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 #include <linux/timecounter.h> 15 #include <linux/timekeeping.h> 16 #include <linux/skbuff.h> 17 18 #define PTP_CLOCK_NAME_LEN 32 19 /** 20 * struct ptp_clock_request - request PTP clock event 21 * 22 * @type: The type of the request. 23 * EXTTS: Configure external trigger timestamping 24 * PEROUT: Configure periodic output signal (e.g. PPS) 25 * PPS: trigger internal PPS event for input 26 * into kernel PPS subsystem 27 * @extts: describes configuration for external trigger timestamping. 28 * This is only valid when event == PTP_CLK_REQ_EXTTS. 29 * @perout: describes configuration for periodic output. 30 * This is only valid when event == PTP_CLK_REQ_PEROUT. 31 */ 32 33 struct ptp_clock_request { 34 enum { 35 PTP_CLK_REQ_EXTTS, 36 PTP_CLK_REQ_PEROUT, 37 PTP_CLK_REQ_PPS, 38 } type; 39 union { 40 struct ptp_extts_request extts; 41 struct ptp_perout_request perout; 42 }; 43 }; 44 45 struct system_device_crosststamp; 46 47 /** 48 * struct ptp_system_timestamp - system time corresponding to a PHC timestamp 49 * @pre_sts: system time snapshot before capturing PHC 50 * @post_sts: system time snapshot after capturing PHC 51 * @clockid: clock-base used for capturing the system timestamps 52 */ 53 struct ptp_system_timestamp { 54 struct system_time_snapshot pre_sts; 55 struct system_time_snapshot post_sts; 56 clockid_t clockid; 57 }; 58 59 /** 60 * struct ptp_clock_info - describes a PTP hardware clock 61 * 62 * @owner: The clock driver should set to THIS_MODULE. 63 * @name: A short "friendly name" to identify the clock and to 64 * help distinguish PHY based devices from MAC based ones. 65 * The string is not meant to be a unique id. 66 * @max_adj: The maximum possible frequency adjustment, in parts per billon. 67 * @n_alarm: The number of programmable alarms. 68 * @n_ext_ts: The number of external time stamp channels. 69 * @n_per_out: The number of programmable periodic signals. 70 * @n_pins: The number of programmable pins. 71 * @n_per_lp: The number of channels that support loopback the periodic 72 * output signal. 73 * @pps: Indicates whether the clock supports a PPS callback. 74 * 75 * @supported_perout_flags: The set of flags the driver supports for the 76 * PTP_PEROUT_REQUEST ioctl. The PTP core will 77 * reject a request with any flag not specified 78 * here. 79 * 80 * @supported_extts_flags: The set of flags the driver supports for the 81 * PTP_EXTTS_REQUEST ioctl. The PTP core will use 82 * this list to reject unsupported requests. 83 * PTP_ENABLE_FEATURE is assumed and does not need to 84 * be included. If PTP_STRICT_FLAGS is *not* set, 85 * then both PTP_RISING_EDGE and PTP_FALLING_EDGE 86 * will be assumed. Note that PTP_STRICT_FLAGS must 87 * be set if the drivers wants to honor 88 * PTP_EXTTS_REQUEST2 and any future flags. 89 * 90 * @pin_config: Array of length 'n_pins'. If the number of 91 * programmable pins is nonzero, then drivers must 92 * allocate and initialize this array. 93 * 94 * clock operations 95 * 96 * @adjfine: Adjusts the frequency of the hardware clock. 97 * parameter scaled_ppm: Desired frequency offset from 98 * nominal frequency in parts per million, but with a 99 * 16 bit binary fractional field. 100 * 101 * @adjphase: Indicates that the PHC should use an internal servo 102 * algorithm to correct the provided phase offset. 103 * parameter delta: PHC servo phase adjustment target 104 * in nanoseconds. 105 * 106 * @getmaxphase: Advertises maximum offset that can be provided 107 * to the hardware clock's phase control functionality 108 * through adjphase. 109 * 110 * @adjtime: Shifts the time of the hardware clock. 111 * parameter delta: Desired change in nanoseconds. 112 * 113 * @gettime64: Reads the current time from the hardware clock. 114 * This method is deprecated. New drivers should implement 115 * the @gettimex64 method instead. 116 * parameter ts: Holds the result. 117 * 118 * @gettimex64: Reads the current time from the hardware clock and optionally 119 * also the system clock. 120 * parameter ts: Holds the PHC timestamp. 121 * parameter sts: If not NULL, it holds a pair of timestamps from 122 * the system clock. The first reading is made right before 123 * reading the lowest bits of the PHC timestamp and the second 124 * reading immediately follows that. 125 * 126 * @getcrosststamp: Reads the current time from the hardware clock and 127 * system clock simultaneously. 128 * parameter cts: Contains timestamp (device,system) pair, 129 * where system time is realtime and monotonic. 