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
  13
  14 /*
  15  * Gadget Zero only needs two bulk endpoints, and is an example of how you
  16  * can write a hardware-agnostic gadget driver running inside a USB device.
  17  * Some hardware details are visible, but don't affect most of the driver.
  18  *
  19  * Use it with the Linux host/master side "usbtest" driver to get a basic
  20  * functional test of your device-side usb stack, or with "usb-skeleton".
  21  *
  22  * It supports two similar configurations.  One sinks whatever the usb host
  23  * writes, and in return sources zeroes.  The other loops whatever the host
  24  * writes back, so the host can read it.
  25  *
  26  * Many drivers will only have one configuration, letting them be much
  27  * simpler if they also don't support high speed operation (like this
  28  * driver does).
  29  *
  30  * Why is *this* driver using two configurations, rather than setting up
  31  * two interfaces with different functions?  To help verify that multiple
  32  * configuration infrastucture is working correctly; also, so that it can
  33  * work with low capability USB controllers without four bulk endpoints.
  34  */
  35
  36 /*
  37  * driver assumes self-powered hardware, and
  38  * has no way for users to trigger remote wakeup.
  39  */
  40
  41 /* #define VERBOSE_DEBUG */
  42
  43 #include <linux/kernel.h>
  44 #include <linux/slab.h>
  45 #include <linux/utsname.h>
  46 #include <linux/device.h>
  47
  48 #include "g_zero.h"
  49 #include "gadget_chips.h"
  50
  51
  52 /*-------------------------------------------------------------------------*/
  53
  54 /*
  55  * Kbuild is not very cooperative with respect to linking separately
  56  * compiled library objects into one module.  So for now we won't use
  57  * separate compilation ... ensuring init/exit sections work to shrink
  58  * the runtime footprint, and giving us at least some parts of what
  59  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
  60  */
  61 #include "composite.c"
  62 #include "usbstring.c"
  63 #include "config.c"
  64 #include "epautoconf.c"
  65
  66 #include "f_sourcesink.c"
  67 #include "f_loopback.c"
  68
  69 /*-------------------------------------------------------------------------*/
  70
  71 #define DRIVER_VERSION          "Cinco de Mayo 2008"
  72
  73 static const char longname[] = "Gadget Zero";
  74
  75 unsigned buflen = 4096;
  76 module_param(buflen, uint, 0);
  77
  78 /*
  79  * Normally the "loopback" configuration is second (index 1) so
  80  * it's not the default.  Here's where to change that order, to
  81  * work better with hosts where config changes are problematic or
  82  * controllers (like original superh) that only support one config.
  83  */
  84 static int loopdefault = 0;
  85 module_param(loopdefault, bool, S_IRUGO|S_IWUSR);
  86
  87 /*-------------------------------------------------------------------------*/
  88
  89 /* Thanks to NetChip Technologies for donating this product ID.
  90  *
  91  * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  92  * Instead:  allocate your own, using normal USB-IF procedures.
  93  */
  94 #ifndef CONFIG_USB_ZERO_HNPTEST
  95 #define DRIVER_VENDOR_NUM       0x0525          /* NetChip */
  96 #define DRIVER_PRODUCT_NUM      0xa4a0          /* Linux-USB "Gadget Zero" */
  97 #define DEFAULT_AUTORESUME      0
  98 #else
  99 #define DRIVER_VENDOR_NUM       0x1a0a          /* OTG test device IDs */
 100 #define DRIVER_PRODUCT_NUM      0xbadd
 101 #define DEFAULT_AUTORESUME      5
 102 #endif
 103
 104 /* If the optional "autoresume" mode is enabled, it provides good
 105  * functional coverage for the "USBCV" test harness from USB-IF.
 106  * It's always set if OTG mode is enabled.
