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 return;
141 case -ECONNRESET:
142 case -ENOENT:
143 case -ESHUTDOWN:
144 case -EILSEQ:
145 case -EPROTO:
146 case -ETIME:
147 return;
148 default:
149 dev_err(&dev->interface->dev,
150 "%s - unknown status received: %d\n", __func__, status);
151 return;
152 }
153
154 /* handle received message */
155 switch (buf[0]) {
156 case CMD_COUNT:
157 case CMD_READ:
158 if (buf[6] == CMD_EOF) {
159 spin_lock_irqsave(&dev->lock, flags);
160 dev->bbu = 0;
161 for (i = 1; i < 6; i++) {
162 dev->bbu += buf[i];
163 if (i != 5)
164 dev->bbu <<= 8;
165 }
166 dev_dbg(&dev->interface->dev, "%s count: %lld\n",
167 __func__, dev->bbu);
168 spin_unlock_irqrestore(&dev->lock, flags);
169
170 kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
171 }
172 else
173 dev_dbg(&dev->interface->dev,
174 "data format error - no EOF\n");
175 break;
176 case CMD_ACK:
177 dev_dbg(&dev->interface->dev, "%s ack: %c\n",
178 __func__, buf[1]);
179 wake_up_interruptible(&dev->waitq);
180 break;
181 }
182
183 retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
184 if (retval) {
185 dev_err(&dev->interface->dev, "%s - usb_submit_urb failed: %d\n",
186 __func__, retval);
187 }
188 }
189
yurex_probe(struct usb_interface * interface,const struct usb_device_id * id)190 static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id)
191 {
192 struct usb_yurex *dev;
193 struct usb_host_interface *iface_desc;
194 struct usb_endpoint_descriptor *endpoint;
195 int retval = -ENOMEM;
196 DEFINE_WAIT(wait);
197 int res;
198
199 /* allocate memory for our device state and initialize it */
200 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
201 if (!dev)
202 goto error;
203 kref_init(&dev->kref);
204 mutex_init(&dev->io_mutex);
205 spin_lock_init(&dev->lock);
206 init_waitqueue_head(&dev->waitq);
207
208 dev->udev = usb_get_dev(interface_to_usbdev(interface));
209 dev->interface = usb_get_intf(interface);
210
211 /* set up the endpoint information */
212 iface_desc = interface->cur_altsetting;
213 res = usb_find_int_in_endpoint(iface_desc, &endpoint);
214 if (res) {
215 dev_err(&interface->dev, "Could not find endpoints\n");
216 retval = res;
217 goto error;
218 }
219
220 dev->int_in_endpointAddr = endpoint->bEndpointAddress;
221
222 /* allocate control URB */
223 dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
224 if (!dev->cntl_urb)
225 goto error;
226
227 /* allocate buffer for control req */
228 dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL);
229 if (!dev->cntl_req)
230 goto error;
231
232 /* allocate buffer for control msg */
233 dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
234 GFP_KERNEL,
235 &dev->cntl_urb->transfer_dma);
236 if (!dev->cntl_buffer) {
237 dev_err(&interface->dev, "Could not allocate cntl_buffer\n");
238 goto error;
239 }
240
241 /* configure control URB */
242 dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
243 USB_RECIP_INTERFACE;
244 dev->cntl_req->bRequest = HID_REQ_SET_REPORT;
245 dev->cntl_req->wValue = cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
246 dev->cntl_req->wIndex = cpu_to_le16(iface_desc->desc.bInterfaceNumber);
247 dev->cntl_req->wLength = cpu_to_le16(YUREX_BUF_SIZE);
248
249 usb_fill_control_urb(dev->cntl_urb, dev->udev,
250 usb_sndctrlpipe(dev->udev, 0),
251 (void *)dev->cntl_req, dev->cntl_buffer,
252 YUREX_BUF_SIZE, yurex_control_callback, dev);
253 dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
254
255
256 /* allocate interrupt URB */
257 dev->urb = usb_alloc_urb(0, GFP_KERNEL);
258 if (!dev->urb)
259 goto error;
260
261 /* allocate buffer for interrupt in */
