xref: /openbmc/linux/drivers/usb/serial/empeg.c (revision b04b4f78)
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 tty_struct *tty, struct usb_serial_port *port,
85 						struct file *filp);
86 static int  empeg_write(struct tty_struct *tty, struct usb_serial_port *port,
87 						const unsigned char *buf,
88 						int count);
89 static int  empeg_write_room(struct tty_struct *tty);
90 static int  empeg_chars_in_buffer(struct tty_struct *tty);
91 static void empeg_throttle(struct tty_struct *tty);
92 static void empeg_unthrottle(struct tty_struct *tty);
93 static int  empeg_startup(struct usb_serial *serial);
94 static void empeg_shutdown(struct usb_serial *serial);
95 static void empeg_set_termios(struct tty_struct *tty,
96 		struct usb_serial_port *port, struct ktermios *old_termios);
97 static void empeg_write_bulk_callback(struct urb *urb);
98 static void empeg_read_bulk_callback(struct urb *urb);
99 
100 static struct usb_device_id id_table [] = {
101 	{ USB_DEVICE(EMPEG_VENDOR_ID, EMPEG_PRODUCT_ID) },
102 	{ }					/* Terminating entry */
103 };
104 
105 MODULE_DEVICE_TABLE(usb, id_table);
106 
107 static struct usb_driver empeg_driver = {
108 	.name =		"empeg",
109 	.probe =	usb_serial_probe,
110 	.disconnect =	usb_serial_disconnect,
111 	.id_table =	id_table,
112 	.no_dynamic_id = 	1,
113 };
114 
115 static struct usb_serial_driver empeg_device = {
116 	.driver = {
117 		.owner =	THIS_MODULE,
118 		.name =		"empeg",
119 	},
120 	.id_table =		id_table,
121 	.usb_driver = 		&empeg_driver,
122 	.num_ports =		1,
123 	.open =			empeg_open,
124 	.close =		empeg_close,
125 	.throttle =		empeg_throttle,
126 	.unthrottle =		empeg_unthrottle,
127 	.attach =		empeg_startup,
128 	.shutdown =		empeg_shutdown,
129 	.set_termios =		empeg_set_termios,
130 	.write =		empeg_write,
131 	.write_room =		empeg_write_room,
132 	.chars_in_buffer =	empeg_chars_in_buffer,
133 	.write_bulk_callback =	empeg_write_bulk_callback,
134 	.read_bulk_callback =	empeg_read_bulk_callback,
135 };
136 
137 #define NUM_URBS			16
138 #define URB_TRANSFER_BUFFER_SIZE	4096
139 
140 static struct urb	*write_urb_pool[NUM_URBS];
141 static spinlock_t	write_urb_pool_lock;
142 static int		bytes_in;
143 static int		bytes_out;
144 
145 /******************************************************************************
146  * Empeg specific driver functions
147  ******************************************************************************/
148 static int empeg_open(struct tty_struct *tty, struct usb_serial_port *port,
149 				struct file *filp)
150 {
151 	struct usb_serial *serial = port->serial;
152 	int result = 0;
153 
154 	dbg("%s - port %d", __func__, port->number);
155 
156 	/* Force default termio settings */
157 	empeg_set_termios(tty, port, NULL) ;
158 
159 	bytes_in = 0;
160 	bytes_out = 0;
161 
162 	/* Start reading from the device */
163 	usb_fill_bulk_urb(
164 		port->read_urb,
165 		serial->dev,
166 		usb_rcvbulkpipe(serial->dev,
167 			port->bulk_in_endpointAddress),
168 		port->read_urb->transfer_buffer,
169 		port->read_urb->transfer_buffer_length,
170 		empeg_read_bulk_callback,
171 		port);
172 
173 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
174 
175 	if (result)
176 		dev_err(&port->dev,
177 			"%s - failed submitting read urb, error %d\n",
178 							__func__, result);
179 
180 	return result;
181 }
182 
183 
184 static void empeg_close(struct tty_struct *tty, struct usb_serial_port *port,
185 				struct file *filp)
186 {
187 	dbg("%s - port %d", __func__, port->number);
188 
189 	/* shutdown our bulk read */
190 	usb_kill_urb(port->read_urb);
