ir-usb.c revision 2e124b4a390ca85325fae75764bef92f0547fa25 
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 */
46static int buffer_size;
47
48/* if overridden by the user, then use the specified number of XBOFs */
49static int xbof = -1;
50
51static int  ir_startup (struct usb_serial *serial);
52static int  ir_open(struct tty_struct *tty, struct usb_serial_port *port);
53static int ir_prepare_write_buffer(struct usb_serial_port *port,
54						void *dest, size_t size);
55static void ir_process_read_urb(struct urb *urb);
56static void ir_set_termios(struct tty_struct *tty,
57		struct usb_serial_port *port, struct ktermios *old_termios);
58
59/* Not that this lot means you can only have one per system */
60static u8 ir_baud;
61static u8 ir_xbof;
62static u8 ir_add_bof;
63
64static const struct usb_device_id ir_id_table[] = {
65	{ USB_DEVICE(0x050f, 0x0180) },		/* KC Technology, KC-180 */
66	{ USB_DEVICE(0x08e9, 0x0100) },		/* XTNDAccess */
67	{ USB_DEVICE(0x09c4, 0x0011) },		/* ACTiSys ACT-IR2000U */
68	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, USB_SUBCLASS_IRDA, 0) },
69	{ }					/* Terminating entry */
70};
71
72MODULE_DEVICE_TABLE(usb, ir_id_table);
73
74static struct usb_serial_driver ir_device = {
75	.driver	= {
76		.owner	= THIS_MODULE,
77		.name	= "ir-usb",
78	},
79	.description		= "IR Dongle",
80	.id_table		= ir_id_table,
81	.num_ports		= 1,
82	.set_termios		= ir_set_termios,
83	.attach			= ir_startup,
84	.open			= ir_open,
85	.prepare_write_buffer	= ir_prepare_write_buffer,
86	.process_read_urb	= ir_process_read_urb,
87};
88
89static struct usb_serial_driver * const serial_drivers[] = {
90	&ir_device, NULL
91};
92
93static 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 */
122static struct usb_irda_cs_descriptor *
123irda_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 < 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
154error:
155	kfree(desc);
156	return NULL;
157}
158
159static 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
197static int ir_startup(struct usb_serial *serial)
198{
199	struct usb_irda_cs_descriptor *irda_desc;
200
201	irda_desc = irda_usb_find_class_desc(serial, 0);
202	if (!irda_desc) {
203		dev_err(&serial->dev->dev,
204			"IRDA class descriptor not found, device not bound\n");
205		return -ENODEV;
206	}
207
208	dev_dbg(&serial->dev->dev,
209		"%s - Baud rates supported:%s%s%s%s%s%s%s%s%s\n",
210		__func__,
211		(irda_desc->wBaudRate & USB_IRDA_BR_2400) ? " 2400" : "",
212		(irda_desc->wBaudRate & USB_IRDA_BR_9600) ? " 9600" : "",
213		(irda_desc->wBaudRate & USB_IRDA_BR_19200) ? " 19200" : "",
214		(irda_desc->wBaudRate & USB_IRDA_BR_38400) ? " 38400" : "",
215		(irda_desc->wBaudRate & USB_IRDA_BR_57600) ? " 57600" : "",
216		(irda_desc->wBaudRate & USB_IRDA_BR_115200) ? " 115200" : "",
217		(irda_desc->wBaudRate & USB_IRDA_BR_576000) ? " 576000" : "",
218		(irda_desc->wBaudRate & USB_IRDA_BR_1152000) ? " 1152000" : "",
219		(irda_desc->wBaudRate & USB_IRDA_BR_4000000) ? " 4000000" : "");
220
221	switch (irda_desc->bmAdditionalBOFs) {
222	case USB_IRDA_AB_48:
223		ir_add_bof = 48;
224		break;
225	case USB_IRDA_AB_24:
226		ir_add_bof = 24;
227		break;
228	case USB_IRDA_AB_12:
229		ir_add_bof = 12;
230		break;
231	case USB_IRDA_AB_6:
232		ir_add_bof = 6;
233		break;
234	case USB_IRDA_AB_3:
235		ir_add_bof = 3;
236		break;
237	case USB_IRDA_AB_2:
238		ir_add_bof = 2;
239		break;
240	case USB_IRDA_AB_1:
241		ir_add_bof = 1;
242		break;
243	case USB_IRDA_AB_0:
244		ir_add_bof = 0;
245		break;
246	default:
247		break;
248	}
249
250	kfree(irda_desc);
251
252	return 0;
253}
254
255static int ir_open(struct tty_struct *tty, struct usb_serial_port *port)
256{
257	int i;
258
259	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
260		port->write_urbs[i]->transfer_flags = URB_ZERO_PACKET;
261
262	/* Start reading from the device */
263	return usb_serial_generic_open(tty, port);
264}
265
266static int ir_prepare_write_buffer(struct usb_serial_port *port,
267						void *dest, size_t size)
268{
269	unsigned char *buf = dest;
270	int count;
271
272	/*
273	 * The first byte of the packet we send to the device contains an
274	 * inbound header which indicates an additional number of BOFs and
275	 * a baud rate change.
