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
56 static int major, minors;
57 static struct class *usb_gadget_class;
58 static DEFINE_IDA(printer_ida);
59 static DEFINE_MUTEX(printer_ida_lock); /* protects access do printer_ida */
60
61 /*-------------------------------------------------------------------------*/
62
63 struct 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
func_to_printer(struct usb_function * f)96 static 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
112 static 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
122 static 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
129 static 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
136 static 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
148 static 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
155 static 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
162 static 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
173 static 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
180 static 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
185 static 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
192 static 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
197 static 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. */
ep_desc(struct usb_gadget * gadget,struct usb_endpoint_descriptor * fs,struct usb_endpoint_descriptor * hs,struct usb_endpoint_descriptor * ss)207 static 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
printer_dev_free(struct kref * kref)224 static 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
231 static struct usb_request *
printer_req_alloc(struct usb_ep * ep,unsigned len,gfp_t gfp_flags)232 printer_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
250 static void
printer_req_free(struct usb_ep * ep,struct usb_request * req)251 printer_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
rx_complete(struct usb_ep * ep,struct usb_request * req)261 static 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
tx_complete(struct usb_ep * ep,struct usb_request * req)310 static 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
340 static int
printer_open(struct inode * inode,struct file * fd)341 printer_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 DBG(dev, "printer_open returned %x\n", ret);
368 return ret;
369 }
370
371 static int
printer_close(struct inode * inode,struct file * fd)372 printer_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 DBG(dev, "printer_close\n");
386
387 return 0;
388 }
389
390 /* This function must be called with interrupts turned off. */
391 static void
setup_rx_reqs(struct printer_dev * dev)392 setup_rx_reqs(struct printer_dev *dev)
393 {
394 struct usb_request *req;
395
396 while (likely(!list_empty(&dev->rx_reqs))) {
397 int error;
398
399 req = container_of(dev->rx_reqs.next,
400 struct usb_request, list);
401 list_del_init(&req->list);
402
403 /* The USB Host sends us whatever amount of data it wants to
404 * so we always set the length field to the full USB_BUFSIZE.
405 * If the amount of data is more than the read() caller asked
406 * for it will be stored in the request buffer until it is
407 * asked for by read().
408 */
409 req->length = USB_BUFSIZE;
410 req->complete = rx_complete;
411
412 /* here, we unlock, and only unlock, to avoid deadlock. */
413 spin_unlock(&dev->lock);
414 error = usb_ep_queue(dev->out_ep, req, GFP_ATOMIC);
415 spin_lock(&dev->lock);
416 if (error) {
417 DBG(dev, "rx submit --> %d\n", error);
418 list_add(&req->list, &dev->rx_reqs);
419 break;
420 }
421 /* if the req is empty, then add it into dev->rx_reqs_active. */
422 else if (list_empty(&req->list))
423 list_add(&req->list, &dev->rx_reqs_active);
424 }
425 }
426
427 static ssize_t
printer_read(struct file * fd,char __user * buf,size_t len,loff_t * ptr)428 printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
429 {
430 struct printer_dev *dev = fd->private_data;
431 unsigned long flags;
432 size_t size;
433 size_t bytes_copied;
434 struct usb_request *req;
435 /* This is a pointer to the current USB rx request. */
436 struct usb_request *current_rx_req;
437 /* This is the number of bytes in the current rx buffer. */
438 size_t current_rx_bytes;
439 /* This is a pointer to the current rx buffer. */
440 u8 *current_rx_buf;
441
442 if (len == 0)
443 return -EINVAL;
444
445 DBG(dev, "printer_read trying to read %d bytes\n", (int)len);
446
447 mutex_lock(&dev->lock_printer_io);
448 spin_lock_irqsave(&dev->lock, flags);
449
450 if (dev->interface < 0) {
451 spin_unlock_irqrestore(&dev->lock, flags);
452 mutex_unlock(&dev->lock_printer_io);
453 return -ENODEV;
454 }
455
456 /* We will use this flag later to check if a printer reset happened
457 * after we turn interrupts back on.
458 */
459 dev->reset_printer = 0;
460
461 setup_rx_reqs(dev);
462
463 bytes_copied = 0;
464 current_rx_req = dev->current_rx_req;
465 current_rx_bytes = dev->current_rx_bytes;
466 current_rx_buf = dev->current_rx_buf;
467 dev->current_rx_req = NULL;
468 dev->current_rx_bytes = 0;
469 dev->current_rx_buf = NULL;
470
471 /* Check if there is any data in the read buffers. Please note that
472 * current_rx_bytes is the number of bytes in the current rx buffer.
473 * If it is zero then check if there are any other rx_buffers that
474 * are on the completed list. We are only out of data if all rx
475 * buffers are empty.
476 */
477 if ((current_rx_bytes == 0) &&
478 (likely(list_empty(&dev->rx_buffers)))) {
479 /* Turn interrupts back on before sleeping. */
480 spin_unlock_irqrestore(&dev->lock, flags);
481
482 /*
483 * If no data is available check if this is a NON-Blocking
484 * call or not.
