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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * f_printer.c - USB printer function driver
4 *
5 * Copied from drivers/usb/gadget/legacy/printer.c,
6 * which was:
7 *
8 * printer.c -- Printer gadget driver
9 *
10 * Copyright (C) 2003-2005 David Brownell
11 * Copyright (C) 2006 Craig W. Nadler
12 */
13
14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/delay.h>
17#include <linux/ioport.h>
18#include <linux/sched.h>
19#include <linux/slab.h>
20#include <linux/mutex.h>
21#include <linux/errno.h>
22#include <linux/init.h>
23#include <linux/idr.h>
24#include <linux/timer.h>
25#include <linux/list.h>
26#include <linux/interrupt.h>
27#include <linux/device.h>
28#include <linux/moduleparam.h>
29#include <linux/fs.h>
30#include <linux/poll.h>
31#include <linux/types.h>
32#include <linux/ctype.h>
33#include <linux/cdev.h>
34
35#include <asm/byteorder.h>
36#include <linux/io.h>
37#include <linux/irq.h>
38#include <linux/uaccess.h>
39#include <asm/unaligned.h>
40
41#include <linux/usb/ch9.h>
42#include <linux/usb/composite.h>
43#include <linux/usb/gadget.h>
44#include <linux/usb/g_printer.h>
45
46#include "u_printer.h"
47
48#define PRINTER_MINORS 4
49#define GET_DEVICE_ID 0
50#define GET_PORT_STATUS 1
51#define SOFT_RESET 2
52
53static int major, minors;
54static struct class *usb_gadget_class;
55static DEFINE_IDA(printer_ida);
56static DEFINE_MUTEX(printer_ida_lock); /* protects access do printer_ida */
57
58/*-------------------------------------------------------------------------*/
59
60struct printer_dev {
61 spinlock_t lock; /* lock this structure */
62 /* lock buffer lists during read/write calls */
63 struct mutex lock_printer_io;
64 struct usb_gadget *gadget;
65 s8 interface;
66 struct usb_ep *in_ep, *out_ep;
67
68 struct list_head rx_reqs; /* List of free RX structs */
69 struct list_head rx_reqs_active; /* List of Active RX xfers */
70 struct list_head rx_buffers; /* List of completed xfers */
71 /* wait until there is data to be read. */
72 wait_queue_head_t rx_wait;
73 struct list_head tx_reqs; /* List of free TX structs */
74 struct list_head tx_reqs_active; /* List of Active TX xfers */
75 /* Wait until there are write buffers available to use. */
76 wait_queue_head_t tx_wait;
77 /* Wait until all write buffers have been sent. */
78 wait_queue_head_t tx_flush_wait;
79 struct usb_request *current_rx_req;
80 size_t current_rx_bytes;
81 u8 *current_rx_buf;
82 u8 printer_status;
83 u8 reset_printer;
84 int minor;
85 struct cdev printer_cdev;
86 u8 printer_cdev_open;
87 wait_queue_head_t wait;
88 unsigned q_len;
89 char *pnp_string; /* We don't own memory! */
90 struct usb_function function;
91};
92
93static inline struct printer_dev *func_to_printer(struct usb_function *f)
94{
95 return container_of(f, struct printer_dev, function);
96}
97
98/*-------------------------------------------------------------------------*/
99
100/*
101 * DESCRIPTORS ... most are static, but strings and (full) configuration
102 * descriptors are built on demand.
103 */
104
105/* holds our biggest descriptor */
106#define USB_DESC_BUFSIZE 256
107#define USB_BUFSIZE 8192
108
109static struct usb_interface_descriptor intf_desc = {
110 .bLength = sizeof(intf_desc),
111 .bDescriptorType = USB_DT_INTERFACE,
112 .bNumEndpoints = 2,
113 .bInterfaceClass = USB_CLASS_PRINTER,
114 .bInterfaceSubClass = 1, /* Printer Sub-Class */
115 .bInterfaceProtocol = 2, /* Bi-Directional */
116 .iInterface = 0
117};
118
119static struct usb_endpoint_descriptor fs_ep_in_desc = {
120 .bLength = USB_DT_ENDPOINT_SIZE,
121 .bDescriptorType = USB_DT_ENDPOINT,
122 .bEndpointAddress = USB_DIR_IN,
123 .bmAttributes = USB_ENDPOINT_XFER_BULK
124};
125
126static struct usb_endpoint_descriptor fs_ep_out_desc = {
127 .bLength = USB_DT_ENDPOINT_SIZE,
128 .bDescriptorType = USB_DT_ENDPOINT,
129 .bEndpointAddress = USB_DIR_OUT,
130 .bmAttributes = USB_ENDPOINT_XFER_BULK
131};
132
133static struct usb_descriptor_header *fs_printer_function[] = {
134 (struct usb_descriptor_header *) &intf_desc,
135 (struct usb_descriptor_header *) &fs_ep_in_desc,
136 (struct usb_descriptor_header *) &fs_ep_out_desc,
137 NULL
138};
139
140/*
141 * usb 2.0 devices need to expose both high speed and full speed
142 * descriptors, unless they only run at full speed.
