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/skbuff.h> 16 17 #define PTP_CLOCK_NAME_LEN 32 18 /** 19 * struct ptp_clock_request - request PTP clock event 20 * 21 * @type: The type of the request. 22 * EXTTS: Configure external trigger timestamping 23 * PEROUT: Configure periodic output signal (e.g. PPS) 24 * PPS: trigger internal PPS event for input 25 * into kernel PPS subsystem 26 * @extts: describes configuration for external trigger timestamping. 27 * This is only valid when event == PTP_CLK_REQ_EXTTS. 28 * @perout: describes configuration for periodic output. 29 * This is only valid when event == PTP_CLK_REQ_PEROUT. 30 */ 31 32 struct ptp_clock_request { 33 enum { 34 PTP_CLK_REQ_EXTTS, 35 PTP_CLK_REQ_PEROUT, 36 PTP_CLK_REQ_PPS, 37 } type; 38 union { 39 struct ptp_extts_request extts; 40 struct ptp_perout_request perout; 41 }; 42 }; 43 44 struct system_device_crosststamp; 45 46 /** 47 * struct ptp_system_timestamp - system time corresponding to a PHC timestamp 48 * @pre_ts: system timestamp before capturing PHC 49 * @post_ts: system timestamp after capturing PHC 50 * @clockid: clock-base used for capturing the system timestamps 51 */ 52 struct ptp_system_timestamp { 53 struct timespec64 pre_ts; 54 struct timespec64 post_ts; 55 clockid_t clockid; 56 }; 57 58 /** 59 * struct ptp_clock_info - describes a PTP hardware clock 60 * 61 * @owner: The clock driver should set to THIS_MODULE. 62 * @name: A short "friendly name" to identify the clock and to 63 * help distinguish PHY based devices from MAC based ones. 64 * The string is not meant to be a unique id. 65 * @max_adj: The maximum possible frequency adjustment, in parts per billon. 66 * @n_alarm: The number of programmable alarms. 67 * @n_ext_ts: The number of external time stamp channels. 68 * @n_per_out: The number of programmable periodic signals. 69 * @n_pins: The number of programmable pins. 70 * @pps: Indicates whether the clock supports a PPS callback. 71 * @pin_config: Array of length 'n_pins'. If the number of 72 * programmable pins is nonzero, then drivers must 73 * allocate and initialize this array. 74 * 75 * clock operations 76 * 77 * @adjfine: Adjusts the frequency of the hardware clock. 78 * parameter scaled_ppm: Desired frequency offset from 79 * nominal frequency in parts per million, but with a 80 * 16 bit binary fractional field. 81 * 82 * @adjphase: Indicates that the PHC should use an internal servo 83 * algorithm to correct the provided phase offset. 84 * parameter delta: PHC servo phase adjustment target 85 * in nanoseconds. 86 * 87 * @getmaxphase: Advertises maximum offset that can be provided 88 * to the hardware clock's phase control functionality 89 * through adjphase. 90 * 91 * @adjtime: Shifts the time of the hardware clock. 92 * parameter delta: Desired change in nanoseconds. 93 * 94 * @gettime64: Reads the current time from the hardware clock. 95 * This method is deprecated. New drivers should implement 96 * the @gettimex64 method instead. 97 * parameter ts: Holds the result. 98 * 99 * @gettimex64: Reads the current time from the hardware clock and optionally 100 * also the system clock. 101 * parameter ts: Holds the PHC timestamp. 102 * parameter sts: If not NULL, it holds a pair of timestamps from 103 * the system clock. The first reading is made right before 104 * reading the lowest bits of the PHC timestamp and the second 105 * reading immediately follows that. 106 * 107 * @getcrosststamp: Reads the current time from the hardware clock and 108 * system clock simultaneously. 109 * parameter cts: Contains timestamp (device,system) pair, 110 * where system time is realtime and monotonic. 111 * 112 * @settime64: Set the current time on the hardware clock. 113 * parameter ts: Time value to set. 114 * 115 * @getcycles64: Reads the current free running cycle counter from the hardware 116 * clock. 117 * If @getcycles64 and @getcyclesx64 are not supported, then 118 * @gettime64 or @gettimex64 will be used as default 119 * implementation. 120 * parameter ts: Holds the result. 121 * 122 * @getcyclesx64: Reads the current free running cycle counter from the 123 * hardware clock and optionally also the system clock. 124 * If @getcycles64 and @getcyclesx64 are not supported, then 125 * @gettimex64 will be used as default implementation if 126 * available. 