v4.19.13 snapshot.
diff --git a/drivers/usb/host/fhci-dbg.c b/drivers/usb/host/fhci-dbg.c
new file mode 100644
index 0000000..100048b
--- /dev/null
+++ b/drivers/usb/host/fhci-dbg.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Freescale QUICC Engine USB Host Controller Driver
+ *
+ * Copyright (c) Freescale Semicondutor, Inc. 2006.
+ *               Shlomi Gridish <gridish@freescale.com>
+ *               Jerry Huang <Chang-Ming.Huang@freescale.com>
+ * Copyright (c) Logic Product Development, Inc. 2007
+ *               Peter Barada <peterb@logicpd.com>
+ * Copyright (c) MontaVista Software, Inc. 2008.
+ *               Anton Vorontsov <avorontsov@ru.mvista.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include "fhci.h"
+
+void fhci_dbg_isr(struct fhci_hcd *fhci, int usb_er)
+{
+	int i;
+
+	if (usb_er == -1) {
+		fhci->usb_irq_stat[12]++;
+		return;
+	}
+
+	for (i = 0; i < 12; ++i) {
+		if (usb_er & (1 << i))
+			fhci->usb_irq_stat[i]++;
+	}
+}
+
+static int fhci_dfs_regs_show(struct seq_file *s, void *v)
+{
+	struct fhci_hcd *fhci = s->private;
+	struct qe_usb_ctlr __iomem *regs = fhci->regs;
+
+	seq_printf(s,
+		"mode: 0x%x\n" "addr: 0x%x\n"
+		"command: 0x%x\n" "ep0: 0x%x\n"
+		"event: 0x%x\n" "mask: 0x%x\n"
+		"status: 0x%x\n" "SOF timer: %d\n"
+		"frame number: %d\n"
+		"lines status: 0x%x\n",
+		in_8(&regs->usb_usmod), in_8(&regs->usb_usadr),
+		in_8(&regs->usb_uscom), in_be16(&regs->usb_usep[0]),
+		in_be16(&regs->usb_usber), in_be16(&regs->usb_usbmr),
+		in_8(&regs->usb_usbs), in_be16(&regs->usb_ussft),
+		in_be16(&regs->usb_usfrn),
+		fhci_ioports_check_bus_state(fhci));
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(fhci_dfs_regs);
+
+static int fhci_dfs_irq_stat_show(struct seq_file *s, void *v)
+{
+	struct fhci_hcd *fhci = s->private;
+	int *usb_irq_stat = fhci->usb_irq_stat;
+
+	seq_printf(s,
+		"RXB: %d\n" "TXB: %d\n" "BSY: %d\n"
+		"SOF: %d\n" "TXE0: %d\n" "TXE1: %d\n"
+		"TXE2: %d\n" "TXE3: %d\n" "IDLE: %d\n"
+		"RESET: %d\n" "SFT: %d\n" "MSF: %d\n"
+		"IDLE_ONLY: %d\n",
+		usb_irq_stat[0], usb_irq_stat[1], usb_irq_stat[2],
+		usb_irq_stat[3], usb_irq_stat[4], usb_irq_stat[5],
+		usb_irq_stat[6], usb_irq_stat[7], usb_irq_stat[8],
+		usb_irq_stat[9], usb_irq_stat[10], usb_irq_stat[11],
+		usb_irq_stat[12]);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(fhci_dfs_irq_stat);
+
+void fhci_dfs_create(struct fhci_hcd *fhci)
+{
+	struct device *dev = fhci_to_hcd(fhci)->self.controller;
+
+	fhci->dfs_root = debugfs_create_dir(dev_name(dev), usb_debug_root);
+
+	debugfs_create_file("regs", S_IFREG | S_IRUGO, fhci->dfs_root, fhci,
+			    &fhci_dfs_regs_fops);
+	debugfs_create_file("irq_stat", S_IFREG | S_IRUGO, fhci->dfs_root, fhci,
+			    &fhci_dfs_irq_stat_fops);
+}
+
+void fhci_dfs_destroy(struct fhci_hcd *fhci)
+{
+	debugfs_remove_recursive(fhci->dfs_root);
+}