name : ptp_clock_kernel.h /* SPDX-License-Identifier: GPL-2.0-or-later */ /* * PTP 1588 clock support * * Copyright (C) 2010 OMICRON electronics GmbH */ #ifndef _PTP_CLOCK_KERNEL_H_ #define _PTP_CLOCK_KERNEL_H_ #include <linux/device.h> #include <linux/pps_kernel.h> #include <linux/ptp_clock.h> #include <linux/timecounter.h> #include <linux/skbuff.h> #define PTP_CLOCK_NAME_LEN 32 /** * struct ptp_clock_request - request PTP clock event * * @type: The type of the request. * EXTTS: Configure external trigger timestamping * PEROUT: Configure periodic output signal (e.g. PPS) * PPS: trigger internal PPS event for input * into kernel PPS subsystem * @extts: describes configuration for external trigger timestamping. * This is only valid when event == PTP_CLK_REQ_EXTTS. * @perout: describes configuration for periodic output. * This is only valid when event == PTP_CLK_REQ_PEROUT. */ struct ptp_clock_request { enum { PTP_CLK_REQ_EXTTS, PTP_CLK_REQ_PEROUT, PTP_CLK_REQ_PPS, } type; union { struct ptp_extts_request extts; struct ptp_perout_request perout; }; }; struct system_device_crosststamp; /** * struct ptp_system_timestamp - system time corresponding to a PHC timestamp * @pre_ts: system timestamp before capturing PHC * @post_ts: system timestamp after capturing PHC */ struct ptp_system_timestamp { struct timespec64 pre_ts; struct timespec64 post_ts; }; /** * struct ptp_clock_info - describes a PTP hardware clock * * @owner: The clock driver should set to THIS_MODULE. * @name: A short "friendly name" to identify the clock and to * help distinguish PHY based devices from MAC based ones. * The string is not meant to be a unique id. * @max_adj: The maximum possible frequency adjustment, in parts per billon. * @n_alarm: The number of programmable alarms. * @n_ext_ts: The number of external time stamp channels. * @n_per_out: The number of programmable periodic signals. * @n_pins: The number of programmable pins. * @pps: Indicates whether the clock supports a PPS callback. * @pin_config: Array of length 'n_pins'. If the number of * programmable pins is nonzero, then drivers must * allocate and initialize this array. * * clock operations * * @adjfine: Adjusts the frequency of the hardware clock. * parameter scaled_ppm: Desired frequency offset from * nominal frequency in parts per million, but with a * 16 bit binary fractional field. * * @adjphase: Indicates that the PHC should use an internal servo * algorithm to correct the provided phase offset. * parameter delta: PHC servo phase adjustment target * in nanoseconds. * * @getmaxphase: Advertises maximum offset that can be provided * to the hardware clock's phase control functionality * through adjphase. * * @adjtime: Shifts the time of the hardware clock. * parameter delta: Desired change in nanoseconds. * * @gettime64: Reads the current time from the hardware clock. * This method is deprecated. New drivers should implement * the @gettimex64 method instead. * parameter ts: Holds the result. * * @gettimex64: Reads the current time from the hardware clock and optionally * also the system clock. * parameter ts: Holds the PHC timestamp. * parameter sts: If not NULL, it holds a pair of timestamps from * the system clock. The first reading is made right before * reading the lowest bits of the PHC timestamp and the second * reading immediately follows that. * * @getcrosststamp: Reads the current time from the hardware clock and * system clock simultaneously. * parameter cts: Contains timestamp (device,system) pair, * where system time is realtime and monotonic. * * @settime64: Set the current time on the hardware clock. * parameter ts: Time value to set. * * @getcycles64: Reads the current free running cycle counter from the hardware * clock. * If @getcycles64 and @getcyclesx64 are not supported, then * @gettime64 or @gettimex64 will be used as default * implementation. * parameter ts: Holds the result. * * @getcyclesx64: Reads the current free running cycle counter from the * hardware clock and optionally also the system clock. * If @getcycles64 and @getcyclesx64 are not supported, then * @gettimex64 will be used as default implementation if * available. * parameter ts: Holds the PHC timestamp. * parameter sts: If not NULL, it holds a pair of timestamps * from the system clock. The first reading is made right before * reading the lowest bits of the PHC timestamp and the second * reading immediately follows that. * * @getcrosscycles: Reads the current free running cycle counter from the * hardware clock and system clock simultaneously. * If @getcycles64 and @getcyclesx64 are not supported, then * @getcrosststamp will be used as default implementation if * available. * parameter cts: Contains timestamp (device,system) pair, * where system time