drivers/usb/gadget/zero.c

   1 /*
   2  * zero.c -- Gadget Zero, for USB development
   3  *
   4  * Copyright (C) 2003-2008 David Brownell
   5  * Copyright (C) 2008 by Nokia Corporation
   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
  23 /*
  24  * Gadget Zero only needs two bulk endpoints, and is an example of how you
  25  * can write a hardware-agnostic gadget driver running inside a USB device.
  26  * Some hardware details are visible, but don't affect most of the driver.
  27  *
  28  * Use it with the Linux host/master side "usbtest" driver to get a basic
  29  * functional test of your device-side usb stack, or with "usb-skeleton".
  30  *
  31  * It supports two similar configurations.  One sinks whatever the usb host
  32  * writes, and in return sources zeroes.  The other loops whatever the host
  33  * writes back, so the host can read it.
  34  *
  35  * Many drivers will only have one configuration, letting them be much
  36  * simpler if they also don't support high speed operation (like this
  37  * driver does).
  38  *
  39  * Why is *this* driver using two configurations, rather than setting up
  40  * two interfaces with different functions?  To help verify that multiple
  41  * configuration infrastucture is working correctly; also, so that it can
  42  * work with low capability USB controllers without four bulk endpoints.
  43  */
  44
  45 /*
  46  * driver assumes self-powered hardware, and
  47  * has no way for users to trigger remote wakeup.
  48  */
  49
  50 /* #define VERBOSE_DEBUG */
  51
  52 #include <linux/kernel.h>
  53 #include <linux/utsname.h>
  54 #include <linux/device.h>
  55
  56 #include "g_zero.h"
  57 #include "gadget_chips.h"
  58
  59
  60 /*-------------------------------------------------------------------------*/
  61
  62 /*
  63  * Kbuild is not very cooperative with respect to linking separately
  64  * compiled library objects into one module.  So for now we won't use
  65  * separate compilation ... ensuring init/exit sections work to shrink
  66  * the runtime footprint, and giving us at least some parts of what
  67  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
  68  */
  69 #include "composite.c"
  70 #include "usbstring.c"
  71 #include "config.c"
  72 #include "epautoconf.c"
  73
  74 #include "f_sourcesink.c"
  75 #include "f_loopback.c"
  76
  77 /*-------------------------------------------------------------------------*/
  78
  79 #define DRIVER_VERSION          "Cinco de Mayo 2008"
  80
  81 static const char longname[] = "Gadget Zero";
  82
  83 unsigned buflen = 4096;
  84 module_param(buflen, uint, 0);
  85
  86 /*
  87  * Normally the "loopback" configuration is second (index 1) so
  88  * it's not the default.  Here's where to change that order, to
  89  * work better with hosts where config changes are problematic or
  90  * controllers (like original superh) that only support one config.
  91  */
  92 static int loopdefault = 0;
  93 module_param(loopdefault, bool, S_IRUGO|S_IWUSR);
  94
  95 /*-------------------------------------------------------------------------*/
  96
  97 /* Thanks to NetChip Technologies for donating this product ID.
  98  *
  99  * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
 100  * Instead:  allocate your own, using normal USB-IF procedures.
 101  */
 102 #ifndef CONFIG_USB_ZERO_HNPTEST
 103 #define DRIVER_VENDOR_NUM       0x0525          /* NetChip */
 104 #define DRIVER_PRODUCT_NUM      0xa4a0          /* Linux-USB "Gadget Zero" */
 105 #define DEFAULT_AUTORESUME      0
 106 #else
 107 #define DRIVER_VENDOR_NUM       0x1a0a          /* OTG test device IDs */
 108 #define DRIVER_PRODUCT_NUM      0xbadd
 109 #define DEFAULT_AUTORESUME      5
 110 #endif
 111
 112 /* If the optional "autoresume" mode is enabled, it provides good
 113  * functional coverage for the "USBCV" test harness from USB-IF.
 114  * It's always set if OTG mode is enabled.
