net: enetc: add ptp timer binding support for i.MX94

The i.MX94 has three PTP timers, and all standalone ENETCs can select
one of them to bind to as their PHC. The 'ptp-timer' property is used
to represent the PTP device of the Ethernet controller. So users can
add 'ptp-timer' to the ENETC node to specify the PTP timer. The driver
parses this property to bind the two hardware devices.

If the "ptp-timer" property is not present, the first timer of the PCIe
bus where the ENETC is located is used as the default bound PTP timer.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20251029013900.407583-5-wei.fang@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/freescale/enetc/netc_blk_ctrl.c

@@ -66,6 +66,7 @@
 /* NETC integrated endpoint register block register */
 #define IERB_EMDIOFAUXR			0x344
 #define IERB_T0FAUXR			0x444
+#define IERB_ETBCR(a)			(0x300c + 0x100 * (a))
 #define IERB_EFAUXR(a)			(0x3044 + 0x100 * (a))
 #define IERB_VFAUXR(a)			(0x4004 + 0x40 * (a))
 #define FAUXR_LDID			GENMASK(3, 0)
@@ -78,10 +79,16 @@
 #define IMX94_ENETC0_BUS_DEVFN		0x100
 #define IMX94_ENETC1_BUS_DEVFN		0x140
 #define IMX94_ENETC2_BUS_DEVFN		0x180
+#define IMX94_TIMER0_BUS_DEVFN		0x1
+#define IMX94_TIMER1_BUS_DEVFN		0x101
+#define IMX94_TIMER2_BUS_DEVFN		0x181
 #define IMX94_ENETC0_LINK		3
 #define IMX94_ENETC1_LINK		4
 #define IMX94_ENETC2_LINK		5
 
+#define NETC_ENETC_ID(a)		(a)
+#define NETC_TIMER_ID(a)		(a)
+
 /* Flags for different platforms */
 #define NETC_HAS_NETCMIX		BIT(0)
 
@@ -345,6 +352,98 @@ static int imx95_ierb_init(struct platform_device *pdev)
 	return 0;
 }
 
+static int imx94_get_enetc_id(struct device_node *np)
+{
+	int bus_devfn = netc_of_pci_get_bus_devfn(np);
+
+	/* Parse ENETC offset */
+	switch (bus_devfn) {
+	case IMX94_ENETC0_BUS_DEVFN:
+		return NETC_ENETC_ID(0);
+	case IMX94_ENETC1_BUS_DEVFN:
+		return NETC_ENETC_ID(1);
+	case IMX94_ENETC2_BUS_DEVFN:
+		return NETC_ENETC_ID(2);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int imx94_get_timer_id(struct device_node *np)
+{
+	int bus_devfn = netc_of_pci_get_bus_devfn(np);
+
+	/* Parse NETC PTP timer ID, the timer0 is on bus 0,
+	 * the timer 1 and timer2 is on bus 1.
+	 */
+	switch (bus_devfn) {
+	case IMX94_TIMER0_BUS_DEVFN:
+		return NETC_TIMER_ID(0);
+	case IMX94_TIMER1_BUS_DEVFN:
+		return NETC_TIMER_ID(1);
+	case IMX94_TIMER2_BUS_DEVFN:
+		return NETC_TIMER_ID(2);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int imx94_enetc_update_tid(struct netc_blk_ctrl *priv,
+				  struct device_node *np)
+{
+	struct device *dev = &priv->pdev->dev;
+	struct device_node *timer_np;
+	int eid, tid;
+
+	eid = imx94_get_enetc_id(np);
+	if (eid < 0) {
+		dev_err(dev, "Failed to get ENETC ID\n");
+		return eid;
+	}
+
+	timer_np = of_parse_phandle(np, "ptp-timer", 0);
+	if (!timer_np) {
+		/* If 'ptp-timer' is not present, the timer1 is the default
+		 * timer of all standalone ENETCs, which is on the same PCIe
+		 * bus as these ENETCs.
+		 */
+		tid = NETC_TIMER_ID(1);
+		goto end;
+	}
+
+	tid = imx94_get_timer_id(timer_np);
+	of_node_put(timer_np);
+	if (tid < 0) {
+		dev_err(dev, "Failed to get NETC Timer ID\n");
+		return tid;
+	}
+
+end:
+	netc_reg_write(priv->ierb, IERB_ETBCR(eid), tid);
+
+	return 0;
+}
+
+static int imx94_ierb_init(struct platform_device *pdev)
+{
+	struct netc_blk_ctrl *priv = platform_get_drvdata(pdev);
+	struct device_node *np = pdev->dev.of_node;
+	int err;
+
+	for_each_child_of_node_scoped(np, child) {
+		for_each_child_of_node_scoped(child, gchild) {
+			if (!of_device_is_compatible(gchild, "pci1131,e101"))
+				continue;
+
+			err = imx94_enetc_update_tid(priv, gchild);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
 static int netc_ierb_init(struct platform_device *pdev)
 {
 	struct netc_blk_ctrl *priv = platform_get_drvdata(pdev);
@@ -441,6 +540,7 @@ static const struct netc_devinfo imx95_devinfo = {
 static const struct netc_devinfo imx94_devinfo = {
 	.flags = NETC_HAS_NETCMIX,
 	.netcmix_init = imx94_netcmix_init,
+	.ierb_init = imx94_ierb_init,
 };
 
 static const struct of_device_id netc_blk_ctrl_match[] = {