summaryrefslogtreecommitdiffstats
path: root/drivers/usb/serial/empeg.c
blob: 79a766e9ca23170160c69f182f1cd69e28d313c2 (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
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
/*
 * USB Empeg empeg-car player driver
 *
 *	Copyright (C) 2000, 2001
 *	    Gary Brubaker (xavyer@ix.netcom.com)
 *
 *	Copyright (C) 1999 - 2001
 *	    Greg Kroah-Hartman (greg@kroah.com)
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License, as published by
 *	the Free Software Foundation, version 2.
 *
 * See Documentation/usb/usb-serial.txt for more information on using this driver
 * 
 * (07/16/2001) gb
 *	remove unused code in empeg_close() (thanks to Oliver Neukum for pointing this
 *	out) and rewrote empeg_set_termios().
 * 
 * (05/30/2001) gkh
 *	switched from using spinlock to a semaphore, which fixes lots of problems.
 *
 * (04/08/2001) gb
 *      Identify version on module load.
 * 
 * (01/22/2001) gb
 *	Added write_room() and chars_in_buffer() support. 
 * 
 * (12/21/2000) gb
 *	Moved termio stuff inside the port->active check.
 *	Moved MOD_DEC_USE_COUNT to end of empeg_close().
 * 
 * (12/03/2000) gb
 *	Added port->tty->ldisc.set_termios(port->tty, NULL) to empeg_open()
 *	This notifies the tty driver that the termios have changed.
 * 
 * (11/13/2000) gb
 *	Moved tty->low_latency = 1 from empeg_read_bulk_callback() to empeg_open()
 *	(It only needs to be set once - Doh!)
 * 
 * (11/11/2000) gb
 *	Updated to work with id_table structure.
 * 
 * (11/04/2000) gb
 *	Forked this from visor.c, and hacked it up to work with an
 *	Empeg ltd. empeg-car player.  Constructive criticism welcomed.
 *	I would like to say, 'Thank You' to Greg Kroah-Hartman for the
 *	use of his code, and for his guidance, advice and patience. :)
 *	A 'Thank You' is in order for John Ripley of Empeg ltd for his
 *	advice, and patience too.
 * 
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>
#include <linux/usb.h>
#include "usb-serial.h"

static int debug;

/*
 * Version Information
 */
#define DRIVER_VERSION "v1.2"
#define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Gary Brubaker <xavyer@ix.netcom.com>"
#define DRIVER_DESC "USB Empeg Mark I/II Driver"

#define EMPEG_VENDOR_ID			0x084f
#define EMPEG_PRODUCT_ID		0x0001

/* function prototypes for an empeg-car player */
static int  empeg_open			(struct usb_serial_port *port, struct file *filp);
static void empeg_close			(struct usb_serial_port *port, struct file *filp);
static int  empeg_write			(struct usb_serial_port *port,
					const unsigned char *buf,
					int count);
static int  empeg_write_room		(struct usb_serial_port *port);
static int  empeg_chars_in_buffer	(struct usb_serial_port *port);
static void empeg_throttle		(struct usb_serial_port *port);
static void empeg_unthrottle		(struct usb_serial_port *port);
static int  empeg_startup		(struct usb_serial *serial);
static void empeg_shutdown		(struct usb_serial *serial);
static int  empeg_ioctl			(struct usb_serial_port *port,
					struct file * file,
					unsigned int cmd,
					unsigned long arg);
static void empeg_set_termios		(struct usb_serial_port *port, struct termios *old_termios);
static void empeg_write_bulk_callback	(struct urb *urb, struct pt_regs *regs);
static void empeg_read_bulk_callback	(struct urb *urb, struct pt_regs *regs);

static struct usb_device_id id_table [] = {
	{ USB_DEVICE(EMPEG_VENDOR_ID, EMPEG_PRODUCT_ID) },
	{ }					/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, id_table);

static struct usb_driver empeg_driver = {
	.name =		"empeg",
	.probe =	usb_serial_probe,
	.disconnect =	usb_serial_disconnect,
	.id_table =	id_table,
	.no_dynamic_id = 	1,
};

