xref: /linux/drivers/hid/hid-uclogic-params.h (revision fde4ce068d1bccacf1e2d6a28697a3847f28e0a6)
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 */
27 enum 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 */
37 enum 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  */
49 struct 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  */
72 struct 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  */
121 struct 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  */
193 struct 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  */
215 struct 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 */
248 struct 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 */
269 extern 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. */
273 extern 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 */
278 extern void uclogic_params_cleanup(struct uclogic_params *params);
279 
280 /* Dump tablet interface parameters with hid_dbg() */
281 extern void uclogic_params_hid_dbg(const struct hid_device *hdev,
282 					const struct uclogic_params *params);
283 
284 #endif /* _HID_UCLOGIC_PARAMS_H */
285