mass_storage.c
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/*
* mass_storage.c -- Mass Storage USB Gadget
*
* Copyright (C) 2003-2008 Alan Stern
* Copyright (C) 2009 Samsung Electronics
* Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
/*
* 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/utsname.h>
#include <linux/usb/ch9.h>
/*-------------------------------------------------------------------------*/
#define DRIVER_DESC "Mass Storage Gadget"
#define DRIVER_VERSION "2009/09/11"
/*-------------------------------------------------------------------------*/
/*
* kbuild is not very cooperative with respect to linking separately
* compiled library objects into one module. So for now we won't use
* separate compilation ... ensuring init/exit sections work to shrink
* the runtime footprint, and giving us at least some parts of what
* a "gcc --combine ... part1.c part2.c part3.c ... " build would.
*/
#include "composite.c"
#include "usbstring.c"
#include "config.c"
#include "epautoconf.c"
#include "f_mass_storage.c"
/*-------------------------------------------------------------------------*/
static struct usb_device_descriptor msg_device_desc = {
.bLength = sizeof msg_device_desc,
.bDescriptorType = USB_DT_DEVICE,
.bcdUSB = cpu_to_le16(0x0200),
.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 struct usb_otg_descriptor otg_descriptor = {
.bLength = sizeof otg_descriptor,
.bDescriptorType = USB_DT_OTG,
/*
* REVISIT SRP-only hardware is possible, although
* it would not be called "OTG" ...
*/
.bmAttributes = USB_OTG_SRP | USB_OTG_HNP,
};
static const struct usb_descriptor_header *otg_desc[] = {
(struct usb_descriptor_header *) &otg_descriptor,
NULL,
};
/****************************** Configurations ******************************/
static struct fsg_module_parameters mod_data = {
.stall = 1
};
FSG_MODULE_PARAMETERS(/* no prefix */, mod_data);
static unsigned long msg_registered;
static void msg_cleanup(void);
static int msg_thread_exits(struct fsg_common *common)
{
msg_cleanup();
return 0;
}
static int __init msg_do_config(struct usb_configuration *c)
{
static const struct fsg_operations ops = {
.thread_exits = msg_thread_exits,
};
static struct fsg_common common;
struct fsg_common *retp;
struct fsg_config config;
int ret;
if (gadget_is_otg(c->cdev->gadget)) {
c->descriptors = otg_desc;
c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
}
fsg_config_from_params(&config, &mod_data);
config.ops = &ops;
retp = fsg_common_init(&common, c->cdev, &config);
if (IS_ERR(retp))
return PTR_ERR(retp);
ret = fsg_bind_config(c->cdev, c, &common);
fsg_common_put(&common);
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 __init msg_bind(struct usb_composite_dev *cdev)
{
int status;
status = usb_add_config(cdev, &msg_config_driver, msg_do_config);
if (status < 0)
return status;
dev_info(&cdev->gadget->dev,
DRIVER_DESC ", version: " DRIVER_VERSION "\n");
set_bit(0, &msg_registered);
return 0;
}
/****************************** Some noise ******************************/
static struct usb_composite_driver msg_driver = {
.name = "g_mass_storage",
.dev = &msg_device_desc,
.iProduct = DRIVER_DESC,
.max_speed = USB_SPEED_SUPER,
.needs_serial = 1,
};
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Michal Nazarewicz");
MODULE_LICENSE("GPL");
static int __init msg_init(void)
{
return usb_composite_probe(&msg_driver, msg_bind);
}
module_init(msg_init);
static void msg_cleanup(void)
{
if (test_and_clear_bit(0, &msg_registered))
usb_composite_unregister(&msg_driver);
}
module_exit(msg_cleanup);