xref: /openbmc/linux/drivers/usb/misc/yurex.c (revision 12eb4683)
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 		dev_err(&urb->dev->dev, "%s - control failed: %d\n",
87 			__func__, status);
88 		wake_up_interruptible(&dev->waitq);
89 		return;
90 	}
91 	/* on success, sender woken up by CMD_ACK int in, or timeout */
92 }
93 
94 static void yurex_delete(struct kref *kref)
95 {
96 	struct usb_yurex *dev = to_yurex_dev(kref);
97 
98 	dev_dbg(&dev->interface->dev, "%s\n", __func__);
99 
100 	usb_put_dev(dev->udev);
101 	if (dev->cntl_urb) {
102 		usb_kill_urb(dev->cntl_urb);
103 		kfree(dev->cntl_req);
104 		if (dev->cntl_buffer)
105 			usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
106 				dev->cntl_buffer, dev->cntl_urb->transfer_dma);
107 		usb_free_urb(dev->cntl_urb);
108 	}
109 	if (dev->urb) {
110 		usb_kill_urb(dev->urb);
111 		if (dev->int_buffer)
112 			usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
113 				dev->int_buffer, dev->urb->transfer_dma);
114 		usb_free_urb(dev->urb);
115 	}
116 	kfree(dev);
117 }
118 
119 /*
120  * usb class driver info in order to get a minor number from the usb core,
121  * and to have the device registered with the driver core
122  */
123 static struct usb_class_driver yurex_class = {
124 	.name =		"yurex%d",
125 	.fops =		&yurex_fops,
126 	.minor_base =	YUREX_MINOR_BASE,
127 };
128 
129 static void yurex_interrupt(struct urb *urb)
130 {
131 	struct usb_yurex *dev = urb->context;
132 	unsigned char *buf = dev->int_buffer;
133 	int status = urb->status;
134 	unsigned long flags;
135 	int retval, i;
136 
137 	switch (status) {
138 	case 0: /*success*/
139 		break;
140 	case -EOVERFLOW:
141 		dev_err(&dev->interface->dev,
142 			"%s - overflow with length %d, actual length is %d\n",
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 		dev_err(&dev->interface->dev,
152 			"%s - unknown status received: %d\n", __func__, status);
153 		goto exit;
154 	}
155 
156 	/* handle received message */
157 	switch (buf[0]) {
158 	case CMD_COUNT:
159 	case CMD_READ:
160 		if (buf[6] == CMD_EOF) {
161 			spin_lock_irqsave(&dev->lock, flags);
162 			dev->bbu = 0;
163 			for (i = 1; i < 6; i++) {
164 				dev->bbu += buf[i];
165 				if (i != 5)
166 					dev->bbu <<= 8;
167 			}
168 			dev_dbg(&dev->interface->dev, "%s count: %lld\n",
169 				__func__, dev->bbu);
170 			spin_unlock_irqrestore(&dev->lock, flags);
171 
172 			kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
173 		}
174 		else
175 			dev_dbg(&dev->interface->dev,
176 				"data format error - no EOF\n");
177 		break;
178 	case CMD_ACK:
179 		dev_dbg(&dev->interface->dev, "%s ack: %c\n",
180 			__func__, buf[1]);
181 		wake_up_interruptible(&dev->waitq);
182 		break;
183 	}
184 
185 exit:
186 	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
187 	if (retval) {
188 		dev_err(&dev->interface->dev, "%s - usb_submit_urb failed: %d\n",
189 			__func__, retval);
190 	}
191 }
192 
193 static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id)
194 {
195 	struct usb_yurex *dev;
196 	struct usb_host_interface *iface_desc;
197 	struct usb_endpoint_descriptor *endpoint;
198 	int retval = -ENOMEM;
199 	int i;
200 	DEFINE_WAIT(wait);
201 
202 	/* allocate memory for our device state and initialize it */
203 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
204 	if (!dev) {
205 		dev_err(&interface->dev, "Out of memory\n");
206 		goto error;
207 	}
208 	kref_init(&dev->kref);
209 	mutex_init(&dev->io_mutex);
210 	spin_lock_init(&dev->lock);
211 	init_waitqueue_head(&dev->waitq);
212 
213 	dev->udev = usb_get_dev(interface_to_usbdev(interface));
214 	dev->interface = interface;
215 
216 	/* set up the endpoint information */
217 	iface_desc = interface->cur_altsetting;
218 	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
219 		endpoint = &iface_desc->endpoint[i].desc;
220 
221 		if (usb_endpoint_is_int_in(endpoint)) {
222 			dev->int_in_endpointAddr = endpoint->bEndpointAddress;
223 			break;
224 		}
225 	}
226 	if (!dev->int_in_endpointAddr) {
227 		retval = -ENODEV;
228 		dev_err(&interface->dev, "Could not find endpoints\n");
229 		goto error;
230 	}
231 
232 
233 	/* allocate control URB */
234 	dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
235 	if (!dev->cntl_urb) {
236 		dev_err(&interface->dev, "Could not allocate control URB\n");
237 		goto error;
238 	}
239 
