1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * Generic USB driver for report based interrupt in/out devices |
4 | * like LD Didactic's USB devices. LD Didactic's USB devices are |
5 | * HID devices which do not use HID report definitons (they use |
6 | * raw interrupt in and our reports only for communication). |
7 | * |
8 | * This driver uses a ring buffer for time critical reading of |
9 | * interrupt in reports and provides read and write methods for |
10 | * raw interrupt reports (similar to the Windows HID driver). |
11 | * Devices based on the book USB COMPLETE by Jan Axelson may need |
12 | * such a compatibility to the Windows HID driver. |
13 | * |
14 | * Copyright (C) 2005 Michael Hund <mhund@ld-didactic.de> |
15 | * |
16 | * Derived from Lego USB Tower driver |
17 | * Copyright (C) 2003 David Glance <advidgsf@sourceforge.net> |
18 | * 2001-2004 Juergen Stuber <starblue@users.sourceforge.net> |
19 | */ |
20 | |
21 | #include <linux/kernel.h> |
22 | #include <linux/errno.h> |
23 | #include <linux/slab.h> |
24 | #include <linux/module.h> |
25 | #include <linux/mutex.h> |
26 | |
27 | #include <linux/uaccess.h> |
28 | #include <linux/input.h> |
29 | #include <linux/usb.h> |
30 | #include <linux/poll.h> |
31 | |
32 | /* Define these values to match your devices */ |
33 | #define USB_VENDOR_ID_LD 0x0f11 /* USB Vendor ID of LD Didactic GmbH */ |
34 | #define USB_DEVICE_ID_LD_CASSY 0x1000 /* USB Product ID of CASSY-S modules with 8 bytes endpoint size */ |
35 | #define USB_DEVICE_ID_LD_CASSY2 0x1001 /* USB Product ID of CASSY-S modules with 64 bytes endpoint size */ |
36 | #define USB_DEVICE_ID_LD_POCKETCASSY 0x1010 /* USB Product ID of Pocket-CASSY */ |
37 | #define USB_DEVICE_ID_LD_POCKETCASSY2 0x1011 /* USB Product ID of Pocket-CASSY 2 (reserved) */ |
38 | #define USB_DEVICE_ID_LD_MOBILECASSY 0x1020 /* USB Product ID of Mobile-CASSY */ |
39 | #define USB_DEVICE_ID_LD_MOBILECASSY2 0x1021 /* USB Product ID of Mobile-CASSY 2 (reserved) */ |
40 | #define USB_DEVICE_ID_LD_MICROCASSYVOLTAGE 0x1031 /* USB Product ID of Micro-CASSY Voltage */ |
41 | #define USB_DEVICE_ID_LD_MICROCASSYCURRENT 0x1032 /* USB Product ID of Micro-CASSY Current */ |
42 | #define USB_DEVICE_ID_LD_MICROCASSYTIME 0x1033 /* USB Product ID of Micro-CASSY Time (reserved) */ |
43 | #define USB_DEVICE_ID_LD_MICROCASSYTEMPERATURE 0x1035 /* USB Product ID of Micro-CASSY Temperature */ |
44 | #define USB_DEVICE_ID_LD_MICROCASSYPH 0x1038 /* USB Product ID of Micro-CASSY pH */ |
45 | #define USB_DEVICE_ID_LD_POWERANALYSERCASSY 0x1040 /* USB Product ID of Power Analyser CASSY */ |
46 | #define USB_DEVICE_ID_LD_CONVERTERCONTROLLERCASSY 0x1042 /* USB Product ID of Converter Controller CASSY */ |
47 | #define USB_DEVICE_ID_LD_MACHINETESTCASSY 0x1043 /* USB Product ID of Machine Test CASSY */ |
48 | #define USB_DEVICE_ID_LD_JWM 0x1080 /* USB Product ID of Joule and Wattmeter */ |
49 | #define USB_DEVICE_ID_LD_DMMP 0x1081 /* USB Product ID of Digital Multimeter P (reserved) */ |
50 | #define USB_DEVICE_ID_LD_UMIP 0x1090 /* USB Product ID of UMI P */ |
51 | #define USB_DEVICE_ID_LD_UMIC 0x10A0 /* USB Product ID of UMI C */ |
52 | #define USB_DEVICE_ID_LD_UMIB 0x10B0 /* USB Product ID of UMI B */ |
53 | #define USB_DEVICE_ID_LD_XRAY 0x1100 /* USB Product ID of X-Ray Apparatus 55481 */ |
54 | #define USB_DEVICE_ID_LD_XRAY2 0x1101 /* USB Product ID of X-Ray Apparatus 554800 */ |
55 | #define USB_DEVICE_ID_LD_XRAYCT 0x1110 /* USB Product ID of X-Ray Apparatus CT 554821*/ |
56 | #define USB_DEVICE_ID_LD_VIDEOCOM 0x1200 /* USB Product ID of VideoCom */ |
57 | #define USB_DEVICE_ID_LD_MOTOR 0x1210 /* USB Product ID of Motor (reserved) */ |
58 | #define USB_DEVICE_ID_LD_COM3LAB 0x2000 /* USB Product ID of COM3LAB */ |
59 | #define USB_DEVICE_ID_LD_TELEPORT 0x2010 /* USB Product ID of Terminal Adapter */ |
