[PATCH net-next 8/9] net: sparx5: Add support for ptp interrupts

From: Horatiu Vultur
Date: Fri Mar 04 2022 - 06:09:08 EST


When doing 2-step timestamping the HW will generate an interrupt when it
managed to timestamp a frame. It is the SW responsibility to read it
from the FIFO.

Signed-off-by: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>
---
.../ethernet/microchip/sparx5/sparx5_main.c | 13 ++
.../ethernet/microchip/sparx5/sparx5_main.h | 2 +
.../ethernet/microchip/sparx5/sparx5_ptp.c | 119 ++++++++++++++++++
3 files changed, 134 insertions(+)

diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_main.c b/drivers/net/ethernet/microchip/sparx5/sparx5_main.c
index f72da757d0fa..5f7c7030ce03 100644
--- a/drivers/net/ethernet/microchip/sparx5/sparx5_main.c
+++ b/drivers/net/ethernet/microchip/sparx5/sparx5_main.c
@@ -693,6 +693,18 @@ static int sparx5_start(struct sparx5 *sparx5)
} else {
sparx5->xtr_irq = -ENXIO;
}
+
+ if (sparx5->ptp_irq >= 0) {
+ err = devm_request_threaded_irq(sparx5->dev, sparx5->ptp_irq,
+ NULL, sparx5_ptp_irq_handler,
+ IRQF_ONESHOT, "sparx5-ptp",
+ sparx5);
+ if (err)
+ sparx5->ptp_irq = -ENXIO;
+
+ sparx5->ptp = 1;
+ }
+
return err;
}

@@ -809,6 +821,7 @@ static int mchp_sparx5_probe(struct platform_device *pdev)

sparx5->fdma_irq = platform_get_irq_byname(sparx5->pdev, "fdma");
sparx5->xtr_irq = platform_get_irq_byname(sparx5->pdev, "xtr");
+ sparx5->ptp_irq = platform_get_irq_byname(sparx5->pdev, "ptp");

/* Read chip ID to check CPU interface */
sparx5->chip_id = spx5_rd(sparx5, GCB_CHIP_ID);
diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_main.h b/drivers/net/ethernet/microchip/sparx5/sparx5_main.h
index 16d691fdee65..33892dfc3b2f 100644
--- a/drivers/net/ethernet/microchip/sparx5/sparx5_main.h
+++ b/drivers/net/ethernet/microchip/sparx5/sparx5_main.h
@@ -270,6 +270,7 @@ struct sparx5 {
spinlock_t ptp_ts_id_lock; /* lock for ts_id */
struct mutex ptp_lock; /* lock for ptp interface state */
u16 ptp_skbs;
+ int ptp_irq;
};

/* sparx5_switchdev.c */
@@ -355,6 +356,7 @@ int sparx5_ptp_txtstamp_request(struct sparx5_port *port,
struct sk_buff *skb);
void sparx5_ptp_txtstamp_release(struct sparx5_port *port,
struct sk_buff *skb);
+irqreturn_t sparx5_ptp_irq_handler(int irq, void *args);

/* Clock period in picoseconds */
static inline u32 sparx5_clk_period(enum sparx5_core_clockfreq cclock)
diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_ptp.c b/drivers/net/ethernet/microchip/sparx5/sparx5_ptp.c
index 976817d826ac..fa377f6e7e08 100644
--- a/drivers/net/ethernet/microchip/sparx5/sparx5_ptp.c
+++ b/drivers/net/ethernet/microchip/sparx5/sparx5_ptp.c
@@ -271,6 +271,125 @@ void sparx5_ptp_txtstamp_release(struct sparx5_port *port,
spin_unlock_irqrestore(&sparx5->ptp_ts_id_lock, flags);
}

