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/device.h>
  46
  47 #include "g_zero.h"
  48 #include "gadget_chips.h"
  49
  50
  51 /*-------------------------------------------------------------------------*/
  52
  53 /*
  54  * Kbuild is not very cooperative with respect to linking separately
  55  * compiled library objects into one module.  So for now we won't use
  56  * separate compilation ... ensuring init/exit sections work to shrink
  57  * the runtime footprint, and giving us at least some parts of what
  58  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
  59  */
  60 #include "f_sourcesink.c"
  61 #include "f_loopback.c"
  62
  63 /*-------------------------------------------------------------------------*/
  64 USB_GADGET_COMPOSITE_OPTIONS();
  65
  66 #define DRIVER_VERSION          "Cinco de Mayo 2008"
  67
  68 static const char longname[] = "Gadget Zero";
  69
  70 unsigned buflen = 4096;         /* only used for bulk endpoints */
  71 module_param(buflen, uint, 0);
  72
  73 /*
  74  * Normally the "loopback" configuration is second (index 1) so
  75  * it's not the default.  Here's where to change that order, to
  76  * work better with hosts where config changes are problematic or
  77  * controllers (like original superh) that only support one config.
  78  */
  79 static bool loopdefault = 0;
  80 module_param(loopdefault, bool, S_IRUGO|S_IWUSR);
  81
  82 /*-------------------------------------------------------------------------*/
  83
  84 /* Thanks to NetChip Technologies for donating this product ID.
  85  *
  86  * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  87  * Instead:  allocate your own, using normal USB-IF procedures.
  88  */
  89 #ifndef CONFIG_USB_ZERO_HNPTEST
  90 #define DRIVER_VENDOR_NUM       0x0525          /* NetChip */
  91 #define DRIVER_PRODUCT_NUM      0xa4a0          /* Linux-USB "Gadget Zero" */
  92 #define DEFAULT_AUTORESUME      0
  93 #else
  94 #define DRIVER_VENDOR_NUM       0x1a0a          /* OTG test device IDs */
  95 #define DRIVER_PRODUCT_NUM      0xbadd
  96 #define DEFAULT_AUTORESUME      5
  97 #endif
  98
  99 /* If the optional "autoresume" mode is enabled, it provides good
 100  * functional coverage for the "USBCV" test harness from USB-IF.
 101  * It's always set if OTG mode is enabled.
 102  */
 103 unsigned autoresume = DEFAULT_AUTORESUME;
 104 module_param(autoresume, uint, S_IRUGO);
 105 MODULE_PARM_DESC(autoresume, "zero, or seconds before remote wakeup");
 106
 107 /*-------------------------------------------------------------------------*/
 108
 109 static struct usb_device_descriptor device_desc = {
 110         .bLength =              sizeof device_desc,
 111         .bDescriptorType =      USB_DT_DEVICE,
 112
 113         .bcdUSB =               cpu_to_le16(0x0200),
 114         .bDeviceClass =         USB_CLASS_VENDOR_SPEC,
 115
 116         .idVendor =             cpu_to_le16(DRIVER_VENDOR_NUM),
 117         .idProduct =            cpu_to_le16(DRIVER_PRODUCT_NUM),
 118         .bNumConfigurations =   2,
 119 };
 120
 121 #ifdef CONFIG_USB_OTG
 122 static struct usb_otg_descriptor otg_descriptor = {
 123         .bLength =              sizeof otg_descriptor,
 124         .bDescriptorType =      USB_DT_OTG,
 125
 126         /* REVISIT SRP-only hardware is possible, although
 127          * it would not be called "OTG" ...
