Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Safe Encapsulated USB Serial Driver | |
3 | * | |
4 | * Copyright (C) 2001 Lineo | |
5 | * Copyright (C) 2001 Hewlett-Packard | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * By: | |
13 | * Stuart Lynne <sl@lineo.com>, Tom Rushworth <tbr@lineo.com> | |
14 | */ | |
15 | ||
16 | /* | |
17 | * The encapsultaion is designed to overcome difficulties with some USB hardware. | |
18 | * | |
19 | * While the USB protocol has a CRC over the data while in transit, i.e. while | |
20 | * being carried over the bus, there is no end to end protection. If the hardware | |
21 | * has any problems getting the data into or out of the USB transmit and receive | |
22 | * FIFO's then data can be lost. | |
23 | * | |
24 | * This protocol adds a two byte trailer to each USB packet to specify the number | |
25 | * of bytes of valid data and a 10 bit CRC that will allow the receiver to verify | |
26 | * that the entire USB packet was received without error. | |
27 | * | |
28 | * Because in this case the sender and receiver are the class and function drivers | |
29 | * there is now end to end protection. | |
30 | * | |
31 | * There is an additional option that can be used to force all transmitted packets | |
32 | * to be padded to the maximum packet size. This provides a work around for some | |
33 | * devices which have problems with small USB packets. | |
34 | * | |
35 | * Assuming a packetsize of N: | |
36 | * | |
37 | * 0..N-2 data and optional padding | |
38 | * | |
39 | * N-2 bits 7-2 - number of bytes of valid data | |
40 | * bits 1-0 top two bits of 10 bit CRC | |
41 | * N-1 bottom 8 bits of 10 bit CRC | |
42 | * | |
43 | * | |
44 | * | Data Length | 10 bit CRC | | |
45 | * + 7 . 6 . 5 . 4 . 3 . 2 . 1 . 0 | 7 . 6 . 5 . 4 . 3 . 2 . 1 . 0 + | |
46 | * | |
47 | * The 10 bit CRC is computed across the sent data, followed by the trailer with | |
48 | * the length set and the CRC set to zero. The CRC is then OR'd into the trailer. | |
49 | * | |
50 | * When received a 10 bit CRC is computed over the entire frame including the trailer | |
51 | * and should be equal to zero. | |
52 | * | |
53 | * Two module parameters are used to control the encapsulation, if both are | |
54 | * turned of the module works as a simple serial device with NO | |
55 | * encapsulation. | |
56 | * | |
57 | * See linux/drivers/usbd/serial_fd for a device function driver | |
58 | * implementation of this. | |
59 | * | |
60 | */ | |
61 | ||
62 | ||
63 | #include <linux/config.h> | |
64 | #include <linux/kernel.h> | |
65 | #include <linux/errno.h> | |
66 | #include <linux/init.h> | |
67 | #include <linux/slab.h> | |
68 | #include <linux/tty.h> | |
69 | #include <linux/tty_driver.h> | |
70 | #include <linux/tty_flip.h> | |
71 | #include <linux/module.h> | |
72 | #include <linux/spinlock.h> | |
73 | #include <asm/uaccess.h> | |
74 | #include <linux/usb.h> | |
75 | #include "usb-serial.h" | |
76 | ||
77 | ||
78 | #ifndef CONFIG_USB_SAFE_PADDED | |
