drivers/usb/gadget/ncm.c

   1 /*
   2  * ncm.c -- NCM gadget driver
   3  *
   4  * Copyright (C) 2010 Nokia Corporation
   5  * Contact: Yauheni Kaliuta <yauheni.kaliuta@nokia.com>
   6  *
   7  * The driver borrows from ether.c which is:
   8  *
   9  * Copyright (C) 2003-2005,2008 David Brownell
  10  * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
  11  * Copyright (C) 2008 Nokia Corporation
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  */
  18
  19 /* #define DEBUG */
  20 /* #define VERBOSE_DEBUG */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/utsname.h>
  24
  25
  26 #include "u_ether.h"
  27
  28 #define DRIVER_DESC             "NCM Gadget"
  29
  30 /*-------------------------------------------------------------------------*/
  31
  32 /*
  33  * Kbuild is not very cooperative with respect to linking separately
  34  * compiled library objects into one module.  So for now we won't use
  35  * separate compilation ... ensuring init/exit sections work to shrink
  36  * the runtime footprint, and giving us at least some parts of what
  37  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
  38  */
  39 #include "composite.c"
  40 #include "usbstring.c"
  41 #include "config.c"
  42 #include "epautoconf.c"
  43
  44 #include "f_ncm.c"
  45 #include "u_ether.c"
  46
  47 /*-------------------------------------------------------------------------*/
  48
  49 /* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  50  * Instead:  allocate your own, using normal USB-IF procedures.
  51  */
  52
  53 /* Thanks to NetChip Technologies for donating this product ID.
  54  * It's for devices with only CDC Ethernet configurations.
  55  */
  56 #define CDC_VENDOR_NUM          0x0525  /* NetChip */
  57 #define CDC_PRODUCT_NUM         0xa4a1  /* Linux-USB Ethernet Gadget */
  58
  59 /*-------------------------------------------------------------------------*/
  60
  61 static struct usb_device_descriptor device_desc = {
  62         .bLength =              sizeof device_desc,
  63         .bDescriptorType =      USB_DT_DEVICE,
  64
  65         .bcdUSB =               cpu_to_le16 (0x0200),
  66
  67         .bDeviceClass =         USB_CLASS_COMM,
  68         .bDeviceSubClass =      0,
  69         .bDeviceProtocol =      0,
  70         /* .bMaxPacketSize0 = f(hardware) */
  71
  72         /* Vendor and product id defaults change according to what configs
  73          * we support.  (As does bNumConfigurations.)  These values can
  74          * also be overridden by module parameters.
  75          */
  76         .idVendor =             cpu_to_le16 (CDC_VENDOR_NUM),
  77         .idProduct =            cpu_to_le16 (CDC_PRODUCT_NUM),
  78         /* .bcdDevice = f(hardware) */
  79         /* .iManufacturer = DYNAMIC */
  80         /* .iProduct = DYNAMIC */
  81         /* NO SERIAL NUMBER */
  82         .bNumConfigurations =   1,
  83 };
  84
  85 static struct usb_otg_descriptor otg_descriptor = {
  86         .bLength =              sizeof otg_descriptor,
  87         .bDescriptorType =      USB_DT_OTG,
  88
  89         /* REVISIT SRP-only hardware is possible, although
  90          * it would not be called "OTG" ...
