arm: tegra: comms: Enable autopm for RAW-IP network driver.
[linux-2.6.git] / drivers / net / usb / kalmia.c
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 {
103         static const char init_msg_1[] =
104                 { 0x57, 0x50, 0x04, 0x00, 0x00, 0x00, 0x00, 0x20, 0x00, 0x00,
105                 0x00, 0x00 };
106         static const char init_msg_2[] =
107                 { 0x57, 0x50, 0x04, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0xf4,
108                 0x00, 0x00 };
109         static const int buflen = 28;
110         char *usb_buf;
111         int status;
112
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);
120         if (status != 0)
121                 return status;
122
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);
126         if (status != 0)
127                 return status;
128
129         memcpy(ethernet_addr, usb_buf + 10, ETH_ALEN);
130
131         kfree(usb_buf);
132         return status;
133 }
134
135 static int
136 kalmia_bind(struct usbnet *dev, struct usb_interface *intf)
137 {
138         int status;
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
201 done:
202         header_start = skb_push(skb, KALMIA_HEADER_LENGTH);
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;
213
214         put_unaligned_le16(content_len, &header_start[2]);
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          */
242         static const u8 HEADER_END_OF_USB_PACKET[] =
243                 { 0x57, 0x5a, 0x00, 0x00, 0x08, 0x00 };
244         static const u8 EXPECTED_UNKNOWN_HEADER_1[] =
245                 { 0x57, 0x43, 0x1e, 0x00, 0x15, 0x02 };
246         static const u8 EXPECTED_UNKNOWN_HEADER_2[] =
247                 { 0x57, 0x50, 0x0e, 0x00, 0x00, 0x00 };
248         int i = 0;
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);
296                 ether_packet_length = get_unaligned_le16(&header_start[2]);
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");