60 | #define USB_DEVICE_ID_LD_NETWORKANALYSER 0x2020 /* USB Product ID of Network Analyser */ |
61 | #define USB_DEVICE_ID_LD_POWERCONTROL 0x2030 /* USB Product ID of Converter Control Unit */ |
62 | #define USB_DEVICE_ID_LD_MACHINETEST 0x2040 /* USB Product ID of Machine Test System */ |
63 | #define USB_DEVICE_ID_LD_MOSTANALYSER 0x2050 /* USB Product ID of MOST Protocol Analyser */ |
64 | #define USB_DEVICE_ID_LD_MOSTANALYSER2 0x2051 /* USB Product ID of MOST Protocol Analyser 2 */ |
65 | #define USB_DEVICE_ID_LD_ABSESP 0x2060 /* USB Product ID of ABS ESP */ |
66 | #define USB_DEVICE_ID_LD_AUTODATABUS 0x2070 /* USB Product ID of Automotive Data Buses */ |
67 | #define USB_DEVICE_ID_LD_MCT 0x2080 /* USB Product ID of Microcontroller technique */ |
68 | #define USB_DEVICE_ID_LD_HYBRID 0x2090 /* USB Product ID of Automotive Hybrid */ |
69 | #define USB_DEVICE_ID_LD_HEATCONTROL 0x20A0 /* USB Product ID of Heat control */ |
70 | |
71 | #ifdef CONFIG_USB_DYNAMIC_MINORS |
72 | #define USB_LD_MINOR_BASE 0 |
73 | #else |
74 | #define USB_LD_MINOR_BASE 176 |
75 | #endif |
76 | |
77 | /* table of devices that work with this driver */ |
78 | static const struct usb_device_id ld_usb_table[] = { |
79 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY) }, |
80 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY2) }, |
81 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY) }, |
82 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY2) }, |
83 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY) }, |
84 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY2) }, |
85 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYVOLTAGE) }, |
86 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYCURRENT) }, |
87 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYTIME) }, |
88 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYTEMPERATURE) }, |
89 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYPH) }, |
90 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERANALYSERCASSY) }, |
91 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CONVERTERCONTROLLERCASSY) }, |
92 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETESTCASSY) }, |
93 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_JWM) }, |
94 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_DMMP) }, |
95 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIP) }, |
96 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIC) }, |
97 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIB) }, |
98 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY) }, |
99 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY2) }, |
100 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_VIDEOCOM) }, |
101 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOTOR) }, |
102 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_COM3LAB) }, |
103 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_TELEPORT) }, |
104 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_NETWORKANALYSER) }, |
105 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERCONTROL) }, |
106 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETEST) }, |
107 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOSTANALYSER) }, |
108 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOSTANALYSER2) }, |
109 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_ABSESP) }, |
110 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_AUTODATABUS) }, |
111 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MCT) }, |
112 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_HYBRID) }, |
113 | { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_HEATCONTROL) }, |
114 | { } /* Terminating entry */ |
115 | }; |
116 | MODULE_DEVICE_TABLE(usb, ld_usb_table); |
