1/*
2 * f_printer.c - USB printer function driver
3 *
4 * Copied from drivers/usb/gadget/legacy/printer.c,
5 * which was:
6 *
7 * printer.c -- Printer gadget driver
8 *
9 * Copyright (C) 2003-2005 David Brownell
10 * Copyright (C) 2006 Craig W. Nadler
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 */
17
18#include <linux/module.h>
19#include <linux/kernel.h>
20#include <linux/delay.h>
21#include <linux/ioport.h>
22#include <linux/sched.h>
23#include <linux/slab.h>
24#include <linux/mutex.h>
25#include <linux/errno.h>
26#include <linux/init.h>
27#include <linux/idr.h>
28#include <linux/timer.h>
29#include <linux/list.h>
30#include <linux/interrupt.h>
31#include <linux/device.h>
32#include <linux/moduleparam.h>
33#include <linux/fs.h>
34#include <linux/poll.h>
35#include <linux/types.h>
36#include <linux/ctype.h>
37#include <linux/cdev.h>
38
39#include <asm/byteorder.h>
40#include <linux/io.h>
41#include <linux/irq.h>
42#include <linux/uaccess.h>
43#include <asm/unaligned.h>
44
45#include <linux/usb/ch9.h>
46#include <linux/usb/composite.h>
47#include <linux/usb/gadget.h>
48#include <linux/usb/g_printer.h>
49
50#include "u_printer.h"
51
52#define PNP_STRING_LEN		1024
53#define PRINTER_MINORS		4
54#define GET_DEVICE_ID		0
55#define GET_PORT_STATUS		1
56#define SOFT_RESET		2
57
58static int major, minors;
59static struct class *usb_gadget_class;
60static DEFINE_IDA(printer_ida);
61static DEFINE_MUTEX(printer_ida_lock); /* protects access do printer_ida */
62
63/*-------------------------------------------------------------------------*/
64
65struct printer_dev {
66	spinlock_t		lock;		/* lock this structure */
67	/* lock buffer lists during read/write calls */
68	struct mutex		lock_printer_io;
69	struct usb_gadget	*gadget;
70	s8			interface;
71	struct usb_ep		*in_ep, *out_ep;
72
73	struct list_head	rx_reqs;	/* List of free RX structs */
74	struct list_head	rx_reqs_active;	/* List of Active RX xfers */
75	struct list_head	rx_buffers;	/* List of completed xfers */
76	/* wait until there is data to be read. */
77	wait_queue_head_t	rx_wait;
78	struct list_head	tx_reqs;	/* List of free TX structs */
79	struct list_head	tx_reqs_active; /* List of Active TX xfers */
80	/* Wait until there are write buffers available to use. */
81	wait_queue_head_t	tx_wait;
82	/* Wait until all write buffers have been sent. */
83	wait_queue_head_t	tx_flush_wait;
84	struct usb_request	*current_rx_req;
85	size_t			current_rx_bytes;
86	u8			*current_rx_buf;
87	u8			printer_status;
88	u8			reset_printer;
89	int			minor;
90	struct cdev		printer_cdev;
91	u8			printer_cdev_open;
92	wait_queue_head_t	wait;
93	unsigned		q_len;
94	char			*pnp_string;	/* We don't own memory! */
95	struct usb_function	function;
96};
97
98static inline struct printer_dev *func_to_printer(struct usb_function *f)
99{
100	return container_of(f, struct printer_dev, function);
101}
102
103/*-------------------------------------------------------------------------*/
104
105/*
106 * DESCRIPTORS ... most are static, but strings and (full) configuration
107 * descriptors are built on demand.
108 */
109
110/* holds our biggest descriptor */
111#define USB_DESC_BUFSIZE		256
112#define USB_BUFSIZE			8192
113
114static struct usb_interface_descriptor intf_desc = {
115	.bLength =		sizeof(intf_desc),
116	.bDescriptorType =	USB_DT_INTERFACE,
117	.bNumEndpoints =	2,
118	.bInterfaceClass =	USB_CLASS_PRINTER,
119	.bInterfaceSubClass =	1,	/* Printer Sub-Class */
120	.bInterfaceProtocol =	2,	/* Bi-Directional */
121	.iInterface =		0
122};
123
124static struct usb_endpoint_descriptor fs_ep_in_desc = {
125	.bLength =		USB_DT_ENDPOINT_SIZE,
126	.bDescriptorType =	USB_DT_ENDPOINT,
127	.bEndpointAddress =	USB_DIR_IN,
128	.bmAttributes =		USB_ENDPOINT_XFER_BULK
129};
130
131static struct usb_endpoint_descriptor fs_ep_out_desc = {
132	.bLength =		USB_DT_ENDPOINT_SIZE,
133	.bDescriptorType =	USB_DT_ENDPOINT,
134	.bEndpointAddress =	USB_DIR_OUT,
135	.bmAttributes =		USB_ENDPOINT_XFER_BULK
136};
137
138static struct usb_descriptor_header *fs_printer_function[] = {
139	(struct usb_descriptor_header *) &intf_desc,
140	(struct usb_descriptor_header *) &fs_ep_in_desc,
141	(struct usb_descriptor_header *) &fs_ep_out_desc,
142	NULL
143};
144
145/*
146 * usb 2.0 devices need to expose both high speed and full speed
147 * descriptors, unless they only run at full speed.