static struct usb_serial_driver empeg_device = {
	.driver = {
		.owner =	THIS_MODULE,
		.name =		"empeg",
	},
	.id_table =		id_table,
	.num_interrupt_in =	0,
	.num_bulk_in =		1,
	.num_bulk_out =		1,
	.num_ports =		1,
	.open =			empeg_open,
	.close =		empeg_close,
	.throttle =		empeg_throttle,
	.unthrottle =		empeg_unthrottle,
	.attach =		empeg_startup,
	.shutdown =		empeg_shutdown,
	.ioctl =		empeg_ioctl,
	.set_termios =		empeg_set_termios,
	.write =		empeg_write,
	.write_room =		empeg_write_room,
	.chars_in_buffer =	empeg_chars_in_buffer,
	.write_bulk_callback =	empeg_write_bulk_callback,
	.read_bulk_callback =	empeg_read_bulk_callback,
};

#define NUM_URBS			16
#define URB_TRANSFER_BUFFER_SIZE	4096

static struct urb	*write_urb_pool[NUM_URBS];
static spinlock_t	write_urb_pool_lock;
static int		bytes_in;
static int		bytes_out;

/******************************************************************************
 * Empeg specific driver functions
 ******************************************************************************/
static int empeg_open (struct usb_serial_port *port, struct file *filp)
{
	struct usb_serial *serial = port->serial;
	int result = 0;

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

	/* Force default termio settings */
	empeg_set_termios (port, NULL) ;

	bytes_in = 0;
	bytes_out = 0;

	/* Start reading from the device */
	usb_fill_bulk_urb(
		port->read_urb,
		serial->dev, 
		usb_rcvbulkpipe(serial->dev,
			port->bulk_in_endpointAddress),
		port->read_urb->transfer_buffer,
		port->read_urb->transfer_buffer_length,
		empeg_read_bulk_callback,
		port);

	result = usb_submit_urb(port->read_urb, GFP_KERNEL);

	if (result)
		dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);

	return result;
}


static void empeg_close (struct usb_serial_port *port, struct file * filp)
{
	dbg("%s - port %d", __FUNCTION__, port->number);

	/* shutdown our bulk read */
	usb_kill_urb(port->read_urb);
	/* Uncomment the following line if you want to see some statistics in your syslog */
	/* dev_info (&port->dev, "Bytes In = %d  Bytes Out = %d\n", bytes_in, bytes_out); */
}


static int empeg_write (struct usb_serial_port *port, const unsigned char *buf, int count)
{
	struct usb_serial *serial = port->serial;
	struct urb *urb;
	const unsigned char *current_position = buf;
	unsigned long flags;
	int status;
	int i;
	int bytes_sent = 0;
	int transfer_size;

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

	while (count > 0) {

		/* try to find a free urb in our list of them */
		urb = NULL;

		spin_lock_irqsave (&write_urb_pool_lock, flags);

		for (i = 0; i < NUM_URBS; ++i) {
			if (write_urb_pool[i]->status != -EINPROGRESS) {
				urb = write_urb_pool[i];
				break;
			}
		}

		spin_unlock_irqrestore (&write_urb_pool_lock, flags);

		if (urb == NULL) {
			dbg("%s - no more free urbs", __FUNCTION__);
			goto exit;
		}

		if (urb->transfer_buffer == NULL) {
			urb->transfer_buffer = kmalloc (URB_TRANSFER_BUFFER_SIZE, GFP_ATOMIC);
			if (urb->transfer_buffer == NULL) {
				dev_err(&port->dev, "%s no more kernel memory...\n", __FUNCTION__);
				goto exit;
			}
		}

		transfer_size = min (count, URB_TRANSFER_BUFFER_SIZE);

		memcpy (urb->transfer_buffer, current_position, transfer_size);

		usb_serial_debug_data(debug, &port->dev, __FUNCTION__, transfer_size, urb->transfer_buffer);

		/* build up our urb */
		usb_fill_bulk_urb (
			urb,
			serial->dev,
			usb_sndbulkpipe(serial->dev,
				port->bulk_out_endpointAddress), 
			urb->transfer_buffer,
			transfer_size,
			empeg_write_bulk_callback,
			port);