143 */
144
145static struct usb_endpoint_descriptor hs_ep_in_desc = {
146 .bLength = USB_DT_ENDPOINT_SIZE,
147 .bDescriptorType = USB_DT_ENDPOINT,
148 .bmAttributes = USB_ENDPOINT_XFER_BULK,
149 .wMaxPacketSize = cpu_to_le16(512)
150};
151
152static struct usb_endpoint_descriptor hs_ep_out_desc = {
153 .bLength = USB_DT_ENDPOINT_SIZE,
154 .bDescriptorType = USB_DT_ENDPOINT,
155 .bmAttributes = USB_ENDPOINT_XFER_BULK,
156 .wMaxPacketSize = cpu_to_le16(512)
157};
158
159static struct usb_descriptor_header *hs_printer_function[] = {
160 (struct usb_descriptor_header *) &intf_desc,
161 (struct usb_descriptor_header *) &hs_ep_in_desc,
162 (struct usb_descriptor_header *) &hs_ep_out_desc,
163 NULL
164};
165
166/*
167 * Added endpoint descriptors for 3.0 devices
168 */
169
170static struct usb_endpoint_descriptor ss_ep_in_desc = {
171 .bLength = USB_DT_ENDPOINT_SIZE,
172 .bDescriptorType = USB_DT_ENDPOINT,
173 .bmAttributes = USB_ENDPOINT_XFER_BULK,
174 .wMaxPacketSize = cpu_to_le16(1024),
175};
176
177static struct usb_ss_ep_comp_descriptor ss_ep_in_comp_desc = {
178 .bLength = sizeof(ss_ep_in_comp_desc),
179 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
180};
181
182static struct usb_endpoint_descriptor ss_ep_out_desc = {
183 .bLength = USB_DT_ENDPOINT_SIZE,
184 .bDescriptorType = USB_DT_ENDPOINT,
185 .bmAttributes = USB_ENDPOINT_XFER_BULK,
186 .wMaxPacketSize = cpu_to_le16(1024),
187};
188
189static struct usb_ss_ep_comp_descriptor ss_ep_out_comp_desc = {
190 .bLength = sizeof(ss_ep_out_comp_desc),
191 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
192};
193
194static struct usb_descriptor_header *ss_printer_function[] = {
195 (struct usb_descriptor_header *) &intf_desc,
196 (struct usb_descriptor_header *) &ss_ep_in_desc,
197 (struct usb_descriptor_header *) &ss_ep_in_comp_desc,
198 (struct usb_descriptor_header *) &ss_ep_out_desc,
199 (struct usb_descriptor_header *) &ss_ep_out_comp_desc,
200 NULL
201};
202
203/* maxpacket and other transfer characteristics vary by speed. */
204static inline struct usb_endpoint_descriptor *ep_desc(struct usb_gadget *gadget,
205 struct usb_endpoint_descriptor *fs,
206 struct usb_endpoint_descriptor *hs,
207 struct usb_endpoint_descriptor *ss)
208{
209 switch (gadget->speed) {
210 case USB_SPEED_SUPER:
211 return ss;
212 case USB_SPEED_HIGH:
213 return hs;
214 default:
215 return fs;
216 }
217}
218
219/*-------------------------------------------------------------------------*/
220
221static struct usb_request *
222printer_req_alloc(struct usb_ep *ep, unsigned len, gfp_t gfp_flags)
223{
224 struct usb_request *req;
225
226 req = usb_ep_alloc_request(ep, gfp_flags);
227
228 if (req != NULL) {
229 req->length = len;
230 req->buf = kmalloc(len, gfp_flags);
231 if (req->buf == NULL) {
232 usb_ep_free_request(ep, req);
233 return NULL;
234 }
235 }
236
237 return req;
238}
239
240static void
241printer_req_free(struct usb_ep *ep, struct usb_request *req)
242{
243 if (ep != NULL && req != NULL) {
244 kfree(req->buf);
245 usb_ep_free_request(ep, req);
246 }
247}
248
249/*-------------------------------------------------------------------------*/
250
251static void rx_complete(struct usb_ep *ep, struct usb_request *req)
252{
253 struct printer_dev *dev = ep->driver_data;
254 int status = req->status;
255 unsigned long flags;
256
257 spin_lock_irqsave(&dev->lock, flags);
258
259 list_del_init(&req->list); /* Remode from Active List */
260
261 switch (status) {
262
263 /* normal completion */
264 case 0:
265 if (req->actual > 0) {
266 list_add_tail(&req->list, &dev->rx_buffers);
267 DBG(dev, "G_Printer : rx length %d\n", req->actual);
268 } else {
269 list_add(&req->list, &dev->rx_reqs);
270 }
271 break;
272
273 /* software-driven interface shutdown */
274 case -ECONNRESET: /* unlink */
275 case -ESHUTDOWN: /* disconnect etc */
276 VDBG(dev, "rx shutdown, code %d\n", status);
277 list_add(&req->list, &dev->rx_reqs);
278 break;
279
280 /* for hardware automagic (such as pxa) */
281 case -ECONNABORTED: /* endpoint reset */
282 DBG(dev, "rx %s reset\n", ep->name);
283 list_add(&req->list, &dev->rx_reqs);
284 break;
285
286 /* data overrun */
287 case -EOVERFLOW:
288 fallthrough;
289
290 default:
291 DBG(dev, "rx status %d\n", status);
292 list_add(&req->list, &dev->rx_reqs);
293 break;
294 }
295
296 wake_up_interruptible(&dev->rx_wait);
297 spin_unlock_irqrestore(&dev->lock, flags);
298}
299
300static void tx_complete(struct usb_ep *ep, struct usb_request *req)
301{
302 struct printer_dev *dev = ep->driver_data;
303
304 switch (req->status) {
305 default:
306 VDBG(dev, "tx err %d\n", req->status);
307 fallthrough;
308 case -ECONNRESET: /* unlink */
309 case -ESHUTDOWN: /* disconnect etc */
310 break;
311 case 0:
312 break;
313 }
314
315 spin_lock(&dev->lock);
316 /* Take the request struct off the active list and put it on the
317 * free list.
318 */
319 list_del_init(&req->list);
320 list_add(&req->list, &dev->tx_reqs);
321 wake_up_interruptible(&dev->tx_wait);
322 if (likely(list_empty(&dev->tx_reqs_active)))
323 wake_up_interruptible(&dev->tx_flush_wait);
324
325 spin_unlock(&dev->lock);
326}
327
328/*-------------------------------------------------------------------------*/
329
330static int
331printer_open(struct inode *inode, struct file *fd)
332{
333 struct printer_dev *dev;
334 unsigned long flags;
335 int ret = -EBUSY;
336
337 dev = container_of(inode->i_cdev, struct printer_dev, printer_cdev);
338
339 spin_lock_irqsave(&dev->lock, flags);
340
341 if (dev->interface < 0) {
342 spin_unlock_irqrestore(&dev->lock, flags);
343 return -ENODEV;
344 }
345
346 if (!dev->printer_cdev_open) {
347 dev->printer_cdev_open = 1;
348 fd->private_data = dev;
349 ret = 0;
350 /* Change the printer status to show that it's on-line. */
351 dev->printer_status |= PRINTER_SELECTED;
352 }
353
354 spin_unlock_irqrestore(&dev->lock, flags);
355
356 DBG(dev, "printer_open returned %x\n", ret);
357 return ret;
358}
359
360static int
361printer_close(struct inode *inode, struct file *fd)
362{
363 struct printer_dev *dev = fd->private_data;
364 unsigned long flags;
365
366 spin_lock_irqsave(&dev->lock, flags);
367 dev->printer_cdev_open = 0;
368 fd->private_data = NULL;
369 /* Change printer status to show that the printer is off-line. */
370 dev->printer_status &= ~PRINTER_SELECTED;
371 spin_unlock_irqrestore(&dev->lock, flags);
372
373 DBG(dev, "printer_close\n");
374
375 return 0;
376}
377
378/* This function must be called with interrupts turned off. */
379static void
380setup_rx_reqs(struct printer_dev *dev)
381{
382 struct usb_request *req;
383
384 while (likely(!list_empty(&dev->rx_reqs))) {
385 int error;
386
387 req = container_of(dev->rx_reqs.next,
388 struct usb_request, list);
389 list_del_init(&req->list);
390
391 /* The USB Host sends us whatever amount of data it wants to
392 * so we always set the length field to the full USB_BUFSIZE.