148 */
149
150static struct usb_endpoint_descriptor hs_ep_in_desc = {
151	.bLength =		USB_DT_ENDPOINT_SIZE,
152	.bDescriptorType =	USB_DT_ENDPOINT,
153	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
154	.wMaxPacketSize =	cpu_to_le16(512)
155};
156
157static struct usb_endpoint_descriptor hs_ep_out_desc = {
158	.bLength =		USB_DT_ENDPOINT_SIZE,
159	.bDescriptorType =	USB_DT_ENDPOINT,
160	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
161	.wMaxPacketSize =	cpu_to_le16(512)
162};
163
164static struct usb_qualifier_descriptor dev_qualifier = {
165	.bLength =		sizeof(dev_qualifier),
166	.bDescriptorType =	USB_DT_DEVICE_QUALIFIER,
167	.bcdUSB =		cpu_to_le16(0x0200),
168	.bDeviceClass =		USB_CLASS_PRINTER,
169	.bNumConfigurations =	1
170};
171
172static struct usb_descriptor_header *hs_printer_function[] = {
173	(struct usb_descriptor_header *) &intf_desc,
174	(struct usb_descriptor_header *) &hs_ep_in_desc,
175	(struct usb_descriptor_header *) &hs_ep_out_desc,
176	NULL
177};
178
179/*
180 * Added endpoint descriptors for 3.0 devices
181 */
182
183static struct usb_endpoint_descriptor ss_ep_in_desc = {
184	.bLength =              USB_DT_ENDPOINT_SIZE,
185	.bDescriptorType =      USB_DT_ENDPOINT,
186	.bmAttributes =         USB_ENDPOINT_XFER_BULK,
187	.wMaxPacketSize =       cpu_to_le16(1024),
188};
189
190static struct usb_ss_ep_comp_descriptor ss_ep_in_comp_desc = {
191	.bLength =              sizeof(ss_ep_in_comp_desc),
192	.bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
193};
194
195static struct usb_endpoint_descriptor ss_ep_out_desc = {
196	.bLength =              USB_DT_ENDPOINT_SIZE,
197	.bDescriptorType =      USB_DT_ENDPOINT,
198	.bmAttributes =         USB_ENDPOINT_XFER_BULK,
199	.wMaxPacketSize =       cpu_to_le16(1024),
200};
201
202static struct usb_ss_ep_comp_descriptor ss_ep_out_comp_desc = {
203	.bLength =              sizeof(ss_ep_out_comp_desc),
204	.bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
205};
206
207static struct usb_descriptor_header *ss_printer_function[] = {
208	(struct usb_descriptor_header *) &intf_desc,
209	(struct usb_descriptor_header *) &ss_ep_in_desc,
210	(struct usb_descriptor_header *) &ss_ep_in_comp_desc,
211	(struct usb_descriptor_header *) &ss_ep_out_desc,
212	(struct usb_descriptor_header *) &ss_ep_out_comp_desc,
213	NULL
214};
215
216/* maxpacket and other transfer characteristics vary by speed. */
217static inline struct usb_endpoint_descriptor *ep_desc(struct usb_gadget *gadget,
218					struct usb_endpoint_descriptor *fs,
219					struct usb_endpoint_descriptor *hs,
220					struct usb_endpoint_descriptor *ss)
221{
222	switch (gadget->speed) {
223	case USB_SPEED_SUPER:
224		return ss;
225	case USB_SPEED_HIGH:
226		return hs;
227	default:
228		return fs;
229	}
230}
231
232/*-------------------------------------------------------------------------*/
233
234static struct usb_request *
235printer_req_alloc(struct usb_ep *ep, unsigned len, gfp_t gfp_flags)
236{
237	struct usb_request	*req;
238
239	req = usb_ep_alloc_request(ep, gfp_flags);
240
241	if (req != NULL) {
242		req->length = len;
243		req->buf = kmalloc(len, gfp_flags);
244		if (req->buf == NULL) {
245			usb_ep_free_request(ep, req);
246			return NULL;
247		}
248	}
249
250	return req;
251}
252
253static void
254printer_req_free(struct usb_ep *ep, struct usb_request *req)
255{
256	if (ep != NULL && req != NULL) {
257		kfree(req->buf);
258		usb_ep_free_request(ep, req);
259	}
260}
261
262/*-------------------------------------------------------------------------*/
263
264static void rx_complete(struct usb_ep *ep, struct usb_request *req)
265{
266	struct printer_dev	*dev = ep->driver_data;
267	int			status = req->status;
268	unsigned long		flags;
269
270	spin_lock_irqsave(&dev->lock, flags);
271
272	list_del_init(&req->list);	/* Remode from Active List */
273
274	switch (status) {
275
276	/* normal completion */
277	case 0:
278		if (req->actual > 0) {
279			list_add_tail(&req->list, &dev->rx_buffers);
280			DBG(dev, "G_Printer : rx length %d\n", req->actual);
281		} else {
282			list_add(&req->list, &dev->rx_reqs);
283		}
284		break;
285
286	/* software-driven interface shutdown */
287	case -ECONNRESET:		/* unlink */
288	case -ESHUTDOWN:		/* disconnect etc */
289		VDBG(dev, "rx shutdown, code %d\n", status);
290		list_add(&req->list, &dev->rx_reqs);
291		break;
292
293	/* for hardware automagic (such as pxa) */
294	case -ECONNABORTED:		/* endpoint reset */
295		DBG(dev, "rx %s reset\n", ep->name);
296		list_add(&req->list, &dev->rx_reqs);
297		break;
298
299	/* data overrun */
300	case -EOVERFLOW:
301		/* FALLTHROUGH */
302
303	default:
304		DBG(dev, "rx status %d\n", status);
305		list_add(&req->list, &dev->rx_reqs);
306		break;
307	}
308
309	wake_up_interruptible(&dev->rx_wait);
310	spin_unlock_irqrestore(&dev->lock, flags);
311}
312
313static void tx_complete(struct usb_ep *ep, struct usb_request *req)
314{
315	struct printer_dev	*dev = ep->driver_data;
316
317	switch (req->status) {
318	default:
319		VDBG(dev, "tx err %d\n", req->status);
320		/* FALLTHROUGH */
321	case -ECONNRESET:		/* unlink */
322	case -ESHUTDOWN:		/* disconnect etc */
323		break;
324	case 0:
325		break;
326	}
327
328	spin_lock(&dev->lock);
329	/* Take the request struct off the active list and put it on the
330	 * free list.
