xref: /openbmc/linux/drivers/usb/misc/uss720.c (revision 384740dc)
1 /*****************************************************************************/
2 
3 /*
4  *	uss720.c  --  USS720 USB Parport Cable.
5  *
6  *	Copyright (C) 1999, 2005
7  *	    Thomas Sailer (t.sailer@alumni.ethz.ch)
8  *
9  *	This program is free software; you can redistribute it and/or modify
10  *	it under the terms of the GNU General Public License as published by
11  *	the Free Software Foundation; either version 2 of the License, or
12  *	(at your option) any later version.
13  *
14  *	This program is distributed in the hope that it will be useful,
15  *	but WITHOUT ANY WARRANTY; without even the implied warranty of
16  *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  *	GNU General Public License for more details.
18  *
19  *	You should have received a copy of the GNU General Public License
20  *	along with this program; if not, write to the Free Software
21  *	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22  *
23  *  Based on parport_pc.c
24  *
25  *  History:
26  *   0.1  04.08.1999  Created
27  *   0.2  07.08.1999  Some fixes mainly suggested by Tim Waugh
28  *		      Interrupt handling currently disabled because
29  *		      usb_request_irq crashes somewhere within ohci.c
30  *		      for no apparent reason (that is for me, anyway)
31  *		      ECP currently untested
32  *   0.3  10.08.1999  fixing merge errors
33  *   0.4  13.08.1999  Added Vendor/Product ID of Brad Hard's cable
34  *   0.5  20.09.1999  usb_control_msg wrapper used
35  *        Nov01.2000  usb_device_table support by Adam J. Richter
36  *        08.04.2001  Identify version on module load.  gb
37  *   0.6  02.09.2005  Fix "scheduling in interrupt" problem by making save/restore
38  *                    context asynchronous
39  *
40  */
41 
42 /*****************************************************************************/
43 
44 #include <linux/module.h>
45 #include <linux/socket.h>
46 #include <linux/parport.h>
47 #include <linux/init.h>
48 #include <linux/usb.h>
49 #include <linux/delay.h>
50 #include <linux/completion.h>
51 #include <linux/kref.h>
52 
53 /*
54  * Version Information
55  */
56 #define DRIVER_VERSION "v0.6"
57 #define DRIVER_AUTHOR "Thomas M. Sailer, t.sailer@alumni.ethz.ch"
58 #define DRIVER_DESC "USB Parport Cable driver for Cables using the Lucent Technologies USS720 Chip"
59 
60 /* --------------------------------------------------------------------- */
61 
62 struct parport_uss720_private {
63 	struct usb_device *usbdev;
64 	struct parport *pp;
65 	struct kref ref_count;
66 	__u8 reg[7];  /* USB registers */
67 	struct list_head asynclist;
68 	spinlock_t asynclock;
69 };
70 
71 struct uss720_async_request {
72 	struct parport_uss720_private *priv;
73 	struct kref ref_count;
74 	struct list_head asynclist;
75 	struct completion compl;
76 	struct urb *urb;
77 	struct usb_ctrlrequest dr;
78 	__u8 reg[7];
79 };
80 
81 /* --------------------------------------------------------------------- */
82 
83 static void destroy_priv(struct kref *kref)
84 {
85 	struct parport_uss720_private *priv = container_of(kref, struct parport_uss720_private, ref_count);
86 
87 	usb_put_dev(priv->usbdev);
88 	kfree(priv);
89 	dbg("destroying priv datastructure");
90 }
91 
92 static void destroy_async(struct kref *kref)
93 {
94 	struct uss720_async_request *rq = container_of(kref, struct uss720_async_request, ref_count);
95 	struct parport_uss720_private *priv = rq->priv;
96 	unsigned long flags;
97 
98 	if (likely(rq->urb))
99 		usb_free_urb(rq->urb);
100 	spin_lock_irqsave(&priv->asynclock, flags);
