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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 
27 #include <linux/kernel.h>
28 #include <linux/errno.h>
29 #include <linux/init.h>
30 #include <linux/slab.h>
31 #include <linux/tty.h>
32 #include <linux/tty_driver.h>
33 #include <linux/tty_flip.h>
34 #include <linux/module.h>
35 #include <linux/spinlock.h>
36 #include <linux/uaccess.h>
37 #include <linux/usb.h>
38 #include <linux/usb/serial.h>
39 #include <linux/usb/irda.h>
40 
41 #define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Johan Hovold <jhovold@gmail.com>"
42 #define DRIVER_DESC "USB IR Dongle driver"
43 
44 /* if overridden by the user, then use their value for the size of the read and
45  * write urbs */
46 static int buffer_size;
47 
48 /* if overridden by the user, then use the specified number of XBOFs */
49 static int xbof = -1;
50 
51 static int  ir_startup (struct usb_serial *serial);
52 static int ir_write(struct tty_struct *tty, struct usb_serial_port *port,
53 		const unsigned char *buf, int count);
54 static int ir_write_room(struct tty_struct *tty);
55 static void ir_write_bulk_callback(struct urb *urb);
56 static void ir_process_read_urb(struct urb *urb);
57 static void ir_set_termios(struct tty_struct *tty,
58 		struct usb_serial_port *port, struct ktermios *old_termios);
59 
60 /* Not that this lot means you can only have one per system */
61 static u8 ir_baud;
62 static u8 ir_xbof;
63 static u8 ir_add_bof;
64 
65 static const struct usb_device_id ir_id_table[] = {
66 	{ USB_DEVICE(0x050f, 0x0180) },		/* KC Technology, KC-180 */
67 	{ USB_DEVICE(0x08e9, 0x0100) },		/* XTNDAccess */
68 	{ USB_DEVICE(0x09c4, 0x0011) },		/* ACTiSys ACT-IR2000U */
69 	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, USB_SUBCLASS_IRDA, 0) },
70 	{ }					/* Terminating entry */
71 };
72 
73 MODULE_DEVICE_TABLE(usb, ir_id_table);
74 
75 static struct usb_serial_driver ir_device = {
76 	.driver	= {
77 		.owner	= THIS_MODULE,
78 		.name	= "ir-usb",
79 	},
80 	.description		= "IR Dongle",
81 	.id_table		= ir_id_table,
82 	.num_ports		= 1,
83 	.set_termios		= ir_set_termios,
84 	.attach			= ir_startup,
85 	.write			= ir_write,
86 	.write_room		= ir_write_room,
87 	.write_bulk_callback	= ir_write_bulk_callback,
88 	.process_read_urb	= ir_process_read_urb,
89 };
90 
91 static struct usb_serial_driver * const serial_drivers[] = {
92 	&ir_device, NULL
93 };
94 
irda_usb_dump_class_desc(struct usb_serial * serial,struct usb_irda_cs_descriptor * desc)95 static inline void irda_usb_dump_class_desc(struct usb_serial *serial,
96 					    struct usb_irda_cs_descriptor *desc)
97 {
98 	struct device *dev = &serial->dev->dev;
99 
100 	dev_dbg(dev, "bLength=%x\n", desc->bLength);
101 	dev_dbg(dev, "bDescriptorType=%x\n", desc->bDescriptorType);
102 	dev_dbg(dev, "bcdSpecRevision=%x\n", __le16_to_cpu(desc->bcdSpecRevision));
103 	dev_dbg(dev, "bmDataSize=%x\n", desc->bmDataSize);
104 	dev_dbg(dev, "bmWindowSize=%x\n", desc->bmWindowSize);
105 	dev_dbg(dev, "bmMinTurnaroundTime=%d\n", desc->bmMinTurnaroundTime);
106 	dev_dbg(dev, "wBaudRate=%x\n", __le16_to_cpu(desc->wBaudRate));
107 	dev_dbg(dev, "bmAdditionalBOFs=%x\n", desc->bmAdditionalBOFs);
108 	dev_dbg(dev, "bIrdaRateSniff=%x\n", desc->bIrdaRateSniff);
109 	dev_dbg(dev, "bMaxUnicastList=%x\n", desc->bMaxUnicastList);
110 }
111 
112 /*------------------------------------------------------------------*/
113 /*
114  * Function irda_usb_find_class_desc(dev, ifnum)
115  *