485 */
486 if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) {
487 mutex_unlock(&dev->lock_printer_io);
488 return -EAGAIN;
489 }
490
491 /* Sleep until data is available */
492 wait_event_interruptible(dev->rx_wait,
493 (likely(!list_empty(&dev->rx_buffers))));
494 spin_lock_irqsave(&dev->lock, flags);
495 }
496
497 /* We have data to return then copy it to the caller's buffer.*/
498 while ((current_rx_bytes || likely(!list_empty(&dev->rx_buffers)))
499 && len) {
500 if (current_rx_bytes == 0) {
501 req = container_of(dev->rx_buffers.next,
502 struct usb_request, list);
503 list_del_init(&req->list);
504
505 if (req->actual && req->buf) {
506 current_rx_req = req;
507 current_rx_bytes = req->actual;
508 current_rx_buf = req->buf;
509 } else {
510 list_add(&req->list, &dev->rx_reqs);
511 continue;
512 }
513 }
514
515 /* Don't leave irqs off while doing memory copies */
516 spin_unlock_irqrestore(&dev->lock, flags);
517
518 if (len > current_rx_bytes)
519 size = current_rx_bytes;
520 else
521 size = len;
522
523 size -= copy_to_user(buf, current_rx_buf, size);
524 bytes_copied += size;
525 len -= size;
526 buf += size;
527
528 spin_lock_irqsave(&dev->lock, flags);
529
530 /* We've disconnected or reset so return. */
531 if (dev->reset_printer) {
532 list_add(¤t_rx_req->list, &dev->rx_reqs);
533 spin_unlock_irqrestore(&dev->lock, flags);
534 mutex_unlock(&dev->lock_printer_io);
535 return -EAGAIN;
536 }
537
538 /* If we not returning all the data left in this RX request
539 * buffer then adjust the amount of data left in the buffer.
540 * Othewise if we are done with this RX request buffer then
541 * requeue it to get any incoming data from the USB host.
542 */
543 if (size < current_rx_bytes) {
544 current_rx_bytes -= size;
545 current_rx_buf += size;
546 } else {
547 list_add(¤t_rx_req->list, &dev->rx_reqs);
548 current_rx_bytes = 0;
549 current_rx_buf = NULL;
550 current_rx_req = NULL;
551 }
552 }
553
554 dev->current_rx_req = current_rx_req;
555 dev->current_rx_bytes = current_rx_bytes;
556 dev->current_rx_buf = current_rx_buf;
557
558 spin_unlock_irqrestore(&dev->lock, flags);
559 mutex_unlock(&dev->lock_printer_io);
560
561 DBG(dev, "printer_read returned %d bytes\n", (int)bytes_copied);
562
563 if (bytes_copied)
564 return bytes_copied;
565 else
566 return -EAGAIN;
567 }
568
569 static ssize_t
printer_write(struct file * fd,const char __user * buf,size_t len,loff_t * ptr)570 printer_write(struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
571 {
572 struct printer_dev *dev = fd->private_data;
573 unsigned long flags;
574 size_t size; /* Amount of data in a TX request. */
575 size_t bytes_copied = 0;
576 struct usb_request *req;
577 int value;
578
579 DBG(dev, "printer_write trying to send %d bytes\n", (int)len);
580
581 if (len == 0)
582 return -EINVAL;
583
584 mutex_lock(&dev->lock_printer_io);
585 spin_lock_irqsave(&dev->lock, flags);
586
587 if (dev->interface < 0) {
588 spin_unlock_irqrestore(&dev->lock, flags);
589 mutex_unlock(&dev->lock_printer_io);
590 return -ENODEV;
591 }
592
593 /* Check if a printer reset happens while we have interrupts on */
594 dev->reset_printer = 0;
595
596 /* Check if there is any available write buffers */
597 if (likely(list_empty(&dev->tx_reqs))) {
598 /* Turn interrupts back on before sleeping. */
599 spin_unlock_irqrestore(&dev->lock, flags);
600
601 /*
602 * If write buffers are available check if this is
603 * a NON-Blocking call or not.
604 */
605 if (fd->f_flags & (O_NONBLOCK|O_NDELAY)) {
606 mutex_unlock(&dev->lock_printer_io);
607 return -EAGAIN;
608 }
609
610 /* Sleep until a write buffer is available */
611 wait_event_interruptible(dev->tx_wait,
612 (likely(!list_empty(&dev->tx_reqs))));
613 spin_lock_irqsave(&dev->lock, flags);
614 }
615
616 while (likely(!list_empty(&dev->tx_reqs)) && len) {
617
618 if (len > USB_BUFSIZE)
619 size = USB_BUFSIZE;
620 else
621 size = len;
622
623 req = container_of(dev->tx_reqs.next, struct usb_request,
624 list);
625 list_del_init(&req->list);
626
627 req->complete = tx_complete;
628 req->length = size;
629
630 /* Check if we need to send a zero length packet. */
631 if (len > size)
632 /* They will be more TX requests so no yet. */
633 req->zero = 0;
634 else
635 /* If the data amount is not a multiple of the
636 * maxpacket size then send a zero length packet.
