xref: /openbmc/linux/drivers/usb/misc/uss720.c (revision 44a54e25)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*****************************************************************************/
3 
4 /*
5  *	uss720.c  --  USS720 USB Parport Cable.
6  *
7  *	Copyright (C) 1999, 2005, 2010
8  *	    Thomas Sailer (t.sailer@alumni.ethz.ch)
9  *
10  *  Based on parport_pc.c
11  *
12  *  History:
13  *   0.1  04.08.1999  Created
14  *   0.2  07.08.1999  Some fixes mainly suggested by Tim Waugh
15  *		      Interrupt handling currently disabled because
16  *		      usb_request_irq crashes somewhere within ohci.c
17  *		      for no apparent reason (that is for me, anyway)
18  *		      ECP currently untested
19  *   0.3  10.08.1999  fixing merge errors
20  *   0.4  13.08.1999  Added Vendor/Product ID of Brad Hard's cable
21  *   0.5  20.09.1999  usb_control_msg wrapper used
22  *        Nov01.2000  usb_device_table support by Adam J. Richter
23  *        08.04.2001  Identify version on module load.  gb
24  *   0.6  02.09.2005  Fix "scheduling in interrupt" problem by making save/restore
25  *                    context asynchronous
26  *
27  */
28 
29 /*****************************************************************************/
30 
31 #include <linux/module.h>
32 #include <linux/socket.h>
33 #include <linux/parport.h>
34 #include <linux/init.h>
35 #include <linux/usb.h>
36 #include <linux/delay.h>
37 #include <linux/completion.h>
38 #include <linux/kref.h>
39 #include <linux/slab.h>
40 #include <linux/sched/signal.h>
41 
42 #define DRIVER_AUTHOR "Thomas M. Sailer, t.sailer@alumni.ethz.ch"
43 #define DRIVER_DESC "USB Parport Cable driver for Cables using the Lucent Technologies USS720 Chip"
44 
45 /* --------------------------------------------------------------------- */
46 
47 struct parport_uss720_private {
48 	struct usb_device *usbdev;
49 	struct parport *pp;
50 	struct kref ref_count;
51 	__u8 reg[7];  /* USB registers */
52 	struct list_head asynclist;
53 	spinlock_t asynclock;
54 };
55 
56 struct uss720_async_request {
57 	struct parport_uss720_private *priv;
58 	struct kref ref_count;
59 	struct list_head asynclist;
60 	struct completion compl;
61 	struct urb *urb;
62 	struct usb_ctrlrequest *dr;
63 	__u8 reg[7];
64 };
65 
66 /* --------------------------------------------------------------------- */
67 
68 static void destroy_priv(struct kref *kref)
69 {
70 	struct parport_uss720_private *priv = container_of(kref, struct parport_uss720_private, ref_count);
71 
72 	dev_dbg(&priv->usbdev->dev, "destroying priv datastructure\n");
73 	usb_put_dev(priv->usbdev);
74 	priv->usbdev = NULL;
75 	kfree(priv);
76 }
77 
78 static void destroy_async(struct kref *kref)
79 {
80 	struct uss720_async_request *rq = container_of(kref, struct uss720_async_request, ref_count);
81 	struct parport_uss720_private *priv = rq->priv;
82 	unsigned long flags;
83 
84 	if (likely(rq->urb))
85 		usb_free_urb(rq->urb);
86 	kfree(rq->dr);
87 	spin_lock_irqsave(&priv->asynclock, flags);
88 	list_del_init(&rq->asynclist);
89 	spin_unlock_irqrestore(&priv->asynclock, flags);
90 	kfree(rq);
91 	kref_put(&priv->ref_count, destroy_priv);
92 }
93 
94 /* --------------------------------------------------------------------- */
95 
96 static void async_complete(struct urb *urb)
97 {
98 	struct uss720_async_request *rq;
99 	struct parport *pp;
100 	struct parport_uss720_private *priv;
