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 <lucht@codemercs.com> and
7 * Christoph Jung <jung@codemercs.com>
8 *
9 * based on
10
11 * usb-skeleton.c by Greg Kroah-Hartman <greg@kroah.com>
12 * brlvger.c by Stephane Dalton <sdalton@videotron.ca>
13 * and Stephane Doyon <s.doyon@videotron.ca>
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 <lucht@codemercs.com>"
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
281 dev = file->private_data;
282
283 /* verify that the device wasn't unplugged */
284 if (!dev || !dev->present)
285 return -ENODEV;
286
287 dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
288 dev->minor, count);
289
290 /* read count must be packet size (+ time stamp) */
291 if ((count != dev->report_size)
292 && (count != (dev->report_size + 1)))
293 return -EINVAL;
294
295 /* repeat until no buffer overrun in callback handler occur */
296 do {
297 atomic_set(&dev->overflow_flag, 0);
298 if ((read_idx = read_index(dev)) == -1) {
299 /* queue empty */
300 if (file->f_flags & O_NONBLOCK)
301 return -EAGAIN;
302 else {
303 //next line will return when there is either new data, or the device is unplugged
304 int r = wait_event_interruptible(dev->read_wait,
305 (!dev->present
306 || (read_idx =
307 read_index
308 (dev)) !=
309 -1));
310 if (r) {
311 //we were interrupted by a signal
312 return -ERESTART;
313 }
314 if (!dev->present) {
315 //The device was unplugged
316 return -ENODEV;
317 }
318 if (read_idx == -1) {
319 // Can this happen ???
320 return 0;
321 }
322 }
323 }
324
325 offset = read_idx * (dev->report_size + 1);
326 if (copy_to_user(buffer, dev->read_queue + offset, count)) {
327 return -EFAULT;
328 }
329 } while (atomic_read(&dev->overflow_flag));
330
331 read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
332 atomic_set(&dev->read_idx, read_idx);
333 return count;
334 }
335
336 /*
337 * iowarrior_write
338 */
iowarrior_write(struct file * file,const char __user * user_buffer,size_t count,loff_t * ppos)339 static ssize_t iowarrior_write(struct file *file,
340 const char __user *user_buffer,
341 size_t count, loff_t *ppos)
342 {
343 struct iowarrior *dev;
344 int retval = 0;
345 char *buf = NULL; /* for IOW24 and IOW56 we need a buffer */
346 struct urb *int_out_urb = NULL;
347
348 dev = file->private_data;
349
350 mutex_lock(&dev->mutex);
351 /* verify that the device wasn't unplugged */
352 if (!dev->present) {
353 retval = -ENODEV;
354 goto exit;
355 }
356 dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
357 dev->minor, count);
358 /* if count is 0 we're already done */
359 if (count == 0) {
360 retval = 0;
361 goto exit;
362 }
363 /* We only accept full reports */
364 if (count != dev->report_size) {
365 retval = -EINVAL;
366 goto exit;
367 }
368 switch (dev->product_id) {
369 case USB_DEVICE_ID_CODEMERCS_IOW24:
370 case USB_DEVICE_ID_CODEMERCS_IOW24SAG:
371 case USB_DEVICE_ID_CODEMERCS_IOWPV1:
372 case USB_DEVICE_ID_CODEMERCS_IOWPV2:
373 case USB_DEVICE_ID_CODEMERCS_IOW40:
374 /* IOW24 and IOW40 use a synchronous call */
375 buf = memdup_user(user_buffer, count);
376 if (IS_ERR(buf)) {
377 retval = PTR_ERR(buf);
378 goto exit;
379 }
380 retval = usb_set_report(dev->interface, 2, 0, buf, count);
381 kfree(buf);
382 goto exit;
383 break;
384 case USB_DEVICE_ID_CODEMERCS_IOW56:
385 case USB_DEVICE_ID_CODEMERCS_IOW56AM:
386 case USB_DEVICE_ID_CODEMERCS_IOW28:
387 case USB_DEVICE_ID_CODEMERCS_IOW28L:
388 case USB_DEVICE_ID_CODEMERCS_IOW100:
389 /* The IOW56 uses asynchronous IO and more urbs */
390 if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
391 /* Wait until we are below the limit for submitted urbs */
392 if (file->f_flags & O_NONBLOCK) {
393 retval = -EAGAIN;
394 goto exit;
395 } else {
