spi-topcliff-pch: add recovery processing in case wait-event timeout
[zen-stable.git] / drivers / usb / misc / legousbtower.c
blob5752220427677c56188597fed2de929bb5fd17c6
1 /*
2 * LEGO USB Tower driver
4 * Copyright (C) 2003 David Glance <davidgsf@sourceforge.net>
5 * 2001-2004 Juergen Stuber <starblue@users.sourceforge.net>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of
10 * the License, or (at your option) any later version.
12 * derived from USB Skeleton driver - 0.5
13 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
15 * History:
17 * 2001-10-13 - 0.1 js
18 * - first version
19 * 2001-11-03 - 0.2 js
20 * - simplified buffering, one-shot URBs for writing
21 * 2001-11-10 - 0.3 js
22 * - removed IOCTL (setting power/mode is more complicated, postponed)
23 * 2001-11-28 - 0.4 js
24 * - added vendor commands for mode of operation and power level in open
25 * 2001-12-04 - 0.5 js
26 * - set IR mode by default (by oversight 0.4 set VLL mode)
27 * 2002-01-11 - 0.5? pcchan
28 * - make read buffer reusable and work around bytes_to_write issue between
29 * uhci and legusbtower
30 * 2002-09-23 - 0.52 david (david@csse.uwa.edu.au)
31 * - imported into lejos project
32 * - changed wake_up to wake_up_interruptible
33 * - changed to use lego0 rather than tower0
34 * - changed dbg() to use __func__ rather than deprecated __func__
35 * 2003-01-12 - 0.53 david (david@csse.uwa.edu.au)
36 * - changed read and write to write everything or
37 * timeout (from a patch by Chris Riesen and Brett Thaeler driver)
38 * - added ioctl functionality to set timeouts
39 * 2003-07-18 - 0.54 davidgsf (david@csse.uwa.edu.au)
40 * - initial import into LegoUSB project
41 * - merge of existing LegoUSB.c driver
42 * 2003-07-18 - 0.56 davidgsf (david@csse.uwa.edu.au)
43 * - port to 2.6 style driver
44 * 2004-02-29 - 0.6 Juergen Stuber <starblue@users.sourceforge.net>
45 * - fix locking
46 * - unlink read URBs which are no longer needed
47 * - allow increased buffer size, eliminates need for timeout on write
48 * - have read URB running continuously
49 * - added poll
50 * - forbid seeking
51 * - added nonblocking I/O
52 * - changed back __func__ to __func__
53 * - read and log tower firmware version
54 * - reset tower on probe, avoids failure of first write
55 * 2004-03-09 - 0.7 Juergen Stuber <starblue@users.sourceforge.net>
56 * - timeout read now only after inactivity, shorten default accordingly
57 * 2004-03-11 - 0.8 Juergen Stuber <starblue@users.sourceforge.net>
58 * - log major, minor instead of possibly confusing device filename
59 * - whitespace cleanup
60 * 2004-03-12 - 0.9 Juergen Stuber <starblue@users.sourceforge.net>
61 * - normalize whitespace in debug messages
62 * - take care about endianness in control message responses
63 * 2004-03-13 - 0.91 Juergen Stuber <starblue@users.sourceforge.net>
64 * - make default intervals longer to accommodate current EHCI driver
65 * 2004-03-19 - 0.92 Juergen Stuber <starblue@users.sourceforge.net>
66 * - replaced atomic_t by memory barriers
67 * 2004-04-21 - 0.93 Juergen Stuber <starblue@users.sourceforge.net>
68 * - wait for completion of write urb in release (needed for remotecontrol)
69 * - corrected poll for write direction (missing negation)
70 * 2004-04-22 - 0.94 Juergen Stuber <starblue@users.sourceforge.net>
71 * - make device locking interruptible
72 * 2004-04-30 - 0.95 Juergen Stuber <starblue@users.sourceforge.net>
73 * - check for valid udev on resubmitting and unlinking urbs