101 	int status = urb->status;
102 
103 	rq = urb->context;
104 	priv = rq->priv;
105 	pp = priv->pp;
106 	if (status) {
107 		dev_err(&urb->dev->dev, "async_complete: urb error %d\n",
108 			status);
109 	} else if (rq->dr->bRequest == 3) {
110 		memcpy(priv->reg, rq->reg, sizeof(priv->reg));
111 #if 0
112 		dev_dbg(&priv->usbdev->dev, "async_complete regs %7ph\n",
113 			priv->reg);
114 #endif
115 		/* if nAck interrupts are enabled and we have an interrupt, call the interrupt procedure */
116 		if (rq->reg[2] & rq->reg[1] & 0x10 && pp)
117 			parport_generic_irq(pp);
118 	}
119 	complete(&rq->compl);
120 	kref_put(&rq->ref_count, destroy_async);
121 }
122 
123 static struct uss720_async_request *submit_async_request(struct parport_uss720_private *priv,
124 							 __u8 request, __u8 requesttype, __u16 value, __u16 index,
125 							 gfp_t mem_flags)
126 {
127 	struct usb_device *usbdev;
128 	struct uss720_async_request *rq;
129 	unsigned long flags;
130 	int ret;
131 
132 	if (!priv)
133 		return NULL;
134 	usbdev = priv->usbdev;
135 	if (!usbdev)
136 		return NULL;
137 	rq = kzalloc(sizeof(struct uss720_async_request), mem_flags);
138 	if (!rq)
139 		return NULL;
140 	kref_init(&rq->ref_count);
141 	INIT_LIST_HEAD(&rq->asynclist);
142 	init_completion(&rq->compl);
143 	kref_get(&priv->ref_count);
144 	rq->priv = priv;
145 	rq->urb = usb_alloc_urb(0, mem_flags);
146 	if (!rq->urb) {
147 		kref_put(&rq->ref_count, destroy_async);
148 		return NULL;
149 	}
150 	rq->dr = kmalloc(sizeof(*rq->dr), mem_flags);
151 	if (!rq->dr) {
152 		kref_put(&rq->ref_count, destroy_async);
153 		return NULL;
154 	}
155 	rq->dr->bRequestType = requesttype;
156 	rq->dr->bRequest = request;
157 	rq->dr->wValue = cpu_to_le16(value);
158 	rq->dr->wIndex = cpu_to_le16(index);
159 	rq->dr->wLength = cpu_to_le16((request == 3) ? sizeof(rq->reg) : 0);
160 	usb_fill_control_urb(rq->urb, usbdev, (requesttype & 0x80) ? usb_rcvctrlpipe(usbdev, 0) : usb_sndctrlpipe(usbdev, 0),
161 			     (unsigned char *)rq->dr,
162 			     (request == 3) ? rq->reg : NULL, (request == 3) ? sizeof(rq->reg) : 0, async_complete, rq);
163 	/* rq->urb->transfer_flags |= URB_ASYNC_UNLINK; */
164 	spin_lock_irqsave(&priv->asynclock, flags);
165 	list_add_tail(&rq->asynclist, &priv->asynclist);
166 	spin_unlock_irqrestore(&priv->asynclock, flags);
167 	kref_get(&rq->ref_count);
168 	ret = usb_submit_urb(rq->urb, mem_flags);
169 	if (!ret)
170 		return rq;
171 	destroy_async(&rq->ref_count);
172 	dev_err(&usbdev->dev, "submit_async_request submit_urb failed with %d\n", ret);
173 	return NULL;
174 }
175 
176 static unsigned int kill_all_async_requests_priv(struct parport_uss720_private *priv)
177 {
178 	struct uss720_async_request *rq;
179 	unsigned long flags;
180 	unsigned int ret = 0;
181 
182 	spin_lock_irqsave(&priv->asynclock, flags);
183 	list_for_each_entry(rq, &priv->asynclist, asynclist) {
184 		usb_unlink_urb(rq->urb);
185 		ret++;
186 	}
187 	spin_unlock_irqrestore(&priv->asynclock, flags);
188 	return ret;
189 }
190 
191 /* --------------------------------------------------------------------- */
192 
193 static int get_1284_register(struct parport *pp, unsigned char reg, unsigned char *val, gfp_t mem_flags)
194 {
195 	struct parport_uss720_private *priv;
196 	struct uss720_async_request *rq;
197 	static const unsigned char regindex[9] = {
198 		4, 0, 1, 5, 5, 0, 2, 3, 6
199 	};
