xref: /openbmc/linux/drivers/usb/serial/ir-usb.c (revision 95e9fd10) 
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_serial_driver ir_device = {
81 	.driver	= {
82 		.owner	= THIS_MODULE,
83 		.name	= "ir-usb",
84 	},
85 	.description		= "IR Dongle",
86 	.id_table		= ir_id_table,
87 	.num_ports		= 1,
88 	.set_termios		= ir_set_termios,
89 	.attach			= ir_startup,
90 	.open			= ir_open,
91 	.prepare_write_buffer	= ir_prepare_write_buffer,
92 	.process_read_urb	= ir_process_read_urb,
93 };
94 
95 static struct usb_serial_driver * const serial_drivers[] = {
96 	&ir_device, NULL
97 };
98 
99 static inline void irda_usb_dump_class_desc(struct usb_serial *serial,
100 					    struct usb_irda_cs_descriptor *desc)
101 {
102 	struct device *dev = &serial->dev->dev;
103 
104 	dev_dbg(dev, "bLength=%x\n", desc->bLength);
105 	dev_dbg(dev, "bDescriptorType=%x\n", desc->bDescriptorType);
106 	dev_dbg(dev, "bcdSpecRevision=%x\n", __le16_to_cpu(desc->bcdSpecRevision));
107 	dev_dbg(dev, "bmDataSize=%x\n", desc->bmDataSize);
108 	dev_dbg(dev, "bmWindowSize=%x\n", desc->bmWindowSize);
109 	dev_dbg(dev, "bmMinTurnaroundTime=%d\n", desc->bmMinTurnaroundTime);
110 	dev_dbg(dev, "wBaudRate=%x\n", __le16_to_cpu(desc->wBaudRate));
111 	dev_dbg(dev, "bmAdditionalBOFs=%x\n", desc->bmAdditionalBOFs);
112 	dev_dbg(dev, "bIrdaRateSniff=%x\n", desc->bIrdaRateSniff);
113 	dev_dbg(dev, "bMaxUnicastList=%x\n", desc->bMaxUnicastList);
114 }
115 
116 /*------------------------------------------------------------------*/
117 /*
118  * Function irda_usb_find_class_desc(dev, ifnum)
119  *
120  *    Returns instance of IrDA class descriptor, or NULL if not found
121  *
122  * The class descriptor is some extra info that IrDA USB devices will
123  * offer to us, describing their IrDA characteristics. We will use that in
124  * irda_usb_init_qos()
125  *
126  * Based on the same function in drivers/net/irda/irda-usb.c
127  */
128 static struct usb_irda_cs_descriptor *
129 irda_usb_find_class_desc(struct usb_serial *serial, unsigned int ifnum)
130 {
131 	struct usb_device *dev = serial->dev;
132 	struct usb_irda_cs_descriptor *desc;
133 	int ret;
134 
135 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
136 	if (!desc)
137 		return NULL;
138 
139 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
140 			USB_REQ_CS_IRDA_GET_CLASS_DESC,
141 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
142 			0, ifnum, desc, sizeof(*desc), 1000);
143 
144 	dev_dbg(&serial->dev->dev, "%s -  ret=%d\n", __func__, ret);
145 	if (ret < sizeof(*desc)) {
146 		dev_dbg(&serial->dev->dev,
147 			"%s - class descriptor read %s (%d)\n", __func__,
148 			(ret < 0) ? "failed" : "too short", ret);
149 		goto error;
150 	}
151 	if (desc->bDescriptorType != USB_DT_CS_IRDA) {
152 		dev_dbg(&serial->dev->dev, "%s - bad class descriptor type\n",
153 			__func__);
154 		goto error;
155 	}
156 
157 	irda_usb_dump_class_desc(serial, desc);
158 	return desc;
159 
160 error:
161 	kfree(desc);
162 	return NULL;
163 }
164 
165 static u8 ir_xbof_change(u8 xbof)
166 {
167 	u8 result;
168 
169 	/* reference irda-usb.c */
170 	switch (xbof) {
171 	case 48:
172 		result = 0x10;
173 		break;
174 	case 28:
175 	case 24:
176 		result = 0x20;
177 		break;
178 	default:
179 	case 12:
