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 * 72 * @supported_perout_flags: The set of flags the driver supports for the 73 * PTP_PEROUT_REQUEST ioctl. The PTP core will 74 * reject a request with any flag not specified 75 * here. 76 * 77 * @supported_extts_flags: The set of flags the driver supports for the 78 * PTP_EXTTS_REQUEST ioctl. The PTP core will use 79 * this list to reject unsupported requests. 80 * PTP_ENABLE_FEATURE is assumed and does not need to 81 * be included. If PTP_STRICT_FLAGS is *not* set, 82 * then both PTP_RISING_EDGE and PTP_FALLING_EDGE 83 * will be assumed. Note that PTP_STRICT_FLAGS must 84 * be set if the drivers wants to honor 85 * PTP_EXTTS_REQUEST2 and any future flags. 86 * 87 * @pin_config: Array of length 'n_pins'. If the number of 88 * programmable pins is nonzero, then drivers must 89 * allocate and initialize this array. 90 * 91 * clock operations 92 * 93 * @adjfine: Adjusts the frequency of the hardware clock. 94 * parameter scaled_ppm: Desired frequency offset from 95 * nominal frequency in parts per million, but with a 96 * 16 bit binary fractional field. 97 * 98 * @adjphase: Indicates that the PHC should use an internal servo 99 * algorithm to correct the provided phase offset. 100 * parameter delta: PHC servo phase adjustment target 101 * in nanoseconds. 102 * 103 * @getmaxphase: Advertises maximum offset that can be provided 104 * to the hardware clock's phase control functionality 105 * through adjphase. 106 * 107 * @adjtime: Shifts the time of the hardware clock. 108 * parameter delta: Desired change in nanoseconds. 109 * 110 * @gettime64: Reads the current time from the hardware clock. 111 * This method is deprecated. New drivers should implement 112 * the @gettimex64 method instead. 113 * parameter ts: Holds the result. 114 * 115 * @gettimex64: Reads the current time from the hardware clock and optionally 116 * also the system clock. 117 * parameter ts: Holds the PHC timestamp. 118 * parameter sts: If not NULL, it holds a pair of timestamps from 119 * the system clock. The first reading is made right before 120 * reading the lowest bits of the PHC timestamp and the second 121 * reading immediately follows that. 122 * 123 * @getcrosststamp: Reads the current time from the hardware clock and 124 * system clock simultaneously. 125 * parameter cts: Contains timestamp (device,system) pair, 126 * where system time is realtime and monotonic. 127 * 128 * @settime64: Set the current time on the hardware clock. 129 * parameter ts: Time value to set. 130 * 131 * @getcycles64: Reads the current free running cycle counter from the hardware 132 * clock. 133 * If @getcycles64 and @getcyclesx64 are not supported, then 134 * @gettime64 or @gettimex64 will be used as default 135 * implementation. 136 * parameter ts: Holds the result. 137 * 138 * @getcyclesx64: Reads the current free running cycle counter from the 139 * hardware clock and optionally also the system clock. 140 * If @getcycles64 and @getcyclesx64 are not supported, then 141 * @gettimex64 will be used as default implementation if 142 * available. 143 * parameter ts: Holds the PHC timestamp. 144 * parameter sts: If not NULL, it holds a pair of timestamps 145 * from the system clock. The first reading is made right before 146 * reading the lowest bits of the PHC timestamp and the second 147 * reading immediately follows that. 148 * 149 * @getcrosscycles: Reads the current free running cycle counter from the 150 * hardware clock and system clock simultaneously. 151 * If @getcycles64 and @getcyclesx64 are not supported, then 152 * @getcrosststamp will be used as default implementation if 153 * available. 154 * parameter cts: Contains timestamp (device,system) pair, 155 * where system time is realtime and monotonic. 156 * 157 * @enable: Request driver to enable or disable an ancillary feature. 158 * parameter request: Desired resource to enable or disable. 159 * parameter on: Caller passes one to enable or zero to disable. 160 * 161 * @verify: Confirm that a pin can perform a given function. The PTP 162 * Hardware Clock subsystem maintains the 'pin_config' 163 * array on behalf of the drivers, but the PHC subsystem 164 * assumes that every pin can perform every function. This 165 * hook gives drivers a way of telling the core about 166 * limitations on specific pins. This function must return 167 * zero if the function can be assigned to this pin, and 168 * nonzero otherwise. 169 * parameter pin: index of the pin in question. 170 * parameter func: the desired function to use. 171 * parameter chan: the function channel index to use. 172 * 173 * @do_aux_work: Request driver to perform auxiliary (periodic) operations 174 * Driver should return delay of the next auxiliary work 175 * scheduling time (>=0) or negative value in case further 176 * scheduling is not required. 