1 /*
2  * USB IR Dongle driver
3  *
4  *	Copyright (C) 2001-2002	Greg Kroah-Hartman (greg@kroah.com)
5  *	Copyright (C) 2002	Gary Brubaker (xavyer@ix.netcom.com)
6  *	Copyright (C) 2010	Johan Hovold (jhovold@gmail.com)
7  *
8  *	This program is free software; you can redistribute it and/or modify
9  *	it under the terms of the GNU General Public License as published by
10  *	the Free Software Foundation; either version 2 of the License, or
11  *	(at your option) any later version.
12  *
13  * This driver allows a USB IrDA device to be used as a "dumb" serial device.
14  * This can be useful if you do not have access to a full IrDA stack on the
15  * other side of the connection.  If you do have an IrDA stack on both devices,
16  * please use the usb-irda driver, as it contains the proper error checking and
17  * other goodness of a full IrDA stack.
18  *
19  * Portions of this driver were taken from drivers/net/irda/irda-usb.c, which
20  * was written by Roman Weissgaerber <weissg@vienna.at>, Dag Brattli
21  * <dag@brattli.net>, and Jean Tourrilhes <jt@hpl.hp.com>
22  *
23  * See Documentation/usb/usb-serial.txt for more information on using this
24  * driver
25  *
26  * 2008_Jun_02  Felipe Balbi <me@felipebalbi.com>
27  *	Introduced common header to be used also in USB Gadget Framework.
28  *	Still needs some other style fixes.
29  *
30  * 2007_Jun_21  Alan Cox <alan@lxorguk.ukuu.org.uk>
31  *	Minimal cleanups for some of the driver problens and tty layer abuse.
32  *	Still needs fixing to allow multiple dongles.
33  *
34  * 2002_Mar_07	greg kh
35  *	moved some needed structures and #define values from the
36  *	net/irda/irda-usb.h file into our file, as we don't want to depend on
37  *	that codebase compiling correctly :)
38  *
39  * 2002_Jan_14  gb
40  *	Added module parameter to force specific number of XBOFs.
41  *	Added ir_xbof_change().
42  *	Reorganized read_bulk_callback error handling.
43  *	Switched from FILL_BULK_URB() to usb_fill_bulk_urb().
44  *
45  * 2001_Nov_08  greg kh
46  *	Changed the irda_usb_find_class_desc() function based on comments and
47  *	code from Martin Diehl.
48  *
49  * 2001_Nov_01	greg kh
50  *	Added support for more IrDA USB devices.
51  *	Added support for zero packet.  Added buffer override paramater, so
52  *	users can transfer larger packets at once if they wish.  Both patches
53  *	came from Dag Brattli <dag@obexcode.com>.
54  *
55  * 2001_Oct_07	greg kh
56  *	initial version released.
