xref: /openbmc/linux/drivers/usb/serial/empeg.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
1 /*
2  * USB Empeg empeg-car player driver
3  *
4  *	Copyright (C) 2000, 2001
5  *	    Gary Brubaker (xavyer@ix.netcom.com)
6  *
7  *	Copyright (C) 1999 - 2001
8  *	    Greg Kroah-Hartman (greg@kroah.com)
9  *
10  *	This program is free software; you can redistribute it and/or modify
11  *	it under the terms of the GNU General Public License, as published by
12  *	the Free Software Foundation, version 2.
13  *
14  * See Documentation/usb/usb-serial.txt for more information on using this driver
15  *
16  * (07/16/2001) gb
17  *	remove unused code in empeg_close() (thanks to Oliver Neukum for pointing this
18  *	out) and rewrote empeg_set_termios().
19  *
20  * (05/30/2001) gkh
21  *	switched from using spinlock to a semaphore, which fixes lots of problems.
22  *
23  * (04/08/2001) gb
24  *      Identify version on module load.
25  *
26  * (01/22/2001) gb
27  *	Added write_room() and chars_in_buffer() support.
28  *
29  * (12/21/2000) gb
30  *	Moved termio stuff inside the port->active check.
31  *	Moved MOD_DEC_USE_COUNT to end of empeg_close().
32  *
33  * (12/03/2000) gb
34  *	Added port->tty->ldisc.set_termios(port->tty, NULL) to empeg_open()
35  *	This notifies the tty driver that the termios have changed.
36  *
37  * (11/13/2000) gb
38  *	Moved tty->low_latency = 1 from empeg_read_bulk_callback() to empeg_open()
39  *	(It only needs to be set once - Doh!)
40  *
41  * (11/11/2000) gb
42  *	Updated to work with id_table structure.
43  *
44  * (11/04/2000) gb
45  *	Forked this from visor.c, and hacked it up to work with an
46  *	Empeg ltd. empeg-car player.  Constructive criticism welcomed.
47  *	I would like to say, 'Thank You' to Greg Kroah-Hartman for the
48  *	use of his code, and for his guidance, advice and patience. :)
49  *	A 'Thank You' is in order for John Ripley of Empeg ltd for his
50  *	advice, and patience too.
51  *
52  */
53 
54 #include <linux/kernel.h>
55 #include <linux/errno.h>
56 #include <linux/init.h>
57 #include <linux/slab.h>
58 #include <linux/tty.h>
59 #include <linux/tty_driver.h>
60 #include <linux/tty_flip.h>
61 #include <linux/module.h>
62 #include <linux/spinlock.h>
63 #include <asm/uaccess.h>
64 #include <linux/usb.h>
65 #include <linux/usb/serial.h>
66 
67 static int debug;
68 
69 /*
70  * Version Information
71  */
72 #define DRIVER_VERSION "v1.2"
73 #define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Gary Brubaker <xavyer@ix.netcom.com>"
74 #define DRIVER_DESC "USB Empeg Mark I/II Driver"
75 
76 #define EMPEG_VENDOR_ID			0x084f
77 #define EMPEG_PRODUCT_ID		0x0001
78 
79 /* function prototypes for an empeg-car player */
80 static int  empeg_open			(struct usb_serial_port *port, struct file *filp);
81 static void empeg_close			(struct usb_serial_port *port, struct file *filp);
82 static int  empeg_write			(struct usb_serial_port *port,
83 					const unsigned char *buf,
84 					int count);
85 static int  empeg_write_room		(struct usb_serial_port *port);
86 static int  empeg_chars_in_buffer	(struct usb_serial_port *port);
87 static void empeg_throttle		(struct usb_serial_port *port);
88 static void empeg_unthrottle		(struct usb_serial_port *port);
89 static int  empeg_startup		(struct usb_serial *serial);
90 static void empeg_shutdown		(struct usb_serial *serial);
91 static int  empeg_ioctl			(struct usb_serial_port *port,