		/* 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", __FUNCTION__, status);
			bytes_sent = status;
			break;
		}

		current_position += transfer_size;
		bytes_sent += transfer_size;
		count -= transfer_size;
		bytes_out += transfer_size;

	}

exit:
	return bytes_sent;

} 


static int empeg_write_room (struct usb_serial_port *port)
{
	unsigned long flags;
	int i;
	int room = 0;

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

	spin_lock_irqsave (&write_urb_pool_lock, flags);

	/* tally up the number of bytes available */
	for (i = 0; i < NUM_URBS; ++i) {
		if (write_urb_pool[i]->status != -EINPROGRESS) {
			room += URB_TRANSFER_BUFFER_SIZE;
		}
	} 

	spin_unlock_irqrestore (&write_urb_pool_lock, flags);

	dbg("%s - returns %d", __FUNCTION__, room);

	return (room);

}


static int empeg_chars_in_buffer (struct usb_serial_port *port)
{
	unsigned long flags;
	int i;
	int chars = 0;

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

	spin_lock_irqsave (&write_urb_pool_lock, flags);

	/* tally up the number of bytes waiting */
	for (i = 0; i < NUM_URBS; ++i) {
		if (write_urb_pool[i]->status == -EINPROGRESS) {
			chars += URB_TRANSFER_BUFFER_SIZE;
		}
	}

	spin_unlock_irqrestore (&write_urb_pool_lock, flags);

	dbg("%s - returns %d", __FUNCTION__, chars);

	return (chars);

}


static void empeg_write_bulk_callback (struct urb *urb, struct pt_regs *regs)
{
	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;

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

	if (urb->status) {
		dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
		return;
	}

	schedule_work(&port->work);
}


static void empeg_read_bulk_callback (struct urb *urb, struct pt_regs *regs)
{
	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
	struct tty_struct *tty;
	unsigned char *data = urb->transfer_buffer;
	int i;
	int result;

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

	if (urb->status) {
		dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
		return;
	}

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

	tty = port->tty;

	if (urb->actual_length) {
		for (i = 0; i < urb->actual_length ; ++i) {
			/* gb - 2000/11/13
			 * If we insert too many characters we'll overflow the buffer.
			 * This means we'll lose bytes - Decidedly bad.
			 */
			if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
				tty_flip_buffer_push(tty);
				}
			tty_insert_flip_char(tty, data[i], 0);
		}
		/* gb - 2000/11/13
		 * Goes straight through instead of scheduling - if tty->low_latency is set.
		 */
		tty_flip_buffer_push(tty);
		bytes_in += urb->actual_length;
	}

	/* Continue trying to always read  */
	usb_fill_bulk_urb(
		port->read_urb,
		port->serial->dev, 
		usb_rcvbulkpipe(port->serial->dev,
			port->bulk_in_endpointAddress),
		port->read_urb->transfer_buffer,
		port->read_urb->transfer_buffer_length,
		empeg_read_bulk_callback,
		port);

	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);

	if (result)
		dev_err(&urb->dev->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);

	return;

}


static void empeg_throttle (struct usb_serial_port *port)
{
	dbg("%s - port %d", __FUNCTION__, port->number);
	usb_kill_urb(port->read_urb);
}


static void empeg_unthrottle (struct usb_serial_port *port)
{
	int result;

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

	port->read_urb->dev = port->serial->dev;

	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);

	if (result)
		dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);

	return;
}


static int  empeg_startup (struct usb_serial *serial)
{
	int r;

	dbg("%s", __FUNCTION__);

	if (serial->dev->actconfig->desc.bConfigurationValue != 1) {
		err("active config #%d != 1 ??",
			serial->dev->actconfig->desc.bConfigurationValue);
		return -ENODEV;
	}
	dbg("%s - reset config", __FUNCTION__);
	r = usb_reset_configuration (serial->dev);

	/* continue on with initialization */
	return r;

}


static void empeg_shutdown (struct usb_serial *serial)
{
	dbg ("%s", __FUNCTION__);
}


static int empeg_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
{
	dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);

	return -ENOIOCTLCMD;
}


static void empeg_set_termios (struct usb_serial_port *port, struct termios *old_termios)
{

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

	if ((!port->tty) || (!port->tty->termios)) {
		dbg("%s - no tty structures", __FUNCTION__);
		return;
	}

