Files
nuttx/include/sys/timex.h
T
dongjiuzhu1 752a405f86 sched/clock: support using CLOCKFD to call clock_adjtime
This patch implements clock_adjtime() with CLOCKFD support, enabling
precise time and frequency adjustments for PTP clocks through the
standard POSIX clock API.

Key changes include:

1. New clock_adjtime() system call:
   - Added sched/clock/clock_adjtime.c implementation
   - Provides POSIX-compliant time adjustment interface
   - Supports both standard clocks and CLOCKFD-based dynamic clocks
   - Added CONFIG_CLOCK_ADJTIME Kconfig option

2. CLOCKFD support in clock_adjtime():
   - Detects CLOCKFD-encoded clockids via CLOCKFD_TO_FD() check
   - Extracts file descriptor and validates through fs_getfilep()
   - Issues PTP_CLOCK_ADJTIME ioctl to underlying PTP clock device
   - Returns clock status and adjustment results via struct timex

3. Enhanced struct timex support:
   - Extended include/sys/timex.h with additional ADJ_* flags
   - Added ADJ_OFFSET, ADJ_FREQUENCY, ADJ_MAXERROR, ADJ_ESTERROR
   - Added ADJ_STATUS, ADJ_TIMECONST, ADJ_TAI, ADJ_SETOFFSET
   - Added ADJ_MICRO, ADJ_NANO for time unit selection
   - Added STA_* status flags for clock state reporting

4. Clock operations supported:
   - ADJ_SETOFFSET: Apply time offset adjustment
   - ADJ_FREQUENCY: Adjust clock frequency (PPM)
   - ADJ_MAXERROR: Set maximum error estimate
   - ADJ_ESTERROR: Set estimated error
   - ADJ_STATUS: Modify clock status bits
   - ADJ_NANO: Use nanosecond resolution
   - ADJ_SETOFFSET: Set absolute time offset

5. API declarations:
   - Added clock_adjtime() prototype in include/nuttx/clock.h
   - Enabled by CONFIG_CLOCK_ADJTIME configuration
   - Compatible with Linux clock_adjtime() interface

Usage example:
  int fd = open("/dev/ptp0", O_RDWR);
  struct timex tx = {0};
  tx.modes = ADJ_FREQUENCY;
  tx.freq = 10000000;  /* Adjust frequency by 10 PPM */
  clock_adjtime(CLOCKFD(fd), &tx);
  close(fd);

This completes the PTP clock framework's POSIX clock API integration,
providing comprehensive time control capabilities for precision timing
applications including PTP synchronization daemons (ptp4l, timemaster).

Signed-off-by: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>
2025-12-30 10:22:09 -03:00

130 lines
5.2 KiB
C

/****************************************************************************
* include/sys/timex.h
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_SYS_TIMEX_H
#define __INCLUDE_SYS_TIMEX_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <sys/time.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Mode codes (timex.mode) */
#define ADJ_OFFSET 0x0001 /* time offset */
#define ADJ_FREQUENCY 0x0002 /* frequency offset */
#define ADJ_MAXERROR 0x0004 /* maximum time error */
#define ADJ_ESTERROR 0x0008 /* estimated time error */
#define ADJ_STATUS 0x0010 /* clock status */
#define ADJ_TIMECONST 0x0020 /* pll time constant */
#define ADJ_TAI 0x0080 /* set TAI offset */
#define ADJ_SETOFFSET 0x0100 /* add 'time' to current time */
#define ADJ_MICRO 0x1000 /* select microsecond resolution */
#define ADJ_NANO 0x2000 /* select nanosecond resolution */
#define ADJ_TICK 0x4000 /* tick value */
#define ADJ_OFFSET_SINGLESHOT 0x8001 /* old-fashioned adjtime */
#define ADJ_OFFSET_SS_READ 0xa001 /* read-only adjtime */
/****************************************************************************
* Public Types
****************************************************************************/
struct timex
{
unsigned int modes; /* mode selector */
long offset; /* time offset (usec) */
long freq; /* frequency offset (scaled ppm) */
long maxerror; /* maximum error (usec) */
long esterror; /* estimated error (usec) */
int status; /* clock command/status */
long constant; /* pll time constant */
long precision; /* clock precision (usec) (read only) */
long tolerance; /* clock frequency tolerance (ppm) (read only) */
struct timeval time; /* (read only, except for ADJ_SETOFFSET) */
long tick; /* (modified) usecs between clock ticks */
long ppsfreq; /* pps frequency (scaled ppm) (ro) */
long jitter; /* pps jitter (us) (ro) */
int shift; /* interval duration (s) (shift) (ro) */
long stabil; /* pps stability (scaled ppm) (ro) */
long jitcnt; /* jitter limit exceeded (ro) */
long calcnt; /* calibration intervals (ro) */
long errcnt; /* calibration errors (ro) */
long stbcnt; /* stability limit exceeded (ro) */
int tai; /* TAI offset (ro) */
};
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Name: clock_adjtime
*
* Description:
* Adjust the frequency and/or phase of a clock.
* This function allows the adjustment of the frequency and/or phase of a
* specified clock. It can be used to synchronize the clock with an
* external time source or to apply a frequency offset.
*
* Input Parameters:
* clk_id - The identifier of the clock to be adjusted. This is typically
* one of the predefined clock IDs such as CLOCK_REALTIME,
* CLOCK_MONOTONIC, or CLOCK_BOOTTIME.
*
* buf - A pointer to a `timex` structure that specifies the adjustment
* parameters. This structure includes fields for the frequency
* adjustment (`freq`), the maximum frequency error (`maxerror`),
* the estimated error (`esterror`), the phase offset (`offset`),
* and flags to indicate the type of adjustment (`status`).
*
* Returned Value:
* Return On success, the function returns 0. On error, it returns
* -1 and sets 'errno` to indicate the specific error that
* occurred.
*
****************************************************************************/
#ifdef CONFIG_CLOCK_ADJTIME
int clock_adjtime(clockid_t clk_id, FAR struct timex *buf);
#endif
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __INCLUDE_SYS_TIMEX_H */