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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#include <linux/kref.h>
35
36#include <asm/byteorder.h>
37#include <linux/io.h>
38#include <linux/irq.h>
39#include <linux/uaccess.h>
40#include <linux/unaligned.h>
41
42#include <linux/usb/ch9.h>
43#include <linux/usb/composite.h>
44#include <linux/usb/gadget.h>
45#include <linux/usb/g_printer.h>
46
47#include "u_printer.h"
48
49#define PRINTER_MINORS 4
50#define GET_DEVICE_ID 0
51#define GET_PORT_STATUS 1
52#define SOFT_RESET 2
53
54#define DEFAULT_Q_LEN 10 /* same as legacy g_printer gadget */
55
56static int major, minors;
57static const struct class usb_gadget_class = {
58 .name = "usb_printer_gadget",
59};
60
61static DEFINE_IDA(printer_ida);
62static DEFINE_MUTEX(printer_ida_lock); /* protects access do printer_ida */
63
64/*-------------------------------------------------------------------------*/
65
66struct printer_dev {
67 spinlock_t lock; /* lock this structure */
68 /* lock buffer lists during read/write calls */
69 struct mutex lock_printer_io;
70 struct usb_gadget *gadget;
71 s8 interface;
72 struct usb_ep *in_ep, *out_ep;
73 struct kref kref;
74 struct list_head rx_reqs; /* List of free RX structs */
75 struct list_head rx_reqs_active; /* List of Active RX xfers */
76 struct list_head rx_buffers; /* List of completed xfers */
77 /* wait until there is data to be read. */
78 wait_queue_head_t rx_wait;
79 struct list_head tx_reqs; /* List of free TX structs */
80 struct list_head tx_reqs_active; /* List of Active TX xfers */
81 /* Wait until there are write buffers available to use. */
82 wait_queue_head_t tx_wait;
83 /* Wait until all write buffers have been sent. */
84 wait_queue_head_t tx_flush_wait;
85 struct usb_request *current_rx_req;
86 size_t current_rx_bytes;
87 u8 *current_rx_buf;
88 u8 printer_status;
89 u8 reset_printer;
90 int minor;
91 struct cdev printer_cdev;
92 u8 printer_cdev_open;
93 wait_queue_head_t wait;
94 unsigned q_len;
95 char **pnp_string; /* We don't own memory! */
96 struct usb_function function;
97};
98
99static inline struct printer_dev *func_to_printer(struct usb_function *f)
100{
101 return container_of(f, struct printer_dev, function);
102}
103
104/*-------------------------------------------------------------------------*/
105
106/*
107 * DESCRIPTORS ... most are static, but strings and (full) configuration
108 * descriptors are built on demand.
109 */
110
111/* holds our biggest descriptor */
112#define USB_DESC_BUFSIZE 256
113#define USB_BUFSIZE 8192
114
115static struct usb_interface_descriptor intf_desc = {
116 .bLength = sizeof(intf_desc),
117 .bDescriptorType = USB_DT_INTERFACE,
118 .bNumEndpoints = 2,
119 .bInterfaceClass = USB_CLASS_PRINTER,
120 .bInterfaceSubClass = 1, /* Printer Sub-Class */
121 .bInterfaceProtocol = 2, /* Bi-Directional */
122 .iInterface = 0
123};
124
125static struct usb_endpoint_descriptor fs_ep_in_desc = {
126 .bLength = USB_DT_ENDPOINT_SIZE,
127 .bDescriptorType = USB_DT_ENDPOINT,
128 .bEndpointAddress = USB_DIR_IN,
129 .bmAttributes = USB_ENDPOINT_XFER_BULK
130};
131
132static struct usb_endpoint_descriptor fs_ep_out_desc = {
133 .bLength = USB_DT_ENDPOINT_SIZE,
134 .bDescriptorType = USB_DT_ENDPOINT,
135 .bEndpointAddress = USB_DIR_OUT,
136 .bmAttributes = USB_ENDPOINT_XFER_BULK
137};
138
139static struct usb_descriptor_header *fs_printer_function[] = {
140 (struct usb_descriptor_header *) &intf_desc,
141 (struct usb_descriptor_header *) &fs_ep_in_desc,
142 (struct usb_descriptor_header *) &fs_ep_out_desc,
143 NULL
144};
145
146/*
147 * usb 2.0 devices need to expose both high speed and full speed
148 * descriptors, unless they only run at full speed.
149 */
150
151static struct usb_endpoint_descriptor hs_ep_in_desc = {
152 .bLength = USB_DT_ENDPOINT_SIZE,
153 .bDescriptorType = USB_DT_ENDPOINT,
154 .bmAttributes = USB_ENDPOINT_XFER_BULK,
155 .wMaxPacketSize = cpu_to_le16(512)
156};
157
158static struct usb_endpoint_descriptor hs_ep_out_desc = {
159 .bLength = USB_DT_ENDPOINT_SIZE,
160 .bDescriptorType = USB_DT_ENDPOINT,
161 .bmAttributes = USB_ENDPOINT_XFER_BULK,
162 .wMaxPacketSize = cpu_to_le16(512)
163};
164
165static struct usb_descriptor_header *hs_printer_function[] = {
166 (struct usb_descriptor_header *) &intf_desc,
167 (struct usb_descriptor_header *) &hs_ep_in_desc,
168 (struct usb_descriptor_header *) &hs_ep_out_desc,
169 NULL
170};
171
172/*
173 * Added endpoint descriptors for 3.0 devices
174 */
175
176static struct usb_endpoint_descriptor ss_ep_in_desc = {
177 .bLength = USB_DT_ENDPOINT_SIZE,
178 .bDescriptorType = USB_DT_ENDPOINT,
179 .bmAttributes = USB_ENDPOINT_XFER_BULK,
180 .wMaxPacketSize = cpu_to_le16(1024),
181};
182
183static struct usb_ss_ep_comp_descriptor ss_ep_in_comp_desc = {
184 .bLength = sizeof(ss_ep_in_comp_desc),
185 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
186};
187
188static struct usb_endpoint_descriptor ss_ep_out_desc = {
189 .bLength = USB_DT_ENDPOINT_SIZE,
190 .bDescriptorType = USB_DT_ENDPOINT,
191 .bmAttributes = USB_ENDPOINT_XFER_BULK,
192 .wMaxPacketSize = cpu_to_le16(1024),
193};
194
195static struct usb_ss_ep_comp_descriptor ss_ep_out_comp_desc = {
196 .bLength = sizeof(ss_ep_out_comp_desc),
197 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
198};
199
200static struct usb_descriptor_header *ss_printer_function[] = {
201 (struct usb_descriptor_header *) &intf_desc,
202 (struct usb_descriptor_header *) &ss_ep_in_desc,
