1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * HID driver for UC-Logic devices not fully compliant with HID standard
4 * - tablet initialization and parameter retrieval
5 *
6 * Copyright (c) 2018 Nikolai Kondrashov
7 */
8
9 /*
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the Free
12 * Software Foundation; either version 2 of the License, or (at your option)
13 * any later version.
14 */
15
16 #include "hid-uclogic-params.h"
17 #include "hid-uclogic-rdesc.h"
18 #include "usbhid/usbhid.h"
19 #include "hid-ids.h"
20 #include <linux/ctype.h>
21 #include <asm/unaligned.h>
22
23 /**
24 * Convert a pen in-range reporting type to a string.
25 *
26 * @inrange: The in-range reporting type to convert.
27 *
28 * Returns:
29 * The string representing the type, or NULL if the type is unknown.
30 */
31 const char *uclogic_params_pen_inrange_to_str(
32 enum uclogic_params_pen_inrange inrange)
33 {
34 switch (inrange) {
35 case UCLOGIC_PARAMS_PEN_INRANGE_NORMAL:
36 return "normal";
37 case UCLOGIC_PARAMS_PEN_INRANGE_INVERTED:
38 return "inverted";
39 case UCLOGIC_PARAMS_PEN_INRANGE_NONE:
40 return "none";
41 default:
42 return NULL;
43 }
44 }
45
46 /**
47 * uclogic_params_get_str_desc - retrieve a string descriptor from a HID
48 * device interface, putting it into a kmalloc-allocated buffer as is, without
49 * character encoding conversion.
50 *
51 * @pbuf: Location for the kmalloc-allocated buffer pointer containing
52 * the retrieved descriptor. Not modified in case of error.
53 * Can be NULL to have retrieved descriptor discarded.
54 * @hdev: The HID device of the tablet interface to retrieve the string
55 * descriptor from. Cannot be NULL.
56 * @idx: Index of the string descriptor to request from the device.
57 * @len: Length of the buffer to allocate and the data to retrieve.
58 *
59 * Returns:
60 * number of bytes retrieved (<= len),
61 * -EPIPE, if the descriptor was not found, or
62 * another negative errno code in case of other error.
63 */
64 static int uclogic_params_get_str_desc(__u8 **pbuf, struct hid_device *hdev,
65 __u8 idx, size_t len)
66 {
67 int rc;
68 struct usb_device *udev = hid_to_usb_dev(hdev);
69 __u8 *buf = NULL;
70
71 /* Check arguments */
72 if (hdev == NULL) {
73 rc = -EINVAL;
74 goto cleanup;
75 }
76
77 buf = kmalloc(len, GFP_KERNEL);
78 if (buf == NULL) {
79 rc = -ENOMEM;
80 goto cleanup;
81 }
82
83 rc = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
84 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
85 (USB_DT_STRING << 8) + idx,
86 0x0409, buf, len,
87 USB_CTRL_GET_TIMEOUT);
88 if (rc == -EPIPE) {
89 hid_dbg(hdev, "string descriptor #%hhu not found\n", idx);
90 goto cleanup;
91 } else if (rc < 0) {
92 hid_err(hdev,
93 "failed retrieving string descriptor #%hhu: %d\n",
94 idx, rc);
95 goto cleanup;
96 }
97
98 if (pbuf != NULL) {
99 *pbuf = buf;
100 buf = NULL;
101 }
102
103 cleanup:
104 kfree(buf);
105 return rc;
106 }
107
108 /**
109 * uclogic_params_pen_cleanup - free resources used by struct
110 * uclogic_params_pen (tablet interface's pen input parameters).
111 * Can be called repeatedly.
112 *
113 * @pen: Pen input parameters to cleanup. Cannot be NULL.
114 */
115 static void uclogic_params_pen_cleanup(struct uclogic_params_pen *pen)
116 {
117 kfree(pen->desc_ptr);
118 memset(pen, 0, sizeof(*pen));
119 }
120
121 /**
122 * uclogic_params_pen_init_v1() - initialize tablet interface pen
123 * input and retrieve its parameters from the device, using v1 protocol.
124 *
125 * @pen: Pointer to the pen parameters to initialize (to be
126 * cleaned up with uclogic_params_pen_cleanup()). Not modified in
127 * case of error, or if parameters are not found. Cannot be NULL.
128 * @pfound: Location for a flag which is set to true if the parameters
129 * were found, and to false if not (e.g. device was
130 * incompatible). Not modified in case of error. Cannot be NULL.
131 * @hdev: The HID device of the tablet interface to initialize and get
132 * parameters from. Cannot be NULL.
133 *
134 * Returns:
135 * Zero, if successful. A negative errno code on error.
136 */
137 static int uclogic_params_pen_init_v1(struct uclogic_params_pen *pen,
138 bool *pfound,
139 struct hid_device *hdev)
140 {
141 int rc;
142 bool found = false;
143 /* Buffer for (part of) the string descriptor */
144 __u8 *buf = NULL;
145 /* Minimum descriptor length required, maximum seen so far is 18 */
146 const int len = 12;
147 s32 resolution;
148 /* Pen report descriptor template parameters */
149 s32 desc_params[UCLOGIC_RDESC_PEN_PH_ID_NUM];
150 __u8 *desc_ptr = NULL;
151
152 /* Check arguments */
153 if (pen == NULL || pfound == NULL || hdev == NULL) {
154 rc = -EINVAL;
155 goto cleanup;
156 }
157
158 /*
159 * Read string descriptor containing pen input parameters.
