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 .name = "ir-usb",
75 },
76 .description = "IR Dongle",
77 .id_table = ir_id_table,
78 .num_ports = 1,
79 .num_bulk_in = 1,
80 .num_bulk_out = 1,
81 .set_termios = ir_set_termios,
82 .attach = ir_startup,
83 .write = ir_write,
84 .write_room = ir_write_room,
85 .write_bulk_callback = ir_write_bulk_callback,
86 .process_read_urb = ir_process_read_urb,
87 };
88
89 static struct usb_serial_driver * const serial_drivers[] = {
90 &ir_device, NULL
91 };
92
irda_usb_dump_class_desc(struct usb_serial * serial,struct usb_irda_cs_descriptor * desc)93 static inline void irda_usb_dump_class_desc(struct usb_serial *serial,
94 struct usb_irda_cs_descriptor *desc)
95 {
96 struct device *dev = &serial->dev->dev;
97
98 dev_dbg(dev, "bLength=%x\n", desc->bLength);
99 dev_dbg(dev, "bDescriptorType=%x\n", desc->bDescriptorType);
100 dev_dbg(dev, "bcdSpecRevision=%x\n", __le16_to_cpu(desc->bcdSpecRevision));
101 dev_dbg(dev, "bmDataSize=%x\n", desc->bmDataSize);
102 dev_dbg(dev, "bmWindowSize=%x\n", desc->bmWindowSize);
103 dev_dbg(dev, "bmMinTurnaroundTime=%d\n", desc->bmMinTurnaroundTime);
104 dev_dbg(dev, "wBaudRate=%x\n", __le16_to_cpu(desc->wBaudRate));
105 dev_dbg(dev, "bmAdditionalBOFs=%x\n", desc->bmAdditionalBOFs);
106 dev_dbg(dev, "bIrdaRateSniff=%x\n", desc->bIrdaRateSniff);
107 dev_dbg(dev, "bMaxUnicastList=%x\n", desc->bMaxUnicastList);
108 }
109
110 /*------------------------------------------------------------------*/
111 /*
112 * Function irda_usb_find_class_desc(dev, ifnum)
113 *
114 * Returns instance of IrDA class descriptor, or NULL if not found
115 *
116 * The class descriptor is some extra info that IrDA USB devices will
117 * offer to us, describing their IrDA characteristics. We will use that in
118 * irda_usb_init_qos()
119 *
120 * Based on the same function in drivers/net/irda/irda-usb.c
121 */
122 static struct usb_irda_cs_descriptor *
irda_usb_find_class_desc(struct usb_serial * serial,unsigned int ifnum)123 irda_usb_find_class_desc(struct usb_serial *serial, unsigned int ifnum)
124 {
125 struct usb_device *dev = serial->dev;
126 struct usb_irda_cs_descriptor *desc;
127 int ret;
128
129 desc = kzalloc(sizeof(*desc), GFP_KERNEL);
130 if (!desc)
131 return NULL;
132
133 ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
134 USB_REQ_CS_IRDA_GET_CLASS_DESC,
135 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
136 0, ifnum, desc, sizeof(*desc), 1000);
137
138 dev_dbg(&serial->dev->dev, "%s - ret=%d\n", __func__, ret);
139 if (ret < (int)sizeof(*desc)) {
140 dev_dbg(&serial->dev->dev,
141 "%s - class descriptor read %s (%d)\n", __func__,
142 (ret < 0) ? "failed" : "too short", ret);
143 goto error;
144 }
145 if (desc->bDescriptorType != USB_DT_CS_IRDA) {
146 dev_dbg(&serial->dev->dev, "%s - bad class descriptor type\n",
147 __func__);
148 goto error;
149 }
150
151 irda_usb_dump_class_desc(serial, desc);
152 return desc;
153
154 error:
155 kfree(desc);
156 return NULL;
157 }
158
ir_xbof_change(u8 xbof)159 static u8 ir_xbof_change(u8 xbof)
160 {
161 u8 result;
162
163 /* reference irda-usb.c */
164 switch (xbof) {
165 case 48:
166 result = 0x10;
167 break;
168 case 28:
169 case 24:
170 result = 0x20;
171 break;
172 default:
173 case 12:
174 result = 0x30;
175 break;
176 case 5:
177 case 6:
178 result = 0x40;
179 break;
180 case 3:
181 result = 0x50;
182 break;
183 case 2:
184 result = 0x60;
185 break;
186 case 1:
187 result = 0x70;
188 break;
189 case 0:
190 result = 0x80;
191 break;
192 }
193
194 return(result);
195 }
196
ir_startup(struct usb_serial * serial)197 static int ir_startup(struct usb_serial *serial)
198 {
199 struct usb_irda_cs_descriptor *irda_desc;
200 int rates;
201
202 irda_desc = irda_usb_find_class_desc(serial, 0);
203 if (!irda_desc) {
204 dev_err(&serial->dev->dev,
205 "IRDA class descriptor not found, device not bound\n");
206 return -ENODEV;
207 }
208
209 rates = le16_to_cpu(irda_desc->wBaudRate);
210
211 dev_dbg(&serial->dev->dev,
212 "%s - Baud rates supported:%s%s%s%s%s%s%s%s%s\n",
