1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Driver for Meywa-Denki & KAYAC YUREX
4 *
5 * Copyright (C) 2010 Tomoki Sekiyama (tomoki.sekiyama@gmail.com)
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/errno.h>
10 #include <linux/slab.h>
11 #include <linux/module.h>
12 #include <linux/kref.h>
13 #include <linux/mutex.h>
14 #include <linux/uaccess.h>
15 #include <linux/usb.h>
16 #include <linux/hid.h>
17
18 #define DRIVER_AUTHOR "Tomoki Sekiyama"
19 #define DRIVER_DESC "Driver for Meywa-Denki & KAYAC YUREX"
20
21 #define YUREX_VENDOR_ID 0x0c45
22 #define YUREX_PRODUCT_ID 0x1010
23
24 #define CMD_ACK '!'
25 #define CMD_ANIMATE 'A'
26 #define CMD_COUNT 'C'
27 #define CMD_LED 'L'
28 #define CMD_READ 'R'
29 #define CMD_SET 'S'
30 #define CMD_VERSION 'V'
31 #define CMD_EOF 0x0d
32 #define CMD_PADDING 0xff
33
34 #define YUREX_BUF_SIZE 8
35 #define YUREX_WRITE_TIMEOUT (HZ*2)
36
37 /* table of devices that work with this driver */
38 static struct usb_device_id yurex_table[] = {
39 { USB_DEVICE(YUREX_VENDOR_ID, YUREX_PRODUCT_ID) },
40 { } /* Terminating entry */
41 };
42 MODULE_DEVICE_TABLE(usb, yurex_table);
43
44 #ifdef CONFIG_USB_DYNAMIC_MINORS
45 #define YUREX_MINOR_BASE 0
46 #else
47 #define YUREX_MINOR_BASE 192
48 #endif
49
50 /* Structure to hold all of our device specific stuff */
51 struct usb_yurex {
52 struct usb_device *udev;
53 struct usb_interface *interface;
54 __u8 int_in_endpointAddr;
55 struct urb *urb; /* URB for interrupt in */
56 unsigned char *int_buffer; /* buffer for intterupt in */
57 struct urb *cntl_urb; /* URB for control msg */
58 struct usb_ctrlrequest *cntl_req; /* req for control msg */
59 unsigned char *cntl_buffer; /* buffer for control msg */
60
61 struct kref kref;
62 struct mutex io_mutex;
63 unsigned long disconnected:1;
64 struct fasync_struct *async_queue;
65 wait_queue_head_t waitq;
66
67 spinlock_t lock;
68 __s64 bbu; /* BBU from device */
69 };
70 #define to_yurex_dev(d) container_of(d, struct usb_yurex, kref)
71
72 static struct usb_driver yurex_driver;
73 static const struct file_operations yurex_fops;
74
75
yurex_control_callback(struct urb * urb)76 static void yurex_control_callback(struct urb *urb)
77 {
78 struct usb_yurex *dev = urb->context;
79 int status = urb->status;
80
81 if (status) {
82 dev_err(&urb->dev->dev, "%s - control failed: %d\n",
83 __func__, status);
84 wake_up_interruptible(&dev->waitq);
85 return;
86 }
87 /* on success, sender woken up by CMD_ACK int in, or timeout */
88 }
89
yurex_delete(struct kref * kref)90 static void yurex_delete(struct kref *kref)
91 {
92 struct usb_yurex *dev = to_yurex_dev(kref);
93
94 dev_dbg(&dev->interface->dev, "%s\n", __func__);
95
96 if (dev->cntl_urb) {
97 usb_kill_urb(dev->cntl_urb);
98 kfree(dev->cntl_req);
99 usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
100 dev->cntl_buffer, dev->cntl_urb->transfer_dma);
101 usb_free_urb(dev->cntl_urb);
102 }
103 if (dev->urb) {
104 usb_kill_urb(dev->urb);
105 usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
106 dev->int_buffer, dev->urb->transfer_dma);
107 usb_free_urb(dev->urb);
108 }
109 usb_put_intf(dev->interface);
110 usb_put_dev(dev->udev);
111 kfree(dev);
112 }
113
114 /*
115 * usb class driver info in order to get a minor number from the usb core,
116 * and to have the device registered with the driver core
117 */
118 static struct usb_class_driver yurex_class = {
119 .name = "yurex%d",
120 .fops = &yurex_fops,
121 .minor_base = YUREX_MINOR_BASE,
122 };
123
yurex_interrupt(struct urb * urb)124 static void yurex_interrupt(struct urb *urb)
125 {
126 struct usb_yurex *dev = urb->context;
127 unsigned char *buf = dev->int_buffer;
128 int status = urb->status;
129 unsigned long flags;
130 int retval, i;