180 		result = 0x30;
181 		break;
182 	case  5:
183 	case  6:
184 		result = 0x40;
185 		break;
186 	case  3:
187 		result = 0x50;
188 		break;
189 	case  2:
190 		result = 0x60;
191 		break;
192 	case  1:
193 		result = 0x70;
194 		break;
195 	case  0:
196 		result = 0x80;
197 		break;
198 	}
199 
200 	return(result);
201 }
202 
203 static int ir_startup(struct usb_serial *serial)
204 {
205 	struct usb_irda_cs_descriptor *irda_desc;
206 
207 	irda_desc = irda_usb_find_class_desc(serial, 0);
208 	if (!irda_desc) {
209 		dev_err(&serial->dev->dev,
210 			"IRDA class descriptor not found, device not bound\n");
211 		return -ENODEV;
212 	}
213 
214 	dev_dbg(&serial->dev->dev,
215 		"%s - Baud rates supported:%s%s%s%s%s%s%s%s%s\n",
216 		__func__,
217 		(irda_desc->wBaudRate & USB_IRDA_BR_2400) ? " 2400" : "",
218 		(irda_desc->wBaudRate & USB_IRDA_BR_9600) ? " 9600" : "",
219 		(irda_desc->wBaudRate & USB_IRDA_BR_19200) ? " 19200" : "",
220 		(irda_desc->wBaudRate & USB_IRDA_BR_38400) ? " 38400" : "",
221 		(irda_desc->wBaudRate & USB_IRDA_BR_57600) ? " 57600" : "",
222 		(irda_desc->wBaudRate & USB_IRDA_BR_115200) ? " 115200" : "",
223 		(irda_desc->wBaudRate & USB_IRDA_BR_576000) ? " 576000" : "",
224 		(irda_desc->wBaudRate & USB_IRDA_BR_1152000) ? " 1152000" : "",
225 		(irda_desc->wBaudRate & USB_IRDA_BR_4000000) ? " 4000000" : "");
226 
227 	switch (irda_desc->bmAdditionalBOFs) {
228 	case USB_IRDA_AB_48:
229 		ir_add_bof = 48;
230 		break;
231 	case USB_IRDA_AB_24:
232 		ir_add_bof = 24;
233 		break;
234 	case USB_IRDA_AB_12:
235 		ir_add_bof = 12;
236 		break;
237 	case USB_IRDA_AB_6:
238 		ir_add_bof = 6;
239 		break;
240 	case USB_IRDA_AB_3:
241 		ir_add_bof = 3;
242 		break;
243 	case USB_IRDA_AB_2:
244 		ir_add_bof = 2;
245 		break;
246 	case USB_IRDA_AB_1:
247 		ir_add_bof = 1;
248 		break;
249 	case USB_IRDA_AB_0:
250 		ir_add_bof = 0;
251 		break;
252 	default:
253 		break;
254 	}
255 
256 	kfree(irda_desc);
257 
258 	return 0;
259 }
260 
261 static int ir_open(struct tty_struct *tty, struct usb_serial_port *port)
262 {
263 	int i;
264 
265 	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
266 		port->write_urbs[i]->transfer_flags = URB_ZERO_PACKET;
267 
268 	/* Start reading from the device */
269 	return usb_serial_generic_open(tty, port);
270 }
271 
272 static int ir_prepare_write_buffer(struct usb_serial_port *port,
273 						void *dest, size_t size)
274 {
275 	unsigned char *buf = dest;
276 	int count;
277 
278 	/*
279 	 * The first byte of the packet we send to the device contains an
280 	 * inbound header which indicates an additional number of BOFs and
281 	 * a baud rate change.
282 	 *
283 	 * See section 5.4.2.2 of the USB IrDA spec.
284 	 */
285 	*buf = ir_xbof | ir_baud;
286 
287 	count = kfifo_out_locked(&port->write_fifo, buf + 1, size - 1,
288 								&port->lock);
289 	return count + 1;
290 }
291 
292 static void ir_process_read_urb(struct urb *urb)
293 {
294 	struct usb_serial_port *port = urb->context;
295 	unsigned char *data = urb->transfer_buffer;
296 	struct tty_struct *tty;
297 
298 	if (!urb->actual_length)
299 		return;
300 	/*
301 	 * The first byte of the packet we get from the device
302 	 * contains a busy indicator and baud rate change.
303 	 * See section 5.4.1.2 of the USB IrDA spec.