74 * 2004-08-03 - 0.96 Juergen Stuber <starblue@users.sourceforge.net>
75 * - move reset into open to clean out spurious data
78 #include <linux/kernel.h>
79 #include <linux/errno.h>
80 #include <linux/init.h>
81 #include <linux/slab.h>
82 #include <linux/module.h>
83 #include <linux/completion.h>
84 #include <linux/mutex.h>
85 #include <asm/uaccess.h>
86 #include <linux/usb.h>
87 #include <linux/poll.h>
90 #ifdef CONFIG_USB_DEBUG
91 static int debug = 4;
92 #else
93 static int debug = 0;
94 #endif
96 /* Use our own dbg macro */
97 #undef dbg
98 #define dbg(lvl, format, arg...) \
99 do { \
100 if (debug >= lvl) \
101 printk(KERN_DEBUG "%s: " format "\n", __FILE__, ##arg); \
102 } while (0)
104 /* Version Information */
105 #define DRIVER_VERSION "v0.96"
106 #define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>"
107 #define DRIVER_DESC "LEGO USB Tower Driver"
109 /* Module parameters */
110 module_param(debug, int, S_IRUGO | S_IWUSR);
111 MODULE_PARM_DESC(debug, "Debug enabled or not");
113 /* The defaults are chosen to work with the latest versions of leJOS and NQC.
116 /* Some legacy software likes to receive packets in one piece.
117 * In this case read_buffer_size should exceed the maximal packet length
118 * (417 for datalog uploads), and packet_timeout should be set.
120 static int read_buffer_size = 480;
121 module_param(read_buffer_size, int, 0);
122 MODULE_PARM_DESC(read_buffer_size, "Read buffer size");
124 /* Some legacy software likes to send packets in one piece.
125 * In this case write_buffer_size should exceed the maximal packet length
126 * (417 for firmware and program downloads).
127 * A problem with long writes is that the following read may time out
128 * if the software is not prepared to wait long enough.
130 static int write_buffer_size = 480;
131 module_param(write_buffer_size, int, 0);
132 MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
134 /* Some legacy software expects reads to contain whole LASM packets.
135 * To achieve this, characters which arrive before a packet timeout
136 * occurs will be returned in a single read operation.
137 * A problem with long reads is that the software may time out
138 * if it is not prepared to wait long enough.
139 * The packet timeout should be greater than the time between the
140 * reception of subsequent characters, which should arrive about
141 * every 5ms for the standard 2400 baud.
142 * Set it to 0 to disable.
144 static int packet_timeout = 50;
145 module_param(packet_timeout, int, 0);
146 MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms");
148 /* Some legacy software expects blocking reads to time out.
149 * Timeout occurs after the specified time of read and write inactivity.
150 * Set it to 0 to disable.
152 static int read_timeout = 200;
153 module_param(read_timeout, int, 0);
154 MODULE_PARM_DESC(read_timeout, "Read timeout in ms");
156 /* As of kernel version 2.6.4 ehci-hcd uses an
157 * "only one interrupt transfer per frame" shortcut
158 * to simplify the scheduling of periodic transfers.
159 * This conflicts with our standard 1ms intervals for in and out URBs.
160 * We use default intervals of 2ms for in and 8ms for out transfers,
161 * which is fast enough for 2400 baud and allows a small additional load.
162 * Increase the interval to allow more devices that do interrupt transfers,
163 * or set to 0 to use the standard interval from the endpoint descriptors.
