SchOS/include/dev/input.h

#pragma once

#include "core/types.h"

// Raw input events -- Linux's evdev interface.
//
// The console gives characters. That is the right thing for a shell and the
// wrong thing for everything else: a character stream has no key *releases*,
// no way to tell left shift from right, no notion of a key being held, and no
// mouse at all. A game holding W to walk forward, or a compositor deciding
// which window a click landed in, needs the events underneath the characters.
//
// The layout is Linux's, deliberately. It is what every program that reads input
// already speaks -- SDL, X, libinput, every game engine -- so a program that
// runs on Linux reads input here without a porting layer. It costs nothing to
// match: the struct is four fields.
//
// Nodes are /dev/input/event0 (keyboard) and /dev/input/event1 (mouse).

struct input_timeval {
  int64 tv_sec;
  int64 tv_usec;
};

struct input_event {
  struct input_timeval time;
  uint16 type;
  uint16 code;
  int32  value;
};

// Event types.
#define EV_SYN          0x00
#define EV_KEY          0x01
#define EV_REL          0x02
#define EV_ABS          0x03
#define EV_MSC          0x04
#define EV_LED          0x11
#define EV_REP          0x14
#define EV_MAX          0x1f

#define SYN_REPORT      0

// Relative axes.
// Absolute axes, for a pointing device that reports where it *is* rather than
// how far it moved -- a tablet, a touchscreen, or a VM's absolute pointer.
// Same numbering as Linux, because /dev/input/eventN claims to speak evdev.
#define ABS_X           0x00
#define ABS_Y           0x01

#define REL_X           0x00
#define REL_Y           0x01
#define REL_WHEEL       0x08
#define REL_MAX         0x0f
#define ABS_MAX         0x3f

// Buttons live in the EV_KEY code space alongside keys, which is why the
// keyboard's codes stop well below 0x100.
#define BTN_LEFT        0x110
#define BTN_RIGHT       0x111
#define BTN_MIDDLE      0x112

// Key codes worth naming. The rest are the AT scancode-set-1 numbers, which
// Linux's keycodes were derived from and still match for everything below
// 0x54 -- that is not a coincidence and it is why the PS/2 path needs no
// translation table for unprefixed bytes.
#define KEY_RESERVED    0
#define KEY_ESC         1
#define KEY_ENTER       28
#define KEY_LEFTCTRL    29
#define KEY_LEFTSHIFT   42
#define KEY_RIGHTSHIFT  54
#define KEY_LEFTALT     56
#define KEY_SPACE       57
#define KEY_RIGHTCTRL   97
#define KEY_RIGHTALT    100
#define KEY_HOME        102
#define KEY_UP          103
#define KEY_PAGEUP      104
#define KEY_LEFT        105
#define KEY_RIGHT       106
#define KEY_END         107
#define KEY_DOWN        108
#define KEY_PAGEDOWN    109
#define KEY_INSERT      110
#define KEY_DELETE      111
#define KEY_LEFTMETA    125
#define KEY_RIGHTMETA   126

#define KEY_MAX         0x2ff           // Linux's; the bitmaps are this wide

// EVIOCGRAB -- take/release exclusive access to a device.
//
// Linux's _IOW('E', 0x90, int). Spelled as the resulting constant rather than
// built from an _IOW macro because SchOS has no ioctl-encoding macros and
// inventing a set just for this would be a bigger change than the feature.
// A non-zero argument grabs, zero releases; the argument is passed by value.
#define EVIOCGRAB       0x40044590
#define EVIOCREVOKE     0x40044591

// The queries a program makes before it reads anything: what the device is
// called, what it can report, what state it is in now. Xorg's evdev driver
// and libinput both decide what a device *is* -- keyboard, mouse, tablet --
// from the capability bitmaps alone, and treat a device that answers ENOTTY
// as no device at all.
//
// Linux's _IOC encoding: direction in bits 31:30 (2 read, 1 write), the size
// of the argument in 29:16, the type ('E') in 15:8, the number in 7:0. The
// variable-length ones carry the caller's buffer size in the size field, so
// they are matched with it masked out.
#define EVIOC_DIR(r)    (((uint)(r) >> 30) & 3)
#define EVIOC_SIZE(r)   (((uint)(r) >> 16) & 0x3fff)
#define EVIOC_TYPE(r)   (((uint)(r) >> 8) & 0xff)
#define EVIOC_NR(r)     ((uint)(r) & 0xff)

#define EVIOCGVERSION   0x80044501
#define EVIOCGID        0x80084502
#define EVIOCGREP       0x80084503
#define EVIOCSREP       0x40084503
#define EVIOCSCLOCKID   0x400445a0
// By number, with the length taken from the request:
#define EVIOCNR_GNAME   0x06
#define EVIOCNR_GPHYS   0x07
#define EVIOCNR_GUNIQ   0x08
#define EVIOCNR_GPROP   0x09
#define EVIOCNR_GKEY    0x18
#define EVIOCNR_GLED    0x19
#define EVIOCNR_GSND    0x1a
#define EVIOCNR_GSW     0x1b
#define EVIOCNR_GBIT    0x20            // + event type, 0x20..0x3f
#define EVIOCNR_GABS    0x40            // + axis, 0x40..0x7f
#define EVIOCNR_SABS    0xc0            // + axis

struct input_id {
  uint16 bustype;
  uint16 vendor;
  uint16 product;
  uint16 version;
};

struct input_absinfo {
  int32 value;
  int32 minimum;
  int32 maximum;
  int32 fuzz;
  int32 flat;
  int32 resolution;
};

#define BUS_I8042       0x11
#define INPUT_PROP_POINTER 0x00

// Which device an event came from. Both are minor numbers under the input
// major, and both are the index into the driver's array.
#define INPUT_KBD       0
#define INPUT_MOUSE     1
#define NINPUTDEV       2