+static void sparx5_get_hwtimestamp(struct sparx5 *sparx5,
+ struct timespec64 *ts,
+ u32 nsec)
+{
+ /* Read current PTP time to get seconds */
+ unsigned long flags;
+ u32 curr_nsec;
+
+ spin_lock_irqsave(&sparx5->ptp_clock_lock, flags);
+
+ spx5_rmw(PTP_PTP_PIN_CFG_PTP_PIN_ACTION_SET(PTP_PIN_ACTION_SAVE) |
+ PTP_PTP_PIN_CFG_PTP_PIN_DOM_SET(SPARX5_PHC_PORT) |
+ PTP_PTP_PIN_CFG_PTP_PIN_SYNC_SET(0),
+ PTP_PTP_PIN_CFG_PTP_PIN_ACTION |
+ PTP_PTP_PIN_CFG_PTP_PIN_DOM |
+ PTP_PTP_PIN_CFG_PTP_PIN_SYNC,
+ sparx5, PTP_PTP_PIN_CFG(TOD_ACC_PIN));
+
+ ts->tv_sec = spx5_rd(sparx5, PTP_PTP_TOD_SEC_LSB(TOD_ACC_PIN));
+ curr_nsec = spx5_rd(sparx5, PTP_PTP_TOD_NSEC(TOD_ACC_PIN));
+
+ ts->tv_nsec = nsec;
+
+ /* Sec has incremented since the ts was registered */
+ if (curr_nsec < nsec)
+ ts->tv_sec--;
+
+ spin_unlock_irqrestore(&sparx5->ptp_clock_lock, flags);
+}
+
+irqreturn_t sparx5_ptp_irq_handler(int irq, void *args)
+{
+ int budget = SPARX5_MAX_PTP_ID;
+ struct sparx5 *sparx5 = args;
+
+ while (budget--) {
+ struct sk_buff *skb, *skb_tmp, *skb_match = NULL;
+ struct skb_shared_hwtstamps shhwtstamps;
+ struct sparx5_port *port;
+ struct timespec64 ts;
+ unsigned long flags;
+ u32 val, id, txport;
+ u32 delay;
+
+ val = spx5_rd(sparx5, REW_PTP_TWOSTEP_CTRL);
+
+ /* Check if a timestamp can be retrieved */
+ if (!(val & REW_PTP_TWOSTEP_CTRL_PTP_VLD))
+ break;
+
+ WARN_ON(val & REW_PTP_TWOSTEP_CTRL_PTP_OVFL);
+
+ if (!(val & REW_PTP_TWOSTEP_CTRL_STAMP_TX))
+ continue;
+
+ /* Retrieve the ts Tx port */
+ txport = REW_PTP_TWOSTEP_CTRL_STAMP_PORT_GET(val);
+
+ /* Retrieve its associated skb */
+ port = sparx5->ports[txport];
+
+ /* Retrieve the delay */
+ delay = spx5_rd(sparx5, REW_PTP_TWOSTEP_STAMP);
+ delay = REW_PTP_TWOSTEP_STAMP_STAMP_NSEC_GET(delay);
+
+ /* Get next timestamp from fifo, which needs to be the
+ * rx timestamp which represents the id of the frame
+ */
+ spx5_rmw(REW_PTP_TWOSTEP_CTRL_PTP_NXT_SET(1),
+ REW_PTP_TWOSTEP_CTRL_PTP_NXT,
+ sparx5, REW_PTP_TWOSTEP_CTRL);
+
+ val = spx5_rd(sparx5, REW_PTP_TWOSTEP_CTRL);
+
+ /* Check if a timestamp can be retried */
+ if (!(val & REW_PTP_TWOSTEP_CTRL_PTP_VLD))
+ break;
+
+ /* Read RX timestamping to get the ID */
+ id = spx5_rd(sparx5, REW_PTP_TWOSTEP_STAMP);
+ id <<= 8;
+ id |= spx5_rd(sparx5, REW_PTP_TWOSTEP_STAMP_SUBNS);
+
+ spin_lock_irqsave(&port->tx_skbs.lock, flags);
+ skb_queue_walk_safe(&port->tx_skbs, skb, skb_tmp) {
+ if (SPARX5_SKB_CB(skb)->ts_id != id)
+ continue;
+
+ __skb_unlink(skb, &port->tx_skbs);
+ skb_match = skb;
+ break;
+ }
+ spin_unlock_irqrestore(&port->tx_skbs.lock, flags);
+
+ /* Next ts */
+ spx5_rmw(REW_PTP_TWOSTEP_CTRL_PTP_NXT_SET(1),
+ REW_PTP_TWOSTEP_CTRL_PTP_NXT,
+ sparx5, REW_PTP_TWOSTEP_CTRL);
+
+ if (WARN_ON(!skb_match))
+ continue;
+
+ spin_lock(&sparx5->ptp_ts_id_lock);
+ sparx5->ptp_skbs--;
+ spin_unlock(&sparx5->ptp_ts_id_lock);
+
+ /* Get the h/w timestamp */
+ sparx5_get_hwtimestamp(sparx5, &ts, delay);
+
+ /* Set the timestamp into the skb */
+ shhwtstamps.hwtstamp = ktime_set(ts.tv_sec, ts.tv_nsec);
+ skb_tstamp_tx(skb_match, &shhwtstamps);
+
+ dev_kfree_skb_any(skb_match);
+ }
+
+ return IRQ_HANDLED;
+}
+
static int sparx5_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
{
struct sparx5_phc *phc = container_of(ptp, struct sparx5_phc, info);
--
2.33.0