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Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux...
[linux-2.6-omap-h63xx.git] / drivers / usb / misc / iowarrior.c
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/init.h>
19 #include <linux/slab.h>
20 #include <linux/sched.h>
21 #include <linux/poll.h>
22 #include <linux/version.h>
23 #include <linux/usb/iowarrior.h>
24
25 /* Version Information */
26 #define DRIVER_VERSION "v0.4.0"
27 #define DRIVER_AUTHOR "Christian Lucht <lucht@codemercs.com>"
28 #define DRIVER_DESC "USB IO-Warrior driver (Linux 2.6.x)"
29
30 #define USB_VENDOR_ID_CODEMERCS         1984
31 /* low speed iowarrior */
32 #define USB_DEVICE_ID_CODEMERCS_IOW40   0x1500
33 #define USB_DEVICE_ID_CODEMERCS_IOW24   0x1501
34 #define USB_DEVICE_ID_CODEMERCS_IOWPV1  0x1511
35 #define USB_DEVICE_ID_CODEMERCS_IOWPV2  0x1512
36 /* full speed iowarrior */
37 #define USB_DEVICE_ID_CODEMERCS_IOW56   0x1503
38
39 /* Get a minor range for your devices from the usb maintainer */
40 #ifdef CONFIG_USB_DYNAMIC_MINORS
41 #define IOWARRIOR_MINOR_BASE    0
42 #else
43 #define IOWARRIOR_MINOR_BASE    208     // SKELETON_MINOR_BASE 192 + 16, not offical yet
44 #endif
45
46 /* interrupt input queue size */
47 #define MAX_INTERRUPT_BUFFER 16
48 /*
49    maximum number of urbs that are submitted for writes at the same time,
50    this applies to the IOWarrior56 only!
51    IOWarrior24 and IOWarrior40 use synchronous usb_control_msg calls.
52 */
53 #define MAX_WRITES_IN_FLIGHT 4
54
55 /* Use our own dbg macro */
56 #undef dbg
57 #define dbg( format, arg... ) do { if( debug ) printk( KERN_DEBUG __FILE__ ": " format "\n" , ## arg ); } while ( 0 )
58
59 MODULE_AUTHOR(DRIVER_AUTHOR);
60 MODULE_DESCRIPTION(DRIVER_DESC);
61 MODULE_LICENSE("GPL");
62
63 /* Module parameters */
64 static int debug = 0;
65 module_param(debug, bool, 0644);
66 MODULE_PARM_DESC(debug, "debug=1 enables debugging messages");
67
68 static struct usb_driver iowarrior_driver;
69
70 /*--------------*/
71 /*     data     */
72 /*--------------*/
73
74 /* Structure to hold all of our device specific stuff */
75 struct iowarrior {
76         struct mutex mutex;                     /* locks this structure */
77         struct usb_device *udev;                /* save off the usb device pointer */
78         struct usb_interface *interface;        /* the interface for this device */
79         unsigned char minor;                    /* the starting minor number for this device */
80         struct usb_endpoint_descriptor *int_out_endpoint;       /* endpoint for reading (needed for IOW56 only) */
81         struct usb_endpoint_descriptor *int_in_endpoint;        /* endpoint for reading */
82         struct urb *int_in_urb;         /* the urb for reading data */
83         unsigned char *int_in_buffer;   /* buffer for data to be read */
84         unsigned char serial_number;    /* to detect lost packages */
85         unsigned char *read_queue;      /* size is MAX_INTERRUPT_BUFFER * packet size */
86         wait_queue_head_t read_wait;
87         wait_queue_head_t write_wait;   /* wait-queue for writing to the device */
88         atomic_t write_busy;            /* number of write-urbs submitted */
89         atomic_t read_idx;
90         atomic_t intr_idx;
91         spinlock_t intr_idx_lock;       /* protects intr_idx */
92         atomic_t overflow_flag;         /* signals an index 'rollover' */
93         int present;                    /* this is 1 as long as the device is connected */
94         int opened;                     /* this is 1 if the device is currently open */
95         char chip_serial[9];            /* the serial number string of the chip connected */
96         int report_size;                /* number of bytes in a report */
97         u16 product_id;
98 };
99
100 /*--------------*/
101 /*    globals   */
102 /*--------------*/
103 /* prevent races between open() and disconnect() */
104 static DECLARE_MUTEX(disconnect_sem);
105
106 /*
107  *  USB spec identifies 5 second timeouts.
