1 files changed, 238 insertions, 0 deletions
diff --git a/drivers/usb/gadget/legacy/mass_storage.c b/drivers/usb/gadget/legacy/mass_storage.c
new file mode 100644
index 000000000..ac1741126
--- /dev/null
+++ b/drivers/usb/gadget/legacy/mass_storage.c
@@ -0,0 +1,238 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * mass_storage.c -- Mass Storage USB Gadget
+ *
+ * Copyright (C) 2003-2008 Alan Stern
+ * Copyright (C) 2009 Samsung Electronics
+ *                    Author: Michal Nazarewicz <mina86@mina86.com>
+ * All rights reserved.
+ */
+
+
+/*
+ * The Mass Storage Gadget acts as a USB Mass Storage device,
+ * appearing to the host as a disk drive or as a CD-ROM drive.  In
+ * addition to providing an example of a genuinely useful gadget
+ * driver for a USB device, it also illustrates a technique of
+ * double-buffering for increased throughput.  Last but not least, it
+ * gives an easy way to probe the behavior of the Mass Storage drivers
+ * in a USB host.
+ *
+ * Since this file serves only administrative purposes and all the
+ * business logic is implemented in f_mass_storage.* file.  Read
+ * comments in this file for more detailed description.
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/usb/ch9.h>
+#include <linux/module.h>
+
+/*-------------------------------------------------------------------------*/
+
+#define DRIVER_DESC		"Mass Storage Gadget"
+#define DRIVER_VERSION		"2009/09/11"
+
+/*
+ * Thanks to NetChip Technologies for donating this product ID.
+ *
+ * DO NOT REUSE THESE IDs with any other driver!!  Ever!!
+ * Instead:  allocate your own, using normal USB-IF procedures.
+ */
+#define FSG_VENDOR_ID	0x0525	/* NetChip */
+#define FSG_PRODUCT_ID	0xa4a5	/* Linux-USB File-backed Storage Gadget */
+
+#include "f_mass_storage.h"
+
+/*-------------------------------------------------------------------------*/
+USB_GADGET_COMPOSITE_OPTIONS();
+
+static struct usb_device_descriptor msg_device_desc = {
+	.bLength =		sizeof msg_device_desc,
+	.bDescriptorType =	USB_DT_DEVICE,
+
+	/* .bcdUSB = DYNAMIC */
+	.bDeviceClass =		USB_CLASS_PER_INTERFACE,
+
+	/* Vendor and product id can be overridden by module parameters.  */
+	.idVendor =		cpu_to_le16(FSG_VENDOR_ID),
+	.idProduct =		cpu_to_le16(FSG_PRODUCT_ID),
+	.bNumConfigurations =	1,
+};
+
+static const struct usb_descriptor_header *otg_desc[2];
+
+static struct usb_string strings_dev[] = {
+	[USB_GADGET_MANUFACTURER_IDX].s = "",
+	[USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
+	[USB_GADGET_SERIAL_IDX].s = "",
+	{  } /* 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_function_instance *fi_msg;
+static struct usb_function *f_msg;
+
+/****************************** Configurations ******************************/
+
+static struct fsg_module_parameters mod_data = {
+	.stall = 1
+};
+#ifdef CONFIG_USB_GADGET_DEBUG_FILES
+
+static unsigned int fsg_num_buffers = CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS;
+
+#else
+
+/*
+ * Number of buffers we will use.
+ * 2 is usually enough for good buffering pipeline
+ */
+#define fsg_num_buffers	CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS
+
+#endif /* CONFIG_USB_GADGET_DEBUG_FILES */
+
+FSG_MODULE_PARAMETERS(/* no prefix */, mod_data);
+
+static int msg_do_config(struct usb_configuration *c)
+{
+	int ret;
+
+	if (gadget_is_otg(c->cdev->gadget)) {
+		c->descriptors = otg_desc;
+		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
+	}
+
+	f_msg = usb_get_function(fi_msg);
+	if (IS_ERR(f_msg))
+		return PTR_ERR(f_msg);
+
+	ret = usb_add_function(c, f_msg);
+	if (ret)
+		goto put_func;
+
+	return 0;
+
+put_func:
+	usb_put_function(f_msg);
+	return ret;
+}
+
+static struct usb_configuration msg_config_driver = {
+	.label			= "Linux File-Backed Storage",
+	.bConfigurationValue	= 1,
+	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
+};
+
+
+/****************************** Gadget Bind ******************************/
+
+static int msg_bind(struct usb_composite_dev *cdev)
+{
+	struct fsg_opts *opts;
+	struct fsg_config config;
+	int status;
+
+	fi_msg = usb_get_function_instance("mass_storage");
+	if (IS_ERR(fi_msg))
+		return PTR_ERR(fi_msg);
+
+	fsg_config_from_params(&config, &mod_data, fsg_num_buffers);
+	opts = fsg_opts_from_func_inst(fi_msg);
+
+	opts->no_configfs = true;
+	status = fsg_common_set_num_buffers(opts->common, fsg_num_buffers);
+	if (status)
+		goto fail;
+
+	status = fsg_common_set_cdev(opts->common, cdev, config.can_stall);
+	if (status)
+		goto fail_set_cdev;
+
+	fsg_common_set_sysfs(opts->common, true);
+	status = fsg_common_create_luns(opts->common, &config);
+	if (status)
+		goto fail_set_cdev;
+
+	fsg_common_set_inquiry_string(opts->common, config.vendor_name,
+				      config.product_name);
+
+	status = usb_string_ids_tab(cdev, strings_dev);
+	if (status < 0)
+		goto fail_string_ids;
+	msg_device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
+
+	if (gadget_is_otg(cdev->gadget) && !otg_desc[0]) {
+		struct usb_descriptor_header *usb_desc;
+
+		usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
+		if (!usb_desc) {
+			status = -ENOMEM;
+			goto fail_string_ids;
+		}
+		usb_otg_descriptor_init(cdev->gadget, usb_desc);
+		otg_desc[0] = usb_desc;
+		otg_desc[1] = NULL;
+	}
+
+	status = usb_add_config(cdev, &msg_config_driver, msg_do_config);
+	if (status < 0)
+		goto fail_otg_desc;
+
+	usb_composite_overwrite_options(cdev, &coverwrite);
+	dev_info(&cdev->gadget->dev,
+		 DRIVER_DESC ", version: " DRIVER_VERSION "\n");
+	return 0;
+
+fail_otg_desc:
+	kfree(otg_desc[0]);
+	otg_desc[0] = NULL;
+fail_string_ids:
+	fsg_common_remove_luns(opts->common);
+fail_set_cdev:
+	fsg_common_free_buffers(opts->common);
+fail:
+	usb_put_function_instance(fi_msg);
+	return status;
+}
+
+static int msg_unbind(struct usb_composite_dev *cdev)
+{
+	if (!IS_ERR(f_msg))
+		usb_put_function(f_msg);
+
+	if (!IS_ERR(fi_msg))
+		usb_put_function_instance(fi_msg);
+
+	kfree(otg_desc[0]);
+	otg_desc[0] = NULL;
+
+	return 0;
+}
+
+/****************************** Some noise ******************************/
+
+static struct usb_composite_driver msg_driver = {
+	.name		= "g_mass_storage",
+	.dev		= &msg_device_desc,
+	.max_speed	= USB_SPEED_SUPER_PLUS,
+	.needs_serial	= 1,
+	.strings	= dev_strings,
+	.bind		= msg_bind,
+	.unbind		= msg_unbind,
+};
+
+module_usb_composite_driver(msg_driver);
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Michal Nazarewicz");
+MODULE_LICENSE("GPL");