1/*
  2 *  Native support for the I/O-Warrior USB devices
  3 *
  4 *  Copyright (c) 2003-2005  Code Mercenaries GmbH
  5 *  written by Christian Lucht <lucht@codemercs.com>
  6 *
  7 *  based on
  8
  9 *  usb-skeleton.c by Greg Kroah-Hartman  <greg@kroah.com>
 10 *  brlvger.c by Stephane Dalton  <sdalton@videotron.ca>
 11 *           and St�hane Doyon   <s.doyon@videotron.ca>
 12 *
 13 *  Released under the GPLv2.
 14 */
 15
 16#include <linux/module.h>
 17#include <linux/usb.h>
 18#include <linux/slab.h>
 19#include <linux/sched.h>
 20#include <linux/mutex.h>
 21#include <linux/poll.h>
 22#include <linux/usb/iowarrior.h>
 23
 24/* Version Information */
 25#define DRIVER_VERSION "v0.4.0"
 26#define DRIVER_AUTHOR "Christian Lucht <lucht@codemercs.com>"
 27#define DRIVER_DESC "USB IO-Warrior driver (Linux 2.6.x)"
 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
 38/* Get a minor range for your devices from the usb maintainer */
 39#ifdef CONFIG_USB_DYNAMIC_MINORS
 40#define IOWARRIOR_MINOR_BASE	0
 41#else
 42#define IOWARRIOR_MINOR_BASE	208	// SKELETON_MINOR_BASE 192 + 16, not official yet
 43#endif
 44
 45/* interrupt input queue size */
 46#define MAX_INTERRUPT_BUFFER 16
 47/*
 48   maximum number of urbs that are submitted for writes at the same time,
 49   this applies to the IOWarrior56 only!
 50   IOWarrior24 and IOWarrior40 use synchronous usb_control_msg calls.
 51*/
 52#define MAX_WRITES_IN_FLIGHT 4
 53
 54MODULE_AUTHOR(DRIVER_AUTHOR);
 55MODULE_DESCRIPTION(DRIVER_DESC);
 56MODULE_LICENSE("GPL");
 57
 58/* Module parameters */
 59static DEFINE_MUTEX(iowarrior_mutex);
 60
 61static struct usb_driver iowarrior_driver;
 62static DEFINE_MUTEX(iowarrior_open_disc_lock);
 63
 64/*--------------*/
 65/*     data     */
 66/*--------------*/
 67
 68/* Structure to hold all of our device specific stuff */
 69struct iowarrior {
 70	struct mutex mutex;			/* locks this structure */
 71	struct usb_device *udev;		/* save off the usb device pointer */
 72	struct usb_interface *interface;	/* the interface for this device */
 73	unsigned char minor;			/* the starting minor number for this device */
 74	struct usb_endpoint_descriptor *int_out_endpoint;	/* endpoint for reading (needed for IOW56 only) */
 75	struct usb_endpoint_descriptor *int_in_endpoint;	/* endpoint for reading */
 76	struct urb *int_in_urb;		/* the urb for reading data */
 77	unsigned char *int_in_buffer;	/* buffer for data to be read */
 78	unsigned char serial_number;	/* to detect lost packages */
 79	unsigned char *read_queue;	/* size is MAX_INTERRUPT_BUFFER * packet size */
 80	wait_queue_head_t read_wait;
 81	wait_queue_head_t write_wait;	/* wait-queue for writing to the device */
 82	atomic_t write_busy;		/* number of write-urbs submitted */
 83	atomic_t read_idx;
 84	atomic_t intr_idx;
 85	spinlock_t intr_idx_lock;	/* protects intr_idx */
 86	atomic_t overflow_flag;		/* signals an index 'rollover' */
 87	int present;			/* this is 1 as long as the device is connected */
 88	int opened;			/* this is 1 if the device is currently open */
 89	char chip_serial[9];		/* the serial number string of the chip connected */
 90	int report_size;		/* number of bytes in a report */
 91	u16 product_id;
 92};
 93
 94/*--------------*/
 95/*    globals   */
 96/*--------------*/
 97
 98/*
 99 *  USB spec identifies 5 second timeouts.
