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v6.8
  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * f_subset.c -- "CDC Subset" Ethernet link function driver
  4 *
  5 * Copyright (C) 2003-2005,2008 David Brownell
  6 * Copyright (C) 2008 Nokia Corporation
  7 */
  8
  9#include <linux/slab.h>
 10#include <linux/kernel.h>
 11#include <linux/module.h>
 12#include <linux/device.h>
 13#include <linux/etherdevice.h>
 14
 15#include "u_ether.h"
 16#include "u_ether_configfs.h"
 17#include "u_gether.h"
 18
 19/*
 20 * This function packages a simple "CDC Subset" Ethernet port with no real
 21 * control mechanisms; just raw data transfer over two bulk endpoints.
 22 * The data transfer model is exactly that of CDC Ethernet, which is
 23 * why we call it the "CDC Subset".
 24 *
 25 * Because it's not standardized, this has some interoperability issues.
 26 * They mostly relate to driver binding, since the data transfer model is
 27 * so simple (CDC Ethernet).  The original versions of this protocol used
 28 * specific product/vendor IDs:  byteswapped IDs for Digital Equipment's
 29 * SA-1100 "Itsy" board, which could run Linux 2.4 kernels and supported
 30 * daughtercards with USB peripheral connectors.  (It was used more often
 31 * with other boards, using the Itsy identifiers.)  Linux hosts recognized
 32 * this with CONFIG_USB_ARMLINUX; these devices have only one configuration
 33 * and one interface.
 34 *
 35 * At some point, MCCI defined a (nonconformant) CDC MDLM variant called
 36 * "SAFE", which happens to have a mode which is identical to the "CDC
 37 * Subset" in terms of data transfer and lack of control model.  This was
 38 * adopted by later Sharp Zaurus models, and by some other software which
 39 * Linux hosts recognize with CONFIG_USB_NET_ZAURUS.
 40 *
 41 * Because Microsoft's RNDIS drivers are far from robust, we added a few
 42 * descriptors to the CDC Subset code, making this code look like a SAFE
 43 * implementation.  This lets you use MCCI's host side MS-Windows drivers
 44 * if you get fed up with RNDIS.  It also makes it easier for composite
 45 * drivers to work, since they can use class based binding instead of
 46 * caring about specific product and vendor IDs.
 47 */
 48
 49struct f_gether {
 50	struct gether			port;
 51
 52	char				ethaddr[14];
 53};
 54
 55static inline struct f_gether *func_to_geth(struct usb_function *f)
 56{
 57	return container_of(f, struct f_gether, port.func);
 58}
 59
 60/*-------------------------------------------------------------------------*/
 61
 62/*
 63 * "Simple" CDC-subset option is a simple vendor-neutral model that most
 64 * full speed controllers can handle:  one interface, two bulk endpoints.
 65 * To assist host side drivers, we fancy it up a bit, and add descriptors so
 66 * some host side drivers will understand it as a "SAFE" variant.
 67 *
 68 * "SAFE" loosely follows CDC WMC MDLM, violating the spec in various ways.
 69 * Data endpoints live in the control interface, there's no data interface.
 70 * And it's not used to talk to a cell phone radio.
 71 */
 72
 73/* interface descriptor: */
 74
 75static struct usb_interface_descriptor subset_data_intf = {
 76	.bLength =		sizeof subset_data_intf,
 77	.bDescriptorType =	USB_DT_INTERFACE,
 78
 79	/* .bInterfaceNumber = DYNAMIC */
 80	.bAlternateSetting =	0,
 81	.bNumEndpoints =	2,
 82	.bInterfaceClass =      USB_CLASS_COMM,
 83	.bInterfaceSubClass =	USB_CDC_SUBCLASS_MDLM,
 84	.bInterfaceProtocol =	0,
 85	/* .iInterface = DYNAMIC */
 86};
 87
 88static struct usb_cdc_header_desc mdlm_header_desc = {
 89	.bLength =		sizeof mdlm_header_desc,
 90	.bDescriptorType =	USB_DT_CS_INTERFACE,
 91	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
 92
 93	.bcdCDC =		cpu_to_le16(0x0110),
 94};
 95
 96static struct usb_cdc_mdlm_desc mdlm_desc = {
 97	.bLength =		sizeof mdlm_desc,
 98	.bDescriptorType =	USB_DT_CS_INTERFACE,
 99	.bDescriptorSubType =	USB_CDC_MDLM_TYPE,
100
101	.bcdVersion =		cpu_to_le16(0x0100),
102	.bGUID = {
103		0x5d, 0x34, 0xcf, 0x66, 0x11, 0x18, 0x11, 0xd6,
104		0xa2, 0x1a, 0x00, 0x01, 0x02, 0xca, 0x9a, 0x7f,
105	},
106};
107
108/* since "usb_cdc_mdlm_detail_desc" is a variable length structure, we
109 * can't really use its struct.  All we do here is say that we're using
110 * the submode of "SAFE" which directly matches the CDC Subset.