393 * If the amount of data is more than the read() caller asked
394 * for it will be stored in the request buffer until it is
395 * asked for by read().
396 */
397 req->length = USB_BUFSIZE;
398 req->complete = rx_complete;
399
400 /* here, we unlock, and only unlock, to avoid deadlock. */
401 spin_unlock(&dev->lock);
402 error = usb_ep_queue(dev->out_ep, req, GFP_ATOMIC);
403 spin_lock(&dev->lock);
404 if (error) {
405 DBG(dev, "rx submit --> %d\n", error);
406 list_add(&req->list, &dev->rx_reqs);
407 break;
408 }
409 /* if the req is empty, then add it into dev->rx_reqs_active. */
410 else if (list_empty(&req->list))
411 list_add(&req->list, &dev->rx_reqs_active);
412 }
413}
414
415static ssize_t
416printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
417{
418 struct printer_dev *dev = fd->private_data;
419 unsigned long flags;
420 size_t size;
421 size_t bytes_copied;
422 struct usb_request *req;
423 /* This is a pointer to the current USB rx request. */
424 struct usb_request *current_rx_req;
425 /* This is the number of bytes in the current rx buffer. */
426 size_t current_rx_bytes;
427 /* This is a pointer to the current rx buffer. */
428 u8 *current_rx_buf;
429
430 if (len == 0)
431 return -EINVAL;
432
433 DBG(dev, "printer_read trying to read %d bytes\n", (int)len);
434
435 mutex_lock(&dev->lock_printer_io);
436 spin_lock_irqsave(&dev->lock, flags);
437
438 if (dev->interface < 0) {
439 spin_unlock_irqrestore(&dev->lock, flags);
440 mutex_unlock(&dev->lock_printer_io);
441 return -ENODEV;
442 }
443
444 /* We will use this flag later to check if a printer reset happened
445 * after we turn interrupts back on.
446 */
447 dev->reset_printer = 0;
448
449 setup_rx_reqs(dev);
450
451 bytes_copied = 0;
452 current_rx_req = dev->current_rx_req;
453 current_rx_bytes = dev->current_rx_bytes;
454 current_rx_buf = dev->current_rx_buf;
455 dev->current_rx_req = NULL;
456 dev->current_rx_bytes = 0;
457 dev->current_rx_buf = NULL;
458
459 /* Check if there is any data in the read buffers. Please note that
460 * current_rx_bytes is the number of bytes in the current rx buffer.
461 * If it is zero then check if there are any other rx_buffers that
462 * are on the completed list. We are only out of data if all rx
463 * buffers are empty.
464 */
465 if ((current_rx_bytes == 0) &&
466 (likely(list_empty(&dev->rx_buffers)))) {
467 /* Turn interrupts back on before sleeping. */
468 spin_unlock_irqrestore(&dev->lock, flags);
469
470 /*
471 * If no data is available check if this is a NON-Blocking
472 * call or not.
473 */
474 if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) {
475 mutex_unlock(&dev->lock_printer_io);
476 return -EAGAIN;
477 }
478
479 /* Sleep until data is available */
480 wait_event_interruptible(dev->rx_wait,
481 (likely(!list_empty(&dev->rx_buffers))));
482 spin_lock_irqsave(&dev->lock, flags);
483 }
484
485 /* We have data to return then copy it to the caller's buffer.*/
486 while ((current_rx_bytes || likely(!list_empty(&dev->rx_buffers)))
487 && len) {
488 if (current_rx_bytes == 0) {
489 req = container_of(dev->rx_buffers.next,
490 struct usb_request, list);
491 list_del_init(&req->list);
492
493 if (req->actual && req->buf) {
494 current_rx_req = req;
495 current_rx_bytes = req->actual;
496 current_rx_buf = req->buf;
497 } else {
498 list_add(&req->list, &dev->rx_reqs);
499 continue;
500 }
501 }
502
503 /* Don't leave irqs off while doing memory copies */
504 spin_unlock_irqrestore(&dev->lock, flags);
505
506 if (len > current_rx_bytes)
507 size = current_rx_bytes;
508 else
509 size = len;
510
511 size -= copy_to_user(buf, current_rx_buf, size);
512 bytes_copied += size;
513 len -= size;
514 buf += size;
515
516 spin_lock_irqsave(&dev->lock, flags);
517
518 /* We've disconnected or reset so return. */
519 if (dev->reset_printer) {
520 list_add(¤t_rx_req->list, &dev->rx_reqs);
521 spin_unlock_irqrestore(&dev->lock, flags);
522 mutex_unlock(&dev->lock_printer_io);
523 return -EAGAIN;
524 }
525
526 /* If we not returning all the data left in this RX request
527 * buffer then adjust the amount of data left in the buffer.
528 * Othewise if we are done with this RX request buffer then
529 * requeue it to get any incoming data from the USB host.
530 */
531 if (size < current_rx_bytes) {
532 current_rx_bytes -= size;
533 current_rx_buf += size;
534 } else {
535 list_add(¤t_rx_req->list, &dev->rx_reqs);
536 current_rx_bytes = 0;
537 current_rx_buf = NULL;
538 current_rx_req = NULL;
539 }
540 }
541
542 dev->current_rx_req = current_rx_req;
543 dev->current_rx_bytes = current_rx_bytes;
544 dev->current_rx_buf = current_rx_buf;
545
546 spin_unlock_irqrestore(&dev->lock, flags);
547 mutex_unlock(&dev->lock_printer_io);
548
549 DBG(dev, "printer_read returned %d bytes\n", (int)bytes_copied);
550
551 if (bytes_copied)
552 return bytes_copied;
553 else
554 return -EAGAIN;
555}
556
557static ssize_t
558printer_write(struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
559{
560 struct printer_dev *dev = fd->private_data;
561 unsigned long flags;
562 size_t size; /* Amount of data in a TX request. */
563 size_t bytes_copied = 0;
564 struct usb_request *req;
565 int value;
566
567 DBG(dev, "printer_write trying to send %d bytes\n", (int)len);
568
569 if (len == 0)
570 return -EINVAL;
571
572 mutex_lock(&dev->lock_printer_io);
573 spin_lock_irqsave(&dev->lock, flags);
574
575 if (dev->interface < 0) {
576 spin_unlock_irqrestore(&dev->lock, flags);
577 mutex_unlock(&dev->lock_printer_io);
578 return -ENODEV;
579 }
580
581 /* Check if a printer reset happens while we have interrupts on */
582 dev->reset_printer = 0;
583
584 /* Check if there is any available write buffers */
585 if (likely(list_empty(&dev->tx_reqs))) {
586 /* Turn interrupts back on before sleeping. */
587 spin_unlock_irqrestore(&dev->lock, flags);
588
589 /*
590 * If write buffers are available check if this is
591 * a NON-Blocking call or not.
