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v5.9
  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
 62MODULE_AUTHOR(DRIVER_AUTHOR);
 63MODULE_DESCRIPTION(DRIVER_DESC);
 64MODULE_LICENSE("GPL");
 65
 66static struct usb_driver iowarrior_driver;
 67
 68/*--------------*/
 69/*     data     */
 70/*--------------*/
 71
 72/* Structure to hold all of our device specific stuff */
 73struct 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/*
103 *  USB spec identifies 5 second timeouts.
104 */
105#define GET_TIMEOUT 5
106#define USB_REQ_GET_REPORT  0x01
107//#if 0
108static int usb_get_report(struct usb_device *dev,
109			  struct usb_host_interface *inter, unsigned char type,
110			  unsigned char id, void *buf, int size)
111{
112	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
113			       USB_REQ_GET_REPORT,
114			       USB_DIR_IN | USB_TYPE_CLASS |
115			       USB_RECIP_INTERFACE, (type << 8) + id,
116			       inter->desc.bInterfaceNumber, buf, size,
117			       GET_TIMEOUT*HZ);
118}
119//#endif
120
121#define USB_REQ_SET_REPORT 0x09
122
123static int usb_set_report(struct usb_interface *intf, unsigned char type,
124			  unsigned char id, void *buf, int size)
125{
126	return usb_control_msg(interface_to_usbdev(intf),
127			       usb_sndctrlpipe(interface_to_usbdev(intf), 0),
128			       USB_REQ_SET_REPORT,
129			       USB_TYPE_CLASS | USB_RECIP_INTERFACE,
130			       (type << 8) + id,
131			       intf->cur_altsetting->desc.bInterfaceNumber, buf,
132			       size, HZ);
133}
134
135/*---------------------*/
136/* driver registration */
137/*---------------------*/
138/* table of devices that work with this driver */
139static const struct usb_device_id iowarrior_ids[] = {
140	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW40)},
141	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24)},
142	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV1)},
143	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV2)},
144	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56)},
145	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24SAG)},
146	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56AM)},
147	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW28)},
148	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW28L)},
149	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW100)},
150	{}			/* Terminating entry */
151};
152MODULE_DEVICE_TABLE(usb, iowarrior_ids);
153
154/*
155 * USB callback handler for reading data
156 */
157static void iowarrior_callback(struct urb *urb)
158{
159	struct iowarrior *dev = urb->context;
160	int intr_idx;
161	int read_idx;
162	int aux_idx;
163	int offset;
164	int status = urb->status;
165	int retval;
166
167	switch (status) {
168	case 0:
169		/* success */
170		break;
171	case -ECONNRESET:
172	case -ENOENT:
173	case -ESHUTDOWN:
174		return;
175	default:
176		goto exit;
177	}
178
179	intr_idx = atomic_read(&dev->intr_idx);
180	/* aux_idx become previous intr_idx */
181	aux_idx = (intr_idx == 0) ? (MAX_INTERRUPT_BUFFER - 1) : (intr_idx - 1);
182	read_idx = atomic_read(&dev->read_idx);
183
184	/* queue is not empty and it's interface 0 */
185	if ((intr_idx != read_idx)
186	    && (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0)) {
187		/* + 1 for serial number */
188		offset = aux_idx * (dev->report_size + 1);
189		if (!memcmp
190		    (dev->read_queue + offset, urb->transfer_buffer,
191		     dev->report_size)) {
192			/* equal values on interface 0 will be ignored */
193			goto exit;
194		}
195	}
196
197	/* aux_idx become next intr_idx */
198	aux_idx = (intr_idx == (MAX_INTERRUPT_BUFFER - 1)) ? 0 : (intr_idx + 1);
199	if (read_idx == aux_idx) {
200		/* queue full, dropping oldest input */
201		read_idx = (++read_idx == MAX_INTERRUPT_BUFFER) ? 0 : read_idx;
202		atomic_set(&dev->read_idx, read_idx);
203		atomic_set(&dev->overflow_flag, 1);
204	}
205
206	/* +1 for serial number */
207	offset = intr_idx * (dev->report_size + 1);
208	memcpy(dev->read_queue + offset, urb->transfer_buffer,
209	       dev->report_size);
210	*(dev->read_queue + offset + (dev->report_size)) = dev->serial_number++;
211
212	atomic_set(&dev->intr_idx, aux_idx);
213	/* tell the blocking read about the new data */
214	wake_up_interruptible(&dev->read_wait);
215
216exit:
217	retval = usb_submit_urb(urb, GFP_ATOMIC);
218	if (retval)
219		dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d\n",
220			__func__, retval);
221
222}
223
224/*
225 * USB Callback handler for write-ops
226 */
227static void iowarrior_write_callback(struct urb *urb)
228{
229	struct iowarrior *dev;
230	int status = urb->status;
231
232	dev = urb->context;
233	/* sync/async unlink faults aren't errors */
234	if (status &&
235	    !(status == -ENOENT ||
236	      status == -ECONNRESET || status == -ESHUTDOWN)) {
237		dev_dbg(&dev->interface->dev,
238			"nonzero write bulk status received: %d\n", status);
239	}
240	/* free up our allocated buffer */
241	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
242			  urb->transfer_buffer, urb->transfer_dma);
243	/* tell a waiting writer the interrupt-out-pipe is available again */
244	atomic_dec(&dev->write_busy);
245	wake_up_interruptible(&dev->write_wait);
246}
247
248/*
249 *	iowarrior_delete
250 */
251static inline void iowarrior_delete(struct iowarrior *dev)
252{
253	dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
254	kfree(dev->int_in_buffer);
255	usb_free_urb(dev->int_in_urb);
256	kfree(dev->read_queue);
257	usb_put_intf(dev->interface);
258	kfree(dev);
259}
260
261/*---------------------*/
262/* fops implementation */
263/*---------------------*/
264
265static int read_index(struct iowarrior *dev)
266{
267	int intr_idx, read_idx;
268
269	read_idx = atomic_read(&dev->read_idx);
270	intr_idx = atomic_read(&dev->intr_idx);
271
272	return (read_idx == intr_idx ? -1 : read_idx);
273}
274
275/*
276 *  iowarrior_read
277 */
278static ssize_t iowarrior_read(struct file *file, char __user *buffer,
279			      size_t count, loff_t *ppos)
280{
281	struct iowarrior *dev;
282	int read_idx;
283	int offset;
284
285	dev = file->private_data;
286
287	/* verify that the device wasn't unplugged */
288	if (!dev || !dev->present)
289		return -ENODEV;
290
291	dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
292		dev->minor, count);
293
294	/* read count must be packet size (+ time stamp) */
295	if ((count != dev->report_size)
296	    && (count != (dev->report_size + 1)))
297		return -EINVAL;
298
299	/* repeat until no buffer overrun in callback handler occur */
300	do {
301		atomic_set(&dev->overflow_flag, 0);
302		if ((read_idx = read_index(dev)) == -1) {
303			/* queue empty */
304			if (file->f_flags & O_NONBLOCK)
305				return -EAGAIN;
306			else {
307				//next line will return when there is either new data, or the device is unplugged
308				int r = wait_event_interruptible(dev->read_wait,
309								 (!dev->present
310								  || (read_idx =
311								      read_index
312								      (dev)) !=
313								  -1));
314				if (r) {
315					//we were interrupted by a signal
316					return -ERESTART;
317				}
318				if (!dev->present) {
319					//The device was unplugged
320					return -ENODEV;
321				}
322				if (read_idx == -1) {
323					// Can this happen ???