165 static int interrupt_in_interval = 2;
166 module_param(interrupt_in_interval, int, 0);
167 MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms");
169 static int interrupt_out_interval = 8;
170 module_param(interrupt_out_interval, int, 0);
171 MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms");
173 /* Define these values to match your device */
174 #define LEGO_USB_TOWER_VENDOR_ID 0x0694
175 #define LEGO_USB_TOWER_PRODUCT_ID 0x0001
177 /* Vendor requests */
178 #define LEGO_USB_TOWER_REQUEST_RESET 0x04
179 #define LEGO_USB_TOWER_REQUEST_GET_VERSION 0xFD
181 struct tower_reset_reply {
182 __le16 size; /* little-endian */
183 __u8 err_code;
184 __u8 spare;
185 } __attribute__ ((packed));
187 struct tower_get_version_reply {
188 __le16 size; /* little-endian */
189 __u8 err_code;
190 __u8 spare;
191 __u8 major;
192 __u8 minor;
193 __le16 build_no; /* little-endian */
194 } __attribute__ ((packed));
197 /* table of devices that work with this driver */
198 static const struct usb_device_id tower_table[] = {
199 { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) },
200 { } /* Terminating entry */
203 MODULE_DEVICE_TABLE (usb, tower_table);
204 static DEFINE_MUTEX(open_disc_mutex);
206 #define LEGO_USB_TOWER_MINOR_BASE 160
209 /* Structure to hold all of our device specific stuff */
210 struct lego_usb_tower {
211 struct mutex lock; /* locks this structure */
212 struct usb_device* udev; /* save off the usb device pointer */
213 unsigned char minor; /* the starting minor number for this device */
215 int open_count; /* number of times this port has been opened */
217 char* read_buffer;
218 size_t read_buffer_length; /* this much came in */
219 size_t read_packet_length; /* this much will be returned on read */
220 spinlock_t read_buffer_lock;
221 int packet_timeout_jiffies;
222 unsigned long read_last_arrival;
224 wait_queue_head_t read_wait;
225 wait_queue_head_t write_wait;
227 char* interrupt_in_buffer;
228 struct usb_endpoint_descriptor* interrupt_in_endpoint;
229 struct urb* interrupt_in_urb;
230 int interrupt_in_interval;
231 int interrupt_in_running;
232 int interrupt_in_done;
234 char* interrupt_out_buffer;
235 struct usb_endpoint_descriptor* interrupt_out_endpoint;
236 struct urb* interrupt_out_urb;
237 int interrupt_out_interval;
238 int interrupt_out_busy;
243 /* local function prototypes */
244 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos);
245 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos);
246 static inline void tower_delete (struct lego_usb_tower *dev);
247 static int tower_open (struct inode *inode, struct file *file);
248 static int tower_release (struct inode *inode, struct file *file);
249 static unsigned int tower_poll (struct file *file, poll_table *wait);
250 static loff_t tower_llseek (struct file *file, loff_t off, int whence);
252 static void tower_abort_transfers (struct lego_usb_tower *dev);
253 static void tower_check_for_read_packet (struct lego_usb_tower *dev);
254 static void tower_interrupt_in_callback (struct urb *urb);
255 static void tower_interrupt_out_callback (struct urb *urb);
257 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id);
258 static void tower_disconnect (struct usb_interface *interface);
261 /* file operations needed when we register this driver */
262 static const struct file_operations tower_fops = {
263 .owner = THIS_MODULE,
264 .read = tower_read,
265 .write = tower_write,
266 .open = tower_open,
267 .release = tower_release,
268 .poll = tower_poll,
269 .llseek = tower_llseek,
272 static char *legousbtower_devnode(struct device *dev, umode_t *mode)
274 return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
278 * usb class driver info in order to get a minor number from the usb core,
