xref: /linux/drivers/usb/serial/ir-usb.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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_open(struct tty_struct *tty, struct usb_serial_port *port);
53 static int ir_prepare_write_buffer(struct usb_serial_port *port,
54 						void *dest, size_t size);
55 static void ir_process_read_urb(struct urb *urb);
56 static 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 */
60 static u8 ir_baud;
61 static u8 ir_xbof;
62 static u8 ir_add_bof;
63 
64 static 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 
72 MODULE_DEVICE_TABLE(usb, ir_id_table);
73 
74 static 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 
89 static struct usb_serial_driver * const serial_drivers[] = {
90 	&ir_device, NULL
91 };
92 
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 *
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 < 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 
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 
197 static 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 
255 static 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 
266 static 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 
286 static 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 
308 static 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 
317 static 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;
414 err_subm:
415 	kfree(transfer_buffer);
416 err_buf:
417 	usb_free_urb(urb);
418 }
419 
420 static 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 
430 static void __exit ir_exit(void)
431 {
432 	usb_serial_deregister_drivers(serial_drivers);
433 }
434 
435 
436 module_init(ir_init);
437 module_exit(ir_exit);
438 
439 MODULE_AUTHOR(DRIVER_AUTHOR);
440 MODULE_DESCRIPTION(DRIVER_DESC);
441 MODULE_LICENSE("GPL");
442 
443 module_param(xbof, int, 0);
444 MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
445 module_param(buffer_size, int, 0);
446 MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
447 
448