1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Native support for the I/O-Warrior USB devices
4 *
5 * Copyright (c) 2003-2005, 2020 Code Mercenaries GmbH
6 * written by Christian Lucht <[email protected]> and
7 * Christoph Jung <[email protected]>
8 *
9 * based on
10
11 * usb-skeleton.c by Greg Kroah-Hartman <[email protected]>
12 * brlvger.c by Stephane Dalton <[email protected]>
13 * and Stephane Doyon <[email protected]>
14 *
15 * Released under the GPLv2.
16 */
17
18 #include <linux/module.h>
19 #include <linux/usb.h>
20 #include <linux/slab.h>
21 #include <linux/sched.h>
22 #include <linux/mutex.h>
23 #include <linux/poll.h>
24 #include <linux/usb/iowarrior.h>
25
26 #define DRIVER_AUTHOR "Christian Lucht <[email protected]>"
27 #define DRIVER_DESC "USB IO-Warrior driver"
28
29 #define USB_VENDOR_ID_CODEMERCS 1984
30 /* low speed iowarrior */
31 #define USB_DEVICE_ID_CODEMERCS_IOW40 0x1500
32 #define USB_DEVICE_ID_CODEMERCS_IOW24 0x1501
33 #define USB_DEVICE_ID_CODEMERCS_IOWPV1 0x1511
34 #define USB_DEVICE_ID_CODEMERCS_IOWPV2 0x1512
35 /* full speed iowarrior */
36 #define USB_DEVICE_ID_CODEMERCS_IOW56 0x1503
37 /* fuller speed iowarrior */
38 #define USB_DEVICE_ID_CODEMERCS_IOW28 0x1504
39 #define USB_DEVICE_ID_CODEMERCS_IOW28L 0x1505
40 #define USB_DEVICE_ID_CODEMERCS_IOW100 0x1506
41
42 /* OEMed devices */
43 #define USB_DEVICE_ID_CODEMERCS_IOW24SAG 0x158a
44 #define USB_DEVICE_ID_CODEMERCS_IOW56AM 0x158b
45
46 /* Get a minor range for your devices from the usb maintainer */
47 #ifdef CONFIG_USB_DYNAMIC_MINORS
48 #define IOWARRIOR_MINOR_BASE 0
49 #else
50 #define IOWARRIOR_MINOR_BASE 208 // SKELETON_MINOR_BASE 192 + 16, not official yet
51 #endif
52
53 /* interrupt input queue size */
54 #define MAX_INTERRUPT_BUFFER 16
55 /*
56 maximum number of urbs that are submitted for writes at the same time,
57 this applies to the IOWarrior56 only!
58 IOWarrior24 and IOWarrior40 use synchronous usb_control_msg calls.
59 */
60 #define MAX_WRITES_IN_FLIGHT 4
61
62 MODULE_AUTHOR(DRIVER_AUTHOR);
63 MODULE_DESCRIPTION(DRIVER_DESC);
64 MODULE_LICENSE("GPL");
65
66 static struct usb_driver iowarrior_driver;
67
68 /*--------------*/
69 /* data */
70 /*--------------*/
71
72 /* Structure to hold all of our device specific stuff */
73 struct iowarrior {
74 struct mutex mutex; /* locks this structure */
75 struct usb_device *udev; /* save off the usb device pointer */
76 struct usb_interface *interface; /* the interface for this device */
77 unsigned char minor; /* the starting minor number for this device */
78 struct usb_endpoint_descriptor *int_out_endpoint; /* endpoint for reading (needed for IOW56 only) */
79 struct usb_endpoint_descriptor *int_in_endpoint; /* endpoint for reading */
80 struct urb *int_in_urb; /* the urb for reading data */
81 unsigned char *int_in_buffer; /* buffer for data to be read */
82 unsigned char serial_number; /* to detect lost packages */
83 unsigned char *read_queue; /* size is MAX_INTERRUPT_BUFFER * packet size */
84 wait_queue_head_t read_wait;
85 wait_queue_head_t write_wait; /* wait-queue for writing to the device */
86 atomic_t write_busy; /* number of write-urbs submitted */
87 atomic_t read_idx;
88 atomic_t intr_idx;
89 atomic_t overflow_flag; /* signals an index 'rollover' */
90 int present; /* this is 1 as long as the device is connected */
91 int opened; /* this is 1 if the device is currently open */
92 char chip_serial[9]; /* the serial number string of the chip connected */
93 int report_size; /* number of bytes in a report */
94 u16 product_id;
95 struct usb_anchor submitted;
96 };
97
98 /*--------------*/
99 /* globals */
100 /*--------------*/
101