57  */
58 
59 #include <linux/kernel.h>
60 #include <linux/errno.h>
61 #include <linux/init.h>
62 #include <linux/slab.h>
63 #include <linux/tty.h>
64 #include <linux/tty_driver.h>
65 #include <linux/tty_flip.h>
66 #include <linux/module.h>
67 #include <linux/spinlock.h>
68 #include <linux/uaccess.h>
69 #include <linux/usb.h>
70 #include <linux/usb/serial.h>
71 #include <linux/usb/irda.h>
72 
73 /*
74  * Version Information
75  */
76 #define DRIVER_VERSION "v0.5"
77 #define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Johan Hovold <jhovold@gmail.com>"
78 #define DRIVER_DESC "USB IR Dongle driver"
79 
80 static int debug;
81 
82 /* if overridden by the user, then use their value for the size of the read and
83  * write urbs */
84 static int buffer_size;
85 
86 /* if overridden by the user, then use the specified number of XBOFs */
87 static int xbof = -1;
88 
89 static int  ir_startup (struct usb_serial *serial);
90 static int  ir_open(struct tty_struct *tty, struct usb_serial_port *port);
91 static int ir_prepare_write_buffer(struct usb_serial_port *port,
92 						void *dest, size_t size);
93 static void ir_process_read_urb(struct urb *urb);
94 static void ir_set_termios(struct tty_struct *tty,
95 		struct usb_serial_port *port, struct ktermios *old_termios);
96 
97 /* Not that this lot means you can only have one per system */
98 static u8 ir_baud;
99 static u8 ir_xbof;
100 static u8 ir_add_bof;
101 
102 static const struct usb_device_id ir_id_table[] = {
103 	{ USB_DEVICE(0x050f, 0x0180) },		/* KC Technology, KC-180 */
104 	{ USB_DEVICE(0x08e9, 0x0100) },		/* XTNDAccess */
105 	{ USB_DEVICE(0x09c4, 0x0011) },		/* ACTiSys ACT-IR2000U */
106 	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, USB_SUBCLASS_IRDA, 0) },
107 	{ }					/* Terminating entry */
108 };
109 
110 MODULE_DEVICE_TABLE(usb, ir_id_table);
111 
112 static struct usb_driver ir_driver = {
113 	.name		= "ir-usb",
114 	.probe		= usb_serial_probe,
115 	.disconnect	= usb_serial_disconnect,
116 	.id_table	= ir_id_table,
117 	.no_dynamic_id	= 1,
118 };
119 
120 static struct usb_serial_driver ir_device = {
121 	.driver	= {
122 		.owner	= THIS_MODULE,
123 		.name	= "ir-usb",
124 	},
125 	.description		= "IR Dongle",
126 	.usb_driver		= &ir_driver,
127 	.id_table		= ir_id_table,
128 	.num_ports		= 1,
129 	.set_termios		= ir_set_termios,
130 	.attach			= ir_startup,
131 	.open			= ir_open,
132 	.prepare_write_buffer	= ir_prepare_write_buffer,
133 	.process_read_urb	= ir_process_read_urb,
134 };
135 
irda_usb_dump_class_desc(struct usb_irda_cs_descriptor * desc)136 static inline void irda_usb_dump_class_desc(struct usb_irda_cs_descriptor *desc)
137 {
138 	dbg("bLength=%x", desc->bLength);
139 	dbg("bDescriptorType=%x", desc->bDescriptorType);
140 	dbg("bcdSpecRevision=%x", __le16_to_cpu(desc->bcdSpecRevision));
141 	dbg("bmDataSize=%x", desc->bmDataSize);
142 	dbg("bmWindowSize=%x", desc->bmWindowSize);
143 	dbg("bmMinTurnaroundTime=%d", desc->bmMinTurnaroundTime);
144 	dbg("wBaudRate=%x", __le16_to_cpu(desc->wBaudRate));
145 	dbg("bmAdditionalBOFs=%x", desc->bmAdditionalBOFs);
146 	dbg("bIrdaRateSniff=%x", desc->bIrdaRateSniff);
147 	dbg("bMaxUnicastList=%x", desc->bMaxUnicastList);
148 }
149 
150 /*------------------------------------------------------------------*/
151 /*
152  * Function irda_usb_find_class_desc(dev, ifnum)
153  *
154  *    Returns instance of IrDA class descriptor, or NULL if not found
155  *
156  * The class descriptor is some extra info that IrDA USB devices will
157  * offer to us, describing their IrDA characteristics. We will use that in
158  * irda_usb_init_qos()
159  *
160  * Based on the same function in drivers/net/irda/irda-usb.c
161  */
162 static struct usb_irda_cs_descriptor *
irda_usb_find_class_desc(struct usb_device * dev,unsigned int ifnum)163 irda_usb_find_class_desc(struct usb_device *dev, unsigned int ifnum)
164 {
165 	struct usb_irda_cs_descriptor *desc;