 107  */
 108 unsigned autoresume = DEFAULT_AUTORESUME;
 109 module_param(autoresume, uint, S_IRUGO);
 110 MODULE_PARM_DESC(autoresume, "zero, or seconds before remote wakeup");
 111
 112 /*-------------------------------------------------------------------------*/
 113
 114 static struct usb_device_descriptor device_desc = {
 115         .bLength =              sizeof device_desc,
 116         .bDescriptorType =      USB_DT_DEVICE,
 117
 118         .bcdUSB =               cpu_to_le16(0x0200),
 119         .bDeviceClass =         USB_CLASS_VENDOR_SPEC,
 120
 121         .idVendor =             cpu_to_le16(DRIVER_VENDOR_NUM),
 122         .idProduct =            cpu_to_le16(DRIVER_PRODUCT_NUM),
 123         .bNumConfigurations =   2,
 124 };
 125
 126 #ifdef CONFIG_USB_OTG
 127 static struct usb_otg_descriptor otg_descriptor = {
 128         .bLength =              sizeof otg_descriptor,
 129         .bDescriptorType =      USB_DT_OTG,
 130
 131         /* REVISIT SRP-only hardware is possible, although
 132          * it would not be called "OTG" ...
 133          */
 134         .bmAttributes =         USB_OTG_SRP | USB_OTG_HNP,
 135 };
 136
 137 const struct usb_descriptor_header *otg_desc[] = {
 138         (struct usb_descriptor_header *) &otg_descriptor,
 139         NULL,
 140 };
 141 #endif
 142
 143 /* string IDs are assigned dynamically */
 144
 145 #define STRING_MANUFACTURER_IDX         0
 146 #define STRING_PRODUCT_IDX              1
 147 #define STRING_SERIAL_IDX               2
 148
 149 static char manufacturer[50];
 150
 151 /* default serial number takes at least two packets */
 152 static char serial[] = "0123456789.0123456789.0123456789";
 153
 154 static struct usb_string strings_dev[] = {
 155         [STRING_MANUFACTURER_IDX].s = manufacturer,
 156         [STRING_PRODUCT_IDX].s = longname,
 157         [STRING_SERIAL_IDX].s = serial,
 158         {  }                    /* end of list */
 159 };
 160
 161 static struct usb_gadget_strings stringtab_dev = {
 162         .language       = 0x0409,       /* en-us */
 163         .strings        = strings_dev,
 164 };
 165
 166 static struct usb_gadget_strings *dev_strings[] = {
 167         &stringtab_dev,
 168         NULL,
 169 };
 170
 171 /*-------------------------------------------------------------------------*/
 172
 173 struct usb_request *alloc_ep_req(struct usb_ep *ep)
 174 {
 175         struct usb_request      *req;
 176
 177         req = usb_ep_alloc_request(ep, GFP_ATOMIC);
 178         if (req) {
 179                 req->length = buflen;
 180                 req->buf = kmalloc(buflen, GFP_ATOMIC);
 181                 if (!req->buf) {
 182                         usb_ep_free_request(ep, req);
 183                         req = NULL;
 184                 }
 185         }
 186         return req;
 187 }
 188
 189 void free_ep_req(struct usb_ep *ep, struct usb_request *req)
 190 {
 191         kfree(req->buf);
 192         usb_ep_free_request(ep, req);
 193 }
 194
 195 static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep)
 196 {
 197         int                     value;
 198
 199         if (ep->driver_data) {
 200                 value = usb_ep_disable(ep);
 201                 if (value < 0)
 202                         DBG(cdev, "disable %s --> %d\n",
 203                                         ep->name, value);
 204                 ep->driver_data = NULL;
 205         }
 206 }
 207
 208 void disable_endpoints(struct usb_composite_dev *cdev,
 209                 struct usb_ep *in, struct usb_ep *out)
 210 {
 211         disable_ep(cdev, in);
 212         disable_ep(cdev, out);
 213 }
 214
 215 /*-------------------------------------------------------------------------*/
 216
 217 static struct timer_list        autoresume_timer;
 218
 219 static void zero_autoresume(unsigned long _c)
 220 {
 221         struct usb_composite_dev        *cdev = (void *)_c;
 222         struct usb_gadget               *g = cdev->gadget;
 223
 224         /* unconfigured devices can't issue wakeups */
 225         if (!cdev->config)
 226                 return;
 227
 228         /* Normally the host would be woken up for something
 229          * more significant than just a timer firing; likely
 230          * because of some direct user request.
