xref: /openbmc/linux/drivers/usb/misc/yurex.c (revision b34e08d5)
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/slab.h>
15 #include <linux/module.h>
16 #include <linux/kref.h>
17 #include <linux/mutex.h>
18 #include <linux/uaccess.h>
19 #include <linux/usb.h>
20 #include <linux/hid.h>
21 
22 #define DRIVER_AUTHOR "Tomoki Sekiyama"
23 #define DRIVER_DESC "Driver for Meywa-Denki & KAYAC YUREX"
24 
25 #define YUREX_VENDOR_ID		0x0c45
26 #define YUREX_PRODUCT_ID	0x1010
27 
28 #define CMD_ACK		'!'
29 #define CMD_ANIMATE	'A'
30 #define CMD_COUNT	'C'
31 #define CMD_LED		'L'
32 #define CMD_READ	'R'
33 #define CMD_SET		'S'
34 #define CMD_VERSION	'V'
35 #define CMD_EOF		0x0d
36 #define CMD_PADDING	0xff
37 
38 #define YUREX_BUF_SIZE		8
39 #define YUREX_WRITE_TIMEOUT	(HZ*2)
40 
41 /* table of devices that work with this driver */
42 static struct usb_device_id yurex_table[] = {
43 	{ USB_DEVICE(YUREX_VENDOR_ID, YUREX_PRODUCT_ID) },
44 	{ }					/* Terminating entry */
45 };
46 MODULE_DEVICE_TABLE(usb, yurex_table);
47 
48 #ifdef CONFIG_USB_DYNAMIC_MINORS
49 #define YUREX_MINOR_BASE	0
50 #else
51 #define YUREX_MINOR_BASE	192
52 #endif
53 
54 /* Structure to hold all of our device specific stuff */
55 struct usb_yurex {
56 	struct usb_device	*udev;
57 	struct usb_interface	*interface;
58 	__u8			int_in_endpointAddr;
59 	struct urb		*urb;		/* URB for interrupt in */
60 	unsigned char           *int_buffer;	/* buffer for intterupt in */
61 	struct urb		*cntl_urb;	/* URB for control msg */
62 	struct usb_ctrlrequest	*cntl_req;	/* req for control msg */
63 	unsigned char		*cntl_buffer;	/* buffer for control msg */
64 
65 	struct kref		kref;
66 	struct mutex		io_mutex;
67 	struct fasync_struct	*async_queue;
68 	wait_queue_head_t	waitq;
69 
70 	spinlock_t		lock;
71 	__s64			bbu;		/* BBU from device */
72 };
73 #define to_yurex_dev(d) container_of(d, struct usb_yurex, kref)
74 
75 static struct usb_driver yurex_driver;
76 static const struct file_operations yurex_fops;
77 
78 
79 static void yurex_control_callback(struct urb *urb)
80 {
81 	struct usb_yurex *dev = urb->context;
82 	int status = urb->status;
83 
84 	if (status) {
85 		dev_err(&urb->dev->dev, "%s - control failed: %d\n",
86 			__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 	dev_dbg(&dev->interface->dev, "%s\n", __func__);
98 
99 	usb_put_dev(dev->udev);
100 	if (dev->cntl_urb) {
101 		usb_kill_urb(dev->cntl_urb);
102 		kfree(dev->cntl_req);
103 		if (dev->cntl_buffer)
104 			usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
105 				dev->cntl_buffer, dev->cntl_urb->transfer_dma);
106 		usb_free_urb(dev->cntl_urb);
107 	}
108 	if (dev->urb) {
109 		usb_kill_urb(dev->urb);
110 		if (dev->int_buffer)
111 			usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
112 				dev->int_buffer, dev->urb->transfer_dma);
113 		usb_free_urb(dev->urb);
114 	}
115 	kfree(dev);
116 }
117 
118 /*
119  * usb class driver info in order to get a minor number from the usb core,
120  * and to have the device registered with the driver core
121  */
122 static struct usb_class_driver yurex_class = {
123 	.name =		"yurex%d",
124 	.fops =		&yurex_fops,
125 	.minor_base =	YUREX_MINOR_BASE,
126 };
127 
128 static void yurex_interrupt(struct urb *urb)
129 {
130 	struct usb_yurex *dev = urb->context;
131 	unsigned char *buf = dev->int_buffer;
132 	int status = urb->status;
133 	unsigned long flags;
134 	int retval, i;
135 
136 	switch (status) {
137 	case 0: /*success*/
138 		break;
139 	case -EOVERFLOW:
140 		dev_err(&dev->interface->dev,
141 			"%s - overflow with length %d, actual length is %d\n",
142 			__func__, YUREX_BUF_SIZE, dev->urb->actual_length);
143 	case -ECONNRESET:
144 	case -ENOENT:
145 	case -ESHUTDOWN:
146 	case -EILSEQ:
147 		/* The device is terminated, clean up */
148 		return;
149 	default:
150 		dev_err(&dev->interface->dev,
151 			"%s - unknown status received: %d\n", __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 			dev_dbg(&dev->interface->dev, "%s count: %lld\n",
168 				__func__, dev->bbu);
