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d4026123 MK |
1 | /* |
2 | * USB network interface driver for Samsung Kalmia based LTE USB modem like the | |
3 | * Samsung GT-B3730 and GT-B3710. | |
4 | * | |
5 | * Copyright (C) 2011 Marius Bjoernstad Kotsbak <marius@kotsbak.com> | |
6 | * | |
7 | * Sponsored by Quicklink Video Distribution Services Ltd. | |
8 | * | |
9 | * Based on the cdc_eem module. | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License as published by | |
13 | * the Free Software Foundation; either version 2 of the License, or | |
14 | * (at your option) any later version. | |
15 | */ | |
16 | ||
17 | #include <linux/module.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/netdevice.h> | |
20 | #include <linux/etherdevice.h> | |
21 | #include <linux/ctype.h> | |
22 | #include <linux/ethtool.h> | |
23 | #include <linux/workqueue.h> | |
24 | #include <linux/mii.h> | |
25 | #include <linux/usb.h> | |
26 | #include <linux/crc32.h> | |
27 | #include <linux/usb/cdc.h> | |
28 | #include <linux/usb/usbnet.h> | |
29 | #include <linux/gfp.h> | |
30 | ||
31 | /* | |
32 | * The Samsung Kalmia based LTE USB modems have a CDC ACM port for modem control | |
33 | * handled by the "option" module and an ethernet data port handled by this | |
34 | * module. | |
35 | * | |
36 | * The stick must first be switched into modem mode by usb_modeswitch | |
37 | * or similar tool. Then the modem gets sent two initialization packets by | |
38 | * this module, which gives the MAC address of the device. User space can then | |
39 | * connect the modem using AT commands through the ACM port and then use | |
40 | * DHCP on the network interface exposed by this module. Network packets are | |
41 | * sent to and from the modem in a proprietary format discovered after watching | |
42 | * the behavior of the windows driver for the modem. | |
43 | * | |
44 | * More information about the use of the modem is available in usb_modeswitch | |
45 | * forum and the project page: | |
46 | * | |
47 | * http://www.draisberghof.de/usb_modeswitch/bb/viewtopic.php?t=465 | |
48 | * https://github.com/mkotsbak/Samsung-GT-B3730-linux-driver | |
49 | */ | |
50 | ||
51 | /* #define DEBUG */ | |
52 | /* #define VERBOSE */ | |
53 | ||
54 | #define KALMIA_HEADER_LENGTH 6 | |
55 | #define KALMIA_ALIGN_SIZE 4 | |
56 | #define KALMIA_USB_TIMEOUT 10000 | |
57 | ||
58 | /*-------------------------------------------------------------------------*/ | |
59 | ||
60 | static int | |
61 | kalmia_send_init_packet(struct usbnet *dev, u8 *init_msg, u8 init_msg_len, | |
62 | u8 *buffer, u8 expected_len) | |
63 | { | |
64 | int act_len; | |
65 | int status; | |
66 | ||
67 | netdev_dbg(dev->net, "Sending init packet"); | |
68 | ||
69 | status = usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 0x02), | |
70 | init_msg, init_msg_len, &act_len, KALMIA_USB_TIMEOUT); | |
71 | if (status != 0) { | |
72 | netdev_err(dev->net, | |
73 | "Error sending init packet. Status %i, length %i\n", | |
74 | status, act_len); | |
75 | return status; | |
76 | } | |
77 | else if (act_len != init_msg_len) { | |
78 | netdev_err(dev->net, | |
79 | "Did not send all of init packet. Bytes sent: %i", | |
80 | act_len); | |
81 | } | |
82 | else { | |
83 | netdev_dbg(dev->net, "Successfully sent init packet."); | |
84 | } | |
85 | ||
86 | status = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, 0x81), | |
87 | buffer, expected_len, &act_len, KALMIA_USB_TIMEOUT); | |
88 | ||
89 | if (status != 0) | |
90 | netdev_err(dev->net, | |
91 | "Error receiving init result. Status %i, length %i\n", | |
