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authorOmar Laazimani <omar.oberthur@gmail.com>2009-05-04 15:01:43 -0400
committerDavid S. Miller <davem@davemloft.net>2009-05-04 15:01:43 -0400
commit9f722c0978b04acba209f8ca1896ad05814bc3a3 (patch)
tree9c596d23beda50080a21a5ed90be3e9f4a6a5d1e /drivers/net/usb
parent0c266898b42fe4e4e2f9edfc9d3474c10f93aa6a (diff)
usbnet: CDC EEM support (v5)
This introduces a CDC Ethernet Emulation Model (EEM) host side driver to support USB EEM devices. EEM is different from the Ethernet Control Model (ECM) currently supported by the "CDC Ethernet" driver. One key difference is that it doesn't require of USB interface alternate settings to manage interface state; some maldesigned hardware can't handle that part of USB. It also avoids a separate USB interface for control and status updates. [ dbrownell@users.sourceforge.net: fix skb leaks, add rx packet checks, improve fault handling, EEM conformance updates, cleanup ] Signed-off-by: Omar Laazimani <omar.oberthur@gmail.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/usb')
-rw-r--r--drivers/net/usb/Kconfig14
-rw-r--r--drivers/net/usb/Makefile1
-rw-r--r--drivers/net/usb/cdc_eem.c381
3 files changed, 396 insertions, 0 deletions
diff --git a/drivers/net/usb/Kconfig b/drivers/net/usb/Kconfig
index 8ee21030e9ac..dfc6cf765fbd 100644
--- a/drivers/net/usb/Kconfig
+++ b/drivers/net/usb/Kconfig
@@ -180,6 +180,20 @@ config USB_NET_CDCETHER
180 IEEE 802 "local assignment" bit is set in the address, a "usbX" 180 IEEE 802 "local assignment" bit is set in the address, a "usbX"
181 name is used instead. 181 name is used instead.
182 182
183config USB_NET_CDC_EEM
184 tristate "CDC EEM support"
185 depends on USB_USBNET && EXPERIMENTAL
186 help
187 This option supports devices conforming to the Communication Device
188 Class (CDC) Ethernet Emulation Model, a specification that's easy to
189 implement in device firmware. The CDC EEM specifications are available
190 from <http://www.usb.org/>.
191
192 This driver creates an interface named "ethX", where X depends on
193 what other networking devices you have in use. However, if the
194 IEEE 802 "local assignment" bit is set in the address, a "usbX"
195 name is used instead.
196
183config USB_NET_DM9601 197config USB_NET_DM9601
184 tristate "Davicom DM9601 based USB 1.1 10/100 ethernet devices" 198 tristate "Davicom DM9601 based USB 1.1 10/100 ethernet devices"
185 depends on USB_USBNET 199 depends on USB_USBNET
diff --git a/drivers/net/usb/Makefile b/drivers/net/usb/Makefile
index 88a87eeb376a..c8aef62cf2b7 100644
--- a/drivers/net/usb/Makefile
+++ b/drivers/net/usb/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_USB_RTL8150) += rtl8150.o
9obj-$(CONFIG_USB_HSO) += hso.o 9obj-$(CONFIG_USB_HSO) += hso.o
10obj-$(CONFIG_USB_NET_AX8817X) += asix.o 10obj-$(CONFIG_USB_NET_AX8817X) += asix.o
11obj-$(CONFIG_USB_NET_CDCETHER) += cdc_ether.o 11obj-$(CONFIG_USB_NET_CDCETHER) += cdc_ether.o
12obj-$(CONFIG_USB_NET_CDC_EEM) += cdc_eem.o
12obj-$(CONFIG_USB_NET_DM9601) += dm9601.o 13obj-$(CONFIG_USB_NET_DM9601) += dm9601.o
13obj-$(CONFIG_USB_NET_SMSC95XX) += smsc95xx.o 14obj-$(CONFIG_USB_NET_SMSC95XX) += smsc95xx.o