127 * parameter ts: Holds the PHC timestamp. 128 * parameter sts: If not NULL, it holds a pair of timestamps 129 * from the system clock. The first reading is made right before 130 * reading the lowest bits of the PHC timestamp and the second 131 * reading immediately follows that. 132 * 133 * @getcrosscycles: Reads the current free running cycle counter from the 134 * hardware clock and system clock simultaneously. 135 * If @getcycles64 and @getcyclesx64 are not supported, then 136 * @getcrosststamp will be used as default implementation if 137 * available. 138 * parameter cts: Contains timestamp (device,system) pair, 139 * where system time is realtime and monotonic. 140 * 141 * @enable: Request driver to enable or disable an ancillary feature. 142 * parameter request: Desired resource to enable or disable. 143 * parameter on: Caller passes one to enable or zero to disable. 144 * 145 * @verify: Confirm that a pin can perform a given function. The PTP 146 * Hardware Clock subsystem maintains the 'pin_config' 147 * array on behalf of the drivers, but the PHC subsystem 148 * assumes that every pin can perform every function. This 149 * hook gives drivers a way of telling the core about 150 * limitations on specific pins. This function must return 151 * zero if the function can be assigned to this pin, and 152 * nonzero otherwise. 153 * parameter pin: index of the pin in question. 154 * parameter func: the desired function to use. 155 * parameter chan: the function channel index to use. 156 * 157 * @do_aux_work: Request driver to perform auxiliary (periodic) operations 158 * Driver should return delay of the next auxiliary work 159 * scheduling time (>=0) or negative value in case further 160 * scheduling is not required. 161 * 162 * Drivers should embed their ptp_clock_info within a private 163 * structure, obtaining a reference to it using container_of(). 164 * 165 * The callbacks must all return zero on success, non-zero otherwise. 166 */ 167 168 struct ptp_clock_info { 169 struct module *owner; 170 char name[PTP_CLOCK_NAME_LEN]; 171 s32 max_adj; 172 int n_alarm; 173 int n_ext_ts; 174 int n_per_out; 175 int n_pins; 176 int pps; 177 struct ptp_pin_desc *pin_config; 178 int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm); 179 int (*adjphase)(struct ptp_clock_info *ptp, s32 phase); 180 s32 (*getmaxphase)(struct ptp_clock_info *ptp); 181 int (*adjtime)(struct ptp_clock_info *ptp, s64 delta); 182 int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts); 183 int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts, 184 struct ptp_system_timestamp *sts); 185 int (*getcrosststamp)(struct ptp_clock_info *ptp, 186 struct system_device_crosststamp *cts); 187 int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts); 188 int (*getcycles64)(struct ptp_clock_info *ptp, struct timespec64 *ts); 189 int (*getcyclesx64)(struct ptp_clock_info *ptp, struct timespec64 *ts, 190 struct ptp_system_timestamp *sts); 191 int (*getcrosscycles)(struct ptp_clock_info *ptp, 192 struct system_device_crosststamp *cts); 193 int (*enable)(struct ptp_clock_info *ptp, 194 struct ptp_clock_request *request, int on); 195 int (*verify)(struct ptp_clock_info *ptp, unsigned int pin, 196 enum ptp_pin_function func, unsigned int chan); 197 long (*do_aux_work)(struct ptp_clock_info *ptp); 198 }; 199 200 struct ptp_clock; 201 202 enum ptp_clock_events { 203 PTP_CLOCK_ALARM, 204 PTP_CLOCK_EXTTS, 205 PTP_CLOCK_EXTOFF, 206 PTP_CLOCK_PPS, 207 PTP_CLOCK_PPSUSR, 208 }; 209 210 /** 211 * struct ptp_clock_event - decribes a PTP hardware clock event 212 * 213 * @type: One of the ptp_clock_events enumeration values. 214 * @index: Identifies the source of the event. 215 * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only). 216 * @offset: When the event occurred (%PTP_CLOCK_EXTOFF only). 217 * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only). 218 */ 219 220 struct ptp_clock_event { 221 int type; 222 int index; 223 union { 224 u64 timestamp; 225 s64 offset; 226 struct pps_event_time pps_times; 227 }; 228 }; 229 230 /** 231 * scaled_ppm_to_ppb() - convert scaled ppm to ppb 232 * 233 * @ppm: Parts per million, but with a 16 bit binary fractional field 234 */ scaled_ppm_to_ppb(long ppm)235 static inline long scaled_ppm_to_ppb(long ppm) 236 { 237 /* 238 * The 'freq' field in the 'struct timex' is in parts per 239 * million, but with a 16 bit binary fractional field. 