240 	/* allocate buffer for control req */
241 	dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL);
242 	if (!dev->cntl_req) {
243 		dev_err(&interface->dev, "Could not allocate cntl_req\n");
244 		goto error;
245 	}
246 
247 	/* allocate buffer for control msg */
248 	dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
249 					      GFP_KERNEL,
250 					      &dev->cntl_urb->transfer_dma);
251 	if (!dev->cntl_buffer) {
252 		dev_err(&interface->dev, "Could not allocate cntl_buffer\n");
253 		goto error;
254 	}
255 
256 	/* configure control URB */
257 	dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
258 				      USB_RECIP_INTERFACE;
259 	dev->cntl_req->bRequest	= HID_REQ_SET_REPORT;
260 	dev->cntl_req->wValue	= cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
261 	dev->cntl_req->wIndex	= cpu_to_le16(iface_desc->desc.bInterfaceNumber);
262 	dev->cntl_req->wLength	= cpu_to_le16(YUREX_BUF_SIZE);
263 
264 	usb_fill_control_urb(dev->cntl_urb, dev->udev,
265 			     usb_sndctrlpipe(dev->udev, 0),
266 			     (void *)dev->cntl_req, dev->cntl_buffer,
267 			     YUREX_BUF_SIZE, yurex_control_callback, dev);
268 	dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
269 
270 
271 	/* allocate interrupt URB */
272 	dev->urb = usb_alloc_urb(0, GFP_KERNEL);
273 	if (!dev->urb) {
274 		dev_err(&interface->dev, "Could not allocate URB\n");
275 		goto error;
276 	}
277 
278 	/* allocate buffer for interrupt in */
279 	dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
280 					GFP_KERNEL, &dev->urb->transfer_dma);
281 	if (!dev->int_buffer) {
282 		dev_err(&interface->dev, "Could not allocate int_buffer\n");
283 		goto error;
284 	}
285 
286 	/* configure interrupt URB */
287 	usb_fill_int_urb(dev->urb, dev->udev,
288 			 usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
289 			 dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
290 			 dev, 1);
291 	dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
292 	if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
293 		retval = -EIO;
294 		dev_err(&interface->dev, "Could not submitting URB\n");
295 		goto error;
296 	}
297 
298 	/* save our data pointer in this interface device */
299 	usb_set_intfdata(interface, dev);
300 
301 	/* we can register the device now, as it is ready */
302 	retval = usb_register_dev(interface, &yurex_class);
303 	if (retval) {
304 		dev_err(&interface->dev,
305 			"Not able to get a minor for this device.\n");
306 		usb_set_intfdata(interface, NULL);
307 		goto error;
308 	}
309 
310 	dev->bbu = -1;
311 
312 	dev_info(&interface->dev,
313 		 "USB YUREX device now attached to Yurex #%d\n",
314 		 interface->minor);
315 
316 	return 0;
317 
318 error:
319 	if (dev)
320 		/* this frees allocated memory */
321 		kref_put(&dev->kref, yurex_delete);
322 	return retval;
323 }
324 
325 static void yurex_disconnect(struct usb_interface *interface)
326 {
327 	struct usb_yurex *dev;
328 	int minor = interface->minor;
329 
330 	dev = usb_get_intfdata(interface);
331 	usb_set_intfdata(interface, NULL);
332 
333 	/* give back our minor */
334 	usb_deregister_dev(interface, &yurex_class);
335 
336 	/* prevent more I/O from starting */
337 	mutex_lock(&dev->io_mutex);
338 	dev->interface = NULL;
339 	mutex_unlock(&dev->io_mutex);
340 
341 	/* wakeup waiters */
342 	kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
343 	wake_up_interruptible(&dev->waitq);
344 
345 	/* decrement our usage count */
346 	kref_put(&dev->kref, yurex_delete);
347 
348 	dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
349 }
350 
351 static struct usb_driver yurex_driver = {
352 	.name =		"yurex",
353 	.probe =	yurex_probe,
354 	.disconnect =	yurex_disconnect,
355 	.id_table =	yurex_table,
356 };
357 
358 
359 static int yurex_fasync(int fd, struct file *file, int on)
360 {
361 	struct usb_yurex *dev;
362 
363 	dev = (struct usb_yurex *)file->private_data;
364 	return fasync_helper(fd, file, on, &dev->async_queue);
365 }
366 
367 static int yurex_open(struct inode *inode, struct file *file)
368 {
369 	struct usb_yurex *dev;
370 	struct usb_interface *interface;
371 	int subminor;
372 	int retval = 0;
373 
374 	subminor = iminor(inode);
375 
376 	interface = usb_find_interface(&yurex_driver, subminor);
377 	if (!interface) {
378 		printk(KERN_ERR "%s - error, can't find device for minor %d",
379 		       __func__, subminor);