100 */
101#define GET_TIMEOUT 5
102#define USB_REQ_GET_REPORT  0x01
103//#if 0
104static 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			       GET_TIMEOUT*HZ);
114}
115//#endif
116
117#define USB_REQ_SET_REPORT 0x09
118
119static 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, HZ);
129}
130
131/*---------------------*/
132/* driver registration */
133/*---------------------*/
134/* table of devices that work with this driver */
135static 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	{}			/* Terminating entry */
142};
143MODULE_DEVICE_TABLE(usb, iowarrior_ids);
144
145/*
146 * USB callback handler for reading data
147 */
148static void iowarrior_callback(struct urb *urb)
149{
150	struct iowarrior *dev = urb->context;
151	int intr_idx;
152	int read_idx;
153	int aux_idx;
154	int offset;
155	int status = urb->status;
156	int retval;
157
158	switch (status) {
159	case 0:
160		/* success */
161		break;
162	case -ECONNRESET:
163	case -ENOENT:
164	case -ESHUTDOWN:
165		return;
166	default:
167		goto exit;
168	}
169
170	spin_lock(&dev->intr_idx_lock);
171	intr_idx = atomic_read(&dev->intr_idx);
172	/* aux_idx become previous intr_idx */
173	aux_idx = (intr_idx == 0) ? (MAX_INTERRUPT_BUFFER - 1) : (intr_idx - 1);
174	read_idx = atomic_read(&dev->read_idx);
175
176	/* queue is not empty and it's interface 0 */
177	if ((intr_idx != read_idx)
178	    && (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0)) {
179		/* + 1 for serial number */
180		offset = aux_idx * (dev->report_size + 1);
181		if (!memcmp
182		    (dev->read_queue + offset, urb->transfer_buffer,
183		     dev->report_size)) {
184			/* equal values on interface 0 will be ignored */
185			spin_unlock(&dev->intr_idx_lock);
186			goto exit;
187		}
188	}
189
190	/* aux_idx become next intr_idx */
191	aux_idx = (intr_idx == (MAX_INTERRUPT_BUFFER - 1)) ? 0 : (intr_idx + 1);
192	if (read_idx == aux_idx) {
193		/* queue full, dropping oldest input */
194		read_idx = (++read_idx == MAX_INTERRUPT_BUFFER) ? 0 : read_idx;
195		atomic_set(&dev->read_idx, read_idx);
196		atomic_set(&dev->overflow_flag, 1);
197	}
198
199	/* +1 for serial number */
200	offset = intr_idx * (dev->report_size + 1);
201	memcpy(dev->read_queue + offset, urb->transfer_buffer,
202	       dev->report_size);
203	*(dev->read_queue + offset + (dev->report_size)) = dev->serial_number++;
204
205	atomic_set(&dev->intr_idx, aux_idx);
206	spin_unlock(&dev->intr_idx_lock);
207	/* tell the blocking read about the new data */
208	wake_up_interruptible(&dev->read_wait);
209
210exit:
211	retval = usb_submit_urb(urb, GFP_ATOMIC);
212	if (retval)
213		dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d\n",
214			__func__, retval);
215
216}
217
218/*
219 * USB Callback handler for write-ops
220 */
221static void iowarrior_write_callback(struct urb *urb)
222{
223	struct iowarrior *dev;
224	int status = urb->status;
225
226	dev = urb->context;
227	/* sync/async unlink faults aren't errors */
228	if (status &&
229	    !(status == -ENOENT ||
230	      status == -ECONNRESET || status == -ESHUTDOWN)) {
231		dev_dbg(&dev->interface->dev,
232			"nonzero write bulk status received: %d\n", status);
233	}
234	/* free up our allocated buffer */
235	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
236			  urb->transfer_buffer, urb->transfer_dma);
237	/* tell a waiting writer the interrupt-out-pipe is available again */
238	atomic_dec(&dev->write_busy);
239	wake_up_interruptible(&dev->write_wait);
240}
241
242/**
243 *	iowarrior_delete
244 */