324					return 0;
325				}
326			}
327		}
328
329		offset = read_idx * (dev->report_size + 1);
330		if (copy_to_user(buffer, dev->read_queue + offset, count)) {
331			return -EFAULT;
332		}
333	} while (atomic_read(&dev->overflow_flag));
334
335	read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
336	atomic_set(&dev->read_idx, read_idx);
337	return count;
338}
339
340/*
341 * iowarrior_write
342 */
343static ssize_t iowarrior_write(struct file *file,
344			       const char __user *user_buffer,
345			       size_t count, loff_t *ppos)
346{
347	struct iowarrior *dev;
348	int retval = 0;
349	char *buf = NULL;	/* for IOW24 and IOW56 we need a buffer */
350	struct urb *int_out_urb = NULL;
351
352	dev = file->private_data;
353
354	mutex_lock(&dev->mutex);
355	/* verify that the device wasn't unplugged */
356	if (!dev->present) {
357		retval = -ENODEV;
358		goto exit;
359	}
360	dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
361		dev->minor, count);
362	/* if count is 0 we're already done */
363	if (count == 0) {
364		retval = 0;
365		goto exit;
366	}
367	/* We only accept full reports */
368	if (count != dev->report_size) {
369		retval = -EINVAL;
370		goto exit;
371	}
372	switch (dev->product_id) {
373	case USB_DEVICE_ID_CODEMERCS_IOW24:
374	case USB_DEVICE_ID_CODEMERCS_IOW24SAG:
375	case USB_DEVICE_ID_CODEMERCS_IOWPV1:
376	case USB_DEVICE_ID_CODEMERCS_IOWPV2:
377	case USB_DEVICE_ID_CODEMERCS_IOW40:
378		/* IOW24 and IOW40 use a synchronous call */
379		buf = memdup_user(user_buffer, count);
380		if (IS_ERR(buf)) {
381			retval = PTR_ERR(buf);
382			goto exit;
383		}
384		retval = usb_set_report(dev->interface, 2, 0, buf, count);
385		kfree(buf);
386		goto exit;
387		break;
388	case USB_DEVICE_ID_CODEMERCS_IOW56:
389	case USB_DEVICE_ID_CODEMERCS_IOW56AM:
390	case USB_DEVICE_ID_CODEMERCS_IOW28:
391	case USB_DEVICE_ID_CODEMERCS_IOW28L:
392	case USB_DEVICE_ID_CODEMERCS_IOW100:
393		/* The IOW56 uses asynchronous IO and more urbs */
394		if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
395			/* Wait until we are below the limit for submitted urbs */
396			if (file->f_flags & O_NONBLOCK) {
397				retval = -EAGAIN;
398				goto exit;
399			} else {
400				retval = wait_event_interruptible(dev->write_wait,
401								  (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
402				if (retval) {
403					/* we were interrupted by a signal */
404					retval = -ERESTART;
405					goto exit;
406				}
407				if (!dev->present) {
408					/* The device was unplugged */
409					retval = -ENODEV;
410					goto exit;
411				}
412				if (!dev->opened) {
413					/* We were closed while waiting for an URB */
414					retval = -ENODEV;
415					goto exit;
416				}
417			}
418		}
419		atomic_inc(&dev->write_busy);
420		int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
421		if (!int_out_urb) {
422			retval = -ENOMEM;
423			goto error_no_urb;
424		}
425		buf = usb_alloc_coherent(dev->udev, dev->report_size,
426					 GFP_KERNEL, &int_out_urb->transfer_dma);
427		if (!buf) {
428			retval = -ENOMEM;
429			dev_dbg(&dev->interface->dev,
430				"Unable to allocate buffer\n");
431			goto error_no_buffer;
432		}
433		usb_fill_int_urb(int_out_urb, dev->udev,
434				 usb_sndintpipe(dev->udev,
435						dev->int_out_endpoint->bEndpointAddress),
436				 buf, dev->report_size,
437				 iowarrior_write_callback, dev,
438				 dev->int_out_endpoint->bInterval);
439		int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
440		if (copy_from_user(buf, user_buffer, count)) {
441			retval = -EFAULT;
442			goto error;
443		}
444		usb_anchor_urb(int_out_urb, &dev->submitted);
445		retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
446		if (retval) {
447			dev_dbg(&dev->interface->dev,
448				"submit error %d for urb nr.%d\n",
449				retval, atomic_read(&dev->write_busy));
450			usb_unanchor_urb(int_out_urb);
451			goto error;
452		}
453		/* submit was ok */
454		retval = count;
455		usb_free_urb(int_out_urb);
456		goto exit;
457		break;
458	default:
459		/* what do we have here ? An unsupported Product-ID ? */
460		dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
461			__func__, dev->product_id);
462		retval = -EFAULT;
463		goto exit;
464		break;
465	}
466error:
467	usb_free_coherent(dev->udev, dev->report_size, buf,
468			  int_out_urb->transfer_dma);
469error_no_buffer:
470	usb_free_urb(int_out_urb);
471error_no_urb:
472	atomic_dec(&dev->write_busy);
473	wake_up_interruptible(&dev->write_wait);
474exit:
475	mutex_unlock(&dev->mutex);
476	return retval;
477}
478
479/*
480 *	iowarrior_ioctl
481 */
482static long iowarrior_ioctl(struct file *file, unsigned int cmd,
483							unsigned long arg)
484{
485	struct iowarrior *dev = NULL;
486	__u8 *buffer;
487	__u8 __user *user_buffer;
488	int retval;
489	int io_res;		/* checks for bytes read/written and copy_to/from_user results */
490
491	dev = file->private_data;
492	if (!dev)
493		return -ENODEV;
494
495	buffer = kzalloc(dev->report_size, GFP_KERNEL);
496	if (!buffer)
497		return -ENOMEM;
498
499	mutex_lock(&dev->mutex);
500
501	/* verify that the device wasn't unplugged */
502	if (!dev->present) {
503		retval = -ENODEV;
504		goto error_out;
505	}
506
507	dev_dbg(&dev->interface->dev, "minor %d, cmd 0x%.4x, arg %ld\n",
508		dev->minor, cmd, arg);
509
510	retval = 0;
511	io_res = 0;
512	switch (cmd) {
513	case IOW_WRITE:
514		if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
515		    dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24SAG ||
516		    dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
517		    dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