396 retval = wait_event_interruptible(dev->write_wait,
397 (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
398 if (retval) {
399 /* we were interrupted by a signal */
400 retval = -ERESTART;
401 goto exit;
402 }
403 if (!dev->present) {
404 /* The device was unplugged */
405 retval = -ENODEV;
406 goto exit;
407 }
408 if (!dev->opened) {
409 /* We were closed while waiting for an URB */
410 retval = -ENODEV;
411 goto exit;
412 }
413 }
414 }
415 atomic_inc(&dev->write_busy);
416 int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
417 if (!int_out_urb) {
418 retval = -ENOMEM;
419 goto error_no_urb;
420 }
421 buf = usb_alloc_coherent(dev->udev, dev->report_size,
422 GFP_KERNEL, &int_out_urb->transfer_dma);
423 if (!buf) {
424 retval = -ENOMEM;
425 dev_dbg(&dev->interface->dev,
426 "Unable to allocate buffer\n");
427 goto error_no_buffer;
428 }
429 usb_fill_int_urb(int_out_urb, dev->udev,
430 usb_sndintpipe(dev->udev,
431 dev->int_out_endpoint->bEndpointAddress),
432 buf, dev->report_size,
433 iowarrior_write_callback, dev,
434 dev->int_out_endpoint->bInterval);
435 int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
436 if (copy_from_user(buf, user_buffer, count)) {
437 retval = -EFAULT;
438 goto error;
439 }
440 usb_anchor_urb(int_out_urb, &dev->submitted);
441 retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
442 if (retval) {
443 dev_dbg(&dev->interface->dev,
444 "submit error %d for urb nr.%d\n",
445 retval, atomic_read(&dev->write_busy));
446 usb_unanchor_urb(int_out_urb);
447 goto error;
448 }
449 /* submit was ok */
450 retval = count;
451 usb_free_urb(int_out_urb);
452 goto exit;
453 break;
454 default:
455 /* what do we have here ? An unsupported Product-ID ? */
456 dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
457 __func__, dev->product_id);
458 retval = -EFAULT;
459 goto exit;
460 break;
461 }
462 error:
463 usb_free_coherent(dev->udev, dev->report_size, buf,
464 int_out_urb->transfer_dma);
465 error_no_buffer:
466 usb_free_urb(int_out_urb);
467 error_no_urb:
468 atomic_dec(&dev->write_busy);
469 wake_up_interruptible(&dev->write_wait);
470 exit:
471 mutex_unlock(&dev->mutex);
472 return retval;
473 }
474
475 /*
476 * iowarrior_ioctl
477 */
iowarrior_ioctl(struct file * file,unsigned int cmd,unsigned long arg)478 static long iowarrior_ioctl(struct file *file, unsigned int cmd,
479 unsigned long arg)
480 {
481 struct iowarrior *dev = NULL;
482 __u8 *buffer;
483 __u8 __user *user_buffer;
484 int retval;
485 int io_res; /* checks for bytes read/written and copy_to/from_user results */
486
487 dev = file->private_data;
488 if (!dev)
489 return -ENODEV;
490
491 buffer = kzalloc(dev->report_size, GFP_KERNEL);
492 if (!buffer)
493 return -ENOMEM;
494
495 mutex_lock(&dev->mutex);
496
497 /* verify that the device wasn't unplugged */
498 if (!dev->present) {
499 retval = -ENODEV;
500 goto error_out;
501 }
502
503 dev_dbg(&dev->interface->dev, "minor %d, cmd 0x%.4x, arg %ld\n",
504 dev->minor, cmd, arg);
505
506 retval = 0;
507 io_res = 0;
508 switch (cmd) {
509 case IOW_WRITE:
510 if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
511 dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24SAG ||
512 dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
513 dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
514 dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
515 user_buffer = (__u8 __user *)arg;
516 io_res = copy_from_user(buffer, user_buffer,
517 dev->report_size);
518 if (io_res) {
519 retval = -EFAULT;
520 } else {
521 io_res = usb_set_report(dev->interface, 2, 0,
522 buffer,
523 dev->report_size);
524 if (io_res < 0)
525 retval = io_res;
526 }
527 } else {
528 retval = -EINVAL;
529 dev_err(&dev->interface->dev,
530 "ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