276	 *
277	 * See section 5.4.2.2 of the USB IrDA spec.
278	 */
279	*buf = ir_xbof | ir_baud;
280
281	count = kfifo_out_locked(&port->write_fifo, buf + 1, size - 1,
282								&port->lock);
283	return count + 1;
284}
285
286static void ir_process_read_urb(struct urb *urb)
287{
288	struct usb_serial_port *port = urb->context;
289	unsigned char *data = urb->transfer_buffer;
290
291	if (!urb->actual_length)
292		return;
293	/*
294	 * The first byte of the packet we get from the device
295	 * contains a busy indicator and baud rate change.
296	 * See section 5.4.1.2 of the USB IrDA spec.
297	 */
298	if (*data & 0x0f)
299		ir_baud = *data & 0x0f;
300
301	if (urb->actual_length == 1)
302		return;
303
304	tty_insert_flip_string(&port->port, data + 1, urb->actual_length - 1);
305	tty_flip_buffer_push(&port->port);
306}
307
308static void ir_set_termios_callback(struct urb *urb)
309{
310	kfree(urb->transfer_buffer);
311
312	if (urb->status)
313		dev_dbg(&urb->dev->dev, "%s - non-zero urb status: %d\n",
314			__func__, urb->status);
315}
316
317static void ir_set_termios(struct tty_struct *tty,
318		struct usb_serial_port *port, struct ktermios *old_termios)
319{
320	struct urb *urb;
321	unsigned char *transfer_buffer;
322	int result;
323	speed_t baud;
324	int ir_baud;
325
326	baud = tty_get_baud_rate(tty);
327
328	/*
329	 * FIXME, we should compare the baud request against the
330	 * capability stated in the IR header that we got in the
331	 * startup function.
332	 */
333
334	switch (baud) {
335	case 2400:
336		ir_baud = USB_IRDA_BR_2400;
337		break;
338	case 9600:
339		ir_baud = USB_IRDA_BR_9600;
340		break;
341	case 19200:
342		ir_baud = USB_IRDA_BR_19200;
343		break;
344	case 38400:
345		ir_baud = USB_IRDA_BR_38400;
346		break;
347	case 57600:
348		ir_baud = USB_IRDA_BR_57600;
349		break;
350	case 115200:
351		ir_baud = USB_IRDA_BR_115200;
352		break;
353	case 576000:
354		ir_baud = USB_IRDA_BR_576000;
355		break;
356	case 1152000:
357		ir_baud = USB_IRDA_BR_1152000;
358		break;
359	case 4000000:
360		ir_baud = USB_IRDA_BR_4000000;
361		break;
362	default:
363		ir_baud = USB_IRDA_BR_9600;
364		baud = 9600;
365	}
366
367	if (xbof == -1)
368		ir_xbof = ir_xbof_change(ir_add_bof);
369	else
370		ir_xbof = ir_xbof_change(xbof) ;
371
372	/* Only speed changes are supported */
373	tty_termios_copy_hw(&tty->termios, old_termios);
374	tty_encode_baud_rate(tty, baud, baud);
375
376	/*
377	 * send the baud change out on an "empty" data packet
378	 */
379	urb = usb_alloc_urb(0, GFP_KERNEL);
380	if (!urb) {
381		dev_err(&port->dev, "%s - no more urbs\n", __func__);
382		return;
383	}
384	transfer_buffer = kmalloc(1, GFP_KERNEL);
385	if (!transfer_buffer) {
386		dev_err(&port->dev, "%s - out of memory\n", __func__);
387		goto err_buf;
388	}
389
390	*transfer_buffer = ir_xbof | ir_baud;
391
392	usb_fill_bulk_urb(
393		urb,
394		port->serial->dev,
395		usb_sndbulkpipe(port->serial->dev,
396			port->bulk_out_endpointAddress),
397		transfer_buffer,
398		1,
399		ir_set_termios_callback,
400		port);
401
402	urb->transfer_flags = URB_ZERO_PACKET;
403
404	result = usb_submit_urb(urb, GFP_KERNEL);
405	if (result) {
406		dev_err(&port->dev, "%s - failed to submit urb: %d\n",
407							__func__, result);
408		goto err_subm;
409	}
410
411	usb_free_urb(urb);
412
413	return;
414err_subm:
415	kfree(transfer_buffer);
416err_buf:
417	usb_free_urb(urb);
418}
419
420static int __init ir_init(void)
421{
422	if (buffer_size) {
423		ir_device.bulk_in_size = buffer_size;
424		ir_device.bulk_out_size = buffer_size;
425	}
426
427	return usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME, ir_id_table);
428}
429
430static void __exit ir_exit(void)
431{
432	usb_serial_deregister_drivers(serial_drivers);
433}
434
435
436module_init(ir_init);
437module_exit(ir_exit);
438
439MODULE_AUTHOR(DRIVER_AUTHOR);
440MODULE_DESCRIPTION(DRIVER_DESC);
441MODULE_LICENSE("GPL");
442
443module_param(xbof, int, 0);
444MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
445module_param(buffer_size, int, 0);
446MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
447
448