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