331	 */
332	list_del_init(&req->list);
333	list_add(&req->list, &dev->tx_reqs);
334	wake_up_interruptible(&dev->tx_wait);
335	if (likely(list_empty(&dev->tx_reqs_active)))
336		wake_up_interruptible(&dev->tx_flush_wait);
337
338	spin_unlock(&dev->lock);
339}
340
341/*-------------------------------------------------------------------------*/
342
343static int
344printer_open(struct inode *inode, struct file *fd)
345{
346	struct printer_dev	*dev;
347	unsigned long		flags;
348	int			ret = -EBUSY;
349
350	dev = container_of(inode->i_cdev, struct printer_dev, printer_cdev);
351
352	spin_lock_irqsave(&dev->lock, flags);
353
354	if (!dev->printer_cdev_open) {
355		dev->printer_cdev_open = 1;
356		fd->private_data = dev;
357		ret = 0;
358		/* Change the printer status to show that it's on-line. */
359		dev->printer_status |= PRINTER_SELECTED;
360	}
361
362	spin_unlock_irqrestore(&dev->lock, flags);
363
364	DBG(dev, "printer_open returned %x\n", ret);
365	return ret;
366}
367
368static int
369printer_close(struct inode *inode, struct file *fd)
370{
371	struct printer_dev	*dev = fd->private_data;
372	unsigned long		flags;
373
374	spin_lock_irqsave(&dev->lock, flags);
375	dev->printer_cdev_open = 0;
376	fd->private_data = NULL;
377	/* Change printer status to show that the printer is off-line. */
378	dev->printer_status &= ~PRINTER_SELECTED;
379	spin_unlock_irqrestore(&dev->lock, flags);
380
381	DBG(dev, "printer_close\n");
382
383	return 0;
384}
385
386/* This function must be called with interrupts turned off. */
387static void
388setup_rx_reqs(struct printer_dev *dev)
389{
390	struct usb_request              *req;
391
392	while (likely(!list_empty(&dev->rx_reqs))) {
393		int error;
394
395		req = container_of(dev->rx_reqs.next,
396				struct usb_request, list);
397		list_del_init(&req->list);
398
399		/* The USB Host sends us whatever amount of data it wants to
400		 * so we always set the length field to the full USB_BUFSIZE.
401		 * If the amount of data is more than the read() caller asked
402		 * for it will be stored in the request buffer until it is
403		 * asked for by read().
404		 */
405		req->length = USB_BUFSIZE;
406		req->complete = rx_complete;
407
408		/* here, we unlock, and only unlock, to avoid deadlock. */
409		spin_unlock(&dev->lock);
410		error = usb_ep_queue(dev->out_ep, req, GFP_ATOMIC);
411		spin_lock(&dev->lock);
412		if (error) {
413			DBG(dev, "rx submit --> %d\n", error);
414			list_add(&req->list, &dev->rx_reqs);
415			break;
416		}
417		/* if the req is empty, then add it into dev->rx_reqs_active. */
418		else if (list_empty(&req->list))
419			list_add(&req->list, &dev->rx_reqs_active);
420	}
421}
422
423static ssize_t
424printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
425{
426	struct printer_dev		*dev = fd->private_data;
427	unsigned long			flags;
428	size_t				size;
429	size_t				bytes_copied;
430	struct usb_request		*req;
431	/* This is a pointer to the current USB rx request. */
432	struct usb_request		*current_rx_req;
433	/* This is the number of bytes in the current rx buffer. */
434	size_t				current_rx_bytes;
435	/* This is a pointer to the current rx buffer. */
436	u8				*current_rx_buf;
437
438	if (len == 0)
439		return -EINVAL;
440
441	DBG(dev, "printer_read trying to read %d bytes\n", (int)len);
442
443	mutex_lock(&dev->lock_printer_io);
444	spin_lock_irqsave(&dev->lock, flags);
445
446	/* We will use this flag later to check if a printer reset happened
447	 * after we turn interrupts back on.
448	 */
449	dev->reset_printer = 0;
450
451	setup_rx_reqs(dev);
452
453	bytes_copied = 0;
454	current_rx_req = dev->current_rx_req;
455	current_rx_bytes = dev->current_rx_bytes;
456	current_rx_buf = dev->current_rx_buf;
457	dev->current_rx_req = NULL;
458	dev->current_rx_bytes = 0;
459	dev->current_rx_buf = NULL;
460
461	/* Check if there is any data in the read buffers. Please note that
462	 * current_rx_bytes is the number of bytes in the current rx buffer.
463	 * If it is zero then check if there are any other rx_buffers that
464	 * are on the completed list. We are only out of data if all rx
465	 * buffers are empty.
466	 */
467	if ((current_rx_bytes == 0) &&
468			(likely(list_empty(&dev->rx_buffers)))) {
469		/* Turn interrupts back on before sleeping. */
470		spin_unlock_irqrestore(&dev->lock, flags);
471
472		/*
473		 * If no data is available check if this is a NON-Blocking
474		 * call or not.
475		 */
476		if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) {
477			mutex_unlock(&dev->lock_printer_io);
478			return -EAGAIN;
479		}
480
481		/* Sleep until data is available */
482		wait_event_interruptible(dev->rx_wait,
483				(likely(!list_empty(&dev->rx_buffers))));
484		spin_lock_irqsave(&dev->lock, flags);
485	}
486
487	/* We have data to return then copy it to the caller's buffer.*/
488	while ((current_rx_bytes || likely(!list_empty(&dev->rx_buffers)))
489			&& len) {
490		if (current_rx_bytes == 0) {
491			req = container_of(dev->rx_buffers.next,
492					struct usb_request, list);
493			list_del_init(&req->list);
494
495			if (req->actual && req->buf) {
496				current_rx_req = req;
497				current_rx_bytes = req->actual;
498				current_rx_buf = req->buf;
499			} else {
500				list_add(&req->list, &dev->rx_reqs);
501				continue;
502			}
503		}
504
505		/* Don't leave irqs off while doing memory copies */
506		spin_unlock_irqrestore(&dev->lock, flags);
507
508		if (len > current_rx_bytes)
509			size = current_rx_bytes;
510		else
511			size = len;
512
513		size -= copy_to_user(buf, current_rx_buf, size);
514		bytes_copied += size;
515		len -= size;
516		buf += size;
517
518		spin_lock_irqsave(&dev->lock, flags);
519
520		/* We've disconnected or reset so return. */
521		if (dev->reset_printer) {
522			list_add(&current_rx_req->list, &dev->rx_reqs);
523			spin_unlock_irqrestore(&dev->lock, flags);
524			mutex_unlock(&dev->lock_printer_io);
525			return -EAGAIN;
526		}
527
528		/* If we not returning all the data left in this RX request
529		 * buffer then adjust the amount of data left in the buffer.
530		 * Othewise if we are done with this RX request buffer then
531		 * requeue it to get any incoming data from the USB host.
