1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * USB IR Dongle driver
4 *
5 * Copyright (C) 2001-2002 Greg Kroah-Hartman (greg@kroah.com)
6 * Copyright (C) 2002 Gary Brubaker (xavyer@ix.netcom.com)
7 * Copyright (C) 2010 Johan Hovold (jhovold@gmail.com)
8 *
9 * This driver allows a USB IrDA device to be used as a "dumb" serial device.
10 * This can be useful if you do not have access to a full IrDA stack on the
11 * other side of the connection. If you do have an IrDA stack on both devices,
12 * please use the usb-irda driver, as it contains the proper error checking and
13 * other goodness of a full IrDA stack.
14 *
15 * Portions of this driver were taken from drivers/net/irda/irda-usb.c, which
16 * was written by Roman Weissgaerber <weissg@vienna.at>, Dag Brattli
17 * <dag@brattli.net>, and Jean Tourrilhes <jt@hpl.hp.com>
18 *
19 * See Documentation/usb/usb-serial.rst for more information on using this
20 * driver
21 */
22
23 #include <linux/kernel.h>
24 #include <linux/errno.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/tty.h>
28 #include <linux/tty_driver.h>
29 #include <linux/tty_flip.h>
30 #include <linux/module.h>
31 #include <linux/spinlock.h>
32 #include <linux/uaccess.h>
33 #include <linux/usb.h>
34 #include <linux/usb/serial.h>
35 #include <linux/usb/irda.h>
36
37 #define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Johan Hovold <jhovold@gmail.com>"
38 #define DRIVER_DESC "USB IR Dongle driver"
39
40 /* if overridden by the user, then use their value for the size of the read and
41 * write urbs */
42 static int buffer_size;
43
44 /* if overridden by the user, then use the specified number of XBOFs */
45 static int xbof = -1;
46
47 static int ir_startup (struct usb_serial *serial);
48 static int ir_write(struct tty_struct *tty, struct usb_serial_port *port,
49 const unsigned char *buf, int count);
50 static int ir_write_room(struct tty_struct *tty);
51 static void ir_write_bulk_callback(struct urb *urb);
52 static void ir_process_read_urb(struct urb *urb);
53 static void ir_set_termios(struct tty_struct *tty,
54 struct usb_serial_port *port, struct ktermios *old_termios);
55
56 /* Not that this lot means you can only have one per system */
57 static u8 ir_baud;
58 static u8 ir_xbof;
59 static u8 ir_add_bof;
60
61 static const struct usb_device_id ir_id_table[] = {
62 { USB_DEVICE(0x050f, 0x0180) }, /* KC Technology, KC-180 */
63 { USB_DEVICE(0x08e9, 0x0100) }, /* XTNDAccess */
64 { USB_DEVICE(0x09c4, 0x0011) }, /* ACTiSys ACT-IR2000U */
65 { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, USB_SUBCLASS_IRDA, 0) },
66 { } /* Terminating entry */
67 };
68
69 MODULE_DEVICE_TABLE(usb, ir_id_table);
70
71 static struct usb_serial_driver ir_device = {
72 .driver = {
73 .owner = THIS_MODULE,
74 .name = "ir-usb",
75 },
76 .description = "IR Dongle",
77 .id_table = ir_id_table,
78 .num_ports = 1,
79 .set_termios = ir_set_termios,
80 .attach = ir_startup,
81 .write = ir_write,
82 .write_room = ir_write_room,
83 .write_bulk_callback = ir_write_bulk_callback,
84 .process_read_urb = ir_process_read_urb,
85 };
86
87 static struct usb_serial_driver * const serial_drivers[] = {
88 &ir_device, NULL
89 };
90
irda_usb_dump_class_desc(struct usb_serial * serial,struct usb_irda_cs_descriptor * desc)91 static inline void irda_usb_dump_class_desc(struct usb_serial *serial,
92 struct usb_irda_cs_descriptor *desc)
93 {
94 struct device *dev = &serial->dev->dev;
95
96 dev_dbg(dev, "bLength=%x\n", desc->bLength);
97 dev_dbg(dev, "bDescriptorType=%x\n", desc->bDescriptorType);
98 dev_dbg(dev, "bcdSpecRevision=%x\n", __le16_to_cpu(desc->bcdSpecRevision));
