source: buchla-emu/emu/kbd.c@ d021bbb

/*
 *  Copyright (C) 2017 The Contributors
 *
 *  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 3 of the License, or (at
 *  your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 *  General Public License for more details.
 *
 *  A copy of the GNU General Public License can be found in the file
 *  "gpl.txt" in the top directory of this repository.
 */

#include <all.h>

#define ver(...) _ver(kbd_verbose, 0, __VA_ARGS__)
#define ver2(...) _ver(kbd_verbose, 1, __VA_ARGS__)
#define ver3(...) _ver(kbd_verbose, 2, __VA_ARGS__)

int32_t kbd_verbose = 0;

#define BUF_SZ 16

static int32_t buf_hd = 0;
static int32_t buf_tl = 0;
static uint8_t buf[BUF_SZ];

static uint8_t reg = 0;
static bool irq = false;

static void xmit(void)
{
        ver2("kbd xmit %d %d", buf_tl, buf_hd);

        if (buf_tl >= buf_hd) {
                return;
        }

        reg = buf[buf_tl % BUF_SZ];
        irq = true;
        ver2("kbd xmit 0x%02x", reg);

        ++buf_tl;

        if (buf_tl >= BUF_SZ) {
                buf_hd -= BUF_SZ;
                buf_tl -= BUF_SZ;
                ver2("kbd adj %d %d", buf_tl, buf_hd);
        }
}

static void out(uint8_t c)
{
        ver2("kbd out %d %d 0x%02x", buf_tl, buf_hd, c);

        if (SDL_LockMutex(cpu_mutex) < 0) {
                fail("SDL_LockMutex() failed: %s", SDL_GetError());
        }

        if (buf_hd >= buf_tl + BUF_SZ) {
                err("keyboard port losing data");
        }
        else {
                buf[buf_hd % BUF_SZ] = c;
                ++buf_hd;

                if (!irq) {
                        xmit();
                }
        }

        if (SDL_UnlockMutex(cpu_mutex) < 0) {
                fail("SDL_UnlockMutex() failed: %s", SDL_GetError());
        }
}

static void but_on(int32_t sig)
{
        out((uint8_t)(0x80 | sig));
        out(0x01);
}

static void but_off(int32_t sig)
{
        out((uint8_t)(0x80 | sig));
        out(0x00);
}

static void key_touch(int32_t sig, int32_t val)
{
        out((uint8_t)(0x80 | sig));
        out(0x01);
        out((uint8_t)val);
}

static void key_off(int32_t sig)
{
        out((uint8_t)(0x80 | sig));
        out(0x00);
}

#if defined NOT_YET
static void pot_128(int32_t sig, int32_t val)
{
        out((uint8_t)(0x80 | sig));
        out((uint8_t)val);
}

static void pot_256(int32_t sig, int32_t val)
{
        out((uint8_t)(0x80 | sig));
        out((uint8_t)((val >> 7) & 0x01));
        out((uint8_t)(val & 0x7f));
}
#endif

void kbd_key(SDL_KeyboardEvent *ev)
{
        static bool on[24];

        if ((ev->keysym.mod & KMOD_SHIFT) != 0 &&
                        ev->keysym.sym >= SDLK_a && ev->keysym.sym <= SDLK_x) {
                int32_t i = ev->keysym.sym - SDLK_a;
                on[i] = !on[i];

                if (on[i]) {
                        key_touch(1 + i, 0x7f);
                }
                else {
                        key_off(1 + i);
                }

                ver2("kbd key %d %s", i, on[i] ? "on" : "off");
        }
}

void kbd_text(SDL_TextInputEvent *ev)
{
        for (int32_t i = 0; ev->text[i] != 0; ++i) {
                if (ev->text[i] >= '0' && ev->text[i] <= '9') {
                        ver2("kbd dat %c", ev->text[i]);
                        int32_t sig = 60 + ev->text[i] - '0';
                        but_on(sig);
                        but_off(sig);
                        continue;
                }

                switch (ev->text[i]) {
                case 'x':
                        ver2("kbd x");
                        but_on(70);
                        but_off(70);
                        break;

                case 'e':
                        ver2("kbd e");
                        but_on(71);
                        but_off(71);
                        break;

                case 'm':
                        ver2("kbd m");
                        but_on(72);
                        but_off(72);
                        break;
                }
        }
}

void kbd_init(void)
{
        ver("kbd init");
}

void kbd_quit(void)
{
        ver("kbd quit");
}

bool kbd_exec(void)
{
        ver3("kbd exec");
        return irq;
}

uint32_t kbd_read(uint32_t off, int32_t sz)
{
        ver2("kbd rd %u:%d", off, sz * 8);

        if (sz != 1 || off > 0) {
                fail("invalid kbd rd %u:%d", off, sz * 8);
        }

        irq = false;
        uint32_t res = reg;

        xmit();

        return res;
}

void kbd_write(uint32_t off, int32_t sz, uint32_t val)
{
        ver2("kbd wr %u:%d 0x%0*x", off, sz * 8, sz * 2, val);
        fail("invalid kbd wr %u:%d", off, sz * 8);
}