532		 */
533		if (size < current_rx_bytes) {
534			current_rx_bytes -= size;
535			current_rx_buf += size;
536		} else {
537			list_add(&current_rx_req->list, &dev->rx_reqs);
538			current_rx_bytes = 0;
539			current_rx_buf = NULL;
540			current_rx_req = NULL;
541		}
542	}
543
544	dev->current_rx_req = current_rx_req;
545	dev->current_rx_bytes = current_rx_bytes;
546	dev->current_rx_buf = current_rx_buf;
547
548	spin_unlock_irqrestore(&dev->lock, flags);
549	mutex_unlock(&dev->lock_printer_io);
550
551	DBG(dev, "printer_read returned %d bytes\n", (int)bytes_copied);
552
553	if (bytes_copied)
554		return bytes_copied;
555	else
556		return -EAGAIN;
557}
558
559static ssize_t
560printer_write(struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
561{
562	struct printer_dev	*dev = fd->private_data;
563	unsigned long		flags;
564	size_t			size;	/* Amount of data in a TX request. */
565	size_t			bytes_copied = 0;
566	struct usb_request	*req;
567
568	DBG(dev, "printer_write trying to send %d bytes\n", (int)len);
569
570	if (len == 0)
571		return -EINVAL;
572
573	mutex_lock(&dev->lock_printer_io);
574	spin_lock_irqsave(&dev->lock, flags);
575
576	/* Check if a printer reset happens while we have interrupts on */
577	dev->reset_printer = 0;
578
579	/* Check if there is any available write buffers */
580	if (likely(list_empty(&dev->tx_reqs))) {
581		/* Turn interrupts back on before sleeping. */
582		spin_unlock_irqrestore(&dev->lock, flags);
583
584		/*
585		 * If write buffers are available check if this is
586		 * a NON-Blocking call or not.
587		 */
588		if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) {
589			mutex_unlock(&dev->lock_printer_io);
590			return -EAGAIN;
591		}
592
593		/* Sleep until a write buffer is available */
594		wait_event_interruptible(dev->tx_wait,
595				(likely(!list_empty(&dev->tx_reqs))));
596		spin_lock_irqsave(&dev->lock, flags);
597	}
598
599	while (likely(!list_empty(&dev->tx_reqs)) && len) {
600
601		if (len > USB_BUFSIZE)
602			size = USB_BUFSIZE;
603		else
604			size = len;
605
606		req = container_of(dev->tx_reqs.next, struct usb_request,
607				list);
608		list_del_init(&req->list);
609
610		req->complete = tx_complete;
611		req->length = size;
612
613		/* Check if we need to send a zero length packet. */
614		if (len > size)
615			/* They will be more TX requests so no yet. */
616			req->zero = 0;
617		else
618			/* If the data amount is not a multiple of the
619			 * maxpacket size then send a zero length packet.
620			 */
621			req->zero = ((len % dev->in_ep->maxpacket) == 0);
622
623		/* Don't leave irqs off while doing memory copies */
624		spin_unlock_irqrestore(&dev->lock, flags);
625
626		if (copy_from_user(req->buf, buf, size)) {
627			list_add(&req->list, &dev->tx_reqs);
628			mutex_unlock(&dev->lock_printer_io);
629			return bytes_copied;
630		}
631
632		bytes_copied += size;
633		len -= size;
634		buf += size;
635
636		spin_lock_irqsave(&dev->lock, flags);
637
638		/* We've disconnected or reset so free the req and buffer */
639		if (dev->reset_printer) {
640			list_add(&req->list, &dev->tx_reqs);
641			spin_unlock_irqrestore(&dev->lock, flags);
642			mutex_unlock(&dev->lock_printer_io);
643			return -EAGAIN;
644		}
645
646		if (usb_ep_queue(dev->in_ep, req, GFP_ATOMIC)) {
647			list_add(&req->list, &dev->tx_reqs);
648			spin_unlock_irqrestore(&dev->lock, flags);
649			mutex_unlock(&dev->lock_printer_io);
650			return -EAGAIN;
651		}
652
653		list_add(&req->list, &dev->tx_reqs_active);
654
655	}
656
657	spin_unlock_irqrestore(&dev->lock, flags);
658	mutex_unlock(&dev->lock_printer_io);
659
660	DBG(dev, "printer_write sent %d bytes\n", (int)bytes_copied);
661
662	if (bytes_copied)
663		return bytes_copied;
664	else
665		return -EAGAIN;
666}
667
668static int
669printer_fsync(struct file *fd, loff_t start, loff_t end, int datasync)
670{
671	struct printer_dev	*dev = fd->private_data;
672	struct inode *inode = file_inode(fd);
673	unsigned long		flags;
674	int			tx_list_empty;
675
676	mutex_lock(&inode->i_mutex);
677	spin_lock_irqsave(&dev->lock, flags);
678	tx_list_empty = (likely(list_empty(&dev->tx_reqs)));
679	spin_unlock_irqrestore(&dev->lock, flags);
680
681	if (!tx_list_empty) {
682		/* Sleep until all data has been sent */
683		wait_event_interruptible(dev->tx_flush_wait,
684				(likely(list_empty(&dev->tx_reqs_active))));
685	}
686	mutex_unlock(&inode->i_mutex);
687
688	return 0;
689}
690
691static unsigned int
692printer_poll(struct file *fd, poll_table *wait)
693{
694	struct printer_dev	*dev = fd->private_data;
695	unsigned long		flags;
696	int			status = 0;
697
698	mutex_lock(&dev->lock_printer_io);
699	spin_lock_irqsave(&dev->lock, flags);
700	setup_rx_reqs(dev);
701	spin_unlock_irqrestore(&dev->lock, flags);
702	mutex_unlock(&dev->lock_printer_io);
703
704	poll_wait(fd, &dev->rx_wait, wait);
705	poll_wait(fd, &dev->tx_wait, wait);
706
707	spin_lock_irqsave(&dev->lock, flags);
708	if (likely(!list_empty(&dev->tx_reqs)))
709		status |= POLLOUT | POLLWRNORM;
710
711	if (likely(dev->current_rx_bytes) ||
712			likely(!list_empty(&dev->rx_buffers)))
713		status |= POLLIN | POLLRDNORM;
714
715	spin_unlock_irqrestore(&dev->lock, flags);
716
717	return status;
718}
719
720static long
721printer_ioctl(struct file *fd, unsigned int code, unsigned long arg)
722{
723	struct printer_dev	*dev = fd->private_data;
724	unsigned long		flags;
725	int			status = 0;
726
727	DBG(dev, "printer_ioctl: cmd=0x%4.4x, arg=%lu\n", code, arg);
728
729	/* handle ioctls */
