drivers/usb/gadget/g_ffs.c

   1 /*
   2  * g_ffs.c -- user mode file system API for USB composite function controllers
   3  *
   4  * Copyright (C) 2010 Samsung Electronics
   5  * Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #define pr_fmt(fmt) "g_ffs: " fmt
  23
  24 #include <linux/module.h>
  25 #include <linux/utsname.h>
  26
  27 /*
  28  * kbuild is not very cooperative with respect to linking separately
  29  * compiled library objects into one module.  So for now we won't use
  30  * separate compilation ... ensuring init/exit sections work to shrink
  31  * the runtime footprint, and giving us at least some parts of what
  32  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
  33  */
  34
  35 #include "composite.c"
  36 #include "usbstring.c"
  37 #include "config.c"
  38 #include "epautoconf.c"
  39
  40 #if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
  41 #  if defined USB_ETH_RNDIS
  42 #    undef USB_ETH_RNDIS
  43 #  endif
  44 #  ifdef CONFIG_USB_FUNCTIONFS_RNDIS
  45 #    define USB_ETH_RNDIS y
  46 #  endif
  47
  48 #  include "f_ecm.c"
  49 #  include "f_subset.c"
  50 #  ifdef USB_ETH_RNDIS
  51 #    include "f_rndis.c"
  52 #    include "rndis.c"
  53 #  endif
  54 #  include "u_ether.c"
  55
  56 static u8 gfs_hostaddr[ETH_ALEN];
  57 #  ifdef CONFIG_USB_FUNCTIONFS_ETH
  58 static int eth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);
  59 #  endif
  60 #else
  61 #  define gether_cleanup() do { } while (0)
  62 #  define gether_setup(gadget, hostaddr)   ((int)0)
  63 #  define gfs_hostaddr NULL
  64 #endif
  65
  66 #include "f_fs.c"
  67
  68 #define DRIVER_NAME     "g_ffs"
  69 #define DRIVER_DESC     "USB Function Filesystem"
  70 #define DRIVER_VERSION  "24 Aug 2004"
  71
  72 MODULE_DESCRIPTION(DRIVER_DESC);
  73 MODULE_AUTHOR("Michal Nazarewicz");
  74 MODULE_LICENSE("GPL");
  75
  76 #define GFS_VENDOR_ID   0x1d6b  /* Linux Foundation */
  77 #define GFS_PRODUCT_ID  0x0105  /* FunctionFS Gadget */
  78
  79 static struct usb_device_descriptor gfs_dev_desc = {
  80         .bLength                = sizeof gfs_dev_desc,
  81         .bDescriptorType        = USB_DT_DEVICE,
  82
  83         .bcdUSB                 = cpu_to_le16(0x0200),
  84         .bDeviceClass           = USB_CLASS_PER_INTERFACE,
  85
  86         .idVendor               = cpu_to_le16(GFS_VENDOR_ID),
  87         .idProduct              = cpu_to_le16(GFS_PRODUCT_ID),
  88 };
  89
  90 module_param_named(bDeviceClass,    gfs_dev_desc.bDeviceClass,    byte,   0644);
  91 MODULE_PARM_DESC(bDeviceClass, "USB Device class");
  92 module_param_named(bDeviceSubClass, gfs_dev_desc.bDeviceSubClass, byte,   0644);
  93 MODULE_PARM_DESC(bDeviceSubClass, "USB Device subclass");
  94 module_param_named(bDeviceProtocol, gfs_dev_desc.bDeviceProtocol, byte,   0644);
  95 MODULE_PARM_DESC(bDeviceProtocol, "USB Device protocol");
  96
  97 static const struct usb_descriptor_header *gfs_otg_desc[] = {
  98         (const struct usb_descriptor_header *)
  99         &(const struct usb_otg_descriptor) {
 100                 .bLength                = sizeof(struct usb_otg_descriptor),
 101                 .bDescriptorType        = USB_DT_OTG,
 102
 103                 /*
 104                  * REVISIT SRP-only hardware is possible, although
 105                  * it would not be called "OTG" ...
