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");