531 dev->product_id);
532 }
533 break;
534 case IOW_READ:
535 user_buffer = (__u8 __user *)arg;
536 io_res = usb_get_report(dev->udev,
537 dev->interface->cur_altsetting, 1, 0,
538 buffer, dev->report_size);
539 if (io_res < 0)
540 retval = io_res;
541 else {
542 io_res = copy_to_user(user_buffer, buffer, dev->report_size);
543 if (io_res)
544 retval = -EFAULT;
545 }
546 break;
547 case IOW_GETINFO:
548 {
549 /* Report available information for the device */
550 struct iowarrior_info info;
551 /* needed for power consumption */
552 struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
553
554 memset(&info, 0, sizeof(info));
555 /* directly from the descriptor */
556 info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
557 info.product = dev->product_id;
558 info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
559
560 /* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
561 info.speed = dev->udev->speed;
562 info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
563 info.report_size = dev->report_size;
564
565 /* serial number string has been read earlier 8 chars or empty string */
566 memcpy(info.serial, dev->chip_serial,
567 sizeof(dev->chip_serial));
568 if (cfg_descriptor == NULL) {
569 info.power = -1; /* no information available */
570 } else {
571 /* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
572 info.power = cfg_descriptor->bMaxPower * 2;
573 }
574 io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
575 sizeof(struct iowarrior_info));
576 if (io_res)
577 retval = -EFAULT;
578 break;
579 }
580 default:
581 /* return that we did not understand this ioctl call */
582 retval = -ENOTTY;
583 break;
584 }
585 error_out:
586 /* unlock the device */
587 mutex_unlock(&dev->mutex);
588 kfree(buffer);
589 return retval;
590 }
591
592 /*
593 * iowarrior_open
594 */
iowarrior_open(struct inode * inode,struct file * file)595 static int iowarrior_open(struct inode *inode, struct file *file)
596 {
597 struct iowarrior *dev = NULL;
598 struct usb_interface *interface;
599 int subminor;
600 int retval = 0;
601
602 subminor = iminor(inode);
603
604 interface = usb_find_interface(&iowarrior_driver, subminor);
605 if (!interface) {
606 pr_err("%s - error, can't find device for minor %d\n",
607 __func__, subminor);
608 return -ENODEV;
609 }
610
611 dev = usb_get_intfdata(interface);
612 if (!dev)
613 return -ENODEV;
614
615 mutex_lock(&dev->mutex);
616
617 /* Only one process can open each device, no sharing. */
618 if (dev->opened) {
619 retval = -EBUSY;
620 goto out;
621 }
622
623 /* setup interrupt handler for receiving values */
624 if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
625 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
626 retval = -EFAULT;
627 goto out;
628 }
629 /* increment our usage count for the driver */
630 ++dev->opened;
631 /* save our object in the file's private structure */
632 file->private_data = dev;
633 retval = 0;
634
635 out:
636 mutex_unlock(&dev->mutex);
637 return retval;
638 }
639
640 /*
641 * iowarrior_release
642 */
iowarrior_release(struct inode * inode,struct file * file)643 static int iowarrior_release(struct inode *inode, struct file *file)
644 {
645 struct iowarrior *dev;
646 int retval = 0;
647
648 dev = file->private_data;
649 if (!dev)
650 return -ENODEV;
651
652 dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
653
654 /* lock our device */
655 mutex_lock(&dev->mutex);
656
657 if (dev->opened <= 0) {
658 retval = -ENODEV; /* close called more than once */
659 mutex_unlock(&dev->mutex);
660 } else {
661 dev->opened = 0; /* we're closing now */
662 retval = 0;
663 if (dev->present) {
664 /*
665 The device is still connected so we only shutdown
666 pending read-/write-ops.
