early_serial.c

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/* SPDX-License-Identifier: GPL-2.0-or-later */
 
/* PILOT Super I/O is only based on LPC observation done on factory system. */
 
#include <arch/io.h>
#include <device/pnp_ops.h>
#include <device/pnp.h>
#include "pilot.h"
 
/* Pilot uses 0x5A/0xA5 pattern to activate deactivate config access. */
void pnp_enter_ext_func_mode(pnp_devfn_t dev)
{
        u16 port = dev >> 8;
        outb(0x5A, port);
}
 
void pnp_exit_ext_func_mode(pnp_devfn_t dev)
{
        u16 port = dev >> 8;
        outb(0xA5, port);
}
 
/* Serial config is a fairly standard procedure. */
void pilot_enable_serial(pnp_devfn_t dev, u16 iobase)
{
        pnp_enter_ext_func_mode(dev);
        pnp_set_logical_device(dev);
        pnp_set_iobase(dev, PNP_IDX_IO0, iobase);
        pnp_set_enable(dev, 1);
        pnp_exit_ext_func_mode(dev);
}
 
void pilot_disable_serial(pnp_devfn_t dev)
{
        pnp_enter_ext_func_mode(dev);
        pnp_set_logical_device(dev);
        pnp_set_iobase(dev, PNP_IDX_IO0, 0x0000);
        pnp_set_enable(dev, 0);
        pnp_exit_ext_func_mode(dev);
}