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 - request PTP clock event
  17  *
  18  * @type:   The type of the request.
  19  *          EXTTS:  Configure external trigger timestamping
  20  *          PEROUT: Configure periodic output signal (e.g. PPS)
  21  *          PPS:    trigger internal PPS event for input
  22  *                  into kernel PPS subsystem
  23  * @extts:  describes configuration for external trigger timestamping.
  24  *          This is only valid when event == PTP_CLK_REQ_EXTTS.
  25  * @perout: describes configuration for periodic output.
  26  *          This is only valid when event == PTP_CLK_REQ_PEROUT.
  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 /**
  44  * struct ptp_system_timestamp - system time corresponding to a PHC timestamp
  45  */
  46 struct ptp_system_timestamp {
  47         struct timespec64 pre_ts;
  48         struct timespec64 post_ts;
  49 };
  50
  51 /**
  52  * struct ptp_clock_info - describes a PTP hardware clock
  53  *
  54  * @owner:     The clock driver should set to THIS_MODULE.
  55  * @name:      A short "friendly name" to identify the clock and to
  56  *             help distinguish PHY based devices from MAC based ones.
  57  *             The string is not meant to be a unique id.
  58  * @max_adj:   The maximum possible frequency adjustment, in parts per billon.
  59  * @n_alarm:   The number of programmable alarms.
  60  * @n_ext_ts:  The number of external time stamp channels.
  61  * @n_per_out: The number of programmable periodic signals.
  62  * @n_pins:    The number of programmable pins.
  63  * @pps:       Indicates whether the clock supports a PPS callback.
  64  * @pin_config: Array of length 'n_pins'. If the number of
  65  *              programmable pins is nonzero, then drivers must
  66  *              allocate and initialize this array.
  67  *
  68  * clock operations
  69  *
  70  * @adjfine:  Adjusts the frequency of the hardware clock.
  71  *            parameter scaled_ppm: Desired frequency offset from
  72  *            nominal frequency in parts per million, but with a
  73  *            16 bit binary fractional field.
  74  *
  75  * @adjfreq:  Adjusts the frequency of the hardware clock.
  76  *            This method is deprecated.  New drivers should implement
  77  *            the @adjfine method instead.
  78  *            parameter delta: Desired frequency offset from nominal frequency
  79  *            in parts per billion
  80  *
  81  * @adjphase:  Adjusts the phase offset of the hardware clock.
  82  *             parameter delta: Desired change in nanoseconds.
  83  *
  84  * @adjtime:  Shifts the time of the hardware clock.
  85  *            parameter delta: Desired change in nanoseconds.
  86  *
  87  * @gettime64:  Reads the current time from the hardware clock.
  88  *              This method is deprecated.  New drivers should implement
  89  *              the @gettimex64 method instead.
  90  *              parameter ts: Holds the result.
  91  *
  92  * @gettimex64:  Reads the current time from the hardware clock and optionally
  93  *               also the system clock.
  94  *               parameter ts: Holds the PHC timestamp.
  95  *               parameter sts: If not NULL, it holds a pair of timestamps from
  96  *               the system clock. The first reading is made right before
  97  *               reading the lowest bits of the PHC timestamp and the second
  98  *               reading immediately follows that.
  99  *
 100  * @getcrosststamp:  Reads the current time from the hardware clock and
 101  *                   system clock simultaneously.
 102  *                   parameter cts: Contains timestamp (device,system) pair,
 103  *                   where system time is realtime and monotonic.
 104  *
 105  * @settime64:  Set the current time on the hardware clock.
 106  *              parameter ts: Time value to set.
 107  *
 108  * @enable:   Request driver to enable or disable an ancillary feature.
 109  *            parameter request: Desired resource to enable or disable.
 110  *            parameter on: Caller passes one to enable or zero to disable.