108  */
109 #define GET_TIMEOUT 5
110 #define USB_REQ_GET_REPORT  0x01
111 //#if 0
112 static int usb_get_report(struct usb_device *dev,
113                           struct usb_host_interface *inter, unsigned char type,
114                           unsigned char id, void *buf, int size)
115 {
116         return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
117                                USB_REQ_GET_REPORT,
118                                USB_DIR_IN | USB_TYPE_CLASS |
119                                USB_RECIP_INTERFACE, (type << 8) + id,
120                                inter->desc.bInterfaceNumber, buf, size,
121                                GET_TIMEOUT*HZ);
122 }
123 //#endif
124
125 #define USB_REQ_SET_REPORT 0x09
126
127 static int usb_set_report(struct usb_interface *intf, unsigned char type,
128                           unsigned char id, void *buf, int size)
129 {
130         return usb_control_msg(interface_to_usbdev(intf),
131                                usb_sndctrlpipe(interface_to_usbdev(intf), 0),
132                                USB_REQ_SET_REPORT,
133                                USB_TYPE_CLASS | USB_RECIP_INTERFACE,
134                                (type << 8) + id,
135                                intf->cur_altsetting->desc.bInterfaceNumber, buf,
136                                size, HZ);
137 }
138
139 /*---------------------*/
140 /* driver registration */
141 /*---------------------*/
142 /* table of devices that work with this driver */
143 static struct usb_device_id iowarrior_ids[] = {
144         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW40)},
145         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW24)},
146         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV1)},
147         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOWPV2)},
148         {USB_DEVICE(USB_VENDOR_ID_CODEMERCS, USB_DEVICE_ID_CODEMERCS_IOW56)},
149         {}                      /* Terminating entry */
150 };
151 MODULE_DEVICE_TABLE(usb, iowarrior_ids);
152
153 /*
154  * USB callback handler for reading data
155  */
156 static void iowarrior_callback(struct urb *urb)
157 {
158         struct iowarrior *dev = (struct iowarrior *)urb->context;
159         int intr_idx;
160         int read_idx;
161         int aux_idx;
162         int offset;
163         int status;
164
165         switch (urb->status) {
166         case 0:
167                 /* success */
168                 break;
169         case -ECONNRESET:
170         case -ENOENT:
171         case -ESHUTDOWN:
172                 return;
173         default:
174                 goto exit;
175         }
176
177         spin_lock(&dev->intr_idx_lock);
178         intr_idx = atomic_read(&dev->intr_idx);
179         /* aux_idx become previous intr_idx */
180         aux_idx = (intr_idx == 0) ? (MAX_INTERRUPT_BUFFER - 1) : (intr_idx - 1);
181         read_idx = atomic_read(&dev->read_idx);
182
183         /* queue is not empty and it's interface 0 */
184         if ((intr_idx != read_idx)
185             && (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0)) {
186                 /* + 1 for serial number */
187                 offset = aux_idx * (dev->report_size + 1);
188                 if (!memcmp
189                     (dev->read_queue + offset, urb->transfer_buffer,
190                      dev->report_size)) {
191                         /* equal values on interface 0 will be ignored */
192                         spin_unlock(&dev->intr_idx_lock);
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         spin_unlock(&dev->intr_idx_lock);
214         /* tell the blocking read about the new data */
215         wake_up_interruptible(&dev->read_wait);
216
217 exit:
218         status = usb_submit_urb(urb, GFP_ATOMIC);
219         if (status)
220                 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed with result %d",
221                         __FUNCTION__, status);
222
223 }
224
225 /*
226  * USB Callback handler for write-ops
227  */
228 static void iowarrior_write_callback(struct urb *urb)
229 {
230         struct iowarrior *dev;
231         dev = (struct iowarrior *)urb->context;
232         /* sync/async unlink faults aren't errors */
233         if (urb->status &&
234             !(urb->status == -ENOENT ||
235               urb->status == -ECONNRESET || urb->status == -ESHUTDOWN)) {
236                 dbg("%s - nonzero write bulk status received: %d",
237                     __func__, urb->status);
238         }
239         /* free up our allocated buffer */
240         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
241                         urb->transfer_buffer, urb->transfer_dma);
242         /* tell a waiting writer the interrupt-out-pipe is available again */
243         atomic_dec(&dev->write_busy);
244         wake_up_interruptible(&dev->write_wait);
245 }
246
247 /**
248  *      iowarrior_delete
249  */
250 static inline void iowarrior_delete(struct iowarrior *dev)
251 {
252         dbg("%s - minor %d", __func__, dev->minor);
253         kfree(dev->int_in_buffer);
254         usb_free_urb(dev->int_in_urb);
255         kfree(dev->read_queue);
256         kfree(dev);
257 }
258
259 /*---------------------*/
260 /* fops implementation */
261 /*---------------------*/
262
263 static int read_index(struct iowarrior *dev)
264 {
265         int intr_idx, read_idx;
266