637 */
638 req->zero = ((len % dev->in_ep->maxpacket) == 0);
639
640 /* Don't leave irqs off while doing memory copies */
641 spin_unlock_irqrestore(&dev->lock, flags);
642
643 if (copy_from_user(req->buf, buf, size)) {
644 list_add(&req->list, &dev->tx_reqs);
645 mutex_unlock(&dev->lock_printer_io);
646 return bytes_copied;
647 }
648
649 bytes_copied += size;
650 len -= size;
651 buf += size;
652
653 spin_lock_irqsave(&dev->lock, flags);
654
655 /* We've disconnected or reset so free the req and buffer */
656 if (dev->reset_printer) {
657 list_add(&req->list, &dev->tx_reqs);
658 spin_unlock_irqrestore(&dev->lock, flags);
659 mutex_unlock(&dev->lock_printer_io);
660 return -EAGAIN;
661 }
662
663 list_add(&req->list, &dev->tx_reqs_active);
664
665 /* here, we unlock, and only unlock, to avoid deadlock. */
666 spin_unlock(&dev->lock);
667 value = usb_ep_queue(dev->in_ep, req, GFP_ATOMIC);
668 spin_lock(&dev->lock);
669 if (value) {
670 list_move(&req->list, &dev->tx_reqs);
671 spin_unlock_irqrestore(&dev->lock, flags);
672 mutex_unlock(&dev->lock_printer_io);
673 return -EAGAIN;
674 }
675 }
676
677 spin_unlock_irqrestore(&dev->lock, flags);
678 mutex_unlock(&dev->lock_printer_io);
679
680 DBG(dev, "printer_write sent %d bytes\n", (int)bytes_copied);
681
682 if (bytes_copied)
683 return bytes_copied;
684 else
685 return -EAGAIN;
686 }
687
688 static int
printer_fsync(struct file * fd,loff_t start,loff_t end,int datasync)689 printer_fsync(struct file *fd, loff_t start, loff_t end, int datasync)
690 {
691 struct printer_dev *dev = fd->private_data;
692 struct inode *inode = file_inode(fd);
693 unsigned long flags;
694 int tx_list_empty;
695
696 inode_lock(inode);
697 spin_lock_irqsave(&dev->lock, flags);
698
699 if (dev->interface < 0) {
700 spin_unlock_irqrestore(&dev->lock, flags);
701 inode_unlock(inode);
702 return -ENODEV;
703 }
704
705 tx_list_empty = (likely(list_empty(&dev->tx_reqs)));
706 spin_unlock_irqrestore(&dev->lock, flags);
707
708 if (!tx_list_empty) {
709 /* Sleep until all data has been sent */
710 wait_event_interruptible(dev->tx_flush_wait,
711 (likely(list_empty(&dev->tx_reqs_active))));
712 }
713 inode_unlock(inode);
714
715 return 0;
716 }
717
718 static __poll_t
printer_poll(struct file * fd,poll_table * wait)719 printer_poll(struct file *fd, poll_table *wait)
720 {
721 struct printer_dev *dev = fd->private_data;
722 unsigned long flags;
723 __poll_t status = 0;
724
725 mutex_lock(&dev->lock_printer_io);
726 spin_lock_irqsave(&dev->lock, flags);
727
728 if (dev->interface < 0) {
729 spin_unlock_irqrestore(&dev->lock, flags);
730 mutex_unlock(&dev->lock_printer_io);
731 return EPOLLERR | EPOLLHUP;
732 }
733
734 setup_rx_reqs(dev);
735 spin_unlock_irqrestore(&dev->lock, flags);
736 mutex_unlock(&dev->lock_printer_io);
737
738 poll_wait(fd, &dev->rx_wait, wait);
739 poll_wait(fd, &dev->tx_wait, wait);
740
741 spin_lock_irqsave(&dev->lock, flags);
742 if (likely(!list_empty(&dev->tx_reqs)))
743 status |= EPOLLOUT | EPOLLWRNORM;
744
745 if (likely(dev->current_rx_bytes) ||
746 likely(!list_empty(&dev->rx_buffers)))
747 status |= EPOLLIN | EPOLLRDNORM;
748
749 spin_unlock_irqrestore(&dev->lock, flags);
750
751 return status;
752 }
753
754 static long
printer_ioctl(struct file * fd,unsigned int code,unsigned long arg)755 printer_ioctl(struct file *fd, unsigned int code, unsigned long arg)
756 {
757 struct printer_dev *dev = fd->private_data;
758 unsigned long flags;
759 int status = 0;
760
761 DBG(dev, "printer_ioctl: cmd=0x%4.4x, arg=%lu\n", code, arg);
762
763 /* handle ioctls */
764
765 spin_lock_irqsave(&dev->lock, flags);
766
767 if (dev->interface < 0) {
768 spin_unlock_irqrestore(&dev->lock, flags);
769 return -ENODEV;
770 }
771
772 switch (code) {
773 case GADGET_GET_PRINTER_STATUS:
774 status = (int)dev->printer_status;
775 break;
776 case GADGET_SET_PRINTER_STATUS:
777 dev->printer_status = (u8)arg;
778 break;
779 default:
780 /* could not handle ioctl */
781 DBG(dev, "printer_ioctl: ERROR cmd=0x%4.4xis not supported\n",
782 code);
783 status = -ENOTTY;
784 }
785
786 spin_unlock_irqrestore(&dev->lock, flags);
787
788 return status;
789 }
790
791 /* used after endpoint configuration */
792 static const struct file_operations printer_io_operations = {
793 .owner = THIS_MODULE,
794 .open = printer_open,
795 .read = printer_read,
796 .write = printer_write,
797 .fsync = printer_fsync,
798 .poll = printer_poll,
799 .unlocked_ioctl = printer_ioctl,