117 | MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>" ); |
118 | MODULE_DESCRIPTION("LD USB Driver" ); |
119 | MODULE_LICENSE("GPL" ); |
120 | |
121 | /* All interrupt in transfers are collected in a ring buffer to |
122 | * avoid racing conditions and get better performance of the driver. |
123 | */ |
124 | static int ring_buffer_size = 128; |
125 | module_param(ring_buffer_size, int, 0000); |
126 | MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports" ); |
127 | |
128 | /* The write_buffer can contain more than one interrupt out transfer. |
129 | */ |
130 | static int write_buffer_size = 10; |
131 | module_param(write_buffer_size, int, 0000); |
132 | MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports" ); |
133 | |
134 | /* As of kernel version 2.6.4 ehci-hcd uses an |
135 | * "only one interrupt transfer per frame" shortcut |
136 | * to simplify the scheduling of periodic transfers. |
137 | * This conflicts with our standard 1ms intervals for in and out URBs. |
138 | * We use default intervals of 2ms for in and 2ms for out transfers, |
139 | * which should be fast enough. |
140 | * Increase the interval to allow more devices that do interrupt transfers, |
141 | * or set to 1 to use the standard interval from the endpoint descriptors. |
142 | */ |
143 | static int min_interrupt_in_interval = 2; |
144 | module_param(min_interrupt_in_interval, int, 0000); |
145 | MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms" ); |
146 | |
147 | static int min_interrupt_out_interval = 2; |
148 | module_param(min_interrupt_out_interval, int, 0000); |
149 | MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms" ); |
150 | |
151 | /* Structure to hold all of our device specific stuff */ |
152 | struct ld_usb { |
153 | struct mutex mutex; /* locks this structure */ |
154 | struct usb_interface *intf; /* save off the usb interface pointer */ |
155 | unsigned long disconnected:1; |
156 | |
157 | int open_count; /* number of times this port has been opened */ |
158 | |
159 | char *ring_buffer; |
160 | unsigned int ring_head; |
161 | unsigned int ring_tail; |
162 | |
163 | wait_queue_head_t read_wait; |
164 | wait_queue_head_t write_wait; |
165 | |
166 | char *interrupt_in_buffer; |
167 | struct usb_endpoint_descriptor *interrupt_in_endpoint; |
168 | struct urb *interrupt_in_urb; |
169 | int interrupt_in_interval; |
170 | size_t interrupt_in_endpoint_size; |
171 | int interrupt_in_running; |
172 | int interrupt_in_done; |
173 | int buffer_overflow; |
174 | spinlock_t rbsl; |
175 | |
176 | char *interrupt_out_buffer; |
177 | struct usb_endpoint_descriptor *interrupt_out_endpoint; |
178 | struct urb *interrupt_out_urb; |
179 | int interrupt_out_interval; |
180 | size_t interrupt_out_endpoint_size; |
181 | int interrupt_out_busy; |
182 | }; |
183 | |
184 | static struct usb_driver ld_usb_driver; |
185 | |
186 | /* |
187 | * ld_usb_abort_transfers |
188 | * aborts transfers and frees associated data structures |
189 | */ |
190 | static void ld_usb_abort_transfers(struct ld_usb *dev) |
191 | { |
192 | /* shutdown transfer */ |
193 | if (dev->interrupt_in_running) { |
194 | dev->interrupt_in_running = 0; |
195 | usb_kill_urb(urb: dev->interrupt_in_urb); |
196 | } |
197 | if (dev->interrupt_out_busy) |
198 | usb_kill_urb(urb: dev->interrupt_out_urb); |
199 | } |
200 | |
201 | /* |
202 | * ld_usb_delete |
203 | */ |
204 | static void ld_usb_delete(struct ld_usb *dev) |
205 | { |
206 | /* free data structures */ |
207 | usb_free_urb(urb: dev->interrupt_in_urb); |
208 | usb_free_urb(urb: dev->interrupt_out_urb); |
209 | kfree(objp: dev->ring_buffer); |
210 | kfree(objp: dev->interrupt_in_buffer); |
211 | kfree(objp: dev->interrupt_out_buffer); |
212 | kfree(objp: dev); |
213 | } |
214 | |
215 | /* |
216 | * ld_usb_interrupt_in_callback |