213 __func__,
214 (rates & USB_IRDA_BR_2400) ? " 2400" : "",
215 (rates & USB_IRDA_BR_9600) ? " 9600" : "",
216 (rates & USB_IRDA_BR_19200) ? " 19200" : "",
217 (rates & USB_IRDA_BR_38400) ? " 38400" : "",
218 (rates & USB_IRDA_BR_57600) ? " 57600" : "",
219 (rates & USB_IRDA_BR_115200) ? " 115200" : "",
220 (rates & USB_IRDA_BR_576000) ? " 576000" : "",
221 (rates & USB_IRDA_BR_1152000) ? " 1152000" : "",
222 (rates & USB_IRDA_BR_4000000) ? " 4000000" : "");
223
224 switch (irda_desc->bmAdditionalBOFs) {
225 case USB_IRDA_AB_48:
226 ir_add_bof = 48;
227 break;
228 case USB_IRDA_AB_24:
229 ir_add_bof = 24;
230 break;
231 case USB_IRDA_AB_12:
232 ir_add_bof = 12;
233 break;
234 case USB_IRDA_AB_6:
235 ir_add_bof = 6;
236 break;
237 case USB_IRDA_AB_3:
238 ir_add_bof = 3;
239 break;
240 case USB_IRDA_AB_2:
241 ir_add_bof = 2;
242 break;
243 case USB_IRDA_AB_1:
244 ir_add_bof = 1;
245 break;
246 case USB_IRDA_AB_0:
247 ir_add_bof = 0;
248 break;
249 default:
250 break;
251 }
252
253 kfree(irda_desc);
254
255 return 0;
256 }
257
ir_write(struct tty_struct * tty,struct usb_serial_port * port,const unsigned char * buf,int count)258 static int ir_write(struct tty_struct *tty, struct usb_serial_port *port,
259 const unsigned char *buf, int count)
260 {
261 struct urb *urb = NULL;
262 unsigned long flags;
263 int ret;
264
265 if (port->bulk_out_size == 0)
266 return -EINVAL;
267
268 if (count == 0)
269 return 0;
270
271 count = min(count, port->bulk_out_size - 1);
272
273 spin_lock_irqsave(&port->lock, flags);
274 if (__test_and_clear_bit(0, &port->write_urbs_free)) {
275 urb = port->write_urbs[0];
276 port->tx_bytes += count;
277 }
278 spin_unlock_irqrestore(&port->lock, flags);
279
280 if (!urb)
281 return 0;
282
283 /*
284 * The first byte of the packet we send to the device contains an
285 * outbound header which indicates an additional number of BOFs and
286 * a baud rate change.
287 *
288 * See section 5.4.2.2 of the USB IrDA spec.
289 */
290 *(u8 *)urb->transfer_buffer = ir_xbof | ir_baud;
291
292 memcpy(urb->transfer_buffer + 1, buf, count);
293
294 urb->transfer_buffer_length = count + 1;
295 urb->transfer_flags = URB_ZERO_PACKET;
296
297 ret = usb_submit_urb(urb, GFP_ATOMIC);
298 if (ret) {
299 dev_err(&port->dev, "failed to submit write urb: %d\n", ret);
300
301 spin_lock_irqsave(&port->lock, flags);
302 __set_bit(0, &port->write_urbs_free);
303 port->tx_bytes -= count;
304 spin_unlock_irqrestore(&port->lock, flags);
305
306 return ret;
307 }
308
309 return count;
310 }
311
ir_write_bulk_callback(struct urb * urb)312 static void ir_write_bulk_callback(struct urb *urb)
313 {
314 struct usb_serial_port *port = urb->context;
315 int status = urb->status;
316 unsigned long flags;
317
318 spin_lock_irqsave(&port->lock, flags);
319 __set_bit(0, &port->write_urbs_free);
320 port->tx_bytes -= urb->transfer_buffer_length - 1;
321 spin_unlock_irqrestore(&port->lock, flags);
322
323 switch (status) {
324 case 0:
325 break;
326 case -ENOENT:
327 case -ECONNRESET:
328 case -ESHUTDOWN:
329 dev_dbg(&port->dev, "write urb stopped: %d\n", status);
330 return;
331 case -EPIPE:
332 dev_err(&port->dev, "write urb stopped: %d\n", status);
333 return;
334 default:
335 dev_err(&port->dev, "nonzero write-urb status: %d\n", status);
336 break;
337 }
338
339 usb_serial_port_softint(port);
340 }
341
ir_write_room(struct tty_struct * tty)342 static unsigned int ir_write_room(struct tty_struct *tty)
343 {
344 struct usb_serial_port *port = tty->driver_data;
345 unsigned int count = 0;
346
347 if (port->bulk_out_size == 0)
348 return 0;
349
350 if (test_bit(0, &port->write_urbs_free))
351 count = port->bulk_out_size - 1;
352
353 return count;
354 }
355
ir_process_read_urb(struct urb * urb)356 static void ir_process_read_urb(struct urb *urb)
357 {
358 struct usb_serial_port *port = urb->context;
359 unsigned char *data = urb->transfer_buffer;
360
361 if (!urb->actual_length)
362 return;
363 /*
364 * The first byte of the packet we get from the device
365 * contains a busy indicator and baud rate change.
