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 __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
108/*
109 * Parameters of frame control inputs of a tablet interface.
110 *
111 * Must use declarative (descriptive) language, not imperative, to simplify
112 * understanding and maintain consistency.
113 *
114 * Noop (preserving functionality) when filled with zeroes.
115 */
116struct uclogic_params_frame {
117 /*
118 * Pointer to report descriptor part describing the frame inputs.
119 * Allocated with kmalloc. NULL if the part is not specified.
120 */
121 __u8 *desc_ptr;
122 /*
123 * Size of the report descriptor.
124 * Only valid, if "desc_ptr" is not NULL.
125 */
126 unsigned int desc_size;
127 /*
128 * Report ID, if reports should be tweaked, zero if not.
129 */
130 unsigned int id;
131 /*
132 * The suffix to add to the input device name, if not NULL.
133 */
134 const char *suffix;
135 /*
136 * Number of the least-significant bit of the 2-bit state of a rotary
137 * encoder, in the report. Cannot point to a 2-bit field crossing a
138 * byte boundary. Zero if not present. Only valid if "id" is not zero.
139 */
140 unsigned int re_lsb;
141 /*
142 * Offset of the Wacom-style device ID byte in the report, to be set
143 * to pad device ID (0xf), for compatibility with Wacom drivers. Zero
144 * if no changes to the report should be made. The ID byte will be set
145 * to zero whenever the byte pointed by "touch_byte" is zero, if
146 * the latter is valid. Only valid if "id" is not zero.
147 */
148 unsigned int dev_id_byte;
149 /*
150 * Offset of the touch ring/strip state byte, in the report.
151 * Zero if not present. If dev_id_byte is also valid and non-zero,
152 * then the device ID byte will be cleared when the byte pointed to by
153 * this offset is zero. Only valid if "id" is not zero.
154 */
155 unsigned int touch_byte;
156 /*
157 * The value to anchor the reversed touch ring/strip reports at.
158 * I.e. one, if the reports should be flipped without offset.
159 * Zero if no reversal should be done.
160 * Only valid if "touch_byte" is valid and not zero.
161 */
162 __s8 touch_flip_at;
163 /*
164 * Maximum value of the touch ring/strip report around which the value
165 * should be wrapped when flipping according to "touch_flip_at".
166 * The minimum valid value is considered to be one, with zero being
167 * out-of-proximity (finger lift) value.
168 * Only valid if "touch_flip_at" is valid and not zero.
169 */
170 __s8 touch_max;
171 /*
172 * Offset of the bitmap dial byte, in the report. Zero if not present.
173 * Only valid if "id" is not zero. A bitmap dial sends reports with a
174 * dedicated bit per direction: 1 means clockwise rotation, 2 means
175 * counterclockwise, as opposed to the normal 1 and -1.
176 */
177 unsigned int bitmap_dial_byte;
178};
179
180/*
181 * List of works to be performed when a certain raw event is received.
182 */
183struct uclogic_raw_event_hook {
184 struct hid_device *hdev;
185 __u8 *event;
186 size_t size;
187 struct work_struct work;
188 struct list_head list;
189};
190
191/*
192 * Tablet interface report parameters.
193 *
194 * Must use declarative (descriptive) language, not imperative, to simplify
195 * understanding and maintain consistency.
196 *
197 * When filled with zeros represents a "noop" configuration - passes all
198 * reports unchanged and lets the generic HID driver handle everything.
199 *
200 * The resulting device report descriptor is assembled from all the report
201 * descriptor parts referenced by the structure. No order of assembly should
202 * be assumed. The structure represents original device report descriptor if
203 * all the parts are NULL.
204 */
205struct uclogic_params {
206 /*
207 * True if the whole interface is invalid, false otherwise.
208 */
209 bool invalid;
210 /*
211 * Pointer to the common part of the replacement report descriptor,
212 * allocated with kmalloc. NULL if no common part is needed.
213 * Only valid, if "invalid" is false.
214 */
215 __u8 *desc_ptr;
216 /*
217 * Size of the common part of the replacement report descriptor.
218 * Only valid, if "desc_ptr" is valid and not NULL.
219 */
220 unsigned int desc_size;
221 /*
222 * Pen parameters and optional report descriptor part.
223 * Only valid, if "invalid" is false.
224 */
225 struct uclogic_params_pen pen;
226 /*
227 * The list of frame control parameters and optional report descriptor
228 * parts. Only valid, if "invalid" is false.
229 */
230 struct uclogic_params_frame frame_list[3];
231 /*
232 * List of event hooks.
233 */
234 struct uclogic_raw_event_hook *event_hooks;
235};
236
237/* Driver data */
238struct uclogic_drvdata {
239 /* Interface parameters */
240 struct uclogic_params params;
241 /* Pointer to the replacement report descriptor. NULL if none. */
242 __u8 *desc_ptr;
243 /*
244 * Size of the replacement report descriptor.
245 * Only valid if desc_ptr is not NULL
246 */
247 unsigned int desc_size;
248 /* Pen input device */
249 struct input_dev *pen_input;
250 /* In-range timer */
251 struct timer_list inrange_timer;
252 /* Last rotary encoder state, or U8_MAX for none */
253 u8 re_state;
254 /* Device quirks */
255 unsigned long quirks;
256};
257
258/* Initialize a tablet interface and discover its parameters */
259extern int uclogic_params_init(struct uclogic_params *params,
260 struct hid_device *hdev);
261
262/* Get a replacement report descriptor for a tablet's interface. */
263extern int uclogic_params_get_desc(const struct uclogic_params *params,
264 __u8 **pdesc,
265 unsigned int *psize);
266
267/* Free resources used by tablet interface's parameters */
268extern void uclogic_params_cleanup(struct uclogic_params *params);
269
270/* Dump tablet interface parameters with hid_dbg() */
271extern void uclogic_params_hid_dbg(const struct hid_device *hdev,
272 const struct uclogic_params *params);
273
274#endif /* _HID_UCLOGIC_PARAMS_H */
275

source code of linux/drivers/hid/hid-uclogic-params.h