79 | #define CONFIG_USB_SAFE_PADDED 0 | |
80 | #endif | |
81 | ||
82 | static int debug; | |
83 | static int safe = 1; | |
84 | static int padded = CONFIG_USB_SAFE_PADDED; | |
85 | ||
86 | #define DRIVER_VERSION "v0.0b" | |
87 | #define DRIVER_AUTHOR "sl@lineo.com, tbr@lineo.com" | |
88 | #define DRIVER_DESC "USB Safe Encapsulated Serial" | |
89 | ||
90 | MODULE_AUTHOR (DRIVER_AUTHOR); | |
91 | MODULE_DESCRIPTION (DRIVER_DESC); | |
92 | MODULE_LICENSE("GPL"); | |
93 | ||
94 | #if defined(CONFIG_USBD_SAFE_SERIAL_VENDOR) && !defined(CONFIG_USBD_SAFE_SERIAL_PRODUCT) | |
521daed8 | 95 | #error "SAFE_SERIAL_VENDOR defined without SAFE_SERIAL_PRODUCT" |
1da177e4 LT |
96 | #endif |
97 | ||
98 | #if ! defined(CONFIG_USBD_SAFE_SERIAL_VENDOR) | |
99 | static __u16 vendor; // no default | |
100 | static __u16 product; // no default | |
101 | module_param(vendor, ushort, 0); | |
102 | MODULE_PARM_DESC(vendor, "User specified USB idVendor (required)"); | |
103 | module_param(product, ushort, 0); | |
104 | MODULE_PARM_DESC(product, "User specified USB idProduct (required)"); | |
105 | #endif | |
106 | ||
107 | module_param(debug, bool, S_IRUGO | S_IWUSR); | |
108 | MODULE_PARM_DESC(debug, "Debug enabled or not"); | |
109 | ||
110 | module_param(safe, bool, 0); | |
111 | MODULE_PARM_DESC(safe, "Turn Safe Encapsulation On/Off"); | |
112 | ||
113 | module_param(padded, bool, 0); | |
114 | MODULE_PARM_DESC(padded, "Pad to full wMaxPacketSize On/Off"); | |
115 | ||
116 | #define CDC_DEVICE_CLASS 0x02 | |
117 | ||
118 | #define CDC_INTERFACE_CLASS 0x02 | |
119 | #define CDC_INTERFACE_SUBCLASS 0x06 | |
120 | ||
121 | #define LINEO_INTERFACE_CLASS 0xff | |
122 | ||
123 | #define LINEO_INTERFACE_SUBCLASS_SAFENET 0x01 | |
124 | #define LINEO_SAFENET_CRC 0x01 | |
125 | #define LINEO_SAFENET_CRC_PADDED 0x02 | |
126 | ||
127 | #define LINEO_INTERFACE_SUBCLASS_SAFESERIAL 0x02 | |
128 | #define LINEO_SAFESERIAL_CRC 0x01 | |
129 | #define LINEO_SAFESERIAL_CRC_PADDED 0x02 | |
130 | ||
131 | ||
132 | #define MY_USB_DEVICE(vend,prod,dc,ic,isc) \ | |
133 | .match_flags = USB_DEVICE_ID_MATCH_DEVICE | USB_DEVICE_ID_MATCH_DEV_CLASS | \ | |
134 | USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS, \ | |
135 | .idVendor = (vend), \ | |
136 | .idProduct = (prod),\ | |
137 | .bDeviceClass = (dc),\ | |
138 | .bInterfaceClass = (ic), \ | |
139 | .bInterfaceSubClass = (isc), | |
140 | ||
141 | static struct usb_device_id id_table[] = { | |
142 | {MY_USB_DEVICE (0x49f, 0xffff, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, // Itsy | |
143 | {MY_USB_DEVICE (0x3f0, 0x2101, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, // Calypso | |
144 | {MY_USB_DEVICE (0x4dd, 0x8001, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, // Iris | |
145 | {MY_USB_DEVICE (0x4dd, 0x8002, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, // Collie | |
146 | {MY_USB_DEVICE (0x4dd, 0x8003, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, // Collie | |
