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  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software
25  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
26  */
27 
28 /* #define DEBUG */
29 /* #define VERBOSE_DEBUG */
30 
31 #include <linux/kernel.h>
32 #include <linux/utsname.h>
33 
34 
35 #include "u_ether.h"
36 
37 #define DRIVER_DESC		"NCM Gadget"
38 
39 /*-------------------------------------------------------------------------*/
40 
41 /*
42  * Kbuild is not very cooperative with respect to linking separately
43  * compiled library objects into one module.  So for now we won't use
44  * separate compilation ... ensuring init/exit sections work to shrink
45  * the runtime footprint, and giving us at least some parts of what
46  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
47  */
48 #include "composite.c"
49 #include "usbstring.c"
50 #include "config.c"
51 #include "epautoconf.c"
52 
53 #include "f_ncm.c"
54 #include "u_ether.c"
55 
56 /*-------------------------------------------------------------------------*/
57 
58 /* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
59  * Instead:  allocate your own, using normal USB-IF procedures.
60  */
61 
62 /* Thanks to NetChip Technologies for donating this product ID.
63  * It's for devices with only CDC Ethernet configurations.
64  */
65 #define CDC_VENDOR_NUM		0x0525	/* NetChip */
66 #define CDC_PRODUCT_NUM		0xa4a1	/* Linux-USB Ethernet Gadget */
67 
68 /*-------------------------------------------------------------------------*/
69 
70 static struct usb_device_descriptor device_desc = {
71 	.bLength =		sizeof device_desc,
72 	.bDescriptorType =	USB_DT_DEVICE,
73 
74 	.bcdUSB =		cpu_to_le16 (0x0200),
75 
76 	.bDeviceClass =		USB_CLASS_COMM,
77 	.bDeviceSubClass =	0,
78 	.bDeviceProtocol =	0,
79 	/* .bMaxPacketSize0 = f(hardware) */
80 
81 	/* Vendor and product id defaults change according to what configs
82 	 * we support.  (As does bNumConfigurations.)  These values can
83 	 * also be overridden by module parameters.
84 	 */
85 	.idVendor =		cpu_to_le16 (CDC_VENDOR_NUM),
86 	.idProduct =		cpu_to_le16 (CDC_PRODUCT_NUM),
87 	/* .bcdDevice = f(hardware) */
88 	/* .iManufacturer = DYNAMIC */
89 	/* .iProduct = DYNAMIC */
90 	/* NO SERIAL NUMBER */
91 	.bNumConfigurations =	1,
92 };
93 
94 static struct usb_otg_descriptor otg_descriptor = {
95 	.bLength =		sizeof otg_descriptor,
96 	.bDescriptorType =	USB_DT_OTG,
97 
98 	/* REVISIT SRP-only hardware is possible, although
99 	 * it would not be called "OTG" ...