592 */
593 if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) {
594 mutex_unlock(&dev->lock_printer_io);
595 return -EAGAIN;
596 }
597
598 /* Sleep until a write buffer is available */
599 wait_event_interruptible(dev->tx_wait,
600 (likely(!list_empty(&dev->tx_reqs))));
601 spin_lock_irqsave(&dev->lock, flags);
602 }
603
604 while (likely(!list_empty(&dev->tx_reqs)) && len) {
605
606 if (len > USB_BUFSIZE)
607 size = USB_BUFSIZE;
608 else
609 size = len;
610
611 req = container_of(dev->tx_reqs.next, struct usb_request,
612 list);
613 list_del_init(&req->list);
614
615 req->complete = tx_complete;
616 req->length = size;
617
618 /* Check if we need to send a zero length packet. */
619 if (len > size)
620 /* They will be more TX requests so no yet. */
621 req->zero = 0;
622 else
623 /* If the data amount is not a multiple of the
624 * maxpacket size then send a zero length packet.
625 */
626 req->zero = ((len % dev->in_ep->maxpacket) == 0);
627
628 /* Don't leave irqs off while doing memory copies */
629 spin_unlock_irqrestore(&dev->lock, flags);
630
631 if (copy_from_user(req->buf, buf, size)) {
632 list_add(&req->list, &dev->tx_reqs);
633 mutex_unlock(&dev->lock_printer_io);
634 return bytes_copied;
635 }
636
637 bytes_copied += size;
638 len -= size;
639 buf += size;
640
641 spin_lock_irqsave(&dev->lock, flags);
642
643 /* We've disconnected or reset so free the req and buffer */
644 if (dev->reset_printer) {
645 list_add(&req->list, &dev->tx_reqs);
646 spin_unlock_irqrestore(&dev->lock, flags);
647 mutex_unlock(&dev->lock_printer_io);
648 return -EAGAIN;
649 }
650
651 list_add(&req->list, &dev->tx_reqs_active);
652
653 /* here, we unlock, and only unlock, to avoid deadlock. */
654 spin_unlock(&dev->lock);
655 value = usb_ep_queue(dev->in_ep, req, GFP_ATOMIC);
656 spin_lock(&dev->lock);
657 if (value) {
658 list_del(&req->list);
659 list_add(&req->list, &dev->tx_reqs);
660 spin_unlock_irqrestore(&dev->lock, flags);
661 mutex_unlock(&dev->lock_printer_io);
662 return -EAGAIN;
663 }
664 }
665
666 spin_unlock_irqrestore(&dev->lock, flags);
667 mutex_unlock(&dev->lock_printer_io);
668
669 DBG(dev, "printer_write sent %d bytes\n", (int)bytes_copied);
670
671 if (bytes_copied)
672 return bytes_copied;
673 else
674 return -EAGAIN;
675}
676
677static int
678printer_fsync(struct file *fd, loff_t start, loff_t end, int datasync)
679{
680 struct printer_dev *dev = fd->private_data;
681 struct inode *inode = file_inode(fd);
682 unsigned long flags;
683 int tx_list_empty;
684
685 inode_lock(inode);
686 spin_lock_irqsave(&dev->lock, flags);
687
688 if (dev->interface < 0) {
689 spin_unlock_irqrestore(&dev->lock, flags);
690 inode_unlock(inode);
691 return -ENODEV;
692 }
693
694 tx_list_empty = (likely(list_empty(&dev->tx_reqs)));
695 spin_unlock_irqrestore(&dev->lock, flags);
696
697 if (!tx_list_empty) {
698 /* Sleep until all data has been sent */
699 wait_event_interruptible(dev->tx_flush_wait,
700 (likely(list_empty(&dev->tx_reqs_active))));
701 }
702 inode_unlock(inode);
703
704 return 0;
705}
706
707static __poll_t
708printer_poll(struct file *fd, poll_table *wait)
709{
710 struct printer_dev *dev = fd->private_data;
711 unsigned long flags;
712 __poll_t status = 0;
713
714 mutex_lock(&dev->lock_printer_io);
715 spin_lock_irqsave(&dev->lock, flags);
716
717 if (dev->interface < 0) {
718 spin_unlock_irqrestore(&dev->lock, flags);
719 mutex_unlock(&dev->lock_printer_io);
720 return EPOLLERR | EPOLLHUP;
721 }
722
723 setup_rx_reqs(dev);
724 spin_unlock_irqrestore(&dev->lock, flags);
725 mutex_unlock(&dev->lock_printer_io);
726
727 poll_wait(fd, &dev->rx_wait, wait);
728 poll_wait(fd, &dev->tx_wait, wait);
729
730 spin_lock_irqsave(&dev->lock, flags);
731 if (likely(!list_empty(&dev->tx_reqs)))
732 status |= EPOLLOUT | EPOLLWRNORM;
733
734 if (likely(dev->current_rx_bytes) ||
735 likely(!list_empty(&dev->rx_buffers)))
736 status |= EPOLLIN | EPOLLRDNORM;
737
738 spin_unlock_irqrestore(&dev->lock, flags);
739
740 return status;
741}
742
743static long
744printer_ioctl(struct file *fd, unsigned int code, unsigned long arg)
745{
746 struct printer_dev *dev = fd->private_data;
747 unsigned long flags;
748 int status = 0;
749
750 DBG(dev, "printer_ioctl: cmd=0x%4.4x, arg=%lu\n", code, arg);
751
752 /* handle ioctls */
753
754 spin_lock_irqsave(&dev->lock, flags);
755
756 if (dev->interface < 0) {
757 spin_unlock_irqrestore(&dev->lock, flags);
758 return -ENODEV;
759 }
760
761 switch (code) {
762 case GADGET_GET_PRINTER_STATUS:
763 status = (int)dev->printer_status;
764 break;
765 case GADGET_SET_PRINTER_STATUS:
766 dev->printer_status = (u8)arg;
767 break;
768 default:
769 /* could not handle ioctl */
770 DBG(dev, "printer_ioctl: ERROR cmd=0x%4.4xis not supported\n",
771 code);
772 status = -ENOTTY;
773 }
774
775 spin_unlock_irqrestore(&dev->lock, flags);
776
777 return status;
778}
779
780/* used after endpoint configuration */
781static const struct file_operations printer_io_operations = {