102 #define USB_REQ_GET_REPORT 0x01
103 //#if 0
usb_get_report(struct usb_device * dev,struct usb_host_interface * inter,unsigned char type,unsigned char id,void * buf,int size)104 static int usb_get_report(struct usb_device *dev,
105 struct usb_host_interface *inter, unsigned char type,
106 unsigned char id, void *buf, int size)
107 {
108 return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
109 USB_REQ_GET_REPORT,
110 USB_DIR_IN | USB_TYPE_CLASS |
111 USB_RECIP_INTERFACE, (type << 8) + id,
112 inter->desc.bInterfaceNumber, buf, size,
113 USB_CTRL_GET_TIMEOUT);
114 }
115 //#endif
116
117 #define USB_REQ_SET_REPORT 0x09
118
usb_set_report(struct usb_interface * intf,unsigned char type,unsigned char id,void * buf,int size)119 static int usb_set_report(struct usb_interface *intf, unsigned char type,
120 unsigned char id, void *buf, int size)
121 {
122 return usb_control_msg(interface_to_usbdev(intf),
123 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
124 USB_REQ_SET_REPORT,
125 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
126 (type << 8) + id,
127 intf->cur_altsetting->desc.bInterfaceNumber, buf,
128 size, 1000);
129 }
130
131 /*---------------------*/
132 /* driver registration */
133 /*---------------------*/
134 /* table of devices that work with this driver */
135 static const struct usb_device_id iowarrior_ids[] = {
136 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW40)},
137 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24)},
138 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV1)},
139 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV2)},
140 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56)},
141 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24SAG)},
142 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56AM)},
143 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW28)},
144 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW28L)},
145 {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW100)},
146 {} /* Terminating entry */
147 };
148 MODULE_DEVICE_TABLE(usb, iowarrior_ids);
149
150 /*
151 * USB callback handler for reading data
152 */
iowarrior_callback(struct urb * urb)153 static void iowarrior_callback(struct urb *urb)
154 {
155 struct iowarrior *dev = urb->context;
156 int intr_idx;
157 int read_idx;
158 int aux_idx;
159 int offset;
160 int status = urb->status;
161 int retval;
162
163 switch (status) {
164 case 0:
165 /* success */
166 break;
167 case -ECONNRESET:
168 case -ENOENT:
169 case -ESHUTDOWN:
170 return;
171 default:
172 goto exit;
173 }
174
175 intr_idx = atomic_read(&dev->intr_idx);
176 /* aux_idx become previous intr_idx */
177 aux_idx = (intr_idx == 0) ? (MAX_INTERRUPT_BUFFER - 1) : (intr_idx - 1);
178 read_idx = atomic_read(&dev->read_idx);
179
180 /* queue is not empty and it's interface 0 */
181 if ((intr_idx != read_idx)
182 && (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0)) {
183 /* + 1 for serial number */
184 offset = aux_idx * (dev->report_size + 1);
185 if (!memcmp
186 (dev->read_queue + offset, urb->transfer_buffer,
187 dev->report_size)) {
188 /* equal values on interface 0 will be ignored */
189 goto exit;
190 }
191 }
192
193 /* aux_idx become next intr_idx */
194 aux_idx = (intr_idx == (MAX_INTERRUPT_BUFFER - 1)) ? 0 : (intr_idx + 1);
195 if (read_idx == aux_idx) {
196 /* queue full, dropping oldest input */
197 read_idx = (++read_idx == MAX_INTERRUPT_BUFFER) ? 0 : read_idx;
198 atomic_set(&dev->read_idx, read_idx);
199 atomic_set(&dev->overflow_flag, 1);
200 }
201
202 /* +1 for serial number */
203 offset = intr_idx * (dev->report_size + 1);
204 memcpy(dev->read_queue + offset, urb->transfer_buffer,