100 	 */
101 	.bmAttributes =		USB_OTG_SRP | USB_OTG_HNP,
102 };
103 
104 static const struct usb_descriptor_header *otg_desc[] = {
105 	(struct usb_descriptor_header *) &otg_descriptor,
106 	NULL,
107 };
108 
109 
110 /* string IDs are assigned dynamically */
111 
112 #define STRING_MANUFACTURER_IDX		0
113 #define STRING_PRODUCT_IDX		1
114 
115 static char manufacturer[50];
116 
117 static struct usb_string strings_dev[] = {
118 	[STRING_MANUFACTURER_IDX].s = manufacturer,
119 	[STRING_PRODUCT_IDX].s = DRIVER_DESC,
120 	{  } /* end of list */
121 };
122 
123 static struct usb_gadget_strings stringtab_dev = {
124 	.language	= 0x0409,	/* en-us */
125 	.strings	= strings_dev,
126 };
127 
128 static struct usb_gadget_strings *dev_strings[] = {
129 	&stringtab_dev,
130 	NULL,
131 };
132 
133 static u8 hostaddr[ETH_ALEN];
134 
135 /*-------------------------------------------------------------------------*/
136 
ncm_do_config(struct usb_configuration * c)137 static int __init ncm_do_config(struct usb_configuration *c)
138 {
139 	/* FIXME alloc iConfiguration string, set it in c->strings */
140 
141 	if (gadget_is_otg(c->cdev->gadget)) {
142 		c->descriptors = otg_desc;
143 		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
144 	}
145 
146 	return ncm_bind_config(c, hostaddr);
147 }
148 
149 static struct usb_configuration ncm_config_driver = {
150 	/* .label = f(hardware) */
151 	.label			= "CDC Ethernet (NCM)",
152 	.bConfigurationValue	= 1,
153 	/* .iConfiguration = DYNAMIC */
154 	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
155 };
156 
157 /*-------------------------------------------------------------------------*/
158 
gncm_bind(struct usb_composite_dev * cdev)159 static int __init gncm_bind(struct usb_composite_dev *cdev)
160 {
161 	int			gcnum;
162 	struct usb_gadget	*gadget = cdev->gadget;
163 	int			status;
164 
165 	/* set up network link layer */
166 	status = gether_setup(cdev->gadget, hostaddr);
167 	if (status < 0)
168 		return status;
169 
170 	gcnum = usb_gadget_controller_number(gadget);
171 	if (gcnum >= 0)
172 		device_desc.bcdDevice = cpu_to_le16(0x0300 | gcnum);
173 	else {
174 		/* We assume that can_support_ecm() tells the truth;
175 		 * but if the controller isn't recognized at all then
176 		 * that assumption is a bit more likely to be wrong.
177 		 */
178 		dev_warn(&gadget->dev,
179 			 "controller '%s' not recognized; trying %s\n",
180 			 gadget->name,
181 			 ncm_config_driver.label);
182 		device_desc.bcdDevice =
183 			cpu_to_le16(0x0300 | 0x0099);
184 	}
185 
186 
187 	/* Allocate string descriptor numbers ... note that string
188 	 * contents can be overridden by the composite_dev glue.
189 	 */
190 
191 	/* device descriptor strings: manufacturer, product */
192 	snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
193 		init_utsname()->sysname, init_utsname()->release,
194 		gadget->name);
195 	status = usb_string_id(cdev);
196 	if (status < 0)
197 		goto fail;
198 	strings_dev[STRING_MANUFACTURER_IDX].id = status;
199 	device_desc.iManufacturer = status;
200 
201 	status = usb_string_id(cdev);
202 	if (status < 0)
203 		goto fail;
204 	strings_dev[STRING_PRODUCT_IDX].id = status;
205 	device_desc.iProduct = status;
206 
207 	status = usb_add_config(cdev, &ncm_config_driver,
208 				ncm_do_config);
209 	if (status < 0)
210 		goto fail;
211 
212 	dev_info(&gadget->dev, "%s\n", DRIVER_DESC);
213 
214 	return 0;
215 
216 fail:
217 	gether_cleanup();
218 	return status;
219 }
220 
gncm_unbind(struct usb_composite_dev * cdev)221 static int __exit gncm_unbind(struct usb_composite_dev *cdev)
222 {
223 	gether_cleanup();
224 	return 0;
225 }
226 
227 static struct usb_composite_driver ncm_driver = {
228 	.name		= "g_ncm",
229 	.dev		= &device_desc,
230 	.strings	= dev_strings,
231 	.unbind		= __exit_p(gncm_unbind),
232 };
233 
234 MODULE_DESCRIPTION(DRIVER_DESC);
235 MODULE_AUTHOR("Yauheni Kaliuta");
236 MODULE_LICENSE("GPL");
237 
init(void)238 static int __init init(void)
239 {
240 	return usb_composite_probe(&ncm_driver, gncm_bind);
241 }
242 module_init(init);
243 
cleanup(void)244 static void __exit cleanup(void)
245 {
246 	usb_composite_unregister(&ncm_driver);
247 }
248 module_exit(cleanup);
249