xref: /linux/drivers/usb/serial/empeg.c (revision 5bdef865eb358b6f3760e25e591ae115e9eeddef)
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
15  * driver
16  *
17  * (07/16/2001) gb
18  *	remove unused code in empeg_close() (thanks to Oliver Neukum for
19  *	pointing this out) and rewrote empeg_set_termios().
20  *
21  * (05/30/2001) gkh
22  *	switched from using spinlock to a semaphore, which fixes lots of
23  * problems.
24  *
25  * (04/08/2001) gb
26  *      Identify version on module load.
27  *
28  * (01/22/2001) gb
29  *	Added write_room() and chars_in_buffer() support.
30  *
31  * (12/21/2000) gb
32  *	Moved termio stuff inside the port->active check.
33  *	Moved MOD_DEC_USE_COUNT to end of empeg_close().
34  *
35  * (12/03/2000) gb
36  *	Added tty->ldisc.set_termios(port, tty, NULL) to empeg_open().
37  *	This notifies the tty driver that the termios have changed.
38  *
39  * (11/13/2000) gb
40  *	Moved tty->low_latency = 1 from empeg_read_bulk_callback() to
41  *	empeg_open() (It only needs to be set once - Doh!)
42  *
43  * (11/11/2000) gb
44  *	Updated to work with id_table structure.
45  *
46  * (11/04/2000) gb
47  *	Forked this from visor.c, and hacked it up to work with an
48  *	Empeg ltd. empeg-car player.  Constructive criticism welcomed.
49  *	I would like to say, 'Thank You' to Greg Kroah-Hartman for the
50  *	use of his code, and for his guidance, advice and patience. :)
51  *	A 'Thank You' is in order for John Ripley of Empeg ltd for his
52  *	advice, and patience too.
53  *
54  */
55 
56 #include <linux/kernel.h>
57 #include <linux/errno.h>
58 #include <linux/init.h>
59 #include <linux/slab.h>
60 #include <linux/tty.h>
61 #include <linux/tty_driver.h>
62 #include <linux/tty_flip.h>
63 #include <linux/module.h>
64 #include <linux/spinlock.h>
65 #include <linux/uaccess.h>
66 #include <linux/usb.h>
67 #include <linux/usb/serial.h>
68 
69 static int debug;
70 
71 /*
72  * Version Information
73  */
74 #define DRIVER_VERSION "v1.2"
75 #define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Gary Brubaker <xavyer@ix.netcom.com>"
76 #define DRIVER_DESC "USB Empeg Mark I/II Driver"
77 
78 #define EMPEG_VENDOR_ID			0x084f
79 #define EMPEG_PRODUCT_ID		0x0001
80 
81 /* function prototypes for an empeg-car player */
82 static int  empeg_open(struct tty_struct *tty, struct usb_serial_port *port,
83 						struct file *filp);
84 static void empeg_close(struct usb_serial_port *port);
85 static int  empeg_write(struct tty_struct *tty, struct usb_serial_port *port,
86 						const unsigned char *buf,
87 						int count);
88 static int  empeg_write_room(struct tty_struct *tty);
89 static int  empeg_chars_in_buffer(struct tty_struct *tty);
90 static void empeg_throttle(struct tty_struct *tty);
91 static void empeg_unthrottle(struct tty_struct *tty);
92 static int  empeg_startup(struct usb_serial *serial);
93 static void empeg_set_termios(struct tty_struct *tty,
94 		struct usb_serial_port *port, struct ktermios *old_termios);
95 static void empeg_write_bulk_callback(struct urb *urb);
96 static void empeg_read_bulk_callback(struct urb *urb);
97 
98 static struct usb_device_id id_table [] = {
99 	{ USB_DEVICE(EMPEG_VENDOR_ID, EMPEG_PRODUCT_ID) },
