xref: /openbmc/linux/drivers/usb/misc/uss720.c (revision fb574682)
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 	kfree(priv);
75 }
76 
77 static void destroy_async(struct kref *kref)
78 {
79 	struct uss720_async_request *rq = container_of(kref, struct uss720_async_request, ref_count);
80 	struct parport_uss720_private *priv = rq->priv;
81 	unsigned long flags;
82 
83 	if (likely(rq->urb))
84 		usb_free_urb(rq->urb);
85 	kfree(rq->dr);
86 	spin_lock_irqsave(&priv->asynclock, flags);
87 	list_del_init(&rq->asynclist);
88 	spin_unlock_irqrestore(&priv->asynclock, flags);
89 	kfree(rq);
90 	kref_put(&priv->ref_count, destroy_priv);
91 }
92 
93 /* --------------------------------------------------------------------- */
94 
95 static void async_complete(struct urb *urb)
96 {
97 	struct uss720_async_request *rq;
98 	struct parport *pp;
99 	struct parport_uss720_private *priv;
100 	int status = urb->status;
101 
102 	rq = urb->context;
103 	priv = rq->priv;
104 	pp = priv->pp;
105 	if (status) {
106 		dev_err(&urb->dev->dev, "async_complete: urb error %d\n",
107 			status);
108 	} else if (rq->dr->bRequest == 3) {
109 		memcpy(priv->reg, rq->reg, sizeof(priv->reg));
110 #if 0
111 		dev_dbg(&priv->usbdev->dev, "async_complete regs %7ph\n",
112 			priv->reg);
113 #endif
114 		/* if nAck interrupts are enabled and we have an interrupt, call the interrupt procedure */
115 		if (rq->reg[2] & rq->reg[1] & 0x10 && pp)
116 			parport_generic_irq(pp);
117 	}
118 	complete(&rq->compl);
119 	kref_put(&rq->ref_count, destroy_async);
120 }
121 
122 static struct uss720_async_request *submit_async_request(struct parport_uss720_private *priv,
123 							 __u8 request, __u8 requesttype, __u16 value, __u16 index,
124 							 gfp_t mem_flags)
125 {
126 	struct usb_device *usbdev;
127 	struct uss720_async_request *rq;
128 	unsigned long flags;
129 	int ret;
130 
131 	if (!priv)
132 		return NULL;
133 	usbdev = priv->usbdev;
134 	if (!usbdev)
135 		return NULL;
136 	rq = kzalloc(sizeof(struct uss720_async_request), mem_flags);
137 	if (!rq)
138 		return NULL;
139 	kref_init(&rq->ref_count);
140 	INIT_LIST_HEAD(&rq->asynclist);
141 	init_completion(&rq->compl);
142 	kref_get(&priv->ref_count);
143 	rq->priv = priv;
144 	rq->urb = usb_alloc_urb(0, mem_flags);
145 	if (!rq->urb) {
146 		kref_put(&rq->ref_count, destroy_async);
147 		return NULL;
148 	}
149 	rq->dr = kmalloc(sizeof(*rq->dr), mem_flags);
150 	if (!rq->dr) {
151 		kref_put(&rq->ref_count, destroy_async);
152 		return NULL;
153 	}
154 	rq->dr->bRequestType = requesttype;
155 	rq->dr->bRequest = request;
156 	rq->dr->wValue = cpu_to_le16(value);
157 	rq->dr->wIndex = cpu_to_le16(index);
158 	rq->dr->wLength = cpu_to_le16((request == 3) ? sizeof(rq->reg) : 0);
159 	usb_fill_control_urb(rq->urb, usbdev, (requesttype & 0x80) ? usb_rcvctrlpipe(usbdev, 0) : usb_sndctrlpipe(usbdev, 0),
160 			     (unsigned char *)rq->dr,
161 			     (request == 3) ? rq->reg : NULL, (request == 3) ? sizeof(rq->reg) : 0, async_complete, rq);
162 	/* rq->urb->transfer_flags |= URB_ASYNC_UNLINK; */
163 	spin_lock_irqsave(&priv->asynclock, flags);
164 	list_add_tail(&rq->asynclist, &priv->asynclist);
165 	spin_unlock_irqrestore(&priv->asynclock, flags);
166 	kref_get(&rq->ref_count);
167 	ret = usb_submit_urb(rq->urb, mem_flags);
168 	if (!ret)
169 		return rq;
170 	destroy_async(&rq->ref_count);
171 	dev_err(&usbdev->dev, "submit_async_request submit_urb failed with %d\n", ret);
172 	return NULL;
173 }
174 
175 static unsigned int kill_all_async_requests_priv(struct parport_uss720_private *priv)
176 {
177 	struct uss720_async_request *rq;
178 	unsigned long flags;
179 	unsigned int ret = 0;
180 
181 	spin_lock_irqsave(&priv->asynclock, flags);
182 	list_for_each_entry(rq, &priv->asynclist, asynclist) {
183 		usb_unlink_urb(rq->urb);
184 		ret++;
185 	}