111 */
112static u8 mdlm_detail_desc[] = {
113	6,
114	USB_DT_CS_INTERFACE,
115	USB_CDC_MDLM_DETAIL_TYPE,
116
117	0,	/* "SAFE" */
118	0,	/* network control capabilities (none) */
119	0,	/* network data capabilities ("raw" encapsulation) */
120};
121
122static struct usb_cdc_ether_desc ether_desc = {
123	.bLength =		sizeof ether_desc,
124	.bDescriptorType =	USB_DT_CS_INTERFACE,
125	.bDescriptorSubType =	USB_CDC_ETHERNET_TYPE,
126
127	/* this descriptor actually adds value, surprise! */
128	/* .iMACAddress = DYNAMIC */
129	.bmEthernetStatistics =	cpu_to_le32(0), /* no statistics */
130	.wMaxSegmentSize =	cpu_to_le16(ETH_FRAME_LEN),
131	.wNumberMCFilters =	cpu_to_le16(0),
132	.bNumberPowerFilters =	0,
133};
134
135/* full speed support: */
136
137static struct usb_endpoint_descriptor fs_subset_in_desc = {
138	.bLength =		USB_DT_ENDPOINT_SIZE,
139	.bDescriptorType =	USB_DT_ENDPOINT,
140
141	.bEndpointAddress =	USB_DIR_IN,
142	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
143};
144
145static struct usb_endpoint_descriptor fs_subset_out_desc = {
146	.bLength =		USB_DT_ENDPOINT_SIZE,
147	.bDescriptorType =	USB_DT_ENDPOINT,
148
149	.bEndpointAddress =	USB_DIR_OUT,
150	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
151};
152
153static struct usb_descriptor_header *fs_eth_function[] = {
154	(struct usb_descriptor_header *) &subset_data_intf,
155	(struct usb_descriptor_header *) &mdlm_header_desc,
156	(struct usb_descriptor_header *) &mdlm_desc,
157	(struct usb_descriptor_header *) &mdlm_detail_desc,
158	(struct usb_descriptor_header *) &ether_desc,
159	(struct usb_descriptor_header *) &fs_subset_in_desc,
160	(struct usb_descriptor_header *) &fs_subset_out_desc,
161	NULL,
162};
163
164/* high speed support: */
165
166static struct usb_endpoint_descriptor hs_subset_in_desc = {
167	.bLength =		USB_DT_ENDPOINT_SIZE,
168	.bDescriptorType =	USB_DT_ENDPOINT,
169
170	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
171	.wMaxPacketSize =	cpu_to_le16(512),
172};
173
174static struct usb_endpoint_descriptor hs_subset_out_desc = {
175	.bLength =		USB_DT_ENDPOINT_SIZE,
176	.bDescriptorType =	USB_DT_ENDPOINT,
177
178	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
179	.wMaxPacketSize =	cpu_to_le16(512),
180};
181
182static struct usb_descriptor_header *hs_eth_function[] = {
183	(struct usb_descriptor_header *) &subset_data_intf,
184	(struct usb_descriptor_header *) &mdlm_header_desc,
185	(struct usb_descriptor_header *) &mdlm_desc,
186	(struct usb_descriptor_header *) &mdlm_detail_desc,
187	(struct usb_descriptor_header *) &ether_desc,
188	(struct usb_descriptor_header *) &hs_subset_in_desc,
189	(struct usb_descriptor_header *) &hs_subset_out_desc,
190	NULL,
191};
192
193/* super speed support: */
194
195static struct usb_endpoint_descriptor ss_subset_in_desc = {
196	.bLength =		USB_DT_ENDPOINT_SIZE,
197	.bDescriptorType =	USB_DT_ENDPOINT,
198
199	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
200	.wMaxPacketSize =	cpu_to_le16(1024),
201};
202
203static struct usb_endpoint_descriptor ss_subset_out_desc = {
204	.bLength =		USB_DT_ENDPOINT_SIZE,
205	.bDescriptorType =	USB_DT_ENDPOINT,
206
207	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
208	.wMaxPacketSize =	cpu_to_le16(1024),
209};
210
211static struct usb_ss_ep_comp_descriptor ss_subset_bulk_comp_desc = {
212	.bLength =		sizeof ss_subset_bulk_comp_desc,
213	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
214
215	/* the following 2 values can be tweaked if necessary */
216	/* .bMaxBurst =		0, */
217	/* .bmAttributes =	0, */
218};
219
220static struct usb_descriptor_header *ss_eth_function[] = {
221	(struct usb_descriptor_header *) &subset_data_intf,
222	(struct usb_descriptor_header *) &mdlm_header_desc,
223	(struct usb_descriptor_header *) &mdlm_desc,
224	(struct usb_descriptor_header *) &mdlm_detail_desc,
225	(struct usb_descriptor_header *) &ether_desc,
226	(struct usb_descriptor_header *) &ss_subset_in_desc,
227	(struct usb_descriptor_header *) &ss_subset_bulk_comp_desc,
228	(struct usb_descriptor_header *) &ss_subset_out_desc,
229	(struct usb_descriptor_header *) &ss_subset_bulk_comp_desc,
230	NULL,
231};
