linux/drivers/usb/gadget/legacy/ncm.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * ncm.c -- NCM gadget driver
   4 *
   5 * Copyright (C) 2010 Nokia Corporation
   6 * Contact: Yauheni Kaliuta <yauheni.kaliuta@nokia.com>
   7 *
   8 * The driver borrows from ether.c which is:
   9 *
  10 * Copyright (C) 2003-2005,2008 David Brownell
  11 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
  12 * Copyright (C) 2008 Nokia Corporation
  13 */
  14
  15/* #define DEBUG */
  16/* #define VERBOSE_DEBUG */
  17
  18#include <linux/kernel.h>
  19#include <linux/module.h>
  20#include <linux/usb/composite.h>
  21
  22#include "u_ether.h"
  23#include "u_ncm.h"
  24
  25#define DRIVER_DESC             "NCM Gadget"
  26
  27/*-------------------------------------------------------------------------*/
  28
  29/* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  30 * Instead:  allocate your own, using normal USB-IF procedures.
  31 */
  32
  33/* Thanks to NetChip Technologies for donating this product ID.
  34 * It's for devices with only CDC Ethernet configurations.
  35 */
  36#define CDC_VENDOR_NUM          0x0525  /* NetChip */
  37#define CDC_PRODUCT_NUM         0xa4a1  /* Linux-USB Ethernet Gadget */
  38
  39/*-------------------------------------------------------------------------*/
  40USB_GADGET_COMPOSITE_OPTIONS();
  41
  42USB_ETHERNET_MODULE_PARAMETERS();
  43
  44static struct usb_device_descriptor device_desc = {
  45        .bLength =              sizeof device_desc,
  46        .bDescriptorType =      USB_DT_DEVICE,
  47
  48        /* .bcdUSB = DYNAMIC */
  49
  50        .bDeviceClass =         USB_CLASS_COMM,
  51        .bDeviceSubClass =      0,
  52        .bDeviceProtocol =      0,
  53        /* .bMaxPacketSize0 = f(hardware) */
  54
  55        /* Vendor and product id defaults change according to what configs
  56         * we support.  (As does bNumConfigurations.)  These values can
  57         * also be overridden by module parameters.
  58         */
  59        .idVendor =             cpu_to_le16 (CDC_VENDOR_NUM),
  60        .idProduct =            cpu_to_le16 (CDC_PRODUCT_NUM),
  61        /* .bcdDevice = f(hardware) */
  62        /* .iManufacturer = DYNAMIC */
  63        /* .iProduct = DYNAMIC */
  64        /* NO SERIAL NUMBER */
  65        .bNumConfigurations =   1,
  66};
  67
  68static const struct usb_descriptor_header *otg_desc[2];
  69
  70/* string IDs are assigned dynamically */
  71static struct usb_string strings_dev[] = {
  72        [USB_GADGET_MANUFACTURER_IDX].s = "",
  73        [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
  74        [USB_GADGET_SERIAL_IDX].s = "",
  75        {  } /* end of list */
  76};
  77
  78static struct usb_gadget_strings stringtab_dev = {
  79        .language       = 0x0409,       /* en-us */
  80        .strings        = strings_dev,
  81};
  82
  83static struct usb_gadget_strings *dev_strings[] = {
  84        &stringtab_dev,
  85        NULL,
  86};
  87
  88static struct usb_function_instance *f_ncm_inst;
  89static struct usb_function *f_ncm;
  90
  91/*-------------------------------------------------------------------------*/
  92
  93static int ncm_do_config(struct usb_configuration *c)
  94{
  95        int status;
  96
  97        /* FIXME alloc iConfiguration string, set it in c->strings */
  98
  99        if (gadget_is_otg(c->cdev->gadget)) {
 100                c->descriptors = otg_desc;
 101                c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 102        }
 103
 104        f_ncm = usb_get_function(f_ncm_inst);
 105        if (IS_ERR(f_ncm))
 106                return PTR_ERR(f_ncm);