147 | {MY_USB_DEVICE (0x4dd, 0x8004, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, // Collie | |
148 | {MY_USB_DEVICE (0x5f9, 0xffff, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, // Sharp tmp | |
149 | #if defined(CONFIG_USB_SAFE_SERIAL_VENDOR) | |
150 | {MY_USB_DEVICE | |
151 | (CONFIG_USB_SAFE_SERIAL_VENDOR, CONFIG_USB_SAFE_SERIAL_PRODUCT, CDC_DEVICE_CLASS, | |
152 | LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, | |
153 | #endif | |
154 | // extra null entry for module | |
155 | // vendor/produc parameters | |
156 | {MY_USB_DEVICE (0, 0, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)}, | |
157 | {} // terminating entry | |
158 | }; | |
159 | ||
160 | MODULE_DEVICE_TABLE (usb, id_table); | |
161 | ||
162 | static struct usb_driver safe_driver = { | |
163 | .owner = THIS_MODULE, | |
164 | .name = "safe_serial", | |
165 | .probe = usb_serial_probe, | |
166 | .disconnect = usb_serial_disconnect, | |
167 | .id_table = id_table, | |
168 | }; | |
169 | ||
170 | static __u16 crc10_table[256] = { | |
171 | 0x000, 0x233, 0x255, 0x066, 0x299, 0x0aa, 0x0cc, 0x2ff, 0x301, 0x132, 0x154, 0x367, 0x198, 0x3ab, 0x3cd, 0x1fe, | |
172 | 0x031, 0x202, 0x264, 0x057, 0x2a8, 0x09b, 0x0fd, 0x2ce, 0x330, 0x103, 0x165, 0x356, 0x1a9, 0x39a, 0x3fc, 0x1cf, | |
173 | 0x062, 0x251, 0x237, 0x004, 0x2fb, 0x0c8, 0x0ae, 0x29d, 0x363, 0x150, 0x136, 0x305, 0x1fa, 0x3c9, 0x3af, 0x19c, | |
174 | 0x053, 0x260, 0x206, 0x035, 0x2ca, 0x0f9, 0x09f, 0x2ac, 0x352, 0x161, 0x107, 0x334, 0x1cb, 0x3f8, 0x39e, 0x1ad, | |
175 | 0x0c4, 0x2f7, 0x291, 0x0a2, 0x25d, 0x06e, 0x008, 0x23b, 0x3c5, 0x1f6, 0x190, 0x3a3, 0x15c, 0x36f, 0x309, 0x13a, | |
176 | 0x0f5, 0x2c6, 0x2a0, 0x093, 0x26c, 0x05f, 0x039, 0x20a, 0x3f4, 0x1c7, 0x1a1, 0x392, 0x16d, 0x35e, 0x338, 0x10b, | |
177 | 0x0a6, 0x295, 0x2f3, 0x0c0, 0x23f, 0x00c, 0x06a, 0x259, 0x3a7, 0x194, 0x1f2, 0x3c1, 0x13e, 0x30d, 0x36b, 0x158, | |
178 | 0x097, 0x2a4, 0x2c2, 0x0f1, 0x20e, 0x03d, 0x05b, 0x268, 0x396, 0x1a5, 0x1c3, 0x3f0, 0x10f, 0x33c, 0x35a, 0x169, | |
179 | 0x188, 0x3bb, 0x3dd, 0x1ee, 0x311, 0x122, 0x144, 0x377, 0x289, 0x0ba, 0x0dc, 0x2ef, 0x010, 0x223, 0x245, 0x076, | |
180 | 0x1b9, 0x38a, 0x3ec, 0x1df, 0x320, 0x113, 0x175, 0x346, 0x2b8, 0x08b, 0x0ed, 0x2de, 0x021, 0x212, 0x274, 0x047, | |
181 | 0x1ea, 0x3d9, 0x3bf, 0x18c, 0x373, 0x140, 0x126, 0x315, 0x2eb, 0x0d8, 0x0be, 0x28d, 0x072, 0x241, 0x227, 0x014, | |
182 | 0x1db, 0x3e8, 0x38e, 0x1bd, 0x342, 0x171, 0x117, 0x324, 0x2da, 0x0e9, 0x08f, 0x2bc, 0x043, 0x270, 0x216, 0x025, | |
183 | 0x14c, 0x37f, 0x319, 0x12a, 0x3d5, 0x1e6, 0x180, 0x3b3, 0x24d, 0x07e, 0x018, 0x22b, 0x0d4, 0x2e7, 0x281, 0x0b2, | |
184 | 0x17d, 0x34e, 0x328, 0x11b, 0x3e4, 0x1d7, 0x1b1, 0x382, 0x27c, 0x04f, 0x029, 0x21a, 0x0e5, 0x2d6, 0x2b0, 0x083, | |
185 | 0x12e, 0x31d, 0x37b, 0x148, 0x3b7, 0x184, 0x1e2, 0x3d1, 0x22f, 0x01c, 0x07a, 0x249, 0x0b6, 0x285, 0x2e3, 0x0d0, | |
186 | 0x11f, 0x32c, 0x34a, 0x179, 0x386, 0x1b5, 0x1d3, 0x3e0, 0x21e, 0x02d, 0x04b, 0x278, 0x087, 0x2b4, 0x2d2, 0x0e1, | |
187 | }; | |
188 | ||
