u-boot/drivers/misc/smsc_lpc47m.c
Bin Meng a2927e09bc x86: Add a simple superio driver for SMSC LPC47M
On most x86 boards, the legacy serial ports (io address 0x3f8/0x2f8)
are provided by a superio chip connected to the LPC bus. We must
program the superio chip so that serial ports are available for us.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
2014-12-13 22:32:05 -07:00

33 lines
573 B
C

/*
* Copyright (C) 2014, Bin Meng <bmeng.cn@gmail.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#include <asm/pnp_def.h>
static void pnp_enter_conf_state(u16 dev)
{
u16 port = dev >> 8;
outb(0x55, port);
}
static void pnp_exit_conf_state(u16 dev)
{
u16 port = dev >> 8;
outb(0xaa, port);
}
void lpc47m_enable_serial(u16 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);
}