169 			spin_unlock_irqrestore(&dev->lock, flags);
170 
171 			kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
172 		}
173 		else
174 			dev_dbg(&dev->interface->dev,
175 				"data format error - no EOF\n");
176 		break;
177 	case CMD_ACK:
178 		dev_dbg(&dev->interface->dev, "%s ack: %c\n",
179 			__func__, buf[1]);
180 		wake_up_interruptible(&dev->waitq);
181 		break;
182 	}
183 
184 exit:
185 	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
186 	if (retval) {
187 		dev_err(&dev->interface->dev, "%s - usb_submit_urb failed: %d\n",
188 			__func__, retval);
189 	}
190 }
191 
192 static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id)
193 {
194 	struct usb_yurex *dev;
195 	struct usb_host_interface *iface_desc;
196 	struct usb_endpoint_descriptor *endpoint;
197 	int retval = -ENOMEM;
198 	int i;
199 	DEFINE_WAIT(wait);
200 
201 	/* allocate memory for our device state and initialize it */
202 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
203 	if (!dev) {
204 		dev_err(&interface->dev, "Out of memory\n");
205 		goto error;
206 	}
207 	kref_init(&dev->kref);
208 	mutex_init(&dev->io_mutex);
209 	spin_lock_init(&dev->lock);
210 	init_waitqueue_head(&dev->waitq);
211 
212 	dev->udev = usb_get_dev(interface_to_usbdev(interface));
213 	dev->interface = interface;
214 
215 	/* set up the endpoint information */
216 	iface_desc = interface->cur_altsetting;
217 	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
218 		endpoint = &iface_desc->endpoint[i].desc;
219 
220 		if (usb_endpoint_is_int_in(endpoint)) {
221 			dev->int_in_endpointAddr = endpoint->bEndpointAddress;
222 			break;
223 		}
224 	}
225 	if (!dev->int_in_endpointAddr) {
226 		retval = -ENODEV;
227 		dev_err(&interface->dev, "Could not find endpoints\n");
228 		goto error;
229 	}
230 
231 
232 	/* allocate control URB */
233 	dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
234 	if (!dev->cntl_urb) {
235 		dev_err(&interface->dev, "Could not allocate control URB\n");
236 		goto error;
237 	}
238 
239 	/* allocate buffer for control req */
240 	dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL);
241 	if (!dev->cntl_req) {
242 		dev_err(&interface->dev, "Could not allocate cntl_req\n");
243 		goto error;
244 	}
245 
246 	/* allocate buffer for control msg */
247 	dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
248 					      GFP_KERNEL,
249 					      &dev->cntl_urb->transfer_dma);
250 	if (!dev->cntl_buffer) {
251 		dev_err(&interface->dev, "Could not allocate cntl_buffer\n");
252 		goto error;
253 	}
254 
255 	/* configure control URB */
256 	dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
257 				      USB_RECIP_INTERFACE;
258 	dev->cntl_req->bRequest	= HID_REQ_SET_REPORT;
259 	dev->cntl_req->wValue	= cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
260 	dev->cntl_req->wIndex	= cpu_to_le16(iface_desc->desc.bInterfaceNumber);
261 	dev->cntl_req->wLength	= cpu_to_le16(YUREX_BUF_SIZE);
262 
263 	usb_fill_control_urb(dev->cntl_urb, dev->udev,
264 			     usb_sndctrlpipe(dev->udev, 0),
265 			     (void *)dev->cntl_req, dev->cntl_buffer,
266 			     YUREX_BUF_SIZE, yurex_control_callback, dev);
267 	dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
268 
269 
270 	/* allocate interrupt URB */
271 	dev->urb = usb_alloc_urb(0, GFP_KERNEL);
272 	if (!dev->urb) {
273 		dev_err(&interface->dev, "Could not allocate URB\n");
274 		goto error;
275 	}
276 
277 	/* allocate buffer for interrupt in */
278 	dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
279 					GFP_KERNEL, &dev->urb->transfer_dma);
280 	if (!dev->int_buffer) {
281 		dev_err(&interface->dev, "Could not allocate int_buffer\n");
282 		goto error;
283 	}
284 
285 	/* configure interrupt URB */
286 	usb_fill_int_urb(dev->urb, dev->udev,
287 			 usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
288 			 dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
289 			 dev, 1);
290 	dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
291 	if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
292 		retval = -EIO;