186 	spin_unlock_irqrestore(&priv->asynclock, flags);
187 	return ret;
188 }
189 
190 /* --------------------------------------------------------------------- */
191 
192 static int get_1284_register(struct parport *pp, unsigned char reg, unsigned char *val, gfp_t mem_flags)
193 {
194 	struct parport_uss720_private *priv;
195 	struct uss720_async_request *rq;
196 	static const unsigned char regindex[9] = {
197 		4, 0, 1, 5, 5, 0, 2, 3, 6
198 	};
199 	int ret;
200 
201 	if (!pp)
202 		return -EIO;
203 	priv = pp->private_data;
204 	rq = submit_async_request(priv, 3, 0xc0, ((unsigned int)reg) << 8, 0, mem_flags);
205 	if (!rq) {
206 		dev_err(&priv->usbdev->dev, "get_1284_register(%u) failed",
207 			(unsigned int)reg);
208 		return -EIO;
209 	}
210 	if (!val) {
211 		kref_put(&rq->ref_count, destroy_async);
212 		return 0;
213 	}
214 	if (wait_for_completion_timeout(&rq->compl, HZ)) {
215 		ret = rq->urb->status;
216 		*val = priv->reg[(reg >= 9) ? 0 : regindex[reg]];
217 		if (ret)
218 			printk(KERN_WARNING "get_1284_register: "
219 			       "usb error %d\n", ret);
220 		kref_put(&rq->ref_count, destroy_async);
221 		return ret;
222 	}
223 	printk(KERN_WARNING "get_1284_register timeout\n");
224 	kill_all_async_requests_priv(priv);
225 	return -EIO;
226 }
227 
228 static int set_1284_register(struct parport *pp, unsigned char reg, unsigned char val, gfp_t mem_flags)
229 {
230 	struct parport_uss720_private *priv;
231 	struct uss720_async_request *rq;
232 
233 	if (!pp)
234 		return -EIO;
235 	priv = pp->private_data;
236 	rq = submit_async_request(priv, 4, 0x40, (((unsigned int)reg) << 8) | val, 0, mem_flags);
237 	if (!rq) {
238 		dev_err(&priv->usbdev->dev, "set_1284_register(%u,%u) failed",
239 			(unsigned int)reg, (unsigned int)val);
240 		return -EIO;
241 	}
242 	kref_put(&rq->ref_count, destroy_async);
243 	return 0;
244 }
245 
246 /* --------------------------------------------------------------------- */
247 
248 /* ECR modes */
249 #define ECR_SPP 00
250 #define ECR_PS2 01
251 #define ECR_PPF 02
252 #define ECR_ECP 03
253 #define ECR_EPP 04
254 
255 /* Safely change the mode bits in the ECR */
256 static int change_mode(struct parport *pp, int m)
257 {
258 	struct parport_uss720_private *priv = pp->private_data;
259 	int mode;
260 	__u8 reg;
261 
262 	if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
263 		return -EIO;
264 	/* Bits <7:5> contain the mode. */
265 	mode = (priv->reg[2] >> 5) & 0x7;
266 	if (mode == m)
267 		return 0;
268 	/* We have to go through mode 000 or 001 */
269 	if (mode > ECR_PS2 && m > ECR_PS2)
270 		if (change_mode(pp, ECR_PS2))
271 			return -EIO;
272 
273 	if (m <= ECR_PS2 && !(priv->reg[1] & 0x20)) {
274 		/* This mode resets the FIFO, so we may
275 		 * have to wait for it to drain first. */
276 		unsigned long expire = jiffies + pp->physport->cad->timeout;
277 		switch (mode) {
278 		case ECR_PPF: /* Parallel Port FIFO mode */
279 		case ECR_ECP: /* ECP Parallel Port mode */
280 			/* Poll slowly. */
281 			for (;;) {
282 				if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
283 					return -EIO;
284 				if (priv->reg[2] & 0x01)
285 					break;
286 				if (time_after_eq (jiffies, expire))
287 					/* The FIFO is stuck. */
288 					return -EBUSY;
289 				msleep_interruptible(10);
290 				if (signal_pending (current))
291 					break;
292 			}
293 		}
294 	}
295 	/* Set the mode. */
296 	if (set_1284_register(pp, 6, m << 5, GFP_KERNEL))
297 		return -EIO;
298 	if (get_1284_register(pp, 6, &reg, GFP_KERNEL))
299 		return -EIO;
300 	return 0;
301 }
302 
303 /*
304  * Clear TIMEOUT BIT in EPP MODE
305  */
306 static int clear_epp_timeout(struct parport *pp)
307 {
308 	unsigned char stat;
309 
310 	if (get_1284_register(pp, 1, &stat, GFP_KERNEL))
311 		return 1;
312 	return stat & 1;
313 }
314 
315 /*
316  * Access functions.
