aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/usb/serial/opticon.c
blob: f37476e22684af0663b46e41d4431692834d741b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
/*
 * Opticon USB barcode to serial driver
 *
 * Copyright (C) 2008 - 2009 Greg Kroah-Hartman <gregkh@suse.de>
 * Copyright (C) 2008 - 2009 Novell Inc.
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License version
 *	2 as published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/uaccess.h>

static int debug;

static const struct usb_device_id id_table[] = {
	{ USB_DEVICE(0x065a, 0x0009) },
	{ },
};
MODULE_DEVICE_TABLE(usb, id_table);

/* This structure holds all of the individual device information */
struct opticon_private {
	struct usb_device *udev;
	struct usb_serial *serial;
	struct usb_serial_port *port;
	unsigned char *bulk_in_buffer;
	struct urb *bulk_read_urb;
	int buffer_size;
	u8 bulk_address;
	spinlock_t lock;	/* protects the following flags */
	bool throttled;
	bool actually_throttled;
	bool rts;
	int outstanding_urbs;
};

/* max number of write urbs in flight */
#define URB_UPPER_LIMIT	4

static void opticon_bulk_callback(struct urb *urb)
{
	struct opticon_private *priv = urb->context;
	unsigned char *data = urb->transfer_buffer;
	struct usb_serial_port *port = priv->port;
	int status = urb->status;
	struct tty_struct *tty;
	int result;
	int data_length;

	dbg("%s - port %d", __func__, port->number);

	switch (status) {
	case 0:
		/* success */
		break;
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
		/* this urb is terminated, clean up */
		dbg("%s - urb shutting down with status: %d",
		    __func__, status);
		return;
	default:
		dbg("%s - nonzero urb status received: %d",
		    __func__, status);
		goto exit;
	}

	usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length,
			      data);

	if (urb->actual_length > 2) {
		data_length = urb->actual_length - 2;

		/*
		 * Data from the device comes with a 2 byte header:
		 *
		 * <0x00><0x00>data...
		 * 	This is real data to be sent to the tty layer
		 * <0x00><0x01)level
		 * 	This is a RTS level change, the third byte is the RTS
		 * 	value (0 for low, 1 for high).
		 */
		if ((data[0] == 0x00) && (data[1] == 0x00)) {
			/* real data, send it to the tty layer */
			tty = tty_port_tty_get(&port->port);
			if (tty) {
				tty_insert_flip_string(tty, data,
							       data_length);
				tty_flip_buffer_push(tty);
				tty_kref_put(tty);
			}
		} else {
			if ((data[0] == 0x00) && (data[1] == 0x01)) {
				if (data[2] == 0x00)
					priv->rts = false;
				else
					priv->rts = true;
			} else {
			dev_dbg(&priv->udev->dev,
				"Unknown data packet received from the device:"
				" %2x %2x\n",
				data[0], data[1]);
			}
		}
	} else {
		dev_dbg(&priv->udev->dev,
			"Improper ammount of data received from the device, "
			"%d bytes", urb->actual_length);
	}

exit:
	spin_lock(&priv->lock);

	/* Continue trying to always read if we should */
	if (!priv->throttled) {
		usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
				  usb_rcvbulkpipe(priv->udev,
						  priv->bulk_address),
				  priv->bulk_in_buffer, priv->buffer_size,
				  opticon_bulk_callback, priv);
		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
		if (result)
			dev_err(&port->dev,
			    "%s - failed resubmitting read urb, error %d\n",
							__func__, result);
	} else
		priv->actually_throttled = true;
	spin_unlock(&priv->lock);
}

static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
{
	struct opticon_private *priv = usb_get_serial_data(port->serial);
	unsigned long flags;
	int result = 0;

	dbg("%s - port %d", __func__, port->number);

	spin_lock_irqsave(&priv->lock, flags);
	priv->throttled = false;
	priv->actually_throttled = false;
	priv->port = port;
	spin_unlock_irqrestore(&priv->lock, flags);

