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/*

 * Copyright (c) 2001-2004 Jakub Jermar

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - Redistributions in binary form must reproduce the above copyright

 *   notice, this list of conditions and the following disclaimer in the

 *   documentation and/or other materials provided with the distribution.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

/** @addtogroup genarch_drivers

 * @{

 */

/**

 * @file

 * @brief EGA driver.

 */

#include <genarch/drivers/ega/ega.h>

#include <putchar.h>

#include <mm/page.h>

#include <mm/as.h>

#include <mm/slab.h>

#include <arch/mm/page.h>

#include <synch/spinlock.h>

#include <arch/types.h>

#include <arch/asm.h>

#include <memstr.h>

#include <console/chardev.h>

#include <console/console.h>

#include <sysinfo/sysinfo.h>

#include <ddi/ddi.h>

/*

 * The EGA driver.

 * Simple and short. Function for displaying characters and "scrolling".

 */

SPINLOCK_INITIALIZE(egalock);

static uint32_t ega_cursor;

static uint8_t *videoram;

static uint8_t *backbuf;

static ioport8_t *ega_base;

#define EMPTY_CHAR  0x0720

chardev_t ega_console;

/*

 * This function takes care of scrolling.

 */

static void ega_check_cursor(void)

{

    if (ega_cursor < EGA_SCREEN)

        return;

    memmove((void *) videoram, (void *) (videoram + EGA_COLS * 2),

        (EGA_SCREEN - EGA_COLS) * 2);

    memmove((void *) backbuf, (void *) (backbuf + EGA_COLS * 2),

        (EGA_SCREEN - EGA_COLS) * 2);

    memsetw(videoram + (EGA_SCREEN - EGA_COLS) * 2, EGA_COLS, EMPTY_CHAR);

    memsetw(backbuf + (EGA_SCREEN - EGA_COLS) * 2, EGA_COLS, EMPTY_CHAR);

    ega_cursor = ega_cursor - EGA_COLS;

}

static void ega_show_cursor(void)

{

    pio_write_8(ega_base + EGA_INDEX_REG, 0x0a);

    uint8_t stat = pio_read_8(ega_base + EGA_DATA_REG);

    pio_write_8(ega_base + EGA_INDEX_REG, 0x0a);

    pio_write_8(ega_base + EGA_DATA_REG, stat & (~(1 << 5)));

}

static void ega_move_cursor(void)

{

    pio_write_8(ega_base + EGA_INDEX_REG, 0x0e);

    pio_write_8(ega_base + EGA_DATA_REG, (uint8_t) ((ega_cursor >> 8) & 0xff));

    pio_write_8(ega_base + EGA_INDEX_REG, 0x0f);

    pio_write_8(ega_base + EGA_DATA_REG, (uint8_t) (ega_cursor & 0xff));

}

static void ega_sync_cursor(void)

{

    pio_write_8(ega_base + EGA_INDEX_REG, 0x0e);

    uint8_t hi = pio_read_8(ega_base + EGA_DATA_REG);

    pio_write_8(ega_base + EGA_INDEX_REG, 0x0f);

    uint8_t lo = pio_read_8(ega_base + EGA_DATA_REG);

    ega_cursor = (hi << 8) | lo;

    if (ega_cursor >= EGA_SCREEN)

        ega_cursor = 0;

    if ((ega_cursor % EGA_COLS) != 0)

        ega_cursor = (ega_cursor + EGA_COLS) - ega_cursor % EGA_COLS;

    memsetw(videoram + ega_cursor * 2, EGA_SCREEN - ega_cursor, EMPTY_CHAR);

    memsetw(backbuf + ega_cursor * 2, EGA_SCREEN - ega_cursor, EMPTY_CHAR);

    ega_check_cursor();

    ega_move_cursor();

    ega_show_cursor();

}

static void ega_display_char(char ch, bool silent)

{

    backbuf[ega_cursor * 2] = ch;

    if (!silent)

        videoram[ega_cursor * 2] = ch;

}

static void ega_putchar(chardev_t *dev __attribute__((unused)), const char ch, bool silent)

{

    ipl_t ipl;

    ipl = interrupts_disable();

    spinlock_lock(&egalock);

    switch (ch) {

    case '\n':

        ega_cursor = (ega_cursor + EGA_COLS) - ega_cursor % EGA_COLS;

        break;

    case '\t':

        ega_cursor = (ega_cursor + 8) - ega_cursor % 8;

        break;

    case '\b':

        if (ega_cursor % EGA_COLS)

            ega_cursor--;

        break;

    default:

        ega_display_char(ch, silent);

        ega_cursor++;

        break;

    }

    ega_check_cursor();

    if (!silent)

        ega_move_cursor();

    spinlock_unlock(&egalock);

    interrupts_restore(ipl);

}

static chardev_operations_t ega_ops = {

    .write = ega_putchar

};

void ega_init(ioport8_t *base, uintptr_t videoram_phys)

{

    /* Initialize the software structure. */

    ega_base = base;

    backbuf = (uint8_t *) malloc(EGA_VRAM_SIZE, 0);

    if (!backbuf)

        panic("Unable to allocate backbuffer.");

    videoram = (uint8_t *) hw_map(videoram_phys, EGA_VRAM_SIZE);

    /* Synchronize the back buffer and cursor position. */

    memcpy(backbuf, videoram, EGA_VRAM_SIZE);

    ega_sync_cursor();

    chardev_initialize("ega_out", &ega_console, &ega_ops);

    stdout = &ega_console;

    sysinfo_set_item_val("fb", NULL, true);

    sysinfo_set_item_val("fb.kind", NULL, 2);

    sysinfo_set_item_val("fb.width", NULL, EGA_COLS);

    sysinfo_set_item_val("fb.height", NULL, EGA_ROWS);

    sysinfo_set_item_val("fb.blinking", NULL, true);

    sysinfo_set_item_val("fb.address.physical", NULL, videoram_phys);

}

void ega_redraw(void)

{

    memcpy(videoram, backbuf, EGA_VRAM_SIZE);

    ega_move_cursor();

    ega_show_cursor();

}

/** @}

 */