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 = DYNAMIC */ 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 = usb_add_function(c, f_msg); 136 if (ret) 137 goto put_func; 138 139 return 0; 140 141 put_func: 142 usb_put_function(f_msg); 143 return ret; 144 } 145 146 static struct usb_configuration msg_config_driver = { 147 .label = "Linux File-Backed Storage", 148 .bConfigurationValue = 1, 149 .bmAttributes = USB_CONFIG_ATT_SELFPOWER, 150 }; 151 152 153 /****************************** Gadget Bind ******************************/ 154 155 static int msg_bind(struct usb_composite_dev *cdev) 156 { 157 static const struct fsg_operations ops = { 158 .thread_exits = msg_thread_exits, 159 }; 160 struct fsg_opts *opts; 161 struct fsg_config config; 162 int status; 163 164 fi_msg = usb_get_function_instance("mass_storage"); 165 if (IS_ERR(fi_msg)) 166 return PTR_ERR(fi_msg); 167 168 fsg_config_from_params(&config, &mod_data, fsg_num_buffers); 169 opts = fsg_opts_from_func_inst(fi_msg); 170 171 opts->no_configfs = true; 172 status = fsg_common_set_num_buffers(opts->common, fsg_num_buffers); 173 if (status) 174 goto fail; 175 176 fsg_common_set_ops(opts->common, &ops); 177 178 status = fsg_common_set_cdev(opts->common, cdev, config.can_stall); 179 if (status) 180 goto fail_set_cdev; 181 182 fsg_common_set_sysfs(opts->common, true); 183 status = fsg_common_create_luns(opts->common, &config); 184 if (status) 185 goto fail_set_cdev; 186 187 fsg_common_set_inquiry_string(opts->common, config.vendor_name, 188 config.product_name); 189 190 status = usb_string_ids_tab(cdev, strings_dev); 191 if (status < 0) 192 goto fail_string_ids; 193 msg_device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id; 194 195 if (gadget_is_otg(cdev->gadget) && !otg_desc[0]) { 196 struct usb_descriptor_header *usb_desc; 197 198 usb_desc = usb_otg_descriptor_alloc(cdev->gadget); 199 if (!usb_desc) 200 goto fail_string_ids; 201 usb_otg_descriptor_init(cdev->gadget, usb_desc); 202 otg_desc[0] = usb_desc; 203 otg_desc[1] = NULL; 204 } 205 206 status = usb_add_config(cdev, &msg_config_driver, msg_do_config); 207 if (status < 0) 208 goto fail_otg_desc; 209 210 usb_composite_overwrite_options(cdev, &coverwrite); 211 dev_info(&cdev->gadget->dev, 212 DRIVER_DESC ", version: " DRIVER_VERSION "\n"); 213 set_bit(0, &msg_registered); 214 return 0; 215 216 fail_otg_desc: 217 kfree(otg_desc[0]); 218 otg_desc[0] = NULL; 219 fail_string_ids: 220 fsg_common_remove_luns(opts->common); 221 fail_set_cdev: 222 fsg_common_free_buffers(opts->common); 223 fail: 224 usb_put_function_instance(fi_msg); 225 return status; 226 } 227 228 static int msg_unbind(struct usb_composite_dev *cdev) 229 { 230 if (!IS_ERR(f_msg)) 231 usb_put_function(f_msg); 232 233 if (!IS_ERR(fi_msg)) 234 usb_put_function_instance(fi_msg); 235 236 kfree(otg_desc[0]); 237 otg_desc[0] = NULL; 238 239 return 0; 240 } 241 242 /****************************** Some noise ******************************/ 243 244 static struct usb_composite_driver msg_driver = { 245 .name = "g_mass_storage", 246 .dev = &msg_device_desc, 247 .max_speed = USB_SPEED_SUPER, 248 .needs_serial = 1, 249 .strings = dev_strings, 250 .bind = msg_bind, 251 .unbind = msg_unbind, 252 }; 253 254 MODULE_DESCRIPTION(DRIVER_DESC); 255 MODULE_AUTHOR("Michal Nazarewicz"); 256 MODULE_LICENSE("GPL"); 257 258 static int __init msg_init(void) 259 { 260 return usb_composite_probe(&msg_driver); 261 } 262 module_init(msg_init); 263 264 static void msg_cleanup(void) 265 { 266 if (test_and_clear_bit(0, &msg_registered)) 267 usb_composite_unregister(&msg_driver); 268 } 269 module_exit(msg_cleanup); 270