 111  *
 112  * @verify:   Confirm that a pin can perform a given function. The PTP
 113  *            Hardware Clock subsystem maintains the 'pin_config'
 114  *            array on behalf of the drivers, but the PHC subsystem
 115  *            assumes that every pin can perform every function. This
 116  *            hook gives drivers a way of telling the core about
 117  *            limitations on specific pins. This function must return
 118  *            zero if the function can be assigned to this pin, and
 119  *            nonzero otherwise.
 120  *            parameter pin: index of the pin in question.
 121  *            parameter func: the desired function to use.
 122  *            parameter chan: the function channel index to use.
 123  *
 124  * @do_aux_work:  Request driver to perform auxiliary (periodic) operations
 125  *                Driver should return delay of the next auxiliary work
 126  *                scheduling time (>=0) or negative value in case further
 127  *                scheduling is not required.
 128  *
 129  * Drivers should embed their ptp_clock_info within a private
 130  * structure, obtaining a reference to it using container_of().
 131  *
 132  * The callbacks must all return zero on success, non-zero otherwise.
 133  */
 134
 135 struct ptp_clock_info {
 136         struct module *owner;
 137         char name[16];
 138         s32 max_adj;
 139         int n_alarm;
 140         int n_ext_ts;
 141         int n_per_out;
 142         int n_pins;
 143         int pps;
 144         struct ptp_pin_desc *pin_config;
 145         int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm);
 146         int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta);
 147         int (*adjphase)(struct ptp_clock_info *ptp, s32 phase);
 148         int (*adjtime)(struct ptp_clock_info *ptp, s64 delta);
 149         int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts);
 150         int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts,
 151                           struct ptp_system_timestamp *sts);
 152         int (*getcrosststamp)(struct ptp_clock_info *ptp,
 153                               struct system_device_crosststamp *cts);
 154         int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts);
 155         int (*enable)(struct ptp_clock_info *ptp,
 156                       struct ptp_clock_request *request, int on);
 157         int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,
 158                       enum ptp_pin_function func, unsigned int chan);
 159         long (*do_aux_work)(struct ptp_clock_info *ptp);
 160 };
 161
 162 struct ptp_clock;
 163
 164 enum ptp_clock_events {
 165         PTP_CLOCK_ALARM,
 166         PTP_CLOCK_EXTTS,
 167         PTP_CLOCK_PPS,
 168         PTP_CLOCK_PPSUSR,
 169 };
 170
 171 /**
 172  * struct ptp_clock_event - decribes a PTP hardware clock event
 173  *
 174  * @type:  One of the ptp_clock_events enumeration values.
 175  * @index: Identifies the source of the event.
 176  * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).
 177  * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
 178  */
 179
 180 struct ptp_clock_event {
 181         int type;
 182         int index;
 183         union {
 184                 u64 timestamp;
 185                 struct pps_event_time pps_times;
 186         };
 187 };
 188
 189 #if IS_REACHABLE(CONFIG_PTP_1588_CLOCK)
 190
 191 /**
 192  * ptp_clock_register() - register a PTP hardware clock driver
 193  *
 194  * @info:   Structure describing the new clock.
 195  * @parent: Pointer to the parent device of the new clock.
 196  *
 197  * Returns a valid pointer on success or PTR_ERR on failure.  If PHC
 198  * support is missing at the configuration level, this function
 199  * returns NULL, and drivers are expected to gracefully handle that
 200  * case separately.
 201  */
 202
 203 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 204                                             struct device *parent);
 205
 206 /**
 207  * ptp_clock_unregister() - unregister a PTP hardware clock driver
 208  *
 209  * @ptp:  The clock to remove from service.
 210  */
 211
 212 extern int ptp_clock_unregister(struct ptp_clock *ptp);
 213
 214 /**
 215  * ptp_clock_event() - notify the PTP layer about an event
 216  *
 217  * @ptp:    The clock obtained from ptp_clock_register().
 218  * @event:  Message structure describing the event.