116  *    Returns instance of IrDA class descriptor, or NULL if not found
117  *
118  * The class descriptor is some extra info that IrDA USB devices will
119  * offer to us, describing their IrDA characteristics. We will use that in
120  * irda_usb_init_qos()
121  *
122  * Based on the same function in drivers/net/irda/irda-usb.c
123  */
124 static struct usb_irda_cs_descriptor *
irda_usb_find_class_desc(struct usb_serial * serial,unsigned int ifnum)125 irda_usb_find_class_desc(struct usb_serial *serial, unsigned int ifnum)
126 {
127 	struct usb_device *dev = serial->dev;
128 	struct usb_irda_cs_descriptor *desc;
129 	int ret;
130 
131 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
132 	if (!desc)
133 		return NULL;
134 
135 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
136 			USB_REQ_CS_IRDA_GET_CLASS_DESC,
137 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
138 			0, ifnum, desc, sizeof(*desc), 1000);
139 
140 	dev_dbg(&serial->dev->dev, "%s -  ret=%d\n", __func__, ret);
141 	if (ret < sizeof(*desc)) {
142 		dev_dbg(&serial->dev->dev,
143 			"%s - class descriptor read %s (%d)\n", __func__,
144 			(ret < 0) ? "failed" : "too short", ret);
145 		goto error;
146 	}
147 	if (desc->bDescriptorType != USB_DT_CS_IRDA) {
148 		dev_dbg(&serial->dev->dev, "%s - bad class descriptor type\n",
149 			__func__);
150 		goto error;
151 	}
152 
153 	irda_usb_dump_class_desc(serial, desc);
154 	return desc;
155 
156 error:
157 	kfree(desc);
158 	return NULL;
159 }
160 
ir_xbof_change(u8 xbof)161 static u8 ir_xbof_change(u8 xbof)
162 {
163 	u8 result;
164 
165 	/* reference irda-usb.c */
166 	switch (xbof) {
167 	case 48:
168 		result = 0x10;
169 		break;
170 	case 28:
171 	case 24:
172 		result = 0x20;
173 		break;
174 	default:
175 	case 12:
176 		result = 0x30;
177 		break;
178 	case  5:
179 	case  6:
180 		result = 0x40;
181 		break;
182 	case  3:
183 		result = 0x50;
184 		break;
185 	case  2:
186 		result = 0x60;
187 		break;
188 	case  1:
189 		result = 0x70;
190 		break;
191 	case  0:
192 		result = 0x80;
193 		break;
194 	}
195 
196 	return(result);
197 }
198 
ir_startup(struct usb_serial * serial)199 static int ir_startup(struct usb_serial *serial)
200 {
201 	struct usb_irda_cs_descriptor *irda_desc;
202 
203 	if (serial->num_bulk_in < 1 || serial->num_bulk_out < 1)
204 		return -ENODEV;
205 
206 	irda_desc = irda_usb_find_class_desc(serial, 0);
207 	if (!irda_desc) {
208 		dev_err(&serial->dev->dev,
209 			"IRDA class descriptor not found, device not bound\n");
210 		return -ENODEV;
211 	}
212 
213 	dev_dbg(&serial->dev->dev,
214 		"%s - Baud rates supported:%s%s%s%s%s%s%s%s%s\n",
215 		__func__,
216 		(irda_desc->wBaudRate & USB_IRDA_BR_2400) ? " 2400" : "",
217 		(irda_desc->wBaudRate & USB_IRDA_BR_9600) ? " 9600" : "",
218 		(irda_desc->wBaudRate & USB_IRDA_BR_19200) ? " 19200" : "",
219 		(irda_desc->wBaudRate & USB_IRDA_BR_38400) ? " 38400" : "",
220 		(irda_desc->wBaudRate & USB_IRDA_BR_57600) ? " 57600" : "",
221 		(irda_desc->wBaudRate & USB_IRDA_BR_115200) ? " 115200" : "",
222 		(irda_desc->wBaudRate & USB_IRDA_BR_576000) ? " 576000" : "",
223 		(irda_desc->wBaudRate & USB_IRDA_BR_1152000) ? " 1152000" : "",
224 		(irda_desc->wBaudRate & USB_IRDA_BR_4000000) ? " 4000000" : "");
225 
226 	switch (irda_desc->bmAdditionalBOFs) {
227 	case USB_IRDA_AB_48:
228 		ir_add_bof = 48;
229 		break;
230 	case USB_IRDA_AB_24:
231 		ir_add_bof = 24;
232 		break;
233 	case USB_IRDA_AB_12:
234 		ir_add_bof = 12;
235 		break;
236 	case USB_IRDA_AB_6:
237 		ir_add_bof = 6;