 115  */
 116 unsigned autoresume = DEFAULT_AUTORESUME;
 117 module_param(autoresume, uint, S_IRUGO);
 118 MODULE_PARM_DESC(autoresume, "zero, or seconds before remote wakeup");
 119
 120 /*-------------------------------------------------------------------------*/
 121
 122 static struct usb_device_descriptor device_desc = {
 123         .bLength =              sizeof device_desc,
 124         .bDescriptorType =      USB_DT_DEVICE,
 125
 126         .bcdUSB =               cpu_to_le16(0x0200),
 127         .bDeviceClass =         USB_CLASS_VENDOR_SPEC,
 128
 129         .idVendor =             cpu_to_le16(DRIVER_VENDOR_NUM),
 130         .idProduct =            cpu_to_le16(DRIVER_PRODUCT_NUM),
 131         .bNumConfigurations =   2,
 132 };
 133
 134 #ifdef CONFIG_USB_OTG
 135 static struct usb_otg_descriptor otg_descriptor = {
 136         .bLength =              sizeof otg_descriptor,
 137         .bDescriptorType =      USB_DT_OTG,
 138
 139         /* REVISIT SRP-only hardware is possible, although
 140          * it would not be called "OTG" ...
 141          */
 142         .bmAttributes =         USB_OTG_SRP | USB_OTG_HNP,
 143 };
 144
 145 const struct usb_descriptor_header *otg_desc[] = {
 146         (struct usb_descriptor_header *) &otg_descriptor,
 147         NULL,
 148 };
 149 #endif
 150
 151 /* string IDs are assigned dynamically */
 152
 153 #define STRING_MANUFACTURER_IDX         0
 154 #define STRING_PRODUCT_IDX              1
 155 #define STRING_SERIAL_IDX               2
 156
 157 static char manufacturer[50];
 158
 159 /* default serial number takes at least two packets */
 160 static char serial[] = "0123456789.0123456789.0123456789";
 161
 162 static struct usb_string strings_dev[] = {
 163         [STRING_MANUFACTURER_IDX].s = manufacturer,
 164         [STRING_PRODUCT_IDX].s = longname,
 165         [STRING_SERIAL_IDX].s = serial,
 166         {  }                    /* end of list */
 167 };
 168
 169 static struct usb_gadget_strings stringtab_dev = {
 170         .language       = 0x0409,       /* en-us */
 171         .strings        = strings_dev,
 172 };
 173
 174 static struct usb_gadget_strings *dev_strings[] = {
 175         &stringtab_dev,
 176         NULL,
 177 };
 178
 179 /*-------------------------------------------------------------------------*/
 180
 181 struct usb_request *alloc_ep_req(struct usb_ep *ep)
 182 {
 183         struct usb_request      *req;
 184
 185         req = usb_ep_alloc_request(ep, GFP_ATOMIC);
 186         if (req) {
 187                 req->length = buflen;
 188                 req->buf = kmalloc(buflen, GFP_ATOMIC);
 189                 if (!req->buf) {
 190                         usb_ep_free_request(ep, req);
 191                         req = NULL;
 192                 }
 193         }
 194         return req;
 195 }
 196
 197 void free_ep_req(struct usb_ep *ep, struct usb_request *req)
 198 {
 199         kfree(req->buf);
 200         usb_ep_free_request(ep, req);
 201 }
 202
 203 static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep)
 204 {
 205         int                     value;
 206
 207         if (ep->driver_data) {
 208                 value = usb_ep_disable(ep);
 209                 if (value < 0)
 210                         DBG(cdev, "disable %s --> %d\n",
 211                                         ep->name, value);
 212                 ep->driver_data = NULL;
 213         }
 214 }
 215
 216 void disable_endpoints(struct usb_composite_dev *cdev,
 217                 struct usb_ep *in, struct usb_ep *out)
 218 {
 219         disable_ep(cdev, in);
 220         disable_ep(cdev, out);
 221 }
 222
 223 /*-------------------------------------------------------------------------*/
 224
 225 static struct timer_list        autoresume_timer;
 226
 227 static void zero_autoresume(unsigned long _c)
 228 {
 229         struct usb_composite_dev        *cdev = (void *)_c;
 230         struct usb_gadget               *g = cdev->gadget;
 231
 232         /* unconfigured devices can't issue wakeups */
 233         if (!cdev->config)
 234                 return;
 235
 236         /* Normally the host would be woken up for something
 237          * more significant than just a timer firing; likely
 238          * because of some direct user request.
