File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/usb/gadget/legacy/serial.c b/drivers/usb/gadget/legacy/serial.c
new file mode 100644
index 0000000..c5d42e0
--- /dev/null
+++ b/drivers/usb/gadget/legacy/serial.c
@@ -0,0 +1,280 @@
+/*
+ * serial.c -- USB gadget serial driver
+ *
+ * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
+ * Copyright (C) 2008 by David Brownell
+ * Copyright (C) 2008 by Nokia Corporation
+ *
+ * This software is distributed under the terms of the GNU General
+ * Public License ("GPL") as published by the Free Software Foundation,
+ * either version 2 of that License or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#include "u_serial.h"
+
+
+/* Defines */
+
+#define GS_VERSION_STR			"v2.4"
+#define GS_VERSION_NUM			0x2400
+
+#define GS_LONG_NAME			"Gadget Serial"
+#define GS_VERSION_NAME			GS_LONG_NAME " " GS_VERSION_STR
+
+/*-------------------------------------------------------------------------*/
+USB_GADGET_COMPOSITE_OPTIONS();
+
+/* Thanks to NetChip Technologies for donating this product ID.
+*
+* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
+* Instead:  allocate your own, using normal USB-IF procedures.
+*/
+#define GS_VENDOR_ID			0x0525	/* NetChip */
+#define GS_PRODUCT_ID			0xa4a6	/* Linux-USB Serial Gadget */
+#define GS_CDC_PRODUCT_ID		0xa4a7	/* ... as CDC-ACM */
+#define GS_CDC_OBEX_PRODUCT_ID		0xa4a9	/* ... as CDC-OBEX */
+
+/* string IDs are assigned dynamically */
+
+#define STRING_DESCRIPTION_IDX		USB_GADGET_FIRST_AVAIL_IDX
+
+static struct usb_string strings_dev[] = {
+	[USB_GADGET_MANUFACTURER_IDX].s = "",
+	[USB_GADGET_PRODUCT_IDX].s = GS_VERSION_NAME,
+	[USB_GADGET_SERIAL_IDX].s = "",
+	[STRING_DESCRIPTION_IDX].s = NULL /* updated; f(use_acm) */,
+	{  } /* end of list */
+};
+
+static struct usb_gadget_strings stringtab_dev = {
+	.language	= 0x0409,	/* en-us */
+	.strings	= strings_dev,
+};
+
+static struct usb_gadget_strings *dev_strings[] = {
+	&stringtab_dev,
+	NULL,
+};
+
+static struct usb_device_descriptor device_desc = {
+	.bLength =		USB_DT_DEVICE_SIZE,
+	.bDescriptorType =	USB_DT_DEVICE,
+	.bcdUSB =		cpu_to_le16(0x0200),
+	/* .bDeviceClass = f(use_acm) */
+	.bDeviceSubClass =	0,
+	.bDeviceProtocol =	0,
+	/* .bMaxPacketSize0 = f(hardware) */
+	.idVendor =		cpu_to_le16(GS_VENDOR_ID),
+	/* .idProduct =	f(use_acm) */
+	.bcdDevice = cpu_to_le16(GS_VERSION_NUM),
+	/* .iManufacturer = DYNAMIC */
+	/* .iProduct = DYNAMIC */
+	.bNumConfigurations =	1,
+};
+
+static const struct usb_descriptor_header *otg_desc[2];
+
+/*-------------------------------------------------------------------------*/
+
+/* Module */
+MODULE_DESCRIPTION(GS_VERSION_NAME);
+MODULE_AUTHOR("Al Borchers");
+MODULE_AUTHOR("David Brownell");
+MODULE_LICENSE("GPL");
+
+static bool use_acm = true;
+module_param(use_acm, bool, 0);
+MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes");
+
+static bool use_obex = false;
+module_param(use_obex, bool, 0);
+MODULE_PARM_DESC(use_obex, "Use CDC OBEX, default=no");
+
+static unsigned n_ports = 1;
+module_param(n_ports, uint, 0);
+MODULE_PARM_DESC(n_ports, "number of ports to create, default=1");
+
+/*-------------------------------------------------------------------------*/
+
+static struct usb_configuration serial_config_driver = {
+	/* .label = f(use_acm) */
+	/* .bConfigurationValue = f(use_acm) */
+	/* .iConfiguration = DYNAMIC */
+	.bmAttributes	= USB_CONFIG_ATT_SELFPOWER,
+};
+
+static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS];
+static struct usb_function *f_serial[MAX_U_SERIAL_PORTS];
+
+static int serial_register_ports(struct usb_composite_dev *cdev,
+		struct usb_configuration *c, const char *f_name)
+{
+	int i;
+	int ret;
+
+	ret = usb_add_config_only(cdev, c);
+	if (ret)
+		goto out;
+
+	for (i = 0; i < n_ports; i++) {
+
+		fi_serial[i] = usb_get_function_instance(f_name);
+		if (IS_ERR(fi_serial[i])) {
+			ret = PTR_ERR(fi_serial[i]);
+			goto fail;
+		}
+
+		f_serial[i] = usb_get_function(fi_serial[i]);
+		if (IS_ERR(f_serial[i])) {
+			ret = PTR_ERR(f_serial[i]);
+			goto err_get_func;
+		}
+
+		ret = usb_add_function(c, f_serial[i]);
+		if (ret)
+			goto err_add_func;
+	}
+
+	return 0;
+
+err_add_func:
+	usb_put_function(f_serial[i]);
+err_get_func:
+	usb_put_function_instance(fi_serial[i]);
+
+fail:
+	i--;
+	while (i >= 0) {
+		usb_remove_function(c, f_serial[i]);
+		usb_put_function(f_serial[i]);
+		usb_put_function_instance(fi_serial[i]);
+		i--;
+	}
+out:
+	return ret;
+}
+
+static int gs_bind(struct usb_composite_dev *cdev)
+{
+	int			status;
+
+	/* Allocate string descriptor numbers ... note that string
+	 * contents can be overridden by the composite_dev glue.
