| Message ID | 1436388401-32168-1-git-send-email-christopher.s.hall@intel.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On Wed, Jul 08, 2015 at 01:46:41PM -0700, Christopher Hall wrote: > This patch allows system and device time ("cross-timestamp") to be > performed by the driver. Currently, the cross-timestamping is performed > in the PTP_SYS_OFFSET ioctl. The PTP clock driver reads gettimeofday() > and the gettime64() callback provided by the driver. The cross-timestamp > is best effort where the latency between the capture of system time > (getnstimeofday()) and the device time (driver callback) may be > significant. The interface looks okay to me. Now all we need is a user of it... Acked-by: Richard Cochran <richardcochran@gmail.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Christopher Hall <christopher.s.hall@intel.com> Date: Wed, 8 Jul 2015 13:46:41 -0700 > This patch allows system and device time ("cross-timestamp") to be > performed by the driver. Currently, the cross-timestamping is performed > in the PTP_SYS_OFFSET ioctl. The PTP clock driver reads gettimeofday() > and the gettime64() callback provided by the driver. The cross-timestamp > is best effort where the latency between the capture of system time > (getnstimeofday()) and the device time (driver callback) may be > significant. Please resubmit this once there is an actual user of this new facility, not beforehand. Thank you. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
I am assuming the patch is rejected at this point. I will re-submit later as soon as I am able to post a full end to end solution. Chris > -----Original Message----- > From: Richard Cochran [mailto:richardcochran@gmail.com] > Sent: Thursday, July 09, 2015 7:58 AM > To: Hall, Christopher S > Cc: tglx@linutronix.de; john.stultz@linaro.org; Ronciak, John; linux- > kernel@vger.kernel.org; netdev@vger.kernel.org > Subject: Re: [PATCH v3] Add support for driver cross-timestamp to > PTP_SYS_OFFSET ioctl > > On Wed, Jul 08, 2015 at 01:46:41PM -0700, Christopher Hall wrote: > > This patch allows system and device time ("cross-timestamp") to be > > performed by the driver. Currently, the cross-timestamping is performed > > in the PTP_SYS_OFFSET ioctl. The PTP clock driver reads gettimeofday() > > and the gettime64() callback provided by the driver. The cross-timestamp > > is best effort where the latency between the capture of system time > > (getnstimeofday()) and the device time (driver callback) may be > > significant. > > The interface looks okay to me. Now all we need is a user of it... > > Acked-by: Richard Cochran <richardcochran@gmail.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/ptp/testptp.c b/Documentation/ptp/testptp.c index 2bc8abc..8004efd 100644 --- a/Documentation/ptp/testptp.c +++ b/Documentation/ptp/testptp.c @@ -276,13 +276,15 @@ int main(int argc, char *argv[]) " %d external time stamp channels\n" " %d programmable periodic signals\n" " %d pulse per second\n" - " %d programmable pins\n", + " %d programmable pins\n" + " %d cross timestamping\n", caps.max_adj, caps.n_alarm, caps.n_ext_ts, caps.n_per_out, caps.pps, - caps.n_pins); + caps.n_pins, + caps.cross_timestamping); } } diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c index da7bae9..f767ad6 100644 --- a/drivers/ptp/ptp_chardev.c +++ b/drivers/ptp/ptp_chardev.c @@ -124,7 +124,7 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); struct ptp_clock_info *ops = ptp->info; struct ptp_clock_time *pct; - struct timespec64 ts; + struct timespec64 ts, systs; int enable, err = 0; unsigned int i, pin_index; @@ -138,6 +138,7 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) caps.n_per_out = ptp->info->n_per_out; caps.pps = ptp->info->pps; caps.n_pins = ptp->info->n_pins; + caps.cross_timestamping = ptp->info->getsynctime64 != NULL; if (copy_to_user((void __user *)arg, &caps, sizeof(caps))) err = -EFAULT; break; @@ -196,19 +197,31 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) break; } pct = &sysoff->ts[0]; - for (i = 0; i < sysoff->n_samples; i++) { - getnstimeofday64(&ts); + if (ptp->info->getsynctime64 && sysoff->n_samples == 1) { + ptp->info->getsynctime64(ptp->info, &ts, &systs); + pct->sec = systs.tv_sec; + pct->nsec = systs.tv_nsec; + pct++; pct->sec = ts.tv_sec; pct->nsec = ts.tv_nsec; pct++; - ptp->info->gettime64(ptp->info, &ts); + pct->sec = systs.tv_sec; + pct->nsec = systs.tv_nsec; + } else { + for (i = 0; i < sysoff->n_samples; i++) { + getnstimeofday64(&ts); + pct->sec = ts.tv_sec; + pct->nsec = ts.tv_nsec; + pct++; + ptp->info->gettime64(ptp->info, &ts); + pct->sec = ts.tv_sec; + pct->nsec = ts.tv_nsec; + pct++; + } + getnstimeofday64(&ts); pct->sec = ts.tv_sec; pct->nsec = ts.tv_nsec; - pct++; } - getnstimeofday64(&ts); - pct->sec = ts.tv_sec; - pct->nsec = ts.tv_nsec; if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff))) err = -EFAULT; break; diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h index b8b7306..8c43345 100644 --- a/include/linux/ptp_clock_kernel.h +++ b/include/linux/ptp_clock_kernel.h @@ -67,6 +67,11 @@ struct ptp_clock_request { * @gettime64: Reads the current time from the hardware clock. * parameter ts: Holds the result. * + * @getsynctime64: Reads the current time from the hardware clock and system + * clock simultaneously. + * parameter dev: Holds the device time + * parameter sys: Holds the system time + * * @settime64: Set the current time on the hardware clock. * parameter ts: Time value to set. * @@ -105,6 +110,8 @@ struct ptp_clock_info { int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta); int (*adjtime)(struct ptp_clock_info *ptp, s64 delta); int (*gettime64)(struct ptp_clock_info *ptp, struct timespec64 *ts); + int (*getsynctime64)(struct ptp_clock_info *ptp, struct timespec64 *dev, + struct timespec64 *sys); int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts); int (*enable)(struct ptp_clock_info *ptp, struct ptp_clock_request *request, int on); diff --git a/include/uapi/linux/ptp_clock.h b/include/uapi/linux/ptp_clock.h index f0b7bfe..ffb2635 100644 --- a/include/uapi/linux/ptp_clock.h +++ b/include/uapi/linux/ptp_clock.h @@ -51,7 +51,9 @@ struct ptp_clock_caps { int n_per_out; /* Number of programmable periodic signals. */ int pps; /* Whether the clock supports a PPS callback. */ int n_pins; /* Number of input/output pins. */ - int rsv[14]; /* Reserved for future use. */ + /* Whether the clock supports precise system-device cross timestamps */ + int cross_timestamping; + int rsv[13]; /* Reserved for future use. */ }; struct ptp_extts_request {
This patch allows system and device time ("cross-timestamp") to be performed by the driver. Currently, the cross-timestamping is performed in the PTP_SYS_OFFSET ioctl. The PTP clock driver reads gettimeofday() and the gettime64() callback provided by the driver. The cross-timestamp is best effort where the latency between the capture of system time (getnstimeofday()) and the device time (driver callback) may be significant. This patch adds an additional callback getsynctime64(). Which will be called when the driver is able to perform a more accurate, implementation specific cross-timestamping. For example, future network devices that implement PCIE PTM will be able to precisely correlate the device clock with the system clock with virtually zero latency between captures. This added callback can be used by the driver to expose this functionality. The callback, getsynctime64(), will only be called when defined and n_samples == 1 because the driver returns only 1 cross-timestamp where multiple samples cannot be chained together. This patch also adds to the capabilities ioctl (PTP_CLOCK_GETCAPS), allowing applications to query whether or not drivers implement the getsynctime callback, providing more precise cross timestamping. Commit Details: Added additional callback to ptp_clock_info: * getsynctime64() This takes 2 arguments referring to system and device time With this callback drivers may provide both system time and device time to ensure precise correlation Modified PTP_SYS_OFFSET ioctl in PTP clock driver to use the above callback if it's available Added capability (PTP_CLOCK_GETCAPS) for checking whether driver supports cross timestamping Added check for cross timestamping flag to testptp.c Signed-off-by: Christopher Hall <christopher.s.hall@intel.com> --- Documentation/ptp/testptp.c | 6 ++++-- drivers/ptp/ptp_chardev.c | 29 +++++++++++++++++++++-------- include/linux/ptp_clock_kernel.h | 7 +++++++ include/uapi/linux/ptp_clock.h | 4 +++- 4 files changed, 35 insertions(+), 11 deletions(-)