160 * The specific string descriptor and data were discovered by sniffing
161 * the Windows driver traffic.
162 * NOTE: This enables fully-functional tablet mode.
163 */
164 rc = uclogic_params_get_str_desc(&buf, hdev, 100, len);
165 if (rc == -EPIPE) {
166 hid_dbg(hdev,
167 "string descriptor with pen parameters not found, assuming not compatible\n");
168 goto finish;
169 } else if (rc < 0) {
170 hid_err(hdev, "failed retrieving pen parameters: %d\n", rc);
171 goto cleanup;
172 } else if (rc != len) {
173 hid_dbg(hdev,
174 "string descriptor with pen parameters has invalid length (got %d, expected %d), assuming not compatible\n",
175 rc, len);
176 goto finish;
177 }
178
179 /*
180 * Fill report descriptor parameters from the string descriptor
181 */
182 desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_LM] =
183 get_unaligned_le16(buf + 2);
184 desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] =
185 get_unaligned_le16(buf + 4);
186 desc_params[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM] =
187 get_unaligned_le16(buf + 8);
188 resolution = get_unaligned_le16(buf + 10);
189 if (resolution == 0) {
190 desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_PM] = 0;
191 desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] = 0;
192 } else {
193 desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_PM] =
194 desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_LM] * 1000 /
195 resolution;
196 desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] =
197 desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] * 1000 /
198 resolution;
199 }
200 kfree(buf);
201 buf = NULL;
202
203 /*
204 * Generate pen report descriptor
205 */
206 desc_ptr = uclogic_rdesc_template_apply(
207 uclogic_rdesc_pen_v1_template_arr,
208 uclogic_rdesc_pen_v1_template_size,
209 desc_params, ARRAY_SIZE(desc_params));
210 if (desc_ptr == NULL) {
211 rc = -ENOMEM;
212 goto cleanup;
213 }
214
215 /*
216 * Fill-in the parameters
217 */
218 memset(pen, 0, sizeof(*pen));
219 pen->desc_ptr = desc_ptr;
220 desc_ptr = NULL;
221 pen->desc_size = uclogic_rdesc_pen_v1_template_size;
222 pen->id = UCLOGIC_RDESC_PEN_V1_ID;
223 pen->inrange = UCLOGIC_PARAMS_PEN_INRANGE_INVERTED;
224 found = true;
225 finish:
226 *pfound = found;
227 rc = 0;
228 cleanup:
229 kfree(desc_ptr);
230 kfree(buf);
231 return rc;
232 }
233
234 /**
235 * uclogic_params_get_le24() - get a 24-bit little-endian number from a
236 * buffer.
237 *
238 * @p: The pointer to the number buffer.
239 *
240 * Returns:
241 * The retrieved number
242 */
243 static s32 uclogic_params_get_le24(const void *p)
244 {
245 const __u8 *b = p;
246 return b[0] | (b[1] << 8UL) | (b[2] << 16UL);
247 }
248
249 /**
250 * uclogic_params_pen_init_v2() - initialize tablet interface pen
251 * input and retrieve its parameters from the device, using v2 protocol.
252 *
253 * @pen: Pointer to the pen parameters to initialize (to be
254 * cleaned up with uclogic_params_pen_cleanup()). Not modified in
255 * case of error, or if parameters are not found. Cannot be NULL.
256 * @pfound: Location for a flag which is set to true if the parameters
257 * were found, and to false if not (e.g. device was
258 * incompatible). Not modified in case of error. Cannot be NULL.
259 * @hdev: The HID device of the tablet interface to initialize and get
260 * parameters from. Cannot be NULL.
261 *
262 * Returns:
263 * Zero, if successful. A negative errno code on error.
264 */
265 static int uclogic_params_pen_init_v2(struct uclogic_params_pen *pen,
266 bool *pfound,
267 struct hid_device *hdev)
268 {
269 int rc;
270 bool found = false;
271 /* Buffer for (part of) the string descriptor */
272 __u8 *buf = NULL;
273 /* Descriptor length required */
274 const int len = 18;
275 s32 resolution;
276 /* Pen report descriptor template parameters */
277 s32 desc_params[UCLOGIC_RDESC_PEN_PH_ID_NUM];
278 __u8 *desc_ptr = NULL;
279
280 /* Check arguments */
281 if (pen == NULL || pfound == NULL || hdev == NULL) {
282 rc = -EINVAL;
283 goto cleanup;
284 }
285
286 /*
287 * Read string descriptor containing pen input parameters.
288 * The specific string descriptor and data were discovered by sniffing
289 * the Windows driver traffic.
290 * NOTE: This enables fully-functional tablet mode.