101 	list_del_init(&rq->asynclist);
102 	spin_unlock_irqrestore(&priv->asynclock, flags);
103 	kfree(rq);
104 	kref_put(&priv->ref_count, destroy_priv);
105 }
106 
107 /* --------------------------------------------------------------------- */
108 
109 static void async_complete(struct urb *urb)
110 {
111 	struct uss720_async_request *rq;
112 	struct parport *pp;
113 	struct parport_uss720_private *priv;
114 	int status = urb->status;
115 
116 	rq = urb->context;
117 	priv = rq->priv;
118 	pp = priv->pp;
119 	if (status) {
120 		err("async_complete: urb error %d", status);
121 	} else if (rq->dr.bRequest == 3) {
122 		memcpy(priv->reg, rq->reg, sizeof(priv->reg));
123 #if 0
124 		dbg("async_complete regs %02x %02x %02x %02x %02x %02x %02x",
125 		    (unsigned int)priv->reg[0], (unsigned int)priv->reg[1], (unsigned int)priv->reg[2],
126 		    (unsigned int)priv->reg[3], (unsigned int)priv->reg[4], (unsigned int)priv->reg[5],
127 		    (unsigned int)priv->reg[6]);
128 #endif
129 		/* if nAck interrupts are enabled and we have an interrupt, call the interrupt procedure */
130 		if (rq->reg[2] & rq->reg[1] & 0x10 && pp)
131 			parport_generic_irq(pp);
132 	}
133 	complete(&rq->compl);
134 	kref_put(&rq->ref_count, destroy_async);
135 }
136 
137 static struct uss720_async_request *submit_async_request(struct parport_uss720_private *priv,
138 							 __u8 request, __u8 requesttype, __u16 value, __u16 index,
139 							 gfp_t mem_flags)
140 {
141 	struct usb_device *usbdev;
142 	struct uss720_async_request *rq;
143 	unsigned long flags;
144 	int ret;
145 
146 	if (!priv)
147 		return NULL;
148 	usbdev = priv->usbdev;
149 	if (!usbdev)
150 		return NULL;
151 	rq = kmalloc(sizeof(struct uss720_async_request), mem_flags);
152 	if (!rq) {
153 		err("submit_async_request out of memory");
154 		return NULL;
155 	}
156 	kref_init(&rq->ref_count);
157 	INIT_LIST_HEAD(&rq->asynclist);
158 	init_completion(&rq->compl);
159 	kref_get(&priv->ref_count);
160 	rq->priv = priv;
161 	rq->urb = usb_alloc_urb(0, mem_flags);
162 	if (!rq->urb) {
163 		kref_put(&rq->ref_count, destroy_async);
164 		err("submit_async_request out of memory");
165 		return NULL;
166 	}
167 	rq->dr.bRequestType = requesttype;
168 	rq->dr.bRequest = request;
169 	rq->dr.wValue = cpu_to_le16(value);
170 	rq->dr.wIndex = cpu_to_le16(index);
171 	rq->dr.wLength = cpu_to_le16((request == 3) ? sizeof(rq->reg) : 0);
172 	usb_fill_control_urb(rq->urb, usbdev, (requesttype & 0x80) ? usb_rcvctrlpipe(usbdev, 0) : usb_sndctrlpipe(usbdev, 0),
173 			     (unsigned char *)&rq->dr,
174 			     (request == 3) ? rq->reg : NULL, (request == 3) ? sizeof(rq->reg) : 0, async_complete, rq);
175 	/* rq->urb->transfer_flags |= URB_ASYNC_UNLINK; */
176 	spin_lock_irqsave(&priv->asynclock, flags);
177 	list_add_tail(&rq->asynclist, &priv->asynclist);
178 	spin_unlock_irqrestore(&priv->asynclock, flags);
179 	ret = usb_submit_urb(rq->urb, mem_flags);
180 	if (!ret) {
181 		kref_get(&rq->ref_count);
182 		return rq;
183 	}
184 	kref_put(&rq->ref_count, destroy_async);
185 	err("submit_async_request submit_urb failed with %d", ret);
186 	return NULL;
187 }
188 
189 static unsigned int kill_all_async_requests_priv(struct parport_uss720_private *priv)
190 {
191 	struct uss720_async_request *rq;
192 	unsigned long flags;
193 	unsigned int ret = 0;
194 
195 	spin_lock_irqsave(&priv->asynclock, flags);
196 	list_for_each_entry(rq, &priv->asynclist, asynclist) {
197 		usb_unlink_urb(rq->urb);
198 		ret++;
199 	}
200 	spin_unlock_irqrestore(&priv->asynclock, flags);
201 	return ret;
202 }
203 
