xref: /linux/drivers/usb/serial/ir-usb.c (revision 88674088d10ca2538b2efd2559f6620ade8ec373) 
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 /*
42  * Version Information
43  */
44 #define DRIVER_VERSION "v0.5"
45 #define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Johan Hovold <jhovold@gmail.com>"
46 #define DRIVER_DESC "USB IR Dongle driver"
47 
48 static bool debug;
49 
50 /* if overridden by the user, then use their value for the size of the read and
51  * write urbs */
52 static int buffer_size;
53 
54 /* if overridden by the user, then use the specified number of XBOFs */
55 static int xbof = -1;
56 
57 static int  ir_startup (struct usb_serial *serial);
58 static int  ir_open(struct tty_struct *tty, struct usb_serial_port *port);
59 static int ir_prepare_write_buffer(struct usb_serial_port *port,
60 						void *dest, size_t size);
61 static void ir_process_read_urb(struct urb *urb);
62 static void ir_set_termios(struct tty_struct *tty,
63 		struct usb_serial_port *port, struct ktermios *old_termios);
64 
65 /* Not that this lot means you can only have one per system */
66 static u8 ir_baud;
67 static u8 ir_xbof;
68 static u8 ir_add_bof;
69 
70 static const struct usb_device_id ir_id_table[] = {
71 	{ USB_DEVICE(0x050f, 0x0180) },		/* KC Technology, KC-180 */
72 	{ USB_DEVICE(0x08e9, 0x0100) },		/* XTNDAccess */
73 	{ USB_DEVICE(0x09c4, 0x0011) },		/* ACTiSys ACT-IR2000U */
74 	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, USB_SUBCLASS_IRDA, 0) },
75 	{ }					/* Terminating entry */
76 };
77 
78 MODULE_DEVICE_TABLE(usb, ir_id_table);
79 
80 static struct usb_driver ir_driver = {
81 	.name		= "ir-usb",
82 	.probe		= usb_serial_probe,
83 	.disconnect	= usb_serial_disconnect,
84 	.id_table	= ir_id_table,
85 };
86 
87 static struct usb_serial_driver ir_device = {
88 	.driver	= {
89 		.owner	= THIS_MODULE,
90 		.name	= "ir-usb",
91 	},
92 	.description		= "IR Dongle",
93 	.id_table		= ir_id_table,
94 	.num_ports		= 1,
95 	.set_termios		= ir_set_termios,
96 	.attach			= ir_startup,
97 	.open			= ir_open,
98 	.prepare_write_buffer	= ir_prepare_write_buffer,
99 	.process_read_urb	= ir_process_read_urb,
100 };
101 
102 static struct usb_serial_driver * const serial_drivers[] = {
103 	&ir_device, NULL
104 };
105 
106 static inline void irda_usb_dump_class_desc(struct usb_irda_cs_descriptor *desc)
107 {
108 	dbg("bLength=%x", desc->bLength);
109 	dbg("bDescriptorType=%x", desc->bDescriptorType);
110 	dbg("bcdSpecRevision=%x", __le16_to_cpu(desc->bcdSpecRevision));
111 	dbg("bmDataSize=%x", desc->bmDataSize);
112 	dbg("bmWindowSize=%x", desc->bmWindowSize);
113 	dbg("bmMinTurnaroundTime=%d", desc->bmMinTurnaroundTime);
114 	dbg("wBaudRate=%x", __le16_to_cpu(desc->wBaudRate));
115 	dbg("bmAdditionalBOFs=%x", desc->bmAdditionalBOFs);
116 	dbg("bIrdaRateSniff=%x", desc->bIrdaRateSniff);
117 	dbg("bMaxUnicastList=%x", desc->bMaxUnicastList);
118 }
119 
120 /*------------------------------------------------------------------*/
121 /*
122  * Function irda_usb_find_class_desc(dev, ifnum)
