2 * f_eem.c -- USB CDC Ethernet (EEM) link function driver
4 * Copyright (C) 2003-2005,2008 David Brownell
5 * Copyright (C) 2008 Nokia Corporation
6 * Copyright (C) 2009 EF Johnson Technologies
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.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include <linux/kernel.h>
24 #include <linux/device.h>
25 #include <linux/etherdevice.h>
26 #include <linux/crc32.h>
27 #include <linux/slab.h>
34 * This function is a "CDC Ethernet Emulation Model" (CDC EEM)
39 struct usb_endpoint_descriptor *in;
40 struct usb_endpoint_descriptor *out;
47 struct eem_ep_descs fs;
48 struct eem_ep_descs hs;
51 static inline struct f_eem *func_to_eem(struct usb_function *f)
53 return container_of(f, struct f_eem, port.func);
56 /*-------------------------------------------------------------------------*/
58 /* interface descriptor: */
60 static struct usb_interface_descriptor eem_intf __initdata = {
61 .bLength = sizeof eem_intf,
62 .bDescriptorType = USB_DT_INTERFACE,
64 /* .bInterfaceNumber = DYNAMIC */
66 .bInterfaceClass = USB_CLASS_COMM,
67 .bInterfaceSubClass = USB_CDC_SUBCLASS_EEM,
68 .bInterfaceProtocol = USB_CDC_PROTO_EEM,
69 /* .iInterface = DYNAMIC */
72 /* full speed support: */
74 static struct usb_endpoint_descriptor eem_fs_in_desc __initdata = {
75 .bLength = USB_DT_ENDPOINT_SIZE,
76 .bDescriptorType = USB_DT_ENDPOINT,
78 .bEndpointAddress = USB_DIR_IN,
79 .bmAttributes = USB_ENDPOINT_XFER_BULK,
82 static struct usb_endpoint_descriptor eem_fs_out_desc __initdata = {
83 .bLength = USB_DT_ENDPOINT_SIZE,
84 .bDescriptorType = USB_DT_ENDPOINT,
86 .bEndpointAddress = USB_DIR_OUT,
87 .bmAttributes = USB_ENDPOINT_XFER_BULK,
90 static struct usb_descriptor_header *eem_fs_function[] __initdata = {
91 /* CDC EEM control descriptors */
92 (struct usb_descriptor_header *) &eem_intf,
93 (struct usb_descriptor_header *) &eem_fs_in_desc,
94 (struct usb_descriptor_header *) &eem_fs_out_desc,
98 /* high speed support: */
100 static struct usb_endpoint_descriptor eem_hs_in_desc __initdata = {
101 .bLength = USB_DT_ENDPOINT_SIZE,
102 .bDescriptorType = USB_DT_ENDPOINT,
104 .bEndpointAddress = USB_DIR_IN,
105 .bmAttributes = USB_ENDPOINT_XFER_BULK,
106 .wMaxPacketSize = cpu_to_le16(512),
109 static struct usb_endpoint_descriptor eem_hs_out_desc __initdata = {
110 .bLength = USB_DT_ENDPOINT_SIZE,
111 .bDescriptorType = USB_DT_ENDPOINT,
113 .bEndpointAddress = USB_DIR_OUT,
114 .bmAttributes = USB_ENDPOINT_XFER_BULK,
115 .wMaxPacketSize = cpu_to_le16(512),
118 static struct usb_descriptor_header *eem_hs_function[] __initdata = {
119 /* CDC EEM control descriptors */
120 (struct usb_descriptor_header *) &eem_intf,
121 (struct usb_descriptor_header *) &eem_hs_in_desc,
122 (struct usb_descriptor_header *) &eem_hs_out_desc,
126 /* string descriptors: */
128 static struct usb_string eem_string_defs[] = {
129 [0].s = "CDC Ethernet Emulation Model (EEM)",
130 { } /* end of list */
133 static struct usb_gadget_strings eem_string_table = {
134 .language = 0x0409, /* en-us */
135 .strings = eem_string_defs,
138 static struct usb_gadget_strings *eem_strings[] = {
143 /*-------------------------------------------------------------------------*/
145 static int eem_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
147 struct usb_composite_dev *cdev = f->config->cdev;
148 int value = -EOPNOTSUPP;
149 u16 w_index = le16_to_cpu(ctrl->wIndex);
150 u16 w_value = le16_to_cpu(ctrl->wValue);
151 u16 w_length = le16_to_cpu(ctrl->wLength);
153 DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
154 ctrl->bRequestType, ctrl->bRequest,
155 w_value, w_index, w_length);
157 /* device either stalls (value < 0) or reports success */
162 static int eem_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
164 struct f_eem *eem = func_to_eem(f);
165 struct usb_composite_dev *cdev = f->config->cdev;
166 struct net_device *net;
