* 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
precise timestamping
Signed-off-by: Christopher Hall <christopher.s.h...@intel.com>
---
drivers/ptp/ptp_chardev.c | 29 +++++++++++++++++++++--------
include/linux/ptp_clock_kernel.h | 8 ++++++++
include/uapi/linux/ptp_clock.h | 4 +++-
3 files changed, 32 insertions(+), 9 deletions(-)
diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index da7bae9..2a83aea 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.precise_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..344f129 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 +110,9 @@ 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..421b637 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 precise_timestamping;
+ int rsv[13]; /* Reserved for future use. */
};
struct ptp_extts_request {
--
1.9.1
--
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