317  */
318 #if 0
319 static int uss720_irq(int usbstatus, void *buffer, int len, void *dev_id)
320 {
321 	struct parport *pp = (struct parport *)dev_id;
322 	struct parport_uss720_private *priv = pp->private_data;
323 
324 	if (usbstatus != 0 || len < 4 || !buffer)
325 		return 1;
326 	memcpy(priv->reg, buffer, 4);
327 	/* if nAck interrupts are enabled and we have an interrupt, call the interrupt procedure */
328 	if (priv->reg[2] & priv->reg[1] & 0x10)
329 		parport_generic_irq(pp);
330 	return 1;
331 }
332 #endif
333 
334 static void parport_uss720_write_data(struct parport *pp, unsigned char d)
335 {
336 	set_1284_register(pp, 0, d, GFP_KERNEL);
337 }
338 
339 static unsigned char parport_uss720_read_data(struct parport *pp)
340 {
341 	unsigned char ret;
342 
343 	if (get_1284_register(pp, 0, &ret, GFP_KERNEL))
344 		return 0;
345 	return ret;
346 }
347 
348 static void parport_uss720_write_control(struct parport *pp, unsigned char d)
349 {
350 	struct parport_uss720_private *priv = pp->private_data;
351 
352 	d = (d & 0xf) | (priv->reg[1] & 0xf0);
353 	if (set_1284_register(pp, 2, d, GFP_KERNEL))
354 		return;
355 	priv->reg[1] = d;
356 }
357 
358 static unsigned char parport_uss720_read_control(struct parport *pp)
359 {
360 	struct parport_uss720_private *priv = pp->private_data;
361 	return priv->reg[1] & 0xf; /* Use soft copy */
362 }
363 
364 static unsigned char parport_uss720_frob_control(struct parport *pp, unsigned char mask, unsigned char val)
365 {
366 	struct parport_uss720_private *priv = pp->private_data;
367 	unsigned char d;
368 
369 	mask &= 0x0f;
370 	val &= 0x0f;
371 	d = (priv->reg[1] & (~mask)) ^ val;
372 	if (set_1284_register(pp, 2, d, GFP_ATOMIC))
373 		return 0;
374 	priv->reg[1] = d;
375 	return d & 0xf;
376 }
377 
378 static unsigned char parport_uss720_read_status(struct parport *pp)
379 {
380 	unsigned char ret;
381 
382 	if (get_1284_register(pp, 1, &ret, GFP_ATOMIC))
383 		return 0;
384 	return ret & 0xf8;
385 }
386 
387 static void parport_uss720_disable_irq(struct parport *pp)
388 {
389 	struct parport_uss720_private *priv = pp->private_data;
390 	unsigned char d;
391 
392 	d = priv->reg[1] & ~0x10;
393 	if (set_1284_register(pp, 2, d, GFP_KERNEL))
394 		return;
395 	priv->reg[1] = d;
396 }
397 
398 static void parport_uss720_enable_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_data_forward (struct parport *pp)
410 {
411 	struct parport_uss720_private *priv = pp->private_data;
412 	unsigned char d;
413 
414 	d = priv->reg[1] & ~0x20;
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_reverse (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_init_state(struct pardevice *dev, struct parport_state *s)
432 {
433 	s->u.pc.ctr = 0xc | (dev->irq_func ? 0x10 : 0x0);
434 	s->u.pc.ecr = 0x24;
435 }
436 
437 static void parport_uss720_save_state(struct parport *pp, struct parport_state *s)
438 {
439 	struct parport_uss720_private *priv = pp->private_data;
440 
441 #if 0
442 	if (get_1284_register(pp, 2, NULL, GFP_ATOMIC))
443 		return;
444 #endif
445 	s->u.pc.ctr = priv->reg[1];
446 	s->u.pc.ecr = priv->reg[2];
447 }
448 
449 static void parport_uss720_restore_state(struct parport *pp, struct parport_state *s)
450 {
