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 22 /* Types of pen in-range reporting */ 23 enum uclogic_params_pen_inrange { 24 /* Normal reports: zero - out of proximity, one - in proximity */ 25 UCLOGIC_PARAMS_PEN_INRANGE_NORMAL = 0, 26 /* Inverted reports: zero - in proximity, one - out of proximity */ 27 UCLOGIC_PARAMS_PEN_INRANGE_INVERTED, 28 /* No reports */ 29 UCLOGIC_PARAMS_PEN_INRANGE_NONE, 30 }; 31 32 /* 33 * Pen report's subreport data. 34 */ 35 struct uclogic_params_pen_subreport { 36 /* 37 * The value of the second byte of the pen report indicating this 38 * subreport. If zero, the subreport should be considered invalid and 39 * not matched. 40 */ 41 __u8 value; 42 43 /* 44 * The ID to be assigned to the report, if the second byte of the pen 45 * report is equal to "value". Only valid if "value" is not zero. 46 */ 47 __u8 id; 48 }; 49 50 /* 51 * Tablet interface's pen input parameters. 52 * 53 * Must use declarative (descriptive) language, not imperative, to simplify 54 * understanding and maintain consistency. 55 * 56 * Noop (preserving functionality) when filled with zeroes. 57 */ 58 struct uclogic_params_pen { 59 /* 60 * True if pen usage is invalid for this interface and should be 61 * ignored, false otherwise. 62 */ 63 bool usage_invalid; 64 /* 65 * Pointer to report descriptor part describing the pen inputs. 66 * Allocated with kmalloc. NULL if the part is not specified. 67 */ 68 __u8 *desc_ptr; 69 /* 70 * Size of the report descriptor. 71 * Only valid, if "desc_ptr" is not NULL. 72 */ 73 unsigned int desc_size; 74 /* Report ID, if reports should be tweaked, zero if not */ 75 unsigned int id; 76 /* The list of subreports, only valid if "id" is not zero */ 77 struct uclogic_params_pen_subreport subreport_list[3]; 78 /* Type of in-range reporting, only valid if "id" is not zero */ 79 enum uclogic_params_pen_inrange inrange; 80 /* 81 * True, if reports include fragmented high resolution coords, with 82 * high-order X and then Y bytes following the pressure field. 83 * Only valid if "id" is not zero. 84 */ 85 bool fragmented_hires; 86 /* 87 * True if the pen reports tilt in bytes at offset 10 (X) and 11 (Y), 88 * and the Y tilt direction is flipped. 89 * Only valid if "id" is not zero. 90 */ 91 bool tilt_y_flipped; 92 }; 93 94 /* 95 * Parameters of frame control inputs of a tablet interface. 96 * 97 * Must use declarative (descriptive) language, not imperative, to simplify 98 * understanding and maintain consistency. 99 * 100 * Noop (preserving functionality) when filled with zeroes. 101 */ 102 struct uclogic_params_frame { 103 /* 104 * Pointer to report descriptor part describing the frame inputs. 105 * Allocated with kmalloc. NULL if the part is not specified. 106 */ 107 __u8 *desc_ptr; 108 /* 109 * Size of the report descriptor. 110 * Only valid, if "desc_ptr" is not NULL. 111 */ 112 unsigned int desc_size; 113 /* 114 * Report ID, if reports should be tweaked, zero if not. 115 */ 116 unsigned int id; 117 /* 118 * The suffix to add to the input device name, if not NULL. 119 */ 120 const char *suffix; 121 /* 122 * Number of the least-significant bit of the 2-bit state of a rotary 123 * encoder, in the report. Cannot point to a 2-bit field crossing a 124 * byte boundary. Zero if not present. Only valid if "id" is not zero. 125 */ 126 unsigned int re_lsb; 127 /* 128 * Offset of the Wacom-style device ID byte in the report, to be set 129 * to pad device ID (0xf), for compatibility with Wacom drivers. Zero 130 * if no changes to the report should be made. The ID byte will be set 131 * to zero whenever the byte pointed by "touch_byte" is zero, if 132 * the latter is valid. Only valid if "id" is not zero. 133 */ 134 unsigned int dev_id_byte; 135 /* 136 * Offset of the touch ring/strip state byte, in the report. 137 * Zero if not present. If dev_id_byte is also valid and non-zero, 138 * then the device ID byte will be cleared when the byte pointed to by 139 * this offset is zero. Only valid if "id" is not zero. 140 */ 141 unsigned int touch_byte; 142 /* 143 * The value to anchor the reversed touch ring/strip reports at. 144 * I.e. one, if the reports should be flipped without offset. 145 * Zero if no reversal should be done. 146 * Only valid if "touch_byte" is valid and not zero. 147 */ 148 __s8 touch_flip_at; 149 /* 150 * Maximum value of the touch ring/strip report around which the value 151 * should be wrapped when flipping according to "touch_flip_at". 152 * The minimum valid value is considered to be one, with zero being 153 * out-of-proximity (finger lift) value. 154 * Only valid if "touch_flip_at" is valid and not zero. 155 */ 156 __s8 touch_max; 157 /* 158 * Offset of the bitmap dial byte, in the report. Zero if not present. 159 * Only valid if "id" is not zero. A bitmap dial sends reports with a 160 * dedicated bit per direction: 1 means clockwise rotation, 2 means 161 * counterclockwise, as opposed to the normal 1 and -1. 162 */ 163 unsigned int bitmap_dial_byte; 164 }; 165 166 /* 167 * Tablet interface report parameters. 168 * 169 * Must use declarative (descriptive) language, not imperative, to simplify 170 * understanding and maintain consistency. 171 * 172 * When filled with zeros represents a "noop" configuration - passes all 173 * reports unchanged and lets the generic HID driver handle everything. 174 * 175 * The resulting device report descriptor is assembled from all the report 176 * descriptor parts referenced by the structure. No order of assembly should 177 * be assumed. The structure represents original device report descriptor if 178 * all the parts are NULL. 179 */ 180 struct uclogic_params { 181 /* 182 * True if the whole interface is invalid, false otherwise. 183 */ 184 bool invalid; 185 /* 186 * Pointer to the common part of the replacement report descriptor, 187 * allocated with kmalloc. NULL if no common part is needed. 188 * Only valid, if "invalid" is false. 189 */ 190 __u8 *desc_ptr; 191 /* 192 * Size of the common part of the replacement report descriptor. 193 * Only valid, if "desc_ptr" is valid and not NULL. 194 */ 195 unsigned int desc_size; 196 /* 197 * Pen parameters and optional report descriptor part. 198 * Only valid, if "invalid" is false. 199 */ 200 struct uclogic_params_pen pen; 201 /* 202 * The list of frame control parameters and optional report descriptor 203 * parts. Only valid, if "invalid" is false. 204 */ 205 struct uclogic_params_frame frame_list[3]; 206 }; 207 208 /* Initialize a tablet interface and discover its parameters */ 209 extern int uclogic_params_init(struct uclogic_params *params, 210 struct hid_device *hdev); 211 212 /* Get a replacement report descriptor for a tablet's interface. */ 213 extern int uclogic_params_get_desc(const struct uclogic_params *params, 214 __u8 **pdesc, 215 unsigned int *psize); 216 217 /* Free resources used by tablet interface's parameters */ 218 extern void uclogic_params_cleanup(struct uclogic_params *params); 219 220 /* Dump tablet interface parameters with hid_dbg() */ 221 extern void uclogic_params_hid_dbg(const struct hid_device *hdev, 222 const struct uclogic_params *params); 223 224 #endif /* _HID_UCLOGIC_PARAMS_H */ 225