92 					struct file * file,
93 					unsigned int cmd,
94 					unsigned long arg);
95 static void empeg_set_termios		(struct usb_serial_port *port, struct ktermios *old_termios);
96 static void empeg_write_bulk_callback	(struct urb *urb);
97 static void empeg_read_bulk_callback	(struct urb *urb);
98 
99 static struct usb_device_id id_table [] = {
100 	{ USB_DEVICE(EMPEG_VENDOR_ID, EMPEG_PRODUCT_ID) },
101 	{ }					/* Terminating entry */
102 };
103 
104 MODULE_DEVICE_TABLE (usb, id_table);
105 
106 static struct usb_driver empeg_driver = {
107 	.name =		"empeg",
108 	.probe =	usb_serial_probe,
109 	.disconnect =	usb_serial_disconnect,
110 	.id_table =	id_table,
111 	.no_dynamic_id = 	1,
112 };
113 
114 static struct usb_serial_driver empeg_device = {
115 	.driver = {
116 		.owner =	THIS_MODULE,
117 		.name =		"empeg",
118 	},
119 	.id_table =		id_table,
120 	.usb_driver = 		&empeg_driver,
121 	.num_interrupt_in =	0,
122 	.num_bulk_in =		1,
123 	.num_bulk_out =		1,
124 	.num_ports =		1,
125 	.open =			empeg_open,
126 	.close =		empeg_close,
127 	.throttle =		empeg_throttle,
128 	.unthrottle =		empeg_unthrottle,
129 	.attach =		empeg_startup,
130 	.shutdown =		empeg_shutdown,
131 	.ioctl =		empeg_ioctl,
132 	.set_termios =		empeg_set_termios,
133 	.write =		empeg_write,
134 	.write_room =		empeg_write_room,
135 	.chars_in_buffer =	empeg_chars_in_buffer,
136 	.write_bulk_callback =	empeg_write_bulk_callback,
137 	.read_bulk_callback =	empeg_read_bulk_callback,
138 };
139 
140 #define NUM_URBS			16
141 #define URB_TRANSFER_BUFFER_SIZE	4096
142 
143 static struct urb	*write_urb_pool[NUM_URBS];
144 static spinlock_t	write_urb_pool_lock;
145 static int		bytes_in;
146 static int		bytes_out;
147 
148 /******************************************************************************
149  * Empeg specific driver functions
150  ******************************************************************************/
151 static int empeg_open (struct usb_serial_port *port, struct file *filp)
152 {
153 	struct usb_serial *serial = port->serial;
154 	int result = 0;
155 
156 	dbg("%s - port %d", __FUNCTION__, port->number);
157 
158 	/* Force default termio settings */
159 	empeg_set_termios (port, NULL) ;
160 
161 	bytes_in = 0;
162 	bytes_out = 0;
163 
164 	/* Start reading from the device */
165 	usb_fill_bulk_urb(
166 		port->read_urb,
167 		serial->dev,
168 		usb_rcvbulkpipe(serial->dev,
169 			port->bulk_in_endpointAddress),
170 		port->read_urb->transfer_buffer,
171 		port->read_urb->transfer_buffer_length,
172 		empeg_read_bulk_callback,
173 		port);
174 
175 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
176 
177 	if (result)
178 		dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
179 
180 	return result;
181 }
182 
183 
184 static void empeg_close (struct usb_serial_port *port, struct file * filp)
185 {
186 	dbg("%s - port %d", __FUNCTION__, port->number);
187 
188 	/* shutdown our bulk read */
189 	usb_kill_urb(port->read_urb);
190 	/* Uncomment the following line if you want to see some statistics in your syslog */
191 	/* dev_info (&port->dev, "Bytes In = %d  Bytes Out = %d\n", bytes_in, bytes_out); */
192 }
193 
194 
195 static int empeg_write (struct usb_serial_port *port, const unsigned char *buf, int count)
196 {
197 	struct usb_serial *serial = port->serial;
198 	struct urb *urb;
199 	const unsigned char *current_position = buf;