451 	struct parport_uss720_private *priv = pp->private_data;
452 
453 	set_1284_register(pp, 2, s->u.pc.ctr, GFP_ATOMIC);
454 	set_1284_register(pp, 6, s->u.pc.ecr, GFP_ATOMIC);
455 	get_1284_register(pp, 2, NULL, GFP_ATOMIC);
456 	priv->reg[1] = s->u.pc.ctr;
457 	priv->reg[2] = s->u.pc.ecr;
458 }
459 
460 static size_t parport_uss720_epp_read_data(struct parport *pp, void *buf, size_t length, int flags)
461 {
462 	struct parport_uss720_private *priv = pp->private_data;
463 	size_t got = 0;
464 
465 	if (change_mode(pp, ECR_EPP))
466 		return 0;
467 	for (; got < length; got++) {
468 		if (get_1284_register(pp, 4, (char *)buf, GFP_KERNEL))
469 			break;
470 		buf++;
471 		if (priv->reg[0] & 0x01) {
472 			clear_epp_timeout(pp);
473 			break;
474 		}
475 	}
476 	change_mode(pp, ECR_PS2);
477 	return got;
478 }
479 
480 static size_t parport_uss720_epp_write_data(struct parport *pp, const void *buf, size_t length, int flags)
481 {
482 #if 0
483 	struct parport_uss720_private *priv = pp->private_data;
484 	size_t written = 0;
485 
486 	if (change_mode(pp, ECR_EPP))
487 		return 0;
488 	for (; written < length; written++) {
489 		if (set_1284_register(pp, 4, (char *)buf, GFP_KERNEL))
490 			break;
491 		((char*)buf)++;
492 		if (get_1284_register(pp, 1, NULL, GFP_KERNEL))
493 			break;
494 		if (priv->reg[0] & 0x01) {
495 			clear_epp_timeout(pp);
496 			break;
497 		}
498 	}
499 	change_mode(pp, ECR_PS2);
500 	return written;
501 #else
502 	struct parport_uss720_private *priv = pp->private_data;
503 	struct usb_device *usbdev = priv->usbdev;
504 	int rlen;
505 	int i;
506 
507 	if (!usbdev)
508 		return 0;
509 	if (change_mode(pp, ECR_EPP))
510 		return 0;
511 	i = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 1), (void *)buf, length, &rlen, 20000);
512 	if (i)
513 		printk(KERN_ERR "uss720: sendbulk ep 1 buf %p len %zu rlen %u\n", buf, length, rlen);
514 	change_mode(pp, ECR_PS2);
515 	return rlen;
516 #endif
517 }
518 
519 static size_t parport_uss720_epp_read_addr(struct parport *pp, void *buf, size_t length, int flags)
520 {
521 	struct parport_uss720_private *priv = pp->private_data;
522 	size_t got = 0;
523 
524 	if (change_mode(pp, ECR_EPP))
525 		return 0;
526 	for (; got < length; got++) {
527 		if (get_1284_register(pp, 3, (char *)buf, GFP_KERNEL))
528 			break;
529 		buf++;
530 		if (priv->reg[0] & 0x01) {
531 			clear_epp_timeout(pp);
532 			break;
533 		}
534 	}
535 	change_mode(pp, ECR_PS2);
536 	return got;
537 }
538 
539 static size_t parport_uss720_epp_write_addr(struct parport *pp, const void *buf, size_t length, int flags)
540 {
541 	struct parport_uss720_private *priv = pp->private_data;
542 	size_t written = 0;
543 
544 	if (change_mode(pp, ECR_EPP))
545 		return 0;
546 	for (; written < length; written++) {
547 		if (set_1284_register(pp, 3, *(char *)buf, GFP_KERNEL))
548 			break;
549 		buf++;
550 		if (get_1284_register(pp, 1, NULL, GFP_KERNEL))
551 			break;
552 		if (priv->reg[0] & 0x01) {
553 			clear_epp_timeout(pp);
554 			break;
555 		}
556 	}
557 	change_mode(pp, ECR_PS2);
558 	return written;
559 }
560 
561 static size_t parport_uss720_ecp_write_data(struct parport *pp, const void *buffer, size_t len, int flags)
562 {