245static inline void iowarrior_delete(struct iowarrior *dev)
246{
247	dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
248	kfree(dev->int_in_buffer);
249	usb_free_urb(dev->int_in_urb);
250	kfree(dev->read_queue);
251	kfree(dev);
252}
253
254/*---------------------*/
255/* fops implementation */
256/*---------------------*/
257
258static int read_index(struct iowarrior *dev)
259{
260	int intr_idx, read_idx;
261
262	read_idx = atomic_read(&dev->read_idx);
263	intr_idx = atomic_read(&dev->intr_idx);
264
265	return (read_idx == intr_idx ? -1 : read_idx);
266}
267
268/**
269 *  iowarrior_read
270 */
271static ssize_t iowarrior_read(struct file *file, char __user *buffer,
272			      size_t count, loff_t *ppos)
273{
274	struct iowarrior *dev;
275	int read_idx;
276	int offset;
277
278	dev = file->private_data;
279
280	/* verify that the device wasn't unplugged */
281	if (dev == NULL || !dev->present)
282		return -ENODEV;
283
284	dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
285		dev->minor, count);
286
287	/* read count must be packet size (+ time stamp) */
288	if ((count != dev->report_size)
289	    && (count != (dev->report_size + 1)))
290		return -EINVAL;
291
292	/* repeat until no buffer overrun in callback handler occur */
293	do {
294		atomic_set(&dev->overflow_flag, 0);
295		if ((read_idx = read_index(dev)) == -1) {
296			/* queue empty */
297			if (file->f_flags & O_NONBLOCK)
298				return -EAGAIN;
299			else {
300				//next line will return when there is either new data, or the device is unplugged
301				int r = wait_event_interruptible(dev->read_wait,
302								 (!dev->present
303								  || (read_idx =
304								      read_index
305								      (dev)) !=
306								  -1));
307				if (r) {
308					//we were interrupted by a signal
309					return -ERESTART;
310				}
311				if (!dev->present) {
312					//The device was unplugged
313					return -ENODEV;
314				}
315				if (read_idx == -1) {
316					// Can this happen ???
317					return 0;
318				}
319			}
320		}
321
322		offset = read_idx * (dev->report_size + 1);
323		if (copy_to_user(buffer, dev->read_queue + offset, count)) {
324			return -EFAULT;
325		}
326	} while (atomic_read(&dev->overflow_flag));
327
328	read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
329	atomic_set(&dev->read_idx, read_idx);
330	return count;
331}
332
333/*
334 * iowarrior_write
335 */
336static ssize_t iowarrior_write(struct file *file,
337			       const char __user *user_buffer,
338			       size_t count, loff_t *ppos)
339{
340	struct iowarrior *dev;
341	int retval = 0;
342	char *buf = NULL;	/* for IOW24 and IOW56 we need a buffer */
343	struct urb *int_out_urb = NULL;
344
345	dev = file->private_data;
346
347	mutex_lock(&dev->mutex);
348	/* verify that the device wasn't unplugged */
349	if (!dev->present) {
350		retval = -ENODEV;
351		goto exit;
352	}
353	dev_dbg(&dev->interface->dev, "minor %d, count = %zd\n",
354		dev->minor, count);
355	/* if count is 0 we're already done */
356	if (count == 0) {
357		retval = 0;
358		goto exit;
359	}
360	/* We only accept full reports */
361	if (count != dev->report_size) {
362		retval = -EINVAL;
363		goto exit;
364	}
365	switch (dev->product_id) {
366	case USB_DEVICE_ID_CODEMERCS_IOW24:
367	case USB_DEVICE_ID_CODEMERCS_IOWPV1:
368	case USB_DEVICE_ID_CODEMERCS_IOWPV2:
369	case USB_DEVICE_ID_CODEMERCS_IOW40:
370		/* IOW24 and IOW40 use a synchronous call */
371		buf = kmalloc(count, GFP_KERNEL);
372		if (!buf) {
373			retval = -ENOMEM;
374			goto exit;
375		}
376		if (copy_from_user(buf, user_buffer, count)) {