204 /* --------------------------------------------------------------------- */
205 
206 static int get_1284_register(struct parport *pp, unsigned char reg, unsigned char *val, gfp_t mem_flags)
207 {
208 	struct parport_uss720_private *priv;
209 	struct uss720_async_request *rq;
210 	static const unsigned char regindex[9] = {
211 		4, 0, 1, 5, 5, 0, 2, 3, 6
212 	};
213 	int ret;
214 
215 	if (!pp)
216 		return -EIO;
217 	priv = pp->private_data;
218 	rq = submit_async_request(priv, 3, 0xc0, ((unsigned int)reg) << 8, 0, mem_flags);
219 	if (!rq) {
220 		err("get_1284_register(%u) failed", (unsigned int)reg);
221 		return -EIO;
222 	}
223 	if (!val) {
224 		kref_put(&rq->ref_count, destroy_async);
225 		return 0;
226 	}
227 	if (wait_for_completion_timeout(&rq->compl, HZ)) {
228 		ret = rq->urb->status;
229 		*val = priv->reg[(reg >= 9) ? 0 : regindex[reg]];
230 		if (ret)
231 			warn("get_1284_register: usb error %d", ret);
232 		kref_put(&rq->ref_count, destroy_async);
233 		return ret;
234 	}
235 	warn("get_1284_register timeout");
236 	kill_all_async_requests_priv(priv);
237 	return -EIO;
238 }
239 
240 static int set_1284_register(struct parport *pp, unsigned char reg, unsigned char val, gfp_t mem_flags)
241 {
242 	struct parport_uss720_private *priv;
243 	struct uss720_async_request *rq;
244 
245 	if (!pp)
246 		return -EIO;
247 	priv = pp->private_data;
248 	rq = submit_async_request(priv, 4, 0x40, (((unsigned int)reg) << 8) | val, 0, mem_flags);
249 	if (!rq) {
250 		err("set_1284_register(%u,%u) failed", (unsigned int)reg, (unsigned int)val);
251 		return -EIO;
252 	}
253 	kref_put(&rq->ref_count, destroy_async);
254 	return 0;
255 }
256 
257 /* --------------------------------------------------------------------- */
258 
259 /* ECR modes */
260 #define ECR_SPP 00
261 #define ECR_PS2 01
262 #define ECR_PPF 02
263 #define ECR_ECP 03
264 #define ECR_EPP 04
265 
266 /* Safely change the mode bits in the ECR */
267 static int change_mode(struct parport *pp, int m)
268 {
269 	struct parport_uss720_private *priv = pp->private_data;
270 	int mode;
271 	__u8 reg;
272 
273 	if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
274 		return -EIO;
275 	/* Bits <7:5> contain the mode. */
276 	mode = (priv->reg[2] >> 5) & 0x7;
277 	if (mode == m)
278 		return 0;
279 	/* We have to go through mode 000 or 001 */
280 	if (mode > ECR_PS2 && m > ECR_PS2)
281 		if (change_mode(pp, ECR_PS2))
282 			return -EIO;
283 
284 	if (m <= ECR_PS2 && !(priv->reg[1] & 0x20)) {
285 		/* This mode resets the FIFO, so we may
286 		 * have to wait for it to drain first. */
287 		unsigned long expire = jiffies + pp->physport->cad->timeout;
288 		switch (mode) {
289 		case ECR_PPF: /* Parallel Port FIFO mode */
290 		case ECR_ECP: /* ECP Parallel Port mode */
291 			/* Poll slowly. */
292 			for (;;) {
293 				if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
294 					return -EIO;
295 				if (priv->reg[2] & 0x01)
296 					break;
297 				if (time_after_eq (jiffies, expire))
298 					/* The FIFO is stuck. */
299 					return -EBUSY;
300 				msleep_interruptible(10);
301 				if (signal_pending (current))
302 					break;
303 			}
304 		}
305 	}
306 	/* Set the mode. */
307 	if (set_1284_register(pp, 6, m << 5, GFP_KERNEL))
308 		return -EIO;
309 	if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
310 		return -EIO;
311 	return 0;
312 }
313 
314 /*
315  * Clear TIMEOUT BIT in EPP MODE
316  */
317 static int clear_epp_timeout(struct parport *pp)
318 {
319 	unsigned char stat;
320 
321 	if (get_1284_register(pp, 1, &stat, GFP_KERNEL))
322 		return 1;
323 	return stat & 1;
324 }
325 
326 /*
327  * Access functions.