205 dev->report_size);
206 *(dev->read_queue + offset + (dev->report_size)) = dev->serial_number++;
207
208 atomic_set(&dev->intr_idx, aux_idx);
209 /* tell the blocking read about the new data */
210 wake_up_interruptible(&dev->read_wait);
211
212 exit:
213 retval = usb_submit_urb(urb, GFP_ATOMIC);
214 if (retval)
215 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d\n",
216 __func__, retval);
217
218 }
219
220 /*
221 * USB Callback handler for write-ops
222 */
iowarrior_write_callback(struct urb * urb)223 static void iowarrior_write_callback(struct urb *urb)
224 {
225 struct iowarrior *dev;
226 int status = urb->status;
227
228 dev = urb->context;
229 /* sync/async unlink faults aren't errors */
230 if (status &&
231 !(status == -ENOENT ||
232 status == -ECONNRESET || status == -ESHUTDOWN)) {
233 dev_dbg(&dev->interface->dev,
234 "nonzero write bulk status received: %d\n", status);
235 }
236 /* free up our allocated buffer */
237 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
238 urb->transfer_buffer, urb->transfer_dma);
239 /* tell a waiting writer the interrupt-out-pipe is available again */
240 atomic_dec(&dev->write_busy);
241 wake_up_interruptible(&dev->write_wait);
242 }
243
244 /*
245 * iowarrior_delete
246 */
iowarrior_delete(struct iowarrior * dev)247 static inline void iowarrior_delete(struct iowarrior *dev)
248 {
249 dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
250 kfree(dev->int_in_buffer);
251 usb_free_urb(dev->int_in_urb);
252 kfree(dev->read_queue);
253 usb_put_intf(dev->interface);
254 kfree(dev);
255 }
256
257 /*---------------------*/
258 /* fops implementation */
259 /*---------------------*/
260
read_index(struct iowarrior * dev)261 static int read_index(struct iowarrior *dev)
262 {
263 int intr_idx, read_idx;
264
265 read_idx = atomic_read(&dev->read_idx);
266 intr_idx = atomic_read(&dev->intr_idx);
267
268 return (read_idx == intr_idx ? -1 : read_idx);
269 }
270
271 /*
272 * iowarrior_read
273 */
iowarrior_read(struct file * file,char __user * buffer,size_t count,loff_t * ppos)274 static ssize_t iowarrior_read(struct file *file, char __user *buffer,
275 size_t count, loff_t *ppos)
276 {
277 struct iowarrior *dev;
278 int read_idx;
279 int offset;
280 int retval;
281
282 dev = file->private_data;
283
284 if (file->f_flags & O_NONBLOCK) {
285 retval = mutex_trylock(&dev->mutex);
286 if (!retval)
287 return -EAGAIN;
288 } else {
289 retval = mutex_lock_interruptible(&dev->mutex);
290 if (retval)
291 return -ERESTARTSYS;
292 }
293
294 /* verify that the device wasn't unplugged */
295 if (!dev->present) {
296 retval = -ENODEV;
297 goto exit;
298 }
299
300 dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
301 dev->minor, count);
302
303 /* read count must be packet size (+ time stamp) */
304 if ((count != dev->report_size)
305 && (count != (dev->report_size + 1))) {
306 retval = -EINVAL;
307 goto exit;
308 }
309
310 /* repeat until no buffer overrun in callback handler occur */
311 do {
312 atomic_set(&dev->overflow_flag, 0);
313 if ((read_idx = read_index(dev)) == -1) {
314 /* queue empty */
315 if (file->f_flags & O_NONBLOCK) {
316 retval = -EAGAIN;
317 goto exit;
318 }
319 else {
320 //next line will return when there is either new data, or the device is unplugged
321 int r = wait_event_interruptible(dev->read_wait,
322 (!dev->present
323 || (read_idx =
324 read_index
325 (dev)) !=
326 -1));
327 if (r) {
328 //we were interrupted by a signal
329 retval = -ERESTART;
330 goto exit;
331 }
332 if (!dev->present) {
333 //The device was unplugged
334 retval = -ENODEV;
335 goto exit;
336 }
337 if (read_idx == -1) {
338 // Can this happen ???
