xref: /openbmc/linux/drivers/usb/misc/yurex.c (revision 90099433)
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 		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 		err("%s - overflow with length %d, actual length is %d",
141 		    __func__, YUREX_BUF_SIZE, dev->urb->actual_length);
142 	case -ECONNRESET:
143 	case -ENOENT:
144 	case -ESHUTDOWN:
145 	case -EILSEQ:
146 		/* The device is terminated, clean up */
147 		return;
148 	default:
149 		err("%s - unknown status received: %d", __func__, status);
150 		goto exit;
151 	}
152 
153 	/* handle received message */
154 	switch (buf[0]) {
155 	case CMD_COUNT:
156 	case CMD_READ:
157 		if (buf[6] == CMD_EOF) {
158 			spin_lock_irqsave(&dev->lock, flags);
159 			dev->bbu = 0;
160 			for (i = 1; i < 6; i++) {
161 				dev->bbu += buf[i];
162 				if (i != 5)
163 					dev->bbu <<= 8;
164 			}
165 			dbg("%s count: %lld", __func__, dev->bbu);
166 			spin_unlock_irqrestore(&dev->lock, flags);
167 
168 			kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
169 		}
170 		else
171 			dbg("data format error - no EOF");
172 		break;
173 	case CMD_ACK:
174 		dbg("%s ack: %c", __func__, buf[1]);
175 		wake_up_interruptible(&dev->waitq);
176 		break;
177 	}
178 
179 exit:
180 	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
181 	if (retval) {
182 		err("%s - usb_submit_urb failed: %d",
183 			__func__, retval);
184 	}
185 }
186 
187 static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id)
188 {
189 	struct usb_yurex *dev;
190 	struct usb_host_interface *iface_desc;
191 	struct usb_endpoint_descriptor *endpoint;
192 	int retval = -ENOMEM;
193 	int i;
194 	DEFINE_WAIT(wait);
195 
196 	/* allocate memory for our device state and initialize it */
197 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
198 	if (!dev) {
199 		err("Out of memory");
200 		goto error;
201 	}
202 	kref_init(&dev->kref);
203 	mutex_init(&dev->io_mutex);
204 	spin_lock_init(&dev->lock);
205 	init_waitqueue_head(&dev->waitq);
206 
207 	dev->udev = usb_get_dev(interface_to_usbdev(interface));
208 	dev->interface = interface;
209 
210 	/* set up the endpoint information */
211 	iface_desc = interface->cur_altsetting;
212 	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
213 		endpoint = &iface_desc->endpoint[i].desc;
214 
215 		if (usb_endpoint_is_int_in(endpoint)) {
216 			dev->int_in_endpointAddr = endpoint->bEndpointAddress;
217 			break;
218 		}
219 	}
220 	if (!dev->int_in_endpointAddr) {
221 		retval = -ENODEV;
222 		err("Could not find endpoints");
223 		goto error;
224 	}
225 
226 
227 	/* allocate control URB */
228 	dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
229 	if (!dev->cntl_urb) {
230 		err("Could not allocate control URB");
231 		goto error;
232 	}
233 
234 	/* allocate buffer for control req */
235 	dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL);
236 	if (!dev->cntl_req) {
237 		err("Could not allocate cntl_req");
238 		goto error;
239 	}
240 
241 	/* allocate buffer for control msg */
242 	dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
243 					      GFP_KERNEL,
244 					      &dev->cntl_urb->transfer_dma);
245 	if (!dev->cntl_buffer) {
246 		err("Could not allocate cntl_buffer");
247 		goto error;
248 	}
249 
250 	/* configure control URB */
251 	dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
252 				      USB_RECIP_INTERFACE;
253 	dev->cntl_req->bRequest	= HID_REQ_SET_REPORT;
254 	dev->cntl_req->wValue	= cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
255 	dev->cntl_req->wIndex	= cpu_to_le16(iface_desc->desc.bInterfaceNumber);
256 	dev->cntl_req->wLength	= cpu_to_le16(YUREX_BUF_SIZE);
257 
258 	usb_fill_control_urb(dev->cntl_urb, dev->udev,
259 			     usb_sndctrlpipe(dev->udev, 0),