291 */
292 rc = uclogic_params_get_str_desc(&buf, hdev, 200, len);
293 if (rc == -EPIPE) {
294 hid_dbg(hdev,
295 "string descriptor with pen parameters not found, assuming not compatible\n");
296 goto finish;
297 } else if (rc < 0) {
298 hid_err(hdev, "failed retrieving pen parameters: %d\n", rc);
299 goto cleanup;
300 } else if (rc != len) {
301 hid_dbg(hdev,
302 "string descriptor with pen parameters has invalid length (got %d, expected %d), assuming not compatible\n",
303 rc, len);
304 goto finish;
305 } else {
306 size_t i;
307 /*
308 * Check it's not just a catch-all UTF-16LE-encoded ASCII
309 * string (such as the model name) some tablets put into all
310 * unknown string descriptors.
311 */
312 for (i = 2;
313 i < len &&
314 (buf[i] >= 0x20 && buf[i] < 0x7f && buf[i + 1] == 0);
315 i += 2);
316 if (i >= len) {
317 hid_dbg(hdev,
318 "string descriptor with pen parameters seems to contain only text, assuming not compatible\n");
319 goto finish;
320 }
321 }
322
323 /*
324 * Fill report descriptor parameters from the string descriptor
325 */
326 desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_LM] =
327 uclogic_params_get_le24(buf + 2);
328 desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] =
329 uclogic_params_get_le24(buf + 5);
330 desc_params[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM] =
331 get_unaligned_le16(buf + 8);
332 resolution = get_unaligned_le16(buf + 10);
333 if (resolution == 0) {
334 desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_PM] = 0;
335 desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] = 0;
336 } else {
337 desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_PM] =
338 desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_LM] * 1000 /
339 resolution;
340 desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] =
341 desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] * 1000 /
342 resolution;
343 }
344 kfree(buf);
345 buf = NULL;
346
347 /*
348 * Generate pen report descriptor
349 */
350 desc_ptr = uclogic_rdesc_template_apply(
351 uclogic_rdesc_pen_v2_template_arr,
352 uclogic_rdesc_pen_v2_template_size,
353 desc_params, ARRAY_SIZE(desc_params));
354 if (desc_ptr == NULL) {
355 rc = -ENOMEM;
356 goto cleanup;
357 }
358
359 /*
360 * Fill-in the parameters
361 */
362 memset(pen, 0, sizeof(*pen));
363 pen->desc_ptr = desc_ptr;
364 desc_ptr = NULL;
365 pen->desc_size = uclogic_rdesc_pen_v2_template_size;
366 pen->id = UCLOGIC_RDESC_PEN_V2_ID;
367 pen->inrange = UCLOGIC_PARAMS_PEN_INRANGE_NONE;
368 pen->fragmented_hires = true;
369 found = true;
370 finish:
371 *pfound = found;
372 rc = 0;
373 cleanup:
374 kfree(desc_ptr);
375 kfree(buf);
376 return rc;
377 }
378
379 /**
380 * uclogic_params_frame_cleanup - free resources used by struct
381 * uclogic_params_frame (tablet interface's frame controls input parameters).
382 * Can be called repeatedly.
383 *
384 * @frame: Frame controls input parameters to cleanup. Cannot be NULL.
385 */
386 static void uclogic_params_frame_cleanup(struct uclogic_params_frame *frame)
387 {
388 kfree(frame->desc_ptr);
389 memset(frame, 0, sizeof(*frame));
390 }
391
392 /**
393 * uclogic_params_frame_init_with_desc() - initialize tablet's frame control
394 * parameters with a static report descriptor.
395 *
396 * @frame: Pointer to the frame parameters to initialize (to be cleaned
397 * up with uclogic_params_frame_cleanup()). Not modified in case
398 * of error. Cannot be NULL.
399 * @desc_ptr: Report descriptor pointer. Can be NULL, if desc_size is zero.
400 * @desc_size: Report descriptor size.
401 * @id: Report ID used for frame reports, if they should be tweaked,
402 * zero if not.
403 *
404 * Returns:
405 * Zero, if successful. A negative errno code on error.
406 */
407 static int uclogic_params_frame_init_with_desc(
408 struct uclogic_params_frame *frame,
409 const __u8 *desc_ptr,
410 size_t desc_size,
411 unsigned int id)
412 {
413 __u8 *copy_desc_ptr;
414
415 if (frame == NULL || (desc_ptr == NULL && desc_size != 0))
416 return -EINVAL;
417
418 copy_desc_ptr = kmemdup(desc_ptr, desc_size, GFP_KERNEL);
419 if (copy_desc_ptr == NULL)
420 return -ENOMEM;
421
422 memset(frame, 0, sizeof(*frame));
423 frame->desc_ptr = copy_desc_ptr;
424 frame->desc_size = desc_size;
425 frame->id = id;
426 return 0;
427 }
428
429 /**
430 * uclogic_params_frame_init_v1_buttonpad() - initialize abstract buttonpad
431 * on a v1 tablet interface.
432 *
433 * @frame: Pointer to the frame parameters to initialize (to be cleaned
434 * up with uclogic_params_frame_cleanup()). Not modified in case
435 * of error, or if parameters are not found. Cannot be NULL.
436 * @pfound: Location for a flag which is set to true if the parameters
437 * were found, and to false if not (e.g. device was
438 * incompatible). Not modified in case of error. Cannot be NULL.
439 * @hdev: The HID device of the tablet interface to initialize and get
440 * parameters from. Cannot be NULL.
441 *
442 * Returns:
443 * Zero, if successful. A negative errno code on error.