100 	{ }					/* Terminating entry */
101 };
102 
103 MODULE_DEVICE_TABLE(usb, id_table);
104 
105 static struct usb_driver empeg_driver = {
106 	.name =		"empeg",
107 	.probe =	usb_serial_probe,
108 	.disconnect =	usb_serial_disconnect,
109 	.id_table =	id_table,
110 	.no_dynamic_id = 	1,
111 };
112 
113 static struct usb_serial_driver empeg_device = {
114 	.driver = {
115 		.owner =	THIS_MODULE,
116 		.name =		"empeg",
117 	},
118 	.id_table =		id_table,
119 	.usb_driver = 		&empeg_driver,
120 	.num_ports =		1,
121 	.open =			empeg_open,
122 	.close =		empeg_close,
123 	.throttle =		empeg_throttle,
124 	.unthrottle =		empeg_unthrottle,
125 	.attach =		empeg_startup,
126 	.set_termios =		empeg_set_termios,
127 	.write =		empeg_write,
128 	.write_room =		empeg_write_room,
129 	.chars_in_buffer =	empeg_chars_in_buffer,
130 	.write_bulk_callback =	empeg_write_bulk_callback,
131 	.read_bulk_callback =	empeg_read_bulk_callback,
132 };
133 
134 #define NUM_URBS			16
135 #define URB_TRANSFER_BUFFER_SIZE	4096
136 
137 static struct urb	*write_urb_pool[NUM_URBS];
138 static spinlock_t	write_urb_pool_lock;
139 static int		bytes_in;
140 static int		bytes_out;
141 
142 /******************************************************************************
143  * Empeg specific driver functions
144  ******************************************************************************/
145 static int empeg_open(struct tty_struct *tty, struct usb_serial_port *port,
146 				struct file *filp)
147 {
148 	struct usb_serial *serial = port->serial;
149 	int result = 0;
150 
151 	dbg("%s - port %d", __func__, port->number);
152 
153 	/* Force default termio settings */
154 	empeg_set_termios(tty, port, NULL) ;
155 
156 	bytes_in = 0;
157 	bytes_out = 0;
158 
159 	/* Start reading from the device */
160 	usb_fill_bulk_urb(
161 		port->read_urb,
162 		serial->dev,
163 		usb_rcvbulkpipe(serial->dev,
164 			port->bulk_in_endpointAddress),
165 		port->read_urb->transfer_buffer,
166 		port->read_urb->transfer_buffer_length,
167 		empeg_read_bulk_callback,
168 		port);
169 
170 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
171 
172 	if (result)
173 		dev_err(&port->dev,
174 			"%s - failed submitting read urb, error %d\n",
175 							__func__, result);
176 
177 	return result;
178 }
179 
180 
181 static void empeg_close(struct usb_serial_port *port)
182 {
183 	dbg("%s - port %d", __func__, port->number);
184 
185 	/* shutdown our bulk read */
186 	usb_kill_urb(port->read_urb);
187 	/* Uncomment the following line if you want to see some statistics in your syslog */
188 	/* dev_info (&port->dev, "Bytes In = %d  Bytes Out = %d\n", bytes_in, bytes_out); */
189 }
190 
191 
192 static int empeg_write(struct tty_struct *tty, struct usb_serial_port *port,
193 					const unsigned char *buf, int count)
194 {
195 	struct usb_serial *serial = port->serial;
196 	struct urb *urb;
197 	const unsigned char *current_position = buf;
198 	unsigned long flags;
199 	int status;
200 	int i;
201 	int bytes_sent = 0;
202 	int transfer_size;
203 
204 	dbg("%s - port %d", __func__, port->number);
205 
206 	while (count > 0) {
207 		/* try to find a free urb in our list of them */