262 dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
263 GFP_KERNEL, &dev->urb->transfer_dma);
264 if (!dev->int_buffer) {
265 dev_err(&interface->dev, "Could not allocate int_buffer\n");
266 goto error;
267 }
268
269 /* configure interrupt URB */
270 usb_fill_int_urb(dev->urb, dev->udev,
271 usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
272 dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
273 dev, 1);
274 dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
275 if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
276 retval = -EIO;
277 dev_err(&interface->dev, "Could not submitting URB\n");
278 goto error;
279 }
280
281 /* save our data pointer in this interface device */
282 usb_set_intfdata(interface, dev);
283 dev->bbu = -1;
284
285 /* we can register the device now, as it is ready */
286 retval = usb_register_dev(interface, &yurex_class);
287 if (retval) {
288 dev_err(&interface->dev,
289 "Not able to get a minor for this device.\n");
290 usb_set_intfdata(interface, NULL);
291 goto error;
292 }
293
294 dev_info(&interface->dev,
295 "USB YUREX device now attached to Yurex #%d\n",
296 interface->minor);
297
298 return 0;
299
300 error:
301 if (dev)
302 /* this frees allocated memory */
303 kref_put(&dev->kref, yurex_delete);
304 return retval;
305 }
306
yurex_disconnect(struct usb_interface * interface)307 static void yurex_disconnect(struct usb_interface *interface)
308 {
309 struct usb_yurex *dev;
310 int minor = interface->minor;
311
312 dev = usb_get_intfdata(interface);
313 usb_set_intfdata(interface, NULL);
314
315 /* give back our minor */
316 usb_deregister_dev(interface, &yurex_class);
317
318 /* prevent more I/O from starting */
319 usb_poison_urb(dev->urb);
320 usb_poison_urb(dev->cntl_urb);
321 mutex_lock(&dev->io_mutex);
322 dev->disconnected = 1;
323 mutex_unlock(&dev->io_mutex);
324
325 /* wakeup waiters */
326 kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
327 wake_up_interruptible(&dev->waitq);
328
329 /* decrement our usage count */
330 kref_put(&dev->kref, yurex_delete);
331
332 dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
333 }
334
335 static struct usb_driver yurex_driver = {
336 .name = "yurex",
337 .probe = yurex_probe,
338 .disconnect = yurex_disconnect,
339 .id_table = yurex_table,
340 };
341
342
yurex_fasync(int fd,struct file * file,int on)343 static int yurex_fasync(int fd, struct file *file, int on)
344 {
345 struct usb_yurex *dev;
346
347 dev = file->private_data;
348 return fasync_helper(fd, file, on, &dev->async_queue);
349 }
350
yurex_open(struct inode * inode,struct file * file)351 static int yurex_open(struct inode *inode, struct file *file)
352 {
353 struct usb_yurex *dev;
354 struct usb_interface *interface;
355 int subminor;
356 int retval = 0;
357
358 subminor = iminor(inode);
359
360 interface = usb_find_interface(&yurex_driver, subminor);
361 if (!interface) {
362 printk(KERN_ERR "%s - error, can't find device for minor %d",
363 __func__, subminor);
364 retval = -ENODEV;
365 goto exit;
366 }
367
368 dev = usb_get_intfdata(interface);
369 if (!dev) {
370 retval = -ENODEV;
371 goto exit;
372 }
373
374 /* increment our usage count for the device */
375 kref_get(&dev->kref);
376
377 /* save our object in the file's private structure */
378 mutex_lock(&dev->io_mutex);
379 file->private_data = dev;
380 mutex_unlock(&dev->io_mutex);
381
382 exit:
383 return retval;
384 }
385
yurex_release(struct inode * inode,struct file * file)386 static int yurex_release(struct inode *inode, struct file *file)
387 {
388 struct usb_yurex *dev;
389
390 dev = file->private_data;
391 if (dev == NULL)
392 return -ENODEV;
393
394 /* decrement the count on our device */