99 dev_dbg(dev, "bmDataSize=%x\n", desc->bmDataSize);
100 dev_dbg(dev, "bmWindowSize=%x\n", desc->bmWindowSize);
101 dev_dbg(dev, "bmMinTurnaroundTime=%d\n", desc->bmMinTurnaroundTime);
102 dev_dbg(dev, "wBaudRate=%x\n", __le16_to_cpu(desc->wBaudRate));
103 dev_dbg(dev, "bmAdditionalBOFs=%x\n", desc->bmAdditionalBOFs);
104 dev_dbg(dev, "bIrdaRateSniff=%x\n", desc->bIrdaRateSniff);
105 dev_dbg(dev, "bMaxUnicastList=%x\n", desc->bMaxUnicastList);
106 }
107
108 /*------------------------------------------------------------------*/
109 /*
110 * Function irda_usb_find_class_desc(dev, ifnum)
111 *
112 * Returns instance of IrDA class descriptor, or NULL if not found
113 *
114 * The class descriptor is some extra info that IrDA USB devices will
115 * offer to us, describing their IrDA characteristics. We will use that in
116 * irda_usb_init_qos()
117 *
118 * Based on the same function in drivers/net/irda/irda-usb.c
119 */
120 static struct usb_irda_cs_descriptor *
irda_usb_find_class_desc(struct usb_serial * serial,unsigned int ifnum)121 irda_usb_find_class_desc(struct usb_serial *serial, unsigned int ifnum)
122 {
123 struct usb_device *dev = serial->dev;
124 struct usb_irda_cs_descriptor *desc;
125 int ret;
126
127 desc = kzalloc(sizeof(*desc), GFP_KERNEL);
128 if (!desc)
129 return NULL;
130
131 ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
132 USB_REQ_CS_IRDA_GET_CLASS_DESC,
133 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
134 0, ifnum, desc, sizeof(*desc), 1000);
135
136 dev_dbg(&serial->dev->dev, "%s - ret=%d\n", __func__, ret);
137 if (ret < (int)sizeof(*desc)) {
138 dev_dbg(&serial->dev->dev,
139 "%s - class descriptor read %s (%d)\n", __func__,
140 (ret < 0) ? "failed" : "too short", ret);
141 goto error;
142 }
143 if (desc->bDescriptorType != USB_DT_CS_IRDA) {
144 dev_dbg(&serial->dev->dev, "%s - bad class descriptor type\n",
145 __func__);
146 goto error;
147 }
148
149 irda_usb_dump_class_desc(serial, desc);
150 return desc;
151
152 error:
153 kfree(desc);
154 return NULL;
155 }
156
ir_xbof_change(u8 xbof)157 static u8 ir_xbof_change(u8 xbof)
158 {
159 u8 result;
160
161 /* reference irda-usb.c */
162 switch (xbof) {
163 case 48:
164 result = 0x10;
165 break;
166 case 28:
167 case 24:
168 result = 0x20;
169 break;
170 default:
171 case 12:
172 result = 0x30;
173 break;
174 case 5:
175 case 6:
176 result = 0x40;
177 break;
178 case 3:
179 result = 0x50;
180 break;
181 case 2:
182 result = 0x60;
183 break;
184 case 1:
185 result = 0x70;
186 break;
187 case 0:
188 result = 0x80;
189 break;
190 }
191
192 return(result);
193 }
194
ir_startup(struct usb_serial * serial)195 static int ir_startup(struct usb_serial *serial)
196 {
197 struct usb_irda_cs_descriptor *irda_desc;
198 int rates;
199
200 if (serial->num_bulk_in < 1 || serial->num_bulk_out < 1)
201 return -ENODEV;
202
203 irda_desc = irda_usb_find_class_desc(serial, 0);
204 if (!irda_desc) {
205 dev_err(&serial->dev->dev,
206 "IRDA class descriptor not found, device not bound\n");
207 return -ENODEV;
208 }
209
210 rates = le16_to_cpu(irda_desc->wBaudRate);
211
212 dev_dbg(&serial->dev->dev,
213 "%s - Baud rates supported:%s%s%s%s%s%s%s%s%s\n",
214 __func__,
215 (rates & USB_IRDA_BR_2400) ? " 2400" : "",
216 (rates & USB_IRDA_BR_9600) ? " 9600" : "",
217 (rates & USB_IRDA_BR_19200) ? " 19200" : "",
218 (rates & USB_IRDA_BR_38400) ? " 38400" : "",
219 (rates & USB_IRDA_BR_57600) ? " 57600" : "",
220 (rates & USB_IRDA_BR_115200) ? " 115200" : "",
221 (rates & USB_IRDA_BR_576000) ? " 576000" : "",
222 (rates & USB_IRDA_BR_1152000) ? " 1152000" : "",