is realtime and monotonic. * * @enable: Request driver to enable or disable an ancillary feature. * parameter request: Desired resource to enable or disable. * parameter on: Caller passes one to enable or zero to disable. * * @verify: Confirm that a pin can perform a given function. The PTP * Hardware Clock subsystem maintains the 'pin_config' * array on behalf of the drivers, but the PHC subsystem * assumes that every pin can perform every function. This * hook gives drivers a way of telling the core about * limitations on specific pins. This function must return * zero if the function can be assigned to this pin, and * nonzero otherwise. * parameter pin: index of the pin in question. * parameter func: the desired function to use. * parameter chan: the function channel index to use. * * @do_aux_work: Request driver to perform auxiliary (periodic) operations * Driver should return delay of the next auxiliary work * scheduling time (>=0) or negative value in case further * scheduling is not required. * * Drivers should embed their ptp_clock_info within a private * structure, obtaining a reference to it using container_of(). * * The callbacks must all return zero on success, non-zero otherwise. */ struct ptp_clock_info { struct module *owner; char name[PTP_CLOCK_NAME_LEN]; s32 max_adj; int n_alarm; int n_ext_ts; int n_per_out; int n_pins; int pps; struct ptp_pin_desc *pin_config; int (*adjfine)(struct ptp_clock_info *ptp, long scaled_ppm); int (*adjphase)(struct ptp_clock_info *ptp, s32 phase); s32 (*getmaxphase)(struct ptp_clock_info *ptp); int (*adjtime)(struct ptp_clock_info *ptp, s64 delta); int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts); int (*gettimex64)(struct ptp_clock_info *ptp, struct timespec64 *ts, struct ptp_system_timestamp *sts); int (*getcrosststamp)(struct ptp_clock_info *ptp, struct system_device_crosststamp *cts); int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts); int (*getcycles64)(struct ptp_clock_info *ptp, struct timespec64 *ts); int (*getcyclesx64)(struct ptp_clock_info *ptp, struct timespec64 *ts, struct ptp_system_timestamp *sts); int (*getcrosscycles)(struct ptp_clock_info *ptp, struct system_device_crosststamp *cts); int (*enable)(struct ptp_clock_info *ptp, struct ptp_clock_request *request, int on); int (*verify)(struct ptp_clock_info *ptp, unsigned int pin, enum ptp_pin_function func, unsigned int chan); long (*do_aux_work)(struct ptp_clock_info *ptp); }; struct ptp_clock; enum ptp_clock_events { PTP_CLOCK_ALARM, PTP_CLOCK_EXTTS, PTP_CLOCK_PPS, PTP_CLOCK_PPSUSR, }; /** * struct ptp_clock_event - decribes a PTP hardware clock event * * @type: One of the ptp_clock_events enumeration values. * @index: Identifies the source of the event. * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only). * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only). */ struct ptp_clock_event { int type; int index; union { u64 timestamp; struct pps_event_time pps_times; }; }; /** * scaled_ppm_to_ppb() - convert scaled ppm to ppb * * @ppm: Parts per million, but with a 16 bit binary fractional field */ static inline long scaled_ppm_to_ppb(long ppm) { /* * The 'freq' field in the 'struct timex' is in parts per * million, but with a 16 bit binary fractional field. * * We want to calculate * * ppb = scaled_ppm * 1000 / 2^16 * * which simplifies to * * ppb = scaled_ppm * 125 / 2^13 */ s64 ppb = 1 + ppm; ppb *= 125; ppb >>= 13; return (long)ppb; } /** * diff_by_scaled_ppm - Calculate difference using scaled ppm * @base: the base increment value to adjust * @scaled_ppm: scaled parts per million to adjust by * @diff: on return, the absolute value of calculated diff * * Calculate the difference to adjust the base increment using scaled parts * per million. * * Use mul_u64_u64_div_u64 to perform the difference calculation in avoid * possible overflow. * * Returns: true if scaled_ppm is negative, false otherwise */ static inline bool diff_by_scaled_ppm(u64 base, long scaled_ppm, u64 *diff) { bool negative = false; if (scaled_ppm < 0) { negative = true; scaled_ppm = -scaled_ppm; } *diff = mul_u64_u64_div_u64(base, (u64)scaled_ppm, 1000000ULL << 16); return negative; } /** * adjust_by_scaled_ppm - Adjust a base increment by scaled parts per million * @base: the base increment value to adjust * @scaled_ppm: scaled parts per million frequency adjustment * * Helper function which calculates a new increment value based on the * requested scaled parts per million adjustment. */ static inline u64 adjust_by_scaled_ppm(u64 base, long scaled_ppm) { u64 diff; if (diff_by_scaled_ppm(base, scaled_ppm, &diff)) return base - diff; return base + diff; } #if IS_ENABLED(CONFIG_PTP_1588_CLOCK) /** * ptp_clock_register() - register a PTP hardware clock driver * * @info: Structure describing the new clock. * @parent: Pointer to the parent device of the new clock. * * Returns a valid pointer on success or PTR_ERR on failure. If PHC * support is missing at the configuration level, this function * returns NULL, and drivers are expected to gracefully handle that * case separately. */ extern struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, struct device *parent); /** * ptp_clock_unregister() - unregister a PTP hardware clock driver * * @ptp: The clock to remove from service. */ extern int ptp_clock_unregister(struct ptp_clock *ptp); /** * ptp_clock_event() - notify the PTP layer about an event * * @ptp: The clock obtained from ptp_clock_register(). * @event: Message structure describing the event. */ extern void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event); /** * ptp_clock_index() - obtain the device index of a PTP clock * * @ptp: The clock obtained from ptp_clock_register(). */ extern int ptp_clock_index(struct ptp_clock *ptp); /** * ptp_find_pin() - obtain the pin index of a given auxiliary function * * The caller must hold ptp_clock::pincfg_mux. Drivers do not have * access to that mutex as ptp_clock is an opaque type. However, the * core code acquires the mutex before invoking the driver's * ptp_clock_info::enable() callback, and so drivers may call this * function from that context. * * @ptp: The clock obtained from ptp_clock_register(). * @func: One of the ptp_pin_function enumerated values. * @chan: The particular functional channel to find. * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1, * or -1 if the auxiliary function cannot be found. */ int ptp_find_pin(struct ptp_clock *ptp, enum ptp_pin_function func, unsigned int chan); /** * ptp_find_pin_unlocked() - wrapper for ptp_find_pin() * * This function acquires the ptp_clock::pincfg_mux mutex before * invoking ptp_find_pin(). Instead of using this function, drivers * should most likely call ptp_find_pin() directly from their * ptp_clock_info::enable() method. * * @ptp: The clock obtained from ptp_clock_register(). * @func: One of the ptp_pin_function enumerated values. * @chan: The particular functional channel to find. * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1, * or -1 if the auxiliary function cannot be found. */ int ptp_find_pin_unlocked(struct ptp_clock *ptp, enum ptp_pin_function func, unsigned int chan); /** * ptp_schedule_worker() - schedule ptp auxiliary work * * @ptp: The clock obtained from ptp_clock_register(). * @delay: number of jiffies to wait before queuing * See kthread_queue_delayed_work() for more info. */ int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay); /** * ptp_cancel_worker_sync() - cancel ptp auxiliary clock * * @ptp: The clock obtained from ptp_clock_register(). */ void ptp_cancel_worker_sync(struct ptp_clock *ptp); #else static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, struct device *parent) { return NULL; } static inline int ptp_clock_unregister(struct ptp_clock *ptp) { return 0; } static inline void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event) { } static inline int ptp_clock_index(struct ptp_clock *ptp) { return -1; } static inline int ptp_find_pin(struct ptp_clock *ptp, enum ptp_pin_function func, unsigned int chan) { return -1; } static inline int ptp_find_pin_unlocked(struct ptp_clock *ptp, enum ptp_pin_function func, unsigned int chan) { return -1; } static inline int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay) { return -EOPNOTSUPP; } static inline void ptp_cancel_worker_sync(struct ptp_clock *ptp) { } #endif #if IS_BUILTIN(CONFIG_PTP_1588_CLOCK) /* * These are called by the network core, and don't work if PTP is in * a loadable module. */ /** * ptp_get_vclocks_index() - get all vclocks index on pclock, and * caller is responsible to free memory * of vclock_index * * @pclock_index: phc index of ptp pclock. * @vclock_index: pointer to pointer of vclock index. * * return number of vclocks. */ int ptp_get_vclocks_index(int pclock_index, int **vclock_index); /** * ptp_convert_timestamp() - convert timestamp to a ptp vclock time * * @hwtstamp: timestamp * @vclock_index: phc index of ptp vclock. * * Returns converted timestamp, or 0 on error. */ ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, int vclock_index); #else static inline int ptp_get_vclocks_index(int pclock_index, int **vclock_index) { return 0; } static inline ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, int vclock_index) { return 0; } #endif static inline void ptp_read_system_prets(struct ptp_system_timestamp *sts) { if (sts) ktime_get_real_ts64(&sts->pre_ts); } static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts) { if (sts) ktime_get_real_ts64(&sts->post_ts); } #endif