168 /* we know alt == 0, so this is an activation or a reset */
172 if (intf == eem->ctrl_id) {
174 if (eem->port.in_ep->driver_data) {
175 DBG(cdev, "reset eem\n");
176 gether_disconnect(&eem->port);
180 DBG(cdev, "init eem\n");
181 eem->port.in = ep_choose(cdev->gadget,
182 eem->hs.in, eem->fs.in);
183 eem->port.out = ep_choose(cdev->gadget,
184 eem->hs.out, eem->fs.out);
187 /* zlps should not occur because zero-length EEM packets
188 * will be inserted in those cases where they would occur
190 eem->port.is_zlp_ok = 1;
191 eem->port.cdc_filter = DEFAULT_FILTER;
192 DBG(cdev, "activate eem\n");
193 net = gether_connect(&eem->port);
204 static void eem_disable(struct usb_function *f)
206 struct f_eem *eem = func_to_eem(f);
207 struct usb_composite_dev *cdev = f->config->cdev;
209 DBG(cdev, "eem deactivated\n");
211 if (eem->port.in_ep->driver_data)
212 gether_disconnect(&eem->port);
215 /*-------------------------------------------------------------------------*/
217 /* EEM function driver setup/binding */
220 eem_bind(struct usb_configuration *c, struct usb_function *f)
222 struct usb_composite_dev *cdev = c->cdev;
223 struct f_eem *eem = func_to_eem(f);
227 /* allocate instance-specific interface IDs */
228 status = usb_interface_id(c, f);
231 eem->ctrl_id = status;
232 eem_intf.bInterfaceNumber = status;
236 /* allocate instance-specific endpoints */
237 ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_in_desc);
240 eem->port.in_ep = ep;
241 ep->driver_data = cdev; /* claim */
243 ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_out_desc);
246 eem->port.out_ep = ep;
247 ep->driver_data = cdev; /* claim */
251 /* copy descriptors, and track endpoint copies */
252 f->descriptors = usb_copy_descriptors(eem_fs_function);
256 eem->fs.in = usb_find_endpoint(eem_fs_function,
257 f->descriptors, &eem_fs_in_desc);
258 eem->fs.out = usb_find_endpoint(eem_fs_function,
259 f->descriptors, &eem_fs_out_desc);
261 /* support all relevant hardware speeds... we expect that when
262 * hardware is dual speed, all bulk-capable endpoints work at
265 if (gadget_is_dualspeed(c->cdev->gadget)) {
266 eem_hs_in_desc.bEndpointAddress =
267 eem_fs_in_desc.bEndpointAddress;
268 eem_hs_out_desc.bEndpointAddress =
269 eem_fs_out_desc.bEndpointAddress;
271 /* copy descriptors, and track endpoint copies */
272 f->hs_descriptors = usb_copy_descriptors(eem_hs_function);
273 if (!f->hs_descriptors)
276 eem->hs.in = usb_find_endpoint(eem_hs_function,
277 f->hs_descriptors, &eem_hs_in_desc);
278 eem->hs.out = usb_find_endpoint(eem_hs_function,
279 f->hs_descriptors, &eem_hs_out_desc);
282 DBG(cdev, "CDC Ethernet (EEM): %s speed IN/%s OUT/%s\n",
283 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
284 eem->port.in_ep->name, eem->port.out_ep->name);
289 usb_free_descriptors(f->descriptors);
291 /* we might as well release our claims on endpoints */
293 eem->port.out_ep->driver_data = NULL;
295 eem->port.in_ep->driver_data = NULL;
297 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
303 eem_unbind(struct usb_configuration *c, struct usb_function *f)
305 struct f_eem *eem = func_to_eem(f);
307 DBG(c->cdev, "eem unbind\n");
309 if (gadget_is_dualspeed(c->cdev->gadget))
310 usb_free_descriptors(f->hs_descriptors);
311 usb_free_descriptors(f->descriptors);
315 static void eem_cmd_complete(struct usb_ep *ep, struct usb_request *req)
320 * Add the EEM header and ethernet checksum.
321 * We currently do not attempt to put multiple ethernet frames
322 * into a single USB transfer
324 static struct sk_buff *eem_wrap(struct gether *port, struct sk_buff *skb)
326 struct sk_buff *skb2 = NULL;
327 struct usb_ep *in = port->in_ep;
331 if (!skb_cloned(skb)) {
332 int headroom = skb_headroom(skb);
333 int tailroom = skb_tailroom(skb);
335 /* When (len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) is 0,
336 * stick two bytes of zero-length EEM packet on the end.