730
731	spin_lock_irqsave(&dev->lock, flags);
732
733	switch (code) {
734	case GADGET_GET_PRINTER_STATUS:
735		status = (int)dev->printer_status;
736		break;
737	case GADGET_SET_PRINTER_STATUS:
738		dev->printer_status = (u8)arg;
739		break;
740	default:
741		/* could not handle ioctl */
742		DBG(dev, "printer_ioctl: ERROR cmd=0x%4.4xis not supported\n",
743				code);
744		status = -ENOTTY;
745	}
746
747	spin_unlock_irqrestore(&dev->lock, flags);
748
749	return status;
750}
751
752/* used after endpoint configuration */
753static const struct file_operations printer_io_operations = {
754	.owner =	THIS_MODULE,
755	.open =		printer_open,
756	.read =		printer_read,
757	.write =	printer_write,
758	.fsync =	printer_fsync,
759	.poll =		printer_poll,
760	.unlocked_ioctl = printer_ioctl,
761	.release =	printer_close,
762	.llseek =	noop_llseek,
763};
764
765/*-------------------------------------------------------------------------*/
766
767static int
768set_printer_interface(struct printer_dev *dev)
769{
770	int			result = 0;
771
772	dev->in_ep->desc = ep_desc(dev->gadget, &fs_ep_in_desc, &hs_ep_in_desc,
773				&ss_ep_in_desc);
774	dev->in_ep->driver_data = dev;
775
776	dev->out_ep->desc = ep_desc(dev->gadget, &fs_ep_out_desc,
777				    &hs_ep_out_desc, &ss_ep_out_desc);
778	dev->out_ep->driver_data = dev;
779
780	result = usb_ep_enable(dev->in_ep);
781	if (result != 0) {
782		DBG(dev, "enable %s --> %d\n", dev->in_ep->name, result);
783		goto done;
784	}
785
786	result = usb_ep_enable(dev->out_ep);
787	if (result != 0) {
788		DBG(dev, "enable %s --> %d\n", dev->in_ep->name, result);
789		goto done;
790	}
791
792done:
793	/* on error, disable any endpoints  */
794	if (result != 0) {
795		(void) usb_ep_disable(dev->in_ep);
796		(void) usb_ep_disable(dev->out_ep);
797		dev->in_ep->desc = NULL;
798		dev->out_ep->desc = NULL;
799	}
800
801	/* caller is responsible for cleanup on error */
802	return result;
803}
804
805static void printer_reset_interface(struct printer_dev *dev)
806{
807	if (dev->interface < 0)
808		return;
809
810	DBG(dev, "%s\n", __func__);
811
812	if (dev->in_ep->desc)
813		usb_ep_disable(dev->in_ep);
814
815	if (dev->out_ep->desc)
816		usb_ep_disable(dev->out_ep);
817
818	dev->in_ep->desc = NULL;
819	dev->out_ep->desc = NULL;
820	dev->interface = -1;
821}
822
823/* Change our operational Interface. */
824static int set_interface(struct printer_dev *dev, unsigned number)
825{
826	int			result = 0;
827
828	/* Free the current interface */
829	printer_reset_interface(dev);
830
831	result = set_printer_interface(dev);
832	if (result)
833		printer_reset_interface(dev);
834	else
835		dev->interface = number;
836
837	if (!result)
838		INFO(dev, "Using interface %x\n", number);
839
840	return result;
841}
842
843static void printer_soft_reset(struct printer_dev *dev)
844{
845	struct usb_request	*req;
846
847	INFO(dev, "Received Printer Reset Request\n");
848
849	if (usb_ep_disable(dev->in_ep))
850		DBG(dev, "Failed to disable USB in_ep\n");
851	if (usb_ep_disable(dev->out_ep))
852		DBG(dev, "Failed to disable USB out_ep\n");
853
854	if (dev->current_rx_req != NULL) {
855		list_add(&dev->current_rx_req->list, &dev->rx_reqs);
856		dev->current_rx_req = NULL;
857	}
858	dev->current_rx_bytes = 0;
859	dev->current_rx_buf = NULL;
860	dev->reset_printer = 1;
861
862	while (likely(!(list_empty(&dev->rx_buffers)))) {
863		req = container_of(dev->rx_buffers.next, struct usb_request,
864				list);
865		list_del_init(&req->list);
866		list_add(&req->list, &dev->rx_reqs);
867	}
868
869	while (likely(!(list_empty(&dev->rx_reqs_active)))) {
870		req = container_of(dev->rx_buffers.next, struct usb_request,
871				list);
872		list_del_init(&req->list);
873		list_add(&req->list, &dev->rx_reqs);
874	}
875
876	while (likely(!(list_empty(&dev->tx_reqs_active)))) {
877		req = container_of(dev->tx_reqs_active.next,
878				struct usb_request, list);
879		list_del_init(&req->list);
880		list_add(&req->list, &dev->tx_reqs);
881	}
882
883	if (usb_ep_enable(dev->in_ep))
884		DBG(dev, "Failed to enable USB in_ep\n");
885	if (usb_ep_enable(dev->out_ep))
886		DBG(dev, "Failed to enable USB out_ep\n");
887
888	wake_up_interruptible(&dev->rx_wait);
889	wake_up_interruptible(&dev->tx_wait);
890	wake_up_interruptible(&dev->tx_flush_wait);
891}
892
893/*-------------------------------------------------------------------------*/
894
895static bool gprinter_req_match(struct usb_function *f,
896			       const struct usb_ctrlrequest *ctrl)
897{
898	struct printer_dev	*dev = func_to_printer(f);
899	u16			w_index = le16_to_cpu(ctrl->wIndex);
900	u16			w_value = le16_to_cpu(ctrl->wValue);
901	u16			w_length = le16_to_cpu(ctrl->wLength);
902
903	if ((ctrl->bRequestType & USB_RECIP_MASK) != USB_RECIP_INTERFACE ||
904	    (ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS)
905		return false;
906
907	switch (ctrl->bRequest) {
908	case GET_DEVICE_ID:
909		w_index >>= 8;
910		if (w_length <= PNP_STRING_LEN &&
911		    (USB_DIR_IN & ctrl->bRequestType))
912			break;
913		return false;
914	case GET_PORT_STATUS:
915		if (!w_value && w_length == 1 &&
916		    (USB_DIR_IN & ctrl->bRequestType))
917			break;
918		return false;
919	case SOFT_RESET:
920		if (!w_value && !w_length &&
921		   !(USB_DIR_IN & ctrl->bRequestType))
922			break;
923		/* fall through */
924	default:
925		return false;
926	}
927	return w_index == dev->interface;
928}
929
930/*
931 * The setup() callback implements all the ep0 functionality that's not
932 * handled lower down.