	/*
         * The empeg-car player wants these particular tty settings.
         * You could, for example, change the baud rate, however the
         * player only supports 115200 (currently), so there is really
         * no point in support for changes to the tty settings.
         * (at least for now)
         *
         * The default requirements for this device are:
         */
	port->tty->termios->c_iflag
		&= ~(IGNBRK	/* disable ignore break */
		| BRKINT	/* disable break causes interrupt */
		| PARMRK	/* disable mark parity errors */
		| ISTRIP	/* disable clear high bit of input characters */
		| INLCR		/* disable translate NL to CR */
		| IGNCR		/* disable ignore CR */
		| ICRNL		/* disable translate CR to NL */
		| IXON);	/* disable enable XON/XOFF flow control */

	port->tty->termios->c_oflag
		&= ~OPOST;	/* disable postprocess output characters */

	port->tty->termios->c_lflag
		&= ~(ECHO	/* disable echo input characters */
		| ECHONL	/* disable echo new line */
		| ICANON	/* disable erase, kill, werase, and rprnt special characters */
		| ISIG		/* disable interrupt, quit, and suspend special characters */
		| IEXTEN);	/* disable non-POSIX special characters */

	port->tty->termios->c_cflag
		&= ~(CSIZE	/* no size */
		| PARENB	/* disable parity bit */
		| CBAUD);	/* clear current baud rate */

	port->tty->termios->c_cflag
		|= (CS8		/* character size 8 bits */
		| B115200);	/* baud rate 115200 */

	/*
	 * Force low_latency on; otherwise the pushes are scheduled;
	 * this is bad as it opens up the possibility of dropping bytes
	 * on the floor.  We don't want to drop bytes on the floor. :)
	 */
	port->tty->low_latency = 1;

	return;
}


static int __init empeg_init (void)
{
	struct urb *urb;
	int i, retval;

	/* create our write urb pool and transfer buffers */ 
	spin_lock_init (&write_urb_pool_lock);
	for (i = 0; i < NUM_URBS; ++i) {
		urb = usb_alloc_urb(0, GFP_KERNEL);
		write_urb_pool[i] = urb;
		if (urb == NULL) {
			err("No more urbs???");
			continue;
		}

		urb->transfer_buffer = kmalloc (URB_TRANSFER_BUFFER_SIZE, GFP_KERNEL);
		if (!urb->transfer_buffer) {
			err("%s - out of memory for urb buffers.", 
			    __FUNCTION__);
			continue;
		}
	}

	retval = usb_serial_register(&empeg_device);
	if (retval)
		goto failed_usb_serial_register;
	retval = usb_register(&empeg_driver);
	if (retval)
		goto failed_usb_register;

	info(DRIVER_VERSION ":" DRIVER_DESC);

	return 0;
failed_usb_register:
	usb_serial_deregister(&empeg_device);
failed_usb_serial_register:
	for (i = 0; i < NUM_URBS; ++i) {
		if (write_urb_pool[i]) {
			kfree(write_urb_pool[i]->transfer_buffer);
			usb_free_urb(write_urb_pool[i]);
		}
	}
	return retval;
}


static void __exit empeg_exit (void)
{
	int i;
	unsigned long flags;

	usb_deregister(&empeg_driver);
	usb_serial_deregister (&empeg_device);

	spin_lock_irqsave (&write_urb_pool_lock, flags);

	for (i = 0; i < NUM_URBS; ++i) {
		if (write_urb_pool[i]) {
			/* FIXME - uncomment the following usb_kill_urb call when
			 * the host controllers get fixed to set urb->dev = NULL after
			 * the urb is finished.  Otherwise this call oopses. */
			/* usb_kill_urb(write_urb_pool[i]); */
			kfree(write_urb_pool[i]->transfer_buffer);
			usb_free_urb (write_urb_pool[i]);
		}
	}

	spin_unlock_irqrestore (&write_urb_pool_lock, flags);
}


module_init(empeg_init);
module_exit(empeg_exit);

MODULE_AUTHOR( DRIVER_AUTHOR );
MODULE_DESCRIPTION( DRIVER_DESC );
MODULE_LICENSE("GPL");

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