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 ON |
59 | int errors; /* the last request tanked */ |
60 | spinlock_t err_lock; /* lock for errors */ | |
1da177e4 | 61 | struct kref kref; |
121e287c | 62 | struct mutex io_mutex; /* synchronize I/O with disconnect */ |
1da177e4 LT |
63 | }; |
64 | #define to_skel_dev(d) container_of(d, struct usb_skel, kref) | |
65 | ||
66 | static struct usb_driver skel_driver; | |
403dfb58 | 67 | static void skel_draw_down(struct usb_skel *dev); |
1da177e4 LT |
68 | |
69 | static void skel_delete(struct kref *kref) | |
c0704541 | 70 | { |
1da177e4 LT |
71 | struct usb_skel *dev = to_skel_dev(kref); |
72 | ||
73 | usb_put_dev(dev->udev); | |
c0704541 LFC |
74 | kfree(dev->bulk_in_buffer); |
75 | kfree(dev); | |
1da177e4 LT |
76 | } |
77 | ||
78 | static int skel_open(struct inode *inode, struct file *file) | |
79 | { | |
80 | struct usb_skel *dev; | |
81 | struct usb_interface *interface; | |
82 | int subminor; | |
83 | int retval = 0; | |
84 | ||
85 | subminor = iminor(inode); | |
86 | ||
87 | interface = usb_find_interface(&skel_driver, subminor); | |
88 | if (!interface) { | |
89 | err ("%s - error, can't find device for minor %d", | |
90 | __FUNCTION__, subminor); | |
91 | retval = -ENODEV; | |
92 | goto exit; | |
93 | } | |
94 | ||
95 | dev = usb_get_intfdata(interface); | |
96 | if (!dev) { | |
97 | retval = -ENODEV; | |
98 | goto exit; | |
99 | } | |
100 | ||
5b064708 ON |
101 | /* increment our usage count for the device */ |
102 | kref_get(&dev->kref); | |
103 | ||
01d883d4 AS |
104 | /* prevent the device from being autosuspended */ |
105 | retval = usb_autopm_get_interface(interface); | |
5b064708 ON |
106 | if (retval) { |
107 | kref_put(&dev->kref, skel_delete); | |
01d883d4 | 108 | goto exit; |
5b064708 | 109 | } |
1da177e4 LT |
110 | |
111 | /* save our object in the file's private structure */ | |
112 | file->private_data = dev; | |
113 | ||
114 | exit: | |
115 | return retval; | |
116 | } | |
117 | ||
118 | static int skel_release(struct inode *inode, struct file *file) | |
119 | { | |
120 | struct usb_skel *dev; | |
121 | ||
122 | dev = (struct usb_skel *)file->private_data; | |
123 | if (dev == NULL) | |
124 | return -ENODEV; | |
125 | ||
01d883d4 AS |
126 | /* allow the device to be autosuspended */ |
127 | mutex_lock(&dev->io_mutex); | |
128 | if (dev->interface) | |
129 | usb_autopm_put_interface(dev->interface); | |
130 | mutex_unlock(&dev->io_mutex); | |
131 | ||
1da177e4 LT |
132 | /* decrement the count on our device */ |
133 | kref_put(&dev->kref, skel_delete); | |
134 | return 0; | |
135 | } | |
136 | ||
403dfb58 ON |
137 | static int skel_flush(struct file *file, fl_owner_t id) |
138 | { | |
139 | struct usb_skel *dev; | |
140 | int res; | |
141 | ||
142 | dev = (struct usb_skel *)file->private_data; | |
143 | if (dev == NULL) | |
144 | return -ENODEV; | |
145 | ||
146 | /* wait for io to stop */ | |
147 | mutex_lock(&dev->io_mutex); | |
148 | skel_draw_down(dev); | |
149 | ||
150 | /* read out errors, leave subsequent opens a clean slate */ | |
151 | spin_lock_irq(&dev->err_lock); | |
152 | res = dev->errors ? (dev->errors == -EPIPE ? -EPIPE : -EIO) : 0; | |
153 | dev->errors = 0; | |
154 | spin_unlock_irq(&dev->err_lock); | |
155 | ||
156 | mutex_unlock(&dev->io_mutex); | |
157 | ||
158 | return res; | |
159 | } | |
160 | ||
1da177e4 LT |
161 | static ssize_t skel_read(struct file *file, char *buffer, size_t count, loff_t *ppos) |
162 | { | |
163 | struct usb_skel *dev; | |
c0704541 | 164 | int retval; |
1da177e4 LT |
165 | int bytes_read; |
166 | ||
167 | dev = (struct usb_skel *)file->private_data; | |
121e287c AS |