14obj-$(CONFIG_USB_NET_GL620A) += gl620a.o 15obj-$(CONFIG_USB_NET_GL620A) += gl620a.o
diff --git a/drivers/net/usb/cdc_eem.c b/drivers/net/usb/cdc_eem.c
new file mode 100644
index 000000000000..80e01778dd3b
--- /dev/null
+++ b/drivers/net/usb/cdc_eem.c
@@ -0,0 +1,381 @@
1/*
2 * USB CDC EEM network interface driver
3 * Copyright (C) 2009 Oberthur Technologies
4 * by Omar Laazimani, Olivier Condemine
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21#include <linux/module.h>
22#include <linux/init.h>
23#include <linux/netdevice.h>
24#include <linux/etherdevice.h>
25#include <linux/ctype.h>
26#include <linux/ethtool.h>
27#include <linux/workqueue.h>
28#include <linux/mii.h>
29#include <linux/usb.h>
30#include <linux/crc32.h>
31#include <linux/usb/cdc.h>
32#include <linux/usb/usbnet.h>
33
34
35/*
36 * This driver is an implementation of the CDC "Ethernet Emulation
37 * Model" (EEM) specification, which encapsulates Ethernet frames
38 * for transport over USB using a simpler USB device model than the
39 * previous CDC "Ethernet Control Model" (ECM, or "CDC Ethernet").
40 *
41 * For details, see www.usb.org/developers/devclass_docs/CDC_EEM10.pdf
42 *
43 * This version has been tested with GIGAntIC WuaoW SIM Smart Card on 2.6.24,
44 * 2.6.27 and 2.6.30rc2 kernel.
45 * It has also been validated on Openmoko Om 2008.12 (based on 2.6.24 kernel).
46 * build on 23-April-2009
47 */
48
49#define EEM_HEAD 2 /* 2 byte header */
50
51/*-------------------------------------------------------------------------*/
52
53static void eem_linkcmd_complete(struct urb *urb)
54{
55 dev_kfree_skb(urb->context);
56 usb_free_urb(urb);
57}
58
59static void eem_linkcmd(struct usbnet *dev, struct sk_buff *skb)
60{
61 struct urb *urb;
62 int status;
63
64 urb = usb_alloc_urb(0, GFP_ATOMIC);
65 if (!urb)
66 goto fail;
67
68 usb_fill_bulk_urb(urb, dev->udev, dev->out,
69 skb->data, skb->len, eem_linkcmd_complete, skb);
70
71 status = usb_submit_urb(urb, GFP_ATOMIC);
72 if (status) {
73 usb_free_urb(urb);
74fail:
75 dev_kfree_skb(skb);
76 devwarn(dev, "link cmd failure\n");
77 return;
78 }
79}
80
81static int eem_bind(struct usbnet *dev, struct usb_interface *intf)
82{
83 int status = 0;
84
85 status = usbnet_get_endpoints(dev, intf);
86 if (status < 0) {
87 usb_set_intfdata(intf, NULL);
88 usb_driver_release_interface(driver_of(intf), intf);
89 return status;
90 }
91
92 /* no jumbogram (16K) support for now */
93
94 dev->net->hard_header_len += EEM_HEAD + ETH_FCS_LEN;
95
96 return 0;
97}
98
99/*
100 * EEM permits packing multiple Ethernet frames into USB transfers
101 * (a "bundle"), but for TX we don't try to do that.
102 */
103static struct sk_buff *eem_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
104 gfp_t flags)
105{
106 struct sk_buff *skb2 = NULL;
107 u16 len = skb->len;
108 u32 crc = 0;
109 int padlen = 0;
110
111 /* When ((len + EEM_HEAD + ETH_FCS_LEN) % dev->maxpacket) is
112 * zero, stick two bytes of zero length EEM packet on the end.
113 * Else the framework would add invalid single byte padding,
114 * since it can't know whether ZLPs will be handled right by
115 * all the relevant hardware and software.
