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
)
317 struct sk_buff
*skb
= (struct sk_buff
*)req
->context
;
319 dev_kfree_skb_any(skb
);
323 * Add the EEM header and ethernet checksum.
324 * We currently do not attempt to put multiple ethernet frames
325 * into a single USB transfer
327 static struct sk_buff
*eem_wrap(struct gether
*port
, struct sk_buff
*skb
)
329 struct sk_buff
*skb2
= NULL
;
330 struct usb_ep
*in
= port
->in_ep
;
334 if (!skb_cloned(skb
)) {
335 int headroom
= skb_headroom(skb
);
336 int tailroom
= skb_tailroom(skb
);
338 /* When (len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) is 0,
339 * stick two bytes of zero-length EEM packet on the end.
341 if (((len
+ EEM_HLEN
+ ETH_FCS_LEN
) % in
->maxpacket
) == 0)
344 if ((tailroom
>= (ETH_FCS_LEN
+ padlen
)) &&
345 (headroom
>= EEM_HLEN
))
349 skb2
= skb_copy_expand(skb
, EEM_HLEN
, ETH_FCS_LEN
+ padlen
, GFP_ATOMIC
);
350 dev_kfree_skb_any(skb
);
356 /* use the "no CRC" option */
357 put_unaligned_be32(0xdeadbeef, skb_put(skb
, 4));
359 /* EEM packet header format:
360 * b0..13: length of ethernet frame
361 * b14: bmCRC (0 == sentinel CRC)
362 * b15: bmType (0 == data)
365 put_unaligned_le16(len
& 0x3FFF, skb_push(skb
, 2));
367 /* add a zero-length EEM packet, if needed */
369 put_unaligned_le16(0, skb_put(skb
, 2));
375 * Remove the EEM header. Note that there can be many EEM packets in a single
376 * USB transfer, so we need to break them out and handle them independently.
378 static int eem_unwrap(struct gether
*port
,
380 struct sk_buff_head
*list
)
382 struct usb_composite_dev
*cdev
= port
->func
.config
->cdev
;
386 struct sk_buff
*skb2
;
390 if (skb
->len
< EEM_HLEN
) {
392 DBG(cdev
, "invalid EEM header\n");
396 /* remove the EEM header */
397 header
= get_unaligned_le16(skb
->data
);
398 skb_pull(skb
, EEM_HLEN
);
400 /* EEM packet header format:
401 * b0..14: EEM type dependent (data or command)
402 * b15: bmType (0 == data, 1 == command)
404 if (header
& BIT(15)) {
405 struct usb_request
*req
= cdev
->req
;
408 /* EEM command packet format:
409 * b0..10: bmEEMCmdParam
411 * b14: reserved (must be zero)
412 * b15: bmType (1 == command)
414 if (header
& BIT(14))
417 bmEEMCmd
= (header
>> 11) & 0x7;
420 len
= header
& 0x7FF;
421 if (skb
->len
< len
) {
426 skb2
= skb_clone(skb
, GFP_ATOMIC
);
427 if (unlikely(!skb2
)) {
428 DBG(cdev
, "EEM echo response error\n");
432 put_unaligned_le16(BIT(15) | BIT(11) | len
,
434 skb_copy_bits(skb2
, 0, req
->buf
, skb2
->len
);
435 req
->length
= skb2
->len
;
436 req
->complete
= eem_cmd_complete
;
439 if (usb_ep_queue(port
->in_ep
, req
, GFP_ATOMIC
))
440 DBG(cdev
, "echo response queue fail\n");
443 case 1: /* echo response */
444 case 2: /* suspend hint */
445 case 3: /* response hint */
446 case 4: /* response complete hint */
448 default: /* reserved */
453 struct sk_buff
*skb3
;
455 /* check for zero-length EEM packet */
459 /* EEM data packet format:
460 * b0..13: length of ethernet frame
461 * b14: bmCRC (0 == sentinel, 1 == calculated)
462 * b15: bmType (0 == data)
464 len
= header
& 0x3FFF;
466 || (len
< (ETH_HLEN
+ ETH_FCS_LEN
))) {
472 if (header
& BIT(14)) {
473 crc
= get_unaligned_le32(skb
->data
+ len
476 skb
->data
, len
- ETH_FCS_LEN
);
478 crc
= get_unaligned_be32(skb
->data
+ len
483 DBG(cdev
, "invalid EEM CRC\n");
487 skb2
= skb_clone(skb
, GFP_ATOMIC
);
488 if (unlikely(!skb2
)) {
489 DBG(cdev
, "unable to unframe EEM packet\n");
492 skb_trim(skb2
, len
- ETH_FCS_LEN
);
494 skb3
= skb_copy_expand(skb2
,
498 if (unlikely(!skb3
)) {
499 DBG(cdev
, "unable to realign EEM packet\n");
500 dev_kfree_skb_any(skb2
);
503 dev_kfree_skb_any(skb2
);
504 skb_queue_tail(list
, skb3
);
511 dev_kfree_skb_any(skb
);
516 * eem_bind_config - add CDC Ethernet (EEM) network link to a configuration
517 * @c: the configuration to support the network link
518 * Context: single threaded during gadget setup
520 * Returns zero on success, else negative errno.
522 * Caller must have called @gether_setup(). Caller is also responsible
523 * for calling @gether_cleanup() before module unload.
525 int __init
eem_bind_config(struct usb_configuration
*c
)
530 /* maybe allocate device-global string IDs */
531 if (eem_string_defs
[0].id
== 0) {
533 /* control interface label */
534 status
= usb_string_id(c
->cdev
);
537 eem_string_defs
[0].id
= status
;
538 eem_intf
.iInterface
= status
;
541 /* allocate and initialize one new instance */
542 eem
= kzalloc(sizeof *eem
, GFP_KERNEL
);
546 eem
->port
.cdc_filter
= DEFAULT_FILTER
;
548 eem
->port
.func
.name
= "cdc_eem";
549 eem
->port
.func
.strings
= eem_strings
;
550 /* descriptors are per-instance copies */
551 eem
->port
.func
.bind
= eem_bind
;
552 eem
->port
.func
.unbind
= eem_unbind
;
553 eem
->port
.func
.set_alt
= eem_set_alt
;
554 eem
->port
.func
.setup
= eem_setup
;
555 eem
->port
.func
.disable
= eem_disable
;
556 eem
->port
.wrap
= eem_wrap
;
557 eem
->port
.unwrap
= eem_unwrap
;
558 eem
->port
.header_len
= EEM_HLEN
;
560 status
= usb_add_function(c
, &eem
->port
.func
);