200 	int ret;
201 
202 	if (!pp)
203 		return -EIO;
204 	priv = pp->private_data;
205 	rq = submit_async_request(priv, 3, 0xc0, ((unsigned int)reg) << 8, 0, mem_flags);
206 	if (!rq) {
207 		dev_err(&priv->usbdev->dev, "get_1284_register(%u) failed",
208 			(unsigned int)reg);
209 		return -EIO;
210 	}
211 	if (!val) {
212 		kref_put(&rq->ref_count, destroy_async);
213 		return 0;
214 	}
215 	if (wait_for_completion_timeout(&rq->compl, HZ)) {
216 		ret = rq->urb->status;
217 		*val = priv->reg[(reg >= 9) ? 0 : regindex[reg]];
218 		if (ret)
219 			printk(KERN_WARNING "get_1284_register: "
220 			       "usb error %d\n", ret);
221 		kref_put(&rq->ref_count, destroy_async);
222 		return ret;
223 	}
224 	printk(KERN_WARNING "get_1284_register timeout\n");
225 	kill_all_async_requests_priv(priv);
226 	return -EIO;
227 }
228 
229 static int set_1284_register(struct parport *pp, unsigned char reg, unsigned char val, gfp_t mem_flags)
230 {
231 	struct parport_uss720_private *priv;
232 	struct uss720_async_request *rq;
233 
234 	if (!pp)
235 		return -EIO;
236 	priv = pp->private_data;
237 	rq = submit_async_request(priv, 4, 0x40, (((unsigned int)reg) << 8) | val, 0, mem_flags);
238 	if (!rq) {
239 		dev_err(&priv->usbdev->dev, "set_1284_register(%u,%u) failed",
240 			(unsigned int)reg, (unsigned int)val);
241 		return -EIO;
242 	}
243 	kref_put(&rq->ref_count, destroy_async);
244 	return 0;
245 }
246 
247 /* --------------------------------------------------------------------- */
248 
249 /* ECR modes */
250 #define ECR_SPP 00
251 #define ECR_PS2 01
252 #define ECR_PPF 02
253 #define ECR_ECP 03
254 #define ECR_EPP 04
255 
256 /* Safely change the mode bits in the ECR */
257 static int change_mode(struct parport *pp, int m)
258 {
259 	struct parport_uss720_private *priv = pp->private_data;
260 	int mode;
261 	__u8 reg;
262 
263 	if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
264 		return -EIO;
265 	/* Bits <7:5> contain the mode. */
266 	mode = (priv->reg[2] >> 5) & 0x7;
267 	if (mode == m)
268 		return 0;
269 	/* We have to go through mode 000 or 001 */
270 	if (mode > ECR_PS2 && m > ECR_PS2)
271 		if (change_mode(pp, ECR_PS2))
272 			return -EIO;
273 
274 	if (m <= ECR_PS2 && !(priv->reg[1] & 0x20)) {
275 		/* This mode resets the FIFO, so we may
276 		 * have to wait for it to drain first. */
277 		unsigned long expire = jiffies + pp->physport->cad->timeout;
278 		switch (mode) {
279 		case ECR_PPF: /* Parallel Port FIFO mode */
280 		case ECR_ECP: /* ECP Parallel Port mode */
281 			/* Poll slowly. */
282 			for (;;) {
283 				if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
284 					return -EIO;
285 				if (priv->reg[2] & 0x01)
286 					break;
287 				if (time_after_eq (jiffies, expire))
288 					/* The FIFO is stuck. */
289 					return -EBUSY;
290 				msleep_interruptible(10);
291 				if (signal_pending (current))
292 					break;
293 			}
294 		}
295 	}
296 	/* Set the mode. */
297 	if (set_1284_register(pp, 6, m << 5, GFP_KERNEL))
298 		return -EIO;
299 	if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
300 		return -EIO;
301 	return 0;
302 }
303 
304 /*
305  * Clear TIMEOUT BIT in EPP MODE
306  */
307 static int clear_epp_timeout(struct parport *pp)
308 {
309 	unsigned char stat;
310 
311 	if (get_1284_register(pp, 1, &stat, GFP_KERNEL))
312 		return 1;
313 	return stat & 1;
314 }
315 
316 /*
317  * Access functions.
