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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(¤t_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(¤t_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 inode_lock(inode);
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 inode_unlock(inode);
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 unsigned long flags;
808
809 if (dev->interface < 0)
810 return;
811
812 DBG(dev, "%s\n", __func__);
813
814 if (dev->in_ep->desc)
815 usb_ep_disable(dev->in_ep);
816
817 if (dev->out_ep->desc)
818 usb_ep_disable(dev->out_ep);
819
820 spin_lock_irqsave(&dev->lock, flags);
821 dev->in_ep->desc = NULL;
822 dev->out_ep->desc = NULL;
823 dev->interface = -1;
824 spin_unlock_irqrestore(&dev->lock, flags);
825}
826
827/* Change our operational Interface. */
828static int set_interface(struct printer_dev *dev, unsigned number)
829{
830 int result = 0;
831
832 /* Free the current interface */
833 printer_reset_interface(dev);
834
835 result = set_printer_interface(dev);
836 if (result)
837 printer_reset_interface(dev);
838 else
839 dev->interface = number;
840
841 if (!result)
842 INFO(dev, "Using interface %x\n", number);
843
844 return result;
845}
846
847static void printer_soft_reset(struct printer_dev *dev)
848{
849 struct usb_request *req;
850
851 INFO(dev, "Received Printer Reset Request\n");
852
853 if (usb_ep_disable(dev->in_ep))
854 DBG(dev, "Failed to disable USB in_ep\n");
855 if (usb_ep_disable(dev->out_ep))
856 DBG(dev, "Failed to disable USB out_ep\n");
857
858 if (dev->current_rx_req != NULL) {
859 list_add(&dev->current_rx_req->list, &dev->rx_reqs);
860 dev->current_rx_req = NULL;
861 }
862 dev->current_rx_bytes = 0;
863 dev->current_rx_buf = NULL;
864 dev->reset_printer = 1;
865
866 while (likely(!(list_empty(&dev->rx_buffers)))) {
867 req = container_of(dev->rx_buffers.next, struct usb_request,
868 list);
869 list_del_init(&req->list);
870 list_add(&req->list, &dev->rx_reqs);
871 }
872
873 while (likely(!(list_empty(&dev->rx_reqs_active)))) {
874 req = container_of(dev->rx_buffers.next, struct usb_request,
875 list);
876 list_del_init(&req->list);
877 list_add(&req->list, &dev->rx_reqs);
878 }
879
880 while (likely(!(list_empty(&dev->tx_reqs_active)))) {
881 req = container_of(dev->tx_reqs_active.next,
882 struct usb_request, list);
883 list_del_init(&req->list);
884 list_add(&req->list, &dev->tx_reqs);
885 }
886
887 if (usb_ep_enable(dev->in_ep))
888 DBG(dev, "Failed to enable USB in_ep\n");
889 if (usb_ep_enable(dev->out_ep))
890 DBG(dev, "Failed to enable USB out_ep\n");
891
892 wake_up_interruptible(&dev->rx_wait);
893 wake_up_interruptible(&dev->tx_wait);
894 wake_up_interruptible(&dev->tx_flush_wait);
895}
896
897/*-------------------------------------------------------------------------*/
898
899static bool gprinter_req_match(struct usb_function *f,
900 const struct usb_ctrlrequest *ctrl)
901{
902 struct printer_dev *dev = func_to_printer(f);
903 u16 w_index = le16_to_cpu(ctrl->wIndex);
904 u16 w_value = le16_to_cpu(ctrl->wValue);
905 u16 w_length = le16_to_cpu(ctrl->wLength);
906
907 if ((ctrl->bRequestType & USB_RECIP_MASK) != USB_RECIP_INTERFACE ||
908 (ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS)
909 return false;
910
911 switch (ctrl->bRequest) {
912 case GET_DEVICE_ID:
913 w_index >>= 8;
914 if (w_length <= PNP_STRING_LEN &&
915 (USB_DIR_IN & ctrl->bRequestType))
916 break;
917 return false;
918 case GET_PORT_STATUS:
919 if (!w_value && w_length == 1 &&
920 (USB_DIR_IN & ctrl->bRequestType))
921 break;
922 return false;
923 case SOFT_RESET:
924 if (!w_value && !w_length &&
925 !(USB_DIR_IN & ctrl->bRequestType))
926 break;
927 /* fall through */
928 default:
929 return false;
930 }
931 return w_index == dev->interface;
932}
933
934/*
935 * The setup() callback implements all the ep0 functionality that's not
936 * handled lower down.
