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Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
c0704541 | 2 | * USB Skeleton driver - 2.2 |
1da177e4 LT |
3 | * |
4 | * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License as | |
8 | * published by the Free Software Foundation, version 2. | |
9 | * | |
c0704541 | 10 | * This driver is based on the 2.6.3 version of drivers/usb/usb-skeleton.c |
121e287c | 11 | * but has been rewritten to be easier to read and use. |
1da177e4 LT |
12 | * |
13 | */ | |
14 | ||
1da177e4 LT |
15 | #include <linux/kernel.h> |
16 | #include <linux/errno.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/kref.h> | |
21 | #include <asm/uaccess.h> | |
22 | #include <linux/usb.h> | |
121e287c | 23 | #include <linux/mutex.h> |
1da177e4 LT |
24 | |
25 | ||
26 | /* Define these values to match your devices */ | |
27 | #define USB_SKEL_VENDOR_ID 0xfff0 | |
28 | #define USB_SKEL_PRODUCT_ID 0xfff0 | |
29 | ||
30 | /* table of devices that work with this driver */ | |
31 | static struct usb_device_id skel_table [] = { | |
32 | { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) }, | |
33 | { } /* Terminating entry */ | |
34 | }; | |
c0704541 | 35 | MODULE_DEVICE_TABLE(usb, skel_table); |
1da177e4 LT |
36 | |
37 | ||
38 | /* Get a minor range for your devices from the usb maintainer */ | |
39 | #define USB_SKEL_MINOR_BASE 192 | |
40 | ||
ff906518 | 41 | /* our private defines. if this grows any larger, use your own .h file */ |
c0704541 | 42 | #define MAX_TRANSFER (PAGE_SIZE - 512) |
ba35e02b ON |
43 | /* MAX_TRANSFER is chosen so that the VM is not stressed by |
44 | allocations > PAGE_SIZE and the number of packets in a page | |
45 | is an integer 512 is the largest possible packet on EHCI */ | |
ff906518 | 46 | #define WRITES_IN_FLIGHT 8 |
ba35e02b | 47 | /* arbitrarily chosen */ |
ff906518 | 48 | |
1da177e4 LT |
49 | /* Structure to hold all of our device specific stuff */ |
50 | struct usb_skel { | |
ba35e02b ON |
51 | struct usb_device *udev; /* the usb device for this device */ |
52 | struct usb_interface *interface; /* the interface for this device */ | |
ff906518 | 53 | struct semaphore limit_sem; /* limiting the number of writes in progress */ |
403dfb58 | 54 | struct usb_anchor submitted; /* in case we need to retract our submissions */ |
c0704541 | 55 | unsigned char *bulk_in_buffer; /* the buffer to receive data */ |
1da177e4 LT |
56 | size_t bulk_in_size; /* the size of the receive buffer */ |
57 | __u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */ | |
58 | __u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */ | |
403dfb58 | 59 | int errors; /* the last request tanked */ |
758f7e16 | 60 | int open_count; /* count the number of openers */ |
403dfb58 | 61 | spinlock_t err_lock; /* lock for errors */ |
1da177e4 | 62 | struct kref kref; |
121e287c | 63 | struct mutex io_mutex; /* synchronize I/O with disconnect */ |
1da177e4 LT |
64 | }; |
65 | #define to_skel_dev(d) container_of(d, struct usb_skel, kref) | |
66 | ||
67 | static struct usb_driver skel_driver; | |
403dfb58 | 68 | static void skel_draw_down(struct usb_skel *dev); |
1da177e4 LT |
69 | |
70 | static void skel_delete(struct kref *kref) | |
