hid-uclogic-params.h

  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 */