203 (struct usb_descriptor_header *) &ss_ep_in_comp_desc,
204 (struct usb_descriptor_header *) &ss_ep_out_desc,
205 (struct usb_descriptor_header *) &ss_ep_out_comp_desc,
206 NULL
207};
208
209/* maxpacket and other transfer characteristics vary by speed. */
210static inline struct usb_endpoint_descriptor *ep_desc(struct usb_gadget *gadget,
211 struct usb_endpoint_descriptor *fs,
212 struct usb_endpoint_descriptor *hs,
213 struct usb_endpoint_descriptor *ss)
214{
215 switch (gadget->speed) {
216 case USB_SPEED_SUPER_PLUS:
217 case USB_SPEED_SUPER:
218 return ss;
219 case USB_SPEED_HIGH:
220 return hs;
221 default:
222 return fs;
223 }
224}
225
226/*-------------------------------------------------------------------------*/
227
228static void printer_dev_free(struct kref *kref)
229{
230 struct printer_dev *dev = container_of(kref, struct printer_dev, kref);
231
232 kfree(dev);
233}
234
235static struct usb_request *
236printer_req_alloc(struct usb_ep *ep, unsigned len, gfp_t gfp_flags)
237{
238 struct usb_request *req;
239
240 req = usb_ep_alloc_request(ep, gfp_flags);
241
242 if (req != NULL) {
243 req->length = len;
244 req->buf = kmalloc(len, gfp_flags);
245 if (req->buf == NULL) {
246 usb_ep_free_request(ep, req);
247 return NULL;
248 }
249 }
250
251 return req;
252}
253
254static void
255printer_req_free(struct usb_ep *ep, struct usb_request *req)
256{
257 if (ep != NULL && req != NULL) {
258 kfree(req->buf);
259 usb_ep_free_request(ep, req);
260 }
261}
262
263/*-------------------------------------------------------------------------*/
264
265static void rx_complete(struct usb_ep *ep, struct usb_request *req)
266{
267 struct printer_dev *dev = ep->driver_data;
268 int status = req->status;
269 unsigned long flags;
270
271 spin_lock_irqsave(&dev->lock, flags);
272
273 list_del_init(&req->list); /* Remode from Active List */
274
275 switch (status) {
276
277 /* normal completion */
278 case 0:
279 if (req->actual > 0) {
280 list_add_tail(&req->list, &dev->rx_buffers);
281 DBG(dev, "G_Printer : rx length %d\n", req->actual);
282 } else {
283 list_add(&req->list, &dev->rx_reqs);
284 }
285 break;
286
287 /* software-driven interface shutdown */
288 case -ECONNRESET: /* unlink */
289 case -ESHUTDOWN: /* disconnect etc */
290 VDBG(dev, "rx shutdown, code %d\n", status);
291 list_add(&req->list, &dev->rx_reqs);
292 break;
293
294 /* for hardware automagic (such as pxa) */
295 case -ECONNABORTED: /* endpoint reset */
296 DBG(dev, "rx %s reset\n", ep->name);
297 list_add(&req->list, &dev->rx_reqs);
298 break;
299
300 /* data overrun */
301 case -EOVERFLOW:
302 fallthrough;
303
304 default:
305 DBG(dev, "rx status %d\n", status);
306 list_add(&req->list, &dev->rx_reqs);
307 break;
308 }
309
310 wake_up_interruptible(&dev->rx_wait);
311 spin_unlock_irqrestore(&dev->lock, flags);
312}
313
314static void tx_complete(struct usb_ep *ep, struct usb_request *req)
315{
316 struct printer_dev *dev = ep->driver_data;
317
318 switch (req->status) {
319 default:
320 VDBG(dev, "tx err %d\n", req->status);
321 fallthrough;
322 case -ECONNRESET: /* unlink */
323 case -ESHUTDOWN: /* disconnect etc */
324 break;
325 case 0:
326 break;
327 }
328
329 spin_lock(&dev->lock);
330 /* Take the request struct off the active list and put it on the
331 * free list.
332 */
333 list_del_init(&req->list);
334 list_add(&req->list, &dev->tx_reqs);
335 wake_up_interruptible(&dev->tx_wait);
336 if (likely(list_empty(&dev->tx_reqs_active)))
337 wake_up_interruptible(&dev->tx_flush_wait);
338
339 spin_unlock(&dev->lock);
340}
341
342/*-------------------------------------------------------------------------*/
343
344static int
345printer_open(struct inode *inode, struct file *fd)
346{
347 struct printer_dev *dev;
348 unsigned long flags;
349 int ret = -EBUSY;
350
351 dev = container_of(inode->i_cdev, struct printer_dev, printer_cdev);
352
353 spin_lock_irqsave(&dev->lock, flags);
354
355 if (dev->interface < 0) {
356 spin_unlock_irqrestore(&dev->lock, flags);
357 return -ENODEV;
358 }
359
360 if (!dev->printer_cdev_open) {
361 dev->printer_cdev_open = 1;
362 fd->private_data = dev;
363 ret = 0;
364 /* Change the printer status to show that it's on-line. */
365 dev->printer_status |= PRINTER_SELECTED;
366 kref_get(&dev->kref);
367 }
368
369 spin_unlock_irqrestore(&dev->lock, flags);
370
371 return ret;
372}
373
374static int
375printer_close(struct inode *inode, struct file *fd)
376{
377 struct printer_dev *dev = fd->private_data;
378 unsigned long flags;
379
380 spin_lock_irqsave(&dev->lock, flags);
381 dev->printer_cdev_open = 0;
382 fd->private_data = NULL;
383 /* Change printer status to show that the printer is off-line. */
384 dev->printer_status &= ~PRINTER_SELECTED;
385 spin_unlock_irqrestore(&dev->lock, flags);
386
387 kref_put(&dev->kref, printer_dev_free);
388
389 return 0;
390}
391
392/* This function must be called with interrupts turned off. */
393static void
394setup_rx_reqs(struct printer_dev *dev)
395{
396 struct usb_request *req;
397
398 while (likely(!list_empty(&dev->rx_reqs))) {
399 int error;
400
401 req = container_of(dev->rx_reqs.next,
402 struct usb_request, list);
403 list_del_init(&req->list);
404
405 /* The USB Host sends us whatever amount of data it wants to
406 * so we always set the length field to the full USB_BUFSIZE.
407 * If the amount of data is more than the read() caller asked
408 * for it will be stored in the request buffer until it is
409 * asked for by read().