377			retval = -EFAULT;
378			kfree(buf);
379			goto exit;
380		}
381		retval = usb_set_report(dev->interface, 2, 0, buf, count);
382		kfree(buf);
383		goto exit;
384		break;
385	case USB_DEVICE_ID_CODEMERCS_IOW56:
386		/* The IOW56 uses asynchronous IO and more urbs */
387		if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
388			/* Wait until we are below the limit for submitted urbs */
389			if (file->f_flags & O_NONBLOCK) {
390				retval = -EAGAIN;
391				goto exit;
392			} else {
393				retval = wait_event_interruptible(dev->write_wait,
394								  (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
395				if (retval) {
396					/* we were interrupted by a signal */
397					retval = -ERESTART;
398					goto exit;
399				}
400				if (!dev->present) {
401					/* The device was unplugged */
402					retval = -ENODEV;
403					goto exit;
404				}
405				if (!dev->opened) {
406					/* We were closed while waiting for an URB */
407					retval = -ENODEV;
408					goto exit;
409				}
410			}
411		}
412		atomic_inc(&dev->write_busy);
413		int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
414		if (!int_out_urb) {
415			retval = -ENOMEM;
416			dev_dbg(&dev->interface->dev,
417				"Unable to allocate urb\n");
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		retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
440		if (retval) {
441			dev_dbg(&dev->interface->dev,
442				"submit error %d for urb nr.%d\n",
443				retval, atomic_read(&dev->write_busy));
444			goto error;
445		}
446		/* submit was ok */
447		retval = count;
448		usb_free_urb(int_out_urb);
449		goto exit;
450		break;
451	default:
452		/* what do we have here ? An unsupported Product-ID ? */
453		dev_err(&dev->interface->dev, "%s - not supported for product=0x%x\n",
454			__func__, dev->product_id);
455		retval = -EFAULT;
456		goto exit;
457		break;
458	}
459error:
460	usb_free_coherent(dev->udev, dev->report_size, buf,
461			  int_out_urb->transfer_dma);
462error_no_buffer:
463	usb_free_urb(int_out_urb);
464error_no_urb:
465	atomic_dec(&dev->write_busy);
466	wake_up_interruptible(&dev->write_wait);
467exit:
468	mutex_unlock(&dev->mutex);
469	return retval;
470}
471
472/**
473 *	iowarrior_ioctl
474 */
475static 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 == NULL) {
486		return -ENODEV;
487	}
488
489	buffer = kzalloc(dev->report_size, GFP_KERNEL);
490	if (!buffer)
491		return -ENOMEM;
492
493	/* lock this object */
494	mutex_lock(&iowarrior_mutex);
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_IOWPV1 ||
512		    dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
513		    dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
514			user_buffer = (__u8 __user *)arg;
515			io_res = copy_from_user(buffer, user_buffer,
516						dev->report_size);
517			if (io_res) {
518				retval = -EFAULT;
519			} else {
520				io_res = usb_set_report(dev->interface, 2, 0,
521							buffer,
522							dev->report_size);
523				if (io_res < 0)
524					retval = io_res;
525			}
526		} else {
527			retval = -EINVAL;
528			dev_err(&dev->interface->dev,
529				"ioctl 'IOW_WRITE' is not supported for product=0x%x.\n",
530				dev->product_id);
531		}
532		break;
533	case IOW_READ:
534		user_buffer = (__u8 __user *)arg;
535		io_res = usb_get_report(dev->udev,
536					dev->interface->cur_altsetting, 1, 0,
537					buffer, dev->report_size);
538		if (io_res < 0)
539			retval = io_res;
540		else {
541			io_res = copy_to_user(user_buffer, buffer, dev->report_size);
542			if (io_res)
543				retval = -EFAULT;
544		}
545		break;
