1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * cdc2.c -- CDC Composite driver, with ECM and ACM support
4 *
5 * Copyright (C) 2008 David Brownell
6 * Copyright (C) 2008 Nokia Corporation
7 */
8
9#include <linux/kernel.h>
10#include <linux/module.h>
11
12#include "u_ether.h"
13#include "u_serial.h"
14#include "u_ecm.h"
15
16
17#define DRIVER_DESC		"CDC Composite Gadget"
18#define DRIVER_VERSION		"King Kamehameha Day 2008"
19
20/*-------------------------------------------------------------------------*/
21
22/* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
23 * Instead:  allocate your own, using normal USB-IF procedures.
24 */
25
26/* Thanks to NetChip Technologies for donating this product ID.
27 * It's for devices with only this composite CDC configuration.
28 */
29#define CDC_VENDOR_NUM		0x0525	/* NetChip */
30#define CDC_PRODUCT_NUM		0xa4aa	/* CDC Composite: ECM + ACM */
31
32USB_GADGET_COMPOSITE_OPTIONS();
33
34USB_ETHERNET_MODULE_PARAMETERS();
35
36/*-------------------------------------------------------------------------*/
37
38static struct usb_device_descriptor device_desc = {
39	.bLength =		sizeof device_desc,
40	.bDescriptorType =	USB_DT_DEVICE,
41
42	/* .bcdUSB = DYNAMIC */
43
44	.bDeviceClass =		USB_CLASS_COMM,
45	.bDeviceSubClass =	0,
46	.bDeviceProtocol =	0,
47	/* .bMaxPacketSize0 = f(hardware) */
48
49	/* Vendor and product id can be overridden by module parameters.  */
50	.idVendor =		cpu_to_le16(CDC_VENDOR_NUM),
51	.idProduct =		cpu_to_le16(CDC_PRODUCT_NUM),
52	/* .bcdDevice = f(hardware) */
53	/* .iManufacturer = DYNAMIC */
54	/* .iProduct = DYNAMIC */
55	/* NO SERIAL NUMBER */
56	.bNumConfigurations =	1,
57};
58
59static const struct usb_descriptor_header *otg_desc[2];
60
61/* string IDs are assigned dynamically */
62static struct usb_string strings_dev[] = {
63	[USB_GADGET_MANUFACTURER_IDX].s = "",
64	[USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
65	[USB_GADGET_SERIAL_IDX].s = "",
66	{  } /* end of list */
67};
68
69static struct usb_gadget_strings stringtab_dev = {
70	.language	= 0x0409,	/* en-us */
71	.strings	= strings_dev,
72};
73
74static struct usb_gadget_strings *dev_strings[] = {
75	&stringtab_dev,
76	NULL,
77};
78
79/*-------------------------------------------------------------------------*/
80static struct usb_function *f_acm;
81static struct usb_function_instance *fi_serial;
82
83static struct usb_function *f_ecm;
84static struct usb_function_instance *fi_ecm;
85
86/*
87 * We _always_ have both CDC ECM and CDC ACM functions.