217 | */ |
218 | static void ld_usb_interrupt_in_callback(struct urb *urb) |
219 | { |
220 | struct ld_usb *dev = urb->context; |
221 | size_t *actual_buffer; |
222 | unsigned int next_ring_head; |
223 | int status = urb->status; |
224 | unsigned long flags; |
225 | int retval; |
226 | |
227 | if (status) { |
228 | if (status == -ENOENT || |
229 | status == -ECONNRESET || |
230 | status == -ESHUTDOWN) { |
231 | goto exit; |
232 | } else { |
233 | dev_dbg(&dev->intf->dev, |
234 | "%s: nonzero status received: %d\n" , __func__, |
235 | status); |
236 | spin_lock_irqsave(&dev->rbsl, flags); |
237 | goto resubmit; /* maybe we can recover */ |
238 | } |
239 | } |
240 | |
241 | spin_lock_irqsave(&dev->rbsl, flags); |
242 | if (urb->actual_length > 0) { |
243 | next_ring_head = (dev->ring_head+1) % ring_buffer_size; |
244 | if (next_ring_head != dev->ring_tail) { |
245 | actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_head * (sizeof(size_t)+dev->interrupt_in_endpoint_size)); |
246 | /* actual_buffer gets urb->actual_length + interrupt_in_buffer */ |
247 | *actual_buffer = urb->actual_length; |
248 | memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length); |
249 | dev->ring_head = next_ring_head; |
250 | dev_dbg(&dev->intf->dev, "%s: received %d bytes\n" , |
251 | __func__, urb->actual_length); |
252 | } else { |
253 | dev_warn(&dev->intf->dev, |
254 | "Ring buffer overflow, %d bytes dropped\n" , |
255 | urb->actual_length); |
256 | dev->buffer_overflow = 1; |
257 | } |
258 | } |
259 | |
260 | resubmit: |
261 | /* resubmit if we're still running */ |
262 | if (dev->interrupt_in_running && !dev->buffer_overflow) { |
263 | retval = usb_submit_urb(urb: dev->interrupt_in_urb, GFP_ATOMIC); |
264 | if (retval) { |
265 | dev_err(&dev->intf->dev, |
266 | "usb_submit_urb failed (%d)\n" , retval); |
267 | dev->buffer_overflow = 1; |
268 | } |
269 | } |
270 | spin_unlock_irqrestore(lock: &dev->rbsl, flags); |
271 | exit: |
272 | dev->interrupt_in_done = 1; |
273 | wake_up_interruptible(&dev->read_wait); |
274 | } |
275 | |
276 | /* |
277 | * ld_usb_interrupt_out_callback |
278 | */ |
279 | static void ld_usb_interrupt_out_callback(struct urb *urb) |
280 | { |
281 | struct ld_usb *dev = urb->context; |
282 | int status = urb->status; |
283 | |
284 | /* sync/async unlink faults aren't errors */ |
285 | if (status && !(status == -ENOENT || |
286 | status == -ECONNRESET || |
287 | status == -ESHUTDOWN)) |
288 | dev_dbg(&dev->intf->dev, |
289 | "%s - nonzero write interrupt status received: %d\n" , |
290 | __func__, status); |
291 | |
292 | dev->interrupt_out_busy = 0; |
293 | wake_up_interruptible(&dev->write_wait); |
294 | } |
295 | |
296 | /* |
297 | * ld_usb_open |
298 | */ |
299 | static int ld_usb_open(struct inode *inode, struct file *file) |
300 | { |
301 | struct ld_usb *dev; |
302 | int subminor; |
303 | int retval; |
304 | struct usb_interface *interface; |
305 | |
306 | stream_open(inode, filp: file); |
307 | subminor = iminor(inode); |
308 | |
309 | interface = usb_find_interface(drv: &ld_usb_driver, minor: subminor); |
310 | |
311 | if (!interface) { |
312 | printk(KERN_ERR "%s - error, can't find device for minor %d\n" , |
313 | __func__, subminor); |
314 | return -ENODEV; |
315 | } |
316 | |
317 | dev = usb_get_intfdata(intf: interface); |
318 | |
319 | if (!dev) |
320 | return -ENODEV; |
321 | |
322 | /* lock this device */ |
323 | if (mutex_lock_interruptible(&dev->mutex)) |
324 | return -ERESTARTSYS; |
325 | |
326 | /* allow opening only once */ |
327 | if (dev->open_count) { |
328 | retval = -EBUSY; |
329 | goto unlock_exit; |
330 | } |
331 | dev->open_count = 1; |
332 | |
333 | /* initialize in direction */ |
334 | dev->ring_head = 0; |
335 | dev->ring_tail = 0; |
336 | dev->buffer_overflow = 0; |
