xref: /openbmc/linux/drivers/usb/misc/yurex.c (revision 11788d9b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for Meywa-Denki & KAYAC YUREX
4  *
5  * Copyright (C) 2010 Tomoki Sekiyama (tomoki.sekiyama@gmail.com)
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/errno.h>
10 #include <linux/slab.h>
11 #include <linux/module.h>
12 #include <linux/kref.h>
13 #include <linux/mutex.h>
14 #include <linux/uaccess.h>
15 #include <linux/usb.h>
16 #include <linux/hid.h>
17 
18 #define DRIVER_AUTHOR "Tomoki Sekiyama"
19 #define DRIVER_DESC "Driver for Meywa-Denki & KAYAC YUREX"
20 
21 #define YUREX_VENDOR_ID		0x0c45
22 #define YUREX_PRODUCT_ID	0x1010
23 
24 #define CMD_ACK		'!'
25 #define CMD_ANIMATE	'A'
26 #define CMD_COUNT	'C'
27 #define CMD_LED		'L'
28 #define CMD_READ	'R'
29 #define CMD_SET		'S'
30 #define CMD_VERSION	'V'
31 #define CMD_EOF		0x0d
32 #define CMD_PADDING	0xff
33 
34 #define YUREX_BUF_SIZE		8
35 #define YUREX_WRITE_TIMEOUT	(HZ*2)
36 
37 /* table of devices that work with this driver */
38 static struct usb_device_id yurex_table[] = {
39 	{ USB_DEVICE(YUREX_VENDOR_ID, YUREX_PRODUCT_ID) },
40 	{ }					/* Terminating entry */
41 };
42 MODULE_DEVICE_TABLE(usb, yurex_table);
43 
44 #ifdef CONFIG_USB_DYNAMIC_MINORS
45 #define YUREX_MINOR_BASE	0
46 #else
47 #define YUREX_MINOR_BASE	192
48 #endif
49 
50 /* Structure to hold all of our device specific stuff */
51 struct usb_yurex {
52 	struct usb_device	*udev;
53 	struct usb_interface	*interface;
54 	__u8			int_in_endpointAddr;
55 	struct urb		*urb;		/* URB for interrupt in */
56 	unsigned char           *int_buffer;	/* buffer for intterupt in */
57 	struct urb		*cntl_urb;	/* URB for control msg */
58 	struct usb_ctrlrequest	*cntl_req;	/* req for control msg */
59 	unsigned char		*cntl_buffer;	/* buffer for control msg */
60 
61 	struct kref		kref;
62 	struct mutex		io_mutex;
63 	unsigned long		disconnected:1;
64 	struct fasync_struct	*async_queue;
65 	wait_queue_head_t	waitq;
66 
67 	spinlock_t		lock;
68 	__s64			bbu;		/* BBU from device */
69 };
70 #define to_yurex_dev(d) container_of(d, struct usb_yurex, kref)
71 
72 static struct usb_driver yurex_driver;
73 static const struct file_operations yurex_fops;
74 
75 
76 static void yurex_control_callback(struct urb *urb)
77 {
78 	struct usb_yurex *dev = urb->context;
79 	int status = urb->status;
80 
81 	if (status) {
82 		dev_err(&urb->dev->dev, "%s - control failed: %d\n",
83 			__func__, status);
84 		wake_up_interruptible(&dev->waitq);
85 		return;
86 	}
87 	/* on success, sender woken up by CMD_ACK int in, or timeout */
88 }
89 
90 static void yurex_delete(struct kref *kref)
91 {
92 	struct usb_yurex *dev = to_yurex_dev(kref);
93 
94 	dev_dbg(&dev->interface->dev, "%s\n", __func__);
95 
96 	if (dev->cntl_urb) {
97 		usb_kill_urb(dev->cntl_urb);
98 		kfree(dev->cntl_req);
99 		if (dev->cntl_buffer)
100 			usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
101 				dev->cntl_buffer, dev->cntl_urb->transfer_dma);
102 		usb_free_urb(dev->cntl_urb);
103 	}
104 	if (dev->urb) {
105 		usb_kill_urb(dev->urb);
106 		if (dev->int_buffer)
107 			usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
108 				dev->int_buffer, dev->urb->transfer_dma);
109 		usb_free_urb(dev->urb);
110 	}
111 	usb_put_intf(dev->interface);
112 	usb_put_dev(dev->udev);
113 	kfree(dev);
114 }
115 
116 /*
117  * usb class driver info in order to get a minor number from the usb core,
118  * and to have the device registered with the driver core
119  */
120 static struct usb_class_driver yurex_class = {
