tjh.dev
Linux kernel mirror (for testing)
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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#ifndef _HID_UCLOGIC_PARAMS_H
17#define _HID_UCLOGIC_PARAMS_H
18
19#include <linux/usb.h>
20#include <linux/hid.h>
21#include <linux/list.h>
22
23#define UCLOGIC_MOUSE_FRAME_QUIRK BIT(0)
24#define UCLOGIC_BATTERY_QUIRK BIT(1)
25
26/* Types of pen in-range reporting */
27enum uclogic_params_pen_inrange {
28 /* Normal reports: zero - out of proximity, one - in proximity */
29 UCLOGIC_PARAMS_PEN_INRANGE_NORMAL = 0,
30 /* Inverted reports: zero - in proximity, one - out of proximity */
31 UCLOGIC_PARAMS_PEN_INRANGE_INVERTED,
32 /* No reports */
33 UCLOGIC_PARAMS_PEN_INRANGE_NONE,
34};
35
36/* Types of frames */
37enum uclogic_params_frame_type {
38 /* Frame with buttons */
39 UCLOGIC_PARAMS_FRAME_BUTTONS = 0,
40 /* Frame with buttons and a dial */
41 UCLOGIC_PARAMS_FRAME_DIAL,
42 /* Frame with buttons and a mouse (shaped as a dial + touchpad) */
43 UCLOGIC_PARAMS_FRAME_MOUSE,
44};
45
46/*
47 * Pen report's subreport data.
48 */
49struct uclogic_params_pen_subreport {
50 /*
51 * The value of the second byte of the pen report indicating this
52 * subreport. If zero, the subreport should be considered invalid and
53 * not matched.
54 */
55 __u8 value;
56
57 /*
58 * The ID to be assigned to the report, if the second byte of the pen
59 * report is equal to "value". Only valid if "value" is not zero.
60 */
61 __u8 id;
62};
63
64/*
65 * Tablet interface's pen input parameters.
66 *
67 * Must use declarative (descriptive) language, not imperative, to simplify
68 * understanding and maintain consistency.
69 *
70 * Noop (preserving functionality) when filled with zeroes.
71 */
72struct uclogic_params_pen {
73 /*
74 * True if pen usage is invalid for this interface and should be
75 * ignored, false otherwise.
76 */
77 bool usage_invalid;
78 /*
79 * Pointer to report descriptor part describing the pen inputs.
80 * Allocated with kmalloc. NULL if the part is not specified.
81 */
82 const __u8 *desc_ptr;
83 /*
84 * Size of the report descriptor.
85 * Only valid, if "desc_ptr" is not NULL.
86 */
87 unsigned int desc_size;
88 /* Report ID, if reports should be tweaked, zero if not */
89 unsigned int id;
90 /* The list of subreports, only valid if "id" is not zero */
91 struct uclogic_params_pen_subreport subreport_list[3];
92 /* Type of in-range reporting, only valid if "id" is not zero */
93 enum uclogic_params_pen_inrange inrange;
94 /*
95 * True, if reports include fragmented high resolution coords, with
96 * high-order X and then Y bytes following the pressure field.
97 * Only valid if "id" is not zero.
98 */
99 bool fragmented_hires;
100 /*
101 * True if the pen reports tilt in bytes at offset 10 (X) and 11 (Y),
102 * and the Y tilt direction is flipped.
103 * Only valid if "id" is not zero.
104 */
105 bool tilt_y_flipped;
106 /*
107 * True, if reports include fragmented high resolution X coords.
108 * This moves bytes 10-11 to the LSB of the X coordinate.
109 */
110 bool fragmented_hires2;
111};
112
113/*
114 * Parameters of frame control inputs of a tablet interface.
115 *
116 * Must use declarative (descriptive) language, not imperative, to simplify
117 * understanding and maintain consistency.
118 *
119 * Noop (preserving functionality) when filled with zeroes.
120 */
121struct uclogic_params_frame {
122 /*
123 * Pointer to report descriptor part describing the frame inputs.
124 * Allocated with kmalloc. NULL if the part is not specified.
125 */
126 const __u8 *desc_ptr;
127 /*
128 * Size of the report descriptor.
129 * Only valid, if "desc_ptr" is not NULL.
130 */
131 unsigned int desc_size;
132 /*
133 * Report ID, if reports should be tweaked, zero if not.
134 */
135 unsigned int id;
136 /*
137 * The suffix to add to the input device name, if not NULL.
138 */
139 const char *suffix;
140 /*
141 * Number of the least-significant bit of the 2-bit state of a rotary
142 * encoder, in the report. Cannot point to a 2-bit field crossing a
143 * byte boundary. Zero if not present. Only valid if "id" is not zero.
144 */
145 unsigned int re_lsb;
146 /*
147 * Offset of the Wacom-style device ID byte in the report, to be set
148 * to pad device ID (0xf), for compatibility with Wacom drivers. Zero
149 * if no changes to the report should be made. The ID byte will be set
150 * to zero whenever the byte pointed by "touch_byte" is zero, if
151 * the latter is valid. Only valid if "id" is not zero.
