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