121 	.name =		"yurex%d",
122 	.fops =		&yurex_fops,
123 	.minor_base =	YUREX_MINOR_BASE,
124 };
125 
126 static void yurex_interrupt(struct urb *urb)
127 {
128 	struct usb_yurex *dev = urb->context;
129 	unsigned char *buf = dev->int_buffer;
130 	int status = urb->status;
131 	unsigned long flags;
132 	int retval, i;
133 
134 	switch (status) {
135 	case 0: /*success*/
136 		break;
137 	/* The device is terminated or messed up, give up */
138 	case -EOVERFLOW:
139 		dev_err(&dev->interface->dev,
140 			"%s - overflow with length %d, actual length is %d\n",
141 			__func__, YUREX_BUF_SIZE, dev->urb->actual_length);
142 	case -ECONNRESET:
143 	case -ENOENT:
144 	case -ESHUTDOWN:
145 	case -EILSEQ:
146 	case -EPROTO:
147 	case -ETIME:
148 		return;
149 	default:
150 		dev_err(&dev->interface->dev,
151 			"%s - unknown status received: %d\n", __func__, status);
152 		return;
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 	retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
185 	if (retval) {
186 		dev_err(&dev->interface->dev, "%s - usb_submit_urb failed: %d\n",
187 			__func__, retval);
188 	}
189 }
190 
191 static int yurex_probe(struct usb_interface *interface, const struct usb_device_id *id)
192 {
193 	struct usb_yurex *dev;
194 	struct usb_host_interface *iface_desc;
195 	struct usb_endpoint_descriptor *endpoint;
196 	int retval = -ENOMEM;
197 	DEFINE_WAIT(wait);
198 	int res;
199 
200 	/* allocate memory for our device state and initialize it */
201 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
202 	if (!dev)
203 		goto error;
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 = usb_get_intf(interface);
211 
212 	/* set up the endpoint information */
213 	iface_desc = interface->cur_altsetting;
214 	res = usb_find_int_in_endpoint(iface_desc, &endpoint);
215 	if (res) {
216 		dev_err(&interface->dev, "Could not find endpoints\n");
217 		retval = res;
218 		goto error;
219 	}
220 
221 	dev->int_in_endpointAddr = endpoint->bEndpointAddress;
222 
223 	/* allocate control URB */
224 	dev->cntl_urb = usb_alloc_urb(0, GFP_KERNEL);
225 	if (!dev->cntl_urb)
226 		goto error;
227 
228 	/* allocate buffer for control req */
229 	dev->cntl_req = kmalloc(YUREX_BUF_SIZE, GFP_KERNEL);
230 	if (!dev->cntl_req)
231 		goto error;
232 
233 	/* allocate buffer for control msg */
234 	dev->cntl_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
235 					      GFP_KERNEL,
236 					      &dev->cntl_urb->transfer_dma);
237 	if (!dev->cntl_buffer) {
238 		dev_err(&interface->dev, "Could not allocate cntl_buffer\n");
239 		goto error;
240 	}
241 
242 	/* configure control URB */
243 	dev->cntl_req->bRequestType = USB_DIR_OUT | USB_TYPE_CLASS |
244 				      USB_RECIP_INTERFACE;
245 	dev->cntl_req->bRequest	= HID_REQ_SET_REPORT;
246 	dev->cntl_req->wValue	= cpu_to_le16((HID_OUTPUT_REPORT + 1) << 8);
247 	dev->cntl_req->wIndex	= cpu_to_le16(iface_desc->desc.bInterfaceNumber);
248 	dev->cntl_req->wLength	= cpu_to_le16(YUREX_BUF_SIZE);
249 
250 	usb_fill_control_urb(dev->cntl_urb, dev->udev,
251 			     usb_sndctrlpipe(dev->udev, 0),
252 			     (void *)dev->cntl_req, dev->cntl_buffer,
253 			     YUREX_BUF_SIZE, yurex_control_callback, dev);
254 	dev->cntl_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
255 
256 
257 	/* allocate interrupt URB */
258 	dev->urb = usb_alloc_urb(0, GFP_KERNEL);
259 	if (!dev->urb)
260 		goto error;
261 
262 	/* allocate buffer for interrupt in */
263 	dev->int_buffer = usb_alloc_coherent(dev->udev, YUREX_BUF_SIZE,
264 					GFP_KERNEL, &dev->urb->transfer_dma);