279 * and to have the device registered with the driver core
281 static struct usb_class_driver tower_class = {
282 .name = "legousbtower%d",
283 .devnode = legousbtower_devnode,
284 .fops = &tower_fops,
285 .minor_base = LEGO_USB_TOWER_MINOR_BASE,
289 /* usb specific object needed to register this driver with the usb subsystem */
290 static struct usb_driver tower_driver = {
291 .name = "legousbtower",
292 .probe = tower_probe,
293 .disconnect = tower_disconnect,
294 .id_table = tower_table,
299 * lego_usb_tower_debug_data
301 static inline void lego_usb_tower_debug_data (int level, const char *function, int size, const unsigned char *data)
303 int i;
305 if (debug < level)
306 return;
308 printk (KERN_DEBUG "%s: %s - length = %d, data = ", __FILE__, function, size);
309 for (i = 0; i < size; ++i) {
310 printk ("%.2x ", data[i]);
312 printk ("\n");
317 * tower_delete
319 static inline void tower_delete (struct lego_usb_tower *dev)
321 dbg(2, "%s: enter", __func__);
323 tower_abort_transfers (dev);
325 /* free data structures */
326 usb_free_urb(dev->interrupt_in_urb);
327 usb_free_urb(dev->interrupt_out_urb);
328 kfree (dev->read_buffer);
329 kfree (dev->interrupt_in_buffer);
330 kfree (dev->interrupt_out_buffer);
331 kfree (dev);
333 dbg(2, "%s: leave", __func__);
338 * tower_open
340 static int tower_open (struct inode *inode, struct file *file)
342 struct lego_usb_tower *dev = NULL;
343 int subminor;
344 int retval = 0;
345 struct usb_interface *interface;
346 struct tower_reset_reply reset_reply;
347 int result;
349 dbg(2, "%s: enter", __func__);
351 nonseekable_open(inode, file);
352 subminor = iminor(inode);
354 interface = usb_find_interface (&tower_driver, subminor);
356 if (!interface) {
357 err ("%s - error, can't find device for minor %d",
358 __func__, subminor);
359 retval = -ENODEV;
360 goto exit;
363 mutex_lock(&open_disc_mutex);
364 dev = usb_get_intfdata(interface);
366 if (!dev) {
367 mutex_unlock(&open_disc_mutex);
368 retval = -ENODEV;
369 goto exit;
372 /* lock this device */
373 if (mutex_lock_interruptible(&dev->lock)) {
374 mutex_unlock(&open_disc_mutex);
375 retval = -ERESTARTSYS;
376 goto exit;
380 /* allow opening only once */
381 if (dev->open_count) {
382 mutex_unlock(&open_disc_mutex);
383 retval = -EBUSY;
384 goto unlock_exit;
386 dev->open_count = 1;
387 mutex_unlock(&open_disc_mutex);
389 /* reset the tower */
390 result = usb_control_msg (dev->udev,
391 usb_rcvctrlpipe(dev->udev, 0),
392 LEGO_USB_TOWER_REQUEST_RESET,
393 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
396 &reset_reply,
397 sizeof(reset_reply),
398 1000);
399 if (result < 0) {
400 err("LEGO USB Tower reset control request failed");
401 retval = result;
402 goto unlock_exit;
405 /* initialize in direction */
406 dev->read_buffer_length = 0;
407 dev->read_packet_length = 0;
408 usb_fill_int_urb (dev->interrupt_in_urb,
409 dev->udev,
410 usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress),
411 dev->interrupt_in_buffer,
412 usb_endpoint_maxp(dev->interrupt_in_endpoint),
413 tower_interrupt_in_callback,
414 dev,
415 dev->interrupt_in_interval);
417 dev->interrupt_in_running = 1;
418 dev->interrupt_in_done = 0;
419 mb();
421 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL);
422 if (retval) {
423 err("Couldn't submit interrupt_in_urb %d", retval);
424 dev->interrupt_in_running = 0;
425 dev->open_count = 0;
426 goto unlock_exit;
429 /* save device in the file's private structure */
430 file->private_data = dev;
432 unlock_exit:
433 mutex_unlock(&dev->lock);
435 exit:
436 dbg(2, "%s: leave, return value %d ", __func__, retval);
438 return retval;
442 * tower_release
444 static int tower_release (struct inode *inode, struct file *file)
446 struct lego_usb_tower *dev;