937 */
938static int printer_func_setup(struct usb_function *f,
939 const struct usb_ctrlrequest *ctrl)
940{
941 struct printer_dev *dev = func_to_printer(f);
942 struct usb_composite_dev *cdev = f->config->cdev;
943 struct usb_request *req = cdev->req;
944 int value = -EOPNOTSUPP;
945 u16 wIndex = le16_to_cpu(ctrl->wIndex);
946 u16 wValue = le16_to_cpu(ctrl->wValue);
947 u16 wLength = le16_to_cpu(ctrl->wLength);
948
949 DBG(dev, "ctrl req%02x.%02x v%04x i%04x l%d\n",
950 ctrl->bRequestType, ctrl->bRequest, wValue, wIndex, wLength);
951
952 switch (ctrl->bRequestType&USB_TYPE_MASK) {
953 case USB_TYPE_CLASS:
954 switch (ctrl->bRequest) {
955 case GET_DEVICE_ID: /* Get the IEEE-1284 PNP String */
956 /* Only one printer interface is supported. */
957 if ((wIndex>>8) != dev->interface)
958 break;
959
960 value = (dev->pnp_string[0] << 8) | dev->pnp_string[1];
961 memcpy(req->buf, dev->pnp_string, value);
962 DBG(dev, "1284 PNP String: %x %s\n", value,
963 &dev->pnp_string[2]);
964 break;
965
966 case GET_PORT_STATUS: /* Get Port Status */
967 /* Only one printer interface is supported. */
968 if (wIndex != dev->interface)
969 break;
970
971 *(u8 *)req->buf = dev->printer_status;
972 value = min_t(u16, wLength, 1);
973 break;
974
975 case SOFT_RESET: /* Soft Reset */
976 /* Only one printer interface is supported. */
977 if (wIndex != dev->interface)
978 break;
979
980 printer_soft_reset(dev);
981
982 value = 0;
983 break;
984
985 default:
986 goto unknown;
987 }
988 break;
989
990 default:
991unknown:
992 VDBG(dev,
993 "unknown ctrl req%02x.%02x v%04x i%04x l%d\n",
994 ctrl->bRequestType, ctrl->bRequest,
995 wValue, wIndex, wLength);
996 break;
997 }
998 /* host either stalls (value < 0) or reports success */
999 if (value >= 0) {
1000 req->length = value;
1001 req->zero = value < wLength;
1002 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
1003 if (value < 0) {
1004 ERROR(dev, "%s:%d Error!\n", __func__, __LINE__);
1005 req->status = 0;
1006 }
1007 }
1008 return value;
1009}
1010
1011static int printer_func_bind(struct usb_configuration *c,
1012 struct usb_function *f)
1013{
1014 struct usb_gadget *gadget = c->cdev->gadget;
1015 struct printer_dev *dev = func_to_printer(f);
1016 struct device *pdev;
1017 struct usb_composite_dev *cdev = c->cdev;
1018 struct usb_ep *in_ep;
1019 struct usb_ep *out_ep = NULL;
1020 struct usb_request *req;
1021 dev_t devt;
1022 int id;
1023 int ret;
1024 u32 i;
1025
1026 id = usb_interface_id(c, f);
1027 if (id < 0)
1028 return id;
1029 intf_desc.bInterfaceNumber = id;
1030
1031 /* finish hookup to lower layer ... */
1032 dev->gadget = gadget;
1033
1034 /* all we really need is bulk IN/OUT */
1035 in_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_in_desc);
1036 if (!in_ep) {
1037autoconf_fail:
1038 dev_err(&cdev->gadget->dev, "can't autoconfigure on %s\n",
1039 cdev->gadget->name);
1040 return -ENODEV;
1041 }
1042