232
233/* string descriptors: */
234
235static struct usb_string geth_string_defs[] = {
236	[0].s = "CDC Ethernet Subset/SAFE",
237	[1].s = "",
238	{  } /* end of list */
239};
240
241static struct usb_gadget_strings geth_string_table = {
242	.language =		0x0409,	/* en-us */
243	.strings =		geth_string_defs,
244};
245
246static struct usb_gadget_strings *geth_strings[] = {
247	&geth_string_table,
248	NULL,
249};
250
251/*-------------------------------------------------------------------------*/
252
253static int geth_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
254{
255	struct f_gether		*geth = func_to_geth(f);
256	struct usb_composite_dev *cdev = f->config->cdev;
257	struct net_device	*net;
258
259	/* we know alt == 0, so this is an activation or a reset */
260
261	if (geth->port.in_ep->enabled) {
262		DBG(cdev, "reset cdc subset\n");
263		gether_disconnect(&geth->port);
264	}
265
266	DBG(cdev, "init + activate cdc subset\n");
267	if (config_ep_by_speed(cdev->gadget, f, geth->port.in_ep) ||
268	    config_ep_by_speed(cdev->gadget, f, geth->port.out_ep)) {
269		geth->port.in_ep->desc = NULL;
270		geth->port.out_ep->desc = NULL;
271		return -EINVAL;
272	}
273
274	net = gether_connect(&geth->port);
275	return PTR_ERR_OR_ZERO(net);
276}
277
278static void geth_disable(struct usb_function *f)
279{
280	struct f_gether	*geth = func_to_geth(f);
281	struct usb_composite_dev *cdev = f->config->cdev;
282
283	DBG(cdev, "net deactivated\n");
284	gether_disconnect(&geth->port);
285}
286
287/*-------------------------------------------------------------------------*/
288
289/* serial function driver setup/binding */
290
291static int
292geth_bind(struct usb_configuration *c, struct usb_function *f)
293{
294	struct usb_composite_dev *cdev = c->cdev;
295	struct f_gether		*geth = func_to_geth(f);
296	struct usb_string	*us;
297	int			status;
298	struct usb_ep		*ep;
299
300	struct f_gether_opts	*gether_opts;
301
302	gether_opts = container_of(f->fi, struct f_gether_opts, func_inst);
303
304	/*
305	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
306	 * configurations are bound in sequence with list_for_each_entry,
307	 * in each configuration its functions are bound in sequence
308	 * with list_for_each_entry, so we assume no race condition
309	 * with regard to gether_opts->bound access
310	 */
311	if (!gether_opts->bound) {
312		mutex_lock(&gether_opts->lock);
313		gether_set_gadget(gether_opts->net, cdev->gadget);
314		status = gether_register_netdev(gether_opts->net);
315		mutex_unlock(&gether_opts->lock);
316		if (status)
317			return status;
318		gether_opts->bound = true;
319	}
320
321	us = usb_gstrings_attach(cdev, geth_strings,
322				 ARRAY_SIZE(geth_string_defs));
323	if (IS_ERR(us))
324		return PTR_ERR(us);
325
326	subset_data_intf.iInterface = us[0].id;
327	ether_desc.iMACAddress = us[1].id;
328
329	/* allocate instance-specific interface IDs */
330	status = usb_interface_id(c, f);
331	if (status < 0)
332		goto fail;
333	subset_data_intf.bInterfaceNumber = status;
334
335	status = -ENODEV;
336
337	/* allocate instance-specific endpoints */
338	ep = usb_ep_autoconfig(cdev->gadget, &fs_subset_in_desc);
339	if (!ep)
340		goto fail;
341	geth->port.in_ep = ep;
342
343	ep = usb_ep_autoconfig(cdev->gadget, &fs_subset_out_desc);
344	if (!ep)
345		goto fail;
346	geth->port.out_ep = ep;
347
348	/* support all relevant hardware speeds... we expect that when
349	 * hardware is dual speed, all bulk-capable endpoints work at
350	 * both speeds
351	 */
352	hs_subset_in_desc.bEndpointAddress = fs_subset_in_desc.bEndpointAddress;
353	hs_subset_out_desc.bEndpointAddress =
354		fs_subset_out_desc.bEndpointAddress;
355
356	ss_subset_in_desc.bEndpointAddress = fs_subset_in_desc.bEndpointAddress;
357	ss_subset_out_desc.bEndpointAddress =
358		fs_subset_out_desc.bEndpointAddress;
359
360	status = usb_assign_descriptors(f, fs_eth_function, hs_eth_function,
361			ss_eth_function, ss_eth_function);
362	if (status)
363		goto fail;
364
365	/* NOTE:  all that is done without knowing or caring about
366	 * the network link ... which is unavailable to this code
367	 * until we're activated via set_alt().
