xref: /openbmc/linux/drivers/usb/misc/yurex.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2  * Driver for Meywa-Denki & KAYAC YUREX
3  *
4  * Copyright (C) 2010 Tomoki Sekiyama (tomoki.sekiyama@gmail.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  */
11 
12 #include <linux/kernel.h>
13 #include <linux/errno.h>
14 #include <linux/init.h>
15 #include <linux/slab.h>
16 #include <linux/module.h>
17 #include <linux/kref.h>
18 #include <linux/mutex.h>
19 #include <linux/uaccess.h>
20 #include <linux/usb.h>
21 #include <linux/hid.h>
22 
23 #define DRIVER_AUTHOR "Tomoki Sekiyama"
24 #define DRIVER_DESC "Driver for Meywa-Denki & KAYAC YUREX"
25 
26 #define YUREX_VENDOR_ID		0x0c45
27 #define YUREX_PRODUCT_ID	0x1010
28 
29 #define CMD_ACK		'!'
30 #define CMD_ANIMATE	'A'
31 #define CMD_COUNT	'C'
32 #define CMD_LED		'L'
33 #define CMD_READ	'R'
34 #define CMD_SET		'S'
35 #define CMD_VERSION	'V'
36 #define CMD_EOF		0x0d
37 #define CMD_PADDING	0xff
38 
39 #define YUREX_BUF_SIZE		8
40 #define YUREX_WRITE_TIMEOUT	(HZ*2)
41 
42 /* table of devices that work with this driver */
43 static struct usb_device_id yurex_table[] = {
44 	{ USB_DEVICE(YUREX_VENDOR_ID, YUREX_PRODUCT_ID) },
45 	{ }					/* Terminating entry */
46 };
47 MODULE_DEVICE_TABLE(usb, yurex_table);
48 
49 #ifdef CONFIG_USB_DYNAMIC_MINORS
50 #define YUREX_MINOR_BASE	0
51 #else
52 #define YUREX_MINOR_BASE	192
53 #endif
54 
55 /* Structure to hold all of our device specific stuff */
56 struct usb_yurex {
57 	struct usb_device	*udev;
58 	struct usb_interface	*interface;
59 	__u8			int_in_endpointAddr;
60 	struct urb		*urb;		/* URB for interrupt in */
61 	unsigned char           *int_buffer;	/* buffer for intterupt in */
62 	struct urb		*cntl_urb;	/* URB for control msg */
63 	struct usb_ctrlrequest	*cntl_req;	/* req for control msg */
64 	unsigned char		*cntl_buffer;	/* buffer for control msg */
65 
66 	struct kref		kref;
67 	struct mutex		io_mutex;
68 	struct fasync_struct	*async_queue;
69 	wait_queue_head_t	waitq;
70 
71 	spinlock_t		lock;
72 	__s64			bbu;		/* BBU from device */
73 };
74 #define to_yurex_dev(d) container_of(d, struct usb_yurex, kref)
75 
76 static struct usb_driver yurex_driver;
77 static const struct file_operations yurex_fops;
78 
79 
80 static void yurex_control_callback(struct urb *urb)
81 {
82 	struct usb_yurex *dev = urb->context;
83 	int status = urb->status;
84 
85 	if (status) {
86 		err("%s - control failed: %d\n", __func__, status);
87 		wake_up_interruptible(&dev->waitq);
88 		return;
89 	}
90 	/* on success, sender woken up by CMD_ACK int in, or timeout */
91 }
92 
93 static void yurex_delete(struct kref *kref)
94 {
95 	struct usb_yurex *dev = to_yurex_dev(kref);
96 
97 	dbg("yurex_delete");
98 
99 	usb_put_dev(dev->udev);
100 	if (dev->cntl_urb) {
101 		usb_kill_urb(dev->cntl_urb);
102 		if (dev->cntl_req)
103 			usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
104 				dev->cntl_req, dev->cntl_urb->setup_dma);
105 		if (dev->cntl_buffer)
106 			usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
107 				dev->cntl_buffer, dev->cntl_urb->transfer_dma);
108 		usb_free_urb(dev->cntl_urb);
109 	}
110 	if (dev->urb) {
111 		usb_kill_urb(dev->urb);
112 		if (dev->int_buffer)
113 			usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
114 				dev->int_buffer, dev->urb->transfer_dma);
115 		usb_free_urb(dev->urb);
116 	}
117 	kfree(dev);
118 }
119 
120 /*
121  * usb class driver info in order to get a minor number from the usb core,
122  * and to have the device registered with the driver core
123  */
124 static struct usb_class_driver yurex_class = {
125 	.name =		"yurex%d",
126 	.fops =		&yurex_fops,
127 	.minor_base =	YUREX_MINOR_BASE,
128 };
129 
130 static void yurex_interrupt(struct urb *urb)
131 {
132 	struct usb_yurex *dev = urb->context;
133 	unsigned char *buf = dev->int_buffer;
134 	int status = urb->status;