c0704541 | 71 | { |
1da177e4 LT |
72 | struct usb_skel *dev = to_skel_dev(kref); |
73 | ||
74 | usb_put_dev(dev->udev); | |
c0704541 LFC |
75 | kfree(dev->bulk_in_buffer); |
76 | kfree(dev); | |
1da177e4 LT |
77 | } |
78 | ||
79 | static int skel_open(struct inode *inode, struct file *file) | |
80 | { | |
81 | struct usb_skel *dev; | |
82 | struct usb_interface *interface; | |
83 | int subminor; | |
84 | int retval = 0; | |
85 | ||
86 | subminor = iminor(inode); | |
87 | ||
88 | interface = usb_find_interface(&skel_driver, subminor); | |
89 | if (!interface) { | |
90 | err ("%s - error, can't find device for minor %d", | |
441b62c1 | 91 | __func__, subminor); |
1da177e4 LT |
92 | retval = -ENODEV; |
93 | goto exit; | |
94 | } | |
95 | ||
96 | dev = usb_get_intfdata(interface); | |
97 | if (!dev) { | |
98 | retval = -ENODEV; | |
99 | goto exit; | |
100 | } | |
101 | ||
5b064708 ON |
102 | /* increment our usage count for the device */ |
103 | kref_get(&dev->kref); | |
104 | ||
758f7e16 ON |
105 | /* lock the device to allow correctly handling errors |
106 | * in resumption */ | |
107 | mutex_lock(&dev->io_mutex); | |
108 | ||
109 | if (!dev->open_count++) { | |
110 | retval = usb_autopm_get_interface(interface); | |
111 | if (retval) { | |
112 | dev->open_count--; | |
113 | mutex_unlock(&dev->io_mutex); | |
114 | kref_put(&dev->kref, skel_delete); | |
115 | goto exit; | |
116 | } | |
117 | } /* else { //uncomment this block if you want exclusive open | |
118 | retval = -EBUSY; | |
119 | dev->open_count--; | |
120 | mutex_unlock(&dev->io_mutex); | |
5b064708 | 121 | kref_put(&dev->kref, skel_delete); |
01d883d4 | 122 | goto exit; |
758f7e16 ON |
123 | } */ |
124 | /* prevent the device from being autosuspended */ | |
1da177e4 LT |
125 | |
126 | /* save our object in the file's private structure */ | |
127 | file->private_data = dev; | |
f7294055 | 128 | mutex_unlock(&dev->io_mutex); |
1da177e4 LT |
129 | |
130 | exit: | |
131 | return retval; | |
132 | } | |
133 | ||
134 | static int skel_release(struct inode *inode, struct file *file) | |
135 | { | |
136 | struct usb_skel *dev; | |
137 | ||
138 | dev = (struct usb_skel *)file->private_data; | |
139 | if (dev == NULL) | |
140 | return -ENODEV; | |
141 | ||
01d883d4 AS |
142 | /* allow the device to be autosuspended */ |
143 | mutex_lock(&dev->io_mutex); | |
758f7e16 | 144 | if (!--dev->open_count && dev->interface) |
01d883d4 AS |
145 | usb_autopm_put_interface(dev->interface); |
146 | mutex_unlock(&dev->io_mutex); | |
147 | ||
1da177e4 LT |
148 | /* decrement the count on our device */ |
149 | kref_put(&dev->kref, skel_delete); | |
150 | return 0; | |
151 | } | |
152 | ||
403dfb58 ON |
153 | static int skel_flush(struct file *file, fl_owner_t id) |
154 | { | |
155 | struct usb_skel *dev; | |
156 | int res; | |
157 | ||
158 | dev = (struct usb_skel *)file->private_data; | |
159 | if (dev == NULL) | |
160 | return -ENODEV; | |
161 | ||
162 | /* wait for io to stop */ | |
163 | mutex_lock(&dev->io_mutex); | |
164 | skel_draw_down(dev); | |
165 | ||
166 | /* read out errors, leave subsequent opens a clean slate */ | |
167 | spin_lock_irq(&dev->err_lock); | |
168 | res = dev->errors ? (dev->errors == -EPIPE ? -EPIPE : -EIO) : 0; | |