368	 */
369
370	DBG(cdev, "CDC Subset: IN/%s OUT/%s\n",
 
 
371			geth->port.in_ep->name, geth->port.out_ep->name);
372	return 0;
373
374fail:
375	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
376
377	return status;
378}
379
380static inline struct f_gether_opts *to_f_gether_opts(struct config_item *item)
381{
382	return container_of(to_config_group(item), struct f_gether_opts,
383			    func_inst.group);
384}
385
386/* f_gether_item_ops */
387USB_ETHERNET_CONFIGFS_ITEM(gether);
388
389/* f_gether_opts_dev_addr */
390USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(gether);
391
392/* f_gether_opts_host_addr */
393USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(gether);
394
395/* f_gether_opts_qmult */
396USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(gether);
397
398/* f_gether_opts_ifname */
399USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(gether);
400
401static struct configfs_attribute *gether_attrs[] = {
402	&gether_opts_attr_dev_addr,
403	&gether_opts_attr_host_addr,
404	&gether_opts_attr_qmult,
405	&gether_opts_attr_ifname,
406	NULL,
407};
408
409static const struct config_item_type gether_func_type = {
410	.ct_item_ops	= &gether_item_ops,
411	.ct_attrs	= gether_attrs,
412	.ct_owner	= THIS_MODULE,
413};
414
415static void geth_free_inst(struct usb_function_instance *f)
416{
417	struct f_gether_opts *opts;
418
419	opts = container_of(f, struct f_gether_opts, func_inst);
420	if (opts->bound)
421		gether_cleanup(netdev_priv(opts->net));
422	else
423		free_netdev(opts->net);
424	kfree(opts);
425}
426
427static struct usb_function_instance *geth_alloc_inst(void)
428{
429	struct f_gether_opts *opts;
430
431	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
432	if (!opts)
433		return ERR_PTR(-ENOMEM);
434	mutex_init(&opts->lock);
435	opts->func_inst.free_func_inst = geth_free_inst;
436	opts->net = gether_setup_default();
437	if (IS_ERR(opts->net)) {
438		struct net_device *net = opts->net;
439		kfree(opts);
440		return ERR_CAST(net);
441	}
442
443	config_group_init_type_name(&opts->func_inst.group, "",
444				    &gether_func_type);
445
446	return &opts->func_inst;
447}
448
449static void geth_free(struct usb_function *f)
450{
451	struct f_gether *eth;
452
453	eth = func_to_geth(f);
454	kfree(eth);
455}
456
457static void geth_unbind(struct usb_configuration *c, struct usb_function *f)
458{
459	geth_string_defs[0].id = 0;
460	usb_free_all_descriptors(f);
461}
462
463static struct usb_function *geth_alloc(struct usb_function_instance *fi)
464{
465	struct f_gether	*geth;
466	struct f_gether_opts *opts;
467	int status;
468
469	/* allocate and initialize one new instance */
470	geth = kzalloc(sizeof(*geth), GFP_KERNEL);
471	if (!geth)
472		return ERR_PTR(-ENOMEM);
473
474	opts = container_of(fi, struct f_gether_opts, func_inst);
475
476	mutex_lock(&opts->lock);
477	opts->refcnt++;
478	/* export host's Ethernet address in CDC format */
479	status = gether_get_host_addr_cdc(opts->net, geth->ethaddr,
480					  sizeof(geth->ethaddr));
481	if (status < 12) {
482		kfree(geth);
483		mutex_unlock(&opts->lock);
484		return ERR_PTR(-EINVAL);
485	}
486	geth_string_defs[1].s = geth->ethaddr;
487
488	geth->port.ioport = netdev_priv(opts->net);
489	mutex_unlock(&opts->lock);
490	geth->port.cdc_filter = DEFAULT_FILTER;
491
492	geth->port.func.name = "cdc_subset";
493	geth->port.func.bind = geth_bind;
494	geth->port.func.unbind = geth_unbind;
495	geth->port.func.set_alt = geth_set_alt;
496	geth->port.func.disable = geth_disable;
497	geth->port.func.free_func = geth_free;
498
499	return &geth->port.func;
500}
501
502DECLARE_USB_FUNCTION_INIT(geth, geth_alloc_inst, geth_alloc);
503MODULE_LICENSE("GPL");
504MODULE_AUTHOR("David Brownell");
v6.2
  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * f_subset.c -- "CDC Subset" Ethernet link function driver
  4 *
  5 * Copyright (C) 2003-2005,2008 David Brownell
  6 * Copyright (C) 2008 Nokia Corporation
  7 */
  8
  9#include <linux/slab.h>
 10#include <linux/kernel.h>
 11#include <linux/module.h>
 12#include <linux/device.h>
 13#include <linux/etherdevice.h>
 14
 15#include "u_ether.h"
 16#include "u_ether_configfs.h"
 17#include "u_gether.h"
 18
 19/*
 20 * This function packages a simple "CDC Subset" Ethernet port with no real
 21 * control mechanisms; just raw data transfer over two bulk endpoints.