135 	unsigned long flags;
136 	int retval, i;
137 
138 	switch (status) {
139 	case 0: /*success*/
140 		break;
141 	case -EOVERFLOW:
142 		err("%s - overflow with length %d, actual length is %d",
143 		    __func__, YUREX_BUF_SIZE, dev->urb->actual_length);
144 	case -ECONNRESET:
145 	case -ENOENT:
146 	case -ESHUTDOWN:
147 	case -EILSEQ:
148 		/* The device is terminated, clean up */
149 		return;
150 	default:
151 		err("%s - unknown status received: %d", __func__, status);
152 		goto exit;
153 	}
154 
155 	/* handle received message */
156 	switch (buf[0]) {
157 	case CMD_COUNT:
158 	case CMD_READ:
159 		if (buf[6] == CMD_EOF) {
160 			spin_lock_irqsave(&dev->lock, flags);
161 			dev->bbu = 0;
162 			for (i = 1; i < 6; i++) {
163 				dev->bbu += buf[i];
164 				if (i != 5)
165 					dev->bbu <<= 8;
166 			}
167 			dbg("%s count: %lld", __func__, dev->bbu);
168 			spin_unlock_irqrestore(&dev->lock, flags);
169 
170 			kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
171 		}
172 		else
173 			dbg("data format error - no EOF");
174 		break;
175 	case CMD_ACK:
176 		dbg("%s ack: %c", __func__, buf[1]);
177 		wake_up_interruptible(&dev->waitq);
178 		break;
179 	}
180 
181 exit:
182 	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
183 	if (retval) {
184 		err("%s - usb_submit_urb failed: %d",
185 			__func__, retval);
186 	}
187 }
188 
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 	int i;
196 	DEFINE_WAIT(wait);
197 
198 	/* allocate memory for our device state and initialize it */
199 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
200 	if (!dev) {
201 		err("Out of memory");
202 		goto error;
203 	}
204 	kref_init(&dev->kref);
205 	mutex_init(&dev->io_mutex);
206 	spin_lock_init(&dev->lock);
207 	init_waitqueue_head(&dev->waitq);
208 
209 	dev->udev = usb_get_dev(interface_to_usbdev(interface));
210 	dev->interface = interface;
211 
212 	/* set up the endpoint information */
213 	iface_desc = interface->cur_altsetting;
214 	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
215 		endpoint = &iface_desc->endpoint[i].desc;
216 
217 		if (usb_endpoint_is_int_in(endpoint)) {
218 			dev->int_in_endpointAddr = endpoint->bEndpointAddress;
219 			break;
220 		}
221 	}
222 	if (!dev->int_in_endpointAddr) {
223 		retval = -ENODEV;
224 		err("Could not find endpoints");
225 		goto error;
226 	}
227 
228 
229 	/* allocate control URB */
230 	dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
231 	if (!dev->cntl_urb) {
232 		err("Could not allocate control URB");
233 		goto error;
234 	}
235 
236 	/* allocate buffer for control req */
237 	dev->cntl_req = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
238 					   GFP_KERNEL,
239 					   &dev->cntl_urb->setup_dma);
240 	if (!dev->cntl_req) {
241 		err("Could not allocate cntl_req");
242 		goto error;
243 	}
244 
245 	/* allocate buffer for control msg */
246 	dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
247 					      GFP_KERNEL,
248 					      &dev->cntl_urb->transfer_dma);
249 	if (!dev->cntl_buffer) {
250 		err("Could not allocate cntl_buffer");
251 		goto error;
252 	}
253 
254 	/* configure control URB */
255 	dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
256 				      USB_RECIP_INTERFACE;
257 	dev->cntl_req->bRequest	= HID_REQ_SET_REPORT;
258 	dev->cntl_req->wValue	= cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
259 	dev->cntl_req->wIndex	= cpu_to_le16(iface_desc->desc.bInterfaceNumber);
260 	dev->cntl_req->wLength	= cpu_to_le16(YUREX_BUF_SIZE);
261 
262 	usb_fill_control_urb(dev->cntl_urb, dev->udev,
263 			     usb_sndctrlpipe(dev->udev, 0),
264 			     (void *)dev->cntl_req, dev->cntl_buffer,
265 			     YUREX_BUF_SIZE, yurex_control_callback, dev);
266 	dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
267 
268 
269 	/* allocate interrupt URB */
270 	dev->urb = usb_alloc_urb(0, GFP_KERNEL);