444 */
445 static int uclogic_params_frame_init_v1_buttonpad(
446 struct uclogic_params_frame *frame,
447 bool *pfound,
448 struct hid_device *hdev)
449 {
450 int rc;
451 bool found = false;
452 struct usb_device *usb_dev = hid_to_usb_dev(hdev);
453 char *str_buf = NULL;
454 const size_t str_len = 16;
455
456 /* Check arguments */
457 if (frame == NULL || pfound == NULL || hdev == NULL) {
458 rc = -EINVAL;
459 goto cleanup;
460 }
461
462 /*
463 * Enable generic button mode
464 */
465 str_buf = kzalloc(str_len, GFP_KERNEL);
466 if (str_buf == NULL) {
467 rc = -ENOMEM;
468 goto cleanup;
469 }
470
471 rc = usb_string(usb_dev, 123, str_buf, str_len);
472 if (rc == -EPIPE) {
473 hid_dbg(hdev,
474 "generic button -enabling string descriptor not found\n");
475 } else if (rc < 0) {
476 goto cleanup;
477 } else if (strncmp(str_buf, "HK On", rc) != 0) {
478 hid_dbg(hdev,
479 "invalid response to enabling generic buttons: \"%s\"\n",
480 str_buf);
481 } else {
482 hid_dbg(hdev, "generic buttons enabled\n");
483 rc = uclogic_params_frame_init_with_desc(
484 frame,
485 uclogic_rdesc_buttonpad_v1_arr,
486 uclogic_rdesc_buttonpad_v1_size,
487 UCLOGIC_RDESC_BUTTONPAD_V1_ID);
488 if (rc != 0)
489 goto cleanup;
490 found = true;
491 }
492
493 *pfound = found;
494 rc = 0;
495 cleanup:
496 kfree(str_buf);
497 return rc;
498 }
499
500 /**
501 * uclogic_params_cleanup - free resources used by struct uclogic_params
502 * (tablet interface's parameters).
503 * Can be called repeatedly.
504 *
505 * @params: Input parameters to cleanup. Cannot be NULL.
506 */
507 void uclogic_params_cleanup(struct uclogic_params *params)
508 {
509 if (!params->invalid) {
510 kfree(params->desc_ptr);
511 if (!params->pen_unused)
512 uclogic_params_pen_cleanup(¶ms->pen);
513 uclogic_params_frame_cleanup(¶ms->frame);
514 memset(params, 0, sizeof(*params));
515 }
516 }
517
518 /**
519 * Get a replacement report descriptor for a tablet's interface.
520 *
521 * @params: The parameters of a tablet interface to get report
522 * descriptor for. Cannot be NULL.
523 * @pdesc: Location for the resulting, kmalloc-allocated report
524 * descriptor pointer, or for NULL, if there's no replacement
525 * report descriptor. Not modified in case of error. Cannot be
526 * NULL.
527 * @psize: Location for the resulting report descriptor size, not set if
528 * there's no replacement report descriptor. Not modified in case
529 * of error. Cannot be NULL.
530 *
531 * Returns:
532 * Zero, if successful.
533 * -EINVAL, if invalid arguments are supplied.
534 * -ENOMEM, if failed to allocate memory.
535 */
536 int uclogic_params_get_desc(const struct uclogic_params *params,
537 __u8 **pdesc,
538 unsigned int *psize)
539 {
540 bool common_present;
541 bool pen_present;
542 bool frame_present;
543 unsigned int size;
544 __u8 *desc = NULL;
545
546 /* Check arguments */
547 if (params == NULL || pdesc == NULL || psize == NULL)
548 return -EINVAL;
549
550 size = 0;
551
552 common_present = (params->desc_ptr != NULL);
553 pen_present = (!params->pen_unused && params->pen.desc_ptr != NULL);
554 frame_present = (params->frame.desc_ptr != NULL);
555
556 if (common_present)
557 size += params->desc_size;
558 if (pen_present)
559 size += params->pen.desc_size;
560 if (frame_present)
561 size += params->frame.desc_size;
562
563 if (common_present || pen_present || frame_present) {
564 __u8 *p;
565
566 desc = kmalloc(size, GFP_KERNEL);
567 if (desc == NULL)
568 return -ENOMEM;
569 p = desc;
570
571 if (common_present) {
572 memcpy(p, params->desc_ptr,
573 params->desc_size);
574 p += params->desc_size;
575 }
576 if (pen_present) {
577 memcpy(p, params->pen.desc_ptr,
578 params->pen.desc_size);
579 p += params->pen.desc_size;
580 }
581 if (frame_present) {
582 memcpy(p, params->frame.desc_ptr,
583 params->frame.desc_size);
584 p += params->frame.desc_size;
585 }
586
587 WARN_ON(p != desc + size);
588
589 *psize = size;
590 }
591
592 *pdesc = desc;
593 return 0;
594 }
595
596 /**
597 * uclogic_params_init_invalid() - initialize tablet interface parameters,
598 * specifying the interface is invalid.
599 *
600 * @params: Parameters to initialize (to be cleaned with
601 * uclogic_params_cleanup()). Cannot be NULL.