 22 * The data transfer model is exactly that of CDC Ethernet, which is
 23 * why we call it the "CDC Subset".
 24 *
 25 * Because it's not standardized, this has some interoperability issues.
 26 * They mostly relate to driver binding, since the data transfer model is
 27 * so simple (CDC Ethernet).  The original versions of this protocol used
 28 * specific product/vendor IDs:  byteswapped IDs for Digital Equipment's
 29 * SA-1100 "Itsy" board, which could run Linux 2.4 kernels and supported
 30 * daughtercards with USB peripheral connectors.  (It was used more often
 31 * with other boards, using the Itsy identifiers.)  Linux hosts recognized
 32 * this with CONFIG_USB_ARMLINUX; these devices have only one configuration
 33 * and one interface.
 34 *
 35 * At some point, MCCI defined a (nonconformant) CDC MDLM variant called
 36 * "SAFE", which happens to have a mode which is identical to the "CDC
 37 * Subset" in terms of data transfer and lack of control model.  This was
 38 * adopted by later Sharp Zaurus models, and by some other software which
 39 * Linux hosts recognize with CONFIG_USB_NET_ZAURUS.
 40 *
 41 * Because Microsoft's RNDIS drivers are far from robust, we added a few
 42 * descriptors to the CDC Subset code, making this code look like a SAFE
 43 * implementation.  This lets you use MCCI's host side MS-Windows drivers
 44 * if you get fed up with RNDIS.  It also makes it easier for composite
 45 * drivers to work, since they can use class based binding instead of
 46 * caring about specific product and vendor IDs.
 47 */
 48
 49struct f_gether {
 50	struct gether			port;
 51
 52	char				ethaddr[14];
 53};
 54
 55static inline struct f_gether *func_to_geth(struct usb_function *f)
 56{
 57	return container_of(f, struct f_gether, port.func);
 58}
 59
 60/*-------------------------------------------------------------------------*/
 61
 62/*
 63 * "Simple" CDC-subset option is a simple vendor-neutral model that most
 64 * full speed controllers can handle:  one interface, two bulk endpoints.
 65 * To assist host side drivers, we fancy it up a bit, and add descriptors so
 66 * some host side drivers will understand it as a "SAFE" variant.
 67 *
 68 * "SAFE" loosely follows CDC WMC MDLM, violating the spec in various ways.
 69 * Data endpoints live in the control interface, there's no data interface.
 70 * And it's not used to talk to a cell phone radio.
 71 */
 72
 73/* interface descriptor: */
 74
 75static struct usb_interface_descriptor subset_data_intf = {
 76	.bLength =		sizeof subset_data_intf,
 77	.bDescriptorType =	USB_DT_INTERFACE,
 78
 79	/* .bInterfaceNumber = DYNAMIC */
 80	.bAlternateSetting =	0,
 81	.bNumEndpoints =	2,
 82	.bInterfaceClass =      USB_CLASS_COMM,
 83	.bInterfaceSubClass =	USB_CDC_SUBCLASS_MDLM,
 84	.bInterfaceProtocol =	0,
 85	/* .iInterface = DYNAMIC */
 86};
 87
 88static struct usb_cdc_header_desc mdlm_header_desc = {
 89	.bLength =		sizeof mdlm_header_desc,
 90	.bDescriptorType =	USB_DT_CS_INTERFACE,
 91	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
 92
 93	.bcdCDC =		cpu_to_le16(0x0110),
 94};
 95
 96static struct usb_cdc_mdlm_desc mdlm_desc = {
 97	.bLength =		sizeof mdlm_desc,
 98	.bDescriptorType =	USB_DT_CS_INTERFACE,
 99	.bDescriptorSubType =	USB_CDC_MDLM_TYPE,
100
101	.bcdVersion =		cpu_to_le16(0x0100),
102	.bGUID = {
103		0x5d, 0x34, 0xcf, 0x66, 0x11, 0x18, 0x11, 0xd6,
104		0xa2, 0x1a, 0x00, 0x01, 0x02, 0xca, 0x9a, 0x7f,
105	},
106};
107
108/* since "usb_cdc_mdlm_detail_desc" is a variable length structure, we
109 * can't really use its struct.  All we do here is say that we're using
110 * the submode of "SAFE" which directly matches the CDC Subset.