116 */
117 if (!((len + EEM_HEAD + ETH_FCS_LEN) % dev->maxpacket))
118 padlen += 2;
119
120 if (!skb_cloned(skb)) {
121 int headroom = skb_headroom(skb);
122 int tailroom = skb_tailroom(skb);
123
124 if ((tailroom >= ETH_FCS_LEN + padlen)
125 && (headroom >= EEM_HEAD))
126 goto done;
127
128 if ((headroom + tailroom)
129 > (EEM_HEAD + ETH_FCS_LEN + padlen)) {
130 skb->data = memmove(skb->head +
131 EEM_HEAD,
132 skb->data,
133 skb->len);
134 skb_set_tail_pointer(skb, len);
135 goto done;
136 }
137 }
138
139 skb2 = skb_copy_expand(skb, EEM_HEAD, ETH_FCS_LEN + padlen, flags);
140 if (!skb2)
141 return NULL;
142
143 dev_kfree_skb_any(skb);
144 skb = skb2;
145
146done:
147 /* we don't use the "no Ethernet CRC" option */
148 crc = crc32_le(~0, skb->data, skb->len);
149 crc = ~crc;
150
151 put_unaligned_le32(crc, skb_put(skb, 4));
152
153 /* EEM packet header format:
154 * b0..13: length of ethernet frame
155 * b14: bmCRC (1 == valid Ethernet CRC)
156 * b15: bmType (0 == data)
157 */
158 len = skb->len;
159 put_unaligned_le16(BIT(14) | len, skb_push(skb, 2));
160
161 /* Bundle a zero length EEM packet if needed */
162 if (padlen)
163 put_unaligned_le16(0, skb_put(skb, 2));
164
165 return skb;
166}
167
168static int eem_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
169{
170 /*
171 * Our task here is to strip off framing, leaving skb with one
172 * data frame for the usbnet framework code to process. But we
173 * may have received multiple EEM payloads, or command payloads.
174 * So we must process _everything_ as if it's a header, except
175 * maybe the last data payload
176 *
177 * REVISIT the framework needs updating so that when we consume
178 * all payloads (the last or only message was a command, or a
179 * zero length EEM packet) that is not accounted as an rx_error.
180 */
181 do {
182 struct sk_buff *skb2 = NULL;
183 u16 header;
184 u16 len = 0;
185
186 /* incomplete EEM header? */
187 if (skb->len < EEM_HEAD)
188 return 0;
189
190 /*
191 * EEM packet header format:
192 * b0..14: EEM type dependant (Data or Command)
193 * b15: bmType
194 */
195 header = get_unaligned_le16(skb->data);
196 skb_pull(skb, EEM_HEAD);
197
198 /*
199 * The bmType bit helps to denote when EEM
200 * packet is data or command :
201 * bmType = 0 : EEM data payload
202 * bmType = 1 : EEM (link) command
203 */
204 if (header & BIT(15)) {
205 u16 bmEEMCmd;
206
207 /*
208 * EEM (link) command packet:
209 * b0..10: bmEEMCmdParam
210 * b11..13: bmEEMCmd
211 * b14: bmReserved (must be 0)
212 * b15: 1 (EEM command)
213 */
214 if (header & BIT(14)) {
215 devdbg(dev, "reserved command %04x\n", header);
216 continue;
217 }
218
219 bmEEMCmd = (header >> 11) & 0x7;
220 switch (bmEEMCmd) {
221
222 /* Responding to echo requests is mandatory. */
223 case 0: /* Echo command */
224 len = header & 0x7FF;
225
226 /* bogus command? */
227 if (skb->len < len)
228 return 0;
229
230 skb2 = skb_clone(skb, GFP_ATOMIC);
231 if (unlikely(!skb2))
232 goto next;
233 skb_trim(skb2, len);
234 put_unaligned_le16(BIT(15) | (1 << 11) | len,
235 skb_push(skb2, 2));
236 eem_linkcmd(dev, skb2);
237 break;
238
239 /*
240 * Host may choose to ignore hints.
