net: stmmac: socfpga: Add hardware supported cross-timestamp

Cross timestamping is supported on Agilex5 platform with Synchronized
Multidrop Timestamp Gathering(SMTG) IP. The hardware cross-timestamp
result is made available the applications through the ioctl call
PTP_SYS_OFFSET_PRECISE, which inturn calls stmmac_getcrosststamp().

Device time is stored in the MAC Auxiliary register. The 64-bit System
time (ARM_ARCH_COUNTER) is stored in SMTG IP. SMTG IP is an MDIO device
with 0xC - 0xF MDIO register space holds 64-bit system time.

This commit is similar to following commit for Intel platforms:
Commit 341f67e424e5 ("net: stmmac: Add hardware supported cross-timestamp")

Signed-off-by: Rohan G Thomas <rohan.g.thomas@altera.com>
Link: https://patch.msgid.link/20251101-agilex5_ext-v2-4-a6b51b4dca4d@altera.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 120 insertions, 0 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
index 1837346ca2d4..49d651948e2b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
@@ -5,6 +5,7 @@
  */
 
 #include <linux/mfd/altera-sysmgr.h>
+#include <linux/clocksource_ids.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_net.h>
@@ -15,8 +16,10 @@
 #include <linux/reset.h>
 #include <linux/stmmac.h>
 
+#include "dwxgmac2.h"
 #include "stmmac.h"
 #include "stmmac_platform.h"
+#include "stmmac_ptp.h"
 
 #define SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_GMII_MII 0x0
 #define SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_RGMII 0x1
@@ -41,6 +44,13 @@
 #define SGMII_ADAPTER_ENABLE		0x0000
 #define SGMII_ADAPTER_DISABLE		0x0001
 
+#define SMTG_MDIO_ADDR		0x15
+#define SMTG_TSC_WORD0		0xC
+#define SMTG_TSC_WORD1		0xD
+#define SMTG_TSC_WORD2		0xE
+#define SMTG_TSC_WORD3		0xF
+#define SMTG_TSC_SHIFT		16
+
 struct socfpga_dwmac;
 struct socfpga_dwmac_ops {
 	int (*set_phy_mode)(struct socfpga_dwmac *dwmac_priv);
@@ -269,6 +279,112 @@ static int socfpga_set_phy_mode_common(int phymode, u32 *val)
 	return 0;
 }
 
