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 #else
 106 #define DRIVER_VENDOR_NUM       0x1a0a          /* OTG test device IDs */
 107 #define DRIVER_PRODUCT_NUM      0xbadd
 108 #endif
 109
 110 /*-------------------------------------------------------------------------*/
 111
 112 static struct usb_device_descriptor device_desc = {
 113         .bLength =              sizeof device_desc,
 114         .bDescriptorType =      USB_DT_DEVICE,
 115
 116         .bcdUSB =               __constant_cpu_to_le16(0x0200),
 117         .bDeviceClass =         USB_CLASS_VENDOR_SPEC,
 118
 119         .idVendor =             __constant_cpu_to_le16(DRIVER_VENDOR_NUM),
 120         .idProduct =            __constant_cpu_to_le16(DRIVER_PRODUCT_NUM),
 121         .bNumConfigurations =   2,
 122 };
 123
 124 #ifdef CONFIG_USB_OTG
 125 static struct usb_otg_descriptor otg_descriptor = {
 126         .bLength =              sizeof otg_descriptor,
 127         .bDescriptorType =      USB_DT_OTG,
 128
 129         /* REVISIT SRP-only hardware is possible, although
 130          * it would not be called "OTG" ...
 131          */
 132         .bmAttributes =         USB_OTG_SRP | USB_OTG_HNP,
 133 };
 134
 135 const struct usb_descriptor_header *otg_desc[] = {
 136         (struct usb_descriptor_header *) &otg_descriptor,
 137         NULL,
 138 };
 139 #endif
 140
 141 /* string IDs are assigned dynamically */
 142
 143 #define STRING_MANUFACTURER_IDX         0
 144 #define STRING_PRODUCT_IDX              1
 145 #define STRING_SERIAL_IDX               2
 146
 147 static char manufacturer[50];
 148
 149 /* default serial number takes at least two packets */
 150 static char serial[] = "0123456789.0123456789.0123456789";
 151
 152 static struct usb_string strings_dev[] = {
 153         [STRING_MANUFACTURER_IDX].s = manufacturer,
 154         [STRING_PRODUCT_IDX].s = longname,
 155         [STRING_SERIAL_IDX].s = serial,
 156         {  }                    /* end of list */
 157 };
 158
 159 static struct usb_gadget_strings stringtab_dev = {
 160         .language       = 0x0409,       /* en-us */
 161         .strings        = strings_dev,
 162 };
 163
 164 static struct usb_gadget_strings *dev_strings[] = {
 165         &stringtab_dev,
 166         NULL,
 167 };
 168
 169 /*-------------------------------------------------------------------------*/
 170
 171 struct usb_request *alloc_ep_req(struct usb_ep *ep)
 172 {
 173         struct usb_request      *req;
 174
 175         req = usb_ep_alloc_request(ep, GFP_ATOMIC);
 176         if (req) {
 177                 req->length = buflen;
 178                 req->buf = kmalloc(buflen, GFP_ATOMIC);
 179                 if (!req->buf) {
 180                         usb_ep_free_request(ep, req);
 181                         req = NULL;
 182                 }
 183         }
 184         return req;
 185 }
 186
 187 void free_ep_req(struct usb_ep *ep, struct usb_request *req)
 188 {
 189         kfree(req->buf);
 190         usb_ep_free_request(ep, req);
 191 }
 192
 193 static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep)
 194 {
 195         int                     value;
 196
 197         if (ep->driver_data) {
 198                 value = usb_ep_disable(ep);
 199                 if (value < 0)
 200                         DBG(cdev, "disable %s --> %d\n",
 201                                         ep->name, value);
 202                 ep->driver_data = NULL;
 203         }
 204 }
 205
 206 void disable_endpoints(struct usb_composite_dev *cdev,
 207                 struct usb_ep *in, struct usb_ep *out)
 208 {
 209         disable_ep(cdev, in);
 210         disable_ep(cdev, out);
 211 }
 212
 213 /*-------------------------------------------------------------------------*/
 214
 215 static int __init zero_bind(struct usb_composite_dev *cdev)
 216 {
 217         int                     gcnum;
 218         struct usb_gadget       *gadget = cdev->gadget;
 219         int                     id;
 220
 221         /* Allocate string descriptor numbers ... note that string
 222          * contents can be overridden by the composite_dev glue.
 223          */
 224         id = usb_string_id(cdev);
 225         if (id < 0)
 226                 return id;
 227         strings_dev[STRING_MANUFACTURER_IDX].id = id;
 228         device_desc.iManufacturer = id;
 229
 230         id = usb_string_id(cdev);
 231         if (id < 0)
 232                 return id;
 233         strings_dev[STRING_PRODUCT_IDX].id = id;
 234         device_desc.iProduct = id;
 235
 236         id = usb_string_id(cdev);
 237         if (id < 0)
 238                 return id;
 239         strings_dev[STRING_SERIAL_IDX].id = id;
 240         device_desc.iSerialNumber = id;
 241
 242         /* Register primary, then secondary configuration.  Note that
 243          * SH3 only allows one config...
 244          */
 245         if (loopdefault) {
 246                 loopback_add(cdev);
 247                 if (!gadget_is_sh(gadget))
 248                         sourcesink_add(cdev);
 249         } else {
 250                 sourcesink_add(cdev);
 251                 if (!gadget_is_sh(gadget))
 252                         loopback_add(cdev);
 253         }
 254
 255         gcnum = usb_gadget_controller_number(gadget);
 256         if (gcnum >= 0)
 257                 device_desc.bcdDevice = cpu_to_le16(0x0200 + gcnum);
 258         else {
 259                 /* gadget zero is so simple (for now, no altsettings) that
 260                  * it SHOULD NOT have problems with bulk-capable hardware.
 261                  * so just warn about unrcognized controllers -- don't panic.
 262                  *
 263                  * things like configuration and altsetting numbering
 264                  * can need hardware-specific attention though.
 265                  */
 266                 pr_warning("%s: controller '%s' not recognized\n",
 267                         longname, gadget->name);
 268                 device_desc.bcdDevice = __constant_cpu_to_le16(0x9999);
 269         }
 270
 271
 272         INFO(cdev, "%s, version: " DRIVER_VERSION "\n", longname);
 273
 274         snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
 275                 init_utsname()->sysname, init_utsname()->release,
 276                 gadget->name);
 277
 278         return 0;
 279 }
 280
 281 static struct usb_composite_driver zero_driver = {
 282         .name           = "zero",
 283         .dev            = &device_desc,
 284         .strings        = dev_strings,
 285         .bind           = zero_bind,
 286 };
 287
 288 MODULE_AUTHOR("David Brownell");
 289 MODULE_LICENSE("GPL");
 290
 291 static int __init init(void)
 292 {
 293         return usb_composite_register(&zero_driver);
 294 }
 295 module_init(init);
 296
 297 static void __exit cleanup(void)
 298 {
 299         usb_composite_unregister(&zero_driver);
 300 }
 301 module_exit(cleanup);