	/* Start reading from the device */
	usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
			  usb_rcvbulkpipe(priv->udev,
					  priv->bulk_address),
			  priv->bulk_in_buffer, priv->buffer_size,
			  opticon_bulk_callback, priv);
	result = usb_submit_urb(priv->bulk_read_urb, GFP_KERNEL);
	if (result)
		dev_err(&port->dev,
			"%s - failed resubmitting read urb, error %d\n",
			__func__, result);
	return result;
}

static void opticon_close(struct usb_serial_port *port)
{
	struct opticon_private *priv = usb_get_serial_data(port->serial);

	dbg("%s - port %d", __func__, port->number);

	/* shutdown our urbs */
	usb_kill_urb(priv->bulk_read_urb);
}

static void opticon_write_bulk_callback(struct urb *urb)
{
	struct opticon_private *priv = urb->context;
	int status = urb->status;
	unsigned long flags;

	/* free up the transfer buffer, as usb_free_urb() does not do this */
	kfree(urb->transfer_buffer);

	if (status)
		dbg("%s - nonzero write bulk status received: %d",
		    __func__, status);

	spin_lock_irqsave(&priv->lock, flags);
	--priv->outstanding_urbs;
	spin_unlock_irqrestore(&priv->lock, flags);

	usb_serial_port_softint(priv->port);
}

static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
			 const unsigned char *buf, int count)
{
	struct opticon_private *priv = usb_get_serial_data(port->serial);
	struct usb_serial *serial = port->serial;
	struct urb *urb;
	unsigned char *buffer;
	unsigned long flags;
	int status;

	dbg("%s - port %d", __func__, port->number);

	spin_lock_irqsave(&priv->lock, flags);
	if (priv->outstanding_urbs > URB_UPPER_LIMIT) {
		spin_unlock_irqrestore(&priv->lock, flags);
		dbg("%s - write limit hit", __func__);
		return 0;
	}
	priv->outstanding_urbs++;
	spin_unlock_irqrestore(&priv->lock, flags);

	buffer = kmalloc(count, GFP_ATOMIC);
	if (!buffer) {
		dev_err(&port->dev, "out of memory\n");
		count = -ENOMEM;
		goto error_no_buffer;
	}

	urb = usb_alloc_urb(0, GFP_ATOMIC);
	if (!urb) {
		dev_err(&port->dev, "no more free urbs\n");
		count = -ENOMEM;
		goto error_no_urb;
	}

	memcpy(buffer, buf, count);

	usb_serial_debug_data(debug, &port->dev, __func__, count, buffer);

	usb_fill_bulk_urb(urb, serial->dev,
			  usb_sndbulkpipe(serial->dev,
					  port->bulk_out_endpointAddress),
			  buffer, count, opticon_write_bulk_callback, priv);

	/* send it down the pipe */
	status = usb_submit_urb(urb, GFP_ATOMIC);
	if (status) {
		dev_err(&port->dev,
		   "%s - usb_submit_urb(write bulk) failed with status = %d\n",
							__func__, status);
		count = status;
		goto error;
	}

	/* we are done with this urb, so let the host driver
	 * really free it when it is finished with it */
	usb_free_urb(urb);

	return count;
error:
	usb_free_urb(urb);
error_no_urb:
	kfree(buffer);
error_no_buffer:
	spin_lock_irqsave(&priv->lock, flags);
	--priv->outstanding_urbs;
	spin_unlock_irqrestore(&priv->lock, flags);
	return count;
}

static int opticon_write_room(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	struct opticon_private *priv = usb_get_serial_data(port->serial);
	unsigned long flags;

	dbg("%s - port %d", __func__, port->number);

