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5fd54ace | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /***************************************************************************** |
3 | * USBLCD Kernel Driver * | |
4 | * Version 1.05 * | |
5 | * (C) 2005 Georges Toth <g.toth@e-biz.lu> * | |
6 | * * | |
7 | * This file is licensed under the GPL. See COPYING in the package. * | |
8 | * Based on usb-skeleton.c 2.0 by Greg Kroah-Hartman (greg@kroah.com) * | |
9 | * * | |
10 | * * | |
11 | * 28.02.05 Complete rewrite of the original usblcd.c driver, * | |
12 | * based on usb_skeleton.c. * | |
13 | * This new driver allows more than one USB-LCD to be connected * | |
14 | * and controlled, at once * | |
15 | *****************************************************************************/ | |
16 | #include <linux/module.h> | |
17 | #include <linux/kernel.h> | |
1da177e4 LT |
18 | #include <linux/slab.h> |
19 | #include <linux/errno.h> | |
d5d1ceac | 20 | #include <linux/mutex.h> |
eb7f5a49 | 21 | #include <linux/rwsem.h> |
507a3ea7 | 22 | #include <linux/uaccess.h> |
1da177e4 LT |
23 | #include <linux/usb.h> |
24 | ||
25 | #define DRIVER_VERSION "USBLCD Driver Version 1.05" | |
26 | ||
27 | #define USBLCD_MINOR 144 | |
28 | ||
29 | #define IOCTL_GET_HARD_VERSION 1 | |
30 | #define IOCTL_GET_DRV_VERSION 2 | |
31 | ||
32 | ||
33b9e162 | 33 | static const struct usb_device_id id_table[] = { |
1da177e4 LT |
34 | { .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, }, |
35 | { }, | |
36 | }; | |
507a3ea7 | 37 | MODULE_DEVICE_TABLE(usb, id_table); |
1da177e4 | 38 | |
1da177e4 | 39 | struct usb_lcd { |
507a3ea7 ZP |
40 | struct usb_device *udev; /* init: probe_lcd */ |
41 | struct usb_interface *interface; /* the interface for | |
42 | this device */ | |
43 | unsigned char *bulk_in_buffer; /* the buffer to receive | |
44 | data */ | |
45 | size_t bulk_in_size; /* the size of the | |
46 | receive buffer */ | |
47 | __u8 bulk_in_endpointAddr; /* the address of the | |
48 | bulk in endpoint */ | |
49 | __u8 bulk_out_endpointAddr; /* the address of the | |
50 | bulk out endpoint */ | |
5afeb104 | 51 | struct kref kref; |
507a3ea7 ZP |
52 | struct semaphore limit_sem; /* to stop writes at |
53 | full throttle from | |
54 | using up all RAM */ | |
55 | struct usb_anchor submitted; /* URBs to wait for | |
56 | before suspend */ | |
eb7f5a49 JH |
57 | struct rw_semaphore io_rwsem; |
58 | unsigned long disconnected:1; | |
1da177e4 LT |
59 | }; |
60 | #define to_lcd_dev(d) container_of(d, struct usb_lcd, kref) | |
61 | ||
5afeb104 ON |
62 | #define USB_LCD_CONCURRENT_WRITES 5 |
63 | ||
1da177e4 LT |
64 | static struct usb_driver lcd_driver; |
65 | ||
66 | ||
67 | static void lcd_delete(struct kref *kref) | |
68 | { | |
69 | struct usb_lcd *dev = to_lcd_dev(kref); | |
70 | ||
71 | usb_put_dev(dev->udev); | |
507a3ea7 ZP |
72 | kfree(dev->bulk_in_buffer); |
73 | kfree(dev); | |
1da177e4 LT |
74 | } |
75 | ||
76 | ||
77 | static int lcd_open(struct inode *inode, struct file *file) | |
78 | { | |
79 | struct usb_lcd *dev; | |
80 | struct usb_interface *interface; | |
7bbe990c | 81 | int subminor, r; |
1da177e4 LT |
82 | |
83 | subminor = iminor(inode); | |
84 | ||
85 | interface = usb_find_interface(&lcd_driver, subminor); | |
