xref: /linux/drivers/usb/serial/ir-usb.c (revision 1e578ec51cace9dcef961225b72b8da46ade13ae) 
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * USB IR Dongle driver
4  *
5  *	Copyright (C) 2001-2002	Greg Kroah-Hartman (greg@kroah.com)
6  *	Copyright (C) 2002	Gary Brubaker (xavyer@ix.netcom.com)
7  *	Copyright (C) 2010	Johan Hovold (jhovold@gmail.com)
8  *
9  * This driver allows a USB IrDA device to be used as a "dumb" serial device.
10  * This can be useful if you do not have access to a full IrDA stack on the
11  * other side of the connection.  If you do have an IrDA stack on both devices,
12  * please use the usb-irda driver, as it contains the proper error checking and
13  * other goodness of a full IrDA stack.
14  *
15  * Portions of this driver were taken from drivers/net/irda/irda-usb.c, which
16  * was written by Roman Weissgaerber <weissg@vienna.at>, Dag Brattli
17  * <dag@brattli.net>, and Jean Tourrilhes <jt@hpl.hp.com>
18  *
19  * See Documentation/usb/usb-serial.rst for more information on using this
20  * driver
21  */
22 
23 #include <linux/kernel.h>
24 #include <linux/errno.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/tty.h>
28 #include <linux/tty_flip.h>
29 #include <linux/module.h>
30 #include <linux/spinlock.h>
31 #include <linux/usb.h>
32 #include <linux/usb/serial.h>
33 #include <linux/usb/irda.h>
34 
35 #define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Johan Hovold <jhovold@gmail.com>"
36 #define DRIVER_DESC "USB IR Dongle driver"
37 
38 /* if overridden by the user, then use their value for the size of the read and
39  * write urbs */
40 static int buffer_size;
41 
42 /* if overridden by the user, then use the specified number of XBOFs */
43 static int xbof = -1;
44 
45 static int  ir_startup (struct usb_serial *serial);
46 static int ir_write(struct tty_struct *tty, struct usb_serial_port *port,
47 		const unsigned char *buf, int count);
48 static unsigned int ir_write_room(struct tty_struct *tty);
49 static void ir_write_bulk_callback(struct urb *urb);
50 static void ir_process_read_urb(struct urb *urb);
51 static void ir_set_termios(struct tty_struct *tty,
52 			   struct usb_serial_port *port,
53 			   const struct ktermios *old_termios);
54 
55 /* Not that this lot means you can only have one per system */
56 static u8 ir_baud;
57 static u8 ir_xbof;
58 static u8 ir_add_bof;
59 
60 static const struct usb_device_id ir_id_table[] = {
61 	{ USB_DEVICE(0x050f, 0x0180) },		/* KC Technology, KC-180 */
62 	{ USB_DEVICE(0x08e9, 0x0100) },		/* XTNDAccess */
63 	{ USB_DEVICE(0x09c4, 0x0011) },		/* ACTiSys ACT-IR2000U */
64 	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, USB_SUBCLASS_IRDA, 0) },
65 	{ }					/* Terminating entry */
66 };
67 
68 MODULE_DEVICE_TABLE(usb, ir_id_table);
69 
70 static struct usb_serial_driver ir_device = {
71 	.driver	= {
72 		.name	= "ir-usb",
73 	},
74 	.description		= "IR Dongle",
75 	.id_table		= ir_id_table,
76 	.num_ports		= 1,
77 	.num_bulk_in		= 1,
78 	.num_bulk_out		= 1,
79 	.set_termios		= ir_set_termios,
80 	.attach			= ir_startup,
81 	.write			= ir_write,
82 	.write_room		= ir_write_room,
83 	.write_bulk_callback	= ir_write_bulk_callback,
84 	.process_read_urb	= ir_process_read_urb,
85 };
86 
87 static struct usb_serial_driver * const serial_drivers[] = {
88 	&ir_device, NULL
89 };
90 
91 static inline void irda_usb_dump_class_desc(struct usb_serial *serial,
92 					    struct usb_irda_cs_descriptor *desc)
93 {
94 	struct device *dev = &serial->dev->dev;
95 
96 	dev_dbg(dev, "bLength=%x\n", desc->bLength);
97 	dev_dbg(dev, "bDescriptorType=%x\n", desc->bDescriptorType);