208 		urb = NULL;
209 
210 		spin_lock_irqsave(&write_urb_pool_lock, flags);
211 
212 		for (i = 0; i < NUM_URBS; ++i) {
213 			if (write_urb_pool[i]->status != -EINPROGRESS) {
214 				urb = write_urb_pool[i];
215 				break;
216 			}
217 		}
218 
219 		spin_unlock_irqrestore(&write_urb_pool_lock, flags);
220 
221 		if (urb == NULL) {
222 			dbg("%s - no more free urbs", __func__);
223 			goto exit;
224 		}
225 
226 		if (urb->transfer_buffer == NULL) {
227 			urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_ATOMIC);
228 			if (urb->transfer_buffer == NULL) {
229 				dev_err(&port->dev,
230 					"%s no more kernel memory...\n",
231 								__func__);
232 				goto exit;
233 			}
234 		}
235 
236 		transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
237 
238 		memcpy(urb->transfer_buffer, current_position, transfer_size);
239 
240 		usb_serial_debug_data(debug, &port->dev, __func__, transfer_size, urb->transfer_buffer);
241 
242 		/* build up our urb */
243 		usb_fill_bulk_urb(
244 			urb,
245 			serial->dev,
246 			usb_sndbulkpipe(serial->dev,
247 					port->bulk_out_endpointAddress),
248 			urb->transfer_buffer,
249 			transfer_size,
250 			empeg_write_bulk_callback,
251 			port);
252 
253 		/* send it down the pipe */
254 		status = usb_submit_urb(urb, GFP_ATOMIC);
255 		if (status) {
256 			dev_err(&port->dev, "%s - usb_submit_urb(write bulk) failed with status = %d\n", __func__, status);
257 			bytes_sent = status;
258 			break;
259 		}
260 
261 		current_position += transfer_size;
262 		bytes_sent += transfer_size;
263 		count -= transfer_size;
264 		bytes_out += transfer_size;
265 
266 	}
267 exit:
268 	return bytes_sent;
269 }
270 
271 
272 static int empeg_write_room(struct tty_struct *tty)
273 {
274 	struct usb_serial_port *port = tty->driver_data;
275 	unsigned long flags;
276 	int i;
277 	int room = 0;
278 
279 	dbg("%s - port %d", __func__, port->number);
280 
281 	spin_lock_irqsave(&write_urb_pool_lock, flags);
282 	/* tally up the number of bytes available */
283 	for (i = 0; i < NUM_URBS; ++i) {
284 		if (write_urb_pool[i]->status != -EINPROGRESS)
285 			room += URB_TRANSFER_BUFFER_SIZE;
286 	}
287 	spin_unlock_irqrestore(&write_urb_pool_lock, flags);
288 	dbg("%s - returns %d", __func__, room);
289 	return room;
290 
291 }
292 
293 
294 static int empeg_chars_in_buffer(struct tty_struct *tty)
295 {
296 	struct usb_serial_port *port = tty->driver_data;
297 	unsigned long flags;
298 	int i;
299 	int chars = 0;
300 
301 	dbg("%s - port %d", __func__, port->number);
302 
303 	spin_lock_irqsave(&write_urb_pool_lock, flags);
304 
305 	/* tally up the number of bytes waiting */
306 	for (i = 0; i < NUM_URBS; ++i) {
307 		if (write_urb_pool[i]->status == -EINPROGRESS)
308 			chars += URB_TRANSFER_BUFFER_SIZE;
309 	}
310 
311 	spin_unlock_irqrestore(&write_urb_pool_lock, flags);
312 	dbg("%s - returns %d", __func__, chars);
313 	return chars;
314 }
315 
316 
317 static void empeg_write_bulk_callback(struct urb *urb)
318 {
319 	struct usb_serial_port *port = urb->context;
320 	int status = urb->status;
321 
322 	dbg("%s - port %d", __func__, port->number);
323 
324 	if (status) {