168 | |
169 | mutex_lock(&dev->io_mutex); | |
170 | if (!dev->interface) { /* disconnect() was called */ | |
171 | retval = -ENODEV; | |
172 | goto exit; | |
173 | } | |
174 | ||
1da177e4 LT |
175 | /* do a blocking bulk read to get data from the device */ |
176 | retval = usb_bulk_msg(dev->udev, | |
177 | usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr), | |
178 | dev->bulk_in_buffer, | |
179 | min(dev->bulk_in_size, count), | |
180 | &bytes_read, 10000); | |
181 | ||
182 | /* if the read was successful, copy the data to userspace */ | |
183 | if (!retval) { | |
184 | if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read)) | |
185 | retval = -EFAULT; | |
186 | else | |
187 | retval = bytes_read; | |
188 | } | |
189 | ||
121e287c AS |
190 | exit: |
191 | mutex_unlock(&dev->io_mutex); | |
1da177e4 LT |
192 | return retval; |
193 | } | |
194 | ||
7d12e780 | 195 | static void skel_write_bulk_callback(struct urb *urb) |
1da177e4 LT |
196 | { |
197 | struct usb_skel *dev; | |
198 | ||
199 | dev = (struct usb_skel *)urb->context; | |
200 | ||
201 | /* sync/async unlink faults aren't errors */ | |
403dfb58 ON |
202 | if (urb->status) { |
203 | if(!(urb->status == -ENOENT || | |
204 | urb->status == -ECONNRESET || | |
205 | urb->status == -ESHUTDOWN)) | |
206 | err("%s - nonzero write bulk status received: %d", | |
207 | __FUNCTION__, urb->status); | |
208 | ||
209 | spin_lock(&dev->err_lock); | |
210 | dev->errors = urb->status; | |
211 | spin_unlock(&dev->err_lock); | |
1da177e4 LT |
212 | } |
213 | ||
214 | /* free up our allocated buffer */ | |
c0704541 | 215 | usb_buffer_free(urb->dev, urb->transfer_buffer_length, |
1da177e4 | 216 | urb->transfer_buffer, urb->transfer_dma); |
ff906518 | 217 | up(&dev->limit_sem); |
1da177e4 LT |
218 | } |
219 | ||
220 | static ssize_t skel_write(struct file *file, const char *user_buffer, size_t count, loff_t *ppos) | |
221 | { | |
222 | struct usb_skel *dev; | |
223 | int retval = 0; | |
224 | struct urb *urb = NULL; | |
225 | char *buf = NULL; | |
c8dd7709 | 226 | size_t writesize = min(count, (size_t)MAX_TRANSFER); |
1da177e4 LT |
227 | |
228 | dev = (struct usb_skel *)file->private_data; | |
229 | ||
230 | /* verify that we actually have some data to write */ | |
231 | if (count == 0) | |
232 | goto exit; | |
233 | ||
ff906518 | 234 | /* limit the number of URBs in flight to stop a user from using up all RAM */ |
c8dd7709 SB |
235 | if (down_interruptible(&dev->limit_sem)) { |
236 | retval = -ERESTARTSYS; | |
237 | goto exit; | |
238 | } | |
ff906518 | 239 | |
403dfb58 ON |
240 | spin_lock_irq(&dev->err_lock); |
241 | if ((retval = dev->errors) < 0) { | |
242 | /* any error is reported once */ | |
243 | dev->errors = 0; | |
244 | /* to preserve notifications about reset */ | |
245 | retval = (retval == -EPIPE) ? retval : -EIO; | |
246 | } | |
247 | spin_unlock_irq(&dev->err_lock); | |
248 | if (retval < 0) | |
249 | goto error; | |
250 | ||
1da177e4 LT |
251 | /* create a urb, and a buffer for it, and copy the data to the urb */ |
252 | urb = usb_alloc_urb(0, GFP_KERNEL); | |
253 | if (!urb) { | |
254 | retval = -ENOMEM; | |
255 | goto error; | |
256 | } | |
257 | ||
ff906518 | 258 | buf = usb_buffer_alloc(dev->udev, writesize, GFP_KERNEL, &urb->transfer_dma); |
1da177e4 LT |
259 | if (!buf) { |
260 | retval = -ENOMEM; | |
261 | goto error; | |
262 | } | |
263 | ||
ff906518 | 264 | if (copy_from_user(buf, user_buffer, writesize)) { |
1da177e4 LT |
265 | retval = -EFAULT; |
266 | goto error; | |
267 | } | |
268 | ||
ba35e02b ON |
269 | /* this lock makes sure we don't submit URBs to gone devices */ |
270 | mutex_lock(&dev->io_mutex); | |