86 | if (!interface) { | |
c9a2baa7 | 87 | pr_err("USBLCD: %s - error, can't find device for minor %d\n", |
abd83e4b | 88 | __func__, subminor); |
d4ead16f | 89 | return -ENODEV; |
1da177e4 LT |
90 | } |
91 | ||
92 | dev = usb_get_intfdata(interface); | |
1da177e4 LT |
93 | |
94 | /* increment our usage count for the device */ | |
95 | kref_get(&dev->kref); | |
96 | ||
7bbe990c ON |
97 | /* grab a power reference */ |
98 | r = usb_autopm_get_interface(interface); | |
99 | if (r < 0) { | |
100 | kref_put(&dev->kref, lcd_delete); | |
101 | return r; | |
102 | } | |
103 | ||
1da177e4 LT |
104 | /* save our object in the file's private structure */ |
105 | file->private_data = dev; | |
106 | ||
d4ead16f | 107 | return 0; |
1da177e4 LT |
108 | } |
109 | ||
110 | static int lcd_release(struct inode *inode, struct file *file) | |
111 | { | |
112 | struct usb_lcd *dev; | |
113 | ||
5bd6e8b3 | 114 | dev = file->private_data; |
1da177e4 LT |
115 | if (dev == NULL) |
116 | return -ENODEV; | |
117 | ||
118 | /* decrement the count on our device */ | |
7bbe990c | 119 | usb_autopm_put_interface(dev->interface); |
1da177e4 LT |
120 | kref_put(&dev->kref, lcd_delete); |
121 | return 0; | |
122 | } | |
123 | ||
507a3ea7 ZP |
124 | static ssize_t lcd_read(struct file *file, char __user * buffer, |
125 | size_t count, loff_t *ppos) | |
1da177e4 LT |
126 | { |
127 | struct usb_lcd *dev; | |
128 | int retval = 0; | |
129 | int bytes_read; | |
130 | ||
5bd6e8b3 | 131 | dev = file->private_data; |
1da177e4 | 132 | |
eb7f5a49 JH |
133 | down_read(&dev->io_rwsem); |
134 | ||
135 | if (dev->disconnected) { | |
136 | retval = -ENODEV; | |
137 | goto out_up_io; | |
138 | } | |
139 | ||
1da177e4 | 140 | /* do a blocking bulk read to get data from the device */ |
507a3ea7 ZP |
141 | retval = usb_bulk_msg(dev->udev, |
142 | usb_rcvbulkpipe(dev->udev, | |
143 | dev->bulk_in_endpointAddr), | |
1da177e4 LT |
144 | dev->bulk_in_buffer, |
145 | min(dev->bulk_in_size, count), | |
146 | &bytes_read, 10000); | |
147 | ||
148 | /* if the read was successful, copy the data to userspace */ | |
149 | if (!retval) { | |
150 | if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read)) | |
151 | retval = -EFAULT; | |
152 | else | |
153 | retval = bytes_read; | |
154 | } | |
155 | ||
eb7f5a49 JH |
156 | out_up_io: |
157 | up_read(&dev->io_rwsem); | |
158 | ||
1da177e4 LT |
159 | return retval; |
160 | } | |
161 | ||
5cb4aeca | 162 | static long lcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
163 | { |
164 | struct usb_lcd *dev; | |
165 | u16 bcdDevice; | |
166 | char buf[30]; | |
167 | ||
5bd6e8b3 | 168 | dev = file->private_data; |
1da177e4 LT |
169 | if (dev == NULL) |
170 | return -ENODEV; | |
507a3ea7 | 171 | |
1da177e4 LT |
172 | switch (cmd) { |
173 | case IOCTL_GET_HARD_VERSION: | |
174 | bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice); | |
507a3ea7 | 175 | sprintf(buf, "%1d%1d.%1d%1d", |
1da177e4 LT |
176 | (bcdDevice & 0xF000)>>12, |
177 | (bcdDevice & 0xF00)>>8, | |
178 | (bcdDevice & 0xF0)>>4, | |
179 | (bcdDevice & 0xF)); | |
507a3ea7 | 180 | if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0) |
1da177e4 LT |
181 | return -EFAULT; |
182 | break; | |
183 | case IOCTL_GET_DRV_VERSION: | |
507a3ea7 ZP |
184 | sprintf(buf, DRIVER_VERSION); |