166 	int ret;
167 
168 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
169 	if (!desc)
170 		return NULL;
171 
172 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
173 			USB_REQ_CS_IRDA_GET_CLASS_DESC,
174 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
175 			0, ifnum, desc, sizeof(*desc), 1000);
176 
177 	dbg("%s -  ret=%d", __func__, ret);
178 	if (ret < sizeof(*desc)) {
179 		dbg("%s - class descriptor read %s (%d)",
180 				__func__,
181 				(ret < 0) ? "failed" : "too short",
182 				ret);
183 		goto error;
184 	}
185 	if (desc->bDescriptorType != USB_DT_CS_IRDA) {
186 		dbg("%s - bad class descriptor type", __func__);
187 		goto error;
188 	}
189 
190 	irda_usb_dump_class_desc(desc);
191 	return desc;
192 
193 error:
194 	kfree(desc);
195 	return NULL;
196 }
197 
ir_xbof_change(u8 xbof)198 static u8 ir_xbof_change(u8 xbof)
199 {
200 	u8 result;
201 
202 	/* reference irda-usb.c */
203 	switch (xbof) {
204 	case 48:
205 		result = 0x10;
206 		break;
207 	case 28:
208 	case 24:
209 		result = 0x20;
210 		break;
211 	default:
212 	case 12:
213 		result = 0x30;
214 		break;
215 	case  5:
216 	case  6:
217 		result = 0x40;
218 		break;
219 	case  3:
220 		result = 0x50;
221 		break;
222 	case  2:
223 		result = 0x60;
224 		break;
225 	case  1:
226 		result = 0x70;
227 		break;
228 	case  0:
229 		result = 0x80;
230 		break;
231 	}
232 
233 	return(result);
234 }
235 
ir_startup(struct usb_serial * serial)236 static int ir_startup(struct usb_serial *serial)
237 {
238 	struct usb_irda_cs_descriptor *irda_desc;
239 
240 	irda_desc = irda_usb_find_class_desc(serial->dev, 0);
241 	if (!irda_desc) {
242 		dev_err(&serial->dev->dev,
243 			"IRDA class descriptor not found, device not bound\n");
244 		return -ENODEV;
245 	}
246 
247 	dbg("%s - Baud rates supported:%s%s%s%s%s%s%s%s%s",
248 		__func__,
249 		(irda_desc->wBaudRate & USB_IRDA_BR_2400) ? " 2400" : "",
250 		(irda_desc->wBaudRate & USB_IRDA_BR_9600) ? " 9600" : "",
251 		(irda_desc->wBaudRate & USB_IRDA_BR_19200) ? " 19200" : "",
252 		(irda_desc->wBaudRate & USB_IRDA_BR_38400) ? " 38400" : "",
253 		(irda_desc->wBaudRate & USB_IRDA_BR_57600) ? " 57600" : "",
254 		(irda_desc->wBaudRate & USB_IRDA_BR_115200) ? " 115200" : "",
255 		(irda_desc->wBaudRate & USB_IRDA_BR_576000) ? " 576000" : "",
256 		(irda_desc->wBaudRate & USB_IRDA_BR_1152000) ? " 1152000" : "",
257 		(irda_desc->wBaudRate & USB_IRDA_BR_4000000) ? " 4000000" : "");
258 
259 	switch (irda_desc->bmAdditionalBOFs) {
260 	case USB_IRDA_AB_48:
261 		ir_add_bof = 48;
262 		break;
263 	case USB_IRDA_AB_24:
264 		ir_add_bof = 24;
265 		break;
266 	case USB_IRDA_AB_12:
267 		ir_add_bof = 12;
268 		break;
269 	case USB_IRDA_AB_6:
270 		ir_add_bof = 6;
271 		break;
272 	case USB_IRDA_AB_3:
273 		ir_add_bof = 3;
274 		break;
275 	case USB_IRDA_AB_2:
276 		ir_add_bof = 2;
277 		break;
278 	case USB_IRDA_AB_1:
279 		ir_add_bof = 1;
280 		break;
281 	case USB_IRDA_AB_0:
282 		ir_add_bof = 0;
283 		break;
284 	default:
285 		break;
286 	}
287 
288 	kfree(irda_desc);
289 
290 	return 0;
291 }
292 
ir_open(struct tty_struct * tty,struct usb_serial_port * port)293 static int ir_open(struct tty_struct *tty, struct usb_serial_port *port)
294 {
295 	int i;
296 
297 	dbg("%s - port %d", __func__, port->number);
298 
299 	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
300 		port->write_urbs[i]->transfer_flags = URB_ZERO_PACKET;
301 
302 	/* Start reading from the device */
303 	return usb_serial_generic_open(tty, port);
304 }
305 
ir_prepare_write_buffer(struct usb_serial_port * port,void * dest,size_t size)306 static int ir_prepare_write_buffer(struct usb_serial_port *port,
307 						void *dest, size_t size)
308 {
309 	unsigned char *buf = dest;
310 	int count;
311 
312 	/*
313 	 * The first byte of the packet we send to the device contains an
314 	 * inbound header which indicates an additional number of BOFs and
315 	 * a baud rate change.