1043 out_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_out_desc);
1044 if (!out_ep)
1045 goto autoconf_fail;
1046
1047 /* assumes that all endpoints are dual-speed */
1048 hs_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
1049 hs_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
1050 ss_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
1051 ss_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
1052
1053 ret = usb_assign_descriptors(f, fs_printer_function,
1054 hs_printer_function, ss_printer_function, NULL);
1055 if (ret)
1056 return ret;
1057
1058 dev->in_ep = in_ep;
1059 dev->out_ep = out_ep;
1060
1061 ret = -ENOMEM;
1062 for (i = 0; i < dev->q_len; i++) {
1063 req = printer_req_alloc(dev->in_ep, USB_BUFSIZE, GFP_KERNEL);
1064 if (!req)
1065 goto fail_tx_reqs;
1066 list_add(&req->list, &dev->tx_reqs);
1067 }
1068
1069 for (i = 0; i < dev->q_len; i++) {
1070 req = printer_req_alloc(dev->out_ep, USB_BUFSIZE, GFP_KERNEL);
1071 if (!req)
1072 goto fail_rx_reqs;
1073 list_add(&req->list, &dev->rx_reqs);
1074 }
1075
1076 /* Setup the sysfs files for the printer gadget. */
1077 devt = MKDEV(major, dev->minor);
1078 pdev = device_create(usb_gadget_class, NULL, devt,
1079 NULL, "g_printer%d", dev->minor);
1080 if (IS_ERR(pdev)) {
1081 ERROR(dev, "Failed to create device: g_printer\n");
1082 ret = PTR_ERR(pdev);
1083 goto fail_rx_reqs;
1084 }
1085
1086 /*
1087 * Register a character device as an interface to a user mode
1088 * program that handles the printer specific functionality.
1089 */
1090 cdev_init(&dev->printer_cdev, &printer_io_operations);
1091 dev->printer_cdev.owner = THIS_MODULE;
1092 ret = cdev_add(&dev->printer_cdev, devt, 1);
1093 if (ret) {
1094 ERROR(dev, "Failed to open char device\n");
1095 goto fail_cdev_add;
1096 }
1097
1098 return 0;
1099
1100fail_cdev_add:
1101 device_destroy(usb_gadget_class, devt);
1102
1103fail_rx_reqs:
1104 while (!list_empty(&dev->rx_reqs)) {
1105 req = container_of(dev->rx_reqs.next, struct usb_request, list);
1106 list_del(&req->list);
1107 printer_req_free(dev->out_ep, req);
1108 }
1109
1110fail_tx_reqs:
1111 while (!list_empty(&dev->tx_reqs)) {
1112 req = container_of(dev->tx_reqs.next, struct usb_request, list);
1113 list_del(&req->list);
1114 printer_req_free(dev->in_ep, req);
1115 }
1116
1117 return ret;
1118
1119}
1120
1121static int printer_func_set_alt(struct usb_function *f,
1122 unsigned intf, unsigned alt)
1123{
1124 struct printer_dev *dev = func_to_printer(f);
1125 int ret = -ENOTSUPP;
1126
1127 if (!alt)
1128 ret = set_interface(dev, intf);
1129
1130 return ret;
1131}
1132
1133static void printer_func_disable(struct usb_function *f)
1134{
1135 struct printer_dev *dev = func_to_printer(f);
1136
1137 DBG(dev, "%s\n", __func__);
1138
1139 printer_reset_interface(dev);
1140}
1141
1142static inline struct f_printer_opts
1143*to_f_printer_opts(struct config_item *item)
1144{