152 */
153 unsigned int dev_id_byte;
154 /*
155 * Offset of the touch ring/strip state byte, in the report.
156 * Zero if not present. If dev_id_byte is also valid and non-zero,
157 * then the device ID byte will be cleared when the byte pointed to by
158 * this offset is zero. Only valid if "id" is not zero.
159 */
160 unsigned int touch_byte;
161 /*
162 * The value to anchor the reversed touch ring/strip reports at.
163 * I.e. one, if the reports should be flipped without offset.
164 * Zero if no reversal should be done.
165 * Only valid if "touch_byte" is valid and not zero.
166 */
167 __s8 touch_flip_at;
168 /*
169 * Maximum value of the touch ring/strip report around which the value
170 * should be wrapped when flipping according to "touch_flip_at".
171 * The minimum valid value is considered to be one, with zero being
172 * out-of-proximity (finger lift) value.
173 * Only valid if "touch_flip_at" is valid and not zero.
174 */
175 __s8 touch_max;
176 /*
177 * Offset of the bitmap dial byte, in the report. Zero if not present.
178 * Only valid if "id" is not zero. A bitmap dial sends reports with a
179 * dedicated bit per direction: 1 means clockwise rotation, 2 means
180 * counterclockwise, as opposed to the normal 1 and -1.
181 */
182 unsigned int bitmap_dial_byte;
183 /*
184 * Destination offset for the second bitmap dial byte, if the tablet
185 * supports a second dial at all.
186 */
187 unsigned int bitmap_second_dial_destination_byte;
188};
189
190/*
191 * List of works to be performed when a certain raw event is received.
192 */
193struct uclogic_raw_event_hook {
194 struct hid_device *hdev;
195 __u8 *event;
196 size_t size;
197 struct work_struct work;
198 struct list_head list;
199};
200
201/*
202 * Tablet interface report parameters.
203 *
204 * Must use declarative (descriptive) language, not imperative, to simplify
205 * understanding and maintain consistency.
206 *
207 * When filled with zeros represents a "noop" configuration - passes all
208 * reports unchanged and lets the generic HID driver handle everything.
209 *
210 * The resulting device report descriptor is assembled from all the report
211 * descriptor parts referenced by the structure. No order of assembly should
212 * be assumed. The structure represents original device report descriptor if
213 * all the parts are NULL.
214 */
215struct uclogic_params {
216 /*
217 * True if the whole interface is invalid, false otherwise.
218 */
219 bool invalid;
220 /*
221 * Pointer to the common part of the replacement report descriptor,
222 * allocated with kmalloc. NULL if no common part is needed.
223 * Only valid, if "invalid" is false.
224 */
225 const __u8 *desc_ptr;
226 /*
227 * Size of the common part of the replacement report descriptor.
228 * Only valid, if "desc_ptr" is valid and not NULL.
229 */
230 unsigned int desc_size;
231 /*
232 * Pen parameters and optional report descriptor part.
233 * Only valid, if "invalid" is false.
234 */
235 struct uclogic_params_pen pen;
236 /*
237 * The list of frame control parameters and optional report descriptor
238 * parts. Only valid, if "invalid" is false.
239 */
240 struct uclogic_params_frame frame_list[3];
241 /*
242 * List of event hooks.
243 */
244 struct uclogic_raw_event_hook *event_hooks;
245};
246
247/* Driver data */
248struct uclogic_drvdata {
249 /* Interface parameters */
250 struct uclogic_params params;
251 /* Pointer to the replacement report descriptor. NULL if none. */
252 const __u8 *desc_ptr;
253 /*
254 * Size of the replacement report descriptor.
255 * Only valid if desc_ptr is not NULL
256 */
257 unsigned int desc_size;
258 /* Pen input device */
259 struct input_dev *pen_input;
260 /* In-range timer */
261 struct timer_list inrange_timer;
262 /* Last rotary encoder state, or U8_MAX for none */
263 u8 re_state;
264 /* Device quirks */
265 unsigned long quirks;
266};
267
268/* Initialize a tablet interface and discover its parameters */
269extern int uclogic_params_init(struct uclogic_params *params,
270 struct hid_device *hdev);
271
272/* Get a replacement report descriptor for a tablet's interface. */
273extern int uclogic_params_get_desc(const struct uclogic_params *params,
274 const __u8 **pdesc,
275 unsigned int *psize);
276
277/* Free resources used by tablet interface's parameters */
278extern void uclogic_params_cleanup(struct uclogic_params *params);
279
280/* Dump tablet interface parameters with hid_dbg() */
281extern void uclogic_params_hid_dbg(const struct hid_device *hdev,
282 const struct uclogic_params *params);
283
284#endif /* _HID_UCLOGIC_PARAMS_H */