 219  */
 220
 221 extern void ptp_clock_event(struct ptp_clock *ptp,
 222                             struct ptp_clock_event *event);
 223
 224 /**
 225  * ptp_clock_index() - obtain the device index of a PTP clock
 226  *
 227  * @ptp:    The clock obtained from ptp_clock_register().
 228  */
 229
 230 extern int ptp_clock_index(struct ptp_clock *ptp);
 231
 232 /**
 233  * scaled_ppm_to_ppb() - convert scaled ppm to ppb
 234  *
 235  * @ppm:    Parts per million, but with a 16 bit binary fractional field
 236  */
 237
 238 extern s32 scaled_ppm_to_ppb(long ppm);
 239
 240 /**
 241  * ptp_find_pin() - obtain the pin index of a given auxiliary function
 242  *
 243  * The caller must hold ptp_clock::pincfg_mux.  Drivers do not have
 244  * access to that mutex as ptp_clock is an opaque type.  However, the
 245  * core code acquires the mutex before invoking the driver's
 246  * ptp_clock_info::enable() callback, and so drivers may call this
 247  * function from that context.
 248  *
 249  * @ptp:    The clock obtained from ptp_clock_register().
 250  * @func:   One of the ptp_pin_function enumerated values.
 251  * @chan:   The particular functional channel to find.
 252  * Return:  Pin index in the range of zero to ptp_clock_caps.n_pins - 1,
 253  *          or -1 if the auxiliary function cannot be found.
 254  */
 255
 256 int ptp_find_pin(struct ptp_clock *ptp,
 257                  enum ptp_pin_function func, unsigned int chan);
 258
 259 /**
 260  * ptp_find_pin_unlocked() - wrapper for ptp_find_pin()
 261  *
 262  * This function acquires the ptp_clock::pincfg_mux mutex before
 263  * invoking ptp_find_pin().  Instead of using this function, drivers
 264  * should most likely call ptp_find_pin() directly from their
 265  * ptp_clock_info::enable() method.
 266  *
 267  */
 268
 269 int ptp_find_pin_unlocked(struct ptp_clock *ptp,
 270                           enum ptp_pin_function func, unsigned int chan);
 271
 272 /**
 273  * ptp_schedule_worker() - schedule ptp auxiliary work
 274  *
 275  * @ptp:    The clock obtained from ptp_clock_register().
 276  * @delay:  number of jiffies to wait before queuing
 277  *          See kthread_queue_delayed_work() for more info.
 278  */
 279
 280 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay);
 281
 282 /**
 283  * ptp_cancel_worker_sync() - cancel ptp auxiliary clock
 284  *
 285  * @ptp:     The clock obtained from ptp_clock_register().
 286  */
 287 void ptp_cancel_worker_sync(struct ptp_clock *ptp);
 288
 289 #else
 290 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 291                                                    struct device *parent)
 292 { return NULL; }
 293 static inline int ptp_clock_unregister(struct ptp_clock *ptp)
 294 { return 0; }
 295 static inline void ptp_clock_event(struct ptp_clock *ptp,
 296                                    struct ptp_clock_event *event)
 297 { }
 298 static inline int ptp_clock_index(struct ptp_clock *ptp)
 299 { return -1; }
 300 static inline int ptp_find_pin(struct ptp_clock *ptp,
 301                                enum ptp_pin_function func, unsigned int chan)
 302 { return -1; }
 303 static inline int ptp_schedule_worker(struct ptp_clock *ptp,
 304                                       unsigned long delay)
 305 { return -EOPNOTSUPP; }
 306 static inline void ptp_cancel_worker_sync(struct ptp_clock *ptp)
 307 { }
 308
 309 #endif
 310
 311 static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts)
 312 {
 313         if (sts)
 314                 ktime_get_real_ts64(&sts->pre_ts);
 315 }
 316
 317 static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts)
 318 {
 319         if (sts)
 320                 ktime_get_real_ts64(&sts->post_ts);
 321 }
 322
 323 #endif