325 		dbg("%s - nonzero write bulk status received: %d",
326 		    __func__, status);
327 		return;
328 	}
329 
330 	usb_serial_port_softint(port);
331 }
332 
333 
334 static void empeg_read_bulk_callback(struct urb *urb)
335 {
336 	struct usb_serial_port *port = urb->context;
337 	struct tty_struct *tty;
338 	unsigned char *data = urb->transfer_buffer;
339 	int result;
340 	int status = urb->status;
341 
342 	dbg("%s - port %d", __func__, port->number);
343 
344 	if (status) {
345 		dbg("%s - nonzero read bulk status received: %d",
346 		    __func__, status);
347 		return;
348 	}
349 
350 	usb_serial_debug_data(debug, &port->dev, __func__,
351 						urb->actual_length, data);
352 	tty = tty_port_tty_get(&port->port);
353 
354 	if (urb->actual_length) {
355 		tty_buffer_request_room(tty, urb->actual_length);
356 		tty_insert_flip_string(tty, data, urb->actual_length);
357 		tty_flip_buffer_push(tty);
358 		bytes_in += urb->actual_length;
359 	}
360 	tty_kref_put(tty);
361 
362 	/* Continue trying to always read  */
363 	usb_fill_bulk_urb(
364 		port->read_urb,
365 		port->serial->dev,
366 		usb_rcvbulkpipe(port->serial->dev,
367 			port->bulk_in_endpointAddress),
368 		port->read_urb->transfer_buffer,
369 		port->read_urb->transfer_buffer_length,
370 		empeg_read_bulk_callback,
371 		port);
372 
373 	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
374 
375 	if (result)
376 		dev_err(&urb->dev->dev,
377 			"%s - failed resubmitting read urb, error %d\n",
378 							__func__, result);
379 
380 	return;
381 
382 }
383 
384 
385 static void empeg_throttle(struct tty_struct *tty)
386 {
387 	struct usb_serial_port *port = tty->driver_data;
388 	dbg("%s - port %d", __func__, port->number);
389 	usb_kill_urb(port->read_urb);
390 }
391 
392 
393 static void empeg_unthrottle(struct tty_struct *tty)
394 {
395 	struct usb_serial_port *port = tty->driver_data;
396 	int result;
397 	dbg("%s - port %d", __func__, port->number);
398 
399 	port->read_urb->dev = port->serial->dev;
400 	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
401 	if (result)
402 		dev_err(&port->dev,
403 			"%s - failed submitting read urb, error %d\n",
404 							__func__, result);
405 }
406 
407 
408 static int  empeg_startup(struct usb_serial *serial)
409 {
410 	int r;
411 
412 	dbg("%s", __func__);
413 
414 	if (serial->dev->actconfig->desc.bConfigurationValue != 1) {
415 		dev_err(&serial->dev->dev, "active config #%d != 1 ??\n",
416 			serial->dev->actconfig->desc.bConfigurationValue);
417 		return -ENODEV;
418 	}
419 	dbg("%s - reset config", __func__);
420 	r = usb_reset_configuration(serial->dev);
421 
422 	/* continue on with initialization */
423 	return r;
424 
425 }
426 
427 
428 static void empeg_set_termios(struct tty_struct *tty,
429 		struct usb_serial_port *port, struct ktermios *old_termios)
430 {
431 	struct ktermios *termios = tty->termios;
432 	dbg("%s - port %d", __func__, port->number);
433 
434 	/*
435 	 * The empeg-car player wants these particular tty settings.
436 	 * You could, for example, change the baud rate, however the
437 	 * player only supports 115200 (currently), so there is really
438 	 * no point in support for changes to the tty settings.