241 * - suspend: peripheral ready to suspend
242 * - response: suggest N millisec polling
243 * - response complete: suggest N sec polling
244 */
245 case 2: /* Suspend hint */
246 case 3: /* Response hint */
247 case 4: /* Response complete hint */
248 continue;
249
250 /*
251 * Hosts should never receive host-to-peripheral
252 * or reserved command codes; or responses to an
253 * echo command we didn't send.
254 */
255 case 1: /* Echo response */
256 case 5: /* Tickle */
257 default: /* reserved */
258 devwarn(dev, "unexpected link command %d\n",
259 bmEEMCmd);
260 continue;
261 }
262
263 } else {
264 u32 crc, crc2;
265 int is_last;
266
267 /* zero length EEM packet? */
268 if (header == 0)
269 continue;
270
271 /*
272 * EEM data packet header :
273 * b0..13: length of ethernet frame
274 * b14: bmCRC
275 * b15: 0 (EEM data)
276 */
277 len = header & 0x3FFF;
278
279 /* bogus EEM payload? */
280 if (skb->len < len)
281 return 0;
282
283 /* bogus ethernet frame? */
284 if (len < (ETH_HLEN + ETH_FCS_LEN))
285 goto next;
286
287 /*
288 * Treat the last payload differently: framework
289 * code expects our "fixup" to have stripped off
290 * headers, so "skb" is a data packet (or error).
291 * Else if it's not the last payload, keep "skb"
292 * for further processing.
293 */
294 is_last = (len == skb->len);
295 if (is_last)
296 skb2 = skb;
297 else {
298 skb2 = skb_clone(skb, GFP_ATOMIC);
299 if (unlikely(!skb2))
300 return 0;
301 }
302
303 crc = get_unaligned_le32(skb2->data
304 + len - ETH_FCS_LEN);
305 skb_trim(skb2, len - ETH_FCS_LEN);
306
307 /*
308 * The bmCRC helps to denote when the CRC field in
309 * the Ethernet frame contains a calculated CRC:
310 * bmCRC = 1 : CRC is calculated
311 * bmCRC = 0 : CRC = 0xDEADBEEF
312 */
313 if (header & BIT(14))
314 crc2 = ~crc32_le(~0, skb2->data, len);
315 else
316 crc2 = 0xdeadbeef;
317
318 if (is_last)
319 return crc == crc2;
320
321 if (unlikely(crc != crc2)) {
322 dev->stats.rx_errors++;
323 dev_kfree_skb_any(skb2);
324 } else
325 usbnet_skb_return(dev, skb2);
326 }
327
328next:
329 skb_pull(skb, len);
330 } while (skb->len);
331
332 return 1;
333}
334
335static const struct driver_info eem_info = {
336 .description = "CDC EEM Device",
337 .flags = FLAG_ETHER,
338 .bind = eem_bind,
339 .rx_fixup = eem_rx_fixup,
340 .tx_fixup = eem_tx_fixup,
341};
342
343/*-------------------------------------------------------------------------*/
344
345static const struct usb_device_id products[] = {
346{
347 USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_EEM,
348 USB_CDC_PROTO_EEM),
349 .driver_info = (unsigned long) &eem_info,
350},
351{
352 /* EMPTY == end of list */
353},
354};
355MODULE_DEVICE_TABLE(usb, products);
356
357static struct usb_driver eem_driver = {
358 .name = "cdc_eem",
359 .id_table = products,
360 .probe = usbnet_probe,
361 .disconnect = usbnet_disconnect,
362 .suspend = usbnet_suspend,
363 .resume = usbnet_resume,
364};
365
366
367static int __init eem_init(void)
368{
369 return usb_register(&eem_driver);
370}
371module_init(eem_init);
372
373static void __exit eem_exit(void)
374{
375 usb_deregister(&eem_driver);
376}
377module_exit(eem_exit);
378
379MODULE_AUTHOR("Omar Laazimani <omar.oberthur@gmail.com>");
380MODULE_DESCRIPTION("USB CDC EEM");
381MODULE_LICENSE("GPL");