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 /* Convert a pen in-range reporting type to a string */ 33 extern const char *uclogic_params_pen_inrange_to_str( 34 enum uclogic_params_pen_inrange inrange); 35 36 /* 37 * Tablet interface's pen input parameters. 38 * 39 * Must use declarative (descriptive) language, not imperative, to simplify 40 * understanding and maintain consistency. 41 * 42 * Noop (preserving functionality) when filled with zeroes. 43 */ 44 struct uclogic_params_pen { 45 /* 46 * Pointer to report descriptor describing the inputs. 47 * Allocated with kmalloc. 48 */ 49 __u8 *desc_ptr; 50 /* 51 * Size of the report descriptor. 52 * Only valid, if "desc_ptr" is not NULL. 53 */ 54 unsigned int desc_size; 55 /* Report ID, if reports should be tweaked, zero if not */ 56 unsigned int id; 57 /* Type of in-range reporting, only valid if "id" is not zero */ 58 enum uclogic_params_pen_inrange inrange; 59 /* 60 * True, if reports include fragmented high resolution coords, with 61 * high-order X and then Y bytes following the pressure field. 62 * Only valid if "id" is not zero. 63 */ 64 bool fragmented_hires; 65 }; 66 67 /* 68 * Parameters of frame control inputs of a tablet interface. 69 * 70 * Must use declarative (descriptive) language, not imperative, to simplify 71 * understanding and maintain consistency. 72 * 73 * Noop (preserving functionality) when filled with zeroes. 74 */ 75 struct uclogic_params_frame { 76 /* 77 * Pointer to report descriptor describing the inputs. 78 * Allocated with kmalloc. 79 */ 80 __u8 *desc_ptr; 81 /* 82 * Size of the report descriptor. 83 * Only valid, if "desc_ptr" is not NULL. 84 */ 85 unsigned int desc_size; 86 /* 87 * Report ID, if reports should be tweaked, zero if not. 88 */ 89 unsigned int id; 90 /* 91 * Number of the least-significant bit of the 2-bit state of a rotary 92 * encoder, in the report. Cannot point to a 2-bit field crossing a 93 * byte boundary. Zero if not present. Only valid if "id" is not zero. 94 */ 95 unsigned int re_lsb; 96 /* 97 * Offset of the Wacom-style device ID byte in the report, to be set 98 * to pad device ID (0xf), for compatibility with Wacom drivers. Zero 99 * if no changes to the report should be made. Only valid if "id" is 100 * not zero. 101 */ 102 unsigned int dev_id_byte; 103 }; 104 105 /* 106 * Tablet interface report parameters. 107 * 108 * Must use declarative (descriptive) language, not imperative, to simplify 109 * understanding and maintain consistency. 110 * 111 * When filled with zeros represents a "noop" configuration - passes all 112 * reports unchanged and lets the generic HID driver handle everything. 113 * 114 * The resulting device report descriptor is assembled from all the report 115 * descriptor parts referenced by the structure. No order of assembly should 116 * be assumed. The structure represents original device report descriptor if 117 * all the parts are NULL. 118 */ 119 struct uclogic_params { 120 /* 121 * True if the whole interface is invalid, false otherwise. 122 */ 123 bool invalid; 124 /* 125 * Pointer to the common part of the replacement report descriptor, 126 * allocated with kmalloc. NULL if no common part is needed. 127 * Only valid, if "invalid" is false. 128 */ 129 __u8 *desc_ptr; 130 /* 131 * Size of the common part of the replacement report descriptor. 132 * Only valid, if "desc_ptr" is not NULL. 133 */ 134 unsigned int desc_size; 135 /* 136 * True, if pen usage in report descriptor is invalid, when present. 137 * Only valid, if "invalid" is false. 138 */ 139 bool pen_unused; 140 /* 141 * Pen parameters and optional report descriptor part. 142 * Only valid if "pen_unused" is valid and false. 143 */ 144 struct uclogic_params_pen pen; 145 /* 146 * Frame control parameters and optional report descriptor part. 147 * Only valid, if "invalid" is false. 148 */ 149 struct uclogic_params_frame frame; 150 /* 151 * Bitmask matching frame controls "sub-report" flag in the second 152 * byte of the pen report, or zero if it's not expected. 153 * Only valid if both "pen" and "frame" are valid, and "frame.id" is 154 * not zero. 155 */ 156 __u8 pen_frame_flag; 157 }; 158 159 /* Initialize a tablet interface and discover its parameters */ 160 extern int uclogic_params_init(struct uclogic_params *params, 161 struct hid_device *hdev); 162 163 /* Tablet interface parameters *printf format string */ 164 #define UCLOGIC_PARAMS_FMT_STR \ 165 ".invalid = %s\n" \ 166 ".desc_ptr = %p\n" \ 167 ".desc_size = %u\n" \ 168 ".pen_unused = %s\n" \ 169 ".pen.desc_ptr = %p\n" \ 170 ".pen.desc_size = %u\n" \ 171 ".pen.id = %u\n" \ 172 ".pen.inrange = %s\n" \ 173 ".pen.fragmented_hires = %s\n" \ 174 ".frame.desc_ptr = %p\n" \ 175 ".frame.desc_size = %u\n" \ 176 ".frame.id = %u\n" \ 177 ".frame.re_lsb = %u\n" \ 178 ".frame.dev_id_byte = %u\n" \ 179 ".pen_frame_flag = 0x%02x\n" 180 181 /* Tablet interface parameters *printf format arguments */ 182 #define UCLOGIC_PARAMS_FMT_ARGS(_params) \ 183 ((_params)->invalid ? "true" : "false"), \ 184 (_params)->desc_ptr, \ 185 (_params)->desc_size, \ 186 ((_params)->pen_unused ? "true" : "false"), \ 187 (_params)->pen.desc_ptr, \ 188 (_params)->pen.desc_size, \ 189 (_params)->pen.id, \ 190 uclogic_params_pen_inrange_to_str((_params)->pen.inrange), \ 191 ((_params)->pen.fragmented_hires ? "true" : "false"), \ 192 (_params)->frame.desc_ptr, \ 193 (_params)->frame.desc_size, \ 194 (_params)->frame.id, \ 195 (_params)->frame.re_lsb, \ 196 (_params)->frame.dev_id_byte, \ 197 (_params)->pen_frame_flag 198 199 /* Get a replacement report descriptor for a tablet's interface. */ 200 extern int uclogic_params_get_desc(const struct uclogic_params *params, 201 __u8 **pdesc, 202 unsigned int *psize); 203 204 /* Free resources used by tablet interface's parameters */ 205 extern void uclogic_params_cleanup(struct uclogic_params *params); 206 207 #endif /* _HID_UCLOGIC_PARAMS_H */ 208