447 int retval = 0;
449 dbg(2, "%s: enter", __func__);
451 dev = file->private_data;
453 if (dev == NULL) {
454 dbg(1, "%s: object is NULL", __func__);
455 retval = -ENODEV;
456 goto exit_nolock;
459 mutex_lock(&open_disc_mutex);
460 if (mutex_lock_interruptible(&dev->lock)) {
461 retval = -ERESTARTSYS;
462 goto exit;
465 if (dev->open_count != 1) {
466 dbg(1, "%s: device not opened exactly once", __func__);
467 retval = -ENODEV;
468 goto unlock_exit;
470 if (dev->udev == NULL) {
471 /* the device was unplugged before the file was released */
473 /* unlock here as tower_delete frees dev */
474 mutex_unlock(&dev->lock);
475 tower_delete (dev);
476 goto exit;
479 /* wait until write transfer is finished */
480 if (dev->interrupt_out_busy) {
481 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
483 tower_abort_transfers (dev);
484 dev->open_count = 0;
486 unlock_exit:
487 mutex_unlock(&dev->lock);
489 exit:
490 mutex_unlock(&open_disc_mutex);
491 exit_nolock:
492 dbg(2, "%s: leave, return value %d", __func__, retval);
493 return retval;
498 * tower_abort_transfers
499 * aborts transfers and frees associated data structures
501 static void tower_abort_transfers (struct lego_usb_tower *dev)
503 dbg(2, "%s: enter", __func__);
505 if (dev == NULL) {
506 dbg(1, "%s: dev is null", __func__);
507 goto exit;
510 /* shutdown transfer */
511 if (dev->interrupt_in_running) {
512 dev->interrupt_in_running = 0;
513 mb();
514 if (dev->udev)
515 usb_kill_urb (dev->interrupt_in_urb);
517 if (dev->interrupt_out_busy && dev->udev)
518 usb_kill_urb(dev->interrupt_out_urb);
520 exit:
521 dbg(2, "%s: leave", __func__);
526 * tower_check_for_read_packet
528 * To get correct semantics for signals and non-blocking I/O
529 * with packetizing we pretend not to see any data in the read buffer
530 * until it has been there unchanged for at least
531 * dev->packet_timeout_jiffies, or until the buffer is full.
533 static void tower_check_for_read_packet (struct lego_usb_tower *dev)
535 spin_lock_irq (&dev->read_buffer_lock);
536 if (!packet_timeout
537 || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies)
538 || dev->read_buffer_length == read_buffer_size) {
539 dev->read_packet_length = dev->read_buffer_length;
541 dev->interrupt_in_done = 0;
542 spin_unlock_irq (&dev->read_buffer_lock);
547 * tower_poll
549 static unsigned int tower_poll (struct file *file, poll_table *wait)
551 struct lego_usb_tower *dev;
552 unsigned int mask = 0;
554 dbg(2, "%s: enter", __func__);
556 dev = file->private_data;
558 if (!dev->udev)
559 return POLLERR | POLLHUP;
561 poll_wait(file, &dev->read_wait, wait);
562 poll_wait(file, &dev->write_wait, wait);
564 tower_check_for_read_packet(dev);
565 if (dev->read_packet_length > 0) {
566 mask |= POLLIN | POLLRDNORM;
568 if (!dev->interrupt_out_busy) {
569 mask |= POLLOUT | POLLWRNORM;
572 dbg(2, "%s: leave, mask = %d", __func__, mask);
574 return mask;
579 * tower_llseek
581 static loff_t tower_llseek (struct file *file, loff_t off, int whence)
583 return -ESPIPE; /* unseekable */
588 * tower_read
590 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
592 struct lego_usb_tower *dev;
593 size_t bytes_to_read;
594 int i;
595 int retval = 0;
596 unsigned long timeout = 0;
598 dbg(2, "%s: enter, count = %Zd", __func__, count);
600 dev = file->private_data;
602 /* lock this object */
603 if (mutex_lock_interruptible(&dev->lock)) {
604 retval = -ERESTARTSYS;
605 goto exit;
608 /* verify that the device wasn't unplugged */
609 if (dev->udev == NULL) {
610 retval = -ENODEV;
611 err("No device or device unplugged %d", retval);
612 goto unlock_exit;
615 /* verify that we actually have some data to read */
616 if (count == 0) {
617 dbg(1, "%s: read request of 0 bytes", __func__);
618 goto unlock_exit;