328  */
329 #if 0
330 static int uss720_irq(int usbstatus, void *buffer, int len, void *dev_id)
331 {
332 	struct parport *pp = (struct parport *)dev_id;
333 	struct parport_uss720_private *priv = pp->private_data;
334 
335 	if (usbstatus != 0 || len < 4 || !buffer)
336 		return 1;
337 	memcpy(priv->reg, buffer, 4);
338 	/* if nAck interrupts are enabled and we have an interrupt, call the interrupt procedure */
339 	if (priv->reg[2] & priv->reg[1] & 0x10)
340 		parport_generic_irq(pp);
341 	return 1;
342 }
343 #endif
344 
345 static void parport_uss720_write_data(struct parport *pp, unsigned char d)
346 {
347 	set_1284_register(pp, 0, d, GFP_KERNEL);
348 }
349 
350 static unsigned char parport_uss720_read_data(struct parport *pp)
351 {
352 	unsigned char ret;
353 
354 	if (get_1284_register(pp, 0, &ret, GFP_KERNEL))
355 		return 0;
356 	return ret;
357 }
358 
359 static void parport_uss720_write_control(struct parport *pp, unsigned char d)
360 {
361 	struct parport_uss720_private *priv = pp->private_data;
362 
363 	d = (d & 0xf) | (priv->reg[1] & 0xf0);
364 	if (set_1284_register(pp, 2, d, GFP_KERNEL))
365 		return;
366 	priv->reg[1] = d;
367 }
368 
369 static unsigned char parport_uss720_read_control(struct parport *pp)
370 {
371 	struct parport_uss720_private *priv = pp->private_data;
372 	return priv->reg[1] & 0xf; /* Use soft copy */
373 }
374 
375 static unsigned char parport_uss720_frob_control(struct parport *pp, unsigned char mask, unsigned char val)
376 {
377 	struct parport_uss720_private *priv = pp->private_data;
378 	unsigned char d;
379 
380 	mask &= 0x0f;
381 	val &= 0x0f;
382 	d = (priv->reg[1] & (~mask)) ^ val;
383 	if (set_1284_register(pp, 2, d, GFP_KERNEL))
384 		return 0;
385 	priv->reg[1] = d;
386 	return d & 0xf;
387 }
388 
389 static unsigned char parport_uss720_read_status(struct parport *pp)
390 {
391 	unsigned char ret;
392 
393 	if (get_1284_register(pp, 1, &ret, GFP_KERNEL))
394 		return 0;
395 	return ret & 0xf8;
396 }
397 
398 static void parport_uss720_disable_irq(struct parport *pp)
399 {
400 	struct parport_uss720_private *priv = pp->private_data;
401 	unsigned char d;
402 
403 	d = priv->reg[1] & ~0x10;
404 	if (set_1284_register(pp, 2, d, GFP_KERNEL))
405 		return;
406 	priv->reg[1] = d;
407 }
408 
409 static void parport_uss720_enable_irq(struct parport *pp)
410 {
411 	struct parport_uss720_private *priv = pp->private_data;
412 	unsigned char d;
413 
414 	d = priv->reg[1] | 0x10;
415 	if (set_1284_register(pp, 2, d, GFP_KERNEL))
416 		return;
417 	priv->reg[1] = d;
418 }
419 
420 static void parport_uss720_data_forward (struct parport *pp)
421 {
422 	struct parport_uss720_private *priv = pp->private_data;
423 	unsigned char d;
424 
425 	d = priv->reg[1] & ~0x20;
426 	if (set_1284_register(pp, 2, d, GFP_KERNEL))
427 		return;
428 	priv->reg[1] = d;
429 }
430 
431 static void parport_uss720_data_reverse (struct parport *pp)
432 {
433 	struct parport_uss720_private *priv = pp->private_data;
434 	unsigned char d;