782 .owner = THIS_MODULE,
783 .open = printer_open,
784 .read = printer_read,
785 .write = printer_write,
786 .fsync = printer_fsync,
787 .poll = printer_poll,
788 .unlocked_ioctl = printer_ioctl,
789 .release = printer_close,
790 .llseek = noop_llseek,
791};
792
793/*-------------------------------------------------------------------------*/
794
795static int
796set_printer_interface(struct printer_dev *dev)
797{
798 int result = 0;
799
800 dev->in_ep->desc = ep_desc(dev->gadget, &fs_ep_in_desc, &hs_ep_in_desc,
801 &ss_ep_in_desc);
802 dev->in_ep->driver_data = dev;
803
804 dev->out_ep->desc = ep_desc(dev->gadget, &fs_ep_out_desc,
805 &hs_ep_out_desc, &ss_ep_out_desc);
806 dev->out_ep->driver_data = dev;
807
808 result = usb_ep_enable(dev->in_ep);
809 if (result != 0) {
810 DBG(dev, "enable %s --> %d\n", dev->in_ep->name, result);
811 goto done;
812 }
813
814 result = usb_ep_enable(dev->out_ep);
815 if (result != 0) {
816 DBG(dev, "enable %s --> %d\n", dev->in_ep->name, result);
817 goto done;
818 }
819
820done:
821 /* on error, disable any endpoints */
822 if (result != 0) {
823 (void) usb_ep_disable(dev->in_ep);
824 (void) usb_ep_disable(dev->out_ep);
825 dev->in_ep->desc = NULL;
826 dev->out_ep->desc = NULL;
827 }
828
829 /* caller is responsible for cleanup on error */
830 return result;
831}
832
833static void printer_reset_interface(struct printer_dev *dev)
834{
835 unsigned long flags;
836
837 if (dev->interface < 0)
838 return;
839
840 DBG(dev, "%s\n", __func__);
841
842 if (dev->in_ep->desc)
843 usb_ep_disable(dev->in_ep);
844
845 if (dev->out_ep->desc)
846 usb_ep_disable(dev->out_ep);
847
848 spin_lock_irqsave(&dev->lock, flags);
849 dev->in_ep->desc = NULL;
850 dev->out_ep->desc = NULL;
851 dev->interface = -1;
852 spin_unlock_irqrestore(&dev->lock, flags);
853}
854
855/* Change our operational Interface. */
856static int set_interface(struct printer_dev *dev, unsigned number)
857{
858 int result = 0;
859
860 /* Free the current interface */
861 printer_reset_interface(dev);
862
863 result = set_printer_interface(dev);
864 if (result)
865 printer_reset_interface(dev);
866 else
867 dev->interface = number;
868
869 if (!result)
870 INFO(dev, "Using interface %x\n", number);
871
872 return result;
873}
874
875static void printer_soft_reset(struct printer_dev *dev)
876{
877 struct usb_request *req;
878
879 INFO(dev, "Received Printer Reset Request\n");
880
881 if (usb_ep_disable(dev->in_ep))
882 DBG(dev, "Failed to disable USB in_ep\n");
883 if (usb_ep_disable(dev->out_ep))
884 DBG(dev, "Failed to disable USB out_ep\n");
885
886 if (dev->current_rx_req != NULL) {
887 list_add(&dev->current_rx_req->list, &dev->rx_reqs);
888 dev->current_rx_req = NULL;
889 }
890 dev->current_rx_bytes = 0;
891 dev->current_rx_buf = NULL;
892 dev->reset_printer = 1;
893
894 while (likely(!(list_empty(&dev->rx_buffers)))) {
895 req = container_of(dev->rx_buffers.next, struct usb_request,
896 list);
897 list_del_init(&req->list);
898 list_add(&req->list, &dev->rx_reqs);
899 }
900
901 while (likely(!(list_empty(&dev->rx_reqs_active)))) {
902 req = container_of(dev->rx_buffers.next, struct usb_request,
903 list);
904 list_del_init(&req->list);
905 list_add(&req->list, &dev->rx_reqs);
906 }
907
908 while (likely(!(list_empty(&dev->tx_reqs_active)))) {
909 req = container_of(dev->tx_reqs_active.next,
910 struct usb_request, list);
911 list_del_init(&req->list);
912 list_add(&req->list, &dev->tx_reqs);
913 }
914
915 if (usb_ep_enable(dev->in_ep))
916 DBG(dev, "Failed to enable USB in_ep\n");
917 if (usb_ep_enable(dev->out_ep))
918 DBG(dev, "Failed to enable USB out_ep\n");
919
920 wake_up_interruptible(&dev->rx_wait);
921 wake_up_interruptible(&dev->tx_wait);
922 wake_up_interruptible(&dev->tx_flush_wait);
923}
924
925/*-------------------------------------------------------------------------*/
926
927static bool gprinter_req_match(struct usb_function *f,
928 const struct usb_ctrlrequest *ctrl,
929 bool config0)
930{
931 struct printer_dev *dev = func_to_printer(f);
932 u16 w_index = le16_to_cpu(ctrl->wIndex);
933 u16 w_value = le16_to_cpu(ctrl->wValue);
934 u16 w_length = le16_to_cpu(ctrl->wLength);
935
936 if (config0)
937 return false;
938
939 if ((ctrl->bRequestType & USB_RECIP_MASK) != USB_RECIP_INTERFACE ||
940 (ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS)
941 return false;
942
943 switch (ctrl->bRequest) {
944 case GET_DEVICE_ID:
945 w_index >>= 8;
946 if (USB_DIR_IN & ctrl->bRequestType)
947 break;
948 return false;
949 case GET_PORT_STATUS:
950 if (!w_value && w_length == 1 &&
951 (USB_DIR_IN & ctrl->bRequestType))
952 break;
953 return false;
954 case SOFT_RESET:
955 if (!w_value && !w_length &&
956 !(USB_DIR_IN & ctrl->bRequestType))
957 break;
958 fallthrough;
959 default:
960 return false;
961 }
962 return w_index == dev->interface;
963}
964
965/*
966 * The setup() callback implements all the ep0 functionality that's not
967 * handled lower down.