267         read_idx = atomic_read(&dev->read_idx);
268         intr_idx = atomic_read(&dev->intr_idx);
269
270         return (read_idx == intr_idx ? -1 : read_idx);
271 }
272
273 /**
274  *  iowarrior_read
275  */
276 static ssize_t iowarrior_read(struct file *file, char __user *buffer,
277                               size_t count, loff_t *ppos)
278 {
279         struct iowarrior *dev;
280         int read_idx;
281         int offset;
282
283         dev = (struct iowarrior *)file->private_data;
284
285         /* verify that the device wasn't unplugged */
286         if (dev == NULL || !dev->present)
287                 return -ENODEV;
288
289         dbg("%s - minor %d, count = %zd", __func__, dev->minor, count);
290
291         /* read count must be packet size (+ time stamp) */
292         if ((count != dev->report_size)
293             && (count != (dev->report_size + 1)))
294                 return -EINVAL;
295
296         /* repeat until no buffer overrun in callback handler occur */
297         do {
298                 atomic_set(&dev->overflow_flag, 0);
299                 if ((read_idx = read_index(dev)) == -1) {
300                         /* queue emty */
301                         if (file->f_flags & O_NONBLOCK)
302                                 return -EAGAIN;
303                         else {
304                                 //next line will return when there is either new data, or the device is unplugged
305                                 int r = wait_event_interruptible(dev->read_wait,
306                                                                  (!dev->present
307                                                                   || (read_idx =
308                                                                       read_index
309                                                                       (dev)) !=
310                                                                   -1));
311                                 if (r) {
312                                         //we were interrupted by a signal
313                                         return -ERESTART;
314                                 }
315                                 if (!dev->present) {
316                                         //The device was unplugged
317                                         return -ENODEV;
318                                 }
319                                 if (read_idx == -1) {
320                                         // Can this happen ???
321                                         return 0;
322                                 }
323                         }
324                 }
325
326                 offset = read_idx * (dev->report_size + 1);
327                 if (copy_to_user(buffer, dev->read_queue + offset, count)) {
328                         return -EFAULT;
329                 }
330         } while (atomic_read(&dev->overflow_flag));
331
332         read_idx = ++read_idx == MAX_INTERRUPT_BUFFER ? 0 : read_idx;
333         atomic_set(&dev->read_idx, read_idx);
334         return count;
335 }
336
337 /*
338  * iowarrior_write
339  */
340 static ssize_t iowarrior_write(struct file *file,
341                                const char __user *user_buffer,
342                                size_t count, loff_t *ppos)
343 {
344         struct iowarrior *dev;
345         int retval = 0;
346         char *buf = NULL;       /* for IOW24 and IOW56 we need a buffer */
347         struct urb *int_out_urb = NULL;
348
349         dev = (struct iowarrior *)file->private_data;
350
351         mutex_lock(&dev->mutex);
352         /* verify that the device wasn't unplugged */
353         if (dev == NULL || !dev->present) {
354                 retval = -ENODEV;
355                 goto exit;
356         }
357         dbg("%s - minor %d, count = %zd", __func__, dev->minor, count);
358         /* if count is 0 we're already done */
359         if (count == 0) {
360                 retval = 0;
361                 goto exit;
362         }
363         /* We only accept full reports */
364         if (count != dev->report_size) {
365                 retval = -EINVAL;
366                 goto exit;
367         }
368         switch (dev->product_id) {
369         case USB_DEVICE_ID_CODEMERCS_IOW24:
370         case USB_DEVICE_ID_CODEMERCS_IOWPV1:
371         case USB_DEVICE_ID_CODEMERCS_IOWPV2:
372         case USB_DEVICE_ID_CODEMERCS_IOW40:
373                 /* IOW24 and IOW40 use a synchronous call */
374                 buf = kmalloc(8, GFP_KERNEL);   /* 8 bytes are enough for both products */
375                 if (!buf) {
376                         retval = -ENOMEM;
377                         goto exit;
378                 }
379                 if (copy_from_user(buf, user_buffer, count)) {
380                         retval = -EFAULT;
381                         kfree(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                 /* The IOW56 uses asynchronous IO and more urbs */
390                 if (atomic_read(&dev->write_busy) == MAX_WRITES_IN_FLIGHT) {
391                         /* Wait until we are below the limit for submitted urbs */
392                         if (file->f_flags & O_NONBLOCK) {
393                                 retval = -EAGAIN;
394                                 goto exit;
395                         } else {
396                                 retval = wait_event_interruptible(dev->write_wait,