800 .release = printer_close,
801 .llseek = noop_llseek,
802 };
803
804 /*-------------------------------------------------------------------------*/
805
806 static int
set_printer_interface(struct printer_dev * dev)807 set_printer_interface(struct printer_dev *dev)
808 {
809 int result = 0;
810
811 dev->in_ep->desc = ep_desc(dev->gadget, &fs_ep_in_desc, &hs_ep_in_desc,
812 &ss_ep_in_desc);
813 dev->in_ep->driver_data = dev;
814
815 dev->out_ep->desc = ep_desc(dev->gadget, &fs_ep_out_desc,
816 &hs_ep_out_desc, &ss_ep_out_desc);
817 dev->out_ep->driver_data = dev;
818
819 result = usb_ep_enable(dev->in_ep);
820 if (result != 0) {
821 DBG(dev, "enable %s --> %d\n", dev->in_ep->name, result);
822 goto done;
823 }
824
825 result = usb_ep_enable(dev->out_ep);
826 if (result != 0) {
827 DBG(dev, "enable %s --> %d\n", dev->out_ep->name, result);
828 goto done;
829 }
830
831 done:
832 /* on error, disable any endpoints */
833 if (result != 0) {
834 (void) usb_ep_disable(dev->in_ep);
835 (void) usb_ep_disable(dev->out_ep);
836 dev->in_ep->desc = NULL;
837 dev->out_ep->desc = NULL;
838 }
839
840 /* caller is responsible for cleanup on error */
841 return result;
842 }
843
printer_reset_interface(struct printer_dev * dev)844 static void printer_reset_interface(struct printer_dev *dev)
845 {
846 unsigned long flags;
847
848 if (dev->interface < 0)
849 return;
850
851 DBG(dev, "%s\n", __func__);
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. */
set_interface(struct printer_dev * dev,unsigned number)867 static 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
printer_soft_reset(struct printer_dev * dev)886 static void printer_soft_reset(struct printer_dev *dev)
887 {
888 struct usb_request *req;
889
890 INFO(dev, "Received Printer Reset Request\n");
891
892 if (usb_ep_disable(dev->in_ep))
893 DBG(dev, "Failed to disable USB in_ep\n");
894 if (usb_ep_disable(dev->out_ep))
895 DBG(dev, "Failed to disable USB out_ep\n");
896
897 if (dev->current_rx_req != NULL) {
898 list_add(&dev->current_rx_req->list, &dev->rx_reqs);
899 dev->current_rx_req = NULL;
900 }
901 dev->current_rx_bytes = 0;
902 dev->current_rx_buf = NULL;
903 dev->reset_printer = 1;
904
905 while (likely(!(list_empty(&dev->rx_buffers)))) {
906 req = container_of(dev->rx_buffers.next, struct usb_request,
907 list);
908 list_del_init(&req->list);
909 list_add(&req->list, &dev->rx_reqs);
910 }
911
912 while (likely(!(list_empty(&dev->rx_reqs_active)))) {
913 req = container_of(dev->rx_buffers.next, struct usb_request,
914 list);
915 list_del_init(&req->list);
916 list_add(&req->list, &dev->rx_reqs);
917 }
918
919 while (likely(!(list_empty(&dev->tx_reqs_active)))) {
920 req = container_of(dev->tx_reqs_active.next,
921 struct usb_request, list);
922 list_del_init(&req->list);
923 list_add(&req->list, &dev->tx_reqs);
924 }
925
926 if (usb_ep_enable(dev->in_ep))
927 DBG(dev, "Failed to enable USB in_ep\n");
928 if (usb_ep_enable(dev->out_ep))
929 DBG(dev, "Failed to enable USB out_ep\n");
930
931 wake_up_interruptible(&dev->rx_wait);
932 wake_up_interruptible(&dev->tx_wait);
933 wake_up_interruptible(&dev->tx_flush_wait);
934 }
935
936 /*-------------------------------------------------------------------------*/
937
gprinter_req_match(struct usb_function * f,const struct usb_ctrlrequest * ctrl,bool config0)938 static bool gprinter_req_match(struct usb_function *f,
939 const struct usb_ctrlrequest *ctrl,
940 bool config0)
941 {
942 struct printer_dev *dev = func_to_printer(f);
943 u16 w_index = le16_to_cpu(ctrl->wIndex);
944 u16 w_value = le16_to_cpu(ctrl->wValue);
945 u16 w_length = le16_to_cpu(ctrl->wLength);
946
947 if (config0)
948 return false;
949
950 if ((ctrl->bRequestType & USB_RECIP_MASK) != USB_RECIP_INTERFACE ||
951 (ctrl->bRequestType & USB_TYPE_MASK) != USB_TYPE_CLASS)
952 return false;
953
954 switch (ctrl->bRequest) {
955 case GET_DEVICE_ID:
956 w_index >>= 8;
957 if (USB_DIR_IN & ctrl->bRequestType)
958 break;
959 return false;
960 case GET_PORT_STATUS:
961 if (!w_value && w_length == 1 &&
962 (USB_DIR_IN & ctrl->bRequestType))
963 break;
964 return false;
965 case SOFT_RESET:
966 if (!w_value && !w_length &&
967 !(USB_DIR_IN & ctrl->bRequestType))
968 break;
969 fallthrough;
970 default:
971 return false;
972 }
973 return w_index == dev->interface;
974 }
975
976 /*
977 * The setup() callback implements all the ep0 functionality that's not
978 * handled lower down.