968 */
969static int printer_func_setup(struct usb_function *f,
970 const struct usb_ctrlrequest *ctrl)
971{
972 struct printer_dev *dev = func_to_printer(f);
973 struct usb_composite_dev *cdev = f->config->cdev;
974 struct usb_request *req = cdev->req;
975 u8 *buf = req->buf;
976 int value = -EOPNOTSUPP;
977 u16 wIndex = le16_to_cpu(ctrl->wIndex);
978 u16 wValue = le16_to_cpu(ctrl->wValue);
979 u16 wLength = le16_to_cpu(ctrl->wLength);
980
981 DBG(dev, "ctrl req%02x.%02x v%04x i%04x l%d\n",
982 ctrl->bRequestType, ctrl->bRequest, wValue, wIndex, wLength);
983
984 switch (ctrl->bRequestType&USB_TYPE_MASK) {
985 case USB_TYPE_CLASS:
986 switch (ctrl->bRequest) {
987 case GET_DEVICE_ID: /* Get the IEEE-1284 PNP String */
988 /* Only one printer interface is supported. */
989 if ((wIndex>>8) != dev->interface)
990 break;
991
992 if (!dev->pnp_string) {
993 value = 0;
994 break;
995 }
996 value = strlen(dev->pnp_string);
997 buf[0] = (value >> 8) & 0xFF;
998 buf[1] = value & 0xFF;
999 memcpy(buf + 2, dev->pnp_string, value);
1000 DBG(dev, "1284 PNP String: %x %s\n", value,
1001 dev->pnp_string);
1002 break;
1003
1004 case GET_PORT_STATUS: /* Get Port Status */
1005 /* Only one printer interface is supported. */
1006 if (wIndex != dev->interface)
1007 break;
1008
1009 buf[0] = dev->printer_status;
1010 value = min_t(u16, wLength, 1);
1011 break;
1012
1013 case SOFT_RESET: /* Soft Reset */
1014 /* Only one printer interface is supported. */
1015 if (wIndex != dev->interface)
1016 break;
1017
1018 printer_soft_reset(dev);
1019
1020 value = 0;
1021 break;
1022
1023 default:
1024 goto unknown;
1025 }
1026 break;
1027
1028 default:
1029unknown:
1030 VDBG(dev,
1031 "unknown ctrl req%02x.%02x v%04x i%04x l%d\n",
1032 ctrl->bRequestType, ctrl->bRequest,
1033 wValue, wIndex, wLength);
1034 break;
1035 }
1036 /* host either stalls (value < 0) or reports success */
1037 if (value >= 0) {
1038 req->length = value;
1039 req->zero = value < wLength;
1040 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
1041 if (value < 0) {
1042 ERROR(dev, "%s:%d Error!\n", __func__, __LINE__);
1043 req->status = 0;
1044 }
1045 }
1046 return value;
1047}
1048
1049static int printer_func_bind(struct usb_configuration *c,
1050 struct usb_function *f)
1051{
1052 struct usb_gadget *gadget = c->cdev->gadget;
1053 struct printer_dev *dev = func_to_printer(f);
1054 struct device *pdev;
1055 struct usb_composite_dev *cdev = c->cdev;
1056 struct usb_ep *in_ep;
1057 struct usb_ep *out_ep = NULL;
1058 struct usb_request *req;
1059 dev_t devt;
1060 int id;
1061 int ret;
1062 u32 i;
1063
1064 id = usb_interface_id(c, f);
1065 if (id < 0)
1066 return id;
1067 intf_desc.bInterfaceNumber = id;
1068
1069 /* finish hookup to lower layer ... */
1070 dev->gadget = gadget;
1071
1072 /* all we really need is bulk IN/OUT */
1073 in_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_in_desc);
1074 if (!in_ep) {
1075autoconf_fail:
1076 dev_err(&cdev->gadget->dev, "can't autoconfigure on %s\n",
1077 cdev->gadget->name);
1078 return -ENODEV;
1079 }
1080
1081 out_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_out_desc);
1082 if (!out_ep)
1083 goto autoconf_fail;
1084
1085 /* assumes that all endpoints are dual-speed */
1086 hs_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
1087 hs_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
1088 ss_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
1089 ss_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
1090
1091 ret = usb_assign_descriptors(f, fs_printer_function,
1092 hs_printer_function, ss_printer_function, NULL);
1093 if (ret)
1094 return ret;
1095
1096 dev->in_ep = in_ep;
1097 dev->out_ep = out_ep;
1098
1099 ret = -ENOMEM;
1100 for (i = 0; i < dev->q_len; i++) {
1101 req = printer_req_alloc(dev->in_ep, USB_BUFSIZE, GFP_KERNEL);
1102 if (!req)
1103 goto fail_tx_reqs;
1104 list_add(&req->list, &dev->tx_reqs);
1105 }
1106
1107 for (i = 0; i < dev->q_len; i++) {
1108 req = printer_req_alloc(dev->out_ep, USB_BUFSIZE, GFP_KERNEL);
1109 if (!req)
1110 goto fail_rx_reqs;
1111 list_add(&req->list, &dev->rx_reqs);
1112 }
1113
1114 /* Setup the sysfs files for the printer gadget. */
1115 devt = MKDEV(major, dev->minor);
1116 pdev = device_create(usb_gadget_class, NULL, devt,
1117 NULL, "g_printer%d", dev->minor);
1118 if (IS_ERR(pdev)) {
1119 ERROR(dev, "Failed to create device: g_printer\n");
1120 ret = PTR_ERR(pdev);
1121 goto fail_rx_reqs;
1122 }
1123
1124 /*
1125 * Register a character device as an interface to a user mode
1126 * program that handles the printer specific functionality.