933 */
934static int printer_func_setup(struct usb_function *f,
935		const struct usb_ctrlrequest *ctrl)
936{
937	struct printer_dev *dev = func_to_printer(f);
938	struct usb_composite_dev *cdev = f->config->cdev;
939	struct usb_request	*req = cdev->req;
940	int			value = -EOPNOTSUPP;
941	u16			wIndex = le16_to_cpu(ctrl->wIndex);
942	u16			wValue = le16_to_cpu(ctrl->wValue);
943	u16			wLength = le16_to_cpu(ctrl->wLength);
944
945	DBG(dev, "ctrl req%02x.%02x v%04x i%04x l%d\n",
946		ctrl->bRequestType, ctrl->bRequest, wValue, wIndex, wLength);
947
948	switch (ctrl->bRequestType&USB_TYPE_MASK) {
949	case USB_TYPE_CLASS:
950		switch (ctrl->bRequest) {
951		case GET_DEVICE_ID: /* Get the IEEE-1284 PNP String */
952			/* Only one printer interface is supported. */
953			if ((wIndex>>8) != dev->interface)
954				break;
955
956			value = (dev->pnp_string[0] << 8) | dev->pnp_string[1];
957			memcpy(req->buf, dev->pnp_string, value);
958			DBG(dev, "1284 PNP String: %x %s\n", value,
959					&dev->pnp_string[2]);
960			break;
961
962		case GET_PORT_STATUS: /* Get Port Status */
963			/* Only one printer interface is supported. */
964			if (wIndex != dev->interface)
965				break;
966
967			*(u8 *)req->buf = dev->printer_status;
968			value = min_t(u16, wLength, 1);
969			break;
970
971		case SOFT_RESET: /* Soft Reset */
972			/* Only one printer interface is supported. */
973			if (wIndex != dev->interface)
974				break;
975
976			printer_soft_reset(dev);
977
978			value = 0;
979			break;
980
981		default:
982			goto unknown;
983		}
984		break;
985
986	default:
987unknown:
988		VDBG(dev,
989			"unknown ctrl req%02x.%02x v%04x i%04x l%d\n",
990			ctrl->bRequestType, ctrl->bRequest,
991			wValue, wIndex, wLength);
992		break;
993	}
994	/* host either stalls (value < 0) or reports success */
995	if (value >= 0) {
996		req->length = value;
997		req->zero = value < wLength;
998		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
999		if (value < 0) {
1000			ERROR(dev, "%s:%d Error!\n", __func__, __LINE__);
1001			req->status = 0;
1002		}
1003	}
1004	return value;
1005}
1006
1007static int printer_func_bind(struct usb_configuration *c,
1008		struct usb_function *f)
1009{
1010	struct usb_gadget *gadget = c->cdev->gadget;
1011	struct printer_dev *dev = func_to_printer(f);
1012	struct device *pdev;
1013	struct usb_composite_dev *cdev = c->cdev;
1014	struct usb_ep *in_ep;
1015	struct usb_ep *out_ep = NULL;
1016	struct usb_request *req;
1017	dev_t devt;
1018	int id;
1019	int ret;
1020	u32 i;
1021
1022	id = usb_interface_id(c, f);
1023	if (id < 0)
1024		return id;
1025	intf_desc.bInterfaceNumber = id;
1026
1027	/* finish hookup to lower layer ... */
1028	dev->gadget = gadget;
1029
1030	/* all we really need is bulk IN/OUT */
1031	in_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_in_desc);
1032	if (!in_ep) {
1033autoconf_fail:
1034		dev_err(&cdev->gadget->dev, "can't autoconfigure on %s\n",
1035			cdev->gadget->name);
1036		return -ENODEV;
1037	}
1038	in_ep->driver_data = in_ep;	/* claim */
1039
1040	out_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_out_desc);
1041	if (!out_ep)
1042		goto autoconf_fail;
1043	out_ep->driver_data = out_ep;	/* claim */
1044
1045	/* assumes that all endpoints are dual-speed */
1046	hs_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
1047	hs_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
1048	ss_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
1049	ss_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
1050
1051	ret = usb_assign_descriptors(f, fs_printer_function,
1052			hs_printer_function, ss_printer_function);
1053	if (ret)
1054		return ret;
1055
1056	dev->in_ep = in_ep;
1057	dev->out_ep = out_ep;
1058
1059	ret = -ENOMEM;
1060	for (i = 0; i < dev->q_len; i++) {
1061		req = printer_req_alloc(dev->in_ep, USB_BUFSIZE, GFP_KERNEL);
1062		if (!req)
1063			goto fail_tx_reqs;
1064		list_add(&req->list, &dev->tx_reqs);
1065	}
1066
1067	for (i = 0; i < dev->q_len; i++) {
1068		req = printer_req_alloc(dev->out_ep, USB_BUFSIZE, GFP_KERNEL);
1069		if (!req)
1070			goto fail_rx_reqs;
1071		list_add(&req->list, &dev->rx_reqs);
1072	}
1073
1074	/* Setup the sysfs files for the printer gadget. */
1075	devt = MKDEV(major, dev->minor);
1076	pdev = device_create(usb_gadget_class, NULL, devt,
1077				  NULL, "g_printer%d", dev->minor);
1078	if (IS_ERR(pdev)) {
1079		ERROR(dev, "Failed to create device: g_printer\n");
1080		ret = PTR_ERR(pdev);
1081		goto fail_rx_reqs;
1082	}
1083
1084	/*
1085	 * Register a character device as an interface to a user mode
1086	 * program that handles the printer specific functionality.
