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