189 | #define CRC10_INITFCS 0x000 // Initial FCS value | |
190 | #define CRC10_GOODFCS 0x000 // Good final FCS value | |
191 | #define CRC10_FCS(fcs, c) ( (((fcs) << 8) & 0x3ff) ^ crc10_table[((fcs) >> 2) & 0xff] ^ (c)) | |
192 | ||
193 | /** | |
194 | * fcs_compute10 - memcpy and calculate 10 bit CRC across buffer | |
195 | * @sp: pointer to buffer | |
196 | * @len: number of bytes | |
197 | * @fcs: starting FCS | |
198 | * | |
199 | * Perform a memcpy and calculate fcs using ppp 10bit CRC algorithm. Return | |
200 | * new 10 bit FCS. | |
201 | */ | |
202 | static __u16 __inline__ fcs_compute10 (unsigned char *sp, int len, __u16 fcs) | |
203 | { | |
204 | for (; len-- > 0; fcs = CRC10_FCS (fcs, *sp++)); | |
205 | return fcs; | |
206 | } | |
207 | ||
208 | static void safe_read_bulk_callback (struct urb *urb, struct pt_regs *regs) | |
209 | { | |
210 | struct usb_serial_port *port = (struct usb_serial_port *) urb->context; | |
211 | unsigned char *data = urb->transfer_buffer; | |
212 | unsigned char length = urb->actual_length; | |
213 | int i; | |
214 | int result; | |
215 | ||
216 | dbg ("%s", __FUNCTION__); | |
217 | ||
218 | if (urb->status) { | |
219 | dbg ("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status); | |
220 | return; | |
221 | } | |
222 | ||
223 | dbg ("safe_read_bulk_callback length: %d", port->read_urb->actual_length); | |
224 | #ifdef ECHO_RCV | |
225 | { | |
226 | int i; | |
227 | unsigned char *cp = port->read_urb->transfer_buffer; | |
228 | for (i = 0; i < port->read_urb->actual_length; i++) { | |
229 | if ((i % 32) == 0) { | |
230 | printk ("\nru[%02x] ", i); | |
231 | } | |
232 | printk ("%02x ", *cp++); | |
233 | } | |
234 | printk ("\n"); | |
235 | } | |
236 | #endif | |
237 | if (safe) { | |
238 | __u16 fcs; | |
239 | if (!(fcs = fcs_compute10 (data, length, CRC10_INITFCS))) { | |
240 | ||
241 | int actual_length = data[length - 2] >> 2; | |
242 | ||
243 | if (actual_length <= (length - 2)) { | |
244 | ||
245 | info ("%s - actual: %d", __FUNCTION__, actual_length); | |
246 | ||
247 | for (i = 0; i < actual_length; i++) { | |
248 | tty_insert_flip_char (port->tty, data[i], 0); | |
249 | } | |
250 | tty_flip_buffer_push (port->tty); | |
251 | } else { | |
252 | err ("%s - inconsistent lengths %d:%d", __FUNCTION__, | |
253 | actual_length, length); | |
254 | } | |
255 | } else { | |
256 | err ("%s - bad CRC %x", __FUNCTION__, fcs); | |
257 | } | |
258 | } else { | |
259 | for (i = 0; i < length; i++) { | |
260 | tty_insert_flip_char (port->tty, data[i], 0); | |
261 | } | |
262 | tty_flip_buffer_push (port->tty); | |
263 | } | |
264 | ||
265 | /* Continue trying to always read */ | |
266 | usb_fill_bulk_urb (urb, port->serial->dev, | |
267 | usb_rcvbulkpipe (port->serial->dev, port->bulk_in_endpointAddress), | |
268 | urb->transfer_buffer, urb->transfer_buffer_length, | |
269 | safe_read_bulk_callback, port); | |
270 | ||
271 | if ((result = usb_submit_urb (urb, GFP_ATOMIC))) { | |
272 | err ("%s - failed resubmitting read urb, error %d", __FUNCTION__, result); | |