410 */
411 req->length = USB_BUFSIZE;
412 req->complete = rx_complete;
413
414 /* here, we unlock, and only unlock, to avoid deadlock. */
415 spin_unlock(&dev->lock);
416 error = usb_ep_queue(dev->out_ep, req, GFP_ATOMIC);
417 spin_lock(&dev->lock);
418 if (error) {
419 DBG(dev, "rx submit --> %d\n", error);
420 list_add(&req->list, &dev->rx_reqs);
421 break;
422 }
423 /* if the req is empty, then add it into dev->rx_reqs_active. */
424 else if (list_empty(&req->list))
425 list_add(&req->list, &dev->rx_reqs_active);
426 }
427}
428
429static ssize_t
430printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
431{
432 struct printer_dev *dev = fd->private_data;
433 unsigned long flags;
434 size_t size, not_copied, copied;
435 size_t bytes_copied;
436 struct usb_request *req;
437 /* This is a pointer to the current USB rx request. */
438 struct usb_request *current_rx_req;
439 /* This is the number of bytes in the current rx buffer. */
440 size_t current_rx_bytes;
441 /* This is a pointer to the current rx buffer. */
442 u8 *current_rx_buf;
443
444 if (len == 0)
445 return -EINVAL;
446
447 DBG(dev, "printer_read trying to read %d bytes\n", (int)len);
448
449 mutex_lock(&dev->lock_printer_io);
450 spin_lock_irqsave(&dev->lock, flags);
451
452 if (dev->interface < 0)
453 goto out_disabled;
454
455 /* We will use this flag later to check if a printer reset happened
456 * after we turn interrupts back on.
457 */
458 dev->reset_printer = 0;
459
460 setup_rx_reqs(dev);
461 /* this dropped the lock - need to retest */
462 if (dev->interface < 0)
463 goto out_disabled;
464
465 bytes_copied = 0;
466 current_rx_req = dev->current_rx_req;
467 current_rx_bytes = dev->current_rx_bytes;
468 current_rx_buf = dev->current_rx_buf;
469 dev->current_rx_req = NULL;
470 dev->current_rx_bytes = 0;
471 dev->current_rx_buf = NULL;
472
473 /* Check if there is any data in the read buffers. Please note that
474 * current_rx_bytes is the number of bytes in the current rx buffer.
475 * If it is zero then check if there are any other rx_buffers that
476 * are on the completed list. We are only out of data if all rx
477 * buffers are empty.
478 */
479 if ((current_rx_bytes == 0) &&
480 (likely(list_empty(&dev->rx_buffers)))) {
481 /* Turn interrupts back on before sleeping. */
482 spin_unlock_irqrestore(&dev->lock, flags);
483
484 /*
485 * If no data is available check if this is a NON-Blocking
486 * call or not.
487 */
488 if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) {
489 mutex_unlock(&dev->lock_printer_io);
490 return -EAGAIN;
491 }
492
493 /* Sleep until data is available */
494 wait_event_interruptible(dev->rx_wait,
495 (likely(!list_empty(&dev->rx_buffers))));
496 spin_lock_irqsave(&dev->lock, flags);
497 if (dev->interface < 0)
498 goto out_disabled;
499 }
500
501 /* We have data to return then copy it to the caller's buffer.*/
502 while ((current_rx_bytes || likely(!list_empty(&dev->rx_buffers)))
503 && len) {
504 if (current_rx_bytes == 0) {
505 req = container_of(dev->rx_buffers.next,
506 struct usb_request, list);
507 list_del_init(&req->list);
508
509 if (req->actual && req->buf) {
510 current_rx_req = req;
511 current_rx_bytes = req->actual;
512 current_rx_buf = req->buf;
513 } else {
514 list_add(&req->list, &dev->rx_reqs);
515 continue;
516 }
517 }
518
519 /* Don't leave irqs off while doing memory copies */
520 spin_unlock_irqrestore(&dev->lock, flags);
521
522 if (len > current_rx_bytes)
523 size = current_rx_bytes;
524 else
525 size = len;
526
527 not_copied = copy_to_user(buf, current_rx_buf, size);
528 copied = size - not_copied;
529
530 bytes_copied += copied;
531 len -= copied;
532 buf += copied;
533
534 spin_lock_irqsave(&dev->lock, flags);
535
536 /* We've disconnected or reset so return. */
537 if (dev->reset_printer) {
538 list_add(&current_rx_req->list, &dev->rx_reqs);
539 spin_unlock_irqrestore(&dev->lock, flags);
540 mutex_unlock(&dev->lock_printer_io);
541 return -EAGAIN;
542 }
543
544 if (dev->interface < 0)
545 goto out_disabled;
546
547 if (!copied) {
548 dev->current_rx_req = current_rx_req;
549 dev->current_rx_bytes = current_rx_bytes;
550 dev->current_rx_buf = current_rx_buf;
551 spin_unlock_irqrestore(&dev->lock, flags);
552 mutex_unlock(&dev->lock_printer_io);
553 return bytes_copied ? bytes_copied : -EFAULT;
554 }
555
556 size = copied;
557
558 /* If we not returning all the data left in this RX request
559 * buffer then adjust the amount of data left in the buffer.
560 * Othewise if we are done with this RX request buffer then
561 * requeue it to get any incoming data from the USB host.
562 */
563 if (size < current_rx_bytes) {
564 current_rx_bytes -= size;
565 current_rx_buf += size;
566 } else {
567 list_add(&current_rx_req->list, &dev->rx_reqs);
568 current_rx_bytes = 0;
569 current_rx_buf = NULL;
570 current_rx_req = NULL;
571 }
572 }
573
574 dev->current_rx_req = current_rx_req;
575 dev->current_rx_bytes = current_rx_bytes;
576 dev->current_rx_buf = current_rx_buf;
577
578 spin_unlock_irqrestore(&dev->lock, flags);
579 mutex_unlock(&dev->lock_printer_io);
580
581 DBG(dev, "printer_read returned %d bytes\n", (int)bytes_copied);
582
583 if (bytes_copied)
584 return bytes_copied;
585 else
586 return -EAGAIN;
587
588out_disabled:
589 spin_unlock_irqrestore(&dev->lock, flags);
590 mutex_unlock(&dev->lock_printer_io);
591 return -ENODEV;
592}
593
594static ssize_t
595printer_write(struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
596{
597 struct printer_dev *dev = fd->private_data;
598 unsigned long flags;
599 size_t size; /* Amount of data in a TX request. */
600 size_t bytes_copied = 0;
601 struct usb_request *req;
602 int value;
603
604 DBG(dev, "printer_write trying to send %d bytes\n", (int)len);
605
606 if (len == 0)
607 return -EINVAL;
608
609 mutex_lock(&dev->lock_printer_io);
610 spin_lock_irqsave(&dev->lock, flags);
611
612 if (dev->interface < 0)
613 goto out_disabled;
614
615 /* Check if a printer reset happens while we have interrupts on */
616 dev->reset_printer = 0;
617
618 /* Check if there is any available write buffers */
619 if (likely(list_empty(&dev->tx_reqs))) {
620 /* Turn interrupts back on before sleeping. */
621 spin_unlock_irqrestore(&dev->lock, flags);
622
623 /*
624 * If write buffers are available check if this is
625 * a NON-Blocking call or not.