191 	/* Uncomment the following line if you want to see some statistics in your syslog */
192 	/* dev_info (&port->dev, "Bytes In = %d  Bytes Out = %d\n", bytes_in, bytes_out); */
193 }
194 
195 
196 static int empeg_write(struct tty_struct *tty, struct usb_serial_port *port,
197 					const unsigned char *buf, int count)
198 {
199 	struct usb_serial *serial = port->serial;
200 	struct urb *urb;
201 	const unsigned char *current_position = buf;
202 	unsigned long flags;
203 	int status;
204 	int i;
205 	int bytes_sent = 0;
206 	int transfer_size;
207 
208 	dbg("%s - port %d", __func__, port->number);
209 
210 	while (count > 0) {
211 		/* try to find a free urb in our list of them */
212 		urb = NULL;
213 
214 		spin_lock_irqsave(&write_urb_pool_lock, flags);
215 
216 		for (i = 0; i < NUM_URBS; ++i) {
217 			if (write_urb_pool[i]->status != -EINPROGRESS) {
218 				urb = write_urb_pool[i];
219 				break;
220 			}
221 		}
222 
223 		spin_unlock_irqrestore(&write_urb_pool_lock, flags);
224 
225 		if (urb == NULL) {
226 			dbg("%s - no more free urbs", __func__);
227 			goto exit;
228 		}
229 
230 		if (urb->transfer_buffer == NULL) {
231 			urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_ATOMIC);
232 			if (urb->transfer_buffer == NULL) {
233 				dev_err(&port->dev,
234 					"%s no more kernel memory...\n",
235 								__func__);
236 				goto exit;
237 			}
238 		}
239 
240 		transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
241 
242 		memcpy(urb->transfer_buffer, current_position, transfer_size);
243 
244 		usb_serial_debug_data(debug, &port->dev, __func__, transfer_size, urb->transfer_buffer);
245 
246 		/* build up our urb */
247 		usb_fill_bulk_urb(
248 			urb,
249 			serial->dev,
250 			usb_sndbulkpipe(serial->dev,
251 					port->bulk_out_endpointAddress),
252 			urb->transfer_buffer,
253 			transfer_size,
254 			empeg_write_bulk_callback,
255 			port);
256 
257 		/* send it down the pipe */
258 		status = usb_submit_urb(urb, GFP_ATOMIC);
259 		if (status) {
260 			dev_err(&port->dev, "%s - usb_submit_urb(write bulk) failed with status = %d\n", __func__, status);
261 			bytes_sent = status;
262 			break;
263 		}
264 
265 		current_position += transfer_size;
266 		bytes_sent += transfer_size;
267 		count -= transfer_size;
268 		bytes_out += transfer_size;
269 
270 	}
271 exit:
272 	return bytes_sent;
273 }
274 
275 
276 static int empeg_write_room(struct tty_struct *tty)
277 {
278 	struct usb_serial_port *port = tty->driver_data;
279 	unsigned long flags;
280 	int i;
281 	int room = 0;
282 
283 	dbg("%s - port %d", __func__, port->number);
284 
285 	spin_lock_irqsave(&write_urb_pool_lock, flags);
286 	/* tally up the number of bytes available */
287 	for (i = 0; i < NUM_URBS; ++i) {
288 		if (write_urb_pool[i]->status != -EINPROGRESS)
289 			room += URB_TRANSFER_BUFFER_SIZE;
290 	}
291 	spin_unlock_irqrestore(&write_urb_pool_lock, flags);
292 	dbg("%s - returns %d", __func__, room);
293 	return room;
294 
295 }
296 
297 
298 static int empeg_chars_in_buffer(struct tty_struct *tty)
299 {
300 	struct usb_serial_port *port = tty->driver_data;
301 	unsigned long flags;
302 	int i;
303 	int chars = 0;
304 
305 	dbg("%s - port %d", __func__, port->number);
306 
307 	spin_lock_irqsave(&write_urb_pool_lock, flags);
308 
309 	/* tally up the number of bytes waiting */
310 	for (i = 0; i < NUM_URBS; ++i) {
311 		if (write_urb_pool[i]->status == -EINPROGRESS)
312 			chars += URB_TRANSFER_BUFFER_SIZE;
313 	}
314 
315 	spin_unlock_irqrestore(&write_urb_pool_lock, flags);
316 	dbg("%s - returns %d", __func__, chars);
