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16#include <linux/module.h>
17#include <linux/kernel.h>
18#include <linux/slab.h>
19#include <linux/errno.h>
20#include <linux/mutex.h>
21#include <linux/rwsem.h>
22#include <linux/uaccess.h>
23#include <linux/usb.h>
24
25#define DRIVER_VERSION "USBLCD Driver Version 1.05"
26
27#define USBLCD_MINOR 144
28
29#define IOCTL_GET_HARD_VERSION 1
30#define IOCTL_GET_DRV_VERSION 2
31
32
33static const struct usb_device_id id_table[] = {
34 { .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, },
35 { },
36};
37MODULE_DEVICE_TABLE(usb, id_table);
38
39struct usb_lcd {
40 struct usb_device *udev;
41 struct usb_interface *interface;
42
43 unsigned char *bulk_in_buffer;
44
45 size_t bulk_in_size;
46
47 __u8 bulk_in_endpointAddr;
48
49 __u8 bulk_out_endpointAddr;
50
51 struct kref kref;
52 struct semaphore limit_sem;
53
54
55 struct usb_anchor submitted;
56
57 struct rw_semaphore io_rwsem;
58 unsigned long disconnected:1;
59};
60#define to_lcd_dev(d) container_of(d, struct usb_lcd, kref)
61
62#define USB_LCD_CONCURRENT_WRITES 5
63
64static struct usb_driver lcd_driver;
65
66
67static void lcd_delete(struct kref *kref)
68{
69 struct usb_lcd *dev = to_lcd_dev(kref);
70
71 usb_put_dev(dev->udev);
72 kfree(dev->bulk_in_buffer);
73 kfree(dev);
74}
75
76
77static int lcd_open(struct inode *inode, struct file *file)
78{
79 struct usb_lcd *dev;
80 struct usb_interface *interface;
81 int subminor, r;
82
83 subminor = iminor(inode);
84
85 interface = usb_find_interface(&lcd_driver, subminor);
86 if (!interface) {
87 pr_err("USBLCD: %s - error, can't find device for minor %d\n",
88 __func__, subminor);
89 return -ENODEV;
90 }
91
92 dev = usb_get_intfdata(interface);
93
94
95 kref_get(&dev->kref);
96
97
98 r = usb_autopm_get_interface(interface);
99 if (r < 0) {
100 kref_put(&dev->kref, lcd_delete);
101 return r;
102 }
103
104
105 file->private_data = dev;
106
107 return 0;
108}
109
110static int lcd_release(struct inode *inode, struct file *file)
111{
112 struct usb_lcd *dev;
113
114 dev = file->private_data;
115 if (dev == NULL)
116 return -ENODEV;
117
118
119 usb_autopm_put_interface(dev->interface);
120 kref_put(&dev->kref, lcd_delete);
121 return 0;
122}
123
124static ssize_t lcd_read(struct file *file, char __user * buffer,
125 size_t count, loff_t *ppos)
126{
127 struct usb_lcd *dev;
128 int retval = 0;
129 int bytes_read;
130
131 dev = file->private_data;
132
133 down_read(&dev->io_rwsem);
134
135 if (dev->disconnected) {
136 retval = -ENODEV;
137 goto out_up_io;
138 }
139
140
141 retval = usb_bulk_msg(dev->udev,
142 usb_rcvbulkpipe(dev->udev,
143 dev->bulk_in_endpointAddr),
144 dev->bulk_in_buffer,
145 min(dev->bulk_in_size, count),
146 &bytes_read, 10000);
147
148
149 if (!retval) {
150 if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read))
151 retval = -EFAULT;
152 else
153 retval = bytes_read;
154 }
155
156out_up_io:
157 up_read(&dev->io_rwsem);
158
159 return retval;
160}
161
162static long lcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
163{
164 struct usb_lcd *dev;
165 u16 bcdDevice;
166 char buf[30];
167
168 dev = file->private_data;
169 if (dev == NULL)
170 return -ENODEV;
171
172 switch (cmd) {
173 case IOCTL_GET_HARD_VERSION:
174 bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice);
175 sprintf(buf, "%1d%1d.%1d%1d",
176 (bcdDevice & 0xF000)>>12,
177 (bcdDevice & 0xF00)>>8,
178 (bcdDevice & 0xF0)>>4,
179 (bcdDevice & 0xF));
180 if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0)
181 return -EFAULT;
182 break;
183 case IOCTL_GET_DRV_VERSION:
184 sprintf(buf, DRIVER_VERSION);
185 if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0)
186 return -EFAULT;
187 break;
188 default:
189 return -ENOTTY;
190 break;
191 }
192
193 return 0;
194}
195
196static void lcd_write_bulk_callback(struct urb *urb)
197{
198 struct usb_lcd *dev;
199 int status = urb->status;
200
201 dev = urb->context;
202
203
204 if (status &&
205 !(status == -ENOENT ||
206 status == -ECONNRESET ||
207 status == -ESHUTDOWN)) {
208 dev_dbg(&dev->interface->dev,
209 "nonzero write bulk status received: %d\n", status);
210 }
211
212
213 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
214 urb->transfer_buffer, urb->transfer_dma);
215 up(&dev->limit_sem);
216}
217
218static ssize_t lcd_write(struct file *file, const char __user * user_buffer,
219 size_t count, loff_t *ppos)
220{
221 struct usb_lcd *dev;
222 int retval = 0, r;
223 struct urb *urb = NULL;
224 char *buf = NULL;
225
226 dev = file->private_data;
227
228
229 if (count == 0)
230 goto exit;
231
232 r = down_interruptible(&dev->limit_sem);
233 if (r < 0)
234 return -EINTR;
235
236 down_read(&dev->io_rwsem);
237
238 if (dev->disconnected) {
239 retval = -ENODEV;
240 goto err_up_io;
241 }
242
243
244 urb = usb_alloc_urb(0, GFP_KERNEL);
245 if (!urb) {
246 retval = -ENOMEM;
247 goto err_up_io;
248 }
249
250 buf = usb_alloc_coherent(dev->udev, count, GFP_KERNEL,
251 &urb->transfer_dma);
252 if (!buf) {
253 retval = -ENOMEM;
254 goto error;
255 }
256
257 if (copy_from_user(buf, user_buffer, count)) {
258 retval = -EFAULT;
259 goto error;
260 }
261
262
263 usb_fill_bulk_urb(urb, dev->udev,
264 usb_sndbulkpipe(dev->udev,
265 dev->bulk_out_endpointAddr),
266 buf, count, lcd_write_bulk_callback, dev);
267 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
268
269 usb_anchor_urb(urb, &dev->submitted);
270
271
272 retval = usb_submit_urb(urb, GFP_KERNEL);
273 if (retval) {
274 dev_err(&dev->udev->dev,
275 "%s - failed submitting write urb, error %d\n",
276 __func__, retval);
277 goto error_unanchor;
278 }
279
280
281
282 usb_free_urb(urb);
283
284 up_read(&dev->io_rwsem);
285exit:
286 return count;
287error_unanchor:
288 usb_unanchor_urb(urb);
289error:
290 usb_free_coherent(dev->udev, count, buf, urb->transfer_dma);
291 usb_free_urb(urb);
292err_up_io:
293 up_read(&dev->io_rwsem);
294 up(&dev->limit_sem);
295 return retval;
296}
297
298static const struct file_operations lcd_fops = {
299 .owner = THIS_MODULE,
300 .read = lcd_read,
301 .write = lcd_write,
302 .open = lcd_open,
303 .unlocked_ioctl = lcd_ioctl,
304 .release = lcd_release,
305 .llseek = noop_llseek,
306};
307
308
309
310
311
312static struct usb_class_driver lcd_class = {
313 .name = "lcd%d",
314 .fops = &lcd_fops,
315 .minor_base = USBLCD_MINOR,
316};
317
318static int lcd_probe(struct usb_interface *interface,
319 const struct usb_device_id *id)
320{
321 struct usb_lcd *dev = NULL;