223 (rates & USB_IRDA_BR_4000000) ? " 4000000" : "");
224
225 switch (irda_desc->bmAdditionalBOFs) {
226 case USB_IRDA_AB_48:
227 ir_add_bof = 48;
228 break;
229 case USB_IRDA_AB_24:
230 ir_add_bof = 24;
231 break;
232 case USB_IRDA_AB_12:
233 ir_add_bof = 12;
234 break;
235 case USB_IRDA_AB_6:
236 ir_add_bof = 6;
237 break;
238 case USB_IRDA_AB_3:
239 ir_add_bof = 3;
240 break;
241 case USB_IRDA_AB_2:
242 ir_add_bof = 2;
243 break;
244 case USB_IRDA_AB_1:
245 ir_add_bof = 1;
246 break;
247 case USB_IRDA_AB_0:
248 ir_add_bof = 0;
249 break;
250 default:
251 break;
252 }
253
254 kfree(irda_desc);
255
256 return 0;
257 }
258
ir_write(struct tty_struct * tty,struct usb_serial_port * port,const unsigned char * buf,int count)259 static int ir_write(struct tty_struct *tty, struct usb_serial_port *port,
260 const unsigned char *buf, int count)
261 {
262 struct urb *urb = NULL;
263 unsigned long flags;
264 int ret;
265
266 if (port->bulk_out_size == 0)
267 return -EINVAL;
268
269 if (count == 0)
270 return 0;
271
272 count = min(count, port->bulk_out_size - 1);
273
274 spin_lock_irqsave(&port->lock, flags);
275 if (__test_and_clear_bit(0, &port->write_urbs_free)) {
276 urb = port->write_urbs[0];
277 port->tx_bytes += count;
278 }
279 spin_unlock_irqrestore(&port->lock, flags);
280
281 if (!urb)
282 return 0;
283
284 /*
285 * The first byte of the packet we send to the device contains an
286 * outbound header which indicates an additional number of BOFs and
287 * a baud rate change.
288 *
289 * See section 5.4.2.2 of the USB IrDA spec.
290 */
291 *(u8 *)urb->transfer_buffer = ir_xbof | ir_baud;
292
293 memcpy(urb->transfer_buffer + 1, buf, count);
294
295 urb->transfer_buffer_length = count + 1;
296 urb->transfer_flags = URB_ZERO_PACKET;
297
298 ret = usb_submit_urb(urb, GFP_ATOMIC);
299 if (ret) {
300 dev_err(&port->dev, "failed to submit write urb: %d\n", ret);
301
302 spin_lock_irqsave(&port->lock, flags);
303 __set_bit(0, &port->write_urbs_free);
304 port->tx_bytes -= count;
305 spin_unlock_irqrestore(&port->lock, flags);
306
307 return ret;
308 }
309
310 return count;
311 }
312
ir_write_bulk_callback(struct urb * urb)313 static void ir_write_bulk_callback(struct urb *urb)
314 {
315 struct usb_serial_port *port = urb->context;
316 int status = urb->status;
317 unsigned long flags;
318
319 spin_lock_irqsave(&port->lock, flags);
320 __set_bit(0, &port->write_urbs_free);
321 port->tx_bytes -= urb->transfer_buffer_length - 1;
322 spin_unlock_irqrestore(&port->lock, flags);
323
324 switch (status) {
325 case 0:
326 break;
327 case -ENOENT:
328 case -ECONNRESET:
329 case -ESHUTDOWN:
330 dev_dbg(&port->dev, "write urb stopped: %d\n", status);
331 return;
332 case -EPIPE:
333 dev_err(&port->dev, "write urb stopped: %d\n", status);
334 return;
335 default:
336 dev_err(&port->dev, "nonzero write-urb status: %d\n", status);
337 break;
338 }
339
340 usb_serial_port_softint(port);
341 }
342
ir_write_room(struct tty_struct * tty)343 static int ir_write_room(struct tty_struct *tty)
344 {
345 struct usb_serial_port *port = tty->driver_data;
346 int count = 0;
347
348 if (port->bulk_out_size == 0)
349 return 0;
350
351 if (test_bit(0, &port->write_urbs_free))
352 count = port->bulk_out_size - 1;
353
354 return count;
355 }
356
ir_process_read_urb(struct urb * urb)357 static void ir_process_read_urb(struct urb *urb)
358 {
359 struct usb_serial_port *port = urb->context;
360 unsigned char *data = urb->transfer_buffer;
361
362 if (!urb->actual_length)
363 return;
364 /*
365 * The first byte of the packet we get from the device
366 * contains a busy indicator and baud rate change.