185 | if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0) | |
1da177e4 LT |
186 | return -EFAULT; |
187 | break; | |
188 | default: | |
189 | return -ENOTTY; | |
1da177e4 LT |
190 | } |
191 | ||
192 | return 0; | |
193 | } | |
194 | ||
7d12e780 | 195 | static void lcd_write_bulk_callback(struct urb *urb) |
1da177e4 LT |
196 | { |
197 | struct usb_lcd *dev; | |
0723af13 | 198 | int status = urb->status; |
1da177e4 | 199 | |
cdc97792 | 200 | dev = urb->context; |
1da177e4 LT |
201 | |
202 | /* sync/async unlink faults aren't errors */ | |
0723af13 GKH |
203 | if (status && |
204 | !(status == -ENOENT || | |
205 | status == -ECONNRESET || | |
507a3ea7 | 206 | status == -ESHUTDOWN)) { |
d8ec7a7c GKH |
207 | dev_dbg(&dev->interface->dev, |
208 | "nonzero write bulk status received: %d\n", status); | |
1da177e4 LT |
209 | } |
210 | ||
211 | /* free up our allocated buffer */ | |
997ea58e DM |
212 | usb_free_coherent(urb->dev, urb->transfer_buffer_length, |
213 | urb->transfer_buffer, urb->transfer_dma); | |
5afeb104 | 214 | up(&dev->limit_sem); |
1da177e4 LT |
215 | } |
216 | ||
507a3ea7 ZP |
217 | static ssize_t lcd_write(struct file *file, const char __user * user_buffer, |
218 | size_t count, loff_t *ppos) | |
1da177e4 LT |
219 | { |
220 | struct usb_lcd *dev; | |
507a3ea7 | 221 | int retval = 0, r; |
1da177e4 LT |
222 | struct urb *urb = NULL; |
223 | char *buf = NULL; | |
507a3ea7 | 224 | |
5bd6e8b3 | 225 | dev = file->private_data; |
507a3ea7 | 226 | |
1da177e4 LT |
227 | /* verify that we actually have some data to write */ |
228 | if (count == 0) | |
229 | goto exit; | |
230 | ||
5afeb104 ON |
231 | r = down_interruptible(&dev->limit_sem); |
232 | if (r < 0) | |
233 | return -EINTR; | |
234 | ||
eb7f5a49 JH |
235 | down_read(&dev->io_rwsem); |
236 | ||
237 | if (dev->disconnected) { | |
238 | retval = -ENODEV; | |
239 | goto err_up_io; | |
240 | } | |
241 | ||
1da177e4 LT |
242 | /* create a urb, and a buffer for it, and copy the data to the urb */ |
243 | urb = usb_alloc_urb(0, GFP_KERNEL); | |
5afeb104 ON |
244 | if (!urb) { |
245 | retval = -ENOMEM; | |
eb7f5a49 | 246 | goto err_up_io; |
5afeb104 | 247 | } |
507a3ea7 ZP |
248 | |
249 | buf = usb_alloc_coherent(dev->udev, count, GFP_KERNEL, | |
250 | &urb->transfer_dma); | |
1da177e4 LT |
251 | if (!buf) { |
252 | retval = -ENOMEM; | |
253 | goto error; | |
254 | } | |
507a3ea7 | 255 | |
1da177e4 LT |
256 | if (copy_from_user(buf, user_buffer, count)) { |
257 | retval = -EFAULT; | |
258 | goto error; | |
259 | } | |
507a3ea7 | 260 | |
1da177e4 LT |
261 | /* initialize the urb properly */ |
262 | usb_fill_bulk_urb(urb, dev->udev, | |
507a3ea7 ZP |
263 | usb_sndbulkpipe(dev->udev, |
264 | dev->bulk_out_endpointAddr), | |
1da177e4 LT |
265 | buf, count, lcd_write_bulk_callback, dev); |
266 | urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; | |
7bbe990c ON |
267 | |
268 | usb_anchor_urb(urb, &dev->submitted); | |
507a3ea7 | 269 | |
1da177e4 LT |
270 | /* send the data out the bulk port */ |
271 | retval = usb_submit_urb(urb, GFP_KERNEL); | |
272 | if (retval) { | |
abd83e4b GKH |
273 | dev_err(&dev->udev->dev, |
274 | "%s - failed submitting write urb, error %d\n", | |
275 | __func__, retval); | |
7bbe990c | 276 | goto error_unanchor; |
1da177e4 | 277 | } |
507a3ea7 ZP |