111 */
112static u8 mdlm_detail_desc[] = {
113	6,
114	USB_DT_CS_INTERFACE,
115	USB_CDC_MDLM_DETAIL_TYPE,
116
117	0,	/* "SAFE" */
118	0,	/* network control capabilities (none) */
119	0,	/* network data capabilities ("raw" encapsulation) */
120};
121
122static struct usb_cdc_ether_desc ether_desc = {
123	.bLength =		sizeof ether_desc,
124	.bDescriptorType =	USB_DT_CS_INTERFACE,
125	.bDescriptorSubType =	USB_CDC_ETHERNET_TYPE,
126
127	/* this descriptor actually adds value, surprise! */
128	/* .iMACAddress = DYNAMIC */
129	.bmEthernetStatistics =	cpu_to_le32(0), /* no statistics */
130	.wMaxSegmentSize =	cpu_to_le16(ETH_FRAME_LEN),
131	.wNumberMCFilters =	cpu_to_le16(0),
132	.bNumberPowerFilters =	0,
133};
134
135/* full speed support: */
136
137static struct usb_endpoint_descriptor fs_subset_in_desc = {
138	.bLength =		USB_DT_ENDPOINT_SIZE,
139	.bDescriptorType =	USB_DT_ENDPOINT,
140
141	.bEndpointAddress =	USB_DIR_IN,
142	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
143};
144
145static struct usb_endpoint_descriptor fs_subset_out_desc = {
146	.bLength =		USB_DT_ENDPOINT_SIZE,
147	.bDescriptorType =	USB_DT_ENDPOINT,
148
149	.bEndpointAddress =	USB_DIR_OUT,
150	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
151};
152
153static struct usb_descriptor_header *fs_eth_function[] = {
154	(struct usb_descriptor_header *) &subset_data_intf,
155	(struct usb_descriptor_header *) &mdlm_header_desc,
156	(struct usb_descriptor_header *) &mdlm_desc,
157	(struct usb_descriptor_header *) &mdlm_detail_desc,
158	(struct usb_descriptor_header *) &ether_desc,
159	(struct usb_descriptor_header *) &fs_subset_in_desc,
160	(struct usb_descriptor_header *) &fs_subset_out_desc,
161	NULL,
162};
163
164/* high speed support: */
165
166static struct usb_endpoint_descriptor hs_subset_in_desc = {
167	.bLength =		USB_DT_ENDPOINT_SIZE,
168	.bDescriptorType =	USB_DT_ENDPOINT,
169
170	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
171	.wMaxPacketSize =	cpu_to_le16(512),
172};
173
174static struct usb_endpoint_descriptor hs_subset_out_desc = {
175	.bLength =		USB_DT_ENDPOINT_SIZE,
176	.bDescriptorType =	USB_DT_ENDPOINT,
177
178	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
179	.wMaxPacketSize =	cpu_to_le16(512),
180};
181
182static struct usb_descriptor_header *hs_eth_function[] = {
183	(struct usb_descriptor_header *) &subset_data_intf,
184	(struct usb_descriptor_header *) &mdlm_header_desc,
185	(struct usb_descriptor_header *) &mdlm_desc,
186	(struct usb_descriptor_header *) &mdlm_detail_desc,
187	(struct usb_descriptor_header *) &ether_desc,
188	(struct usb_descriptor_header *) &hs_subset_in_desc,
189	(struct usb_descriptor_header *) &hs_subset_out_desc,
190	NULL,
191};
192
193/* super speed support: */
194
195static struct usb_endpoint_descriptor ss_subset_in_desc = {
196	.bLength =		USB_DT_ENDPOINT_SIZE,
197	.bDescriptorType =	USB_DT_ENDPOINT,
198
199	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
200	.wMaxPacketSize =	cpu_to_le16(1024),
201};
202
203static struct usb_endpoint_descriptor ss_subset_out_desc = {
204	.bLength =		USB_DT_ENDPOINT_SIZE,
205	.bDescriptorType =	USB_DT_ENDPOINT,
206
207	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
208	.wMaxPacketSize =	cpu_to_le16(1024),
209};
210
211static struct usb_ss_ep_comp_descriptor ss_subset_bulk_comp_desc = {
212	.bLength =		sizeof ss_subset_bulk_comp_desc,
213	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
214
215	/* the following 2 values can be tweaked if necessary */
216	/* .bMaxBurst =		0, */
217	/* .bmAttributes =	0, */
218};
219
220static struct usb_descriptor_header *ss_eth_function[] = {
221	(struct usb_descriptor_header *) &subset_data_intf,
222	(struct usb_descriptor_header *) &mdlm_header_desc,
223	(struct usb_descriptor_header *) &mdlm_desc,
224	(struct usb_descriptor_header *) &mdlm_detail_desc,
225	(struct usb_descriptor_header *) &ether_desc,
226	(struct usb_descriptor_header *) &ss_subset_in_desc,
227	(struct usb_descriptor_header *) &ss_subset_bulk_comp_desc,
228	(struct usb_descriptor_header *) &ss_subset_out_desc,
229	(struct usb_descriptor_header *) &ss_subset_bulk_comp_desc,
230	NULL,
231};
