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_driver.h>
29#include <linux/tty_flip.h>
30#include <linux/module.h>
31#include <linux/spinlock.h>
32#include <linux/uaccess.h>
33#include <linux/usb.h>
34#include <linux/usb/serial.h>
35#include <linux/usb/irda.h>
36
37#define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Johan Hovold <jhovold@gmail.com>"
38#define DRIVER_DESC "USB IR Dongle driver"
39
40/* if overridden by the user, then use their value for the size of the read and
41 * write urbs */
42static int buffer_size;
43
44/* if overridden by the user, then use the specified number of XBOFs */
45static int xbof = -1;
46
47static int  ir_startup (struct usb_serial *serial);
48static int ir_write(struct tty_struct *tty, struct usb_serial_port *port,
49		const unsigned char *buf, int count);
50static unsigned int ir_write_room(struct tty_struct *tty);
51static void ir_write_bulk_callback(struct urb *urb);
52static void ir_process_read_urb(struct urb *urb);
53static void ir_set_termios(struct tty_struct *tty,
54			   struct usb_serial_port *port,
55			   const struct ktermios *old_termios);
56
57/* Not that this lot means you can only have one per system */
58static u8 ir_baud;
59static u8 ir_xbof;
60static u8 ir_add_bof;
61
62static const struct usb_device_id ir_id_table[] = {
63	{ USB_DEVICE(0x050f, 0x0180) },		/* KC Technology, KC-180 */
64	{ USB_DEVICE(0x08e9, 0x0100) },		/* XTNDAccess */
65	{ USB_DEVICE(0x09c4, 0x0011) },		/* ACTiSys ACT-IR2000U */
66	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, USB_SUBCLASS_IRDA, 0) },
67	{ }					/* Terminating entry */
68};
69
70MODULE_DEVICE_TABLE(usb, ir_id_table);
71
72static struct usb_serial_driver ir_device = {
73	.driver	= {
74		.owner	= THIS_MODULE,
75		.name	= "ir-usb",
76	},
77	.description		= "IR Dongle",
78	.id_table		= ir_id_table,
79	.num_ports		= 1,
80	.num_bulk_in		= 1,
81	.num_bulk_out		= 1,
82	.set_termios		= ir_set_termios,
83	.attach			= ir_startup,
84	.write			= ir_write,
85	.write_room		= ir_write_room,
86	.write_bulk_callback	= ir_write_bulk_callback,
87	.process_read_urb	= ir_process_read_urb,
88};
89
90static struct usb_serial_driver * const serial_drivers[] = {
91	&ir_device, NULL
92};
93
94static inline void irda_usb_dump_class_desc(struct usb_serial *serial,
95					    struct usb_irda_cs_descriptor *desc)
96{
97	struct device *dev = &serial->dev->dev;
98
99	dev_dbg(dev, "bLength=%x\n", desc->bLength);
100	dev_dbg(dev, "bDescriptorType=%x\n", desc->bDescriptorType);
101	dev_dbg(dev, "bcdSpecRevision=%x\n", __le16_to_cpu(desc->bcdSpecRevision));
102	dev_dbg(dev, "bmDataSize=%x\n", desc->bmDataSize);
103	dev_dbg(dev, "bmWindowSize=%x\n", desc->bmWindowSize);
104	dev_dbg(dev, "bmMinTurnaroundTime=%d\n", desc->bmMinTurnaroundTime);
105	dev_dbg(dev, "wBaudRate=%x\n", __le16_to_cpu(desc->wBaudRate));
106	dev_dbg(dev, "bmAdditionalBOFs=%x\n", desc->bmAdditionalBOFs);
107	dev_dbg(dev, "bIrdaRateSniff=%x\n", desc->bIrdaRateSniff);
108	dev_dbg(dev, "bMaxUnicastList=%x\n", desc->bMaxUnicastList);
109}
110
111/*------------------------------------------------------------------*/
112/*
113 * Function irda_usb_find_class_desc(dev, ifnum)