273 | } | |
274 | } | |
275 | ||
276 | static int safe_write (struct usb_serial_port *port, const unsigned char *buf, int count) | |
277 | { | |
278 | unsigned char *data; | |
279 | int result; | |
280 | int i; | |
281 | int packet_length; | |
282 | ||
283 | dbg ("safe_write port: %p %d urb: %p count: %d", port, port->number, port->write_urb, | |
284 | count); | |
285 | ||
286 | if (!port->write_urb) { | |
287 | dbg ("%s - write urb NULL", __FUNCTION__); | |
288 | return (0); | |
289 | } | |
290 | ||
291 | dbg ("safe_write write_urb: %d transfer_buffer_length", | |
292 | port->write_urb->transfer_buffer_length); | |
293 | ||
294 | if (!port->write_urb->transfer_buffer_length) { | |
295 | dbg ("%s - write urb transfer_buffer_length zero", __FUNCTION__); | |
296 | return (0); | |
297 | } | |
298 | if (count == 0) { | |
299 | dbg ("%s - write request of 0 bytes", __FUNCTION__); | |
300 | return (0); | |
301 | } | |
507ca9bc GKH |
302 | spin_lock(&port->lock); |
303 | if (port->write_urb_busy) { | |
304 | spin_unlock(&port->lock); | |
305 | dbg("%s - already writing", __FUNCTION__); | |
306 | return 0; | |
1da177e4 | 307 | } |
507ca9bc GKH |
308 | port->write_urb_busy = 1; |
309 | spin_unlock(&port->lock); | |
1da177e4 LT |
310 | |
311 | packet_length = port->bulk_out_size; // get max packetsize | |
312 | ||
313 | i = packet_length - (safe ? 2 : 0); // get bytes to send | |
314 | count = (count > i) ? i : count; | |
315 | ||
316 | ||
317 | // get the data into the transfer buffer | |
318 | data = port->write_urb->transfer_buffer; | |
319 | memset (data, '0', packet_length); | |
320 | ||
321 | memcpy (data, buf, count); | |
322 | ||
323 | if (safe) { | |
324 | __u16 fcs; | |
325 | ||
326 | // pad if necessary | |
327 | if (!padded) { | |
328 | packet_length = count + 2; | |
329 | } | |
330 | // set count | |
331 | data[packet_length - 2] = count << 2; | |
332 | data[packet_length - 1] = 0; | |
333 | ||
334 | // compute fcs and insert into trailer | |
335 | fcs = fcs_compute10 (data, packet_length, CRC10_INITFCS); | |
336 | data[packet_length - 2] |= fcs >> 8; | |
337 | data[packet_length - 1] |= fcs & 0xff; | |
338 | ||
339 | // set length to send | |
340 | port->write_urb->transfer_buffer_length = packet_length; | |
341 | } else { | |
342 | port->write_urb->transfer_buffer_length = count; | |
343 | } | |
344 | ||
345 | usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, port->write_urb->transfer_buffer); | |
346 | #ifdef ECHO_TX | |
347 | { | |
348 | int i; | |
349 | unsigned char *cp = port->write_urb->transfer_buffer; | |
350 | for (i = 0; i < port->write_urb->transfer_buffer_length; i++) { | |
351 | if ((i % 32) == 0) { | |
352 | printk ("\nsu[%02x] ", i); | |
353 | } | |
354 | printk ("%02x ", *cp++); | |
355 | } | |
356 | printk ("\n"); | |
357 | } | |
358 | #endif | |
359 | port->write_urb->dev = port->serial->dev; | |
360 | if ((result = usb_submit_urb (port->write_urb, GFP_KERNEL))) { | |
507ca9bc | 361 | port->write_urb_busy = 0; |