92 | status, act_len); | |
93 | else if (act_len != expected_len) | |
94 | netdev_err(dev->net, "Unexpected init result length: %i\n", | |
95 | act_len); | |
96 | ||
97 | return status; | |
98 | } | |
99 | ||
100 | static int | |
101 | kalmia_init_and_get_ethernet_addr(struct usbnet *dev, u8 *ethernet_addr) | |
102 | { | |
bd0d7aa6 | 103 | static const char init_msg_1[] = |
d4026123 MK |
104 | { 0x57, 0x50, 0x04, 0x00, 0x00, 0x00, 0x00, 0x20, 0x00, 0x00, |
105 | 0x00, 0x00 }; | |
bd0d7aa6 | 106 | static const char init_msg_2[] = |
d4026123 MK |
107 | { 0x57, 0x50, 0x04, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0xf4, |
108 | 0x00, 0x00 }; | |
bd0d7aa6 | 109 | static const int buflen = 28; |
7cdfa4a3 | 110 | char *usb_buf; |
d4026123 MK |
111 | int status; |
112 | ||
7cdfa4a3 MK |
113 | usb_buf = kmalloc(buflen, GFP_DMA | GFP_KERNEL); |
114 | if (!usb_buf) | |
115 | return -ENOMEM; | |
116 | ||
117 | memcpy(usb_buf, init_msg_1, 12); | |
118 | status = kalmia_send_init_packet(dev, usb_buf, sizeof(init_msg_1) | |
119 | / sizeof(init_msg_1[0]), usb_buf, 24); | |
d4026123 MK |
120 | if (status != 0) |
121 | return status; | |
122 | ||
7cdfa4a3 MK |
123 | memcpy(usb_buf, init_msg_2, 12); |
124 | status = kalmia_send_init_packet(dev, usb_buf, sizeof(init_msg_2) | |
125 | / sizeof(init_msg_2[0]), usb_buf, 28); | |
d4026123 MK |
126 | if (status != 0) |
127 | return status; | |
128 | ||
7cdfa4a3 | 129 | memcpy(ethernet_addr, usb_buf + 10, ETH_ALEN); |
d4026123 | 130 | |
7cdfa4a3 | 131 | kfree(usb_buf); |
d4026123 MK |
132 | return status; |
133 | } | |
134 | ||
135 | static int | |
136 | kalmia_bind(struct usbnet *dev, struct usb_interface *intf) | |
137 | { | |
5c18e80b | 138 | int status; |
d4026123 MK |
139 | u8 ethernet_addr[ETH_ALEN]; |
140 | ||
141 | /* Don't bind to AT command interface */ | |
142 | if (intf->cur_altsetting->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC) | |
143 | return -EINVAL; | |
144 | ||
145 | dev->in = usb_rcvbulkpipe(dev->udev, 0x81 & USB_ENDPOINT_NUMBER_MASK); | |
146 | dev->out = usb_sndbulkpipe(dev->udev, 0x02 & USB_ENDPOINT_NUMBER_MASK); | |
147 | dev->status = NULL; | |
148 | ||
149 | dev->net->hard_header_len += KALMIA_HEADER_LENGTH; | |
150 | dev->hard_mtu = 1400; | |
151 | dev->rx_urb_size = dev->hard_mtu * 10; // Found as optimal after testing | |
152 | ||
153 | status = kalmia_init_and_get_ethernet_addr(dev, ethernet_addr); | |
154 | ||
155 | if (status < 0) { | |
156 | usb_set_intfdata(intf, NULL); | |
157 | usb_driver_release_interface(driver_of(intf), intf); | |
158 | return status; | |
159 | } | |
160 | ||
161 | memcpy(dev->net->dev_addr, ethernet_addr, ETH_ALEN); | |
162 | memcpy(dev->net->perm_addr, ethernet_addr, ETH_ALEN); | |
163 | ||
164 | return status; | |
165 | } | |
166 | ||
167 | static struct sk_buff * | |
168 | kalmia_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags) | |
169 | { | |
170 | struct sk_buff *skb2 = NULL; | |
171 | u16 content_len; | |
172 | unsigned char *header_start; | |
173 | unsigned char ether_type_1, ether_type_2; | |
174 | u8 remainder, padlen = 0; | |
175 | ||
176 | if (!skb_cloned(skb)) { | |
177 | int headroom = skb_headroom(skb); | |
178 | int tailroom = skb_tailroom(skb); | |
179 | ||
180 | if ((tailroom >= KALMIA_ALIGN_SIZE) && (headroom | |
181 | >= KALMIA_HEADER_LENGTH)) | |
182 | goto done; | |
183 | ||
184 | if ((headroom + tailroom) > (KALMIA_HEADER_LENGTH | |
185 | + KALMIA_ALIGN_SIZE)) { | |
186 | skb->data = memmove(skb->head + KALMIA_HEADER_LENGTH, | |
187 | skb->data, skb->len); | |
188 | skb_set_tail_pointer(skb, skb->len); | |