169 | dev->errors = 0; | |
170 | spin_unlock_irq(&dev->err_lock); | |
171 | ||
172 | mutex_unlock(&dev->io_mutex); | |
173 | ||
174 | return res; | |
175 | } | |
176 | ||
1da177e4 LT |
177 | static ssize_t skel_read(struct file *file, char *buffer, size_t count, loff_t *ppos) |
178 | { | |
179 | struct usb_skel *dev; | |
c0704541 | 180 | int retval; |
1da177e4 LT |
181 | int bytes_read; |
182 | ||
183 | dev = (struct usb_skel *)file->private_data; | |
121e287c AS |
184 | |
185 | mutex_lock(&dev->io_mutex); | |
186 | if (!dev->interface) { /* disconnect() was called */ | |
187 | retval = -ENODEV; | |
188 | goto exit; | |
189 | } | |
190 | ||
1da177e4 LT |
191 | /* do a blocking bulk read to get data from the device */ |
192 | retval = usb_bulk_msg(dev->udev, | |
193 | usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr), | |
194 | dev->bulk_in_buffer, | |
195 | min(dev->bulk_in_size, count), | |
196 | &bytes_read, 10000); | |
197 | ||
198 | /* if the read was successful, copy the data to userspace */ | |
199 | if (!retval) { | |
200 | if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read)) | |
201 | retval = -EFAULT; | |
202 | else | |
203 | retval = bytes_read; | |
204 | } | |
205 | ||
121e287c AS |
206 | exit: |
207 | mutex_unlock(&dev->io_mutex); | |
1da177e4 LT |
208 | return retval; |
209 | } | |
210 | ||
7d12e780 | 211 | static void skel_write_bulk_callback(struct urb *urb) |
1da177e4 LT |
212 | { |
213 | struct usb_skel *dev; | |
214 | ||
cdc97792 | 215 | dev = urb->context; |
1da177e4 LT |
216 | |
217 | /* sync/async unlink faults aren't errors */ | |
403dfb58 ON |
218 | if (urb->status) { |
219 | if(!(urb->status == -ENOENT || | |
220 | urb->status == -ECONNRESET || | |
221 | urb->status == -ESHUTDOWN)) | |
222 | err("%s - nonzero write bulk status received: %d", | |
441b62c1 | 223 | __func__, urb->status); |
403dfb58 ON |
224 | |
225 | spin_lock(&dev->err_lock); | |
226 | dev->errors = urb->status; | |
227 | spin_unlock(&dev->err_lock); | |
1da177e4 LT |
228 | } |
229 | ||
230 | /* free up our allocated buffer */ | |
c0704541 | 231 | usb_buffer_free(urb->dev, urb->transfer_buffer_length, |
1da177e4 | 232 | urb->transfer_buffer, urb->transfer_dma); |
ff906518 | 233 | up(&dev->limit_sem); |
1da177e4 LT |
234 | } |
235 | ||
236 | static ssize_t skel_write(struct file *file, const char *user_buffer, size_t count, loff_t *ppos) | |
237 | { | |
238 | struct usb_skel *dev; | |
239 | int retval = 0; | |
240 | struct urb *urb = NULL; | |
241 | char *buf = NULL; | |
c8dd7709 | 242 | size_t writesize = min(count, (size_t)MAX_TRANSFER); |
1da177e4 LT |
243 | |
244 | dev = (struct usb_skel *)file->private_data; | |
245 | ||
246 | /* verify that we actually have some data to write */ | |
247 | if (count == 0) | |
248 | goto exit; | |
249 | ||
ff906518 | 250 | /* limit the number of URBs in flight to stop a user from using up all RAM */ |
c8dd7709 SB |
251 | if (down_interruptible(&dev->limit_sem)) { |
252 | retval = -ERESTARTSYS; | |
253 | goto exit; | |
254 | } | |
ff906518 | 255 | |
403dfb58 ON |
256 | spin_lock_irq(&dev->err_lock); |
257 | if ((retval = dev->errors) < 0) { | |
258 | /* any error is reported once */ | |
