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1da177e4 LT |
1 | /* |
2 | * USB Skeleton driver - 2.0 | |
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 | * | |
10 | * This driver is based on the 2.6.3 version of drivers/usb/usb-skeleton.c | |
11 | * but has been rewritten to be easy to read and use, as no locks are now | |
12 | * needed anymore. | |
13 | * | |
14 | */ | |
15 | ||
16 | #include <linux/config.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/errno.h> | |
19 | #include <linux/init.h> | |
20 | #include <linux/slab.h> | |
21 | #include <linux/module.h> | |
22 | #include <linux/kref.h> | |
23 | #include <asm/uaccess.h> | |
24 | #include <linux/usb.h> | |
25 | ||
26 | ||
27 | /* Define these values to match your devices */ | |
28 | #define USB_SKEL_VENDOR_ID 0xfff0 | |
29 | #define USB_SKEL_PRODUCT_ID 0xfff0 | |
30 | ||
31 | /* table of devices that work with this driver */ | |
32 | static struct usb_device_id skel_table [] = { | |
33 | { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) }, | |
34 | { } /* Terminating entry */ | |
35 | }; | |
36 | MODULE_DEVICE_TABLE (usb, skel_table); | |
37 | ||
38 | ||
39 | /* Get a minor range for your devices from the usb maintainer */ | |
40 | #define USB_SKEL_MINOR_BASE 192 | |
41 | ||
42 | /* Structure to hold all of our device specific stuff */ | |
43 | struct usb_skel { | |
44 | struct usb_device * udev; /* the usb device for this device */ | |
45 | struct usb_interface * interface; /* the interface for this device */ | |
46 | unsigned char * bulk_in_buffer; /* the buffer to receive data */ | |
47 | size_t bulk_in_size; /* the size of the receive buffer */ | |
48 | __u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */ | |
49 | __u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */ | |
50 | struct kref kref; | |
51 | }; | |
52 | #define to_skel_dev(d) container_of(d, struct usb_skel, kref) | |
53 | ||
54 | static struct usb_driver skel_driver; | |
55 | ||
56 | static void skel_delete(struct kref *kref) | |
57 | { | |
58 | struct usb_skel *dev = to_skel_dev(kref); | |
59 | ||
60 | usb_put_dev(dev->udev); | |
61 | kfree (dev->bulk_in_buffer); | |
62 | kfree (dev); | |
63 | } | |
64 | ||
65 | static int skel_open(struct inode *inode, struct file *file) | |
66 | { | |
67 | struct usb_skel *dev; | |
68 | struct usb_interface *interface; | |
69 | int subminor; | |
70 | int retval = 0; | |
71 | ||
72 | subminor = iminor(inode); | |
73 | ||
74 | interface = usb_find_interface(&skel_driver, subminor); | |
75 | if (!interface) { | |
76 | err ("%s - error, can't find device for minor %d", | |
77 | __FUNCTION__, subminor); | |
78 | retval = -ENODEV; | |
79 | goto exit; | |
80 | } | |
81 | ||
82 | dev = usb_get_intfdata(interface); | |
83 | if (!dev) { | |
84 | retval = -ENODEV; | |
85 | goto exit; | |
86 | } | |
87 | ||
88 | /* increment our usage count for the device */ | |
89 | kref_get(&dev->kref); | |
90 | ||
91 | /* save our object in the file's private structure */ | |
92 | file->private_data = dev; | |
93 | ||
94 | exit: | |
95 | return retval; | |
96 | } | |
97 | ||
98 | static int skel_release(struct inode *inode, struct file *file) | |
99 | { | |
100 | struct usb_skel *dev; | |
101 | ||
102 | dev = (struct usb_skel *)file->private_data; | |
103 | if (dev == NULL) | |
104 | return -ENODEV; | |
105 | ||
106 | /* decrement the count on our device */ | |
107 | kref_put(&dev->kref, skel_delete); | |
108 | return 0; | |
109 | } | |
110 | ||
111 | static ssize_t skel_read(struct file *file, char *buffer, size_t count, loff_t *ppos) | |
112 | { | |
113 | struct usb_skel *dev; | |
114 | int retval = 0; | |
115 | int bytes_read; | |
116 | ||
117 | dev = (struct usb_skel *)file->private_data; | |
118 | ||
119 | /* do a blocking bulk read to get data from the device */ | |
120 | retval = usb_bulk_msg(dev->udev, | |
121 | usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr), | |
122 | dev->bulk_in_buffer, | |
123 | min(dev->bulk_in_size, count), | |
124 | &bytes_read, 10000); | |
125 | ||
