1 files changed, 107 insertions, 0 deletions
diff --git a/drivers/usb/serial/usb_debug.c b/drivers/usb/serial/usb_debug.c
new file mode 100644
index 0000000000..6934970f18
--- /dev/null
+++ b/drivers/usb/serial/usb_debug.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * USB Debug cable driver
+ *
+ * Copyright (C) 2006 Greg Kroah-Hartman <greg@kroah.com>
+ */
+
+#include <linux/gfp.h>
+#include <linux/kernel.h>
+#include <linux/tty.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+
+#define USB_DEBUG_MAX_PACKET_SIZE	8
+#define USB_DEBUG_BRK_SIZE		8
+static const char USB_DEBUG_BRK[USB_DEBUG_BRK_SIZE] = {
+	0x00,
+	0xff,
+	0x01,
+	0xfe,
+	0x00,
+	0xfe,
+	0x01,
+	0xff,
+};
+
+static const struct usb_device_id id_table[] = {
+	{ USB_DEVICE(0x0525, 0x127a) },
+	{ },
+};
+
+static const struct usb_device_id dbc_id_table[] = {
+	{ USB_DEVICE(0x1d6b, 0x0010) },
+	{ USB_DEVICE(0x1d6b, 0x0011) },
+	{ },
+};
+
+static const struct usb_device_id id_table_combined[] = {
+	{ USB_DEVICE(0x0525, 0x127a) },
+	{ USB_DEVICE(0x1d6b, 0x0010) },
+	{ USB_DEVICE(0x1d6b, 0x0011) },
+	{ },
+};
+MODULE_DEVICE_TABLE(usb, id_table_combined);
+
+/* This HW really does not support a serial break, so one will be
+ * emulated when ever the break state is set to true.
+ */
+static int usb_debug_break_ctl(struct tty_struct *tty, int break_state)
+{
+	struct usb_serial_port *port = tty->driver_data;
+	int ret;
+
+	if (!break_state)
+		return 0;
+
+	ret = usb_serial_generic_write(tty, port, USB_DEBUG_BRK, USB_DEBUG_BRK_SIZE);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static void usb_debug_process_read_urb(struct urb *urb)
+{
+	struct usb_serial_port *port = urb->context;
+
+	if (urb->actual_length == USB_DEBUG_BRK_SIZE &&
+		memcmp(urb->transfer_buffer, USB_DEBUG_BRK,
+						USB_DEBUG_BRK_SIZE) == 0) {
+		usb_serial_handle_break(port);
+		return;
+	}
+
+	usb_serial_generic_process_read_urb(urb);
+}
+
+static struct usb_serial_driver debug_device = {
+	.driver = {
+		.owner =	THIS_MODULE,
+		.name =		"debug",
+	},
+	.id_table =		id_table,
+	.num_ports =		1,
+	.bulk_out_size =	USB_DEBUG_MAX_PACKET_SIZE,
+	.break_ctl =		usb_debug_break_ctl,
+	.process_read_urb =	usb_debug_process_read_urb,
+};
+
+static struct usb_serial_driver dbc_device = {
+	.driver = {
+		.owner =	THIS_MODULE,
+		.name =		"xhci_dbc",
+	},
+	.id_table =		dbc_id_table,
+	.num_ports =		1,
+	.break_ctl =		usb_debug_break_ctl,
+	.process_read_urb =	usb_debug_process_read_urb,
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+	&debug_device, &dbc_device, NULL
+};
+
+module_usb_serial_driver(serial_drivers, id_table_combined);
+MODULE_LICENSE("GPL v2");