667 */
668 usb_kill_urb(dev->int_in_urb);
669 wake_up_interruptible(&dev->read_wait);
670 wake_up_interruptible(&dev->write_wait);
671 mutex_unlock(&dev->mutex);
672 } else {
673 /* The device was unplugged, cleanup resources */
674 mutex_unlock(&dev->mutex);
675 iowarrior_delete(dev);
676 }
677 }
678 return retval;
679 }
680
iowarrior_poll(struct file * file,poll_table * wait)681 static __poll_t iowarrior_poll(struct file *file, poll_table * wait)
682 {
683 struct iowarrior *dev = file->private_data;
684 __poll_t mask = 0;
685
686 if (!dev->present)
687 return EPOLLERR | EPOLLHUP;
688
689 poll_wait(file, &dev->read_wait, wait);
690 poll_wait(file, &dev->write_wait, wait);
691
692 if (!dev->present)
693 return EPOLLERR | EPOLLHUP;
694
695 if (read_index(dev) != -1)
696 mask |= EPOLLIN | EPOLLRDNORM;
697
698 if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
699 mask |= EPOLLOUT | EPOLLWRNORM;
700 return mask;
701 }
702
703 /*
704 * File operations needed when we register this driver.
705 * This assumes that this driver NEEDS file operations,
706 * of course, which means that the driver is expected
707 * to have a node in the /dev directory. If the USB
708 * device were for a network interface then the driver
709 * would use "struct net_driver" instead, and a serial
710 * device would use "struct tty_driver".
711 */
712 static const struct file_operations iowarrior_fops = {
713 .owner = THIS_MODULE,
714 .write = iowarrior_write,
715 .read = iowarrior_read,
716 .unlocked_ioctl = iowarrior_ioctl,
717 .open = iowarrior_open,
718 .release = iowarrior_release,
719 .poll = iowarrior_poll,
720 .llseek = noop_llseek,
721 };
722
iowarrior_devnode(struct device * dev,umode_t * mode)723 static char *iowarrior_devnode(struct device *dev, umode_t *mode)
724 {
725 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
726 }
727
728 /*
729 * usb class driver info in order to get a minor number from the usb core,
730 * and to have the device registered with devfs and the driver core
731 */
732 static struct usb_class_driver iowarrior_class = {
733 .name = "iowarrior%d",
734 .devnode = iowarrior_devnode,
735 .fops = &iowarrior_fops,
736 .minor_base = IOWARRIOR_MINOR_BASE,
737 };
738
739 /*---------------------------------*/
740 /* probe and disconnect functions */
741 /*---------------------------------*/
742 /*
743 * iowarrior_probe
744 *
745 * Called by the usb core when a new device is connected that it thinks
746 * this driver might be interested in.
747 */
iowarrior_probe(struct usb_interface * interface,const struct usb_device_id * id)748 static int iowarrior_probe(struct usb_interface *interface,
749 const struct usb_device_id *id)
750 {
751 struct usb_device *udev = interface_to_usbdev(interface);
752 struct iowarrior *dev = NULL;
753 struct usb_host_interface *iface_desc;
754 int retval = -ENOMEM;
755 int res;
756
757 /* allocate memory for our device state and initialize it */
758 dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
759 if (!dev)
760 return retval;
761
762 mutex_init(&dev->mutex);
763
764 atomic_set(&dev->intr_idx, 0);
765 atomic_set(&dev->read_idx, 0);
766 atomic_set(&dev->overflow_flag, 0);
767 init_waitqueue_head(&dev->read_wait);
768 atomic_set(&dev->write_busy, 0);
769 init_waitqueue_head(&dev->write_wait);
770
771 dev->udev = udev;
772 dev->interface = usb_get_intf(interface);
773
774 iface_desc = interface->cur_altsetting;
775 dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
776
777 init_usb_anchor(&dev->submitted);
778
779 res = usb_find_last_int_in_endpoint(iface_desc, &dev->int_in_endpoint);
780 if (res) {
781 dev_err(&interface->dev, "no interrupt-in endpoint found\n");
782 retval = res;
783 goto error;
784 }
785
786 if ((dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56) ||
787 (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56AM) ||
788 (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28) ||
789 (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28L) ||
790 (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW100)) {
791 res = usb_find_last_int_out_endpoint(iface_desc,
792 &dev->int_out_endpoint);
793 if (res) {
794 dev_err(&interface->dev, "no interrupt-out endpoint found\n");
795 retval = res;
796 goto error;
797 }
798 }
799
800 /* we have to check the report_size often, so remember it in the endianness suitable for our machine */
801 dev->report_size = usb_endpoint_maxp(dev->int_in_endpoint);
802
803 /*
804 * Some devices need the report size to be different than the
805 * endpoint size.