626 */
627 if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) {
628 mutex_unlock(&dev->lock_printer_io);
629 return -EAGAIN;
630 }
631
632 /* Sleep until a write buffer is available */
633 wait_event_interruptible(dev->tx_wait,
634 (likely(!list_empty(&dev->tx_reqs))));
635 spin_lock_irqsave(&dev->lock, flags);
636 if (dev->interface < 0)
637 goto out_disabled;
638 }
639
640 while (likely(!list_empty(&dev->tx_reqs)) && len) {
641
642 if (len > USB_BUFSIZE)
643 size = USB_BUFSIZE;
644 else
645 size = len;
646
647 req = container_of(dev->tx_reqs.next, struct usb_request,
648 list);
649 list_del_init(&req->list);
650
651 req->complete = tx_complete;
652 req->length = size;
653
654 /* Check if we need to send a zero length packet. */
655 if (len > size)
656 /* They will be more TX requests so no yet. */
657 req->zero = 0;
658 else
659 /* If the data amount is not a multiple of the
660 * maxpacket size then send a zero length packet.
661 */
662 req->zero = ((len % dev->in_ep->maxpacket) == 0);
663
664 /* Don't leave irqs off while doing memory copies */
665 spin_unlock_irqrestore(&dev->lock, flags);
666
667 if (copy_from_user(req->buf, buf, size)) {
668 list_add(&req->list, &dev->tx_reqs);
669 mutex_unlock(&dev->lock_printer_io);
670 return bytes_copied;
671 }
672
673 bytes_copied += size;
674 len -= size;
675 buf += size;
676
677 spin_lock_irqsave(&dev->lock, flags);
678
679 /* We've disconnected or reset so free the req and buffer */
680 if (dev->reset_printer) {
681 list_add(&req->list, &dev->tx_reqs);
682 spin_unlock_irqrestore(&dev->lock, flags);
683 mutex_unlock(&dev->lock_printer_io);
684 return -EAGAIN;
685 }
686
687 if (dev->interface < 0)
688 goto out_disabled;
689
690 list_add(&req->list, &dev->tx_reqs_active);
691
692 /* here, we unlock, and only unlock, to avoid deadlock. */
693 spin_unlock(&dev->lock);
694 value = usb_ep_queue(dev->in_ep, req, GFP_ATOMIC);
695 spin_lock(&dev->lock);
696 if (value) {
697 list_move(&req->list, &dev->tx_reqs);
698 spin_unlock_irqrestore(&dev->lock, flags);
699 mutex_unlock(&dev->lock_printer_io);
700 return -EAGAIN;
701 }
702 if (dev->interface < 0)
703 goto out_disabled;
704 }
705
706 spin_unlock_irqrestore(&dev->lock, flags);
707 mutex_unlock(&dev->lock_printer_io);
708
709 DBG(dev, "printer_write sent %d bytes\n", (int)bytes_copied);
710
711 if (bytes_copied)
712 return bytes_copied;
713 else
714 return -EAGAIN;
715
716out_disabled:
717 spin_unlock_irqrestore(&dev->lock, flags);
718 mutex_unlock(&dev->lock_printer_io);
719 return -ENODEV;
720}
721
722static int
723printer_fsync(struct file *fd, loff_t start, loff_t end, int datasync)
724{
725 struct printer_dev *dev = fd->private_data;
726 struct inode *inode = file_inode(fd);
727 unsigned long flags;
728 int tx_list_empty;
729
730 inode_lock(inode);
731 spin_lock_irqsave(&dev->lock, flags);
732
733 if (dev->interface < 0) {
734 spin_unlock_irqrestore(&dev->lock, flags);
735 inode_unlock(inode);
736 return -ENODEV;
737 }
738
739 tx_list_empty = (likely(list_empty(&dev->tx_reqs)));
740 spin_unlock_irqrestore(&dev->lock, flags);
741
742 if (!tx_list_empty) {
743 /* Sleep until all data has been sent */
744 wait_event_interruptible(dev->tx_flush_wait,
745 (likely(list_empty(&dev->tx_reqs_active))));
746 }
747 inode_unlock(inode);
748
749 return 0;
750}
751
752static __poll_t
753printer_poll(struct file *fd, poll_table *wait)
754{
755 struct printer_dev *dev = fd->private_data;
756 unsigned long flags;
757 __poll_t status = 0;
758
759 mutex_lock(&dev->lock_printer_io);
760 spin_lock_irqsave(&dev->lock, flags);
761
762 if (dev->interface < 0) {
763 spin_unlock_irqrestore(&dev->lock, flags);
764 mutex_unlock(&dev->lock_printer_io);
765 return EPOLLERR | EPOLLHUP;
766 }
767
768 setup_rx_reqs(dev);
769 spin_unlock_irqrestore(&dev->lock, flags);
770 mutex_unlock(&dev->lock_printer_io);
771
772 poll_wait(fd, &dev->rx_wait, wait);
773 poll_wait(fd, &dev->tx_wait, wait);
774
775 spin_lock_irqsave(&dev->lock, flags);
776 if (likely(!list_empty(&dev->tx_reqs)))
777 status |= EPOLLOUT | EPOLLWRNORM;
778
779 if (likely(dev->current_rx_bytes) ||
780 likely(!list_empty(&dev->rx_buffers)))
781 status |= EPOLLIN | EPOLLRDNORM;
782
783 spin_unlock_irqrestore(&dev->lock, flags);
784
785 return status;
786}
787
788static long
789printer_ioctl(struct file *fd, unsigned int code, unsigned long arg)
790{
791 struct printer_dev *dev = fd->private_data;
792 unsigned long flags;
793 int status = 0;
794
795 DBG(dev, "printer_ioctl: cmd=0x%4.4x, arg=%lu\n", code, arg);
796
797 /* handle ioctls */
798
799 spin_lock_irqsave(&dev->lock, flags);
800
801 if (dev->interface < 0) {
802 spin_unlock_irqrestore(&dev->lock, flags);
803 return -ENODEV;
804 }
805
806 switch (code) {
807 case GADGET_GET_PRINTER_STATUS:
808 status = (int)dev->printer_status;
809 break;
810 case GADGET_SET_PRINTER_STATUS:
811 dev->printer_status = (u8)arg;
812 break;
813 default:
814 /* could not handle ioctl */
815 DBG(dev, "printer_ioctl: ERROR cmd=0x%4.4xis not supported\n",
816 code);
817 status = -ENOTTY;
818 }
819
