xref: /openbmc/linux/drivers/usb/misc/yurex.c (revision 609e478b)
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 	dev->bbu = -1;
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_info(&interface->dev,
311 		 "USB YUREX device now attached to Yurex #%d\n",
312 		 interface->minor);
313 
314 	return 0;
315 
316 error:
317 	if (dev)
318 		/* this frees allocated memory */
319 		kref_put(&dev->kref, yurex_delete);
320 	return retval;
321 }
322 
323 static void yurex_disconnect(struct usb_interface *interface)
324 {
325 	struct usb_yurex *dev;
326 	int minor = interface->minor;
327 
328 	dev = usb_get_intfdata(interface);
329 	usb_set_intfdata(interface, NULL);
330 
331 	/* give back our minor */
332 	usb_deregister_dev(interface, &yurex_class);
333 
334 	/* prevent more I/O from starting */
335 	mutex_lock(&dev->io_mutex);
336 	dev->interface = NULL;
337 	mutex_unlock(&dev->io_mutex);
338 
339 	/* wakeup waiters */
340 	kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
341 	wake_up_interruptible(&dev->waitq);
342 
343 	/* decrement our usage count */
344 	kref_put(&dev->kref, yurex_delete);
345 
346 	dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
347 }
348 
349 static struct usb_driver yurex_driver = {
350 	.name =		"yurex",
351 	.probe =	yurex_probe,
352 	.disconnect =	yurex_disconnect,
353 	.id_table =	yurex_table,
354 };
355 
356 
357 static int yurex_fasync(int fd, struct file *file, int on)
358 {
359 	struct usb_yurex *dev;
360 
361 	dev = file->private_data;
362 	return fasync_helper(fd, file, on, &dev->async_queue);
363 }
364 
365 static int yurex_open(struct inode *inode, struct file *file)
366 {
367 	struct usb_yurex *dev;
368 	struct usb_interface *interface;
369 	int subminor;
370 	int retval = 0;
371 
372 	subminor = iminor(inode);
373 
374 	interface = usb_find_interface(&yurex_driver, subminor);
375 	if (!interface) {
376 		printk(KERN_ERR "%s - error, can't find device for minor %d",
377 		       __func__, subminor);
378 		retval = -ENODEV;
379 		goto exit;
380 	}
381 
382 	dev = usb_get_intfdata(interface);
383 	if (!dev) {
384 		retval = -ENODEV;
385 		goto exit;
386 	}
387 
388 	/* increment our usage count for the device */
389 	kref_get(&dev->kref);
390 
391 	/* save our object in the file's private structure */
392 	mutex_lock(&dev->io_mutex);
393 	file->private_data = dev;
394 	mutex_unlock(&dev->io_mutex);
395 
396 exit:
397 	return retval;
398 }
399 
400 static int yurex_release(struct inode *inode, struct file *file)
401 {
402 	struct usb_yurex *dev;
403 
404 	dev = file->private_data;
405 	if (dev == NULL)
406 		return -ENODEV;
407 
408 	/* decrement the count on our device */
409 	kref_put(&dev->kref, yurex_delete);
410 	return 0;
411 }
412 
413 static ssize_t yurex_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
414 {
415 	struct usb_yurex *dev;
416 	int retval = 0;
417 	int bytes_read = 0;
418 	char in_buffer[20];
419 	unsigned long flags;
420 
421 	dev = file->private_data;
422 
423 	mutex_lock(&dev->io_mutex);
424 	if (!dev->interface) {		/* already disconnected */
425 		retval = -ENODEV;
426 		goto exit;
427 	}
428 
429 	spin_lock_irqsave(&dev->lock, flags);
430 	bytes_read = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
431 	spin_unlock_irqrestore(&dev->lock, flags);
432 
433 	if (*ppos < bytes_read) {
434 		if (copy_to_user(buffer, in_buffer + *ppos, bytes_read - *ppos))
435 			retval = -EFAULT;
436 		else {
437 			retval = bytes_read - *ppos;
438 			*ppos += bytes_read;
439 		}
440 	}
441 
442 exit:
443 	mutex_unlock(&dev->io_mutex);
444 	return retval;
445 }
446 
447 static ssize_t yurex_write(struct file *file, const char *user_buffer, size_t count, loff_t *ppos)
448 {
449 	struct usb_yurex *dev;
450 	int i, set = 0, retval = 0;
451 	char buffer[16];
452 	char *data = buffer;
453 	unsigned long long c, c2 = 0;
454 	signed long timeout = 0;
455 	DEFINE_WAIT(wait);
456 
457 	count = min(sizeof(buffer), count);
458 	dev = file->private_data;
459 
460 	/* verify that we actually have some data to write */
461 	if (count == 0)
462 		goto error;
463 
464 	mutex_lock(&dev->io_mutex);
465 	if (!dev->interface) {		/* already disconnected */
466 		mutex_unlock(&dev->io_mutex);
467 		retval = -ENODEV;
468 		goto error;
469 	}
470 
471 	if (copy_from_user(buffer, user_buffer, count)) {
472 		mutex_unlock(&dev->io_mutex);
473 		retval = -EFAULT;
474 		goto error;
475 	}
476 	memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
477 
478 	switch (buffer[0]) {
479 	case CMD_ANIMATE:
480 	case CMD_LED:
481 		dev->cntl_buffer[0] = buffer[0];
482 		dev->cntl_buffer[1] = buffer[1];
483 		dev->cntl_buffer[2] = CMD_EOF;
484 		break;
485 	case CMD_READ:
486 	case CMD_VERSION:
487 		dev->cntl_buffer[0] = buffer[0];
488 		dev->cntl_buffer[1] = 0x00;
489 		dev->cntl_buffer[2] = CMD_EOF;
490 		break;
491 	case CMD_SET:
492 		data++;
493 		/* FALL THROUGH */
494 	case '0' ... '9':
495 		set = 1;
496 		c = c2 = simple_strtoull(data, NULL, 0);
497 		dev->cntl_buffer[0] = CMD_SET;
498 		for (i = 1; i < 6; i++) {
499 			dev->cntl_buffer[i] = (c>>32) & 0xff;
500 			c <<= 8;
501 		}
502 		buffer[6] = CMD_EOF;
503 		break;
504 	default:
505 		mutex_unlock(&dev->io_mutex);
506 		return -EINVAL;
507 	}
508 
509 	/* send the data as the control msg */
510 	prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
511 	dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__,
512 		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 		dev_err(&dev->interface->dev,
522 			"%s - failed to send bulk msg, error %d\n",
523 			__func__, retval);
524 		goto error;
525 	}
526 	if (set && timeout)
527 		dev->bbu = c2;
528 	return timeout ? count : -EIO;
529 
530 error:
531 	return retval;
532 }
533 
534 static const struct file_operations yurex_fops = {
535 	.owner =	THIS_MODULE,
536 	.read =		yurex_read,
537 	.write =	yurex_write,
538 	.open =		yurex_open,
539 	.release =	yurex_release,
540 	.fasync	=	yurex_fasync,
541 	.llseek =	default_llseek,
542 };
543 
544 module_usb_driver(yurex_driver);
545 
546 MODULE_LICENSE("GPL");
547