238 		break;
239 	case USB_IRDA_AB_3:
240 		ir_add_bof = 3;
241 		break;
242 	case USB_IRDA_AB_2:
243 		ir_add_bof = 2;
244 		break;
245 	case USB_IRDA_AB_1:
246 		ir_add_bof = 1;
247 		break;
248 	case USB_IRDA_AB_0:
249 		ir_add_bof = 0;
250 		break;
251 	default:
252 		break;
253 	}
254 
255 	kfree(irda_desc);
256 
257 	return 0;
258 }
259 
ir_write(struct tty_struct * tty,struct usb_serial_port * port,const unsigned char * buf,int count)260 static int ir_write(struct tty_struct *tty, struct usb_serial_port *port,
261 		const unsigned char *buf, int count)
262 {
263 	struct urb *urb = NULL;
264 	unsigned long flags;
265 	int ret;
266 
267 	if (port->bulk_out_size == 0)
268 		return -EINVAL;
269 
270 	if (count == 0)
271 		return 0;
272 
273 	count = min(count, port->bulk_out_size - 1);
274 
275 	spin_lock_irqsave(&port->lock, flags);
276 	if (__test_and_clear_bit(0, &port->write_urbs_free)) {
277 		urb = port->write_urbs[0];
278 		port->tx_bytes += count;
279 	}
280 	spin_unlock_irqrestore(&port->lock, flags);
281 
282 	if (!urb)
283 		return 0;
284 
285 	/*
286 	 * The first byte of the packet we send to the device contains an
287 	 * outbound header which indicates an additional number of BOFs and
288 	 * a baud rate change.
289 	 *
290 	 * See section 5.4.2.2 of the USB IrDA spec.
291 	 */
292 	*(u8 *)urb->transfer_buffer = ir_xbof | ir_baud;
293 
294 	memcpy(urb->transfer_buffer + 1, buf, count);
295 
296 	urb->transfer_buffer_length = count + 1;
297 	urb->transfer_flags = URB_ZERO_PACKET;
298 
299 	ret = usb_submit_urb(urb, GFP_ATOMIC);
300 	if (ret) {
301 		dev_err(&port->dev, "failed to submit write urb: %d\n", ret);
302 
303 		spin_lock_irqsave(&port->lock, flags);
304 		__set_bit(0, &port->write_urbs_free);
305 		port->tx_bytes -= count;
306 		spin_unlock_irqrestore(&port->lock, flags);
307 
308 		return ret;
309 	}
310 
311 	return count;
312 }
313 
ir_write_bulk_callback(struct urb * urb)314 static void ir_write_bulk_callback(struct urb *urb)
315 {
316 	struct usb_serial_port *port = urb->context;
317 	int status = urb->status;
318 	unsigned long flags;
319 
320 	spin_lock_irqsave(&port->lock, flags);
321 	__set_bit(0, &port->write_urbs_free);
322 	port->tx_bytes -= urb->transfer_buffer_length - 1;
323 	spin_unlock_irqrestore(&port->lock, flags);
324 
325 	switch (status) {
326 	case 0:
327 		break;
328 	case -ENOENT:
329 	case -ECONNRESET:
330 	case -ESHUTDOWN:
331 		dev_dbg(&port->dev, "write urb stopped: %d\n", status);
332 		return;
333 	case -EPIPE:
334 		dev_err(&port->dev, "write urb stopped: %d\n", status);
335 		return;
336 	default:
337 		dev_err(&port->dev, "nonzero write-urb status: %d\n", status);
338 		break;
339 	}
340 
341 	usb_serial_port_softint(port);
342 }
343 
ir_write_room(struct tty_struct * tty)344 static int ir_write_room(struct tty_struct *tty)
345 {
346 	struct usb_serial_port *port = tty->driver_data;
347 	int count = 0;
348 
349 	if (port->bulk_out_size == 0)
350 		return 0;
351 
352 	if (test_bit(0, &port->write_urbs_free))
353 		count = port->bulk_out_size - 1;
354 
355 	return count;
356 }
357 
ir_process_read_urb(struct urb * urb)358 static void ir_process_read_urb(struct urb *urb)
359 {
360 	struct usb_serial_port *port = urb->context;
361 	unsigned char *data = urb->transfer_buffer;
362 
363 	if (!urb->actual_length)
364 		return;
365 	/*
366 	 * The first byte of the packet we get from the device
367 	 * contains a busy indicator and baud rate change.
368 	 * See section 5.4.1.2 of the USB IrDA spec.