  91          */
  92         .bmAttributes =         USB_OTG_SRP | USB_OTG_HNP,
  93 };
  94
  95 static const struct usb_descriptor_header *otg_desc[] = {
  96         (struct usb_descriptor_header *) &otg_descriptor,
  97         NULL,
  98 };
  99
 100
 101 /* string IDs are assigned dynamically */
 102
 103 #define STRING_MANUFACTURER_IDX         0
 104 #define STRING_PRODUCT_IDX              1
 105
 106 static char manufacturer[50];
 107
 108 static struct usb_string strings_dev[] = {
 109         [STRING_MANUFACTURER_IDX].s = manufacturer,
 110         [STRING_PRODUCT_IDX].s = DRIVER_DESC,
 111         {  } /* end of list */
 112 };
 113
 114 static struct usb_gadget_strings stringtab_dev = {
 115         .language       = 0x0409,       /* en-us */
 116         .strings        = strings_dev,
 117 };
 118
 119 static struct usb_gadget_strings *dev_strings[] = {
 120         &stringtab_dev,
 121         NULL,
 122 };
 123
 124 static u8 hostaddr[ETH_ALEN];
 125
 126 /*-------------------------------------------------------------------------*/
 127
 128 static int __init ncm_do_config(struct usb_configuration *c)
 129 {
 130         /* FIXME alloc iConfiguration string, set it in c->strings */
 131
 132         if (gadget_is_otg(c->cdev->gadget)) {
 133                 c->descriptors = otg_desc;
 134                 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 135         }
 136
 137         return ncm_bind_config(c, hostaddr);
 138 }
 139
 140 static struct usb_configuration ncm_config_driver = {
 141         /* .label = f(hardware) */
 142         .label                  = "CDC Ethernet (NCM)",
 143         .bConfigurationValue    = 1,
 144         /* .iConfiguration = DYNAMIC */
 145         .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
 146 };
 147
 148 /*-------------------------------------------------------------------------*/
 149
 150 static int __init gncm_bind(struct usb_composite_dev *cdev)
 151 {
 152         int                     gcnum;
 153         struct usb_gadget       *gadget = cdev->gadget;
 154         int                     status;
 155
 156         /* set up network link layer */
 157         status = gether_setup(cdev->gadget, hostaddr);
 158         if (status < 0)
 159                 return status;
 160
 161         gcnum = usb_gadget_controller_number(gadget);
 162         if (gcnum >= 0)
 163                 device_desc.bcdDevice = cpu_to_le16(0x0300 | gcnum);
 164         else {
 165                 /* We assume that can_support_ecm() tells the truth;
 166                  * but if the controller isn't recognized at all then
 167                  * that assumption is a bit more likely to be wrong.
 168                  */
 169                 dev_warn(&gadget->dev,
 170                          "controller '%s' not recognized; trying %s\n",
 171                          gadget->name,
 172                          ncm_config_driver.label);
 173                 device_desc.bcdDevice =
 174                         cpu_to_le16(0x0300 | 0x0099);
 175         }
 176
 177
 178         /* Allocate string descriptor numbers ... note that string
 179          * contents can be overridden by the composite_dev glue.
 180          */
 181
 182         /* device descriptor strings: manufacturer, product */
 183         snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
 184                 init_utsname()->sysname, init_utsname()->release,
 185                 gadget->name);
 186         status = usb_string_id(cdev);
 187         if (status < 0)
 188                 goto fail;
 189         strings_dev[STRING_MANUFACTURER_IDX].id = status;
 190         device_desc.iManufacturer = status;
 191
 192         status = usb_string_id(cdev);
 193         if (status < 0)
 194                 goto fail;
 195         strings_dev[STRING_PRODUCT_IDX].id = status;
 196         device_desc.iProduct = status;
 197
 198         status = usb_add_config(cdev, &ncm_config_driver,
 199                                 ncm_do_config);
 200         if (status < 0)
 201                 goto fail;
 202
 203         dev_info(&gadget->dev, "%s\n", DRIVER_DESC);
 204
 205         return 0;
 206
 207 fail:
 208         gether_cleanup();
 209         return status;
 210 }
 211
 212 static int __exit gncm_unbind(struct usb_composite_dev *cdev)
 213 {
 214         gether_cleanup();
 215         return 0;
 216 }
 217
 218 static __refdata struct usb_composite_driver ncm_driver = {
 219         .name           = "g_ncm",
 220         .dev            = &device_desc,
 221         .strings        = dev_strings,
 222         .max_speed      = USB_SPEED_HIGH,
 223         .unbind         = __exit_p(gncm_unbind),
 224 };
 225
 226 MODULE_DESCRIPTION(DRIVER_DESC);
 227 MODULE_AUTHOR("Yauheni Kaliuta");
 228 MODULE_LICENSE("GPL");
 229
 230 static int __init init(void)
 231 {
 232         return usb_composite_probe(&ncm_driver, gncm_bind);
 233 }
 234 module_init(init);
 235
 236 static void __exit cleanup(void)
 237 {
 238         usb_composite_unregister(&ncm_driver);
 239 }
 240 module_exit(cleanup);