317 	return chars;
318 }
319 
320 
321 static void empeg_write_bulk_callback(struct urb *urb)
322 {
323 	struct usb_serial_port *port = urb->context;
324 	int status = urb->status;
325 
326 	dbg("%s - port %d", __func__, port->number);
327 
328 	if (status) {
329 		dbg("%s - nonzero write bulk status received: %d",
330 		    __func__, status);
331 		return;
332 	}
333 
334 	usb_serial_port_softint(port);
335 }
336 
337 
338 static void empeg_read_bulk_callback(struct urb *urb)
339 {
340 	struct usb_serial_port *port = urb->context;
341 	struct tty_struct *tty;
342 	unsigned char *data = urb->transfer_buffer;
343 	int result;
344 	int status = urb->status;
345 
346 	dbg("%s - port %d", __func__, port->number);
347 
348 	if (status) {
349 		dbg("%s - nonzero read bulk status received: %d",
350 		    __func__, status);
351 		return;
352 	}
353 
354 	usb_serial_debug_data(debug, &port->dev, __func__,
355 						urb->actual_length, data);
356 	tty = tty_port_tty_get(&port->port);
357 
358 	if (urb->actual_length) {
359 		tty_buffer_request_room(tty, urb->actual_length);
360 		tty_insert_flip_string(tty, data, urb->actual_length);
361 		tty_flip_buffer_push(tty);
362 		bytes_in += urb->actual_length;
363 	}
364 	tty_kref_put(tty);
365 
366 	/* Continue trying to always read  */
367 	usb_fill_bulk_urb(
368 		port->read_urb,
369 		port->serial->dev,
370 		usb_rcvbulkpipe(port->serial->dev,
371 			port->bulk_in_endpointAddress),
372 		port->read_urb->transfer_buffer,
373 		port->read_urb->transfer_buffer_length,
374 		empeg_read_bulk_callback,
375 		port);
376 
377 	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
378 
379 	if (result)
380 		dev_err(&urb->dev->dev,
381 			"%s - failed resubmitting read urb, error %d\n",
382 							__func__, result);
383 
384 	return;
385 
386 }
387 
388 
389 static void empeg_throttle(struct tty_struct *tty)
390 {
391 	struct usb_serial_port *port = tty->driver_data;
392 	dbg("%s - port %d", __func__, port->number);
393 	usb_kill_urb(port->read_urb);
394 }
395 
396 
397 static void empeg_unthrottle(struct tty_struct *tty)
398 {
399 	struct usb_serial_port *port = tty->driver_data;
400 	int result;
401 	dbg("%s - port %d", __func__, port->number);
402 
403 	port->read_urb->dev = port->serial->dev;
404 	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
405 	if (result)
406 		dev_err(&port->dev,
407 			"%s - failed submitting read urb, error %d\n",
408 							__func__, result);
409 }
410 
411 
412 static int  empeg_startup(struct usb_serial *serial)
413 {
414 	int r;
415 
416 	dbg("%s", __func__);
417 
418 	if (serial->dev->actconfig->desc.bConfigurationValue != 1) {
419 		dev_err(&serial->dev->dev, "active config #%d != 1 ??\n",
420 			serial->dev->actconfig->desc.bConfigurationValue);
421 		return -ENODEV;
422 	}
423 	dbg("%s - reset config", __func__);
424 	r = usb_reset_configuration(serial->dev);
425 
426 	/* continue on with initialization */
427 	return r;
428 
429 }
430 
431 
432 static void empeg_shutdown(struct usb_serial *serial)
433 {
434 	dbg("%s", __func__);
435 }
436 
437 
438 static void empeg_set_termios(struct tty_struct *tty,
439 		struct usb_serial_port *port, struct ktermios *old_termios)
440 {
441 	struct ktermios *termios = tty->termios;
442 	dbg("%s - port %d", __func__, port->number);
443 
444 	/*
445 	 * The empeg-car player wants these particular tty settings.
446 	 * You could, for example, change the baud rate, however the
447 	 * player only supports 115200 (currently), so there is really
448 	 * no point in support for changes to the tty settings.