397                                                                   (!dev->present || (atomic_read (&dev-> write_busy) < MAX_WRITES_IN_FLIGHT)));
398                                 if (retval) {
399                                         /* we were interrupted by a signal */
400                                         retval = -ERESTART;
401                                         goto exit;
402                                 }
403                                 if (!dev->present) {
404                                         /* The device was unplugged */
405                                         retval = -ENODEV;
406                                         goto exit;
407                                 }
408                                 if (!dev->opened) {
409                                         /* We were closed while waiting for an URB */
410                                         retval = -ENODEV;
411                                         goto exit;
412                                 }
413                         }
414                 }
415                 atomic_inc(&dev->write_busy);
416                 int_out_urb = usb_alloc_urb(0, GFP_KERNEL);
417                 if (!int_out_urb) {
418                         retval = -ENOMEM;
419                         dbg("%s Unable to allocate urb ", __func__);
420                         goto error_no_urb;
421                 }
422                 buf = usb_buffer_alloc(dev->udev, dev->report_size,
423                                        GFP_KERNEL, &int_out_urb->transfer_dma);
424                 if (!buf) {
425                         retval = -ENOMEM;
426                         dbg("%s Unable to allocate buffer ", __func__);
427                         goto error_no_buffer;
428                 }
429                 usb_fill_int_urb(int_out_urb, dev->udev,
430                                  usb_sndintpipe(dev->udev,
431                                                 dev->int_out_endpoint->bEndpointAddress),
432                                  buf, dev->report_size,
433                                  iowarrior_write_callback, dev,
434                                  dev->int_out_endpoint->bInterval);
435                 int_out_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
436                 if (copy_from_user(buf, user_buffer, count)) {
437                         retval = -EFAULT;
438                         goto error;
439                 }
440                 retval = usb_submit_urb(int_out_urb, GFP_KERNEL);
441                 if (retval) {
442                         dbg("%s submit error %d for urb nr.%d", __func__,
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",
454                         __FUNCTION__, dev->product_id);
455                 retval = -EFAULT;
456                 goto exit;
457                 break;
458         }
459 error:
460         usb_buffer_free(dev->udev, dev->report_size, buf,
461                         int_out_urb->transfer_dma);
462 error_no_buffer:
463         usb_free_urb(int_out_urb);
464 error_no_urb:
465         atomic_dec(&dev->write_busy);
466         wake_up_interruptible(&dev->write_wait);
467 exit:
468         mutex_unlock(&dev->mutex);
469         return retval;
470 }
471
472 /**
473  *      iowarrior_ioctl
474  */
475 static int iowarrior_ioctl(struct inode *inode, struct file *file,
476                            unsigned int cmd, 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 = (struct iowarrior *)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(&dev->mutex);
495
496         /* verify that the device wasn't unplugged */
497         if (!dev->present) {
498                 mutex_unlock(&dev->mutex);
499                 return -ENODEV;
500         }
501
502         dbg("%s - minor %d, cmd 0x%.4x, arg %ld", __func__, dev->minor, cmd,
503             arg);
504
505         retval = 0;
506         io_res = 0;
507         switch (cmd) {
508         case IOW_WRITE:
509                 if (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW24 ||
510                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV1 ||
511                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOWPV2 ||
512                     dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW40) {
513                         user_buffer = (__u8 __user *)arg;
514                         io_res = copy_from_user(buffer, user_buffer,
515                                                 dev->report_size);
516                         if (io_res) {
517                                 retval = -EFAULT;
518                         } else {
519                                 io_res = usb_set_report(dev->interface, 2, 0,
520                                                         buffer,
521                                                         dev->report_size);
522                                 if (io_res < 0)
523                                         retval = io_res;
524                         }
525                 } else {
526                         retval = -EINVAL;
527                         dev_err(&dev->interface->dev,
528                                 "ioctl 'IOW_WRITE' is not supported for product=0x%x.",
529                                 dev->product_id);
530                 }
531                 break;
532         case IOW_READ:
533                 user_buffer = (__u8 __user *)arg;