1145 return container_of(to_config_group(item), struct f_printer_opts,
1146 func_inst.group);
1147}
1148
1149static void printer_attr_release(struct config_item *item)
1150{
1151 struct f_printer_opts *opts = to_f_printer_opts(item);
1152
1153 usb_put_function_instance(&opts->func_inst);
1154}
1155
1156static struct configfs_item_operations printer_item_ops = {
1157 .release = printer_attr_release,
1158};
1159
1160static ssize_t f_printer_opts_pnp_string_show(struct config_item *item,
1161 char *page)
1162{
1163 struct f_printer_opts *opts = to_f_printer_opts(item);
1164 int result;
1165
1166 mutex_lock(&opts->lock);
1167 result = strlcpy(page, opts->pnp_string + 2, PNP_STRING_LEN - 2);
1168 mutex_unlock(&opts->lock);
1169
1170 return result;
1171}
1172
1173static ssize_t f_printer_opts_pnp_string_store(struct config_item *item,
1174 const char *page, size_t len)
1175{
1176 struct f_printer_opts *opts = to_f_printer_opts(item);
1177 int result, l;
1178
1179 mutex_lock(&opts->lock);
1180 result = strlcpy(opts->pnp_string + 2, page, PNP_STRING_LEN - 2);
1181 l = strlen(opts->pnp_string + 2) + 2;
1182 opts->pnp_string[0] = (l >> 8) & 0xFF;
1183 opts->pnp_string[1] = l & 0xFF;
1184 mutex_unlock(&opts->lock);
1185
1186 return result;
1187}
1188
1189CONFIGFS_ATTR(f_printer_opts_, pnp_string);
1190
1191static ssize_t f_printer_opts_q_len_show(struct config_item *item,
1192 char *page)
1193{
1194 struct f_printer_opts *opts = to_f_printer_opts(item);
1195 int result;
1196
1197 mutex_lock(&opts->lock);
1198 result = sprintf(page, "%d\n", opts->q_len);
1199 mutex_unlock(&opts->lock);
1200
1201 return result;
1202}
1203
1204static ssize_t f_printer_opts_q_len_store(struct config_item *item,
1205 const char *page, size_t len)
1206{
1207 struct f_printer_opts *opts = to_f_printer_opts(item);
1208 int ret;
1209 u16 num;
1210
1211 mutex_lock(&opts->lock);
1212 if (opts->refcnt) {
1213 ret = -EBUSY;
1214 goto end;
1215 }
1216
1217 ret = kstrtou16(page, 0, &num);
1218 if (ret)
1219 goto end;
1220
1221 opts->q_len = (unsigned)num;
1222 ret = len;
1223end:
1224 mutex_unlock(&opts->lock);
1225 return ret;
1226}
1227
1228CONFIGFS_ATTR(f_printer_opts_, q_len);
1229
1230static struct configfs_attribute *printer_attrs[] = {
1231 &f_printer_opts_attr_pnp_string,
1232 &f_printer_opts_attr_q_len,
1233 NULL,
1234};
1235
1236static struct config_item_type printer_func_type = {
1237 .ct_item_ops = &printer_item_ops,
1238 .ct_attrs = printer_attrs,
1239 .ct_owner = THIS_MODULE,
1240};
1241
1242static inline int gprinter_get_minor(void)
1243{
1244 int ret;
1245
1246 ret = ida_simple_get(&printer_ida, 0, 0, GFP_KERNEL);
1247 if (ret >= PRINTER_MINORS) {
1248 ida_simple_remove(&printer_ida, ret);
1249 ret = -ENODEV;
1250 }
1251
1252 return ret;
1253}
1254
1255static inline void gprinter_put_minor(int minor)
1256{
1257 ida_simple_remove(&printer_ida, minor);
1258}
1259
1260static int gprinter_setup(int);
1261static void gprinter_cleanup(void);
