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 <mina86@mina86.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 15 16 /* 17 * The Mass Storage Gadget acts as a USB Mass Storage device, 18 * appearing to the host as a disk drive or as a CD-ROM drive. In 19 * addition to providing an example of a genuinely useful gadget 20 * driver for a USB device, it also illustrates a technique of 21 * double-buffering for increased throughput. Last but not least, it 22 * gives an easy way to probe the behavior of the Mass Storage drivers 23 * in a USB host. 24 * 25 * Since this file serves only administrative purposes and all the 26 * business logic is implemented in f_mass_storage.* file. Read 27 * comments in this file for more detailed description. 28 */ 29 30 31 #include <linux/kernel.h> 32 #include <linux/usb/ch9.h> 33 #include <linux/module.h> 34 35 /*-------------------------------------------------------------------------*/ 36 37 #define DRIVER_DESC "Mass Storage Gadget" 38 #define DRIVER_VERSION "2009/09/11" 39 40 /* 41 * Thanks to NetChip Technologies for donating this product ID. 42 * 43 * DO NOT REUSE THESE IDs with any other driver!! Ever!! 44 * Instead: allocate your own, using normal USB-IF procedures. 45 */ 46 #define FSG_VENDOR_ID 0x0525 /* NetChip */ 47 #define FSG_PRODUCT_ID 0xa4a5 /* Linux-USB File-backed Storage Gadget */ 48 49 #include "f_mass_storage.h" 50 51 /*-------------------------------------------------------------------------*/ 52 USB_GADGET_COMPOSITE_OPTIONS(); 53 54 static struct usb_device_descriptor msg_device_desc = { 55 .bLength = sizeof msg_device_desc, 56 .bDescriptorType = USB_DT_DEVICE, 57 58 .bcdUSB = cpu_to_le16(0x0200), 59 .bDeviceClass = USB_CLASS_PER_INTERFACE, 60 61 /* Vendor and product id can be overridden by module parameters. */ 62 .idVendor = cpu_to_le16(FSG_VENDOR_ID), 63 .idProduct = cpu_to_le16(FSG_PRODUCT_ID), 64 .bNumConfigurations = 1, 65 }; 66 67 static const struct usb_descriptor_header *otg_desc[2]; 68 69 static struct usb_string strings_dev[] = { 70 [USB_GADGET_MANUFACTURER_IDX].s = "", 71 [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC, 72 [USB_GADGET_SERIAL_IDX].s = "", 73 { } /* end of list */ 74 }; 75 76 static struct usb_gadget_strings stringtab_dev = { 77 .language = 0x0409, /* en-us */ 78 .strings = strings_dev, 79 }; 80 81 static struct usb_gadget_strings *dev_strings[] = { 82 &stringtab_dev, 83 NULL, 84 }; 85 86 static struct usb_function_instance *fi_msg; 87 static struct usb_function *f_msg; 88 89 /****************************** Configurations ******************************/ 90 91 static struct fsg_module_parameters mod_data = { 92 .stall = 1 93 }; 94 #ifdef CONFIG_USB_GADGET_DEBUG_FILES 95 96 static unsigned int fsg_num_buffers = CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS; 97 98 #else 99 100 /* 101 * Number of buffers we will use. 102 * 2 is usually enough for good buffering pipeline 103 */ 104 #define fsg_num_buffers CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS 105 106 #endif /* CONFIG_USB_GADGET_DEBUG_FILES */ 107 108 FSG_MODULE_PARAMETERS(/* no prefix */, mod_data); 109 110 static unsigned long msg_registered; 111 static void msg_cleanup(void); 112 113 static int msg_thread_exits(struct fsg_common *common) 114 { 115 msg_cleanup(); 116 return 0; 117 } 118 119 static int msg_do_config(struct usb_configuration *c) 120 { 121 struct fsg_opts *opts; 122 int ret; 123 124 if (gadget_is_otg(c->cdev->gadget)) { 125 c->descriptors = otg_desc; 126 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP; 127 } 128 129 opts = fsg_opts_from_func_inst(fi_msg); 130 131 f_msg = usb_get_function(fi_msg); 