177 * 178 * Drivers should embed their ptp_clock_info within a private 179 * structure, obtaining a reference to it using container_of(). 180 * 181 * The callbacks must all return zero on success, non-zero otherwise. 182 */ 183 184 struct ptp_clock_info { 185 struct module *owner; 186 char name[PTP_CLOCK_NAME_LEN]; 187 s32 max_adj; 188 int n_alarm; 189 int n_ext_ts; 190 int n_per_out; 191 int n_pins; 192 int pps; 193 unsigned int supported_perout_flags; 194 unsigned int supported_extts_flags; 195 struct ptp_pin_desc *pin_config; 196 int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm); 197 int (*adjphase)(struct ptp_clock_info *ptp, s32 phase); 198 s32 (*getmaxphase)(struct ptp_clock_info *ptp); 199 int (*adjtime)(struct ptp_clock_info *ptp, s64 delta); 200 int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts); 201 int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts, 202 struct ptp_system_timestamp *sts); 203 int (*getcrosststamp)(struct ptp_clock_info *ptp, 204 struct system_device_crosststamp *cts); 205 int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts); 206 int (*getcycles64)(struct ptp_clock_info *ptp, struct timespec64 *ts); 207 int (*getcyclesx64)(struct ptp_clock_info *ptp, struct timespec64 *ts, 208 struct ptp_system_timestamp *sts); 209 int (*getcrosscycles)(struct ptp_clock_info *ptp, 210 struct system_device_crosststamp *cts); 211 int (*enable)(struct ptp_clock_info *ptp, 212 struct ptp_clock_request *request, int on); 213 int (*verify)(struct ptp_clock_info *ptp, unsigned int pin, 214 enum ptp_pin_function func, unsigned int chan); 215 long (*do_aux_work)(struct ptp_clock_info *ptp); 216 }; 217 218 struct ptp_clock; 219 220 enum ptp_clock_events { 221 PTP_CLOCK_ALARM, 222 PTP_CLOCK_EXTTS, 223 PTP_CLOCK_EXTOFF, 224 PTP_CLOCK_PPS, 225 PTP_CLOCK_PPSUSR, 226 }; 227 228 /** 229 * struct ptp_clock_event - decribes a PTP hardware clock event 230 * 231 * @type: One of the ptp_clock_events enumeration values. 232 * @index: Identifies the source of the event. 233 * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only). 234 * @offset: When the event occurred (%PTP_CLOCK_EXTOFF only). 235 * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only). 236 */ 237 238 struct ptp_clock_event { 239 int type; 240 int index; 241 union { 242 u64 timestamp; 243 s64 offset; 244 struct pps_event_time pps_times; 245 }; 246 }; 247 248 /** 249 * scaled_ppm_to_ppb() - convert scaled ppm to ppb 250 * 251 * @ppm: Parts per million, but with a 16 bit binary fractional field 252 */ 253 static inline long scaled_ppm_to_ppb(long ppm) 254 { 255 /* 256 * The 'freq' field in the 'struct timex' is in parts per 257 * million, but with a 16 bit binary fractional field. 258 * 259 * We want to calculate 260 * 261 * ppb = scaled_ppm * 1000 / 2^16 262 * 263 * which simplifies to 264 * 265 * ppb = scaled_ppm * 125 / 2^13 266 */ 267 s64 ppb = 1 + ppm; 268 269 ppb *= 125; 270 ppb >>= 13; 271 return (long)ppb; 272 } 273 274 /** 275 * diff_by_scaled_ppm - Calculate difference using scaled ppm 276 * @base: the base increment value to adjust 277 * @scaled_ppm: scaled parts per million to adjust by 278 * @diff: on return, the absolute value of calculated diff 279 * 280 * Calculate the difference to adjust the base increment using scaled parts 281 * per million. 282 * 283 * Use mul_u64_u64_div_u64 to perform the difference calculation in avoid 284 * possible overflow. 285 * 286 * Returns: true if scaled_ppm is negative, false otherwise 287 */ 288 static inline bool diff_by_scaled_ppm(u64 base, long scaled_ppm, u64 *diff) 289 { 290 bool negative = false; 291 292 if (scaled_ppm < 0) { 293 negative = true; 294 scaled_ppm = -scaled_ppm; 295 } 296 297 *diff = mul_u64_u64_div_u64(base, (u64)scaled_ppm, 1000000ULL << 16); 298 299 return negative; 300 } 301 302 /** 303 * adjust_by_scaled_ppm - Adjust a base increment by scaled parts per million 304 * @base: the base increment value to adjust 305 * @scaled_ppm: scaled parts per million frequency adjustment 306 * 307 * Helper function which calculates a new increment value based on the 308 * requested scaled parts per million adjustment. 309 */ 310 static inline u64 adjust_by_scaled_ppm(u64 base, long scaled_ppm) 311 { 312 u64 diff; 313 314 if (diff_by_scaled_ppm(base, scaled_ppm, &diff)) 315 return base - diff; 316 317 return base + diff; 318 } 319 320 #if IS_ENABLED(CONFIG_PTP_1588_CLOCK) 321 322 /** 323 * ptp_clock_register() - register a PTP hardware clock driver 324 * 325 * @info: Structure describing the new clock. 326 * @parent: Pointer to the parent device of the new clock. 327 * 328 * Returns: a valid pointer on success or PTR_ERR on failure. If PHC 329 * support is missing at the configuration level, this function 330 * returns NULL, and drivers are expected to gracefully handle that 331 * case separately. 