338 if (((len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) == 0)
341 if ((tailroom >= (ETH_FCS_LEN + padlen)) &&
342 (headroom >= EEM_HLEN))
346 skb2 = skb_copy_expand(skb, EEM_HLEN, ETH_FCS_LEN + padlen, GFP_ATOMIC);
347 dev_kfree_skb_any(skb);
353 /* use the "no CRC" option */
354 put_unaligned_be32(0xdeadbeef, skb_put(skb, 4));
356 /* EEM packet header format:
357 * b0..13: length of ethernet frame
358 * b14: bmCRC (0 == sentinel CRC)
359 * b15: bmType (0 == data)
362 put_unaligned_le16(len & 0x3FFF, skb_push(skb, 2));
364 /* add a zero-length EEM packet, if needed */
366 put_unaligned_le16(0, skb_put(skb, 2));
372 * Remove the EEM header. Note that there can be many EEM packets in a single
373 * USB transfer, so we need to break them out and handle them independently.
375 static int eem_unwrap(struct gether *port,
377 struct sk_buff_head *list)
379 struct usb_composite_dev *cdev = port->func.config->cdev;
383 struct sk_buff *skb2;
387 if (skb->len < EEM_HLEN) {
389 DBG(cdev, "invalid EEM header\n");
393 /* remove the EEM header */
394 header = get_unaligned_le16(skb->data);
395 skb_pull(skb, EEM_HLEN);
397 /* EEM packet header format:
398 * b0..14: EEM type dependent (data or command)
399 * b15: bmType (0 == data, 1 == command)
401 if (header & BIT(15)) {
402 struct usb_request *req = cdev->req;
405 /* EEM command packet format:
406 * b0..10: bmEEMCmdParam
408 * b14: reserved (must be zero)
409 * b15: bmType (1 == command)
411 if (header & BIT(14))
414 bmEEMCmd = (header >> 11) & 0x7;
417 len = header & 0x7FF;
418 if (skb->len < len) {
423 skb2 = skb_clone(skb, GFP_ATOMIC);
424 if (unlikely(!skb2)) {
425 DBG(cdev, "EEM echo response error\n");
429 put_unaligned_le16(BIT(15) | BIT(11) | len,
431 skb_copy_bits(skb, 0, req->buf, skb->len);
432 req->length = skb->len;
433 req->complete = eem_cmd_complete;
435 if (usb_ep_queue(port->in_ep, req, GFP_ATOMIC))
436 DBG(cdev, "echo response queue fail\n");
439 case 1: /* echo response */
440 case 2: /* suspend hint */
441 case 3: /* response hint */
442 case 4: /* response complete hint */
444 default: /* reserved */
449 struct sk_buff *skb3;
451 /* check for zero-length EEM packet */
455 /* EEM data packet format:
456 * b0..13: length of ethernet frame
457 * b14: bmCRC (0 == sentinel, 1 == calculated)
458 * b15: bmType (0 == data)
460 len = header & 0x3FFF;
462 || (len < (ETH_HLEN + ETH_FCS_LEN))) {
468 if (header & BIT(14)) {
469 crc = get_unaligned_le32(skb->data + len
473 skb->len - ETH_FCS_LEN);
475 crc = get_unaligned_be32(skb->data + len
480 DBG(cdev, "invalid EEM CRC\n");
484 skb2 = skb_clone(skb, GFP_ATOMIC);
485 if (unlikely(!skb2)) {
486 DBG(cdev, "unable to unframe EEM packet\n");
489 skb_trim(skb2, len - ETH_FCS_LEN);
491 skb3 = skb_copy_expand(skb2,
495 if (unlikely(!skb3)) {
496 DBG(cdev, "unable to realign EEM packet\n");
497 dev_kfree_skb_any(skb2);
500 dev_kfree_skb_any(skb2);
501 skb_queue_tail(list, skb3);
508 dev_kfree_skb_any(skb);
513 * eem_bind_config - add CDC Ethernet (EEM) network link to a configuration
514 * @c: the configuration to support the network link
515 * Context: single threaded during gadget setup
517 * Returns zero on success, else negative errno.
519 * Caller must have called @gether_setup(). Caller is also responsible
520 * for calling @gether_cleanup() before module unload.
522 int __init eem_bind_config(struct usb_configuration *c)
527 /* maybe allocate device-global string IDs */
528 if (eem_string_defs[0].id == 0) {
530 /* control interface label */
531 status = usb_string_id(c->cdev);
534 eem_string_defs[0].id = status;
535 eem_intf.iInterface = status;
538 /* allocate and initialize one new instance */
539 eem = kzalloc(sizeof *eem, GFP_KERNEL);
543 eem->port.cdc_filter = DEFAULT_FILTER;
545 eem->port.func.name = "cdc_eem";
546 eem->port.func.strings = eem_strings;
547 /* descriptors are per-instance copies */
548 eem->port.func.bind = eem_bind;
549 eem->port.func.unbind = eem_unbind;
550 eem->port.func.set_alt = eem_set_alt;
551 eem->port.func.setup = eem_setup;
552 eem->port.func.disable = eem_disable;
553 eem->port.wrap = eem_wrap;
554 eem->port.unwrap = eem_unwrap;
555 eem->port.header_len = EEM_HLEN;
557 status = usb_add_function(c, &eem->port.func);