602 */
603 static void uclogic_params_init_invalid(struct uclogic_params *params)
604 {
605 params->invalid = true;
606 }
607
608 /**
609 * uclogic_params_init_with_opt_desc() - initialize tablet interface
610 * parameters with an optional replacement report descriptor. Only modify
611 * report descriptor, if the original report descriptor matches the expected
612 * size.
613 *
614 * @params: Parameters to initialize (to be cleaned with
615 * uclogic_params_cleanup()). Not modified in case of
616 * error. Cannot be NULL.
617 * @hdev: The HID device of the tablet interface create the
618 * parameters for. Cannot be NULL.
619 * @orig_desc_size: Expected size of the original report descriptor to
620 * be replaced.
621 * @desc_ptr: Pointer to the replacement report descriptor.
622 * Can be NULL, if desc_size is zero.
623 * @desc_size: Size of the replacement report descriptor.
624 *
625 * Returns:
626 * Zero, if successful. -EINVAL if an invalid argument was passed.
627 * -ENOMEM, if failed to allocate memory.
628 */
629 static int uclogic_params_init_with_opt_desc(struct uclogic_params *params,
630 struct hid_device *hdev,
631 unsigned int orig_desc_size,
632 __u8 *desc_ptr,
633 unsigned int desc_size)
634 {
635 __u8 *desc_copy_ptr = NULL;
636 unsigned int desc_copy_size;
637 int rc;
638
639 /* Check arguments */
640 if (params == NULL || hdev == NULL ||
641 (desc_ptr == NULL && desc_size != 0)) {
642 rc = -EINVAL;
643 goto cleanup;
644 }
645
646 /* Replace report descriptor, if it matches */
647 if (hdev->dev_rsize == orig_desc_size) {
648 hid_dbg(hdev,
649 "device report descriptor matches the expected size, replacing\n");
650 desc_copy_ptr = kmemdup(desc_ptr, desc_size, GFP_KERNEL);
651 if (desc_copy_ptr == NULL) {
652 rc = -ENOMEM;
653 goto cleanup;
654 }
655 desc_copy_size = desc_size;
656 } else {
657 hid_dbg(hdev,
658 "device report descriptor doesn't match the expected size (%u != %u), preserving\n",
659 hdev->dev_rsize, orig_desc_size);
660 desc_copy_ptr = NULL;
661 desc_copy_size = 0;
662 }
663
664 /* Output parameters */
665 memset(params, 0, sizeof(*params));
666 params->desc_ptr = desc_copy_ptr;
667 desc_copy_ptr = NULL;
668 params->desc_size = desc_copy_size;
669
670 rc = 0;
671 cleanup:
672 kfree(desc_copy_ptr);
673 return rc;
674 }
675
676 /**
677 * uclogic_params_init_with_pen_unused() - initialize tablet interface
678 * parameters preserving original reports and generic HID processing, but
679 * disabling pen usage.
680 *
681 * @params: Parameters to initialize (to be cleaned with
682 * uclogic_params_cleanup()). Not modified in case of
683 * error. Cannot be NULL.
684 */
685 static void uclogic_params_init_with_pen_unused(struct uclogic_params *params)
686 {
687 memset(params, 0, sizeof(*params));
688 params->pen_unused = true;
689 }
690
691 /**
692 * uclogic_params_init() - initialize a Huion tablet interface and discover
693 * its parameters.
694 *
695 * @params: Parameters to fill in (to be cleaned with
696 * uclogic_params_cleanup()). Not modified in case of error.
697 * Cannot be NULL.
698 * @hdev: The HID device of the tablet interface to initialize and get
699 * parameters from. Cannot be NULL.
700 *
701 * Returns:
702 * Zero, if successful. A negative errno code on error.
703 */
704 static int uclogic_params_huion_init(struct uclogic_params *params,
705 struct hid_device *hdev)
706 {
707 int rc;
708 struct usb_device *udev = hid_to_usb_dev(hdev);
709 struct usb_interface *iface = to_usb_interface(hdev->dev.parent);
710 __u8 bInterfaceNumber = iface->cur_altsetting->desc.bInterfaceNumber;
711 bool found;
712 /* The resulting parameters (noop) */
713 struct uclogic_params p = {0, };
714 static const char transition_ver[] = "HUION_T153_160607";
715 char *ver_ptr = NULL;
716 const size_t ver_len = sizeof(transition_ver) + 1;
717
718 /* Check arguments */
719 if (params == NULL || hdev == NULL) {
720 rc = -EINVAL;
721 goto cleanup;
722 }
723
724 /* If it's not a pen interface */
725 if (bInterfaceNumber != 0) {
726 /* TODO: Consider marking the interface invalid */
727 uclogic_params_init_with_pen_unused(&p);
728 goto output;
729 }
730
731 /* Try to get firmware version */
732 ver_ptr = kzalloc(ver_len, GFP_KERNEL);
733 if (ver_ptr == NULL) {
734 rc = -ENOMEM;
735 goto cleanup;
736 }
737 rc = usb_string(udev, 201, ver_ptr, ver_len);
738 if (rc == -EPIPE) {
