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64
65#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
66
67#include <linux/kernel.h>
68#include <linux/errno.h>
69#include <linux/gfp.h>
70#include <linux/init.h>
71#include <linux/tty.h>
72#include <linux/tty_driver.h>
73#include <linux/tty_flip.h>
74#include <linux/module.h>
75#include <linux/spinlock.h>
76#include <linux/uaccess.h>
77#include <linux/usb.h>
78#include <linux/usb/serial.h>
79
80
81#ifndef CONFIG_USB_SERIAL_SAFE_PADDED
82#define CONFIG_USB_SERIAL_SAFE_PADDED 0
83#endif
84
85static bool safe = 1;
86static bool padded = CONFIG_USB_SERIAL_SAFE_PADDED;
87
88#define DRIVER_AUTHOR "sl@lineo.com, tbr@lineo.com, Johan Hovold <jhovold@gmail.com>"
89#define DRIVER_DESC "USB Safe Encapsulated Serial"
90
91MODULE_AUTHOR(DRIVER_AUTHOR);
92MODULE_DESCRIPTION(DRIVER_DESC);
93MODULE_LICENSE("GPL");
94
95static __u16 vendor;
96static __u16 product;
97module_param(vendor, ushort, 0);
98MODULE_PARM_DESC(vendor, "User specified USB idVendor (required)");
99module_param(product, ushort, 0);
100MODULE_PARM_DESC(product, "User specified USB idProduct (required)");
101
102module_param(safe, bool, 0);
103MODULE_PARM_DESC(safe, "Turn Safe Encapsulation On/Off");
104
105module_param(padded, bool, 0);
106MODULE_PARM_DESC(padded, "Pad to full wMaxPacketSize On/Off");
107
108#define CDC_DEVICE_CLASS 0x02
109
110#define CDC_INTERFACE_CLASS 0x02
111#define CDC_INTERFACE_SUBCLASS 0x06
112
113#define LINEO_INTERFACE_CLASS 0xff
114
115#define LINEO_INTERFACE_SUBCLASS_SAFENET 0x01
116#define LINEO_SAFENET_CRC 0x01
117#define LINEO_SAFENET_CRC_PADDED 0x02
118
119#define LINEO_INTERFACE_SUBCLASS_SAFESERIAL 0x02
120#define LINEO_SAFESERIAL_CRC 0x01
121#define LINEO_SAFESERIAL_CRC_PADDED 0x02
122
123
124#define MY_USB_DEVICE(vend, prod, dc, ic, isc) \
125 .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
126 USB_DEVICE_ID_MATCH_DEV_CLASS | \
127 USB_DEVICE_ID_MATCH_INT_CLASS | \
128 USB_DEVICE_ID_MATCH_INT_SUBCLASS, \
129 .idVendor = (vend), \
130 .idProduct = (prod),\
131 .bDeviceClass = (dc),\
132 .bInterfaceClass = (ic), \
133 .bInterfaceSubClass = (isc),
134
135static struct usb_device_id id_table[] = {
136 {MY_USB_DEVICE(0x49f, 0xffff, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)},
137 {MY_USB_DEVICE(0x3f0, 0x2101, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)},
138 {MY_USB_DEVICE(0x4dd, 0x8001, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)},
139 {MY_USB_DEVICE(0x4dd, 0x8002, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)},
140 {MY_USB_DEVICE(0x4dd, 0x8003, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)},
141 {MY_USB_DEVICE(0x4dd, 0x8004, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)},