 106                  */
 107                 .bmAttributes           = USB_OTG_SRP | USB_OTG_HNP,
 108         },
 109
 110         NULL
 111 };
 112
 113 /* String IDs are assigned dynamically */
 114 static struct usb_string gfs_strings[] = {
 115 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 116         { .s = "FunctionFS + RNDIS" },
 117 #endif
 118 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 119         { .s = "FunctionFS + ECM" },
 120 #endif
 121 #ifdef CONFIG_USB_FUNCTIONFS_GENERIC
 122         { .s = "FunctionFS" },
 123 #endif
 124         {  } /* end of list */
 125 };
 126
 127 static struct usb_gadget_strings *gfs_dev_strings[] = {
 128         &(struct usb_gadget_strings) {
 129                 .language       = 0x0409,       /* en-us */
 130                 .strings        = gfs_strings,
 131         },
 132         NULL,
 133 };
 134
 135 struct gfs_configuration {
 136         struct usb_configuration c;
 137         int (*eth)(struct usb_configuration *c, u8 *ethaddr);
 138 } gfs_configurations[] = {
 139 #ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 140         {
 141                 .eth            = rndis_bind_config,
 142         },
 143 #endif
 144
 145 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 146         {
 147                 .eth            = eth_bind_config,
 148         },
 149 #endif
 150
 151 #ifdef CONFIG_USB_FUNCTIONFS_GENERIC
 152         {
 153         },
 154 #endif
 155 };
 156
 157 static int gfs_bind(struct usb_composite_dev *cdev);
 158 static int gfs_unbind(struct usb_composite_dev *cdev);
 159 static int gfs_do_config(struct usb_configuration *c);
 160
 161 static struct usb_composite_driver gfs_driver = {
 162         .name           = DRIVER_NAME,
 163         .dev            = &gfs_dev_desc,
 164         .strings        = gfs_dev_strings,
 165         .max_speed      = USB_SPEED_HIGH,
 166         .unbind         = gfs_unbind,
 167         .iProduct       = DRIVER_DESC,
 168 };
 169
 170 static struct ffs_data *gfs_ffs_data;
 171 static unsigned long gfs_registered;
 172
 173 static int  gfs_init(void)
 174 {
 175         ENTER();
 176
 177         return functionfs_init();
 178 }
 179 module_init(gfs_init);
 180
 181 static void  gfs_exit(void)
 182 {
 183         ENTER();
 184
 185         if (test_and_clear_bit(0, &gfs_registered))
 186                 usb_composite_unregister(&gfs_driver);
 187
 188         functionfs_cleanup();
 189 }
 190 module_exit(gfs_exit);
 191
 192 static int functionfs_ready_callback(struct ffs_data *ffs)
 193 {
 194         int ret;
 195
 196         ENTER();
 197
 198         if (WARN_ON(test_and_set_bit(0, &gfs_registered)))
 199                 return -EBUSY;
 200
 201         gfs_ffs_data = ffs;
 202         ret = usb_composite_probe(&gfs_driver, gfs_bind);
 203         if (unlikely(ret < 0))
 204                 clear_bit(0, &gfs_registered);
 205         return ret;
 206 }
 207
 208 static void functionfs_closed_callback(struct ffs_data *ffs)
 209 {
 210         ENTER();
 211
 212         if (test_and_clear_bit(0, &gfs_registered))
 213                 usb_composite_unregister(&gfs_driver);
 214 }
 215
 216 static int functionfs_check_dev_callback(const char *dev_name)
 217 {
 218         return 0;
 219 }
 220
 221 static int gfs_bind(struct usb_composite_dev *cdev)
 222 {
 223         int ret, i;
 224
 225         ENTER();
 226
 227         if (WARN_ON(!gfs_ffs_data))
 228                 return -ENODEV;
 229
 230         ret = gether_setup(cdev->gadget, gfs_hostaddr);
 231         if (unlikely(ret < 0))
 232                 goto error_quick;
 233
 234         ret = usb_string_ids_tab(cdev, gfs_strings);