621 if (read_timeout) {
622 timeout = jiffies + read_timeout * HZ / 1000;
625 /* wait for data */
626 tower_check_for_read_packet (dev);
627 while (dev->read_packet_length == 0) {
628 if (file->f_flags & O_NONBLOCK) {
629 retval = -EAGAIN;
630 goto unlock_exit;
632 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies);
633 if (retval < 0) {
634 goto unlock_exit;
637 /* reset read timeout during read or write activity */
638 if (read_timeout
639 && (dev->read_buffer_length || dev->interrupt_out_busy)) {
640 timeout = jiffies + read_timeout * HZ / 1000;
642 /* check for read timeout */
643 if (read_timeout && time_after (jiffies, timeout)) {
644 retval = -ETIMEDOUT;
645 goto unlock_exit;
647 tower_check_for_read_packet (dev);
650 /* copy the data from read_buffer into userspace */
651 bytes_to_read = min(count, dev->read_packet_length);
653 if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) {
654 retval = -EFAULT;
655 goto unlock_exit;
658 spin_lock_irq (&dev->read_buffer_lock);
659 dev->read_buffer_length -= bytes_to_read;
660 dev->read_packet_length -= bytes_to_read;
661 for (i=0; i<dev->read_buffer_length; i++) {
662 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read];
664 spin_unlock_irq (&dev->read_buffer_lock);
666 retval = bytes_to_read;
668 unlock_exit:
669 /* unlock the device */
670 mutex_unlock(&dev->lock);
672 exit:
673 dbg(2, "%s: leave, return value %d", __func__, retval);
674 return retval;
679 * tower_write
681 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
683 struct lego_usb_tower *dev;
684 size_t bytes_to_write;
685 int retval = 0;
687 dbg(2, "%s: enter, count = %Zd", __func__, count);
689 dev = file->private_data;
691 /* lock this object */
692 if (mutex_lock_interruptible(&dev->lock)) {
693 retval = -ERESTARTSYS;
694 goto exit;
697 /* verify that the device wasn't unplugged */
698 if (dev->udev == NULL) {
699 retval = -ENODEV;
700 err("No device or device unplugged %d", retval);
701 goto unlock_exit;
704 /* verify that we actually have some data to write */
705 if (count == 0) {
706 dbg(1, "%s: write request of 0 bytes", __func__);
707 goto unlock_exit;
710 /* wait until previous transfer is finished */
711 while (dev->interrupt_out_busy) {
712 if (file->f_flags & O_NONBLOCK) {
713 retval = -EAGAIN;
714 goto unlock_exit;
716 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy);
717 if (retval) {
718 goto unlock_exit;
722 /* write the data into interrupt_out_buffer from userspace */
723 bytes_to_write = min_t(int, count, write_buffer_size);
724 dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __func__, count, bytes_to_write);
726 if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) {
727 retval = -EFAULT;
728 goto unlock_exit;
731 /* send off the urb */
732 usb_fill_int_urb(dev->interrupt_out_urb,
733 dev->udev,
734 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
735 dev->interrupt_out_buffer,
736 bytes_to_write,
737 tower_interrupt_out_callback,
738 dev,
739 dev->interrupt_out_interval);
741 dev->interrupt_out_busy = 1;
742 wmb();
744 retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL);
745 if (retval) {
746 dev->interrupt_out_busy = 0;
747 err("Couldn't submit interrupt_out_urb %d", retval);
748 goto unlock_exit;
750 retval = bytes_to_write;
752 unlock_exit:
753 /* unlock the device */
754 mutex_unlock(&dev->lock);
756 exit:
757 dbg(2, "%s: leave, return value %d", __func__, retval);
759 return retval;
764 * tower_interrupt_in_callback
766 static void tower_interrupt_in_callback (struct urb *urb)
768 struct lego_usb_tower *dev = urb->context;
769 int status = urb->status;
770 int retval;
772 dbg(4, "%s: enter, status %d", __func__, status);
774 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
