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