98 	dev_dbg(dev, "bcdSpecRevision=%x\n", __le16_to_cpu(desc->bcdSpecRevision));
99 	dev_dbg(dev, "bmDataSize=%x\n", desc->bmDataSize);
100 	dev_dbg(dev, "bmWindowSize=%x\n", desc->bmWindowSize);
101 	dev_dbg(dev, "bmMinTurnaroundTime=%d\n", desc->bmMinTurnaroundTime);
102 	dev_dbg(dev, "wBaudRate=%x\n", __le16_to_cpu(desc->wBaudRate));
103 	dev_dbg(dev, "bmAdditionalBOFs=%x\n", desc->bmAdditionalBOFs);
104 	dev_dbg(dev, "bIrdaRateSniff=%x\n", desc->bIrdaRateSniff);
105 	dev_dbg(dev, "bMaxUnicastList=%x\n", desc->bMaxUnicastList);
106 }
107 
108 /*------------------------------------------------------------------*/
109 /*
110  * Function irda_usb_find_class_desc(dev, ifnum)
111  *
112  *    Returns instance of IrDA class descriptor, or NULL if not found
113  *
114  * The class descriptor is some extra info that IrDA USB devices will
115  * offer to us, describing their IrDA characteristics. We will use that in
116  * irda_usb_init_qos()
117  *
118  * Based on the same function in drivers/net/irda/irda-usb.c
119  */
120 static struct usb_irda_cs_descriptor *
121 irda_usb_find_class_desc(struct usb_serial *serial, unsigned int ifnum)
122 {
123 	struct usb_device *dev = serial->dev;
124 	struct usb_irda_cs_descriptor *desc;
125 	int ret;
126 
127 	desc = kzalloc_obj(*desc);
128 	if (!desc)
129 		return NULL;
130 
131 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
132 			USB_REQ_CS_IRDA_GET_CLASS_DESC,
133 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
134 			0, ifnum, desc, sizeof(*desc), 1000);
135 
136 	dev_dbg(&serial->dev->dev, "%s -  ret=%d\n", __func__, ret);
137 	if (ret < (int)sizeof(*desc)) {
138 		dev_dbg(&serial->dev->dev,
139 			"%s - class descriptor read %s (%d)\n", __func__,
140 			(ret < 0) ? "failed" : "too short", ret);
141 		goto error;
142 	}
143 	if (desc->bDescriptorType != USB_DT_CS_IRDA) {
144 		dev_dbg(&serial->dev->dev, "%s - bad class descriptor type\n",
145 			__func__);
146 		goto error;
147 	}
148 
149 	irda_usb_dump_class_desc(serial, desc);
150 	return desc;
151 
152 error:
153 	kfree(desc);
154 	return NULL;
155 }
156 
157 static u8 ir_xbof_change(u8 xbof)
158 {
159 	u8 result;
160 
161 	/* reference irda-usb.c */
162 	switch (xbof) {
163 	case 48:
164 		result = 0x10;
165 		break;
166 	case 28:
167 	case 24:
168 		result = 0x20;
169 		break;
170 	default:
171 	case 12:
172 		result = 0x30;
173 		break;
174 	case  5:
175 	case  6:
176 		result = 0x40;
177 		break;
178 	case  3:
179 		result = 0x50;
180 		break;
181 	case  2:
182 		result = 0x60;
183 		break;
184 	case  1:
185 		result = 0x70;
186 		break;
187 	case  0:
188 		result = 0x80;
189 		break;
190 	}
191 
192 	return(result);
193 }
194 
195 static int ir_startup(struct usb_serial *serial)
196 {
197 	struct usb_irda_cs_descriptor *irda_desc;
198 	int rates;
199 
200 	irda_desc = irda_usb_find_class_desc(serial, 0);
201 	if (!irda_desc) {
202 		dev_err(&serial->dev->dev,
203 			"IRDA class descriptor not found, device not bound\n");
204 		return -ENODEV;
205 	}
206 
207 	rates = le16_to_cpu(irda_desc->wBaudRate);
208 
209 	dev_dbg(&serial->dev->dev,
210 		"%s - Baud rates supported:%s%s%s%s%s%s%s%s%s\n",
211 		__func__,
212 		(rates & USB_IRDA_BR_2400) ? " 2400" : "",
213 		(rates & USB_IRDA_BR_9600) ? " 9600" : "",
214 		(rates & USB_IRDA_BR_19200) ? " 19200" : "",
215 		(rates & USB_IRDA_BR_38400) ? " 38400" : "",
216 		(rates & USB_IRDA_BR_57600) ? " 57600" : "",
217 		(rates & USB_IRDA_BR_115200) ? " 115200" : "",
218 		(rates & USB_IRDA_BR_576000) ? " 576000" : "",
219 		(rates & USB_IRDA_BR_1152000) ? " 1152000" : "",