 107
 108        status = usb_add_function(c, f_ncm);
 109        if (status < 0) {
 110                usb_put_function(f_ncm);
 111                return status;
 112        }
 113
 114        return 0;
 115}
 116
 117static struct usb_configuration ncm_config_driver = {
 118        /* .label = f(hardware) */
 119        .label                  = "CDC Ethernet (NCM)",
 120        .bConfigurationValue    = 1,
 121        /* .iConfiguration = DYNAMIC */
 122        .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
 123};
 124
 125/*-------------------------------------------------------------------------*/
 126
 127static int gncm_bind(struct usb_composite_dev *cdev)
 128{
 129        struct usb_gadget       *gadget = cdev->gadget;
 130        struct f_ncm_opts       *ncm_opts;
 131        int                     status;
 132
 133        f_ncm_inst = usb_get_function_instance("ncm");
 134        if (IS_ERR(f_ncm_inst))
 135                return PTR_ERR(f_ncm_inst);
 136
 137        ncm_opts = container_of(f_ncm_inst, struct f_ncm_opts, func_inst);
 138
 139        gether_set_qmult(ncm_opts->net, qmult);
 140        if (!gether_set_host_addr(ncm_opts->net, host_addr))
 141                pr_info("using host ethernet address: %s", host_addr);
 142        if (!gether_set_dev_addr(ncm_opts->net, dev_addr))
 143                pr_info("using self ethernet address: %s", dev_addr);
 144
 145        /* Allocate string descriptor numbers ... note that string
 146         * contents can be overridden by the composite_dev glue.
 147         */
 148
 149        status = usb_string_ids_tab(cdev, strings_dev);
 150        if (status < 0)
 151                goto fail;
 152        device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
 153        device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
 154
 155        if (gadget_is_otg(gadget) && !otg_desc[0]) {
 156                struct usb_descriptor_header *usb_desc;
 157
 158                usb_desc = usb_otg_descriptor_alloc(gadget);
 159                if (!usb_desc) {
 160                        status = -ENOMEM;
 161                        goto fail;
 162                }
 163                usb_otg_descriptor_init(gadget, usb_desc);
 164                otg_desc[0] = usb_desc;
 165                otg_desc[1] = NULL;
 166        }
 167
 168        status = usb_add_config(cdev, &ncm_config_driver,
 169                                ncm_do_config);
 170        if (status < 0)
 171                goto fail1;
 172
 173        usb_composite_overwrite_options(cdev, &coverwrite);
 174        dev_info(&gadget->dev, "%s\n", DRIVER_DESC);
 175
 176        return 0;
 177
 178fail1:
 179        kfree(otg_desc[0]);
 180        otg_desc[0] = NULL;
 181fail:
 182        usb_put_function_instance(f_ncm_inst);
 183        return status;
 184}
 185
 186static int gncm_unbind(struct usb_composite_dev *cdev)
 187{
 188        if (!IS_ERR_OR_NULL(f_ncm))
 189                usb_put_function(f_ncm);
 190        if (!IS_ERR_OR_NULL(f_ncm_inst))
 191                usb_put_function_instance(f_ncm_inst);
 192        kfree(otg_desc[0]);
 193        otg_desc[0] = NULL;
 194
 195        return 0;
 196}
 197
 198static struct usb_composite_driver ncm_driver = {
 199        .name           = "g_ncm",
 200        .dev            = &device_desc,
 201        .strings        = dev_strings,
 202        .max_speed      = USB_SPEED_SUPER,
 203        .bind           = gncm_bind,
 204        .unbind         = gncm_unbind,
 205};
 206
 207module_usb_composite_driver(ncm_driver);
 208
 209MODULE_DESCRIPTION(DRIVER_DESC);
 210MODULE_AUTHOR("Yauheni Kaliuta");
 211MODULE_LICENSE("GPL");
 212