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