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