[PATCH 5/5] Enables cross timestamping in the e1000e driver

Christopher Hall
2015-07-28T00:46:09Z

Adds getsynctime64() callback which captures "raw" cross timestamp
between ART and Ethernet device clock
Translates captured ART to REALTIME clock

Signed-off-by: Christopher Hall <christopher.s.hall@intel.com>
---
drivers/net/ethernet/intel/e1000e/defines.h | 7 +++
drivers/net/ethernet/intel/e1000e/ptp.c | 83 +++++++++++++++++++++++++++++
drivers/net/ethernet/intel/e1000e/regs.h | 4 ++
3 files changed, 94 insertions(+)

diff --git a/drivers/net/ethernet/intel/e1000e/defines.h b/drivers/net/ethernet/intel/e1000e/defines.h
index 133d407..9f16269 100644
--- a/drivers/net/ethernet/intel/e1000e/defines.h
+++ b/drivers/net/ethernet/intel/e1000e/defines.h
@@ -527,6 +527,13 @@
#define E1000_RXCW_C 0x20000000 /* Receive config */
#define E1000_RXCW_SYNCH 0x40000000 /* Receive config synch */

+/* HH Time Sync */
+#define E1000_TSYNCTXCTL_MAX_ALLOWED_DLY_MASK 0x0000F000 /* max delay */
+#define E1000_TSYNCTXCTL_SYNC_COMP 0x40000000 /* sync complete
+ */
+#define E1000_TSYNCTXCTL_START_SYNC 0x80000000 /* initiate sync
+ */
+
#define E1000_TSYNCTXCTL_VALID 0x00000001 /* Tx timestamp valid */
#define E1000_TSYNCTXCTL_ENABLED 0x00000010 /* enable Tx timestamping */

diff --git a/drivers/net/ethernet/intel/e1000e/ptp.c b/drivers/net/ethernet/intel/e1000e/ptp.c
index 25a0ad5..bd8b888 100644
--- a/drivers/net/ethernet/intel/e1000e/ptp.c
+++ b/drivers/net/ethernet/intel/e1000e/ptp.c
@@ -25,6 +25,7 @@
*/

#include "e1000.h"
+#include <asm/art.h>

/**
* e1000e_phc_adjfreq - adjust the frequency of the hardware clock
@@ -98,6 +99,87 @@ static int e1000e_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
return 0;
}

+#define HW_WAIT_COUNT (2)
+#define HW_RETRY_COUNT (2)
+
+static int e1000e_phc_read_timestamp_pair(struct e1000_adapter *adapter,
+ u64 *systim, u64 *plttim)
+{
+ struct e1000_hw *hw = &adapter->hw;
+ int i, j;
+ u32 tsync_ctrl;
+ int ret;
+
+ if (hw->mac.type < e1000_pch_spt)
+ return -ENXIO;
+
+ for (j = 0; j < HW_RETRY_COUNT; ++j) {
+ tsync_ctrl = er32(TSYNCTXCTL);
+ tsync_ctrl |= E1000_TSYNCTXCTL_START_SYNC |
+ E1000_TSYNCTXCTL_MAX_ALLOWED_DLY_MASK;
+ ew32(TSYNCTXCTL, tsync_ctrl);
+ ret = 0;
+ for (i = 0; i < HW_WAIT_COUNT; ++i) {
+ udelay(2);
+ tsync_ctrl = er32(TSYNCTXCTL);
+ if (tsync_ctrl & E1000_TSYNCTXCTL_SYNC_COMP)
+ break;
+ }
+
+ if (i == HW_WAIT_COUNT) {
+ ret = -ETIMEDOUT;
+ } else if (ret == 0) {
+ *plttim = er32(PLTSTMPH);
+ *plttim <<= 32;
+ *plttim |= er32(PLTSTMPL);
+ *systim = er32(SYSSTMPH);
+ *systim <<= 32;
+ *systim |= er32(SYSSTMPL);
+ break;
+ }
+ }
+
+ return ret;
+}
+
+#define SYNCTIME_RETRY_COUNT (2)
+
+static int e1000e_phc_getsynctime(struct ptp_clock_info *ptp,
+ struct timespec64 *devts,
+ struct timespec64 *systs)
+{
+ struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
+ ptp_clock_info);
+ unsigned long flags;
+ u32 remainder;
+ u64 plttim, systim;
+
+ int i, ret;
+
+ if (!has_art())
+ return -ENXIO;
+
+ for (i = 0; i < SYNCTIME_RETRY_COUNT; ++i) {
+ ret = e1000e_phc_read_timestamp_pair
+ (adapter, &systim, &plttim);
+ if (ret != 0)
+ continue;
+
+ ret = art_to_realtime64(systs, plttim);
+ if (ret == 0) {
+ spin_lock_irqsave(&adapter->systim_lock, flags);
+ systim = timecounter_cyc2time(&adapter->tc, systim);
+ spin_unlock_irqrestore(&adapter->systim_lock, flags);
+ devts->tv_sec =
+ div_u64_rem(systim, NSEC_PER_SEC, &remainder);
+ devts->tv_nsec = remainder;
+ break;
+ }
+ }
+
+ return ret;
+}
+
/**
* e1000e_phc_gettime - Reads the current time from the hardware clock
* @ptp: ptp clock structure
@@ -190,6 +272,7 @@ static const struct ptp_clock_info e1000e_ptp_clock_info = {
.adjfreq = e1000e_phc_adjfreq,
.adjtime = e1000e_phc_adjtime,
.gettime64 = e1000e_phc_gettime,
+ .getsynctime64 = e1000e_phc_getsynctime,
.settime64 = e1000e_phc_settime,
.enable = e1000e_phc_enable,
};
diff --git a/drivers/net/ethernet/intel/e1000e/regs.h b/drivers/net/ethernet/intel/e1000e/regs.h
index b24e5fe..4dd5b54 100644
--- a/drivers/net/ethernet/intel/e1000e/regs.h
+++ b/drivers/net/ethernet/intel/e1000e/regs.h
@@ -246,6 +246,10 @@
#define E1000_SYSTIML 0x0B600 /* System time register Low - RO */
#define E1000_SYSTIMH 0x0B604 /* System time register High - RO */
#define E1000_TIMINCA 0x0B608 /* Increment attributes register - RW */
+#define E1000_SYSSTMPL 0x0B648 /* HH Timesync system stamp low register */
+#define E1000_SYSSTMPH 0x0B64C /* HH Timesync system stamp hi register */
+#define E1000_PLTSTMPL 0x0B640 /* HH Timesync platform stamp low register */
+#define E1000_PLTSTMPH 0x0B644 /* HH Timesync platform stamp hi register */
#define E1000_RXMTRL 0x0B634 /* Time sync Rx EtherType and Msg Type - RW */
#define E1000_RXUDP 0x0B638 /* Time Sync Rx UDP Port - RW */

--
1.9.1