337 | usb_fill_int_urb(urb: dev->interrupt_in_urb, |
338 | interface_to_usbdev(interface), |
339 | usb_rcvintpipe(interface_to_usbdev(interface), |
340 | dev->interrupt_in_endpoint->bEndpointAddress), |
341 | transfer_buffer: dev->interrupt_in_buffer, |
342 | buffer_length: dev->interrupt_in_endpoint_size, |
343 | complete_fn: ld_usb_interrupt_in_callback, |
344 | context: dev, |
345 | interval: dev->interrupt_in_interval); |
346 | |
347 | dev->interrupt_in_running = 1; |
348 | dev->interrupt_in_done = 0; |
349 | |
350 | retval = usb_submit_urb(urb: dev->interrupt_in_urb, GFP_KERNEL); |
351 | if (retval) { |
352 | dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n" , retval); |
353 | dev->interrupt_in_running = 0; |
354 | dev->open_count = 0; |
355 | goto unlock_exit; |
356 | } |
357 | |
358 | /* save device in the file's private structure */ |
359 | file->private_data = dev; |
360 | |
361 | unlock_exit: |
362 | mutex_unlock(lock: &dev->mutex); |
363 | |
364 | return retval; |
365 | } |
366 | |
367 | /* |
368 | * ld_usb_release |
369 | */ |
370 | static int ld_usb_release(struct inode *inode, struct file *file) |
371 | { |
372 | struct ld_usb *dev; |
373 | int retval = 0; |
374 | |
375 | dev = file->private_data; |
376 | |
377 | if (dev == NULL) { |
378 | retval = -ENODEV; |
379 | goto exit; |
380 | } |
381 | |
382 | mutex_lock(&dev->mutex); |
383 | |
384 | if (dev->open_count != 1) { |
385 | retval = -ENODEV; |
386 | goto unlock_exit; |
387 | } |
388 | if (dev->disconnected) { |
389 | /* the device was unplugged before the file was released */ |
390 | mutex_unlock(lock: &dev->mutex); |
391 | /* unlock here as ld_usb_delete frees dev */ |
392 | ld_usb_delete(dev); |
393 | goto exit; |
394 | } |
395 | |
396 | /* wait until write transfer is finished */ |
397 | if (dev->interrupt_out_busy) |
398 | wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ); |
399 | ld_usb_abort_transfers(dev); |
400 | dev->open_count = 0; |
401 | |
402 | unlock_exit: |
403 | mutex_unlock(lock: &dev->mutex); |
404 | |
405 | exit: |
406 | return retval; |
407 | } |
408 | |
409 | /* |
410 | * ld_usb_poll |
411 | */ |
412 | static __poll_t ld_usb_poll(struct file *file, poll_table *wait) |
413 | { |
414 | struct ld_usb *dev; |
415 | __poll_t mask = 0; |
416 | |
417 | dev = file->private_data; |
418 | |
419 | if (dev->disconnected) |
420 | return EPOLLERR | EPOLLHUP; |
421 | |
422 | poll_wait(filp: file, wait_address: &dev->read_wait, p: wait); |
423 | poll_wait(filp: file, wait_address: &dev->write_wait, p: wait); |
424 | |
425 | if (dev->ring_head != dev->ring_tail) |
426 | mask |= EPOLLIN | EPOLLRDNORM; |
427 | if (!dev->interrupt_out_busy) |
428 | mask |= EPOLLOUT | EPOLLWRNORM; |
429 | |
430 | return mask; |
431 | } |
432 | |
433 | /* |
434 | * ld_usb_read |
435 | */ |
436 | static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count, |
437 | loff_t *ppos) |
438 | { |
439 | struct ld_usb *dev; |
440 | size_t *actual_buffer; |
441 | size_t bytes_to_read; |
442 | int retval = 0; |
443 | int rv; |
444 | |
445 | dev = file->private_data; |
446 | |
447 | /* verify that we actually have some data to read */ |
448 | if (count == 0) |
449 | goto exit; |
450 | |
451 | /* lock this object */ |
452 | if (mutex_lock_interruptible(&dev->mutex)) { |
453 | retval = -ERESTARTSYS; |
454 | goto exit; |
455 | } |
456 | |
457 | /* verify that the device wasn't unplugged */ |
458 | if (dev->disconnected) { |
459 | retval = -ENODEV; |
460 | printk(KERN_ERR "ldusb: No device or device unplugged %d\n" , retval); |
461 | goto unlock_exit; |
462 | } |
463 | |
464 | /* wait for data */ |
465 | spin_lock_irq(lock: &dev->rbsl); |
466 | while (dev->ring_head == dev->ring_tail) { |
467 | dev->interrupt_in_done = 0; |
468 | spin_unlock_irq(lock: &dev->rbsl); |