318  */
319 #if 0
320 static int uss720_irq(int usbstatus, void *buffer, int len, void *dev_id)
321 {
322 	struct parport *pp = (struct parport *)dev_id;
323 	struct parport_uss720_private *priv = pp->private_data;
324 
325 	if (usbstatus != 0 || len < 4 || !buffer)
326 		return 1;
327 	memcpy(priv->reg, buffer, 4);
328 	/* if nAck interrupts are enabled and we have an interrupt, call the interrupt procedure */
329 	if (priv->reg[2] & priv->reg[1] & 0x10)
330 		parport_generic_irq(pp);
331 	return 1;
332 }
333 #endif
334 
335 static void parport_uss720_write_data(struct parport *pp, unsigned char d)
336 {
337 	set_1284_register(pp, 0, d, GFP_KERNEL);
338 }
339 
340 static unsigned char parport_uss720_read_data(struct parport *pp)
341 {
342 	unsigned char ret;
343 
344 	if (get_1284_register(pp, 0, &ret, GFP_KERNEL))
345 		return 0;
346 	return ret;
347 }
348 
349 static void parport_uss720_write_control(struct parport *pp, unsigned char d)
350 {
351 	struct parport_uss720_private *priv = pp->private_data;
352 
353 	d = (d & 0xf) | (priv->reg[1] & 0xf0);
354 	if (set_1284_register(pp, 2, d, GFP_KERNEL))
355 		return;
356 	priv->reg[1] = d;
357 }
358 
359 static unsigned char parport_uss720_read_control(struct parport *pp)
360 {
361 	struct parport_uss720_private *priv = pp->private_data;
362 	return priv->reg[1] & 0xf; /* Use soft copy */
363 }
364 
365 static unsigned char parport_uss720_frob_control(struct parport *pp, unsigned char mask, unsigned char val)
366 {
367 	struct parport_uss720_private *priv = pp->private_data;
368 	unsigned char d;
369 
370 	mask &= 0x0f;
371 	val &= 0x0f;
372 	d = (priv->reg[1] & (~mask)) ^ val;
373 	if (set_1284_register(pp, 2, d, GFP_ATOMIC))
374 		return 0;
375 	priv->reg[1] = d;
376 	return d & 0xf;
377 }
378 
379 static unsigned char parport_uss720_read_status(struct parport *pp)
380 {
381 	unsigned char ret;
382 
383 	if (get_1284_register(pp, 1, &ret, GFP_ATOMIC))
384 		return 0;
385 	return ret & 0xf8;
386 }
387 
388 static void parport_uss720_disable_irq(struct parport *pp)
389 {
390 	struct parport_uss720_private *priv = pp->private_data;
391 	unsigned char d;
392 
393 	d = priv->reg[1] & ~0x10;
394 	if (set_1284_register(pp, 2, d, GFP_KERNEL))
395 		return;
396 	priv->reg[1] = d;
397 }
398 
399 static void parport_uss720_enable_irq(struct parport *pp)
400 {
401 	struct parport_uss720_private *priv = pp->private_data;
402 	unsigned char d;
403 
404 	d = priv->reg[1] | 0x10;
405 	if (set_1284_register(pp, 2, d, GFP_KERNEL))
406 		return;
407 	priv->reg[1] = d;
408 }
409 
410 static void parport_uss720_data_forward (struct parport *pp)
411 {
412 	struct parport_uss720_private *priv = pp->private_data;
413 	unsigned char d;
414 
415 	d = priv->reg[1] & ~0x20;
416 	if (set_1284_register(pp, 2, d, GFP_KERNEL))
417 		return;
418 	priv->reg[1] = d;
419 }
420 
421 static void parport_uss720_data_reverse (struct parport *pp)
422 {
423 	struct parport_uss720_private *priv = pp->private_data;
424 	unsigned char d;
425 
426 	d = priv->reg[1] | 0x20;
427 	if (set_1284_register(pp, 2, d, GFP_KERNEL))
428 		return;
