early_serial.c

Go to the documentation of this file.

/* 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);
}