1127 */
1128 cdev_init(&dev->printer_cdev, &printer_io_operations);
1129 dev->printer_cdev.owner = THIS_MODULE;
1130 ret = cdev_add(&dev->printer_cdev, devt, 1);
1131 if (ret) {
1132 ERROR(dev, "Failed to open char device\n");
1133 goto fail_cdev_add;
1134 }
1135
1136 return 0;
1137
1138fail_cdev_add:
1139 device_destroy(usb_gadget_class, devt);
1140
1141fail_rx_reqs:
1142 while (!list_empty(&dev->rx_reqs)) {
1143 req = container_of(dev->rx_reqs.next, struct usb_request, list);
1144 list_del(&req->list);
1145 printer_req_free(dev->out_ep, req);
1146 }
1147
1148fail_tx_reqs:
1149 while (!list_empty(&dev->tx_reqs)) {
1150 req = container_of(dev->tx_reqs.next, struct usb_request, list);
1151 list_del(&req->list);
1152 printer_req_free(dev->in_ep, req);
1153 }
1154
1155 return ret;
1156
1157}
1158
1159static int printer_func_set_alt(struct usb_function *f,
1160 unsigned intf, unsigned alt)
1161{
1162 struct printer_dev *dev = func_to_printer(f);
1163 int ret = -ENOTSUPP;
1164
1165 if (!alt)
1166 ret = set_interface(dev, intf);
1167
1168 return ret;
1169}
1170
1171static void printer_func_disable(struct usb_function *f)
1172{
1173 struct printer_dev *dev = func_to_printer(f);
1174
1175 DBG(dev, "%s\n", __func__);
1176
1177 printer_reset_interface(dev);
1178}
1179
1180static inline struct f_printer_opts
1181*to_f_printer_opts(struct config_item *item)
1182{
1183 return container_of(to_config_group(item), struct f_printer_opts,
1184 func_inst.group);
1185}
1186
1187static void printer_attr_release(struct config_item *item)
1188{
1189 struct f_printer_opts *opts = to_f_printer_opts(item);
1190
1191 usb_put_function_instance(&opts->func_inst);
1192}
1193
1194static struct configfs_item_operations printer_item_ops = {
1195 .release = printer_attr_release,
1196};
1197
1198static ssize_t f_printer_opts_pnp_string_show(struct config_item *item,
1199 char *page)
1200{
1201 struct f_printer_opts *opts = to_f_printer_opts(item);
1202 int result = 0;
1203
1204 mutex_lock(&opts->lock);
1205 if (!opts->pnp_string)
1206 goto unlock;
1207
1208 result = strlcpy(page, opts->pnp_string, PAGE_SIZE);
1209 if (result >= PAGE_SIZE) {
1210 result = PAGE_SIZE;
1211 } else if (page[result - 1] != '\n' && result + 1 < PAGE_SIZE) {
1212 page[result++] = '\n';
1213 page[result] = '\0';
1214 }
1215
1216unlock:
1217 mutex_unlock(&opts->lock);
1218
1219 return result;
1220}
1221
1222static ssize_t f_printer_opts_pnp_string_store(struct config_item *item,
1223 const char *page, size_t len)
1224{
1225 struct f_printer_opts *opts = to_f_printer_opts(item);
1226 char *new_pnp;
1227 int result;
1228
1229 mutex_lock(&opts->lock);
1230
1231 new_pnp = kstrndup(page, len, GFP_KERNEL);
1232 if (!new_pnp) {
1233 result = -ENOMEM;
1234 goto unlock;
1235 }
1236
1237 if (opts->pnp_string_allocated)
1238 kfree(opts->pnp_string);
1239
1240 opts->pnp_string_allocated = true;
1241 opts->pnp_string = new_pnp;
1242 result = len;
1243unlock:
1244 mutex_unlock(&opts->lock);
1245
1246 return result;
1247}
1248
1249CONFIGFS_ATTR(f_printer_opts_, pnp_string);
1250
1251static ssize_t f_printer_opts_q_len_show(struct config_item *item,
1252 char *page)
1253{
1254 struct f_printer_opts *opts = to_f_printer_opts(item);
1255 int result;
1256
1257 mutex_lock(&opts->lock);
1258 result = sprintf(page, "%d\n", opts->q_len);
1259 mutex_unlock(&opts->lock);
1260
1261 return result;
1262}
1263
1264static ssize_t f_printer_opts_q_len_store(struct config_item *item,
1265 const char *page, size_t len)
1266{
1267 struct f_printer_opts *opts = to_f_printer_opts(item);
1268 int ret;
1269 u16 num;
1270
1271 mutex_lock(&opts->lock);
1272 if (opts->refcnt) {
1273 ret = -EBUSY;
1274 goto end;
1275 }
1276
1277 ret = kstrtou16(page, 0, &num);
1278 if (ret)
1279 goto end;
1280
1281 opts->q_len = (unsigned)num;
1282 ret = len;
1283end:
1284 mutex_unlock(&opts->lock);
1285 return ret;
1286}
1287
1288CONFIGFS_ATTR(f_printer_opts_, q_len);
1289
1290static struct configfs_attribute *printer_attrs[] = {
1291 &f_printer_opts_attr_pnp_string,
1292 &f_printer_opts_attr_q_len,
1293 NULL,
1294};
1295
1296static const struct config_item_type printer_func_type = {
1297 .ct_item_ops = &printer_item_ops,
1298 .ct_attrs = printer_attrs,
1299 .ct_owner = THIS_MODULE,
1300};
1301
1302static inline int gprinter_get_minor(void)
1303{
1304 int ret;
1305
1306 ret = ida_simple_get(&printer_ida, 0, 0, GFP_KERNEL);
1307 if (ret >= PRINTER_MINORS) {
1308 ida_simple_remove(&printer_ida, ret);
1309 ret = -ENODEV;
1310 }
1311
1312 return ret;
1313}
1314
1315static inline void gprinter_put_minor(int minor)
1316{
1317 ida_simple_remove(&printer_ida, minor);
1318}
1319
1320static int gprinter_setup(int);
1321static void gprinter_cleanup(void);
1322
1323static void gprinter_free_inst(struct usb_function_instance *f)
1324{
1325 struct f_printer_opts *opts;
1326
1327 opts = container_of(f, struct f_printer_opts, func_inst);
1328
1329 mutex_lock(&printer_ida_lock);
1330
1331 gprinter_put_minor(opts->minor);
1332 if (ida_is_empty(&printer_ida))
1333 gprinter_cleanup();
1334
1335 mutex_unlock(&printer_ida_lock);
1336
1337 if (opts->pnp_string_allocated)
1338 kfree(opts->pnp_string);
1339 kfree(opts);
1340}
1341
1342static struct usb_function_instance *gprinter_alloc_inst(void)
1343{
1344 struct f_printer_opts *opts;