232
233/* string descriptors: */
234
235static struct usb_string geth_string_defs[] = {
236	[0].s = "CDC Ethernet Subset/SAFE",
237	[1].s = "",
238	{  } /* end of list */
239};
240
241static struct usb_gadget_strings geth_string_table = {
242	.language =		0x0409,	/* en-us */
243	.strings =		geth_string_defs,
244};
245
246static struct usb_gadget_strings *geth_strings[] = {
247	&geth_string_table,
248	NULL,
249};
250
251/*-------------------------------------------------------------------------*/
252
253static int geth_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
254{
255	struct f_gether		*geth = func_to_geth(f);
256	struct usb_composite_dev *cdev = f->config->cdev;
257	struct net_device	*net;
258
259	/* we know alt == 0, so this is an activation or a reset */
260
261	if (geth->port.in_ep->enabled) {
262		DBG(cdev, "reset cdc subset\n");
263		gether_disconnect(&geth->port);
264	}
265
266	DBG(cdev, "init + activate cdc subset\n");
267	if (config_ep_by_speed(cdev->gadget, f, geth->port.in_ep) ||
268	    config_ep_by_speed(cdev->gadget, f, geth->port.out_ep)) {
269		geth->port.in_ep->desc = NULL;
270		geth->port.out_ep->desc = NULL;
271		return -EINVAL;
272	}
273
274	net = gether_connect(&geth->port);
275	return PTR_ERR_OR_ZERO(net);
276}
277
278static void geth_disable(struct usb_function *f)
279{
280	struct f_gether	*geth = func_to_geth(f);
281	struct usb_composite_dev *cdev = f->config->cdev;
282
283	DBG(cdev, "net deactivated\n");
284	gether_disconnect(&geth->port);
285}
286
287/*-------------------------------------------------------------------------*/
288
289/* serial function driver setup/binding */
290
291static int
292geth_bind(struct usb_configuration *c, struct usb_function *f)
293{
294	struct usb_composite_dev *cdev = c->cdev;
295	struct f_gether		*geth = func_to_geth(f);
296	struct usb_string	*us;
297	int			status;
298	struct usb_ep		*ep;
299
300	struct f_gether_opts	*gether_opts;
301
302	gether_opts = container_of(f->fi, struct f_gether_opts, func_inst);
303
304	/*
305	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
306	 * configurations are bound in sequence with list_for_each_entry,
307	 * in each configuration its functions are bound in sequence
308	 * with list_for_each_entry, so we assume no race condition
309	 * with regard to gether_opts->bound access
310	 */
311	if (!gether_opts->bound) {
312		mutex_lock(&gether_opts->lock);
313		gether_set_gadget(gether_opts->net, cdev->gadget);
314		status = gether_register_netdev(gether_opts->net);
315		mutex_unlock(&gether_opts->lock);
316		if (status)
317			return status;
318		gether_opts->bound = true;
319	}
320
321	us = usb_gstrings_attach(cdev, geth_strings,
322				 ARRAY_SIZE(geth_string_defs));
323	if (IS_ERR(us))
324		return PTR_ERR(us);
325
326	subset_data_intf.iInterface = us[0].id;
327	ether_desc.iMACAddress = us[1].id;
328
329	/* allocate instance-specific interface IDs */
330	status = usb_interface_id(c, f);
331	if (status < 0)
332		goto fail;
333	subset_data_intf.bInterfaceNumber = status;
334
335	status = -ENODEV;
336
337	/* allocate instance-specific endpoints */
338	ep = usb_ep_autoconfig(cdev->gadget, &fs_subset_in_desc);
339	if (!ep)
340		goto fail;
341	geth->port.in_ep = ep;
342
343	ep = usb_ep_autoconfig(cdev->gadget, &fs_subset_out_desc);
344	if (!ep)
345		goto fail;
346	geth->port.out_ep = ep;
347
348	/* support all relevant hardware speeds... we expect that when
349	 * hardware is dual speed, all bulk-capable endpoints work at
350	 * both speeds
351	 */
352	hs_subset_in_desc.bEndpointAddress = fs_subset_in_desc.bEndpointAddress;
353	hs_subset_out_desc.bEndpointAddress =
354		fs_subset_out_desc.bEndpointAddress;
355
356	ss_subset_in_desc.bEndpointAddress = fs_subset_in_desc.bEndpointAddress;
357	ss_subset_out_desc.bEndpointAddress =
358		fs_subset_out_desc.bEndpointAddress;
359
360	status = usb_assign_descriptors(f, fs_eth_function, hs_eth_function,
361			ss_eth_function, ss_eth_function);
362	if (status)
363		goto fail;
364
365	/* NOTE:  all that is done without knowing or caring about
366	 * the network link ... which is unavailable to this code
367	 * until we're activated via set_alt().