142 {MY_USB_DEVICE(0x5f9, 0xffff, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)},
143
144 {MY_USB_DEVICE(0, 0, CDC_DEVICE_CLASS, LINEO_INTERFACE_CLASS, LINEO_INTERFACE_SUBCLASS_SAFESERIAL)},
145 {}
146};
147
148MODULE_DEVICE_TABLE(usb, id_table);
149
150static const __u16 crc10_table[256] = {
151 0x000, 0x233, 0x255, 0x066, 0x299, 0x0aa, 0x0cc, 0x2ff,
152 0x301, 0x132, 0x154, 0x367, 0x198, 0x3ab, 0x3cd, 0x1fe,
153 0x031, 0x202, 0x264, 0x057, 0x2a8, 0x09b, 0x0fd, 0x2ce,
154 0x330, 0x103, 0x165, 0x356, 0x1a9, 0x39a, 0x3fc, 0x1cf,
155 0x062, 0x251, 0x237, 0x004, 0x2fb, 0x0c8, 0x0ae, 0x29d,
156 0x363, 0x150, 0x136, 0x305, 0x1fa, 0x3c9, 0x3af, 0x19c,
157 0x053, 0x260, 0x206, 0x035, 0x2ca, 0x0f9, 0x09f, 0x2ac,
158 0x352, 0x161, 0x107, 0x334, 0x1cb, 0x3f8, 0x39e, 0x1ad,
159 0x0c4, 0x2f7, 0x291, 0x0a2, 0x25d, 0x06e, 0x008, 0x23b,
160 0x3c5, 0x1f6, 0x190, 0x3a3, 0x15c, 0x36f, 0x309, 0x13a,
161 0x0f5, 0x2c6, 0x2a0, 0x093, 0x26c, 0x05f, 0x039, 0x20a,
162 0x3f4, 0x1c7, 0x1a1, 0x392, 0x16d, 0x35e, 0x338, 0x10b,
163 0x0a6, 0x295, 0x2f3, 0x0c0, 0x23f, 0x00c, 0x06a, 0x259,
164 0x3a7, 0x194, 0x1f2, 0x3c1, 0x13e, 0x30d, 0x36b, 0x158,
165 0x097, 0x2a4, 0x2c2, 0x0f1, 0x20e, 0x03d, 0x05b, 0x268,
166 0x396, 0x1a5, 0x1c3, 0x3f0, 0x10f, 0x33c, 0x35a, 0x169,
167 0x188, 0x3bb, 0x3dd, 0x1ee, 0x311, 0x122, 0x144, 0x377,
168 0x289, 0x0ba, 0x0dc, 0x2ef, 0x010, 0x223, 0x245, 0x076,
169 0x1b9, 0x38a, 0x3ec, 0x1df, 0x320, 0x113, 0x175, 0x346,
170 0x2b8, 0x08b, 0x0ed, 0x2de, 0x021, 0x212, 0x274, 0x047,
171 0x1ea, 0x3d9, 0x3bf, 0x18c, 0x373, 0x140, 0x126, 0x315,
172 0x2eb, 0x0d8, 0x0be, 0x28d, 0x072, 0x241, 0x227, 0x014,
173 0x1db, 0x3e8, 0x38e, 0x1bd, 0x342, 0x171, 0x117, 0x324,
174 0x2da, 0x0e9, 0x08f, 0x2bc, 0x043, 0x270, 0x216, 0x025,
175 0x14c, 0x37f, 0x319, 0x12a, 0x3d5, 0x1e6, 0x180, 0x3b3,
176 0x24d, 0x07e, 0x018, 0x22b, 0x0d4, 0x2e7, 0x281, 0x0b2,
177 0x17d, 0x34e, 0x328, 0x11b, 0x3e4, 0x1d7, 0x1b1, 0x382,
178 0x27c, 0x04f, 0x029, 0x21a, 0x0e5, 0x2d6, 0x2b0, 0x083,
179 0x12e, 0x31d, 0x37b, 0x148, 0x3b7, 0x184, 0x1e2, 0x3d1,
180 0x22f, 0x01c, 0x07a, 0x249, 0x0b6, 0x285, 0x2e3, 0x0d0,
181 0x11f, 0x32c, 0x34a, 0x179, 0x386, 0x1b5, 0x1d3, 0x3e0,
182 0x21e, 0x02d, 0x04b, 0x278, 0x087, 0x2b4, 0x2d2, 0x0e1,
183};
184
185#define CRC10_INITFCS 0x000
186#define CRC10_GOODFCS 0x000
187#define CRC10_FCS(fcs, c) ((((fcs) << 8) & 0x3ff) ^ crc10_table[((fcs) >> 2) & 0xff] ^ (c))
188
189
190
191
192
193
194
195
196
197
198static __u16 __inline__ fcs_compute10(unsigned char *sp, int len, __u16 fcs)
199{
200 for (; len-- > 0; fcs = CRC10_FCS(fcs, *sp++));
201 return fcs;
202}
203
204static void safe_process_read_urb(struct urb *urb)
205{
206 struct usb_serial_port *port = urb->context;
207 unsigned char *data = urb->transfer_buffer;
208 unsigned char length = urb->actual_length;
