2 * ether.c -- Ethernet gadget driver, with CDC and non-CDC options
4 * Copyright (C) 2003-2005,2008 David Brownell
5 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
6 * Copyright (C) 2008 Nokia Corporation
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
14 /* #define VERBOSE_DEBUG */
16 #include <linux/kernel.h>
18 #if defined USB_ETH_RNDIS
21 #ifdef CONFIG_USB_ETH_RNDIS
22 # define USB_ETH_RNDIS y
29 * Ethernet gadget driver -- with CDC and non-CDC options
30 * Builds on hardware support for a full duplex link.
32 * CDC Ethernet is the standard USB solution for sending Ethernet frames
33 * using USB. Real hardware tends to use the same framing protocol but look
34 * different for control features. This driver strongly prefers to use
35 * this USB-IF standard as its open-systems interoperability solution;
36 * most host side USB stacks (except from Microsoft) support it.
38 * This is sometimes called "CDC ECM" (Ethernet Control Model) to support
39 * TLA-soup. "CDC ACM" (Abstract Control Model) is for modems, and a new
40 * "CDC EEM" (Ethernet Emulation Model) is starting to spread.
42 * There's some hardware that can't talk CDC ECM. We make that hardware
43 * implement a "minimalist" vendor-agnostic CDC core: same framing, but
44 * link-level setup only requires activating the configuration. Only the
45 * endpoint descriptors, and product/vendor IDs, are relevant; no control
46 * operations are available. Linux supports it, but other host operating
47 * systems may not. (This is a subset of CDC Ethernet.)
49 * It turns out that if you add a few descriptors to that "CDC Subset",
50 * (Windows) host side drivers from MCCI can treat it as one submode of
51 * a proprietary scheme called "SAFE" ... without needing to know about
52 * specific product/vendor IDs. So we do that, making it easier to use
53 * those MS-Windows drivers. Those added descriptors make it resemble a
54 * CDC MDLM device, but they don't change device behavior at all. (See
55 * MCCI Engineering report 950198 "SAFE Networking Functions".)
57 * A third option is also in use. Rather than CDC Ethernet, or something
58 * simpler, Microsoft pushes their own approach: RNDIS. The published
59 * RNDIS specs are ambiguous and appear to be incomplete, and are also
60 * needlessly complex. They borrow more from CDC ACM than CDC ECM.
63 #define DRIVER_DESC "Ethernet Gadget"
64 #define DRIVER_VERSION "Memorial Day 2008"
67 #define PREFIX "RNDIS/"
73 * This driver aims for interoperability by using CDC ECM unless
77 * returns false, in which case it supports the CDC Subset. By default,
78 * that returns true; most hardware has no problems with CDC ECM, that's
79 * a good default. Previous versions of this driver had no default; this
80 * version changes that, removing overhead for new controller support.
82 * IF YOUR HARDWARE CAN'T SUPPORT CDC ECM, UPDATE THAT ROUTINE!
85 static inline bool has_rndis(void)
94 /*-------------------------------------------------------------------------*/
97 * Kbuild is not very cooperative with respect to linking separately
98 * compiled library objects into one module. So for now we won't use
99 * separate compilation ... ensuring init/exit sections work to shrink
100 * the runtime footprint, and giving us at least some parts of what
101 * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
104 #include "f_subset.c"
112 /*-------------------------------------------------------------------------*/
113 USB_GADGET_COMPOSITE_OPTIONS();
115 /* DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!!
116 * Instead: allocate your own, using normal USB-IF procedures.
119 /* Thanks to NetChip Technologies for donating this product ID.
120 * It's for devices with only CDC Ethernet configurations.
122 #define CDC_VENDOR_NUM 0x0525 /* NetChip */
123 #define CDC_PRODUCT_NUM 0xa4a1 /* Linux-USB Ethernet Gadget */
125 /* For hardware that can't talk CDC, we use the same vendor ID that
126 * ARM Linux has used for ethernet-over-usb, both with sa1100 and
127 * with pxa250. We're protocol-compatible, if the host-side drivers
128 * use the endpoint descriptors. bcdDevice (version) is nonzero, so
129 * drivers that need to hard-wire endpoint numbers have a hook.