1087	 */
1088	cdev_init(&dev->printer_cdev, &printer_io_operations);
1089	dev->printer_cdev.owner = THIS_MODULE;
1090	ret = cdev_add(&dev->printer_cdev, devt, 1);
1091	if (ret) {
1092		ERROR(dev, "Failed to open char device\n");
1093		goto fail_cdev_add;
1094	}
1095
1096	return 0;
1097
1098fail_cdev_add:
1099	device_destroy(usb_gadget_class, devt);
1100
1101fail_rx_reqs:
1102	while (!list_empty(&dev->rx_reqs)) {
1103		req = container_of(dev->rx_reqs.next, struct usb_request, list);
1104		list_del(&req->list);
1105		printer_req_free(dev->out_ep, req);
1106	}
1107
1108fail_tx_reqs:
1109	while (!list_empty(&dev->tx_reqs)) {
1110		req = container_of(dev->tx_reqs.next, struct usb_request, list);
1111		list_del(&req->list);
1112		printer_req_free(dev->in_ep, req);
1113	}
1114
1115	return ret;
1116
1117}
1118
1119static int printer_func_set_alt(struct usb_function *f,
1120		unsigned intf, unsigned alt)
1121{
1122	struct printer_dev *dev = func_to_printer(f);
1123	int ret = -ENOTSUPP;
1124
1125	if (!alt)
1126		ret = set_interface(dev, intf);
1127
1128	return ret;
1129}
1130
1131static void printer_func_disable(struct usb_function *f)
1132{
1133	struct printer_dev *dev = func_to_printer(f);
1134	unsigned long		flags;
1135
1136	DBG(dev, "%s\n", __func__);
1137
1138	spin_lock_irqsave(&dev->lock, flags);
1139	printer_reset_interface(dev);
1140	spin_unlock_irqrestore(&dev->lock, flags);
1141}
1142
1143static inline struct f_printer_opts
1144*to_f_printer_opts(struct config_item *item)
1145{
1146	return container_of(to_config_group(item), struct f_printer_opts,
1147			    func_inst.group);
1148}
1149
1150CONFIGFS_ATTR_STRUCT(f_printer_opts);
1151CONFIGFS_ATTR_OPS(f_printer_opts);
1152
1153static void printer_attr_release(struct config_item *item)
1154{
1155	struct f_printer_opts *opts = to_f_printer_opts(item);
1156
1157	usb_put_function_instance(&opts->func_inst);
1158}
1159
1160static struct configfs_item_operations printer_item_ops = {
1161	.release	= printer_attr_release,
1162	.show_attribute	= f_printer_opts_attr_show,
1163	.store_attribute = f_printer_opts_attr_store,
1164};
1165
1166static ssize_t f_printer_opts_pnp_string_show(struct f_printer_opts *opts,
1167					      char *page)
1168{
1169	int result;
1170
1171	mutex_lock(&opts->lock);
1172	result = strlcpy(page, opts->pnp_string + 2, PNP_STRING_LEN - 2);
1173	mutex_unlock(&opts->lock);
1174
1175	return result;
1176}
1177
1178static ssize_t f_printer_opts_pnp_string_store(struct f_printer_opts *opts,
1179					       const char *page, size_t len)
1180{
1181	int result, l;
1182
1183	mutex_lock(&opts->lock);
1184	result = strlcpy(opts->pnp_string + 2, page, PNP_STRING_LEN - 2);
1185	l = strlen(opts->pnp_string + 2) + 2;
1186	opts->pnp_string[0] = (l >> 8) & 0xFF;
1187	opts->pnp_string[1] = l & 0xFF;
1188	mutex_unlock(&opts->lock);
1189
1190	return result;
1191}
1192
1193static struct f_printer_opts_attribute f_printer_opts_pnp_string =
1194	__CONFIGFS_ATTR(pnp_string, S_IRUGO | S_IWUSR,
1195			f_printer_opts_pnp_string_show,
1196			f_printer_opts_pnp_string_store);
1197
1198static ssize_t f_printer_opts_q_len_show(struct f_printer_opts *opts,
1199					 char *page)
1200{
1201	int result;
1202
1203	mutex_lock(&opts->lock);
1204	result = sprintf(page, "%d\n", opts->q_len);
1205	mutex_unlock(&opts->lock);
1206
1207	return result;
1208}
1209
1210static ssize_t f_printer_opts_q_len_store(struct f_printer_opts *opts,
1211					  const char *page, size_t len)
1212{
1213	int ret;
1214	u16 num;
1215
1216	mutex_lock(&opts->lock);
1217	if (opts->refcnt) {
1218		ret = -EBUSY;
1219		goto end;
1220	}
1221
1222	ret = kstrtou16(page, 0, &num);
1223	if (ret)
1224		goto end;
1225
1226	opts->q_len = (unsigned)num;
1227	ret = len;
1228end:
1229	mutex_unlock(&opts->lock);
1230	return ret;
1231}
1232
1233static struct f_printer_opts_attribute f_printer_opts_q_len =
1234	__CONFIGFS_ATTR(q_len, S_IRUGO | S_IWUSR, f_printer_opts_q_len_show,
1235			f_printer_opts_q_len_store);
1236
1237static struct configfs_attribute *printer_attrs[] = {
1238	&f_printer_opts_pnp_string.attr,
1239	&f_printer_opts_q_len.attr,
1240	NULL,
1241};
1242
1243static struct config_item_type printer_func_type = {
1244	.ct_item_ops	= &printer_item_ops,
1245	.ct_attrs	= printer_attrs,
1246	.ct_owner	= THIS_MODULE,
1247};
1248
1249static inline int gprinter_get_minor(void)
1250{
1251	return ida_simple_get(&printer_ida, 0, 0, GFP_KERNEL);
1252}
1253
1254static inline void gprinter_put_minor(int minor)
1255{
1256	ida_simple_remove(&printer_ida, minor);
1257}
1258
1259static int gprinter_setup(int);
1260static void gprinter_cleanup(void);
1261
1262static void gprinter_free_inst(struct usb_function_instance *f)
1263{
1264	struct f_printer_opts *opts;
1265
1266	opts = container_of(f, struct f_printer_opts, func_inst);
1267
1268	mutex_lock(&printer_ida_lock);
1269
1270	gprinter_put_minor(opts->minor);
1271	if (idr_is_empty(&printer_ida.idr))
1272		gprinter_cleanup();
1273
1274	mutex_unlock(&printer_ida_lock);
1275
1276	kfree(opts);
1277}
1278
1279static struct usb_function_instance *gprinter_alloc_inst(void)
1280{
1281	struct f_printer_opts *opts;
1282	struct usb_function_instance *ret;
1283	int status = 0;
1284
1285	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1286	if (!opts)
