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/module.h>
  24 #include <linux/usb/composite.h>
  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 "f_ncm.c"
  40 #include "u_ether.c"
  41
  42 /*-------------------------------------------------------------------------*/
  43
  44 /* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  45  * Instead:  allocate your own, using normal USB-IF procedures.
  46  */
  47
  48 /* Thanks to NetChip Technologies for donating this product ID.
  49  * It's for devices with only CDC Ethernet configurations.
  50  */
  51 #define CDC_VENDOR_NUM          0x0525  /* NetChip */
  52 #define CDC_PRODUCT_NUM         0xa4a1  /* Linux-USB Ethernet Gadget */
  53
  54 /*-------------------------------------------------------------------------*/
  55 USB_GADGET_COMPOSITE_OPTIONS();
  56
  57 static struct usb_device_descriptor device_desc = {
  58         .bLength =              sizeof device_desc,
  59         .bDescriptorType =      USB_DT_DEVICE,
  60
  61         .bcdUSB =               cpu_to_le16 (0x0200),
  62
  63         .bDeviceClass =         USB_CLASS_COMM,
  64         .bDeviceSubClass =      0,
  65         .bDeviceProtocol =      0,
  66         /* .bMaxPacketSize0 = f(hardware) */
  67
  68         /* Vendor and product id defaults change according to what configs
  69          * we support.  (As does bNumConfigurations.)  These values can
  70          * also be overridden by module parameters.
  71          */
  72         .idVendor =             cpu_to_le16 (CDC_VENDOR_NUM),
  73         .idProduct =            cpu_to_le16 (CDC_PRODUCT_NUM),
  74         /* .bcdDevice = f(hardware) */
  75         /* .iManufacturer = DYNAMIC */
  76         /* .iProduct = DYNAMIC */
  77         /* NO SERIAL NUMBER */
  78         .bNumConfigurations =   1,
  79 };
  80
  81 static struct usb_otg_descriptor otg_descriptor = {
  82         .bLength =              sizeof otg_descriptor,
  83         .bDescriptorType =      USB_DT_OTG,
  84
  85         /* REVISIT SRP-only hardware is possible, although
  86          * it would not be called "OTG" ...
  87          */
  88         .bmAttributes =         USB_OTG_SRP | USB_OTG_HNP,
  89 };
  90
  91 static const struct usb_descriptor_header *otg_desc[] = {
  92         (struct usb_descriptor_header *) &otg_descriptor,
  93         NULL,
  94 };
  95
  96 /* string IDs are assigned dynamically */
  97 static struct usb_string strings_dev[] = {
  98         [USB_GADGET_MANUFACTURER_IDX].s = "",
  99         [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
 100         [USB_GADGET_SERIAL_IDX].s = "",
 101         {  } /* end of list */
 102 };
 103
 104 static struct usb_gadget_strings stringtab_dev = {
 105         .language       = 0x0409,       /* en-us */
 106         .strings        = strings_dev,
 107 };
 108
 109 static struct usb_gadget_strings *dev_strings[] = {
 110         &stringtab_dev,
 111         NULL,
 112 };
 113
 114 struct eth_dev *the_dev;
 115 static u8 hostaddr[ETH_ALEN];
 116
 117 /*-------------------------------------------------------------------------*/
 118
 119 static int __init ncm_do_config(struct usb_configuration *c)
 120 {
 121         /* FIXME alloc iConfiguration string, set it in c->strings */
 122
 123         if (gadget_is_otg(c->cdev->gadget)) {
 124                 c->descriptors = otg_desc;
 125                 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 126         }
 127
 128         return ncm_bind_config(c, hostaddr, the_dev);
 129 }
 130
 131 static struct usb_configuration ncm_config_driver = {
 132         /* .label = f(hardware) */
 133         .label                  = "CDC Ethernet (NCM)",
 134         .bConfigurationValue    = 1,
 135         /* .iConfiguration = DYNAMIC */
 136         .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
 137 };
 138
 139 /*-------------------------------------------------------------------------*/
 140
 141 static int __init gncm_bind(struct usb_composite_dev *cdev)
 142 {
 143         struct usb_gadget       *gadget = cdev->gadget;
 144         int                     status;
 145
 146         /* set up network link layer */
 147         the_dev = gether_setup(cdev->gadget, hostaddr);
 148         if (IS_ERR(the_dev))
 149                 return PTR_ERR(the_dev);
 150
 151         /* Allocate string descriptor numbers ... note that string
 152          * contents can be overridden by the composite_dev glue.
 153          */
 154
 155         status = usb_string_ids_tab(cdev, strings_dev);
 156         if (status < 0)
 157                 goto fail;
 158         device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
 159         device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
 160
 161         status = usb_add_config(cdev, &ncm_config_driver,
 162                                 ncm_do_config);
 163         if (status < 0)
 164                 goto fail;
 165
 166         usb_composite_overwrite_options(cdev, &coverwrite);
 167         dev_info(&gadget->dev, "%s\n", DRIVER_DESC);
 168
 169         return 0;
 170
 171 fail:
 172         gether_cleanup(the_dev);
 173         return status;
 174 }
 175
 176 static int __exit gncm_unbind(struct usb_composite_dev *cdev)
 177 {
 178         gether_cleanup(the_dev);
 179         return 0;
 180 }
 181
 182 static __refdata struct usb_composite_driver ncm_driver = {
 183         .name           = "g_ncm",
 184         .dev            = &device_desc,
 185         .strings        = dev_strings,
 186         .max_speed      = USB_SPEED_HIGH,
 187         .bind           = gncm_bind,
 188         .unbind         = __exit_p(gncm_unbind),
 189 };
 190
 191 MODULE_DESCRIPTION(DRIVER_DESC);
 192 MODULE_AUTHOR("Yauheni Kaliuta");
 193 MODULE_LICENSE("GPL");
 194
 195 static int __init init(void)
 196 {
 197         return usb_composite_probe(&ncm_driver);
 198 }
 199 module_init(init);
 200
 201 static void __exit cleanup(void)
 202 {
 203         usb_composite_unregister(&ncm_driver);
 204 }
 205 module_exit(cleanup);