bnxt_en: Add driver support to use Real Time Counter for PTP

Add support for RTC mode if it is supported by firmware.  In RTC
mode, the PHC is set to the 64-bit clock.  Because the legacy interface
is 48-bit, the driver still has to keep track of the upper 16 bits and
handle the rollover.

Cc: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 69 insertions, 4 deletions

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
index 921aa7f75c9a..066e5a9bb29e 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
@@ -19,6 +19,20 @@
 #include "bnxt_hwrm.h"
 #include "bnxt_ptp.h"
 
+static int bnxt_ptp_cfg_settime(struct bnxt *bp, u64 time)
+{
+	struct hwrm_func_ptp_cfg_input *req;
+	int rc;
+
+	rc = hwrm_req_init(bp, req, HWRM_FUNC_PTP_CFG);
+	if (rc)
+		return rc;
+
+	req->enables = cpu_to_le16(FUNC_PTP_CFG_REQ_ENABLES_PTP_SET_TIME);
+	req->ptp_set_time = cpu_to_le64(time);
+	return hwrm_req_send(bp, req);
+}
+
 int bnxt_ptp_parse(struct sk_buff *skb, u16 *seq_id, u16 *hdr_off)
 {
 	unsigned int ptp_class;
@@ -48,6 +62,9 @@ static int bnxt_ptp_settime(struct ptp_clock_info *ptp_info,
 						ptp_info);
 	u64 ns = timespec64_to_ns(ts);
 
+	if (ptp->bp->fw_cap & BNXT_FW_CAP_PTP_RTC)
+		return bnxt_ptp_cfg_settime(ptp->bp, ns);
+
 	spin_lock_bh(&ptp->ptp_lock);
 	timecounter_init(&ptp->tc, &ptp->cc, ns);
 	spin_unlock_bh(&ptp->ptp_lock);
@@ -730,6 +747,41 @@ static void bnxt_ptp_timecounter_init(struct bnxt *bp, bool init_tc)
 		timecounter_init(&ptp->tc, &ptp->cc, ktime_to_ns(ktime_get_real()));
 }
 
+/* Caller holds ptp_lock */
+void bnxt_ptp_rtc_timecounter_init(struct bnxt_ptp_cfg *ptp, u64 ns)
+{
+	timecounter_init(&ptp->tc, &ptp->cc, ns);
+	/* For RTC, cycle_last must be in sync with the timecounter value. */
+	ptp->tc.cycle_last = ns & ptp->cc.mask;
+}
+
+int bnxt_ptp_init_rtc(struct bnxt *bp, bool phc_cfg)
+{
+	struct timespec64 tsp;
+	u64 ns;
+	int rc;
+
+	if (!bp->ptp_cfg || !(bp->fw_cap & BNXT_FW_CAP_PTP_RTC))
+		return -ENODEV;
+
+	if (!phc_cfg) {
+		ktime_get_real_ts64(&tsp);
+		ns = timespec64_to_ns(&tsp);
+		rc = bnxt_ptp_cfg_settime(bp, ns);
+		if (rc)
+			return rc;
+	} else {
+		rc = bnxt_hwrm_port_ts_query(bp, PORT_TS_QUERY_REQ_FLAGS_CURRENT_TIME, &ns);
+		if (rc)
+			return rc;
+	}
+	spin_lock_bh(&bp->ptp_cfg->ptp_lock);
+	bnxt_ptp_rtc_timecounter_init(bp->ptp_cfg, ns);
+	spin_unlock_bh(&bp->ptp_cfg->ptp_lock);
+
+	return 0;
+}
+
 static void bnxt_ptp_free(struct bnxt *bp)
 {
 	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
@@ -742,7 +794,7 @@ static void bnxt_ptp_free(struct bnxt *bp)
 	}
 }
 
-int bnxt_ptp_init(struct bnxt *bp)
+int bnxt_ptp_init(struct bnxt *bp, bool phc_cfg)
 {
 	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
 	int rc;
@@ -754,6 +806,13 @@ int bnxt_ptp_init(struct bnxt *bp)
 	if (rc)
 		return rc;
 
+	if (bp->fw_cap & BNXT_FW_CAP_PTP_RTC) {
+		bnxt_ptp_timecounter_init(bp, false);
+		rc = bnxt_ptp_init_rtc(bp, phc_cfg);
+		if (rc)
+			goto out;
+	}
+
 	if (ptp->ptp_clock && bnxt_pps_config_ok(bp))
 		return 0;
 
@@ -762,7 +821,8 @@ int bnxt_ptp_init(struct bnxt *bp)
 	atomic_set(&ptp->tx_avail, BNXT_MAX_TX_TS);
 	spin_lock_init(&ptp->ptp_lock);
 
-	bnxt_ptp_timecounter_init(bp, true);
+	if (!(bp->fw_cap & BNXT_FW_CAP_PTP_RTC))
+		bnxt_ptp_timecounter_init(bp, true);
 
 	ptp->ptp_info = bnxt_ptp_caps;
 	if ((bp->fw_cap & BNXT_FW_CAP_PTP_PPS)) {
@@ -774,8 +834,8 @@ int bnxt_ptp_init(struct bnxt *bp)
 		int err = PTR_ERR(ptp->ptp_clock);
 
 		ptp->ptp_clock = NULL;
-		bnxt_unmap_ptp_regs(bp);
-		return err;
+		rc = err;
+		goto out;
 	}
 	if (bp->flags & BNXT_FLAG_CHIP_P5) {
 		spin_lock_bh(&ptp->ptp_lock);
@@ -785,6 +845,11 @@ int bnxt_ptp_init(struct bnxt *bp)
 		ptp_schedule_worker(ptp->ptp_clock, 0);
 	}
 	return 0;
+
+out:
+	bnxt_ptp_free(bp);
+	bnxt_unmap_ptp_regs(bp);
+	return rc;
 }
 
 void bnxt_ptp_clear(struct bnxt *bp)