380 		retval = -ENODEV;
381 		goto exit;
382 	}
383 
384 	dev = usb_get_intfdata(interface);
385 	if (!dev) {
386 		retval = -ENODEV;
387 		goto exit;
388 	}
389 
390 	/* increment our usage count for the device */
391 	kref_get(&dev->kref);
392 
393 	/* save our object in the file's private structure */
394 	mutex_lock(&dev->io_mutex);
395 	file->private_data = dev;
396 	mutex_unlock(&dev->io_mutex);
397 
398 exit:
399 	return retval;
400 }
401 
402 static int yurex_release(struct inode *inode, struct file *file)
403 {
404 	struct usb_yurex *dev;
405 
406 	dev = (struct usb_yurex *)file->private_data;
407 	if (dev == NULL)
408 		return -ENODEV;
409 
410 	/* decrement the count on our device */
411 	kref_put(&dev->kref, yurex_delete);
412 	return 0;
413 }
414 
415 static ssize_t yurex_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
416 {
417 	struct usb_yurex *dev;
418 	int retval = 0;
419 	int bytes_read = 0;
420 	char in_buffer[20];
421 	unsigned long flags;
422 
423 	dev = (struct usb_yurex *)file->private_data;
424 
425 	mutex_lock(&dev->io_mutex);
426 	if (!dev->interface) {		/* already disconnected */
427 		retval = -ENODEV;
428 		goto exit;
429 	}
430 
431 	spin_lock_irqsave(&dev->lock, flags);
432 	bytes_read = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
433 	spin_unlock_irqrestore(&dev->lock, flags);
434 
435 	if (*ppos < bytes_read) {
436 		if (copy_to_user(buffer, in_buffer + *ppos, bytes_read - *ppos))
437 			retval = -EFAULT;
438 		else {
439 			retval = bytes_read - *ppos;
440 			*ppos += bytes_read;
441 		}
442 	}
443 
444 exit:
445 	mutex_unlock(&dev->io_mutex);
446 	return retval;
447 }
448 
449 static ssize_t yurex_write(struct file *file, const char *user_buffer, size_t count, loff_t *ppos)
450 {
451 	struct usb_yurex *dev;
452 	int i, set = 0, retval = 0;
453 	char buffer[16];
454 	char *data = buffer;
455 	unsigned long long c, c2 = 0;
456 	signed long timeout = 0;
457 	DEFINE_WAIT(wait);
458 
459 	count = min(sizeof(buffer), count);
460 	dev = (struct usb_yurex *)file->private_data;
461 
462 	/* verify that we actually have some data to write */
463 	if (count == 0)
464 		goto error;
465 
466 	mutex_lock(&dev->io_mutex);
467 	if (!dev->interface) {		/* alreaday disconnected */
468 		mutex_unlock(&dev->io_mutex);
469 		retval = -ENODEV;
470 		goto error;
471 	}
472 
473 	if (copy_from_user(buffer, user_buffer, count)) {
474 		mutex_unlock(&dev->io_mutex);
475 		retval = -EFAULT;
476 		goto error;
477 	}
478 	memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
479 
480 	switch (buffer[0]) {
481 	case CMD_ANIMATE:
482 	case CMD_LED:
483 		dev->cntl_buffer[0] = buffer[0];
484 		dev->cntl_buffer[1] = buffer[1];
485 		dev->cntl_buffer[2] = CMD_EOF;
486 		break;
487 	case CMD_READ:
488 	case CMD_VERSION:
489 		dev->cntl_buffer[0] = buffer[0];
490 		dev->cntl_buffer[1] = 0x00;
491 		dev->cntl_buffer[2] = CMD_EOF;
492 		break;
493 	case CMD_SET:
494 		data++;
495 		/* FALL THROUGH */
496 	case '0' ... '9':
497 		set = 1;
498 		c = c2 = simple_strtoull(data, NULL, 0);
499 		dev->cntl_buffer[0] = CMD_SET;
500 		for (i = 1; i < 6; i++) {
501 			dev->cntl_buffer[i] = (c>>32) & 0xff;
502 			c <<= 8;
503 		}
504 		buffer[6] = CMD_EOF;
505 		break;
506 	default:
507 		mutex_unlock(&dev->io_mutex);
508 		return -EINVAL;
509 	}
510 
511 	/* send the data as the control msg */
512 	prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
513 	dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__,
514 		dev->cntl_buffer[0]);
515 	retval = usb_submit_urb(dev->cntl_urb, GFP_KERNEL);
516 	if (retval >= 0)
517 		timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
518 	finish_wait(&dev->waitq, &wait);
519 
520 	mutex_unlock(&dev->io_mutex);
521 
522 	if (retval < 0) {
523 		dev_err(&dev->interface->dev,
524 			"%s - failed to send bulk msg, error %d\n",
525 			__func__, retval);
526 		goto error;
527 	}
528 	if (set && timeout)
529 		dev->bbu = c2;
530 	return timeout ? count : -EIO;
531 
532 error:
533 	return retval;
534 }
535 
536 static const struct file_operations yurex_fops = {
537 	.owner =	THIS_MODULE,
538 	.read =		yurex_read,
539 	.write =	yurex_write,
540 	.open =		yurex_open,
541 	.release =	yurex_release,
542 	.fasync	=	yurex_fasync,
543 	.llseek =	default_llseek,
544 };
545 
546 module_usb_driver(yurex_driver);
547 
548 MODULE_LICENSE("GPL");
549