316 	 *
317 	 * See section 5.4.2.2 of the USB IrDA spec.
318 	 */
319 	*buf = ir_xbof | ir_baud;
320 
321 	count = kfifo_out_locked(&port->write_fifo, buf + 1, size - 1,
322 								&port->lock);
323 	return count + 1;
324 }
325 
ir_process_read_urb(struct urb * urb)326 static void ir_process_read_urb(struct urb *urb)
327 {
328 	struct usb_serial_port *port = urb->context;
329 	unsigned char *data = urb->transfer_buffer;
330 	struct tty_struct *tty;
331 
332 	if (!urb->actual_length)
333 		return;
334 	/*
335 	 * The first byte of the packet we get from the device
336 	 * contains a busy indicator and baud rate change.
337 	 * See section 5.4.1.2 of the USB IrDA spec.
338 	 */
339 	if (*data & 0x0f)
340 		ir_baud = *data & 0x0f;
341 
342 	if (urb->actual_length == 1)
343 		return;
344 
345 	tty = tty_port_tty_get(&port->port);
346 	if (!tty)
347 		return;
348 	tty_insert_flip_string(tty, data + 1, urb->actual_length - 1);
349 	tty_flip_buffer_push(tty);
350 	tty_kref_put(tty);
351 }
352 
ir_set_termios_callback(struct urb * urb)353 static void ir_set_termios_callback(struct urb *urb)
354 {
355 	struct usb_serial_port *port = urb->context;
356 	int status = urb->status;
357 
358 	dbg("%s - port %d", __func__, port->number);
359 
360 	kfree(urb->transfer_buffer);
361 
362 	if (status)
363 		dbg("%s - non-zero urb status: %d", __func__, status);
364 }
365 
ir_set_termios(struct tty_struct * tty,struct usb_serial_port * port,struct ktermios * old_termios)366 static void ir_set_termios(struct tty_struct *tty,
367 		struct usb_serial_port *port, struct ktermios *old_termios)
368 {
369 	struct urb *urb;
370 	unsigned char *transfer_buffer;
371 	int result;
372 	speed_t baud;
373 	int ir_baud;
374 
375 	dbg("%s - port %d", __func__, port->number);
376 
377 	baud = tty_get_baud_rate(tty);
378 
379 	/*
380 	 * FIXME, we should compare the baud request against the
381 	 * capability stated in the IR header that we got in the
382 	 * startup function.