265 	if (!dev->int_buffer) {
266 		dev_err(&interface->dev, "Could not allocate int_buffer\n");
267 		goto error;
268 	}
269 
270 	/* configure interrupt URB */
271 	usb_fill_int_urb(dev->urb, dev->udev,
272 			 usb_rcvintpipe(dev->udev, dev->int_in_endpointAddr),
273 			 dev->int_buffer, YUREX_BUF_SIZE, yurex_interrupt,
274 			 dev, 1);
275 	dev->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
276 	if (usb_submit_urb(dev->urb, GFP_KERNEL)) {
277 		retval = -EIO;
278 		dev_err(&interface->dev, "Could not submitting URB\n");
279 		goto error;
280 	}
281 
282 	/* save our data pointer in this interface device */
283 	usb_set_intfdata(interface, dev);
284 	dev->bbu = -1;
285 
286 	/* we can register the device now, as it is ready */
287 	retval = usb_register_dev(interface, &yurex_class);
288 	if (retval) {
289 		dev_err(&interface->dev,
290 			"Not able to get a minor for this device.\n");
291 		usb_set_intfdata(interface, NULL);
292 		goto error;
293 	}
294 
295 	dev_info(&interface->dev,
296 		 "USB YUREX device now attached to Yurex #%d\n",
297 		 interface->minor);
298 
299 	return 0;
300 
301 error:
302 	if (dev)
303 		/* this frees allocated memory */
304 		kref_put(&dev->kref, yurex_delete);
305 	return retval;
306 }
307 
308 static void yurex_disconnect(struct usb_interface *interface)
309 {
310 	struct usb_yurex *dev;
311 	int minor = interface->minor;
312 
313 	dev = usb_get_intfdata(interface);
314 	usb_set_intfdata(interface, NULL);
315 
316 	/* give back our minor */
317 	usb_deregister_dev(interface, &yurex_class);
318 
319 	/* prevent more I/O from starting */
320 	usb_poison_urb(dev->urb);
321 	usb_poison_urb(dev->cntl_urb);
322 	mutex_lock(&dev->io_mutex);
323 	dev->disconnected = 1;
324 	mutex_unlock(&dev->io_mutex);
325 
326 	/* wakeup waiters */
327 	kill_fasync(&dev->async_queue, SIGIO, POLL_IN);
328 	wake_up_interruptible(&dev->waitq);
329 
330 	/* decrement our usage count */
331 	kref_put(&dev->kref, yurex_delete);
332 
333 	dev_info(&interface->dev, "USB YUREX #%d now disconnected\n", minor);
334 }
335 
336 static struct usb_driver yurex_driver = {
337 	.name =		"yurex",
338 	.probe =	yurex_probe,
339 	.disconnect =	yurex_disconnect,
340 	.id_table =	yurex_table,
341 };
342 
343 
344 static int yurex_fasync(int fd, struct file *file, int on)
345 {
346 	struct usb_yurex *dev;
347 
348 	dev = file->private_data;
349 	return fasync_helper(fd, file, on, &dev->async_queue);
350 }
351 
352 static int yurex_open(struct inode *inode, struct file *file)
353 {
354 	struct usb_yurex *dev;
355 	struct usb_interface *interface;
356 	int subminor;
357 	int retval = 0;
358 
359 	subminor = iminor(inode);
360 
361 	interface = usb_find_interface(&yurex_driver, subminor);
362 	if (!interface) {
363 		printk(KERN_ERR "%s - error, can't find device for minor %d",
364 		       __func__, subminor);
365 		retval = -ENODEV;
366 		goto exit;
367 	}
368 
369 	dev = usb_get_intfdata(interface);
370 	if (!dev) {
371 		retval = -ENODEV;
372 		goto exit;
373 	}
374 
375 	/* increment our usage count for the device */
376 	kref_get(&dev->kref);
377 
378 	/* save our object in the file's private structure */
379 	mutex_lock(&dev->io_mutex);
380 	file->private_data = dev;
381 	mutex_unlock(&dev->io_mutex);
382 
383 exit:
384 	return retval;
385 }
386 
387 static int yurex_release(struct inode *inode, struct file *file)
388 {
389 	struct usb_yurex *dev;
390 
391 	dev = file->private_data;
392 	if (dev == NULL)
393 		return -ENODEV;
394 
395 	/* decrement the count on our device */