776 if (status) {
777 if (status == -ENOENT ||
778 status == -ECONNRESET ||
779 status == -ESHUTDOWN) {
780 goto exit;
781 } else {
782 dbg(1, "%s: nonzero status received: %d", __func__, status);
783 goto resubmit; /* maybe we can recover */
787 if (urb->actual_length > 0) {
788 spin_lock (&dev->read_buffer_lock);
789 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) {
790 memcpy (dev->read_buffer + dev->read_buffer_length,
791 dev->interrupt_in_buffer,
792 urb->actual_length);
793 dev->read_buffer_length += urb->actual_length;
794 dev->read_last_arrival = jiffies;
795 dbg(3, "%s: received %d bytes", __func__, urb->actual_length);
796 } else {
797 printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __func__, urb->actual_length);
799 spin_unlock (&dev->read_buffer_lock);
802 resubmit:
803 /* resubmit if we're still running */
804 if (dev->interrupt_in_running && dev->udev) {
805 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC);
806 if (retval) {
807 err("%s: usb_submit_urb failed (%d)", __func__, retval);
811 exit:
812 dev->interrupt_in_done = 1;
813 wake_up_interruptible (&dev->read_wait);
815 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
816 dbg(4, "%s: leave, status %d", __func__, status);
821 * tower_interrupt_out_callback
823 static void tower_interrupt_out_callback (struct urb *urb)
825 struct lego_usb_tower *dev = urb->context;
826 int status = urb->status;
828 dbg(4, "%s: enter, status %d", __func__, status);
829 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
831 /* sync/async unlink faults aren't errors */
832 if (status && !(status == -ENOENT ||
833 status == -ECONNRESET ||
834 status == -ESHUTDOWN)) {
835 dbg(1, "%s - nonzero write bulk status received: %d",
836 __func__, status);
839 dev->interrupt_out_busy = 0;
840 wake_up_interruptible(&dev->write_wait);
842 lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
843 dbg(4, "%s: leave, status %d", __func__, status);
848 * tower_probe
850 * Called by the usb core when a new device is connected that it thinks
851 * this driver might be interested in.
853 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id)
855 struct usb_device *udev = interface_to_usbdev(interface);
856 struct lego_usb_tower *dev = NULL;
857 struct usb_host_interface *iface_desc;
858 struct usb_endpoint_descriptor* endpoint;
859 struct tower_get_version_reply get_version_reply;
860 int i;
861 int retval = -ENOMEM;
862 int result;
864 dbg(2, "%s: enter", __func__);
866 if (udev == NULL)
867 dev_info(&interface->dev, "udev is NULL.\n");
869 /* allocate memory for our device state and initialize it */
871 dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL);
873 if (dev == NULL) {
874 err ("Out of memory");
875 goto exit;
878 mutex_init(&dev->lock);
880 dev->udev = udev;
881 dev->open_count = 0;
883 dev->read_buffer = NULL;
884 dev->read_buffer_length = 0;
885 dev->read_packet_length = 0;
886 spin_lock_init (&dev->read_buffer_lock);
887 dev->packet_timeout_jiffies = packet_timeout * HZ / 1000;
888 dev->read_last_arrival = jiffies;
890 init_waitqueue_head (&dev->read_wait);
891 init_waitqueue_head (&dev->write_wait);
893 dev->interrupt_in_buffer = NULL;
894 dev->interrupt_in_endpoint = NULL;
895 dev->interrupt_in_urb = NULL;
896 dev->interrupt_in_running = 0;
897 dev->interrupt_in_done = 0;
899 dev->interrupt_out_buffer = NULL;
900 dev->interrupt_out_endpoint = NULL;
901 dev->interrupt_out_urb = NULL;
902 dev->interrupt_out_busy = 0;
904 iface_desc = interface->cur_altsetting;
906 /* set up the endpoint information */
907 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
908 endpoint = &iface_desc->endpoint[i].desc;
910 if (usb_endpoint_xfer_int(endpoint)) {
911 if (usb_endpoint_dir_in(endpoint))
912 dev->interrupt_in_endpoint = endpoint;