518		    dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
519			user_buffer = (__u8 __user *)arg;
520			io_res = copy_from_user(buffer, user_buffer,
521						dev->report_size);
522			if (io_res) {
523				retval = -EFAULT;
524			} else {
525				io_res = usb_set_report(dev->interface, 2, 0,
526							buffer,
527							dev->report_size);
528				if (io_res < 0)
529					retval = io_res;
530			}
531		} else {
532			retval = -EINVAL;
533			dev_err(&dev->interface->dev,
534				"ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
535				dev->product_id);
536		}
537		break;
538	case IOW_READ:
539		user_buffer = (__u8 __user *)arg;
540		io_res = usb_get_report(dev->udev,
541					dev->interface->cur_altsetting, 1, 0,
542					buffer, dev->report_size);
543		if (io_res < 0)
544			retval = io_res;
545		else {
546			io_res = copy_to_user(user_buffer, buffer, dev->report_size);
547			if (io_res)
548				retval = -EFAULT;
549		}
550		break;
551	case IOW_GETINFO:
552		{
553			/* Report available information for the device */
554			struct iowarrior_info info;
555			/* needed for power consumption */
556			struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
557
558			memset(&info, 0, sizeof(info));
559			/* directly from the descriptor */
560			info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
561			info.product = dev->product_id;
562			info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
563
564			/* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
565			info.speed = dev->udev->speed;
566			info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
567			info.report_size = dev->report_size;
568
569			/* serial number string has been read earlier 8 chars or empty string */
570			memcpy(info.serial, dev->chip_serial,
571			       sizeof(dev->chip_serial));
572			if (cfg_descriptor == NULL) {
573				info.power = -1;	/* no information available */
574			} else {
575				/* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
576				info.power = cfg_descriptor->bMaxPower * 2;
577			}
578			io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
579					 sizeof(struct iowarrior_info));
580			if (io_res)
581				retval = -EFAULT;
582			break;
583		}
584	default:
585		/* return that we did not understand this ioctl call */
586		retval = -ENOTTY;
587		break;
588	}
589error_out:
590	/* unlock the device */
591	mutex_unlock(&dev->mutex);
592	kfree(buffer);
593	return retval;
594}
595
596/*
597 *	iowarrior_open
598 */
599static int iowarrior_open(struct inode *inode, struct file *file)
600{
601	struct iowarrior *dev = NULL;
602	struct usb_interface *interface;
603	int subminor;
604	int retval = 0;
605
606	subminor = iminor(inode);
607
608	interface = usb_find_interface(&iowarrior_driver, subminor);
609	if (!interface) {
610		pr_err("%s - error, can't find device for minor %d\n",
611		       __func__, subminor);
612		return -ENODEV;
613	}
614
615	dev = usb_get_intfdata(interface);
616	if (!dev)
617		return -ENODEV;
618
619	mutex_lock(&dev->mutex);
620
621	/* Only one process can open each device, no sharing. */
622	if (dev->opened) {
623		retval = -EBUSY;
624		goto out;
625	}
626
627	/* setup interrupt handler for receiving values */
628	if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
629		dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
630		retval = -EFAULT;
631		goto out;
632	}
633	/* increment our usage count for the driver */
634	++dev->opened;
635	/* save our object in the file's private structure */
636	file->private_data = dev;
637	retval = 0;
638
639out:
640	mutex_unlock(&dev->mutex);
641	return retval;
642}
643
644/*
645 *	iowarrior_release
646 */
647static int iowarrior_release(struct inode *inode, struct file *file)
648{
649	struct iowarrior *dev;
650	int retval = 0;
651
652	dev = file->private_data;
653	if (!dev)
654		return -ENODEV;
655
656	dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
657
658	/* lock our device */
659	mutex_lock(&dev->mutex);
660
661	if (dev->opened <= 0) {
662		retval = -ENODEV;	/* close called more than once */
663		mutex_unlock(&dev->mutex);
664	} else {
665		dev->opened = 0;	/* we're closing now */
666		retval = 0;
667		if (dev->present) {
668			/*
669			   The device is still connected so we only shutdown
670			   pending read-/write-ops.
671			 */
672			usb_kill_urb(dev->int_in_urb);
673			wake_up_interruptible(&dev->read_wait);
674			wake_up_interruptible(&dev->write_wait);
675			mutex_unlock(&dev->mutex);
676		} else {
677			/* The device was unplugged, cleanup resources */
678			mutex_unlock(&dev->mutex);
679			iowarrior_delete(dev);
680		}
681	}
682	return retval;
683}
684
685static __poll_t iowarrior_poll(struct file *file, poll_table * wait)
686{
687	struct iowarrior *dev = file->private_data;
688	__poll_t mask = 0;
689
690	if (!dev->present)
691		return EPOLLERR | EPOLLHUP;
692
693	poll_wait(file, &dev->read_wait, wait);
694	poll_wait(file, &dev->write_wait, wait);
695
696	if (!dev->present)
697		return EPOLLERR | EPOLLHUP;
698
699	if (read_index(dev) != -1)
700		mask |= EPOLLIN | EPOLLRDNORM;
701
702	if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
703		mask |= EPOLLOUT | EPOLLWRNORM;
704	return mask;
705}
706
707/*
708 * File operations needed when we register this driver.
709 * This assumes that this driver NEEDS file operations,
710 * of course, which means that the driver is expected
711 * to have a node in the /dev directory. If the USB
712 * device were for a network interface then the driver
713 * would use "struct net_driver" instead, and a serial
714 * device would use "struct tty_driver".