1da177e4 LT |
362 | err ("%s - failed submitting write urb, error %d", __FUNCTION__, result); |
363 | return 0; | |
364 | } | |
365 | dbg ("%s urb: %p submitted", __FUNCTION__, port->write_urb); | |
366 | ||
367 | return (count); | |
368 | } | |
369 | ||
370 | static int safe_write_room (struct usb_serial_port *port) | |
371 | { | |
372 | int room = 0; // Default: no room | |
373 | ||
374 | dbg ("%s", __FUNCTION__); | |
375 | ||
507ca9bc | 376 | if (port->write_urb_busy) |
1da177e4 LT |
377 | room = port->bulk_out_size - (safe ? 2 : 0); |
378 | ||
379 | if (room) { | |
380 | dbg ("safe_write_room returns %d", room); | |
381 | } | |
382 | ||
383 | return (room); | |
384 | } | |
385 | ||
386 | static int safe_startup (struct usb_serial *serial) | |
387 | { | |
388 | switch (serial->interface->cur_altsetting->desc.bInterfaceProtocol) { | |
389 | case LINEO_SAFESERIAL_CRC: | |
390 | break; | |
391 | case LINEO_SAFESERIAL_CRC_PADDED: | |
392 | padded = 1; | |
393 | break; | |
394 | default: | |
395 | return -EINVAL; | |
396 | } | |
397 | return 0; | |
398 | } | |
399 | ||
ea65370d | 400 | static struct usb_serial_driver safe_device = { |
1da177e4 LT |
401 | .owner = THIS_MODULE, |
402 | .name = "Safe", | |
403 | .id_table = id_table, | |
404 | .num_interrupt_in = NUM_DONT_CARE, | |
405 | .num_bulk_in = NUM_DONT_CARE, | |
406 | .num_bulk_out = NUM_DONT_CARE, | |
407 | .num_ports = 1, | |
408 | .write = safe_write, | |
409 | .write_room = safe_write_room, | |
410 | .read_bulk_callback = safe_read_bulk_callback, | |
411 | .attach = safe_startup, | |
412 | }; | |
413 | ||
414 | static int __init safe_init (void) | |
415 | { | |
416 | int i, retval; | |
417 | ||
418 | info (DRIVER_VERSION " " DRIVER_AUTHOR); | |
419 | info (DRIVER_DESC); | |
420 | info ("vendor: %x product: %x safe: %d padded: %d\n", vendor, product, safe, padded); | |
421 | ||
422 | // if we have vendor / product parameters patch them into id list | |
423 | if (vendor || product) { | |
424 | info ("vendor: %x product: %x\n", vendor, product); | |
425 | ||
426 | for (i = 0; i < (sizeof (id_table) / sizeof (struct usb_device_id)); i++) { | |
427 | if (!id_table[i].idVendor && !id_table[i].idProduct) { | |
428 | id_table[i].idVendor = vendor; | |
429 | id_table[i].idProduct = product; | |
430 | break; | |
431 | } | |
432 | } | |
433 | } | |
434 | ||
435 | retval = usb_serial_register(&safe_device); | |
436 | if (retval) | |
437 | goto failed_usb_serial_register; | |
438 | retval = usb_register(&safe_driver); | |
439 | if (retval) | |
440 | goto failed_usb_register; | |
441 | ||
442 | return 0; | |
443 | failed_usb_register: | |
444 | usb_serial_deregister(&safe_device); | |
445 | failed_usb_serial_register: | |
446 | return retval; | |
447 | } | |
448 | ||
449 | static void __exit safe_exit (void) | |
450 | { | |
451 | usb_deregister (&safe_driver); | |
452 | usb_serial_deregister (&safe_device); | |
453 | } | |
454 | ||
455 | module_init (safe_init); | |
456 | module_exit (safe_exit); |