435 
436 	d = priv->reg[1] | 0x20;
437 	if (set_1284_register(pp, 2, d, GFP_KERNEL))
438 		return;
439 	priv->reg[1] = d;
440 }
441 
442 static void parport_uss720_init_state(struct pardevice *dev, struct parport_state *s)
443 {
444 	s->u.pc.ctr = 0xc | (dev->irq_func ? 0x10 : 0x0);
445 	s->u.pc.ecr = 0x24;
446 }
447 
448 static void parport_uss720_save_state(struct parport *pp, struct parport_state *s)
449 {
450 	struct parport_uss720_private *priv = pp->private_data;
451 
452 #if 0
453 	if (get_1284_register(pp, 2, NULL, GFP_ATOMIC))
454 		return;
455 #endif
456 	s->u.pc.ctr = priv->reg[1];
457 	s->u.pc.ecr = priv->reg[2];
458 }
459 
460 static void parport_uss720_restore_state(struct parport *pp, struct parport_state *s)
461 {
462 	struct parport_uss720_private *priv = pp->private_data;
463 
464 	set_1284_register(pp, 2, s->u.pc.ctr, GFP_ATOMIC);
465 	set_1284_register(pp, 6, s->u.pc.ecr, GFP_ATOMIC);
466 	get_1284_register(pp, 2, NULL, GFP_ATOMIC);
467 	priv->reg[1] = s->u.pc.ctr;
468 	priv->reg[2] = s->u.pc.ecr;
469 }
470 
471 static size_t parport_uss720_epp_read_data(struct parport *pp, void *buf, size_t length, int flags)
472 {
473 	struct parport_uss720_private *priv = pp->private_data;
474 	size_t got = 0;
475 
476 	if (change_mode(pp, ECR_EPP))
477 		return 0;
478 	for (; got < length; got++) {
479 		if (get_1284_register(pp, 4, (char *)buf, GFP_KERNEL))
480 			break;
481 		buf++;
482 		if (priv->reg[0] & 0x01) {
483 			clear_epp_timeout(pp);
484 			break;
485 		}
486 	}
487 	change_mode(pp, ECR_PS2);
488 	return got;
489 }
490 
491 static size_t parport_uss720_epp_write_data(struct parport *pp, const void *buf, size_t length, int flags)
492 {
493 #if 0
494 	struct parport_uss720_private *priv = pp->private_data;
495 	size_t written = 0;
496 
497 	if (change_mode(pp, ECR_EPP))
498 		return 0;
499 	for (; written < length; written++) {
500 		if (set_1284_register(pp, 4, (char *)buf, GFP_KERNEL))
501 			break;
502 		((char*)buf)++;
503 		if (get_1284_register(pp, 1, NULL, GFP_KERNEL))
504 			break;
505 		if (priv->reg[0] & 0x01) {
506 			clear_epp_timeout(pp);
507 			break;
508 		}
509 	}
510 	change_mode(pp, ECR_PS2);
511 	return written;
512 #else
513 	struct parport_uss720_private *priv = pp->private_data;
514 	struct usb_device *usbdev = priv->usbdev;
515 	int rlen;
516 	int i;
517 
518 	if (!usbdev)
519 		return 0;
520 	if (change_mode(pp, ECR_EPP))
521 		return 0;
522 	i = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 1), (void *)buf, length, &rlen, 20000);
523 	if (i)
524 		printk(KERN_ERR "uss720: sendbulk ep 1 buf %p len %Zu rlen %u\n", buf, length, rlen);
525 	change_mode(pp, ECR_PS2);
526 	return rlen;
527 #endif
528 }
529 
530 static size_t parport_uss720_epp_read_addr(struct parport *pp, void *buf, size_t length, int flags)
531 {
532 	struct parport_uss720_private *priv = pp->private_data;
533 	size_t got = 0;
534 
535 	if (change_mode(pp, ECR_EPP))
536 		return 0;
537 	for (; got < length; got++) {
