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_PPS, 204 PTP_CLOCK_PPSUSR, 205 }; 206 207 /** 208 * struct ptp_clock_event - decribes a PTP hardware clock event 209 * 210 * @type: One of the ptp_clock_events enumeration values. 211 * @index: Identifies the source of the event. 212 * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only). 213 * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only). 214 */ 215 216 struct ptp_clock_event { 217 int type; 218 int index; 219 union { 220 u64 timestamp; 221 struct pps_event_time pps_times; 222 }; 223 }; 224 225 /** 226 * scaled_ppm_to_ppb() - convert scaled ppm to ppb 227 * 228 * @ppm: Parts per million, but with a 16 bit binary fractional field 229 */ 230 static inline long scaled_ppm_to_ppb(long ppm) 231 { 232 /* 233 * The 'freq' field in the 'struct timex' is in parts per 234 * million, but with a 16 bit binary fractional field. 235 * 236 * We want to calculate 237 * 238 * ppb = scaled_ppm * 1000 / 2^16 239 * 240 * which simplifies to 241 * 242 * ppb = scaled_ppm * 125 / 2^13 243 */ 244 s64 ppb = 1 + ppm; 245 246 ppb *= 125; 247 ppb >>= 13; 248 return (long)ppb; 249 } 250 251 /** 252 * diff_by_scaled_ppm - Calculate difference using scaled ppm 253 * @base: the base increment value to adjust 254 * @scaled_ppm: scaled parts per million to adjust by 255 * @diff: on return, the absolute value of calculated diff 256 * 257 * Calculate the difference to adjust the base increment using scaled parts 258 * per million. 259 * 260 * Use mul_u64_u64_div_u64 to perform the difference calculation in avoid 261 * possible overflow. 262 * 263 * Returns: true if scaled_ppm is negative, false otherwise 264 */ 265 static inline bool diff_by_scaled_ppm(u64 base, long scaled_ppm, u64 *diff) 266 { 267 bool negative = false; 268 269 if (scaled_ppm < 0) { 270 negative = true; 271 scaled_ppm = -scaled_ppm; 272 } 273 274 *diff = mul_u64_u64_div_u64(base, (u64)scaled_ppm, 1000000ULL << 16); 275 276 return negative; 277 } 278 279 /** 280 * adjust_by_scaled_ppm - Adjust a base increment by scaled parts per million 281 * @base: the base increment value to adjust 282 * @scaled_ppm: scaled parts per million frequency adjustment 283 * 284 * Helper function which calculates a new increment value based on the 285 * requested scaled parts per million adjustment. 286 */ 287 static inline u64 adjust_by_scaled_ppm(u64 base, long scaled_ppm) 288 { 289 u64 diff; 290 291 if (diff_by_scaled_ppm(base, scaled_ppm, &diff)) 292 return base - diff; 293 294 return base + diff; 295 } 296 297 #if IS_ENABLED(CONFIG_PTP_1588_CLOCK) 298 299 /** 300 * ptp_clock_register() - register a PTP hardware clock driver 301 * 302 * @info: Structure describing the new clock. 303 * @parent: Pointer to the parent device of the new clock. 304 * 305 * Returns a valid pointer on success or PTR_ERR on failure. If PHC 306 * support is missing at the configuration level, this function 307 * returns NULL, and drivers are expected to gracefully handle that 308 * case separately. 309 */ 310 311 extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, 312 struct device *parent); 313 314 /** 315 * ptp_clock_unregister() - unregister a PTP hardware clock driver 316 * 317 * @ptp: The clock to remove from service. 318 */ 319 320 extern int ptp_clock_unregister(struct ptp_clock *ptp); 321 322 /** 323 * ptp_clock_event() - notify the PTP layer about an event 324 * 325 * @ptp: The clock obtained from ptp_clock_register(). 326 * @event: Message structure describing the event. 327 */ 328 329 extern void ptp_clock_event(struct ptp_clock *ptp, 330 struct ptp_clock_event *event); 331 332 /** 333 * ptp_clock_index() - obtain the device index of a PTP clock 334 * 335 * @ptp: The clock obtained from ptp_clock_register(). 336 */ 337 338 extern int ptp_clock_index(struct ptp_clock *ptp); 339 340 /** 341 * ptp_find_pin() - obtain the pin index of a given auxiliary function 342 * 343 * The caller must hold ptp_clock::pincfg_mux. Drivers do not have 344 * access to that mutex as ptp_clock is an opaque type. However, the 345 * core code acquires the mutex before invoking the driver's 346 * ptp_clock_info::enable() callback, and so drivers may call this 347 * function from that context. 