449 	 * (at least for now)
450 	 *
451 	 * The default requirements for this device are:
452 	 */
453 	termios->c_iflag
454 		&= ~(IGNBRK	/* disable ignore break */
455 		| BRKINT	/* disable break causes interrupt */
456 		| PARMRK	/* disable mark parity errors */
457 		| ISTRIP	/* disable clear high bit of input characters */
458 		| INLCR		/* disable translate NL to CR */
459 		| IGNCR		/* disable ignore CR */
460 		| ICRNL		/* disable translate CR to NL */
461 		| IXON);	/* disable enable XON/XOFF flow control */
462 
463 	termios->c_oflag
464 		&= ~OPOST;	/* disable postprocess output characters */
465 
466 	termios->c_lflag
467 		&= ~(ECHO	/* disable echo input characters */
468 		| ECHONL	/* disable echo new line */
469 		| ICANON	/* disable erase, kill, werase, and rprnt special characters */
470 		| ISIG		/* disable interrupt, quit, and suspend special characters */
471 		| IEXTEN);	/* disable non-POSIX special characters */
472 
473 	termios->c_cflag
474 		&= ~(CSIZE	/* no size */
475 		| PARENB	/* disable parity bit */
476 		| CBAUD);	/* clear current baud rate */
477 
478 	termios->c_cflag
479 		|= CS8;		/* character size 8 bits */
480 
481 	tty_encode_baud_rate(tty, 115200, 115200);
482 }
483 
484 
485 static int __init empeg_init(void)
486 {
487 	struct urb *urb;
488 	int i, retval;
489 
490 	/* create our write urb pool and transfer buffers */
491 	spin_lock_init(&write_urb_pool_lock);
492 	for (i = 0; i < NUM_URBS; ++i) {
493 		urb = usb_alloc_urb(0, GFP_KERNEL);
494 		write_urb_pool[i] = urb;
495 		if (urb == NULL) {
496 			printk(KERN_ERR "empeg: No more urbs???\n");
497 			continue;
498 		}
499 
500 		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
501 								GFP_KERNEL);
502 		if (!urb->transfer_buffer) {
503 			printk(KERN_ERR "empeg: %s - out of memory for urb "
504 			       "buffers.", __func__);
505 			continue;
506 		}
507 	}
508 
509 	retval = usb_serial_register(&empeg_device);
510 	if (retval)
511 		goto failed_usb_serial_register;
512 	retval = usb_register(&empeg_driver);
513 	if (retval)
514 		goto failed_usb_register;
515 
516 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
517 	       DRIVER_DESC "\n");
518 
519 	return 0;
520 failed_usb_register:
521 	usb_serial_deregister(&empeg_device);
522 failed_usb_serial_register:
523 	for (i = 0; i < NUM_URBS; ++i) {
524 		if (write_urb_pool[i]) {
525 			kfree(write_urb_pool[i]->transfer_buffer);
526 			usb_free_urb(write_urb_pool[i]);
527 		}
528 	}
529 	return retval;
530 }
531 
532 
533 static void __exit empeg_exit(void)
534 {
535 	int i;
536 	unsigned long flags;
537 
538 	usb_deregister(&empeg_driver);
539 	usb_serial_deregister(&empeg_device);
540 
541 	spin_lock_irqsave(&write_urb_pool_lock, flags);
542 
543 	for (i = 0; i < NUM_URBS; ++i) {
544 		if (write_urb_pool[i]) {
545 			/* FIXME - uncomment the following usb_kill_urb call
546 			 * when the host controllers get fixed to set urb->dev
547 			 * = NULL after the urb is finished.  Otherwise this
548 			 * call oopses. */
549 			/* usb_kill_urb(write_urb_pool[i]); */
550 			kfree(write_urb_pool[i]->transfer_buffer);
551 			usb_free_urb(write_urb_pool[i]);
552 		}
553 	}
554 	spin_unlock_irqrestore(&write_urb_pool_lock, flags);
555 }
556 
557 
558 module_init(empeg_init);
559 module_exit(empeg_exit);
560 
561 MODULE_AUTHOR(DRIVER_AUTHOR);
562 MODULE_DESCRIPTION(DRIVER_DESC);
563 MODULE_LICENSE("GPL");
564 
565 module_param(debug, bool, S_IRUGO | S_IWUSR);
566 MODULE_PARM_DESC(debug, "Debug enabled or not");
567