200 	unsigned long flags;
201 	int status;
202 	int i;
203 	int bytes_sent = 0;
204 	int transfer_size;
205 
206 	dbg("%s - port %d", __FUNCTION__, port->number);
207 
208 	while (count > 0) {
209 
210 		/* try to find a free urb in our list of them */
211 		urb = NULL;
212 
213 		spin_lock_irqsave (&write_urb_pool_lock, flags);
214 
215 		for (i = 0; i < NUM_URBS; ++i) {
216 			if (write_urb_pool[i]->status != -EINPROGRESS) {
217 				urb = write_urb_pool[i];
218 				break;
219 			}
220 		}
221 
222 		spin_unlock_irqrestore (&write_urb_pool_lock, flags);
223 
224 		if (urb == NULL) {
225 			dbg("%s - no more free urbs", __FUNCTION__);
226 			goto exit;
227 		}
228 
229 		if (urb->transfer_buffer == NULL) {
230 			urb->transfer_buffer = kmalloc (URB_TRANSFER_BUFFER_SIZE, GFP_ATOMIC);
231 			if (urb->transfer_buffer == NULL) {
232 				dev_err(&port->dev, "%s no more kernel memory...\n", __FUNCTION__);
233 				goto exit;
234 			}
235 		}
236 
237 		transfer_size = min (count, URB_TRANSFER_BUFFER_SIZE);
238 
239 		memcpy (urb->transfer_buffer, current_position, transfer_size);
240 
241 		usb_serial_debug_data(debug, &port->dev, __FUNCTION__, transfer_size, urb->transfer_buffer);
242 
243 		/* build up our urb */
244 		usb_fill_bulk_urb (
245 			urb,
246 			serial->dev,
247 			usb_sndbulkpipe(serial->dev,
248 				port->bulk_out_endpointAddress),
249 			urb->transfer_buffer,
250 			transfer_size,
251 			empeg_write_bulk_callback,
252 			port);
253 
254 		/* send it down the pipe */
255 		status = usb_submit_urb(urb, GFP_ATOMIC);
256 		if (status) {
257 			dev_err(&port->dev, "%s - usb_submit_urb(write bulk) failed with status = %d\n", __FUNCTION__, status);
258 			bytes_sent = status;
259 			break;
260 		}
261 
262 		current_position += transfer_size;
263 		bytes_sent += transfer_size;
264 		count -= transfer_size;
265 		bytes_out += transfer_size;
266 
267 	}
268 
269 exit:
270 	return bytes_sent;
271 
272 }
273 
274 
275 static int empeg_write_room (struct usb_serial_port *port)
276 {
277 	unsigned long flags;
278 	int i;
279 	int room = 0;
280 
281 	dbg("%s - port %d", __FUNCTION__, port->number);
282 
283 	spin_lock_irqsave (&write_urb_pool_lock, flags);
284 
285 	/* tally up the number of bytes available */
286 	for (i = 0; i < NUM_URBS; ++i) {
287 		if (write_urb_pool[i]->status != -EINPROGRESS) {
288 			room += URB_TRANSFER_BUFFER_SIZE;
289 		}
290 	}
291 
292 	spin_unlock_irqrestore (&write_urb_pool_lock, flags);
293 
294 	dbg("%s - returns %d", __FUNCTION__, room);
295 
296 	return (room);
297 
298 }
299 
300 
301 static int empeg_chars_in_buffer (struct usb_serial_port *port)
302 {
303 	unsigned long flags;
304 	int i;
305 	int chars = 0;
306 
307 	dbg("%s - port %d", __FUNCTION__, port->number);
308 
309 	spin_lock_irqsave (&write_urb_pool_lock, flags);
310 
311 	/* tally up the number of bytes waiting */
312 	for (i = 0; i < NUM_URBS; ++i) {
313 		if (write_urb_pool[i]->status == -EINPROGRESS) {
314 			chars += URB_TRANSFER_BUFFER_SIZE;
315 		}
316 	}
317 
318 	spin_unlock_irqrestore (&write_urb_pool_lock, flags);
319 
320 	dbg("%s - returns %d", __FUNCTION__, chars);
321 
322 	return (chars);
323 
324 }
325 
326 
327 static void empeg_write_bulk_callback (struct urb *urb)
328 {
329 	struct usb_serial_port *port = urb->context;
330 	int status = urb->status;
331 
332 	dbg("%s - port %d", __FUNCTION__, port->number);
333 
