ones.
  44  *             The string is not meant to be a unique id.
  45  * @max_adj:   The maximum possible frequency adjustment, in parts per billon.
  46  * @n_alarm:   The number of programmable alarms.
  47  * @n_ext_ts:  The number of external time stamp channels.
  48  * @n_per_out: The number of programmable periodic signals.
  49  * @n_pins:    The number of programmable pins.
  50  * @pps:       Indicates whether the clock supports a PPS callback.
  51  * @pin_config: Array of length 'n_pins'. If the number of
  52  *              programmable pins is nonzero, then drivers must
  53  *              allocate and initialize this array.
  54  *
  55  * clock operations
  56  *
  57  * @adjfine:  Adjusts the frequency of the hardware clock.
  58  *            parameter scaled_ppm: Desired frequency offset from
  59  *            nominal frequency in parts per million, but with a
  60  *            16 bit binary fractional field.
  61  *
  62  * @adjfreq:  Adjusts the frequency of the hardware clock.
  63  *            This method is deprecated.  New drivers should implement
  64  *            the @adjfine method instead.
  65  *            parameter delta: Desired frequency offset from nominal frequency
  66  *            in parts per billion
  67  *
  68  * @adjtime:  Shifts the time of the hardware clock.
  69  *            parameter delta: Desired change in nanoseconds.
  70  *
  71  * @gettime64:  Reads the current time from the hardware clock.
  72  *              This method is deprecated.  New drivers should implement
  73  *              the @gettimex64 method instead.
  74  *              parameter ts: Holds the result.
  75  *
  76  * @gettimex64:  Reads the current time from the hardware clock and optionally
  77  *               also the system clock.
  78  *               parameter ts: Holds the PHC timestamp.
  79  *               parameter sts: If not NULL, it holds a pair of timestamps from
  80  *               the system clock. The first reading is made right before
  81  *               reading the lowest bits of the PHC timestamp and the second
  82  *               reading immediately follows that.
  83  *
  84  * @getcrosststamp:  Reads the current time from the hardware clock and
  85  *                   system clock simultaneously.
  86  *                   parameter cts: Contains timestamp (device,system) pair,
  87  *                   where system time is realtime and monotonic.
  88  *
  89  * @settime64:  Set the current time on the hardware clock.
  90  *              parameter ts: Time value to set.
  91  *
  92  * @enable:   Request driver to enable or disable an ancillary feature.
  93  *            parameter request: Desired resource to enable or disable.
  94  *            parameter on: Caller passes one to enable or zero to disable.
  95  *
  96  * @verify:   Confirm that a pin can perform a given function. The PTP
  97  *            Hardware Clock subsystem maintains the 'pin_config'
  98  *            array on behalf of the drivers, but the PHC subsystem
  99  *            assumes that every pin can perform every function. This
 100  *            hook gives drivers a way of telling the core about
 101  *            limitations on specific pins. This function must return
 102  *            zero if the function can be assigned to this pin, and
 103  *            nonzero otherwise.
 104  *            parameter pin: index of the pin in question.
 105  *            parameter func: the desired function to use.
 106  *            parameter chan: the function channel index to use.
 107  *
 108  * @do_work:  Request driver to perform auxiliary (periodic) operations
 109  *            Driver should return delay of the next auxiliary work scheduling
 110  *            time (>=0) or negative value in case further scheduling
 111  *            is not required.
 112  *
 113  * Drivers should embed their ptp_clock_info within a private
 114  * structure, obtaining a reference to it using container_of().
 115  *
 116  * The callbacks must all return zero on success, non-zero otherwise.
 117  */
 118
 119 struct ptp_clock_info {
 120         struct module *owner;
 121         char name[16];
 122         s32 max_adj;
 123         int n_alarm;
 124         int n_ext_ts;
 125         int n_per_out;
 126         int n_pins;
 127         int pps;
 128         struct ptp_pin_desc *pin_config;
 129         int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm);
 130         int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
 131         int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
 132         int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
 133         int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
 134                           struct ptp_system_timestamp *sts);
 135         int (*getcrosststamp)(struct ptp_clock_info *ptp,
 136                               struct system_device_crosststamp *cts);
 137         int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts);
 138         int (*enable)(struct ptp_clock_info *ptp,
 139                       struct ptp_clock_request *request, int on);
 140         int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
 141                       enum ptp_pin_function func, unsigned int chan);
 142         long (*do_aux_work)(struct ptp_clock_info *ptp);
 143 };
 144
 145 struct ptp_clock;
 146
 147 enum ptp_clock_events {
 148         PTP_CLOCK_ALARM,
 149         PTP_CLOCK_EXTTS,
 150         PTP_CLOCK_PPS,
 151         PTP_CLOCK_PPSUSR,
 152 };
 153
 154 /**
 155  * struct ptp_clock_event - decribes a PTP hardware clock event
 156  *
 157  * @type:  One of the ptp_clock_events enumeration values.
 158  * @index: Identifies the source of the event.