546	case IOW_GETINFO:
547		{
548			/* Report available information for the device */
549			struct iowarrior_info info;
550			/* needed for power consumption */
551			struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
552
553			memset(&info, 0, sizeof(info));
554			/* directly from the descriptor */
555			info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
556			info.product = dev->product_id;
557			info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
558
559			/* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
560			info.speed = le16_to_cpu(dev->udev->speed);
561			info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
562			info.report_size = dev->report_size;
563
564			/* serial number string has been read earlier 8 chars or empty string */
565			memcpy(info.serial, dev->chip_serial,
566			       sizeof(dev->chip_serial));
567			if (cfg_descriptor == NULL) {
568				info.power = -1;	/* no information available */
569			} else {
570				/* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
571				info.power = cfg_descriptor->bMaxPower * 2;
572			}
573			io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
574					 sizeof(struct iowarrior_info));
575			if (io_res)
576				retval = -EFAULT;
577			break;
578		}
579	default:
580		/* return that we did not understand this ioctl call */
581		retval = -ENOTTY;
582		break;
583	}
584error_out:
585	/* unlock the device */
586	mutex_unlock(&dev->mutex);
587	mutex_unlock(&iowarrior_mutex);
588	kfree(buffer);
589	return retval;
590}
591
592/**
593 *	iowarrior_open
594 */
595static 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	mutex_lock(&iowarrior_mutex);
603	subminor = iminor(inode);
604
605	interface = usb_find_interface(&iowarrior_driver, subminor);
606	if (!interface) {
607		mutex_unlock(&iowarrior_mutex);
608		printk(KERN_ERR "%s - error, can't find device for minor %d\n",
609		       __func__, subminor);
610		return -ENODEV;
611	}
612
613	mutex_lock(&iowarrior_open_disc_lock);
614	dev = usb_get_intfdata(interface);
615	if (!dev) {
616		mutex_unlock(&iowarrior_open_disc_lock);
617		mutex_unlock(&iowarrior_mutex);
618		return -ENODEV;
619	}
620
621	mutex_lock(&dev->mutex);
622	mutex_unlock(&iowarrior_open_disc_lock);
623
624	/* Only one process can open each device, no sharing. */
625	if (dev->opened) {
626		retval = -EBUSY;
627		goto out;
628	}
629
630	/* setup interrupt handler for receiving values */
631	if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
632		dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
633		retval = -EFAULT;
634		goto out;
635	}
636	/* increment our usage count for the driver */
637	++dev->opened;
638	/* save our object in the file's private structure */
639	file->private_data = dev;
640	retval = 0;
641
642out:
643	mutex_unlock(&dev->mutex);
644	mutex_unlock(&iowarrior_mutex);
645	return retval;
646}
647
648/**
649 *	iowarrior_release
650 */
651static int iowarrior_release(struct inode *inode, struct file *file)
652{
653	struct iowarrior *dev;
654	int retval = 0;
655
656	dev = file->private_data;
657	if (dev == NULL) {
658		return -ENODEV;
659	}
660
661	dev_dbg(&dev->interface->dev, "minor %d\n", dev->minor);
662
663	/* lock our device */
664	mutex_lock(&dev->mutex);
665
666	if (dev->opened <= 0) {
667		retval = -ENODEV;	/* close called more than once */
668		mutex_unlock(&dev->mutex);
669	} else {
670		dev->opened = 0;	/* we're closing now */
671		retval = 0;
672		if (dev->present) {
673			/*
674			   The device is still connected so we only shutdown
675			   pending read-/write-ops.