820 spin_unlock_irqrestore(&dev->lock, flags);
821
822 return status;
823}
824
825/* used after endpoint configuration */
826static const struct file_operations printer_io_operations = {
827 .owner = THIS_MODULE,
828 .open = printer_open,
829 .read = printer_read,
830 .write = printer_write,
831 .fsync = printer_fsync,
832 .poll = printer_poll,
833 .unlocked_ioctl = printer_ioctl,
834 .release = printer_close,
835 .llseek = noop_llseek,
836};
837
838/*-------------------------------------------------------------------------*/
839
840static int
841set_printer_interface(struct printer_dev *dev)
842{
843 int result = 0;
844
845 dev->in_ep->desc = ep_desc(dev->gadget, &fs_ep_in_desc, &hs_ep_in_desc,
846 &ss_ep_in_desc);
847 dev->in_ep->driver_data = dev;
848
849 dev->out_ep->desc = ep_desc(dev->gadget, &fs_ep_out_desc,
850 &hs_ep_out_desc, &ss_ep_out_desc);
851 dev->out_ep->driver_data = dev;
852
853 result = usb_ep_enable(dev->in_ep);
854 if (result != 0) {
855 DBG(dev, "enable %s --> %d\n", dev->in_ep->name, result);
856 goto done;
857 }
858
859 result = usb_ep_enable(dev->out_ep);
860 if (result != 0) {
861 DBG(dev, "enable %s --> %d\n", dev->out_ep->name, result);
862 goto done;
863 }
864
865done:
866 /* on error, disable any endpoints */
867 if (result != 0) {
868 (void) usb_ep_disable(dev->in_ep);
869 (void) usb_ep_disable(dev->out_ep);
870 dev->in_ep->desc = NULL;
871 dev->out_ep->desc = NULL;
872 }
873
874 /* caller is responsible for cleanup on error */
875 return result;
876}
877
878static void printer_reset_interface(struct printer_dev *dev)
879{
880 unsigned long flags;
881
882 if (dev->interface < 0)
883 return;
884
885 if (dev->in_ep->desc)
886 usb_ep_disable(dev->in_ep);
887
888 if (dev->out_ep->desc)
889 usb_ep_disable(dev->out_ep);
890
891 spin_lock_irqsave(&dev->lock, flags);
892 dev->in_ep->desc = NULL;
893 dev->out_ep->desc = NULL;
894 dev->interface = -1;
895 spin_unlock_irqrestore(&dev->lock, flags);
896}
897
898/* Change our operational Interface. */
899static int set_interface(struct printer_dev *dev, unsigned number)
900{
901 int result = 0;
902
903 /* Free the current interface */
904 printer_reset_interface(dev);
905
906 result = set_printer_interface(dev);
907 if (result)
908 printer_reset_interface(dev);
909 else
910 dev->interface = number;
911
912 if (!result)
913 INFO(dev, "Using interface %x\n", number);
914
915 return result;
916}
917
918static void printer_soft_reset(struct printer_dev *dev)
919{
920 struct usb_request *req;
921
922 if (usb_ep_disable(dev->in_ep))
923 DBG(dev, "Failed to disable USB in_ep\n");
924 if (usb_ep_disable(dev->out_ep))
925 DBG(dev, "Failed to disable USB out_ep\n");
926
927 if (dev->current_rx_req != NULL) {
928 list_add(&dev->current_rx_req->list, &dev->rx_reqs);
929 dev->current_rx_req = NULL;
930 }
931 dev->current_rx_bytes = 0;
932 dev->current_rx_buf = NULL;
933 dev->reset_printer = 1;
934
935 while (likely(!(list_empty(&dev->rx_buffers)))) {
936 req = container_of(dev->rx_buffers.next, struct usb_request,
937 list);
938 list_del_init(&req->list);
939 list_add(&req->list, &dev->rx_reqs);
940 }
941
942 while (likely(!(list_empty(&dev->rx_reqs_active)))) {
943 req = container_of(dev->rx_buffers.next, struct usb_request,
944 list);
945 list_del_init(&req->list);
946 list_add(&req->list, &dev->rx_reqs);
947 }
948
949 while (likely(!(list_empty(&dev->tx_reqs_active)))) {
950 req = container_of(dev->tx_reqs_active.next,
951 struct usb_request, list);
952 list_del_init(&req->list);
953 list_add(&req->list, &dev->tx_reqs);
954 }
955
956 if (usb_ep_enable(dev->in_ep))
957 DBG(dev, "Failed to enable USB in_ep\n");
958 if (usb_ep_enable(dev->out_ep))
959 DBG(dev, "Failed to enable USB out_ep\n");
960
961 wake_up_interruptible(&dev->rx_wait);
962 wake_up_interruptible(&dev->tx_wait);
963 wake_up_interruptible(&dev->tx_flush_wait);
964}
965
966/*-------------------------------------------------------------------------*/
967
968static bool gprinter_req_match(struct usb_function *f,
969 const struct usb_ctrlrequest *ctrl,
970 bool config0)
971{
972 struct printer_dev *dev = func_to_printer(f);
973 u16 w_index = le16_to_cpu(ctrl->wIndex);
974 u16 w_value = le16_to_cpu(ctrl->wValue);
975 u16 w_length = le16_to_cpu(ctrl->wLength);
976
977 if (config0)
978 return false;
979
980 if ((ctrl->bRequestType & USB_RECIP_MASK) != USB_RECIP_INTERFACE ||
981 (ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS)
982 return false;
983
984 switch (ctrl->bRequest) {
985 case GET_DEVICE_ID:
986 w_index >>= 8;
987 if (USB_DIR_IN & ctrl->bRequestType)
988 break;
989 return false;
990 case GET_PORT_STATUS:
991 if (!w_value && w_length == 1 &&
992 (USB_DIR_IN & ctrl->bRequestType))
993 break;
994 return false;
995 case SOFT_RESET:
996 if (!w_value && !w_length &&
997 !(USB_DIR_IN & ctrl->bRequestType))
998 break;
999 fallthrough;
1000 default:
1001 return false;
1002 }
1003 return w_index == dev->interface;
1004}
1005
1006/*
1007 * The setup() callback implements all the ep0 functionality that's not
1008 * handled lower down.