367 * See section 5.4.1.2 of the USB IrDA spec.
368 */
369 if (*data & 0x0f)
370 ir_baud = *data & 0x0f;
371
372 if (urb->actual_length == 1)
373 return;
374
375 tty_insert_flip_string(&port->port, data + 1, urb->actual_length - 1);
376 tty_flip_buffer_push(&port->port);
377 }
378
ir_set_termios_callback(struct urb * urb)379 static void ir_set_termios_callback(struct urb *urb)
380 {
381 kfree(urb->transfer_buffer);
382
383 if (urb->status)
384 dev_dbg(&urb->dev->dev, "%s - non-zero urb status: %d\n",
385 __func__, urb->status);
386 }
387
ir_set_termios(struct tty_struct * tty,struct usb_serial_port * port,struct ktermios * old_termios)388 static void ir_set_termios(struct tty_struct *tty,
389 struct usb_serial_port *port, struct ktermios *old_termios)
390 {
391 struct urb *urb;
392 unsigned char *transfer_buffer;
393 int result;
394 speed_t baud;
395 int ir_baud;
396
397 baud = tty_get_baud_rate(tty);
398
399 /*
400 * FIXME, we should compare the baud request against the
401 * capability stated in the IR header that we got in the
402 * startup function.
403 */
404
405 switch (baud) {
406 case 2400:
407 ir_baud = USB_IRDA_LS_2400;
408 break;
409 case 9600:
410 ir_baud = USB_IRDA_LS_9600;
411 break;
412 case 19200:
413 ir_baud = USB_IRDA_LS_19200;
414 break;
415 case 38400:
416 ir_baud = USB_IRDA_LS_38400;
417 break;
418 case 57600:
419 ir_baud = USB_IRDA_LS_57600;
420 break;
421 case 115200:
422 ir_baud = USB_IRDA_LS_115200;
423 break;
424 case 576000:
425 ir_baud = USB_IRDA_LS_576000;
426 break;
427 case 1152000:
428 ir_baud = USB_IRDA_LS_1152000;
429 break;
430 case 4000000:
431 ir_baud = USB_IRDA_LS_4000000;
432 break;
433 default:
434 ir_baud = USB_IRDA_LS_9600;
435 baud = 9600;
436 }
437
438 if (xbof == -1)
439 ir_xbof = ir_xbof_change(ir_add_bof);
440 else
441 ir_xbof = ir_xbof_change(xbof) ;
442
443 /* Only speed changes are supported */
444 tty_termios_copy_hw(&tty->termios, old_termios);
445 tty_encode_baud_rate(tty, baud, baud);
446
447 /*
448 * send the baud change out on an "empty" data packet
449 */
450 urb = usb_alloc_urb(0, GFP_KERNEL);
451 if (!urb)
452 return;
453
454 transfer_buffer = kmalloc(1, GFP_KERNEL);
455 if (!transfer_buffer)
456 goto err_buf;
457
458 *transfer_buffer = ir_xbof | ir_baud;
459
460 usb_fill_bulk_urb(
461 urb,
462 port->serial->dev,
463 usb_sndbulkpipe(port->serial->dev,
464 port->bulk_out_endpointAddress),
465 transfer_buffer,
466 1,
467 ir_set_termios_callback,
468 port);
469
470 urb->transfer_flags = URB_ZERO_PACKET;
471
472 result = usb_submit_urb(urb, GFP_KERNEL);
473 if (result) {
474 dev_err(&port->dev, "%s - failed to submit urb: %d\n",
475 __func__, result);
476 goto err_subm;
477 }
478
479 usb_free_urb(urb);
480
481 return;
482 err_subm:
483 kfree(transfer_buffer);
484 err_buf:
485 usb_free_urb(urb);
486 }
487
ir_init(void)488 static int __init ir_init(void)
489 {
490 if (buffer_size) {
491 ir_device.bulk_in_size = buffer_size;
492 ir_device.bulk_out_size = buffer_size;
493 }
494
495 return usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME, ir_id_table);
496 }
497
ir_exit(void)498 static void __exit ir_exit(void)
499 {
500 usb_serial_deregister_drivers(serial_drivers);
501 }
502
503
504 module_init(ir_init);
505 module_exit(ir_exit);
506
507 MODULE_AUTHOR(DRIVER_AUTHOR);
508 MODULE_DESCRIPTION(DRIVER_DESC);
509 MODULE_LICENSE("GPL");
510
511 module_param(xbof, int, 0);
512 MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
513 module_param(buffer_size, int, 0);
514 MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
515
516