278 | |
279 | /* release our reference to this urb, | |
280 | the USB core will eventually free it entirely */ | |
1da177e4 LT |
281 | usb_free_urb(urb); |
282 | ||
eb7f5a49 | 283 | up_read(&dev->io_rwsem); |
1da177e4 LT |
284 | exit: |
285 | return count; | |
7bbe990c ON |
286 | error_unanchor: |
287 | usb_unanchor_urb(urb); | |
1da177e4 | 288 | error: |
997ea58e | 289 | usb_free_coherent(dev->udev, count, buf, urb->transfer_dma); |
1da177e4 | 290 | usb_free_urb(urb); |
eb7f5a49 JH |
291 | err_up_io: |
292 | up_read(&dev->io_rwsem); | |
5afeb104 | 293 | up(&dev->limit_sem); |
1da177e4 LT |
294 | return retval; |
295 | } | |
296 | ||
066202dd | 297 | static const struct file_operations lcd_fops = { |
507a3ea7 ZP |
298 | .owner = THIS_MODULE, |
299 | .read = lcd_read, | |
300 | .write = lcd_write, | |
301 | .open = lcd_open, | |
5cb4aeca | 302 | .unlocked_ioctl = lcd_ioctl, |
507a3ea7 ZP |
303 | .release = lcd_release, |
304 | .llseek = noop_llseek, | |
1da177e4 LT |
305 | }; |
306 | ||
307 | /* | |
d6e5bcf4 GKH |
308 | * usb class driver info in order to get a minor number from the usb core, |
309 | * and to have the device registered with the driver core | |
310 | */ | |
1da177e4 | 311 | static struct usb_class_driver lcd_class = { |
507a3ea7 ZP |
312 | .name = "lcd%d", |
313 | .fops = &lcd_fops, | |
314 | .minor_base = USBLCD_MINOR, | |
1da177e4 LT |
315 | }; |
316 | ||
507a3ea7 ZP |
317 | static int lcd_probe(struct usb_interface *interface, |
318 | const struct usb_device_id *id) | |
1da177e4 LT |
319 | { |
320 | struct usb_lcd *dev = NULL; | |
aac96ef9 | 321 | struct usb_endpoint_descriptor *bulk_in, *bulk_out; |
1da177e4 | 322 | int i; |
aac96ef9 | 323 | int retval; |
1da177e4 LT |
324 | |
325 | /* allocate memory for our device state and initialize it */ | |
80b6ca48 | 326 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
a1841732 | 327 | if (!dev) |
aac96ef9 JH |
328 | return -ENOMEM; |
329 | ||
1da177e4 | 330 | kref_init(&dev->kref); |
5afeb104 | 331 | sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES); |
eb7f5a49 | 332 | init_rwsem(&dev->io_rwsem); |
7bbe990c | 333 | init_usb_anchor(&dev->submitted); |
1da177e4 LT |
334 | |
335 | dev->udev = usb_get_dev(interface_to_usbdev(interface)); | |
336 | dev->interface = interface; | |
337 | ||
338 | if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) { | |
3b6004f3 | 339 | dev_warn(&interface->dev, "USBLCD model not supported.\n"); |
696a4ace JS |
340 | retval = -ENODEV; |
341 | goto error; | |
1da177e4 | 342 | } |
507a3ea7 | 343 | |
1da177e4 LT |
344 | /* set up the endpoint information */ |
345 | /* use only the first bulk-in and bulk-out endpoints */ | |
aac96ef9 JH |
346 | retval = usb_find_common_endpoints(interface->cur_altsetting, |
347 | &bulk_in, &bulk_out, NULL, NULL); | |
348 | if (retval) { | |
abd83e4b GKH |
349 | dev_err(&interface->dev, |
350 | "Could not find both bulk-in and bulk-out endpoints\n"); | |
1da177e4 LT |
351 | goto error; |
352 | } | |
353 | ||
aac96ef9 JH |
354 | dev->bulk_in_size = usb_endpoint_maxp(bulk_in); |
355 | dev->bulk_in_endpointAddr = bulk_in->bEndpointAddress; | |
356 | dev->bulk_in_buffer = kmalloc(dev->bulk_in_size, GFP_KERNEL); | |
357 | if (!dev->bulk_in_buffer) { | |
358 | retval = -ENOMEM; | |
359 | goto error; | |