534                 io_res = usb_get_report(dev->udev,
535                                         dev->interface->cur_altsetting, 1, 0,
536                                         buffer, dev->report_size);
537                 if (io_res < 0)
538                         retval = io_res;
539                 else {
540                         io_res = copy_to_user(user_buffer, buffer, dev->report_size);
541                         if (io_res < 0)
542                                 retval = -EFAULT;
543                 }
544                 break;
545         case IOW_GETINFO:
546                 {
547                         /* Report available information for the device */
548                         struct iowarrior_info info;
549                         /* needed for power consumption */
550                         struct usb_config_descriptor *cfg_descriptor = &dev->udev->actconfig->desc;
551
552                         /* directly from the descriptor */
553                         info.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
554                         info.product = dev->product_id;
555                         info.revision = le16_to_cpu(dev->udev->descriptor.bcdDevice);
556
557                         /* 0==UNKNOWN, 1==LOW(usb1.1) ,2=FULL(usb1.1), 3=HIGH(usb2.0) */
558                         info.speed = le16_to_cpu(dev->udev->speed);
559                         info.if_num = dev->interface->cur_altsetting->desc.bInterfaceNumber;
560                         info.report_size = dev->report_size;
561
562                         /* serial number string has been read earlier 8 chars or empty string */
563                         memcpy(info.serial, dev->chip_serial,
564                                sizeof(dev->chip_serial));
565                         if (cfg_descriptor == NULL) {
566                                 info.power = -1;        /* no information available */
567                         } else {
568                                 /* the MaxPower is stored in units of 2mA to make it fit into a byte-value */
569                                 info.power = cfg_descriptor->bMaxPower * 2;
570                         }
571                         io_res = copy_to_user((struct iowarrior_info __user *)arg, &info,
572                                          sizeof(struct iowarrior_info));
573                         if (io_res < 0)
574                                 retval = -EFAULT;
575                         break;
576                 }
577         default:
578                 /* return that we did not understand this ioctl call */
579                 retval = -ENOTTY;
580                 break;
581         }
582
583         /* unlock the device */
584         mutex_unlock(&dev->mutex);
585         return retval;
586 }
587
588 /**
589  *      iowarrior_open
590  */
591 static int iowarrior_open(struct inode *inode, struct file *file)
592 {
593         struct iowarrior *dev = NULL;
594         struct usb_interface *interface;
595         int subminor;
596         int retval = 0;
597
598         dbg("%s", __func__);
599
600         subminor = iminor(inode);
601
602         /* prevent disconnects */
603         down(&disconnect_sem);
604
605         interface = usb_find_interface(&iowarrior_driver, subminor);
606         if (!interface) {
607                 err("%s - error, can't find device for minor %d", __FUNCTION__,
608                     subminor);
609                 retval = -ENODEV;
610                 goto out;
611         }
612
613         dev = usb_get_intfdata(interface);
614         if (!dev) {
615                 retval = -ENODEV;
616                 goto out;
617         }
618
619         /* Only one process can open each device, no sharing. */
620         if (dev->opened) {
621                 retval = -EBUSY;
622                 goto out;
623         }
624
625         /* setup interrupt handler for receiving values */
626         if ((retval = usb_submit_urb(dev->int_in_urb, GFP_KERNEL)) < 0) {
627                 dev_err(&interface->dev, "Error %d while submitting URB\n", retval);
628                 retval = -EFAULT;
629                 goto out;
630         }
631         /* increment our usage count for the driver */
632         ++dev->opened;
633         /* save our object in the file's private structure */
634         file->private_data = dev;
635         retval = 0;
636
637 out:
638         up(&disconnect_sem);
639         return retval;
640 }
641
642 /**
643  *      iowarrior_release
644  */
645 static int iowarrior_release(struct inode *inode, struct file *file)
646 {
647         struct iowarrior *dev;
648         int retval = 0;
649
650         dev = (struct iowarrior *)file->private_data;
651         if (dev == NULL) {
652                 return -ENODEV;
653         }
654
655         dbg("%s - minor %d", __func__, dev->minor);
656
657         /* lock our device */
658         mutex_lock(&dev->mutex);
659
660         if (dev->opened <= 0) {
661                 retval = -ENODEV;       /* close called more than once */
662                 mutex_unlock(&dev->mutex);
663         } else {
664                 dev->opened = 0;        /* we're closeing now */
665                 retval = 0;
666                 if (dev->present) {
667                         /*
668                            The device is still connected so we only shutdown
669                            pending read-/write-ops.