715 */
716static const struct file_operations iowarrior_fops = {
717	.owner = THIS_MODULE,
718	.write = iowarrior_write,
719	.read = iowarrior_read,
720	.unlocked_ioctl = iowarrior_ioctl,
721	.open = iowarrior_open,
722	.release = iowarrior_release,
723	.poll = iowarrior_poll,
724	.llseek = noop_llseek,
725};
726
727static char *iowarrior_devnode(struct device *dev, umode_t *mode)
728{
729	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
730}
731
732/*
733 * usb class driver info in order to get a minor number from the usb core,
734 * and to have the device registered with devfs and the driver core
735 */
736static struct usb_class_driver iowarrior_class = {
737	.name = "iowarrior%d",
738	.devnode = iowarrior_devnode,
739	.fops = &iowarrior_fops,
740	.minor_base = IOWARRIOR_MINOR_BASE,
741};
742
743/*---------------------------------*/
744/*  probe and disconnect functions */
745/*---------------------------------*/
746/*
747 *	iowarrior_probe
748 *
749 *	Called by the usb core when a new device is connected that it thinks
750 *	this driver might be interested in.
751 */
752static int iowarrior_probe(struct usb_interface *interface,
753			   const struct usb_device_id *id)
754{
755	struct usb_device *udev = interface_to_usbdev(interface);
756	struct iowarrior *dev = NULL;
757	struct usb_host_interface *iface_desc;
758	int retval = -ENOMEM;
759	int res;
760
761	/* allocate memory for our device state and initialize it */
762	dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
763	if (!dev)
764		return retval;
765
766	mutex_init(&dev->mutex);
767
768	atomic_set(&dev->intr_idx, 0);
769	atomic_set(&dev->read_idx, 0);
770	atomic_set(&dev->overflow_flag, 0);
771	init_waitqueue_head(&dev->read_wait);
772	atomic_set(&dev->write_busy, 0);
773	init_waitqueue_head(&dev->write_wait);
774
775	dev->udev = udev;
776	dev->interface = usb_get_intf(interface);
777
778	iface_desc = interface->cur_altsetting;
779	dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
780
781	init_usb_anchor(&dev->submitted);
782
783	res = usb_find_last_int_in_endpoint(iface_desc, &dev->int_in_endpoint);
784	if (res) {
785		dev_err(&interface->dev, "no interrupt-in endpoint found\n");
786		retval = res;
787		goto error;
788	}
789
790	if ((dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56) ||
791	    (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56AM) ||
792	    (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28) ||
793	    (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28L) ||
794	    (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW100)) {
795		res = usb_find_last_int_out_endpoint(iface_desc,
796				&dev->int_out_endpoint);
797		if (res) {
798			dev_err(&interface->dev, "no interrupt-out endpoint found\n");
799			retval = res;
800			goto error;
801		}
802	}
803
804	/* we have to check the report_size often, so remember it in the endianness suitable for our machine */
805	dev->report_size = usb_endpoint_maxp(dev->int_in_endpoint);
806
807	/*
808	 * Some devices need the report size to be different than the
809	 * endpoint size.
810	 */
811	if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
812		switch (dev->product_id) {
813		case USB_DEVICE_ID_CODEMERCS_IOW56:
814		case USB_DEVICE_ID_CODEMERCS_IOW56AM:
815			dev->report_size = 7;
816			break;
817
818		case USB_DEVICE_ID_CODEMERCS_IOW28:
819		case USB_DEVICE_ID_CODEMERCS_IOW28L:
820			dev->report_size = 4;
821			break;
822
823		case USB_DEVICE_ID_CODEMERCS_IOW100:
824			dev->report_size = 13;
825			break;
826		}
827	}
828
829	/* create the urb and buffer for reading */
830	dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
831	if (!dev->int_in_urb)
832		goto error;
833	dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
834	if (!dev->int_in_buffer)
835		goto error;
836	usb_fill_int_urb(dev->int_in_urb, dev->udev,
837			 usb_rcvintpipe(dev->udev,
838					dev->int_in_endpoint->bEndpointAddress),
839			 dev->int_in_buffer, dev->report_size,
840			 iowarrior_callback, dev,
841			 dev->int_in_endpoint->bInterval);
842	/* create an internal buffer for interrupt data from the device */
843	dev->read_queue =
844	    kmalloc_array(dev->report_size + 1, MAX_INTERRUPT_BUFFER,
845			  GFP_KERNEL);
846	if (!dev->read_queue)
847		goto error;
848	/* Get the serial-number of the chip */
849	memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
850	usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
851		   sizeof(dev->chip_serial));
852	if (strlen(dev->chip_serial) != 8)
853		memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
854
855	/* Set the idle timeout to 0, if this is interface 0 */
856	if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
857	    usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
858			    0x0A,
859			    USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
860			    0, NULL, 0, USB_CTRL_SET_TIMEOUT);
861	}
862	/* allow device read and ioctl */
863	dev->present = 1;
864
865	/* we can register the device now, as it is ready */
866	usb_set_intfdata(interface, dev);
867
868	retval = usb_register_dev(interface, &iowarrior_class);
869	if (retval) {
870		/* something prevented us from registering this driver */
871		dev_err(&interface->dev, "Not able to get a minor for this device.\n");
872		goto error;
873	}
874
875	dev->minor = interface->minor;
876
877	/* let the user know what node this device is now attached to */
878	dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
879		 "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
880		 iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
881	return retval;
882
883error:
884	iowarrior_delete(dev);
885	return retval;
886}
887
888/*
889 *	iowarrior_disconnect
890 *
891 *	Called by the usb core when the device is removed from the system.
892 */
893static void iowarrior_disconnect(struct usb_interface *interface)
894{
895	struct iowarrior *dev = usb_get_intfdata(interface);
896	int minor = dev->minor;
897
898	usb_deregister_dev(interface, &iowarrior_class);
899
900	mutex_lock(&dev->mutex);
901
902	/* prevent device read, write and ioctl */
903	dev->present = 0;
904
905	if (dev->opened) {
906		/* There is a process that holds a filedescriptor to the device ,
907		   so we only shutdown read-/write-ops going on.
908		   Deleting the device is postponed until close() was called.
909		 */
910		usb_kill_urb(dev->int_in_urb);
911		usb_kill_anchored_urbs(&dev->submitted);
912		wake_up_interruptible(&dev->read_wait);
913		wake_up_interruptible(&dev->write_wait);
914		mutex_unlock(&dev->mutex);
915	} else {
916		/* no process is using the device, cleanup now */
917		mutex_unlock(&dev->mutex);
918		iowarrior_delete(dev);
919	}
920
921	dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
922		 minor - IOWARRIOR_MINOR_BASE);
923}
924
925/* usb specific object needed to register this driver with the usb subsystem */
926static struct usb_driver iowarrior_driver = {
927	.name = "iowarrior",
928	.probe = iowarrior_probe,
929	.disconnect = iowarrior_disconnect,
930	.id_table = iowarrior_ids,
931};
932
933module_usb_driver(iowarrior_driver);
v5.14.15
  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
 62MODULE_AUTHOR(DRIVER_AUTHOR);
 63MODULE_DESCRIPTION(DRIVER_DESC);
 64MODULE_LICENSE("GPL");
 65
 66static struct usb_driver iowarrior_driver;
 67
 68/*--------------*/
 69/*     data     */
 70/*--------------*/
 71
 72/* Structure to hold all of our device specific stuff */
 73struct 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/*
103 *  USB spec identifies 5 second timeouts.