114 *
115 *    Returns instance of IrDA class descriptor, or NULL if not found
116 *
117 * The class descriptor is some extra info that IrDA USB devices will
118 * offer to us, describing their IrDA characteristics. We will use that in
119 * irda_usb_init_qos()
120 *
121 * Based on the same function in drivers/net/irda/irda-usb.c
122 */
123static struct usb_irda_cs_descriptor *
124irda_usb_find_class_desc(struct usb_serial *serial, unsigned int ifnum)
125{
126	struct usb_device *dev = serial->dev;
127	struct usb_irda_cs_descriptor *desc;
128	int ret;
129
130	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
131	if (!desc)
132		return NULL;
133
134	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
135			USB_REQ_CS_IRDA_GET_CLASS_DESC,
136			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
137			0, ifnum, desc, sizeof(*desc), 1000);
138
139	dev_dbg(&serial->dev->dev, "%s -  ret=%d\n", __func__, ret);
140	if (ret < (int)sizeof(*desc)) {
141		dev_dbg(&serial->dev->dev,
142			"%s - class descriptor read %s (%d)\n", __func__,
143			(ret < 0) ? "failed" : "too short", ret);
144		goto error;
145	}
146	if (desc->bDescriptorType != USB_DT_CS_IRDA) {
147		dev_dbg(&serial->dev->dev, "%s - bad class descriptor type\n",
148			__func__);
149		goto error;
150	}
151
152	irda_usb_dump_class_desc(serial, desc);
153	return desc;
154
155error:
156	kfree(desc);
157	return NULL;
158}
159
160static u8 ir_xbof_change(u8 xbof)
161{
162	u8 result;
163
164	/* reference irda-usb.c */
165	switch (xbof) {
166	case 48:
167		result = 0x10;
168		break;
169	case 28:
170	case 24:
171		result = 0x20;
172		break;
173	default:
174	case 12:
175		result = 0x30;
176		break;
177	case  5:
178	case  6:
179		result = 0x40;
180		break;
181	case  3:
182		result = 0x50;
183		break;
184	case  2:
185		result = 0x60;
186		break;
187	case  1:
188		result = 0x70;
189		break;
190	case  0:
191		result = 0x80;
192		break;
193	}
194
195	return(result);
196}
197
198static int ir_startup(struct usb_serial *serial)
199{
200	struct usb_irda_cs_descriptor *irda_desc;
201	int rates;
202
203	irda_desc = irda_usb_find_class_desc(serial, 0);
204	if (!irda_desc) {
205		dev_err(&serial->dev->dev,
206			"IRDA class descriptor not found, device not bound\n");
207		return -ENODEV;
208	}
209
210	rates = le16_to_cpu(irda_desc->wBaudRate);
211
212	dev_dbg(&serial->dev->dev,
213		"%s - Baud rates supported:%s%s%s%s%s%s%s%s%s\n",
214		__func__,
215		(rates & USB_IRDA_BR_2400) ? " 2400" : "",
216		(rates & USB_IRDA_BR_9600) ? " 9600" : "",
217		(rates & USB_IRDA_BR_19200) ? " 19200" : "",
218		(rates & USB_IRDA_BR_38400) ? " 38400" : "",
219		(rates & USB_IRDA_BR_57600) ? " 57600" : "",
220		(rates & USB_IRDA_BR_115200) ? " 115200" : "",
221		(rates & USB_IRDA_BR_576000) ? " 576000" : "",
222		(rates & USB_IRDA_BR_1152000) ? " 1152000" : "",
223		(rates & USB_IRDA_BR_4000000) ? " 4000000" : "");
224
225	switch (irda_desc->bmAdditionalBOFs) {
226	case USB_IRDA_AB_48:
227		ir_add_bof = 48;
228		break;
229	case USB_IRDA_AB_24:
230		ir_add_bof = 24;
231		break;
232	case USB_IRDA_AB_12:
233		ir_add_bof = 12;
234		break;
235	case USB_IRDA_AB_6:
