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(g: c->cdev->gadget)) {
100 c->descriptors = otg_desc;
101 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
102 }
103
104 f_ncm = usb_get_function(fi: f_ncm_inst);
105 if (IS_ERR(ptr: f_ncm))
106 return PTR_ERR(ptr: f_ncm);
107
108 status = usb_add_function(c, f_ncm);
109 if (status < 0) {
110 usb_put_function(f: 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(name: "ncm");
134 if (IS_ERR(ptr: f_ncm_inst))
135 return PTR_ERR(ptr: f_ncm_inst);
136
137 ncm_opts = container_of(f_ncm_inst, struct f_ncm_opts, func_inst);
138
139 gether_set_qmult(net: ncm_opts->net, qmult);
140 if (!gether_set_host_addr(net: ncm_opts->net, host_addr))
141 pr_info("using host ethernet address: %s", host_addr);
142 if (!gether_set_dev_addr(net: 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(c: cdev, str: 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(g: 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, otg_desc: 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, covr: &coverwrite);
174 dev_info(&gadget->dev, "%s\n", DRIVER_DESC);
175
176 return 0;
177
178fail1:
179 kfree(objp: otg_desc[0]);
180 otg_desc[0] = NULL;
181fail:
182 usb_put_function_instance(fi: f_ncm_inst);
183 return status;
184}
185
186static int gncm_unbind(struct usb_composite_dev *cdev)
187{
188 if (!IS_ERR_OR_NULL(ptr: f_ncm))
189 usb_put_function(f: f_ncm);
190 if (!IS_ERR_OR_NULL(ptr: f_ncm_inst))
191 usb_put_function_instance(fi: f_ncm_inst);
192 kfree(objp: 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

source code of linux/drivers/usb/gadget/legacy/ncm.c