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