xref: /openbmc/linux/drivers/usb/serial/empeg.c (revision e8e0929d)
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 static void empeg_close(struct usb_serial_port *port);
84 static int  empeg_write(struct tty_struct *tty, struct usb_serial_port *port,
85 						const unsigned char *buf,
86 						int count);
87 static int  empeg_write_room(struct tty_struct *tty);
88 static int  empeg_chars_in_buffer(struct tty_struct *tty);
89 static void empeg_throttle(struct tty_struct *tty);
90 static void empeg_unthrottle(struct tty_struct *tty);
91 static int  empeg_startup(struct usb_serial *serial);
92 static void empeg_init_termios(struct tty_struct *tty);
93 static void empeg_write_bulk_callback(struct urb *urb);
94 static void empeg_read_bulk_callback(struct urb *urb);
95 
96 static struct usb_device_id id_table [] = {
97 	{ USB_DEVICE(EMPEG_VENDOR_ID, EMPEG_PRODUCT_ID) },
98 	{ }					/* Terminating entry */
99 };
100 
101 MODULE_DEVICE_TABLE(usb, id_table);
102 
103 static struct usb_driver empeg_driver = {
104 	.name =		"empeg",
105 	.probe =	usb_serial_probe,
106 	.disconnect =	usb_serial_disconnect,
107 	.id_table =	id_table,
108 	.no_dynamic_id = 	1,
109 };
110 
111 static struct usb_serial_driver empeg_device = {
112 	.driver = {
113 		.owner =	THIS_MODULE,
114 		.name =		"empeg",
115 	},
116 	.id_table =		id_table,
117 	.usb_driver = 		&empeg_driver,
118 	.num_ports =		1,
119 	.open =			empeg_open,
120 	.close =		empeg_close,
121 	.throttle =		empeg_throttle,
122 	.unthrottle =		empeg_unthrottle,
123 	.attach =		empeg_startup,
124 	.init_termios =		empeg_init_termios,
125 	.write =		empeg_write,
126 	.write_room =		empeg_write_room,
127 	.chars_in_buffer =	empeg_chars_in_buffer,
128 	.write_bulk_callback =	empeg_write_bulk_callback,
129 	.read_bulk_callback =	empeg_read_bulk_callback,
130 };
131 
132 #define NUM_URBS			16
133 #define URB_TRANSFER_BUFFER_SIZE	4096
134 
135 static struct urb	*write_urb_pool[NUM_URBS];
136 static spinlock_t	write_urb_pool_lock;
137 static int		bytes_in;
138 static int		bytes_out;
139 
140 /******************************************************************************
141  * Empeg specific driver functions
142  ******************************************************************************/
143 static int empeg_open(struct tty_struct *tty,struct usb_serial_port *port)
144 {
145 	struct usb_serial *serial = port->serial;
146 	int result = 0;
147 
148 	dbg("%s - port %d", __func__, port->number);
149 
150 	bytes_in = 0;
151 	bytes_out = 0;
152 
153 	/* Start reading from the device */
154 	usb_fill_bulk_urb(
155 		port->read_urb,
156 		serial->dev,
157 		usb_rcvbulkpipe(serial->dev,
158 			port->bulk_in_endpointAddress),
159 		port->read_urb->transfer_buffer,
160 		port->read_urb->transfer_buffer_length,
161 		empeg_read_bulk_callback,
162 		port);
163 
164 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
165 
166 	if (result)
167 		dev_err(&port->dev,
168 			"%s - failed submitting read urb, error %d\n",
169 							__func__, result);
170 
171 	return result;
172 }
173 
174 
175 static void empeg_close(struct usb_serial_port *port)
176 {
177 	dbg("%s - port %d", __func__, port->number);
178 
179 	/* shutdown our bulk read */
180 	usb_kill_urb(port->read_urb);
181 	/* Uncomment the following line if you want to see some statistics in your syslog */
182 	/* dev_info (&port->dev, "Bytes In = %d  Bytes Out = %d\n", bytes_in, bytes_out); */