271 | if (!dev->interface) { /* disconnect() was called */ | |
272 | mutex_unlock(&dev->io_mutex); | |
273 | retval = -ENODEV; | |
274 | goto error; | |
275 | } | |
276 | ||
1da177e4 LT |
277 | /* initialize the urb properly */ |
278 | usb_fill_bulk_urb(urb, dev->udev, | |
279 | usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr), | |
ff906518 | 280 | buf, writesize, skel_write_bulk_callback, dev); |
1da177e4 | 281 | urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; |
403dfb58 | 282 | usb_anchor_urb(urb, &dev->submitted); |
1da177e4 LT |
283 | |
284 | /* send the data out the bulk port */ | |
285 | retval = usb_submit_urb(urb, GFP_KERNEL); | |
ba35e02b | 286 | mutex_unlock(&dev->io_mutex); |
1da177e4 LT |
287 | if (retval) { |
288 | err("%s - failed submitting write urb, error %d", __FUNCTION__, retval); | |
403dfb58 | 289 | goto error_unanchor; |
1da177e4 LT |
290 | } |
291 | ||
292 | /* release our reference to this urb, the USB core will eventually free it entirely */ | |
293 | usb_free_urb(urb); | |
294 | ||
ba35e02b | 295 | |
ff906518 | 296 | return writesize; |
1da177e4 | 297 | |
403dfb58 ON |
298 | error_unanchor: |
299 | usb_unanchor_urb(urb); | |
1da177e4 | 300 | error: |
121e287c AS |
301 | if (urb) { |
302 | usb_buffer_free(dev->udev, writesize, buf, urb->transfer_dma); | |
303 | usb_free_urb(urb); | |
304 | } | |
ff906518 | 305 | up(&dev->limit_sem); |
121e287c AS |
306 | |
307 | exit: | |
1da177e4 LT |
308 | return retval; |
309 | } | |
310 | ||
066202dd | 311 | static const struct file_operations skel_fops = { |
1da177e4 LT |
312 | .owner = THIS_MODULE, |
313 | .read = skel_read, | |
314 | .write = skel_write, | |
315 | .open = skel_open, | |
316 | .release = skel_release, | |
403dfb58 | 317 | .flush = skel_flush, |
1da177e4 LT |
318 | }; |
319 | ||
c0704541 | 320 | /* |
1da177e4 | 321 | * usb class driver info in order to get a minor number from the usb core, |
595b14cb | 322 | * and to have the device registered with the driver core |
1da177e4 LT |
323 | */ |
324 | static struct usb_class_driver skel_class = { | |
d6e5bcf4 | 325 | .name = "skel%d", |
1da177e4 | 326 | .fops = &skel_fops, |
1da177e4 LT |
327 | .minor_base = USB_SKEL_MINOR_BASE, |
328 | }; | |
329 | ||
330 | static int skel_probe(struct usb_interface *interface, const struct usb_device_id *id) | |
331 | { | |
c0704541 | 332 | struct usb_skel *dev; |
1da177e4 LT |
333 | struct usb_host_interface *iface_desc; |
334 | struct usb_endpoint_descriptor *endpoint; | |
335 | size_t buffer_size; | |
336 | int i; | |
337 | int retval = -ENOMEM; | |
338 | ||
339 | /* allocate memory for our device state and initialize it */ | |
ff906518 | 340 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
c0704541 | 341 | if (!dev) { |
1da177e4 LT |
342 | err("Out of memory"); |
343 | goto error; | |
344 | } | |
1da177e4 | 345 | kref_init(&dev->kref); |
ff906518 | 346 | sema_init(&dev->limit_sem, WRITES_IN_FLIGHT); |
121e287c | 347 | mutex_init(&dev->io_mutex); |
403dfb58 ON |
348 | spin_lock_init(&dev->err_lock); |
349 | init_usb_anchor(&dev->submitted); | |
1da177e4 LT |
350 | |
351 | dev->udev = usb_get_dev(interface_to_usbdev(interface)); | |
352 | dev->interface = interface; | |
353 | ||
354 | /* set up the endpoint information */ | |
355 | /* use only the first bulk-in and bulk-out endpoints */ | |
356 | iface_desc = interface->cur_altsetting; | |
357 | for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { | |
358 | endpoint = &iface_desc->endpoint[i].desc; | |
359 | ||
360 | if (!dev->bulk_in_endpointAddr && | |
c0704541 | 361 | usb_endpoint_is_bulk_in(endpoint)) { |
1da177e4 LT |
362 | /* we found a bulk in endpoint */ |
