/* vim: tabstop=4 shiftwidth=4 noexpandtab
 * This file is part of ToaruOS and is released under the terms
 * of the NCSA / University of Illinois License - see LICENSE.md
 * Copyright (C) 2011-2018 K. Lange
 *
 * Low-level keyboard interrupt driver.
 *
 * Creates a device file (keyboard_pipe) that can be read
 * to retreive keyboard events.
 *
 */

#include <kernel/system.h>
#include <kernel/logging.h>
#include <kernel/fs.h>
#include <kernel/pipe.h>
#include <kernel/process.h>
#include <kernel/module.h>

#define KEY_DEVICE  0x60
#define KEY_PENDING 0x64
#define KEY_IRQ     1

static fs_node_t * keyboard_pipe;

/*
 * Wait on the keyboard.
 */
static void keyboard_wait(void) {
	while(inportb(KEY_PENDING) & 2);
}

/*
 * Keyboard interrupt callback
 */
static int keyboard_handler(struct regs *r) {
	unsigned char scancode;
	if (inportb(KEY_PENDING) & 0x01) {
		scancode = inportb(KEY_DEVICE);

		write_fs(keyboard_pipe, 0, 1, (uint8_t []){scancode});
	}

	irq_ack(KEY_IRQ);
	return 1;
}

/*
 * Install the keyboard driver and initialize the
 * pipe device for userspace.
 */
static int keyboard_install(void) {
	debug_print(NOTICE, "Initializing PS/2 keyboard driver");

	/* Create a device pipe */
	keyboard_pipe = make_pipe(128);

	keyboard_pipe->flags = FS_CHARDEVICE;

	vfs_mount("/dev/kbd", keyboard_pipe);

	/* Install the interrupt handler */
	irq_install_handler(KEY_IRQ, keyboard_handler, "ps2 kbd");

	return 0;
}

static void keyboard_reset_ps2(void) {
	uint8_t tmp = inportb(0x61);
	outportb(0x61, tmp | 0x80);
	outportb(0x61, tmp & 0x7F);
	inportb(KEY_DEVICE);
}

static int keyboard_uninstall(void) {
	/* TODO */
	return 0;
}

MODULE_DEF(ps2kbd, keyboard_install, keyboard_uninstall);