676			 */
677			usb_kill_urb(dev->int_in_urb);
678			wake_up_interruptible(&dev->read_wait);
679			wake_up_interruptible(&dev->write_wait);
680			mutex_unlock(&dev->mutex);
681		} else {
682			/* The device was unplugged, cleanup resources */
683			mutex_unlock(&dev->mutex);
684			iowarrior_delete(dev);
685		}
686	}
687	return retval;
688}
689
690static unsigned iowarrior_poll(struct file *file, poll_table * wait)
691{
692	struct iowarrior *dev = file->private_data;
693	unsigned int mask = 0;
694
695	if (!dev->present)
696		return POLLERR | POLLHUP;
697
698	poll_wait(file, &dev->read_wait, wait);
699	poll_wait(file, &dev->write_wait, wait);
700
701	if (!dev->present)
702		return POLLERR | POLLHUP;
703
704	if (read_index(dev) != -1)
705		mask |= POLLIN | POLLRDNORM;
706
707	if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
708		mask |= POLLOUT | POLLWRNORM;
709	return mask;
710}
711
712/*
713 * File operations needed when we register this driver.
714 * This assumes that this driver NEEDS file operations,
715 * of course, which means that the driver is expected
716 * to have a node in the /dev directory. If the USB
717 * device were for a network interface then the driver
718 * would use "struct net_driver" instead, and a serial
719 * device would use "struct tty_driver".
720 */
721static const struct file_operations iowarrior_fops = {
722	.owner = THIS_MODULE,
723	.write = iowarrior_write,
724	.read = iowarrior_read,
725	.unlocked_ioctl = iowarrior_ioctl,
726	.open = iowarrior_open,
727	.release = iowarrior_release,
728	.poll = iowarrior_poll,
729	.llseek = noop_llseek,
730};
731
732static char *iowarrior_devnode(struct device *dev, umode_t *mode)
733{
734	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
735}
736
737/*
738 * usb class driver info in order to get a minor number from the usb core,
739 * and to have the device registered with devfs and the driver core
740 */
741static struct usb_class_driver iowarrior_class = {
742	.name = "iowarrior%d",
743	.devnode = iowarrior_devnode,
744	.fops = &iowarrior_fops,
745	.minor_base = IOWARRIOR_MINOR_BASE,
746};
747
748/*---------------------------------*/
749/*  probe and disconnect functions */
750/*---------------------------------*/
751/**
752 *	iowarrior_probe
753 *
754 *	Called by the usb core when a new device is connected that it thinks
755 *	this driver might be interested in.
756 */
757static int iowarrior_probe(struct usb_interface *interface,
758			   const struct usb_device_id *id)
759{
760	struct usb_device *udev = interface_to_usbdev(interface);
761	struct iowarrior *dev = NULL;
762	struct usb_host_interface *iface_desc;
763	struct usb_endpoint_descriptor *endpoint;
764	int i;
765	int retval = -ENOMEM;
766
767	/* allocate memory for our device state and initialize it */
768	dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
769	if (dev == NULL) {
770		dev_err(&interface->dev, "Out of memory\n");
771		return retval;
772	}
773
774	mutex_init(&dev->mutex);
775
776	atomic_set(&dev->intr_idx, 0);
777	atomic_set(&dev->read_idx, 0);
778	spin_lock_init(&dev->intr_idx_lock);
779	atomic_set(&dev->overflow_flag, 0);
780	init_waitqueue_head(&dev->read_wait);
781	atomic_set(&dev->write_busy, 0);
782	init_waitqueue_head(&dev->write_wait);
783
784	dev->udev = udev;
785	dev->interface = interface;
786
787	iface_desc = interface->cur_altsetting;
788	dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
789
790	if (iface_desc->desc.bNumEndpoints < 1) {
791		dev_err(&interface->dev, "Invalid number of endpoints\n");
792		retval = -EINVAL;
793		goto error;
794	}
795
796	/* set up the endpoint information */
797	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
798		endpoint = &iface_desc->endpoint[i].desc;
799
800		if (usb_endpoint_is_int_in(endpoint))
801			dev->int_in_endpoint = endpoint;
802		if (usb_endpoint_is_int_out(endpoint))
803			/* this one will match for the IOWarrior56 only */
804			dev->int_out_endpoint = endpoint;
805	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
806	/* we have to check the report_size often, so remember it in the endianness suitable for our machine */
807	dev->report_size = usb_endpoint_maxp(dev->int_in_endpoint);
