1 // SPDX-License-Identifier: GPL-2.0+
3  * ether.c -- Ethernet gadget driver, with CDC and non-CDC options
5  * Copyright (C) 2003-2005,2008 David Brownell
6  * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
26  * Ethernet gadget driver -- with CDC and non-CDC options
29  * CDC Ethernet is the standard USB solution for sending Ethernet frames
32  * this USB-IF standard as its open-systems interoperability solution;
35  * This is sometimes called "CDC ECM" (Ethernet Control Model) to support
36  * TLA-soup.  "CDC ACM" (Abstract Control Model) is for modems, and a new
37  * "CDC EEM" (Ethernet Emulation Model) is starting to spread.
39  * There's some hardware that can't talk CDC ECM.  We make that hardware
40  * implement a "minimalist" vendor-agnostic CDC core:  same framing, but
41  * link-level setup only requires activating the configuration.  Only the
44  * systems may not.  (This is a subset of CDC Ethernet.)
46  * It turns out that if you add a few descriptors to that "CDC Subset",
50  * those MS-Windows drivers.  Those added descriptors make it resemble a
51  * CDC MDLM device, but they don't change device behavior at all.  (See
54  * A third option is also in use.  Rather than CDC Ethernet, or something
57  * needlessly complex.  They borrow more from CDC ACM than CDC ECM.
70  * This driver aims for interoperability by using CDC ECM unless
74  * returns false, in which case it supports the CDC Subset.  By default,
75  * that returns true; most hardware has no problems with CDC ECM, that's
79  *	IF YOUR HARDWARE CAN'T SUPPORT CDC ECM, UPDATE THAT ROUTINE!
103 /*-------------------------------------------------------------------------*/
108 /* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
109  * Instead:  allocate your own, using normal USB-IF procedures.
113  * It's for devices with only CDC Ethernet configurations.
116 #define CDC_PRODUCT_NUM		0xa4a1	/* Linux-USB Ethernet Gadget */
118 /* For hardware that can't talk CDC, we use the same vendor ID that
119  * ARM Linux has used for ethernet-over-usb, both with sa1100 and
120  * with pxa250.  We're protocol-compatible, if the host-side drivers
122  * drivers that need to hard-wire endpoint numbers have a hook.
124  * The protocol is a minimal subset of CDC Ether, which works on any bulk
126  * RNDIS (like SA-1100, with no interrupt endpoint, or anything that
127  * doesn't handle control-OUT).
134  * used with CDC Ethernet, Linux 2.4 hosts will need updates to choose
135  * the non-RNDIS configuration.
144 /*-------------------------------------------------------------------------*/
180 	.language	= 0x0409,	/* en-us */
201 /*-------------------------------------------------------------------------*/
212 	/* FIXME alloc iConfiguration string, set it in c->strings */  in rndis_do_config()
214 	if (gadget_is_otg(c->cdev->gadget)) {  in rndis_do_config()
215 		c->descriptors = otg_desc;  in rndis_do_config()
216 		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;  in rndis_do_config()
237 /*-------------------------------------------------------------------------*/
245 MODULE_PARM_DESC(use_eem, "use CDC EEM mode");
248  * We _always_ have an ECM, CDC Subset, or EEM configuration.
254 	/* FIXME alloc iConfiguration string, set it in c->strings */  in eth_do_config()
256 	if (gadget_is_otg(c->cdev->gadget)) {  in eth_do_config()
257 		c->descriptors = otg_desc;  in eth_do_config()
258 		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;  in eth_do_config()
271 	} else if (can_support_ecm(c->cdev->gadget)) {  in eth_do_config()
302 /*-------------------------------------------------------------------------*/
306 	struct usb_gadget	*gadget = cdev->gadget;  in eth_bind()
322 		net = eem_opts->net;  in eth_bind()
324 		eth_config_driver.label = "CDC Ethernet (EEM)";  in eth_bind()
336 		net = ecm_opts->net;  in eth_bind()
338 		eth_config_driver.label = "CDC Ethernet (ECM)";  in eth_bind()
340 		/* CDC Subset */  in eth_bind()
349 		net = geth_opts->net;  in eth_bind()
351 		eth_config_driver.label = "CDC Subset/SAFE";  in eth_bind()
366 		/* RNDIS plus ECM-or-Subset */  in eth_bind()
367 		gether_set_gadget(net, cdev->gadget);  in eth_bind()
373 			eem_opts->bound = true;  in eth_bind()
375 			ecm_opts->bound = true;  in eth_bind()
377 			geth_opts->bound = true;  in eth_bind()
407 			status = -ENOMEM;  in eth_bind()
428 	dev_info(&gadget->dev, "%s, version: " DRIVER_VERSION "\n",  in eth_bind()
458 	} else if (can_support_ecm(cdev->gadget)) {  in eth_unbind()