+	 */
+
+	status = usb_string_ids_tab(cdev, strings_dev);
+	if (status < 0)
+		goto fail;
+	device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
+	device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
+	status = strings_dev[STRING_DESCRIPTION_IDX].id;
+	serial_config_driver.iConfiguration = status;
+
+	if (gadget_is_otg(cdev->gadget)) {
+		if (!otg_desc[0]) {
+			struct usb_descriptor_header *usb_desc;
+
+			usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
+			if (!usb_desc) {
+				status = -ENOMEM;
+				goto fail;
+			}
+			usb_otg_descriptor_init(cdev->gadget, usb_desc);
+			otg_desc[0] = usb_desc;
+			otg_desc[1] = NULL;
+		}
+		serial_config_driver.descriptors = otg_desc;
+		serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
+	}
+
+	/* register our configuration */
+	if (use_acm) {
+		status  = serial_register_ports(cdev, &serial_config_driver,
+				"acm");
+		usb_ep_autoconfig_reset(cdev->gadget);
+	} else if (use_obex)
+		status = serial_register_ports(cdev, &serial_config_driver,
+				"obex");
+	else {
+		status = serial_register_ports(cdev, &serial_config_driver,
+				"gser");
+	}
+	if (status < 0)
+		goto fail1;
+
+	usb_composite_overwrite_options(cdev, &coverwrite);
+	INFO(cdev, "%s\n", GS_VERSION_NAME);
+
+	return 0;
+fail1:
+	kfree(otg_desc[0]);
+	otg_desc[0] = NULL;
+fail:
+	return status;
+}
+
+static int gs_unbind(struct usb_composite_dev *cdev)
+{
+	int i;
+
+	for (i = 0; i < n_ports; i++) {
+		usb_put_function(f_serial[i]);
+		usb_put_function_instance(fi_serial[i]);
+	}
+
+	kfree(otg_desc[0]);
+	otg_desc[0] = NULL;
+
+	return 0;
+}
+
+static struct usb_composite_driver gserial_driver = {
+	.name		= "g_serial",
+	.dev		= &device_desc,
+	.strings	= dev_strings,
+	.max_speed	= USB_SPEED_SUPER,
+	.bind		= gs_bind,
+	.unbind		= gs_unbind,
+};
+
+static int __init init(void)
+{
+	/* We *could* export two configs; that'd be much cleaner...
+	 * but neither of these product IDs was defined that way.
+	 */
+	if (use_acm) {
+		serial_config_driver.label = "CDC ACM config";
+		serial_config_driver.bConfigurationValue = 2;
+		device_desc.bDeviceClass = USB_CLASS_COMM;
+		device_desc.idProduct =
+				cpu_to_le16(GS_CDC_PRODUCT_ID);
+	} else if (use_obex) {
+		serial_config_driver.label = "CDC OBEX config";
+		serial_config_driver.bConfigurationValue = 3;
+		device_desc.bDeviceClass = USB_CLASS_COMM;
+		device_desc.idProduct =
+			cpu_to_le16(GS_CDC_OBEX_PRODUCT_ID);
+	} else {
+		serial_config_driver.label = "Generic Serial config";
+		serial_config_driver.bConfigurationValue = 1;
+		device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
+		device_desc.idProduct =
+				cpu_to_le16(GS_PRODUCT_ID);
+	}
+	strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label;
+
+	return usb_composite_probe(&gserial_driver);
+}
+module_init(init);
+
+static void __exit cleanup(void)
+{
+	usb_composite_unregister(&gserial_driver);
+}
+module_exit(cleanup);