259 | dev->errors = 0; | |
260 | /* to preserve notifications about reset */ | |
261 | retval = (retval == -EPIPE) ? retval : -EIO; | |
262 | } | |
263 | spin_unlock_irq(&dev->err_lock); | |
264 | if (retval < 0) | |
265 | goto error; | |
266 | ||
1da177e4 LT |
267 | /* create a urb, and a buffer for it, and copy the data to the urb */ |
268 | urb = usb_alloc_urb(0, GFP_KERNEL); | |
269 | if (!urb) { | |
270 | retval = -ENOMEM; | |
271 | goto error; | |
272 | } | |
273 | ||
ff906518 | 274 | buf = usb_buffer_alloc(dev->udev, writesize, GFP_KERNEL, &urb->transfer_dma); |
1da177e4 LT |
275 | if (!buf) { |
276 | retval = -ENOMEM; | |
277 | goto error; | |
278 | } | |
279 | ||
ff906518 | 280 | if (copy_from_user(buf, user_buffer, writesize)) { |
1da177e4 LT |
281 | retval = -EFAULT; |
282 | goto error; | |
283 | } | |
284 | ||
ba35e02b ON |
285 | /* this lock makes sure we don't submit URBs to gone devices */ |
286 | mutex_lock(&dev->io_mutex); | |
287 | if (!dev->interface) { /* disconnect() was called */ | |
288 | mutex_unlock(&dev->io_mutex); | |
289 | retval = -ENODEV; | |
290 | goto error; | |
291 | } | |
292 | ||
1da177e4 LT |
293 | /* initialize the urb properly */ |
294 | usb_fill_bulk_urb(urb, dev->udev, | |
295 | usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr), | |
ff906518 | 296 | buf, writesize, skel_write_bulk_callback, dev); |
1da177e4 | 297 | urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; |
403dfb58 | 298 | usb_anchor_urb(urb, &dev->submitted); |
1da177e4 LT |
299 | |
300 | /* send the data out the bulk port */ | |
301 | retval = usb_submit_urb(urb, GFP_KERNEL); | |
ba35e02b | 302 | mutex_unlock(&dev->io_mutex); |
1da177e4 | 303 | if (retval) { |
441b62c1 | 304 | err("%s - failed submitting write urb, error %d", __func__, retval); |
403dfb58 | 305 | goto error_unanchor; |
1da177e4 LT |
306 | } |
307 | ||
308 | /* release our reference to this urb, the USB core will eventually free it entirely */ | |
309 | usb_free_urb(urb); | |
310 | ||
ba35e02b | 311 | |
ff906518 | 312 | return writesize; |
1da177e4 | 313 | |
403dfb58 ON |
314 | error_unanchor: |
315 | usb_unanchor_urb(urb); | |
1da177e4 | 316 | error: |
121e287c AS |
317 | if (urb) { |
318 | usb_buffer_free(dev->udev, writesize, buf, urb->transfer_dma); | |
319 | usb_free_urb(urb); | |
320 | } | |
ff906518 | 321 | up(&dev->limit_sem); |
121e287c AS |
322 | |
323 | exit: | |
1da177e4 LT |
324 | return retval; |
325 | } | |
326 | ||
066202dd | 327 | static const struct file_operations skel_fops = { |
1da177e4 LT |
328 | .owner = THIS_MODULE, |
329 | .read = skel_read, | |
330 | .write = skel_write, | |
331 | .open = skel_open, | |
332 | .release = skel_release, | |
403dfb58 | 333 | .flush = skel_flush, |
1da177e4 LT |
334 | }; |
335 | ||
c0704541 | 336 | /* |
1da177e4 | 337 | * usb class driver info in order to get a minor number from the usb core, |
595b14cb | 338 | * and to have the device registered with the driver core |
1da177e4 LT |
339 | */ |
340 | static struct usb_class_driver skel_class = { | |
d6e5bcf4 | 341 | .name = "skel%d", |
1da177e4 | 342 | .fops = &skel_fops, |
1da177e4 LT |
343 | .minor_base = USB_SKEL_MINOR_BASE, |
344 | }; | |
345 | ||