348 * 349 * @ptp: The clock obtained from ptp_clock_register(). 350 * @func: One of the ptp_pin_function enumerated values. 351 * @chan: The particular functional channel to find. 352 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1, 353 * or -1 if the auxiliary function cannot be found. 354 */ 355 356 int ptp_find_pin(struct ptp_clock *ptp, 357 enum ptp_pin_function func, unsigned int chan); 358 359 /** 360 * ptp_find_pin_unlocked() - wrapper for ptp_find_pin() 361 * 362 * This function acquires the ptp_clock::pincfg_mux mutex before 363 * invoking ptp_find_pin(). Instead of using this function, drivers 364 * should most likely call ptp_find_pin() directly from their 365 * ptp_clock_info::enable() method. 366 * 367 * @ptp: The clock obtained from ptp_clock_register(). 368 * @func: One of the ptp_pin_function enumerated values. 369 * @chan: The particular functional channel to find. 370 * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1, 371 * or -1 if the auxiliary function cannot be found. 372 */ 373 374 int ptp_find_pin_unlocked(struct ptp_clock *ptp, 375 enum ptp_pin_function func, unsigned int chan); 376 377 /** 378 * ptp_schedule_worker() - schedule ptp auxiliary work 379 * 380 * @ptp: The clock obtained from ptp_clock_register(). 381 * @delay: number of jiffies to wait before queuing 382 * See kthread_queue_delayed_work() for more info. 383 */ 384 385 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay); 386 387 /** 388 * ptp_cancel_worker_sync() - cancel ptp auxiliary clock 389 * 390 * @ptp: The clock obtained from ptp_clock_register(). 391 */ 392 void ptp_cancel_worker_sync(struct ptp_clock *ptp); 393 394 #else 395 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, 396 struct device *parent) 397 { return NULL; } 398 static inline int ptp_clock_unregister(struct ptp_clock *ptp) 399 { return 0; } 400 static inline void ptp_clock_event(struct ptp_clock *ptp, 401 struct ptp_clock_event *event) 402 { } 403 static inline int ptp_clock_index(struct ptp_clock *ptp) 404 { return -1; } 405 static inline int ptp_find_pin(struct ptp_clock *ptp, 406 enum ptp_pin_function func, unsigned int chan) 407 { return -1; } 408 static inline int ptp_find_pin_unlocked(struct ptp_clock *ptp, 409 enum ptp_pin_function func, 410 unsigned int chan) 411 { return -1; } 412 static inline int ptp_schedule_worker(struct ptp_clock *ptp, 413 unsigned long delay) 414 { return -EOPNOTSUPP; } 415 static inline void ptp_cancel_worker_sync(struct ptp_clock *ptp) 416 { } 417 #endif 418 419 #if IS_BUILTIN(CONFIG_PTP_1588_CLOCK) 420 /* 421 * These are called by the network core, and don't work if PTP is in 422 * a loadable module. 423 */ 424 425 /** 426 * ptp_get_vclocks_index() - get all vclocks index on pclock, and 427 * caller is responsible to free memory 428 * of vclock_index 429 * 430 * @pclock_index: phc index of ptp pclock. 431 * @vclock_index: pointer to pointer of vclock index. 432 * 433 * return number of vclocks. 434 */ 435 int ptp_get_vclocks_index(int pclock_index, int **vclock_index); 436 437 /** 438 * ptp_convert_timestamp() - convert timestamp to a ptp vclock time 439 * 440 * @hwtstamp: timestamp 441 * @vclock_index: phc index of ptp vclock. 442 * 443 * Returns converted timestamp, or 0 on error. 444 */ 445 ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, int vclock_index); 446 #else 447 static inline int ptp_get_vclocks_index(int pclock_index, int **vclock_index) 448 { return 0; } 449 static inline ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, 450 int vclock_index) 451 { return 0; } 452 453 #endif 454 455 static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts) 456 { 457 if (sts) 458 ktime_get_real_ts64(&sts->pre_ts); 459 } 460 461 static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts) 462 { 463 if (sts) 464 ktime_get_real_ts64(&sts->post_ts); 465 } 466 467 #endif 468