339 retval = 0;
340 goto exit;
341 }
342 }
343 }
344
345 offset = read_idx * (dev->report_size + 1);
346 if (copy_to_user(buffer, dev->read_queue + offset, count)) {
347 retval = -EFAULT;
348 goto exit;
349 }
350 } while (atomic_read(&dev->overflow_flag));
351
352 read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
353 atomic_set(&dev->read_idx, read_idx);
354 mutex_unlock(&dev->mutex);
355 return count;
356
357 exit:
358 mutex_unlock(&dev->mutex);
359 return retval;
360 }
361
362 /*
363 * iowarrior_write
364 */
iowarrior_write(struct file * file,const char __user * user_buffer,size_t count,loff_t * ppos)365 static ssize_t iowarrior_write(struct file *file,
366 const char __user *user_buffer,
367 size_t count, loff_t *ppos)
368 {
369 struct iowarrior *dev;
370 int retval = 0;
371 char *buf = NULL; /* for IOW24 and IOW56 we need a buffer */
372 struct urb *int_out_urb = NULL;
373
374 dev = file->private_data;
375
376 mutex_lock(&dev->mutex);
377 /* verify that the device wasn't unplugged */
378 if (!dev->present) {
379 retval = -ENODEV;
380 goto exit;
381 }
382 dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
383 dev->minor, count);
384 /* if count is 0 we're already done */
385 if (count == 0) {
386 retval = 0;
387 goto exit;
388 }
389 /* We only accept full reports */
390 if (count != dev->report_size) {
391 retval = -EINVAL;
392 goto exit;
393 }
394 switch (dev->product_id) {
395 case USB_DEVICE_ID_CODEMERCS_IOW24:
396 case USB_DEVICE_ID_CODEMERCS_IOW24SAG:
397 case USB_DEVICE_ID_CODEMERCS_IOWPV1:
398 case USB_DEVICE_ID_CODEMERCS_IOWPV2:
399 case USB_DEVICE_ID_CODEMERCS_IOW40:
400 /* IOW24 and IOW40 use a synchronous call */
401 buf = memdup_user(user_buffer, count);
402 if (IS_ERR(buf)) {
403 retval = PTR_ERR(buf);
404 goto exit;
405 }
406 retval = usb_set_report(dev->interface, 2, 0, buf, count);
407 kfree(buf);
408 goto exit;
409 case USB_DEVICE_ID_CODEMERCS_IOW56:
410 case USB_DEVICE_ID_CODEMERCS_IOW56AM:
411 case USB_DEVICE_ID_CODEMERCS_IOW28:
412 case USB_DEVICE_ID_CODEMERCS_IOW28L:
413 case USB_DEVICE_ID_CODEMERCS_IOW100:
414 /* The IOW56 uses asynchronous IO and more urbs */
415 if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
416 /* Wait until we are below the limit for submitted urbs */
417 if (file->f_flags & O_NONBLOCK) {
418 retval = -EAGAIN;
419 goto exit;
420 } else {
421 retval = wait_event_interruptible(dev->write_wait,
422 (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
423 if (retval) {
424 /* we were interrupted by a signal */
425 retval = -ERESTART;
426 goto exit;
427 }
428 if (!dev->present) {
429 /* The device was unplugged */
430 retval = -ENODEV;
431 goto exit;
432 }
433 if (!dev->opened) {
434 /* We were closed while waiting for an URB */
435 retval = -ENODEV;
436 goto exit;
437 }
438 }
439 }
440 atomic_inc(&dev->write_busy);
441 int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
442 if (!int_out_urb) {
443 retval = -ENOMEM;
444 goto error_no_urb;
445 }
446 buf = usb_alloc_coherent(dev->udev, dev->report_size,
447 GFP_KERNEL, &int_out_urb->transfer_dma);
448 if (!buf) {
449 retval = -ENOMEM;
450 dev_dbg(&dev->interface->dev,
451 "Unable to allocate buffer\n");
452 goto error_no_buffer;
453 }
454 usb_fill_int_urb(int_out_urb, dev->udev,
455 usb_sndintpipe(dev->udev,