123  *
124  *    Returns instance of IrDA class descriptor, or NULL if not found
125  *
126  * The class descriptor is some extra info that IrDA USB devices will
127  * offer to us, describing their IrDA characteristics. We will use that in
128  * irda_usb_init_qos()
129  *
130  * Based on the same function in drivers/net/irda/irda-usb.c
131  */
132 static struct usb_irda_cs_descriptor *
133 irda_usb_find_class_desc(struct usb_device *dev, unsigned int ifnum)
134 {
135 	struct usb_irda_cs_descriptor *desc;
136 	int ret;
137 
138 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
139 	if (!desc)
140 		return NULL;
141 
142 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
143 			USB_REQ_CS_IRDA_GET_CLASS_DESC,
144 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
145 			0, ifnum, desc, sizeof(*desc), 1000);
146 
147 	dbg("%s -  ret=%d", __func__, ret);
148 	if (ret < sizeof(*desc)) {
149 		dbg("%s - class descriptor read %s (%d)",
150 				__func__,
151 				(ret < 0) ? "failed" : "too short",
152 				ret);
153 		goto error;
154 	}
155 	if (desc->bDescriptorType != USB_DT_CS_IRDA) {
156 		dbg("%s - bad class descriptor type", __func__);
157 		goto error;
158 	}
159 
160 	irda_usb_dump_class_desc(desc);
161 	return desc;
162 
163 error:
164 	kfree(desc);
165 	return NULL;
166 }
167 
168 static u8 ir_xbof_change(u8 xbof)
169 {
170 	u8 result;
171 
172 	/* reference irda-usb.c */
173 	switch (xbof) {
174 	case 48:
175 		result = 0x10;
176 		break;
177 	case 28:
178 	case 24:
179 		result = 0x20;
180 		break;
181 	default:
182 	case 12:
183 		result = 0x30;
184 		break;
185 	case  5:
186 	case  6:
187 		result = 0x40;
188 		break;
189 	case  3:
190 		result = 0x50;
191 		break;
192 	case  2:
193 		result = 0x60;
194 		break;
195 	case  1:
196 		result = 0x70;
197 		break;
198 	case  0:
199 		result = 0x80;
200 		break;
201 	}
202 
203 	return(result);
204 }
205 
206 static int ir_startup(struct usb_serial *serial)
207 {
208 	struct usb_irda_cs_descriptor *irda_desc;
209 
210 	irda_desc = irda_usb_find_class_desc(serial->dev, 0);
211 	if (!irda_desc) {
212 		dev_err(&serial->dev->dev,
213 			"IRDA class descriptor not found, device not bound\n");
214 		return -ENODEV;
215 	}
216 
217 	dbg("%s - Baud rates supported:%s%s%s%s%s%s%s%s%s",
218 		__func__,
219 		(irda_desc->wBaudRate & USB_IRDA_BR_2400) ? " 2400" : "",
220 		(irda_desc->wBaudRate & USB_IRDA_BR_9600) ? " 9600" : "",
221 		(irda_desc->wBaudRate & USB_IRDA_BR_19200) ? " 19200" : "",
222 		(irda_desc->wBaudRate & USB_IRDA_BR_38400) ? " 38400" : "",
223 		(irda_desc->wBaudRate & USB_IRDA_BR_57600) ? " 57600" : "",
224 		(irda_desc->wBaudRate & USB_IRDA_BR_115200) ? " 115200" : "",
225 		(irda_desc->wBaudRate & USB_IRDA_BR_576000) ? " 576000" : "",
226 		(irda_desc->wBaudRate & USB_IRDA_BR_1152000) ? " 1152000" : "",
227 		(irda_desc->wBaudRate & USB_IRDA_BR_4000000) ? " 4000000" : "");
228 
229 	switch (irda_desc->bmAdditionalBOFs) {
230 	case USB_IRDA_AB_48:
231 		ir_add_bof = 48;
232 		break;