304 	 */
305 	if (*data & 0x0f)
306 		ir_baud = *data & 0x0f;
307 
308 	if (urb->actual_length == 1)
309 		return;
310 
311 	tty = tty_port_tty_get(&port->port);
312 	if (!tty)
313 		return;
314 	tty_insert_flip_string(tty, data + 1, urb->actual_length - 1);
315 	tty_flip_buffer_push(tty);
316 	tty_kref_put(tty);
317 }
318 
319 static void ir_set_termios_callback(struct urb *urb)
320 {
321 	kfree(urb->transfer_buffer);
322 
323 	if (urb->status)
324 		dev_dbg(&urb->dev->dev, "%s - non-zero urb status: %d\n",
325 			__func__, urb->status);
326 }
327 
328 static void ir_set_termios(struct tty_struct *tty,
329 		struct usb_serial_port *port, struct ktermios *old_termios)
330 {
331 	struct urb *urb;
332 	unsigned char *transfer_buffer;
333 	int result;
334 	speed_t baud;
335 	int ir_baud;
336 
337 	baud = tty_get_baud_rate(tty);
338 
339 	/*
340 	 * FIXME, we should compare the baud request against the
341 	 * capability stated in the IR header that we got in the
342 	 * startup function.
343 	 */
344 
345 	switch (baud) {
346 	case 2400:
347 		ir_baud = USB_IRDA_BR_2400;
348 		break;
349 	case 9600:
350 		ir_baud = USB_IRDA_BR_9600;
351 		break;
352 	case 19200:
353 		ir_baud = USB_IRDA_BR_19200;
354 		break;
355 	case 38400:
356 		ir_baud = USB_IRDA_BR_38400;
357 		break;
358 	case 57600:
359 		ir_baud = USB_IRDA_BR_57600;
360 		break;
361 	case 115200:
362 		ir_baud = USB_IRDA_BR_115200;
363 		break;
364 	case 576000:
365 		ir_baud = USB_IRDA_BR_576000;
366 		break;
367 	case 1152000:
368 		ir_baud = USB_IRDA_BR_1152000;
369 		break;
370 	case 4000000:
371 		ir_baud = USB_IRDA_BR_4000000;
372 		break;
373 	default:
374 		ir_baud = USB_IRDA_BR_9600;
375 		baud = 9600;
376 	}
377 
378 	if (xbof == -1)
379 		ir_xbof = ir_xbof_change(ir_add_bof);
380 	else
381 		ir_xbof = ir_xbof_change(xbof) ;
382 
383 	/* Only speed changes are supported */
384 	tty_termios_copy_hw(tty->termios, old_termios);
385 	tty_encode_baud_rate(tty, baud, baud);
386 
387 	/*
388 	 * send the baud change out on an "empty" data packet
389 	 */
390 	urb = usb_alloc_urb(0, GFP_KERNEL);
391 	if (!urb) {
392 		dev_err(&port->dev, "%s - no more urbs\n", __func__);
393 		return;
394 	}
395 	transfer_buffer = kmalloc(1, GFP_KERNEL);
396 	if (!transfer_buffer) {
397 		dev_err(&port->dev, "%s - out of memory\n", __func__);
398 		goto err_buf;
399 	}
400 
401 	*transfer_buffer = ir_xbof | ir_baud;
402 
403 	usb_fill_bulk_urb(
404 		urb,
405 		port->serial->dev,
406 		usb_sndbulkpipe(port->serial->dev,
407 			port->bulk_out_endpointAddress),
408 		transfer_buffer,
409 		1,
410 		ir_set_termios_callback,
411 		port);
412 
413 	urb->transfer_flags = URB_ZERO_PACKET;
414 
415 	result = usb_submit_urb(urb, GFP_KERNEL);
416 	if (result) {
417 		dev_err(&port->dev, "%s - failed to submit urb: %d\n",
418 							__func__, result);
419 		goto err_subm;
420 	}
421 
422 	usb_free_urb(urb);
423 
424 	return;
425 err_subm:
426 	kfree(transfer_buffer);
427 err_buf:
428 	usb_free_urb(urb);
429 }
430 
431 static int __init ir_init(void)
432 {
433 	int retval;
434 
435 	if (buffer_size) {
436 		ir_device.bulk_in_size = buffer_size;
437 		ir_device.bulk_out_size = buffer_size;
438 	}
439 
440 	retval = usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME, ir_id_table);
441 	if (retval == 0)
442 		printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
443 			       DRIVER_DESC "\n");
444 	return retval;
445 }
446 
447 static void __exit ir_exit(void)
448 {
449 	usb_serial_deregister_drivers(serial_drivers);
450 }
451 
452 
453 module_init(ir_init);
454 module_exit(ir_exit);
455 
456 MODULE_AUTHOR(DRIVER_AUTHOR);
457 MODULE_DESCRIPTION(DRIVER_DESC);
458 MODULE_LICENSE("GPL");
459 
460 module_param(debug, bool, S_IRUGO | S_IWUSR);
461 MODULE_PARM_DESC(debug, "Debug enabled or not");
462 module_param(xbof, int, 0);
463 MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
464 module_param(buffer_size, int, 0);
465 MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
466 
467