131 * The protocol is a minimal subset of CDC Ether, which works on any bulk
132 * hardware that's not deeply broken ... even on hardware that can't talk
133 * RNDIS (like SA-1100, with no interrupt endpoint, or anything that
134 * doesn't handle control-OUT).
136 #define SIMPLE_VENDOR_NUM 0x049f
137 #define SIMPLE_PRODUCT_NUM 0x505a
139 /* For hardware that can talk RNDIS and either of the above protocols,
140 * use this ID ... the windows INF files will know it. Unless it's
141 * used with CDC Ethernet, Linux 2.4 hosts will need updates to choose
142 * the non-RNDIS configuration.
144 #define RNDIS_VENDOR_NUM 0x0525 /* NetChip */
145 #define RNDIS_PRODUCT_NUM 0xa4a2 /* Ethernet/RNDIS Gadget */
147 /* For EEM gadgets */
148 #define EEM_VENDOR_NUM 0x1d6b /* Linux Foundation */
149 #define EEM_PRODUCT_NUM 0x0102 /* EEM Gadget */
151 /*-------------------------------------------------------------------------*/
153 static struct usb_device_descriptor device_desc
= {
154 .bLength
= sizeof device_desc
,
155 .bDescriptorType
= USB_DT_DEVICE
,
157 .bcdUSB
= cpu_to_le16 (0x0200),
159 .bDeviceClass
= USB_CLASS_COMM
,
160 .bDeviceSubClass
= 0,
161 .bDeviceProtocol
= 0,
162 /* .bMaxPacketSize0 = f(hardware) */
164 /* Vendor and product id defaults change according to what configs
165 * we support. (As does bNumConfigurations.) These values can
166 * also be overridden by module parameters.
168 .idVendor
= cpu_to_le16 (CDC_VENDOR_NUM
),
169 .idProduct
= cpu_to_le16 (CDC_PRODUCT_NUM
),
170 /* .bcdDevice = f(hardware) */
171 /* .iManufacturer = DYNAMIC */
172 /* .iProduct = DYNAMIC */
173 /* NO SERIAL NUMBER */
174 .bNumConfigurations
= 1,
177 static struct usb_otg_descriptor otg_descriptor
= {
178 .bLength
= sizeof otg_descriptor
,
179 .bDescriptorType
= USB_DT_OTG
,
181 /* REVISIT SRP-only hardware is possible, although
182 * it would not be called "OTG" ...
184 .bmAttributes
= USB_OTG_SRP
| USB_OTG_HNP
,
187 static const struct usb_descriptor_header
*otg_desc
[] = {
188 (struct usb_descriptor_header
*) &otg_descriptor
,
192 static struct usb_string strings_dev
[] = {
193 [USB_GADGET_MANUFACTURER_IDX
].s
= "",
194 [USB_GADGET_PRODUCT_IDX
].s
= PREFIX DRIVER_DESC
,
195 [USB_GADGET_SERIAL_IDX
].s
= "",
196 { } /* end of list */
199 static struct usb_gadget_strings stringtab_dev
= {
200 .language
= 0x0409, /* en-us */
201 .strings
= strings_dev
,
204 static struct usb_gadget_strings
*dev_strings
[] = {
209 static u8 hostaddr
[ETH_ALEN
];
210 static struct eth_dev
*the_dev
;
211 /*-------------------------------------------------------------------------*/
214 * We may not have an RNDIS configuration, but if we do it needs to be
215 * the first one present. That's to make Microsoft's drivers happy,
216 * and to follow DOCSIS 1.0 (cable modem standard).
218 static int __init
rndis_do_config(struct usb_configuration
*c
)
220 /* FIXME alloc iConfiguration string, set it in c->strings */
222 if (gadget_is_otg(c
->cdev
->gadget
)) {
223 c
->descriptors
= otg_desc
;
224 c
->bmAttributes
|= USB_CONFIG_ATT_WAKEUP
;
227 return rndis_bind_config(c
, hostaddr
, the_dev
);
230 static struct usb_configuration rndis_config_driver
= {
232 .bConfigurationValue
= 2,
233 /* .iConfiguration = DYNAMIC */
234 .bmAttributes
= USB_CONFIG_ATT_SELFPOWER
,
237 /*-------------------------------------------------------------------------*/
239 #ifdef CONFIG_USB_ETH_EEM
240 static bool use_eem
= 1;
244 module_param(use_eem
, bool, 0);
245 MODULE_PARM_DESC(use_eem
, "use CDC EEM mode");
248 * We _always_ have an ECM, CDC Subset, or EEM configuration.