104 */
105#define GET_TIMEOUT 5
106#define USB_REQ_GET_REPORT  0x01
107//#if 0
108static int usb_get_report(struct usb_device *dev,
109			  struct usb_host_interface *inter, unsigned char type,
110			  unsigned char id, void *buf, int size)
111{
112	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
113			       USB_REQ_GET_REPORT,
114			       USB_DIR_IN | USB_TYPE_CLASS |
115			       USB_RECIP_INTERFACE, (type << 8) + id,
116			       inter->desc.bInterfaceNumber, buf, size,
117			       GET_TIMEOUT*HZ);
118}
119//#endif
120
121#define USB_REQ_SET_REPORT 0x09
122
123static int usb_set_report(struct usb_interface *intf, unsigned char type,
124			  unsigned char id, void *buf, int size)
125{
126	return usb_control_msg(interface_to_usbdev(intf),
127			       usb_sndctrlpipe(interface_to_usbdev(intf), 0),
128			       USB_REQ_SET_REPORT,
129			       USB_TYPE_CLASS | USB_RECIP_INTERFACE,
130			       (type << 8) + id,
131			       intf->cur_altsetting->desc.bInterfaceNumber, buf,
132			       size, HZ);
133}
134
135/*---------------------*/
136/* driver registration */
137/*---------------------*/
138/* table of devices that work with this driver */
139static const struct usb_device_id iowarrior_ids[] = {
140	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW40)},
141	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24)},
142	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV1)},
143	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV2)},
144	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56)},
145	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24SAG)},
146	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56AM)},
147	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW28)},
148	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW28L)},
149	{USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW100)},
150	{}			/* Terminating entry */
151};
152MODULE_DEVICE_TABLE(usb, iowarrior_ids);
153
154/*
155 * USB callback handler for reading data
156 */
157static void iowarrior_callback(struct urb *urb)
158{
159	struct iowarrior *dev = urb->context;
160	int intr_idx;
161	int read_idx;
162	int aux_idx;
163	int offset;
164	int status = urb->status;
165	int retval;
166
167	switch (status) {
168	case 0:
169		/* success */
170		break;
171	case -ECONNRESET:
172	case -ENOENT:
173	case -ESHUTDOWN:
174		return;
175	default:
176		goto exit;
177	}
178
179	intr_idx = atomic_read(&dev->intr_idx);
180	/* aux_idx become previous intr_idx */
181	aux_idx = (intr_idx == 0) ? (MAX_INTERRUPT_BUFFER - 1) : (intr_idx - 1);
182	read_idx = atomic_read(&dev->read_idx);
183
184	/* queue is not empty and it's interface 0 */
185	if ((intr_idx != read_idx)
186	    && (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0)) {
187		/* + 1 for serial number */
188		offset = aux_idx * (dev->report_size + 1);
189		if (!memcmp
190		    (dev->read_queue + offset, urb->transfer_buffer,
191		     dev->report_size)) {
192			/* equal values on interface 0 will be ignored */
193			goto exit;
194		}
195	}
196
197	/* aux_idx become next intr_idx */
198	aux_idx = (intr_idx == (MAX_INTERRUPT_BUFFER - 1)) ? 0 : (intr_idx + 1);
199	if (read_idx == aux_idx) {
200		/* queue full, dropping oldest input */
201		read_idx = (++read_idx == MAX_INTERRUPT_BUFFER) ? 0 : read_idx;
202		atomic_set(&dev->read_idx, read_idx);
203		atomic_set(&dev->overflow_flag, 1);
204	}
205
206	/* +1 for serial number */
207	offset = intr_idx * (dev->report_size + 1);
208	memcpy(dev->read_queue + offset, urb->transfer_buffer,
209	       dev->report_size);
210	*(dev->read_queue + offset + (dev->report_size)) = dev->serial_number++;
211
212	atomic_set(&dev->intr_idx, aux_idx);
213	/* tell the blocking read about the new data */
214	wake_up_interruptible(&dev->read_wait);
215
216exit:
217	retval = usb_submit_urb(urb, GFP_ATOMIC);
218	if (retval)
219		dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d\n",
220			__func__, retval);
221
222}
223
224/*
225 * USB Callback handler for write-ops
226 */
227static void iowarrior_write_callback(struct urb *urb)
228{
229	struct iowarrior *dev;
230	int status = urb->status;
231
232	dev = urb->context;
233	/* sync/async unlink faults aren't errors */
234	if (status &&
235	    !(status == -ENOENT ||
236	      status == -ECONNRESET || status == -ESHUTDOWN)) {
237		dev_dbg(&dev->interface->dev,
238			"nonzero write bulk status received: %d\n", status);
239	}
240	/* free up our allocated buffer */
241	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
242			  urb->transfer_buffer, urb->transfer_dma);
243	/* tell a waiting writer the interrupt-out-pipe is available again */
244	atomic_dec(&dev->write_busy);
245	wake_up_interruptible(&dev->write_wait);
246}
247
248/*
249 *	iowarrior_delete
250 */
251static inline void iowarrior_delete(struct iowarrior *dev)
252{
253	dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
254	kfree(dev->int_in_buffer);
255	usb_free_urb(dev->int_in_urb);
256	kfree(dev->read_queue);
257	usb_put_intf(dev->interface);
258	kfree(dev);
259}
260
261/*---------------------*/
262/* fops implementation */
263/*---------------------*/
264
265static int read_index(struct iowarrior *dev)
266{
267	int intr_idx, read_idx;
268
269	read_idx = atomic_read(&dev->read_idx);
270	intr_idx = atomic_read(&dev->intr_idx);
271
272	return (read_idx == intr_idx ? -1 : read_idx);
273}
274
275/*
276 *  iowarrior_read
277 */
278static ssize_t iowarrior_read(struct file *file, char __user *buffer,
279			      size_t count, loff_t *ppos)
280{
281	struct iowarrior *dev;
282	int read_idx;
283	int offset;
284
285	dev = file->private_data;
286
287	/* verify that the device wasn't unplugged */
288	if (!dev || !dev->present)
289		return -ENODEV;
290
291	dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
292		dev->minor, count);
293
294	/* read count must be packet size (+ time stamp) */
295	if ((count != dev->report_size)
296	    && (count != (dev->report_size + 1)))
297		return -EINVAL;
298
299	/* repeat until no buffer overrun in callback handler occur */
300	do {
301		atomic_set(&dev->overflow_flag, 0);
302		if ((read_idx = read_index(dev)) == -1) {
303			/* queue empty */
304			if (file->f_flags & O_NONBLOCK)
305				return -EAGAIN;
306			else {
307				//next line will return when there is either new data, or the device is unplugged
308				int r = wait_event_interruptible(dev->read_wait,
309								 (!dev->present
310								  || (read_idx =
311								      read_index
312								      (dev)) !=
313								  -1));
314				if (r) {
315					//we were interrupted by a signal
316					return -ERESTART;
317				}
318				if (!dev->present) {
319					//The device was unplugged
320					return -ENODEV;
321				}
322				if (read_idx == -1) {
323					// Can this happen ???