979 */
printer_func_setup(struct usb_function * f,const struct usb_ctrlrequest * ctrl)980 static int printer_func_setup(struct usb_function *f,
981 const struct usb_ctrlrequest *ctrl)
982 {
983 struct printer_dev *dev = func_to_printer(f);
984 struct usb_composite_dev *cdev = f->config->cdev;
985 struct usb_request *req = cdev->req;
986 u8 *buf = req->buf;
987 int value = -EOPNOTSUPP;
988 u16 wIndex = le16_to_cpu(ctrl->wIndex);
989 u16 wValue = le16_to_cpu(ctrl->wValue);
990 u16 wLength = le16_to_cpu(ctrl->wLength);
991
992 DBG(dev, "ctrl req%02x.%02x v%04x i%04x l%d\n",
993 ctrl->bRequestType, ctrl->bRequest, wValue, wIndex, wLength);
994
995 switch (ctrl->bRequestType&USB_TYPE_MASK) {
996 case USB_TYPE_CLASS:
997 switch (ctrl->bRequest) {
998 case GET_DEVICE_ID: /* Get the IEEE-1284 PNP String */
999 /* Only one printer interface is supported. */
1000 if ((wIndex>>8) != dev->interface)
1001 break;
1002
1003 if (!dev->pnp_string) {
1004 value = 0;
1005 break;
1006 }
1007 value = strlen(dev->pnp_string);
1008 buf[0] = (value >> 8) & 0xFF;
1009 buf[1] = value & 0xFF;
1010 memcpy(buf + 2, dev->pnp_string, value);
1011 DBG(dev, "1284 PNP String: %x %s\n", value,
1012 dev->pnp_string);
1013 break;
1014
1015 case GET_PORT_STATUS: /* Get Port Status */
1016 /* Only one printer interface is supported. */
1017 if (wIndex != dev->interface)
1018 break;
1019
1020 buf[0] = dev->printer_status;
1021 value = min_t(u16, wLength, 1);
1022 break;
1023
1024 case SOFT_RESET: /* Soft Reset */
1025 /* Only one printer interface is supported. */
1026 if (wIndex != dev->interface)
1027 break;
1028
1029 printer_soft_reset(dev);
1030
1031 value = 0;
1032 break;
1033
1034 default:
1035 goto unknown;
1036 }
1037 break;
1038
1039 default:
1040 unknown:
1041 VDBG(dev,
1042 "unknown ctrl req%02x.%02x v%04x i%04x l%d\n",
1043 ctrl->bRequestType, ctrl->bRequest,
1044 wValue, wIndex, wLength);
1045 break;
1046 }
1047 /* host either stalls (value < 0) or reports success */
1048 if (value >= 0) {
1049 req->length = value;
1050 req->zero = value < wLength;
1051 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
1052 if (value < 0) {
1053 ERROR(dev, "%s:%d Error!\n", __func__, __LINE__);
1054 req->status = 0;
1055 }
1056 }
1057 return value;
1058 }
1059
printer_func_bind(struct usb_configuration * c,struct usb_function * f)1060 static int printer_func_bind(struct usb_configuration *c,
1061 struct usb_function *f)
1062 {
1063 struct usb_gadget *gadget = c->cdev->gadget;
1064 struct printer_dev *dev = func_to_printer(f);
1065 struct device *pdev;
1066 struct usb_composite_dev *cdev = c->cdev;
1067 struct usb_ep *in_ep;
1068 struct usb_ep *out_ep = NULL;
1069 struct usb_request *req;
1070 dev_t devt;
1071 int id;
1072 int ret;
1073 u32 i;
1074
1075 id = usb_interface_id(c, f);
1076 if (id < 0)
1077 return id;
1078 intf_desc.bInterfaceNumber = id;
1079
1080 /* finish hookup to lower layer ... */
1081 dev->gadget = gadget;
1082
1083 /* all we really need is bulk IN/OUT */
1084 in_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_in_desc);
1085 if (!in_ep) {
1086 autoconf_fail:
1087 dev_err(&cdev->gadget->dev, "can't autoconfigure on %s\n",
1088 cdev->gadget->name);
1089 return -ENODEV;
1090 }
1091
1092 out_ep = usb_ep_autoconfig(cdev->gadget, &fs_ep_out_desc);
1093 if (!out_ep)
1094 goto autoconf_fail;
1095
1096 /* assumes that all endpoints are dual-speed */
1097 hs_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
1098 hs_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
1099 ss_ep_in_desc.bEndpointAddress = fs_ep_in_desc.bEndpointAddress;
1100 ss_ep_out_desc.bEndpointAddress = fs_ep_out_desc.bEndpointAddress;
1101
1102 ret = usb_assign_descriptors(f, fs_printer_function,
1103 hs_printer_function, ss_printer_function,
1104 ss_printer_function);
1105 if (ret)
1106 return ret;
1107
1108 dev->in_ep = in_ep;
1109 dev->out_ep = out_ep;
1110
1111 ret = -ENOMEM;
1112 for (i = 0; i < dev->q_len; i++) {
1113 req = printer_req_alloc(dev->in_ep, USB_BUFSIZE, GFP_KERNEL);
1114 if (!req)
1115 goto fail_tx_reqs;
1116 list_add(&req->list, &dev->tx_reqs);
1117 }
1118
1119 for (i = 0; i < dev->q_len; i++) {
1120 req = printer_req_alloc(dev->out_ep, USB_BUFSIZE, GFP_KERNEL);
1121 if (!req)
1122 goto fail_rx_reqs;
1123 list_add(&req->list, &dev->rx_reqs);
1124 }
1125
1126 /* Setup the sysfs files for the printer gadget. */
1127 devt = MKDEV(major, dev->minor);
1128 pdev = device_create(usb_gadget_class, NULL, devt,
1129 NULL, "g_printer%d", dev->minor);
1130 if (IS_ERR(pdev)) {
1131 ERROR(dev, "Failed to create device: g_printer\n");
1132 ret = PTR_ERR(pdev);
1133 goto fail_rx_reqs;
1134 }
1135
1136 /*
1137 * Register a character device as an interface to a user mode
1138 * program that handles the printer specific functionality.