1345 struct usb_function_instance *ret;
1346 int status = 0;
1347
1348 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1349 if (!opts)
1350 return ERR_PTR(-ENOMEM);
1351
1352 mutex_init(&opts->lock);
1353 opts->func_inst.free_func_inst = gprinter_free_inst;
1354 ret = &opts->func_inst;
1355
1356 mutex_lock(&printer_ida_lock);
1357
1358 if (ida_is_empty(&printer_ida)) {
1359 status = gprinter_setup(PRINTER_MINORS);
1360 if (status) {
1361 ret = ERR_PTR(status);
1362 kfree(opts);
1363 goto unlock;
1364 }
1365 }
1366
1367 opts->minor = gprinter_get_minor();
1368 if (opts->minor < 0) {
1369 ret = ERR_PTR(opts->minor);
1370 kfree(opts);
1371 if (ida_is_empty(&printer_ida))
1372 gprinter_cleanup();
1373 goto unlock;
1374 }
1375 config_group_init_type_name(&opts->func_inst.group, "",
1376 &printer_func_type);
1377
1378unlock:
1379 mutex_unlock(&printer_ida_lock);
1380 return ret;
1381}
1382
1383static void gprinter_free(struct usb_function *f)
1384{
1385 struct printer_dev *dev = func_to_printer(f);
1386 struct f_printer_opts *opts;
1387
1388 opts = container_of(f->fi, struct f_printer_opts, func_inst);
1389 kfree(dev);
1390 mutex_lock(&opts->lock);
1391 --opts->refcnt;
1392 mutex_unlock(&opts->lock);
1393}
1394
1395static void printer_func_unbind(struct usb_configuration *c,
1396 struct usb_function *f)
1397{
1398 struct printer_dev *dev;
1399 struct usb_request *req;
1400
1401 dev = func_to_printer(f);
1402
1403 device_destroy(usb_gadget_class, MKDEV(major, dev->minor));
1404
1405 /* Remove Character Device */
1406 cdev_del(&dev->printer_cdev);
1407
1408 /* we must already have been disconnected ... no i/o may be active */
1409 WARN_ON(!list_empty(&dev->tx_reqs_active));
1410 WARN_ON(!list_empty(&dev->rx_reqs_active));
1411
1412 /* Free all memory for this driver. */
1413 while (!list_empty(&dev->tx_reqs)) {
1414 req = container_of(dev->tx_reqs.next, struct usb_request,
1415 list);
1416 list_del(&req->list);
1417 printer_req_free(dev->in_ep, req);
1418 }
1419
1420 if (dev->current_rx_req != NULL)
1421 printer_req_free(dev->out_ep, dev->current_rx_req);
1422
1423 while (!list_empty(&dev->rx_reqs)) {
1424 req = container_of(dev->rx_reqs.next,
1425 struct usb_request, list);
1426 list_del(&req->list);
1427 printer_req_free(dev->out_ep, req);
1428 }
1429
1430 while (!list_empty(&dev->rx_buffers)) {
1431 req = container_of(dev->rx_buffers.next,
1432 struct usb_request, list);
1433 list_del(&req->list);
1434 printer_req_free(dev->out_ep, req);
1435 }
1436 usb_free_all_descriptors(f);
1437}
1438
1439static struct usb_function *gprinter_alloc(struct usb_function_instance *fi)
1440{
1441 struct printer_dev *dev;
1442 struct f_printer_opts *opts;
1443
1444 opts = container_of(fi, struct f_printer_opts, func_inst);
1445
1446 mutex_lock(&opts->lock);
1447 if (opts->minor >= minors) {
1448 mutex_unlock(&opts->lock);
1449 return ERR_PTR(-ENOENT);
1450 }
1451
1452 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1453 if (!dev) {
1454 mutex_unlock(&opts->lock);
1455 return ERR_PTR(-ENOMEM);
1456 }
1457
1458 ++opts->refcnt;
1459 dev->minor = opts->minor;
1460 dev->pnp_string = opts->pnp_string;
1461 dev->q_len = opts->q_len;
1462 mutex_unlock(&opts->lock);
1463
1464 dev->function.name = "printer";
1465 dev->function.bind = printer_func_bind;
1466 dev->function.setup = printer_func_setup;
1467 dev->function.unbind = printer_func_unbind;
1468 dev->function.set_alt = printer_func_set_alt;
1469 dev->function.disable = printer_func_disable;
1470 dev->function.req_match = gprinter_req_match;
1471 dev->function.free_func = gprinter_free;
1472
1473 INIT_LIST_HEAD(&dev->tx_reqs);
1474 INIT_LIST_HEAD(&dev->rx_reqs);
1475 INIT_LIST_HEAD(&dev->rx_buffers);
1476 INIT_LIST_HEAD(&dev->tx_reqs_active);
1477 INIT_LIST_HEAD(&dev->rx_reqs_active);
1478
1479 spin_lock_init(&dev->lock);
1480 mutex_init(&dev->lock_printer_io);
1481 init_waitqueue_head(&dev->rx_wait);
1482 init_waitqueue_head(&dev->tx_wait);
1483 init_waitqueue_head(&dev->tx_flush_wait);
1484
1485 dev->interface = -1;
1486 dev->printer_cdev_open = 0;
1487 dev->printer_status = PRINTER_NOT_ERROR;
1488 dev->current_rx_req = NULL;
1489 dev->current_rx_bytes = 0;
1490 dev->current_rx_buf = NULL;
1491
1492 return &dev->function;
1493}
1494
1495DECLARE_USB_FUNCTION_INIT(printer, gprinter_alloc_inst, gprinter_alloc);
1496MODULE_LICENSE("GPL");
1497MODULE_AUTHOR("Craig Nadler");
1498
1499static int gprinter_setup(int count)
1500{
1501 int status;
1502 dev_t devt;
1503
1504 usb_gadget_class = class_create(THIS_MODULE, "usb_printer_gadget");
1505 if (IS_ERR(usb_gadget_class)) {
1506 status = PTR_ERR(usb_gadget_class);
1507 usb_gadget_class = NULL;
1508 pr_err("unable to create usb_gadget class %d\n", status);
1509 return status;
1510 }
1511
1512 status = alloc_chrdev_region(&devt, 0, count, "USB printer gadget");
1513 if (status) {
1514 pr_err("alloc_chrdev_region %d\n", status);
1515 class_destroy(usb_gadget_class);
1516 usb_gadget_class = NULL;
1517 return status;
1518 }
1519
1520 major = MAJOR(devt);
1521 minors = count;
1522
1523 return status;
1524}
1525
1526static void gprinter_cleanup(void)
1527{
1528 if (major) {
1529 unregister_chrdev_region(MKDEV(major, 0), minors);
1530 major = minors = 0;
1531 }
1532 class_destroy(usb_gadget_class);
1533 usb_gadget_class = NULL;
1534}