322 struct usb_endpoint_descriptor *bulk_in, *bulk_out;
323 int i;
324 int retval;
325
326
327 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
328 if (!dev)
329 return -ENOMEM;
330
331 kref_init(&dev->kref);
332 sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES);
333 init_rwsem(&dev->io_rwsem);
334 init_usb_anchor(&dev->submitted);
335
336 dev->udev = usb_get_dev(interface_to_usbdev(interface));
337 dev->interface = interface;
338
339 if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) {
340 dev_warn(&interface->dev, "USBLCD model not supported.\n");
341 retval = -ENODEV;
342 goto error;
343 }
344
345
346
347 retval = usb_find_common_endpoints(interface->cur_altsetting,
348 &bulk_in, &bulk_out, NULL, NULL);
349 if (retval) {
350 dev_err(&interface->dev,
351 "Could not find both bulk-in and bulk-out endpoints\n");
352 goto error;
353 }
354
355 dev->bulk_in_size = usb_endpoint_maxp(bulk_in);
356 dev->bulk_in_endpointAddr = bulk_in->bEndpointAddress;
357 dev->bulk_in_buffer = kmalloc(dev->bulk_in_size, GFP_KERNEL);
358 if (!dev->bulk_in_buffer) {
359 retval = -ENOMEM;
360 goto error;
361 }
362
363 dev->bulk_out_endpointAddr = bulk_out->bEndpointAddress;
364
365
366 usb_set_intfdata(interface, dev);
367
368
369 retval = usb_register_dev(interface, &lcd_class);
370 if (retval) {
371
372 dev_err(&interface->dev,
373 "Not able to get a minor for this device.\n");
374 goto error;
375 }
376
377 i = le16_to_cpu(dev->udev->descriptor.bcdDevice);
378
379 dev_info(&interface->dev, "USBLCD Version %1d%1d.%1d%1d found "
380 "at address %d\n", (i & 0xF000)>>12, (i & 0xF00)>>8,
381 (i & 0xF0)>>4, (i & 0xF), dev->udev->devnum);
382
383
384 dev_info(&interface->dev, "USB LCD device now attached to USBLCD-%d\n",
385 interface->minor);
386 return 0;
387
388error:
389 kref_put(&dev->kref, lcd_delete);
390 return retval;
391}
392
393static void lcd_draw_down(struct usb_lcd *dev)
394{
395 int time;
396
397 time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000);
398 if (!time)
399 usb_kill_anchored_urbs(&dev->submitted);
400}
401
402static int lcd_suspend(struct usb_interface *intf, pm_message_t message)
403{
404 struct usb_lcd *dev = usb_get_intfdata(intf);
405
406 if (!dev)
407 return 0;
408 lcd_draw_down(dev);
409 return 0;
410}
411
412static int lcd_resume(struct usb_interface *intf)
413{
414 return 0;
415}
416
417static void lcd_disconnect(struct usb_interface *interface)
418{
419 struct usb_lcd *dev = usb_get_intfdata(interface);
420 int minor = interface->minor;
421
422
423 usb_deregister_dev(interface, &lcd_class);
424
425 down_write(&dev->io_rwsem);
426 dev->disconnected = 1;
427 up_write(&dev->io_rwsem);
428
429 usb_kill_anchored_urbs(&dev->submitted);
430
431
432 kref_put(&dev->kref, lcd_delete);
433
434 dev_info(&interface->dev, "USB LCD #%d now disconnected\n", minor);
435}
436
437static struct usb_driver lcd_driver = {
438 .name = "usblcd",
439 .probe = lcd_probe,
440 .disconnect = lcd_disconnect,
441 .suspend = lcd_suspend,
442 .resume = lcd_resume,
443 .id_table = id_table,
444 .supports_autosuspend = 1,
445};
446
447module_usb_driver(lcd_driver);
448
449MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>");
450MODULE_DESCRIPTION(DRIVER_VERSION);
451MODULE_LICENSE("GPL");
452