456 dev->int_out_endpoint->bEndpointAddress),
457 buf, dev->report_size,
458 iowarrior_write_callback, dev,
459 dev->int_out_endpoint->bInterval);
460 int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
461 if (copy_from_user(buf, user_buffer, count)) {
462 retval = -EFAULT;
463 goto error;
464 }
465 usb_anchor_urb(int_out_urb, &dev->submitted);
466 retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
467 if (retval) {
468 dev_dbg(&dev->interface->dev,
469 "submit error %d for urb nr.%d\n",
470 retval, atomic_read(&dev->write_busy));
471 usb_unanchor_urb(int_out_urb);
472 goto error;
473 }
474 /* submit was ok */
475 retval = count;
476 usb_free_urb(int_out_urb);
477 goto exit;
478 default:
479 /* what do we have here ? An unsupported Product-ID ? */
480 dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
481 __func__, dev->product_id);
482 retval = -EFAULT;
483 goto exit;
484 }
485 error:
486 usb_free_coherent(dev->udev, dev->report_size, buf,
487 int_out_urb->transfer_dma);
488 error_no_buffer:
489 usb_free_urb(int_out_urb);
490 error_no_urb:
491 atomic_dec(&dev->write_busy);
492 wake_up_interruptible(&dev->write_wait);
493 exit:
494 mutex_unlock(&dev->mutex);
495 return retval;
496 }
497
498 /*
499 * iowarrior_ioctl
500 */
iowarrior_ioctl(struct file * file,unsigned int cmd,unsigned long arg)501 static long iowarrior_ioctl(struct file *file, unsigned int cmd,
502 unsigned long arg)
503 {
504 struct iowarrior *dev = NULL;
505 __u8 *buffer;
506 __u8 __user *user_buffer;
507 int retval;
508 int io_res; /* checks for bytes read/written and copy_to/from_user results */
509
510 dev = file->private_data;
511 if (!dev)
512 return -ENODEV;
513
514 buffer = kzalloc(dev->report_size, GFP_KERNEL);
515 if (!buffer)
516 return -ENOMEM;
517
518 mutex_lock(&dev->mutex);
519
520 /* verify that the device wasn't unplugged */
521 if (!dev->present) {
522 retval = -ENODEV;
523 goto error_out;
524 }
525
526 dev_dbg(&dev->interface->dev, "minor %d, cmd 0x%.4x, arg %ld\n",
527 dev->minor, cmd, arg);
528
529 retval = 0;
530 switch (cmd) {
531 case IOW_WRITE:
532 if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
533 dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24SAG ||
534 dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
535 dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
536 dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
537 user_buffer = (__u8 __user *)arg;
538 io_res = copy_from_user(buffer, user_buffer,
539 dev->report_size);
540 if (io_res) {
541 retval = -EFAULT;
542 } else {
543 io_res = usb_set_report(dev->interface, 2, 0,
544 buffer,
545 dev->report_size);
546 if (io_res < 0)
547 retval = io_res;
548 }
549 } else {
550 retval = -EINVAL;
551 dev_err(&dev->interface->dev,
552 "ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
553 dev->product_id);
554 }
555 break;
556 case IOW_READ:
557 user_buffer = (__u8 __user *)arg;
558 io_res = usb_get_report(dev->udev,
559 dev->interface->cur_altsetting, 1, 0,
560 buffer, dev->report_size);
561 if (io_res < 0)
562 retval = io_res;
563 else {
564 io_res = copy_to_user(user_buffer, buffer, dev->report_size);
565 if (io_res)
566 retval = -EFAULT;
567 }
568 break;
569 case IOW_GETINFO:
570 {
571 /* Report available information for the device */