	/*
	 * We really can take almost anything the user throws at us
	 * but let's pick a nice big number to tell the tty
	 * layer that we have lots of free space, unless we don't.
	 */
	spin_lock_irqsave(&priv->lock, flags);
	if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
		spin_unlock_irqrestore(&priv->lock, flags);
		dbg("%s - write limit hit", __func__);
		return 0;
	}
	spin_unlock_irqrestore(&priv->lock, flags);

	return 2048;
}

static void opticon_throttle(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	struct opticon_private *priv = usb_get_serial_data(port->serial);
	unsigned long flags;

	dbg("%s - port %d", __func__, port->number);
	spin_lock_irqsave(&priv->lock, flags);
	priv->throttled = true;
	spin_unlock_irqrestore(&priv->lock, flags);
}


static void opticon_unthrottle(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	struct opticon_private *priv = usb_get_serial_data(port->serial);
	unsigned long flags;
	int result, was_throttled;

	dbg("%s - port %d", __func__, port->number);

	spin_lock_irqsave(&priv->lock, flags);
	priv->throttled = false;
	was_throttled = priv->actually_throttled;
	priv->actually_throttled = false;
	spin_unlock_irqrestore(&priv->lock, flags);

	priv->bulk_read_urb->dev = port->serial->dev;
	if (was_throttled) {
		result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
		if (result)
			dev_err(&port->dev,
				"%s - failed submitting read urb, error %d\n",
							__func__, result);
	}
}

static int opticon_tiocmget(struct tty_struct *tty, struct file *file)
{
	struct usb_serial_port *port = tty->driver_data;
	struct opticon_private *priv = usb_get_serial_data(port->serial);
	unsigned long flags;
	int result = 0;

	dbg("%s - port %d", __func__, port->number);

	spin_lock_irqsave(&priv->lock, flags);
	if (priv->rts)
		result = TIOCM_RTS;
	spin_unlock_irqrestore(&priv->lock, flags);

	dbg("%s - %x", __func__, result);
	return result;
}

static int get_serial_info(struct opticon_private *priv,
			   struct serial_struct __user *serial)
{
	struct serial_struct tmp;

	if (!serial)
		return -EFAULT;

	memset(&tmp, 0x00, sizeof(tmp));

	/* fake emulate a 16550 uart to make userspace code happy */
	tmp.type		= PORT_16550A;
	tmp.line		= priv->serial->minor;
	tmp.port		= 0;
	tmp.irq			= 0;
	tmp.flags		= ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
	tmp.xmit_fifo_size	= 1024;
	tmp.baud_base		= 9600;
	tmp.close_delay		= 5*HZ;
	tmp.closing_wait	= 30*HZ;

	if (copy_to_user(serial, &tmp, sizeof(*serial)))
		return -EFAULT;
	return 0;
}

static int opticon_ioctl(struct tty_struct *tty, struct file *file,
			 unsigned int cmd, unsigned long arg)
{
	struct usb_serial_port *port = tty->driver_data;
	struct opticon_private *priv = usb_get_serial_data(port->serial);

	dbg("%s - port %d, cmd = 0x%x", __func__, port->number, cmd);

	switch (cmd) {
	case TIOCGSERIAL:
		return get_serial_info(priv,
				       (struct serial_struct __user *)arg);
	}

	return -ENOIOCTLCMD;
}

static int opticon_startup(struct usb_serial *serial)
{
	struct opticon_private *priv;
	struct usb_host_interface *intf;
	int i;
	int retval = -ENOMEM;
	bool bulk_in_found = false;

	/* create our private serial structure */
	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (priv == NULL) {
		dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
		return -ENOMEM;
	}
	spin_lock_init(&priv->lock);
	priv->serial = serial;
	priv->port = serial->port[0];
	priv->udev = serial->dev;

	/* find our bulk endpoint */
	intf = serial->interface->altsetting;
	for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
		struct usb_endpoint_descriptor *endpoint;

		endpoint = &intf->endpoint[i].desc;
		if (!usb_endpoint_is_bulk_in(endpoint))
			continue;

		priv->bulk_read_urb = usb_alloc_urb(0, GFP_KERNEL);
		if (!priv->bulk_read_urb) {
			dev_err(&priv->udev->dev, "out of memory\n");
			goto error;
		}

		priv->buffer_size = le16_to_cpu(endpoint->wMaxPacketSize) * 2;
		priv->bulk_in_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
		if (!priv->bulk_in_buffer) {
			dev_err(&priv->udev->dev, "out of memory\n");
			goto error;
		}

		priv->bulk_address = endpoint->bEndpointAddress;