1009 */
1010static int printer_func_setup(struct usb_function *f,
1011 const struct usb_ctrlrequest *ctrl)
1012{
1013 struct printer_dev *dev = func_to_printer(f);
1014 struct usb_composite_dev *cdev = f->config->cdev;
1015 struct usb_request *req = cdev->req;
1016 u8 *buf = req->buf;
1017 int value = -EOPNOTSUPP;
1018 u16 wIndex = le16_to_cpu(ctrl->wIndex);
1019 u16 wValue = le16_to_cpu(ctrl->wValue);
1020 u16 wLength = le16_to_cpu(ctrl->wLength);
1021
1022 DBG(dev, "ctrl req%02x.%02x v%04x i%04x l%d\n",
1023 ctrl->bRequestType, ctrl->bRequest, wValue, wIndex, wLength);
1024
1025 switch (ctrl->bRequestType&USB_TYPE_MASK) {
1026 case USB_TYPE_CLASS:
1027 switch (ctrl->bRequest) {
1028 case GET_DEVICE_ID: /* Get the IEEE-1284 PNP String */
1029 /* Only one printer interface is supported. */
1030 if ((wIndex>>8) != dev->interface)
1031 break;
1032
1033 if (!*dev->pnp_string) {
1034 value = 0;
1035 break;
1036 }
1037 value = strlen(*dev->pnp_string);
1038 buf[0] = (value >> 8) & 0xFF;
1039 buf[1] = value & 0xFF;
1040 memcpy(buf + 2, *dev->pnp_string, value);
1041 DBG(dev, "1284 PNP String: %x %s\n", value,
1042 *dev->pnp_string);
1043 break;
1044
1045 case GET_PORT_STATUS: /* Get Port Status */
1046 /* Only one printer interface is supported. */
1047 if (wIndex != dev->interface)
1048 break;
1049
1050 buf[0] = dev->printer_status;
1051 value = min_t(u16, wLength, 1);
1052 break;
1053
1054 case SOFT_RESET: /* Soft Reset */
1055 /* Only one printer interface is supported. */
1056 if (wIndex != dev->interface)
1057 break;
1058
1059 printer_soft_reset(dev);
1060
1061 value = 0;
1062 break;
1063
1064 default:
1065 goto unknown;
1066 }
1067 break;
1068
1069 default:
1070unknown:
1071 VDBG(dev,
1072 "unknown ctrl req%02x.%02x v%04x i%04x l%d\n",
1073 ctrl->bRequestType, ctrl->bRequest,
1074 wValue, wIndex, wLength);
1075 break;
1076 }
1077 /* host either stalls (value < 0) or reports success */
1078 if (value >= 0) {
1079 req->length = value;
1080 req->zero = value < wLength;
1081 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
1082 if (value < 0) {
1083 ERROR(dev, "%s:%d Error!\n", __func__, __LINE__);
1084 req->status = 0;
1085 }
1086 }
1087 return value;
1088}
1089
1090static int printer_func_bind(struct usb_configuration *c,
1091 struct usb_function *f)
1092{
1093 struct usb_gadget *gadget = c->cdev->gadget;
1094 struct printer_dev *dev = func_to_printer(f);
1095 struct device *pdev;
1096 struct usb_composite_dev *cdev = c->cdev;
1097 struct usb_ep *in_ep;
1098 struct usb_ep *out_ep = NULL;
1099 struct usb_request *req;
1100 dev_t devt;
1101 int id;
1102 int ret;
1103 u32 i;
1104
1105 id = usb_interface_id(c, f);
1106 if (id < 0)
1107 return id;
1108 intf_desc.bInterfaceNumber = id;
1109
1110 /* finish hookup to lower layer ... */
1111 dev->gadget = gadget;
1112
1113 /* all we really need is bulk IN/OUT */
1114 in_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_in_desc);
1115 if (!in_ep) {
1116autoconf_fail:
1117 dev_err(&cdev->gadget->dev, "can't autoconfigure on %s\n",
1118 cdev->gadget->name);
1119 return -ENODEV;
1120 }
1121
1122 out_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_out_desc);
1123 if (!out_ep)
1124 goto autoconf_fail;
1125
1126 /* assumes that all endpoints are dual-speed */
1127 hs_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
1128 hs_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
1129 ss_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
1130 ss_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
1131
1132 ret = usb_assign_descriptors(f, fs_printer_function,
1133 hs_printer_function, ss_printer_function,
1134 ss_printer_function);
1135 if (ret)
1136 return ret;
1137
1138 dev->in_ep = in_ep;
1139 dev->out_ep = out_ep;
1140
1141 ret = -ENOMEM;
1142 for (i = 0; i < dev->q_len; i++) {
1143 req = printer_req_alloc(dev->in_ep, USB_BUFSIZE, GFP_KERNEL);
1144 if (!req)
1145 goto fail_tx_reqs;
1146 list_add(&req->list, &dev->tx_reqs);
1147 }
1148
1149 for (i = 0; i < dev->q_len; i++) {
1150 req = printer_req_alloc(dev->out_ep, USB_BUFSIZE, GFP_KERNEL);
1151 if (!req)
1152 goto fail_rx_reqs;
1153 list_add(&req->list, &dev->rx_reqs);
1154 }
1155
1156 /* Setup the sysfs files for the printer gadget. */
1157 devt = MKDEV(major, dev->minor);
1158 pdev = device_create(&usb_gadget_class, NULL, devt,
1159 NULL, "g_printer%d", dev->minor);
1160 if (IS_ERR(pdev)) {
1161 ERROR(dev, "Failed to create device: g_printer\n");
1162 ret = PTR_ERR(pdev);
1163 goto fail_rx_reqs;
1164 }
1165
1166 /*
1167 * Register a character device as an interface to a user mode
1168 * program that handles the printer specific functionality.