334 	if (status) {
335 		dbg("%s - nonzero write bulk status received: %d",
336 		    __FUNCTION__, status);
337 		return;
338 	}
339 
340 	usb_serial_port_softint(port);
341 }
342 
343 
344 static void empeg_read_bulk_callback (struct urb *urb)
345 {
346 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
347 	struct tty_struct *tty;
348 	unsigned char *data = urb->transfer_buffer;
349 	int result;
350 	int status = urb->status;
351 
352 	dbg("%s - port %d", __FUNCTION__, port->number);
353 
354 	if (status) {
355 		dbg("%s - nonzero read bulk status received: %d",
356 		    __FUNCTION__, status);
357 		return;
358 	}
359 
360 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
361 
362 	tty = port->tty;
363 
364 	if (urb->actual_length) {
365 		tty_buffer_request_room(tty, urb->actual_length);
366 		tty_insert_flip_string(tty, data, urb->actual_length);
367 		tty_flip_buffer_push(tty);
368 		bytes_in += urb->actual_length;
369 	}
370 
371 	/* Continue trying to always read  */
372 	usb_fill_bulk_urb(
373 		port->read_urb,
374 		port->serial->dev,
375 		usb_rcvbulkpipe(port->serial->dev,
376 			port->bulk_in_endpointAddress),
377 		port->read_urb->transfer_buffer,
378 		port->read_urb->transfer_buffer_length,
379 		empeg_read_bulk_callback,
380 		port);
381 
382 	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
383 
384 	if (result)
385 		dev_err(&urb->dev->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
386 
387 	return;
388 
389 }
390 
391 
392 static void empeg_throttle (struct usb_serial_port *port)
393 {
394 	dbg("%s - port %d", __FUNCTION__, port->number);
395 	usb_kill_urb(port->read_urb);
396 }
397 
398 
399 static void empeg_unthrottle (struct usb_serial_port *port)
400 {
401 	int result;
402 
403 	dbg("%s - port %d", __FUNCTION__, port->number);
404 
405 	port->read_urb->dev = port->serial->dev;
406 
407 	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
408 
409 	if (result)
410 		dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
411 
412 	return;
413 }
414 
415 
416 static int  empeg_startup (struct usb_serial *serial)
417 {
418 	int r;
419 
420 	dbg("%s", __FUNCTION__);
421 
422 	if (serial->dev->actconfig->desc.bConfigurationValue != 1) {
423 		err("active config #%d != 1 ??",
424 			serial->dev->actconfig->desc.bConfigurationValue);
425 		return -ENODEV;
426 	}
427 	dbg("%s - reset config", __FUNCTION__);
428 	r = usb_reset_configuration (serial->dev);
429 
430 	/* continue on with initialization */
431 	return r;
432 
433 }
434 
435 
436 static void empeg_shutdown (struct usb_serial *serial)
437 {
438 	dbg ("%s", __FUNCTION__);
439 }
440 
441 
442 static int empeg_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
443 {
444 	dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);
445 
446 	return -ENOIOCTLCMD;
447 }
448 
449 
450 static void empeg_set_termios (struct usb_serial_port *port, struct ktermios *old_termios)
451 {
452 
453 	dbg("%s - port %d", __FUNCTION__, port->number);
454 
455 	if ((!port->tty) || (!port->tty->termios)) {
456 		dbg("%s - no tty structures", __FUNCTION__);
457 		return;
458 	}
459 
460 	/*
461          * The empeg-car player wants these particular tty settings.
462          * You could, for example, change the baud rate, however the
463          * player only supports 115200 (currently), so there is really
464          * no point in support for changes to the tty settings.