806 */
807 if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
808 switch (dev->product_id) {
809 case USB_DEVICE_ID_CODEMERCS_IOW56:
810 case USB_DEVICE_ID_CODEMERCS_IOW56AM:
811 dev->report_size = 7;
812 break;
813
814 case USB_DEVICE_ID_CODEMERCS_IOW28:
815 case USB_DEVICE_ID_CODEMERCS_IOW28L:
816 dev->report_size = 4;
817 break;
818
819 case USB_DEVICE_ID_CODEMERCS_IOW100:
820 dev->report_size = 12;
821 break;
822 }
823 }
824
825 /* create the urb and buffer for reading */
826 dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
827 if (!dev->int_in_urb)
828 goto error;
829 dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
830 if (!dev->int_in_buffer)
831 goto error;
832 usb_fill_int_urb(dev->int_in_urb, dev->udev,
833 usb_rcvintpipe(dev->udev,
834 dev->int_in_endpoint->bEndpointAddress),
835 dev->int_in_buffer, dev->report_size,
836 iowarrior_callback, dev,
837 dev->int_in_endpoint->bInterval);
838 /* create an internal buffer for interrupt data from the device */
839 dev->read_queue =
840 kmalloc_array(dev->report_size + 1, MAX_INTERRUPT_BUFFER,
841 GFP_KERNEL);
842 if (!dev->read_queue)
843 goto error;
844 /* Get the serial-number of the chip */
845 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
846 usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
847 sizeof(dev->chip_serial));
848 if (strlen(dev->chip_serial) != 8)
849 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
850
851 /* Set the idle timeout to 0, if this is interface 0 */
852 if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
853 usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
854 0x0A,
855 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
856 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
857 }
858 /* allow device read and ioctl */
859 dev->present = 1;
860
861 /* we can register the device now, as it is ready */
862 usb_set_intfdata(interface, dev);
863
864 retval = usb_register_dev(interface, &iowarrior_class);
865 if (retval) {
866 /* something prevented us from registering this driver */
867 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
868 goto error;
869 }
870
871 dev->minor = interface->minor;
872
873 /* let the user know what node this device is now attached to */
874 dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
875 "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
876 iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
877 return retval;
878
879 error:
880 iowarrior_delete(dev);
881 return retval;
882 }
883
884 /*
885 * iowarrior_disconnect
886 *
887 * Called by the usb core when the device is removed from the system.
888 */
iowarrior_disconnect(struct usb_interface * interface)889 static void iowarrior_disconnect(struct usb_interface *interface)
890 {
891 struct iowarrior *dev = usb_get_intfdata(interface);
892 int minor = dev->minor;
893
894 usb_deregister_dev(interface, &iowarrior_class);
895
896 mutex_lock(&dev->mutex);
897
898 /* prevent device read, write and ioctl */
899 dev->present = 0;
900
901 if (dev->opened) {
902 /* There is a process that holds a filedescriptor to the device ,
903 so we only shutdown read-/write-ops going on.
904 Deleting the device is postponed until close() was called.
905 */
906 usb_kill_urb(dev->int_in_urb);
907 usb_kill_anchored_urbs(&dev->submitted);
908 wake_up_interruptible(&dev->read_wait);
909 wake_up_interruptible(&dev->write_wait);
910 mutex_unlock(&dev->mutex);
911 } else {
912 /* no process is using the device, cleanup now */
913 mutex_unlock(&dev->mutex);
914 iowarrior_delete(dev);
915 }
916
917 dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
918 minor - IOWARRIOR_MINOR_BASE);
919 }
920
921 /* usb specific object needed to register this driver with the usb subsystem */
922 static struct usb_driver iowarrior_driver = {
923 .name = "iowarrior",
924 .probe = iowarrior_probe,
925 .disconnect = iowarrior_disconnect,
926 .id_table = iowarrior_ids,
927 };
928
929 module_usb_driver(iowarrior_driver);
930