538 		if (get_1284_register(pp, 3, (char *)buf, GFP_KERNEL))
539 			break;
540 		buf++;
541 		if (priv->reg[0] & 0x01) {
542 			clear_epp_timeout(pp);
543 			break;
544 		}
545 	}
546 	change_mode(pp, ECR_PS2);
547 	return got;
548 }
549 
550 static size_t parport_uss720_epp_write_addr(struct parport *pp, const void *buf, size_t length, int flags)
551 {
552 	struct parport_uss720_private *priv = pp->private_data;
553 	size_t written = 0;
554 
555 	if (change_mode(pp, ECR_EPP))
556 		return 0;
557 	for (; written < length; written++) {
558 		if (set_1284_register(pp, 3, *(char *)buf, GFP_KERNEL))
559 			break;
560 		buf++;
561 		if (get_1284_register(pp, 1, NULL, GFP_KERNEL))
562 			break;
563 		if (priv->reg[0] & 0x01) {
564 			clear_epp_timeout(pp);
565 			break;
566 		}
567 	}
568 	change_mode(pp, ECR_PS2);
569 	return written;
570 }
571 
572 static size_t parport_uss720_ecp_write_data(struct parport *pp, const void *buffer, size_t len, int flags)
573 {
574 	struct parport_uss720_private *priv = pp->private_data;
575 	struct usb_device *usbdev = priv->usbdev;
576 	int rlen;
577 	int i;
578 
579 	if (!usbdev)
580 		return 0;
581 	if (change_mode(pp, ECR_ECP))
582 		return 0;
583 	i = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 1), (void *)buffer, len, &rlen, 20000);
584 	if (i)
585 		printk(KERN_ERR "uss720: sendbulk ep 1 buf %p len %Zu rlen %u\n", buffer, len, rlen);
586 	change_mode(pp, ECR_PS2);
587 	return rlen;
588 }
589 
590 static size_t parport_uss720_ecp_read_data(struct parport *pp, void *buffer, size_t len, int flags)
591 {
592 	struct parport_uss720_private *priv = pp->private_data;
593 	struct usb_device *usbdev = priv->usbdev;
594 	int rlen;
595 	int i;
596 
597 	if (!usbdev)
598 		return 0;
599 	if (change_mode(pp, ECR_ECP))
600 		return 0;
601 	i = usb_bulk_msg(usbdev, usb_rcvbulkpipe(usbdev, 2), buffer, len, &rlen, 20000);
602 	if (i)
603 		printk(KERN_ERR "uss720: recvbulk ep 2 buf %p len %Zu rlen %u\n", buffer, len, rlen);
604 	change_mode(pp, ECR_PS2);
605 	return rlen;
606 }
607 
608 static size_t parport_uss720_ecp_write_addr(struct parport *pp, const void *buffer, size_t len, int flags)
609 {
610 	size_t written = 0;
611 
612 	if (change_mode(pp, ECR_ECP))
613 		return 0;
614 	for (; written < len; written++) {
615 		if (set_1284_register(pp, 5, *(char *)buffer, GFP_KERNEL))
616 			break;
617 		buffer++;
618 	}
619 	change_mode(pp, ECR_PS2);
620 	return written;
621 }
622 
623 static size_t parport_uss720_write_compat(struct parport *pp, const void *buffer, size_t len, int flags)
624 {
625 	struct parport_uss720_private *priv = pp->private_data;
626 	struct usb_device *usbdev = priv->usbdev;
627 	int rlen;
628 	int i;
629 
630 	if (!usbdev)
631 		return 0;
632 	if (change_mode(pp, ECR_PPF))
633 		return 0;
634 	i = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 1), (void *)buffer, len, &rlen, 20000);
635 	if (i)
636 		printk(KERN_ERR "uss720: sendbulk ep 1 buf %p len %Zu rlen %u\n", buffer, len, rlen);
