xref: /linux/drivers/hid/hid-uclogic-params.h (revision 3a39d672e7f48b8d6b91a09afa4b55352773b4b5)
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 
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  */
116 struct 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 	const __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  */
183 struct 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  */
205 struct 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 	const __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 */
238 struct uclogic_drvdata {
239 	/* Interface parameters */
240 	struct uclogic_params params;
241 	/* Pointer to the replacement report descriptor. NULL if none. */
242 	const __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 */
259 extern 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. */
263 extern int uclogic_params_get_desc(const struct uclogic_params *params,
264 					const __u8 **pdesc,
265 					unsigned int *psize);
266 
267 /* Free resources used by tablet interface's parameters */
268 extern void uclogic_params_cleanup(struct uclogic_params *params);
269 
270 /* Dump tablet interface parameters with hid_dbg() */
271 extern void uclogic_params_hid_dbg(const struct hid_device *hdev,
272 					const struct uclogic_params *params);
273 
274 #endif /* _HID_UCLOGIC_PARAMS_H */
275