469 | if (file->f_flags & O_NONBLOCK) { |
470 | retval = -EAGAIN; |
471 | goto unlock_exit; |
472 | } |
473 | retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done); |
474 | if (retval < 0) |
475 | goto unlock_exit; |
476 | |
477 | spin_lock_irq(lock: &dev->rbsl); |
478 | } |
479 | spin_unlock_irq(lock: &dev->rbsl); |
480 | |
481 | /* actual_buffer contains actual_length + interrupt_in_buffer */ |
482 | actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_tail * (sizeof(size_t)+dev->interrupt_in_endpoint_size)); |
483 | if (*actual_buffer > dev->interrupt_in_endpoint_size) { |
484 | retval = -EIO; |
485 | goto unlock_exit; |
486 | } |
487 | bytes_to_read = min(count, *actual_buffer); |
488 | if (bytes_to_read < *actual_buffer) |
489 | dev_warn(&dev->intf->dev, "Read buffer overflow, %zu bytes dropped\n" , |
490 | *actual_buffer-bytes_to_read); |
491 | |
492 | /* copy one interrupt_in_buffer from ring_buffer into userspace */ |
493 | if (copy_to_user(to: buffer, from: actual_buffer+1, n: bytes_to_read)) { |
494 | retval = -EFAULT; |
495 | goto unlock_exit; |
496 | } |
497 | retval = bytes_to_read; |
498 | |
499 | spin_lock_irq(lock: &dev->rbsl); |
500 | dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size; |
501 | |
502 | if (dev->buffer_overflow) { |
503 | dev->buffer_overflow = 0; |
504 | spin_unlock_irq(lock: &dev->rbsl); |
505 | rv = usb_submit_urb(urb: dev->interrupt_in_urb, GFP_KERNEL); |
506 | if (rv < 0) |
507 | dev->buffer_overflow = 1; |
508 | } else { |
509 | spin_unlock_irq(lock: &dev->rbsl); |
510 | } |
511 | |
512 | unlock_exit: |
513 | /* unlock the device */ |
514 | mutex_unlock(lock: &dev->mutex); |
515 | |
516 | exit: |
517 | return retval; |
518 | } |
519 | |
520 | /* |
521 | * ld_usb_write |
522 | */ |
523 | static ssize_t ld_usb_write(struct file *file, const char __user *buffer, |
524 | size_t count, loff_t *ppos) |
525 | { |
526 | struct ld_usb *dev; |
527 | size_t bytes_to_write; |
528 | int retval = 0; |
529 | |
530 | dev = file->private_data; |
531 | |
532 | /* verify that we actually have some data to write */ |
533 | if (count == 0) |
534 | goto exit; |
535 | |
536 | /* lock this object */ |
537 | if (mutex_lock_interruptible(&dev->mutex)) { |
538 | retval = -ERESTARTSYS; |
539 | goto exit; |
540 | } |
541 | |
542 | /* verify that the device wasn't unplugged */ |
543 | if (dev->disconnected) { |
544 | retval = -ENODEV; |
545 | printk(KERN_ERR "ldusb: No device or device unplugged %d\n" , retval); |
546 | goto unlock_exit; |
547 | } |
548 | |
549 | /* wait until previous transfer is finished */ |
550 | if (dev->interrupt_out_busy) { |
551 | if (file->f_flags & O_NONBLOCK) { |
552 | retval = -EAGAIN; |
553 | goto unlock_exit; |
554 | } |
555 | retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy); |
556 | if (retval < 0) { |
557 | goto unlock_exit; |
558 | } |
559 | } |
560 | |
561 | /* write the data into interrupt_out_buffer from userspace */ |
562 | bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size); |
563 | if (bytes_to_write < count) |
564 | dev_warn(&dev->intf->dev, "Write buffer overflow, %zu bytes dropped\n" , |
565 | count - bytes_to_write); |
566 | dev_dbg(&dev->intf->dev, "%s: count = %zu, bytes_to_write = %zu\n" , |
567 | __func__, count, bytes_to_write); |
568 | |
569 | if (copy_from_user(to: dev->interrupt_out_buffer, from: buffer, n: bytes_to_write)) { |
570 | retval = -EFAULT; |
571 | goto unlock_exit; |
572 | } |
573 | |
574 | if (dev->interrupt_out_endpoint == NULL) { |
575 | /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */ |
576 | retval = usb_control_msg(interface_to_usbdev(dev->intf), |
577 | usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0), |
578 | request: 9, |
579 | USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT, |
580 | value: 1 << 8, index: 0, |