363 | buffer_size = le16_to_cpu(endpoint->wMaxPacketSize); | |
364 | dev->bulk_in_size = buffer_size; | |
365 | dev->bulk_in_endpointAddr = endpoint->bEndpointAddress; | |
366 | dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL); | |
367 | if (!dev->bulk_in_buffer) { | |
368 | err("Could not allocate bulk_in_buffer"); | |
369 | goto error; | |
370 | } | |
371 | } | |
372 | ||
373 | if (!dev->bulk_out_endpointAddr && | |
c0704541 | 374 | usb_endpoint_is_bulk_out(endpoint)) { |
1da177e4 LT |
375 | /* we found a bulk out endpoint */ |
376 | dev->bulk_out_endpointAddr = endpoint->bEndpointAddress; | |
377 | } | |
378 | } | |
379 | if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) { | |
380 | err("Could not find both bulk-in and bulk-out endpoints"); | |
381 | goto error; | |
382 | } | |
383 | ||
384 | /* save our data pointer in this interface device */ | |
385 | usb_set_intfdata(interface, dev); | |
386 | ||
387 | /* we can register the device now, as it is ready */ | |
388 | retval = usb_register_dev(interface, &skel_class); | |
389 | if (retval) { | |
390 | /* something prevented us from registering this driver */ | |
391 | err("Not able to get a minor for this device."); | |
392 | usb_set_intfdata(interface, NULL); | |
393 | goto error; | |
394 | } | |
395 | ||
396 | /* let the user know what node this device is now attached to */ | |
397 | info("USB Skeleton device now attached to USBSkel-%d", interface->minor); | |
398 | return 0; | |
399 | ||
400 | error: | |
401 | if (dev) | |
ba35e02b | 402 | /* this frees allocated memory */ |
1da177e4 LT |
403 | kref_put(&dev->kref, skel_delete); |
404 | return retval; | |
405 | } | |
406 | ||
407 | static void skel_disconnect(struct usb_interface *interface) | |
408 | { | |
409 | struct usb_skel *dev; | |
410 | int minor = interface->minor; | |
411 | ||
1da177e4 LT |
412 | dev = usb_get_intfdata(interface); |
413 | usb_set_intfdata(interface, NULL); | |
414 | ||
415 | /* give back our minor */ | |
416 | usb_deregister_dev(interface, &skel_class); | |
417 | ||
121e287c AS |
418 | /* prevent more I/O from starting */ |
419 | mutex_lock(&dev->io_mutex); | |
420 | dev->interface = NULL; | |
421 | mutex_unlock(&dev->io_mutex); | |
422 | ||
1da177e4 LT |
423 | /* decrement our usage count */ |
424 | kref_put(&dev->kref, skel_delete); | |
425 | ||
426 | info("USB Skeleton #%d now disconnected", minor); | |
427 | } | |
428 | ||
403dfb58 ON |
429 | static void skel_draw_down(struct usb_skel *dev) |
430 | { | |
431 | int time; | |
432 | ||
433 | time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000); | |
434 | if (!time) | |
435 | usb_kill_anchored_urbs(&dev->submitted); | |
436 | } | |
437 | ||
1da177e4 | 438 | static struct usb_driver skel_driver = { |
1da177e4 LT |
439 | .name = "skeleton", |
440 | .probe = skel_probe, | |
441 | .disconnect = skel_disconnect, | |
442 | .id_table = skel_table, | |
ba35e02b | 443 | .supports_autosuspend = 1, |
1da177e4 LT |
444 | }; |
445 | ||
446 | static int __init usb_skel_init(void) | |
447 | { | |
448 | int result; | |
449 | ||
450 | /* register this driver with the USB subsystem */ | |
451 | result = usb_register(&skel_driver); | |
452 | if (result) | |
453 | err("usb_register failed. Error number %d", result); | |
454 | ||
455 | return result; | |
456 | } | |
457 | ||
458 | static void __exit usb_skel_exit(void) | |
459 | { | |
460 | /* deregister this driver with the USB subsystem */ | |
461 | usb_deregister(&skel_driver); | |
462 | } | |
463 | ||
c0704541 LFC |
464 | module_init(usb_skel_init); |
465 | module_exit(usb_skel_exit); | |
1da177e4 LT |
466 | |
467 | MODULE_LICENSE("GPL"); |