source: mainline/kernel/arch/mips32/src/drivers/msim.c@ f1d1f5d3

/*
 * Copyright (C) 2005 Ondrej Palkovsky
 * 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 mips32  
 * @{
 */
/** @file
 */

#include <interrupt.h>
#include <console/chardev.h>
#include <arch/drivers/msim.h>
#include <arch/cp0.h>
#include <console/console.h>

static chardev_t console;

static void msim_write(chardev_t *dev, const char ch);
static void msim_enable(chardev_t *dev);
static void msim_disable(chardev_t *dev);
static char msim_do_read(chardev_t *dev);

static chardev_operations_t msim_ops = {
        .resume = msim_enable,
        .suspend = msim_disable,
        .write = msim_write,
        .read = msim_do_read,
};

/** Putchar that works with MSIM & gxemul */
void msim_write(chardev_t *dev, const char ch)
{
        *((char *) MSIM_VIDEORAM) = ch;
}

/* Called from getc(). */
void msim_enable(chardev_t *dev)
{
        cp0_unmask_int(MSIM_KBD_IRQ);
}

/* Called from getc(). */
void msim_disable(chardev_t *dev)
{
        cp0_mask_int(MSIM_KBD_IRQ);
}

#include <print.h>
/** Read character using polling, assume interrupts disabled */
static char msim_do_read(chardev_t *dev)
{
        char ch;

        while (1) {
                ch = *((volatile char *) MSIM_KBD_ADDRESS);
                if (ch) {
                        if (ch == '\r')
                                return '\n';
                        if (ch == 0x7f)
                                return '\b';
                        return ch;
                }
        }
}

/** Process keyboard interrupt. */
static void msim_interrupt(int n, istate_t *istate)
{
        char ch = 0;

        ch = *((char *) MSIM_KBD_ADDRESS);
        if (ch =='\r')
                ch = '\n';
        if (ch == 0x7f)
                ch = '\b';
        chardev_push_character(&console, ch);
}


/* Return console object representing msim console */
void msim_console(void)
{
        chardev_initialize("msim_console", &console, &msim_ops);

        int_register(MSIM_KBD_IRQ, "msim_kbd", msim_interrupt);

        cp0_unmask_int(MSIM_KBD_IRQ);

        stdin = &console;
        stdout = &console;
}

static iroutine oldvector;
void msim_kbd_grab(void)
{
        oldvector = int_register(MSIM_KBD_IRQ, "msim_kbd", msim_interrupt);
}
void msim_kbd_release(void)
{
        if (oldvector)
                int_register(MSIM_KBD_IRQ, "user_interrupt", oldvector);
}

/** @}
 */