linux/drivers/net/ethernet/intel/e1000e/ptp.c

// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 1999 - 2018 Intel Corporation. */

/* PTP 1588 Hardware Clock (PHC)
 * Derived from PTP Hardware Clock driver for Intel 82576 and 82580 (igb)
 * Copyright (C) 2011 Richard Cochran <[email protected]>
 */

#include "e1000.h"

#ifdef CONFIG_E1000E_HWTS
#include <linux/clocksource.h>
#include <linux/ktime.h>
#include <asm/tsc.h>
#endif

/**
 * e1000e_phc_adjfine - adjust the frequency of the hardware clock
 * @ptp: ptp clock structure
 * @delta: Desired frequency chance in scaled parts per million
 *
 * Adjust the frequency of the PHC cycle counter by the indicated delta from
 * the base frequency.
 *
 * Scaled parts per million is ppm but with a 16 bit binary fractional field.
 **/
static int e1000e_phc_adjfine(struct ptp_clock_info *ptp, long delta)
{ … }

/**
 * e1000e_phc_adjtime - Shift the time of the hardware clock
 * @ptp: ptp clock structure
 * @delta: Desired change in nanoseconds
 *
 * Adjust the timer by resetting the timecounter structure.
 **/
static int e1000e_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
{ … }

#ifdef CONFIG_E1000E_HWTS
#define MAX_HW_WAIT_COUNT …

/**
 * e1000e_phc_get_syncdevicetime - Callback given to timekeeping code reads system/device registers
 * @device: current device time
 * @system: system counter value read synchronously with device time
 * @ctx: context provided by timekeeping code
 *
 * Read device and system (ART) clock simultaneously and return the corrected
 * clock values in ns.
 **/
static int e1000e_phc_get_syncdevicetime(ktime_t *device,
					 struct system_counterval_t *system,
					 void *ctx)
{ … }

/**
 * e1000e_phc_getcrosststamp - Reads the current system/device cross timestamp
 * @ptp: ptp clock structure
 * @xtstamp: structure containing timestamp
 *
 * Read device and system (ART) clock simultaneously and return the scaled
 * clock values in ns.
 **/
static int e1000e_phc_getcrosststamp(struct ptp_clock_info *ptp,
				     struct system_device_crosststamp *xtstamp)
{ … }
#endif/*CONFIG_E1000E_HWTS*/

/**
 * e1000e_phc_gettimex - Reads the current time from the hardware clock and
 *                       system clock
 * @ptp: ptp clock structure
 * @ts: timespec structure to hold the current PHC time
 * @sts: structure to hold the current system time
 *
 * Read the timecounter and return the correct value in ns after converting
 * it into a struct timespec.
 **/
static int e1000e_phc_gettimex(struct ptp_clock_info *ptp,
			       struct timespec64 *ts,
			       struct ptp_system_timestamp *sts)
{ … }

/**
 * e1000e_phc_settime - Set the current time on the hardware clock
 * @ptp: ptp clock structure
 * @ts: timespec containing the new time for the cycle counter
 *
 * Reset the timecounter to use a new base value instead of the kernel
 * wall timer value.
 **/
static int e1000e_phc_settime(struct ptp_clock_info *ptp,
			      const struct timespec64 *ts)
{ … }

/**
 * e1000e_phc_enable - enable or disable an ancillary feature
 * @ptp: ptp clock structure
 * @request: Desired resource to enable or disable
 * @on: Caller passes one to enable or zero to disable
 *
 * Enable (or disable) ancillary features of the PHC subsystem.
 * Currently, no ancillary features are supported.
 **/
static int e1000e_phc_enable(struct ptp_clock_info __always_unused *ptp,
			     struct ptp_clock_request __always_unused *request,
			     int __always_unused on)
{ … }

static void e1000e_systim_overflow_work(struct work_struct *work)
{ … }

static const struct ptp_clock_info e1000e_ptp_clock_info = …;

/**
 * e1000e_ptp_init - initialize PTP for devices which support it
 * @adapter: board private structure
 *
 * This function performs the required steps for enabling PTP support.
 * If PTP support has already been loaded it simply calls the cyclecounter
 * init routine and exits.
 **/
void e1000e_ptp_init(struct e1000_adapter *adapter)
{ … }

/**
 * e1000e_ptp_remove - disable PTP device and stop the overflow check
 * @adapter: board private structure
 *
 * Stop the PTP support, and cancel the delayed work.
 **/
void e1000e_ptp_remove(struct e1000_adapter *adapter)
{ … }