131
132 switch (status) {
133 case 0: /*success*/
134 break;
135 /* The device is terminated or messed up, give up */
136 case -EOVERFLOW:
137 dev_err(&dev->interface->dev,
138 "%s - overflow with length %d, actual length is %d\n",
139 __func__, YUREX_BUF_SIZE, dev->urb->actual_length);
140 case -ECONNRESET:
141 case -ENOENT:
142 case -ESHUTDOWN:
143 case -EILSEQ:
144 case -EPROTO:
145 case -ETIME:
146 return;
147 default:
148 dev_err(&dev->interface->dev,
149 "%s - unknown status received: %d\n", __func__, status);
150 return;
151 }
152
153 /* handle received message */
154 switch (buf[0]) {
155 case CMD_COUNT:
156 case CMD_READ:
157 if (buf[6] == CMD_EOF) {
158 spin_lock_irqsave(&dev->lock, flags);
159 dev->bbu = 0;
160 for (i = 1; i < 6; i++) {
161 dev->bbu += buf[i];
162 if (i != 5)
163 dev->bbu <<= 8;
164 }
165 dev_dbg(&dev->interface->dev, "%s count: %lld\n",
166 __func__, dev->bbu);
167 spin_unlock_irqrestore(&dev->lock, flags);
168
169 kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
170 }
171 else
172 dev_dbg(&dev->interface->dev,
173 "data format error - no EOF\n");
174 break;
175 case CMD_ACK:
176 dev_dbg(&dev->interface->dev, "%s ack: %c\n",
177 __func__, buf[1]);
178 wake_up_interruptible(&dev->waitq);
179 break;
180 }
181
182 retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
183 if (retval) {
184 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed: %d\n",
185 __func__, retval);
186 }
187 }
188
yurex_probe(struct usb_interface * interface,const struct usb_device_id * id)189 static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id)
190 {
191 struct usb_yurex *dev;
192 struct usb_host_interface *iface_desc;
193 struct usb_endpoint_descriptor *endpoint;
194 int retval = -ENOMEM;
195 DEFINE_WAIT(wait);
196 int res;
197
198 /* allocate memory for our device state and initialize it */
199 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
200 if (!dev)
201 goto error;
202 kref_init(&dev->kref);
203 mutex_init(&dev->io_mutex);
204 spin_lock_init(&dev->lock);
205 init_waitqueue_head(&dev->waitq);
206
207 dev->udev = usb_get_dev(interface_to_usbdev(interface));
208 dev->interface = usb_get_intf(interface);
209
210 /* set up the endpoint information */
211 iface_desc = interface->cur_altsetting;
212 res = usb_find_int_in_endpoint(iface_desc, &endpoint);
213 if (res) {
214 dev_err(&interface->dev, "Could not find endpoints\n");
215 retval = res;
216 goto error;
217 }
218
219 dev->int_in_endpointAddr = endpoint->bEndpointAddress;
220
221 /* allocate control URB */
222 dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
223 if (!dev->cntl_urb)
224 goto error;
225
226 /* allocate buffer for control req */
227 dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL);
228 if (!dev->cntl_req)
229 goto error;
230
231 /* allocate buffer for control msg */
232 dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
233 GFP_KERNEL,
234 &dev->cntl_urb->transfer_dma);
235 if (!dev->cntl_buffer) {
236 dev_err(&interface->dev, "Could not allocate cntl_buffer\n");
237 goto error;
238 }
239
240 /* configure control URB */
241 dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
242 USB_RECIP_INTERFACE;
243 dev->cntl_req->bRequest = HID_REQ_SET_REPORT;
244 dev->cntl_req->wValue = cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
245 dev->cntl_req->wIndex = cpu_to_le16(iface_desc->desc.bInterfaceNumber);
246 dev->cntl_req->wLength = cpu_to_le16(YUREX_BUF_SIZE);
247
248 usb_fill_control_urb(dev->cntl_urb, dev->udev,
249 usb_sndctrlpipe(dev->udev, 0),
250 (void *)dev->cntl_req, dev->cntl_buffer,
251 YUREX_BUF_SIZE, yurex_control_callback, dev);
252 dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
253
254
255 /* allocate interrupt URB */