240 * 241 * We want to calculate 242 * 243 * ppb = scaled_ppm * 1000 / 2^16 244 * 245 * which simplifies to 246 * 247 * ppb = scaled_ppm * 125 / 2^13 248 */ 249 s64 ppb = 1 + ppm; 250 251 ppb *= 125; 252 ppb >>= 13; 253 return (long)ppb; 254 } 255 256 /** 257 * diff_by_scaled_ppm - Calculate difference using scaled ppm 258 * @base: the base increment value to adjust 259 * @scaled_ppm: scaled parts per million to adjust by 260 * @diff: on return, the absolute value of calculated diff 261 * 262 * Calculate the difference to adjust the base increment using scaled parts 263 * per million. 264 * 265 * Use mul_u64_u64_div_u64 to perform the difference calculation in avoid 266 * possible overflow. 267 * 268 * Returns: true if scaled_ppm is negative, false otherwise 269 */ diff_by_scaled_ppm(u64 base,long scaled_ppm,u64 * diff)270 static inline bool diff_by_scaled_ppm(u64 base, long scaled_ppm, u64 *diff) 271 { 272 bool negative = false; 273 274 if (scaled_ppm < 0) { 275 negative = true; 276 scaled_ppm = -scaled_ppm; 277 } 278 279 *diff = mul_u64_u64_div_u64(base, (u64)scaled_ppm, 1000000ULL << 16); 280 281 return negative; 282 } 283 284 /** 285 * adjust_by_scaled_ppm - Adjust a base increment by scaled parts per million 286 * @base: the base increment value to adjust 287 * @scaled_ppm: scaled parts per million frequency adjustment 288 * 289 * Helper function which calculates a new increment value based on the 290 * requested scaled parts per million adjustment. 291 */ adjust_by_scaled_ppm(u64 base,long scaled_ppm)292 static inline u64 adjust_by_scaled_ppm(u64 base, long scaled_ppm) 293 { 294 u64 diff; 295 296 if (diff_by_scaled_ppm(base, scaled_ppm, &diff)) 297 return base - diff; 298 299 return base + diff; 300 } 301 302 #if IS_ENABLED(CONFIG_PTP_1588_CLOCK) 303 304 /** 305 * ptp_clock_register() - register a PTP hardware clock driver 306 * 307 * @info: Structure describing the new clock. 308 * @parent: Pointer to the parent device of the new clock. 309 * 310 * Returns a valid pointer on success or PTR_ERR on failure. If PHC 311 * support is missing at the configuration level, this function 312 * returns NULL, and drivers are expected to gracefully handle that 313 * case separately. 314 */ 315 316 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, 317 struct device *parent); 318 319 /** 320 * ptp_clock_unregister() - unregister a PTP hardware clock driver 321 * 322 * @ptp: The clock to remove from service. 323 */ 324 325 extern int ptp_clock_unregister(struct ptp_clock *ptp); 326 327 /** 328 * ptp_clock_event() - notify the PTP layer about an event 329 * 330 * @ptp: The clock obtained from ptp_clock_register(). 331 * @event: Message structure describing the event. 332 */ 333 334 extern void ptp_clock_event(struct ptp_clock *ptp, 335 struct ptp_clock_event *event); 336 337 /** 338 * ptp_clock_index() - obtain the device index of a PTP clock 339 * 340 * @ptp: The clock obtained from ptp_clock_register(). 341 */ 342 343 extern int ptp_clock_index(struct ptp_clock *ptp); 344 345 /** 346 * ptp_find_pin() - obtain the pin index of a given auxiliary function 347 * 348 * The caller must hold ptp_clock::pincfg_mux. Drivers do not have 349 * access to that mutex as ptp_clock is an opaque type. However, the 350 * core code acquires the mutex before invoking the driver's 351 * ptp_clock_info::enable() callback, and so drivers may call this 352 * function from that context. 353 * 354 * @ptp: The clock obtained from ptp_clock_register(). 355 * @func: One of the ptp_pin_function enumerated values. 356 * @chan: The particular functional channel to find. 357 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1, 358 * or -1 if the auxiliary function cannot be found. 359 */ 360 361 int ptp_find_pin(struct ptp_clock *ptp, 362 enum ptp_pin_function func, unsigned int chan); 363 364 /** 365 * ptp_find_pin_unlocked() - wrapper for ptp_find_pin() 366 * 367 * This function acquires the ptp_clock::pincfg_mux mutex before 368 * invoking ptp_find_pin(). Instead of using this function, drivers 369 * should most likely call ptp_find_pin() directly from their 370 * ptp_clock_info::enable() method. 371 * 372 * @ptp: The clock obtained from ptp_clock_register(). 