465          * (at least for now)
466          *
467          * The default requirements for this device are:
468          */
469 	port->tty->termios->c_iflag
470 		&= ~(IGNBRK	/* disable ignore break */
471 		| BRKINT	/* disable break causes interrupt */
472 		| PARMRK	/* disable mark parity errors */
473 		| ISTRIP	/* disable clear high bit of input characters */
474 		| INLCR		/* disable translate NL to CR */
475 		| IGNCR		/* disable ignore CR */
476 		| ICRNL		/* disable translate CR to NL */
477 		| IXON);	/* disable enable XON/XOFF flow control */
478 
479 	port->tty->termios->c_oflag
480 		&= ~OPOST;	/* disable postprocess output characters */
481 
482 	port->tty->termios->c_lflag
483 		&= ~(ECHO	/* disable echo input characters */
484 		| ECHONL	/* disable echo new line */
485 		| ICANON	/* disable erase, kill, werase, and rprnt special characters */
486 		| ISIG		/* disable interrupt, quit, and suspend special characters */
487 		| IEXTEN);	/* disable non-POSIX special characters */
488 
489 	port->tty->termios->c_cflag
490 		&= ~(CSIZE	/* no size */
491 		| PARENB	/* disable parity bit */
492 		| CBAUD);	/* clear current baud rate */
493 
494 	port->tty->termios->c_cflag
495 		|= (CS8		/* character size 8 bits */
496 		| B115200);	/* baud rate 115200 */
497 
498 	/*
499 	 * Force low_latency on; otherwise the pushes are scheduled;
500 	 * this is bad as it opens up the possibility of dropping bytes
501 	 * on the floor.  We don't want to drop bytes on the floor. :)
502 	 */
503 	port->tty->low_latency = 1;
504 
505 	return;
506 }
507 
508 
509 static int __init empeg_init (void)
510 {
511 	struct urb *urb;
512 	int i, retval;
513 
514 	/* create our write urb pool and transfer buffers */
515 	spin_lock_init (&write_urb_pool_lock);
516 	for (i = 0; i < NUM_URBS; ++i) {
517 		urb = usb_alloc_urb(0, GFP_KERNEL);
518 		write_urb_pool[i] = urb;
519 		if (urb == NULL) {
520 			err("No more urbs???");
521 			continue;
522 		}
523 
524 		urb->transfer_buffer = kmalloc (URB_TRANSFER_BUFFER_SIZE, GFP_KERNEL);
525 		if (!urb->transfer_buffer) {
526 			err("%s - out of memory for urb buffers.",
527 			    __FUNCTION__);
528 			continue;
529 		}
530 	}
531 
532 	retval = usb_serial_register(&empeg_device);
533 	if (retval)
534 		goto failed_usb_serial_register;
535 	retval = usb_register(&empeg_driver);
536 	if (retval)
537 		goto failed_usb_register;
538 
539 	info(DRIVER_VERSION ":" DRIVER_DESC);
540 
541 	return 0;
542 failed_usb_register:
543 	usb_serial_deregister(&empeg_device);
544 failed_usb_serial_register:
545 	for (i = 0; i < NUM_URBS; ++i) {
546 		if (write_urb_pool[i]) {
547 			kfree(write_urb_pool[i]->transfer_buffer);
548 			usb_free_urb(write_urb_pool[i]);
549 		}
550 	}
551 	return retval;
552 }
553 
554 
555 static void __exit empeg_exit (void)
556 {
557 	int i;
558 	unsigned long flags;
559 
560 	usb_deregister(&empeg_driver);
561 	usb_serial_deregister (&empeg_device);
562 
563 	spin_lock_irqsave (&write_urb_pool_lock, flags);
564 
565 	for (i = 0; i < NUM_URBS; ++i) {
566 		if (write_urb_pool[i]) {
567 			/* FIXME - uncomment the following usb_kill_urb call when
568 			 * the host controllers get fixed to set urb->dev = NULL after
569 			 * the urb is finished.  Otherwise this call oopses. */
570 			/* usb_kill_urb(write_urb_pool[i]); */
571 			kfree(write_urb_pool[i]->transfer_buffer);
572 			usb_free_urb (write_urb_pool[i]);
573 		}
574 	}
575 
576 	spin_unlock_irqrestore (&write_urb_pool_lock, flags);
577 }
578 
579 
580 module_init(empeg_init);
581 module_exit(empeg_exit);
582 
583 MODULE_AUTHOR( DRIVER_AUTHOR );
584 MODULE_DESCRIPTION( DRIVER_DESC );
585 MODULE_LICENSE("GPL");
586 
587 module_param(debug, bool, S_IRUGO | S_IWUSR);
588 MODULE_PARM_DESC(debug, "Debug enabled or not");
589