563 	struct parport_uss720_private *priv = pp->private_data;
564 	struct usb_device *usbdev = priv->usbdev;
565 	int rlen;
566 	int i;
567 
568 	if (!usbdev)
569 		return 0;
570 	if (change_mode(pp, ECR_ECP))
571 		return 0;
572 	i = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 1), (void *)buffer, len, &rlen, 20000);
573 	if (i)
574 		printk(KERN_ERR "uss720: sendbulk ep 1 buf %p len %zu rlen %u\n", buffer, len, rlen);
575 	change_mode(pp, ECR_PS2);
576 	return rlen;
577 }
578 
579 static size_t parport_uss720_ecp_read_data(struct parport *pp, void *buffer, size_t len, int flags)
580 {
581 	struct parport_uss720_private *priv = pp->private_data;
582 	struct usb_device *usbdev = priv->usbdev;
583 	int rlen;
584 	int i;
585 
586 	if (!usbdev)
587 		return 0;
588 	if (change_mode(pp, ECR_ECP))
589 		return 0;
590 	i = usb_bulk_msg(usbdev, usb_rcvbulkpipe(usbdev, 2), buffer, len, &rlen, 20000);
591 	if (i)
592 		printk(KERN_ERR "uss720: recvbulk ep 2 buf %p len %zu rlen %u\n", buffer, len, rlen);
593 	change_mode(pp, ECR_PS2);
594 	return rlen;
595 }
596 
597 static size_t parport_uss720_ecp_write_addr(struct parport *pp, const void *buffer, size_t len, int flags)
598 {
599 	size_t written = 0;
600 
601 	if (change_mode(pp, ECR_ECP))
602 		return 0;
603 	for (; written < len; written++) {
604 		if (set_1284_register(pp, 5, *(char *)buffer, GFP_KERNEL))
605 			break;
606 		buffer++;
607 	}
608 	change_mode(pp, ECR_PS2);
609 	return written;
610 }
611 
612 static size_t parport_uss720_write_compat(struct parport *pp, const void *buffer, size_t len, int flags)
613 {
614 	struct parport_uss720_private *priv = pp->private_data;
615 	struct usb_device *usbdev = priv->usbdev;
616 	int rlen;
617 	int i;
618 
619 	if (!usbdev)
620 		return 0;
621 	if (change_mode(pp, ECR_PPF))
622 		return 0;
623 	i = usb_bulk_msg(usbdev, usb_sndbulkpipe(usbdev, 1), (void *)buffer, len, &rlen, 20000);
624 	if (i)
625 		printk(KERN_ERR "uss720: sendbulk ep 1 buf %p len %zu rlen %u\n", buffer, len, rlen);
626 	change_mode(pp, ECR_PS2);
627 	return rlen;
628 }
629 
630 /* --------------------------------------------------------------------- */
631 
632 static struct parport_operations parport_uss720_ops =
633 {
634 	.owner =		THIS_MODULE,
635 	.write_data =		parport_uss720_write_data,
636 	.read_data =		parport_uss720_read_data,
637 
638 	.write_control =	parport_uss720_write_control,
639 	.read_control =		parport_uss720_read_control,
640 	.frob_control =		parport_uss720_frob_control,
641 
642 	.read_status =		parport_uss720_read_status,
643 
644 	.enable_irq =		parport_uss720_enable_irq,
645 	.disable_irq =		parport_uss720_disable_irq,
646 
647 	.data_forward =		parport_uss720_data_forward,
648 	.data_reverse =		parport_uss720_data_reverse,
649 
650 	.init_state =		parport_uss720_init_state,
651 	.save_state =		parport_uss720_save_state,
652 	.restore_state =	parport_uss720_restore_state,
653 
654 	.epp_write_data =	parport_uss720_epp_write_data,
655 	.epp_read_data =	parport_uss720_epp_read_data,
656 	.epp_write_addr =	parport_uss720_epp_write_addr,
657 	.epp_read_addr =	parport_uss720_epp_read_addr,
658 
659 	.ecp_write_data =	parport_uss720_ecp_write_data,
660 	.ecp_read_data =	parport_uss720_ecp_read_data,
