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 unsigned 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,
55 const struct ktermios *old_termios);
56
57 /* Not that this lot means you can only have one per system */
58 static u8 ir_baud;
59 static u8 ir_xbof;
60 static u8 ir_add_bof;
61
62 static const struct usb_device_id ir_id_table[] = {
63 { USB_DEVICE(0x050f, 0x0180) }, /* KC Technology, KC-180 */
64 { USB_DEVICE(0x08e9, 0x0100) }, /* XTNDAccess */
65 { USB_DEVICE(0x09c4, 0x0011) }, /* ACTiSys ACT-IR2000U */
66 { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, USB_SUBCLASS_IRDA, 0) },
67 { } /* Terminating entry */
68 };
69
70 MODULE_DEVICE_TABLE(usb, ir_id_table);
71
72 static struct usb_serial_driver ir_device = {
73 .driver = {
74 .owner = THIS_MODULE,
75 .name = "ir-usb",
76 },
77 .description = "IR Dongle",
78 .id_table = ir_id_table,
79 .num_ports = 1,
80 .num_bulk_in = 1,
81 .num_bulk_out = 1,
82 .set_termios = ir_set_termios,
83 .attach = ir_startup,
84 .write = ir_write,
85 .write_room = ir_write_room,
86 .write_bulk_callback = ir_write_bulk_callback,
87 .process_read_urb = ir_process_read_urb,
88 };
89
90 static struct usb_serial_driver * const serial_drivers[] = {
91 &ir_device, NULL
92 };
93
irda_usb_dump_class_desc(struct usb_serial * serial,struct usb_irda_cs_descriptor * desc)94 static inline void irda_usb_dump_class_desc(struct usb_serial *serial,
95 struct usb_irda_cs_descriptor *desc)
96 {
97 struct device *dev = &serial->dev->dev;
98
99 dev_dbg(dev, "bLength=%x\n", desc->bLength);
100 dev_dbg(dev, "bDescriptorType=%x\n", desc->bDescriptorType);
101 dev_dbg(dev, "bcdSpecRevision=%x\n", __le16_to_cpu(desc->bcdSpecRevision));
102 dev_dbg(dev, "bmDataSize=%x\n", desc->bmDataSize);
103 dev_dbg(dev, "bmWindowSize=%x\n", desc->bmWindowSize);
104 dev_dbg(dev, "bmMinTurnaroundTime=%d\n", desc->bmMinTurnaroundTime);
105 dev_dbg(dev, "wBaudRate=%x\n", __le16_to_cpu(desc->wBaudRate));
106 dev_dbg(dev, "bmAdditionalBOFs=%x\n", desc->bmAdditionalBOFs);
107 dev_dbg(dev, "bIrdaRateSniff=%x\n", desc->bIrdaRateSniff);
108 dev_dbg(dev, "bMaxUnicastList=%x\n", desc->bMaxUnicastList);
109 }
110
111 /*------------------------------------------------------------------*/
112 /*
113 * Function irda_usb_find_class_desc(dev, ifnum)
114 *
115 * Returns instance of IrDA class descriptor, or NULL if not found
116 *
117 * The class descriptor is some extra info that IrDA USB devices will
118 * offer to us, describing their IrDA characteristics. We will use that in
119 * irda_usb_init_qos()
120 *
121 * Based on the same function in drivers/net/irda/irda-usb.c
122 */
123 static struct usb_irda_cs_descriptor *
irda_usb_find_class_desc(struct usb_serial * serial,unsigned int ifnum)124 irda_usb_find_class_desc(struct usb_serial *serial, unsigned int ifnum)
125 {
126 struct usb_device *dev = serial->dev;
127 struct usb_irda_cs_descriptor *desc;
128 int ret;
129
130 desc = kzalloc(sizeof(*desc), GFP_KERNEL);
131 if (!desc)
132 return NULL;
133
134 ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
135 USB_REQ_CS_IRDA_GET_CLASS_DESC,
136 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
137 0, ifnum, desc, sizeof(*desc), 1000);
138
139 dev_dbg(&serial->dev->dev, "%s - ret=%d\n", __func__, ret);
140 if (ret < (int)sizeof(*desc)) {
141 dev_dbg(&serial->dev->dev,
142 "%s - class descriptor read %s (%d)\n", __func__,
143 (ret < 0) ? "failed" : "too short", ret);
144 goto error;
145 }
146 if (desc->bDescriptorType != USB_DT_CS_IRDA) {
147 dev_dbg(&serial->dev->dev, "%s - bad class descriptor type\n",
148 __func__);
149 goto error;
150 }
151
152 irda_usb_dump_class_desc(serial, desc);
153 return desc;
154
155 error:
156 kfree(desc);