132 if (IS_ERR(f_msg)) 133 return PTR_ERR(f_msg); 134 135 ret = fsg_common_run_thread(opts->common); 136 if (ret) 137 goto put_func; 138 139 ret = usb_add_function(c, f_msg); 140 if (ret) 141 goto put_func; 142 143 return 0; 144 145 put_func: 146 usb_put_function(f_msg); 147 return ret; 148 } 149 150 static struct usb_configuration msg_config_driver = { 151 .label = "Linux File-Backed Storage", 152 .bConfigurationValue = 1, 153 .bmAttributes = USB_CONFIG_ATT_SELFPOWER, 154 }; 155 156 157 /****************************** Gadget Bind ******************************/ 158 159 static int msg_bind(struct usb_composite_dev *cdev) 160 { 161 static const struct fsg_operations ops = { 162 .thread_exits = msg_thread_exits, 163 }; 164 struct fsg_opts *opts; 165 struct fsg_config config; 166 int status; 167 168 fi_msg = usb_get_function_instance("mass_storage"); 169 if (IS_ERR(fi_msg)) 170 return PTR_ERR(fi_msg); 171 172 fsg_config_from_params(&config, &mod_data, fsg_num_buffers); 173 opts = fsg_opts_from_func_inst(fi_msg); 174 175 opts->no_configfs = true; 176 status = fsg_common_set_num_buffers(opts->common, fsg_num_buffers); 177 if (status) 178 goto fail; 179 180 fsg_common_set_ops(opts->common, &ops); 181 182 status = fsg_common_set_cdev(opts->common, cdev, config.can_stall); 183 if (status) 184 goto fail_set_cdev; 185 186 fsg_common_set_sysfs(opts->common, true); 187 status = fsg_common_create_luns(opts->common, &config); 188 if (status) 189 goto fail_set_cdev; 190 191 fsg_common_set_inquiry_string(opts->common, config.vendor_name, 192 config.product_name); 193 194 status = usb_string_ids_tab(cdev, strings_dev); 195 if (status < 0) 196 goto fail_string_ids; 197 msg_device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id; 198 199 if (gadget_is_otg(cdev->gadget) && !otg_desc[0]) { 200 struct usb_descriptor_header *usb_desc; 201 202 usb_desc = usb_otg_descriptor_alloc(cdev->gadget); 203 if (!usb_desc) 204 goto fail_string_ids; 205 usb_otg_descriptor_init(cdev->gadget, usb_desc); 206 otg_desc[0] = usb_desc; 207 otg_desc[1] = NULL; 208 } 209 210 status = usb_add_config(cdev, &msg_config_driver, msg_do_config); 211 if (status < 0) 212 goto fail_otg_desc; 213 214 usb_composite_overwrite_options(cdev, &coverwrite); 215 dev_info(&cdev->gadget->dev, 216 DRIVER_DESC ", version: " DRIVER_VERSION "\n"); 217 set_bit(0, &msg_registered); 218 return 0; 219 220 fail_otg_desc: 221 kfree(otg_desc[0]); 222 otg_desc[0] = NULL; 223 fail_string_ids: 224 fsg_common_remove_luns(opts->common); 225 fail_set_cdev: 226 fsg_common_free_buffers(opts->common); 227 fail: 228 usb_put_function_instance(fi_msg); 229 return status; 230 } 231 232 static int msg_unbind(struct usb_composite_dev *cdev) 233 { 234 if (!IS_ERR(f_msg)) 235 usb_put_function(f_msg); 236 237 if (!IS_ERR(fi_msg)) 238 usb_put_function_instance(fi_msg); 239 240 kfree(otg_desc[0]); 241 otg_desc[0] = NULL; 242 243 return 0; 244 } 245 246 /****************************** Some noise ******************************/ 247 248 static struct usb_composite_driver msg_driver = { 249 .name = "g_mass_storage", 250 .dev = &msg_device_desc, 251 .max_speed = USB_SPEED_SUPER, 252 .needs_serial = 1, 253 .strings = dev_strings, 254 .bind = msg_bind, 255 .unbind = msg_unbind, 256 }; 257 258 MODULE_DESCRIPTION(DRIVER_DESC); 259 MODULE_AUTHOR("Michal Nazarewicz"); 260 MODULE_LICENSE("GPL"); 261 262 static int __init msg_init(void) 263 { 264 return usb_composite_probe(&msg_driver); 265 } 266 module_init(msg_init); 267 268 static void msg_cleanup(void) 269 { 270 if (test_and_clear_bit(0, &msg_registered)) 271 usb_composite_unregister(&msg_driver); 272 } 273 module_exit(msg_cleanup); 274