 159  * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
 160  * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
 161  */
 162
 163 struct ptp_clock_event {
 164         int type;
 165         int index;
 166         union {
 167                 u64 timestamp;
 168                 struct pps_event_time pps_times;
 169         };
 170 };
 171
 172 #if IS_REACHABLE(CONFIG_PTP_1588_CLOCK)
 173
 174 /**
 175  * ptp_clock_register() - register a PTP hardware clock driver
 176  *
 177  * @info:   Structure describing the new clock.
 178  * @parent: Pointer to the parent device of the new clock.
 179  *
 180  * Returns a valid pointer on success or PTR_ERR on failure.  If PHC
 181  * support is missing at the configuration level, this function
 182  * returns NULL, and drivers are expected to gracefully handle that
 183  * case separately.
 184  */
 185
 186 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 187                                             struct device *parent);
 188
 189 /**
 190  * ptp_clock_unregister() - unregister a PTP hardware clock driver
 191  *
 192  * @ptp:  The clock to remove from service.
 193  */
 194
 195 extern int ptp_clock_unregister(struct ptp_clock *ptp);
 196
 197 /**
 198  * ptp_clock_event() - notify the PTP layer about an event
 199  *
 200  * @ptp:    The clock obtained from ptp_clock_register().
 201  * @event:  Message structure describing the event.
 202  */
 203
 204 extern void ptp_clock_event(struct ptp_clock *ptp,
 205                             struct ptp_clock_event *event);
 206
 207 /**
 208  * ptp_clock_index() - obtain the device index of a PTP clock
 209  *
 210  * @ptp:    The clock obtained from ptp_clock_register().
 211  */
 212
 213 extern int ptp_clock_index(struct ptp_clock *ptp);
 214
 215 /**
 216  * scaled_ppm_to_ppb() - convert scaled ppm to ppb
 217  *
 218  * @ppm:    Parts per million, but with a 16 bit binary fractional field
 219  */
 220
 221 extern s32 scaled_ppm_to_ppb(long ppm);
 222
 223 /**
 224  * ptp_find_pin() - obtain the pin index of a given auxiliary function
 225  *
 226  * The caller must hold ptp_clock::pincfg_mux.  Drivers do not have
 227  * access to that mutex as ptp_clock is an opaque type.  However, the
 228  * core code acquires the mutex before invoking the driver's
 229  * ptp_clock_info::enable() callback, and so drivers may call this
 230  * function from that context.
 231  *
 232  * @ptp:    The clock obtained from ptp_clock_register().
 233  * @func:   One of the ptp_pin_function enumerated values.
 234  * @chan:   The particular functional channel to find.
 235  * Return:  Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
 236  *          or -1 if the auxiliary function cannot be found.
 237  */
 238
 239 int ptp_find_pin(struct ptp_clock *ptp,
 240                  enum ptp_pin_function func, unsigned int chan);
 241
 242 /**
 243  * ptp_find_pin_unlocked() - wrapper for ptp_find_pin()
 244  *
 245  * This function acquires the ptp_clock::pincfg_mux mutex before
 246  * invoking ptp_find_pin().  Instead of using this function, drivers
 247  * should most likely call ptp_find_pin() directly from their
 248  * ptp_clock_info::enable() method.
 249  *
 250  */
 251
 252 int ptp_find_pin_unlocked(struct ptp_clock *ptp,
 253                           enum ptp_pin_function func, unsigned int chan);
 254
 255 /**
 256  * ptp_schedule_worker() - schedule ptp auxiliary work
 257  *
 258  * @ptp:    The clock obtained from ptp_clock_register().
 259  * @delay:  number of jiffies to wait before queuing
 260  *          See kthread_queue_delayed_work() for more info.
 261  */
 262
 263 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay);
 264
 265 /**
 266  * ptp_cancel_worker_sync() - cancel ptp auxiliary clock
 267  *
 268  * @ptp:     The clock obtained from ptp_clock_register().
 269  */
 270 void ptp_cancel_worker_sync(struct ptp_clock *ptp);
 271
 272 #else
 273 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 274                                                    struct device *parent)
 275 { return NULL; }
 276 static inline int ptp_clock_unregister(struct ptp_clock *ptp)
 277 { return 0; }
 278 static inline void ptp_clock_event(struct ptp_clock *ptp,
 279                                    struct ptp_clock_event *event)
 280 { }
 281 static inline int ptp_clock_index(struct ptp_clock *ptp)
 282 { return -1; }
 283 static inline int ptp_find_pin(struct ptp_clock *ptp,
 284                                enum ptp_pin_function func, unsigned int chan)
 285 { return -1; }
 286 static inline int ptp_schedule_worker(struct ptp_clock *ptp,
 287                                       unsigned long delay)
 288 { return -EOPNOTSUPP; }
 289 static inline void ptp_cancel_worker_sync(struct ptp_clock *ptp)
 290 { }
 291
 292 #endif
 293
 294 static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts)
 295 {
 296         if (sts)
 297                 ktime_get_real_ts64(&sts->pre_ts);
 298 }
 299
 300 static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts)
 301 {
 302         if (sts)
 303                 ktime_get_real_ts64(&sts->post_ts);
 304 }
 305
 306 #endif