130 * 131 * @settime64: Set the current time on the hardware clock. 132 * parameter ts: Time value to set. 133 * 134 * @getcycles64: Reads the current free running cycle counter from the hardware 135 * clock. 136 * If @getcycles64 and @getcyclesx64 are not supported, then 137 * @gettime64 or @gettimex64 will be used as default 138 * implementation. 139 * parameter ts: Holds the result. 140 * 141 * @getcyclesx64: Reads the current free running cycle counter from the 142 * hardware clock and optionally also the system clock. 143 * If @getcycles64 and @getcyclesx64 are not supported, then 144 * @gettimex64 will be used as default implementation if 145 * available. 146 * parameter ts: Holds the PHC timestamp. 147 * parameter sts: If not NULL, it holds a pair of timestamps 148 * from the system clock. The first reading is made right before 149 * reading the lowest bits of the PHC timestamp and the second 150 * reading immediately follows that. 151 * 152 * @getcrosscycles: Reads the current free running cycle counter from the 153 * hardware clock and system clock simultaneously. 154 * If @getcycles64 and @getcyclesx64 are not supported, then 155 * @getcrosststamp will be used as default implementation if 156 * available. 157 * parameter cts: Contains timestamp (device,system) pair, 158 * where system time is realtime and monotonic. 159 * 160 * @enable: Request driver to enable or disable an ancillary feature. 161 * parameter request: Desired resource to enable or disable. 162 * parameter on: Caller passes one to enable or zero to disable. 163 * 164 * @verify: Confirm that a pin can perform a given function. The PTP 165 * Hardware Clock subsystem maintains the 'pin_config' 166 * array on behalf of the drivers, but the PHC subsystem 167 * assumes that every pin can perform every function. This 168 * hook gives drivers a way of telling the core about 169 * limitations on specific pins. This function must return 170 * zero if the function can be assigned to this pin, and 171 * nonzero otherwise. 172 * parameter pin: index of the pin in question. 173 * parameter func: the desired function to use. 174 * parameter chan: the function channel index to use. 175 * 176 * @do_aux_work: Request driver to perform auxiliary (periodic) operations 177 * Driver should return delay of the next auxiliary work 178 * scheduling time (>=0) or negative value in case further 179 * scheduling is not required. 180 * 181 * @perout_loopback: Request driver to enable or disable the periodic output 182 * signal loopback. 183 * parameter index: index of the periodic output signal channel. 184 * parameter on: caller passes one to enable or zero to disable. 185 * 186 * Drivers should embed their ptp_clock_info within a private 187 * structure, obtaining a reference to it using container_of(). 188 * 189 * The callbacks must all return zero on success, non-zero otherwise. 190 */ 191 192 struct ptp_clock_info { 193 struct module *owner; 194 char name[PTP_CLOCK_NAME_LEN]; 195 s32 max_adj; 196 int n_alarm; 197 int n_ext_ts; 198 int n_per_out; 199 int n_pins; 200 int n_per_lp; 201 int pps; 202 unsigned int supported_perout_flags; 203 unsigned int supported_extts_flags; 204 struct ptp_pin_desc *pin_config; 205 int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm); 206 int (*adjphase)(struct ptp_clock_info *ptp, s32 phase); 207 s32 (*getmaxphase)(struct ptp_clock_info *ptp); 208 int (*adjtime)(struct ptp_clock_info *ptp, s64 delta); 209 int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts); 210 int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts, 211 struct ptp_system_timestamp *sts); 212 int (*getcrosststamp)(struct ptp_clock_info *ptp, 213 struct system_device_crosststamp *cts); 214 int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts); 215 int (*getcycles64)(struct ptp_clock_info *ptp, struct timespec64 *ts); 216 int (*getcyclesx64)(struct ptp_clock_info *ptp, struct timespec64 *ts, 217 struct ptp_system_timestamp *sts); 218 int (*getcrosscycles)(struct ptp_clock_info *ptp, 219 struct system_device_crosststamp *cts); 220 int (*enable)(struct ptp_clock_info *ptp, 221 struct ptp_clock_request *request, int on); 222 int (*verify)(struct ptp_clock_info *ptp, unsigned int pin, 223 enum ptp_pin_function func, unsigned int chan); 224 long (*do_aux_work)(struct ptp_clock_info *ptp); 225 int (*perout_loopback)(struct ptp_clock_info *ptp, unsigned int index, 226 int on); 227 }; 228 229 struct ptp_clock; 230 231 enum ptp_clock_events { 232 PTP_CLOCK_ALARM, 233 PTP_CLOCK_EXTTS, 234 PTP_CLOCK_EXTOFF, 235 PTP_CLOCK_PPS, 236 PTP_CLOCK_PPSUSR, 237 }; 238 239 /** 240 * struct ptp_clock_event - decribes a PTP hardware clock event 241 * 242 * @type: One of the ptp_clock_events enumeration values. 