256 dev->urb = usb_alloc_urb(0, GFP_KERNEL);
257 if (!dev->urb)
258 goto error;
259
260 /* allocate buffer for interrupt in */
261 dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
262 GFP_KERNEL, &dev->urb->transfer_dma);
263 if (!dev->int_buffer) {
264 dev_err(&interface->dev, "Could not allocate int_buffer\n");
265 goto error;
266 }
267
268 /* configure interrupt URB */
269 usb_fill_int_urb(dev->urb, dev->udev,
270 usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
271 dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
272 dev, 1);
273 dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
274 if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
275 retval = -EIO;
276 dev_err(&interface->dev, "Could not submitting URB\n");
277 goto error;
278 }
279
280 /* save our data pointer in this interface device */
281 usb_set_intfdata(interface, dev);
282 dev->bbu = -1;
283
284 /* we can register the device now, as it is ready */
285 retval = usb_register_dev(interface, &yurex_class);
286 if (retval) {
287 dev_err(&interface->dev,
288 "Not able to get a minor for this device.\n");
289 usb_set_intfdata(interface, NULL);
290 goto error;
291 }
292
293 dev_info(&interface->dev,
294 "USB YUREX device now attached to Yurex #%d\n",
295 interface->minor);
296
297 return 0;
298
299 error:
300 if (dev)
301 /* this frees allocated memory */
302 kref_put(&dev->kref, yurex_delete);
303 return retval;
304 }
305
yurex_disconnect(struct usb_interface * interface)306 static void yurex_disconnect(struct usb_interface *interface)
307 {
308 struct usb_yurex *dev;
309 int minor = interface->minor;
310
311 dev = usb_get_intfdata(interface);
312 usb_set_intfdata(interface, NULL);
313
314 /* give back our minor */
315 usb_deregister_dev(interface, &yurex_class);
316
317 /* prevent more I/O from starting */
318 usb_poison_urb(dev->urb);
319 usb_poison_urb(dev->cntl_urb);
320 mutex_lock(&dev->io_mutex);
321 dev->disconnected = 1;
322 mutex_unlock(&dev->io_mutex);
323
324 /* wakeup waiters */
325 kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
326 wake_up_interruptible(&dev->waitq);
327
328 /* decrement our usage count */
329 kref_put(&dev->kref, yurex_delete);
330
331 dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
332 }
333
334 static struct usb_driver yurex_driver = {
335 .name = "yurex",
336 .probe = yurex_probe,
337 .disconnect = yurex_disconnect,
338 .id_table = yurex_table,
339 };
340
341
yurex_fasync(int fd,struct file * file,int on)342 static int yurex_fasync(int fd, struct file *file, int on)
343 {
344 struct usb_yurex *dev;
345
346 dev = file->private_data;
347 return fasync_helper(fd, file, on, &dev->async_queue);
348 }
349
yurex_open(struct inode * inode,struct file * file)350 static int yurex_open(struct inode *inode, struct file *file)
351 {
352 struct usb_yurex *dev;
353 struct usb_interface *interface;
354 int subminor;
355 int retval = 0;
356
357 subminor = iminor(inode);
358
359 interface = usb_find_interface(&yurex_driver, subminor);
360 if (!interface) {
361 printk(KERN_ERR "%s - error, can't find device for minor %d",
362 __func__, subminor);
363 retval = -ENODEV;
364 goto exit;
365 }
366
367 dev = usb_get_intfdata(interface);
368 if (!dev) {
369 retval = -ENODEV;
370 goto exit;
371 }
372
373 /* increment our usage count for the device */
374 kref_get(&dev->kref);
375
376 /* save our object in the file's private structure */
377 mutex_lock(&dev->io_mutex);
378 file->private_data = dev;
379 mutex_unlock(&dev->io_mutex);
380
381 exit:
382 return retval;
383 }
384
yurex_release(struct inode * inode,struct file * file)385 static int yurex_release(struct inode *inode, struct file *file)
386 {
387 struct usb_yurex *dev;
388
389 dev = file->private_data;
