src/superio/smsc/lpc47m15x/early_serial.c

/* SPDX-License-Identifier: GPL-2.0-only */

/* Pre-RAM driver for the SMSC LPC47M15X Super I/O chip */

#include <arch/io.h>
#include <device/pnp_ops.h>
#include <device/pnp.h>
#include <stdint.h>

#include "lpc47m15x.h"

static void pnp_enter_conf_state(pnp_devfn_t dev)
{
	u16 port = dev >> 8;
	outb(0x55, port);
}

static void pnp_exit_conf_state(pnp_devfn_t dev)
{
	u16 port = dev >> 8;
	outb(0xaa, port);
}

void lpc47m15x_enable_serial(pnp_devfn_t dev, u16 iobase)
{
	pnp_enter_conf_state(dev);
	pnp_set_logical_device(dev);
	pnp_set_enable(dev, 0);
	pnp_set_iobase(dev, PNP_IDX_IO0, iobase);
	pnp_set_enable(dev, 1);
	pnp_exit_conf_state(dev);
}