260 			     (void *)dev->cntl_req, dev->cntl_buffer,
261 			     YUREX_BUF_SIZE, yurex_control_callback, dev);
262 	dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
263 
264 
265 	/* allocate interrupt URB */
266 	dev->urb = usb_alloc_urb(0, GFP_KERNEL);
267 	if (!dev->urb) {
268 		err("Could not allocate URB");
269 		goto error;
270 	}
271 
272 	/* allocate buffer for interrupt in */
273 	dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
274 					GFP_KERNEL, &dev->urb->transfer_dma);
275 	if (!dev->int_buffer) {
276 		err("Could not allocate int_buffer");
277 		goto error;
278 	}
279 
280 	/* configure interrupt URB */
281 	usb_fill_int_urb(dev->urb, dev->udev,
282 			 usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
283 			 dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
284 			 dev, 1);
285 	dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
286 	if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
287 		retval = -EIO;
288 		err("Could not submitting URB");
289 		goto error;
290 	}
291 
292 	/* save our data pointer in this interface device */
293 	usb_set_intfdata(interface, dev);
294 
295 	/* we can register the device now, as it is ready */
296 	retval = usb_register_dev(interface, &yurex_class);
297 	if (retval) {
298 		err("Not able to get a minor for this device.");
299 		usb_set_intfdata(interface, NULL);
300 		goto error;
301 	}
302 
303 	dev->bbu = -1;
304 
305 	dev_info(&interface->dev,
306 		 "USB YUREX device now attached to Yurex #%d\n",
307 		 interface->minor);
308 
309 	return 0;
310 
311 error:
312 	if (dev)
313 		/* this frees allocated memory */
314 		kref_put(&dev->kref, yurex_delete);
315 	return retval;
316 }
317 
318 static void yurex_disconnect(struct usb_interface *interface)
319 {
320 	struct usb_yurex *dev;
321 	int minor = interface->minor;
322 
323 	dev = usb_get_intfdata(interface);
324 	usb_set_intfdata(interface, NULL);
325 
326 	/* give back our minor */
327 	usb_deregister_dev(interface, &yurex_class);
328 
329 	/* prevent more I/O from starting */
330 	mutex_lock(&dev->io_mutex);
331 	dev->interface = NULL;
332 	mutex_unlock(&dev->io_mutex);
333 
334 	/* wakeup waiters */
335 	kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
336 	wake_up_interruptible(&dev->waitq);
337 
338 	/* decrement our usage count */
339 	kref_put(&dev->kref, yurex_delete);
340 
341 	dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
342 }
343 
344 static struct usb_driver yurex_driver = {
345 	.name =		"yurex",
346 	.probe =	yurex_probe,
347 	.disconnect =	yurex_disconnect,
348 	.id_table =	yurex_table,
349 };
350 
351 
352 static int yurex_fasync(int fd, struct file *file, int on)
353 {
354 	struct usb_yurex *dev;
355 
356 	dev = (struct usb_yurex *)file->private_data;
357 	return fasync_helper(fd, file, on, &dev->async_queue);
358 }
359 
360 static int yurex_open(struct inode *inode, struct file *file)
361 {
362 	struct usb_yurex *dev;
363 	struct usb_interface *interface;
364 	int subminor;
365 	int retval = 0;
366 
367 	subminor = iminor(inode);
368 
369 	interface = usb_find_interface(&yurex_driver, subminor);
370 	if (!interface) {
371 		err("%s - error, can't find device for minor %d",
372 		    __func__, subminor);
373 		retval = -ENODEV;
374 		goto exit;
375 	}
376 
377 	dev = usb_get_intfdata(interface);
378 	if (!dev) {
379 		retval = -ENODEV;
380 		goto exit;
381 	}
382 
383 	/* increment our usage count for the device */
384 	kref_get(&dev->kref);
385 
386 	/* save our object in the file's private structure */
387 	mutex_lock(&dev->io_mutex);
388 	file->private_data = dev;
389 	mutex_unlock(&dev->io_mutex);
390 
391 exit:
392 	return retval;
393 }
394 
395 static int yurex_release(struct inode *inode, struct file *file)
396 {
397 	struct usb_yurex *dev;
398 