360 | } | |
361 | ||
362 | dev->bulk_out_endpointAddr = bulk_out->bEndpointAddress; | |
363 | ||
1da177e4 LT |
364 | /* save our data pointer in this interface device */ |
365 | usb_set_intfdata(interface, dev); | |
366 | ||
367 | /* we can register the device now, as it is ready */ | |
368 | retval = usb_register_dev(interface, &lcd_class); | |
369 | if (retval) { | |
370 | /* something prevented us from registering this driver */ | |
abd83e4b GKH |
371 | dev_err(&interface->dev, |
372 | "Not able to get a minor for this device.\n"); | |
1da177e4 LT |
373 | goto error; |
374 | } | |
375 | ||
376 | i = le16_to_cpu(dev->udev->descriptor.bcdDevice); | |
377 | ||
1b29a375 GKH |
378 | dev_info(&interface->dev, "USBLCD Version %1d%1d.%1d%1d found " |
379 | "at address %d\n", (i & 0xF000)>>12, (i & 0xF00)>>8, | |
507a3ea7 | 380 | (i & 0xF0)>>4, (i & 0xF), dev->udev->devnum); |
1da177e4 LT |
381 | |
382 | /* let the user know what node this device is now attached to */ | |
1b29a375 GKH |
383 | dev_info(&interface->dev, "USB LCD device now attached to USBLCD-%d\n", |
384 | interface->minor); | |
1da177e4 LT |
385 | return 0; |
386 | ||
387 | error: | |
aac96ef9 | 388 | kref_put(&dev->kref, lcd_delete); |
1da177e4 LT |
389 | return retval; |
390 | } | |
391 | ||
7bbe990c ON |
392 | static void lcd_draw_down(struct usb_lcd *dev) |
393 | { | |
394 | int time; | |
395 | ||
396 | time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000); | |
397 | if (!time) | |
398 | usb_kill_anchored_urbs(&dev->submitted); | |
399 | } | |
400 | ||
401 | static int lcd_suspend(struct usb_interface *intf, pm_message_t message) | |
402 | { | |
403 | struct usb_lcd *dev = usb_get_intfdata(intf); | |
404 | ||
405 | if (!dev) | |
406 | return 0; | |
407 | lcd_draw_down(dev); | |
408 | return 0; | |
409 | } | |
410 | ||
507a3ea7 | 411 | static int lcd_resume(struct usb_interface *intf) |
7bbe990c ON |
412 | { |
413 | return 0; | |
414 | } | |
415 | ||
1da177e4 LT |
416 | static void lcd_disconnect(struct usb_interface *interface) |
417 | { | |
61991d02 | 418 | struct usb_lcd *dev = usb_get_intfdata(interface); |
507a3ea7 | 419 | int minor = interface->minor; |
1da177e4 | 420 | |
507a3ea7 ZP |
421 | /* give back our minor */ |
422 | usb_deregister_dev(interface, &lcd_class); | |
423 | ||
eb7f5a49 JH |
424 | down_write(&dev->io_rwsem); |
425 | dev->disconnected = 1; | |
426 | up_write(&dev->io_rwsem); | |
427 | ||
428 | usb_kill_anchored_urbs(&dev->submitted); | |
429 | ||
1da177e4 LT |
430 | /* decrement our usage count */ |
431 | kref_put(&dev->kref, lcd_delete); | |
432 | ||
1b29a375 | 433 | dev_info(&interface->dev, "USB LCD #%d now disconnected\n", minor); |
1da177e4 LT |
434 | } |
435 | ||
436 | static struct usb_driver lcd_driver = { | |
1da177e4 LT |
437 | .name = "usblcd", |
438 | .probe = lcd_probe, | |
439 | .disconnect = lcd_disconnect, | |
7bbe990c ON |
440 | .suspend = lcd_suspend, |
441 | .resume = lcd_resume, | |
1da177e4 | 442 | .id_table = id_table, |
7bbe990c | 443 | .supports_autosuspend = 1, |
1da177e4 LT |
444 | }; |
445 | ||
65db4305 | 446 | module_usb_driver(lcd_driver); |
1da177e4 LT |
447 | |
448 | MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>"); | |
449 | MODULE_DESCRIPTION(DRIVER_VERSION); | |
450 | MODULE_LICENSE("GPL"); |