396 	kref_put(&dev->kref, yurex_delete);
397 	return 0;
398 }
399 
400 static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
401 			  loff_t *ppos)
402 {
403 	struct usb_yurex *dev;
404 	int len = 0;
405 	char in_buffer[20];
406 	unsigned long flags;
407 
408 	dev = file->private_data;
409 
410 	mutex_lock(&dev->io_mutex);
411 	if (dev->disconnected) {		/* already disconnected */
412 		mutex_unlock(&dev->io_mutex);
413 		return -ENODEV;
414 	}
415 
416 	spin_lock_irqsave(&dev->lock, flags);
417 	len = snprintf(in_buffer, 20, "%lld\n", dev->bbu);
418 	spin_unlock_irqrestore(&dev->lock, flags);
419 	mutex_unlock(&dev->io_mutex);
420 
421 	if (WARN_ON_ONCE(len >= sizeof(in_buffer)))
422 		return -EIO;
423 
424 	return simple_read_from_buffer(buffer, count, ppos, in_buffer, len);
425 }
426 
427 static ssize_t yurex_write(struct file *file, const char __user *user_buffer,
428 			   size_t count, loff_t *ppos)
429 {
430 	struct usb_yurex *dev;
431 	int i, set = 0, retval = 0;
432 	char buffer[16 + 1];
433 	char *data = buffer;
434 	unsigned long long c, c2 = 0;
435 	signed long timeout = 0;
436 	DEFINE_WAIT(wait);
437 
438 	count = min(sizeof(buffer) - 1, count);
439 	dev = file->private_data;
440 
441 	/* verify that we actually have some data to write */
442 	if (count == 0)
443 		goto error;
444 
445 	mutex_lock(&dev->io_mutex);
446 	if (dev->disconnected) {		/* already disconnected */
447 		mutex_unlock(&dev->io_mutex);
448 		retval = -ENODEV;
449 		goto error;
450 	}
451 
452 	if (copy_from_user(buffer, user_buffer, count)) {
453 		mutex_unlock(&dev->io_mutex);
454 		retval = -EFAULT;
455 		goto error;
456 	}
457 	buffer[count] = 0;
458 	memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
459 
460 	switch (buffer[0]) {
461 	case CMD_ANIMATE:
462 	case CMD_LED:
463 		dev->cntl_buffer[0] = buffer[0];
464 		dev->cntl_buffer[1] = buffer[1];
465 		dev->cntl_buffer[2] = CMD_EOF;
466 		break;
467 	case CMD_READ:
468 	case CMD_VERSION:
469 		dev->cntl_buffer[0] = buffer[0];
470 		dev->cntl_buffer[1] = 0x00;
471 		dev->cntl_buffer[2] = CMD_EOF;
472 		break;
473 	case CMD_SET:
474 		data++;
475 		fallthrough;
476 	case '0' ... '9':
477 		set = 1;
478 		c = c2 = simple_strtoull(data, NULL, 0);
479 		dev->cntl_buffer[0] = CMD_SET;
480 		for (i = 1; i < 6; i++) {
481 			dev->cntl_buffer[i] = (c>>32) & 0xff;
482 			c <<= 8;
483 		}
484 		buffer[6] = CMD_EOF;
485 		break;
486 	default:
487 		mutex_unlock(&dev->io_mutex);
488 		return -EINVAL;
489 	}
490 
491 	/* send the data as the control msg */
492 	prepare_to_wait(&dev->waitq, &wait, TASK_INTERRUPTIBLE);
493 	dev_dbg(&dev->interface->dev, "%s - submit %c\n", __func__,
494 		dev->cntl_buffer[0]);
495 	retval = usb_submit_urb(dev->cntl_urb, GFP_KERNEL);
496 	if (retval >= 0)
497 		timeout = schedule_timeout(YUREX_WRITE_TIMEOUT);
498 	finish_wait(&dev->waitq, &wait);
499 
500 	mutex_unlock(&dev->io_mutex);
501 
502 	if (retval < 0) {
503 		dev_err(&dev->interface->dev,
504 			"%s - failed to send bulk msg, error %d\n",
505 			__func__, retval);
506 		goto error;
507 	}
508 	if (set && timeout)
509 		dev->bbu = c2;
510 	return timeout ? count : -EIO;
511 
512 error:
513 	return retval;
514 }
515 
516 static const struct file_operations yurex_fops = {
517 	.owner =	THIS_MODULE,
518 	.read =		yurex_read,
519 	.write =	yurex_write,
520 	.open =		yurex_open,
521 	.release =	yurex_release,
522 	.fasync	=	yurex_fasync,
523 	.llseek =	default_llseek,
524 };
525 
526 module_usb_driver(yurex_driver);
527 
528 MODULE_LICENSE("GPL");
529