220 		(rates & USB_IRDA_BR_4000000) ? " 4000000" : "");
221 
222 	switch (irda_desc->bmAdditionalBOFs) {
223 	case USB_IRDA_AB_48:
224 		ir_add_bof = 48;
225 		break;
226 	case USB_IRDA_AB_24:
227 		ir_add_bof = 24;
228 		break;
229 	case USB_IRDA_AB_12:
230 		ir_add_bof = 12;
231 		break;
232 	case USB_IRDA_AB_6:
233 		ir_add_bof = 6;
234 		break;
235 	case USB_IRDA_AB_3:
236 		ir_add_bof = 3;
237 		break;
238 	case USB_IRDA_AB_2:
239 		ir_add_bof = 2;
240 		break;
241 	case USB_IRDA_AB_1:
242 		ir_add_bof = 1;
243 		break;
244 	case USB_IRDA_AB_0:
245 		ir_add_bof = 0;
246 		break;
247 	default:
248 		break;
249 	}
250 
251 	kfree(irda_desc);
252 
253 	return 0;
254 }
255 
256 static int ir_write(struct tty_struct *tty, struct usb_serial_port *port,
257 		const unsigned char *buf, int count)
258 {
259 	struct urb *urb = NULL;
260 	unsigned long flags;
261 	int ret;
262 
263 	if (port->bulk_out_size == 0)
264 		return -EINVAL;
265 
266 	if (count == 0)
267 		return 0;
268 
269 	count = min(count, port->bulk_out_size - 1);
270 
271 	spin_lock_irqsave(&port->lock, flags);
272 	if (__test_and_clear_bit(0, &port->write_urbs_free)) {
273 		urb = port->write_urbs[0];
274 		port->tx_bytes += count;
275 	}
276 	spin_unlock_irqrestore(&port->lock, flags);
277 
278 	if (!urb)
279 		return 0;
280 
281 	/*
282 	 * The first byte of the packet we send to the device contains an
283 	 * outbound header which indicates an additional number of BOFs and
284 	 * a baud rate change.
285 	 *
286 	 * See section 5.4.2.2 of the USB IrDA spec.
287 	 */
288 	*(u8 *)urb->transfer_buffer = ir_xbof | ir_baud;
289 
290 	memcpy(urb->transfer_buffer + 1, buf, count);
291 
292 	urb->transfer_buffer_length = count + 1;
293 	urb->transfer_flags = URB_ZERO_PACKET;
294 
295 	ret = usb_submit_urb(urb, GFP_ATOMIC);
296 	if (ret) {
297 		dev_err(&port->dev, "failed to submit write urb: %d\n", ret);
298 
299 		spin_lock_irqsave(&port->lock, flags);
300 		__set_bit(0, &port->write_urbs_free);
301 		port->tx_bytes -= count;
302 		spin_unlock_irqrestore(&port->lock, flags);
303 
304 		return ret;
305 	}
306 
307 	return count;
308 }
309 
310 static void ir_write_bulk_callback(struct urb *urb)
311 {
312 	struct usb_serial_port *port = urb->context;
313 	int status = urb->status;
314 	unsigned long flags;
315 
316 	spin_lock_irqsave(&port->lock, flags);
317 	__set_bit(0, &port->write_urbs_free);
318 	port->tx_bytes -= urb->transfer_buffer_length - 1;
319 	spin_unlock_irqrestore(&port->lock, flags);
320 
321 	switch (status) {
322 	case 0:
323 		break;
324 	case -ENOENT:
325 	case -ECONNRESET:
326 	case -ESHUTDOWN:
327 		dev_dbg(&port->dev, "write urb stopped: %d\n", status);
328 		return;
329 	case -EPIPE:
330 		dev_err(&port->dev, "write urb stopped: %d\n", status);
331 		return;
332 	default:
333 		dev_err(&port->dev, "nonzero write-urb status: %d\n", status);
334 		break;
335 	}
336 
337 	usb_serial_port_softint(port);
338 }
339 
340 static unsigned int ir_write_room(struct tty_struct *tty)
341 {
342 	struct usb_serial_port *port = tty->driver_data;
343 	unsigned int count = 0;
344 
345 	if (port->bulk_out_size == 0)
346 		return 0;
347 
348 	if (test_bit(0, &port->write_urbs_free))
349 		count = port->bulk_out_size - 1;
350 
351 	return count;
352 }
353 
354 static void ir_process_read_urb(struct urb *urb)
355 {
356 	struct usb_serial_port *port = urb->context;
357 	unsigned char *data = urb->transfer_buffer;
358 
359 	if (!urb->actual_length)
360 		return;
361 	/*
362 	 * The first byte of the packet we get from the device
363 	 * contains a busy indicator and baud rate change.