581 | data: dev->interrupt_out_buffer, |
582 | size: bytes_to_write, |
583 | USB_CTRL_SET_TIMEOUT); |
584 | if (retval < 0) |
585 | dev_err(&dev->intf->dev, |
586 | "Couldn't submit HID_REQ_SET_REPORT %d\n" , |
587 | retval); |
588 | goto unlock_exit; |
589 | } |
590 | |
591 | /* send off the urb */ |
592 | usb_fill_int_urb(urb: dev->interrupt_out_urb, |
593 | interface_to_usbdev(dev->intf), |
594 | usb_sndintpipe(interface_to_usbdev(dev->intf), |
595 | dev->interrupt_out_endpoint->bEndpointAddress), |
596 | transfer_buffer: dev->interrupt_out_buffer, |
597 | buffer_length: bytes_to_write, |
598 | complete_fn: ld_usb_interrupt_out_callback, |
599 | context: dev, |
600 | interval: dev->interrupt_out_interval); |
601 | |
602 | dev->interrupt_out_busy = 1; |
603 | wmb(); |
604 | |
605 | retval = usb_submit_urb(urb: dev->interrupt_out_urb, GFP_KERNEL); |
606 | if (retval) { |
607 | dev->interrupt_out_busy = 0; |
608 | dev_err(&dev->intf->dev, |
609 | "Couldn't submit interrupt_out_urb %d\n" , retval); |
610 | goto unlock_exit; |
611 | } |
612 | retval = bytes_to_write; |
613 | |
614 | unlock_exit: |
615 | /* unlock the device */ |
616 | mutex_unlock(lock: &dev->mutex); |
617 | |
618 | exit: |
619 | return retval; |
620 | } |
621 | |
622 | /* file operations needed when we register this driver */ |
623 | static const struct file_operations ld_usb_fops = { |
624 | .owner = THIS_MODULE, |
625 | .read = ld_usb_read, |
626 | .write = ld_usb_write, |
627 | .open = ld_usb_open, |
628 | .release = ld_usb_release, |
629 | .poll = ld_usb_poll, |
630 | .llseek = no_llseek, |
631 | }; |
632 | |
633 | /* |
634 | * usb class driver info in order to get a minor number from the usb core, |
635 | * and to have the device registered with the driver core |
636 | */ |
637 | static struct usb_class_driver ld_usb_class = { |
638 | .name = "ldusb%d" , |
639 | .fops = &ld_usb_fops, |
640 | .minor_base = USB_LD_MINOR_BASE, |
641 | }; |
642 | |
643 | /* |
644 | * ld_usb_probe |
645 | * |
646 | * Called by the usb core when a new device is connected that it thinks |
647 | * this driver might be interested in. |
648 | */ |
649 | static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id) |
650 | { |
651 | struct usb_device *udev = interface_to_usbdev(intf); |
652 | struct ld_usb *dev = NULL; |
653 | struct usb_host_interface *iface_desc; |
654 | char *buffer; |
655 | int retval = -ENOMEM; |
656 | int res; |
657 | |
658 | /* allocate memory for our device state and initialize it */ |
659 | |
660 | dev = kzalloc(size: sizeof(*dev), GFP_KERNEL); |
661 | if (!dev) |
662 | goto exit; |
663 | mutex_init(&dev->mutex); |
664 | spin_lock_init(&dev->rbsl); |
665 | dev->intf = intf; |
666 | init_waitqueue_head(&dev->read_wait); |
667 | init_waitqueue_head(&dev->write_wait); |
668 | |
669 | /* workaround for early firmware versions on fast computers */ |
670 | if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) && |
671 | ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) || |
672 | (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) && |
673 | (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) { |
674 | buffer = kmalloc(size: 256, GFP_KERNEL); |
675 | if (!buffer) |
676 | goto error; |
677 | /* usb_string makes SETUP+STALL to leave always ControlReadLoop */ |
678 | usb_string(dev: udev, index: 255, buf: buffer, size: 256); |
679 | kfree(objp: buffer); |
680 | } |
681 | |
682 | iface_desc = intf->cur_altsetting; |
683 | |
684 | res = usb_find_last_int_in_endpoint(alt: iface_desc, |
685 | int_in: &dev->interrupt_in_endpoint); |
686 | if (res) { |
687 | dev_err(&intf->dev, "Interrupt in endpoint not found\n" ); |
688 | retval = res; |
689 | goto error; |
690 | } |
691 | |
692 | res = usb_find_last_int_out_endpoint(alt: iface_desc, |