395 kref_put(&dev->kref, yurex_delete);
396 return 0;
397 }
398
yurex_read(struct file * file,char __user * buffer,size_t count,loff_t * ppos)399 static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
400 loff_t *ppos)
401 {
402 struct usb_yurex *dev;
403 int len = 0;
404 char in_buffer[20];
405 unsigned long flags;
406
407 dev = file->private_data;
408
409 mutex_lock(&dev->io_mutex);
410 if (dev->disconnected) { /* already disconnected */
411 mutex_unlock(&dev->io_mutex);
412 return -ENODEV;
413 }
414
415 spin_lock_irqsave(&dev->lock, flags);
416 len = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
417 spin_unlock_irqrestore(&dev->lock, flags);
418 mutex_unlock(&dev->io_mutex);
419
420 if (WARN_ON_ONCE(len >= sizeof(in_buffer)))
421 return -EIO;
422
423 return simple_read_from_buffer(buffer, count, ppos, in_buffer, len);
424 }
425
yurex_write(struct file * file,const char __user * user_buffer,size_t count,loff_t * ppos)426 static ssize_t yurex_write(struct file *file, const char __user *user_buffer,
427 size_t count, loff_t *ppos)
428 {
429 struct usb_yurex *dev;
430 int i, set = 0, retval = 0;
431 char buffer[16 + 1];
432 char *data = buffer;
433 unsigned long long c, c2 = 0;
434 signed long timeout = 0;
435 DEFINE_WAIT(wait);
436
437 count = min(sizeof(buffer) - 1, count);
438 dev = file->private_data;
439
440 /* verify that we actually have some data to write */
441 if (count == 0)
442 goto error;
443
444 mutex_lock(&dev->io_mutex);
445 if (dev->disconnected) { /* already disconnected */
446 mutex_unlock(&dev->io_mutex);
447 retval = -ENODEV;
448 goto error;
449 }
450
451 if (copy_from_user(buffer, user_buffer, count)) {
452 mutex_unlock(&dev->io_mutex);
453 retval = -EFAULT;
454 goto error;
455 }
456 buffer[count] = 0;
457 memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
458
459 switch (buffer[0]) {
460 case CMD_ANIMATE:
461 case CMD_LED:
462 dev->cntl_buffer[0] = buffer[0];
463 dev->cntl_buffer[1] = buffer[1];
464 dev->cntl_buffer[2] = CMD_EOF;
465 break;
466 case CMD_READ:
467 case CMD_VERSION:
468 dev->cntl_buffer[0] = buffer[0];
469 dev->cntl_buffer[1] = 0x00;
470 dev->cntl_buffer[2] = CMD_EOF;
471 break;
472 case CMD_SET:
473 data++;
474 fallthrough;
475 case '0' ... '9':
476 set = 1;
477 c = c2 = simple_strtoull(data, NULL, 0);
478 dev->cntl_buffer[0] = CMD_SET;
479 for (i = 1; i < 6; i++) {
480 dev->cntl_buffer[i] = (c>>32) & 0xff;
481 c <<= 8;
482 }
483 buffer[6] = CMD_EOF;
484 break;
485 default:
486 mutex_unlock(&dev->io_mutex);
487 return -EINVAL;
488 }
489
490 /* send the data as the control msg */
491 prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
492 dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__,
493 dev->cntl_buffer[0]);
494 retval = usb_submit_urb(dev->cntl_urb, GFP_ATOMIC);
495 if (retval >= 0)
496 timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
497 finish_wait(&dev->waitq, &wait);
498
499 /* make sure URB is idle after timeout or (spurious) CMD_ACK */
500 usb_kill_urb(dev->cntl_urb);
501
502 mutex_unlock(&dev->io_mutex);
503
504 if (retval < 0) {
505 dev_err(&dev->interface->dev,
506 "%s - failed to send bulk msg, error %d\n",
507 __func__, retval);
508 goto error;
509 }
510 if (set && timeout)
511 dev->bbu = c2;
512 return timeout ? count : -EIO;
513
514 error:
515 return retval;
516 }
517
518 static const struct file_operations yurex_fops = {
519 .owner = THIS_MODULE,
520 .read = yurex_read,
521 .write = yurex_write,
522 .open = yurex_open,
523 .release = yurex_release,
524 .fasync = yurex_fasync,
525 .llseek = default_llseek,
526 };
527
528 module_usb_driver(yurex_driver);
529
530 MODULE_LICENSE("GPL");
531