209 int actual_length;
210 __u16 fcs;
211
212 if (!length)
213 return;
214
215 if (!safe)
216 goto out;
217
218 fcs = fcs_compute10(data, length, CRC10_INITFCS);
219 if (fcs) {
220 dev_err(&port->dev, "%s - bad CRC %x\n", __func__, fcs);
221 return;
222 }
223
224 actual_length = data[length - 2] >> 2;
225 if (actual_length > (length - 2)) {
226 dev_err(&port->dev, "%s - inconsistent lengths %d:%d\n",
227 __func__, actual_length, length);
228 return;
229 }
230 dev_info(&urb->dev->dev, "%s - actual: %d\n", __func__, actual_length);
231 length = actual_length;
232out:
233 tty_insert_flip_string(&port->port, data, length);
234 tty_flip_buffer_push(&port->port);
235}
236
237static int safe_prepare_write_buffer(struct usb_serial_port *port,
238 void *dest, size_t size)
239{
240 unsigned char *buf = dest;
241 int count;
242 int trailer_len;
243 int pkt_len;
244 __u16 fcs;
245
246 trailer_len = safe ? 2 : 0;
247
248 count = kfifo_out_locked(&port->write_fifo, buf, size - trailer_len,
249 &port->lock);
250 if (!safe)
251 return count;
252
253
254 if (padded) {
255 pkt_len = size;
256 memset(buf + count, '0', pkt_len - count - trailer_len);
257 } else {
258 pkt_len = count + trailer_len;
259 }
260
261
262 buf[pkt_len - 2] = count << 2;
263 buf[pkt_len - 1] = 0;
264
265
266 fcs = fcs_compute10(buf, pkt_len, CRC10_INITFCS);
267 buf[pkt_len - 2] |= fcs >> 8;
268 buf[pkt_len - 1] |= fcs & 0xff;
269
270 return pkt_len;
271}
272
273static int safe_startup(struct usb_serial *serial)
274{
275 switch (serial->interface->cur_altsetting->desc.bInterfaceProtocol) {
276 case LINEO_SAFESERIAL_CRC:
277 break;
278 case LINEO_SAFESERIAL_CRC_PADDED:
279 padded = 1;
280 break;
281 default:
282 return -EINVAL;
283 }
284 return 0;
285}
286
287static struct usb_serial_driver safe_device = {
288 .driver = {
289 .owner = THIS_MODULE,
290 .name = "safe_serial",
291 },
292 .id_table = id_table,
293 .num_ports = 1,
294 .process_read_urb = safe_process_read_urb,
295 .prepare_write_buffer = safe_prepare_write_buffer,
296 .attach = safe_startup,
297};
298
299static struct usb_serial_driver * const serial_drivers[] = {
300 &safe_device, NULL
301};
302
303static int __init safe_init(void)
304{
305 int i;
306
307
308 if (vendor || product) {
309 pr_info("vendor: %x product: %x\n", vendor, product);
310
311 for (i = 0; i < ARRAY_SIZE(id_table); i++) {
312 if (!id_table[i].idVendor && !id_table[i].idProduct) {
313 id_table[i].idVendor = vendor;
314 id_table[i].idProduct = product;
315 break;
316 }
317 }
318 }
319
320 return usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME, id_table);
321}
322
323static void __exit safe_exit(void)
324{
325 usb_serial_deregister_drivers(serial_drivers);
326}
327
328module_init(safe_init);
329module_exit(safe_exit);
330