243 * @index: Identifies the source of the event. 244 * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only). 245 * @offset: When the event occurred (%PTP_CLOCK_EXTOFF only). 246 * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only). 247 */ 248 249 struct ptp_clock_event { 250 int type; 251 int index; 252 union { 253 u64 timestamp; 254 s64 offset; 255 struct pps_event_time pps_times; 256 }; 257 }; 258 259 /** 260 * scaled_ppm_to_ppb() - convert scaled ppm to ppb 261 * 262 * @ppm: Parts per million, but with a 16 bit binary fractional field 263 */ 264 static inline long scaled_ppm_to_ppb(long ppm) 265 { 266 /* 267 * The 'freq' field in the 'struct timex' is in parts per 268 * million, but with a 16 bit binary fractional field. 269 * 270 * We want to calculate 271 * 272 * ppb = scaled_ppm * 1000 / 2^16 273 * 274 * which simplifies to 275 * 276 * ppb = scaled_ppm * 125 / 2^13 277 */ 278 s64 ppb = 1 + ppm; 279 280 ppb *= 125; 281 ppb >>= 13; 282 return (long)ppb; 283 } 284 285 /** 286 * diff_by_scaled_ppm - Calculate difference using scaled ppm 287 * @base: the base increment value to adjust 288 * @scaled_ppm: scaled parts per million to adjust by 289 * @diff: on return, the absolute value of calculated diff 290 * 291 * Calculate the difference to adjust the base increment using scaled parts 292 * per million. 293 * 294 * Use mul_u64_u64_div_u64 to perform the difference calculation in avoid 295 * possible overflow. 296 * 297 * Returns: true if scaled_ppm is negative, false otherwise 298 */ 299 static inline bool diff_by_scaled_ppm(u64 base, long scaled_ppm, u64 *diff) 300 { 301 bool negative = false; 302 303 if (scaled_ppm < 0) { 304 negative = true; 305 scaled_ppm = -scaled_ppm; 306 } 307 308 *diff = mul_u64_u64_div_u64(base, (u64)scaled_ppm, 1000000ULL << 16); 309 310 return negative; 311 } 312 313 /** 314 * adjust_by_scaled_ppm - Adjust a base increment by scaled parts per million 315 * @base: the base increment value to adjust 316 * @scaled_ppm: scaled parts per million frequency adjustment 317 * 318 * Helper function which calculates a new increment value based on the 319 * requested scaled parts per million adjustment. 320 */ 321 static inline u64 adjust_by_scaled_ppm(u64 base, long scaled_ppm) 322 { 323 u64 diff; 324 325 if (diff_by_scaled_ppm(base, scaled_ppm, &diff)) 326 return base - diff; 327 328 return base + diff; 329 } 330 331 #if IS_ENABLED(CONFIG_PTP_1588_CLOCK) 332 333 /** 334 * ptp_clock_register() - register a PTP hardware clock driver 335 * 336 * @info: Structure describing the new clock. 337 * @parent: Pointer to the parent device of the new clock. 338 * 339 * Returns: a valid pointer on success or PTR_ERR on failure. If PHC 340 * support is missing at the configuration level, this function 341 * returns NULL, and drivers are expected to gracefully handle that 342 * case separately. 343 */ 344 345 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, 346 struct device *parent); 347 348 /** 349 * ptp_clock_unregister() - unregister a PTP hardware clock driver 350 * 351 * @ptp: The clock to remove from service. 352 */ 353 354 extern int ptp_clock_unregister(struct ptp_clock *ptp); 355 356 /** 357 * ptp_clock_event() - notify the PTP layer about an event 358 * 359 * @ptp: The clock obtained from ptp_clock_register(). 360 * @event: Message structure describing the event. 361 */ 362 363 extern void ptp_clock_event(struct ptp_clock *ptp, 364 struct ptp_clock_event *event); 365 366 /** 367 * ptp_clock_index() - obtain the device index of a PTP clock 368 * 369 * @ptp: The clock obtained from ptp_clock_register(). 370 */ 371 372 extern int ptp_clock_index(struct ptp_clock *ptp); 373 374 /** 375 * ptp_clock_index_by_of_node() - obtain the device index of 376 * a PTP clock based on the PTP device of_node 377 * 378 * @np: The device of_node pointer of the PTP device. 379 * Return: The PHC index on success or -1 on failure. 380 */ 381 int ptp_clock_index_by_of_node(struct device_node *np); 382 383 /** 384 * ptp_clock_index_by_dev() - obtain the device index of 385 * a PTP clock based on the PTP device. 386 * 387 * @parent: The parent device (PTP device) pointer of the PTP clock. 388 * Return: The PHC index on success or -1 on failure. 