346 | static int skel_probe(struct usb_interface *interface, const struct usb_device_id *id) | |
347 | { | |
c0704541 | 348 | struct usb_skel *dev; |
1da177e4 LT |
349 | struct usb_host_interface *iface_desc; |
350 | struct usb_endpoint_descriptor *endpoint; | |
351 | size_t buffer_size; | |
352 | int i; | |
353 | int retval = -ENOMEM; | |
354 | ||
355 | /* allocate memory for our device state and initialize it */ | |
ff906518 | 356 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
c0704541 | 357 | if (!dev) { |
1da177e4 LT |
358 | err("Out of memory"); |
359 | goto error; | |
360 | } | |
1da177e4 | 361 | kref_init(&dev->kref); |
ff906518 | 362 | sema_init(&dev->limit_sem, WRITES_IN_FLIGHT); |
121e287c | 363 | mutex_init(&dev->io_mutex); |
403dfb58 ON |
364 | spin_lock_init(&dev->err_lock); |
365 | init_usb_anchor(&dev->submitted); | |
1da177e4 LT |
366 | |
367 | dev->udev = usb_get_dev(interface_to_usbdev(interface)); | |
368 | dev->interface = interface; | |
369 | ||
370 | /* set up the endpoint information */ | |
371 | /* use only the first bulk-in and bulk-out endpoints */ | |
372 | iface_desc = interface->cur_altsetting; | |
373 | for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { | |
374 | endpoint = &iface_desc->endpoint[i].desc; | |
375 | ||
376 | if (!dev->bulk_in_endpointAddr && | |
c0704541 | 377 | usb_endpoint_is_bulk_in(endpoint)) { |
1da177e4 LT |
378 | /* we found a bulk in endpoint */ |
379 | buffer_size = le16_to_cpu(endpoint->wMaxPacketSize); | |
380 | dev->bulk_in_size = buffer_size; | |
381 | dev->bulk_in_endpointAddr = endpoint->bEndpointAddress; | |
382 | dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL); | |
383 | if (!dev->bulk_in_buffer) { | |
384 | err("Could not allocate bulk_in_buffer"); | |
385 | goto error; | |
386 | } | |
387 | } | |
388 | ||
389 | if (!dev->bulk_out_endpointAddr && | |
c0704541 | 390 | usb_endpoint_is_bulk_out(endpoint)) { |
1da177e4 LT |
391 | /* we found a bulk out endpoint */ |
392 | dev->bulk_out_endpointAddr = endpoint->bEndpointAddress; | |
393 | } | |
394 | } | |
395 | if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) { | |
396 | err("Could not find both bulk-in and bulk-out endpoints"); | |
397 | goto error; | |
398 | } | |
399 | ||
400 | /* save our data pointer in this interface device */ | |
401 | usb_set_intfdata(interface, dev); | |
402 | ||
403 | /* we can register the device now, as it is ready */ | |
404 | retval = usb_register_dev(interface, &skel_class); | |
405 | if (retval) { | |
406 | /* something prevented us from registering this driver */ | |
407 | err("Not able to get a minor for this device."); | |
408 | usb_set_intfdata(interface, NULL); | |
409 | goto error; | |
410 | } | |
411 | ||
412 | /* let the user know what node this device is now attached to */ | |
a5f5ea23 MK |
413 | dev_info(&interface->dev, |
414 | "USB Skeleton device now attached to USBSkel-%d", | |
415 | interface->minor); | |
1da177e4 LT |
416 | return 0; |
417 | ||
418 | error: | |
419 | if (dev) | |
ba35e02b | 420 | /* this frees allocated memory */ |
1da177e4 LT |
421 | kref_put(&dev->kref, skel_delete); |
422 | return retval; | |
423 | } | |
424 | ||
425 | static void skel_disconnect(struct usb_interface *interface) | |