572 struct iowarrior_info info;
573 /* needed for power consumption */
574 struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
575
576 memset(&info, 0, sizeof(info));
577 /* directly from the descriptor */
578 info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
579 info.product = dev->product_id;
580 info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
581
582 /* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
583 info.speed = dev->udev->speed;
584 info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
585 info.report_size = dev->report_size;
586
587 /* serial number string has been read earlier 8 chars or empty string */
588 memcpy(info.serial, dev->chip_serial,
589 sizeof(dev->chip_serial));
590 if (cfg_descriptor == NULL) {
591 info.power = -1; /* no information available */
592 } else {
593 /* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
594 info.power = cfg_descriptor->bMaxPower * 2;
595 }
596 io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
597 sizeof(struct iowarrior_info));
598 if (io_res)
599 retval = -EFAULT;
600 break;
601 }
602 default:
603 /* return that we did not understand this ioctl call */
604 retval = -ENOTTY;
605 break;
606 }
607 error_out:
608 /* unlock the device */
609 mutex_unlock(&dev->mutex);
610 kfree(buffer);
611 return retval;
612 }
613
614 /*
615 * iowarrior_open
616 */
iowarrior_open(struct inode * inode,struct file * file)617 static int iowarrior_open(struct inode *inode, struct file *file)
618 {
619 struct iowarrior *dev = NULL;
620 struct usb_interface *interface;
621 int subminor;
622 int retval = 0;
623
624 subminor = iminor(inode);
625
626 interface = usb_find_interface(&iowarrior_driver, subminor);
627 if (!interface) {
628 pr_err("%s - error, can't find device for minor %d\n",
629 __func__, subminor);
630 return -ENODEV;
631 }
632
633 dev = usb_get_intfdata(interface);
634 if (!dev)
635 return -ENODEV;
636
637 mutex_lock(&dev->mutex);
638
639 /* Only one process can open each device, no sharing. */
640 if (dev->opened) {
641 retval = -EBUSY;
642 goto out;
643 }
644
645 /* setup interrupt handler for receiving values */
646 if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
647 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
648 retval = -EFAULT;
649 goto out;
650 }
651 /* increment our usage count for the driver */
652 ++dev->opened;
653 /* save our object in the file's private structure */
654 file->private_data = dev;
655 retval = 0;
656
657 out:
658 mutex_unlock(&dev->mutex);
659 return retval;
660 }
661
662 /*
663 * iowarrior_release
664 */
iowarrior_release(struct inode * inode,struct file * file)665 static int iowarrior_release(struct inode *inode, struct file *file)
666 {
667 struct iowarrior *dev;
668 int retval = 0;
669
670 dev = file->private_data;
671 if (!dev)
672 return -ENODEV;
673
674 dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
675
676 /* lock our device */
677 mutex_lock(&dev->mutex);
678
679 if (dev->opened <= 0) {
680 retval = -ENODEV; /* close called more than once */
681 mutex_unlock(&dev->mutex);
682 } else {
683 dev->opened = 0; /* we're closing now */
684 retval = 0;
685 if (dev->present) {
686 /*
687 The device is still connected so we only shutdown
688 pending read-/write-ops.