389 */ 390 int ptp_clock_index_by_dev(struct device *parent); 391 392 /** 393 * ptp_find_pin() - obtain the pin index of a given auxiliary function 394 * 395 * The caller must hold ptp_clock::pincfg_mux. Drivers do not have 396 * access to that mutex as ptp_clock is an opaque type. However, the 397 * core code acquires the mutex before invoking the driver's 398 * ptp_clock_info::enable() callback, and so drivers may call this 399 * function from that context. 400 * 401 * @ptp: The clock obtained from ptp_clock_register(). 402 * @func: One of the ptp_pin_function enumerated values. 403 * @chan: The particular functional channel to find. 404 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1, 405 * or -1 if the auxiliary function cannot be found. 406 */ 407 408 int ptp_find_pin(struct ptp_clock *ptp, 409 enum ptp_pin_function func, unsigned int chan); 410 411 /** 412 * ptp_find_pin_unlocked() - wrapper for ptp_find_pin() 413 * 414 * This function acquires the ptp_clock::pincfg_mux mutex before 415 * invoking ptp_find_pin(). Instead of using this function, drivers 416 * should most likely call ptp_find_pin() directly from their 417 * ptp_clock_info::enable() method. 418 * 419 * @ptp: The clock obtained from ptp_clock_register(). 420 * @func: One of the ptp_pin_function enumerated values. 421 * @chan: The particular functional channel to find. 422 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1, 423 * or -1 if the auxiliary function cannot be found. 424 */ 425 426 int ptp_find_pin_unlocked(struct ptp_clock *ptp, 427 enum ptp_pin_function func, unsigned int chan); 428 429 /** 430 * ptp_schedule_worker() - schedule ptp auxiliary work 431 * 432 * @ptp: The clock obtained from ptp_clock_register(). 433 * @delay: number of jiffies to wait before queuing 434 * See kthread_queue_delayed_work() for more info. 435 */ 436 437 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay); 438 439 /** 440 * ptp_cancel_worker_sync() - cancel ptp auxiliary clock 441 * 442 * @ptp: The clock obtained from ptp_clock_register(). 443 */ 444 void ptp_cancel_worker_sync(struct ptp_clock *ptp); 445 446 #else 447 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, 448 struct device *parent) 449 { return NULL; } 450 static inline int ptp_clock_unregister(struct ptp_clock *ptp) 451 { return 0; } 452 static inline void ptp_clock_event(struct ptp_clock *ptp, 453 struct ptp_clock_event *event) 454 { } 455 static inline int ptp_clock_index(struct ptp_clock *ptp) 456 { return -1; } 457 static inline int ptp_clock_index_by_of_node(struct device_node *np) 458 { return -1; } 459 static inline int ptp_clock_index_by_dev(struct device *parent) 460 { return -1; } 461 static inline int ptp_find_pin(struct ptp_clock *ptp, 462 enum ptp_pin_function func, unsigned int chan) 463 { return -1; } 464 static inline int ptp_find_pin_unlocked(struct ptp_clock *ptp, 465 enum ptp_pin_function func, 466 unsigned int chan) 467 { return -1; } 468 static inline int ptp_schedule_worker(struct ptp_clock *ptp, 469 unsigned long delay) 470 { return -EOPNOTSUPP; } 471 static inline void ptp_cancel_worker_sync(struct ptp_clock *ptp) 472 { } 473 #endif 474 475 #if IS_BUILTIN(CONFIG_PTP_1588_CLOCK) 476 /* 477 * These are called by the network core, and don't work if PTP is in 478 * a loadable module. 479 */ 480 481 /** 482 * ptp_get_vclocks_index() - get all vclocks index on pclock, and 483 * caller is responsible to free memory 484 * of vclock_index 485 * 486 * @pclock_index: phc index of ptp pclock. 487 * @vclock_index: pointer to pointer of vclock index. 488 * 489 * return number of vclocks. 490 */ 491 int ptp_get_vclocks_index(int pclock_index, int **vclock_index); 492 493 /** 494 * ptp_convert_timestamp() - convert timestamp to a ptp vclock time 495 * 496 * @hwtstamp: timestamp 497 * @vclock_index: phc index of ptp vclock. 498 * 499 * Returns: converted timestamp, or 0 on error. 500 */ 501 ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, int vclock_index); 502 #else 503 static inline int ptp_get_vclocks_index(int pclock_index, int **vclock_index) 504 { return 0; } 505 static inline ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, 506 int vclock_index) 507 { return 0; } 508 509 #endif 510 511 static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts) 512 { 513 if (sts) 514 ktime_get_snapshot_id(sts->clockid, &sts->pre_sts); 515 } 516 517 static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts) 518 { 519 if (sts) 520 ktime_get_snapshot_id(sts->clockid, &sts->post_sts); 521 } 522 523 #endif 524