324					return 0;
325				}
326			}
327		}
328
329		offset = read_idx * (dev->report_size + 1);
330		if (copy_to_user(buffer, dev->read_queue + offset, count)) {
331			return -EFAULT;
332		}
333	} while (atomic_read(&dev->overflow_flag));
334
335	read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
336	atomic_set(&dev->read_idx, read_idx);
337	return count;
338}
339
340/*
341 * iowarrior_write
342 */
343static ssize_t iowarrior_write(struct file *file,
344			       const char __user *user_buffer,
345			       size_t count, loff_t *ppos)
346{
347	struct iowarrior *dev;
348	int retval = 0;
349	char *buf = NULL;	/* for IOW24 and IOW56 we need a buffer */
350	struct urb *int_out_urb = NULL;
351
352	dev = file->private_data;
353
354	mutex_lock(&dev->mutex);
355	/* verify that the device wasn't unplugged */
356	if (!dev->present) {
357		retval = -ENODEV;
358		goto exit;
359	}
360	dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
361		dev->minor, count);
362	/* if count is 0 we're already done */
363	if (count == 0) {
364		retval = 0;
365		goto exit;
366	}
367	/* We only accept full reports */
368	if (count != dev->report_size) {
369		retval = -EINVAL;
370		goto exit;
371	}
372	switch (dev->product_id) {
373	case USB_DEVICE_ID_CODEMERCS_IOW24:
374	case USB_DEVICE_ID_CODEMERCS_IOW24SAG:
375	case USB_DEVICE_ID_CODEMERCS_IOWPV1:
376	case USB_DEVICE_ID_CODEMERCS_IOWPV2:
377	case USB_DEVICE_ID_CODEMERCS_IOW40:
378		/* IOW24 and IOW40 use a synchronous call */
379		buf = memdup_user(user_buffer, count);
380		if (IS_ERR(buf)) {
381			retval = PTR_ERR(buf);
382			goto exit;
383		}
384		retval = usb_set_report(dev->interface, 2, 0, buf, count);
385		kfree(buf);
386		goto exit;
 
387	case USB_DEVICE_ID_CODEMERCS_IOW56:
388	case USB_DEVICE_ID_CODEMERCS_IOW56AM:
389	case USB_DEVICE_ID_CODEMERCS_IOW28:
390	case USB_DEVICE_ID_CODEMERCS_IOW28L:
391	case USB_DEVICE_ID_CODEMERCS_IOW100:
392		/* The IOW56 uses asynchronous IO and more urbs */
393		if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
394			/* Wait until we are below the limit for submitted urbs */
395			if (file->f_flags & O_NONBLOCK) {
396				retval = -EAGAIN;
397				goto exit;
398			} else {
399				retval = wait_event_interruptible(dev->write_wait,
400								  (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
401				if (retval) {
402					/* we were interrupted by a signal */
403					retval = -ERESTART;
404					goto exit;
405				}
406				if (!dev->present) {
407					/* The device was unplugged */
408					retval = -ENODEV;
409					goto exit;
410				}
411				if (!dev->opened) {
412					/* We were closed while waiting for an URB */
413					retval = -ENODEV;
414					goto exit;
415				}
416			}
417		}
418		atomic_inc(&dev->write_busy);
419		int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
420		if (!int_out_urb) {
421			retval = -ENOMEM;
422			goto error_no_urb;
423		}
424		buf = usb_alloc_coherent(dev->udev, dev->report_size,
425					 GFP_KERNEL, &int_out_urb->transfer_dma);
426		if (!buf) {
427			retval = -ENOMEM;
428			dev_dbg(&dev->interface->dev,
429				"Unable to allocate buffer\n");
430			goto error_no_buffer;
431		}
432		usb_fill_int_urb(int_out_urb, dev->udev,
433				 usb_sndintpipe(dev->udev,
434						dev->int_out_endpoint->bEndpointAddress),
435				 buf, dev->report_size,
436				 iowarrior_write_callback, dev,
437				 dev->int_out_endpoint->bInterval);
438		int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
439		if (copy_from_user(buf, user_buffer, count)) {
440			retval = -EFAULT;
441			goto error;
442		}
443		usb_anchor_urb(int_out_urb, &dev->submitted);
444		retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
445		if (retval) {
446			dev_dbg(&dev->interface->dev,
447				"submit error %d for urb nr.%d\n",
448				retval, atomic_read(&dev->write_busy));
449			usb_unanchor_urb(int_out_urb);
450			goto error;
451		}
452		/* submit was ok */
453		retval = count;
454		usb_free_urb(int_out_urb);
455		goto exit;
 
456	default:
457		/* what do we have here ? An unsupported Product-ID ? */
458		dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
459			__func__, dev->product_id);
460		retval = -EFAULT;
461		goto exit;
 
462	}
463error:
464	usb_free_coherent(dev->udev, dev->report_size, buf,
465			  int_out_urb->transfer_dma);
466error_no_buffer:
467	usb_free_urb(int_out_urb);
468error_no_urb:
469	atomic_dec(&dev->write_busy);
470	wake_up_interruptible(&dev->write_wait);
471exit:
472	mutex_unlock(&dev->mutex);
473	return retval;
474}
475
476/*
477 *	iowarrior_ioctl
478 */
479static long iowarrior_ioctl(struct file *file, unsigned int cmd,
480							unsigned long arg)
481{
482	struct iowarrior *dev = NULL;
483	__u8 *buffer;
484	__u8 __user *user_buffer;
485	int retval;
486	int io_res;		/* checks for bytes read/written and copy_to/from_user results */
487
488	dev = file->private_data;
489	if (!dev)
490		return -ENODEV;
491
492	buffer = kzalloc(dev->report_size, GFP_KERNEL);
493	if (!buffer)
494		return -ENOMEM;
495
496	mutex_lock(&dev->mutex);
497
498	/* verify that the device wasn't unplugged */
499	if (!dev->present) {
500		retval = -ENODEV;
501		goto error_out;
502	}
503
504	dev_dbg(&dev->interface->dev, "minor %d, cmd 0x%.4x, arg %ld\n",
505		dev->minor, cmd, arg);
506
507	retval = 0;
508	io_res = 0;
509	switch (cmd) {
510	case IOW_WRITE:
511		if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
512		    dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24SAG ||
513		    dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
514		    dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