429 	priv->reg[1] = d;
430 }
431 
432 static void parport_uss720_init_state(struct pardevice *dev, struct parport_state *s)
433 {
434 	s->u.pc.ctr = 0xc | (dev->irq_func ? 0x10 : 0x0);
435 	s->u.pc.ecr = 0x24;
436 }
437 
438 static void parport_uss720_save_state(struct parport *pp, struct parport_state *s)
439 {
440 	struct parport_uss720_private *priv = pp->private_data;
441 
442 #if 0
443 	if (get_1284_register(pp, 2, NULL, GFP_ATOMIC))
444 		return;
445 #endif
446 	s->u.pc.ctr = priv->reg[1];
447 	s->u.pc.ecr = priv->reg[2];
448 }
449 
450 static void parport_uss720_restore_state(struct parport *pp, struct parport_state *s)
451 {
452 	struct parport_uss720_private *priv = pp->private_data;
453 
454 	set_1284_register(pp, 2, s->u.pc.ctr, GFP_ATOMIC);
455 	set_1284_register(pp, 6, s->u.pc.ecr, GFP_ATOMIC);
456 	get_1284_register(pp, 2, NULL, GFP_ATOMIC);
457 	priv->reg[1] = s->u.pc.ctr;
458 	priv->reg[2] = s->u.pc.ecr;
459 }
460 
461 static size_t parport_uss720_epp_read_data(struct parport *pp, void *buf, size_t length, int flags)
462 {
463 	struct parport_uss720_private *priv = pp->private_data;
464 	size_t got = 0;
465 
466 	if (change_mode(pp, ECR_EPP))
467 		return 0;
468 	for (; got < length; got++) {
469 		if (get_1284_register(pp, 4, (char *)buf, GFP_KERNEL))
470 			break;
471 		buf++;
472 		if (priv->reg[0] & 0x01) {
473 			clear_epp_timeout(pp);
474 			break;
475 		}
476 	}
477 	change_mode(pp, ECR_PS2);
478 	return got;
479 }
480 
481 static size_t parport_uss720_epp_write_data(struct parport *pp, const void *buf, size_t length, int flags)
482 {
483 #if 0
484 	struct parport_uss720_private *priv = pp->private_data;
485 	size_t written = 0;
486 
487 	if (change_mode(pp, ECR_EPP))
488 		return 0;
489 	for (; written < length; written++) {
490 		if (set_1284_register(pp, 4, (char *)buf, GFP_KERNEL))
491 			break;
492 		((char*)buf)++;
493 		if (get_1284_register(pp, 1, NULL, GFP_KERNEL))
494 			break;
495 		if (priv->reg[0] & 0x01) {
496 			clear_epp_timeout(pp);
497 			break;
498 		}
499 	}
500 	change_mode(pp, ECR_PS2);
501 	return written;
502 #else
503 	struct parport_uss720_private *priv = pp->private_data;
504 	struct usb_device *usbdev = priv->usbdev;
505 	int rlen = 0;
506 	int i;
507 
508 	if (!usbdev)
509 		return 0;
510 	if (change_mode(pp, ECR_EPP))
511 		return 0;
512 	i = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 1), (void *)buf, length, &rlen, 20000);
513 	if (i)
514 		printk(KERN_ERR "uss720: sendbulk ep 1 buf %p len %zu rlen %u\n", buf, length, rlen);
515 	change_mode(pp, ECR_PS2);
516 	return rlen;
517 #endif
518 }
519 
520 static size_t parport_uss720_epp_read_addr(struct parport *pp, void *buf, size_t length, int flags)
521 {
522 	struct parport_uss720_private *priv = pp->private_data;
523 	size_t got = 0;
524 
525 	if (change_mode(pp, ECR_EPP))
526 		return 0;
527 	for (; got < length; got++) {
528 		if (get_1284_register(pp, 3, (char *)buf, GFP_KERNEL))
529 			break;
530 		buf++;
531 		if (priv->reg[0] & 0x01) {
532 			clear_epp_timeout(pp);
533 			break;
534 		}
535 	}
536 	change_mode(pp, ECR_PS2);