689 */
690 usb_kill_urb(dev->int_in_urb);
691 wake_up_interruptible(&dev->read_wait);
692 wake_up_interruptible(&dev->write_wait);
693 mutex_unlock(&dev->mutex);
694 } else {
695 /* The device was unplugged, cleanup resources */
696 mutex_unlock(&dev->mutex);
697 iowarrior_delete(dev);
698 }
699 }
700 return retval;
701 }
702
iowarrior_poll(struct file * file,poll_table * wait)703 static __poll_t iowarrior_poll(struct file *file, poll_table * wait)
704 {
705 struct iowarrior *dev = file->private_data;
706 __poll_t mask = 0;
707
708 if (!dev->present)
709 return EPOLLERR | EPOLLHUP;
710
711 poll_wait(file, &dev->read_wait, wait);
712 poll_wait(file, &dev->write_wait, wait);
713
714 if (!dev->present)
715 return EPOLLERR | EPOLLHUP;
716
717 if (read_index(dev) != -1)
718 mask |= EPOLLIN | EPOLLRDNORM;
719
720 if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
721 mask |= EPOLLOUT | EPOLLWRNORM;
722 return mask;
723 }
724
725 /*
726 * File operations needed when we register this driver.
727 * This assumes that this driver NEEDS file operations,
728 * of course, which means that the driver is expected
729 * to have a node in the /dev directory. If the USB
730 * device were for a network interface then the driver
731 * would use "struct net_driver" instead, and a serial
732 * device would use "struct tty_driver".
733 */
734 static const struct file_operations iowarrior_fops = {
735 .owner = THIS_MODULE,
736 .write = iowarrior_write,
737 .read = iowarrior_read,
738 .unlocked_ioctl = iowarrior_ioctl,
739 .open = iowarrior_open,
740 .release = iowarrior_release,
741 .poll = iowarrior_poll,
742 .llseek = noop_llseek,
743 };
744
iowarrior_devnode(const struct device * dev,umode_t * mode)745 static char *iowarrior_devnode(const struct device *dev, umode_t *mode)
746 {
747 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
748 }
749
750 /*
751 * usb class driver info in order to get a minor number from the usb core,
752 * and to have the device registered with devfs and the driver core
753 */
754 static struct usb_class_driver iowarrior_class = {
755 .name = "iowarrior%d",
756 .devnode = iowarrior_devnode,
757 .fops = &iowarrior_fops,
758 .minor_base = IOWARRIOR_MINOR_BASE,
759 };
760
761 /*---------------------------------*/
762 /* probe and disconnect functions */
763 /*---------------------------------*/
764 /*
765 * iowarrior_probe
766 *
767 * Called by the usb core when a new device is connected that it thinks
768 * this driver might be interested in.
769 */
iowarrior_probe(struct usb_interface * interface,const struct usb_device_id * id)770 static int iowarrior_probe(struct usb_interface *interface,
771 const struct usb_device_id *id)
772 {
773 struct usb_device *udev = interface_to_usbdev(interface);
774 struct iowarrior *dev = NULL;
775 struct usb_host_interface *iface_desc;
776 int retval = -ENOMEM;
777 int res;
778
779 /* allocate memory for our device state and initialize it */
780 dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
781 if (!dev)
782 return retval;
783
784 mutex_init(&dev->mutex);
785
786 atomic_set(&dev->intr_idx, 0);
787 atomic_set(&dev->read_idx, 0);
788 atomic_set(&dev->overflow_flag, 0);
789 init_waitqueue_head(&dev->read_wait);
790 atomic_set(&dev->write_busy, 0);
791 init_waitqueue_head(&dev->write_wait);
792
793 dev->udev = udev;
794 dev->interface = usb_get_intf(interface);
795
796 iface_desc = interface->cur_altsetting;
797 dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
798
799 init_usb_anchor(&dev->submitted);
800
801 res = usb_find_last_int_in_endpoint(iface_desc, &dev->int_in_endpoint);
802 if (res) {
803 dev_err(&interface->dev, "no interrupt-in endpoint found\n");
804 retval = res;
805 goto error;
806 }
807
808 if ((dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56) ||
809 (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56AM) ||
810 (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28) ||
811 (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28L) ||
812 (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW100)) {
813 res = usb_find_last_int_out_endpoint(iface_desc,
814 &dev->int_out_endpoint);
815 if (res) {
816 dev_err(&interface->dev, "no interrupt-out endpoint found\n");
817 retval = res;
818 goto error;
819 }
820 }
821
822 /* we have to check the report_size often, so remember it in the endianness suitable for our machine */
823 dev->report_size = usb_endpoint_maxp(dev->int_in_endpoint);
824
825 /*
826 * Some devices need the report size to be different than the
827 * endpoint size.