515		    dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
516			user_buffer = (__u8 __user *)arg;
517			io_res = copy_from_user(buffer, user_buffer,
518						dev->report_size);
519			if (io_res) {
520				retval = -EFAULT;
521			} else {
522				io_res = usb_set_report(dev->interface, 2, 0,
523							buffer,
524							dev->report_size);
525				if (io_res < 0)
526					retval = io_res;
527			}
528		} else {
529			retval = -EINVAL;
530			dev_err(&dev->interface->dev,
531				"ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
532				dev->product_id);
533		}
534		break;
535	case IOW_READ:
536		user_buffer = (__u8 __user *)arg;
537		io_res = usb_get_report(dev->udev,
538					dev->interface->cur_altsetting, 1, 0,
539					buffer, dev->report_size);
540		if (io_res < 0)
541			retval = io_res;
542		else {
543			io_res = copy_to_user(user_buffer, buffer, dev->report_size);
544			if (io_res)
545				retval = -EFAULT;
546		}
547		break;
548	case IOW_GETINFO:
549		{
550			/* Report available information for the device */
551			struct iowarrior_info info;
552			/* needed for power consumption */
553			struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
554
555			memset(&info, 0, sizeof(info));
556			/* directly from the descriptor */
557			info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
558			info.product = dev->product_id;
559			info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
560
561			/* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
562			info.speed = dev->udev->speed;
563			info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
564			info.report_size = dev->report_size;
565
566			/* serial number string has been read earlier 8 chars or empty string */
567			memcpy(info.serial, dev->chip_serial,
568			       sizeof(dev->chip_serial));
569			if (cfg_descriptor == NULL) {
570				info.power = -1;	/* no information available */
571			} else {
572				/* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
573				info.power = cfg_descriptor->bMaxPower * 2;
574			}
575			io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
576					 sizeof(struct iowarrior_info));
577			if (io_res)
578				retval = -EFAULT;
579			break;
580		}
581	default:
582		/* return that we did not understand this ioctl call */
583		retval = -ENOTTY;
584		break;
585	}
586error_out:
587	/* unlock the device */
588	mutex_unlock(&dev->mutex);
589	kfree(buffer);
590	return retval;
591}
592
593/*
594 *	iowarrior_open
595 */
596static int iowarrior_open(struct inode *inode, struct file *file)
597{
598	struct iowarrior *dev = NULL;
599	struct usb_interface *interface;
600	int subminor;
601	int retval = 0;
602
603	subminor = iminor(inode);
604
605	interface = usb_find_interface(&iowarrior_driver, subminor);
606	if (!interface) {
607		pr_err("%s - error, can't find device for minor %d\n",
608		       __func__, subminor);
609		return -ENODEV;
610	}
611
612	dev = usb_get_intfdata(interface);
613	if (!dev)
614		return -ENODEV;
615
616	mutex_lock(&dev->mutex);
617
618	/* Only one process can open each device, no sharing. */
619	if (dev->opened) {
620		retval = -EBUSY;
621		goto out;
622	}
623
624	/* setup interrupt handler for receiving values */
625	if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
626		dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
627		retval = -EFAULT;
628		goto out;
629	}
630	/* increment our usage count for the driver */
631	++dev->opened;
632	/* save our object in the file's private structure */
633	file->private_data = dev;
634	retval = 0;
635
636out:
637	mutex_unlock(&dev->mutex);
638	return retval;
639}
640
641/*
642 *	iowarrior_release
643 */
644static int iowarrior_release(struct inode *inode, struct file *file)
645{
646	struct iowarrior *dev;
647	int retval = 0;
648
649	dev = file->private_data;
650	if (!dev)
651		return -ENODEV;
652
653	dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
654
655	/* lock our device */
656	mutex_lock(&dev->mutex);
657
658	if (dev->opened <= 0) {
659		retval = -ENODEV;	/* close called more than once */
660		mutex_unlock(&dev->mutex);
661	} else {
662		dev->opened = 0;	/* we're closing now */
663		retval = 0;
664		if (dev->present) {
665			/*
666			   The device is still connected so we only shutdown
667			   pending read-/write-ops.
668			 */
669			usb_kill_urb(dev->int_in_urb);
670			wake_up_interruptible(&dev->read_wait);
671			wake_up_interruptible(&dev->write_wait);
672			mutex_unlock(&dev->mutex);
673		} else {
674			/* The device was unplugged, cleanup resources */
675			mutex_unlock(&dev->mutex);
676			iowarrior_delete(dev);
677		}
678	}
679	return retval;
680}
681
682static __poll_t iowarrior_poll(struct file *file, poll_table * wait)
683{
684	struct iowarrior *dev = file->private_data;
685	__poll_t mask = 0;
686
687	if (!dev->present)
688		return EPOLLERR | EPOLLHUP;
689
690	poll_wait(file, &dev->read_wait, wait);
691	poll_wait(file, &dev->write_wait, wait);
692
693	if (!dev->present)
694		return EPOLLERR | EPOLLHUP;
695
696	if (read_index(dev) != -1)
697		mask |= EPOLLIN | EPOLLRDNORM;
698
699	if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
700		mask |= EPOLLOUT | EPOLLWRNORM;
701	return mask;
702}
703
704/*
705 * File operations needed when we register this driver.
706 * This assumes that this driver NEEDS file operations,
707 * of course, which means that the driver is expected
708 * to have a node in the /dev directory. If the USB
709 * device were for a network interface then the driver
710 * would use "struct net_driver" instead, and a serial
711 * device would use "struct tty_driver".
