blob: 7c3ce2b3a56440ee56ea6ee787a20e8c4dd3f5cd [file] [log] [blame]
/*
* This file is part of the coreboot project.
*
* Copyright (C) 2014 Edward O'Callaghan <eocallaghan@alterapraxis.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
/*
* A generic romstage (pre-ram) driver for various Winbond Super I/O chips.
*
* The following is derived directly from the vendor Winbond's data-sheets:
*
* To toggle between `configuration mode` and `normal operation mode` as to
* manipulation the various LDN's in Winbond Super I/O's we are required to
* pass magic numbers `passwords keys`.
*
* WINBOUND_ENTRY_KEY := enable configuration : 0x87
* WINBOUND_EXIT_KEY := disable configuration : 0xAA
*
* To modify a LDN's configuration register, we use the index port to select
* the index of the LDN and then write to the data port to alter the
* parameters. A default index, data port pair is 0x4E, 0x4F respectively, a
* user modified pair is 0x2E, 0x2F respectively.
*
*/
#include <arch/io.h>
#include <device/pnp.h>
#include <stdint.h>
#include "winbond.h"
#define WINBOND_ENTRY_KEY 0x87
#define WINBOND_EXIT_KEY 0xAA
/* Enable configuration: pass entry key '0x87' into index port dev. */
void pnp_enter_conf_state(pnp_devfn_t dev)
{
u16 port = dev >> 8;
outb(WINBOND_ENTRY_KEY, port);
outb(WINBOND_ENTRY_KEY, port);
}
/* Disable configuration: pass exit key '0xAA' into index port dev. */
void pnp_exit_conf_state(pnp_devfn_t dev)
{
u16 port = dev >> 8;
outb(WINBOND_EXIT_KEY, port);
}
/* Bring up early serial debugging output before the RAM is initialized. */
void winbond_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);
}
void winbond_set_pinmux(pnp_devfn_t dev, uint8_t offset, uint8_t mask, uint8_t state)
{
uint8_t byte;
/* Configure pin mux */
pnp_enter_conf_state(dev);
byte = pnp_read_config(dev, offset);
byte &= ~mask;
byte |= state;
pnp_write_config(dev, offset, byte);
pnp_exit_conf_state(dev);
}
void winbond_set_clksel_48(pnp_devfn_t dev)
{
u8 reg8;
pnp_enter_conf_state(dev);
reg8 = pnp_read_config(dev, 0x24);
reg8 |= (1 << 6); /* Set the clock input to 48MHz. */
pnp_write_config(dev, 0x24, reg8);
pnp_exit_conf_state(dev);
}