157 return NULL;
158 }
159
ir_xbof_change(u8 xbof)160 static u8 ir_xbof_change(u8 xbof)
161 {
162 u8 result;
163
164 /* reference irda-usb.c */
165 switch (xbof) {
166 case 48:
167 result = 0x10;
168 break;
169 case 28:
170 case 24:
171 result = 0x20;
172 break;
173 default:
174 case 12:
175 result = 0x30;
176 break;
177 case 5:
178 case 6:
179 result = 0x40;
180 break;
181 case 3:
182 result = 0x50;
183 break;
184 case 2:
185 result = 0x60;
186 break;
187 case 1:
188 result = 0x70;
189 break;
190 case 0:
191 result = 0x80;
192 break;
193 }
194
195 return(result);
196 }
197
ir_startup(struct usb_serial * serial)198 static int ir_startup(struct usb_serial *serial)
199 {
200 struct usb_irda_cs_descriptor *irda_desc;
201 int rates;
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 unsigned int ir_write_room(struct tty_struct *tty)
344 {
345 struct usb_serial_port *port = tty->driver_data;
346 unsigned 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(struct tty_struct * tty,struct usb_serial_port * port,const struct ktermios * old_termios)379 static void ir_set_termios(struct tty_struct *tty,
380 struct usb_serial_port *port,
381 const struct ktermios *old_termios)
382 {
383 struct usb_device *udev = port->serial->dev;
384 unsigned char *transfer_buffer;
385 int actual_length;
386 speed_t baud;
387 int ir_baud;
388 int ret;
389
390 baud = tty_get_baud_rate(tty);
391
392 /*
393 * FIXME, we should compare the baud request against the
394 * capability stated in the IR header that we got in the
395 * startup function.
396 */
397
398 switch (baud) {
399 case 2400:
400 ir_baud = USB_IRDA_LS_2400;
401 break;
402 case 9600:
403 ir_baud = USB_IRDA_LS_9600;
404 break;
405 case 19200:
406 ir_baud = USB_IRDA_LS_19200;
407 break;
408 case 38400:
409 ir_baud = USB_IRDA_LS_38400;
410 break;
411 case 57600:
412 ir_baud = USB_IRDA_LS_57600;
413 break;
414 case 115200:
415 ir_baud = USB_IRDA_LS_115200;
416 break;
417 case 576000:
418 ir_baud = USB_IRDA_LS_576000;
419 break;
420 case 1152000:
421 ir_baud = USB_IRDA_LS_1152000;
422 break;
423 case 4000000:
424 ir_baud = USB_IRDA_LS_4000000;
425 break;
426 default:
427 ir_baud = USB_IRDA_LS_9600;
428 baud = 9600;
429 }
430
431 if (xbof == -1)
432 ir_xbof = ir_xbof_change(ir_add_bof);
433 else
434 ir_xbof = ir_xbof_change(xbof) ;
435
436 /* Only speed changes are supported */
437 tty_termios_copy_hw(&tty->termios, old_termios);
438 tty_encode_baud_rate(tty, baud, baud);
439
440 /*
441 * send the baud change out on an "empty" data packet
442 */
443 transfer_buffer = kmalloc(1, GFP_KERNEL);
444 if (!transfer_buffer)
445 return;
446
447 *transfer_buffer = ir_xbof | ir_baud;
448
449 ret = usb_bulk_msg(udev,
450 usb_sndbulkpipe(udev, port->bulk_out_endpointAddress),
451 transfer_buffer, 1, &actual_length, 5000);
452 if (ret || actual_length != 1) {
453 if (!ret)
454 ret = -EIO;
455 dev_err(&port->dev, "failed to change line speed: %d\n", ret);
456 }
457
458 kfree(transfer_buffer);
459 }
460
ir_init(void)461 static int __init ir_init(void)
462 {
463 if (buffer_size) {
464 ir_device.bulk_in_size = buffer_size;
465 ir_device.bulk_out_size = buffer_size;
466 }
467
468 return usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME, ir_id_table);
469 }
470
ir_exit(void)471 static void __exit ir_exit(void)
472 {
473 usb_serial_deregister_drivers(serial_drivers);
474 }
475
476
477 module_init(ir_init);
478 module_exit(ir_exit);
479
480 MODULE_AUTHOR(DRIVER_AUTHOR);
481 MODULE_DESCRIPTION(DRIVER_DESC);
482 MODULE_LICENSE("GPL");
483
484 module_param(xbof, int, 0);
485 MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
486 module_param(buffer_size, int, 0);
487 MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
488
489