293 		dev_err(&interface->dev, "Could not submitting URB\n");
294 		goto error;
295 	}
296 
297 	/* save our data pointer in this interface device */
298 	usb_set_intfdata(interface, dev);
299 
300 	/* we can register the device now, as it is ready */
301 	retval = usb_register_dev(interface, &yurex_class);
302 	if (retval) {
303 		dev_err(&interface->dev,
304 			"Not able to get a minor for this device.\n");
305 		usb_set_intfdata(interface, NULL);
306 		goto error;
307 	}
308 
309 	dev->bbu = -1;
310 
311 	dev_info(&interface->dev,
312 		 "USB YUREX device now attached to Yurex #%d\n",
313 		 interface->minor);
314 
315 	return 0;
316 
317 error:
318 	if (dev)
319 		/* this frees allocated memory */
320 		kref_put(&dev->kref, yurex_delete);
321 	return retval;
322 }
323 
324 static void yurex_disconnect(struct usb_interface *interface)
325 {
326 	struct usb_yurex *dev;
327 	int minor = interface->minor;
328 
329 	dev = usb_get_intfdata(interface);
330 	usb_set_intfdata(interface, NULL);
331 
332 	/* give back our minor */
333 	usb_deregister_dev(interface, &yurex_class);
334 
335 	/* prevent more I/O from starting */
336 	mutex_lock(&dev->io_mutex);
337 	dev->interface = NULL;
338 	mutex_unlock(&dev->io_mutex);
339 
340 	/* wakeup waiters */
341 	kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
342 	wake_up_interruptible(&dev->waitq);
343 
344 	/* decrement our usage count */
345 	kref_put(&dev->kref, yurex_delete);
346 
347 	dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
348 }
349 
350 static struct usb_driver yurex_driver = {
351 	.name =		"yurex",
352 	.probe =	yurex_probe,
353 	.disconnect =	yurex_disconnect,
354 	.id_table =	yurex_table,
355 };
356 
357 
358 static int yurex_fasync(int fd, struct file *file, int on)
359 {
360 	struct usb_yurex *dev;
361 
362 	dev = (struct usb_yurex *)file->private_data;
363 	return fasync_helper(fd, file, on, &dev->async_queue);
364 }
365 
366 static int yurex_open(struct inode *inode, struct file *file)
367 {
368 	struct usb_yurex *dev;
369 	struct usb_interface *interface;
370 	int subminor;
371 	int retval = 0;
372 
373 	subminor = iminor(inode);
374 
375 	interface = usb_find_interface(&yurex_driver, subminor);
376 	if (!interface) {
377 		printk(KERN_ERR "%s - error, can't find device for minor %d",
378 		       __func__, subminor);
379 		retval = -ENODEV;
380 		goto exit;
381 	}
382 
383 	dev = usb_get_intfdata(interface);
384 	if (!dev) {
385 		retval = -ENODEV;
386 		goto exit;
387 	}
388 
389 	/* increment our usage count for the device */
390 	kref_get(&dev->kref);
391 
392 	/* save our object in the file's private structure */
393 	mutex_lock(&dev->io_mutex);
394 	file->private_data = dev;
395 	mutex_unlock(&dev->io_mutex);
396 
397 exit:
398 	return retval;
399 }
400 
401 static int yurex_release(struct inode *inode, struct file *file)
402 {
403 	struct usb_yurex *dev;
404 
405 	dev = (struct usb_yurex *)file->private_data;
406 	if (dev == NULL)
407 		return -ENODEV;
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) {		/* already 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 	dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__,
513 		dev->cntl_buffer[0]);
514 	retval = usb_submit_urb(dev->cntl_urb, GFP_KERNEL);
515 	if (retval >= 0)
516 		timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
517 	finish_wait(&dev->waitq, &wait);
518 
519 	mutex_unlock(&dev->io_mutex);
520 
521 	if (retval < 0) {
522 		dev_err(&dev->interface->dev,
523 			"%s - failed to send bulk msg, error %d\n",
524 			__func__, retval);
525 		goto error;
526 	}
527 	if (set && timeout)
528 		dev->bbu = c2;
529 	return timeout ? count : -EIO;
530 
531 error:
532 	return retval;
533 }
534 
535 static const struct file_operations yurex_fops = {
536 	.owner =	THIS_MODULE,
537 	.read =		yurex_read,
538 	.write =	yurex_write,
539 	.open =		yurex_open,
540 	.release =	yurex_release,
541 	.fasync	=	yurex_fasync,
542 	.llseek =	default_llseek,
543 };
544 
545 module_usb_driver(yurex_driver);
546 
547 MODULE_LICENSE("GPL");
548