 239          */
 240         if (g->speed != USB_SPEED_UNKNOWN) {
 241                 int status = usb_gadget_wakeup(g);
 242                 INFO(cdev, "%s --> %d\n", __func__, status);
 243         }
 244 }
 245
 246 static void zero_suspend(struct usb_composite_dev *cdev)
 247 {
 248         if (cdev->gadget->speed == USB_SPEED_UNKNOWN)
 249                 return;
 250
 251         if (autoresume) {
 252                 mod_timer(&autoresume_timer, jiffies + (HZ * autoresume));
 253                 DBG(cdev, "suspend, wakeup in %d seconds\n", autoresume);
 254         } else
 255                 DBG(cdev, "%s\n", __func__);
 256 }
 257
 258 static void zero_resume(struct usb_composite_dev *cdev)
 259 {
 260         DBG(cdev, "%s\n", __func__);
 261         del_timer(&autoresume_timer);
 262 }
 263
 264 /*-------------------------------------------------------------------------*/
 265
 266 static int __init zero_bind(struct usb_composite_dev *cdev)
 267 {
 268         int                     gcnum;
 269         struct usb_gadget       *gadget = cdev->gadget;
 270         int                     id;
 271
 272         /* Allocate string descriptor numbers ... note that string
 273          * contents can be overridden by the composite_dev glue.
 274          */
 275         id = usb_string_id(cdev);
 276         if (id < 0)
 277                 return id;
 278         strings_dev[STRING_MANUFACTURER_IDX].id = id;
 279         device_desc.iManufacturer = id;
 280
 281         id = usb_string_id(cdev);
 282         if (id < 0)
 283                 return id;
 284         strings_dev[STRING_PRODUCT_IDX].id = id;
 285         device_desc.iProduct = id;
 286
 287         id = usb_string_id(cdev);
 288         if (id < 0)
 289                 return id;
 290         strings_dev[STRING_SERIAL_IDX].id = id;
 291         device_desc.iSerialNumber = id;
 292
 293         setup_timer(&autoresume_timer, zero_autoresume, (unsigned long) cdev);
 294
 295         /* Register primary, then secondary configuration.  Note that
 296          * SH3 only allows one config...
 297          */
 298         if (loopdefault) {
 299                 loopback_add(cdev, autoresume != 0);
 300                 if (!gadget_is_sh(gadget))
 301                         sourcesink_add(cdev, autoresume != 0);
 302         } else {
 303                 sourcesink_add(cdev, autoresume != 0);
 304                 if (!gadget_is_sh(gadget))
 305                         loopback_add(cdev, autoresume != 0);
 306         }
 307
 308         gcnum = usb_gadget_controller_number(gadget);
 309         if (gcnum >= 0)
 310                 device_desc.bcdDevice = cpu_to_le16(0x0200 + gcnum);
 311         else {
 312                 /* gadget zero is so simple (for now, no altsettings) that
 313                  * it SHOULD NOT have problems with bulk-capable hardware.
 314                  * so just warn about unrcognized controllers -- don't panic.
 315                  *
 316                  * things like configuration and altsetting numbering
 317                  * can need hardware-specific attention though.
 318                  */
 319                 pr_warning("%s: controller '%s' not recognized\n",
 320                         longname, gadget->name);
 321                 device_desc.bcdDevice = cpu_to_le16(0x9999);
 322         }
 323
 324
 325         INFO(cdev, "%s, version: " DRIVER_VERSION "\n", longname);
 326
 327         snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
 328                 init_utsname()->sysname, init_utsname()->release,
 329                 gadget->name);
 330
 331         return 0;
 332 }
 333
 334 static int zero_unbind(struct usb_composite_dev *cdev)
 335 {
 336         del_timer_sync(&autoresume_timer);
 337         return 0;
 338 }
 339
 340 static struct usb_composite_driver zero_driver = {
 341         .name           = "zero",
 342         .dev            = &device_desc,
 343         .strings        = dev_strings,
 344         .bind           = zero_bind,
 345         .unbind         = zero_unbind,
 346         .suspend        = zero_suspend,
 347         .resume         = zero_resume,
 348 };
 349
 350 MODULE_AUTHOR("David Brownell");
 351 MODULE_LICENSE("GPL");
 352
 353 static int __init init(void)
 354 {
 355         return usb_composite_register(&zero_driver);
 356 }
 357 module_init(init);
 358
 359 static void __exit cleanup(void)
 360 {
 361         usb_composite_unregister(&zero_driver);
 362 }
 363 module_exit(cleanup);