 128          */
 129         .bmAttributes =         USB_OTG_SRP | USB_OTG_HNP,
 130 };
 131
 132 const struct usb_descriptor_header *otg_desc[] = {
 133         (struct usb_descriptor_header *) &otg_descriptor,
 134         NULL,
 135 };
 136 #endif
 137
 138 /* string IDs are assigned dynamically */
 139 /* default serial number takes at least two packets */
 140 static char serial[] = "0123456789.0123456789.0123456789";
 141
 142 static struct usb_string strings_dev[] = {
 143         [USB_GADGET_MANUFACTURER_IDX].s = "",
 144         [USB_GADGET_PRODUCT_IDX].s = longname,
 145         [USB_GADGET_SERIAL_IDX].s = serial,
 146         {  }                    /* end of list */
 147 };
 148
 149 static struct usb_gadget_strings stringtab_dev = {
 150         .language       = 0x0409,       /* en-us */
 151         .strings        = strings_dev,
 152 };
 153
 154 static struct usb_gadget_strings *dev_strings[] = {
 155         &stringtab_dev,
 156         NULL,
 157 };
 158
 159 /*-------------------------------------------------------------------------*/
 160
 161 struct usb_request *alloc_ep_req(struct usb_ep *ep, int len)
 162 {
 163         struct usb_request      *req;
 164
 165         req = usb_ep_alloc_request(ep, GFP_ATOMIC);
 166         if (req) {
 167                 if (len)
 168                         req->length = len;
 169                 else
 170                         req->length = buflen;
 171                 req->buf = kmalloc(req->length, GFP_ATOMIC);
 172                 if (!req->buf) {
 173                         usb_ep_free_request(ep, req);
 174                         req = NULL;
 175                 }
 176         }
 177         return req;
 178 }
 179
 180 void free_ep_req(struct usb_ep *ep, struct usb_request *req)
 181 {
 182         kfree(req->buf);
 183         usb_ep_free_request(ep, req);
 184 }
 185
 186 static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep)
 187 {
 188         int                     value;
 189
 190         if (ep->driver_data) {
 191                 value = usb_ep_disable(ep);
 192                 if (value < 0)
 193                         DBG(cdev, "disable %s --> %d\n",
 194                                         ep->name, value);
 195                 ep->driver_data = NULL;
 196         }
 197 }
 198
 199 void disable_endpoints(struct usb_composite_dev *cdev,
 200                 struct usb_ep *in, struct usb_ep *out,
 201                 struct usb_ep *iso_in, struct usb_ep *iso_out)
 202 {
 203         disable_ep(cdev, in);
 204         disable_ep(cdev, out);
 205         if (iso_in)
 206                 disable_ep(cdev, iso_in);
 207         if (iso_out)
 208                 disable_ep(cdev, iso_out);
 209 }
 210
 211 /*-------------------------------------------------------------------------*/
 212
 213 static struct timer_list        autoresume_timer;
 214
 215 static void zero_autoresume(unsigned long _c)
 216 {
 217         struct usb_composite_dev        *cdev = (void *)_c;
 218         struct usb_gadget               *g = cdev->gadget;
 219
 220         /* unconfigured devices can't issue wakeups */
 221         if (!cdev->config)
 222                 return;
 223
 224         /* Normally the host would be woken up for something
 225          * more significant than just a timer firing; likely
 226          * because of some direct user request.
 227          */
 228         if (g->speed != USB_SPEED_UNKNOWN) {
 229                 int status = usb_gadget_wakeup(g);
 230                 INFO(cdev, "%s --> %d\n", __func__, status);
 231         }
 232 }
 233
 234 static void zero_suspend(struct usb_composite_dev *cdev)
 235 {
 236         if (cdev->gadget->speed == USB_SPEED_UNKNOWN)
 237                 return;
 238
 239         if (autoresume) {
 240                 mod_timer(&autoresume_timer, jiffies + (HZ * autoresume));
 241                 DBG(cdev, "suspend, wakeup in %d seconds\n", autoresume);
 242         } else
 243                 DBG(cdev, "%s\n", __func__);
 244 }
 245
 246 static void zero_resume(struct usb_composite_dev *cdev)
 247 {
 248         DBG(cdev, "%s\n", __func__);
 249         del_timer(&autoresume_timer);
 250 }
 251
 252 /*-------------------------------------------------------------------------*/
 253
 254 static int __init zero_bind(struct usb_composite_dev *cdev)
 255 {
 256         int                     status;
 257
 258         /* Allocate string descriptor numbers ... note that string
 259          * contents can be overridden by the composite_dev glue.
 260          */
 261         status = usb_string_ids_tab(cdev, strings_dev);
 262         if (status < 0)
 263                 return status;
 264
 265         device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
 266         device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
 267         device_desc.iSerialNumber = strings_dev[USB_GADGET_SERIAL_IDX].id;
 268
 269         setup_timer(&autoresume_timer, zero_autoresume, (unsigned long) cdev);
 270
 271         /* Register primary, then secondary configuration.  Note that
 272          * SH3 only allows one config...
 273          */
 274         if (loopdefault) {
 275                 loopback_add(cdev, autoresume != 0);
 276                 sourcesink_add(cdev, autoresume != 0);
 277         } else {
 278                 sourcesink_add(cdev, autoresume != 0);
 279                 loopback_add(cdev, autoresume != 0);
 280         }
 281
 282         usb_composite_overwrite_options(cdev, &coverwrite);
 283
 284         INFO(cdev, "%s, version: " DRIVER_VERSION "\n", longname);
 285
 286         return 0;
 287 }
 288
 289 static int zero_unbind(struct usb_composite_dev *cdev)
 290 {
 291         del_timer_sync(&autoresume_timer);
 292         return 0;
 293 }
 294
 295 static __refdata struct usb_composite_driver zero_driver = {
 296         .name           = "zero",
 297         .dev            = &device_desc,
 298         .strings        = dev_strings,
 299         .max_speed      = USB_SPEED_SUPER,
 300         .bind           = zero_bind,
 301         .unbind         = zero_unbind,
 302         .suspend        = zero_suspend,
 303         .resume         = zero_resume,
 304 };
 305
 306 MODULE_AUTHOR("David Brownell");
 307 MODULE_LICENSE("GPL");
 308
 309 static int __init init(void)
 310 {
 311         return usb_composite_probe(&zero_driver);
 312 }
 313 module_init(init);
 314
 315 static void __exit cleanup(void)
 316 {
 317         usb_composite_unregister(&zero_driver);
 318 }
 319 module_exit(cleanup);