+static void get_smtgtime(struct mii_bus *mii, int smtg_addr, u64 *smtg_time)
+{
+	u64 ns;
+
+	ns = mdiobus_read(mii, smtg_addr, SMTG_TSC_WORD3);
+	ns <<= SMTG_TSC_SHIFT;
+	ns |= mdiobus_read(mii, smtg_addr, SMTG_TSC_WORD2);
+	ns <<= SMTG_TSC_SHIFT;
+	ns |= mdiobus_read(mii, smtg_addr, SMTG_TSC_WORD1);
+	ns <<= SMTG_TSC_SHIFT;
+	ns |= mdiobus_read(mii, smtg_addr, SMTG_TSC_WORD0);
+
+	*smtg_time = ns;
+}
+
+static int smtg_crosststamp(ktime_t *device, struct system_counterval_t *system,
+			    void *ctx)
+{
+	struct stmmac_priv *priv = (struct stmmac_priv *)ctx;
+	u32 num_snapshot, gpio_value, acr_value;
+	void __iomem *ptpaddr = priv->ptpaddr;
+	void __iomem *ioaddr = priv->hw->pcsr;
+	unsigned long flags;
+	u64 smtg_time = 0;
+	u64 ptp_time = 0;
+	int i, ret;
+	u32 v;
+
+	/* Both internal crosstimestamping and external triggered event
+	 * timestamping cannot be run concurrently.
+	 */
+	if (priv->plat->flags & STMMAC_FLAG_EXT_SNAPSHOT_EN)
+		return -EBUSY;
+
+	mutex_lock(&priv->aux_ts_lock);
+	/* Enable Internal snapshot trigger */
+	acr_value = readl(ptpaddr + PTP_ACR);
+	acr_value &= ~PTP_ACR_MASK;
+	switch (priv->plat->int_snapshot_num) {
+	case AUX_SNAPSHOT0:
+		acr_value |= PTP_ACR_ATSEN0;
+		break;
+	case AUX_SNAPSHOT1:
+		acr_value |= PTP_ACR_ATSEN1;
+		break;
+	case AUX_SNAPSHOT2:
+		acr_value |= PTP_ACR_ATSEN2;
+		break;
+	case AUX_SNAPSHOT3:
+		acr_value |= PTP_ACR_ATSEN3;
+		break;
+	default:
+		mutex_unlock(&priv->aux_ts_lock);
+		return -EINVAL;
+	}
+	writel(acr_value, ptpaddr + PTP_ACR);
+
+	/* Clear FIFO */
+	acr_value = readl(ptpaddr + PTP_ACR);
+	acr_value |= PTP_ACR_ATSFC;
+	writel(acr_value, ptpaddr + PTP_ACR);
+	/* Release the mutex */
+	mutex_unlock(&priv->aux_ts_lock);
+
+	/* Trigger Internal snapshot signal. Create a rising edge by just toggle
+	 * the GPO0 to low and back to high.
+	 */
+	gpio_value = readl(ioaddr + XGMAC_GPIO_STATUS);
+	gpio_value &= ~XGMAC_GPIO_GPO0;
+	writel(gpio_value, ioaddr + XGMAC_GPIO_STATUS);
+	gpio_value |= XGMAC_GPIO_GPO0;
+	writel(gpio_value, ioaddr + XGMAC_GPIO_STATUS);
+
+	/* Poll for time sync operation done */
+	ret = readl_poll_timeout(priv->ioaddr + XGMAC_INT_STATUS, v,
+				 (v & XGMAC_INT_TSIS), 100, 10000);
+	if (ret) {
+		netdev_err(priv->dev, "%s: Wait for time sync operation timeout\n",
+			   __func__);
+		return ret;
+	}
+
+	*system = (struct system_counterval_t) {
+		.cycles = 0,
+		.cs_id = CSID_ARM_ARCH_COUNTER,
+		.use_nsecs = false,
+	};
+
+	num_snapshot = (readl(ioaddr + XGMAC_TIMESTAMP_STATUS) &
+			XGMAC_TIMESTAMP_ATSNS_MASK) >>
+			XGMAC_TIMESTAMP_ATSNS_SHIFT;
+
+	/* Repeat until the timestamps are from the FIFO last segment */
+	for (i = 0; i < num_snapshot; i++) {
+		read_lock_irqsave(&priv->ptp_lock, flags);
+		stmmac_get_ptptime(priv, ptpaddr, &ptp_time);
+		*device = ns_to_ktime(ptp_time);
+		read_unlock_irqrestore(&priv->ptp_lock, flags);
+	}
+
+	get_smtgtime(priv->mii, SMTG_MDIO_ADDR, &smtg_time);
+	system->cycles = smtg_time;
+
+	return 0;
+}
+
 static int socfpga_gen5_set_phy_mode(struct socfpga_dwmac *dwmac)
 {
 	struct regmap *sys_mgr_base_addr = dwmac->sys_mgr_base_addr;
@@ -473,6 +589,10 @@ static void socfpga_agilex5_setup_plat_dat(struct socfpga_dwmac *dwmac)
 		/* Tx Queues 0 - 5 doesn't support TBS on Agilex5 */
 		break;
 	}
+
+	/* Hw supported cross-timestamp */
+	plat_dat->int_snapshot_num = AUX_SNAPSHOT0;
+	plat_dat->crosststamp = smtg_crosststamp;
 }
 
 static int socfpga_dwmac_probe(struct platform_device *pdev)