426 | { | |
427 | struct usb_skel *dev; | |
428 | int minor = interface->minor; | |
429 | ||
1da177e4 LT |
430 | dev = usb_get_intfdata(interface); |
431 | usb_set_intfdata(interface, NULL); | |
432 | ||
433 | /* give back our minor */ | |
434 | usb_deregister_dev(interface, &skel_class); | |
435 | ||
121e287c AS |
436 | /* prevent more I/O from starting */ |
437 | mutex_lock(&dev->io_mutex); | |
438 | dev->interface = NULL; | |
439 | mutex_unlock(&dev->io_mutex); | |
440 | ||
e73c7247 ON |
441 | usb_kill_anchored_urbs(&dev->submitted); |
442 | ||
1da177e4 LT |
443 | /* decrement our usage count */ |
444 | kref_put(&dev->kref, skel_delete); | |
445 | ||
a5f5ea23 | 446 | dev_info(&interface->dev, "USB Skeleton #%d now disconnected", minor); |
1da177e4 LT |
447 | } |
448 | ||
403dfb58 ON |
449 | static void skel_draw_down(struct usb_skel *dev) |
450 | { | |
451 | int time; | |
452 | ||
453 | time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000); | |
454 | if (!time) | |
455 | usb_kill_anchored_urbs(&dev->submitted); | |
456 | } | |
457 | ||
758f7e16 ON |
458 | static int skel_suspend(struct usb_interface *intf, pm_message_t message) |
459 | { | |
460 | struct usb_skel *dev = usb_get_intfdata(intf); | |
461 | ||
462 | if (!dev) | |
463 | return 0; | |
464 | skel_draw_down(dev); | |
465 | return 0; | |
466 | } | |
467 | ||
468 | static int skel_resume (struct usb_interface *intf) | |
469 | { | |
470 | return 0; | |
471 | } | |
472 | ||
87d093e2 ON |
473 | static int skel_pre_reset(struct usb_interface *intf) |
474 | { | |
475 | struct usb_skel *dev = usb_get_intfdata(intf); | |
476 | ||
477 | mutex_lock(&dev->io_mutex); | |
478 | skel_draw_down(dev); | |
479 | ||
480 | return 0; | |
481 | } | |
482 | ||
483 | static int skel_post_reset(struct usb_interface *intf) | |
484 | { | |
485 | struct usb_skel *dev = usb_get_intfdata(intf); | |
486 | ||
487 | /* we are sure no URBs are active - no locking needed */ | |
488 | dev->errors = -EPIPE; | |
489 | mutex_unlock(&dev->io_mutex); | |
490 | ||
491 | return 0; | |
492 | } | |
493 | ||
1da177e4 | 494 | static struct usb_driver skel_driver = { |
1da177e4 LT |
495 | .name = "skeleton", |
496 | .probe = skel_probe, | |
497 | .disconnect = skel_disconnect, | |
758f7e16 ON |
498 | .suspend = skel_suspend, |
499 | .resume = skel_resume, | |
87d093e2 ON |
500 | .pre_reset = skel_pre_reset, |
501 | .post_reset = skel_post_reset, | |
1da177e4 | 502 | .id_table = skel_table, |
ba35e02b | 503 | .supports_autosuspend = 1, |
1da177e4 LT |
504 | }; |
505 | ||
506 | static int __init usb_skel_init(void) | |
507 | { | |
508 | int result; | |
509 | ||
510 | /* register this driver with the USB subsystem */ | |
511 | result = usb_register(&skel_driver); | |
512 | if (result) | |
513 | err("usb_register failed. Error number %d", result); | |
514 | ||
515 | return result; | |
516 | } | |
517 | ||
518 | static void __exit usb_skel_exit(void) | |
519 | { | |
520 | /* deregister this driver with the USB subsystem */ | |
521 | usb_deregister(&skel_driver); | |
522 | } | |
523 | ||
c0704541 LFC |
524 | module_init(usb_skel_init); |
525 | module_exit(usb_skel_exit); | |
1da177e4 LT |
526 | |
527 | MODULE_LICENSE("GPL"); |