233 	case USB_IRDA_AB_24:
234 		ir_add_bof = 24;
235 		break;
236 	case USB_IRDA_AB_12:
237 		ir_add_bof = 12;
238 		break;
239 	case USB_IRDA_AB_6:
240 		ir_add_bof = 6;
241 		break;
242 	case USB_IRDA_AB_3:
243 		ir_add_bof = 3;
244 		break;
245 	case USB_IRDA_AB_2:
246 		ir_add_bof = 2;
247 		break;
248 	case USB_IRDA_AB_1:
249 		ir_add_bof = 1;
250 		break;
251 	case USB_IRDA_AB_0:
252 		ir_add_bof = 0;
253 		break;
254 	default:
255 		break;
256 	}
257 
258 	kfree(irda_desc);
259 
260 	return 0;
261 }
262 
263 static int ir_open(struct tty_struct *tty, struct usb_serial_port *port)
264 {
265 	int i;
266 
267 	dbg("%s - port %d", __func__, port->number);
268 
269 	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
270 		port->write_urbs[i]->transfer_flags = URB_ZERO_PACKET;
271 
272 	/* Start reading from the device */
273 	return usb_serial_generic_open(tty, port);
274 }
275 
276 static int ir_prepare_write_buffer(struct usb_serial_port *port,
277 						void *dest, size_t size)
278 {
279 	unsigned char *buf = dest;
280 	int count;
281 
282 	/*
283 	 * The first byte of the packet we send to the device contains an
284 	 * inbound header which indicates an additional number of BOFs and
285 	 * a baud rate change.
286 	 *
287 	 * See section 5.4.2.2 of the USB IrDA spec.
288 	 */
289 	*buf = ir_xbof | ir_baud;
290 
291 	count = kfifo_out_locked(&port->write_fifo, buf + 1, size - 1,
292 								&port->lock);
293 	return count + 1;
294 }
295 
296 static void ir_process_read_urb(struct urb *urb)
297 {
298 	struct usb_serial_port *port = urb->context;
299 	unsigned char *data = urb->transfer_buffer;
300 	struct tty_struct *tty;
301 
302 	if (!urb->actual_length)
303 		return;
304 	/*
305 	 * The first byte of the packet we get from the device
306 	 * contains a busy indicator and baud rate change.
307 	 * See section 5.4.1.2 of the USB IrDA spec.
308 	 */
309 	if (*data & 0x0f)
310 		ir_baud = *data & 0x0f;
311 
312 	if (urb->actual_length == 1)
313 		return;
314 
315 	tty = tty_port_tty_get(&port->port);
316 	if (!tty)
317 		return;
318 	tty_insert_flip_string(tty, data + 1, urb->actual_length - 1);
319 	tty_flip_buffer_push(tty);
320 	tty_kref_put(tty);
321 }
322 
323 static void ir_set_termios_callback(struct urb *urb)
324 {
325 	struct usb_serial_port *port = urb->context;
326 	int status = urb->status;
327 
328 	dbg("%s - port %d", __func__, port->number);
329 
330 	kfree(urb->transfer_buffer);
331 
332 	if (status)
333 		dbg("%s - non-zero urb status: %d", __func__, status);
334 }
335 
336 static void ir_set_termios(struct tty_struct *tty,
337 		struct usb_serial_port *port, struct ktermios *old_termios)
338 {
339 	struct urb *urb;
340 	unsigned char *transfer_buffer;
341 	int result;
342 	speed_t baud;
343 	int ir_baud;
344 
345 	dbg("%s - port %d", __func__, port->number);
346 
347 	baud = tty_get_baud_rate(tty);
348 
349 	/*
350 	 * FIXME, we should compare the baud request against the
351 	 * capability stated in the IR header that we got in the
352 	 * startup function.