368	 */
369
370	DBG(cdev, "CDC Subset: %s speed IN/%s OUT/%s\n",
371			gadget_is_superspeed(c->cdev->gadget) ? "super" :
372			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
373			geth->port.in_ep->name, geth->port.out_ep->name);
374	return 0;
375
376fail:
377	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
378
379	return status;
380}
381
382static inline struct f_gether_opts *to_f_gether_opts(struct config_item *item)
383{
384	return container_of(to_config_group(item), struct f_gether_opts,
385			    func_inst.group);
386}
387
388/* f_gether_item_ops */
389USB_ETHERNET_CONFIGFS_ITEM(gether);
390
391/* f_gether_opts_dev_addr */
392USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(gether);
393
394/* f_gether_opts_host_addr */
395USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(gether);
396
397/* f_gether_opts_qmult */
398USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(gether);
399
400/* f_gether_opts_ifname */
401USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(gether);
402
403static struct configfs_attribute *gether_attrs[] = {
404	&gether_opts_attr_dev_addr,
405	&gether_opts_attr_host_addr,
406	&gether_opts_attr_qmult,
407	&gether_opts_attr_ifname,
408	NULL,
409};
410
411static const struct config_item_type gether_func_type = {
412	.ct_item_ops	= &gether_item_ops,
413	.ct_attrs	= gether_attrs,
414	.ct_owner	= THIS_MODULE,
415};
416
417static void geth_free_inst(struct usb_function_instance *f)
418{
419	struct f_gether_opts *opts;
420
421	opts = container_of(f, struct f_gether_opts, func_inst);
422	if (opts->bound)
423		gether_cleanup(netdev_priv(opts->net));
424	else
425		free_netdev(opts->net);
426	kfree(opts);
427}
428
429static struct usb_function_instance *geth_alloc_inst(void)
430{
431	struct f_gether_opts *opts;
432
433	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
434	if (!opts)
435		return ERR_PTR(-ENOMEM);
436	mutex_init(&opts->lock);
437	opts->func_inst.free_func_inst = geth_free_inst;
438	opts->net = gether_setup_default();
439	if (IS_ERR(opts->net)) {
440		struct net_device *net = opts->net;
441		kfree(opts);
442		return ERR_CAST(net);
443	}
444
445	config_group_init_type_name(&opts->func_inst.group, "",
446				    &gether_func_type);
447
448	return &opts->func_inst;
449}
450
451static void geth_free(struct usb_function *f)
452{
453	struct f_gether *eth;
454
455	eth = func_to_geth(f);
456	kfree(eth);
457}
458
459static void geth_unbind(struct usb_configuration *c, struct usb_function *f)
460{
461	geth_string_defs[0].id = 0;
462	usb_free_all_descriptors(f);
463}
464
465static struct usb_function *geth_alloc(struct usb_function_instance *fi)
466{
467	struct f_gether	*geth;
468	struct f_gether_opts *opts;
469	int status;
470
471	/* allocate and initialize one new instance */
472	geth = kzalloc(sizeof(*geth), GFP_KERNEL);
473	if (!geth)
474		return ERR_PTR(-ENOMEM);
475
476	opts = container_of(fi, struct f_gether_opts, func_inst);
477
478	mutex_lock(&opts->lock);
479	opts->refcnt++;
480	/* export host's Ethernet address in CDC format */
481	status = gether_get_host_addr_cdc(opts->net, geth->ethaddr,
482					  sizeof(geth->ethaddr));
483	if (status < 12) {
484		kfree(geth);
485		mutex_unlock(&opts->lock);
486		return ERR_PTR(-EINVAL);
487	}
488	geth_string_defs[1].s = geth->ethaddr;
489
490	geth->port.ioport = netdev_priv(opts->net);
491	mutex_unlock(&opts->lock);
492	geth->port.cdc_filter = DEFAULT_FILTER;
493
494	geth->port.func.name = "cdc_subset";
495	geth->port.func.bind = geth_bind;
496	geth->port.func.unbind = geth_unbind;
497	geth->port.func.set_alt = geth_set_alt;
498	geth->port.func.disable = geth_disable;
499	geth->port.func.free_func = geth_free;
500
501	return &geth->port.func;
502}
503
504DECLARE_USB_FUNCTION_INIT(geth, geth_alloc_inst, geth_alloc);
505MODULE_LICENSE("GPL");
506MODULE_AUTHOR("David Brownell");