[net-next, v4, 06/11] ptp: add kernel API ptp_convert_timestamp()

From: Yangbo Lu
Date: Fri Jun 25 2021 - 05:24:47 EST


Add kernel API ptp_convert_timestamp() to convert raw hardware timestamp
to a specified ptp vclock time.

Signed-off-by: Yangbo Lu <yangbo.lu@xxxxxxx>
---
Changes for v2:
- Split from v1 patch #1 and #2.
- Fixed build warning.
Changes for v3:
- Converted HW timestamps to PHC bound, instead of previous
binding domain value to PHC idea.
Changes for v4:
- Fixed build issue.
---
drivers/ptp/ptp_vclock.c | 34 ++++++++++++++++++++++++++++++++
include/linux/ptp_clock_kernel.h | 13 ++++++++++++
2 files changed, 47 insertions(+)

diff --git a/drivers/ptp/ptp_vclock.c b/drivers/ptp/ptp_vclock.c
index cefab29a0592..e0f87c57749a 100644
--- a/drivers/ptp/ptp_vclock.c
+++ b/drivers/ptp/ptp_vclock.c
@@ -183,3 +183,37 @@ int ptp_get_vclocks_index(int pclock_index, int **vclock_index)
return num;
}
EXPORT_SYMBOL(ptp_get_vclocks_index);
+
+void ptp_convert_timestamp(struct skb_shared_hwtstamps *hwtstamps,
+ int vclock_index)
+{
+ char name[PTP_CLOCK_NAME_LEN] = "";
+ struct ptp_vclock *vclock;
+ struct ptp_clock *ptp;
+ unsigned long flags;
+ struct device *dev;
+ u64 ns;
+
+ snprintf(name, PTP_CLOCK_NAME_LEN, "ptp%d", vclock_index);
+ dev = class_find_device_by_name(ptp_class, name);
+ if (!dev)
+ return;
+
+ ptp = dev_get_drvdata(dev);
+ if (!ptp->is_virtual_clock) {
+ put_device(dev);
+ return;
+ }
+
+ vclock = info_to_vclock(ptp->info);
+
+ ns = ktime_to_ns(hwtstamps->hwtstamp);
+
+ spin_lock_irqsave(&vclock->lock, flags);
+ ns = timecounter_cyc2time(&vclock->tc, ns);
+ spin_unlock_irqrestore(&vclock->lock, flags);
+
+ put_device(dev);
+ hwtstamps->hwtstamp = ns_to_ktime(ns);
+}
+EXPORT_SYMBOL(ptp_convert_timestamp);
diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h
index 300a984fec87..71fac9237725 100644
--- a/include/linux/ptp_clock_kernel.h
+++ b/include/linux/ptp_clock_kernel.h
@@ -12,6 +12,7 @@
#include <linux/pps_kernel.h>
#include <linux/ptp_clock.h>
#include <linux/timecounter.h>
+#include <linux/skbuff.h>

#define PTP_CLOCK_NAME_LEN 32
/**
@@ -318,6 +319,15 @@ void ptp_cancel_worker_sync(struct ptp_clock *ptp);
*/
int ptp_get_vclocks_index(int pclock_index, int **vclock_index);

+/**
+ * ptp_convert_timestamp() - convert timestamp to a ptp vclock time
+ *
+ * @hwtstamps: skb_shared_hwtstamps structure pointer
+ * @vclock_index: phc index of ptp vclock.
+ */
+void ptp_convert_timestamp(struct skb_shared_hwtstamps *hwtstamps,
+ int vclock_index);
+
#else
static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
struct device *parent)
@@ -339,6 +349,9 @@ static inline void ptp_cancel_worker_sync(struct ptp_clock *ptp)
{ }
static inline int ptp_get_vclocks_index(int pclock_index, int **vclock_index)
{ return 0; }
+static inline void ptp_convert_timestamp(struct skb_shared_hwtstamps *hwtstamps,
+ int vclock_index)
+{ }

#endif

--
2.25.1