537 	return got;
538 }
539 
540 static size_t parport_uss720_epp_write_addr(struct parport *pp, const void *buf, size_t length, int flags)
541 {
542 	struct parport_uss720_private *priv = pp->private_data;
543 	size_t written = 0;
544 
545 	if (change_mode(pp, ECR_EPP))
546 		return 0;
547 	for (; written < length; written++) {
548 		if (set_1284_register(pp, 3, *(char *)buf, GFP_KERNEL))
549 			break;
550 		buf++;
551 		if (get_1284_register(pp, 1, NULL, GFP_KERNEL))
552 			break;
553 		if (priv->reg[0] & 0x01) {
554 			clear_epp_timeout(pp);
555 			break;
556 		}
557 	}
558 	change_mode(pp, ECR_PS2);
559 	return written;
560 }
561 
562 static size_t parport_uss720_ecp_write_data(struct parport *pp, const void *buffer, size_t len, int flags)
563 {
564 	struct parport_uss720_private *priv = pp->private_data;
565 	struct usb_device *usbdev = priv->usbdev;
566 	int rlen = 0;
567 	int i;
568 
569 	if (!usbdev)
570 		return 0;
571 	if (change_mode(pp, ECR_ECP))
572 		return 0;
573 	i = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 1), (void *)buffer, len, &rlen, 20000);
574 	if (i)
575 		printk(KERN_ERR "uss720: sendbulk ep 1 buf %p len %zu rlen %u\n", buffer, len, rlen);
576 	change_mode(pp, ECR_PS2);
577 	return rlen;
578 }
579 
580 static size_t parport_uss720_ecp_read_data(struct parport *pp, void *buffer, size_t len, int flags)
581 {
582 	struct parport_uss720_private *priv = pp->private_data;
583 	struct usb_device *usbdev = priv->usbdev;
584 	int rlen = 0;
585 	int i;
586 
587 	if (!usbdev)
588 		return 0;
589 	if (change_mode(pp, ECR_ECP))
590 		return 0;
591 	i = usb_bulk_msg(usbdev, usb_rcvbulkpipe(usbdev, 2), buffer, len, &rlen, 20000);
592 	if (i)
593 		printk(KERN_ERR "uss720: recvbulk ep 2 buf %p len %zu rlen %u\n", buffer, len, rlen);
594 	change_mode(pp, ECR_PS2);
595 	return rlen;
596 }
597 
598 static size_t parport_uss720_ecp_write_addr(struct parport *pp, const void *buffer, size_t len, int flags)
599 {
600 	size_t written = 0;
601 
602 	if (change_mode(pp, ECR_ECP))
603 		return 0;
604 	for (; written < len; written++) {
605 		if (set_1284_register(pp, 5, *(char *)buffer, GFP_KERNEL))
606 			break;
607 		buffer++;
608 	}
609 	change_mode(pp, ECR_PS2);
610 	return written;
611 }
612 
613 static size_t parport_uss720_write_compat(struct parport *pp, const void *buffer, size_t len, int flags)
614 {
615 	struct parport_uss720_private *priv = pp->private_data;
616 	struct usb_device *usbdev = priv->usbdev;
617 	int rlen = 0;
618 	int i;
619 
620 	if (!usbdev)
621 		return 0;
622 	if (change_mode(pp, ECR_PPF))
623 		return 0;
624 	i = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 1), (void *)buffer, len, &rlen, 20000);
625 	if (i)
626 		printk(KERN_ERR "uss720: sendbulk ep 1 buf %p len %zu rlen %u\n", buffer, len, rlen);
627 	change_mode(pp, ECR_PS2);
628 	return rlen;
629 }
630 
631 /* --------------------------------------------------------------------- */
632 
633 static struct parport_operations parport_uss720_ops =
634 {
635 	.owner =		THIS_MODULE,
636 	.write_data =		parport_uss720_write_data,