637 	change_mode(pp, ECR_PS2);
638 	return rlen;
639 }
640 
641 /* --------------------------------------------------------------------- */
642 
643 static struct parport_operations parport_uss720_ops =
644 {
645 	.owner =		THIS_MODULE,
646 	.write_data =		parport_uss720_write_data,
647 	.read_data =		parport_uss720_read_data,
648 
649 	.write_control =	parport_uss720_write_control,
650 	.read_control =		parport_uss720_read_control,
651 	.frob_control =		parport_uss720_frob_control,
652 
653 	.read_status =		parport_uss720_read_status,
654 
655 	.enable_irq =		parport_uss720_enable_irq,
656 	.disable_irq =		parport_uss720_disable_irq,
657 
658 	.data_forward =		parport_uss720_data_forward,
659 	.data_reverse =		parport_uss720_data_reverse,
660 
661 	.init_state =		parport_uss720_init_state,
662 	.save_state =		parport_uss720_save_state,
663 	.restore_state =	parport_uss720_restore_state,
664 
665 	.epp_write_data =	parport_uss720_epp_write_data,
666 	.epp_read_data =	parport_uss720_epp_read_data,
667 	.epp_write_addr =	parport_uss720_epp_write_addr,
668 	.epp_read_addr =	parport_uss720_epp_read_addr,
669 
670 	.ecp_write_data =	parport_uss720_ecp_write_data,
671 	.ecp_read_data =	parport_uss720_ecp_read_data,
672 	.ecp_write_addr =	parport_uss720_ecp_write_addr,
673 
674 	.compat_write_data =	parport_uss720_write_compat,
675 	.nibble_read_data =	parport_ieee1284_read_nibble,
676 	.byte_read_data =	parport_ieee1284_read_byte,
677 };
678 
679 /* --------------------------------------------------------------------- */
680 
681 static int uss720_probe(struct usb_interface *intf,
682 			const struct usb_device_id *id)
683 {
684 	struct usb_device *usbdev = usb_get_dev(interface_to_usbdev(intf));
685 	struct usb_host_interface *interface;
686 	struct usb_host_endpoint *endpoint;
687 	struct parport_uss720_private *priv;
688 	struct parport *pp;
689 	unsigned char reg;
690 	int i;
691 
692 	dbg("probe: vendor id 0x%x, device id 0x%x\n",
693 	    le16_to_cpu(usbdev->descriptor.idVendor),
694 	    le16_to_cpu(usbdev->descriptor.idProduct));
695 
696 	/* our known interfaces have 3 alternate settings */
697 	if (intf->num_altsetting != 3) {
698 		usb_put_dev(usbdev);
699 		return -ENODEV;
700 	}
701 	i = usb_set_interface(usbdev, intf->altsetting->desc.bInterfaceNumber, 2);
702 	dbg("set inteface result %d", i);
703 
704 	interface = intf->cur_altsetting;
705 
706 	/*
707 	 * Allocate parport interface
708 	 */
709 	if (!(priv = kzalloc(sizeof(struct parport_uss720_private), GFP_KERNEL))) {
710 		usb_put_dev(usbdev);
711 		return -ENOMEM;
712 	}
713 	priv->pp = NULL;
714 	priv->usbdev = usbdev;
715 	kref_init(&priv->ref_count);
716 	spin_lock_init(&priv->asynclock);
717 	INIT_LIST_HEAD(&priv->asynclist);
718 	if (!(pp = parport_register_port(0, PARPORT_IRQ_NONE, PARPORT_DMA_NONE, &parport_uss720_ops))) {
719 		warn("could not register parport");
720 		goto probe_abort;
721 	}
722 
723 	priv->pp = pp;
724 	pp->private_data = priv;