332 */ 333 334 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, 335 struct device *parent); 336 337 /** 338 * ptp_clock_unregister() - unregister a PTP hardware clock driver 339 * 340 * @ptp: The clock to remove from service. 341 */ 342 343 extern int ptp_clock_unregister(struct ptp_clock *ptp); 344 345 /** 346 * ptp_clock_event() - notify the PTP layer about an event 347 * 348 * @ptp: The clock obtained from ptp_clock_register(). 349 * @event: Message structure describing the event. 350 */ 351 352 extern void ptp_clock_event(struct ptp_clock *ptp, 353 struct ptp_clock_event *event); 354 355 /** 356 * ptp_clock_index() - obtain the device index of a PTP clock 357 * 358 * @ptp: The clock obtained from ptp_clock_register(). 359 */ 360 361 extern int ptp_clock_index(struct ptp_clock *ptp); 362 363 /** 364 * ptp_find_pin() - obtain the pin index of a given auxiliary function 365 * 366 * The caller must hold ptp_clock::pincfg_mux. Drivers do not have 367 * access to that mutex as ptp_clock is an opaque type. However, the 368 * core code acquires the mutex before invoking the driver's 369 * ptp_clock_info::enable() callback, and so drivers may call this 370 * function from that context. 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(struct ptp_clock *ptp, 380 enum ptp_pin_function func, unsigned int chan); 381 382 /** 383 * ptp_find_pin_unlocked() - wrapper for ptp_find_pin() 384 * 385 * This function acquires the ptp_clock::pincfg_mux mutex before 386 * invoking ptp_find_pin(). Instead of using this function, drivers 387 * should most likely call ptp_find_pin() directly from their 388 * ptp_clock_info::enable() method. 389 * 390 * @ptp: The clock obtained from ptp_clock_register(). 391 * @func: One of the ptp_pin_function enumerated values. 392 * @chan: The particular functional channel to find. 393 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1, 394 * or -1 if the auxiliary function cannot be found. 395 */ 396 397 int ptp_find_pin_unlocked(struct ptp_clock *ptp, 398 enum ptp_pin_function func, unsigned int chan); 399 400 /** 401 * ptp_schedule_worker() - schedule ptp auxiliary work 402 * 403 * @ptp: The clock obtained from ptp_clock_register(). 404 * @delay: number of jiffies to wait before queuing 405 * See kthread_queue_delayed_work() for more info. 406 */ 407 408 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay); 409 410 /** 411 * ptp_cancel_worker_sync() - cancel ptp auxiliary clock 412 * 413 * @ptp: The clock obtained from ptp_clock_register(). 414 */ 415 void ptp_cancel_worker_sync(struct ptp_clock *ptp); 416 417 #else 418 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, 419 struct device *parent) 420 { return NULL; } 421 static inline int ptp_clock_unregister(struct ptp_clock *ptp) 422 { return 0; } 423 static inline void ptp_clock_event(struct ptp_clock *ptp, 424 struct ptp_clock_event *event) 425 { } 426 static inline int ptp_clock_index(struct ptp_clock *ptp) 427 { return -1; } 428 static inline int ptp_find_pin(struct ptp_clock *ptp, 429 enum ptp_pin_function func, unsigned int chan) 430 { return -1; } 431 static inline int ptp_find_pin_unlocked(struct ptp_clock *ptp, 432 enum ptp_pin_function func, 433 unsigned int chan) 434 { return -1; } 435 static inline int ptp_schedule_worker(struct ptp_clock *ptp, 436 unsigned long delay) 437 { return -EOPNOTSUPP; } 438 static inline void ptp_cancel_worker_sync(struct ptp_clock *ptp) 439 { } 440 #endif 441 442 #if IS_BUILTIN(CONFIG_PTP_1588_CLOCK) 443 /* 444 * These are called by the network core, and don't work if PTP is in 445 * a loadable module. 446 */ 447 448 /** 449 * ptp_get_vclocks_index() - get all vclocks index on pclock, and 450 * caller is responsible to free memory 451 * of vclock_index 452 * 453 * @pclock_index: phc index of ptp pclock. 454 * @vclock_index: pointer to pointer of vclock index. 455 * 456 * return number of vclocks. 457 */ 458 int ptp_get_vclocks_index(int pclock_index, int **vclock_index); 459 460 /** 461 * ptp_convert_timestamp() - convert timestamp to a ptp vclock time 462 * 463 * @hwtstamp: timestamp 464 * @vclock_index: phc index of ptp vclock. 465 * 466 * Returns: converted timestamp, or 0 on error. 467 */ 468 ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, int vclock_index); 469 #else 470 static inline int ptp_get_vclocks_index(int pclock_index, int **vclock_index) 471 { return 0; } 472 static inline ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, 473 int vclock_index) 474 { return 0; } 475 476 #endif 477 478 static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts) 479 { 480 if (sts) 481 ktime_get_clock_ts64(sts->clockid, &sts->pre_ts); 482 } 483 484 static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts) 485 { 486 if (sts) 487 ktime_get_clock_ts64(sts->clockid, &sts->post_ts); 488 } 489 490 #endif 491