236		ir_add_bof = 6;
237		break;
238	case USB_IRDA_AB_3:
239		ir_add_bof = 3;
240		break;
241	case USB_IRDA_AB_2:
242		ir_add_bof = 2;
243		break;
244	case USB_IRDA_AB_1:
245		ir_add_bof = 1;
246		break;
247	case USB_IRDA_AB_0:
248		ir_add_bof = 0;
249		break;
250	default:
251		break;
252	}
253
254	kfree(irda_desc);
255
256	return 0;
257}
258
259static int ir_write(struct tty_struct *tty, struct usb_serial_port *port,
260		const unsigned char *buf, int count)
261{
262	struct urb *urb = NULL;
263	unsigned long flags;
264	int ret;
265
266	if (port->bulk_out_size == 0)
267		return -EINVAL;
268
269	if (count == 0)
270		return 0;
271
272	count = min(count, port->bulk_out_size - 1);
273
274	spin_lock_irqsave(&port->lock, flags);
275	if (__test_and_clear_bit(0, &port->write_urbs_free)) {
276		urb = port->write_urbs[0];
277		port->tx_bytes += count;
278	}
279	spin_unlock_irqrestore(&port->lock, flags);
280
281	if (!urb)
282		return 0;
283
284	/*
285	 * The first byte of the packet we send to the device contains an
286	 * outbound header which indicates an additional number of BOFs and
287	 * a baud rate change.
288	 *
289	 * See section 5.4.2.2 of the USB IrDA spec.
290	 */
291	*(u8 *)urb->transfer_buffer = ir_xbof | ir_baud;
292
293	memcpy(urb->transfer_buffer + 1, buf, count);
294
295	urb->transfer_buffer_length = count + 1;
296	urb->transfer_flags = URB_ZERO_PACKET;
297
298	ret = usb_submit_urb(urb, GFP_ATOMIC);
299	if (ret) {
300		dev_err(&port->dev, "failed to submit write urb: %d\n", ret);
301
302		spin_lock_irqsave(&port->lock, flags);
303		__set_bit(0, &port->write_urbs_free);
304		port->tx_bytes -= count;
305		spin_unlock_irqrestore(&port->lock, flags);
306
307		return ret;
308	}
309
310	return count;
311}
312
313static void ir_write_bulk_callback(struct urb *urb)
314{
315	struct usb_serial_port *port = urb->context;
316	int status = urb->status;
317	unsigned long flags;
318
319	spin_lock_irqsave(&port->lock, flags);
320	__set_bit(0, &port->write_urbs_free);
321	port->tx_bytes -= urb->transfer_buffer_length - 1;
322	spin_unlock_irqrestore(&port->lock, flags);
323
324	switch (status) {
325	case 0:
326		break;
327	case -ENOENT:
328	case -ECONNRESET:
329	case -ESHUTDOWN:
330		dev_dbg(&port->dev, "write urb stopped: %d\n", status);
331		return;
332	case -EPIPE:
333		dev_err(&port->dev, "write urb stopped: %d\n", status);
334		return;
335	default:
336		dev_err(&port->dev, "nonzero write-urb status: %d\n", status);
337		break;
338	}
339
340	usb_serial_port_softint(port);
341}
342
343static unsigned int ir_write_room(struct tty_struct *tty)
344{
345	struct usb_serial_port *port = tty->driver_data;
346	unsigned int count = 0;
347
348	if (port->bulk_out_size == 0)
349		return 0;
350
351	if (test_bit(0, &port->write_urbs_free))
352		count = port->bulk_out_size - 1;
353
354	return count;
355}
356
357static void ir_process_read_urb(struct urb *urb)
358{
359	struct usb_serial_port *port = urb->context;
360	unsigned char *data = urb->transfer_buffer;
361
362	if (!urb->actual_length)
363		return;
364	/*
365	 * The first byte of the packet we get from the device
366	 * contains a busy indicator and baud rate change.