1262
1263static void gprinter_free_inst(struct usb_function_instance *f)
1264{
1265 struct f_printer_opts *opts;
1266
1267 opts = container_of(f, struct f_printer_opts, func_inst);
1268
1269 mutex_lock(&printer_ida_lock);
1270
1271 gprinter_put_minor(opts->minor);
1272 if (idr_is_empty(&printer_ida.idr))
1273 gprinter_cleanup();
1274
1275 mutex_unlock(&printer_ida_lock);
1276
1277 kfree(opts);
1278}
1279
1280static struct usb_function_instance *gprinter_alloc_inst(void)
1281{
1282 struct f_printer_opts *opts;
1283 struct usb_function_instance *ret;
1284 int status = 0;
1285
1286 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1287 if (!opts)
1288 return ERR_PTR(-ENOMEM);
1289
1290 mutex_init(&opts->lock);
1291 opts->func_inst.free_func_inst = gprinter_free_inst;
1292 ret = &opts->func_inst;
1293
1294 mutex_lock(&printer_ida_lock);
1295
1296 if (idr_is_empty(&printer_ida.idr)) {
1297 status = gprinter_setup(PRINTER_MINORS);
1298 if (status) {
1299 ret = ERR_PTR(status);
1300 kfree(opts);
1301 goto unlock;
1302 }
1303 }
1304
1305 opts->minor = gprinter_get_minor();
1306 if (opts->minor < 0) {
1307 ret = ERR_PTR(opts->minor);
1308 kfree(opts);
1309 if (idr_is_empty(&printer_ida.idr))
1310 gprinter_cleanup();
1311 goto unlock;
1312 }
1313 config_group_init_type_name(&opts->func_inst.group, "",
1314 &printer_func_type);
1315
1316unlock:
1317 mutex_unlock(&printer_ida_lock);
1318 return ret;
1319}
1320
1321static void gprinter_free(struct usb_function *f)
1322{
1323 struct printer_dev *dev = func_to_printer(f);
1324 struct f_printer_opts *opts;
1325
1326 opts = container_of(f->fi, struct f_printer_opts, func_inst);
1327 kfree(dev);
1328 mutex_lock(&opts->lock);
1329 --opts->refcnt;
1330 mutex_unlock(&opts->lock);
1331}
1332
1333static void printer_func_unbind(struct usb_configuration *c,
1334 struct usb_function *f)
1335{
1336 struct printer_dev *dev;
1337 struct usb_request *req;
1338
1339 dev = func_to_printer(f);
1340
1341 device_destroy(usb_gadget_class, MKDEV(major, dev->minor));
1342
1343 /* Remove Character Device */
1344 cdev_del(&dev->printer_cdev);
1345
1346 /* we must already have been disconnected ... no i/o may be active */
1347 WARN_ON(!list_empty(&dev->tx_reqs_active));
1348 WARN_ON(!list_empty(&dev->rx_reqs_active));
1349
1350 /* Free all memory for this driver. */
1351 while (!list_empty(&dev->tx_reqs)) {
1352 req = container_of(dev->tx_reqs.next, struct usb_request,
1353 list);
1354 list_del(&req->list);
1355 printer_req_free(dev->in_ep, req);
1356 }
1357
1358 if (dev->current_rx_req != NULL)
1359 printer_req_free(dev->out_ep, dev->current_rx_req);
1360
1361 while (!list_empty(&dev->rx_reqs)) {
1362 req = container_of(dev->rx_reqs.next,
1363 struct usb_request, list);
1364 list_del(&req->list);
1365 printer_req_free(dev->out_ep, req);
1366 }
1367
1368 while (!list_empty(&dev->rx_buffers)) {
1369 req = container_of(dev->rx_buffers.next,