126 | /* if the read was successful, copy the data to userspace */ | |
127 | if (!retval) { | |
128 | if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read)) | |
129 | retval = -EFAULT; | |
130 | else | |
131 | retval = bytes_read; | |
132 | } | |
133 | ||
134 | return retval; | |
135 | } | |
136 | ||
137 | static void skel_write_bulk_callback(struct urb *urb, struct pt_regs *regs) | |
138 | { | |
139 | struct usb_skel *dev; | |
140 | ||
141 | dev = (struct usb_skel *)urb->context; | |
142 | ||
143 | /* sync/async unlink faults aren't errors */ | |
144 | if (urb->status && | |
145 | !(urb->status == -ENOENT || | |
146 | urb->status == -ECONNRESET || | |
147 | urb->status == -ESHUTDOWN)) { | |
148 | dbg("%s - nonzero write bulk status received: %d", | |
149 | __FUNCTION__, urb->status); | |
150 | } | |
151 | ||
152 | /* free up our allocated buffer */ | |
153 | usb_buffer_free(urb->dev, urb->transfer_buffer_length, | |
154 | urb->transfer_buffer, urb->transfer_dma); | |
155 | } | |
156 | ||
157 | static ssize_t skel_write(struct file *file, const char *user_buffer, size_t count, loff_t *ppos) | |
158 | { | |
159 | struct usb_skel *dev; | |
160 | int retval = 0; | |
161 | struct urb *urb = NULL; | |
162 | char *buf = NULL; | |
163 | ||
164 | dev = (struct usb_skel *)file->private_data; | |
165 | ||
166 | /* verify that we actually have some data to write */ | |
167 | if (count == 0) | |
168 | goto exit; | |
169 | ||
170 | /* create a urb, and a buffer for it, and copy the data to the urb */ | |
171 | urb = usb_alloc_urb(0, GFP_KERNEL); | |
172 | if (!urb) { | |
173 | retval = -ENOMEM; | |
174 | goto error; | |
175 | } | |
176 | ||
177 | buf = usb_buffer_alloc(dev->udev, count, GFP_KERNEL, &urb->transfer_dma); | |
178 | if (!buf) { | |
179 | retval = -ENOMEM; | |
180 | goto error; | |
181 | } | |
182 | ||
183 | if (copy_from_user(buf, user_buffer, count)) { | |
184 | retval = -EFAULT; | |
185 | goto error; | |
186 | } | |
187 | ||
188 | /* initialize the urb properly */ | |
189 | usb_fill_bulk_urb(urb, dev->udev, | |
190 | usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr), | |
191 | buf, count, skel_write_bulk_callback, dev); | |
192 | urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; | |
193 | ||
194 | /* send the data out the bulk port */ | |
195 | retval = usb_submit_urb(urb, GFP_KERNEL); | |
196 | if (retval) { | |
197 | err("%s - failed submitting write urb, error %d", __FUNCTION__, retval); | |
198 | goto error; | |
199 | } | |
200 | ||
201 | /* release our reference to this urb, the USB core will eventually free it entirely */ | |
202 | usb_free_urb(urb); | |
203 | ||
204 | exit: | |
205 | return count; | |
206 | ||
207 | error: | |
208 | usb_buffer_free(dev->udev, count, buf, urb->transfer_dma); | |
209 | usb_free_urb(urb); | |
210 | return retval; | |
211 | } | |
212 | ||
213 | static struct file_operations skel_fops = { | |
214 | .owner = THIS_MODULE, | |
215 | .read = skel_read, | |
216 | .write = skel_write, | |
217 | .open = skel_open, | |
218 | .release = skel_release, | |
219 | }; | |
220 | ||
221 | /* | |
222 | * usb class driver info in order to get a minor number from the usb core, | |
223 | * and to have the device registered with devfs and the driver core | |
224 | */ | |
225 | static struct usb_class_driver skel_class = { | |
d6e5bcf4 | 226 | .name = "skel%d", |
1da177e4 | 227 | .fops = &skel_fops, |
1da177e4 LT |
228 | .minor_base = USB_SKEL_MINOR_BASE, |
229 | }; | |
230 | ||
231 | static int skel_probe(struct usb_interface *interface, const struct usb_device_id *id) | |
232 | { | |
233 | struct usb_skel *dev = NULL; | |
234 | struct usb_host_interface *iface_desc; | |
235 | struct usb_endpoint_descriptor *endpoint; | |
236 | size_t buffer_size; | |
237 | int i; | |
238 | int retval = -ENOMEM; | |
239 | ||
240 | /* allocate memory for our device state and initialize it */ | |
241 | dev = kmalloc(sizeof(*dev), GFP_KERNEL); | |
242 | if (dev == NULL) { | |
243 | err("Out of memory"); | |
244 | goto error; | |
245 | } | |
246 | memset(dev, 0x00, sizeof(*dev)); | |