739 *ver_ptr = '\0';
740 } else if (rc < 0) {
741 hid_err(hdev,
742 "failed retrieving Huion firmware version: %d\n", rc);
743 goto cleanup;
744 }
745
746 /* If this is a transition firmware */
747 if (strcmp(ver_ptr, transition_ver) == 0) {
748 hid_dbg(hdev,
749 "transition firmware detected, not probing pen v2 parameters\n");
750 } else {
751 /* Try to probe v2 pen parameters */
752 rc = uclogic_params_pen_init_v2(&p.pen, &found, hdev);
753 if (rc != 0) {
754 hid_err(hdev,
755 "failed probing pen v2 parameters: %d\n", rc);
756 goto cleanup;
757 } else if (found) {
758 hid_dbg(hdev, "pen v2 parameters found\n");
759 /* Create v2 buttonpad parameters */
760 rc = uclogic_params_frame_init_with_desc(
761 &p.frame,
762 uclogic_rdesc_buttonpad_v2_arr,
763 uclogic_rdesc_buttonpad_v2_size,
764 UCLOGIC_RDESC_BUTTONPAD_V2_ID);
765 if (rc != 0) {
766 hid_err(hdev,
767 "failed creating v2 buttonpad parameters: %d\n",
768 rc);
769 goto cleanup;
770 }
771 /* Set bitmask marking frame reports in pen reports */
772 p.pen_frame_flag = 0x20;
773 goto output;
774 }
775 hid_dbg(hdev, "pen v2 parameters not found\n");
776 }
777
778 /* Try to probe v1 pen parameters */
779 rc = uclogic_params_pen_init_v1(&p.pen, &found, hdev);
780 if (rc != 0) {
781 hid_err(hdev,
782 "failed probing pen v1 parameters: %d\n", rc);
783 goto cleanup;
784 } else if (found) {
785 hid_dbg(hdev, "pen v1 parameters found\n");
786 /* Try to probe v1 buttonpad */
787 rc = uclogic_params_frame_init_v1_buttonpad(
788 &p.frame,
789 &found, hdev);
790 if (rc != 0) {
791 hid_err(hdev, "v1 buttonpad probing failed: %d\n", rc);
792 goto cleanup;
793 }
794 hid_dbg(hdev, "buttonpad v1 parameters%s found\n",
795 (found ? "" : " not"));
796 if (found) {
797 /* Set bitmask marking frame reports */
798 p.pen_frame_flag = 0x20;
799 }
800 goto output;
801 }
802 hid_dbg(hdev, "pen v1 parameters not found\n");
803
804 uclogic_params_init_invalid(&p);
805
806 output:
807 /* Output parameters */
808 memcpy(params, &p, sizeof(*params));
809 memset(&p, 0, sizeof(p));
810 rc = 0;
811 cleanup:
812 kfree(ver_ptr);
813 uclogic_params_cleanup(&p);
814 return rc;
815 }
816
817 /**
818 * uclogic_params_init() - initialize a tablet interface and discover its
819 * parameters.
820 *
821 * @params: Parameters to fill in (to be cleaned with
822 * uclogic_params_cleanup()). Not modified in case of error.
823 * Cannot be NULL.
824 * @hdev: The HID device of the tablet interface to initialize and get
825 * parameters from. Cannot be NULL. Must be using the USB low-level
826 * driver, i.e. be an actual USB tablet.
827 *
828 * Returns:
829 * Zero, if successful. A negative errno code on error.
830 */
831 int uclogic_params_init(struct uclogic_params *params,
832 struct hid_device *hdev)
833 {
834 int rc;
835 struct usb_device *udev = hid_to_usb_dev(hdev);
836 __u8 bNumInterfaces = udev->config->desc.bNumInterfaces;
837 struct usb_interface *iface = to_usb_interface(hdev->dev.parent);
838 __u8 bInterfaceNumber = iface->cur_altsetting->desc.bInterfaceNumber;
839 bool found;
840 /* The resulting parameters (noop) */
841 struct uclogic_params p = {0, };
842
843 /* Check arguments */
844 if (params == NULL || hdev == NULL ||
845 !hid_is_using_ll_driver(hdev, &usb_hid_driver)) {
846 rc = -EINVAL;
847 goto cleanup;
848 }
849
850 /*
851 * Set replacement report descriptor if the original matches the
852 * specified size. Otherwise keep interface unchanged.
853 */
854 #define WITH_OPT_DESC(_orig_desc_token, _new_desc_token) \
855 uclogic_params_init_with_opt_desc( \
856 &p, hdev, \
857 UCLOGIC_RDESC_##_orig_desc_token##_SIZE, \
858 uclogic_rdesc_##_new_desc_token##_arr, \
859 uclogic_rdesc_##_new_desc_token##_size)
860
861 #define VID_PID(_vid, _pid) \
862 (((__u32)(_vid) << 16) | ((__u32)(_pid) & U16_MAX))
863
864 /*
865 * Handle specific interfaces for specific tablets.
866 *
867 * Observe the following logic:
868 *
869 * If the interface is recognized as producing certain useful input:
870 * Mark interface as valid.
871 * Output interface parameters.
872 * Else, if the interface is recognized as *not* producing any useful
873 * input:
874 * Mark interface as invalid.
875 * Else:
876 * Mark interface as valid.
877 * Output noop parameters.
878 *
879 * Rule of thumb: it is better to disable a broken interface than let
880 * it spew garbage input.