670                          */
671                         usb_kill_urb(dev->int_in_urb);
672                         wake_up_interruptible(&dev->read_wait);
673                         wake_up_interruptible(&dev->write_wait);
674                         mutex_unlock(&dev->mutex);
675                 } else {
676                         /* The device was unplugged, cleanup resources */
677                         mutex_unlock(&dev->mutex);
678                         iowarrior_delete(dev);
679                 }
680         }
681         return retval;
682 }
683
684 static unsigned iowarrior_poll(struct file *file, poll_table * wait)
685 {
686         struct iowarrior *dev = file->private_data;
687         unsigned int mask = 0;
688
689         if (!dev->present)
690                 return POLLERR | POLLHUP;
691
692         poll_wait(file, &dev->read_wait, wait);
693         poll_wait(file, &dev->write_wait, wait);
694
695         if (!dev->present)
696                 return POLLERR | POLLHUP;
697
698         if (read_index(dev) != -1)
699                 mask |= POLLIN | POLLRDNORM;
700
701         if (atomic_read(&dev->write_busy) < MAX_WRITES_IN_FLIGHT)
702                 mask |= POLLOUT | POLLWRNORM;
703         return mask;
704 }
705
706 /*
707  * File operations needed when we register this driver.
708  * This assumes that this driver NEEDS file operations,
709  * of course, which means that the driver is expected
710  * to have a node in the /dev directory. If the USB
711  * device were for a network interface then the driver
712  * would use "struct net_driver" instead, and a serial
713  * device would use "struct tty_driver".
714  */
715 static struct file_operations iowarrior_fops = {
716         .owner = THIS_MODULE,
717         .write = iowarrior_write,
718         .read = iowarrior_read,
719         .ioctl = iowarrior_ioctl,
720         .open = iowarrior_open,
721         .release = iowarrior_release,
722         .poll = iowarrior_poll,
723 };
724
725 /*
726  * usb class driver info in order to get a minor number from the usb core,
727  * and to have the device registered with devfs and the driver core
728  */
729 static struct usb_class_driver iowarrior_class = {
730         .name = "iowarrior%d",
731         .fops = &iowarrior_fops,
732         .minor_base = IOWARRIOR_MINOR_BASE,
733 };
734
735 /*---------------------------------*/
736 /*  probe and disconnect functions */
737 /*---------------------------------*/
738 /**
739  *      iowarrior_probe
740  *
741  *      Called by the usb core when a new device is connected that it thinks
742  *      this driver might be interested in.
743  */
744 static int iowarrior_probe(struct usb_interface *interface,
745                            const struct usb_device_id *id)
746 {
747         struct usb_device *udev = interface_to_usbdev(interface);
748         struct iowarrior *dev = NULL;
749         struct usb_host_interface *iface_desc;
750         struct usb_endpoint_descriptor *endpoint;
751         int i;
752         int retval = -ENOMEM;
753
754         /* allocate memory for our device state and intialize it */
755         dev = kzalloc(sizeof(struct iowarrior), GFP_KERNEL);
756         if (dev == NULL) {
757                 dev_err(&interface->dev, "Out of memory");
758                 return retval;
759         }
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         /* set up the endpoint information */
778         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
779                 endpoint = &iface_desc->endpoint[i].desc;
780
781                 if (usb_endpoint_is_int_in(endpoint))
782                         dev->int_in_endpoint = endpoint;
783                 if (usb_endpoint_is_int_out(endpoint))
784                         /* this one will match for the IOWarrior56 only */
785                         dev->int_out_endpoint = endpoint;
786         }
787         /* we have to check the report_size often, so remember it in the endianess suitable for our machine */
788         dev->report_size = le16_to_cpu(dev->int_in_endpoint->wMaxPacketSize);
789         if ((dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) &&
790             (dev->product_id == USB_DEVICE_ID_CODEMERCS_IOW56))
791                 /* IOWarrior56 has wMaxPacketSize different from report size */
792                 dev->report_size = 7;
793
794         /* create the urb and buffer for reading */
795         dev->int_in_urb = usb_alloc_urb(0, GFP_KERNEL);
796         if (!dev->int_in_urb) {