88 */
89static int cdc_do_config(struct usb_configuration *c)
90{
91	int	status;
92
93	if (gadget_is_otg(c->cdev->gadget)) {
94		c->descriptors = otg_desc;
95		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
96	}
97
98	f_ecm = usb_get_function(fi_ecm);
99	if (IS_ERR(f_ecm)) {
100		status = PTR_ERR(f_ecm);
101		goto err_get_ecm;
102	}
103
104	status = usb_add_function(c, f_ecm);
105	if (status)
106		goto err_add_ecm;
107
108	f_acm = usb_get_function(fi_serial);
109	if (IS_ERR(f_acm)) {
110		status = PTR_ERR(f_acm);
111		goto err_get_acm;
112	}
113
114	status = usb_add_function(c, f_acm);
115	if (status)
116		goto err_add_acm;
117	return 0;
118
119err_add_acm:
120	usb_put_function(f_acm);
121err_get_acm:
122	usb_remove_function(c, f_ecm);
123err_add_ecm:
124	usb_put_function(f_ecm);
125err_get_ecm:
126	return status;
127}
128
129static struct usb_configuration cdc_config_driver = {
130	.label			= "CDC Composite (ECM + ACM)",
131	.bConfigurationValue	= 1,
132	/* .iConfiguration = DYNAMIC */
133	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
134};
135
136/*-------------------------------------------------------------------------*/
137
138static int cdc_bind(struct usb_composite_dev *cdev)
139{
140	struct usb_gadget	*gadget = cdev->gadget;
141	struct f_ecm_opts	*ecm_opts;
142	int			status;
143
144	if (!can_support_ecm(cdev->gadget)) {
145		dev_err(&gadget->dev, "controller '%s' not usable\n",
146				gadget->name);
147		return -EINVAL;
148	}
149
150	fi_ecm = usb_get_function_instance("ecm");
151	if (IS_ERR(fi_ecm))
152		return PTR_ERR(fi_ecm);
153
154	ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
155
156	gether_set_qmult(ecm_opts->net, qmult);
157	if (!gether_set_host_addr(ecm_opts->net, host_addr))
158		pr_info("using host ethernet address: %s", host_addr);
159	if (!gether_set_dev_addr(ecm_opts->net, dev_addr))
160		pr_info("using self ethernet address: %s", dev_addr);
161
162	fi_serial = usb_get_function_instance("acm");
163	if (IS_ERR(fi_serial)) {
164		status = PTR_ERR(fi_serial);
165		goto fail;
166	}
167
168	/* Allocate string descriptor numbers ... note that string
169	 * contents can be overridden by the composite_dev glue.
170	 */
171
172	status = usb_string_ids_tab(cdev, strings_dev);
173	if (status < 0)
174		goto fail1;
175	device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
176	device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
177
178	if (gadget_is_otg(gadget) && !otg_desc[0]) {
179		struct usb_descriptor_header *usb_desc;
180
181		usb_desc = usb_otg_descriptor_alloc(gadget);
182		if (!usb_desc) {
183			status = -ENOMEM;
184			goto fail1;
185		}
186		usb_otg_descriptor_init(gadget, usb_desc);
187		otg_desc[0] = usb_desc;
188		otg_desc[1] = NULL;
189	}
190
191	/* register our configuration */
192	status = usb_add_config(cdev, &cdc_config_driver, cdc_do_config);
193	if (status < 0)
194		goto fail2;
195
196	usb_composite_overwrite_options(cdev, &coverwrite);
197	dev_info(&gadget->dev, "%s, version: " DRIVER_VERSION "\n",
198			DRIVER_DESC);
199
200	return 0;
201
202fail2:
203	kfree(otg_desc[0]);
204	otg_desc[0] = NULL;
205fail1:
206	usb_put_function_instance(fi_serial);
207fail:
208	usb_put_function_instance(fi_ecm);
209	return status;
210}
211
212static int cdc_unbind(struct usb_composite_dev *cdev)
213{
214	usb_put_function(f_acm);
215	usb_put_function_instance(fi_serial);
216	if (!IS_ERR_OR_NULL(f_ecm))
217		usb_put_function(f_ecm);
218	if (!IS_ERR_OR_NULL(fi_ecm))
219		usb_put_function_instance(fi_ecm);
220	kfree(otg_desc[0]);
221	otg_desc[0] = NULL;
222
223	return 0;
224}
225
226static struct usb_composite_driver cdc_driver = {
227	.name		= "g_cdc",
228	.dev		= &device_desc,
229	.strings	= dev_strings,
230	.max_speed	= USB_SPEED_SUPER,
231	.bind		= cdc_bind,
232	.unbind		= cdc_unbind,
233};
234
235module_usb_composite_driver(cdc_driver);
236
237MODULE_DESCRIPTION(DRIVER_DESC);
238MODULE_AUTHOR("David Brownell");
239MODULE_LICENSE("GPL");
240