/* SPDX-License-Identifier: GPL-2.0+ */
/*
* HID driver for UC-Logic devices not fully compliant with HID standard
* - tablet initialization and parameter retrieval
*
* Copyright (c) 2018 Nikolai Kondrashov
*/
/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*/
#ifndef _HID_UCLOGIC_PARAMS_H
#define _HID_UCLOGIC_PARAMS_H
#include <linux/usb.h>
#include <linux/hid.h>
/* Types of pen in-range reporting */
enum uclogic_params_pen_inrange {
/* Normal reports: zero - out of proximity, one - in proximity */
UCLOGIC_PARAMS_PEN_INRANGE_NORMAL = 0,
/* Inverted reports: zero - in proximity, one - out of proximity */
UCLOGIC_PARAMS_PEN_INRANGE_INVERTED,
/* No reports */
UCLOGIC_PARAMS_PEN_INRANGE_NONE,
};
/* Convert a pen in-range reporting type to a string */
extern const char *uclogic_params_pen_inrange_to_str(
enum uclogic_params_pen_inrange inrange);
/*
* Tablet interface's pen input parameters.
*
* Must use declarative (descriptive) language, not imperative, to simplify
* understanding and maintain consistency.
*
* Noop (preserving functionality) when filled with zeroes.
*/
struct uclogic_params_pen {
/*
* Pointer to report descriptor describing the inputs.
* Allocated with kmalloc.
*/
__u8 *desc_ptr;
/*
* Size of the report descriptor.
* Only valid, if "desc_ptr" is not NULL.
*/
unsigned int desc_size;
/* Report ID, if reports should be tweaked, zero if not */
unsigned int id;
/* Type of in-range reporting, only valid if "id" is not zero */
enum uclogic_params_pen_inrange inrange;
/*
* True, if reports include fragmented high resolution coords, with
* high-order X and then Y bytes following the pressure field.
* Only valid if "id" is not zero.
*/
bool fragmented_hires;
};
/*
* Parameters of frame control inputs of a tablet interface.
*
* Must use declarative (descriptive) language, not imperative, to simplify
* understanding and maintain consistency.
*
* Noop (preserving functionality) when filled with zeroes.
*/
struct uclogic_params_frame {
/*
* Pointer to report descriptor describing the inputs.
* Allocated with kmalloc.
*/
__u8 *desc_ptr;
/*
* Size of the report descriptor.
* Only valid, if "desc_ptr" is not NULL.
*/
unsigned int desc_size;
/*
* Report ID, if reports should be tweaked, zero if not.
*/
unsigned int id;
/*
* Number of the least-significant bit of the 2-bit state of a rotary
* encoder, in the report. Cannot point to a 2-bit field crossing a
* byte boundary. Zero if not present. Only valid if "id" is not zero.
*/
unsigned int re_lsb;
/*
* Offset of the Wacom-style device ID byte in the report, to be set
* to pad device ID (0xf), for compatibility with Wacom drivers. Zero
* if no changes to the report should be made. Only valid if "id" is
* not zero.
*/
unsigned int dev_id_byte;
};
/*
* Tablet interface report parameters.
*
* Must use declarative (descriptive) language, not imperative, to simplify
* understanding and maintain consistency.
*
* When filled with zeros represents a "noop" configuration - passes all
* reports unchanged and lets the generic HID driver handle everything.
*
* The resulting device report descriptor is assembled from all the report
* descriptor parts referenced by the structure. No order of assembly should
* be assumed. The structure represents original device report descriptor if
* all the parts are NULL.
*/
struct uclogic_params {
/*
* True if the whole interface is invalid, false otherwise.
*/
bool invalid;
/*
* Pointer to the common part of the replacement report descriptor,
* allocated with kmalloc. NULL if no common part is needed.
* Only valid, if "invalid" is false.
*/
__u8 *desc_ptr;
/*
* Size of the common part of the replacement report descriptor.
* Only valid, if "desc_ptr" is not NULL.
*/
unsigned int desc_size;
/*
* True, if pen usage in report descriptor is invalid, when present.
* Only valid, if "invalid" is false.
*/
bool pen_unused;
/*
* Pen parameters and optional report descriptor part.
* Only valid if "pen_unused" is valid and false.
*/
struct uclogic_params_pen pen;
/*
* Frame control parameters and optional report descriptor part.
* Only valid, if "invalid" is false.
*/
struct uclogic_params_frame frame;
/*
* Bitmask matching frame controls "sub-report" flag in the second
* byte of the pen report, or zero if it's not expected.
* Only valid if both "pen" and "frame" are valid, and "frame.id" is
* not zero.
*/
__u8 pen_frame_flag;
};
/* Initialize a tablet interface and discover its parameters */
extern int uclogic_params_init(struct uclogic_params *params,
struct hid_device *hdev);
/* Tablet interface parameters *printf format string */
#define UCLOGIC_PARAMS_FMT_STR \
".invalid = %s\n" \
".desc_ptr = %p\n" \
".desc_size = %u\n" \
".pen_unused = %s\n" \
".pen.desc_ptr = %p\n" \
".pen.desc_size = %u\n" \
".pen.id = %u\n" \
".pen.inrange = %s\n" \
".pen.fragmented_hires = %s\n" \
".frame.desc_ptr = %p\n" \
".frame.desc_size = %u\n" \
".frame.id = %u\n" \
".frame.re_lsb = %u\n" \
".frame.dev_id_byte = %u\n" \
".pen_frame_flag = 0x%02x\n"
/* Tablet interface parameters *printf format arguments */
#define UCLOGIC_PARAMS_FMT_ARGS(_params) \
((_params)->invalid ? "true" : "false"), \
(_params)->desc_ptr, \
(_params)->desc_size, \
((_params)->pen_unused ? "true" : "false"), \
(_params)->pen.desc_ptr, \
(_params)->pen.desc_size, \
(_params)->pen.id, \
uclogic_params_pen_inrange_to_str((_params)->pen.inrange), \
((_params)->pen.fragmented_hires ? "true" : "false"), \
(_params)->frame.desc_ptr, \
(_params)->frame.desc_size, \
(_params)->frame.id, \
(_params)->frame.re_lsb, \
(_params)->frame.dev_id_byte, \
(_params)->pen_frame_flag
/* Get a replacement report descriptor for a tablet's interface. */
extern int uclogic_params_get_desc(const struct uclogic_params *params,
__u8 **pdesc,
unsigned int *psize);
/* Free resources used by tablet interface's parameters */
extern void uclogic_params_cleanup(struct uclogic_params *params);
#endif /* _HID_UCLOGIC_PARAMS_H */