913 else
914 dev->interrupt_out_endpoint = endpoint;
917 if(dev->interrupt_in_endpoint == NULL) {
918 err("interrupt in endpoint not found");
919 goto error;
921 if (dev->interrupt_out_endpoint == NULL) {
922 err("interrupt out endpoint not found");
923 goto error;
926 dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL);
927 if (!dev->read_buffer) {
928 err("Couldn't allocate read_buffer");
929 goto error;
931 dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL);
932 if (!dev->interrupt_in_buffer) {
933 err("Couldn't allocate interrupt_in_buffer");
934 goto error;
936 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
937 if (!dev->interrupt_in_urb) {
938 err("Couldn't allocate interrupt_in_urb");
939 goto error;
941 dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL);
942 if (!dev->interrupt_out_buffer) {
943 err("Couldn't allocate interrupt_out_buffer");
944 goto error;
946 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
947 if (!dev->interrupt_out_urb) {
948 err("Couldn't allocate interrupt_out_urb");
949 goto error;
951 dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
952 dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
954 /* we can register the device now, as it is ready */
955 usb_set_intfdata (interface, dev);
957 retval = usb_register_dev (interface, &tower_class);
959 if (retval) {
960 /* something prevented us from registering this driver */
961 err ("Not able to get a minor for this device.");
962 usb_set_intfdata (interface, NULL);
963 goto error;
965 dev->minor = interface->minor;
967 /* let the user know what node this device is now attached to */
968 dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major "
969 "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE),
970 USB_MAJOR, dev->minor);
972 /* get the firmware version and log it */
973 result = usb_control_msg (udev,
974 usb_rcvctrlpipe(udev, 0),
975 LEGO_USB_TOWER_REQUEST_GET_VERSION,
976 USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
979 &get_version_reply,
980 sizeof(get_version_reply),
981 1000);
982 if (result < 0) {
983 err("LEGO USB Tower get version control request failed");
984 retval = result;
985 goto error;
987 dev_info(&interface->dev, "LEGO USB Tower firmware version is %d.%d "
988 "build %d\n", get_version_reply.major,
989 get_version_reply.minor,
990 le16_to_cpu(get_version_reply.build_no));
993 exit:
994 dbg(2, "%s: leave, return value 0x%.8lx (dev)", __func__, (long) dev);
996 return retval;
998 error:
999 tower_delete(dev);
1000 return retval;
1005 * tower_disconnect
1007 * Called by the usb core when the device is removed from the system.
1009 static void tower_disconnect (struct usb_interface *interface)
1011 struct lego_usb_tower *dev;
1012 int minor;
1014 dbg(2, "%s: enter", __func__);
1016 dev = usb_get_intfdata (interface);
1017 mutex_lock(&open_disc_mutex);
1018 usb_set_intfdata (interface, NULL);
1020 minor = dev->minor;
1022 /* give back our minor */
1023 usb_deregister_dev (interface, &tower_class);
1025 mutex_lock(&dev->lock);
1026 mutex_unlock(&open_disc_mutex);
1028 /* if the device is not opened, then we clean up right now */
1029 if (!dev->open_count) {
1030 mutex_unlock(&dev->lock);
1031 tower_delete (dev);
1032 } else {
1033 dev->udev = NULL;
1034 /* wake up pollers */
1035 wake_up_interruptible_all(&dev->read_wait);
1036 wake_up_interruptible_all(&dev->write_wait);
1037 mutex_unlock(&dev->lock);
1040 dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n",
1041 (minor - LEGO_USB_TOWER_MINOR_BASE));
1043 dbg(2, "%s: leave", __func__);
1046 module_usb_driver(tower_driver);
1048 MODULE_AUTHOR(DRIVER_AUTHOR);
1049 MODULE_DESCRIPTION(DRIVER_DESC);
1050 #ifdef MODULE_LICENSE
1051 MODULE_LICENSE("GPL");
1052 #endif