early_smbus.c

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/* SPDX-License-Identifier: GPL-2.0-or-later */
 
#include <stdint.h>
#include <device/pci_ops.h>
#include <device/pci.h>
#include <device/pci_ids.h>
#include <device/pci_def.h>
#include <device/smbus_host.h>
#include "i82371eb.h"
 
void i82371eb_early_init(void)
{
        enable_smbus();
        enable_pm();
}
 
uintptr_t smbus_base(void)
{
        return SMBUS_IO_BASE;
}
 
int smbus_enable_iobar(uintptr_t base)
{
        u8 reg8;
        u16 reg16;
 
        /* Get the SMBus/PM device of the 82371AB/EB/MB. */
        const pci_devfn_t dev = pci_locate_device(PCI_ID(PCI_VID_INTEL,
                                PCI_DID_INTEL_82371AB_SMB_ACPI), 0);
 
        /* Set the SMBus I/O base. */
        pci_write_config32(dev, SMBBA, base | 1);
 
        /* Enable the SMBus controller host interface. */
        reg8 = pci_read_config8(dev, SMBHSTCFG);
        reg8 |= SMB_HST_EN;
        pci_write_config8(dev, SMBHSTCFG, reg8);
 
        /* Enable access to the SMBus I/O space. */
        reg16 = pci_read_config16(dev, PCI_COMMAND);
        reg16 |= PCI_COMMAND_IO;
        pci_write_config16(dev, PCI_COMMAND, reg16);
 
        return 0;
}