1169 */
1170 cdev_init(&dev->printer_cdev, &printer_io_operations);
1171 dev->printer_cdev.owner = THIS_MODULE;
1172 ret = cdev_add(&dev->printer_cdev, devt, 1);
1173 if (ret) {
1174 ERROR(dev, "Failed to open char device\n");
1175 goto fail_cdev_add;
1176 }
1177
1178 return 0;
1179
1180fail_cdev_add:
1181 device_destroy(&usb_gadget_class, devt);
1182
1183fail_rx_reqs:
1184 while (!list_empty(&dev->rx_reqs)) {
1185 req = container_of(dev->rx_reqs.next, struct usb_request, list);
1186 list_del(&req->list);
1187 printer_req_free(dev->out_ep, req);
1188 }
1189
1190fail_tx_reqs:
1191 while (!list_empty(&dev->tx_reqs)) {
1192 req = container_of(dev->tx_reqs.next, struct usb_request, list);
1193 list_del(&req->list);
1194 printer_req_free(dev->in_ep, req);
1195 }
1196
1197 usb_free_all_descriptors(f);
1198 return ret;
1199
1200}
1201
1202static int printer_func_set_alt(struct usb_function *f,
1203 unsigned intf, unsigned alt)
1204{
1205 struct printer_dev *dev = func_to_printer(f);
1206 int ret = -ENOTSUPP;
1207
1208 if (!alt)
1209 ret = set_interface(dev, intf);
1210
1211 return ret;
1212}
1213
1214static void printer_func_disable(struct usb_function *f)
1215{
1216 struct printer_dev *dev = func_to_printer(f);
1217
1218 printer_reset_interface(dev);
1219}
1220
1221static inline struct f_printer_opts
1222*to_f_printer_opts(struct config_item *item)
1223{
1224 return container_of(to_config_group(item), struct f_printer_opts,
1225 func_inst.group);
1226}
1227
1228static void printer_attr_release(struct config_item *item)
1229{
1230 struct f_printer_opts *opts = to_f_printer_opts(item);
1231
1232 usb_put_function_instance(&opts->func_inst);
1233}
1234
1235static const struct configfs_item_operations printer_item_ops = {
1236 .release = printer_attr_release,
1237};
1238
1239static ssize_t f_printer_opts_pnp_string_show(struct config_item *item,
1240 char *page)
1241{
1242 struct f_printer_opts *opts = to_f_printer_opts(item);
1243 int result = 0;
1244
1245 mutex_lock(&opts->lock);
1246 if (!opts->pnp_string)
1247 goto unlock;
1248
1249 result = strscpy(page, opts->pnp_string, PAGE_SIZE);
1250 if (result < 1) {
1251 result = PAGE_SIZE;
1252 } else if (page[result - 1] != '\n' && result + 1 < PAGE_SIZE) {
1253 page[result++] = '\n';
1254 page[result] = '\0';
1255 }
1256
1257unlock:
1258 mutex_unlock(&opts->lock);
1259
1260 return result;
1261}
1262
1263static ssize_t f_printer_opts_pnp_string_store(struct config_item *item,
1264 const char *page, size_t len)
1265{
1266 struct f_printer_opts *opts = to_f_printer_opts(item);
1267 char *new_pnp;
1268 int result;
1269
1270 mutex_lock(&opts->lock);
1271
1272 new_pnp = kstrndup(page, len, GFP_KERNEL);
1273 if (!new_pnp) {
1274 result = -ENOMEM;
1275 goto unlock;
1276 }
1277
1278 if (opts->pnp_string_allocated)
1279 kfree(opts->pnp_string);
1280
1281 opts->pnp_string_allocated = true;
1282 opts->pnp_string = new_pnp;
1283 result = len;
1284unlock:
1285 mutex_unlock(&opts->lock);
1286
1287 return result;
1288}
1289
1290CONFIGFS_ATTR(f_printer_opts_, pnp_string);
1291
1292static ssize_t f_printer_opts_q_len_show(struct config_item *item,
1293 char *page)
1294{
1295 struct f_printer_opts *opts = to_f_printer_opts(item);
1296 int result;
1297
1298 mutex_lock(&opts->lock);
1299 result = sprintf(page, "%d\n", opts->q_len);
1300 mutex_unlock(&opts->lock);
1301
1302 return result;
1303}
1304
1305static ssize_t f_printer_opts_q_len_store(struct config_item *item,
1306 const char *page, size_t len)
1307{
1308 struct f_printer_opts *opts = to_f_printer_opts(item);
1309 int ret;
1310 u16 num;
1311
1312 mutex_lock(&opts->lock);
1313 if (opts->refcnt) {
1314 ret = -EBUSY;
1315 goto end;
1316 }
1317
1318 ret = kstrtou16(page, 0, &num);
1319 if (ret)
1320 goto end;
1321
1322 opts->q_len = (unsigned)num;
1323 ret = len;
1324end:
1325 mutex_unlock(&opts->lock);
1326 return ret;
1327}
1328
1329CONFIGFS_ATTR(f_printer_opts_, q_len);
1330
1331static struct configfs_attribute *printer_attrs[] = {
1332 &f_printer_opts_attr_pnp_string,
1333 &f_printer_opts_attr_q_len,
1334 NULL,
1335};
1336
1337static const struct config_item_type printer_func_type = {
1338 .ct_item_ops = &printer_item_ops,
1339 .ct_attrs = printer_attrs,
1340 .ct_owner = THIS_MODULE,
1341};
1342
1343static inline int gprinter_get_minor(void)
1344{
1345 int ret;
1346
1347 ret = ida_alloc(&printer_ida, GFP_KERNEL);
1348 if (ret >= PRINTER_MINORS) {
1349 ida_free(&printer_ida, ret);
1350 ret = -ENODEV;
1351 }
1352
1353 return ret;
1354}
1355
1356static inline void gprinter_put_minor(int minor)
1357{
1358 ida_free(&printer_ida, minor);
1359}
1360
1361static int gprinter_setup(int);
1362static void gprinter_cleanup(void);
1363
1364static void gprinter_free_inst(struct usb_function_instance *f)
1365{
1366 struct f_printer_opts *opts;
1367
1368 opts = container_of(f, struct f_printer_opts, func_inst);
1369
1370 mutex_lock(&printer_ida_lock);
1371
1372 gprinter_put_minor(opts->minor);
1373 if (ida_is_empty(&printer_ida))
1374 gprinter_cleanup();
1375
1376 mutex_unlock(&printer_ida_lock);
1377
1378 if (opts->pnp_string_allocated)
1379 kfree(opts->pnp_string);
1380 kfree(opts);
1381}
1382
1383static struct usb_function_instance *gprinter_alloc_inst(void)
1384{
1385 struct f_printer_opts *opts;