		/* set up our bulk urb */
		usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
				  usb_rcvbulkpipe(priv->udev,
						  endpoint->bEndpointAddress),
				  priv->bulk_in_buffer, priv->buffer_size,
				  opticon_bulk_callback, priv);

		bulk_in_found = true;
		break;
		}

	if (!bulk_in_found) {
		dev_err(&priv->udev->dev,
			"Error - the proper endpoints were not found!\n");
		goto error;
	}

	usb_set_serial_data(serial, priv);
	return 0;

error:
	usb_free_urb(priv->bulk_read_urb);
	kfree(priv->bulk_in_buffer);
	kfree(priv);
	return retval;
}

static void opticon_disconnect(struct usb_serial *serial)
{
	struct opticon_private *priv = usb_get_serial_data(serial);

	dbg("%s", __func__);

	usb_kill_urb(priv->bulk_read_urb);
	usb_free_urb(priv->bulk_read_urb);
}

static void opticon_release(struct usb_serial *serial)
{
	struct opticon_private *priv = usb_get_serial_data(serial);

	dbg("%s", __func__);

	kfree(priv->bulk_in_buffer);
	kfree(priv);
}

static int opticon_suspend(struct usb_interface *intf, pm_message_t message)
{
	struct usb_serial *serial = usb_get_intfdata(intf);
	struct opticon_private *priv = usb_get_serial_data(serial);

	usb_kill_urb(priv->bulk_read_urb);
	return 0;
}

static int opticon_resume(struct usb_interface *intf)
{
	struct usb_serial *serial = usb_get_intfdata(intf);
	struct opticon_private *priv = usb_get_serial_data(serial);
	struct usb_serial_port *port = serial->port[0];
	int result;

	mutex_lock(&port->port.mutex);
	/* This is protected by the port mutex against close/open */
	if (test_bit(ASYNCB_INITIALIZED, &port->port.flags))
		result = usb_submit_urb(priv->bulk_read_urb, GFP_NOIO);
	else
		result = 0;
	mutex_unlock(&port->port.mutex);
	return result;
}

static struct usb_driver opticon_driver = {
	.name =		"opticon",
	.probe =	usb_serial_probe,
	.disconnect =	usb_serial_disconnect,
	.suspend =	opticon_suspend,
	.resume =	opticon_resume,
	.id_table =	id_table,
	.no_dynamic_id = 	1,
};

static struct usb_serial_driver opticon_device = {
	.driver = {
		.owner =	THIS_MODULE,
		.name =		"opticon",
	},
	.id_table =		id_table,
	.usb_driver = 		&opticon_driver,
	.num_ports =		1,
	.attach =		opticon_startup,
	.open =			opticon_open,
	.close =		opticon_close,
	.write =		opticon_write,
	.write_room = 		opticon_write_room,
	.disconnect =		opticon_disconnect,
	.release =		opticon_release,
	.throttle = 		opticon_throttle,
	.unthrottle =		opticon_unthrottle,
	.ioctl =		opticon_ioctl,
	.tiocmget =		opticon_tiocmget,
};

static int __init opticon_init(void)
{
	int retval;

	retval = usb_serial_register(&opticon_device);
	if (retval)
		return retval;
	retval = usb_register(&opticon_driver);
	if (retval)
		usb_serial_deregister(&opticon_device);
	return retval;
}

static void __exit opticon_exit(void)
{
	usb_deregister(&opticon_driver);
	usb_serial_deregister(&opticon_device);
}

module_init(opticon_init);
module_exit(opticon_exit);
MODULE_LICENSE("GPL");

module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");