399 	dev = (struct usb_yurex *)file->private_data;
400 	if (dev == NULL)
401 		return -ENODEV;
402 
403 	yurex_fasync(-1, file, 0);
404 
405 	/* decrement the count on our device */
406 	kref_put(&dev->kref, yurex_delete);
407 	return 0;
408 }
409 
410 static ssize_t yurex_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
411 {
412 	struct usb_yurex *dev;
413 	int retval = 0;
414 	int bytes_read = 0;
415 	char in_buffer[20];
416 	unsigned long flags;
417 
418 	dev = (struct usb_yurex *)file->private_data;
419 
420 	mutex_lock(&dev->io_mutex);
421 	if (!dev->interface) {		/* already disconnected */
422 		retval = -ENODEV;
423 		goto exit;
424 	}
425 
426 	spin_lock_irqsave(&dev->lock, flags);
427 	bytes_read = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
428 	spin_unlock_irqrestore(&dev->lock, flags);
429 
430 	if (*ppos < bytes_read) {
431 		if (copy_to_user(buffer, in_buffer + *ppos, bytes_read - *ppos))
432 			retval = -EFAULT;
433 		else {
434 			retval = bytes_read - *ppos;
435 			*ppos += bytes_read;
436 		}
437 	}
438 
439 exit:
440 	mutex_unlock(&dev->io_mutex);
441 	return retval;
442 }
443 
444 static ssize_t yurex_write(struct file *file, const char *user_buffer, size_t count, loff_t *ppos)
445 {
446 	struct usb_yurex *dev;
447 	int i, set = 0, retval = 0;
448 	char buffer[16];
449 	char *data = buffer;
450 	unsigned long long c, c2 = 0;
451 	signed long timeout = 0;
452 	DEFINE_WAIT(wait);
453 
454 	count = min(sizeof(buffer), count);
455 	dev = (struct usb_yurex *)file->private_data;
456 
457 	/* verify that we actually have some data to write */
458 	if (count == 0)
459 		goto error;
460 
461 	mutex_lock(&dev->io_mutex);
462 	if (!dev->interface) {		/* alreaday disconnected */
463 		mutex_unlock(&dev->io_mutex);
464 		retval = -ENODEV;
465 		goto error;
466 	}
467 
468 	if (copy_from_user(buffer, user_buffer, count)) {
469 		mutex_unlock(&dev->io_mutex);
470 		retval = -EFAULT;
471 		goto error;
472 	}
473 	memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
474 
475 	switch (buffer[0]) {
476 	case CMD_ANIMATE:
477 	case CMD_LED:
478 		dev->cntl_buffer[0] = buffer[0];
479 		dev->cntl_buffer[1] = buffer[1];
480 		dev->cntl_buffer[2] = CMD_EOF;
481 		break;
482 	case CMD_READ:
483 	case CMD_VERSION:
484 		dev->cntl_buffer[0] = buffer[0];
485 		dev->cntl_buffer[1] = 0x00;
486 		dev->cntl_buffer[2] = CMD_EOF;
487 		break;
488 	case CMD_SET:
489 		data++;
490 		/* FALL THROUGH */
491 	case '0' ... '9':
492 		set = 1;
493 		c = c2 = simple_strtoull(data, NULL, 0);
494 		dev->cntl_buffer[0] = CMD_SET;
495 		for (i = 1; i < 6; i++) {
496 			dev->cntl_buffer[i] = (c>>32) & 0xff;
497 			c <<= 8;
498 		}
499 		buffer[6] = CMD_EOF;
500 		break;
501 	default:
502 		mutex_unlock(&dev->io_mutex);
503 		return -EINVAL;
504 	}
505 
506 	/* send the data as the control msg */
507 	prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
508 	dbg("%s - submit %c", __func__, dev->cntl_buffer[0]);
509 	retval = usb_submit_urb(dev->cntl_urb, GFP_KERNEL);
510 	if (retval >= 0)
511 		timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
512 	finish_wait(&dev->waitq, &wait);
513 
514 	mutex_unlock(&dev->io_mutex);
515 
516 	if (retval < 0) {
517 		err("%s - failed to send bulk msg, error %d", __func__, retval);
518 		goto error;
519 	}
520 	if (set && timeout)
521 		dev->bbu = c2;
522 	return timeout ? count : -EIO;
523 
524 error:
525 	return retval;
526 }
527 
528 static const struct file_operations yurex_fops = {
529 	.owner =	THIS_MODULE,
530 	.read =		yurex_read,
531 	.write =	yurex_write,
532 	.open =		yurex_open,
533 	.release =	yurex_release,
534 	.fasync	=	yurex_fasync,
535 	.llseek =	default_llseek,
536 };
537 
538 module_usb_driver(yurex_driver);
539 
540 MODULE_LICENSE("GPL");
541