693 | int_out: &dev->interrupt_out_endpoint); |
694 | if (res) |
695 | dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n" ); |
696 | |
697 | dev->interrupt_in_endpoint_size = usb_endpoint_maxp(epd: dev->interrupt_in_endpoint); |
698 | dev->ring_buffer = kcalloc(n: ring_buffer_size, |
699 | size: sizeof(size_t) + dev->interrupt_in_endpoint_size, |
700 | GFP_KERNEL); |
701 | if (!dev->ring_buffer) |
702 | goto error; |
703 | dev->interrupt_in_buffer = kmalloc(size: dev->interrupt_in_endpoint_size, GFP_KERNEL); |
704 | if (!dev->interrupt_in_buffer) |
705 | goto error; |
706 | dev->interrupt_in_urb = usb_alloc_urb(iso_packets: 0, GFP_KERNEL); |
707 | if (!dev->interrupt_in_urb) |
708 | goto error; |
709 | dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? usb_endpoint_maxp(epd: dev->interrupt_out_endpoint) : |
710 | udev->descriptor.bMaxPacketSize0; |
711 | dev->interrupt_out_buffer = |
712 | kmalloc_array(n: write_buffer_size, |
713 | size: dev->interrupt_out_endpoint_size, GFP_KERNEL); |
714 | if (!dev->interrupt_out_buffer) |
715 | goto error; |
716 | dev->interrupt_out_urb = usb_alloc_urb(iso_packets: 0, GFP_KERNEL); |
717 | if (!dev->interrupt_out_urb) |
718 | goto error; |
719 | dev->interrupt_in_interval = max_t(int, min_interrupt_in_interval, |
720 | dev->interrupt_in_endpoint->bInterval); |
721 | if (dev->interrupt_out_endpoint) |
722 | dev->interrupt_out_interval = max_t(int, min_interrupt_out_interval, |
723 | dev->interrupt_out_endpoint->bInterval); |
724 | |
725 | /* we can register the device now, as it is ready */ |
726 | usb_set_intfdata(intf, data: dev); |
727 | |
728 | retval = usb_register_dev(intf, class_driver: &ld_usb_class); |
729 | if (retval) { |
730 | /* something prevented us from registering this driver */ |
731 | dev_err(&intf->dev, "Not able to get a minor for this device.\n" ); |
732 | usb_set_intfdata(intf, NULL); |
733 | goto error; |
734 | } |
735 | |
736 | /* let the user know what node this device is now attached to */ |
737 | dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n" , |
738 | (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor); |
739 | |
740 | exit: |
741 | return retval; |
742 | |
743 | error: |
744 | ld_usb_delete(dev); |
745 | |
746 | return retval; |
747 | } |
748 | |
749 | /* |
750 | * ld_usb_disconnect |
751 | * |
752 | * Called by the usb core when the device is removed from the system. |
753 | */ |
754 | static void ld_usb_disconnect(struct usb_interface *intf) |
755 | { |
756 | struct ld_usb *dev; |
757 | int minor; |
758 | |
759 | dev = usb_get_intfdata(intf); |
760 | usb_set_intfdata(intf, NULL); |
761 | |
762 | minor = intf->minor; |
763 | |
764 | /* give back our minor */ |
765 | usb_deregister_dev(intf, class_driver: &ld_usb_class); |
766 | |
767 | usb_poison_urb(urb: dev->interrupt_in_urb); |
768 | usb_poison_urb(urb: dev->interrupt_out_urb); |
769 | |
770 | mutex_lock(&dev->mutex); |
771 | |
772 | /* if the device is not opened, then we clean up right now */ |
773 | if (!dev->open_count) { |
774 | mutex_unlock(lock: &dev->mutex); |
775 | ld_usb_delete(dev); |
776 | } else { |
777 | dev->disconnected = 1; |
778 | /* wake up pollers */ |
779 | wake_up_interruptible_all(&dev->read_wait); |
780 | wake_up_interruptible_all(&dev->write_wait); |
781 | mutex_unlock(lock: &dev->mutex); |
782 | } |
783 | |
784 | dev_info(&intf->dev, "LD USB Device #%d now disconnected\n" , |
785 | (minor - USB_LD_MINOR_BASE)); |
786 | } |
787 | |
788 | /* usb specific object needed to register this driver with the usb subsystem */ |
789 | static struct usb_driver ld_usb_driver = { |
790 | .name = "ldusb" , |
791 | .probe = ld_usb_probe, |
792 | .disconnect = ld_usb_disconnect, |
793 | .id_table = ld_usb_table, |
794 | }; |
795 | |
796 | module_usb_driver(ld_usb_driver); |
797 | |
798 | |