183 }
184 
185 
186 static int empeg_write(struct tty_struct *tty, struct usb_serial_port *port,
187 					const unsigned char *buf, int count)
188 {
189 	struct usb_serial *serial = port->serial;
190 	struct urb *urb;
191 	const unsigned char *current_position = buf;
192 	unsigned long flags;
193 	int status;
194 	int i;
195 	int bytes_sent = 0;
196 	int transfer_size;
197 
198 	dbg("%s - port %d", __func__, port->number);
199 
200 	while (count > 0) {
201 		/* try to find a free urb in our list of them */
202 		urb = NULL;
203 
204 		spin_lock_irqsave(&write_urb_pool_lock, flags);
205 
206 		for (i = 0; i < NUM_URBS; ++i) {
207 			if (write_urb_pool[i]->status != -EINPROGRESS) {
208 				urb = write_urb_pool[i];
209 				break;
210 			}
211 		}
212 
213 		spin_unlock_irqrestore(&write_urb_pool_lock, flags);
214 
215 		if (urb == NULL) {
216 			dbg("%s - no more free urbs", __func__);
217 			goto exit;
218 		}
219 
220 		if (urb->transfer_buffer == NULL) {
221 			urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_ATOMIC);
222 			if (urb->transfer_buffer == NULL) {
223 				dev_err(&port->dev,
224 					"%s no more kernel memory...\n",
225 								__func__);
226 				goto exit;
227 			}
228 		}
229 
230 		transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
231 
232 		memcpy(urb->transfer_buffer, current_position, transfer_size);
233 
234 		usb_serial_debug_data(debug, &port->dev, __func__, transfer_size, urb->transfer_buffer);
235 
236 		/* build up our urb */
237 		usb_fill_bulk_urb(
238 			urb,
239 			serial->dev,
240 			usb_sndbulkpipe(serial->dev,
241 					port->bulk_out_endpointAddress),
242 			urb->transfer_buffer,
243 			transfer_size,
244 			empeg_write_bulk_callback,
245 			port);
246 
247 		/* send it down the pipe */
248 		status = usb_submit_urb(urb, GFP_ATOMIC);
249 		if (status) {
250 			dev_err(&port->dev, "%s - usb_submit_urb(write bulk) failed with status = %d\n", __func__, status);
251 			bytes_sent = status;
252 			break;
253 		}
254 
255 		current_position += transfer_size;
256 		bytes_sent += transfer_size;
257 		count -= transfer_size;
258 		bytes_out += transfer_size;
259 
260 	}
261 exit:
262 	return bytes_sent;
263 }
264 
265 
266 static int empeg_write_room(struct tty_struct *tty)
267 {
268 	struct usb_serial_port *port = tty->driver_data;
269 	unsigned long flags;
270 	int i;
271 	int room = 0;
272 
273 	dbg("%s - port %d", __func__, port->number);
274 
275 	spin_lock_irqsave(&write_urb_pool_lock, flags);
276 	/* tally up the number of bytes available */
277 	for (i = 0; i < NUM_URBS; ++i) {
278 		if (write_urb_pool[i]->status != -EINPROGRESS)
279 			room += URB_TRANSFER_BUFFER_SIZE;
280 	}
281 	spin_unlock_irqrestore(&write_urb_pool_lock, flags);
282 	dbg("%s - returns %d", __func__, room);
283 	return room;
284 
285 }
286 
287 
288 static int empeg_chars_in_buffer(struct tty_struct *tty)
289 {
290 	struct usb_serial_port *port = tty->driver_data;
291 	unsigned long flags;
292 	int i;
293 	int chars = 0;
294 
295 	dbg("%s - port %d", __func__, port->number);
296 
297 	spin_lock_irqsave(&write_urb_pool_lock, flags);
298 
299 	/* tally up the number of bytes waiting */
300 	for (i = 0; i < NUM_URBS; ++i) {
301 		if (write_urb_pool[i]->status == -EINPROGRESS)
302 			chars += URB_TRANSFER_BUFFER_SIZE;
303 	}
304 
305 	spin_unlock_irqrestore(&write_urb_pool_lock, flags);