366 * See section 5.4.1.2 of the USB IrDA spec.
367 */
368 if (*data & 0x0f)
369 ir_baud = *data & 0x0f;
370
371 if (urb->actual_length == 1)
372 return;
373
374 tty_insert_flip_string(&port->port, data + 1, urb->actual_length - 1);
375 tty_flip_buffer_push(&port->port);
376 }
377
ir_set_termios(struct tty_struct * tty,struct usb_serial_port * port,const struct ktermios * old_termios)378 static void ir_set_termios(struct tty_struct *tty,
379 struct usb_serial_port *port,
380 const struct ktermios *old_termios)
381 {
382 struct usb_device *udev = port->serial->dev;
383 unsigned char *transfer_buffer;
384 int actual_length;
385 speed_t baud;
386 int ir_baud;
387 int ret;
388
389 baud = tty_get_baud_rate(tty);
390
391 /*
392 * FIXME, we should compare the baud request against the
393 * capability stated in the IR header that we got in the
394 * startup function.
395 */
396
397 switch (baud) {
398 case 2400:
399 ir_baud = USB_IRDA_LS_2400;
400 break;
401 case 9600:
402 ir_baud = USB_IRDA_LS_9600;
403 break;
404 case 19200:
405 ir_baud = USB_IRDA_LS_19200;
406 break;
407 case 38400:
408 ir_baud = USB_IRDA_LS_38400;
409 break;
410 case 57600:
411 ir_baud = USB_IRDA_LS_57600;
412 break;
413 case 115200:
414 ir_baud = USB_IRDA_LS_115200;
415 break;
416 case 576000:
417 ir_baud = USB_IRDA_LS_576000;
418 break;
419 case 1152000:
420 ir_baud = USB_IRDA_LS_1152000;
421 break;
422 case 4000000:
423 ir_baud = USB_IRDA_LS_4000000;
424 break;
425 default:
426 ir_baud = USB_IRDA_LS_9600;
427 baud = 9600;
428 }
429
430 if (xbof == -1)
431 ir_xbof = ir_xbof_change(ir_add_bof);
432 else
433 ir_xbof = ir_xbof_change(xbof) ;
434
435 /* Only speed changes are supported */
436 tty_termios_copy_hw(&tty->termios, old_termios);
437 tty_encode_baud_rate(tty, baud, baud);
438
439 /*
440 * send the baud change out on an "empty" data packet
441 */
442 transfer_buffer = kmalloc(1, GFP_KERNEL);
443 if (!transfer_buffer)
444 return;
445
446 *transfer_buffer = ir_xbof | ir_baud;
447
448 ret = usb_bulk_msg(udev,
449 usb_sndbulkpipe(udev, port->bulk_out_endpointAddress),
450 transfer_buffer, 1, &actual_length, 5000);
451 if (ret || actual_length != 1) {
452 if (!ret)
453 ret = -EIO;
454 dev_err(&port->dev, "failed to change line speed: %d\n", ret);
455 }
456
457 kfree(transfer_buffer);
458 }
459
ir_init(void)460 static int __init ir_init(void)
461 {
462 if (buffer_size) {
463 ir_device.bulk_in_size = buffer_size;
464 ir_device.bulk_out_size = buffer_size;
465 }
466
467 return usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME, ir_id_table);
468 }
469
ir_exit(void)470 static void __exit ir_exit(void)
471 {
472 usb_serial_deregister_drivers(serial_drivers);
473 }
474
475
476 module_init(ir_init);
477 module_exit(ir_exit);
478
479 MODULE_AUTHOR(DRIVER_AUTHOR);
480 MODULE_DESCRIPTION(DRIVER_DESC);
481 MODULE_LICENSE("GPL");
482
483 module_param(xbof, int, 0);
484 MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
485 module_param(buffer_size, int, 0);
486 MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
487
488