367	 * See section 5.4.1.2 of the USB IrDA spec.
368	 */
369	if (*data & 0x0f)
370		ir_baud = *data & 0x0f;
371
372	if (urb->actual_length == 1)
373		return;
374
375	tty_insert_flip_string(&port->port, data + 1, urb->actual_length - 1);
376	tty_flip_buffer_push(&port->port);
377}
378
379static void ir_set_termios(struct tty_struct *tty,
380			   struct usb_serial_port *port,
381			   const struct ktermios *old_termios)
382{
383	struct usb_device *udev = port->serial->dev;
384	unsigned char *transfer_buffer;
385	int actual_length;
386	speed_t baud;
387	int ir_baud;
388	int ret;
389
390	baud = tty_get_baud_rate(tty);
391
392	/*
393	 * FIXME, we should compare the baud request against the
394	 * capability stated in the IR header that we got in the
395	 * startup function.
396	 */
397
398	switch (baud) {
399	case 2400:
400		ir_baud = USB_IRDA_LS_2400;
401		break;
402	case 9600:
403		ir_baud = USB_IRDA_LS_9600;
404		break;
405	case 19200:
406		ir_baud = USB_IRDA_LS_19200;
407		break;
408	case 38400:
409		ir_baud = USB_IRDA_LS_38400;
410		break;
411	case 57600:
412		ir_baud = USB_IRDA_LS_57600;
413		break;
414	case 115200:
415		ir_baud = USB_IRDA_LS_115200;
416		break;
417	case 576000:
418		ir_baud = USB_IRDA_LS_576000;
419		break;
420	case 1152000:
421		ir_baud = USB_IRDA_LS_1152000;
422		break;
423	case 4000000:
424		ir_baud = USB_IRDA_LS_4000000;
425		break;
426	default:
427		ir_baud = USB_IRDA_LS_9600;
428		baud = 9600;
429	}
430
431	if (xbof == -1)
432		ir_xbof = ir_xbof_change(ir_add_bof);
433	else
434		ir_xbof = ir_xbof_change(xbof) ;
435
436	/* Only speed changes are supported */
437	tty_termios_copy_hw(&tty->termios, old_termios);
438	tty_encode_baud_rate(tty, baud, baud);
439
440	/*
441	 * send the baud change out on an "empty" data packet
442	 */
443	transfer_buffer = kmalloc(1, GFP_KERNEL);
444	if (!transfer_buffer)
445		return;
446
447	*transfer_buffer = ir_xbof | ir_baud;
448
449	ret = usb_bulk_msg(udev,
450			usb_sndbulkpipe(udev, port->bulk_out_endpointAddress),
451			transfer_buffer, 1, &actual_length, 5000);
452	if (ret || actual_length != 1) {
453		if (!ret)
454			ret = -EIO;
455		dev_err(&port->dev, "failed to change line speed: %d\n", ret);
456	}
457
458	kfree(transfer_buffer);
459}
460
461static int __init ir_init(void)
462{
463	if (buffer_size) {
464		ir_device.bulk_in_size = buffer_size;
465		ir_device.bulk_out_size = buffer_size;
466	}
467
468	return usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME, ir_id_table);
469}
470
471static void __exit ir_exit(void)
472{
473	usb_serial_deregister_drivers(serial_drivers);
474}
475
476
477module_init(ir_init);
478module_exit(ir_exit);
479
480MODULE_AUTHOR(DRIVER_AUTHOR);
481MODULE_DESCRIPTION(DRIVER_DESC);
482MODULE_LICENSE("GPL");
483
484module_param(xbof, int, 0);
485MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
486module_param(buffer_size, int, 0);
487MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
488
489