808	if ((dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) &&
809	    (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56))
810		/* IOWarrior56 has wMaxPacketSize different from report size */
811		dev->report_size = 7;
812
813	/* create the urb and buffer for reading */
814	dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
815	if (!dev->int_in_urb) {
816		dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
817		goto error;
818	}
819	dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
820	if (!dev->int_in_buffer) {
821		dev_err(&interface->dev, "Couldn't allocate int_in_buffer\n");
822		goto error;
823	}
824	usb_fill_int_urb(dev->int_in_urb, dev->udev,
825			 usb_rcvintpipe(dev->udev,
826					dev->int_in_endpoint->bEndpointAddress),
827			 dev->int_in_buffer, dev->report_size,
828			 iowarrior_callback, dev,
829			 dev->int_in_endpoint->bInterval);
830	/* create an internal buffer for interrupt data from the device */
831	dev->read_queue =
832	    kmalloc(((dev->report_size + 1) * MAX_INTERRUPT_BUFFER),
833		    GFP_KERNEL);
834	if (!dev->read_queue) {
835		dev_err(&interface->dev, "Couldn't allocate read_queue\n");
836		goto error;
837	}
838	/* Get the serial-number of the chip */
839	memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
840	usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
841		   sizeof(dev->chip_serial));
842	if (strlen(dev->chip_serial) != 8)
843		memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
844
845	/* Set the idle timeout to 0, if this is interface 0 */
846	if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
847	    usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
848			    0x0A,
849			    USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
850			    0, NULL, 0, USB_CTRL_SET_TIMEOUT);
851	}
852	/* allow device read and ioctl */
853	dev->present = 1;
854
855	/* we can register the device now, as it is ready */
856	usb_set_intfdata(interface, dev);
857
858	retval = usb_register_dev(interface, &iowarrior_class);
859	if (retval) {
860		/* something prevented us from registering this driver */
861		dev_err(&interface->dev, "Not able to get a minor for this device.\n");
862		usb_set_intfdata(interface, NULL);
863		goto error;
864	}
865
866	dev->minor = interface->minor;
867
868	/* let the user know what node this device is now attached to */
869	dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
870		 "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
871		 iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
872	return retval;
873
874error:
875	iowarrior_delete(dev);
876	return retval;
877}
878
879/**
880 *	iowarrior_disconnect
881 *
882 *	Called by the usb core when the device is removed from the system.
883 */
884static void iowarrior_disconnect(struct usb_interface *interface)
885{
886	struct iowarrior *dev;
887	int minor;
888
889	dev = usb_get_intfdata(interface);
890	mutex_lock(&iowarrior_open_disc_lock);
891	usb_set_intfdata(interface, NULL);
892
893	minor = dev->minor;
894
895	/* give back our minor */
896	usb_deregister_dev(interface, &iowarrior_class);
897
898	mutex_lock(&dev->mutex);
899
900	/* prevent device read, write and ioctl */
901	dev->present = 0;
902
903	mutex_unlock(&dev->mutex);
904	mutex_unlock(&iowarrior_open_disc_lock);
905
906	if (dev->opened) {
907		/* There is a process that holds a filedescriptor to the device ,
908		   so we only shutdown read-/write-ops going on.
909		   Deleting the device is postponed until close() was called.
910		 */
911		usb_kill_urb(dev->int_in_urb);
912		wake_up_interruptible(&dev->read_wait);
913		wake_up_interruptible(&dev->write_wait);
914	} else {
915		/* no process is using the device, cleanup now */
916		iowarrior_delete(dev);
917	}
918
919	dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
920		 minor - IOWARRIOR_MINOR_BASE);
921}
922
923/* usb specific object needed to register this driver with the usb subsystem */
924static struct usb_driver iowarrior_driver = {
925	.name = "iowarrior",
926	.probe = iowarrior_probe,
927	.disconnect = iowarrior_disconnect,
928	.id_table = iowarrior_ids,
929};
930
931module_usb_driver(iowarrior_driver);