353 	 */
354 
355 	switch (baud) {
356 	case 2400:
357 		ir_baud = USB_IRDA_BR_2400;
358 		break;
359 	case 9600:
360 		ir_baud = USB_IRDA_BR_9600;
361 		break;
362 	case 19200:
363 		ir_baud = USB_IRDA_BR_19200;
364 		break;
365 	case 38400:
366 		ir_baud = USB_IRDA_BR_38400;
367 		break;
368 	case 57600:
369 		ir_baud = USB_IRDA_BR_57600;
370 		break;
371 	case 115200:
372 		ir_baud = USB_IRDA_BR_115200;
373 		break;
374 	case 576000:
375 		ir_baud = USB_IRDA_BR_576000;
376 		break;
377 	case 1152000:
378 		ir_baud = USB_IRDA_BR_1152000;
379 		break;
380 	case 4000000:
381 		ir_baud = USB_IRDA_BR_4000000;
382 		break;
383 	default:
384 		ir_baud = USB_IRDA_BR_9600;
385 		baud = 9600;
386 	}
387 
388 	if (xbof == -1)
389 		ir_xbof = ir_xbof_change(ir_add_bof);
390 	else
391 		ir_xbof = ir_xbof_change(xbof) ;
392 
393 	/* Only speed changes are supported */
394 	tty_termios_copy_hw(tty->termios, old_termios);
395 	tty_encode_baud_rate(tty, baud, baud);
396 
397 	/*
398 	 * send the baud change out on an "empty" data packet
399 	 */
400 	urb = usb_alloc_urb(0, GFP_KERNEL);
401 	if (!urb) {
402 		dev_err(&port->dev, "%s - no more urbs\n", __func__);
403 		return;
404 	}
405 	transfer_buffer = kmalloc(1, GFP_KERNEL);
406 	if (!transfer_buffer) {
407 		dev_err(&port->dev, "%s - out of memory\n", __func__);
408 		goto err_buf;
409 	}
410 
411 	*transfer_buffer = ir_xbof | ir_baud;
412 
413 	usb_fill_bulk_urb(
414 		urb,
415 		port->serial->dev,
416 		usb_sndbulkpipe(port->serial->dev,
417 			port->bulk_out_endpointAddress),
418 		transfer_buffer,
419 		1,
420 		ir_set_termios_callback,
421 		port);
422 
423 	urb->transfer_flags = URB_ZERO_PACKET;
424 
425 	result = usb_submit_urb(urb, GFP_KERNEL);
426 	if (result) {
427 		dev_err(&port->dev, "%s - failed to submit urb: %d\n",
428 							__func__, result);
429 		goto err_subm;
430 	}
431 
432 	usb_free_urb(urb);
433 
434 	return;
435 err_subm:
436 	kfree(transfer_buffer);
437 err_buf:
438 	usb_free_urb(urb);
439 }
440 
441 static int __init ir_init(void)
442 {
443 	int retval;
444 
445 	if (buffer_size) {
446 		ir_device.bulk_in_size = buffer_size;
447 		ir_device.bulk_out_size = buffer_size;
448 	}
449 
450 	retval = usb_serial_register_drivers(&ir_driver, serial_drivers);
451 	if (retval == 0)
452 		printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
453 			       DRIVER_DESC "\n");
454 	return retval;
455 }
456 
457 static void __exit ir_exit(void)
458 {
459 	usb_serial_deregister_drivers(&ir_driver, serial_drivers);
460 }
461 
462 
463 module_init(ir_init);
464 module_exit(ir_exit);
465 
466 MODULE_AUTHOR(DRIVER_AUTHOR);
467 MODULE_DESCRIPTION(DRIVER_DESC);
468 MODULE_LICENSE("GPL");
469 
470 module_param(debug, bool, S_IRUGO | S_IWUSR);
471 MODULE_PARM_DESC(debug, "Debug enabled or not");
472 module_param(xbof, int, 0);
473 MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
474 module_param(buffer_size, int, 0);
475 MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
476 
477