drivers/usb/gadget/mass_storage.c

   1 /*
   2  * mass_storage.c -- Mass Storage USB Gadget
   3  *
   4  * Copyright (C) 2003-2008 Alan Stern
   5  * Copyright (C) 2009 Samsung Electronics
   6  *                    Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
   7  * All rights reserved.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  */
  23
  24
  25 /*
  26  * The Mass Storage Gadget acts as a USB Mass Storage device,
  27  * appearing to the host as a disk drive or as a CD-ROM drive.  In
  28  * addition to providing an example of a genuinely useful gadget
  29  * driver for a USB device, it also illustrates a technique of
  30  * double-buffering for increased throughput.  Last but not least, it
  31  * gives an easy way to probe the behavior of the Mass Storage drivers
  32  * in a USB host.
  33  *
  34  * Since this file serves only administrative purposes and all the
  35  * business logic is implemented in f_mass_storage.* file.  Read
  36  * comments in this file for more detailed description.
  37  */
  38
  39
  40 #include <linux/kernel.h>
  41 #include <linux/utsname.h>
  42 #include <linux/usb/ch9.h>
  43
  44
  45 /*-------------------------------------------------------------------------*/
  46
  47 #define DRIVER_DESC             "Mass Storage Gadget"
  48 #define DRIVER_VERSION          "2009/09/11"
  49
  50 /*-------------------------------------------------------------------------*/
  51
  52 /*
  53  * kbuild is not very cooperative with respect to linking separately
  54  * compiled library objects into one module.  So for now we won't use
  55  * separate compilation ... ensuring init/exit sections work to shrink
  56  * the runtime footprint, and giving us at least some parts of what
  57  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
  58  */
  59
  60 #include "composite.c"
  61 #include "usbstring.c"
  62 #include "config.c"
  63 #include "epautoconf.c"
  64 #include "f_mass_storage.c"
  65
  66 /*-------------------------------------------------------------------------*/
  67
  68 static struct usb_device_descriptor msg_device_desc = {
  69         .bLength =              sizeof msg_device_desc,
  70         .bDescriptorType =      USB_DT_DEVICE,
  71
  72         .bcdUSB =               cpu_to_le16(0x0200),
  73         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
  74
  75         /* Vendor and product id can be overridden by module parameters.  */
  76         .idVendor =             cpu_to_le16(FSG_VENDOR_ID),
  77         .idProduct =            cpu_to_le16(FSG_PRODUCT_ID),
  78         /* .bcdDevice = f(hardware) */
  79         /* .iManufacturer = DYNAMIC */
  80         /* .iProduct = DYNAMIC */
  81         /* NO SERIAL NUMBER */
  82         .bNumConfigurations =   1,
  83 };
  84
  85 static struct usb_otg_descriptor otg_descriptor = {
  86         .bLength =              sizeof otg_descriptor,
  87         .bDescriptorType =      USB_DT_OTG,
  88
  89         /* REVISIT SRP-only hardware is possible, although
  90          * it would not be called "OTG" ...