247 | kref_init(&dev->kref); | |
248 | ||
249 | dev->udev = usb_get_dev(interface_to_usbdev(interface)); | |
250 | dev->interface = interface; | |
251 | ||
252 | /* set up the endpoint information */ | |
253 | /* use only the first bulk-in and bulk-out endpoints */ | |
254 | iface_desc = interface->cur_altsetting; | |
255 | for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { | |
256 | endpoint = &iface_desc->endpoint[i].desc; | |
257 | ||
258 | if (!dev->bulk_in_endpointAddr && | |
6b216df8 CC |
259 | ((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) |
260 | == USB_DIR_IN) && | |
1da177e4 LT |
261 | ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) |
262 | == USB_ENDPOINT_XFER_BULK)) { | |
263 | /* we found a bulk in endpoint */ | |
264 | buffer_size = le16_to_cpu(endpoint->wMaxPacketSize); | |
265 | dev->bulk_in_size = buffer_size; | |
266 | dev->bulk_in_endpointAddr = endpoint->bEndpointAddress; | |
267 | dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL); | |
268 | if (!dev->bulk_in_buffer) { | |
269 | err("Could not allocate bulk_in_buffer"); | |
270 | goto error; | |
271 | } | |
272 | } | |
273 | ||
274 | if (!dev->bulk_out_endpointAddr && | |
6b216df8 CC |
275 | ((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) |
276 | == USB_DIR_OUT) && | |
1da177e4 LT |
277 | ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) |
278 | == USB_ENDPOINT_XFER_BULK)) { | |
279 | /* we found a bulk out endpoint */ | |
280 | dev->bulk_out_endpointAddr = endpoint->bEndpointAddress; | |
281 | } | |
282 | } | |
283 | if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) { | |
284 | err("Could not find both bulk-in and bulk-out endpoints"); | |
285 | goto error; | |
286 | } | |
287 | ||
288 | /* save our data pointer in this interface device */ | |
289 | usb_set_intfdata(interface, dev); | |
290 | ||
291 | /* we can register the device now, as it is ready */ | |
292 | retval = usb_register_dev(interface, &skel_class); | |
293 | if (retval) { | |
294 | /* something prevented us from registering this driver */ | |
295 | err("Not able to get a minor for this device."); | |
296 | usb_set_intfdata(interface, NULL); | |
297 | goto error; | |
298 | } | |
299 | ||
300 | /* let the user know what node this device is now attached to */ | |
301 | info("USB Skeleton device now attached to USBSkel-%d", interface->minor); | |
302 | return 0; | |
303 | ||
304 | error: | |
305 | if (dev) | |
306 | kref_put(&dev->kref, skel_delete); | |
307 | return retval; | |
308 | } | |
309 | ||
310 | static void skel_disconnect(struct usb_interface *interface) | |
311 | { | |
312 | struct usb_skel *dev; | |
313 | int minor = interface->minor; | |
314 | ||
315 | /* prevent skel_open() from racing skel_disconnect() */ | |
316 | lock_kernel(); | |
317 | ||
318 | dev = usb_get_intfdata(interface); | |
319 | usb_set_intfdata(interface, NULL); | |
320 | ||
321 | /* give back our minor */ | |
322 | usb_deregister_dev(interface, &skel_class); | |
323 | ||
324 | unlock_kernel(); | |
325 | ||
326 | /* decrement our usage count */ | |
327 | kref_put(&dev->kref, skel_delete); | |
328 | ||
329 | info("USB Skeleton #%d now disconnected", minor); | |
330 | } | |
331 | ||
332 | static struct usb_driver skel_driver = { | |
1da177e4 LT |
333 | .name = "skeleton", |
334 | .probe = skel_probe, | |
335 | .disconnect = skel_disconnect, | |
336 | .id_table = skel_table, | |
337 | }; | |
338 | ||
339 | static int __init usb_skel_init(void) | |
340 | { | |
341 | int result; | |
342 | ||
343 | /* register this driver with the USB subsystem */ | |
344 | result = usb_register(&skel_driver); | |
345 | if (result) | |
346 | err("usb_register failed. Error number %d", result); | |
347 | ||
348 | return result; | |
349 | } | |
350 | ||
351 | static void __exit usb_skel_exit(void) | |
352 | { | |
353 | /* deregister this driver with the USB subsystem */ | |
354 | usb_deregister(&skel_driver); | |
355 | } | |
356 | ||
357 | module_init (usb_skel_init); | |
358 | module_exit (usb_skel_exit); | |
359 | ||
360 | MODULE_LICENSE("GPL"); |