1370 struct usb_request, list);
1371 list_del(&req->list);
1372 printer_req_free(dev->out_ep, req);
1373 }
1374 usb_free_all_descriptors(f);
1375}
1376
1377static struct usb_function *gprinter_alloc(struct usb_function_instance *fi)
1378{
1379 struct printer_dev *dev;
1380 struct f_printer_opts *opts;
1381
1382 opts = container_of(fi, struct f_printer_opts, func_inst);
1383
1384 mutex_lock(&opts->lock);
1385 if (opts->minor >= minors) {
1386 mutex_unlock(&opts->lock);
1387 return ERR_PTR(-ENOENT);
1388 }
1389
1390 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1391 if (!dev) {
1392 mutex_unlock(&opts->lock);
1393 return ERR_PTR(-ENOMEM);
1394 }
1395
1396 ++opts->refcnt;
1397 dev->minor = opts->minor;
1398 dev->pnp_string = opts->pnp_string;
1399 dev->q_len = opts->q_len;
1400 mutex_unlock(&opts->lock);
1401
1402 dev->function.name = "printer";
1403 dev->function.bind = printer_func_bind;
1404 dev->function.setup = printer_func_setup;
1405 dev->function.unbind = printer_func_unbind;
1406 dev->function.set_alt = printer_func_set_alt;
1407 dev->function.disable = printer_func_disable;
1408 dev->function.req_match = gprinter_req_match;
1409 dev->function.free_func = gprinter_free;
1410
1411 INIT_LIST_HEAD(&dev->tx_reqs);
1412 INIT_LIST_HEAD(&dev->rx_reqs);
1413 INIT_LIST_HEAD(&dev->rx_buffers);
1414 INIT_LIST_HEAD(&dev->tx_reqs_active);
1415 INIT_LIST_HEAD(&dev->rx_reqs_active);
1416
1417 spin_lock_init(&dev->lock);
1418 mutex_init(&dev->lock_printer_io);
1419 init_waitqueue_head(&dev->rx_wait);
1420 init_waitqueue_head(&dev->tx_wait);
1421 init_waitqueue_head(&dev->tx_flush_wait);
1422
1423 dev->interface = -1;
1424 dev->printer_cdev_open = 0;
1425 dev->printer_status = PRINTER_NOT_ERROR;
1426 dev->current_rx_req = NULL;
1427 dev->current_rx_bytes = 0;
1428 dev->current_rx_buf = NULL;
1429
1430 return &dev->function;
1431}
1432
1433DECLARE_USB_FUNCTION_INIT(printer, gprinter_alloc_inst, gprinter_alloc);
1434MODULE_LICENSE("GPL");
1435MODULE_AUTHOR("Craig Nadler");
1436
1437static int gprinter_setup(int count)
1438{
1439 int status;
1440 dev_t devt;
1441
1442 usb_gadget_class = class_create(THIS_MODULE, "usb_printer_gadget");
1443 if (IS_ERR(usb_gadget_class)) {
1444 status = PTR_ERR(usb_gadget_class);
1445 usb_gadget_class = NULL;
1446 pr_err("unable to create usb_gadget class %d\n", status);
1447 return status;
1448 }
1449
1450 status = alloc_chrdev_region(&devt, 0, count, "USB printer gadget");
1451 if (status) {
1452 pr_err("alloc_chrdev_region %d\n", status);
1453 class_destroy(usb_gadget_class);
1454 usb_gadget_class = NULL;
1455 return status;
1456 }
1457
1458 major = MAJOR(devt);
1459 minors = count;
1460
1461 return status;
1462}
1463
1464static void gprinter_cleanup(void)
1465{
1466 if (major) {
1467 unregister_chrdev_region(MKDEV(major, 0), minors);
1468 major = minors = 0;
1469 }
1470 class_destroy(usb_gadget_class);
1471 usb_gadget_class = NULL;
1472}