383 	 */
384 
385 	switch (baud) {
386 	case 2400:
387 		ir_baud = USB_IRDA_BR_2400;
388 		break;
389 	case 9600:
390 		ir_baud = USB_IRDA_BR_9600;
391 		break;
392 	case 19200:
393 		ir_baud = USB_IRDA_BR_19200;
394 		break;
395 	case 38400:
396 		ir_baud = USB_IRDA_BR_38400;
397 		break;
398 	case 57600:
399 		ir_baud = USB_IRDA_BR_57600;
400 		break;
401 	case 115200:
402 		ir_baud = USB_IRDA_BR_115200;
403 		break;
404 	case 576000:
405 		ir_baud = USB_IRDA_BR_576000;
406 		break;
407 	case 1152000:
408 		ir_baud = USB_IRDA_BR_1152000;
409 		break;
410 	case 4000000:
411 		ir_baud = USB_IRDA_BR_4000000;
412 		break;
413 	default:
414 		ir_baud = USB_IRDA_BR_9600;
415 		baud = 9600;
416 	}
417 
418 	if (xbof == -1)
419 		ir_xbof = ir_xbof_change(ir_add_bof);
420 	else
421 		ir_xbof = ir_xbof_change(xbof) ;
422 
423 	/* Only speed changes are supported */
424 	tty_termios_copy_hw(tty->termios, old_termios);
425 	tty_encode_baud_rate(tty, baud, baud);
426 
427 	/*
428 	 * send the baud change out on an "empty" data packet
429 	 */
430 	urb = usb_alloc_urb(0, GFP_KERNEL);
431 	if (!urb) {
432 		dev_err(&port->dev, "%s - no more urbs\n", __func__);
433 		return;
434 	}
435 	transfer_buffer = kmalloc(1, GFP_KERNEL);
436 	if (!transfer_buffer) {
437 		dev_err(&port->dev, "%s - out of memory\n", __func__);
438 		goto err_buf;
439 	}
440 
441 	*transfer_buffer = ir_xbof | ir_baud;
442 
443 	usb_fill_bulk_urb(
444 		urb,
445 		port->serial->dev,
446 		usb_sndbulkpipe(port->serial->dev,
447 			port->bulk_out_endpointAddress),
448 		transfer_buffer,
449 		1,
450 		ir_set_termios_callback,
451 		port);
452 
453 	urb->transfer_flags = URB_ZERO_PACKET;
454 
455 	result = usb_submit_urb(urb, GFP_KERNEL);
456 	if (result) {
457 		dev_err(&port->dev, "%s - failed to submit urb: %d\n",
458 							__func__, result);
459 		goto err_subm;
460 	}
461 
462 	usb_free_urb(urb);
463 
464 	return;
465 err_subm:
466 	kfree(transfer_buffer);
467 err_buf:
468 	usb_free_urb(urb);
469 }
470 
ir_init(void)471 static int __init ir_init(void)
472 {
473 	int retval;
474 
475 	if (buffer_size) {
476 		ir_device.bulk_in_size = buffer_size;
477 		ir_device.bulk_out_size = buffer_size;
478 	}
479 
480 	retval = usb_serial_register(&ir_device);
481 	if (retval)
482 		goto failed_usb_serial_register;
483 
484 	retval = usb_register(&ir_driver);
485 	if (retval)
486 		goto failed_usb_register;
487 
488 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
489 	       DRIVER_DESC "\n");
490 
491 	return 0;
492 
493 failed_usb_register:
494 	usb_serial_deregister(&ir_device);
495 
496 failed_usb_serial_register:
497 	return retval;
498 }
499 
ir_exit(void)500 static void __exit ir_exit(void)
501 {
502 	usb_deregister(&ir_driver);
503 	usb_serial_deregister(&ir_device);
504 }
505 
506 
507 module_init(ir_init);
508 module_exit(ir_exit);
509 
510 MODULE_AUTHOR(DRIVER_AUTHOR);
511 MODULE_DESCRIPTION(DRIVER_DESC);
512 MODULE_LICENSE("GPL");
513 
514 module_param(debug, bool, S_IRUGO | S_IWUSR);
515 MODULE_PARM_DESC(debug, "Debug enabled or not");
516 module_param(xbof, int, 0);
517 MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
518 module_param(buffer_size, int, 0);
519 MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
520 
521