797                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
798                 goto error;
799         }
800         dev->int_in_buffer = kmalloc(dev->report_size, GFP_KERNEL);
801         if (!dev->int_in_buffer) {
802                 dev_err(&interface->dev, "Couldn't allocate int_in_buffer\n");
803                 goto error;
804         }
805         usb_fill_int_urb(dev->int_in_urb, dev->udev,
806                          usb_rcvintpipe(dev->udev,
807                                         dev->int_in_endpoint->bEndpointAddress),
808                          dev->int_in_buffer, dev->report_size,
809                          iowarrior_callback, dev,
810                          dev->int_in_endpoint->bInterval);
811         /* create an internal buffer for interrupt data from the device */
812         dev->read_queue =
813             kmalloc(((dev->report_size + 1) * MAX_INTERRUPT_BUFFER),
814                     GFP_KERNEL);
815         if (!dev->read_queue) {
816                 dev_err(&interface->dev, "Couldn't allocate read_queue\n");
817                 goto error;
818         }
819         /* Get the serial-number of the chip */
820         memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
821         usb_string(udev, udev->descriptor.iSerialNumber, dev->chip_serial,
822                    sizeof(dev->chip_serial));
823         if (strlen(dev->chip_serial) != 8)
824                 memset(dev->chip_serial, 0x00, sizeof(dev->chip_serial));
825
826         /* Set the idle timeout to 0, if this is interface 0 */
827         if (dev->interface->cur_altsetting->desc.bInterfaceNumber == 0) {
828             usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
829                             0x0A,
830                             USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
831                             0, NULL, 0, USB_CTRL_SET_TIMEOUT);
832         }
833         /* allow device read and ioctl */
834         dev->present = 1;
835
836         /* we can register the device now, as it is ready */
837         usb_set_intfdata(interface, dev);
838
839         retval = usb_register_dev(interface, &iowarrior_class);
840         if (retval) {
841                 /* something prevented us from registering this driver */
842                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
843                 usb_set_intfdata(interface, NULL);
844                 goto error;
845         }
846
847         dev->minor = interface->minor;
848
849         /* let the user know what node this device is now attached to */
850         dev_info(&interface->dev, "IOWarrior product=0x%x, serial=%s interface=%d "
851                  "now attached to iowarrior%d\n", dev->product_id, dev->chip_serial,
852                  iface_desc->desc.bInterfaceNumber, dev->minor - IOWARRIOR_MINOR_BASE);
853         return retval;
854
855 error:
856         iowarrior_delete(dev);
857         return retval;
858 }
859
860 /**
861  *      iowarrior_disconnect
862  *
863  *      Called by the usb core when the device is removed from the system.
864  */
865 static void iowarrior_disconnect(struct usb_interface *interface)
866 {
867         struct iowarrior *dev;
868         int minor;
869
870         /* prevent races with open() */
871         down(&disconnect_sem);
872
873         dev = usb_get_intfdata(interface);
874         usb_set_intfdata(interface, NULL);
875
876         mutex_lock(&dev->mutex);
877
878         minor = dev->minor;
879
880         /* give back our minor */
881         usb_deregister_dev(interface, &iowarrior_class);
882
883         /* prevent device read, write and ioctl */
884         dev->present = 0;
885
886         mutex_unlock(&dev->mutex);
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         up(&disconnect_sem);
901
902         dev_info(&interface->dev, "I/O-Warror #%d now disconnected\n",
903                  minor - IOWARRIOR_MINOR_BASE);
904 }
905
906 /* usb specific object needed to register this driver with the usb subsystem */
907 static struct usb_driver iowarrior_driver = {
908         .name = "iowarrior",
909         .probe = iowarrior_probe,
910         .disconnect = iowarrior_disconnect,
911         .id_table = iowarrior_ids,
912 };
913
914 static int __init iowarrior_init(void)
915 {
916         return usb_register(&iowarrior_driver);
917 }
918
919 static void __exit iowarrior_exit(void)
920 {
921         usb_deregister(&iowarrior_driver);
922 }
923
924 module_init(iowarrior_init);
925 module_exit(iowarrior_exit);