  91          */
  92         .bmAttributes =         USB_OTG_SRP | USB_OTG_HNP,
  93 };
  94
  95 static const struct usb_descriptor_header *otg_desc[] = {
  96         (struct usb_descriptor_header *) &otg_descriptor,
  97         NULL,
  98 };
  99
 100
 101 /* string IDs are assigned dynamically */
 102
 103 #define STRING_MANUFACTURER_IDX         0
 104 #define STRING_PRODUCT_IDX              1
 105 #define STRING_CONFIGURATION_IDX        2
 106
 107 static char manufacturer[50];
 108
 109 static struct usb_string strings_dev[] = {
 110         [STRING_MANUFACTURER_IDX].s = manufacturer,
 111         [STRING_PRODUCT_IDX].s = DRIVER_DESC,
 112         [STRING_CONFIGURATION_IDX].s = "Self Powered",
 113         {  } /* end of list */
 114 };
 115
 116 static struct usb_gadget_strings stringtab_dev = {
 117         .language       = 0x0409,       /* en-us */
 118         .strings        = strings_dev,
 119 };
 120
 121 static struct usb_gadget_strings *dev_strings[] = {
 122         &stringtab_dev,
 123         NULL,
 124 };
 125
 126
 127
 128 /****************************** Configurations ******************************/
 129
 130 static struct fsg_module_parameters mod_data = {
 131         .stall = 1
 132 };
 133 FSG_MODULE_PARAMETERS(/* no prefix */, mod_data);
 134
 135 static unsigned long msg_registered = 0;
 136 static void msg_cleanup(void);
 137
 138 static int __init msg_do_config(struct usb_configuration *c)
 139 {
 140         struct fsg_common *common;
 141         struct fsg_config config;
 142         int ret;
 143
 144         if (gadget_is_otg(c->cdev->gadget)) {
 145                 c->descriptors = otg_desc;
 146                 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 147         }
 148
 149         fsg_config_from_params(&config, &mod_data);
 150         config.thread_exits = (void(*)(struct fsg_common*))&msg_cleanup;
 151         common = fsg_common_init(0, c->cdev, &config);
 152         if (IS_ERR(common))
 153                 return PTR_ERR(common);
 154
 155         ret = fsg_add(c->cdev, c, common);
 156         fsg_common_put(common);
 157         return ret;
 158 }
 159
 160 static struct usb_configuration msg_config_driver = {
 161         .label                  = "Linux File-Backed Storage",
 162         .bind                   = msg_do_config,
 163         .bConfigurationValue    = 1,
 164         /* .iConfiguration = DYNAMIC */
 165         .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
 166 };
 167
 168
 169
 170 /****************************** Gadget Bind ******************************/
 171
 172
 173 static int __init msg_bind(struct usb_composite_dev *cdev)
 174 {
 175         struct usb_gadget *gadget = cdev->gadget;
 176         int status;
 177
 178         /* Allocate string descriptor numbers ... note that string
 179          * contents can be overridden by the composite_dev glue.
 180          */
 181
 182         /* device descriptor strings: manufacturer, product */
 183         snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
 184                  init_utsname()->sysname, init_utsname()->release,
 185                  gadget->name);
 186         status = usb_string_id(cdev);
 187         if (status < 0)
 188                 return status;
 189         strings_dev[STRING_MANUFACTURER_IDX].id = status;
 190         msg_device_desc.iManufacturer = status;
 191
 192         status = usb_string_id(cdev);
 193         if (status < 0)
 194                 return status;
 195         strings_dev[STRING_PRODUCT_IDX].id = status;
 196         msg_device_desc.iProduct = status;
 197
 198         status = usb_string_id(cdev);
 199         if (status < 0)
 200                 return status;
 201         strings_dev[STRING_CONFIGURATION_IDX].id = status;
 202         msg_config_driver.iConfiguration = status;
 203
 204         /* register our second configuration */
 205         status = usb_add_config(cdev, &msg_config_driver);
 206         if (status < 0)
 207                 return status;
 208
 209         dev_info(&gadget->dev, DRIVER_DESC ", version: " DRIVER_VERSION "\n");
 210         set_bit(0, &msg_registered);
 211         return 0;
 212 }
 213
 214
 215 /****************************** Some noise ******************************/
 216
 217
 218 static struct usb_composite_driver msg_driver = {
 219         .name           = "g_mass_storage",
 220         .dev            = &msg_device_desc,
 221         .strings        = dev_strings,
 222         .bind           = msg_bind,
 223 };
 224
 225 MODULE_DESCRIPTION(DRIVER_DESC);
 226 MODULE_AUTHOR("Michal Nazarewicz");
 227 MODULE_LICENSE("GPL");
 228
 229 static int __init msg_init(void)
 230 {
 231         return usb_composite_register(&msg_driver);
 232 }
 233 module_init(msg_init);
 234
 235 static void msg_cleanup(void)
 236 {
 237         if (test_and_clear_bit(0, &msg_registered))
 238                 usb_composite_unregister(&msg_driver);
 239 }
 240 module_exit(msg_cleanup);