881 */
882
883 switch (VID_PID(hdev->vendor, hdev->product)) {
884 case VID_PID(USB_VENDOR_ID_UCLOGIC,
885 USB_DEVICE_ID_UCLOGIC_TABLET_PF1209):
886 rc = WITH_OPT_DESC(PF1209_ORIG, pf1209_fixed);
887 if (rc != 0)
888 goto cleanup;
889 break;
890 case VID_PID(USB_VENDOR_ID_UCLOGIC,
891 USB_DEVICE_ID_UCLOGIC_TABLET_WP4030U):
892 rc = WITH_OPT_DESC(WPXXXXU_ORIG, wp4030u_fixed);
893 if (rc != 0)
894 goto cleanup;
895 break;
896 case VID_PID(USB_VENDOR_ID_UCLOGIC,
897 USB_DEVICE_ID_UCLOGIC_TABLET_WP5540U):
898 if (hdev->dev_rsize == UCLOGIC_RDESC_WP5540U_V2_ORIG_SIZE) {
899 if (bInterfaceNumber == 0) {
900 /* Try to probe v1 pen parameters */
901 rc = uclogic_params_pen_init_v1(&p.pen,
902 &found, hdev);
903 if (rc != 0) {
904 hid_err(hdev,
905 "pen probing failed: %d\n",
906 rc);
907 goto cleanup;
908 }
909 if (!found) {
910 hid_warn(hdev,
911 "pen parameters not found");
912 }
913 } else {
914 uclogic_params_init_invalid(&p);
915 }
916 } else {
917 rc = WITH_OPT_DESC(WPXXXXU_ORIG, wp5540u_fixed);
918 if (rc != 0)
919 goto cleanup;
920 }
921 break;
922 case VID_PID(USB_VENDOR_ID_UCLOGIC,
923 USB_DEVICE_ID_UCLOGIC_TABLET_WP8060U):
924 rc = WITH_OPT_DESC(WPXXXXU_ORIG, wp8060u_fixed);
925 if (rc != 0)
926 goto cleanup;
927 break;
928 case VID_PID(USB_VENDOR_ID_UCLOGIC,
929 USB_DEVICE_ID_UCLOGIC_TABLET_WP1062):
930 rc = WITH_OPT_DESC(WP1062_ORIG, wp1062_fixed);
931 if (rc != 0)
932 goto cleanup;
933 break;
934 case VID_PID(USB_VENDOR_ID_UCLOGIC,
935 USB_DEVICE_ID_UCLOGIC_WIRELESS_TABLET_TWHL850):
936 switch (bInterfaceNumber) {
937 case 0:
938 rc = WITH_OPT_DESC(TWHL850_ORIG0, twhl850_fixed0);
939 if (rc != 0)
940 goto cleanup;
941 break;
942 case 1:
943 rc = WITH_OPT_DESC(TWHL850_ORIG1, twhl850_fixed1);
944 if (rc != 0)
945 goto cleanup;
946 break;
947 case 2:
948 rc = WITH_OPT_DESC(TWHL850_ORIG2, twhl850_fixed2);
949 if (rc != 0)
950 goto cleanup;
951 break;
952 }
953 break;
954 case VID_PID(USB_VENDOR_ID_UCLOGIC,
955 USB_DEVICE_ID_UCLOGIC_TABLET_TWHA60):
956 /*
957 * If it is not a three-interface version, which is known to
958 * respond to initialization.
959 */
960 if (bNumInterfaces != 3) {
961 switch (bInterfaceNumber) {
962 case 0:
963 rc = WITH_OPT_DESC(TWHA60_ORIG0,
964 twha60_fixed0);
965 if (rc != 0)
966 goto cleanup;
967 break;
968 case 1:
969 rc = WITH_OPT_DESC(TWHA60_ORIG1,
970 twha60_fixed1);
971 if (rc != 0)
972 goto cleanup;
973 break;
974 }
975 break;
976 }
977 /* FALL THROUGH */
978 case VID_PID(USB_VENDOR_ID_HUION,
979 USB_DEVICE_ID_HUION_TABLET):
980 case VID_PID(USB_VENDOR_ID_HUION,
981 USB_DEVICE_ID_HUION_HS64):
982 case VID_PID(USB_VENDOR_ID_UCLOGIC,
983 USB_DEVICE_ID_HUION_TABLET):
984 case VID_PID(USB_VENDOR_ID_UCLOGIC,
985 USB_DEVICE_ID_YIYNOVA_TABLET):
986 case VID_PID(USB_VENDOR_ID_UCLOGIC,
987 USB_DEVICE_ID_UCLOGIC_UGEE_TABLET_81):
988 case VID_PID(USB_VENDOR_ID_UCLOGIC,
989 USB_DEVICE_ID_UCLOGIC_DRAWIMAGE_G3):
990 case VID_PID(USB_VENDOR_ID_UCLOGIC,
991 USB_DEVICE_ID_UCLOGIC_UGEE_TABLET_45):
992 case VID_PID(USB_VENDOR_ID_UCLOGIC,
993 USB_DEVICE_ID_UCLOGIC_UGEE_TABLET_47):
994 rc = uclogic_params_huion_init(&p, hdev);
995 if (rc != 0)
996 goto cleanup;
997 break;
998 case VID_PID(USB_VENDOR_ID_UGTIZER,
999 USB_DEVICE_ID_UGTIZER_TABLET_GP0610):
1000 case VID_PID(USB_VENDOR_ID_UGEE,
1001 USB_DEVICE_ID_UGEE_XPPEN_TABLET_G540):
1002 case VID_PID(USB_VENDOR_ID_UGEE,
