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