369 	 */
370 	if (*data & 0x0f)
371 		ir_baud = *data & 0x0f;
372 
373 	if (urb->actual_length == 1)
374 		return;
375 
376 	tty_insert_flip_string(&port->port, data + 1, urb->actual_length - 1);
377 	tty_flip_buffer_push(&port->port);
378 }
379 
ir_set_termios_callback(struct urb * urb)380 static void ir_set_termios_callback(struct urb *urb)
381 {
382 	kfree(urb->transfer_buffer);
383 
384 	if (urb->status)
385 		dev_dbg(&urb->dev->dev, "%s - non-zero urb status: %d\n",
386 			__func__, urb->status);
387 }
388 
ir_set_termios(struct tty_struct * tty,struct usb_serial_port * port,struct ktermios * old_termios)389 static void ir_set_termios(struct tty_struct *tty,
390 		struct usb_serial_port *port, struct ktermios *old_termios)
391 {
392 	struct urb *urb;
393 	unsigned char *transfer_buffer;
394 	int result;
395 	speed_t baud;
396 	int ir_baud;
397 
398 	baud = tty_get_baud_rate(tty);
399 
400 	/*
401 	 * FIXME, we should compare the baud request against the
402 	 * capability stated in the IR header that we got in the
403 	 * startup function.
404 	 */
405 
406 	switch (baud) {
407 	case 2400:
408 		ir_baud = USB_IRDA_LS_2400;
409 		break;
410 	case 9600:
411 		ir_baud = USB_IRDA_LS_9600;
412 		break;
413 	case 19200:
414 		ir_baud = USB_IRDA_LS_19200;
415 		break;
416 	case 38400:
417 		ir_baud = USB_IRDA_LS_38400;
418 		break;
419 	case 57600:
420 		ir_baud = USB_IRDA_LS_57600;
421 		break;
422 	case 115200:
423 		ir_baud = USB_IRDA_LS_115200;
424 		break;
425 	case 576000:
426 		ir_baud = USB_IRDA_LS_576000;
427 		break;
428 	case 1152000:
429 		ir_baud = USB_IRDA_LS_1152000;
430 		break;
431 	case 4000000:
432 		ir_baud = USB_IRDA_LS_4000000;
433 		break;
434 	default:
435 		ir_baud = USB_IRDA_LS_9600;
436 		baud = 9600;
437 	}
438 
439 	if (xbof == -1)
440 		ir_xbof = ir_xbof_change(ir_add_bof);
441 	else
442 		ir_xbof = ir_xbof_change(xbof) ;
443 
444 	/* Only speed changes are supported */
445 	tty_termios_copy_hw(&tty->termios, old_termios);
446 	tty_encode_baud_rate(tty, baud, baud);
447 
448 	/*
449 	 * send the baud change out on an "empty" data packet
450 	 */
451 	urb = usb_alloc_urb(0, GFP_KERNEL);
452 	if (!urb)
453 		return;
454 
455 	transfer_buffer = kmalloc(1, GFP_KERNEL);
456 	if (!transfer_buffer)
457 		goto err_buf;
458 
459 	*transfer_buffer = ir_xbof | ir_baud;
460 
461 	usb_fill_bulk_urb(
462 		urb,
463 		port->serial->dev,
464 		usb_sndbulkpipe(port->serial->dev,
465 			port->bulk_out_endpointAddress),
466 		transfer_buffer,
467 		1,
468 		ir_set_termios_callback,
469 		port);
470 
471 	urb->transfer_flags = URB_ZERO_PACKET;
472 
473 	result = usb_submit_urb(urb, GFP_KERNEL);
474 	if (result) {
475 		dev_err(&port->dev, "%s - failed to submit urb: %d\n",
476 							__func__, result);
477 		goto err_subm;
478 	}
479 
480 	usb_free_urb(urb);
481 
482 	return;
483 err_subm:
484 	kfree(transfer_buffer);
485 err_buf:
486 	usb_free_urb(urb);
487 }
488 
ir_init(void)489 static int __init ir_init(void)
490 {
491 	if (buffer_size) {
492 		ir_device.bulk_in_size = buffer_size;
493 		ir_device.bulk_out_size = buffer_size;
494 	}
495 
496 	return usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME, ir_id_table);
497 }
498 
ir_exit(void)499 static void __exit ir_exit(void)
500 {
501 	usb_serial_deregister_drivers(serial_drivers);
502 }
503 
504 
505 module_init(ir_init);
506 module_exit(ir_exit);
507 
508 MODULE_AUTHOR(DRIVER_AUTHOR);
509 MODULE_DESCRIPTION(DRIVER_DESC);
510 MODULE_LICENSE("GPL");
511 
512 module_param(xbof, int, 0);
513 MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
514 module_param(buffer_size, int, 0);
515 MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
516 
517