1003 USB_DEVICE_ID_UGEE_XPPEN_TABLET_G640):
1004 case VID_PID(USB_VENDOR_ID_UGEE,
1005 USB_DEVICE_ID_UGEE_TABLET_RAINBOW_CV720):
1006 /* If this is the pen interface */
1007 if (bInterfaceNumber == 1) {
1008 /* Probe v1 pen parameters */
1009 rc = uclogic_params_pen_init_v1(&p.pen, &found, hdev);
1010 if (rc != 0) {
1011 hid_err(hdev, "pen probing failed: %d\n", rc);
1012 goto cleanup;
1013 }
1014 if (!found) {
1015 hid_warn(hdev, "pen parameters not found");
1016 uclogic_params_init_invalid(&p);
1017 }
1018 } else {
1019 /* TODO: Consider marking the interface invalid */
1020 uclogic_params_init_with_pen_unused(&p);
1021 }
1022 break;
1023 case VID_PID(USB_VENDOR_ID_UGEE,
1024 USB_DEVICE_ID_UGEE_XPPEN_TABLET_DECO01):
1025 /* If this is the pen and frame interface */
1026 if (bInterfaceNumber == 1) {
1027 /* Probe v1 pen parameters */
1028 rc = uclogic_params_pen_init_v1(&p.pen, &found, hdev);
1029 if (rc != 0) {
1030 hid_err(hdev, "pen probing failed: %d\n", rc);
1031 goto cleanup;
1032 }
1033 /* Initialize frame parameters */
1034 rc = uclogic_params_frame_init_with_desc(
1035 &p.frame,
1036 uclogic_rdesc_xppen_deco01_frame_arr,
1037 uclogic_rdesc_xppen_deco01_frame_size,
1038 0);
1039 if (rc != 0)
1040 goto cleanup;
1041 } else {
1042 /* TODO: Consider marking the interface invalid */
1043 uclogic_params_init_with_pen_unused(&p);
1044 }
1045 break;
1046 case VID_PID(USB_VENDOR_ID_UGEE,
1047 USB_DEVICE_ID_UGEE_TABLET_G5):
1048 /* Ignore non-pen interfaces */
1049 if (bInterfaceNumber != 1) {
1050 uclogic_params_init_invalid(&p);
1051 break;
1052 }
1053
1054 rc = uclogic_params_pen_init_v1(&p.pen, &found, hdev);
1055 if (rc != 0) {
1056 hid_err(hdev, "pen probing failed: %d\n", rc);
1057 goto cleanup;
1058 } else if (found) {
1059 rc = uclogic_params_frame_init_with_desc(
1060 &p.frame,
1061 uclogic_rdesc_ugee_g5_frame_arr,
1062 uclogic_rdesc_ugee_g5_frame_size,
1063 UCLOGIC_RDESC_UGEE_G5_FRAME_ID);
1064 if (rc != 0) {
1065 hid_err(hdev,
1066 "failed creating buttonpad parameters: %d\n",
1067 rc);
1068 goto cleanup;
1069 }
1070 p.frame.re_lsb =
1071 UCLOGIC_RDESC_UGEE_G5_FRAME_RE_LSB;
1072 p.frame.dev_id_byte =
1073 UCLOGIC_RDESC_UGEE_G5_FRAME_DEV_ID_BYTE;
1074 } else {
1075 hid_warn(hdev, "pen parameters not found");
1076 uclogic_params_init_invalid(&p);
1077 }
1078
1079 break;
1080 case VID_PID(USB_VENDOR_ID_UGEE,
1081 USB_DEVICE_ID_UGEE_TABLET_EX07S):
1082 /* Ignore non-pen interfaces */
1083 if (bInterfaceNumber != 1) {
1084 uclogic_params_init_invalid(&p);
1085 break;
1086 }
1087
1088 rc = uclogic_params_pen_init_v1(&p.pen, &found, hdev);
1089 if (rc != 0) {
1090 hid_err(hdev, "pen probing failed: %d\n", rc);
1091 goto cleanup;
1092 } else if (found) {
1093 rc = uclogic_params_frame_init_with_desc(
1094 &p.frame,
1095 uclogic_rdesc_ugee_ex07_buttonpad_arr,
1096 uclogic_rdesc_ugee_ex07_buttonpad_size,
1097 0);
1098 if (rc != 0) {
1099 hid_err(hdev,
1100 "failed creating buttonpad parameters: %d\n",
1101 rc);
1102 goto cleanup;
1103 }
1104 } else {
1105 hid_warn(hdev, "pen parameters not found");
1106 uclogic_params_init_invalid(&p);
1107 }
1108
1109 break;
1110 }
1111
1112 #undef VID_PID
1113 #undef WITH_OPT_DESC
1114
1115 /* Output parameters */
1116 memcpy(params, &p, sizeof(*params));
1117 memset(&p, 0, sizeof(p));
1118 rc = 0;
1119 cleanup:
1120 uclogic_params_cleanup(&p);
1121 return rc;
1122 }