661 	.ecp_write_addr =	parport_uss720_ecp_write_addr,
662 
663 	.compat_write_data =	parport_uss720_write_compat,
664 	.nibble_read_data =	parport_ieee1284_read_nibble,
665 	.byte_read_data =	parport_ieee1284_read_byte,
666 };
667 
668 /* --------------------------------------------------------------------- */
669 
670 static int uss720_probe(struct usb_interface *intf,
671 			const struct usb_device_id *id)
672 {
673 	struct usb_device *usbdev = usb_get_dev(interface_to_usbdev(intf));
674 	struct usb_host_interface *interface;
675 	struct usb_endpoint_descriptor *epd;
676 	struct parport_uss720_private *priv;
677 	struct parport *pp;
678 	unsigned char reg;
679 	int i;
680 
681 	dev_dbg(&intf->dev, "probe: vendor id 0x%x, device id 0x%x\n",
682 		le16_to_cpu(usbdev->descriptor.idVendor),
683 		le16_to_cpu(usbdev->descriptor.idProduct));
684 
685 	/* our known interfaces have 3 alternate settings */
686 	if (intf->num_altsetting != 3) {
687 		usb_put_dev(usbdev);
688 		return -ENODEV;
689 	}
690 	i = usb_set_interface(usbdev, intf->altsetting->desc.bInterfaceNumber, 2);
691 	dev_dbg(&intf->dev, "set interface result %d\n", i);
692 
693 	interface = intf->cur_altsetting;
694 
695 	if (interface->desc.bNumEndpoints < 3) {
696 		usb_put_dev(usbdev);
697 		return -ENODEV;
698 	}
699 
700 	/*
701 	 * Allocate parport interface
702 	 */
703 	priv = kzalloc(sizeof(struct parport_uss720_private), GFP_KERNEL);
704 	if (!priv) {
705 		usb_put_dev(usbdev);
706 		return -ENOMEM;
707 	}
708 	priv->pp = NULL;
709 	priv->usbdev = usbdev;
710 	kref_init(&priv->ref_count);
711 	spin_lock_init(&priv->asynclock);
712 	INIT_LIST_HEAD(&priv->asynclist);
713 	pp = parport_register_port(0, PARPORT_IRQ_NONE, PARPORT_DMA_NONE, &parport_uss720_ops);
714 	if (!pp) {
715 		printk(KERN_WARNING "uss720: could not register parport\n");
716 		goto probe_abort;
717 	}
718 
719 	priv->pp = pp;
720 	pp->private_data = priv;
721 	pp->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_TRISTATE | PARPORT_MODE_EPP | PARPORT_MODE_ECP | PARPORT_MODE_COMPAT;
722 
723 	/* set the USS720 control register to manual mode, no ECP compression, enable all ints */
724 	set_1284_register(pp, 7, 0x00, GFP_KERNEL);
725 	set_1284_register(pp, 6, 0x30, GFP_KERNEL);  /* PS/2 mode */
726 	set_1284_register(pp, 2, 0x0c, GFP_KERNEL);
727 	/* debugging */
728 	get_1284_register(pp, 0, &reg, GFP_KERNEL);
729 	dev_dbg(&intf->dev, "reg: %7ph\n", priv->reg);
730 
731 	i = usb_find_last_int_in_endpoint(interface, &epd);
732 	if (!i) {
733 		dev_dbg(&intf->dev, "epaddr %d interval %d\n",
734 				epd->bEndpointAddress, epd->bInterval);
735 	}
736 	parport_announce_port(pp);
737 
738 	usb_set_intfdata(intf, pp);
739 	return 0;
740 
741 probe_abort:
742 	kill_all_async_requests_priv(priv);
743 	kref_put(&priv->ref_count, destroy_priv);
744 	return -ENODEV;
745 }
746 
747 static void uss720_disconnect(struct usb_interface *intf)
748 {
749 	struct parport *pp = usb_get_intfdata(intf);
750 	struct parport_uss720_private *priv;
751 
752 	dev_dbg(&intf->dev, "disconnect\n");
753 	usb_set_intfdata(intf, NULL);
754 	if (pp) {
755 		priv = pp->private_data;
756 		priv->usbdev = NULL;
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