early_serial.c

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/* SPDX-License-Identifier: GPL-2.0-or-later */
 
#include <arch/io.h>
#include <device/pnp_ops.h>
#include <device/pnp.h>
#include <stdint.h>
#include "lpc47m10x.h"
 
void pnp_enter_conf_state(pnp_devfn_t dev)
{
        u16 port = dev >> 8;
        outb(0x55, port);
}
 
void pnp_exit_conf_state(pnp_devfn_t dev)
{
        u16 port = dev >> 8;
        outb(0xaa, port);
}
 
/**
 * Configure the base I/O port of the specified serial device and enable the
 * serial device.
 *
 * @param dev High 8 bits = Super I/O port, low 8 bits = logical device number.
 * @param iobase Processor I/O port address to assign to this serial device.
 */
void lpc47m10x_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);
}