439 	 * (at least for now)
440 	 *
441 	 * The default requirements for this device are:
442 	 */
443 	termios->c_iflag
444 		&= ~(IGNBRK	/* disable ignore break */
445 		| BRKINT	/* disable break causes interrupt */
446 		| PARMRK	/* disable mark parity errors */
447 		| ISTRIP	/* disable clear high bit of input characters */
448 		| INLCR		/* disable translate NL to CR */
449 		| IGNCR		/* disable ignore CR */
450 		| ICRNL		/* disable translate CR to NL */
451 		| IXON);	/* disable enable XON/XOFF flow control */
452 
453 	termios->c_oflag
454 		&= ~OPOST;	/* disable postprocess output characters */
455 
456 	termios->c_lflag
457 		&= ~(ECHO	/* disable echo input characters */
458 		| ECHONL	/* disable echo new line */
459 		| ICANON	/* disable erase, kill, werase, and rprnt special characters */
460 		| ISIG		/* disable interrupt, quit, and suspend special characters */
461 		| IEXTEN);	/* disable non-POSIX special characters */
462 
463 	termios->c_cflag
464 		&= ~(CSIZE	/* no size */
465 		| PARENB	/* disable parity bit */
466 		| CBAUD);	/* clear current baud rate */
467 
468 	termios->c_cflag
469 		|= CS8;		/* character size 8 bits */
470 
471 	tty_encode_baud_rate(tty, 115200, 115200);
472 }
473 
474 
475 static int __init empeg_init(void)
476 {
477 	struct urb *urb;
478 	int i, retval;
479 
480 	/* create our write urb pool and transfer buffers */
481 	spin_lock_init(&write_urb_pool_lock);
482 	for (i = 0; i < NUM_URBS; ++i) {
483 		urb = usb_alloc_urb(0, GFP_KERNEL);
484 		write_urb_pool[i] = urb;
485 		if (urb == NULL) {
486 			printk(KERN_ERR "empeg: No more urbs???\n");
487 			continue;
488 		}
489 
490 		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
491 								GFP_KERNEL);
492 		if (!urb->transfer_buffer) {
493 			printk(KERN_ERR "empeg: %s - out of memory for urb "
494 			       "buffers.", __func__);
495 			continue;
496 		}
497 	}
498 
499 	retval = usb_serial_register(&empeg_device);
500 	if (retval)
501 		goto failed_usb_serial_register;
502 	retval = usb_register(&empeg_driver);
503 	if (retval)
504 		goto failed_usb_register;
505 
506 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
507 	       DRIVER_DESC "\n");
508 
509 	return 0;
510 failed_usb_register:
511 	usb_serial_deregister(&empeg_device);
512 failed_usb_serial_register:
513 	for (i = 0; i < NUM_URBS; ++i) {
514 		if (write_urb_pool[i]) {
515 			kfree(write_urb_pool[i]->transfer_buffer);
516 			usb_free_urb(write_urb_pool[i]);
517 		}
518 	}
519 	return retval;
520 }
521 
522 
523 static void __exit empeg_exit(void)
524 {
525 	int i;
526 	unsigned long flags;
527 
528 	usb_deregister(&empeg_driver);
529 	usb_serial_deregister(&empeg_device);
530 
531 	spin_lock_irqsave(&write_urb_pool_lock, flags);
532 
533 	for (i = 0; i < NUM_URBS; ++i) {
534 		if (write_urb_pool[i]) {
535 			/* FIXME - uncomment the following usb_kill_urb call
536 			 * when the host controllers get fixed to set urb->dev
537 			 * = NULL after the urb is finished.  Otherwise this
538 			 * call oopses. */
539 			/* usb_kill_urb(write_urb_pool[i]); */
540 			kfree(write_urb_pool[i]->transfer_buffer);
541 			usb_free_urb(write_urb_pool[i]);
542 		}
543 	}
544 	spin_unlock_irqrestore(&write_urb_pool_lock, flags);
545 }
546 
547 
548 module_init(empeg_init);
549 module_exit(empeg_exit);
550 
551 MODULE_AUTHOR(DRIVER_AUTHOR);
552 MODULE_DESCRIPTION(DRIVER_DESC);
553 MODULE_LICENSE("GPL");
554 
555 module_param(debug, bool, S_IRUGO | S_IWUSR);
556 MODULE_PARM_DESC(debug, "Debug enabled or not");
557