189 | goto done; | |
190 | } | |
191 | } | |
192 | ||
193 | skb2 = skb_copy_expand(skb, KALMIA_HEADER_LENGTH, | |
194 | KALMIA_ALIGN_SIZE, flags); | |
195 | if (!skb2) | |
196 | return NULL; | |
197 | ||
198 | dev_kfree_skb_any(skb); | |
199 | skb = skb2; | |
200 | ||
7cdfa4a3 MK |
201 | done: |
202 | header_start = skb_push(skb, KALMIA_HEADER_LENGTH); | |
d4026123 MK |
203 | ether_type_1 = header_start[KALMIA_HEADER_LENGTH + 12]; |
204 | ether_type_2 = header_start[KALMIA_HEADER_LENGTH + 13]; | |
205 | ||
206 | netdev_dbg(dev->net, "Sending etherType: %02x%02x", ether_type_1, | |
207 | ether_type_2); | |
208 | ||
209 | /* According to empiric data for data packages */ | |
210 | header_start[0] = 0x57; | |
211 | header_start[1] = 0x44; | |
212 | content_len = skb->len - KALMIA_HEADER_LENGTH; | |
d4026123 | 213 | |
7cdfa4a3 | 214 | put_unaligned_le16(content_len, &header_start[2]); |
d4026123 MK |
215 | header_start[4] = ether_type_1; |
216 | header_start[5] = ether_type_2; | |
217 | ||
218 | /* Align to 4 bytes by padding with zeros */ | |
219 | remainder = skb->len % KALMIA_ALIGN_SIZE; | |
220 | if (remainder > 0) { | |
221 | padlen = KALMIA_ALIGN_SIZE - remainder; | |
222 | memset(skb_put(skb, padlen), 0, padlen); | |
223 | } | |
224 | ||
225 | netdev_dbg( | |
226 | dev->net, | |
227 | "Sending package with length %i and padding %i. Header: %02x:%02x:%02x:%02x:%02x:%02x.", | |
228 | content_len, padlen, header_start[0], header_start[1], | |
229 | header_start[2], header_start[3], header_start[4], | |
230 | header_start[5]); | |
231 | ||
232 | return skb; | |
233 | } | |
234 | ||
235 | static int | |
236 | kalmia_rx_fixup(struct usbnet *dev, struct sk_buff *skb) | |
237 | { | |
238 | /* | |
239 | * Our task here is to strip off framing, leaving skb with one | |
240 | * data frame for the usbnet framework code to process. | |
241 | */ | |
bd0d7aa6 | 242 | static const u8 HEADER_END_OF_USB_PACKET[] = |
d4026123 | 243 | { 0x57, 0x5a, 0x00, 0x00, 0x08, 0x00 }; |
bd0d7aa6 | 244 | static const u8 EXPECTED_UNKNOWN_HEADER_1[] = |
d4026123 | 245 | { 0x57, 0x43, 0x1e, 0x00, 0x15, 0x02 }; |
bd0d7aa6 | 246 | static const u8 EXPECTED_UNKNOWN_HEADER_2[] = |
d4026123 | 247 | { 0x57, 0x50, 0x0e, 0x00, 0x00, 0x00 }; |
7cdfa4a3 | 248 | int i = 0; |
d4026123 MK |
249 | |
250 | /* incomplete header? */ | |
251 | if (skb->len < KALMIA_HEADER_LENGTH) | |
252 | return 0; | |
253 | ||
254 | do { | |
255 | struct sk_buff *skb2 = NULL; | |
256 | u8 *header_start; | |
257 | u16 usb_packet_length, ether_packet_length; | |
258 | int is_last; | |
259 | ||
260 | header_start = skb->data; | |
261 | ||
262 | if (unlikely(header_start[0] != 0x57 || header_start[1] != 0x44)) { | |
263 | if (!memcmp(header_start, EXPECTED_UNKNOWN_HEADER_1, | |
264 | sizeof(EXPECTED_UNKNOWN_HEADER_1)) || !memcmp( | |
265 | header_start, EXPECTED_UNKNOWN_HEADER_2, | |
266 | sizeof(EXPECTED_UNKNOWN_HEADER_2))) { | |
267 | netdev_dbg( | |
268 | dev->net, | |
269 | "Received expected unknown frame header: %02x:%02x:%02x:%02x:%02x:%02x. Package length: %i\n", | |
270 | header_start[0], header_start[1], | |
271 | header_start[2], header_start[3], | |
272 | header_start[4], header_start[5], | |
273 | skb->len - KALMIA_HEADER_LENGTH); | |
274 | } | |
275 | else { | |
276 | netdev_err( | |
277 | dev->net, | |
278 | "Received unknown frame header: %02x:%02x:%02x:%02x:%02x:%02x. Package length: %i\n", | |
279 | header_start[0], header_start[1], | |
280 | header_start[2], header_start[3], | |
281 | header_start[4], header_start[5], | |
282 | skb->len - KALMIA_HEADER_LENGTH); | |
283 | return 0; | |
284 | } | |