637 	.read_data =		parport_uss720_read_data,
638 
639 	.write_control =	parport_uss720_write_control,
640 	.read_control =		parport_uss720_read_control,
641 	.frob_control =		parport_uss720_frob_control,
642 
643 	.read_status =		parport_uss720_read_status,
644 
645 	.enable_irq =		parport_uss720_enable_irq,
646 	.disable_irq =		parport_uss720_disable_irq,
647 
648 	.data_forward =		parport_uss720_data_forward,
649 	.data_reverse =		parport_uss720_data_reverse,
650 
651 	.init_state =		parport_uss720_init_state,
652 	.save_state =		parport_uss720_save_state,
653 	.restore_state =	parport_uss720_restore_state,
654 
655 	.epp_write_data =	parport_uss720_epp_write_data,
656 	.epp_read_data =	parport_uss720_epp_read_data,
657 	.epp_write_addr =	parport_uss720_epp_write_addr,
658 	.epp_read_addr =	parport_uss720_epp_read_addr,
659 
660 	.ecp_write_data =	parport_uss720_ecp_write_data,
661 	.ecp_read_data =	parport_uss720_ecp_read_data,
662 	.ecp_write_addr =	parport_uss720_ecp_write_addr,
663 
664 	.compat_write_data =	parport_uss720_write_compat,
665 	.nibble_read_data =	parport_ieee1284_read_nibble,
666 	.byte_read_data =	parport_ieee1284_read_byte,
667 };
668 
669 /* --------------------------------------------------------------------- */
670 
671 static int uss720_probe(struct usb_interface *intf,
672 			const struct usb_device_id *id)
673 {
674 	struct usb_device *usbdev = usb_get_dev(interface_to_usbdev(intf));
675 	struct usb_host_interface *interface;
676 	struct usb_endpoint_descriptor *epd;
677 	struct parport_uss720_private *priv;
678 	struct parport *pp;
679 	unsigned char reg;
680 	int i;
681 
682 	dev_dbg(&intf->dev, "probe: vendor id 0x%x, device id 0x%x\n",
683 		le16_to_cpu(usbdev->descriptor.idVendor),
684 		le16_to_cpu(usbdev->descriptor.idProduct));
685 
686 	/* our known interfaces have 3 alternate settings */
687 	if (intf->num_altsetting != 3) {
688 		usb_put_dev(usbdev);
689 		return -ENODEV;
690 	}
691 	i = usb_set_interface(usbdev, intf->altsetting->desc.bInterfaceNumber, 2);
692 	dev_dbg(&intf->dev, "set interface result %d\n", i);
693 
694 	interface = intf->cur_altsetting;
695 
696 	if (interface->desc.bNumEndpoints < 3) {
697 		usb_put_dev(usbdev);
698 		return -ENODEV;
699 	}
700 
701 	/*
702 	 * Allocate parport interface
703 	 */
704 	priv = kzalloc(sizeof(struct parport_uss720_private), GFP_KERNEL);
705 	if (!priv) {
706 		usb_put_dev(usbdev);
707 		return -ENOMEM;
708 	}
709 	priv->pp = NULL;
710 	priv->usbdev = usbdev;
711 	kref_init(&priv->ref_count);
712 	spin_lock_init(&priv->asynclock);
713 	INIT_LIST_HEAD(&priv->asynclist);
714 	pp = parport_register_port(0, PARPORT_IRQ_NONE, PARPORT_DMA_NONE, &parport_uss720_ops);
715 	if (!pp) {
716 		printk(KERN_WARNING "uss720: could not register parport\n");
717 		goto probe_abort;
718 	}
719 
720 	priv->pp = pp;
721 	pp->private_data = priv;
722 	pp->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_TRISTATE | PARPORT_MODE_EPP | PARPORT_MODE_ECP | PARPORT_MODE_COMPAT;
723 
724 	/* set the USS720 control register to manual mode, no ECP compression, enable all ints */
