/* 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
* @clockid: clock-base used for capturing the system timestamps
*/
struct ptp_system_timestamp {
struct timespec64 pre_ts;
struct timespec64 post_ts;
clockid_t clockid;
};
/**
* 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_EXTOFF,
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).
* @offset: When the event occurred (%PTP_CLOCK_EXTOFF only).
* @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).
*/
struct ptp_clock_event {
int type;
int index;
union {
u64 timestamp;
s64 offset;
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) {
switch (sts->clockid) {
case CLOCK_REALTIME:
ktime_get_real_ts64(&sts->pre_ts);
break;
case CLOCK_MONOTONIC:
ktime_get_ts64(&sts->pre_ts);
break;
case CLOCK_MONOTONIC_RAW:
ktime_get_raw_ts64(&sts->pre_ts);
break;
default:
break;
}
}
}
static inline void ptp_read_system_postts(struct ptp_system_timestamp *sts)
{
if (sts) {
switch (sts->clockid) {
case CLOCK_REALTIME:
ktime_get_real_ts64(&sts->post_ts);
break;
case CLOCK_MONOTONIC:
ktime_get_ts64(&sts->post_ts);
break;
case CLOCK_MONOTONIC_RAW:
ktime_get_raw_ts64(&sts->post_ts);
break;
default:
break;
}
}
}
#endif
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