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// 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");
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