271 	if (!dev->urb) {
272 		err("Could not allocate URB");
273 		goto error;
274 	}
275 
276 	/* allocate buffer for interrupt in */
277 	dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
278 					GFP_KERNEL, &dev->urb->transfer_dma);
279 	if (!dev->int_buffer) {
280 		err("Could not allocate int_buffer");
281 		goto error;
282 	}
283 
284 	/* configure interrupt URB */
285 	usb_fill_int_urb(dev->urb, dev->udev,
286 			 usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
287 			 dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
288 			 dev, 1);
289 	dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
290 	if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
291 		retval = -EIO;
292 		err("Could not submitting URB");
293 		goto error;
294 	}
295 
296 	/* save our data pointer in this interface device */
297 	usb_set_intfdata(interface, dev);
298 
299 	/* we can register the device now, as it is ready */
300 	retval = usb_register_dev(interface, &yurex_class);
301 	if (retval) {
302 		err("Not able to get a minor for this device.");
303 		usb_set_intfdata(interface, NULL);
304 		goto error;
305 	}
306 
307 	dev->bbu = -1;
308 
309 	dev_info(&interface->dev,
310 		 "USB YUREX device now attached to Yurex #%d\n",
311 		 interface->minor);
312 
313 	return 0;
314 
315 error:
316 	if (dev)
317 		/* this frees allocated memory */
318 		kref_put(&dev->kref, yurex_delete);
319 	return retval;
320 }
321 
322 static void yurex_disconnect(struct usb_interface *interface)
323 {
324 	struct usb_yurex *dev;
325 	int minor = interface->minor;
326 
327 	dev = usb_get_intfdata(interface);
328 	usb_set_intfdata(interface, NULL);
329 
330 	/* give back our minor */
331 	usb_deregister_dev(interface, &yurex_class);
332 
333 	/* prevent more I/O from starting */
334 	mutex_lock(&dev->io_mutex);
335 	dev->interface = NULL;
336 	mutex_unlock(&dev->io_mutex);
337 
338 	/* wakeup waiters */
339 	kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
340 	wake_up_interruptible(&dev->waitq);
341 
342 	/* decrement our usage count */
343 	kref_put(&dev->kref, yurex_delete);
344 
345 	dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
346 }
347 
348 static struct usb_driver yurex_driver = {
349 	.name =		"yurex",
350 	.probe =	yurex_probe,
351 	.disconnect =	yurex_disconnect,
352 	.id_table =	yurex_table,
353 };
354 
355 
356 static int yurex_fasync(int fd, struct file *file, int on)
357 {
358 	struct usb_yurex *dev;
359 
360 	dev = (struct usb_yurex *)file->private_data;
361 	return fasync_helper(fd, file, on, &dev->async_queue);
362 }
363 
364 static int yurex_open(struct inode *inode, struct file *file)
365 {
366 	struct usb_yurex *dev;
367 	struct usb_interface *interface;
368 	int subminor;
369 	int retval = 0;
370 
371 	subminor = iminor(inode);
372 
373 	interface = usb_find_interface(&yurex_driver, subminor);
374 	if (!interface) {
375 		err("%s - error, can't find device for minor %d",
376 		    __func__, subminor);
377 		retval = -ENODEV;
378 		goto exit;
379 	}
380 
381 	dev = usb_get_intfdata(interface);
382 	if (!dev) {
383 		retval = -ENODEV;
384 		goto exit;
385 	}
386 
387 	/* increment our usage count for the device */
388 	kref_get(&dev->kref);
389 
390 	/* save our object in the file's private structure */
391 	mutex_lock(&dev->io_mutex);
392 	file->private_data = dev;
393 	mutex_unlock(&dev->io_mutex);
394 
395 exit:
396 	return retval;
397 }
398 
399 static int yurex_release(struct inode *inode, struct file *file)
400 {
401 	struct usb_yurex *dev;
402 
403 	dev = (struct usb_yurex *)file->private_data;
404 	if (dev == NULL)
405 		return -ENODEV;
406 
407 	yurex_fasync(-1, file, 0);
408 
409 	/* decrement the count on our device */
410 	kref_put(&dev->kref, yurex_delete);
411 	return 0;
412 }
413 
414 static ssize_t yurex_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
415 {
416 	struct usb_yurex *dev;
