/*
 * Copyright (C) 2019-2022 Intel Corporation.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

/* cmos io device
 * - nvram 0x10 ~ 0x1F is used for android device reboot to bootloader or
 *   recovery or normal boot usage
 * - vrpmb 0x20 ~ 0x9F is used to store vrpmb for guest, read to clear
 */

#include <stdio.h>
#include <stdbool.h>

#include "inout.h"
#include "vmmapi.h"
#include "vrpmb.h"
#include "log.h"

#define CMOS_ADDR		0x74
#define CMOS_DATA		0x75

#define CMOS_NAME		"cmos_io"
#define CMOS_VRPMB_START	0x20
#define CMOS_VRPMB_END		0x9F

/* cmos buffer used to store write/read contents,
 * and it should not be cleared when reboot
 */
static	uint8_t cmos_buffer[CMOS_BUF_SIZE];

/* #define CMOS_DEBUG */
#ifdef CMOS_DEBUG
static FILE * dbg_file;
#define DPRINTF(format, args...) \
do { fprintf(dbg_file, format, args); fflush(dbg_file); } while (0)
#else
#define DPRINTF(format, arg...)
#endif

static int
cmos_io_handler(struct vmctx *ctx, int vcpu, int in, int port, int bytes,
				uint32_t *eax, void *arg)
{
	static int buf_offset;
	static int next_ops;  /* 0 for addr, 1 for data, in pair (addr,data)*/

#ifdef CMOS_DEBUG
	if (!dbg_file)
		dbg_file = fopen("/tmp/cmos_log", "a+");
#endif

	DPRINTF("%s port =0x%x, in=%d, size=%d, val=0x%x, ops=%d\n",
		__func__, port, in, bytes, (uint8_t)*eax, next_ops);

	if (port == CMOS_ADDR) {

		/* if port is addr, ops should be 0 */
		if (next_ops != 0) {
			next_ops = 0;
			return -1;
		}

		buf_offset = (uint8_t)(*eax);
		next_ops = 1;

	} else if (port == CMOS_DATA) {

		if (next_ops != 1) {
			next_ops = 0;
			return -1;
		}

		if (in) {
			*eax = cmos_buffer[buf_offset];
			/* read to clear for Key range */
			if ((buf_offset >= CMOS_VRPMB_START) &&
			    (buf_offset <= CMOS_VRPMB_END))
				cmos_buffer[buf_offset] = 0;
		}
		else
			cmos_buffer[buf_offset] = (uint8_t)*eax;

		next_ops = 0;
	}

	return 0;
}

INOUT_PORT(cmos_io, CMOS_ADDR, IOPORT_F_INOUT, cmos_io_handler);
INOUT_PORT(cmos_io, CMOS_DATA, IOPORT_F_INOUT, cmos_io_handler);

int init_cmos_vrpmb(struct vmctx *ctx)
{
	uint8_t *vrpmb_buffer = &cmos_buffer[CMOS_VRPMB_START];

	/* get vrpmb key, and store it to cmos buffer */
	if (!get_vrpmb_key(vrpmb_buffer, RPMB_KEY_LEN)) {
		pr_err("SW_LOAD: failed to get vrpmb key\n");
		return -1;
	}
	return 0;
}