285 | } | |
286 | else | |
287 | netdev_dbg( | |
288 | dev->net, | |
289 | "Received header: %02x:%02x:%02x:%02x:%02x:%02x. Package length: %i\n", | |
290 | header_start[0], header_start[1], header_start[2], | |
291 | header_start[3], header_start[4], header_start[5], | |
292 | skb->len - KALMIA_HEADER_LENGTH); | |
293 | ||
294 | /* subtract start header and end header */ | |
295 | usb_packet_length = skb->len - (2 * KALMIA_HEADER_LENGTH); | |
7cdfa4a3 | 296 | ether_packet_length = get_unaligned_le16(&header_start[2]); |
d4026123 MK |
297 | skb_pull(skb, KALMIA_HEADER_LENGTH); |
298 | ||
299 | /* Some small packets misses end marker */ | |
300 | if (usb_packet_length < ether_packet_length) { | |
301 | ether_packet_length = usb_packet_length | |
302 | + KALMIA_HEADER_LENGTH; | |
303 | is_last = true; | |
304 | } | |
305 | else { | |
306 | netdev_dbg(dev->net, "Correct package length #%i", i | |
307 | + 1); | |
308 | ||
309 | is_last = (memcmp(skb->data + ether_packet_length, | |
310 | HEADER_END_OF_USB_PACKET, | |
311 | sizeof(HEADER_END_OF_USB_PACKET)) == 0); | |
312 | if (!is_last) { | |
313 | header_start = skb->data + ether_packet_length; | |
314 | netdev_dbg( | |
315 | dev->net, | |
316 | "End header: %02x:%02x:%02x:%02x:%02x:%02x. Package length: %i\n", | |
317 | header_start[0], header_start[1], | |
318 | header_start[2], header_start[3], | |
319 | header_start[4], header_start[5], | |
320 | skb->len - KALMIA_HEADER_LENGTH); | |
321 | } | |
322 | } | |
323 | ||
324 | if (is_last) { | |
325 | skb2 = skb; | |
326 | } | |
327 | else { | |
328 | skb2 = skb_clone(skb, GFP_ATOMIC); | |
329 | if (unlikely(!skb2)) | |
330 | return 0; | |
331 | } | |
332 | ||
333 | skb_trim(skb2, ether_packet_length); | |
334 | ||
335 | if (is_last) { | |
336 | return 1; | |
337 | } | |
338 | else { | |
339 | usbnet_skb_return(dev, skb2); | |
340 | skb_pull(skb, ether_packet_length); | |
341 | } | |
342 | ||
343 | i++; | |
344 | } | |
345 | while (skb->len); | |
346 | ||
347 | return 1; | |
348 | } | |
349 | ||
350 | static const struct driver_info kalmia_info = { | |
351 | .description = "Samsung Kalmia LTE USB dongle", | |
352 | .flags = FLAG_WWAN, | |
353 | .bind = kalmia_bind, | |
354 | .rx_fixup = kalmia_rx_fixup, | |
355 | .tx_fixup = kalmia_tx_fixup | |
356 | }; | |
357 | ||
358 | /*-------------------------------------------------------------------------*/ | |
359 | ||
360 | static const struct usb_device_id products[] = { | |
361 | /* The unswitched USB ID, to get the module auto loaded: */ | |
362 | { USB_DEVICE(0x04e8, 0x689a) }, | |
363 | /* The stick swithed into modem (by e.g. usb_modeswitch): */ | |
364 | { USB_DEVICE(0x04e8, 0x6889), | |
365 | .driver_info = (unsigned long) &kalmia_info, }, | |
366 | { /* EMPTY == end of list */} }; | |
367 | MODULE_DEVICE_TABLE( usb, products); | |
368 | ||
369 | static struct usb_driver kalmia_driver = { | |
370 | .name = "kalmia", | |
371 | .id_table = products, | |
372 | .probe = usbnet_probe, | |
373 | .disconnect = usbnet_disconnect, | |
374 | .suspend = usbnet_suspend, | |
375 | .resume = usbnet_resume | |
376 | }; | |
377 | ||
378 | static int __init kalmia_init(void) | |
379 | { | |
380 | return usb_register(&kalmia_driver); | |
381 | } | |
382 | module_init( kalmia_init); | |
383 | ||
384 | static void __exit kalmia_exit(void) | |
385 | { | |
386 | usb_deregister(&kalmia_driver); | |
387 | } | |
388 | module_exit( kalmia_exit); | |
389 | ||
390 | MODULE_AUTHOR("Marius Bjoernstad Kotsbak <marius@kotsbak.com>"); | |
391 | MODULE_DESCRIPTION("Samsung Kalmia USB network driver"); | |
392 | MODULE_LICENSE("GPL"); |