725 	set_1284_register(pp, 7, 0x00, GFP_KERNEL);
726 	set_1284_register(pp, 6, 0x30, GFP_KERNEL);  /* PS/2 mode */
727 	set_1284_register(pp, 2, 0x0c, GFP_KERNEL);
728 	/* debugging */
729 	get_1284_register(pp, 0, &reg, GFP_KERNEL);
730 	dev_dbg(&intf->dev, "reg: %7ph\n", priv->reg);
731 
732 	i = usb_find_last_int_in_endpoint(interface, &epd);
733 	if (!i) {
734 		dev_dbg(&intf->dev, "epaddr %d interval %d\n",
735 				epd->bEndpointAddress, epd->bInterval);
736 	}
737 	parport_announce_port(pp);
738 
739 	usb_set_intfdata(intf, pp);
740 	return 0;
741 
742 probe_abort:
743 	kill_all_async_requests_priv(priv);
744 	kref_put(&priv->ref_count, destroy_priv);
745 	return -ENODEV;
746 }
747 
748 static void uss720_disconnect(struct usb_interface *intf)
749 {
750 	struct parport *pp = usb_get_intfdata(intf);
751 	struct parport_uss720_private *priv;
752 
753 	dev_dbg(&intf->dev, "disconnect\n");
754 	usb_set_intfdata(intf, NULL);
755 	if (pp) {
756 		priv = pp->private_data;
757 		priv->pp = NULL;
758 		dev_dbg(&intf->dev, "parport_remove_port\n");
759 		parport_remove_port(pp);
760 		parport_put_port(pp);
761 		kill_all_async_requests_priv(priv);
762 		kref_put(&priv->ref_count, destroy_priv);
763 	}
764 	dev_dbg(&intf->dev, "disconnect done\n");
765 }
766 
767 /* table of cables that work through this driver */
768 static const struct usb_device_id uss720_table[] = {
769 	{ USB_DEVICE(0x047e, 0x1001) },
770 	{ USB_DEVICE(0x04b8, 0x0002) },
771 	{ USB_DEVICE(0x04b8, 0x0003) },
772 	{ USB_DEVICE(0x050d, 0x0002) },
773 	{ USB_DEVICE(0x050d, 0x1202) },
774 	{ USB_DEVICE(0x0557, 0x2001) },
775 	{ USB_DEVICE(0x05ab, 0x0002) },
776 	{ USB_DEVICE(0x06c6, 0x0100) },
777 	{ USB_DEVICE(0x0729, 0x1284) },
778 	{ USB_DEVICE(0x1293, 0x0002) },
779 	{ }						/* Terminating entry */
780 };
781 
782 MODULE_DEVICE_TABLE (usb, uss720_table);
783 
784 
785 static struct usb_driver uss720_driver = {
786 	.name =		"uss720",
787 	.probe =	uss720_probe,
788 	.disconnect =	uss720_disconnect,
789 	.id_table =	uss720_table,
790 };
791 
792 /* --------------------------------------------------------------------- */
793 
794 MODULE_AUTHOR(DRIVER_AUTHOR);
795 MODULE_DESCRIPTION(DRIVER_DESC);
796 MODULE_LICENSE("GPL");
797 
798 static int __init uss720_init(void)
799 {
800 	int retval;
801 	retval = usb_register(&uss720_driver);
802 	if (retval)
803 		goto out;
804 
805 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_DESC "\n");
806 	printk(KERN_INFO KBUILD_MODNAME ": NOTE: this is a special purpose "
807 	       "driver to allow nonstandard\n");
808 	printk(KERN_INFO KBUILD_MODNAME ": protocols (eg. bitbang) over "
809 	       "USS720 usb to parallel cables\n");
810 	printk(KERN_INFO KBUILD_MODNAME ": If you just want to connect to a "
811 	       "printer, use usblp instead\n");
812 out:
813 	return retval;
814 }
815 
816 static void __exit uss720_cleanup(void)
817 {
818 	usb_deregister(&uss720_driver);
819 }
820 
821 module_init(uss720_init);
822 module_exit(uss720_cleanup);
823 
824 /* --------------------------------------------------------------------- */
825