306 	dbg("%s - returns %d", __func__, chars);
307 	return chars;
308 }
309 
310 
311 static void empeg_write_bulk_callback(struct urb *urb)
312 {
313 	struct usb_serial_port *port = urb->context;
314 	int status = urb->status;
315 
316 	dbg("%s - port %d", __func__, port->number);
317 
318 	if (status) {
319 		dbg("%s - nonzero write bulk status received: %d",
320 		    __func__, status);
321 		return;
322 	}
323 
324 	usb_serial_port_softint(port);
325 }
326 
327 
328 static void empeg_read_bulk_callback(struct urb *urb)
329 {
330 	struct usb_serial_port *port = urb->context;
331 	struct tty_struct *tty;
332 	unsigned char *data = urb->transfer_buffer;
333 	int result;
334 	int status = urb->status;
335 
336 	dbg("%s - port %d", __func__, port->number);
337 
338 	if (status) {
339 		dbg("%s - nonzero read bulk status received: %d",
340 		    __func__, status);
341 		return;
342 	}
343 
344 	usb_serial_debug_data(debug, &port->dev, __func__,
345 						urb->actual_length, data);
346 	tty = tty_port_tty_get(&port->port);
347 
348 	if (urb->actual_length) {
349 		tty_buffer_request_room(tty, urb->actual_length);
350 		tty_insert_flip_string(tty, data, urb->actual_length);
351 		tty_flip_buffer_push(tty);
352 		bytes_in += urb->actual_length;
353 	}
354 	tty_kref_put(tty);
355 
356 	/* Continue trying to always read  */
357 	usb_fill_bulk_urb(
358 		port->read_urb,
359 		port->serial->dev,
360 		usb_rcvbulkpipe(port->serial->dev,
361 			port->bulk_in_endpointAddress),
362 		port->read_urb->transfer_buffer,
363 		port->read_urb->transfer_buffer_length,
364 		empeg_read_bulk_callback,
365 		port);
366 
367 	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
368 
369 	if (result)
370 		dev_err(&urb->dev->dev,
371 			"%s - failed resubmitting read urb, error %d\n",
372 							__func__, result);
373 
374 	return;
375 
376 }
377 
378 
379 static void empeg_throttle(struct tty_struct *tty)
380 {
381 	struct usb_serial_port *port = tty->driver_data;
382 	dbg("%s - port %d", __func__, port->number);
383 	usb_kill_urb(port->read_urb);
384 }
385 
386 
387 static void empeg_unthrottle(struct tty_struct *tty)
388 {
389 	struct usb_serial_port *port = tty->driver_data;
390 	int result;
391 	dbg("%s - port %d", __func__, port->number);
392 
393 	port->read_urb->dev = port->serial->dev;
394 	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
395 	if (result)
396 		dev_err(&port->dev,
397 			"%s - failed submitting read urb, error %d\n",
398 							__func__, result);
399 }
400 
401 
402 static int  empeg_startup(struct usb_serial *serial)
403 {
404 	int r;
405 
406 	dbg("%s", __func__);
407 
408 	if (serial->dev->actconfig->desc.bConfigurationValue != 1) {
409 		dev_err(&serial->dev->dev, "active config #%d != 1 ??\n",
410 			serial->dev->actconfig->desc.bConfigurationValue);
411 		return -ENODEV;
412 	}
413 	dbg("%s - reset config", __func__);
414 	r = usb_reset_configuration(serial->dev);
415 
416 	/* continue on with initialization */
417 	return r;
418 
419 }
420 
421 
422 static void empeg_init_termios(struct tty_struct *tty)
423 {
424 	struct ktermios *termios = tty->termios;
425 
426 	/*
427 	 * The empeg-car player wants these particular tty settings.
428 	 * You could, for example, change the baud rate, however the
429 	 * player only supports 115200 (currently), so there is really
430 	 * no point in support for changes to the tty settings.