828 */
829 if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
830 switch (dev->product_id) {
831 case USB_DEVICE_ID_CODEMERCS_IOW56:
832 case USB_DEVICE_ID_CODEMERCS_IOW56AM:
833 dev->report_size = 7;
834 break;
835
836 case USB_DEVICE_ID_CODEMERCS_IOW28:
837 case USB_DEVICE_ID_CODEMERCS_IOW28L:
838 dev->report_size = 4;
839 break;
840
841 case USB_DEVICE_ID_CODEMERCS_IOW100:
842 dev->report_size = 12;
843 break;
844 }
845 }
846
847 /* create the urb and buffer for reading */
848 dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
849 if (!dev->int_in_urb)
850 goto error;
851 dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
852 if (!dev->int_in_buffer)
853 goto error;
854 usb_fill_int_urb(dev->int_in_urb, dev->udev,
855 usb_rcvintpipe(dev->udev,
856 dev->int_in_endpoint->bEndpointAddress),
857 dev->int_in_buffer, dev->report_size,
858 iowarrior_callback, dev,
859 dev->int_in_endpoint->bInterval);
860 /* create an internal buffer for interrupt data from the device */
861 dev->read_queue =
862 kmalloc_array(dev->report_size + 1, MAX_INTERRUPT_BUFFER,
863 GFP_KERNEL);
864 if (!dev->read_queue)
865 goto error;
866 /* Get the serial-number of the chip */
867 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
868 usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
869 sizeof(dev->chip_serial));
870 if (strlen(dev->chip_serial) != 8)
871 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
872
873 /* Set the idle timeout to 0, if this is interface 0 */
874 if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
875 usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
876 0x0A,
877 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
878 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
879 }
880 /* allow device read and ioctl */
881 dev->present = 1;
882
883 /* we can register the device now, as it is ready */
884 usb_set_intfdata(interface, dev);
885
886 retval = usb_register_dev(interface, &iowarrior_class);
887 if (retval) {
888 /* something prevented us from registering this driver */
889 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
890 goto error;
891 }
892
893 dev->minor = interface->minor;
894
895 /* let the user know what node this device is now attached to */
896 dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
897 "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
898 iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
899 return retval;
900
901 error:
902 iowarrior_delete(dev);
903 return retval;
904 }
905
906 /*
907 * iowarrior_disconnect
908 *
909 * Called by the usb core when the device is removed from the system.
910 */
iowarrior_disconnect(struct usb_interface * interface)911 static void iowarrior_disconnect(struct usb_interface *interface)
912 {
913 struct iowarrior *dev = usb_get_intfdata(interface);
914
915 usb_deregister_dev(interface, &iowarrior_class);
916
917 mutex_lock(&dev->mutex);
918
919 /* prevent device read, write and ioctl */
920 dev->present = 0;
921
922 if (dev->opened) {
923 /* There is a process that holds a filedescriptor to the device ,
924 so we only shutdown read-/write-ops going on.
925 Deleting the device is postponed until close() was called.
926 */
927 usb_kill_urb(dev->int_in_urb);
928 usb_kill_anchored_urbs(&dev->submitted);
929 wake_up_interruptible(&dev->read_wait);
930 wake_up_interruptible(&dev->write_wait);
931 mutex_unlock(&dev->mutex);
932 } else {
933 /* no process is using the device, cleanup now */
934 mutex_unlock(&dev->mutex);
935 iowarrior_delete(dev);
936 }
937 }
938
939 /* usb specific object needed to register this driver with the usb subsystem */
940 static struct usb_driver iowarrior_driver = {
941 .name = "iowarrior",
942 .probe = iowarrior_probe,
943 .disconnect = iowarrior_disconnect,
944 .id_table = iowarrior_ids,
945 };
946
947 module_usb_driver(iowarrior_driver);
948