417 	int retval = 0;
418 	int bytes_read = 0;
419 	char in_buffer[20];
420 	unsigned long flags;
421 
422 	dev = (struct usb_yurex *)file->private_data;
423 
424 	mutex_lock(&dev->io_mutex);
425 	if (!dev->interface) {		/* already disconnected */
426 		retval = -ENODEV;
427 		goto exit;
428 	}
429 
430 	spin_lock_irqsave(&dev->lock, flags);
431 	bytes_read = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
432 	spin_unlock_irqrestore(&dev->lock, flags);
433 
434 	if (*ppos < bytes_read) {
435 		if (copy_to_user(buffer, in_buffer + *ppos, bytes_read - *ppos))
436 			retval = -EFAULT;
437 		else {
438 			retval = bytes_read - *ppos;
439 			*ppos += bytes_read;
440 		}
441 	}
442 
443 exit:
444 	mutex_unlock(&dev->io_mutex);
445 	return retval;
446 }
447 
448 static ssize_t yurex_write(struct file *file, const char *user_buffer, size_t count, loff_t *ppos)
449 {
450 	struct usb_yurex *dev;
451 	int i, set = 0, retval = 0;
452 	char buffer[16];
453 	char *data = buffer;
454 	unsigned long long c, c2 = 0;
455 	signed long timeout = 0;
456 	DEFINE_WAIT(wait);
457 
458 	count = min(sizeof(buffer), count);
459 	dev = (struct usb_yurex *)file->private_data;
460 
461 	/* verify that we actually have some data to write */
462 	if (count == 0)
463 		goto error;
464 
465 	mutex_lock(&dev->io_mutex);
466 	if (!dev->interface) {		/* alreaday disconnected */
467 		mutex_unlock(&dev->io_mutex);
468 		retval = -ENODEV;
469 		goto error;
470 	}
471 
472 	if (copy_from_user(buffer, user_buffer, count)) {
473 		mutex_unlock(&dev->io_mutex);
474 		retval = -EFAULT;
475 		goto error;
476 	}
477 	memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
478 
479 	switch (buffer[0]) {
480 	case CMD_ANIMATE:
481 	case CMD_LED:
482 		dev->cntl_buffer[0] = buffer[0];
483 		dev->cntl_buffer[1] = buffer[1];
484 		dev->cntl_buffer[2] = CMD_EOF;
485 		break;
486 	case CMD_READ:
487 	case CMD_VERSION:
488 		dev->cntl_buffer[0] = buffer[0];
489 		dev->cntl_buffer[1] = 0x00;
490 		dev->cntl_buffer[2] = CMD_EOF;
491 		break;
492 	case CMD_SET:
493 		data++;
494 		/* FALL THROUGH */
495 	case '0' ... '9':
496 		set = 1;
497 		c = c2 = simple_strtoull(data, NULL, 0);
498 		dev->cntl_buffer[0] = CMD_SET;
499 		for (i = 1; i < 6; i++) {
500 			dev->cntl_buffer[i] = (c>>32) & 0xff;
501 			c <<= 8;
502 		}
503 		buffer[6] = CMD_EOF;
504 		break;
505 	default:
506 		mutex_unlock(&dev->io_mutex);
507 		return -EINVAL;
508 	}
509 
510 	/* send the data as the control msg */
511 	prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
512 	dbg("%s - submit %c", __func__, dev->cntl_buffer[0]);
513 	retval = usb_submit_urb(dev->cntl_urb, GFP_KERNEL);
514 	if (retval >= 0)
515 		timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
516 	finish_wait(&dev->waitq, &wait);
517 
518 	mutex_unlock(&dev->io_mutex);
519 
520 	if (retval < 0) {
521 		err("%s - failed to send bulk msg, error %d", __func__, retval);
522 		goto error;
523 	}
524 	if (set && timeout)
525 		dev->bbu = c2;
526 	return timeout ? count : -EIO;
527 
528 error:
529 	return retval;
530 }
531 
532 static const struct file_operations yurex_fops = {
533 	.owner =	THIS_MODULE,
534 	.read =		yurex_read,
535 	.write =	yurex_write,
536 	.open =		yurex_open,
537 	.release =	yurex_release,
538 	.fasync	=	yurex_fasync,
539 	.llseek =	default_llseek,
540 };
541 
542 
543 static int __init usb_yurex_init(void)
544 {
545 	int result;
546 
547 	/* register this driver with the USB subsystem */
548 	result = usb_register(&yurex_driver);
549 	if (result)
550 		err("usb_register failed. Error number %d", result);
551 
552 	return result;
553 }
554 
555 static void __exit usb_yurex_exit(void)
556 {
557 	/* deregister this driver with the USB subsystem */
558 	usb_deregister(&yurex_driver);
559 }
560 
561 module_init(usb_yurex_init);
562 module_exit(usb_yurex_exit);
563 
564 MODULE_LICENSE("GPL");
565