725 	pp->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_TRISTATE | PARPORT_MODE_EPP | PARPORT_MODE_ECP | PARPORT_MODE_COMPAT;
726 
727 	/* set the USS720 control register to manual mode, no ECP compression, enable all ints */
728 	set_1284_register(pp, 7, 0x00, GFP_KERNEL);
729 	set_1284_register(pp, 6, 0x30, GFP_KERNEL);  /* PS/2 mode */
730 	set_1284_register(pp, 2, 0x0c, GFP_KERNEL);
731 	/* debugging */
732 	get_1284_register(pp, 0, &reg, GFP_KERNEL);
733 	dbg("reg: %02x %02x %02x %02x %02x %02x %02x",
734 	    priv->reg[0], priv->reg[1], priv->reg[2], priv->reg[3], priv->reg[4], priv->reg[5], priv->reg[6]);
735 
736 	endpoint = &interface->endpoint[2];
737 	dbg("epaddr %d interval %d", endpoint->desc.bEndpointAddress, endpoint->desc.bInterval);
738 	parport_announce_port(pp);
739 
740 	usb_set_intfdata(intf, pp);
741 	return 0;
742 
743 probe_abort:
744 	kill_all_async_requests_priv(priv);
745 	kref_put(&priv->ref_count, destroy_priv);
746 	return -ENODEV;
747 }
748 
749 static void uss720_disconnect(struct usb_interface *intf)
750 {
751 	struct parport *pp = usb_get_intfdata(intf);
752 	struct parport_uss720_private *priv;
753 	struct usb_device *usbdev;
754 
755 	dbg("disconnect");
756 	usb_set_intfdata(intf, NULL);
757 	if (pp) {
758 		priv = pp->private_data;
759 		usbdev = priv->usbdev;
760 		priv->usbdev = NULL;
761 		priv->pp = NULL;
762 		dbg("parport_remove_port");
763 		parport_remove_port(pp);
764 		parport_put_port(pp);
765 		kill_all_async_requests_priv(priv);
766 		kref_put(&priv->ref_count, destroy_priv);
767 	}
768 	dbg("disconnect done");
769 }
770 
771 /* table of cables that work through this driver */
772 static struct usb_device_id uss720_table [] = {
773 	{ USB_DEVICE(0x047e, 0x1001) },
774 	{ USB_DEVICE(0x0557, 0x2001) },
775 	{ USB_DEVICE(0x0729, 0x1284) },
776 	{ USB_DEVICE(0x1293, 0x0002) },
777 	{ }						/* Terminating entry */
778 };
779 
780 MODULE_DEVICE_TABLE (usb, uss720_table);
781 
782 
783 static struct usb_driver uss720_driver = {
784 	.name =		"uss720",
785 	.probe =	uss720_probe,
786 	.disconnect =	uss720_disconnect,
787 	.id_table =	uss720_table,
788 };
789 
790 /* --------------------------------------------------------------------- */
791 
792 MODULE_AUTHOR(DRIVER_AUTHOR);
793 MODULE_DESCRIPTION(DRIVER_DESC);
794 MODULE_LICENSE("GPL");
795 
796 static int __init uss720_init(void)
797 {
798 	int retval;
799 	retval = usb_register(&uss720_driver);
800 	if (retval)
801 		goto out;
802 
803 	info(DRIVER_VERSION ":" DRIVER_DESC);
804 	info("NOTE: this is a special purpose driver to allow nonstandard");
805 	info("protocols (eg. bitbang) over USS720 usb to parallel cables");
806 	info("If you just want to connect to a printer, use usblp instead");
807 out:
808 	return retval;
809 }
810 
811 static void __exit uss720_cleanup(void)
812 {
813 	usb_deregister(&uss720_driver);
814 }
815 
816 module_init(uss720_init);
817 module_exit(uss720_cleanup);
818 
819 /* --------------------------------------------------------------------- */
820