431 	 * (at least for now)
432 	 *
433 	 * The default requirements for this device are:
434 	 */
435 	termios->c_iflag
436 		&= ~(IGNBRK	/* disable ignore break */
437 		| BRKINT	/* disable break causes interrupt */
438 		| PARMRK	/* disable mark parity errors */
439 		| ISTRIP	/* disable clear high bit of input characters */
440 		| INLCR		/* disable translate NL to CR */
441 		| IGNCR		/* disable ignore CR */
442 		| ICRNL		/* disable translate CR to NL */
443 		| IXON);	/* disable enable XON/XOFF flow control */
444 
445 	termios->c_oflag
446 		&= ~OPOST;	/* disable postprocess output characters */
447 
448 	termios->c_lflag
449 		&= ~(ECHO	/* disable echo input characters */
450 		| ECHONL	/* disable echo new line */
451 		| ICANON	/* disable erase, kill, werase, and rprnt special characters */
452 		| ISIG		/* disable interrupt, quit, and suspend special characters */
453 		| IEXTEN);	/* disable non-POSIX special characters */
454 
455 	termios->c_cflag
456 		&= ~(CSIZE	/* no size */
457 		| PARENB	/* disable parity bit */
458 		| CBAUD);	/* clear current baud rate */
459 
460 	termios->c_cflag
461 		|= CS8;		/* character size 8 bits */
462 
463 	tty_encode_baud_rate(tty, 115200, 115200);
464 }
465 
466 
467 static int __init empeg_init(void)
468 {
469 	struct urb *urb;
470 	int i, retval;
471 
472 	/* create our write urb pool and transfer buffers */
473 	spin_lock_init(&write_urb_pool_lock);
474 	for (i = 0; i < NUM_URBS; ++i) {
475 		urb = usb_alloc_urb(0, GFP_KERNEL);
476 		write_urb_pool[i] = urb;
477 		if (urb == NULL) {
478 			printk(KERN_ERR "empeg: No more urbs???\n");
479 			continue;
480 		}
481 
482 		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
483 								GFP_KERNEL);
484 		if (!urb->transfer_buffer) {
485 			printk(KERN_ERR "empeg: %s - out of memory for urb "
486 			       "buffers.", __func__);
487 			continue;
488 		}
489 	}
490 
491 	retval = usb_serial_register(&empeg_device);
492 	if (retval)
493 		goto failed_usb_serial_register;
494 	retval = usb_register(&empeg_driver);
495 	if (retval)
496 		goto failed_usb_register;
497 
498 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
499 	       DRIVER_DESC "\n");
500 
501 	return 0;
502 failed_usb_register:
503 	usb_serial_deregister(&empeg_device);
504 failed_usb_serial_register:
505 	for (i = 0; i < NUM_URBS; ++i) {
506 		if (write_urb_pool[i]) {
507 			kfree(write_urb_pool[i]->transfer_buffer);
508 			usb_free_urb(write_urb_pool[i]);
509 		}
510 	}
511 	return retval;
512 }
513 
514 
515 static void __exit empeg_exit(void)
516 {
517 	int i;
518 	unsigned long flags;
519 
520 	usb_deregister(&empeg_driver);
521 	usb_serial_deregister(&empeg_device);
522 
523 	spin_lock_irqsave(&write_urb_pool_lock, flags);
524 
525 	for (i = 0; i < NUM_URBS; ++i) {
526 		if (write_urb_pool[i]) {
527 			/* FIXME - uncomment the following usb_kill_urb call
528 			 * when the host controllers get fixed to set urb->dev
529 			 * = NULL after the urb is finished.  Otherwise this
530 			 * call oopses. */
531 			/* usb_kill_urb(write_urb_pool[i]); */
532 			kfree(write_urb_pool[i]->transfer_buffer);
533 			usb_free_urb(write_urb_pool[i]);
534 		}
535 	}
536 	spin_unlock_irqrestore(&write_urb_pool_lock, flags);
537 }
538 
539 
540 module_init(empeg_init);
541 module_exit(empeg_exit);
542 
543 MODULE_AUTHOR(DRIVER_AUTHOR);
544 MODULE_DESCRIPTION(DRIVER_DESC);
545 MODULE_LICENSE("GPL");
546 
547 module_param(debug, bool, S_IRUGO | S_IWUSR);
548 MODULE_PARM_DESC(debug, "Debug enabled or not");
549