 231          */
 232         if (g->speed != USB_SPEED_UNKNOWN) {
 233                 int status = usb_gadget_wakeup(g);
 234                 INFO(cdev, "%s --> %d\n", __func__, status);
 235         }
 236 }
 237
 238 static void zero_suspend(struct usb_composite_dev *cdev)
 239 {
 240         if (cdev->gadget->speed == USB_SPEED_UNKNOWN)
 241                 return;
 242
 243         if (autoresume) {
 244                 mod_timer(&autoresume_timer, jiffies + (HZ * autoresume));
 245                 DBG(cdev, "suspend, wakeup in %d seconds\n", autoresume);
 246         } else
 247                 DBG(cdev, "%s\n", __func__);
 248 }
 249
 250 static void zero_resume(struct usb_composite_dev *cdev)
 251 {
 252         DBG(cdev, "%s\n", __func__);
 253         del_timer(&autoresume_timer);
 254 }
 255
 256 /*-------------------------------------------------------------------------*/
 257
 258 static int __init zero_bind(struct usb_composite_dev *cdev)
 259 {
 260         int                     gcnum;
 261         struct usb_gadget       *gadget = cdev->gadget;
 262         int                     id;
 263
 264         /* Allocate string descriptor numbers ... note that string
 265          * contents can be overridden by the composite_dev glue.
 266          */
 267         id = usb_string_id(cdev);
 268         if (id < 0)
 269                 return id;
 270         strings_dev[STRING_MANUFACTURER_IDX].id = id;
 271         device_desc.iManufacturer = id;
 272
 273         id = usb_string_id(cdev);
 274         if (id < 0)
 275                 return id;
 276         strings_dev[STRING_PRODUCT_IDX].id = id;
 277         device_desc.iProduct = id;
 278
 279         id = usb_string_id(cdev);
 280         if (id < 0)
 281                 return id;
 282         strings_dev[STRING_SERIAL_IDX].id = id;
 283         device_desc.iSerialNumber = id;
 284
 285         setup_timer(&autoresume_timer, zero_autoresume, (unsigned long) cdev);
 286
 287         /* Register primary, then secondary configuration.  Note that
 288          * SH3 only allows one config...
 289          */
 290         if (loopdefault) {
 291                 loopback_add(cdev, autoresume != 0);
 292                 sourcesink_add(cdev, autoresume != 0);
 293         } else {
 294                 sourcesink_add(cdev, autoresume != 0);
 295                 loopback_add(cdev, autoresume != 0);
 296         }
 297
 298         gcnum = usb_gadget_controller_number(gadget);
 299         if (gcnum >= 0)
 300                 device_desc.bcdDevice = cpu_to_le16(0x0200 + gcnum);
 301         else {
 302                 /* gadget zero is so simple (for now, no altsettings) that
 303                  * it SHOULD NOT have problems with bulk-capable hardware.
 304                  * so just warn about unrcognized controllers -- don't panic.
 305                  *
 306                  * things like configuration and altsetting numbering
 307                  * can need hardware-specific attention though.
 308                  */
 309                 pr_warning("%s: controller '%s' not recognized\n",
 310                         longname, gadget->name);
 311                 device_desc.bcdDevice = cpu_to_le16(0x9999);
 312         }
 313
 314
 315         INFO(cdev, "%s, version: " DRIVER_VERSION "\n", longname);
 316
 317         snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
 318                 init_utsname()->sysname, init_utsname()->release,
 319                 gadget->name);
 320
 321         return 0;
 322 }
 323
 324 static int zero_unbind(struct usb_composite_dev *cdev)
 325 {
 326         del_timer_sync(&autoresume_timer);
 327         return 0;
 328 }
 329
 330 static struct usb_composite_driver zero_driver = {
 331         .name           = "zero",
 332         .dev            = &device_desc,
 333         .strings        = dev_strings,
 334         .max_speed      = USB_SPEED_SUPER,
 335         .unbind         = zero_unbind,
 336         .suspend        = zero_suspend,
 337         .resume         = zero_resume,
 338 };
 339
 340 MODULE_AUTHOR("David Brownell");
 341 MODULE_LICENSE("GPL");
 342
 343 static int __init init(void)
 344 {
 345         return usb_composite_probe(&zero_driver, zero_bind);
 346 }
 347 module_init(init);
 348
 349 static void __exit cleanup(void)
 350 {
 351         usb_composite_unregister(&zero_driver);
 352 }
 353 module_exit(cleanup);