364 	 * See section 5.4.1.2 of the USB IrDA spec.
365 	 */
366 	if (*data & 0x0f)
367 		ir_baud = *data & 0x0f;
368 
369 	if (urb->actual_length == 1)
370 		return;
371 
372 	tty_insert_flip_string(&port->port, data + 1, urb->actual_length - 1);
373 	tty_flip_buffer_push(&port->port);
374 }
375 
376 static void ir_set_termios(struct tty_struct *tty,
377 			   struct usb_serial_port *port,
378 			   const struct ktermios *old_termios)
379 {
380 	struct usb_device *udev = port->serial->dev;
381 	unsigned char *transfer_buffer;
382 	int actual_length;
383 	speed_t baud;
384 	int ir_baud;
385 	int ret;
386 
387 	baud = tty_get_baud_rate(tty);
388 
389 	/*
390 	 * FIXME, we should compare the baud request against the
391 	 * capability stated in the IR header that we got in the
392 	 * startup function.
393 	 */
394 
395 	switch (baud) {
396 	case 2400:
397 		ir_baud = USB_IRDA_LS_2400;
398 		break;
399 	case 9600:
400 		ir_baud = USB_IRDA_LS_9600;
401 		break;
402 	case 19200:
403 		ir_baud = USB_IRDA_LS_19200;
404 		break;
405 	case 38400:
406 		ir_baud = USB_IRDA_LS_38400;
407 		break;
408 	case 57600:
409 		ir_baud = USB_IRDA_LS_57600;
410 		break;
411 	case 115200:
412 		ir_baud = USB_IRDA_LS_115200;
413 		break;
414 	case 576000:
415 		ir_baud = USB_IRDA_LS_576000;
416 		break;
417 	case 1152000:
418 		ir_baud = USB_IRDA_LS_1152000;
419 		break;
420 	case 4000000:
421 		ir_baud = USB_IRDA_LS_4000000;
422 		break;
423 	default:
424 		ir_baud = USB_IRDA_LS_9600;
425 		baud = 9600;
426 	}
427 
428 	if (xbof == -1)
429 		ir_xbof = ir_xbof_change(ir_add_bof);
430 	else
431 		ir_xbof = ir_xbof_change(xbof) ;
432 
433 	/* Only speed changes are supported */
434 	tty_termios_copy_hw(&tty->termios, old_termios);
435 	tty_encode_baud_rate(tty, baud, baud);
436 
437 	/*
438 	 * send the baud change out on an "empty" data packet
439 	 */
440 	transfer_buffer = kmalloc(1, GFP_KERNEL);
441 	if (!transfer_buffer)
442 		return;
443 
444 	*transfer_buffer = ir_xbof | ir_baud;
445 
446 	ret = usb_bulk_msg(udev,
447 			usb_sndbulkpipe(udev, port->bulk_out_endpointAddress),
448 			transfer_buffer, 1, &actual_length, 5000);
449 	if (ret || actual_length != 1) {
450 		if (!ret)
451 			ret = -EIO;
452 		dev_err(&port->dev, "failed to change line speed: %d\n", ret);
453 	}
454 
455 	kfree(transfer_buffer);
456 }
457 
458 static int __init ir_init(void)
459 {
460 	if (buffer_size) {
461 		ir_device.bulk_in_size = buffer_size;
462 		ir_device.bulk_out_size = buffer_size;
463 	}
464 
465 	return usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME, ir_id_table);
466 }
467 
468 static void __exit ir_exit(void)
469 {
470 	usb_serial_deregister_drivers(serial_drivers);
471 }
472 
473 
474 module_init(ir_init);
475 module_exit(ir_exit);
476 
477 MODULE_AUTHOR(DRIVER_AUTHOR);
478 MODULE_DESCRIPTION(DRIVER_DESC);
479 MODULE_LICENSE("GPL");
480 
481 module_param(xbof, int, 0);
482 MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
483 module_param(buffer_size, int, 0);
484 MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
485 
486