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