373 * @func: One of the ptp_pin_function enumerated values. 374 * @chan: The particular functional channel to find. 375 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1, 376 * or -1 if the auxiliary function cannot be found. 377 */ 378 379 int ptp_find_pin_unlocked(struct ptp_clock *ptp, 380 enum ptp_pin_function func, unsigned int chan); 381 382 /** 383 * ptp_schedule_worker() - schedule ptp auxiliary work 384 * 385 * @ptp: The clock obtained from ptp_clock_register(). 386 * @delay: number of jiffies to wait before queuing 387 * See kthread_queue_delayed_work() for more info. 388 */ 389 390 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay); 391 392 /** 393 * ptp_cancel_worker_sync() - cancel ptp auxiliary clock 394 * 395 * @ptp: The clock obtained from ptp_clock_register(). 396 */ 397 void ptp_cancel_worker_sync(struct ptp_clock *ptp); 398 399 #else ptp_clock_register(struct ptp_clock_info * info,struct device * parent)400 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, 401 struct device *parent) 402 { return NULL; } ptp_clock_unregister(struct ptp_clock * ptp)403 static inline int ptp_clock_unregister(struct ptp_clock *ptp) 404 { return 0; } ptp_clock_event(struct ptp_clock * ptp,struct ptp_clock_event * event)405 static inline void ptp_clock_event(struct ptp_clock *ptp, 406 struct ptp_clock_event *event) 407 { } ptp_clock_index(struct ptp_clock * ptp)408 static inline int ptp_clock_index(struct ptp_clock *ptp) 409 { return -1; } ptp_find_pin(struct ptp_clock * ptp,enum ptp_pin_function func,unsigned int chan)410 static inline int ptp_find_pin(struct ptp_clock *ptp, 411 enum ptp_pin_function func, unsigned int chan) 412 { return -1; } ptp_find_pin_unlocked(struct ptp_clock * ptp,enum ptp_pin_function func,unsigned int chan)413 static inline int ptp_find_pin_unlocked(struct ptp_clock *ptp, 414 enum ptp_pin_function func, 415 unsigned int chan) 416 { return -1; } ptp_schedule_worker(struct ptp_clock * ptp,unsigned long delay)417 static inline int ptp_schedule_worker(struct ptp_clock *ptp, 418 unsigned long delay) 419 { return -EOPNOTSUPP; } ptp_cancel_worker_sync(struct ptp_clock * ptp)420 static inline void ptp_cancel_worker_sync(struct ptp_clock *ptp) 421 { } 422 #endif 423 424 #if IS_BUILTIN(CONFIG_PTP_1588_CLOCK) 425 /* 426 * These are called by the network core, and don't work if PTP is in 427 * a loadable module. 428 */ 429 430 /** 431 * ptp_get_vclocks_index() - get all vclocks index on pclock, and 432 * caller is responsible to free memory 433 * of vclock_index 434 * 435 * @pclock_index: phc index of ptp pclock. 436 * @vclock_index: pointer to pointer of vclock index. 437 * 438 * return number of vclocks. 439 */ 440 int ptp_get_vclocks_index(int pclock_index, int **vclock_index); 441 442 /** 443 * ptp_convert_timestamp() - convert timestamp to a ptp vclock time 444 * 445 * @hwtstamp: timestamp 446 * @vclock_index: phc index of ptp vclock. 447 * 448 * Returns converted timestamp, or 0 on error. 449 */ 450 ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, int vclock_index); 451 #else ptp_get_vclocks_index(int pclock_index,int ** vclock_index)452 static inline int ptp_get_vclocks_index(int pclock_index, int **vclock_index) 453 { return 0; } ptp_convert_timestamp(const ktime_t * hwtstamp,int vclock_index)454 static inline ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, 455 int vclock_index) 456 { return 0; } 457 458 #endif 459 ptp_read_system_prets(struct ptp_system_timestamp * sts)460 static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts) 461 { 462 if (sts) { 463 switch (sts->clockid) { 464 case CLOCK_REALTIME: 465 ktime_get_real_ts64(&sts->pre_ts); 466 break; 467 case CLOCK_MONOTONIC: 468 ktime_get_ts64(&sts->pre_ts); 469 break; 470 case CLOCK_MONOTONIC_RAW: 471 ktime_get_raw_ts64(&sts->pre_ts); 472 break; 473 default: 474 break; 475 } 476 } 477 } 478 ptp_read_system_postts(struct ptp_system_timestamp * sts)479 static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts) 480 { 481 if (sts) { 482 switch (sts->clockid) { 483 case CLOCK_REALTIME: 484 ktime_get_real_ts64(&sts->post_ts); 485 break; 486 case CLOCK_MONOTONIC: 487 ktime_get_ts64(&sts->post_ts); 488 break; 489 case CLOCK_MONOTONIC_RAW: 490 ktime_get_raw_ts64(&sts->post_ts); 491 break; 492 default: 493 break; 494 } 495 } 496 } 497 498 #endif 499