 235         if (unlikely(ret < 0))
 236                 goto error;
 237
 238         ret = functionfs_bind(gfs_ffs_data, cdev);
 239         if (unlikely(ret < 0))
 240                 goto error;
 241
 242         for (i = 0; i < ARRAY_SIZE(gfs_configurations); ++i) {
 243                 struct gfs_configuration *c = gfs_configurations + i;
 244
 245                 c->c.label                      = gfs_strings[i].s;
 246                 c->c.iConfiguration             = gfs_strings[i].id;
 247                 c->c.bConfigurationValue        = 1 + i;
 248                 c->c.bmAttributes               = USB_CONFIG_ATT_SELFPOWER;
 249
 250                 ret = usb_add_config(cdev, &c->c, gfs_do_config);
 251                 if (unlikely(ret < 0))
 252                         goto error_unbind;
 253         }
 254
 255         return 0;
 256
 257 error_unbind:
 258         functionfs_unbind(gfs_ffs_data);
 259 error:
 260         gether_cleanup();
 261 error_quick:
 262         gfs_ffs_data = NULL;
 263         return ret;
 264 }
 265
 266 static int gfs_unbind(struct usb_composite_dev *cdev)
 267 {
 268         ENTER();
 269
 270         /*
 271          * We may have been called in an error recovery from
 272          * composite_bind() after gfs_unbind() failure so we need to
 273          * check if gfs_ffs_data is not NULL since gfs_bind() handles
 274          * all error recovery itself.  I'd rather we werent called
 275          * from composite on orror recovery, but what you're gonna
 276          * do...?
 277          */
 278         if (gfs_ffs_data) {
 279                 gether_cleanup();
 280                 functionfs_unbind(gfs_ffs_data);
 281                 gfs_ffs_data = NULL;
 282         }
 283
 284         return 0;
 285 }
 286
 287 static int gfs_do_config(struct usb_configuration *c)
 288 {
 289         struct gfs_configuration *gc =
 290                 container_of(c, struct gfs_configuration, c);
 291         int ret;
 292
 293         if (WARN_ON(!gfs_ffs_data))
 294                 return -ENODEV;
 295
 296         if (gadget_is_otg(c->cdev->gadget)) {
 297                 c->descriptors = gfs_otg_desc;
 298                 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 299         }
 300
 301         if (gc->eth) {
 302                 ret = gc->eth(c, gfs_hostaddr);
 303                 if (unlikely(ret < 0))
 304                         return ret;
 305         }
 306
 307         ret = functionfs_bind_config(c->cdev, c, gfs_ffs_data);
 308         if (unlikely(ret < 0))
 309                 return ret;
 310
 311         /*
 312          * After previous do_configs there may be some invalid
 313          * pointers in c->interface array.  This happens every time
 314          * a user space function with fewer interfaces than a user
 315          * space function that was run before the new one is run.  The
 316          * compasit's set_config() assumes that if there is no more
 317          * then MAX_CONFIG_INTERFACES interfaces in a configuration
 318          * then there is a NULL pointer after the last interface in
 319          * c->interface array.  We need to make sure this is true.
 320          */
 321         if (c->next_interface_id < ARRAY_SIZE(c->interface))
 322                 c->interface[c->next_interface_id] = NULL;
 323
 324         return 0;
 325 }
 326
 327 #ifdef CONFIG_USB_FUNCTIONFS_ETH
 328
 329 static int eth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN])
 330 {
 331         return can_support_ecm(c->cdev->gadget)
 332                 ? ecm_bind_config(c, ethaddr)
 333                 : geth_bind_config(c, ethaddr);
 334 }
 335
 336 #endif