1139 */
1140 cdev_init(&dev->printer_cdev, &printer_io_operations);
1141 dev->printer_cdev.owner = THIS_MODULE;
1142 ret = cdev_add(&dev->printer_cdev, devt, 1);
1143 if (ret) {
1144 ERROR(dev, "Failed to open char device\n");
1145 goto fail_cdev_add;
1146 }
1147
1148 return 0;
1149
1150 fail_cdev_add:
1151 device_destroy(usb_gadget_class, devt);
1152
1153 fail_rx_reqs:
1154 while (!list_empty(&dev->rx_reqs)) {
1155 req = container_of(dev->rx_reqs.next, struct usb_request, list);
1156 list_del(&req->list);
1157 printer_req_free(dev->out_ep, req);
1158 }
1159
1160 fail_tx_reqs:
1161 while (!list_empty(&dev->tx_reqs)) {
1162 req = container_of(dev->tx_reqs.next, struct usb_request, list);
1163 list_del(&req->list);
1164 printer_req_free(dev->in_ep, req);
1165 }
1166
1167 usb_free_all_descriptors(f);
1168 return ret;
1169
1170 }
1171
printer_func_set_alt(struct usb_function * f,unsigned intf,unsigned alt)1172 static int printer_func_set_alt(struct usb_function *f,
1173 unsigned intf, unsigned alt)
1174 {
1175 struct printer_dev *dev = func_to_printer(f);
1176 int ret = -ENOTSUPP;
1177
1178 if (!alt)
1179 ret = set_interface(dev, intf);
1180
1181 return ret;
1182 }
1183
printer_func_disable(struct usb_function * f)1184 static void printer_func_disable(struct usb_function *f)
1185 {
1186 struct printer_dev *dev = func_to_printer(f);
1187
1188 DBG(dev, "%s\n", __func__);
1189
1190 printer_reset_interface(dev);
1191 }
1192
1193 static inline struct f_printer_opts
to_f_printer_opts(struct config_item * item)1194 *to_f_printer_opts(struct config_item *item)
1195 {
1196 return container_of(to_config_group(item), struct f_printer_opts,
1197 func_inst.group);
1198 }
1199
printer_attr_release(struct config_item * item)1200 static void printer_attr_release(struct config_item *item)
1201 {
1202 struct f_printer_opts *opts = to_f_printer_opts(item);
1203
1204 usb_put_function_instance(&opts->func_inst);
1205 }
1206
1207 static struct configfs_item_operations printer_item_ops = {
1208 .release = printer_attr_release,
1209 };
1210
f_printer_opts_pnp_string_show(struct config_item * item,char * page)1211 static ssize_t f_printer_opts_pnp_string_show(struct config_item *item,
1212 char *page)
1213 {
1214 struct f_printer_opts *opts = to_f_printer_opts(item);
1215 int result = 0;
1216
1217 mutex_lock(&opts->lock);
1218 if (!opts->pnp_string)
1219 goto unlock;
1220
1221 result = strlcpy(page, opts->pnp_string, PAGE_SIZE);
1222 if (result >= PAGE_SIZE) {
1223 result = PAGE_SIZE;
1224 } else if (page[result - 1] != '\n' && result + 1 < PAGE_SIZE) {
1225 page[result++] = '\n';
1226 page[result] = '\0';
1227 }
1228
1229 unlock:
1230 mutex_unlock(&opts->lock);
1231
1232 return result;
1233 }
1234
f_printer_opts_pnp_string_store(struct config_item * item,const char * page,size_t len)1235 static ssize_t f_printer_opts_pnp_string_store(struct config_item *item,
1236 const char *page, size_t len)
1237 {
1238 struct f_printer_opts *opts = to_f_printer_opts(item);
1239 char *new_pnp;
1240 int result;
1241
1242 mutex_lock(&opts->lock);
1243
1244 new_pnp = kstrndup(page, len, GFP_KERNEL);
1245 if (!new_pnp) {
1246 result = -ENOMEM;
1247 goto unlock;
1248 }
1249
1250 if (opts->pnp_string_allocated)
1251 kfree(opts->pnp_string);
1252
1253 opts->pnp_string_allocated = true;
1254 opts->pnp_string = new_pnp;
1255 result = len;
1256 unlock:
1257 mutex_unlock(&opts->lock);
1258
1259 return result;
1260 }
1261
1262 CONFIGFS_ATTR(f_printer_opts_, pnp_string);
1263
f_printer_opts_q_len_show(struct config_item * item,char * page)1264 static ssize_t f_printer_opts_q_len_show(struct config_item *item,
1265 char *page)
1266 {
1267 struct f_printer_opts *opts = to_f_printer_opts(item);
1268 int result;
1269
1270 mutex_lock(&opts->lock);
1271 result = sprintf(page, "%d\n", opts->q_len);
1272 mutex_unlock(&opts->lock);
1273
1274 return result;
1275 }
1276