1386 struct usb_function_instance *ret;
1387 int status = 0;
1388
1389 opts = kzalloc_obj(*opts);
1390 if (!opts)
1391 return ERR_PTR(-ENOMEM);
1392
1393 mutex_init(&opts->lock);
1394 opts->func_inst.free_func_inst = gprinter_free_inst;
1395 ret = &opts->func_inst;
1396
1397 /* Make sure q_len is initialized, otherwise the bound device can't support read/write! */
1398 opts->q_len = DEFAULT_Q_LEN;
1399
1400 mutex_lock(&printer_ida_lock);
1401
1402 if (ida_is_empty(&printer_ida)) {
1403 status = gprinter_setup(PRINTER_MINORS);
1404 if (status) {
1405 ret = ERR_PTR(status);
1406 kfree(opts);
1407 goto unlock;
1408 }
1409 }
1410
1411 opts->minor = gprinter_get_minor();
1412 if (opts->minor < 0) {
1413 ret = ERR_PTR(opts->minor);
1414 kfree(opts);
1415 if (ida_is_empty(&printer_ida))
1416 gprinter_cleanup();
1417 goto unlock;
1418 }
1419 config_group_init_type_name(&opts->func_inst.group, "",
1420 &printer_func_type);
1421
1422unlock:
1423 mutex_unlock(&printer_ida_lock);
1424 return ret;
1425}
1426
1427static void gprinter_free(struct usb_function *f)
1428{
1429 struct printer_dev *dev = func_to_printer(f);
1430 struct f_printer_opts *opts;
1431
1432 opts = container_of(f->fi, struct f_printer_opts, func_inst);
1433
1434 kref_put(&dev->kref, printer_dev_free);
1435 mutex_lock(&opts->lock);
1436 --opts->refcnt;
1437 mutex_unlock(&opts->lock);
1438}
1439
1440static void printer_func_unbind(struct usb_configuration *c,
1441 struct usb_function *f)
1442{
1443 struct printer_dev *dev;
1444 struct usb_request *req;
1445
1446 dev = func_to_printer(f);
1447
1448 device_destroy(&usb_gadget_class, MKDEV(major, dev->minor));
1449
1450 /* Remove Character Device */
1451 cdev_del(&dev->printer_cdev);
1452
1453 /* we must already have been disconnected ... no i/o may be active */
1454 WARN_ON(!list_empty(&dev->tx_reqs_active));
1455 WARN_ON(!list_empty(&dev->rx_reqs_active));
1456
1457 /* Free all memory for this driver. */
1458 while (!list_empty(&dev->tx_reqs)) {
1459 req = container_of(dev->tx_reqs.next, struct usb_request,
1460 list);
1461 list_del(&req->list);
1462 printer_req_free(dev->in_ep, req);
1463 }
1464
1465 if (dev->current_rx_req != NULL)
1466 printer_req_free(dev->out_ep, dev->current_rx_req);
1467
1468 while (!list_empty(&dev->rx_reqs)) {
1469 req = container_of(dev->rx_reqs.next,
1470 struct usb_request, list);
1471 list_del(&req->list);
1472 printer_req_free(dev->out_ep, req);
1473 }
1474
1475 while (!list_empty(&dev->rx_buffers)) {
1476 req = container_of(dev->rx_buffers.next,
1477 struct usb_request, list);
1478 list_del(&req->list);
1479 printer_req_free(dev->out_ep, req);
1480 }
1481 usb_free_all_descriptors(f);
1482}
1483
1484static struct usb_function *gprinter_alloc(struct usb_function_instance *fi)
1485{
1486 struct printer_dev *dev;
1487 struct f_printer_opts *opts;
1488
1489 opts = container_of(fi, struct f_printer_opts, func_inst);
1490
1491 mutex_lock(&opts->lock);
1492 if (opts->minor >= minors) {
1493 mutex_unlock(&opts->lock);
1494 return ERR_PTR(-ENOENT);
1495 }
1496
1497 dev = kzalloc_obj(*dev);
1498 if (!dev) {
1499 mutex_unlock(&opts->lock);
1500 return ERR_PTR(-ENOMEM);
1501 }
1502
1503 kref_init(&dev->kref);
1504 ++opts->refcnt;
1505 dev->minor = opts->minor;
1506 dev->pnp_string = &opts->pnp_string;
1507 dev->q_len = opts->q_len;
1508 mutex_unlock(&opts->lock);
1509
1510 dev->function.name = "printer";
1511 dev->function.bind = printer_func_bind;
1512 dev->function.setup = printer_func_setup;
1513 dev->function.unbind = printer_func_unbind;
1514 dev->function.set_alt = printer_func_set_alt;
1515 dev->function.disable = printer_func_disable;
1516 dev->function.req_match = gprinter_req_match;
1517 dev->function.free_func = gprinter_free;
1518
1519 INIT_LIST_HEAD(&dev->tx_reqs);
1520 INIT_LIST_HEAD(&dev->rx_reqs);
1521 INIT_LIST_HEAD(&dev->rx_buffers);
1522 INIT_LIST_HEAD(&dev->tx_reqs_active);
1523 INIT_LIST_HEAD(&dev->rx_reqs_active);
1524
1525 spin_lock_init(&dev->lock);
1526 mutex_init(&dev->lock_printer_io);
1527 init_waitqueue_head(&dev->rx_wait);
1528 init_waitqueue_head(&dev->tx_wait);
1529 init_waitqueue_head(&dev->tx_flush_wait);
1530
1531 dev->interface = -1;
1532 dev->printer_cdev_open = 0;
1533 dev->printer_status = PRINTER_NOT_ERROR;
1534 dev->current_rx_req = NULL;
1535 dev->current_rx_bytes = 0;
1536 dev->current_rx_buf = NULL;
1537
1538 return &dev->function;
1539}
1540
1541DECLARE_USB_FUNCTION_INIT(printer, gprinter_alloc_inst, gprinter_alloc);
1542MODULE_DESCRIPTION("USB printer function driver");
1543MODULE_LICENSE("GPL");
1544MODULE_AUTHOR("Craig Nadler");
1545
1546static int gprinter_setup(int count)
1547{
1548 int status;
1549 dev_t devt;
1550
1551 status = class_register(&usb_gadget_class);
1552 if (status)
1553 return status;
1554
1555 status = alloc_chrdev_region(&devt, 0, count, "USB printer gadget");
1556 if (status) {
1557 pr_err("alloc_chrdev_region %d\n", status);
1558 class_unregister(&usb_gadget_class);
1559 return status;
1560 }
1561
1562 major = MAJOR(devt);
1563 minors = count;
1564
1565 return status;
1566}
1567
1568static void gprinter_cleanup(void)
1569{
1570 if (major) {
1571 unregister_chrdev_region(MKDEV(major, 0), minors);
1572 major = minors = 0;
1573 }
1574 class_unregister(&usb_gadget_class);
1575}