390 if (dev == NULL)
391 return -ENODEV;
392
393 /* decrement the count on our device */
394 kref_put(&dev->kref, yurex_delete);
395 return 0;
396 }
397
yurex_read(struct file * file,char __user * buffer,size_t count,loff_t * ppos)398 static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
399 loff_t *ppos)
400 {
401 struct usb_yurex *dev;
402 int len = 0;
403 char in_buffer[20];
404 unsigned long flags;
405
406 dev = file->private_data;
407
408 mutex_lock(&dev->io_mutex);
409 if (dev->disconnected) { /* already disconnected */
410 mutex_unlock(&dev->io_mutex);
411 return -ENODEV;
412 }
413
414 spin_lock_irqsave(&dev->lock, flags);
415 len = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
416 spin_unlock_irqrestore(&dev->lock, flags);
417 mutex_unlock(&dev->io_mutex);
418
419 if (WARN_ON_ONCE(len >= sizeof(in_buffer)))
420 return -EIO;
421
422 return simple_read_from_buffer(buffer, count, ppos, in_buffer, len);
423 }
424
yurex_write(struct file * file,const char __user * user_buffer,size_t count,loff_t * ppos)425 static ssize_t yurex_write(struct file *file, const char __user *user_buffer,
426 size_t count, loff_t *ppos)
427 {
428 struct usb_yurex *dev;
429 int i, set = 0, retval = 0;
430 char buffer[16 + 1];
431 char *data = buffer;
432 unsigned long long c, c2 = 0;
433 signed long timeout = 0;
434 DEFINE_WAIT(wait);
435
436 count = min(sizeof(buffer) - 1, count);
437 dev = file->private_data;
438
439 /* verify that we actually have some data to write */
440 if (count == 0)
441 goto error;
442
443 mutex_lock(&dev->io_mutex);
444 if (dev->disconnected) { /* already disconnected */
445 mutex_unlock(&dev->io_mutex);
446 retval = -ENODEV;
447 goto error;
448 }
449
450 if (copy_from_user(buffer, user_buffer, count)) {
451 mutex_unlock(&dev->io_mutex);
452 retval = -EFAULT;
453 goto error;
454 }
455 buffer[count] = 0;
456 memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
457
458 switch (buffer[0]) {
459 case CMD_ANIMATE:
460 case CMD_LED:
461 dev->cntl_buffer[0] = buffer[0];
462 dev->cntl_buffer[1] = buffer[1];
463 dev->cntl_buffer[2] = CMD_EOF;
464 break;
465 case CMD_READ:
466 case CMD_VERSION:
467 dev->cntl_buffer[0] = buffer[0];
468 dev->cntl_buffer[1] = 0x00;
469 dev->cntl_buffer[2] = CMD_EOF;
470 break;
471 case CMD_SET:
472 data++;
473 fallthrough;
474 case '0' ... '9':
475 set = 1;
476 c = c2 = simple_strtoull(data, NULL, 0);
477 dev->cntl_buffer[0] = CMD_SET;
478 for (i = 1; i < 6; i++) {
479 dev->cntl_buffer[i] = (c>>32) & 0xff;
480 c <<= 8;
481 }
482 buffer[6] = CMD_EOF;
483 break;
484 default:
485 mutex_unlock(&dev->io_mutex);
486 return -EINVAL;
487 }
488
489 /* send the data as the control msg */
490 prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
491 dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__,
492 dev->cntl_buffer[0]);
493 retval = usb_submit_urb(dev->cntl_urb, GFP_ATOMIC);
494 if (retval >= 0)
495 timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
496 finish_wait(&dev->waitq, &wait);
497
498 /* make sure URB is idle after timeout or (spurious) CMD_ACK */
499 usb_kill_urb(dev->cntl_urb);
500
501 mutex_unlock(&dev->io_mutex);
502
503 if (retval < 0) {
504 dev_err(&dev->interface->dev,
505 "%s - failed to send bulk msg, error %d\n",
506 __func__, retval);
507 goto error;
508 }
509 if (set && timeout)
510 dev->bbu = c2;
511 return timeout ? count : -EIO;
512
513 error:
514 return retval;
515 }
516
517 static const struct file_operations yurex_fops = {
518 .owner = THIS_MODULE,
519 .read = yurex_read,
520 .write = yurex_write,
521 .open = yurex_open,
522 .release = yurex_release,
523 .fasync = yurex_fasync,
524 .llseek = default_llseek,
525 };
526
527 module_usb_driver(yurex_driver);
528
529 MODULE_LICENSE("GPL");
530