f_printer_opts_q_len_store(struct config_item * item,const char * page,size_t len)1277 static ssize_t f_printer_opts_q_len_store(struct config_item *item,
1278 const char *page, size_t len)
1279 {
1280 struct f_printer_opts *opts = to_f_printer_opts(item);
1281 int ret;
1282 u16 num;
1283
1284 mutex_lock(&opts->lock);
1285 if (opts->refcnt) {
1286 ret = -EBUSY;
1287 goto end;
1288 }
1289
1290 ret = kstrtou16(page, 0, &num);
1291 if (ret)
1292 goto end;
1293
1294 opts->q_len = (unsigned)num;
1295 ret = len;
1296 end:
1297 mutex_unlock(&opts->lock);
1298 return ret;
1299 }
1300
1301 CONFIGFS_ATTR(f_printer_opts_, q_len);
1302
1303 static struct configfs_attribute *printer_attrs[] = {
1304 &f_printer_opts_attr_pnp_string,
1305 &f_printer_opts_attr_q_len,
1306 NULL,
1307 };
1308
1309 static const struct config_item_type printer_func_type = {
1310 .ct_item_ops = &printer_item_ops,
1311 .ct_attrs = printer_attrs,
1312 .ct_owner = THIS_MODULE,
1313 };
1314
gprinter_get_minor(void)1315 static inline int gprinter_get_minor(void)
1316 {
1317 int ret;
1318
1319 ret = ida_simple_get(&printer_ida, 0, 0, GFP_KERNEL);
1320 if (ret >= PRINTER_MINORS) {
1321 ida_simple_remove(&printer_ida, ret);
1322 ret = -ENODEV;
1323 }
1324
1325 return ret;
1326 }
1327
gprinter_put_minor(int minor)1328 static inline void gprinter_put_minor(int minor)
1329 {
1330 ida_simple_remove(&printer_ida, minor);
1331 }
1332
1333 static int gprinter_setup(int);
1334 static void gprinter_cleanup(void);
1335
gprinter_free_inst(struct usb_function_instance * f)1336 static void gprinter_free_inst(struct usb_function_instance *f)
1337 {
1338 struct f_printer_opts *opts;
1339
1340 opts = container_of(f, struct f_printer_opts, func_inst);
1341
1342 mutex_lock(&printer_ida_lock);
1343
1344 gprinter_put_minor(opts->minor);
1345 if (ida_is_empty(&printer_ida))
1346 gprinter_cleanup();
1347
1348 mutex_unlock(&printer_ida_lock);
1349
1350 if (opts->pnp_string_allocated)
1351 kfree(opts->pnp_string);
1352 kfree(opts);
1353 }
1354
gprinter_alloc_inst(void)1355 static struct usb_function_instance *gprinter_alloc_inst(void)
1356 {
1357 struct f_printer_opts *opts;
1358 struct usb_function_instance *ret;
1359 int status = 0;
1360
1361 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1362 if (!opts)
1363 return ERR_PTR(-ENOMEM);
1364
1365 mutex_init(&opts->lock);
1366 opts->func_inst.free_func_inst = gprinter_free_inst;
1367 ret = &opts->func_inst;
1368
1369 /* Make sure q_len is initialized, otherwise the bound device can't support read/write! */
1370 opts->q_len = DEFAULT_Q_LEN;
1371
1372 mutex_lock(&printer_ida_lock);
1373
1374 if (ida_is_empty(&printer_ida)) {
1375 status = gprinter_setup(PRINTER_MINORS);
1376 if (status) {
1377 ret = ERR_PTR(status);
1378 kfree(opts);
1379 goto unlock;
1380 }
1381 }
1382
1383 opts->minor = gprinter_get_minor();
1384 if (opts->minor < 0) {
1385 ret = ERR_PTR(opts->minor);
1386 kfree(opts);
1387 if (ida_is_empty(&printer_ida))
1388 gprinter_cleanup();
1389 goto unlock;
1390 }
1391 config_group_init_type_name(&opts->func_inst.group, "",
1392 &printer_func_type);
1393
1394 unlock:
1395 mutex_unlock(&printer_ida_lock);
1396 return ret;
1397 }
1398
gprinter_free(struct usb_function * f)1399 static void gprinter_free(struct usb_function *f)
1400 {
1401 struct printer_dev *dev = func_to_printer(f);
1402 struct f_printer_opts *opts;
1403
1404 opts = container_of(f->fi, struct f_printer_opts, func_inst);
1405
1406 kref_put(&dev->kref, printer_dev_free);
1407 mutex_lock(&opts->lock);
1408 --opts->refcnt;
1409 mutex_unlock(&opts->lock);
1410 }
1411
printer_func_unbind(struct usb_configuration * c,struct usb_function * f)1412 static void printer_func_unbind(struct usb_configuration *c,
1413 struct usb_function *f)
1414 {
1415 struct printer_dev *dev;
1416 struct usb_request *req;
1417
1418 dev = func_to_printer(f);
1419
1420 device_destroy(usb_gadget_class, MKDEV(major, dev->minor));
1421
1422 /* Remove Character Device */