712 */
713static const struct file_operations iowarrior_fops = {
714	.owner = THIS_MODULE,
715	.write = iowarrior_write,
716	.read = iowarrior_read,
717	.unlocked_ioctl = iowarrior_ioctl,
718	.open = iowarrior_open,
719	.release = iowarrior_release,
720	.poll = iowarrior_poll,
721	.llseek = noop_llseek,
722};
723
724static char *iowarrior_devnode(struct device *dev, umode_t *mode)
725{
726	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
727}
728
729/*
730 * usb class driver info in order to get a minor number from the usb core,
731 * and to have the device registered with devfs and the driver core
732 */
733static struct usb_class_driver iowarrior_class = {
734	.name = "iowarrior%d",
735	.devnode = iowarrior_devnode,
736	.fops = &iowarrior_fops,
737	.minor_base = IOWARRIOR_MINOR_BASE,
738};
739
740/*---------------------------------*/
741/*  probe and disconnect functions */
742/*---------------------------------*/
743/*
744 *	iowarrior_probe
745 *
746 *	Called by the usb core when a new device is connected that it thinks
747 *	this driver might be interested in.
748 */
749static int iowarrior_probe(struct usb_interface *interface,
750			   const struct usb_device_id *id)
751{
752	struct usb_device *udev = interface_to_usbdev(interface);
753	struct iowarrior *dev = NULL;
754	struct usb_host_interface *iface_desc;
755	int retval = -ENOMEM;
756	int res;
757
758	/* allocate memory for our device state and initialize it */
759	dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
760	if (!dev)
761		return retval;
762
763	mutex_init(&dev->mutex);
764
765	atomic_set(&dev->intr_idx, 0);
766	atomic_set(&dev->read_idx, 0);
767	atomic_set(&dev->overflow_flag, 0);
768	init_waitqueue_head(&dev->read_wait);
769	atomic_set(&dev->write_busy, 0);
770	init_waitqueue_head(&dev->write_wait);
771
772	dev->udev = udev;
773	dev->interface = usb_get_intf(interface);
774
775	iface_desc = interface->cur_altsetting;
776	dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
777
778	init_usb_anchor(&dev->submitted);
779
780	res = usb_find_last_int_in_endpoint(iface_desc, &dev->int_in_endpoint);
781	if (res) {
782		dev_err(&interface->dev, "no interrupt-in endpoint found\n");
783		retval = res;
784		goto error;
785	}
786
787	if ((dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56) ||
788	    (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56AM) ||
789	    (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28) ||
790	    (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW28L) ||
791	    (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW100)) {
792		res = usb_find_last_int_out_endpoint(iface_desc,
793				&dev->int_out_endpoint);
794		if (res) {
795			dev_err(&interface->dev, "no interrupt-out endpoint found\n");
796			retval = res;
797			goto error;
798		}
799	}
800
801	/* we have to check the report_size often, so remember it in the endianness suitable for our machine */
802	dev->report_size = usb_endpoint_maxp(dev->int_in_endpoint);
803
804	/*
805	 * Some devices need the report size to be different than the
806	 * endpoint size.
807	 */
808	if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
809		switch (dev->product_id) {
810		case USB_DEVICE_ID_CODEMERCS_IOW56:
811		case USB_DEVICE_ID_CODEMERCS_IOW56AM:
812			dev->report_size = 7;
813			break;
814
815		case USB_DEVICE_ID_CODEMERCS_IOW28:
816		case USB_DEVICE_ID_CODEMERCS_IOW28L:
817			dev->report_size = 4;
818			break;
819
820		case USB_DEVICE_ID_CODEMERCS_IOW100:
821			dev->report_size = 13;
822			break;
823		}
824	}
825
826	/* create the urb and buffer for reading */
827	dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
828	if (!dev->int_in_urb)
829		goto error;
830	dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
831	if (!dev->int_in_buffer)
832		goto error;
833	usb_fill_int_urb(dev->int_in_urb, dev->udev,
834			 usb_rcvintpipe(dev->udev,
835					dev->int_in_endpoint->bEndpointAddress),
836			 dev->int_in_buffer, dev->report_size,
837			 iowarrior_callback, dev,
838			 dev->int_in_endpoint->bInterval);
839	/* create an internal buffer for interrupt data from the device */
840	dev->read_queue =
841	    kmalloc_array(dev->report_size + 1, MAX_INTERRUPT_BUFFER,
842			  GFP_KERNEL);
843	if (!dev->read_queue)
844		goto error;
845	/* Get the serial-number of the chip */
846	memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
847	usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
848		   sizeof(dev->chip_serial));
849	if (strlen(dev->chip_serial) != 8)
850		memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
851
852	/* Set the idle timeout to 0, if this is interface 0 */
853	if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
854	    usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
855			    0x0A,
856			    USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
857			    0, NULL, 0, USB_CTRL_SET_TIMEOUT);
858	}
859	/* allow device read and ioctl */
860	dev->present = 1;
861
862	/* we can register the device now, as it is ready */
863	usb_set_intfdata(interface, dev);
864
865	retval = usb_register_dev(interface, &iowarrior_class);
866	if (retval) {
867		/* something prevented us from registering this driver */
868		dev_err(&interface->dev, "Not able to get a minor for this device.\n");
869		goto error;
870	}
871
872	dev->minor = interface->minor;
873
874	/* let the user know what node this device is now attached to */
875	dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
876		 "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
877		 iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
878	return retval;
879
880error:
881	iowarrior_delete(dev);
882	return retval;
883}
884
885/*
886 *	iowarrior_disconnect
887 *
888 *	Called by the usb core when the device is removed from the system.
889 */
890static void iowarrior_disconnect(struct usb_interface *interface)
891{
892	struct iowarrior *dev = usb_get_intfdata(interface);
893	int minor = dev->minor;
894
895	usb_deregister_dev(interface, &iowarrior_class);
896
897	mutex_lock(&dev->mutex);
898
899	/* prevent device read, write and ioctl */
900	dev->present = 0;
901
902	if (dev->opened) {
903		/* There is a process that holds a filedescriptor to the device ,
904		   so we only shutdown read-/write-ops going on.
905		   Deleting the device is postponed until close() was called.
906		 */
907		usb_kill_urb(dev->int_in_urb);
908		usb_kill_anchored_urbs(&dev->submitted);
909		wake_up_interruptible(&dev->read_wait);
910		wake_up_interruptible(&dev->write_wait);
911		mutex_unlock(&dev->mutex);
912	} else {
913		/* no process is using the device, cleanup now */
914		mutex_unlock(&dev->mutex);
915		iowarrior_delete(dev);
916	}
917
918	dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
919		 minor - IOWARRIOR_MINOR_BASE);
920}
921
922/* usb specific object needed to register this driver with the usb subsystem */
923static struct usb_driver iowarrior_driver = {
924	.name = "iowarrior",
925	.probe = iowarrior_probe,
926	.disconnect = iowarrior_disconnect,
927	.id_table = iowarrior_ids,
928};
929
930module_usb_driver(iowarrior_driver);