250 static int __init
eth_do_config(struct usb_configuration
*c
)
252 /* FIXME alloc iConfiguration string, set it in c->strings */
254 if (gadget_is_otg(c
->cdev
->gadget
)) {
255 c
->descriptors
= otg_desc
;
256 c
->bmAttributes
|= USB_CONFIG_ATT_WAKEUP
;
260 return eem_bind_config(c
, the_dev
);
261 else if (can_support_ecm(c
->cdev
->gadget
))
262 return ecm_bind_config(c
, hostaddr
, the_dev
);
264 return geth_bind_config(c
, hostaddr
, the_dev
);
267 static struct usb_configuration eth_config_driver
= {
268 /* .label = f(hardware) */
269 .bConfigurationValue
= 1,
270 /* .iConfiguration = DYNAMIC */
271 .bmAttributes
= USB_CONFIG_ATT_SELFPOWER
,
274 /*-------------------------------------------------------------------------*/
276 static int __init
eth_bind(struct usb_composite_dev
*cdev
)
278 struct usb_gadget
*gadget
= cdev
->gadget
;
281 /* set up network link layer */
282 the_dev
= gether_setup(cdev
->gadget
, hostaddr
);
284 return PTR_ERR(the_dev
);
286 /* set up main config label and device descriptor */
289 eth_config_driver
.label
= "CDC Ethernet (EEM)";
290 device_desc
.idVendor
= cpu_to_le16(EEM_VENDOR_NUM
);
291 device_desc
.idProduct
= cpu_to_le16(EEM_PRODUCT_NUM
);
292 } else if (can_support_ecm(cdev
->gadget
)) {
294 eth_config_driver
.label
= "CDC Ethernet (ECM)";
297 eth_config_driver
.label
= "CDC Subset/SAFE";
299 device_desc
.idVendor
= cpu_to_le16(SIMPLE_VENDOR_NUM
);
300 device_desc
.idProduct
= cpu_to_le16(SIMPLE_PRODUCT_NUM
);
302 device_desc
.bDeviceClass
= USB_CLASS_VENDOR_SPEC
;
306 /* RNDIS plus ECM-or-Subset */
307 device_desc
.idVendor
= cpu_to_le16(RNDIS_VENDOR_NUM
);
308 device_desc
.idProduct
= cpu_to_le16(RNDIS_PRODUCT_NUM
);
309 device_desc
.bNumConfigurations
= 2;
312 /* Allocate string descriptor numbers ... note that string
313 * contents can be overridden by the composite_dev glue.
316 status
= usb_string_ids_tab(cdev
, strings_dev
);
319 device_desc
.iManufacturer
= strings_dev
[USB_GADGET_MANUFACTURER_IDX
].id
;
320 device_desc
.iProduct
= strings_dev
[USB_GADGET_PRODUCT_IDX
].id
;
322 /* register our configuration(s); RNDIS first, if it's used */
324 status
= usb_add_config(cdev
, &rndis_config_driver
,
330 status
= usb_add_config(cdev
, ð_config_driver
, eth_do_config
);
334 usb_composite_overwrite_options(cdev
, &coverwrite
);
335 dev_info(&gadget
->dev
, "%s, version: " DRIVER_VERSION
"\n",
341 gether_cleanup(the_dev
);
345 static int __exit
eth_unbind(struct usb_composite_dev
*cdev
)
347 gether_cleanup(the_dev
);
351 static __refdata
struct usb_composite_driver eth_driver
= {
354 .strings
= dev_strings
,
355 .max_speed
= USB_SPEED_SUPER
,
357 .unbind
= __exit_p(eth_unbind
),
360 MODULE_DESCRIPTION(PREFIX DRIVER_DESC
);
361 MODULE_AUTHOR("David Brownell, Benedikt Spanger");
362 MODULE_LICENSE("GPL");
364 static int __init
init(void)
366 return usb_composite_probe(ð_driver
);
370 static void __exit
cleanup(void)
372 usb_composite_unregister(ð_driver
);
374 module_exit(cleanup
);