1423 cdev_del(&dev->printer_cdev);
1424
1425 /* we must already have been disconnected ... no i/o may be active */
1426 WARN_ON(!list_empty(&dev->tx_reqs_active));
1427 WARN_ON(!list_empty(&dev->rx_reqs_active));
1428
1429 /* Free all memory for this driver. */
1430 while (!list_empty(&dev->tx_reqs)) {
1431 req = container_of(dev->tx_reqs.next, struct usb_request,
1432 list);
1433 list_del(&req->list);
1434 printer_req_free(dev->in_ep, req);
1435 }
1436
1437 if (dev->current_rx_req != NULL)
1438 printer_req_free(dev->out_ep, dev->current_rx_req);
1439
1440 while (!list_empty(&dev->rx_reqs)) {
1441 req = container_of(dev->rx_reqs.next,
1442 struct usb_request, list);
1443 list_del(&req->list);
1444 printer_req_free(dev->out_ep, req);
1445 }
1446
1447 while (!list_empty(&dev->rx_buffers)) {
1448 req = container_of(dev->rx_buffers.next,
1449 struct usb_request, list);
1450 list_del(&req->list);
1451 printer_req_free(dev->out_ep, req);
1452 }
1453 usb_free_all_descriptors(f);
1454 }
1455
gprinter_alloc(struct usb_function_instance * fi)1456 static struct usb_function *gprinter_alloc(struct usb_function_instance *fi)
1457 {
1458 struct printer_dev *dev;
1459 struct f_printer_opts *opts;
1460
1461 opts = container_of(fi, struct f_printer_opts, func_inst);
1462
1463 mutex_lock(&opts->lock);
1464 if (opts->minor >= minors) {
1465 mutex_unlock(&opts->lock);
1466 return ERR_PTR(-ENOENT);
1467 }
1468
1469 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1470 if (!dev) {
1471 mutex_unlock(&opts->lock);
1472 return ERR_PTR(-ENOMEM);
1473 }
1474
1475 kref_init(&dev->kref);
1476 ++opts->refcnt;
1477 dev->minor = opts->minor;
1478 dev->pnp_string = opts->pnp_string;
1479 dev->q_len = opts->q_len;
1480 mutex_unlock(&opts->lock);
1481
1482 dev->function.name = "printer";
1483 dev->function.bind = printer_func_bind;
1484 dev->function.setup = printer_func_setup;
1485 dev->function.unbind = printer_func_unbind;
1486 dev->function.set_alt = printer_func_set_alt;
1487 dev->function.disable = printer_func_disable;
1488 dev->function.req_match = gprinter_req_match;
1489 dev->function.free_func = gprinter_free;
1490
1491 INIT_LIST_HEAD(&dev->tx_reqs);
1492 INIT_LIST_HEAD(&dev->rx_reqs);
1493 INIT_LIST_HEAD(&dev->rx_buffers);
1494 INIT_LIST_HEAD(&dev->tx_reqs_active);
1495 INIT_LIST_HEAD(&dev->rx_reqs_active);
1496
1497 spin_lock_init(&dev->lock);
1498 mutex_init(&dev->lock_printer_io);
1499 init_waitqueue_head(&dev->rx_wait);
1500 init_waitqueue_head(&dev->tx_wait);
1501 init_waitqueue_head(&dev->tx_flush_wait);
1502
1503 dev->interface = -1;
1504 dev->printer_cdev_open = 0;
1505 dev->printer_status = PRINTER_NOT_ERROR;
1506 dev->current_rx_req = NULL;
1507 dev->current_rx_bytes = 0;
1508 dev->current_rx_buf = NULL;
1509
1510 return &dev->function;
1511 }
1512
1513 DECLARE_USB_FUNCTION_INIT(printer, gprinter_alloc_inst, gprinter_alloc);
1514 MODULE_LICENSE("GPL");
1515 MODULE_AUTHOR("Craig Nadler");
1516
gprinter_setup(int count)1517 static int gprinter_setup(int count)
1518 {
1519 int status;
1520 dev_t devt;
1521
1522 usb_gadget_class = class_create(THIS_MODULE, "usb_printer_gadget");
1523 if (IS_ERR(usb_gadget_class)) {
1524 status = PTR_ERR(usb_gadget_class);
1525 usb_gadget_class = NULL;
1526 pr_err("unable to create usb_gadget class %d\n", status);
1527 return status;
1528 }
1529
1530 status = alloc_chrdev_region(&devt, 0, count, "USB printer gadget");
1531 if (status) {
1532 pr_err("alloc_chrdev_region %d\n", status);
1533 class_destroy(usb_gadget_class);
1534 usb_gadget_class = NULL;
1535 return status;
1536 }
1537
1538 major = MAJOR(devt);
1539 minors = count;
1540
1541 return status;
1542 }
1543
gprinter_cleanup(void)1544 static void gprinter_cleanup(void)
1545 {
1546 if (major) {
1547 unregister_chrdev_region(MKDEV(major, 0), minors);
1548 major = minors = 0;
1549 }
1550 class_destroy(usb_gadget_class);
1551 usb_gadget_class = NULL;
1552 }
1553