1287		return ERR_PTR(-ENOMEM);
1288
1289	mutex_init(&opts->lock);
1290	opts->func_inst.free_func_inst = gprinter_free_inst;
1291	ret = &opts->func_inst;
1292
1293	mutex_lock(&printer_ida_lock);
1294
1295	if (idr_is_empty(&printer_ida.idr)) {
1296		status = gprinter_setup(PRINTER_MINORS);
1297		if (status) {
1298			ret = ERR_PTR(status);
1299			kfree(opts);
1300			goto unlock;
1301		}
1302	}
1303
1304	opts->minor = gprinter_get_minor();
1305	if (opts->minor < 0) {
1306		ret = ERR_PTR(opts->minor);
1307		kfree(opts);
1308		if (idr_is_empty(&printer_ida.idr))
1309			gprinter_cleanup();
1310		goto unlock;
1311	}
1312	config_group_init_type_name(&opts->func_inst.group, "",
1313				    &printer_func_type);
1314
1315unlock:
1316	mutex_unlock(&printer_ida_lock);
1317	return ret;
1318}
1319
1320static void gprinter_free(struct usb_function *f)
1321{
1322	struct printer_dev *dev = func_to_printer(f);
1323	struct f_printer_opts *opts;
1324
1325	opts = container_of(f->fi, struct f_printer_opts, func_inst);
1326	kfree(dev);
1327	mutex_lock(&opts->lock);
1328	--opts->refcnt;
1329	mutex_unlock(&opts->lock);
1330}
1331
1332static void printer_func_unbind(struct usb_configuration *c,
1333		struct usb_function *f)
1334{
1335	struct printer_dev	*dev;
1336	struct usb_request	*req;
1337
1338	dev = func_to_printer(f);
1339
1340	device_destroy(usb_gadget_class, MKDEV(major, dev->minor));
1341
1342	/* Remove Character Device */
1343	cdev_del(&dev->printer_cdev);
1344
1345	/* we must already have been disconnected ... no i/o may be active */
1346	WARN_ON(!list_empty(&dev->tx_reqs_active));
1347	WARN_ON(!list_empty(&dev->rx_reqs_active));
1348
1349	/* Free all memory for this driver. */
1350	while (!list_empty(&dev->tx_reqs)) {
1351		req = container_of(dev->tx_reqs.next, struct usb_request,
1352				list);
1353		list_del(&req->list);
1354		printer_req_free(dev->in_ep, req);
1355	}
1356
1357	if (dev->current_rx_req != NULL)
1358		printer_req_free(dev->out_ep, dev->current_rx_req);
1359
1360	while (!list_empty(&dev->rx_reqs)) {
1361		req = container_of(dev->rx_reqs.next,
1362				struct usb_request, list);
1363		list_del(&req->list);
1364		printer_req_free(dev->out_ep, req);
1365	}
1366
1367	while (!list_empty(&dev->rx_buffers)) {
1368		req = container_of(dev->rx_buffers.next,
1369				struct usb_request, list);
1370		list_del(&req->list);
1371		printer_req_free(dev->out_ep, req);
1372	}
1373	usb_free_all_descriptors(f);
1374}
1375
1376static struct usb_function *gprinter_alloc(struct usb_function_instance *fi)
1377{
1378	struct printer_dev	*dev;
1379	struct f_printer_opts	*opts;
1380
1381	opts = container_of(fi, struct f_printer_opts, func_inst);
1382
1383	mutex_lock(&opts->lock);
1384	if (opts->minor >= minors) {
1385		mutex_unlock(&opts->lock);
1386		return ERR_PTR(-ENOENT);
1387	}
1388
1389	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1390	if (!dev) {
1391		mutex_unlock(&opts->lock);
1392		return ERR_PTR(-ENOMEM);
1393	}
1394
1395	++opts->refcnt;
1396	dev->minor = opts->minor;
1397	dev->pnp_string = opts->pnp_string;
1398	dev->q_len = opts->q_len;
1399	mutex_unlock(&opts->lock);
1400
1401	dev->function.name = "printer";
1402	dev->function.bind = printer_func_bind;
1403	dev->function.setup = printer_func_setup;
1404	dev->function.unbind = printer_func_unbind;
1405	dev->function.set_alt = printer_func_set_alt;
1406	dev->function.disable = printer_func_disable;
1407	dev->function.req_match = gprinter_req_match;
1408	dev->function.free_func = gprinter_free;
1409
1410	INIT_LIST_HEAD(&dev->tx_reqs);
1411	INIT_LIST_HEAD(&dev->rx_reqs);
1412	INIT_LIST_HEAD(&dev->rx_buffers);
1413	INIT_LIST_HEAD(&dev->tx_reqs_active);
1414	INIT_LIST_HEAD(&dev->rx_reqs_active);
1415
1416	spin_lock_init(&dev->lock);
1417	mutex_init(&dev->lock_printer_io);
1418	init_waitqueue_head(&dev->rx_wait);
1419	init_waitqueue_head(&dev->tx_wait);
1420	init_waitqueue_head(&dev->tx_flush_wait);
1421
1422	dev->interface = -1;
1423	dev->printer_cdev_open = 0;
1424	dev->printer_status = PRINTER_NOT_ERROR;
1425	dev->current_rx_req = NULL;
1426	dev->current_rx_bytes = 0;
1427	dev->current_rx_buf = NULL;
1428
1429	return &dev->function;
1430}
1431
1432DECLARE_USB_FUNCTION_INIT(printer, gprinter_alloc_inst, gprinter_alloc);
1433MODULE_LICENSE("GPL");
1434MODULE_AUTHOR("Craig Nadler");
1435
1436static int gprinter_setup(int count)
1437{
1438	int status;
1439	dev_t devt;
1440
1441	usb_gadget_class = class_create(THIS_MODULE, "usb_printer_gadget");
1442	if (IS_ERR(usb_gadget_class)) {
1443		status = PTR_ERR(usb_gadget_class);
1444		usb_gadget_class = NULL;
1445		pr_err("unable to create usb_gadget class %d\n", status);
1446		return status;
1447	}
1448
1449	status = alloc_chrdev_region(&devt, 0, count, "USB printer gadget");
1450	if (status) {
1451		pr_err("alloc_chrdev_region %d\n", status);
1452		class_destroy(usb_gadget_class);
1453		usb_gadget_class = NULL;
1454		return status;
1455	}
1456
1457	major = MAJOR(devt);
1458	minors = count;
1459
1460	return status;
1461}
1462
1463static void gprinter_cleanup(void)
1464{
1465	if (major) {
1466		unregister_chrdev_region(MKDEV(major, 0), minors);
1467		major = minors = 0;
1468	}
1469	class_destroy(usb_gadget_class);
1470	usb_gadget_class = NULL;
1471}
1472